Henley’s Book of Recipes (part 5)

—The spoiling of eggs is due to the entrance of air carrying germs through the shells. Normally the shell has a surface coating of mucilaginous matter, which prevents for a time the entrance of these harmful organisms into the egg. But if this coating is removed or softened by washing or otherwise the keeping quality of the egg is much reduced. These facts explain why many methods of preservation have not been entirely successful, and suggest that the methods employed should be based upon the idea of protecting and rendering more effective the natural coating of the shell, so that air bearing the germs that cause decomposition may be completely excluded.

Eggs are often packed in lime, salt, or other products, or are put in cold storage for winter use, but such eggs are very far from being perfect when they come upon the market. German authorities declare that water glass more closely conforms to the requirements of a good preservative than any of the substances commonly employed. A 10 per cent solution of water glass is said to preserve eggs so effectually that at the end of three and one-half months eggs still appeared to be perfectly fresh. In most packed eggs the yolk settles to one side, and the egg is then inferior in quality. In eggs preserved in water glass the yolk retained its normal position in the egg, and in taste they were not to be distinguished from fresh, unpacked store eggs.

Of twenty methods tested in Germany, the three which proved most effective were coating the eggs with vaseline, preserving them in limewater, and preserving them in water glass. The conclusion was reached that the last is preferable, because varnishing the eggs with vaseline takes considerable time, and treating them with limewater is likely to give the eggs a limy flavor. {285}

Other methods follow:

I.—Eggs can be preserved for winter use by coating them, when perfectly fresh, with paraffine. As the spores of fungi get into eggs almost as soon as they are laid, it is necessary to rub every egg with chloroform or wrap it a few minutes in a chloroform soaked rag before dipping it into the melted paraffine. If only a trace of the chloroform enters the shell the development of such germs as may have gained access to freshly laid eggs is prevented. The paraffine coating excludes all future contamination from germ-laden air, and with no fungi growing within, they retain their freshness and natural taste.

II.—Preserving with Lime.—Dissolve in each gallon of water 12 ounces of quicklime, 6 ounces of common salt, 1 drachm of soda, / 2 drachm saltpeter, / 2 drachm tartar, and 1 / 2 drachms of borax. The fluid is brought into a barrel and sufficient quicklime to cover the bottom is then poured in. Upon this is placed a layer of eggs, quicklime is again thrown in and so on until the barrel is filled so that the liquor stands about 10 inches deep over the last layer of eggs. The barrel is then covered with a cloth, upon which is scattered some lime.

III.—Melt 4 ounces of clear beeswax in a porcelain dish over a gentle fire, and stir in 8 ounces of olive oil. Let the solution of wax in oil cool somewhat, then dip the fresh eggs one by one into it so as to coat every part of the shell. A momentary dip is sufficient, all excess of the mixture being wiped off with a cotton cloth. The oil is absorbed in the shell, the wax hermetically closing all the pores.

IV.—The Reinhard method is said to cause such chemical changes in the surface of the eggshell that it is closed up perfectly air-tight and an admittance of air is entirely excluded, even in case of long-continued storing. The eggs are for a short time exposed to the direct action of sulphuric acid, whereby the surface of the eggshell, which consists chiefly of lime carbonate, is transformed into lime sulphate. The dense texture of the surface thus produced forms a complete protection against the access of the outside air, which admits of storing the egg for a very long time, without the contents of the egg suffering any disadvantageous changes regarding taste and odor. The egg does not require any special treatment to prevent cracking on boiling, etc.

Some object to this on the ground that sulphuric acid is a dangerous poison, that might, on occasion, penetrate the shell.

V.—Take about half a dozen eggs and place them in a netting (not so many as would chill the water below the boiling point, even for an instant), into a boiling solution of boric acid, withdraw immediately, and pack. Or put up, in oil, carrying 2 per cent or 3 per cent of salicylic acid. Eggs treated in this way are said to taste, after six months, absolutely as fresh as they were when first put up. The eggs should be as fresh as possible, and should be thoroughly clean before dipping. The philosophy of the process is that the dipping in boiling boric acid solution not only kills all bacteria existing on, or in, the shell and membrane, but reinforces these latter by a very thin layer of coagulated albumen; while the packing in salicylated oil prevents the admission of fresh germs from the atmosphere. Salicylic acid is objected to on the same grounds as sulphuric acid.

VI.—Dissolve sodium silicate in boiling water, to about the consistency of a syrup (or about 1 part of the silicate to 3 parts water). The eggs should be as fresh as possible, and must be thoroughly clean. They should be immersed in the solution in such manner that every part of each egg is covered with the liquid, then removed and let dry. If the solution is kept at or near the boiling temperature, the preservative effect is said to be much more certain and to last longer.

EGG CHOCOLATE: See Beverages.

EGG DYES: See Dyes.

EGG LEMONADE: See Beverages, under Lemonade.

EGG PHOSPHATE: See Beverages.

EGG-STAIN REMOVER: See Cleaning Preparations and Methods.

EGGS, TESTS FOR: See Foods.

EIKONOGEN DEVELOPER: See Photography.

EKTOGAN: See Antiseptics. {286}

Elaine Substitute.

A substitute for elaine for woolen yarns is obtained by boiling 4 pounds carrageen moss in 25 gallons water for 3 hours. The soda is then put in and the boiling continued for another half hour; 2 pounds fleabane seeds are gradually added, and a little water to make up for the evaporation. After a further 1 / 2 hours boiling, the extract is passed through a fine sieve and well mixed with 25 pounds cottonseed oil, 12 / 2 pounds sweet oil, and 12 / 2 pounds ammonia solution of 0.96 specific gravity. Next day stir in 25 pounds saponified elaine and 13 pounds of odorless petroleum of 0.885 specific gravity. The resulting emulsion keeps well, dissolves perfectly in lukewarm water, and answers its purpose excellently.

ELECTRODEPOSITION PROCESSES: See Plating.

ELECTROLYSIS IN BOILERS: See Boiler Compounds.

Electroplating and Electrotyping

(See also Plating.)

Process Of Electroplating.

First, clean the articles to be plated. To remove grease, warm the pieces before a slow fire of charcoal or coke, or in a dull red stove. Delicate or soldered articles should be boiled in a solution of caustic potash, the latter being dissolved in 10 times its weight of water.

The scouring bath is composed of 100 parts of water to from 5 to 20 parts of sulphuric acid. The articles may be put in hot and should be left in the bath till the surface turns to an ocher red tint.

The articles, after having been cleansed of grease by the potash solution, must be washed in water and rinsed before being scoured. Copper or glass tongs must then be used for moving the articles, as they must not afterwards be handled. For small pieces, suitable earthenware or porcelain strainers may be used.

The next stage is the spent nitric acid bath. This consists of nitric acid weakened by previous use. The articles are left in until the red color disappears, so that after rinsing they show a uniform metallic tint. The rinsing should be thoroughly carried out.

Having been well shaken and drained, the articles are next subjected to the strong nitric acid bath, which is made up as follows:

Nitric acid of 36° Bé 100 volumes

Chloride of sodium (common salt) 1 volume

Calcined soot (lampblack) 1 volume

The articles must be immersed in this bath for only a few seconds. Avoid overheating or using too cold a bath. They are next rinsed thoroughly with cold water and are again subjected to a strong nitric acid bath to give them a bright or dull appearance as required.

To produce a bright finish, plunge them for a few seconds (moving them about rapidly at the same time) in a cold bath of the following composition:

Nitric acid 100 volumes

Sulphuric acid 100 volumes

Chloride of sodium 1 volume

Again rinse thoroughly in cold water. The corresponding bath giving a dull or matt appearance is composed of:

Nitric acid 200 volumes

Sulphuric acid 100 volumes

Sea salt 1 volume

Sulphate of zinc 1 to 5 volumes

The duration of immersion in this bath varies from 5 to 20 minutes, according to the dullness required. Wash with plenty of water. The articles will then have an unpleasant appearance, which will disappear on plunging them for a moment into the brightening bath and rinsing quickly.

The pieces are next treated with the nitrate of mercury bath for a few seconds.

Plain water 10,000 parts

Nitrate of mercury 10 parts

Sulphuric acid 20 parts

It is necessary to stir this bath before using it. For large articles the proportion of mercury should be greater. An article badly cleaned will come out in various shades and lacking its metallic brightness. It is better to throw a spent bath away than attempt to strengthen it.

The various pieces, after having passed through these several processes, are then ready for the plating bath.

A few words on the subject of gilding may not be amiss. Small articles are gilded hot, large ones cold. The cold cyanide of gold and potassium bath is composed as follows:

Distilled water 10,000 parts

Pure cyanide of potassium 200 parts

Pure gold 100 parts

The gold, transformed into chloride, is dissolved in 2,000 parts of water and {287} the cyanide in 8,000 parts. The two solutions are then mixed and boiled for half an hour.

The anode must be entirely submerged in the bath, suspended from platinum wires and withdrawn immediately the bath is out of action.

Hot Gold Bath.

—Zinc, tin, lead, antimony and the alloys of these metals are better if previously covered with copper.

The following are the formulas for the other metals per 10,000 parts of distilled water:

Crystallized phosphate of soda, 600 parts; alloys rich in copper castings, 500 parts.

Bisulphide of soda, 100 parts; alloys rich in copper, 125 parts.

Pure cyanide of potassium, 10 parts; alloys rich in copper, 5 parts. Pure gold transformed into chloride, 10 parts; alloys rich in copper, 10 parts.

Dissolve the phosphate of soda hot in 8,000 parts water, let the chloride of gold cool in 1,000 parts water; mix little by little the second solution with the first; dissolve the cyanide and bisulphide in 1,000 parts water and mix this last solution with the other two. The temperature of the bath may vary between 122° and 175° F.

Silvering.

—For amateurs a bath of 10 parts silver per 1,000 is sufficient. Dissolve 150 parts nitrate of silver, equivalent to 100 parts pure silver, in 10,000 parts of water and add 250 parts pure cyanide of potassium. Stir it up until completely dissolved, and then filter the solution. Silvering is generally effected cold, except in the case of small articles. Iron, steel, zinc, lead, and tin are better if previously copper-plated and then silvered hot. The cleaned articles are first treated in a nitrate of mercury bath, being kept continually in motion.

With excess of current the pieces become gray, and blacken. In the cold bath anodes of platinum or silver should be employed. Old baths are, in this case, preferable to new. They may, if required, be artificially aged by the addition of 1 or 2 parts in 1,000 of liquid ammonia.

If the anode blackens, the bath is too weak. If it becomes white, there is too much current, and the deposit, being too rapid, does not adhere. The deposit may be taken as normal and regular when the anode becomes gray during the passage of the current and white again when it ceases to flow.

The nickel vat should be of glass, porcelain, or earthenware, or a case lined with impermeable gum. The best nickel bath is prepared by dissolving to saturation, in hot distilled water, nickel sulphate and ammonium, free from oxides or alkalies and alkaline earthy metals. The proportion of salt to dissolve is 1 part, by weight, to 10 of water. Filter after cooling and the bath is then ready for use.

When the bath is ready and the battery set up, the wires from the latter are joined by binding screws to two metal bars resting on the edge of the vat. The bar joined to the positive pole of the battery supports, through the intervention of a nickel-plated copper hook, a plate of nickel, constituting the soluble anode, which restores to the bath the metal deposited on the cathode by the electrolytic action. From the other bar are suspended the articles to be plated. These latter should be well polished before being put into the bath. To remove all grease, scrub them with brushes soaked in a hot solution of whiting, boiled in water and carbonate of soda.

Copper and its alloys are cleaned well in a few seconds by immersion in a bath composed of 10 parts, by weight, of water, and 1 part of nitric acid. For rough articles, 2 parts water, 1 nitric acid, and 1 sulphuric acid. For steel and polished castings, 100 parts water to 1 sulphuric acid. The articles should remain in the bath until the whole surface is of a uniform gray tint. They are then rubbed with powdered pumice stone till the solid metal appears. Iron and steel castings are left in the bath for three or four hours and then scrubbed with well-sifted sand.

If the current be too strong, the nickel is deposited gray or even black. An hour or so is time enough to render the coat sufficiently thick and in a condition to stand polishing. When the articles are removed from the bath they are washed in water and dried in hot sawdust.

To polish the articles they should be taken in one hand and rubbed rapidly backward and forward on a strip of cloth soaked in polishing powder boiled in water, the cloth being firmly fixed at one end and held in the other hand. The hollow parts are polished by means of cloth pads of various sizes fixed on sticks. These pads must be dipped in the polishing paste when using them. The articles, when well brightened, are washed in water to get rid of the paste and the wool threads, and finally dried in sawdust. {288}

Some Notes On Electrotyping, Plating, And Gilding.

The first step in the process is the preparation of the mold. The substance originally used for the construction of this was plaster of Paris. This substance is, however, porous and must be rendered impermeable. The materials most commonly used of later years are stearine, wax, marine glue, gelatin, india rubber, and fusible alloys. With hollow molds it is a good plan to arrange an internal skeleton of platinum, for ultimate connection with the anodes, in order to secure a good electrical contact with all parts of the mold. When covering several pieces at once, it is as well to connect each of them with the negative pole by an iron or lead wire of suitable dimensions.

Having prepared the molds in the usual way—by obtaining an impression in the material when soft, and allowing it to set—they should be given a metallic coating on their active surfaces of pure powdered plumbago applied with a polishing brush.

For delicate and intricate objects, the wet process is most suitable. It consists in painting the object with two or more coats of nitrate of silver and ultimately reducing it by a solution of phosphorus in bisulphide of carbon.

The plating baths are prepared as follows:

A quantity of water is put in a jar and to it is added from 8 to 10 parts in 100 of sulphuric acid, in small quantities, stirring continually in order to dissipate the heat generated by the admixture of acid and water. Sulphate of copper (bluestone) is then dissolved in the acidulated water at the normal temperature until it will take up no more. The solution is always used cold and must be maintained in a saturated condition by the addition of copper sulphate crystals or suitable anodes.

For use it should be poured into vessels of clay, porcelain, glass, hard brown earthenware, or india rubber. For large baths wood may be used, lined on the interior with an impervious coating of acid-proof cement, india rubber, marine glue, or even varnished lead sheets.

If the solution be too weak and the current on the other hand be too strong, the resulting deposit will be of a black color. If too concentrated a solution and too weak a current be employed, a crystalline deposit is obtained. To insure a perfect result, a happy medium in all things is necessary.

During the process of deposition, the pieces should be moved about in the bath as much as possible in order to preserve the homogeneity of the liquid. If this be not attended to, stratification and circulation of the liquid is produced by the decomposition of the anode, and is rendered visible by the appearance of long, vertical lines on the cathode.

For amateurs and others performing small and occasional experiments, the following simple apparatus will be serviceable. Place the solution of sulphate of copper in an earthenware or porcelain jar, in the center of which is a porous pot containing amalgamated zinc and a solution of sulphuric acid and water, about 2 or 3 parts in 100. At the top of the zinc a brass rod is fixed, supporting a circle of the same metal, the diameter of which is between that of the containing vessel and the porous pot. From this metallic circle the pieces are suspended in such a manner that the parts to be covered are turned toward the porous pot. Two small horsehair bags filled with copper sulphate crystals are suspended in the solution to maintain its saturation.

Elm Tea.

Powdered slippery elm bark (or the equivalent in whole bar) 2 teaspoonfuls

Boiling water 1 cup

Sugar, enough.

Lemon juice, enough.

Pour the water upon the bark. When cool, strain and flavor with lemon juice and add sugar. This is soothing in case of inflammation of the mucous membrane.

Embalming Fluids.

Success in the use of any embalming fluid depends largely on manipulation, an important part of the process being the thorough removal of fluid from the circulatory system before undertaking the injection of the embalming liquid.

I.— Solution zinc chloride (U. S. P.) 1 gallon

Solution sodium chloride 6 ounces to pint 6 pints

Solution mercury bichloride, 1 ounce to pint 4 pints

Alcohol 4 pints

Carbolic acid (pure) 8 ounces

Glycerine 24 fluidounces

{289}

Mix the glycerine and carbolic acid, then all the other ingredients, when a clear solution of 3 gallons results, which is the proper amount for a body weighing 150 pounds.

II.— Arsenious acid 100 parts

Sodium hydrate 50 parts

Carbolic acid and water, of each a sufficient quantity.

Dissolve the arsenious acid and the soda in 140 parts of water by the aid of heat. When the solution is cold, drop carbolic acid into it until it becomes opalescent, and finally add water until the finished product measures 700 parts.

III.— Salicylic acid 4 drachms

Boric acid 5 drachms

Potassium carbonate 1 drachm

Oil of cinnamon 3 drachms

Oil of cloves 3 drachms

Glycerine 5 ounces

Alcohol 12 ounces

Hot water 12 ounces

Dissolve the first 3 ingredients in the water and glycerine, the oils in the alcohol, and mix the solutions.

IV.— Thymol 15 grains

Alcohol / 2 ounce

Glycerine 10 ounces

Water 5 ounces

V.— Cooking salt 500 parts

Alum 750 parts

Arsenious acid 350 parts

Zinc chloride 120 parts

Mercury chloride 90 parts

Formaldehyde solution, 40 per cent 6,000 parts

Water, up to 24,000 parts

VI.— Arsenious acid 360 grains

Mercuric chloride 1 / 4 ounces

Alcohol 9 ounces

Sol. ac. carbolic, 5 per cent 120 ounces

From 10 to 12 pints are injected into the carotid artery—at first slowly and afterwards at intervals of from 15 to 30 minutes.

EMERALD (IMITATION): See Gems, Artificial.

Emery:

Emery Grinder.

—Shellac, melted together with emery and fixed to a short metal rod, forms the grinder used for opening the holes in enameled watch dials and similar work. The grinder is generally rotated with the thumb and forefinger, and water is used to lubricate its cutting part, which soon wears away. The grinder is reshaped by heating the shellac and molding the mass while it is in a plastic condition.

Preparing Emery For Lapping.

—To prepare emery for lapping screw-gages, plugs, etc., fill a half-pint bottle with machine oil and flour emery, 7 parts oil to 1 part emery, by bulk. Mix thoroughly and let stand for 20 minutes to settle. Take the bottle and pour off one-half the contents without disturbing the settlings. The portion poured off contains only the finest emery and will never scratch the work.

For surface lapping put some flour emery in a linen bag and tie up closely with a string. Dust out the emery by striking the bag against the surface plate; use turpentine for rough lapping and the dry surface plate for finishing.

Removing Glaze From Emery Wheels.

—If the wheel is not altogether too hard, it can sometimes be remedied by reducing the face of the wheel to about / 8 inch, or by reducing the speed, or by both. Emery wheels should be turned off so that they will run true before using. A wheel that glazes immediately after it has been turned off, can sometimes be corrected by loosening the nut, and allowing the wheel to assume a slightly different position, when it is again tightened.

Emery Substitute.

—For making artificial emery, 1,634 parts of the following substances may be employed: Seven hundred and fifty-nine parts of bauxite, 700 parts of coke, and 96 parts of a flux, which may be a carbonate of lime, of potash, or of soda, preferably carbonate of lime on account of its low price. These materials are arranged in alternate layers and fused in an oven having a good draught. They are said to yield an artificial emery similar to the natural emery of Smyrna and Naxos, and at low cost.

Emulsifiers:

Rosin Soap As An Emulsifier.

—The soap should be made by boiling gently for 2 hours, in an evaporating dish, a mixture of 1,800 grains rosin and 300 caustic soda with 20 fluidounces water. Upon cooling, the soap separates as a yellow mass, which is drained from the liquid, squeezed, then heated on a water bath until it is dry and friable. Fixed oils may be emulsified by adding 1 ounce {290} to a solution of 10 grains soap in 1 ounce water. Volatile oils require 10 grains rosin soap, 2 / 4 ounces water, and 2 drachms oil. Creosote requires double this amount of soap. Thymol may be rendered miscible with water by dissolving 18 grains together with 20 grains soap in 3 fluidounces alcohol, then adding enough water to make 6 fluidounces. Of course many other substances may be emulsified with the same emulsifier.

Yolk Of Egg As An Emulsifier.

—The domestic ointment of Unona, consisting of a mixture of oil and yolk of egg, is miscible in all proportions with water. It is proposed to utilize this fact by substituting a diluted ointment for the gum emulsions in general use, the following being given as a general formula:

Yolk of egg 10 parts

Balsam Peru 1 to 2 parts

Zinc oxide 5 to 10 parts

Distilled water 100 parts

If desired, 33 parts of vinegar may be substituted for the same amount of water, while oil of cade, oil of birch, lianthral or storax may be substituted for the balsam Peru, and an equal quantity of talc, magnesium carbonate, sulphur of bismuth subcarbonate, may be introduced in place of the oxide of zinc. A further variation in the character of the liquid may be introduced by the use of medicated or perfumed waters instead of the plain distilled water. Where so diluted, as in the above formula, the yolk of egg separates out after long standing, but the mixture quickly reëmulsifies upon shaking. Tar and balsams can be emulsified by mixing with double their quantity of yolk of egg, then diluting by the addition of small quantities of water or milk.

Emulgen.

—This emulsifying agent has the following composition: Gluten, 5; gum acacia, 5; gum tragacanth, 20; glycerine, 20; water, 50; alcohol, 10. This mixture forms a clear grayish jelly.

EMULSIONS OF PETROLEUM: See Petroleum.

Enameling

(See also Ceramics, Glazes, Paints, Waterproofing, and Varnishes.)

Commercial Enameling.

Commercial enameling includes: (1) Hollow ware enameling for domestic use; (2) hollow ware enameling for chemical use; (3) enameling locomotive and other tubes; (4) enameling drain and water pipes; (5) signboard enameling.

There is one defect to which all enamel ware is subject, and that is chipping. This may be caused by (1) imperfect mixing of the enamels; (2) imperfect fusing; (3) imperfect pickling of the iron; (4) rough usage. With ordinary care a well-enameled article has been known to last in daily use for 10 or 12 years, whereas defective enameling, say, on a sign tablet—which is exempt from rough usage—may not have a life exceeding a few months. All enameled articles, such as hollow ware and sign tablets, first receive a coating of a composition chiefly composed of glass called “gray,” and this is followed by a deposit of “white,” any additional color required being laid above the white. In the mixing and depositing of these mixtures lie the secrets of successful enameling. The “gray” has to be fused not only on but also into the metal at a bright red—almost white—heat, and it is obvious that its constituents must be arranged and proportioned to expand and contract in a somewhat uniform manner with the iron itself. The “white” has to be fused on the surface of the gray, but the gray being much harder is not affected by the second firing. If it were liquid it would become mixed with the white and destroy its purity. Frequently, owing to inferior chemicals, imperfect mixing or fusing, a second coating of white is necessary, in order to produce a surface of the necessary purity and luster. The difficulties of enameling are thus easily understood. Unless the metals and chemicals are so arranged and manipulated that their capacities of expansion and contraction are approximately the same, inferior work will be produced. Oxide of iron on the surface of the plates, inferior chemicals, incorrect mixings, insufficient or overheating in the process of fusing, prevent that chemical combination which is essential to successful enameling. The coatings will be laid on and not combined, with the result that there will be inequalities in expansion and contraction which will cause the enamel to chip off immediately if submitted to anything approaching rough usage, and in a very short time if submitted to chemical or ordinary atmospheric conditions.

The manufacture of sign tablets is the simplest form to which this important art is adapted. Sign-tablet enameling is, however, kept as great a secret as any other type. This branch of the industry {291} is divided up as follows: (1) Setting the plates; (2) scaling and pickling the plates; (3) mixing the enamel constituents; (4) melting the enamel constituents; (5) grinding the enamel constituents; (6) applying the enamel; (7) drying the enamel coatings; (8) fusing the enamel on the articles; (9) lettering—including alphabetical and other drawing, spacing, and artistic art in arrangement; (10) stencil cutting on paper and stencil metal; (11) brushing; (12) refusing. Distinctive branches of this work have distinctive experts, the arrangement being generally as follows: Nos. 1 and 2 may or may not be combined; Nos. 3 and 5 may or may not be combined; Nos. 4, 7, 8, and 12 generally combined; No. 6 generally the work of girls; Nos. 9 and 10 generally combined; No. 11 generally the work of girls and boys. The twelve processes, therefore, require six classes of trained workpeople, and incompetence or carelessness at any section can only result in imperfect plates or “wasters.”

A brief description of these processes will enable the reader to understand the more detailed and technical description to follow, and is, therefore, not out of place. Ordinary iron sheets will do for the manufacture of sign tablets; but a specially prepared charcoal plate can be had at a slightly increased price. The latter type is the best, for in many cases the scaling and pickling may, to a certain extent, be dispensed with. To make this article, however, as complete as possible, we shall begin from the lowest rung of the manufacturing ladder—i. e., from the first steps in the working of suitable iron.

I.—Setting.—The plates may be received in sheets, and cut to the required size at the enameling factory, or, what is more general, received in sizes according to specification. The former are more liable to have buckled slightly or become dented, and have to be restored to a smooth and uniform surface by hammering on a flat plate. The operation seems simple, but an inexperienced operator may entirely fail to produce the desired result, and, if he does succeed, it is with the expenditure of a great amount of time. An expert setter with comparatively few and well-directed strokes brings an imperfect plate into truth and in readiness for the next operation.

II.—Scaling and Pickling.—The annealing of the sheets in special furnaces loosens the scale, which can then be easily removed, after which immersion for some time in diluted sulphuric or muriatic acid thoroughly cleans the plate. Firing to a red heat follows, and then a generous course of scrubbing, and the last traces of acid are removed by dipping in boiling soda solution. Scouring with sand and washing in clean water may follow, and the metal has then a perfect and chemically clean surface.

III.—Mixing the Enamel Constituents.—Ground, foundation, or gray.—All articles, whether hollow ware or plates, are operated upon in a very similar manner. Both require the foundation coating generally called “gray.” The gray constituents vary considerably in different manufactures; but as regards the use of lead, it is universally conceded that while it may in many instances be used with advantage in the enameling of sign tablets, etc., it should under no circumstances be introduced into the coating of articles for culinary purposes, or in which acids are to be used. The first successful commercial composition of this covering was: Cullet (broken glass), carbonate of soda, and boracic acid. This composition remained constant for many years, but ultimately gave place to the following: Cullet, red lead, borax, niter. The borax and red lead form the fluxes, while the niter is to “purify” the mass. Some of the later mixings consist of the following: Silica powder, crystallized or calcium borax, white lead, fused together. This would be called a frit, and with it should be pulverized powdered silica, clay, magnesia. This recipe is one requiring a very high temperature for fusing: Silica powder, borax, fused and ground with silica, clay, magnesia. This requires a slightly lower temperature: Frit of silica powder, borax, feldspar, fused together, and then ground with clay, feldspar, and magnesia.

The approximate quantities of each constituent will be given later, but it must always be remembered that no hard-and-fast line can be laid down. Chemicals vary in purity, the furnaces vary in temperature, the pounding, grinding, and mixing are not always done alike, and each of these exerts a certain influence on the character of the “melt.” These compositions may be applied to the metal either in the form of a powder or of a liquid. Some few years ago the powder coating was in general use, but at the present time the liquid form is in favor, as it is considered easier of application, capable of giving a coating more uniform in thickness and less costly. In using the powder coating the plate is rubbed with a cloth dipped in a gum {292} solution, and the powder then carefully dusted through a sieve over the surface. In this condition the plate is submitted to the fusing process. In using the liquid material the plate surface is dipped into or has the liquid mixing carefully poured over it, any surplus being drained off, and any parts which are not to be coated being wiped clean by a cloth. The coating is then dried in suitable stoves, after which it is ready for fusing on to the iron. The gray coating should be fairly uniform and smooth, free from holes or blisters, and thoroughly covering every part of the iron which is to be subjected to any outside influence. Cooling slowly is important. Rapid cooling frequently causes chipping of the coating, and in any case it will greatly reduce the tenacity of the connection existing between the glaze and the metal.

Generally the next surface is a white one, and it depends upon the class of article, the character of the enamels, and the efficiency of application, whether one coat or two will be required. Roughly speaking, the coating is composed of a glass to which is added oxide of tin, oxide of lead, or some other suitable opaque white chemical. The mixture must be so constituted as to fuse at a lower temperature than the foundation covering. If its temperature of fusion were the same the result would be that the gray would melt on the iron and become incorporated with the white, thus loosening the attachment of the mass to the iron and also destroying the purity of the white itself. Bone ash is sometimes used, as it becomes uniformly distributed throughout the melt, and remains in suspension instead of settling. Bone ash and oxide of lead are, however, in much less demand than oxide of tin. The lead is especially falling into disfavor, for the following reasons: Firstly, it requires special and laborious treatment; secondly, it gives a yellowish-white color; thirdly, it cannot resist the action of acids. The following is a recipe which was in very general use for some years: Glass (cullet), powdered flint, lead, soda (crystals), niter, arsenic. Another consists of the following: Borax, glass, silica powder, oxide of tin, niter, soda, magnesia, clay. These are fused together, and when being ground a mixture of Nos. 1, 3, 7, and boracic acid is added.

Enamel mixings containing glass or china are now generally in use, although for several years the experience of manufacturers using glass was not satisfactory. Improved compositions and working now make this constituent a most useful, and, in fact, an almost essential element. The glass should be white broken glass, and as uniform in character as possible, as colored glass would impart a tinge of its own color to the mixing.

The following are two distinct glazes which do not contain glass or porcelain: Feldspar, oxide of tin, niter, soda. This is free from any poisonous body and requires no additions: Silica powder, oxide of tin, borax, soda, niter, carbonate of ammonia, or magnesia.

Alkalies.—Of the alkalies which are necessary to produce complete fusion of and combination with the quartz, soda is chiefly applied in enamel manufactures, as the fusing temperature is then lower.

Bone Ash.—This material will not add opacity, but only semi-transparency to the enamel, and is therefore not much used.

Boracic Acid.—Boracic acid is sometimes substituted for silicic acid, but generally about 15 per cent of the former to 85 per cent of the latter is added. Borax as a flux is, however, much more easily used and is therefore largely employed in enamel factories.

Borax.—Calcined borax, that is, borax from which a large proportion of the natural moisture has been eliminated, is best for enamel purposes. It is a flux that melts at medium heat, and enters into the formation of the vitreous basis. Borax has also the property of thoroughly distributing oxide colors in the enamels.

Clay.—Only a fairly pure clay can be used in enamel mixings, and the varieties of clay available are therefore limited. The two best are pipe—or white—clay and china clay—kaolin. The latter is purer than the former, and in addition to acting as a flux, it is used to increase the viscosity of mixings and therefore the opacity. It is used in much the same way as oxide of tin.

Cryolite.—Ground cryolite is a white mineral, easily fusible, and sometimes used in enamel mixings. It is closely associated with aluminum.

Cullet.—This is the general material used as a basis. Clear glass only should be introduced; and as the compositions of glass vary greatly, small experimental frits should always be made to arrive at the correct quantity to be added.

Feldspar.—The introduction of feldspar into an enamel frit increases consistency. The common white variety is {293} generally used, and its preliminary treatment by pounding is similar to that adopted with quartz.

Fluor-Spar.—In this mineral we have another flux, which fuses at a red heat.

