A Cyclopædia of Practical Receipts, &c. Volume II (part 1)

Ink, Lithograph′ic. Prep. 1. Mastic (in tears), 8 oz.; shell-lac, 12 oz.; Venice turpentine, 1 oz.; melt together, add, of wax, 1 lb.; tallow, 6 oz.; when dissolved, further add of hard tallow soap (in shavings), 6 oz.; and when the whole is perfectly combined add of lampblack, 4 oz.; lastly, mix well, cool a little, and then pour it into moulds, or upon a slab, and when cold cut it into square pieces.

2. (Lasteyrie.) Dry tallow soap, mastic (in tears), and common soda (in fine powder), of each 30 parts; shell-lac, 150 parts; lampblack, 12 parts; mix as last. Both the above are used for writing on lithographic stones.

3. (Autographic.)—a. Take of white wax, 8 oz., and white soap, 2 to 3 oz.; melt, and when well combined, add of lampblack, 1 oz.; mix well, heat it strongly, and then add of shell-lac, 2 oz.; again heat it strongly, stir well together, cool a little, and pour it out as before. With this ink lines may be drawn of the finest to the fullest class, without danger of its spreading, and the copy may be kept for years before being transferred.

b. From white soap and white wax, of each 10 oz.; mutton suet, 3 oz.; shell-lac and mastic, of each 5 oz.; lampblack, 3⁄2 oz.; mix as above. Both the above are used for writing on lithographic paper. When the last is employed, the transfer must be made within a week.

Obs. The above inks are rubbed down with a little water in a small cup or saucer for use, in the same way as common water-colour cakes or Indian ink. In winter the operation should be performed near the fire, or the saucer should be placed over a basin containing a little tepid water. Either a steel pen or a camel-hair pencil may be employed with the ink. See Lithography.

Ink, Mark′ing. Syn. Indelible ink, Permanent i. Of this there are several varieties, of which the following are the most valuable and commonly used:—

1. Nitrate of silver, ⁄4 oz.; hot distilled water, 7 fl. dr.; dissolve, add of mucilage, ⁄4 oz.; previously rubbed with sap green or syrup of buckthorn, q. s. to colour. The linen must be first moistened with ‘liquid pounce,’ or ‘the preparation,’ as it is commonly called, and when it has again become dry, written on with a clean quill pen. The ink will bear dilution if the writing is not required very black.

The POUNCE or PREPARATION. A solution of carbonate of soda, 1⁄2 oz.; in water, 1 pint, slightly coloured with a little sap green or syrup of buckthorn, to enable the spots wetted with it to be afterwards known.

2. (Without preparation.) Take of nitrate of silver, ⁄4 oz.; water, ⁄4 oz.; dissolve, add as much of the strongest liquor of ammonia as will dissolve the precipitate formed on its first addition, then further add of mucilage, 1⁄2 dr., and a little sap green, syrup of buckthorn, or finely powdered indigo, to colour. Writing executed with this ink turns black on being passed over a hot Italian iron, or held near the fire.

3. Terchloride of gold, 1⁄2 dr.; water, 7 fl. dr.; mucilage, 2 dr.; sap green, q. s. to colour. To be written with on a ground prepared with a weak solution of protochloride of tin, and dried. Dark purple.

4. (Rev. J. B. Reade.) Nitrate of silver, 1 oz., tartaric acid (pure), 3 dr., are triturated together in a mortar in the dry state; a little water is then added, by which crystals of tartrate of silver are formed, and the nitric acid set free; the latter is then saturated with liquor of ammonia, sufficient being added to dissolve all the newly-formed tartrate of silver, avoiding unnecessary excess; lastly, a little gum and colouring matter is added.