Fluxes.—These are for the purpose of regulating the temperature of fusion of a mixing—frit—some being better adapted for this purpose than others. This, however, is not the only consideration, for the character of the flux depends upon the composition or chemical changes to which the ingredients are to be subjected. The fluxes are borax, clays, cullet, porcelain, feldspar, gypsum, and fluorspar.

Glass.—Glass is composed of lime, silicic acid, and soda or potash. The use of the glass is to form the hard, crystal-like foundation.

Gypsum.—This mineral is sometimes used in conjunction with baryta and fluor-spar.

Lead.—Crystallized carbonate of lead, or “lead white,” is frequently used in enamels when a low temperature for fusion is required. It should never be used on articles to be submitted to chemical action, or for culinary use. Minium is a specially prepared oxide of lead, and suitable for enameling purposes, but is expensive.

Lime.—Lime is in the form of carbonate of calcium when used.

Magnesium Carbonate is used only in small quantities in enamel mixings. It necessitates a higher temperature for fusion, but does not affect the color to the slightest extent if pure.

Manganese.—As a decolorant, this mineral is very powerful, and therefore only small quantities must be used. Purity of the mineral is essential—i. e., it should contain from 95 to 98 per cent of binoxide of manganese.

Niter.—At a certain temperature niter shows a chemical change, which, when affected by some of the other constituents, assists in the formation of the vitreous base.

Porcelain.—Broken uncolored porcelain is sometimes used in enamel manufacture. Its composition: Quartz, china clay, and feldspar. It increases viscosity.

Red Lead.—This decolorant is sometimes called purifier. It will, however, interfere with certain coloring media, and when this is the case its use should at once be discontinued.

Silicic Acid.—Quartz, sand, rock crystal, and flint stone are all forms of this acid in crystallized form. By itself it is practically infusible, but it can be incorporated with other materials to form mixings requiring varying temperatures for fusion.

Soda.—The soda in general use is carbonate of soda—58 per cent—or enameling soda. The latter is specially prepared, so as to free it almost entirely from iron, and admit of the production of a pure white enamel when such is required.

Tin Oxide.—All enamels must contain white ingredients to produce opacity, and the most generally used is oxide of tin. By itself it cannot be fused, but with proper manipulation it becomes diffused throughout the enamel mass. On the quantity added depends the denseness or degree of opacity imparted to the enamel.

It will be understood that the enamel constituents are divided into four distinct groups: I. Fundamental media. II. Flux media. III. Decolorant media. IV. Coloring media. We have briefly considered the three first named, and we will now proceed to No. IV. The coloring material used is in every case a metallic oxide, so that, so far as this goes, the coloring of an enamel frit is easy enough. Great care is, however, necessary, and at times many difficulties present themselves, which can only be overcome by experience. Coloring oxides are very frequently adulterated, and certain kinds of the adulterants are injurious to the frit and to the finish of the color.

Comparison Of Hollow Ware And Sign-tablet Enameling.

—The enameling for sign tablets is much the same as for hollow ware; the mixings are practically alike, but, as a general rule, the mixing is applied in a much more liquid form on the latter. It is easy to understand that hollow ware in everyday use receives rougher usage than tablets. By handling, it is submitted to compression, expansion, and more or less violence due to falls, knocks, etc., and unless, therefore, the enamel coating follows the changes of the metal due to these causes, the connection between the two will become loosened and chipping will take place.

The enamel, therefore, though much alike for both purposes, should be so prepared for hollow ware that it will be capable of withstanding the changes to which we have referred. In all cases it must be remembered that the thinner the coat of the enamel the better it will be {294} distributed over the iron, and the greater will be its adherence to the iron. Any article heavily enameled is always liable to chip, especially if submitted to the slightest bending action, and therefore any excess of material added to a plate means that it will always be readily liable to separate from the plate. In hollow-ware enameling the preparation of each frit generally receives somewhat more attention than for plate enameling. The grinding is more effectively carried out, in order to remove almost every possibility of roughness on any part of the surface, especially the inside surface.

The iron used in tablet and hollow-ware manufacture is rolled sheet iron. It is supplied in a variety of qualities. Charcoal iron is purer than ordinary plate iron, more ductile, and therefore capable of being driven out to various forms and depths by stamping presses. The surface of the charcoal iron is not so liable to become oxidized, and therefore can be more readily made chemically clean for the reception of the enamels. Some manufacturers use charcoal plates for tablet work, but these are expensive; the ordinary plates, carefully pickled and cleaned, adapt themselves to the work satisfactorily.

The sheet irons generally used for the enameling purposes referred to vary in gauge. The finer the iron the greater must be the care used in coating it with enamel. Thin iron will rapidly become hot or cool, the temperatures changing much more quickly than that of the mixing. Unless care, therefore, is used, the result of fusing will be that the enamel mass will not have become thoroughly liquid, and its adherence to the iron will be imperfect.

If, however, the temperature is gradually raised to the maximum, and sympathetic combination takes place, the dangers of rapid cooling are avoided. Again, the iron, in losing its temperature more rapidly than the enamel, will contract, thus loosening its contact with the glaze, and the latter will either then, or after a short period of usage, chip off. We then arrive at the following hard-and-fast rules: (1) In all classes of enameling, but particularly where thin iron sheets are used, the temperature of the plate and its covering must be raised very gradually and very uniformly. (2) In all cases a plate which has had a glaze fused on its surface must be cooled very gradually and very uniformly. The importance of these rules cannot be over-estimated, and will, therefore, be referred to in a more practical way later.

In enameling factories no causes are more prolific in the production of waste than these, and in many cases the defects produced are erroneously attributed to something else. Cast iron is much easier to enamel than wrought iron. This is due to the granular character of its composition. It retains the enamels in its small microscopic recesses, and greater uniformity can be arrived at with greater ease. Cast-iron enameled sign tablets and hollow ware were at one time made, but their great weight made it impossible for them ever to come into general use.

Wrought-iron plates, if examined microscopically, will show that they are of a fibrous structure, the fibers running in the direction in which they have been rolled. The enamels, therefore, will be more liable to flow longitudinally than transversely, and this tendency will be more accentuated at some places than at others. This, however, is prevented by giving the iron sheets what might be described as a cast-iron finish. The sheets to be enameled should be thoroughly scoured in all directions by quartz or flint sand, no part of the surface being neglected. This thorough scrubbing will roughen the surface sufficiently to make it uniformly retentive of enamel mixture, and in no cases should it be omitted or carelessly carried out.

Copper Enameling.

—On a clean copper surface the enameling process is easy. The foundation glaze is not essential, and when required the most beautiful results of blended colors can be obtained by very little additional experience to ordinary enameling.

When the vase or other article has been hammered out to the required shape in copper, it is passed on to another class of artisans, who prepare it for the hands of the enameler. The design or designs are sketched carefully. The working appliances consist only of a pointed tool, two or three small punches of varying sizes, and a hammer. With this small equipment the operator sets to work. The spaces between each dividing line are gradually lowered by hammering, and when this has been uniformly completed, each little recess is ready to receive its allotment of enamel. More accurate work even than this can be obtained by the introduction of flat wire. This wire is soldered or fixed on the vase, and forms the outline for the entire design. It may be of brass, copper, or gold, but is fixed and built round every item of the whole design with the most {295} laborious care. It stands above the surface of the design on the copper articles, but the little recesses formed by it are then gradually filled up by enamel in successive fusings. The whole surface of the article is now ground perfectly smooth and polished until its luster is raised to the highest point possible, and when this stage has been reached the article is ready for the market.

From The Sheet To The Sign Tablet.

—The plates are generally in lengths of 6 feet by 2 feet, 6 feet by 3 feet, etc., the gauge generally being from 14 to 22, according to the size and class of plates to be enameled. These must be cut, but some enamelers prefer to order their plates in specified sizes, which does away with the necessity of cutting at the enameling factory. In order, however, to make this article complete, we will assume that a stock of large plates is kept on hand, the sizes being 6 feet by 3 feet and 6 feet by 2 feet. An order for sign tablets is given; particulars, say as follows: Length, 2 feet by 12 inches, white letters on blue ground; lettering, The Engineer, 33 Norfolk Street; block letters, no border line, 2 holes. For ordinary purposes these particulars would be sufficient for the enameler.

Stage I.—Cutting the plate is the first operation. The plates 6 feet by 2 feet would first be cut down the center in a circular cutting machine, thus forming two strips, 6 feet by 12 inches. Each strip would then be cut into three lengths of 2 feet each. If a guillotine had to be used instead of a circular cutter, the plate would be first cut transversely at distances of 2 feet, thus forming three square pieces of 2 feet by 2 feet. These would then be subdivided longitudinally into two lengths each, the pieces being then 2 feet by 12 inches. Each sheet would thus be cut into six plates.

Stage II.—The cut plates should next have any roughness removed from the edges, then punched with two holes—one at each end, followed by leveling or setting. This is done by hammering carefully on a true flat surface.

Stage III.—The plates should then be taken and dipped into a hydrochloric acid bath made up of equal quantities of the acid and water. The plates are then raised to a red heat in the stoves, and on removal it will be found that the scale—iron oxide—has become loosened, and will readily fall off, leaving a clean metallic surface. A second course of cleaning then follows in diluted sulphuric acid—1 part acid to 20 parts water. In this bath the iron may be kept for about 12 hours. In some cases a much stronger bath is used, and the plates are left in only a very short time. The bath is constructed of hard wood coated inside with suitable varnish.

In mixing the sulphuric acid bath it must be remembered that the acid should be slowly poured into the water under continuous stirring. Following the bath, the metal is rinsed in water, after which it is thoroughly scoured with fine flinty sand. Rinsing again follows, but in boiling water, and then the metal is allowed to dry. The enameling process should immediately follow the drying, for if kept for any length of time the surface of the metal again becomes oxidized. In hollow-ware enameling the hydrochloric acid bath may be omitted.

Stage IV.—The plates are now ready for the reception of the foundation or gray coating. If powder is used the plate is wiped over with a gum solution, and then the powder is carefully and uniformly dusted through a fine sieve over the surface. The plate is then reversed and the operation repeated on the other side. If a liquid “gray” is to be used it should have a consistency of cream, and be poured or brushed with equal care over the two surfaces in succession, after the plate has been heated to be only just bearable to the touch. The plates are then put on rests, or petits, in a drying stove heated to about 160° F., and when thoroughly dry they are ready for the fusing operation. The petits, with the plates, are placed on a long fork fixed on a wagon, which can be moved backward and forward on rails; the door of the fusing oven is then raised and the wagon moved forward. The fork enters the oven just above fire clay brick supports arranged to receive the petits. The fork is then withdrawn and the door closed. The stove has a cherry-red, almost white, heat and in a few minutes the enamel coating has been uniformly melted, and the plates are ready to be removed on the petits and fork in the same manner as they were inserted. Rapid cooling must now be carefully avoided, otherwise the enamel and the iron will be liable to separate, and chipping will result. The temperature of fusion should be about 2,192° F.† When all the plates have been thus prepared they are carefully examined and defective ones laid aside, the others being now ready for the next operation. {296}

† Melting a piece of copper will approximately represent this temperature.

Stage V.—The coating of the plate with white is the next stage. The temperature of fusion of the white glaze is lower than that of the gray, so that the plate will remain a shorter time in the stove, or be submitted to a somewhat lower temperature. The latter system is to be strongly recommended in order to prevent any possibility of fusion of the ground mass. The white should be made as liquid as possible consistent with good results. The advantages of thin coatings have already been explained, but if the mixing is too thin the ground coating will not only be irregularly covered. but, in fusion, bubbles will be produced, owing to the steam escaping, and these are fatal to the sale of any kind of enameled ware. When the plate has been thoroughly dried and fusion has taken place, slow and steady cooling is absolutely essential. Special muffles are frequently built for this purpose, and their use is the means of preventing a large number of wasters. Before putting on the glaze, care must be taken to remove the gray from any part which is not to be coated. The temperature of fusion should be about 1,890° F.,† and the time taken is about 5 minutes.

† Melting a piece of brass will represent this temperature.

Stage VI.—The stencil must be cut with perfect exactitude. The letters should be as clear as possible, proportioned, and spaced to obtain the best effects as regards boldness and appearance. Stencils may be cut either from paper or from specially prepared soft metal, called stencil metal. The former are satisfactory enough when only a few plates are required from one stencil, but when large quantities are required, say, 60 upward, metal stencils should be used. The paper should be thick, tough, and strong, and is prepared in the following manner: Shellac is dissolved in methylated spirits to the ordinary liquid gum form, and this is spread over both sides of the paper with a brush. When thoroughly dry a second protective coating is added, and the paper is then ready for stencil work. The stencil cutter’s outfit consists of suitable knives, steel rule, scales of various fractions to an inch, a large sheet of glass on which the cutting is done, and alphabets and numerals of various characters and types. For ordinary lettering one stencil is enough, but for more intricate designs 2, 3, and even 4 stencils may be required. In the preparation of the plates referred to in the paragraph preceding Stage I, only 1 stencil would be necessary. The paper before preparation would be measured out to the exact size of the plate, and the letters would be drawn in. The cutting would then be done, and the result shown at Fig. 1 would be obtained, the black parts being cut out. The lines or corners of each letter or figure should be perfectly clear and clean, for any flaw in the stencil will be reproduced on the plate.

Stage VII.—The next stage is the application of the blue enamel. The operation is almost identical with that of the white, but when the coating has been applied and dried, the lettering must be brushed out before it is fused. The coating is generally applied by a badger brush after a little gum water has been added; the effect of this is to make the blue more compact.

Stage VIII.—The next operation is brushing; the stencil is carefully placed over the plate, and held in position, and with a small hand brush with hard bristles the stencil is brushed over. This brushing removes all the blue coating, which shows the lettering and leaves the rest of the white intact. When this has been done, the stencil is removed and the connecting ribs of the lettering—some of which are marked X in Fig. 2—are then removed by hand, the instrument generally being a pointed stick of box or other similar wood.

Stage IX.—Fusing follows as in the case of the white glaze, and the plate is complete. One coat of blue should be sufficient, but if any defects are apparent a second layer is necessary.

The white and blue glazes are applied only on the front side of the plate, the back side being left coated with gray only.

From The Sheet To The Hollow Ware.

—In hollow-ware enameling, the iron is received in squares, circles, or oblongs, of the size required for the ware to be turned out. It is soft and ductile, and by means of suitable punches and dies it is driven in a stamping press to the necessary shape. For shallow articles only one operation is necessary, but for deeper articles from 2 to 6 operations may be {297} required, annealing in a specially constructed furnace taking place between each. Following the “drawing” operations comes that of trimming; this may be done in a press or spinning lathe, the object being to trim the edges and remove all roughness. The articles are now ready for enameling. For explanation, let us suppose they are tumblers, to be white inside, and blue outside. The gray is first laid on, then the white, and lastly the blue—that is, after the pickling and cleaning operations have been performed. The line of demarcation between the blue and white must be clear, otherwise the appearance of the article will not be satisfactory. The process of enameling is exactly the same as for sign-plate enameling, but more care must be exercised in order to obtain a smoother surface. While the liquid enamels are being applied, circular articles should be steadily rotated in order to let the coating flow uniformly and prevent thick and thin places. The enameling of “whole drawn” ironware presents no difficulty to the ordinary enameler, but with articles which are seamed or riveted, special care and experience is necessary.

Seamed or riveted parts are, of course, thicker than the ordinary plate, will expand and contract differently, will take longer to heat and longer to cool, and the conclusion, therefore, that must be arrived at is that the thickness should be reduced as much as possible, and the joints be made as smooth as possible. Unless special precautions are taken, cracks will be seen on articles of this kind running in straight lines from the rivets or seams. To avoid these, the enamel liquid must be reduced to the greatest stage of liquidity, the heat must be raised slowly, and in cooling the articles should pass through, say, 2 or 3 muffles, each one having a lower temperature than the preceding one. It is now generally conceded that the slower and more uniform the cooling process, the greater will be the durability of the enamel. Feldspar is an almost absolutely necessary addition to the gray in successful hollow-ware enameling, and the compositions of both gray and white should be such as to demand a high temperature for fusion. The utensils with the gray coating should first be raised to almost a red heat in a muffle, and then placed in a furnace raised to a white heat. The white should be treated similarly, and in this way the time taken for complete fusion at the last stage will be about 4 minutes.

The outside enamel on utensils is less viscous than the inside enamel, and should also be applied as thinly as possible.

Stoves And Furnaces.

—Fritting and Fusing.—The best results are obtained in enameling when the thoroughly ground and mixed constituents are fused together, reground, and then applied to the metal surface. In cheap enamels the gray is sometimes applied without being previously melted, but it lacks the durability which is obtained by thorough fusion and regrinding. In smelting enamel one of two kinds of furnaces may be used, viz., tank or crucible. The former is better adapted to the melting of considerable quantities of ordinary enamel, while the latter is more suitable for smaller quantities or for finer enamels as the mixture is protected from the direct action of the flames by covers on the crucibles. The number of tanks and crucibles in connection with each furnace depends upon the heating capacity of the furnace and upon the out-turn required. They are so arranged that all or any of them can be used or put out of use readily by means of valves and dampers. Generally, they are arranged in groups of from 6 to 12, placed in a straight or circular line, but the object aimed at is complete combustion of the fuel, and the utilization of the heat to the fullest extent. One arrangement is to have the flame pass along the bottom and sides of the tank and then over the top to the chimney.

The general system in use is, however, the crucible system. The crucibles are made from the best fire clay, and the most satisfactory are sold under the name of “Hessian crucibles.” The chief objection to the use of the crucibles is that of cost. They are expensive, and in many factories the life of the crucible is very short, in some cases not extending beyond one period of fusion. When this, however, is the rule rather than the exception, the results are due to carelessness. Sudden heating or cooling of the crucible will cause it to crack or fall to pieces, but for this there is no excuse. Running the molten material quickly out of the crucible and replacing it hurriedly with a fresh cold mixing is liable—in fact, almost certain—to produce fracture, not only causing the destruction of the crucible, but also the loss of the mixing. New crucibles should be thoroughly dried in a gentle heat for some days and then gradually raised to the requisite temperature which they {298} must sustain for the purposes of fusion. Sometimes unglazed porcelain crucibles specially prepared with a large proportion of china clay are used. These are, however, expensive and require special attention during the first melt. The life of all crucibles can be lengthened by: (1) Gradually heating them before putting them into the fire; (2) never replacing a frit with a cold mass for the succeeding one; it should first be heated in a stove and then introduced into the crucible; (3) carefully protecting the hot crucibles from cold draughts or rapid cooling.

Melting And Melting Furnaces.

—The arrangement of the melting furnace must be such as to protect the whole of the crucible from chills. The usual pit furnaces, with slight modifications, are suitable for this purpose. The crucible shown at b in Fig. 3 is of the type already described; at the top it is fitted with a lid, a, hinged at the middle, and at the bottom it is pierced by a 2-inch conical hole.† The hole, while melting is going on, is plugged up with a specially prepared stopper. The crucible stands on a tubular fireproof support, c, which allows the molten mass to be easily run off into a tub of water, which is placed in the chamber, d. The fuel is thrown in from the top, and the supply must be kept uniform. From 4 to 6 of these furnaces are connected with the same chimney; but before passing to the chimney the hot gases are in some cases used for heating purposes in connection with the drying stove. The plug used may be either a permanent iron one coated with a very hard enamel or made from a composition of quartz powder and water. An uncovered iron plug would be unsuitable owing to the action of the iron on the ingredients of the mixing.

† Two inches for gray, one inch for glaze; the hole should he wider at the top.

In some cases only a very small hole is made in the crucible and no stopper used, the fusion of the mixing automatically closing up the hole. In some other factories no hole is made in the crucible, and when fusion is complete the crucible is removed and the mixing poured out. The two latter systems are bad; in the first there is always some waste of material through leakage, and in the latter the operation of removing the crucible is clumsy and difficult, while the exposure to the colder atmosphere frequently causes rupture.

The plug used should be connected with a rod, as shown in Fig. 3, which passes through a slot in one-half of the hinged lid, a. When fusion is complete this half is turned over, and the plug pulled up, thus allowing the molten mass to fall through into the vat of water placed underneath. The mixing in the crucibles, as it becomes molten, settles down, and more material can then be added until the crucible is nearly full. If the mixing is correctly composed, and has been thoroughly fused, it should flow freely from the crucible when the plug is withdrawn. Fusing generally requires only to be done once, but for fine enamels the operation may be repeated. The running off into the water is necessary in order to make the mass brittle and easy to grind. If this was not done it would again form into hard flinty lumps and require much time and labor to reduce to a powder.

A careful record should be kept of the loss in weight of the dried material at each operation. The weighings should be made at the following points: (1) Before and after melting; (2) after crushing.

The time required for melting varies greatly, but from 6 to 9 hours may be considered as the extreme limits. Gas is much used for raising the necessary heat for melting. The generator may be {299} placed in any convenient position, but a very good system is to have it in the center of a battery of muffles, any or all of which can be brought into use. When quartz stoppers are used there is considerable trouble in their preparation, and as each new batch of material requires a fresh stopper, wrought-iron stoppers have been introduced in many factories. These are coated with an enamel requiring a much higher temperature of fusion than the fundamental substance, and this coating prevents the iron having any injurious action on the frit.

Fusing.

—For fusing the enamel muffle furnaces are used; these furnaces are simple in construction, being designed specially for: (1) Minimum consumption of fuel; (2) maximum heat in the muffle; (3) protection of the inside of the muffle from dust, draughts, etc.

The muffle furnaces may be of any size, but in order to economize fuel, it is obvious that they should be no larger than is necessary for the class and quantity of work being turned out. For sign-plate enameling the interior of the muffle may be as much as 10 feet by 5 feet wide by 3 feet in height, but a furnace of this kind would be absolutely ruinous for a concern where only about a dozen small hollow-ware articles were enameled at a time. The best system is to have 2 or 3 muffle furnaces of different dimensions, as in this way all or any one of them can be brought into use as the character and number of the articles may require. The temperature throughout the muffle is not uniform, the end next to the furnace being hotter than that next to the door. In plate enameling it is therefore necessary that the plates should be turned so that uniform fusion of the enamel may take place. In the working of hollow ware the articles should be first placed at the front of the muffle and then moved toward the back. The front of the furnace is closed in by a vertically sliding door or lid, and in this an aperture is cut, through which the process of fusion can be inspected. All openings to the muffle should be used as little as possible; otherwise cold air is admitted, and the inside temperature rapidly lowered.

Fig. 4 shows a simple arrangement of a muffle furnace; a is the furnace itself, with an opening, e, through which the fuel is fed; b is the muffle; c shows the firebars, and d the cinder box; f is a rest or plate on which is placed the articles to be enameled. The plate or petits on which the articles rest while being put into the muffle should be almost red hot, as the whole heat of the muffle in this way begins to act immediately on the enamel coating. The articles inside the muffles can be moved about when necessary, either by a hook or a pair of tongs, but care must be taken that every part of the vessel or plate is submitted to the same amount of heat.

In Figs. 5, 6, and 7 are given drawings of an arrangement of furnaces, etc., connected with an enameling factory at {300} present working. The stoves shown in Fig. 5 are drying stoves fired from the end by charcoal, and having a temperature of about 160° F. Fig. 6 shows the arrangement of the flues for the passage of the gases round the fusing oven. The section through the line A B, Fig. 5, as shown in Fig. 7, and the section through the frit kilns, as shown in Fig. 8, are sufficiently explanatory. The frit kilns and the fusing oven flues both lead to the brick chimney, but the stoves are connected to a wrought-iron chimney shown in Fig. 6. Another arrangement would have been to so arrange the stoves that the gases from the frit kilns could have been utilized for heating purposes.

Fuel.

—The consumption of fuel in an enameling factory is the most serious item of the expenditure. Ill-constructed or badly proportioned stoves may represent any loss of coal from a quarter to one ton per day, and as great and uniform temperatures must be maintained, fuel of low quality and price is not desirable. In the melting stoves either arranged as tank or crucible furnaces, the character of the coal must not be neglected, as light dust, iron oxide, or injurious gases will enter into the crucibles through any opening, especially if the draught is not very great. Almost any of the various kinds of fuel may be used, provided that the system of combustion is specially arranged for in the construction of the furnaces. Charcoal is one of the best fuels available, its calorific value being so great; but its cost is in some places almost prohibitive. Wood burns too quickly, and is therefore expensive, and necessitates incessant firing.

For practical purposes we are thus often left to a selection of some type of coal. A coal with comparatively little heating power at a cheap price will be found more expensive in the end than one costing more, but capable of more rapid combustion and possessing more heat yielding gases. Cheap and hard coals give the fireman an amount of labor which is excessive. The proper maintenance of the temperature of the stove is almost impossible. Anthracite is excellent in every way, as it consists of nearly pure carbon, giving off a high degree of heat without smoke. Its use, of course, necessitates the use of a blower, but to this there can be no objection. Any coal which will burn freely and clean, giving off no excessive smoke, and capable of almost complete combustion, will give satisfaction in enameling; but it must not be forgotten that the consumption of fuel is so large that both price and quality must be carefully considered. Experimental tests must be made from time to time. A cheap, common coal will never give good results, and a good expensive coal will make the cost of manufacture so great that the prices of the enameled articles will render them unsalable. Any ordinary small factory will use from 2 to 4 tons per day of coal, and it will thus be seen that the financial success of a concern lies to a very great extent at the mouth of the furnace. Coke is a good medium for obtaining the necessary heat required in enameling if it can be got at a reasonable price. With a good draught a uniform temperature can be easily kept up, and the use of this by-product is, therefore, to be recommended. {301}

With good coal and a furnace constructed to utilize the heat given off to the fullest extent, there may still be unnecessary waste. The arrangement of the bars should only be made by those who fully understand the character of the coal and the objects in view. The fireman in charge should be thoroughly experienced and reliable, as much waste is frequently traced to imperfect feeding of the fuel.

Each charge of articles should be as large as possible, as fusing will take place equally as well on many articles as on few. The charges should follow one another as rapidly as can be conveniently carried out; and where this is not done there is a lack of organization which should be immediately remedied.

Mills.

—Any hard substances must first be broken up and pounded in a pounding or stamping mill, or in any other suitable manner, thus reducing the lumps to a granular condition. When this has been done, the coarse is separated from the fine parts and the former again operated on. The next process is roller grinding for reducing the hard fritted granular particles to a fine powder. These mills vary in construction, but a satisfactory type is shown in Fig. 9. Motion is conveyed by a belt to the driving pulley, and this is transmitted from the pinion to the large bevel, which is connected by a shaft to the ground plate. As this revolves the material causes the mill wheels to revolve, and in this way the material is reduced to a powder. The rollers are of reduced diameter on the inner side to prevent slippage, and when all the parts are made of iron, the metal must be close grained and of very hard structure, so as to reduce the amount removed by wear to a minimum. When the materials are ground wet, the powder should be carefully protected from dust and thoroughly dried before passing to the next operation.

The glazing or enamel mills are shown in Fig. 10. These mills consist of a strong iron frame securely bolted to a stone foundation. In the sketch shown the framing carries 2 mills, but 3 or 4 can be arranged for. A common arrangement for small factories consists of 2 large mills, and 1 smaller mill, driven from the same shaft. One of the mills is used for foundation or gray mixings, the second for white, and the smallest one for colored mixings. In these mills it is essential that the construction is such as to prevent any iron fitting coming into contact with the mixing, for, as has already been explained, the iron will cause discoloration. The ground plate is composed of quartz and is immovable. It is surrounded by a wooden casing—as shown at a—and bound together by iron hoops. The millstones are heavy, rectangular blocks of quartz, called “French burr stone,” and into the center the spindle, b, is led. The powdered material mixed with about three times its bulk of water is poured into the vats, a, and the grinding stones are then set in motion. When a condition ready for enameling has been reached the mixture is run off through the valves, c. Each mill can be thrown out of gear when required, by means of a clutch box, without interfering with the working of the others. The grinding stones wear rapidly and require to be refaced from time to time. To avoid stoppage of the work, therefore, it is advisable to always have a spare set in readiness to replace those removed for refacing. The composition of the stones should not be neglected, for, in many cases, faults in the enamel have been traced to the wearing away of stones containing earthy or metallic matter. {302}

Enamel Mixing.

—All constituents of which an enamel glaze is composed must be intimately mixed together. This can only be done by reducing each to a fine powder and thoroughly stirring them up together. This part of the work is often carried out in a very superficial manner, one material showing much larger lumps than another. Under circumstances such as these it is absurd to imagine that in fusion equal distribution will take place. What really happens is that some parts of the mass are insufficiently supplied with certain properties while others have too much. A mixture of this class can produce only unsatisfactory results in every respect, for the variations referred to will produce variations in the completeness of fusion in the viscous character of the mass, and in the color.

The mixing can be done by thoroughly stirring the various ingredients together, and a much better and cheaper system is mixing in rotating barrels or churns. These are mounted on axles which rest in bearings, one axle being long enough to carry a pulley. From the driving shaft a belt is led to the cask, which then rotates at a speed of from 40 to 60 revolutions per minute, and in about a quarter of an hour the operation is complete. The cask should not exceed the 5-gallon size, and should at no time be more than two-thirds full. Two casks of this kind give better results than one twice the size. The materials are shot into the cask in their correct proportions through a large bung hole, which is then closed over by a close-fitting lid.

Mixings.

—For gray or fundamental coatings:

I.— Almost any kind of glass 49 per cent

Oxide of lead 47 per cent

Fused borax 4 per cent

II.— Glass (any kind) 61 per cent

Red lead 22 per cent

Borax 16 per cent

Niter 1 per cent

III.— Quartz 67.5 per cent

Borax 29.5 per cent

Soda (enameling) 3 per cent

The above is specially adapted for iron pipes.

IV.— Frit of silica powder 60 per cent

Borax 33 per cent

White lead 7 per cent

Fused and then ground with—

• Three-tenths weight of silica frit.
• Clay, three-tenths weight of silica frit.
• Magnesia, one-sixth weight of white lead.

V.— Silica 65 per cent

Borax 14 per cent

Oxide of lead 4 per cent

Clay 15 per cent

Magnesia 2 per cent

No. V gives a fair average of several mixings which are in use, but it can be varied slightly to suit different conditions of work.

Defects In The Gray Or Ground Coating.

—Chipping is the most disastrous. This may be prevented by the addition of some bitter salt, say from 3 to 4 per cent of the weight of the frit.

The addition of magnesia when it has been omitted from the frit may also act as a preventive, but it should only be added in very small quantities, not exceeding 2.5 per cent, otherwise the temperature required for fusion will be very great.

Coating And Fusion.

—Difficulties of either may generally be done away with by reducing the magnesia used in the frit to a minimum.

A soft surface is always the outcome of a mixing which can be fused at a low temperature. It is due to too much lead or an insufficiency of clay or silica powder.

A hard surface is due to the quantity of lead in the mixing being too small. Increase the quantity and introduce potash, say about 2.5 per cent.

The gray or fundamental mixing should be kept together in a condition only just sufficiently liquid to allow of being poured out. When required to be applied to the plate, the water necessary to lower it to the consistency of thick cream can then be added gradually, energetic stirring of the mass taking place simultaneously in order to obtain uniform distribution.

The time required for fusion may vary from 15 minutes to 25 minutes, but should never exceed the latter. If it does, it shows that the mixing is too viscous, and the remedy would be the addition and thorough intermixture of calcined borax or boracic acid. Should this fail, then remelting or a new frit is necessary.

A highly glazed surface on leaving the muffle shows that the composition is too fluid and requires the addition of clay, glass, silica powder or other substance to increase the viscosity.

As has been already explained, the glaze is much more important than the fundamental coating. Discoloration or slight flaws which could be tolerated in the latter would be fatal to the former. {303}

In glazes, oxide of lead need not be used. It should never be used in a coating for vessels which are to contain acids or be used as cooking utensils. It may be used in sign-tablet production.

For pipes the following glaze gives good results:

I.— Feldspar 33 per cent

Borax 22.5 per cent

Quartz 16.5 per cent

Oxide of tin 15 per cent

Soda 8 per cent

Fluorspar 3.75 per cent

Saltpeter 2.25 per cent

For sign tablets the following gives fair results, although some of the succeeding ones are in more general use:

II.— Cullet 20 per cent

Powdered flint 15 per cent

Lead 52 per cent

Soda 4.5 per cent

Arsenic 4.5 per cent

Niter 4 per cent

III.— Frit of silica powder 30 per cent

Oxide of tin 18 per cent

Borax 17 per cent

Soda 8.6 per cent

Niter 7.5 per cent

White lead 5.5 per cent

Carbonate of ammonia 5.5 per cent

Magnesia 4 per cent

Silica powder 4 per cent

The following are useful for culinary utensils, as they do not contain lead:

IV.— Frit of silica powder 26 per cent

Oxide of tin 21 per cent

Borax 20 per cent

Soda 10.25 per cent

Niter 7 per cent

Carbonate of ammonia 5 per cent

Magnesia 3.25 per cent

This should be ground up with the following:

Silica powder 4.25 per cent

Oxide of tin 2.25 per cent

Soda 0.5 per cent

Magnesia 0.5 per cent

V.— Feldspar 41 per cent

Borax 35 per cent

Oxide of tin 17 per cent

Niter 7 per cent

VI.— Borax 30 per cent

Feldspar 22 per cent

Silicate powder 17.5 per cent

Oxide of tin 15 per cent

Soda 13.5 per cent

Niter 2 per cent

Borax will assist fusion. Quartz mixings require more soda than feldspar mixings.

VII.— Borax 28 per cent

Oxide of tin 19.5 per cent

Cullet (powdered white glass) 18 per cent

Silica powder 17.5 per cent

Niter 9.5 per cent

Magnesia 5 per cent

Clay 2.5 per cent

VIII.— Borax 26.75 per cent

Cullet 19 per cent

Silica powder 18.5 per cent

Oxide of tin 19 per cent

Niter 9.25 per cent

Magnesia 4.5 per cent

Soda 3 per cent

To No. VII must be added—while being ground—the following percentages of the weight of the frit:

Silica powder 18 per cent

Borax 9 per cent

Magnesia 5.25 per cent

Boracic acid 1.5 per cent

To No. VIII should be similarly added the following percentages of the frit:

Silica powder 1.75 per cent

Magnesia 1.75 per cent

Soda 1 per cent

This mixing is one which is used in the production of some of the best types of hollow ware for culinary purposes. The glaze should be kept in tubs mixed with water until used, and it should be carefully protected from dust.

Defects In The Glaze Or White.

—A bad white may be due to its being insufficiently opaque. More oxide of tin is required. Cracks may be prevented by the addition of carbonate of ammonia. Insufficient luster can be avoided by adding to the quantity of soda and reducing the borax. If the gray shows through the white it proves that the temperature of fusion is too high or the viscosity of the mixing is too great. If the coating is not uniformly spread it may be due to the glaze being too thin; add magnesia. If the glaze separates from the gray add some bitter salt. Viscosity will be increased by reducing the quantity of borax. Immunity against chemical reaction is procured by increasing the quantity of borax. An improved luster will be obtained by adding native carbonate of soda. The greater the quantity of silicic acid the greater must be the temperature for fusion. To reduce the temperature add borax. Clay will increase the difficulty {304} of fusion. Oxide of lead will make a frit more easily fusible. A purer white can be obtained by adding a small quantity of smalt.

Water.

—The character of the water used in the mixing of enamels is too frequently taken for granted, for unsuitable water may render a mixing almost entirely useless. Clean water, and with little or no sulphur present, is essential. For very fine enamels it is advisable to use carefully filtered water which has shown, after analysis, that it is free from any matter which is injurious to any of the enamel constituents.

How To Tell The Character Of Enamel.

—In the case of sign tablets the characteristics looked to are appearance and the adherence of the coatings to the iron. For the latter the tests are simple. The plate if slightly bent should not crack the coating. An enamel plate placed in boiling water for some time and then plunged into very cold water should not show any cracks, however small, even after repeated treatment of this kind.

Culinary utensils, and those to hold chemicals, should not only look well, but should be capable of resisting the action of acids. Lead should never enter into the composition of enamels of this class, as they then become easily acted upon, and in the case of chipping present a menace to health. The presence of lead is easily detected. Destroy the outside coating of the enamel at some spot by the application of strong nitric acid. Wash the part and apply a drop of ammonium sulphide. If lead is present, the part will become almost black, but remains unchanged in color if it is absent.

Another simple test is to switch up an egg in a vessel and allow it to stand for about 24 hours. When poured out and rinsed with water a dark stain will remain if lead is present in the enamel. To test the power of chemical resistance is equally simple. Boil diluted vinegar in the vessel for several minutes, and if a sediment is formed and the luster and smoothness of the glaze destroyed or partially destroyed, it follows that it is incapable of resisting the attacks of acids for any length of time. There are several other tests adopted, but those given present little difficulty in carrying out, and give reliable results.

Wasters And Seconds: Repairing Old Articles.

—In all enameling there must be certain articles turned out which are defective, but the percentage should never be very great. The causes which most frequently tend to the production of wasters are new mixings and a temperature of fusion which is either too high or too low. There are two ways of disposing of defective articles, viz.: (1) Chipping off the bad spots, patching them up and selling them as “seconds”; (2) throwing the articles into the waste heap. The best firms adopt the latter course, because the recoating and firing of defective parts practically means a repetition of the whole process, thus adding greatly to the cost, while the selling price is reduced. Overheating in fusion is generally shown by blisters or by the enamel being too thin in various places. Chipping may be also due to this cause, the excessive heat having practically fused the fundamental coating.

At this stage the defects may be remedied by breaking off the faulty parts, patching them up, and then recoating the whole. With sign tablets there is no objection to doing so, but with hollow ware the fact remains that the article is faulty, no matter how carefully defects may be hidden. As white is the most general coating used, and shows up the defects more than the colored coatings, the greatest care is necessary at every stage of the manufacture. While glowing on the article, it should appear uniformly yellow, but on cooling it should revert to a pure white shade. On examining different makes of white coated articles, it will be found that some are more opaque than others. The former are less durable than the latter, because they contain a large percentage of oxide of tin, which reduces the elasticity. To ensure hardness the mixing must be very liquid, and this cannot be arrived at when a large quantity of oxide of tin is introduced.

Old utensils which have become broken or chipped can be repaired, although, except in the case of large articles, this is rarely done. The operations necessary are: (1) The defective parts chipped off; (2) submitted to a red heat for a few moments; (3) coated with gray on the exposed iron; (4) fused; (5) coated with the glaze on the gray; (6) fused.

To Repair Enameled Signs.—

Copal 5 parts

Damar 5 parts

Venice turpentine 4 parts

Powder the rosins, mix with the turpentine and add enough alcohol to form a thick liquid. To this add finely powdered zinc white in sufficient quantity to yield a plastic mass. Coloring {305} matter may, of course, be added if desired.

The mass after application is polished when it has become sufficiently hard.

Enamel For Copper Cooking Vessels.

—White fluorspar is ground to a fine powder and strongly calcined with an equal volume of unburnt gypsum, at a light glowing heat, stirring diligently. Grind the mixture to a paste with water, paint the vessel with it, using a brush, or pour in the paste like a glaze and dry the same. Increase the heat gradually and bring the vessels with the glass substance quickly into strong heat, under a suitable covering or a mantle of burnt clay. The substance soon forms a white opaque enamel, which adheres firmly to the copper. It can stand pretty hard knocks without cracking, is adapted for cooking purposes and not attacked by acid matters. If the glassy substance is desired to cling well and firmly to the copper, a sudden and severe heat must be observed.

To Pickle Black Iron-plate Scrap Before Enameling.

—The black iron-plate scraps are first dipped clean in a mixture of about 1 part of sulphuric acid and 20 to 22 parts of water heated to 30° to 40° C. (86° to 104° F.), and sharp quartz sand is then used for scouring. They are then plunged for a few seconds in boiling water, taken out, and allowed to dry. Rinsing with cold water and allowing to dry thus may cause rust. The grains of quartz cut grooves in the fibers of the iron; this helps the grounding to adhere well. With many kinds of plate it is advisable to anneal after pickling, shutting off the air; by this means the plates will be thoroughly clean and free from oxidation. Much practice is required.—The Engineer.

Enameled Iron Recipes.

The first thing is to produce a flux to fuse at a moderate heat, which, by flowing upon the plate, forms a uniform surface for the white or colored enamels to work upon.

Flux for Enameled Iron.—

White lead 10 parts

Ball clay 1 part

Flint glass 10 parts

Whiting 1 part

The plates may then be coated with any of the following mixtures, which may either be spread on as a powder with a little gum, as in the case of the flux, or the colors may be mixed with oil and the plates dipped therein when coated; the plate requires heating sufficiently to run the enamels bright.

Soft Enamels for Iron, White.—

Flint glass 16 parts

Oxide of tin 1 / 2 parts

Niter 1 / 2 parts

Red lead 4 parts

Flint or china clay 1 part

Black.—

Red oxide of iron 1 / 4 parts

Carbonate of cobalt 1 / 4 parts

Red lead 6 parts

Borax 2 parts

Lynn sand 2 parts

Yellow Coral.—

Chromate of lead 1 part

Red lead 2 / 4 parts

Flint 1 part

Borax / 4 part

Canary.—

Oxide of uranium 1 part

Red lead 4 / 2 parts

Flint 1 / 2 parts

Flint glass 1 part

Turquoise.—

Red lead 40 parts

Flint glass 12 parts

Borax 16 parts

Flint 12 parts

Enamel white 14 parts

Oxide of copper 7 parts

Oxide of cobalt / 4 part

Red Brown.—

Calcined sulphate of iron 1 part

Flux No. 8 (see page ) 3 parts

Mazarine Blue.—

Oxide of cobalt 10 parts

Paris white 9 parts

Sulphate barytes 1 part

Fire the above at an intense heat and for use take

Above stain 1 part

Flux No. 8 (see page ) 3 parts

Sky Blue.—

Flint glass 30 parts

White lead 10 parts

Pearlash 2 parts

Common salt 2 parts

Oxide of cobalt 4 parts

Enamel, white 4 parts

Chrome Green.—

Borax 10 parts

Oxide of chrome 4 / 2 parts

White lead 9 parts

Flint glass 9 parts

Oxide of cobalt 2 parts

Oxide of tin 1 part

Coral Red.—

Bichromate potash 1 part

Red lead 4 / 2 parts

Sugar of lead 1 / 2 parts

Flint 1 / 2 parts

Flint glass 1 part

Enamel White.—Soft:

Red lead 80 parts

Opal glass 50 parts

Flint 50 parts

Borax 24 parts

Arsenic 8 parts

Niter 6 parts

Enamel White.—

Red lead 10 parts

Flint 6 parts

Boracic acid 4 parts

Niter 1 part

Soda crystals 1 part

Where the enameled work is intended to be exposed to the weather do not use flux No. 8, but substitute the following:

White lead 1 part

Ground flint glass 1 part

All the enamels should, after being mixed, be melted in crucibles, poured out when in liquid, and powdered or ground for use.

Fusible Enamel Colors.

The following colors are fusible by heat, and are all suitable for the decoration of china and glass. In the following collection of recipes certain terms are employed which may not be quite understood by persons who are not connected with either the glass or porcelain industries, such as “glost fire” and “run down,” and in such cases reference must be made to the following definitions:

“Run down.” Sufficient heat to melt into liquid.

“Glost fire.” Ordinary glaze heat.

“Grind only.” No calcination required.

“Hard fire.” Highest heat attainable.

“Frit.” The ingredients partly composing a glaze, which require calcination.

“Stone.” Always best Cornwall stone.

“Paris white.” Superior quality of whiting.

“Parts.” Always so many parts by weight, unless otherwise stated.

“D. L. Zinc.” Particular brand not essential. Any good quality oxide of zinc will do.

Ruby and Maroon.—Preparation of silver:

Nitric acid 1 ounce

Water 1 ounce

Dissolve the silver till saturated, then put a plate of copper in the solution to precipitate the silver in a metallic state. Wash well with water to remove the acetate of copper.

Flux for Above.—Six dwts. white lead to 1 ounce prepared silver.

Tin Solution.—Put the acid (aqua regia) in a bottle, add tin in small quantities until it becomes a dark-red color; let it stand about 4 days before use. When the acid becomes saturated it will turn red at the bottom of the bottle, then shake it up and add more tin; let it stand and it will become clear.

Aqua Regia.—

Nitric acid 2 parts

Muriatic acid 1 part

Dissolve grain gold in the aqua regia so as to make a saturated solution. Take a basin and fill it 3 parts full of water; drop the solution of gold into it till it becomes an amber color. Into this solution of gold gradually drop the solution of tin, until the precipitate is complete. Wash the precipitate until the water becomes tasteless, then dry slowly and flux as follows:

Flux No. I.—

Borax 3 parts

Red lead 3 parts

Flint 2 parts

Run down.

Rose Mixture.—

Purple of Cassius 1 ounce

Flux No. 1 6 ounces

Prepared silver 3 dwts.

Flint glass 2 ounces

Grind.

Purple Mixture.—

Purple of Cassius 1 ounce

Flux No. 8 (see page ) 2 / 2 ounces

Flint glass 2 ounces

Grind.

Ruby.—

Purple mixture 2 / 2 parts

Rose mixture 1 / 2 parts

Grind.

Maroon.—

Rose mixture 1 part

Purple mixture 2 parts

Grind. {307}

Black—Extra quality.—

Red oxide of iron 12 parts

Carbonate of cobalt 12 parts

Oxide of cobalt 1 part

Black flux A (see next formula) 80 parts

Glost fire.

Black Flux A.—

Red lead 3 parts

Calcined borax / 2 part

Lynn sand 1 part

Run down.

Black No. 2.—

Oxide of copper 1 part

Carbonate of cobalt / 2 part

Flux No. 8 (see next column) 4 parts

Grind only.

Enamel White.—

Arsenic 2 / 2 parts

Niter 1 / 2 parts

Borax 4 parts

Flint 16 parts

Glass 16 parts

Red lead 32 parts

Glost fire.

Turquoise.—China:

Calcined copper 5 parts

Whiting 5 parts

Phosphate of soda 8 parts

Oxide of zinc 16 parts

Soda crystals 4 parts

Magnesia 2 parts

Red lead 8 parts

Flux T (see next formula) 52 parts

Glost fire.

Flux T.—

Borax 2 parts

Sand 1 part

Run down.

Orange.—

Orange U. G. 1 part

Flux No. 8 (see next column) 3 parts

Grind only.

Blue Green.—

Flint glass 8 parts

Enamel white 25 parts

Borax 8 parts

Red lead 24 parts

Flint 6 parts

Oxide of copper 2 / 2 parts

Glost heat.

Coral Red.—

Chromate of potash 1 part

Sugar of lead 1 / 2 parts

Dissolve in hot water, then dry. Take 1 part of above, 3 parts flux for coral. Grind.

Flux for Coral.—

Red lead 4 / 2 parts

Flint 1 / 2 parts

Flint glass 1 / 2 parts

Run down.

Turquoise.—

Oxide of copper 5 parts

Borax 10 parts

Flint 12 parts

Enamel white 14 parts

Red lead 40 parts

Glost fire.

Flux No. 8.—

Red lead 6 parts

Borax 4 parts

Flint 2 parts

Run down.

Russian Green.—

Malachite green 10 parts

Enamel yellow 5 parts

Majolica white 5 parts

Flux No. 8 (see previous formula) 2 parts

Grind only.

Amber.—

Oxide of uranium 1 part

Coral flux 8 parts

Grind only.

Gordon Green.—

Yellow U. G. 5 parts

Flux No. 8 (see above) 15 parts

Malachite green 10 parts

Grind only.

Celadon.—

Enamel light blue 1 part

Malachite green 1 part

Flux No. 8 (see above) 15 parts

Grind only.

Red Brown.—

Sulphate of iron, fired 1 part

Flux No. 8 (see above) 3 parts

Grind only.

Matt Blue.—

Flux No. 8 (see above) 10 / 2 parts

Oxide of zinc 5 parts

Oxide of cobalt 4 parts

Glost fire, then take

Of above base 1 part

Flux No. 8 (see above) 1 / 8 parts

Grind only. {308}

Preparation Of Enamels.

The base of enamel is glass, colored different shades by the addition of metallic oxides mixed and melted with it.

The oxide of cobalt produces blue; red is obtained by the Cassius process. The purple of Cassius, which is one of the most brilliant of colors, is used almost exclusively in enameling and miniature painting; it is produced by adding to a solution of gold chloride a solution of tin chloride mixed with ferric chloride until a green color appears. The oxide of iron and of copper also produces red, but of a less rich tone; chrome produces green, and manganese violet; black is produced by the mixture of these oxides. Antimony and arsenic also enter into the composition of enamels.

Enamels are of two classes—opaque and transparent. The opacity is caused by the presence of tin.

When the mingled glass and oxides have been put in the crucible, this is placed in the furnace, heated to a temperature of 1,832° or 2,200° F. When the mixture becomes fused, it is stirred with a metal rod. Two or three hours are necessary for the operation. The enamel is then poured into water, which divides it into grains, or formed into cakes or masses, which are left to cool.

For applying enamels to metals, gold, silver, or copper, it is necessary to reduce them to powder, which is effected in an agate mortar with the aid of a pestle of the same material. During the operation the enamel ought to be soaked in water.

For dissolving the impurities which may have been formed during the work, a few drops of nitric acid are poured in immediately afterwards, well mixed, and then got rid of by repeated washing with filtered water. This should be carefully done, stirring the enamel powder with a glass rod, in order to keep the particles in suspension.

The powder is allowed to repose at the bottom of the vessel, after making sure by the taste of the water that it does not contain any trace of acid; only then is the enamel ready for use.

For enameling a jewel or other object it is necessary, first to heat it strongly, in order to burn off any fatty matter, and afterwards to cleanse it in a solution of nitric acid diluted with boiling water. After rinsing with pure water and wiping with a very clean cloth, it is heated slightly and is then ready to receive the enamel.

Enamels are applied with a steel tool in the form of a spatula; water is the vehicle. When the layers of enamel have been applied, the contained water is removed by means of a fine linen rag, pressing slightly on the parts that have received the enamel. The tissue absorbs the water, and nothing remains on the object except the enamel powder. It is placed before the fire to remove every trace of moisture. Thus prepared and put on a fire-clap slab, it is ready for its passage to the heat which fixes the enamel. This operation is conducted in a furnace, with a current of air whose temperature is about 1,832° F. In this operation the fire-chamber ought not to contain any gas.

Enamels are fused at a temperature of 1,292° to 1,472° F. Great attention is needed, for experience alone is the guide, and the duration of the process is quite short. On coming from the fire, the molecules composing the enamel powder have been fused together and present to the eye a vitreous surface covering the metal and adhering to it perfectly. Under the action of the heat the metallic oxides contained in the enamel have met the oxide of the metal and formed one body with it, thus adhering completely.

Jewelers’ Enamels.

Melt together:

Transparent Red.—Cassius gold purple, 65 parts, by weight; crystal glass, 30 parts, by weight; borax, 4 parts, by weight.

Transparent Blue.—Crystal glass, 34 parts, by weight; borax, 6 parts, by weight; cobalt oxide, 4 parts, by weight.

Dark Blue.—Crystal glass, 30 parts, by weight; borax, 6 parts, by weight; cobalt oxide, 4 parts, by weight; bone black, 4 parts, by weight; arsenic acid, 2 parts, by weight.

Transparent Green.—Crystal glass, 80 parts, by weight; cupric oxide, 4 parts, by weight; borax, 2 parts, by weight.

Dark Green.—Crystal glass, 30 parts, by weight; borax, 8 parts, by weight; cupric oxide, 4 parts, by weight; bone black, 4 parts by weight; arsenic acid, 2 parts, by weight.

Black.—Crystal glass, 30 parts, by weight; borax, 8 parts, by weight; cupric oxide, 4 parts, by weight; ferric oxide, 3 parts, by weight; cobalt oxide, 4 parts, by weight; manganic oxide, 4 parts, by weight.

White.—I.—Crystal glass, 30 parts, by weight; stannic oxide, 6 parts, by weight; borax, 6 parts, by weight; arsenic acid, 2 parts, by weight.

II.—Crystal glass, 30 parts, by weight; sodium antimonate, 10 parts, by weight. {309}

The finely pulverized colored enamel is applied with a brush and lavender oil on the white enamel already fused in and then only heated until it melts. For certain purposes, the color compositions may also be fused in without a white ground. The glass used for white, No. 2, must be free from lead, otherwise the enamel will be unsightly.

Various Enamels For Precious Metals

: White.—Crystal glass, 30 parts, by weight; oxide of tin, 6 parts, by weight; borax, 6 parts, by weight; dioxide of arsenic, 2 parts, by weight, or silicious sand, 50 parts, by weight; powder, consisting of 15 of tin per 100 of lead, 100 parts, by weight; carbonate of potassium, 40 parts, by weight. Fuse the whole with a quantity of manganese. To take away the accidental coloring, pour it into water, and after having pulverized it, melt again 3 or 4 times.

Opaque Blue.—Crystal glass, 30 parts, by weight; borax, 6 parts, by weight; cobalt oxide, 4 parts, by weight; calcined bone, 4 parts, by weight; dioxide of arsenic, 2 parts, by weight.

Transparent Green.—Crystal glass, 30 parts, by weight; blue verditer, 4 parts, by weight; borax, 2 parts, by weight.

Opaque Green.—Crystal glass, 30 parts, by weight; borax, 8 parts, by weight; blue verditer, 4 parts, by weight; calcined bone, 4 parts, by weight; dioxide of arsenic, 2 parts, by weight.

Black.—I.—Crystal glass, 30 parts, by weight; borax, 8 parts, by weight; oxide of copper, 4 parts, by weight; oxide of iron, 3 parts, by weight; oxide of cobalt, 4 parts, by weight; oxide of manganese, 4 parts, by weight.

II.—Take / 2 part, by weight, of silver; 2 / 2 parts of copper; 3 / 2 parts of lead, and 2 / 2 parts of muriate of ammonia. Melt together and pour into a crucible with twice as much pulverized sulphur; the crucible is then to be immediately covered that the sulphur may not take fire, and the mixture is to be calcined over a smelting fire until the superfluous sulphur is burned away. The compound is then to be coarsely pounded, and, with a solution of muriate of ammonia, to be formed into a paste which is to be placed upon the article it is designed to enamel. The article must then be held over a spirit lamp till the compound upon it melts and flows. After this it may be smoothed and polished up in safety.

See also Varnishes and Ceramics for other enamel formulas.

ENAMEL COLORS, QUICK DRYING: See Varnishes.

ENAMEL REMOVERS: See Cleaning Preparations and Methods.

ENAMELING ALLOYS: See Alloys.

ENGINES (GASOLINE), ANTI-FREEZING SOLUTION FOR: See Freezing Preventives.

Engraving Spoon Handles.

After the first monogram has been engraved, rub it with a mixture of 3 parts of beeswax, 3 of tallow, 1 of Canada balsam, and 1 of olive oil. Remove any superfluous quantity, then moisten a piece of paper with the tongue, and press it evenly upon the engraving. Lay a dry piece of paper over it, hold both firmly with thumb and forefinger of left hand, and rub over the surface with a polishing tool of steel or bone. The wet paper is thereby pressed into the engraving, and, with care, a clear impression is made. Remove the paper carefully, place it in the same position on another handle, and a clear impression will be left. The same paper can be used 2 dozen times or more.

ENGRAVING ON STEEL: See Steel.

Engravings: Their Preservation

(See also Pictures, Prints, and Lithographs.)

Cleaning Of Copperplate Engravings.

—Wash the sheet on both sides by means of a soft sponge or brush with water to which 40 parts of ammonium carbonate has been added per 1,000 parts of water, and rinse the paper each time with clear water. Next moisten with water in which a little wine vinegar has been admixed, rinse the sheet again with water containing a little chloride of lime, and dry in the air, preferably in the sun. The paper will become perfectly clear without the print being injured.

Restoration Of Old Prints.

—Old engravings, woodcuts, or printed sheets that have turned yellow may be rendered white by first washing carefully in water containing a little hyposulphite of soda, and then dipping for a minute in javelle water. To prepare the latter, put 4 pounds of bicarbonate of soda in a pan, pour over it 1 gallon of boiling water; boil for 15 minutes, then stir in 1 {310} pound of chloride of lime. When cold, pour off the clear liquid, and keep in a jug ready for use.

Surprising results are obtained from the use of hydrogen peroxide in the restoration of old copper or steel engravings or lithographs which have become soiled or yellow, and this without the least injury to the picture. The cellulose which makes the substance of the paper resists the action of ozone, and the black carbon color of these prints is indestructible.

To remove grease or other spots of dirt before bleaching, the engravings are treated with benzine. This is done by laying each one out flat in a shallow vessel and pouring the benzine over it. As benzine evaporates very rapidly, the vessel must be kept well covered, and since its vapors are also exceedingly inflammable, no fire or smoking should be allowed in the room. The picture is left for several hours, then lifted out and dried in the air, and finally brushed several times with a soft brush. The dust which was kept upon the paper by the grease now lies more loosely upon it and can easily be removed by brushing.

In many cases the above treatment is sufficient to improve the appearance of the picture. In the case of very old or badly soiled engravings, it is followed by a second, consisting in the immersion of the picture in a solution of sodium carbonate or a very dilute solution of caustic soda, it being left as before for several hours. After the liquid has been poured off, the picture must be repeatedly rinsed in clear water, to remove any remnant of the soda.

By these means the paper is so far cleansed that only spots of mold or other discolorations remain. These may be removed by hydrogen peroxide, in a fairly strong solution. The commercial peroxide may be diluted with 2 parts water.

The picture is laid in a shallow vessel, the peroxide poured over it, and the vessel placed in a strong light. Very soon the discolorations will pale.

To Reduce Engravings.

—Plaster casts, as we know, can be perceptibly reduced in size by treatment with water or alcohol, and if this is properly done, the reduction is so even that the cast loses nothing of its clear outline, but sometimes even gains in this respect by contraction. If it is desired to reduce an engraved plate, make a plaster cast of it, treat this with water or alcohol, and fill the new cast with some easily fusible metal. This model, which will be considerably smaller than the original, is to be made again in plaster, and again treated, until the desired size is reached. In this way anything of the kind, even medallions, can be reproduced on a smaller scale.

ENLARGEMENTS: See Photography.

ENVELOPE GUM: See Adhesives, under Mucilages.

EPIZOOTY: See Veterinary Formulas.

Essences and Extracts of Fruits

Preservation Of Fruit Juices.

—The juices of pulpy fruits, when fresh, contain an active principle known as pectin, which is the coagulating substance that forms the basis of fruit jellies. This it is which prevents the juice of berries and similar fruits from passing through filtering media. Pectin may be precipitated by the addition of alcohol, or by fermentation. The latter is the best, as the addition of alcohol to the fresh juices destroys their aroma and injures the taste. The induction of a light fermentation is far the better method, not only preserving, when carefully conducted, the taste and aroma of the fruit, but yielding far more juice. The fruit is crushed and the juice subsequently carefully but strongly pressed out. Sometimes the crushed fruit is allowed to stand awhile, and to proceed to a light fermentation before pressure is applied; but while a greater amount of juice is thus obtained, the aroma and flavor of the product are very sensibly injured by the procedure.

To the juice thus obtained, add from 1 to 2 per cent of sugar, and put away in a cool place (where the temperature will not rise over 70° or 75° F.). Fermentation soon begins, and will proceed for a few days. As soon as the development of carbonic acid gas ceases, the juice begins to clear itself, from the surface downward, and in a short time all solid matter will lie in a mass at the bottom, leaving the liquid bright and clear. Draw off the latter with a siphon, very carefully, so as not to disturb the sedimentary matter. Fermentation should be induced in closed vessels only, as when conducted in open containers a fungoid growth is apt to form on the surface, sometimes causing putrefactive, and at others, an acetic, fermentation, in either event spoiling the juice for {311} subsequent use, except as a vinegar. The vessels, to effect the end desired, should be filled only two-thirds or three-fourths full, and then carefully closed with a tight-fitting cork, through which is passed a tube of glass, bent at the upper end, the short end of which passes below the surface of a vessel filled with water. As soon as fermentation commences the carbonic acid developed thereby escapes through the tube into the water, whence it passes off into the atmosphere. When bubbles no longer pass off from the tube the operation should be interrupted, and decantation or siphoning, with subsequent filtration, commenced.

By proceeding in this manner all the aroma and flavor of the juices are retained. If it is intended for preservation for any length of time the juice should be heated on a water bath to about 176° F. and poured, while hot, into bottles which have been asepticized by filling with cold water, and placing in a vessel similarly filled, bringing to a boiling temperature, and maintaining at this temperature until the juice, while still hot, is poured into them. If now closed with corks similarly asepticized, or by dipping into hot melted paraffine, the juice may be kept unaltered for years. It is better, however, to make the juice at once into syrup, using the best refined sugar, and boiling in a copper kettle (iron or tin spoil the color), following the usual precautions as to skimming, etc. The syrup should be poured hot into the bottles previously heated as before described.

Ripe fruit may be kept in suitable quantities for a considerable time if covered with a solution of saccharine and left undisturbed, this, too, without deteriorating the taste, color, or aroma of the fruit if packed with care.

Whole fruit may be stored in bulk, by carefully and without fracture filling into convenient-sized jars or bottles, and pouring thereon a solution containing a quarter of an ounce of refined saccharine to the gallon of water, so filling each vessel that the solution is within an inch of the cork when pressed into position. The corks should first of all be immersed in melted paraffine wax, then drained, and allowed to cool. When fruit juices alone are required for storage purposes they are prepared by subjecting the juicy fruits to considerable pressure, by which process the juices are liberated.

The sound ripe fruits are crushed and packed into felt or flannel bags. The fruit should be carefully selected, rotten or impaired portions being carefully removed; this is important, or the whole stock would be spoiled. Several methods are adopted for preserving and clarifying fruit juices.

A common way in which they are kept from fermenting is by the use of salicylic acid or other antiseptic substance, which destroys the fermentative germ, or otherwise retards its action for a considerable time. The use of this acid is seriously objected to by some as injurious to the consumer. About 2 ounces of salicylic acid, previously dissolved in alcohol, to 25 gallons of juice, or 40 grains to the gallon, is generally considered the proper proportion.

Another method adopted is to fill the freshly prepared cold juice into bottles until it reaches the necks, and on the top of this fruit juice a little glycerine is placed.