5. (Rev. J. B. Reade.) To the last is added an ammoniacal solution of a salt of gold. Mr Reade has used for this purpose the ‘purple of Cassius,’ the hyposulphate, the ammonio-iodide, the ammonio-periodide of gold, but any other compound of gold which is soluble in ammonia will do as well. This ink is unacted on by nearly all those reagents which remove writing executed with solutions of the salts of silver alone, as cyanide of potassium, the chlorides of lime and soda, &c.

6. (Redwood.) Nitrate of silver and pure bitartrate of potassa, of each 1 oz. (or 4 parts), are rubbed together in a glass or Wedgwood-ware mortar, and after a short time liquor of ammonia, 4 oz. (16 parts, or q. s.), is added; when the solution is complete, archil, 4 dr. (or 2 parts); white sugar, 6 dr. (or 3 parts); and powdered gum, 10 dr. (or 5 parts), are dissolved in the liquor, after which sufficient water is added to make the whole measure exactly 6 fl. oz., when it is ready to be bottled for use. The last three are used in the same manner as No. 2.

7. (Dr Smellie.) From sulphate of iron, 1 dr.; vermilion, 4 dr.; boiled linseed oil, 1 oz.; triturated together until perfectly smooth. Used with type.

8. (Soubeiran.) Nitrate of copper, 3 parts; carbonate of soda, 4 parts; nitrate of silver, 8 parts; mix, and dissolve in liquor of ammonia, 100 parts. Used like No. 2.

9. (Ure.) A strong solution of chloride of platinum, with a little potassa, and sugar and gum, to thicken.

10. The fluid contained between the kernel and shell of the cashew nut. On linen and cotton it turns gradually black, and is very durable. This has been called ANACARDIUM or CASHEW-NUT INK.

11. Sulphate of manganese, 2 parts; lampblack, 1 part; sugar, 4 parts; all in fine powder, and triturated to a paste with a little water. Used with types or stencil-plates; the part, when dry, being well rinsed in water. Brown.

12. Black oxide of manganese and hydrate of potassa are mixed, heated to redness in a crucible, and then triturated with an equal weight of pure white clay, and water, q. s. to give it due consistence. Used like the last. (Brown.)

13. (Aniline Black Marking Ink.) This ink is prepared by means of two solutions, one of copper, the other of aniline, prepared as follows:—

(1.) Copper solution. 8·52 grams of crystallised chloride of copper, 10·65 grams of chlorate of soda, and 5·35 grams of chloride of ammonium are dissolved in 60 grams of water.

(2.) Aniline solution. 20 grams of hydrochlorate of aniline are dissolved in 30 grams of distilled water, and to this are added 20 grams of solution of gum Arabic (1 part of gum to 2 of water) and 10 grams of glycerin.

By mixing in the cold 4 parts of the aniline solution, with 1 part of the copper solution, a greenish liquid is obtained which can be employed directly for the marking; but as this liquid can only be preserved for a few days without decomposition, it is advisable to keep the solution separately, until the ink is required for use.

The ink may be used either with a pen, or a stencil plate and brush; if it do not flow freely from the pen it may be diluted with a little water without fear of weakening the intensity of the colour. At first the writing appears of a pale green colour, but after exposure to the air it becomes black, or it may be changed to a black colour immediately, by passing a hot iron over the back of the fabric, or heating it over the flame of a spirit lamp. As, however, a dry heat is apt to make the fibre saturated with the ink, brittle, it is preferable to hold the marked fabric over a vessel, containing water in full ebullition; the heat of the vapour is sufficient to determine almost immediately, the reaction by which aniline black is formed. After the steaming, the writing should be washed in hot soapsuds, which gives the ink a fine blue shade. The ink is not acted upon by acids or alkalies, and if care be taken that the fibres are well saturated with it, there is no danger of its being removed by washing. (‘Dingler’s Journal.’)