Juices thus preserved will keep in an unchanged condition in any season. Probably one of the best methods of preserving fruit juices is to add 15 per cent of 95 per cent alcohol. On such an addition, albumen and mucilaginous matter will be deposited. The juice may then be stored in large bottles, jars, or barrels, if securely closed, and when clear, so that further clarification is unnecessary, the juice should finally be decanted or siphoned off.

A method applicable to most berries is as follows:

Take fresh, ripe berries, stem them, and rub through a No. 8 sieve, rejecting all soft and green fruit. Add to each gallon of pulp thus obtained 8 pounds of granulated sugar. Put on the fire and bring just to a boil, stirring constantly. Just before removing from the fire, add to each gallon 1 ounce of a saturated alcoholic solution of salicylic acid, stirring well. Remove the scum, and, while still hot, put into jars and hermetically seal. Put the jars in cold water, and raise them to the boiling point, to prevent them from bursting by sudden expansion on pouring hot fruit into them. Fill the jars entirely full, so as to leave no air space when fruit cools and contracts.

Prevention Of Foaming And Partial Caramelization Of Fruit Juices.

—Fresh fruit juices carry a notable amount of free carbonic acid, which must make its escape on heating the liquid. This will do easily enough if the juice be heated in its natural state, but the addition of the sugar so increases the density of the fluid that the acid finds escape difficult, and often the result is foaming. As to the burning or partial caramelization of {312} the syrup, that is easily accounted for in the greater density of the syrup at the bottom of the kettle—the lighter portion, or that still carrying imprisoned gases, remaining on top until it is freed from them. Constant stirring can prevent this only partially, since it cannot entirely overcome the results of the natural forces in action. The consequence is more or less caramelization. The remedy is very simple. Boil the juices first, adding distilled water to make up for the loss by evaporation, and add the sugar afterwards.

Essences And Extracts:

Almond Extracts.—

I.— Oil of bitter almonds 90 minims

Alcohol, 94 per cent, quantity sufficient to make 8 ounces.

II.— Oil of bitter almonds 80 minims

Alcohol 7 ounces

Distilled water, quantity sufficient to make 8 ounces.

III.— Oil of bitter almonds, deprived of its hydrocyanic acid 1 ounce

Alcohol 15 ounces

In order to remove the hydrocyanic acid in oil of bitter almonds, dissolve 2 parts of ferrous sulphate in 16 parts of distilled water; in another vessel slake 1 part freshly burned quicklime in a similar quantity of distilled water, and to this add the solution of iron sulphate, after the same has cooled. In the mixture put 4 parts of almond oil, and thoroughly agitate the liquids together. Repeat the agitation at an interval of 5 minutes, then filter. Put the filtrate into a glass retort and distil until all the oil has passed over. Remove any water that may be with the distillate by decantation, or otherwise.

Apricot Extract.—

Linalyl formate 90 minims

Glycerine 1 ounce

Amyl valerianate 4 drachms

Alcohol 11 ounces

Fluid extract orris 1 ounce

Water, quantity sufficient to make 1 pint.

Apple Extract.—

Glycerine 1 ounce

Amyl valerianate 4 drachms

Linalyl formate 45 minims

Fluid extract orris 1 ounce

Alcohol 11 ounces

Water, quantity sufficient to make 1 pint.

Apple Syrup.

—I.—Peel and remove the cores of, say, 5 parts of apples and cut them into little bits. Put in a suitable vessel and pour over them a mixture of 5 parts each of common white wine and water, and let macerate together for 5 days at from 125° to 135° F., the vessel being closed during the time. Then strain the liquid through a linen cloth, using gentle pressure on the solid matter, forcing as much as possible of it through the cloth. Boil 30 parts of sugar and 20 parts of water together, and when boiling add to the resulting syrup the apple juice; let it boil up for a minute or so, and strain through flannel.

II.—Good ripe apples are cut into small pieces and pounded to a pulp in a mortar of any metal with the exception of iron. To 1 part of this pulp add 11 parts of water. Allow this to stand for 12 hours. Colate. To 11 parts of the colature add 1 part of sugar. Boil for 5 minutes. Skim carefully. Bottle slightly warm. A small quantity of tartaric acid may be added to heighten the flavor.

Banana Syrup.

—Cut the fruit in slices and place in a jar; sprinkle with sugar and cover the jar, which is then enveloped in straw and placed in cold water and the latter is heated to the boiling point. The jar is then removed, allowed to cool, and the juice poured into bottles.

Cinnamon Essence.—

Oil of cinnamon 2 drachms

Cinnamon, powdered 4 ounces

Alcohol, deodorized 16 ounces

Distilled water 16 ounces

Dissolve the oil in the alcohol, and add the water, an ounce at a time, with agitation after each addition. Moisten the cinnamon with a little of the water, add, and agitate. Cork tightly, and put in a warm place, to macerate, 2 weeks, giving the flask a vigorous agitation several times a day. Finally, filter through paper, and keep in small vials, tightly stoppered.

Chocolate Extract.

—Probably the best form of chocolate extract is made as follows:

Curaçao cocoa 400 parts

Vanilla, chopped fine 1 part

Alcohol of 55 per cent 2,000 parts

Mix and macerate together for 15 days, express and set aside. Pack the residue in a percolator, and pour on boiling water (soft) and percolate until 575 parts pass through. Put the percolate {313} in a flask, cork, and let cool, then mix with the alcoholic extract. If it be desired to make a syrup, before mixing the extract, add 1,000 parts of sugar to the percolate, and with gentle heat dissolve the sugar. Mix the syrup thus formed, after cooling, with the alcoholic extract.

Coffee Extracts.

—In making coffee extract, care must be used to avoid extracting the bitter properties of the coffee, as this is where most manufacturers fail; in trying to get a strong extract they succeed only in getting a bitter one.

I.—The coffee should be a mixture of Mocha, 3 parts; Old Government Java, 5 parts; or, as some prefer, Mocha, 3 parts; Java, 3 parts; best old Rio, 2 parts.

Coffee, freshly roasted and pulverized 100 parts

Boiling water 600 parts

Pack the coffee, moistened with boiling water, in a strainer, or dipper, placed in a vessel standing in the water bath at boiling point, and let 400 parts of the water, in active ebullition, pass slowly through it. Draw off the liquid as quickly as possible (best into a vessel previously heated by boiling water to nearly the boiling point), add 200 parts of boiling water, and pass the whole again through the strainer (the container remaining in the water bath). Remove from the bath; add 540 parts of sugar, and dissolve by agitation while still hot.

II.—The following is based upon Liebig’s method of making coffee for table use: Moisten 50 parts of coffee, freshly roasted and powdered as before, with cold water, and add to it a little egg albumen and stir in. Pour over the whole 400 parts of boiling water, set on the fire, and let come to a boil. As the liquid foams, stir down with a spoon, but let it come to a boil for a moment; add a little cold water, cover tightly, and set aside in a warm place. Exhaust the residual coffee with 300 parts of boiling water, as detailed in the first process, and to the filtrate add carefully the now clarified extract, up to 600 parts, by adding boiling water. Proceed to make the syrup by the method detailed above.

III.—To make a more permanent extract of coffee saturate 600 parts of freshly roasted coffee, ground moderately fine, with any desired quantity of a 1 in 3 mixture of alcohol of 94 per cent and distilled water, and pack in a percolator. Close the faucet and let stand, closely stoppered, for 24 hours; then pour on the residue of the alcohol and water, and let run through, adding sufficient water, at the last, so as to compensate for what boils away. Set this aside, and continue the percolation, with boiling water, until the powder is exhausted. Evaporate the resultant percolate down to the consistency of the alcoholic extract, and mix the two. If desired, the result may be evaporated down to condition of an extract. To dissolve, add boiling water.

IV.—This essence is expressly adapted to boiling purposes. Take 3 pounds of good coffee, 4 ounces of granulated sugar, 4 pints of pure alcohol, 6 pints of hot water. Have coffee fresh roasted and of a medium grinding. Pack in a glass percolator, and percolate it with a menstruum, consisting of the water and the alcohol. Repeat the percolation until the desired strength is obtained, or the coffee exhausted; then add the sugar and filter.

V.— Mocha coffee 1 pound

Java coffee 1 pound

Glycerine, quantity sufficient.

Water, quantity sufficient.

Grind the two coffees fine, and mix, then moisten with a mixture of 1 part of glycerine and 3 parts of water, and pack in a glass percolator, and percolate slowly until 30 ounces of the percolate is obtained. It is a more complete extraction if the menstruum be poured on in the condition of boiling, and it be allowed to macerate for 20 minutes before percolation commences. Coffee extract should, by preference, be made in a glass percolator. A glycerine menstruum is preferable to one of dilute alcohol, giving a finer product.

VI.— Coffee, Java, roasted, No. 20 powder 4 ounces

Glycerine, pure 4 fluidounces

Water, quantity sufficient.

Boiling, quantity sufficient.

Moisten the coffee slightly with water, and pack firmly in a tin percolator; pour on water, gradually, until 4 fluidounces are obtained, then set aside. Place the coffee in a clean tin vessel, with 8 fluidounces of water, and boil for 5 minutes. Again place the coffee in the percolator with the water (infusion), and when the liquid has passed, or drained off, pack the grounds firmly, and pour on boiling water until 8 fluidounces are obtained. When cold, mix the first product, and add the glycerine, bottle, and cork well.

The excellence of this extract of coffee, from the manner of its preparation, will be found by experience to be incomparably superior to that made by the {314} formulas usually recommended, the reason being apparent in the first step in the process.

Coffee Essence.—

Best ground Mocha coffee 4 pounds

Best ground chicory 2 pounds

Boil with 2 gallons of water in a closed vessel and when cold, strain, press, and make up to 2 gallons, and to this add

Rectified spirit of wine 8 ounces

Pure glycerine (fluid) 16 ounces

Add syrup enough to make 4 gallons, and mix intimately.

Cucumber Essence.

—Press the juice from cucumbers, mix with an equal volume of alcohol and distil. If the distillate is not sufficiently perfumed, more juice may be added and the mixture distilled. It is said that the essence thus prepared will not spoil when mixed with fats in the preparation of cosmetics.

Fruit Jelly Extract.

—Fill into separate paper bags:

Medium finely powdered gelatin 18 parts

Medium finely powdered citric acid 3 parts

Likewise into a glass bottle a mixture of any desired

Fruit essence 1 part

Spirit of wine 1 part

and dissolve in the mixture for obtaining the desired color, raspberry red or lemon yellow, / 10 part.

For use, dissolve the gelatin and the citric acid in boiling water, adding

Sugar 125 parts

and mixing before cooling with the fruit essence mixture.

Ginger Extracts.

—The following is an excellent method of preparing a soluble essence or extract of ginger:

I.— Jamaica ginger 24 ounces

Rectified spirits, 60 per cent 45 ounces

Water 15 ounces

Mix and let macerate together with frequent agitations for 10 days, then percolate, press off, and filter. The yield should be 45 ounces. Of this take 40 ounces and mix with an equal amount of distilled water. Dissolve 6 drachms of sodium phosphate in 5 ounces of boiling water; let cool and add the solution to the filtrate and water, mixing well. Add 2 drachms of calcium chloride dissolved in 5 ounces of water, nearly cold, and again thoroughly shake the whole. Let stand for 12 hours; then filter.

Put the filtrate in a still, and distil off, at as slow a temperature as possible, 30 ounces. Set this distillate to one side, and continue the distillation till another 40 ounces have passed, then let the still cool. The residue in the still, some 18 ounces, is the desired essence. Pour out all that is possible and wash the still with the 30 ounces of distillate first set aside. This takes up all that is essential. Finally, filter once more, through double filter paper and preserve the filtrate—about 40 ounces, of an amber-colored liquid containing all of the essentials of Jamaica ginger.

Soluble Essence of Ginger.—II.—The following is Harrop’s method of proceeding:

Fluid extract of ginger (U.S.) 4 ounces

Pumice, in moderately fine powder 1 ounce

Water enough to make 12 ounces

Pour the fluid extract into a bottle, add the pumice and shake the mixture and repeat the shaking in the course of several hours. Now add the water in proportion of about 2 ounces, shaking well and frequently after each addition. When all is added repeat the agitation occasionally during 24 hours, then filter, returning the last portion of the filtrate until it comes through clear, and if necessary add sufficient water to make 12 ounces.

III.— Jamaica ginger, ground 2 pounds

Pumice stone, ground 2 ounces

Lime, slaked 2 ounces

Alcohol, dilute 4 pints

Rub the ginger with the pumice stone and lime until thoroughly mixed. Moisten with the dilute alcohol until saturated and place in a narrow percolator, being careful not to use force in packing, but simply putting it in to obtain the position of a powder to be percolated, so that the menstruum will go through uniformly. Finally, add the dilute alcohol and proceed until 4 pints of percolate are obtained. Allow the liquid to stand for 24 hours; then filter if necessary.

IV.— Tincture ginger 480 parts

Tincture capsicum 12 parts

Oleoresin ginger 8 parts

Magnesium carbonate 16 parts

Rub the oleoresin with the magnesia, and add the tinctures; add about 400 {315} parts of water, in divided portions, stirring vigorously the while. Transfer the mixture to a bottle, and allow to stand 1 week, shaking frequently; then filter, and make up 960 parts with water.

V.— Fluid extract of ginger (U. S. P.) 4 ounces

Pumice, powdered and washed 1 ounce

Water enough to make 12 ounces

Pour the fluid extract of ginger into a bottle, and add the pumice, shake thoroughly, set aside, and repeat the operation in the course of several hours. Add the water, in the proportion of about 2 ounces at a time, agitating vigorously after each addition. When all is added, repeat the agitation occasionally during 24 hours, then filter, returning the first portion of the filtrate until it comes through bright and clear. If necessary, pass water through the filter, enough to make 12 fluidounces of filtrate.

VI.— Strongest tincture of ginger 1 pint

Fresh slaked lime. 1 / 2 ounces

Salt of tartar / 4 ounce

VII.— Jamaica ginger, ground 32 parts

Pumice stone, powdered 32 parts

Lime, slaked 2 parts

Alcohol, dilute, sufficient to make 32 parts

Rub the ginger with the pumice stone and lime, then moisten with alcohol until it is saturated with it. Put in a narrow percolator, using no force in packing. Allow the mass to stand for 24 hours, then let run through. Filter if necessary.

VIII.—The following is insoluble:

Cochin ginger, cut fine 1,000 parts

Alcohol, 95 per cent 2,500 parts

Water 1,250 parts

Glycerine 250 parts

Digest together for 8 days in a very warm, not to say hot, place. Decant, press off the roots, and add to the colature, then filter through paper. This makes a strong, natural tasting essence.

IX.—Green Ginger Extract.—The green ginger root is freed from the epidermis and surface dried by exposure to the air for a few hours. It is then cut into thin slices and macerated for some days with an equal weight of rectified spirit, which when filtered will yield an essence possessing a very fine aroma and forming an almost perfectly clear solution in water. If the ginger is allowed to dry more than the few hours mentioned it will not produce a soluble essence. It is used in some of the imported ginger ales as a flavoring only, and makes a lovely ginger flavor.

Hop Syrup.

—A palatable preparation not inferior to many of the so-called hop bitters:

Hops 2 parts

Dandelion 2 parts

Gentian 2 parts

Chamomile 2 parts

Stillingia 2 parts

Orange peel 2 parts

Alcohol 75 parts

Water 75 parts

Syrup, simple 50 parts

Coarsely powder the drugs and exhaust with the water and alcohol mixed. Decant, press out and filter, and finally add the syrup. The dose is a wineglassful 2 or 3 times daily.

Lemon Essences.

—I.—Macerate the cut-up fresh peelings of 40 lemons and 30 China oranges in 8 quarts of alcohol and 2 quarts of water, for 2 or 3 days, then distil off 8 quarts. Every 100 parts of this distillate is mixed with 75 parts of citric acid dissolved in 200 parts of water, colored with a trace of orange and filtered through talc. Each 200 parts of the filtrate is then mixed with 2 quarts of syrup.

II.—Twenty-five middle-sized lemons are thinly peeled, the peelings finely cut, and the whole, lemons and peels, put to macerate in a mixture of 3 pints 90 per cent alcohol and 5 quarts water. Let macerate for 24 hours. Add 10 drops lemon and 10 drops orange oil; then slowly distil off 4 quarts. The distillate will be turbid, but if left to stand in a cool, dark place for a week it will filter off clear, and should make a clear mixture with equal parts of water and simple syrup. If it does not, add with a pipette, drop by drop, sufficient alcohol to make it do so. Finally, dissolve in the mixture 4 drachms of vanillin, and color with a few drops of tincture of turmeric and a little caramel.

III.—Peel thinly and lightly, 25 medium-sized fresh lemons and 1 orange, and cut the peelings into very small pieces. Macerate in 55 drachms 96 per cent alcohol, for 6 hours. Filter off the macerate without pressing. Dilute the filtrate with 3 pints water and set aside for eight days, shaking frequently. At {316} the end of this time filter. The filtrate is usually clear, and if so, add 4 drachms of vanillin. If not, proceed as in the second formula above.

IV.—Oil of lemon, select, 8 fluidounces; oil of lemon grass (fresh), 1 fluidrachm; peel, freshly grated, of 12 lemons; alcohol, 7 pints; boiled water, 1 pint.

Mix and macerate for 7 days. If in a hurry for the product, percolate through the lemon peel and filter. The addition of any other substance than the oil and rind of the lemon is not recommended.

V.— Fresh oil of lemon 64 parts

Lemon peel (outer rind) freshly grated 32 parts

Oil of lemon grass 1 part

Alcohol 500 parts

Mix, let macerate for 14 days, and filter.

VI.— Essence of lemon 1 / 4 ounces

Rectified spirit of wine 6 ounces

Pure glycerine 3 ounces

Pure phosphate calcium 4 ounces

Distilled water to make 1 pint.

Mix essence of lemon, spirit of wine, glycerine, and 8 ounces of distilled water, agitate briskly in a quart bottle for 10 minutes, and introduce phosphate of calcium and again shake. Put in a filter and let it pass through twice. Digest in filtrate for 2 or 3 days, add 1 / 2 ounces fresh lemon peel, and again filter.

VII.— Oil of lemon 6 parts

Lemon peel (freshly grated) 4 parts

Alcohol, sufficient.

Dissolve the oil of lemon in 90 parts of alcohol, add the lemon peel, and macerate for 24 hours. Filter through paper, adding through the filter enough alcohol to make the filtrate weigh 100 parts.

VIII.— Exterior rind of lemon 2 ounces

Alcohol, 95 per cent, deodorized 32 ounces

Oil of lemon, recent 3 fluidounces

Expose the lemon rind to the air until perfectly dry, then bruise in a wedgwood mortar, and add it to the alcohol, agitating until the color is extracted; then add the lemon oil.

Natural Lemon Juice.

—I.—Take 4.20 parts of crystallized citric acid; 2 parts essence of lemons; 3 parts of alcohol of 96 per cent; / 2 part calcium carbonate; 50 / 20 parts sodium phosphate, and / 200 part calcium citrate, and dissolve the whole in sufficient water to make 60 parts.

II.—Squeeze out the lemon juice, strain it to get rid of the seeds and larger particles of pulp, etc., heat it to the boiling point, let it cool down, add talc, shake well together and filter. If it is to be kept a long time (as on a sea voyage) a little alcohol is added.

Limejuice.

—This may be clarified by heating it either alone or mixed with a small quantity of egg albumen, in a suitable vessel, without stirring, to near the boiling point of water, until the impurities have coagulated and either risen to the top or sunk to the bottom. It is then filtered into clean bottles, which should be completely filled and closed (with pointed corks), so that each cork has to displace a portion of the liquid to be inserted. The bottles are sealed and kept at an even temperature (in a cellar). In this way the juice may be satisfactorily preserved.

Nutmeg Essence.

—Oil of nutmeg, 2 drachms; mace, in powder, 1 ounce; alcohol, 95 per cent, deodorized, 32 ounces.

Dissolve the oil in the alcohol by agitation, add the mace, agitate, then stopper tightly, and macerate 12 hours. Filter through paper.

Orange Extract.

—Grated peel of 24 oranges; alcohol, 1 quart; water, 1 quart; oil of orange, 4 drachms. Macerate the orange peel and oil of orange with alcohol for 2 weeks. Add distilled water and filter.

Orange Extract, Soluble.

—I.—Pure oil of orange, 1 / 4 fluidounces; carbonate of magnesium, 2 ounces; alcohol, 12 fluidounces; water, quantity sufficient to make 2 pints.

II.—Dissolve oil of orange in the alcohol, and rub it with the carbonate of magnesium, in a mortar. Pour the mixture into a quart bottle, and fill the bottle with water. Allow to macerate for a week or more, shaking every day. Then filter through paper, adding enough water through the paper to make filtrate measure 2 pints.

Orange Peel, Soluble Extract.—

Freshly grated orange rind 1 part

Deodorized alcohol 1 part

Macerate for 4 days and express. Add the expressed liquid to 10 per cent of its weight of powdered magnesium carbonate {317} in a mortar, and rub thoroughly until a smooth, creamy mixture results; then gradually add the water, constantly stirring. Let stand for 48 hours, then filter through paper. Keep in an amber bottle and cool place. To make syrup of orange, add 1 part of this extract to 7 parts of heavy simple syrup.

Peach Extract.—

Linalyl formate 120 minims

Amyl valerianate 8 drachms

Fluid extract orris 2 ounces

Oenanthic ether 2 drachms

Oil rue (pure German) 30 minims

Chloroform 2 drachms

Glycerine 2 ounces

Alcohol, 70 per cent, to 3 pints.

Pineapple Essence.

—A ripe, but not too soft, pineapple, weighing about, say, 1 pound, is mashed up in a mortar with Tokay wine, 6 ounces. The mass is then brought into a flask with 1 pint of water, and allowed to stand 2 hours. Alcohol, 90 per cent, / 4 pint, is then added and the mixture distilled until 7 quarts of distillate have been collected. Cognac, 9 ounces, is then added to the distillation.

Pistachio Essence.—

I.— Essence of almond 2 fluidounces

Tincture of vanilla 4 fluidounces

Oil of neroli 1 drop

II.— Oil of orange peel 4 fluidrachms

Oil of cassia 1 fluidrachm

Oil of bitter almond 15 minims

Oil of calamus 15 minims

Oil of nutmeg 1 / 2 fluidrachms

Oil of clove 30 minims

Alcohol 12 fluidounces

Water 4 fluidounces

Magnesium carbonate 2 drachms

Shake together, allow to stand 24 hours, and filter.

Pomegranate Essence.—

Oil of sweet orange 3 parts

Oil of cloves 3 parts

Tincture of vanilla 15 parts

Tincture of ginger 10 parts

Maraschino liqueur 150 parts

Tincture of coccionella 165 parts

Distilled water 150 parts

Phosphoric acid, dilute 45 parts

Alcohol, 95 per cent, quantity sufficient to make 1000 parts.

Mix and dissolve.

Quince Extract.—

Fluid extract orris 2 ounces

Oenanthic ether 1 / 2 ounces

Linalyl formate 90 minims

Glycerine 2 ounces

Alcohol, 70 per cent, to 3 pints.

Raspberry Syrup, Without Alcohol Or Antiseptics.

—The majority of producers of fruit juices are firmly convinced that the preservation of these juices without the addition of alcohol, salicylic acid, etc., is impossible. Herr Steiner’s process to the contrary is here reproduced:

The fruit is crushed and pressed; the juice, with 2 per cent of sugar added, is poured into containers to about three-quarters of their capacity, and there allowed to ferment. The containers are stoppered with a cork through which runs a tube, whose open end is protected by a bit of gum tubing, the extremity of which is immersed in a glass filled with water. It should not go deeper than / 10 of an inch high. The evolution of carbonic gas begins in about 4 hours and is so sharp that the point of the tube must not be immersed any deeper.

Ordinarily fermentation ceases on the tenth day, a fact that may be ascertained by shaking the container sharply, when, if it has ceased, no bubbles of gas will appear on the surface of the water.

The fermented juice is then filtered to get rid of the pectinic matters, yeast, etc., and the filtrate should be poured back on the filter several times. The juice filters quickly and comes off very clear. The necessary amount of sugar to make a syrup is now added to the liquid and allowed to dissolve gradually for 12 hours. At the end of this time the liquid is put on the fire and allowed to boil up at once, by which operation the solution of the sugar is made complete. Straining through a tin strainer and filling into heated bottles completes the process.

The addition of sugar to the freshly pressed juice has the advantage of causing the fermentation to progress to the full limit, and also to preserve, by the alcohol produced by fermentation, the beautiful red color of the juice.

Any fermentation that may be permitted prior to the pressing out of the juices is at the expense of aroma and flavor; but whether fermentation occurs before or after pressure of the berry, the ordinary alcohol test cannot determine whether the juice has been completely fermented (and consequently whether the pectins have been completely separated) or not. Since, in spite of the fact that the liquid remains limpid after 4 days’ {318} fermentation, the production of alcohol is progressing all the time—a demonstration that fermentation cannot then be completed, and that at least 10 days will be required for this purpose.

An abortive raspberry syrup is always due to an incomplete or faulty fermentation, for too often does it occur that incompletely fermented juices after a little time lose color and become turbid.

The habit of clarifying juices by shaking up with a bit of paper, talc, etc., or boiling with albumen is a useless waste of time and labor. By the process indicated the entire process of clarification occurs automatically, so to speak.

Deep Red Raspberry Syrup.

—A much deeper and richer color than that ordinarily attained may be secured by adding to crushed raspberries, before fermentation, small quantities of sugar, sifted over the surface in layers. The ethylic alcohol produced by fermentation in this manner aids in the extraction of the red coloring matter of the fruit. Moreover, the fermented juice should never be cooked over a fire, but by superheated steam. Only in this way can caramelization be completely avoided. Only sugar free from ultramarine and chalk should be used in making the syrup, as these impurities also have a bad influence on the color.

Raspberry Essences.—

I.— Raspberries, fresh 16 ounces

Angelica (California) 6 fluidounces

Brandy (California) 6 ounces

Alcohol 6 ounces

Water, quantity sufficient.

Mash the berries to a pulp in a mortar or bowl, and transfer to a flask, along with the Angelica, brandy, alcohol, and about 8 ounces of water. Let macerate overnight, then distil off until 32 ounces have passed over. Color red. The addition of a trifle of essence of vanilla improves this essence.

II.— Fresh raspberries 200 grams

Water, distilled 100 grams

Vanilla essence 2 grams

Pulp the raspberries, let stand at a temperature of about 70° F. for 48 hours, and then add 100 grams of water. Fifty grams are then distilled off, and alcohol, 90 per cent, 25 grams, in which 0.01 vanillin has been previously dissolved, is added to the distillate.

Sarsaparilla, Soluble Extract.—

Pure oil of wintergreen 5 fluidrachms

Pure oil of sassafras 5 fluidrachms

Pure oil of anise 5 fluidrachms

Carbonate of magnesium 2 / 2 ounces

Alcohol 1 pint

Water, quantity sufficient to make 2 pints.

Dissolve the various oils in the alcohol, and rub with carbonate of magnesium in a mortar. Pour the mixture into a quart bottle, and fill the bottle with water. Allow to macerate for a week or more, shaking every day. Then filter through the paper, adding enough water through the paper to make the finished product measure 2 pints.

Strawberry Juice.

—Put into the water bath 1,000 parts of distilled water and 600 parts of sugar and boil, with constant skimming, until no more scum arises. Add 5 parts of citric acid and continue the boiling until about 1,250 parts are left. Stir in, little by little, 500 parts of fresh strawberries, properly stemmed, and be particularly careful not to crush the fruit. When all the berries are added, cover the vessel, remove from the fire, put into a warm place and let stand, closely covered, for 3 hours, or until the mass has cooled down to the surrounding temperature, then strain off through flannel, being careful not to crush the berries. Prepare a sufficient number of pint bottles by filling them with warm water, putting them into a kettle of the same and heating them to boiling, then rapidly emptying and draining as quickly as possible. Into these pour the hot juice, cork and seal the bottles as rapidly as possible. Juice thus prepared retains all the aroma and flavor of the fresh berry, and if carefully corked and sealed up will retain its properties a year.

Strawberry Essence.—

Strawberries, fresh 16 ounces

Angelica (California) 6 fluidounces

Brandy (California) 6 ounces

Alcohol 8 ounces

Water, quantity sufficient.

Mash the berries to a pulp in a mortar or bowl, and transfer to a flask, along with the Angelica, brandy, alcohol, and about 8 ounces of water. Let macerate overnight, then distil off until 32 ounces have passed over. Color strawberry red. The addition of a little essence of vanilla and a hint of lemon improves this essence. {319}

Tea Extract.—

I.— Best Souchong tea 175 parts

Cinnamon 3 parts

Cloves 3 parts

Vanilla 1 part

Arrack 800 parts

Rum 200 parts

Coarsely powder the cinnamon, clove, etc., mix the ingredients, and let macerate for 3 days, then filter, press off, and make up to 1,000 parts, if necessary, by adding rum. The Souchong may be replaced by any other brand of tea, and the place of the arrack may be occupied by Santa Cruz, or New England rum. The addition of fluid extract of kola nut not only improves the taste, but gives the drink a remarkably stimulating property. The preparation makes a clear solution with either hot or cold water and keeps well.

II.—Tea, any desirable variety, 16 ounces; glycerine, 4 ounces; hot water, 4 pints; water, sufficient to make 1 pint.

Reduce the tea to a powder, moisten with sufficient of the glycerine and alcohol mixed, with 4 ounces of water added, pack in percolator, and pour on the alcohol (diluted with glycerine and water) until 12 ounces of percolate have been obtained. Set this aside, and complete the percolation with the hot water. When this has passed through, evaporate to 4 ounces, and add it to the percolate first obtained.

Tonka Extract.—

Tonka beans 1 ounce

Magnesium carbonate, quantity sufficient.

Balsam of Peru 2 drachms

Sugar 4 ounces

Alcohol 8 ounces

Water sufficient to make 16 ounces.

Mix the tonka, balsam of Peru, and magnesia, and rub together, gradually adding the sugar until a homogeneous powder is obtained. Pack in a percolator; mix the alcohol with an equal amount of water, and pour over the powder, close the exit of the percolator, and let macerate for 24 to 36 hours, then open the percolator, and let pass through, gradually adding water until 16 ounces pass through.

Vanilla Extracts.

—I.—Vanilla, in fine bits, 250 parts, is put into 1,350 parts of mixture, of 2,500 parts 95 per cent alcohol, and 1,500 parts distilled water. Cover tightly, put on the water bath, and digest for 1 hour, at 140° F. Pour off the liquid and set aside. To the residue in the bath, add half the remaining water, and treat in the same manner. Pack the vanilla in an extraction apparatus, and treat with 250 parts of alcohol and water, mixed in the same proportions as before. Mix the results of the three infusions first made, filter, and wash the filter paper with the results of the percolation, allowing the filtered percolate to mingle with the filtrate of the mixed infusions.

II.—Take 60 parts of the best vanilla beans, cut into little pieces, and put into a deep vessel, wrapped with a cloth to retain the heat as long as possible. Shake over the vanilla 1 part of potassium carbonate in powder, and immediately add 240 parts distilled water, in an active state of ebullition. Cover the vessel closely, set aside until it is completely cold, and then add 720 parts alcohol. Cover closely, and set aside in a moderately warm place for 15 days, when the liquid is strained off, the residue pressed, and the whole colate filtered. The addition of 1 part musk to the vanilla before pouring on the hot water improves this essence.

To prepare vanilla fountain syrup with extracts I or II, mix 25 minims of the extract with 1 pint simple syrup. Color with caramel.

III.— Vanilla beans, cut fine 1 ounce

Sugar 3 ounces

Alcohol, 50 per cent 1 pint

Beat sugar and vanilla together to a fine powder. Pour on the dilute alcohol, cork the vessel, and let stand for 2 weeks, shaking it up 2 or 3 times a day.

IV.— Vanilla beans, chopped fine 30 parts

Potassium carbonate 1 part

Boiling water 1,450 parts

Alcohol 450 parts

Essence of musk 1 part

Dissolve the potassium carbonate in the boiling water, add the vanilla, cover the vessel, and let stand in a moderately warm place until cold. Transfer to a wide-mouthed jar, add the alcohol, cork, and let macerate for 15 days; then decant the clear essence and filter the remainder. Mix the two liquids and add the essence of musk.

V.—Cut 60 parts of best vanilla beans into small bits; put into a deep vessel, which should be well wrapped in a woolen cloth to retain heat as long as possible. Shake over the beans 1 part of potassium carbonate, in powder, then pour over the mass 240 parts distilled water, in an {320} active state of ebullition, cover the vessel closely, and set aside in a moderately warm place. When quite cold add 720 parts alcohol, close the vessel tightly, and set aside in a moderately warm place, to macerate for 15 days, then strain off, press out, and set aside for a day or two. The liquid may then be filtered and bottled. The addition of a little musk to the beans before pouring on the hot water, is thought by many to greatly improve the product. One part of this extract added to 300 parts simple syrup is excellent for fountain purposes.

VI.— Vanilla beans 8 ounces

Glycerine 6 ounces

Granulated sugar 1 pound

Water 4 pints

Alcohol of cologne spirits 4 pints

Cut or grind the beans very fine; rub with the glycerine and put in a wooden keg; dissolve the sugar in the water, first heating the water, if convenient; mix the water and spirits, and add to the vanilla; pour in keg. Keep in a warm place from 3 to 6 months before using. Shake often. To clear, percolate through the dregs. If a dark, rich color is desired add a little sugar coloring.

VII.— Vanilla beans, good quality 16 ounces

Alcohol 64 fluidounces

Glycerine 24 fluidounces

Water 10 fluidounces

Dilute alcohol, quantity sufficient.

Mix and macerate, with frequent agitation, for 3 weeks, filter, and add dilute alcohol to make 1 gallon.

VIII.— Vanilla beans, good quality 8 ounces

Pumice stone, lump 1 ounce

Rock candy 8 ounces

Alcohol and water, of each a sufficiency.

Cut the beans to fine shreds and triturate well with the pumice stone and rock candy. Place the whole in a percolator and percolate with a menstruum composed of 9 parts alcohol and 7 parts water until the percolate passes through clear. Bring the bulk up to 1 gallon with the same menstruum and set aside to ripen.

IX.—Cut up, as finely as possible, 20 parts of vanilla bean and with 40 parts of milk sugar (rendered as dry as possible by being kept in a drying closet until it no longer loses weight) rub to a coarse powder. Moisten with 10 parts of dilute alcohol, pack somewhat loosely in a closed percolator and let stand for 2 hours. Add 40 parts of dilute alcohol, close the percolator, and let stand 8 days. At the end of this time add 110 parts of dilute alcohol, and let pass through. The residue will repay working over. Dry it well, add 5 parts of vanillin, and 110 parts of milk sugar and pass through a sieve, then treat as before.

The following are cheap extracts:

X.— Vanilla beans, chopped fine 5 parts

Tonka beans, powdered 10 parts

Sugar, powdered 14 parts

Alcohol, 95 per cent 25 parts

Water, quantity sufficient to make 100 parts.

Rub the sugar and vanilla to a fine powder, add the tonka beans, and incorporate. Pack into a filter, and pour on 10 parts of alcohol, cut with 15 parts of water; close the faucet, and let macerate overnight. In the morning percolate with the remaining alcohol, added to 80 parts of water, until 100 parts of percolate pass through.

XI.— Vanilla beans 4 ounces

Tonka beans 8 ounces

Deodorized alcohol 8 pints

Simple syrup 2 pints

Cut and bruise the vanilla beans, afterwards bruising the tonka beans. Macerate for 14 days in one-half of the spirit, with occasional agitation. Pour off the clear liquor and set aside; pour the remaining spirits in the magma, and heat by means of the water bath to about 170° F. in a loosely covered vessel. Keep at this temperature 2 or 3 hours, and strain through flannel, with slight pressure. Mix the two portions of liquid, and filter through felt. Add the syrup.

White Pine And Tar Syrup.—

White pine bark 75 parts

Wild cherry bark 75 parts

Spikenard root 10 parts

Balm of Gilead buds 10 parts

Sanguinaria root 8 parts

Sassafras bark 7 parts

Sugar 750 parts

Chloroform 6 parts

Syrup of tar 75 parts

Alcohol, enough.

Water, enough.

Syrup enough to make 1,000 parts.

Reduce the first six ingredients to a coarse powder and by using a menstruum composed of 1 in 3 alcohol, obtain 500 parts of a tincture from them. In this {321} dissolve the sugar, add the syrup of tar and the chloroform, and, finally, enough syrup to bring the measure of the finished product up to 1,000 parts.

Wild Cherry Extract.—

Oenanthic ether 2 fluidrachms

Amyl acetate 2 fluidrachms

Oil of bitter almonds (free from hydrocyanic acid) 1 fluidrachm

Fluid extract of wild cherry 3 fluidounces

Glycerine 2 fluidounces

Deodorized alcohol enough to make 16 fluidounces.

Harmless Colors For Use In Syrups, Etc.:

Red.—Cochineal syrup, prepared as follows:

I.— Cochineal in coarse powder 6 parts

Potassium carbonate 3 parts

Distilled water 15 parts

Alcohol, 95 per cent 12 parts

Simple syrup to make 500 parts.

Rub the cochineal and potassium together, adding the water and alcohol little by little, under constant trituration. Let stand overnight, add the syrup, and filter.

II.— Carmine, in fine powder 1 part

Stronger ammonia water 4 parts

Distilled water to make 24 parts.

Rub up the carmine and ammonia and to the solution add the water, little by little, under constant trituration. If in standing this shows a tendency to separate, a drop or two of ammonia will correct the trouble.

Besides these there is caramel, which, of course, you know.

Pink.—

III.— Carmine 1 part

Liquor potassæ 6 parts

Distilled water 40 parts

Mix. If the color is too high, dilute with distilled water until the requisite color is obtained.

To Test Fruit Juices And Syrups For Aniline Colors.

—Add to a sample of the syrup or juice, in a test tube, its own volume of distilled water, and agitate to get a thorough mixture, then add a few drops of the standard solution of lead diacetate, shake, and filter. If the syrup is free from aniline coloring matter the filtrate will be clear as crystal, since the lead salt precipitates natural coloring matters, but has no effect upon the aniline colors.

To Test Fruit Juices For Salicylic Acid.

—Put a portion of the juice to be tested in a large test tube, add the same volume of ether, close the mouth of the tube and shake gently for 30 seconds. Set aside until the liquid separates into two layers. Draw off the supernatant ethereal portion and evaporate to dryness in a capsule. Dissolve the residue in alcohol, dilute with 3 volumes of water, and add 1 drop of tincture of iron chloride. If salicylic acid be present the characteristic purple color will instantly disappear.

Syrups Selected from the For­mu­lary of the Phar­ma­ceu­ti­cal So­ci­ety of Ant­werp.—

Dionine Syrup.—Dionine, 1 part; distilled water, 19 parts; simple syrup, 1,980 parts. Mix.

Jaborandi Syrup.—Tincture of jaborandi, 1 part; simple syrup, 19 parts. Mix.

Convallaria Syrup.—Extract of convallaria, 1 part; distilled water, 4 parts; simple syrup, 95 parts. Dissolve the extract in the water and mix.

Codeine Phosphate Syrup.—Codeine phosphate, 3 parts; distilled water, 17 parts; simple syrup, 980 parts. Dissolve the codeine in the water and mix with the syrup.

Licorice Syrup.—Incised licorice root, 4 parts; dilute solution of ammonia, 1 part; water, 20 parts. Mix and macerate for 12 hours at 58° to 66° F. with frequent agitation; press, heat the liquid to boiling, then evaporate to two parts on the water bath; add alcohol, 2 parts; allow to stand for 12 hours; then filter. Add to the filtrate enough simple syrup to bring the final weight to 20 parts.

Maize Stigma Syrup.—Extract of maize stigmas, 1 part; distilled water, 4 parts; simple syrup, 95 parts. Dissolve the extract in the water, filter, and add the syrup.

Ammonium Valerianate Solution.—Ammonium valerianate, 2 parts; alcoholic extract of valerian, 1 part; distilled water, 47 parts.

Kola Tincture.—Powdered kola nuts, 1 part; alcohol, 60 per cent, 5 parts. Macerate for 6 days, press, and filter.

Bidet’s Liquid Vesicant.—Tincture of cantharides, tincture of rosemary, chloroform, equal parts.

Peptone Wine.—Dried peptone, 1 part; Malaga wine, 19 parts. Dissolve without heat and filter after standing for several days. {322}

Etching

General Instructions For Etching.

—In etching, two factors come into consideration, (1) that which covers that part of the metal not exposed to the etching fluid (the resist), and (2) the etching fluid itself.

In the process, a distinction is to be made between etching in relief and etching in intaglio. In relief etching, the design is drawn or painted upon the surface with the liquid etching-ground, so that after etching and removal of the etching-ground, it appears raised. In intaglio etching, the whole surface is covered with the etching-ground, and the design put on with a needle; the ground being thus removed at the points touched by the drawing, the latter, after etching and removal of the etching-ground, is sunken.

Covering Agents Or Resists.

—The plate is enclosed by a border made of grafting wax (yellow beeswax, 8 parts; pine rosin, 10 parts; beef tallow, 2 parts; turpentine, 10 parts); or a mixture of yellow wax, 8 parts; lard, 3 parts; Burgundy pitch, / 2 part. This mixture is also used to cover the sides of vessels to be etched. Another compound consists of wax, 5 parts; cobbler’s wax, 2 / 2 parts; turpentine, 1 part.

Etching-ground.

—I.—Soft: Wax, 2 parts; asphalt, 1 part; mastic, 1 part. II.— Wax, 3 parts; asphalt, 4 parts. III.— Mastic, 16 parts; Burgundy pitch, 50 parts; melted wax, 125 parts; and melted asphalt, 200 parts added successively, and, after cooling, turpentine oil, 500 parts. If the ground should be deep black, lampblack is added.

Hard: Burgundy pitch, 125 parts; rosin, 125 parts, melted; and walnut oil, 100 parts, added, the whole to be boiled until it can be drawn out into long threads.

Etching-ground For Copper Engraving.

—White wax, 120 parts; mastic, 15 parts; Burgundy pitch, 60 parts; Syrian asphalt, 120 parts, melted together; and 5 parts concentrated solution of rubber in rubber oil added.

Ground For Relief Etching.

—I.—Syrian asphalt, 500 parts, dissolved in turpentine oil, 1,000 parts. II.—Asphalt, rosin, and wax, 200 parts of each, are melted, and dissolved in turpentine oil, 1,200 parts. The under side of the metal plate is protected by a coating of a spirituous shellac solution, or by a solution of asphalt, 300 parts, in benzol, 600 parts.

For Strongly Acid Solutions.

—I.—Black pitch, 1 part; Japanese wax, 2 parts; rosin, 1 / 2 parts; Damar rosin, 1 part, melted together and mixed with turpentine oil, 1 part. II.—Heavy black printers’ ink, 3 parts; rosin, 1 part; wax, 1 part.

For electro-etching, the following ground is recommended: Wax, 4 parts; asphalt, 4 parts; pitch, 1 part.

If absolute surety is required respecting the resistance of the etching-ground to the action of the etching fluids, several etching-grounds are put on, one over the other; first (for instance), a solution of rubber in benzol, then a spirituous shellac solution, and a third stratum of asphalt dissolved in turpentine oil.

If the etching is to be of different degrees of depth, the places where it is to be faint are stopped out with varnish, after they are deep enough, and the object is put back into the bath for further etching.

For putting on a design before the etching, the following method may be used: Cover the metal plate, tin plate for example, with a colored or colorless spirit varnish; after drying, cover this, in a dark room, with a solution of gelatin, 5 parts, and red potassium chromate, 1 part, in water, 100 parts; or with a solution of albumen, 2 parts; ammonium bichromate, 2 parts, in water, 200 parts. After drying, put the plate, covered with a stencil, in a copying or printing frame, and expose to light. The sensitive gelatin stratum will become insoluble at the places exposed. Place in water, and the gelatin will be dissolved at the places covered by the stencil; dry, and remove the spirit varnish from the places with spirit, then put into the etching fluid.

Etching Fluids.

—The etching fluid is usually poured over the metallic surface, which is enclosed in a border, as described before. If the whole object is to be put into the fluid, it must be entirely covered with the etching-ground. After etching it is washed with pure water, dried with a linen cloth, and the etching-ground is then washed off with turpentine oil or a light volatile camphor oil. The latter is very good for the purpose.

Etching Fluids For Iron And Steel.

—I.—Pure nitric acid, diluted for light etching with 4 to 8 parts of water, for deep etching with an equal weight of water.

II.—Tartaric acid, 1 part, by weight; mercuric chloride, 15 parts, by weight; water, 420 parts; nitric acid, 16 to 20 drops, if 1 part equals 28 / 2 grains. {323}

III.—Spirit, 80 per cent, 120 parts, by weight; pure nitric acid, 8 parts; silver nitrate, 1 part.

IV.—Pure acetic acid, 30 per cent, 40 parts, by weight; absolute alcohol, 10 parts; pure nitric acid, 10 parts.

V.—Fuming nitric acid, 10 parts, by weight; pure acetic acid, 30 per cent, 50 parts, diluted with water if necessary or desired.

VI.—A chromic acid solution.

VII.—Bromine, 1 part; water, 100 parts. Or—mercuric chloride, 1 part; water, 30 parts.

VIII.—Antimonic chloride, 1 part; water, 6 parts; hydrochloric acid, 6 parts.

For Delicate Etchings On Steel.

—I.—Iodine, 2 parts; potassium iodide, 4 parts; water, 40 parts.

II.—Silver acetate, 8 parts, by weight; alcohol, 250 parts; water, 250 parts; pure nitric acid, 260 parts; ether, 64 parts; oxalic acid, 4 parts.

III.—A copper chloride solution.

Etching Powder For Iron And Steel.

—Blue vitriol, 50 parts; common salt, 50 parts; mixed and moistened with water.

For lustrous figures on a dull ground, as on sword blades, the whole surface is polished, the portions which are to remain bright covered with stencils and the object exposed to the fumes of nitric acid. This is best done by pouring sulphuric acid, 20 parts, over common salt, 10 parts.

Relief Etching Of Copper, Steel, And Brass.

—Instead of nitric acid, which has a tendency to lift up the etching-ground, by evolution of gases, it is better to use a mixture of potassium bichromate, 150 parts; water, 800 parts; and concentrated sulphuric acid, 200 parts. The etching is slow, but even, and there is no odor.

For Etching Copper, Brass, And Tombac.

—Pure nitric acid diluted with water to 18° Bé. The bubbles of gas given out should immediately be removed with a feather that the etching may be even.

Another compound consists of a boiling solution of potassium chlorate, 2 parts, in water, 20 parts, poured into a mixture of nitric acid, 10 parts, and water, 70 parts. For delicate etchings dilute still more with 100 to 200 parts of water.

Etching Fluid For Copper.

—Weak: A boiling solution of potassium chlorate, 20 parts, in water, 200 parts, poured into a mixture of pure hydrochloric acid, 20 parts; water, 500 parts.

Stronger: A boiling solution of potassium chlorate, 25 parts, in water, 250 parts, poured into a mixture of pure hydrochloric acid, 250 parts; water, 400 parts.

Very strong: A boiling solution of potassium chlorate, 30 parts, in water, 300 parts, poured into a mixture of pure hydrochloric acid, 300 parts; water, 300 parts.

For etching on copper a saturated solution of bromine in dilute hydrochloric acid may also be used; or a mixture of potassium bichromate, / 2 part; water, 1 part; crude nitric acid, 3 parts.

The following are also much used for copper and copper alloys:

I.—A copper chloride solution acidified with hydrochloric acid.

II.—Copper nitrate dissolved in water.

III.—A ferric chloride solution of 30° to 45° Bé. If chrome gelatin or chrome albumen is used for the etching-ground, a spirituous ferric chloride solution is employed. The etching process can be made slower by adding common salt to the ferric chloride solution.

Matt Etching Of Copper.

—White vitriol, 1 to 5 parts; common salt, 1 part; concentrated sulphuric acid, 100 parts; nitric acid (36° Bé.), 200 parts, mixed together. The sulphuric acid is to be poured carefully into the nitric acid, not the reverse.

Etching Fluid For Brass.

—Nitric acid, 8 parts; mixed with water, 80 parts; into this mixture pour a hot solution of potassium chlorate, 3 parts, in water, 50 parts.

Etching Fluid For Brass To Make Stencils.

—Mix nitric acid, of 1.3 specific weight, with enough fuming nitric acid to give a deep yellow color. This mixture acts violently, and will eat through the strongest sheet brass.

Etching Fluid For Zinc.

—Boil pounded gallnuts, 40 parts, with water, 560 parts, until the whole amounts to 200 parts; filter, and add nitric acid, 2 parts, and a few drops of hydrochloric acid. Ferric chloride and antimonic chloride solutions may also be used to etch zinc.

Relief Etching Of Zinc.

—The design is to be drawn with a solution of platinum chloride, 1 part, and rubber, 1 part, in water, 12 parts. The zinc plate is placed in dilute sulphuric acid (1 in 16). The black drawing will remain as it is.

Another compound for the drawing is made of blue vitriol, 2 parts; copper chloride, 3 parts; water, 64 parts; pure hydrochloric acid, 1.1 specific weight. After the drawing is made, lay the plate in dilute nitric acid (1 in 8). {324}

Etching Fluid For Aluminum.

—Dilute hydrochloric acid serves this purpose. Aluminum containing iron can be matted with soda lye, followed by treatment with nitric acid. The lye dissolves the aluminum, and the nitric acid dissolves the iron. Aluminum bronze is etched with nitric acid.

Etching Fluid For Tin Or Pewter.

—Ferric chloride, or highly diluted nitric acid.

Etching Fluids For Silver.

—I.—Dilute pure nitric acid.

II.—Nitric acid (specific weight, 1.185), 172 parts; water, 320 parts; potassium bichromate, 30 parts.

Etching Fluid For Gold.

—Dilute aqua regia (= nitric and sulphuric acids, in the proportion of 1 in 3).

Etching Fluid For Copper, Zinc, And Steel.

—A mixture of 4 parts of acetic acid (30 per cent), and alcohol, 1 part; to this is added gradually, nitric acid, 1 part.

Etching Fluid For Lead, Antimony, And Britannia Metal.

—Dilute nitric acid.

Etching Powder For Metals

(Tin, Silver, Iron, German Silver, Copper, and Zinc).—Blue vitriol, 1 part; ferric oxide, 4 parts. The powder, moistened, is applied to the places to be etched, as, for instance, knife blades. Calcined green vitriol can also be used.

Electro-etching.

—This differs from ordinary etching in the use of a bath, which does not of itself affect the metal, but is made capable of doing so by the galvanic current.

Ordinary etching, seen under the microscope, consists of a succession of uneven depressions, which widen out considerably at a certain depth. In electro-etching, the line under the microscope appears as a perfectly even furrow, not eaten out beneath, however deeply cut. The work is, accordingly, finer and sharper; the fumes from the acids are also avoided, and the etching can be modified by regulation of the current. The preparation of the surface, by covering, stopping-out, etc., is the same as in ordinary etching. At some uncovered place a conducting wire is soldered on with soft solder, and covered with a coat of varnish. The plate is then suspended in the bath, and acts as the anode, with another similar plate for the cathode. If gradations in etching are desired, the plates are taken out after a time, rinsed, and covered, and returned to the bath.

For the bath dilute acids are used, or saline solutions. Thus, for copper, dilute sulphuric acid, 1 in 20. For copper and brass, a blue vitriol solution. For zinc, white vitriol or a zinc chloride solution. For steel and iron, green vitriol, or an ammonium chloride solution. For tin, a tin-salt solution. For silver, a silver nitrate or potassium cyanide solution. For gold and platinum, gold chloride and platinum chloride solutions, or a potassium cyanide solution. For electro-etching a Leclauché or Bunsen battery is to be recommended. In the former, the negative zinc pole is connected with a plate of the same metal as that to be etched, and the positive iron pole with the plate to be etched. In the Bunsen battery, the carbon pole is connected with the object to be etched, the zinc pole with the metal plate.

Etching Bath For Brass.

—1.—Mix nitric acid (specified gravity, 1.4), 8 parts, with water, 80 parts. 2.—Chlorate of potash, 3 parts, dissolved in 50 parts of water. Mix 1 and 2. For protecting those portions which are not to be etched, any suitable acid-proof composition can be used.

Etching On Copper.

—I.—In order to do regular and quick etching on copper take a copper plate silvered on the etching side. Trace on this plate, either with varnish or lithographic ink, the design. When the tracing is dry, place the plate in an iron bath, using a battery. The designs traced with the varnish or ink are not attacked by the etching fluid. When the plate is taken from the bath and has been washed and dried, remove the varnish or ink with essence of turpentine; next pour mercury on the places reserved by the varnish or ink; the mercury will attack the silvered portions and the etching is quickly made. When the mercury has done its duty gather up the excess and return to the bottle with a paper funnel. Wash the plate in strong alum water, and heat.

II.—The plate must be first polished either with emery or fine pumice stone, and after it has been dried with care, spread thereon a varnish composed of equal parts of yellow wax and essence of turpentine. The solution of the wax in the essence is accomplished in the cold; next a little oil of turpentine and some lampblack are added. This varnish is allowed to dry on, away from dust and humidity. When dry, trace the design with a very fine point. Make a border with modeling wax, so as to prevent the acid from running off. Pour on nitric acid if the plate is of copper, or {325} hydrochloric acid diluted with water if the plate is of zinc, allow the acid to act according to the desired depth of the engraving; wash several times and remove the varnish by heating the plate lightly. Wash with essence of turpentine and dry well in sawdust or in the stove. For relief engraving the designs are traced before the engraving on the plate with the resist varnish instead of covering the plate entirely. These designs must be delicately executed and without laps, as the acid eats away all the parts not protected by the varnish.

Etching Fluids For Copper.

—I.—A new etching fluid for copper plate is hydrogen peroxide, to which a little dilute ammonia water is added. It is said to bite in very rapidly and with great regularity and uniformity.

II.—Another fluid is fuming hydrochloric acid (specific gravity, 1.19), 10 parts; water, 70 parts. To this add a solution of potassium chlorate, 2 parts, dissolved in 20 parts of hot water. If the articles to be etched are very delicate and fine this should be diluted with from 100 to 200 parts of water.

Etching On Glass.

Names, designs, etc., can be etched on glass in three ways: First, by means of an engraving wheel, a method which requires some manual skill. Second, by means of a sand blast, making a stencil of the name, fixing this on the glass, and then, by means of a blast of air, blowing sand on the glass. Third, by the use of hydrofluoric acid. The glass is covered with beeswax, paraffine wax, or some acid resisting ink or varnish; the name or device is then etched out of the wax by means of a knife, and the glass dipped in hydrofluoric acid, which eats away the glass at those parts where the wax has been cut away.

Fancy work, ornamental figures, lettering, and monograms are most easily and neatly cut into glass by the sand-blast process. Lines and figures on tubes, jars, etc., may be deeply etched by smearing the surface of the glass with beeswax, drawing the lines with a steel point, and exposing the glass to the fumes of hydrofluoric acid. This acid is obtained by putting powdered fluorspar into a tray made of sheet lead and pouring sulphuric acid on it, after which the tray is slightly warmed. The proportions will vary with the purity of the materials used, fluorspar (except when in crystals) being generally mixed with a large quantity of other matter. Enough acid to make a thin paste with the powdered spar will be about right. Where a lead tray is not at hand, the powdered spar may be poured on the glass and the acid poured on it and left for some time. As a general rule, the marks are opaque, but sometimes they are transparent. In this case cut them deeply and fill up with black varnish, if they are required to be very plain, as in the case of graduated vessels. Liquid hydrofluoric acid has been recommended for etching, but is not always suitable, as it leaves the surface on which it acts transparent.

There are two methods of marking bottles—dry etching, or by stamping with etching inks. The first process is usually followed in glass factories. A rubber stamp is necessary for this process, and the letters should be made as large and clean cut as possible without crowding them too much. Besides this, an etching powder is required.

A small quantity of the powder is poured into a porcelain dish, and this is placed on a sand bath or over a gentle fire, and heated until it is absolutely dry, so that it can be rubbed down to an impalpable powder.

The bottle or other glass to be marked must be perfectly clean and dry. The etching powder takes better when the vessel is somewhat warm. The stamp should be provided with a roller which is kept constantly supplied with a viscid oil which it distributes on the stamp and which the stamp transfers to the glass surface. The powder is dusted on the imprint thus made, by means of a camel’s-hair brush. Any surplus falling on the unoiled surface may be removed with a fine long-haired pencil. The printed bottle is transferred to a damp place and kept for several minutes, the dampness aiding the etching powder in its work on the glass surface. The bottle is then well washed in plain water.

Glass cylinders, large flasks, carboys, etc., may be treated in a somewhat different manner. The stamp here is inserted, face upward, between two horizontal boards, in such a manner that its face projects about a quarter of a millimeter (say 0.01 inch) above the surface. Oil is applied to the surface, after which the cylinder, carboy, or what not, is rolled along the board and over the stamp. The design is thus neatly transferred to the glass surface, and the rest of the operation is as in the previous case.

For an etching ink for glassware the following is recommended:

Ammonium fluoride 2 drachms

Barium sulphate 2 drachms

Reduce to a fine powder in a mortar, {326} then transfer to a lead dish and make into a thin writing-cream with hydrofluoric acid or fuming sulphuric acid. Use a piece of lead to stir the mixture. The ink may be put up in bottles coated with paraffine, which can be done by heating the bottle, pouring in some melted paraffine, and letting it flow all around. The writing is done with a quill, and in about half a minute the ink is washed off.

Extreme caution must be observed in handling the acid, since when brought in contact with the skin it produces dangerous sores very difficult to heal. The vapor is also dangerously poisonous when inhaled.

Hydrofluoric Formulas.

—I.—Dissolve about 0.72 ounces fluoride of soda with 0.14 ounces sulphate of potash in / 2 pint of water. Make another solution of 0.28 ounces chloride of zinc and 1.30 ounces hydrochloric acid in an equal quantity of water. Mix the solutions and apply to the glass vessel with a pin or brush. At the end of half an hour the design should be sufficiently etched.

II.—A mixture consisting of ammonium fluoride, common salt, and carbonate of soda is prepared, and then placed in a gutta-percha bottle containing fuming hydrofluoric acid and concentrated sulphuric acid. In a separate vessel which is made of lead, potassium fluoride is mixed with hydrochloric acid, and a little of this solution is added to the former, along with a small quantity of sodium silicate and ammonia. Some of the solution is dropped upon a rubber pad, and by means of a suitable rubber stamp, bearing the design which is to be reproduced, is transferred to the glass vessel that is to be etched.

Etching With Wax.

—Spread wax or a preservative varnish on the glass, and trace on this wax or varnish the letters or designs. If letters are desired, trace them by hand or by the use of letters cut out in tin, which apply on the wax, the inside contours being taken with a fine point. When this is done, remove the excess of wax from the glass, leaving only the full wax letters undisturbed. Make an edge of wax all along the glass plate so as to prevent the acid from running over when you pour it on to attack the glass. At the end of 3 to 4 hours remove the acid, wash the glass well with hot water, next pour on essence of turpentine or alcohol to take off the wax or the preservative varnish. Pass again through clean water; the glass plate will have become dead wherever the acid has eaten in, only the letters remaining polished. For fancy designs it suffices to put on the back of the plate a black or colored varnish, or tin foil, etc., to obtain a brilliant effect.

Etching Glass By Means Of Glue.

—It is necessary only to cover a piece of ordinary or flint glass with a coat of glue dissolved in water in order to see that the layer of glue, upon contracting through the effect of drying, becomes detached from the glass and removes therefrom numerous scales of varying thickness. The glass thus etched presents a sort of regular and decorative design similar to the flowers of frost deposited on windowpanes in winter. When salts that are readily crystallizable and that exert no chemical action upon the gelatin are dissolved in the latter the figures etched upon the glass exhibit a crystalline appearance that recalls fern fronds.

Hyposulphite of soda and chlorate and nitrate of potash produce nearly the same effects. A large number of mineral substances are attacked by gelatin. Toughened glass is easily etched, and the same is the case with fluorspar and polished marble. A piece of rock crystal, cut at right angles with the axis and coated with isinglass, the action of which seems to be particularly energetic, is likewise attacked at different points, and the parts detached present a conchoidal appearance. The contraction of the gelatin may be rendered visible by applying a coating of glue to sheets of cardboard or lead, which bend backward in drying and assume the form of an irregular cylinder.

Such etching of glass and different mineral substances by the action of gelatin may be employed for the decoration of numerous objects.

Dissolve some common glue in ordinary water, heated by a water bath, and add 6 per cent of its weight of potash alum. After the glue has become perfectly melted, homogeneous, and of the consistency of syrup, apply a layer, while it is still hot, to a glass object by means of a brush. If the object is of ground glass the action of the glue will be still more energetic. After half an hour apply a second coat in such a way as to obtain a smooth, transparent surface destitute of air bubbles. After the glue has become so hard that it no longer yields to the pressure of the finger nail (say, in about 24 hours), put the article in a warmer place, in which the temperature must not exceed 105° F. When the object is removed from the oven, after a few hours, the glue will detach itself with {327} a noise and removes with it numerous flakes of glass. All that the piece then requires is to be carefully washed and dried.

The designs thus obtained are not always the same, the thickness of the coat of glue, the time of drying, and various other conditions seeming to act to modify the form and number of the flakes detached.

It is indispensable to employ glass objects of adequate thickness, since, in covering mousseline glass with a layer of glue, the mechanical action that it has to support during desiccation is so powerful that it will break with an explosion. Glue, therefore, must not be allowed to dry in glass vessels, since they would be corroded and broken in a short time.

Indelible Labels On Bottles.

—To affix indelible labels on bottles an etching liquid is employed which is produced as follows:

Liquid I, in one bottle.—Dissolve 36 parts of sodium fluoride in 500 parts of distilled water and add 7 parts of potassium sulphate.

Liquid II, in another bottle.—Dissolve zinc chloride, 14 parts, in 500 parts of distilled water, and add 65 parts of concentrated hydrochloric acid.

For use mix equal parts together and add a little dissolved India ink to render the writing more visible.

The mixing cannot, however, be conducted in a vessel. It is best to use a cube of paraffine which has been hollowed out.