14. In addition to the above formulæ, the following of M. Henry may be worthy of attention in large establishments where economy is an object:—Take 1 oz. of iron filings and 3 oz. of vinegar, or diluted acetic acid. Mix the filings with half the vinegar, and agitate them continually till the mixture becomes thick, then add the rest of the vinegar and 1 oz. of water. Apply heat to assist the action, and when the iron is dissolved, add 3 oz. of sulphate of iron, and 1 oz. of gum previously dissolved in 4 oz. of water; and mix the whole with a gentle heat. To be used with brush and stencil plates.

15. (Crimson Marking Ink.) Dissolve 1 oz. of nitrate of silver, and 1⁄2 oz. of carbonate of soda in crystals, separately in distilled water, mix the solutions, collect and wash the precipitate on a filter, introduce the washed precipitate still moist into a Wedgwood mortar, and add to it tartaric acid 2 dr. and 40 gr., rubbing together till effervescence has ceased; dissolve carmine 6 grains, in liquor ammoniæ (·882) 6 oz., and add to it the tartrate of silver, then mix in white sugar, 6 dr., and powdered gum Arabic, 10 dr., and add as much distilled water as will make 6 oz. (‘Pharm. Journal.’)

Obs. The products of the first two of the above formulæ constitute the marking ink of the shops. They have, however, no claim to the title of ‘INDELIBLE INK,’ “which no art can extract without injuring the fabric”—as is generally represented. On the contrary, they may be discharged with almost as much facility as common iron-moulds. This may be easily and cheaply effected by means of ammonia, cyanide of potassium, the chlorides of lime and soda, and some of the hyposulphites, without in the least injuring the texture of the fabric to which they may be applied. The only precaution required is that of rinsing the part in clean water immediately after the operation. The ‘marking ink without preparation’ is more easily extracted than that ‘with preparation.’ The former has also the disadvantage of not keeping so well as the latter, and of depositing a portion of fulminating silver, under some circumstances, which renders its use dangerous. The thinner inks, when intended to be used with type or plates, are thickened by adding a little more gum, or some sugar.

Ink, Mark′ing. Syn. Packer’s ink. Ink bottoms. Used by packers for marking bales, boxes, &c.

Ink, Perpet′ual. Prep. 1. Pitch, 3 lbs.; melt over the fire, and add of lampblack, ⁄4 lb.; mix well.

2. Trinidad asphaltum and oil of turpentine, equal parts. Used in a melted state to fill in the letters on tombstones, marbles, &c. Without actual violence, it will endure as long as the stone itself.

Ink, Print′er’s. See Printing Ink.

Ink, Pur′ple. 1. A strong decoction of logwood, to which a little alum or chloride of tin has been added.

2. (Normandy.) To 12 lbs. of Campeachy wood add as many gallons of boiling water, pour the solution through a funnel with a strainer made of coarse flannel, or 1 lb. of hydrate, or acetate of deutoxide of copper finely powdered (having at the bottom of the funnel a piece of sponge); then add immediately 14 lbs. of alum, and for every 340 galls. of liquid add 80 lbs. of gum Arabic or gum Senegal. Let these remain for three or four days and a beautiful purple colour will be produced.

Ink, Red. Prep. 1. Brazil wood (ground), 4 oz.; white-wine vinegar (hot), 1⁄4 pint; digest in glass or a well-tinned copper or enamel saucepan, until the next day, then gently simmer for half an hour, adding towards the end gum Arabic and alum, of each ⁄2 oz.

2. Ground Brazil wood, 10 oz.; white vinegar, 10 pints; macerate for 4 or 5 days; then boil as before to one half, and add of roach alum, 4⁄2 oz.; gum, 5 oz.; and when dissolved, bottle for use.

3. As the last, but using water or beer instead of vinegar.

4. Cochineal (in powder), 1 oz.; hot water, ⁄2 pint; digest, and when quite cold, add of spirit of hartshorn, ⁄4 pint (or liquor of ammonia, 1 oz., diluted with 3 or 4 oz. of water); macerate for a few days longer, and then decant the clear. Very fine.