Etching On Marble Or Ivory

(see also Ivory).—Cover the objects with a coat of wax dissolved in 90 per cent alcohol, then trace the desired designs by removing the wax with a sharp tool and distribute on the tracing the following mixture: Hydrochloric acid, 1 part; acetic acid, 1 part. Repeat this operation several times, until the desired depth is attained. Then take off the varnish with alcohol. The etching may be embellished, filling up the hollows with any colored varnish, by wiping the surface with a piece of linen fixed on a stick, to rub the varnish into the cavities after it has been applied with a brush. The hollows may be gilded or silvered by substituting “mixtion” for the varnish and applying on this mixtion a leaf of gold or silver, cut in pieces a little larger than the design to be covered; press down the gold by means of a soft brush so as to cause it to penetrate to the bottom; let dry and remove the protruding edges.

Etching On Steel.

—The print should be heavily inked and powdered with dragon’s blood several times. After each powdering heat slightly and additional powder will stick, forming a heavy coating in 2 or 3 operations. Before proceeding to heat up, the plate should receive a light etching in a weak solution of the acid described later on. The purpose of this preliminary etching is to clean up the print, so that the lines will not tend to thicken, as would be the case otherwise. Next a good strong heating should be given. On top the dragon’s blood plumbago may be used in addition. For etching use nitric acid mixed with an even amount of acetic acid. Some operators use vinegar, based on the same theory. When commencing the etching, start with a weak solution and increase as soon as the plate is deep enough to allow another powdering. If the operator is familiar with lithography, and understands rolling up the print with a lithoroller, the etching of steel is not harder than etching on zinc.

Liquids For Etching Steel.—

I.— Iodine 2 parts

Potassium iodide 5 parts

Water 40 parts

II.— Nitric acid 60 parts

Water 120 parts

Alcohol 200 parts

Copper nitrate 8 parts

III.— Glacial acetic acid 4 parts

Nitric acid 1 part

Alcohol 1 part

IV.—Mix 1 ounce sulphate of copper, / 4 ounce alum, / 2 teaspoonful of salt (reduced to powder), with 1 gill of vinegar and 20 drops of nitric acid. This fluid can be used either for etching deeply or for frosting, according to the time it is allowed to act. The parts of the work which are not to be etched should be protected with beeswax or some similar substance.

V.—Nitric acid, 60 parts; water, 120 parts; alcohol, 200 parts; and copper nitrate, 8 parts. Keep in a glass-stoppered bottle. To use the fluid, cover the surface to be marked with a thin even coat of wax and mark the lines with a machinist’s scriber. Wrap clean cotton waste around the end of the scriber or a stick, and dip in the fluid, applying it to the marked surface. In a few minutes the wax may be scraped off, when fine lines will appear where the scriber marked the wax. The drippings from a lighted wax candle can be used for the {328} coating, and this may be evenly spread with a knife heated in the candle flame.

VI.—For Hardened Steel.—Heat an iron or an old pillar-file with a smooth side, and with it spread a thin, even coat of beeswax over the brightened surface to be etched. With a sharp lead pencil (which is preferable to a scriber) write or mark as wanted through the wax so as to be sure to strike the steel surface. Then daub on with a stick etching acid made as follows: Nitric acid, 3 parts; muriatic acid, 1 part. If a lead pencil has been used the acid will begin to bubble immediately. Two or three minutes of the bubbling or foaming will be sufficient for marking; then soak up the acid with a small piece of blotting paper and remove the beeswax with a piece of cotton waste wet with benzine, and if the piece be small enough dip it into a saturated solution of sal soda, or if the piece be large swab over it with a piece of waste. This neutralizes the remaining acid and prevents rusting, which oil will not do.

If it is desired to coat the piece with beeswax without heating it, dissolve pure beeswax in benzine until of the consistency of thick cream and pour on to the steel, and even spread it by rocking or blowing, and lay aside for it to harden; then use the lead pencil, etc., as before. This method will take longer. Keep work from near the fire or an open flame.

EUCALYPTUS BONBONS FOR COLDS AND COUGHS: See Cold and Cough Mixtures.

EXPECTORANTS: See Cold and Cough Mixtures.

Explosives

Explosives may be divided into two great classes—mechanical mixtures and chemical compounds. In the former the combustible substances are intimately mixed with some oxygen supplying material, as in the case of gunpowder, where carbon and sulphur are intimately mixed with potassium nitrate; while gun cotton and nitro-glycerine are examples of the latter class, where each molecule of the substance contains the necessary oxygen for the oxidation of the carbon and hydrogen present, the oxygen being in feeble combination with nitrogen. Many explosives are, however, mechanical mixtures of compounds which are themselves explosive, e. g., cordite, which is mainly composed of gun cotton and nitro-glycerine.

The most common and familiar of explosives is undoubtedly gunpowder. The mixture first adopted appears to have consisted of equal parts of the three ingredients—sulphur, charcoal, and niter; but some time later the proportions, even now taken for all ordinary purposes, were introduced, namely:

Potassium nitrate 75 parts

Charcoal 15 parts

Sulphur 10 parts

100 parts

Since gunpowder is a mechanical mixture, it is clear that the first aim of the maker must be to obtain perfect incorporation, and, necessarily, in order to obtain this, the materials must be in a very finely divided state. Moreover, in order that uniformity of effect may be obtained, purity of the original substances, the percentage of moisture present, and the density of the finished powder are of importance.

The weighed quantities of the ingredients are first mixed in gun metal or copper drums, having blades in the interior capable of working in the opposite direction to that in which the drum itself is traveling. After passing through a sieve, the mixture (green charge) is passed on to the incorporating mills, where it is thoroughly ground under heavy metal rollers, a small quantity of water being added to prevent dust and facilitating incorporation, and during this process the risk of explosion is greater possibly than at any other stage in the manufacture. There are usually 6 mills working in the same building, with partitions between. Over the bed of each mill is a horizontal board, the “flash board,” which is connected with a tank of water overhead, the arrangement being such that the upsetting of one tank discharges the contents of the other tanks onto the corresponding mill beds below, so that in the event of an accident the charge is drowned in each case. The “mill cake” is now broken down between rollers, the “meal” produced being placed in strong oak boxes and subjected to hydraulic pressure, thus increasing its density and hardness, at the same time bringing the ingredients into more intimate contact. After once more breaking down the material (press cake), the powder only requires special treatment to adapt it for the various purposes for which it is intended.

The products of the combustion of powder and its manner of burning are {329} largely influenced by the pressure, a property well illustrated by the failure of a red-hot platinum wire to ignite a mass of powder in a vacuum, only a few grains actually in contact with the platinum undergoing combustion.

Nitro-glycerine is a substance of a similar chemical nature to gun cotton, the principles of its formation and purification being very similar, only in this case the materials and product are liquids, thereby rendering the operations of manufacture and washing much less difficult. The glycerine is sprayed into the acid mixture by compressed-air injectors, care being taken that the temperature during nitration does not rise above 86° F. The nitro-glycerine formed readily separates from the mixed acids, and being insoluble in cold water, the washing is comparatively simple.

Nitro-glycerine is an oily liquid readily soluble in most organic solvents, but becomes solid at 3° or 4° above the freezing point of water, and in this condition is less sensitive. It detonates when heated to 500° F., or by a sudden blow, yielding carbon dioxide, oxygen, nitrogen, and water. Being a fluid under ordinary conditions, its uses as an explosive were limited, and Alfred Nobel conceived the idea of mixing it with other substances which would act as absorbents, first using charcoal and afterwards an infusorial earth, “kieselguhr,” and obtaining what he termed “dynamite.” Nobel found that “collodion cotton”—soluble gun cotton—could be converted by treatment with nitro-glycerine into a jellylike mass which was more trustworthy in action than the components alone, and from its nature the substance was christened “blasting gelatin.”

Nobel took out a patent for a smokeless powder for use in guns, in which these ingredients were adopted with or without the use of retarding agents. The powders of this class are ballistite and filite, the former being in sheets, the latter in threads. Originally camphor was introduced, but its use has been abandoned, a small quantity of aniline taking its place.

Sir Frederick Abel and Prof. Dewar patented in 1889 the use of trinitro-cellulose and nitro-glycerine, for although, as is well known, this form of nitro-cellulose is not soluble in nitro-glycerine, yet by dissolving the bodies in a mutual solvent, perfect incorporation can be attained. Acetone is the solvent used in the preparation of “cordite,” and for all ammunition except blank charges a certain proportion of vaseline is also added. The combustion of the powder without vaseline gives products so free from solid or liquid substances that excessive friction of the projectile in the gun causes rapid wearing of the rifling, and it is chiefly to overcome this that the vaseline is introduced, for on explosion a thin film of solid matter is deposited in the gun, and acts as a lubricant.

The proportion of the ingredients are:

Nitro-glycerine 58 parts

Gun-cotton 37 parts

Vaseline 5 parts

Gun cotton to be used for cordite is prepared as previously described, but the alkali is omitted, and the mass is not submitted to great pressure, to avoid making it so dense that ready absorption of nitro-glycerine would not take place. The nitro-glycerine is poured over the dried gun cotton and first well mixed by hand, afterwards in a kneading machine with the requisite quantity of acetone for 3 / 2 hours. A water jacket is provided, since, on mixing, the temperature rises. The vaseline is now added, and the kneading continued for a similar period. The cordite paste is first subjected to a preliminary pressing, and is finally forced through a hole of the proper size in a plate either by hand or by hydraulic pressure. The smaller sizes are wound on drums, while the larger cordite is cut off in suitable lengths, the drums and cut material being dried at 100° F., thus driving off the remainder of the acetone.

Cordite varies from yellow to dark brown in color, according to its thickness. When ignited it burns with a strong flame, which may be extinguished by a vigorous puff of air. Macnab and Ristori give the yield of permanent gases from English cordite as 647 cubic centimeters, containing a much higher per cent of carbon monoxide than the gases evolved from the old form of powder. Sir Andrew Noble failed in attempts to detonate the substance, and a rifle bullet fired into the mass only caused it to burn quietly.

Dynamite.

—Dynamite is ordinarily made up of 75 per cent nitro-glycerine, 25 per cent infusorial earth; dualine contains 80 per cent nitro-glycerine, 20 per cent nitro-cellulose; rend-rock has 40 per cent nitro-glycerine, 40 per cent nitrate of potash, 13 per cent cellulose, 7 per cent paraffine; giant powder, 36 per cent nitro-glycerine, 48 per cent nitrate of potash, 8 per cent sulphur, 8 per cent rosin or charcoal.

Smokeless Powder.

—The base of smokeless powders is nitrated cellulose, {330} which has been treated in one of various ways to make it burn slower than gun cotton, and also to render it less sensitive to heat and shocks. As a rule, these powders are not only less inflammable than gun cotton, but require stronger detonators. As metallic salts cause smoke, they are not used in these powders. The smokeless powders now in use may be divided into three groups: (1) Those consisting of mixtures of nitro-glycerine and nitrated cellulose, which have been converted into a hard, hornlike mass, either with or without the aid of a solvent. To this group belongs ballistite, containing 50 per cent of nitro-glycerine, 49 per cent of nitrated cellulose, and 1 per cent of diphenylamin; also cordite (see further on), Lenord’s powder, and amberite. This last contains 40 parts of nitro-glycerine and 56 parts of nitrated cellulose. (2) Those consisting mainly of nitrated cellulose of any kind, which has been rendered hard and horny by treatment with some solvent which is afterwards evaporated. These are prepared by treating nitrated cellulose with ether or benzine, which dissolves the collodion, and when evaporated leaves a hard film of collodion on the surface of each grain. Sometimes a little camphor is added to the solvent, and, remaining in the powder, greatly retards its combustion. (3) Those consisting of nitro-derivatives of the aromatic hydrocarbons, either with or without the admixture of nitrated cellulose; to this group belong Dupont’s powder, consisting of nitrated cellulose dissolved in nitro-benzine; indurite, consisting of cellulose hexanitrate (freed from collodion by extraction with methyl alcohol), made into a paste with nitro-benzine, and hardened by treatment with steam until the excess of nitro-benzine is removed; and plastomeite, consisting of dinitrotoluene and nitrated wood pulp.

Cordite is the specific name of a smokeless powder which has been adopted by the English government as a military explosive. It contains nitro-glycerine, 58 parts; gun cotton, 37 parts; and petrolatum, 5 parts. The nitro-glycerine and gun cotton are first mixed, 19.2 parts of acetone added, and the pasty mass kneaded for several hours. The petrolatum is then added and the mixture again kneaded. The paste is then forced through fine openings to form threads, which are dried at about 105° F. until the acetone evaporates. The threads, which resemble brown twine, are then cut into short lengths for use.

Another process for the manufacture of smokeless powder is as follows: Straw, preferably oat-straw, is treated in the usual way with a mixture of nitric acid and concentrated sulphuric acid, and then washed in water to free it from these, then boiled with water, and again with a solution of potassium carbonate. It is next subjected, for 2 to 6 hours, to the action of a solution composed of 1,000 parts of water, 12.5 parts of potassium nitrate, 3.5 parts of potassium chlorate, 12.5 parts of zinc sulphate, and 12.5 parts of potassium permanganate. The excess of solution is pressed out, and the mass is then pulverized, granulated, and finally dried.

The warning as to the danger of experimenting with the manufacture of ordinary gunpowder applies with renewed force when nitro-glycerine is the subject of the experiment.

Berge’s Blasting Powder.

—This is composed of chlorate of potash, 1 part; chromate of potash, 0.1 part; sugar, 0.45 parts; yellow wax, 0.09 parts. The proportions indicated may vary within certain limits, according to the force desired. For the preparation, the chlorate and the chromate of potash, as well as the sugar, are ground separately and very finely, and sifted so that the grains of the different substances may have the same size. At first any two of the substances are mixed as thoroughly as possible, then the third is added. The yellow wax, cut in small pieces, is finally added, and all the substances are worked together to produce a homogeneous product. The sugar may be replaced with charcoal or any other combustible body. For commercial needs, the compound may be colored with any inert matter, also pulverized.

Safety In Explosives

.—Ammoniacal salts have been used in the manufacture of explosives to render them proof against firedamp, but not with the full success desired. Ammonium chloride has been utilized, but inconveniences are met with, and the vapor is quite disagreeable. In coöperation with equivalent quantities of soda and potash, its action is regarded as favorable. Tests employing benzine vapor and coal dust were made, and the comparative security calculated to be as given below.

I.—Donarite, composed as follows: 80 per cent of nitrate of ammonia, 12 of trinitrotoluol, 4 of flour, 3.8 of nitro-glycerine, and 0.2 per cent of cotton collodion. Security: Donarite alone, 87 parts; 95 per cent of donarite and 5 per {331} cent of ammonium chloride, 125 parts; 90 per cent of donarite and 10 per cent of ammonium chloride, 250 parts; 86 per cent of donarite and 5.5 per cent of ammonium chloride, with 8.5 per cent of nitrate of soda, 425 parts. The force of the explosion is decreased about 8 per cent, while the security is quintupled.

II.—Roburite, with the following composition: 72.5 per cent nitrate of ammonia; 12 binitro-benzol; 10 nitrate of potash; 5 sulphate of ammonia; 0.5 per cent permanganate of potash. Security: Roburite only, 325 parts; ammonium chloride, taking the place of sulphate of ammonia, 400 parts. Here an intensification of the explosive force is simultaneously produced.

III.—Ammon carbonite I, composed thus: 4 per cent nitro-glycerine; 75.5 nitrate of ammonia; 9.5 nitrate of potash; 9.5 coal dust; 10.5 flour. Security: Ammon carbonite I only, 250 parts; 95 per cent A. C. I. and 5 per cent ammonium chloride, 400 parts; 92 per cent A. C. I. and 8 per cent ammonium chloride, 500 parts. The addition of 5 per cent ammonium chloride diminishes the explosive force only 3 per cent.

IV.—An explosive of nitro-glycerine base composed thus: 30 per cent nitro-glycerine; 1 per cent cotton collodion; 52.6 nitrate of ammonia; 13 nitrate of potash; 3 to 4 per cent starch. Security of this mixture, 150 parts.

V.—Thirty per cent nitro-glycerine; 1 per cent cotton collodion; 47.3 nitrate of ammonia; 11.6 nitrate of potash; 3.1 starch; 7 per cent ammonium chloride. This mixture has a security of 350 parts.

Inflammable Explosive With Chlorate Of Potash.

—Take as an agent promoting combustion, potassium chlorate; as a combustible agent, an oxidized, nitrated, or natural rosin. If, to such a mixture, another body is added in order to render it soft and plastic, such as oil, nitro-benzine, glucose, glycerine, the benefit of the discovery is lost, for the mixture is rendered combustible with nitro-benzine, fecula, sulphur, etc., and inexplosive with glycerine, glucose, and the oil.

Of all the chlorates and perchlorates, potassium chlorate (KClO3) responds the best to what is desired. As to the rosins, they may be varied, or even mixed. To obtain the oxidation or nitration of the rosins, they are heated with nitric acid, more or less concentrated, and with or without the addition of sulphuric acid. An oxidation, sufficient and without danger, can be secured by a simple and practical means. This is boiling them for several hours in water containing nitric acid, which is renewed from time to time in correspondence with its decomposition. The rosins recommended by M. Turpin are of the terebinthine group, having for average formula C20H30O2. Colophony is the type.

The products, thus nitrated, are washed with boiling water, and, on occasion, by a solution slightly alkaline, with a final washing with pure water, and dried at a temperature of 230° F. or in the open air.

The mixing of the constituents of this explosive is preferably cold. For this purpose they are used in the state of fine powder, and when mixed in the tub, 2 / 2 to 5 per cent of a volatile dissolvent is added, as alcohol, carbon sulphide, ether, or benzine. As soon as thoroughly mingled, the mass is put either in an ordinary grainer, or in a cylinder of wire cloth revolving horizontally on its axis, with glass gobilles forming a screen, by the aid of which the graining is rapidly accomplished. Thus a powder more or less finely granulated is produced free from dust.

The proportions preferably employed are:

1. Potassium chlorate 85 parts

Natural rosin 15 parts

2. Potassium chlorate 80 parts

Nitrated rosin 20 parts

For employment in firedamp mines, there is added to these compounds from 20 to 40 per cent of one of the following substances: Ammonium oxalate, ammonium carbonate, oxalic acid, sodium bicarbonate, calcium fluoride, or other substance of the nature to lower sufficiently the temperature of the explosive flame.

Gun Cotton.

—For the production of a high-grade gun cotton, it is important that the cotton used should approach as near as possible pure cellulose. The waste from cotton mills, thoroughly purified, is usually employed. After careful chemical examination has been made to ascertain its freedom from grease and other impurities, the cotton waste is picked over by hand to remove such impurities as wood, cardboard, string, etc. The cotton is then passed through the “teasing machine,” which opens out all knots and lumps, thereby reducing it to a state more suitable for the acid treatment and exposing to view any foreign substances which may have escaped notice in the previous picking. The cotton is then dried. When {332} perfectly dry, it is removed to air-tight iron cases, in which it is allowed to cool. The iron cases are taken to the dipping houses, and the cotton waste weighed into small portions, which are then transferred as rapidly as possible to the mixed acids, allowed to remain a few minutes, then removed to the grating and the excess of acid squeezed out. The cotton now containing about ten times its weight of acid is placed in an earthenware pot and transferred to the steeping pits, where it is allowed to remain for 24 hours, a low temperature being maintained by a stream of cold water.

The cotton is now wholly converted into nitro-cellulose. The superfluous acid is next removed by a centrifugal extractor, after which the gun cotton is taken out of the machine and immediately immersed in a large volume of water, and thoroughly washed until it shows no acid reaction. The moisture is then run out and the gun cotton is conveyed by tramway to the boiling vats, where it undergoes several boilings by means of steam. When the “heat test” shows that a sufficient degree of stability has been obtained, the gun cotton is removed to a beating engine, and reduced to a very fine state of division. When this process is completed the pulp is run by gravity along wooden shoots, provided with “grit traps” and electromagnets, which catch any traces of sand, iron, etc., into large “poachers,” in which the gun cotton is continuously agitated, together with a large quantity of water. In this way it is thoroughly washed and a blend made of a large quantity of gun cotton.

Soluble Gun Cotton.

—Soluble gun cotton is made on the same lines, except that greater attention has to be paid to the physical condition of the cotton used, and to the temperature and strength of acid mixture, etc.

The term “soluble” usually implies that the gun cotton is dissolved by a mixture of ethyl-ether and ethyl-alcohol, 2 parts of the former to 1 of the latter being the proportions which yield the best solvent action. The classification of nitro-celluloses according to their solubility in ether-alcohol is misleading, except when the nitrogen contents are also quoted.

The number of solvents for gun cotton which have at various times been proposed is very large. Among the more important may be mentioned the following: Alcohols (used chiefly in conjunction with other solvents), methyl, ethyl, propyl, and amyl, methyl-amyl ether, acetic ether, di-ethyl-ketone, methyl-ethyl ketone, amyl nitrate and acetate, nitro-benzole, nitro-toluol, nitrated oils, glacial acetic acid, camphor dissolved in alcohol, etc.

Some of the above may be called selective solvents, i. e., they dissolve one particular variety of gun cotton better than others, so that solubility in any given solvent must not be used to indicate solubility in another. No nitro-cotton is entirely soluble in any solvent. The solution, after standing some time, always deposits a small amount of insoluble matter. Therefore, in making collodion solutions, care should be taken to place the containing bottles in a place free from vibration and shock. After standing a few weeks the clear supernatant liquid may be decanted off. On a larger scale collodion solutions are filtered under pressure through layers of tightly packed cotton wool. The state of division is important. When the end in view is the production of a strong film or thread, it is advisable to use unpulped or only slightly pulped nitro-cellulose. In this condition it also dissolves more easily than the finely pulped material.

Fulminates:

Fulminating Antimony.

—Tartar emetic (dried), 100 parts; lampblack or charcoal powder, 3 parts. Triturate together, put into a crucible that it will three-fourths fill (previously rubbed inside with charcoal powder). Cover it with a layer of dry charcoal powder, and lute on the cover. After 3 hours’ exposure to a strong heat in a reverberatory furnace, and 6 or 7 hours’ cooling, cautiously transfer the solid contents of the crucible, as quickly as possible, without breaking, to a wide-mouthed stoppered phial, where, after some time, it will spontaneously crumble to a powder. When the above process is properly conducted, the resulting powder contains potassium, and fulminates violently on contact with water. A piece the size of a pea introduced into a mass of gunpowder explodes it on being thrown into water, or on its being moistened in any other manner.

Fulminating Bismuth.

—Take bismuth, 120 parts; carbureted cream of tartar, 60 parts; niter, 1 part.

Fulminating Copper.

—Digest copper (in powder of filings) with fulminate of mercury or of silver, and a little water. {333} It forms soluble green crystals that explode with a green flame.

Fulminating Mercury.

—Take mercury, 100 parts; nitric acid (specific gravity, 1.4), 1,000 parts (or 740 parts, by measure). Dissolve by a gentle heat, and when the solution has acquired the temperature of 130° F., slowly pour it through a glass funnel tube into alcohol (specific gravity, .830), 830 parts (or 1,000 parts, by measure). As soon as the effervescence is over, and white fumes cease to be evolved, filter through double paper, wash with cold water, and dry by steam (not hotter than 212° F.) or hot water. The fulminate is then to be packed in 100-grain paper parcels, and these stored in a tight box or corked bottle. Product 130 per cent of the weight of mercury employed.

Fulminating Powder.

—I.—Niter, 3 parts; carbonate of potash (dry), 2 parts; flowers of sulphur, 1 part; reduce them separately to fine powder, before mixing them. A little of this compound (20 to 30 grains), slowly heated on a shovel over the fire, first fuses and becomes brown, and then explodes with a deafening report.

II.—Sulphur, 1 part; chlorate of potassa, 3 parts. When triturated, with strong pressure, in a marble or wedgwood-ware mortar, it produces a series of loud reports. It also fulminates by percussion.

III.—Chlorate of potassa, 6 parts; pure lampblack, 4 parts; sulphur, 1 part. A little placed on an anvil detonates with a loud report when struck with a hammer.

EXPOSURES IN PHOTOGRAPHING: See Photography.

EXTRACTS: See Essences and Extracts.

EXTRACTS, TESTS FOR: See Foods.

Eye Lotions:

“Black Eye” Lotion.

—“Black eyes” or other temporary discolorations of the skin may be disguised by the application of pink grease paint, or collodion colored by means of a little carmine. As lotions the following have been recommended:

I.— Ammonium chloride 1 part

Alcohol 1 part

Water 10 parts

Diluted acetic acid may be substituted for half of the water, and the alcohol may be replaced by tincture of arnica, with advantage.

II.— Potassium nitrate 15 grains

Ammonium chloride 30 grains

Aromatic vinegar 4 drachms

Water to make 8 ounces.

III.—The following is to be applied with camel’s-hair pencil every 1, 2, or 3 hours. Be careful not to get it in the eyes, as it smarts. It will remove the black discoloration overnight:

Oxalic acid 15 grains

Distilled water 1 ounce

Foreign Matter In The Eye.

—If a piece of iron or other foreign matter in the eye irritates it, and there is no way of removing it until morning, take a raw Irish potato, grate it, and use as a poultice on the eye. It will ease the eye so one can sleep, and sometimes draws the piece out.

Drops Of Lime In The Eye.

—If lime has dropped in the eye, the pouring-in of or the wiping-out with a few drops of oil is the best remedy, as the causticity of the lime is Arrested thereby. Poppy-seed oil or olive oil is prescribed, but pure linseed oil ought to render the same service, as it is also used in the household. Subsequently, the eye may be rinsed out with syrup, as the saccharine substance will harden any remaining particles of lime and destroy all causticity entirely.

FABRIC CLEANERS: See Cleaning Preparations and Methods and also Household Formulas.

FABRICS, WATERPROOFING OF: See Waterproofing.

FACE BLACK AND FACE POWDER: See Cosmetics.

Fats

Bear Fat.

—Fresh bears’ fat is white and very similar to lard in appearance. The flank fat is softer and more transparent than the kidney fat, and its odor recalls that of fresh bacon. Bears’ fat differs from the fats of the dog, fox, and cat in having a lower specific gravity, a very low melting point, and a fairly high iodine value.

Bleaching Bone Fat.

—Bone fat, which is principally obtained from horse bones, is very dark colored in the crude state, and of an extremely disagreeable smell. To remedy these defects it may be bleached by the air or chemicals, the former method only giving good results {334} when the fat has been recovered by means of steam. It consists in cutting up the fat into small fragments and exposing it to the air for several days, the mass being turned over at intervals with a shovel. When sufficiently bleached in this manner, the fat is boiled with half its own weight of water, which done, about 3 or 4 per cent of salt is added, and the whole is boiled over again. This treatment, which takes 2 or 3 weeks, sweetens the fat, makes it of the consistency of butter, and reduces the color to a pale yellow. Light seems to play no part in the operation, the change being effected solely by the oxygen of the air. The chemical treatment has the advantage of being more rapid, sufficient decoloration being produced in a few hours. The fat, which should be free from gelatin, phosphate of lime, and water, is placed in an iron pan along with an equal weight of brine of 14° to 15° Bé. strength, with which it is boiled for 3 hours and left to rest overnight. Next day the fat is drawn off into a wooden vessel, where it is treated by degrees with a mixture of 2 parts of potassium bichromate, dissolved in 6 of boiling water, and 8 parts of hydrochloric acid (density 22° Bé.), this quantity being sufficient for 400 parts of fat. Decoloration proceeds gradually, and when complete the fat is washed with hot water.

Bleaching Tallows And Fats.

—Instead of exposing to the sun, which is always attended with danger of rendering fats rancid, it is better to liquefy these at a gentle heat, and then add / 5 in weight of a mixture of equal parts of kaolin and water. The fatty matter should be worked up for a time and then left to separate. Kaolin has the advantage of cheapness in price and of being readily procured.

Freshly burned animal charcoal would perhaps be a more satisfactory decolorizer than kaolin, but it is more expensive to start with, and not so easy to regenerate.

Exposure of tallow to the action of steam under high pressure (a temperature of 250° or 260° F.) is also said to render it whiter and harder.

Coloring Matter In Fats.

—A simple method for the detection of the addition of coloring matter to fats is here described. Ten parts, by measure, of the melted fat are put into a small separating funnel and dissolved in 10 parts, by measure, of petroleum ether. The solution is then treated with 15 parts, by measure, of glacial acetic acid and the whole shaken thoroughly. The addition of coloring matter is known by the red or yellow coloration which appears in the lower layer of acetic acid after the contents of the funnel have been allowed to settle. If only a slight addition of coloring matter is suspected, the acetic acid solution is run off into a porcelain basin and the latter heated on a water bath, when the coloration will be seen more readily. This test is intended for butter and margarine, but is also suitable for tallow, lard, etc.

Fatty Acid Fermentation Process.

—The production of fatty acids from fats and oils by fermentation is growing in importance. These particulars, which are the actual results from recent experiments on a somewhat extended scale, are given: Seven hundred and fifty pounds of cottonseed oil are mixed with 45 gallons of water and 3 / 2 pounds of acetic acid; this mixture is heated to a temperature of 85° F. Castor-oil seeds, 53 pounds, decorticated and ground, are mixed thoroughly with 3 gallons of water and 4 / 2 gallons of the oil, and this mixture is stirred into the oil and water; the whole mass is then kept mixed for 12 hours by blowing air through, after which it is allowed to stand for another 12 hours, being given a gentle stir by hand at the end of every hour. After 24 hours the mass is heated to a temperature of 180° F., which stops the fermentation and at the same time allows the fatty acids to separate more freely. To assist in this effect there is added 1 gallon of sulphuric acid (1 in 3) solution.

After 2 hours’ standing, the mass will have separated into three layers—fatty acids on the top, glycerine water below, and a middle, undefined layer. The glycerine water is run away, and the whole mass left to stand for 2 hours. The middle portion is run off from the separated fatty acids into another vessel, where it is mixed with 10 gallons of hot water, thoroughly stirred, and allowed to stand for 16 hours or more. The watery layer at the bottom, which contains some glycerine, is then run off, while the residue is mixed with a further quantity of 10 gallons of water, and again allowed to stand. The water which separates out, also the layer of fatty acids that forms on the top, are run off and mixed with the portions previously obtained. The various glycerine waters are treated to recover the glycerine, while the fatty acids are made marketable in any convenient way. {335}

Preservation Of Fats.

—To produce fats and oils containing both iodine and sulphur, whereby they are preserved from going rancid, and consequently can be utilized to more advantage for the usual purposes, such as the manufacture of soaps, candles, etc., following is the Loebell method:

The essential feature of the process is that the iodine is not merely held in solution by the oil or fat, but enters into chemical combination with the same; the sulphur also combines chemically with the oil or fat, and from their reactions the preserving properties are derived.

The process consists of heating, for example, 6 parts of oil with 1 part of sulphur to a temperature varying between 300° and 400° F., then, when at about 195° F., a solution of iodine and oil is added to the mixture, which is constantly agitated until cool to prevent lumps forming. A product is thus obtained which acquires the consistency of butter, and contains both iodine and sulphur in combination.

Purifying Oils And Fats.