5. (Buchner.) Pure carmine, 20 gr.; liquor of ammonia, 3 fl. oz.; dissolve, then add of powdered gum, 18 gr. Half a drachm of powdered drop lake may be substituted for the carmine where expense is an object. Colour superb.

6. (Henzeler.) Brazil wood, 2 oz.; alum and cream of tartar, of each ⁄2 oz.; rain water, 16 fl. oz.; boil to one half, strain, add of gum (dissolved), ⁄2 oz.; and when cold, further add a tincture made by digesting powdered cochineal, 1⁄2 dr., in rectified spirit, 1⁄2 fl. oz.

7. (Redwood.) Garancine and liquor of ammonia, of each 1 oz.; distilled water (cold), 1 pint; triturate together in a mortar, filter, and dissolve in the solution, gum Arabic ⁄2 oz.

Ink, Se′pia. See Sepia.

Ink, Sil′ver. From silver leaf or powdered silver, as GOLD INK.

Ink, Sympathet′ic. Syn. Diplomatic ink, Invisible i. Fluids which, when used for writing, remain invisible until the paper is heated, or acted on by some other chemical agent. Sympathetic inks have been frequently employed as the instruments of secret correspondence, and have often escaped detection; but by heating the paper before the fire until it begins to grow discoloured by the heat, the whole of them may be rendered visible.

The following are the most common and amusing sympathetic inks:—1. Sulphate of copper and sal ammoniac, equal parts, dissolved in water; writes colourless, but turns YELLOW when heated.—2. Onion juice; like the last.—3. A weak infusion of galls; turns BLACK when moistened with weak copperas water:—4. A weak solution of sulphate of iron; turns BLUE when moistened with a weak solution of prussiate of potassa, and BLACK when moistened with infusion of galls.—5. The diluted solutions of nitrate of silver and of terchloride of gold; become respectively DARK BROWN and PURPLE when exposed to the sunlight.—6. Aqua fortis, spirits of salts, oil of vitriol, common salt, or saltpetre, dissolved in a large quantity of water; turns YELLOW or BROWN when heated.—7. Solution of chloride or nitromuriate of cobalt; turns GREEN when heated, and disappears again on cooling. If the salt is pure, the marks turn BLUE.—8. Solution of acetate of cobalt, to which a little nitre has been added; becomes ROSE COLOURED when heated, and disappears on cooling.—9. A weak solution of the mixed chlorides of cobalt and nickel; turns GREEN. The last three are about the best of our sympathetic inks.—10. Solution of acetate of lead; turns BROWNISH-BLACK when exposed to the fumes of sulphuretted hydrogen.—11. A weak solution of nitrate of mercury; turned BLACK by heat and sulphuretted fumes.—12. Rice water or decoction of starch; turned BLUE by a solution of iodine in weak spirit, and by the fumes of iodine, if the paper is first slightly moistened by exposure to steam or damp air.

Ink, Vi′olet. The same as PURPLE INK, but weaker.

Ink, Yel′low. 1. From gamboge (in coarse powder), 1 oz.; hot water, 5 oz.; dissolve, and when cold, add of spirit, ⁄4 oz.

2. Boil French berries, ⁄2 lb., and alum, 1 oz., in rain water, 1 quart, for half an hour, or longer, then strain and dissolve in the hot liquor gum Arabic, 1 oz.

Ink, Zinc Labels, to write on. Syn. Horticultural ink. 1. Dissolve 100 gr. of tetrachloride of platinum in a pint of water. A little mucilage and lamp black may be added.

2. Sal ammoniac 1 dr.; verdigris, 1 dr.; lampblack, ⁄2 dr.; water, 10 dr.; mix.

INK POW′DERS. Prep. 1. Aleppo galls, 4 oz.; sulphate of iron, 1⁄2 oz.; gum Arabic, 1 oz.; lump sugar, ⁄4 oz.; (all quite dry and in powder); mix, and divide into 3 packets. A pint of boiling water poured over one of them produces, in a few hours, a pint of excellent ink.