—In purifying fatty oils and fats for edible purposes the chief thing is to remove the free fatty acids, which is done by the aid of solutions of alkalies and alkaline earths. The subsequent precipitation of the resulting soapy emulsions, especially when lime is used, entails prolonged heating to temperatures sometimes as high as the boiling point of water. Furthermore, the amount of alkalies taken is always greater than is chemically necessary, the consequence being that some of the organic substances present are attacked, and malodorous products are formed, a condition necessitating the employment of animal charcoal, etc., as deodorizer.

To prevent the formation of these untoward products, which must injuriously affect the quality of edible oils, C. Fresenius proposes to accelerate the dispersion of the said emulsions by subjecting the mixtures to an excess pressure of 1 to 1 / 2 atmospheres and a corresponding temperature of about 220° F., for a short time, the formation of decomposition products, and any injurious influence on the taste and smell of the substance being prevented by the addition of fresh charcoal, etc., beforehand. Charcoal may, and must in certain cases, be replaced for this purpose by infusorial earth or fuller’s earth. When this process is applied to cottonseed oil, 100 parts of the oil are mixed with / 10 part of fresh, pure charcoal, and / 2 part of pure fuller’s earth. The mixture is next neutralized with lime-water, and placed in an autoclave, where it is kept for an hour under pressure, and at a temperature of 220° F. Under these conditions the emulsion soon separates, and when this is accomplished the whole is left to cool down in a closed vessel.

FATS, DECOMPOSITION OF: See Oil.

Feather Bleaching and Coloring:

See also Dyes.

Bleaching And Coloring Feathers.

—Feathers, in their natural state, are not adapted to undergo the processes of dyeing and bleaching; they must be prepared by removing their oil and dirt. This is usually done by washing them in moderately warm soap and water, and rinsing in warm and cold water; or the oil may be chemically removed by the use of benzine. To remove it entirely, the feathers must be left in the cleansing fluid from a half hour to an hour, when they may be subjected to the process of bleaching.

Bleaching Plumes.

—Plumes may be almost entirely bleached by the use of hydrogen peroxide, without injuring their texture.

In specially constructed glass troughs, made the length of an average ostrich feather, 15 or 20 of these feathers can be treated at a time. The bleaching fluid is made from a 30 per cent solution of hydrogen peroxide, with enough ammonia added to make it neutral; in other words when neutral, blue litmus paper will not turn red, and red will take a pale violet tinge. The previously cleansed feathers are entirely immersed in this bleaching bath, which may be diluted if desired. The trough is covered with a glass plate and put in a dark place. From time to time the feathers are stirred and turned, adding more hydrogen peroxide. This process requires 10 to 12 hours and if necessary should be repeated. After bleaching they are rinsed in distilled water or rain water, dried in the air, and kept in motion while drying.

To insure success in coloring feathers in delicate tints, they must be free from all impurities, and evenly white. It has been found of advantage to rub the quill of heavy ostrich plumes while still moist with carbonate of ammonia before the dyeing is begun.

Methods Of Dyeing Feathers.

—I.—A boiling hot neutral solution, the feathers to be dried in a rotating apparatus. Suitable dyes for this method are chrysoidin, {336} A, C; crystal vesuvin, 4 B C; phosphin extra, leather yellow, O H; leather red, O, G B; leather brown, O; morocco red, O; azophocphine, G O, B R O; fuchsine, cerise, G R; grenadine, O; safranine, O; methylene violet, malachite green, crystal brilliant green, methylene green, methylene gray, coal black II.

II.—A boiling hot sulphuric solution. Dyes, acid fuchsine, orseilline, R B; acid cerise, O; acid maroon, O; opal blue, blue de lyon, R B; cotton blue, No. 2, China blue No. 2, naphthalene green, O; patent blue, V A; fast blue, O R; fast blue black, O; deep black, G; azo yellow, victorine yellow, orange No. 2, fast brown O, ponceau G R R R, fast red O, Bordeaux, G B R.

III.—An acetic solution. Dyes, Bengal pink G B, phloxine G O, rosolan O B O F, rhodamine O 4 G, eosine A G, erythrosine.

By appropriate mixtures of the dyes of any one class, plumes can be dyed every possible color. After dyeing they are rinsed, and dried in a rotating apparatus. The final process is that of curling, which is done by turning them round and round over a gentle heat. For white feathers a little sulphur may be burned in the fire; for black or colored ones a little sugar.

IV.—The spray method. The solution of the dye to be used is put into an atomizer, and the spray directed to that part of the feather which it is desired to color. By using different colors the most marvelous effects and most delicate transitions from one color to another are obtained. Any kind of an atomizer can be used, the rubber bulb, pump, or bellows; the result is the same.

FELT WATERPROOFING: See Waterproofing.

FERMENTATION PROCESS, FATTY ACID: See Fats.

FERMENTATION, PREVENTION OF: See Anti-Ferments and Wines and Liquors.

FERROUS OXALATE DEVELOPER: See Photography.

Fertilizers

(See also Phosphate, Artificial.)

Plant Fertilizers.

—Plants are as sensitive to excessively minute quantities of nutrient substances, such as salts of potassium, in the soil, as they are to minute quantities of poisonous substances. Poisons are said to be infinitely more sensitive reagents for the presence of certain metallic salts than the most delicate chemical, the statement having been made that a trace of copper which might be obtained by distilling in a copper retort is fatal to the white and yellow lupin, the castor-oil plant, and spirogyra. Coupin has found salts of silver, mercury, copper, and cadmium especially fatal to plants. With copper sulphate the limit of sensitiveness is placed at 1 in 700,000,000. Devaux asserts that both phanerogams and cryptogams are poisoned by solutions of salts of lead or copper diluted to the extent of 1 in 10,000,000, or less.

As a result of a series of experiments, Schloesing stated that the nitrification of ammonium salts is not for all plants a necessary preliminary to the absorption of nitrogen by the plant. While for some plants, as for example buckwheat, the preferable form of the food material is that of a nitrate, others, for instance, tropeolum, thrive even better when the nitrogen is presented to them in an ammoniacal form.

Artificial Fertilizers For Pot Plants.

—Experiments on vegetation have shown that a plant will thrive when the lacking substances are supplied in a suitable form, e. g., in the following combinations:

I.—Calcium nitrate, potassium nitrate, potassium phosphate, magnesium phosphate, ferric phosphate (sodium chloride).

II.—Calcium nitrate, ammonium nitrate, potassium sulphate, magnesium phosphate, iron chloride (or sulphate) (sodium silicate).

It is well known that in nature nitrates are formed wherever decomposition of organic nitrogenous substances takes place in the air, the ammonia formed by the decomposition being oxidized to nitric acid. These conditions for the formation of nitrates are present in nearly every cornfield, and they are also the cause of the presence of nitrates in water that has its source near stables, etc. In Peruvian guano nitrogen is present partly in the form of potassium nitrate, partly as ammonium phosphate and sulphate. As a nitrate it acts more rapidly than in the form of ammonia, but in the latter case the effect is more lasting. Phosphoric acid occurs in guano combined with ammonia, potash, and chiefly with lime, the last being slower and more lasting in action than the others. {337}

Nearly all artificial fertilizers conform, more or less, to one of the following general formulas:

I.—Artificial Flower Fertilizer.—

1 2 3

Ammonium nitrate 0.40 1.60 40.0 parts

Ammonium phosphate 0.20 0.80 20.0 parts

Potassium nitrate 0.25 1.00 25.0 parts

Ammonium chloride 0.05 0.20 5.0 parts

Calcium sulphate 0.06 0.24 6.0 parts

Ferrous sulphate 0.04 0.16 4.0 parts

1.00 4.00 100.0 parts

Dissolve 1 part in 1,000 parts water, and water the flowers with it 2 or 3 times weekly. Dissolve 4 parts in 1,000 parts water, and water with this quantity 10 or 12 pots of medium size.

II.—Compost for Indoor Plants.—

1 2 3

Ammonium sulphate 0.30 1.20 30.0 parts

Sodium chloride 0.30 1.20 30.0 parts

Potassium nitrate 0.15 0.60 15.0 parts

Magnesium sulphate 0.15 0.60 15.0 parts

Magnesium phosphate 0.04 0.20 4.0 parts

Sodium phosphate 0.06 0.24 6.0 parts

1.00 4.00 100.0 parts

One part to be dissolved in 1,000 parts water and the flowers watered up to 3 times daily. Dissolve 4 parts in 1,000 parts water, and water with this solution daily:

III.—Plant Food Solution.—

1 2

Potassium chloride 0.16 or 12.5 parts

Calcium nitrate 0.71 or 58.0 parts

Magnesium sulphate 0.125 or 12.0 parts

Potassium phosphate 0.133 or 15.0 parts

Iron phosphate, recently precipitated 0.032 or 2.5 parts

1.160 or 100.0 parts

This turbid mixture (1 part in 1,000 parts) is used alternately with water for watering a pot of about 1 quart capacity; for smaller or larger pots in proportion. After using the amount indicated, the watering is continued with water alone.

IV.—Fertilizer with Organic Matter, for Pot Flowers.—

Potassium nitrate 100.0 parts

Ammonium phosphate 100.0 parts

Phosphoric acid 2.5 parts

Simple syrup 1,000 parts

Add not more than 10 parts to 1,000 parts water, and water alternately with this and with water alone. For cactaceæ, crassulaceæ, and similar plants, which do not assimilate organic matter directly, use distilled water instead of syrup.

Chlorotic plants are painted with a dilute iron solution or iron is added to the soil, which causes them to assume their natural green color. The iron is used in form of ferric chloride or ferrous sulphate.

V.— Sodium phosphate 4 ounces

Sodium nitrate 4 ounces

Ammonium sulphate 2 ounces

Sugar 1 ounce

Use 2 teaspoonfuls to a gallon of water.

VI.— Ammonium phosphate 30 parts

Sodium nitrate 25 parts

Potassium nitrate 25 parts

Ammonium sulphate 20 parts

Water 100,000 parts

One application of this a week is enough for the slower growing plants, and 2 for the more rapid growing herbaceous ones.

VII.— Calcium phosphate 4 ounces

Potassium nitrate 1 ounce

Potassium phosphate 1 ounce

Magnesium sulphate 1 ounce

Iron (ferric) phosphate 100 grains

VIII.—Pot plants, especially flowering plants kept around the house, should be treated to an occasional dose of the following:

Ammonium chloride 2 parts

Sodium phosphate 4 parts

Sodium nitrate 3 parts

Water 80 parts

Mix and dissolve. To use, add 25 drops to the quart of water, and use as in ordinary watering.

IX.— Sugar 1 part

Potassium nitrate 2 parts

Ammonium sulphate 4 parts

X.— Ferric phosphate 1 part

Magnesium sulphate 2 parts

Potassium phosphate 2 parts

Potassium nitrate 2 parts

Calcium acid phosphate 8 parts

About a teaspoonful of either of these mixtures is added to a gallon of water, and the plants sprinkled with the liquid.

For hastening the growth of flowers, the following fertilizer is recommended: {338}

XI.— Potassium nitrate 30 parts

Potassium phosphate 25 parts

Ammonium sulphate 10 parts

Ammonium nitrate 35 parts

The following five are especially recommended for indoor use:

XII.— Sodium chloride 10 parts

Potassium nitrate 5 parts

Magnesium sulphate 5 parts

Magnesia 1 part

Sodium phosphate 2 parts

Mixed and bottled. Dissolve a teaspoonful daily in a quart of water and water the plants with the solution.

XIII.— Ammonium nitrate 40 parts

Potassium nitrate 90 parts

Ammonium phosphate 50 parts

Two grams is sufficient for a medium-sized flower pot.

XIV.— Ammonium sulphate 10 parts

Sodium chloride 10 parts

Potassium nitrate 5 parts

Magnesium sulphate 5 parts

Magnesium carbonate 1 part

Sodium phosphate 20 parts

One teaspoonful to 1 quart of water.

XV.— Ammonium nitrate 40 parts

Ammonium phosphate 20 parts

Potassium nitrate 0.25 parts

Ammonium chloride 5 parts

Calcium sulphate 6 parts

Ferrous sulphate 4 parts

Dissolve 2 parts in 1,000 of water, and water the plants with the solution.

XVI.— Potassium nitrate 20 parts

Potassium phosphate 25 parts

Ammonium sulphate 10 parts

Ammonium nitrate 35 parts

This mixture produces a luxuriant foliage. If blooms are desired, dispense with the ammonium nitrate.

XVII.—Saltpeter, 5 parts; cooking salt, 10 parts; bitter salt, 5 parts; magnesia, 1 part; sodium phosphate, 2 parts. Mix and fill in bottles. Dissolve a teaspoonful in 1 / 4 pints of hot water, and water the flower pots with it each day.

XVIII.—Ammonium sulphate, 30 parts; sodium chloride, 30 parts; potash niter, 15 parts; magnesium sulphate, 15 parts; magnesium phosphate, 4 parts; sodium phosphate, 6 parts. Dissolve 1 part in 1,000 parts water, and apply 3 times per day.

XIX.—Calcium nitrate, 71 parts; potassium chlorate, 15 parts; magnesium sulphate, 12.5 parts; potassium phosphate, 13.3 parts; freshly precipitated ferric phosphate, 3.2 parts. A solution of 1 in 1,000 of this mixture is applied, alternating with water, to the plants. After using a certain quantity, pour on only water.

XX.—Ammonium phosphate, 300 parts; sodium nitrate, 250 parts; potassium nitrate, 250 parts; and ammonium sulphate, 200 parts, are mixed together. To every 1,000 parts of water dissolve 2 parts of the mixture, and water the potted plants once a week with this solution.

XXI.—Potash niter, 20 parts; calcium carbonate, 20 parts; sodium chlorate, 20 parts; calcium phosphate, 20 parts; sodium silicate, 14 parts; ferrous sulphate, 1.5 parts. Dissolve 1 part of the mixture in 1,000 parts water.

Preparing Bone For Fertilizer.

—Bone, in its various forms, is the only one of the insoluble phosphates that is now used directly upon the soil, or without other change than is accomplished by mechanical action or grinding. The terms used to indicate the character of the bone have reference rather to their mechanical form than to the relative availability of the phosphoric acid contained in them. The terms raw bone, fine bone, boiled and steamed bone, etc., are used to indicate methods of preparation, and inasmuch as bone is a material which is useful largely in proportion to its rate of decay, its fineness has an important bearing upon availability, since the finer the bone the more surface is exposed to the action of those forces which cause decay or solution, and the quicker will the constituents become available. In the process of boiling or steaming, not only is the bone made finer but its physical character in other respects is also changed, the particles, whether fine or coarse, being made soft and crumbly rather than dense or hard; hence it is more likely to act quickly than if the same degree of fineness be obtained by simple grinding. The phosphoric acid in fine steamed bone may all become available in 1 or 2 years, while the coarser fatty raw bone sometimes resists final decay for 3 or 4 years or even longer. {339} Bone contains considerable nitrogen, a fact which should be remembered in its use, particularly if used in comparison with other phosphatic materials which do not contain this element. Pure raw bone contains on an average 22 per cent of phosphoric acid and 4 per cent of nitrogen. By steaming or boiling, a portion of the organic substance containing nitrogen is extracted, which has the effect of proportionately increasing the phosphoric acid in the product; hence a steamed bone may contain as high as 28 per cent of phosphoric acid and as low as 1 per cent of nitrogen. Steamed bone is usually, therefore, much richer in phosphoric acid and has less nitrogen than the raw bone.

Brewers’ Yeast And Fertilizers.

—A mixture is made of about 2 parts of yeast with 1 part of sodium chloride and 5 parts of calcium sulphate, by weight, for use as a manure. Pure or impure yeast, or yeast previously treated for the extraction of a portion of its constituents, may be used, and the gypsum may be replaced by other earthy substances of a similar non-corrosive nature.

Authorities seem to agree that lime is necessary to the plant, and if it be wholly lacking in the soil, even though an abundance of all the other essential elements is present, it cannot develop normally. Many soils are well provided with lime by nature and it is seldom or never necessary for those who cultivate them to resort to liming. It would be just as irrational to apply lime where it is not needed as to omit it where it is required, and hence arises the necessity of ascertaining the needs of particular soils in this respect.

The method usually resorted to for ascertaining the amount of lime in soils is to treat them with some strong mineral acid, such as hydrochloric acid, and determine the amount of lime which is thus dissolved. The fact that beets of all kinds make a ready response to liming on soils which are deficient in lime may be utilized as the basis of testing.

FEVER IN CATTLE: See Veterinary Formulas.

FIG SQUARES: See Confectionery.

Files

Composition Files.

—These files, which are frequently used by watchmakers and other metal workers for grinding and polishing, and the color of which resembles silver, are composed of 8 parts copper, 2 parts tin, 1 part zinc, 1 part lead. They are cast in forms and treated upon the grindstone; the metal is very hard, and therefore worked with difficulty with the file.

To Keep Files Clean

(see also Cleaning Preparations and Methods).—The uneven working of a file is usually due to the fact that filings clog the teeth of the file. To obviate this evil, scratch brush the files before use, and then grease them with olive oil. A file prepared in this manner lasts for a longer time, does not become so quickly filled with filings and can be conveniently cleaned with an ordinary rough brush.

Recutting Old Files.

—Old files may be rendered useful again by the following process: Boil them in a potash bath, brush them with a hard brush and wipe off. Plunge for half a minute into nitric acid, and pass over a cloth stretched tightly on a flat piece of wood. The effect will be that the acid remains in the grooves, and will take away the steel without attacking the top, which has been wiped dry. The operation may be repeated according to the depth to be obtained. Before using the files thus treated they should be rinsed in water and dried.

FILE METAL: See Alloys.

FILLERS FOR LETTERS: See Lettering.

FILLERS FOR WOOD: See Wood.

Filters for Water.

A filter which possesses the advantages of being easily and cheaply cleaned when dirty, and which frees water from mechanical impurities with rapidity, may be formed by placing a stratum of sponge between two perforated metallic plates, united by a central screw, and arranged in such a manner as to permit of the sponge being compressed as required. Water, under gentle pressure, flows with such rapidity through the pores of compressed sponge, that it is said that a few square feet of this substance will perfectly filter several millions of gallons of water daily.

The sponges are cleaned thoroughly, rolled together as much as possible, and placed in the escape pipe of a percolator in such a manner that the larger portion of the sponge is in the pipe while the smaller portion, spreading by itself, protrudes over the pipe toward the interior {340} of the percolator, thus forming a flat filter covering it. After a thorough moistening of the sponge it is said to admit of a very quick and clear filtration of large quantities of tinctures, juices, etc.

For filtering water on a small scale, and for domestic use, “alcarrazas,” diaphragms of porous earthenware and filtering-stone and layers of sand and charcoal, etc., are commonly employed as filtering.

A cheap, useful form of portable filter is the following, given in the proceedings of the British Association: “Take any common vessel, perforated below, such as a flower pot, fill the lower portion with coarse pebbles, over which place a layer of finer ones, and on these a layer of clean coarse sand. On the top of this a piece of burnt clay perforated with small holes should be put, and on this again a stratum of 3 or 4 inches thick of well-burnt, pounded animal charcoal. A filter thus formed will last a considerable time, and will be found particularly useful in removing noxious and putrescent substances held in solution by water.”

The “portable filters,” in stoneware, that are commonly sold in the shops, contain a stratum of sand, or coarsely powdered charcoal; before, however, having access to this, the water has to pass through a sponge, to remove the coarser portion of the impurities.

Alum Process Of Water Purification.

—Water may be filtered and purified by precipitation, by means of alum, by adding a 4 per cent solution to the water to be clarified until a precipitate is no longer produced. After allowing the turbid mixture to stand for 8 hours, the clear portion may be decanted or be siphoned off. About 2 grains of alum is ordinarily required to purify a gallon of water. Potassa alum only should be used, as ammonia alum cannot be used for this purpose. The amount of alum required varies with the water, so that an initial experiment is required whenever water from a new source is being purified. If the purification is properly done, the water will not contain any alum, but only a trace of potassium sulphate, for the aluminum of the double sulphate unites with the various impurities to form an insoluble compound which gradually settles out, mechanically carrying with it suspended matter, while the sulphuric acid radical unites with the calcium in the water to form insoluble calcium sulphate.

FILTER PAPER: See Paper.

FILM-STRIPPING: See Photography.

FINGER-TIPS, SPARKS FROM: See Pyrotechnics.

FIRES, COLORED: See Pyrotechnics.

FIREARM LUBRICANTS: See Lubricants.

Fire Extinguishers:

I.— Calcium chloride 184 parts

Magnesium chloride 57 parts

Sodium chloride 13 parts

Potassium bromide 22 parts

Barium chloride 3 parts

Water to make 1,000 parts

Dissolve and fill into hand grenades.

II.— Iron sulphate 4 parts

Ammonium sulphate 16 parts

Water 100 parts

Mix, dissolve, and fill into flasks.

III.— Sodium chloride 430 parts

Alum 195 parts

Glauber salts 50 parts

Sodium carbonate, impure 35 parts

Water glass 266 parts

Water 233 parts

Mix, etc.

IV.— Sodium chloride 90 parts

Ammonium chloride 45 parts

Water 300 parts

Mix, dissolve, and put into quart flasks of very thin glass, which are to be kept conveniently disposed in the dwelling rooms, etc., of all public institutions.

V.—Make 6 solutions as follows:

a.— Ammonium chloride 20 parts

Water 2,000 parts

b.— Alum, calcined and powdered 35 parts

Water 1,000 parts

c.— Ammonium sulphate, powdered 30 parts

Water 500 parts

d.— Sodium chloride 20 parts

Water 4,000 parts

e.— Sodium carbonate 35 parts

Water 500 parts

f.— Liquid water glass 450 parts

{341}

Mix the solutions in the order named and to the mixture, while still yellow and turbid, add 2,000 parts of water, and let stand. When the precipitate has subsided fill off the clear liquid into thin glass (preferably blue, to deter decomposition) containers each of 3 pints to a half gallon capacity.

VI.— Calcium chloride 30 parts

Magnesium chloride 10 parts

Water 60 parts

VII.— Sodium chloride 20 parts

Ammonium chloride 9 parts

Water 71 parts

VIII.— Sodium carbonate 16 parts

Sodium chloride 64 parts

Water 920 parts

The most effective of all extinguishers is ammonia water. It is almost instantaneous in its effect, and a small quantity only is required to extinguish any fire. Next in value is carbonic acid gas. This may be thrown from siphons or soda-water tanks. The vessel containing it should be thrown into the fire in such a way as to insure its breaking.

Dry Powder Fire Extinguishers.

—The efficacy of these is doubted by good authorities. They should be tested before adoption.

I.— Alum 24 parts

Ammonium sulphate 52 parts

Ferrous sulphate 4 parts

II.— Sodium chloride 8 parts

Sodium bicarbonate 6 parts

Sodium sulphate 2 parts

Calcium chloride 2 parts

Sodium silicate 2 parts

III.— Sodium chloride 6 parts

Ammonium chloride 6 parts

Sodium bicarbonate 8 parts

IV.— Ammonium chloride 10 parts

Sodium sulphate 6 parts

Sodium bicarbonate 4 parts

Oil Extinguisher.

—To extinguish oils which have taken fire, a fine-meshed wire net of the size of a boiling pan should be kept on hand in every varnish factory, etc. In the same moment when the netting is laid upon the burning surface, the flame is extinguished because it is a glowing mass of gas, which the iron wire quickly cools off so that it cannot glow any more. The use of water is excluded, and that of earth and sand undesirable, because both dirty the oil.

Substitute For Fire Grenades.

—A common quart bottle filled with a saturated solution of common salt makes a cheap and efficient substitute for the ordinary hand grenade. The salt forms a coating on all that the water touches and makes it nearly incombustible.

Fireproofing

For Textiles.

—I.—Up to the present this has generally been accomplished by the use of a combination of water glass or soluble glass and tungstate of soda. The following is cheaper and more suitable for the purpose:

Equal parts, by weight, of commercial white copperas, Epsom salt, and sal ammoniac are mingled together and mixed with three times their weight of ammonia alum. This mixture soon changes into a moist pulp or paste, that must be dried by a low heat. When dressing the material, add / 2 part of this combination to every 1 part of starch.

II.—Good results are also obtained from the following formula: Supersaturate a quantity of superphosphate of lime with ammonia, filter, and decolorize it with animal charcoal. Concentrate the solution and mix with it 5 per cent of gelatinous silica, evaporate the water, dry, and pulverize. For use mix 30 parts of this powder with 35 parts of gum and 35 parts of starch in sufficient water to make of suitable consistency.

III.—As a sample of the Melunay process, introduced in France, the following has been published: Apply to a cotton fabric like flannellet, or other cotton goods, a solution of stannate of soda (or a salt chemically equivalent) of the strength of 5 to 10° Bé., then dry the fabric and saturate it again, this time with a solution of a titanium salt; any soluble titanium salt is suitable. This salt should be so concentrated that each 1,000 parts may contain about 62 parts of titanium oxide. The fabrics are again dried, and the titanium is ultimately fixed by means of a suitable alkaline bath. It is advantageous to employ for this purpose a solution of silicate of soda of about 14° Bé., but a mixed bath, composed of tungstate of soda and ammonium chloride, may be employed. The objects are afterwards washed, dried, and finished as necessary for trade. A variation consists in treating the objects in a mixed bath containing titanium, tungsten, and a suitable solvent.

IV.—Boil together, with constant {342} stirring, the following ingredients until a homogeneous mass results:

Linseed oil 77 parts

Litharge 10 parts

Sugar of lead 2 parts

Lampblack 4 parts

Oil turpentine 2 parts

Umber 0.4 parts

Japanese wax 0.3 parts

Soap powder 1.2 parts

Manila copal 0.7 parts

Caoutchouc varnish 2 parts

V.—For Light Woven Fabrics.—Ammonium sulphate, 8 parts, by weight; ammonium carbonate, 2.5 parts; borax, 2; boracic acid, 3; starch, 2; or dextrin, 0.4, or gelatin, 0.4; water, 100. The fabric is to be saturated with the mixture, previously heated to 86° F., and dried; it can then be calendered in the ordinary way. The cost is only 2 or 3 cents for 16 yards or more of material.

VI.—For Rope and Straw Matting.—Ammonium chloride (sal ammoniac), 15 parts, by weight; boracic acid, 6 parts; borax, 3; water, 100. The articles are to be left in the solution, heated to 212° F. for about 3 hours, then squeezed out and dried. The mixture costs about 5 cents a quart.

VII.—For Clothing.—The following starch is recommended: Sodium tungstate, perfectly neutral, 30 parts; borax, 20; wheat or rice starch, 60. The constituents are to be finely pulverized, sharply dried, and mixed, and the starch used like any other. Articles stiffened with it, if set on fire, will not burst into flame, but only smolder.

VIII.—For Tents.—

Water 100 parts by weight

Ammonium sulphate, chemically pure 14 parts by weight

Boracic acid 1 parts by weight

Hartshorn salt 1 parts by weight

Borax 3 parts by weight

Glue water 2 parts by weight

Boil the water, put ammonium sulphate into a vat, pour a part of the boiling water on and then add the remaining materials in rotation. Next follow the rest of the hot water. The vat should be kept covered until the solution is complete.

IX.—For Stage Decorations.—Much recommended and used as a fireproofing composition is a cheap mixture of borax, bitter salt, and water; likewise for canvas a mixture of ammonium sulphate, gypsum, and water. Ammonium sulphate and sodium tungstate are also named for impregnating the canvas before painting.

X.—For Mosquito Netting.—Immerse in a 20 per cent solution of ammonium sulphate. One pound of netting will require from 20 to 24 ounces of the solution to thoroughly saturate. After withdrawing from the bath, do not wring it out, but spread it over a pole or some such object, and let it get about half dry, then iron it out with a hot iron. The material (ammonium sulphate) is inoffensive.

Fireproofing Of Wood.

—Strictly speaking, it is impossible to render wood completely incombustible, but an almost absolute immunity against the attacks of fire can be imparted.

Gay-Lussac was one of the first to lay down the principal conditions indispensable for rendering organic matters in general, and wood in particular, uninflammable.

During the whole duration of the action of the heat the fibers must be kept from contact with the air, which would cause combustion. The presence of borates, silicates, etc., imparts this property to organic bodies.

Combustible gases, disengaged by the action of the heat, must be mingled in sufficient proportion with other gases difficult of combustion in such a way that the disorganization of bodies by heat will be reduced to a simple calcination without production of flame. Salts volatile or decomposable by heat and not combustible, like certain ammoniacal salts, afford excellent results.

Numerous processes have been recommended for combating the inflammability of organic tissues, some consisting in external applications, others in injection, under a certain pressure, of saline solutions.

By simple superficial applications only illusory protection is attained, for these coverings, instead of fireproofing the objects on which they are applied, preserve them only for the moment from a slight flame. Resistance to the fire being of only short duration, these coatings scale off or are rapidly reduced to ashes and the parts covered are again exposed. It often happens, too, that such coatings have disappeared before the occurrence of a fire, so that the so-called remedy becomes injurious from the false security occasioned. {343}

Some formulas recommended are as follows:

I.—For immersion or imbibition the following solution is advised: Ammonium phosphate, 100 parts; boracic acid, 10 parts per 1,000; or ammonium sulphate, 135 parts; sodium borate, 15 parts; boracic acid, 5 parts per 1,000. For each of these formulas two coats are necessary.

II.—For application with the brush the following compositions are the best:

a. Apply hot, sodium silicate, 100 parts; Spanish white, 50 parts; glue, 100 parts.

b. Apply successively and hot; for first application, water, 100 parts; aluminum sulphate, 20 parts; second application, water, 100 parts; liquid sodium silicate, 50 parts.

c. First application, 2 coats, hot; water, 100 parts; sodium silicate, 50 parts; second application, 2 coatings; boiling water, 75 parts; gelatin, white, 200 parts; work up with asbestos, 50 parts; borax, 30 parts; and boracic acid, 10 parts.

Oil paints rendered uninflammable by the addition of phosphate of ammonia and borax in the form of impalpable powders incorporated in the mass, mortar of plaster and asbestos and asbestos paint, are still employed for preserving temporarily from limited exposure to a fire.

III.— Sodium silicate, solid 350 parts

Asbestos, powdered 350 parts

Water, boiling 1,000 parts

Mix. Give several coatings, letting each dry before applying the next.

IV.— Asbestos, powdered 35 parts

Sodium borate 20 parts

Water 100 parts

Gum lac 10 to 15 parts

Dissolve the borax in the water by the aid of heat, and in the hot solution dissolve the lac. When solution is complete incorporate the asbestos. These last solutions give a superficial protection, the efficiency of which depends upon the number of coatings given.

V.—Prepare a syrupy solution of sodium silicate, 1 part, and water, 3 parts, and coat the wood 2 to 3 times, thus imparting to it great hardness. After drying, it is given a coating of lime of the consistency of milk, and when this is almost dry, is fixed by a strong solution of soluble glass, 2 parts of the syrupy mass to 3 parts of water. If the lime is applied thick, repeat the treatment with the soluble glass.

VI.—Subject the wood or wooden objects for 6 to 8 hours to the boiling heat of a solution of 33 parts of manganese chloride, 20 parts of orthophosphoric acid, 12 parts of magnesium carbonate, 10 parts of boracic acid, and 25 parts of ammonium chloride in 1,000 parts of water. The wood thus treated is said to be perfectly incombustible even at great heat, and, besides, to be also protected by this method against decay, injury by insects, and putrefaction.

VII.—One of the simplest methods is to saturate the timber with a solution of tungstate of soda; if this is done in a vacuum chamber, by means of which the wood is partly deprived of the air contained in its cells, a very satisfactory result will be obtained. Payne’s process consists in treating wood under these conditions first with solution of sulphate of iron, and then with chloride of calcium; calcium sulphate is thus precipitated in the tissues of the timber, which is rendered incombustible and much more durable. There are several other methods besides these, phosphate of ammonia and tungstate being most useful. A coat of common whitewash is an excellent means of lessening the combustibility of soft wood.

Fireproofing Wood Pulp.

—The pulp is introduced into a boiler containing a hot solution of sulphate and phosphate of ammonia and provided with a stirring and mixing apparatus, as well as with an arrangement for regulating the temperature. After treatment, the pulp is taken out and compressed in order to free it from its humidity. When dry, it may be used for the manufacture of paper or for analogous purposes. Sawdust treated in the same manner may be used for packing goods, for deadening walls, and as a jacketing for steam pipes.

Fireproofing For Wood, Straw, Textiles, Etc.

—The material to be made fireproof is treated with a solution of 10 to 20 parts of potassium carbonate and 4 to 8 parts of ammonium borate in 100 parts of water. Wherever excessive heat occurs, this compound, which covers the substance, is formed into a glassy mass, thus protecting the stuff from burning; at the same time a considerable amount of carbonic acid is given off, which smothers the flames. {344}

Miscellaneous Formulas For Fireproofing.

I.—In coating steel or other furnaces, first brush over the brickwork to be covered a solution made by boiling 1 pound each of silicate of soda and alum in 4 gallons of water, and follow immediately with composition:

Silica 50 parts

Plastic fire clay 10 parts

Ball clay 3 parts

Mix well.

Fireproof Compositions.—II.—For furnaces, etc.:

Pure silica (in grain) 60 parts

Ground flint 8 parts

Plaster of Paris 3 parts

Ball clay 3 parts

Mix well together by passing once or more through a fine sieve, and use in the same way as cement.

Fireproof Paper.—Paper is rendered fireproof by saturating it with a solution of

Ammonium sulphate 8 parts

Boracic acid 3 parts

Borax 2 parts

Water 100 parts

For the same purpose sodium tungstate may also be employed.

Fireproof Coating.—A fireproof coating (so-called) consists of water, 100 parts; strong glue, 20 parts; silicate of soda, 38° Bé., 50 parts; carbonate of soda, 35 parts; cork in pieces of the size of a pea, 100 parts.

Colored Fireproofing.—I.—Ammonium sulphate, 70 parts; borax, 50 parts; glue, 1 part; and water up to 1,000 parts.

II.—Solution of glue, 5 parts, zinc chloride, 2 parts; sal ammoniac, 80 parts; borax, 57 parts; and water up to 700 parts.

If the coating is to be made visible by coloration, an addition of 10 parts of Cassel brown and 6 parts of soda per 1,000 parts is recommended, which may be dissolved separately in a portion of the water used.

FIREPROOFING CELLULOID: See Celluloid.

FIREPROOFING OF PAPER: See Paper.

FIREWORKS: See Pyrotechnics.

FILIGREE GILDING: See Plating.

Fish Bait.

Oil of rhodium 3 parts

Oil of cumin 2 parts

Tincture of musk 1 part

Mix. Put a drop or two on the bait, or rub trigger of trap with the solution.

Fixatives for Crayon Drawings, Etc.

I.— Shellac 40 parts by weight

Sandarac 20 parts by weight

Spirit of wine 940 parts by weight

II.—During the Civil War, when both alcohol and shellac often were not purchasable, and where, in the field especially, ink was almost unknown, and sized paper, of any description, a rarity, men in the field were compelled to use the pencil for correspondence of all sorts. Where the communication was of a nature to make its permanency desirable, the paper was simply dipped in skim milk, which effected the purpose admirably. Such documents written with a pencil on unsized paper have stood the wear and rubbing of upward of 40 years.

To Fix Pounced Designs.—Take beer or milk or alcohol, in which a little bleached shellac has been dissolved, and blow one of these liquids upon the freshly pounced design by means of an atomizer. After drying, the drawing will have the desired fixedness.

FIXING BATHS FOR PAPER AND NEGATIVES: See Photography.

FLANNELS, WHITENING OF: See Laundry Preparations.

FLASH-LIGHT APPARATUS AND POWDERS: See Photography.

FLAVORINGS: See Condiments.

FLEA DESTROYERS: See Insecticides.

FLIES IN THE HOUSE: See Household Formulas.

FLIES AND PAINT: See Paint.

Floor Dressings

(See also Paint, Polishes, Waxes, and Wood.)

Oil Stains For Hard Floors.

—I.—Burnt sienna, slate brown, or wine black, is ground with strong oil varnish in the paint mill. The glazing color obtained {345} is thinned with a mixture of oil of turpentine and applied with a brush on the respective object. The superfluous stain is at once wiped away with a rag, so that only the absorbed stain remains in the wood. If this is uneven, go over the light places again with dark stain. In a similar manner all otherwise tinted and colored oil stains are produced by merely grinding the respective color with the corresponding addition of oil. Thus, green, red, and even blue and violet shades on wood can be obtained, it being necessary only to make a previous experiment with the stains on a piece of suitable wood. In the case of soft wood, however, it is advisable to stain the whole previously with ordinary nut stain (not too dark), and only after drying to coat with oil stain, because the autumn rings of the wood take no color, and would appear too light, and, therefore, disturb the effect.

II.—Boil 25 parts, by weight, of fustic and 12 parts of Brazil wood with 2,400 parts of soapmakers’ lye and 12 parts of potash, until the liquid measures about 12 quarts. Dissolve in it, while warm, 30 parts of annatto and 75 of wax, and stir until cold. There will be a sufficient quantity of the brownish-red stain to keep the floor of a large room in good order for a year. The floor should be swept with a brush broom daily, and wiped up twice a week with a damp cloth, applying the stain, when necessary, to places where there is much wear, and rubbing it in with a hard brush. Every 6 weeks put the stain all over the floor, and brush it in well.

III.— Neatsfoot oil 1 part

Cottonseed oil 1 part

Petroleum oil 1 part

IV.— Beeswax 8 parts

Water 56 parts

Potassium carbonate 4 parts

Dissolve the potash in 12 parts of water; heat together the wax and the remaining water till the wax is liquefied; then mix the two and boil together until a perfect emulsion is effected. Color, if desired, with a solution of annatto.

V.— Paraffine oil 8 parts

Kerosene 1 part

Limewater 1 part

Mix thoroughly. A coat of the mixture is applied to the floor with a mop.

Paraffining Of Floors.

—The cracks and joints of the parquet floor are filled with a putty consisting of Spanish white, 540 parts; glue, 180 parts; sienna, 150 parts; umber, 110 parts; and calcareous earth, 20 parts. After 48 hours apply the paraffine, which is previously dissolved in petroleum, or preferably employed in a boiling condition, in which case it will enter slightly into the floor. When solidification sets in, the superfluous paraffine is scratched off and an even, smooth surface of glossy color results, which withstands acids and alkalies.

Ball-room Floor Powder.—

Hard paraffine 1 pound

Powdered boric acid 7 pounds

Oil lavender 1 drachm

Oil neroli 20 minims

Melt the paraffine and add the boric acid and the perfumes. Mix well, and sift through a / 16 mesh sieve.

Renovating Old Parquet Floors.

—Caustic soda lye, prepared by boiling for 45 minutes with 1 part calcined soda, and 1 part slaked lime with 15 parts water, in a cast-iron pot, is applied to the parquet to be renovated by means of a cloth attached to a stick. After a while rub off the floor with a stiff brush, fine sand, and a sufficient quantity of water, to remove the dirt and old wax. Spread a mixture of concentrated sulphuric acid and water in the proportion of 1 to 8 on the floor. The sulphuric acid will remove the particles of dirt and wax which have entered the floor and enliven the color of the wood. Finally, wax the parquet after it has been washed off with water and dried completely.

FLOOR OIL: See Oils.

FLOOR PAPER: See Paper.

FLOOR POLISH: See Polishes.

FLOOR VARNISHES: See Varnishes.

FLOOR WATERPROOFING: See Waterproofing.

FLOOR WAX: See Waxes.

FLORICIN OIL: See Oil.

Flower Preservatives.

I.—To preserve flowers they should be dipped in melted paraffine, which should be just hot enough to maintain its fluidity. The flowers should be dipped one at a time, held by the stalks and moved about for an instant to get rid of air bubbles. Fresh cut flowers, free from moisture, {346} are said to make excellent specimens when treated in this way. A solution in which cut flowers may be kept immersed is made as follows:

Salicylic acid 20 grains

Formaldehyde 10 minims

Alcohol 2 fluidounces

Distilled water 1 quart

II.—The English method of preserving flowers so as to retain their form and color is to imbed the plants in a mixture of equal quantities of plaster of Paris and lime, and gradually heat them to a temperature of 100° F. After this the flower looks dusty, but if it is laid aside for an hour so as to absorb sufficient moisture to destroy its brittleness, it can be dusted without injury. To remove the hoary appearance which is often left, even after dusting, a varnish composed of 5 ounces of dammar and 16 ounces of oil of turpentine should be used and a second coat given if necessary. When the gum has been dissolved in the turpentine, 16 ounces of benzoline should be added, and the whole should be strained through fine muslin.

III.—Five hundred parts ether, 20 parts transparent copal, and 20 parts sand. The flowers should be immersed in the varnish for 2 minutes, then allowed to dry for 10 minutes, and this treatment should be repeated 5 or 6 times.

IV.—Place the flowers in a solution of 30 grains of salicylic acid in 1 quart of water.

V.—Moisten 1,000 parts of fine white sand that has been previously well washed and thoroughly dried and sifted, with a solution consisting of 3 parts of stearine, 3 parts of paraffine, 3 parts of salicylic acid, and 100 parts of alcohol. Work the sand up thoroughly so that every grain of it is impregnated with the mixture, and then spread it out and let it become perfectly dry. To use, place the flowers in a suitable box, the bottom of which has been covered with a portion of the prepared sand, and then dust the latter over them until all the interstices have been completely filled with it. Close the box lightly and put it in a place where it can be maintained at a temperature of from 86° to 104° F. for 2 or 3 days. At the expiration of this time remove the box and let the sand escape. The flowers can then be put into suitable receptacles or glass cases without fear of deterioration. Wilted or withered flowers should be freshened up by dipping into a suitable aniline solution, which will restore their color.

VI.—Stand the flowers upright in a box of proper size and pour over and around them fine dry sand, until the flowers are completely surrounded in every direction. Leave them in this way for 8 or 10 days, then carefully pour off the sand. The flowers retain their color and shape perfectly, but in very fleshy, juicy specimens the sand must be renewed. To be effective the sand must be as nearly dry as possible.

VII.—A method of preserving cut flowers in a condition of freshness is to dissolve small amounts of ammonium chloride, potassium nitrate, sodium carbonate or camphor in the water into which the stems are inserted. The presence of one or more of these drugs keeps the flowers from losing their turgidity by stimulating the cells to action and by opposing germ growth. Flowers that have already wilted are said to revive quickly if the stems are inserted in a weak camphor water.

Stuccoed Gypsum Flowers.

—Take natural flowers, and coat the lower sides of their petals and stamens with paraffine or with a mixture of glue, gypsum, and lime, which is applied lightly. Very fine parts of the flowers, such as stamens, etc., may be previously supported by special attachments of textures, wire, etc. After the drying of the coating the whole is covered with shellac solution or with a mixture of glue, gypsum, lime with lead acetate, oil, mucilage, glycerine, colophony, etc. If desired, the surface may be painted with bronzes in various shades. Such flowers are much employed in the shape of festoons for decorating walls, etc.

Artificial Coloring Of Flowers.

—A method employed by florists to impart a green color to the white petals of “carnation pinks” consists in allowing long-stemmed flowers to stand in water containing a green aniline dye. When the flowers are fresh they absorb the fluid readily, and the dye is carried to the petals.

Where the original color of the flower is white, colored stripes can be produced upon the petals by putting the cut ends into water impregnated with a suitable aniline dye. Some dyes can thus be taken up by the capillary action of the stem and deposited in the tissue of the petal. If flowers are placed over a basin of water containing a very small amount of ammonia in a bell glass, the colors of the petals will generally show some marked change. Many violet-colored flowers when so treated will become {347} green, and if the petals contain several tints they will show greens where reds were, yellows where they were white, and deep carmine will become black. When such flowers are put into water they will retain their changed colors for hours.

If violet asters are moistened with very dilute nitric acid, the ray florets become red and acquire an agreeable odor.

FLUID MEASURES: See Weights and Measures.

Fluorescent Liquids.

Æsculin gives pale blue by (1) reflected light, straw color by (2) transmitted light.

Amido-phthalic acid, pale violet (1), pale yellow (2). Amido-terephthalic acid, bright green (1), pale green (2).

Eosine, yellow green (1), orange (2).

Fluorescein, intense green (1), orange yellow (2).

Fraxin, blue green (1), pale green (2).

Magdala red, opaque scarlet (1), brilliant carmine (2).

Quinine, pale blue (1), no color (2).

Safranine, yellow red (1), crimson (2).

FLUXES USED IN ENAMELING: See Enameling.

FLUXES FOR SOLDERING: See Soldering.

Fly-Papers and Fly-Poisons

(See also Insecticides.)

Sticky Fly-papers.

—The sticky material applied to the paper is the following:

I.— Boiled linseed oil 5 to 7 parts

Gum thus 2 to 3 parts

Non-drying oil 3 to 7 parts

For the non-drying oil, cottonseed, castor, or neatsfoot will answer—in fact, any of the cheaper oils that do not readily dry or harden will answer. The proper amount of each ingredient depends upon the condition of the boiled oil. If it is boiled down very stiff, more of the other ingredients will be necessary, while if thin, less will be required.

II.— Rosin 8 parts

Rapeseed oil 4 parts

Honey 1 part

Melt the rosin and oil together, and incorporate the honey. Two parts of raw linseed oil and 2 parts of honey may be used along with 8 parts of rosin instead of the foregoing. Use paper already sized, as it comes from the mills, on which to spread the mixture.

III.— Castor oil 12 ounces

Rosin 27 ounces

Melt together and spread on paper sized with glue, using 12 ounces glue to 4 pints water.

IV.— Rosin 8 ounces

Venice turpentine 2 ounces

Castor oil 2 ounces

Spread on paper sized with glue.

Poisonous Fly-papers.—

I.— Quassia chips 150 parts

Chloride of cobalt 10 parts

Tartar emetic 2 parts

Tincture of long pepper (1 to 4) 80 parts

Water 400 parts

Boil the quassia in the water until the liquid is reduced one-half, strain, add the other ingredients, saturate common absorbent paper with the solution, and dry. The paper is used in the ordinary way.

II.— Potassium bichromate 10 ounces

Sugar 3 drachms

Oil of black pepper 2 drachms

Alcohol 2 ounces

Water 14 ounces

Mix and let stand for several days, then soak unsized paper with the solution.

III.— Cobalt chloride 4 drachms

Hot water 16 ounces

Brown sugar 1 ounce

Dissolve the cobalt in the water and add the sugar, saturate unsized paper in the solution, and hang up to dry.

IV.— Quassia chips 150 parts

Cobalt chloride 10 parts

Tartrate antimony 2 parts

Tincture of pepper 80 parts

Water 400 parts

Boil chips in the water until the volume of the latter is reduced one-half, add other ingredients and saturate paper and dry.

Fly-poison.—

Pepper 4 ounces

Quassia 4 ounces

Sugar 8 ounces

Diluted alcohol 4 ounces

Mix dry and sprinkle around where the flies can get it.

Non-poisonous Fly-papers.

—I.—Mix 25 parts of quassia decoction (1:10) with 6 parts of brown sugar and 3 parts of ground pepper, and place on flat dishes.

II.—Mix 1 part of ground pepper and 1 part of brown sugar with 16 parts milk {348} or cream, and put the mixture on flat plates.

III.—Macerate 20 parts of quassia wood with 100 parts of water for 24 hours, boil one-half hour, and squeeze off 24 hours. The liquid is mixed with 3 parts of molasses, and evaporated to 10 parts. Next add 1 part of alcohol. Soak blotting paper with this mixture, and put on plates.

IV.—Dissolve 5 parts of potassium bichromate, 15 parts of sugar, and 1 part of essential pepper oil in 60 parts of water, and add 10 parts of alcohol. Saturate unsized paper with this solution and dry well.

V.—Boil together for half an hour

Ground quassia wood 18 pounds

Broken colocynth 3 pounds

Ground long pepper 5 pounds

Water 80 pounds

Then percolate and make up to 60 pounds if necessary with more water. Then add 4 pounds of syrup. Unsized paper is soaked in this, and dried as quickly as possible to prevent it from getting sour.

VI.—Mix together

Ordinary syrup 100 ounces

Honey 30 ounces

Extract of quassia wood 4 ounces

Oil of aniseed, a few drops.

Removing The Gum Of Sticky Fly-paper.

—The “gum” of sticky fly-paper that has “leaked” over furniture and shelfware can be removed without causing injury to either furniture or bottles.

The “gum” of sticky fly-paper, while being quite adhesive, is easily dissolved with alcohol (grain or wood) or oil of turpentine. Alcohol will not injure the shelfware, but it should not be used on varnished furniture; in the latter case turpentine should be used.

FLY PROTECTIVES FOR ANIMALS: See Insecticides.

Foam Preparations.

A harmless gum cream is the following:

I.—Digest 100 parts of Panama wood for 8 days with 400 parts of water and 100 parts of spirits of wine (90 per cent). Pour off without strong pressure and filter.

For every 5 parts of lemonade syrup take 5 parts of this extract, whereby a magnificent, always uniform foam is obtained on the lemonade.

II.—Heat 200 parts of quillaia bark with distilled water during an hour in a vapor bath, with frequent stirring, and squeeze out. Thin with water if necessary and filter.

Food Adulterants, Simple Tests for Their Detection.

Abstract of a monograph by W. D. Bigelow and Burton J. Howard, published by the Department of Agriculture.

Generally speaking, the methods of chemical analysis employed in food laboratories can be manipulated only by one who has had at least the usual college course in chemistry, and some special training in the examination of foods is almost as necessary. Again, most of the apparatus and chemicals necessary are entirely beyond the reach of the home, and the time consumed by the ordinary examination of a food is in itself prohibitive.

Yet there are some simple tests which serve to point out certain forms of adulteration and can be employed by the careful housewife with the reagents in her medicine closet and the apparatus in her kitchen. The number may be greatly extended by the purchase of a very few articles that may be procured for a few cents at any drug store. In applying these tests, one general rule must always be kept carefully in mind. Every one, whether layman or chemist, must familiarize himself with a reaction before drawing any conclusions from it. For instance, before testing a sample of supposed coffee for starch, the method should be applied to a sample of pure coffee (which can always be procured unground) and to a mixture of pure coffee and starch prepared by the operator.

Many manufacturers and dealers in foods have the ordinary senses so highly developed that by their aid alone they can form an intelligent opinion of the nature of a product, or of the character, and sometimes even of the proportion of adulterants present. This is especially true of such articles as coffee, wine, salad oils, flavoring extracts, butter, and milk. The housewife finds herself constantly submitting her purchases to this test. Her broad experience develops her senses of taste and smell to a high degree, and her discrimination is often sharper and more accurate than she herself realizes. The manufacturer who has developed his natural senses most {349} highly appreciates best the assistance or collaboration of the chemist, who can often come to his relief when his own powers do not avail. So the housewife, by a few simple chemical tests, can broaden her field of vision and detect many impurities that are not evident to the senses.

There are here given methods adapted to this purpose, which may be applied to milk, butter, coffee, spices, olive oil, vinegar, jams and jellies, and flavoring extracts. In addition to this some general methods for the detection of coloring matter and preservatives will be given. All of the tests here described may be performed with utensils found in any well-appointed kitchen. It will be convenient, however, to secure a small glass funnel, about 3 inches in diameter, since filtration is directed in a number of the methods prescribed. Filter paper can best be prepared for the funnel by cutting a circular piece about the proper size and folding it once through the middle, and then again at right angles to the first fold. The paper may then be opened without unfolding in such a way that three thicknesses lie together on one side and only one thickness on the other. In this way the paper may be made to fit nicely into the funnel.

Some additional apparatus, such as test tubes, racks for supporting them, and glass rods, will be found more convenient for one who desires to do considerable work on this subject, but can be dispensed with. The most convenient size for test tubes is a diameter of from / 2 to / 8 inch, and a length of from 5 to 6 inches. A graduated cylinder will also be found very convenient. If this is graduated according to the metric system, a cylinder containing about 100 cubic centimeters will be found to be convenient; if the English liquid measure is used it may be graduated to from 3 to 8 ounces.

Chemical Reagents.

—The word “reagent” is applied to “any substance used to effect chemical change in another substance for the purpose of identifying its component parts or determining its percentage composition.” The following reagents are required in the methods here given:

• Turmeric paper.
• Iron alum (crystal or powdered form).
• Hydrochloric acid† (muriatic acid), concentrated.
• Iodine tincture.
• Potassium permanganate, 1 per cent solution.
• Alcohol (grain alcohol).
• Chloroform.
• Boric acid or borax.
• Ammonia water.
• Halphen’s reagent.

† Caution.—All tests in which hydrochloric acid is used should be conducted in glass or earthenware, for this acid attacks and will injure metal vessels. Care must also be taken not to bring it into contact with the flesh or clothes. If, by accident, a drop of it falls upon the clothes, ammonia, or in its absence a solution of saleratus or sal soda (washing soda), in water, should be applied promptly.

With the exception of the last reagent mentioned, these substances may be obtained in any pharmacy. The Halphen reagent should be prepared by a druggist, certainly not by an inexperienced person.

It is prepared as follows: An approximately 1 per cent solution of sulphur is made by dissolving about / 3 of a teaspoonful of precipitated sulphur in 3 or 4 ounces of carbon bisulphide. This solution mixed with an equal volume of amyl alcohol forms the reagent required by the method. A smaller quantity than that indicated by these directions may, of course, be prepared.

If turmeric paper be not available it may be made as follows: Place a bit of turmeric powder (obtainable at any drug store) in alcohol, allow it to stand for a few minutes, stir, allow it to stand again until it settles, dip a strip of filter paper into the solution, and dry it.

Determination Of Preservatives.

—The following methods cover all of the more important commercial preservatives with the exception of sulphites and fluorides. These are quite frequently used for preserving foods—the former with meat products and the latter with fruit products—but, unfortunately, the methods for their detection are not suitable for household use.

Detection Of Salicylic Acid.

—The determination of salicylic acid can best be made with liquids. Solid and semi-solid foods, such as jelly, should be dissolved, when soluble, in sufficient water to make them thinly liquid. Foods containing insoluble matter, such as jam, marmalade, and sausage, may be macerated with water and strained through a piece of white cotton cloth. The maceration may be performed by rubbing in a teacup or other convenient vessel with a heavy spoon.

Salicylic acid is used for preserving {350} fruit products of all kinds, including beverages. It is frequently sold by drug stores as fruit acid. Preserving powders consisting entirely of salicylic acid are often carried from house to house by agents. It may be detected as follows:

Between 2 and 3 ounces of the liquid obtained from the fruit products, as described above, are placed in a narrow bottle holding 5 ounces, about a quarter of a teaspoonful of cream of tartar (or, better, a few drops of sulphuric acid) is added, the mixture shaken for 2 or 3 minutes, and filtered into a second small bottle. Three or 4 ta­ble­spoon­fuls of chloroform are added to the clear liquid in the second bottle and the liquids mixed by a somewhat vigorous rotary motion, poured into an ordinary glass tumbler, and allowed to stand till the chloroform settles out in the bottom. Shaking is avoided, as it causes an emulsion which is difficult to break up. As much as possible of the chloroform layer (which now contains the salicylic acid) is removed (without any admixture of the aqueous liquid) by means of a medicine dropper and placed in a test tube or small bottle with about an equal amount of water and a small fragment—a little larger than a pinhead—of iron alum. The mixture is thoroughly shaken and allowed to stand till the chloroform again settles to the bottom. The presence of salicylic acid is then indicated by the purple color of the upper layer of liquid.

Detection Of Benzoic Acid.

—Benzoic acid is also used for preserving fruit products. Extract the sample with chloroform as in the case of salicylic acid; remove the chloroform layer and place it in a white saucer, or, better, in a plain glass sauce dish. Set a basin of water—as warm as the hand can bear—on the outside window ledge and place the dish containing the chloroform extract in it, closing the window until the chloroform has completely evaporated. In this manner the operation may be conducted with safety even by one who is not accustomed to handling chloroform. In warm weather the vessel of warm water may, of course, be omitted. Benzoic acid, if present in considerable amount, will now appear in the dish in characteristic flat crystals. On warming the dish the unmistakable irritating odor of benzoic acid may be obtained. This method will detect benzoic acid in tomato catsup or other articles in which it is used in large quantities. It is not sufficiently delicate, however, for the smaller amount used with some articles, such as wine. It is often convenient to extract a larger quantity of the sample and divide the chloroform layer into two portions, testing one for salicylic acid and the other for benzoic acid.

Detection Of Boric Acid And Borax.

—Boric acid (also called boracic acid) and its compound with sodium (borax) are often used to preserve animal products, such as sausage, butter, and sometimes milk. For the detection of boric acid and borax, solids should be macerated with a small amount of water and strained through a white cotton cloth. The liquid obtained by treating solids in this manner is clarified somewhat by thoroughly chilling and filtering through filter paper.

In testing butter place a heaping teaspoonful of the sample in a teacup, add a couple of teaspoonfuls of hot water, and stand the cup in a vessel containing a little hot water until the butter is thoroughly melted. Mix the contents of the cup well by stirring with a teaspoon and set the cup with the spoon in it in a cold place until the butter is solid. The spoon with the butter (which adheres to it) is now removed from the cup and the turbid liquid remaining strained through a white cotton cloth, or, better, through filter paper. The liquid will not all pass through the cloth or filter paper, but a sufficient amount for the test may be secured readily.

In testing milk for boric acid 2 or 3 ta­ble­spoon­fuls of milk are placed in a bottle with twice that amount of a solution of a teaspoonful of alum in a pint of water, shaken vigorously, and filtered through filter paper. Here again a clear or only slightly turbid liquid passes through the paper.

About a teaspoonful of the liquid obtained by any one of the methods mentioned above is placed in any dish, not metal, and 5 drops of hydrochloric (muriatic) acid added. A strip of turmeric paper is dipped into the liquid and then held in a warm place—near a stove or lamp—till dry. If boric acid or borax was present in the sample the turmeric paper becomes bright cherry red when dry. A drop of household ammonia changes the red color to dark green or greenish black. If too much hydrochloric acid is used the turmeric paper may take on a brownish-red color even in the absence of boric acid. In this case, however, ammonia changes the color to brown just as it does turmeric paper which has not been dipped into the acid solution. {351}

Detection Of Formaldehyde.

—Formaldehyde is rarely used with other foods than milk. The method for its detection in milk is given later. For its detection in other foods it is usually necessary first to separate it by distillation, a process which is scarcely available for the average person without laboratory training and special apparatus. For this reason no method is suggested here for the detection of formaldehyde in other foods than milk.

Detection Of Saccharine.

—Saccharine has a certain preservative power, but it is used not so much for this effect as because of the very sweet taste which it imparts. It is extracted by means of chloroform, as described under the detection of salicylic acid. In the case of solid and semi-solid foods, the sample must, of course, be prepared by extraction with water, as described under salicylic acid. The residue left after the evaporation of the chloroform, if a considerable amount of saccharine is present, has a distinctly sweet taste.

The only other substance having a sweet taste which may be present in foods, i. e., sugar, is not soluble in chloroform, and therefore does not interfere with this reaction. Certain other bodies (tannins) which have an astringent taste are present, and as they are soluble in chloroform may sometimes mask the test for saccharine, but with practice this difficulty is obviated.

Determination Of Artificial Colors: Detection Of Coal-tar Dyes.

—Coloring matters used with foods are usually soluble in water. If the food under examination be a liquid, it may therefore be treated directly by the method given below. If it be a solid or a pasty substance, soluble in water either in the cold or after heating, it may be dissolved in sufficient water to form a thin liquid. If it contains some insoluble material, it may be treated with sufficient water to dissolve the soluble portion with the formation of a thin liquid and filtered, and then strained through a clean white cotton cloth to separate the insoluble portion. About a half teacupful of the liquid thus described is heated to boiling, after adding a few drops of hydrochloric acid and a small piece of white woolen cloth or a few strands of white woolen yarn. (Before using, the wool should be boiled with water containing a little soda, to remove any fat it may contain, and then washed with water.) The wool is again washed, first with hot and then with cold water, the water pressed out as completely as possible, and the color of the fabric noted. If no marked color is produced, the test may be discontinued and the product considered free from artificial colors. If the fabric is colored, it may have taken up coal-tar colors, some foreign vegetable colors, and if a fruit product is being examined, some of the natural coloring matter of the fruit. Rinse the fabric in hot water, and then boil for 2 or 3 minutes in about one-third of a teacupful of water and 2 or 3 teaspoonfuls of household ammonia. Remove and free from as much of the liquid as possible by squeezing or wringing. Usually the fabric will retain the greater part of the natural fruit color, while the coal-tar color dissolves in dilute ammonia. The liquid is then stirred with a splinter of wood and hydrochloric acid added, a drop or two at a time, until there is no longer any odor of ammonia. (The atmosphere of the vessel is sometimes charged with the ammonia for several minutes after it has all been driven out of the liquid; therefore one should blow into the dish to remove this air before deciding whether the ammonia odor has been removed or not.) When enough acid has been added the liquid has a sour taste, as may be determined by touching the splinter, used in stirring, to the tongue.

A fresh piece of white woolen cloth is boiled in this liquid and thoroughly washed. If this piece of cloth has a distinct color the food under examination is artificially colored. The color used may have been a coal-tar derivative, commonly called an aniline dye, or an artificial color chemically prepared from some vegetable color. If of the first class the dyed fabric is usually turned purple or blue by ammonia. In either case, if the second fabric has a distinct color, it is evident that the product under examination is artificially colored. Of course a dull, faint tint must be disregarded.

Detection Of Copper.

—The presence of copper, often used to deepen the green tint of imported canned peas, beans, spinach, etc., may be detected as follows:

Mash some of the sample in a dish with a stiff kitchen spoon. Place a teaspoonful of the pulp in a teacup with 3 teaspoonfuls of water and add 30 drops of strong hydrochloric acid with a medicine dropper. Set the cup on the stove in a saucepan containing boiling water. Drop a bright iron brad or nail (wire nails are the best and tin carpet tacks {352} will not answer the purpose) into the cup and keep the water in the saucepan boiling for 20 minutes, stirring the contents of the cup frequently with a splinter of wood. Pour out the contents of the cup and examine the nail. If present in an appreciable amount the nail will be heavily plated with copper.

Caution.—Be careful not to allow the hydrochloric acid to come in contact with metals or with the flesh or clothing.

Detection Of Turmeric.