2. Aleppo galls, 3 lbs.; copperas, 1 lb.; gum Arabic, ⁄2 lb.; white sugar, ⁄4 lb.; all in powder; mix, and divide into two-ounce packets, to be used as the last. Ink powders are very useful in travelling.

INK STAINS, to remove. See Spots.

INOCULA′TION. Syn. Inoculatio, L. In medicine and surgery, the application of poisonous or infectious matter to any part of the body for the purpose of propagating a milder form of disease, and thus preventing or lessening the virulence of future attacks. In this country the term is generally restricted to the artificial propagation of smallpox. See Vaccination.

INOSIN′IC ACID. An acid said by Liebig to exist in the juice of the flesh of animals, after it has deposited its kreatine.

IN′OSITE. A species of unfermentable sugar, discovered by Scherer in the juice of flesh. It forms beautiful crystals.

IN′SECTS. Syn. Insecta, L. A class of invertebrate animals belonging to the subkingdom Annuloso. The true insect is defined as an articulated animal, having six legs, 2 antennæ, 2 compound eyes; a small brain at the anterior extremity of a double medullary cord; its circulation is effected by a pulsating dorsal vessel, provided with numerous valves; its respiration by tracheæ, which form 2 lateral trunks, and ramify through the body. The generation of insects is oviparous. There are two distinct sexes. The adult state is attained through a series of metamorphoses. In general, every insect possesses 2 pairs of wings; the trunk in the adult animal is usually composed of 3 chief parts—the head, thorax, and abdomen. The trunk of an insect may also be described as consisting of 13 segments, of which 1 constitutes the head, 3 constitute the thorax, and 9 the abdomen. Insects are arranged in the following orders:—1. Hymenoptera, including bees, wasps, ichneumon-flies, &c.—2. Coleoptera, including all those kinds commonly called beetles.—3. Neuroptera, dragon-flies, ephemeræ, white ants, &c.—4. Strepsiptera, the stylops, &c.—5. Lepidoptera, the butterflies and moths.—6. Diptera, the house-fly and other 2-winged insects.—7. Orthoptera, crickets, grasshoppers, locusts, earwigs, &c.—8. Hemiptera, bugs, frog-hoppers, aphides, &c.—9. Aptera, fleas, &c. There are several animals belonging to the classes MYRIOPODA and ARACHNIDA which are commonly but erroneously called ‘insects.’ Of these the centipedes, spiders, and acarides, or mites, are well-known examples. Several useful products, as SILK, WAX, HONEY, COCHINEAL, LAC, CANTHARIDES, &c., are supplied by insects. The class includes numerous creatures which are extremely destructive, and others which are regarded as domestic pests. In the articles devoted to these offensive insects various methods of exterminating them are noticed. A powder for destroying insects has recently been introduced into this country, and has been found peculiarly efficacious. This powder, which is known under various names (INSECTS-DESTROYING POWDER, DUMONT’S INSECTICIDE, &c.), is produced by the Pyrethrum roseum Caucasicum, a composite flower growing wild in the Caucasus. The central or tubular florets of the disc are alone employed, and when ground, furnish the powder of commerce. This powder, though so destructive to insect life, has no injurious effect upon man or domestic animals. See Acari, Ant, Bee, Bug, Bites and Stings, Cantharides, Cochineal, Lac, Pediculi, Silk, &c.

INSECT′ICIDE POWDER. See Insects.

INTEM′PERANCE. Under this head we refer to habitual indulgence in the use of spirituous or fermented liquors, whether accompanied or not by fits of intoxication or drunkenness.

The pernicious influence of intoxicating liquors upon individuals and upon society has been so often and ably exposed by the clergy, judges, and magistrates, and by philanthropists of every kind, that it would be folly to do more than refer to it here. Fully one half of the dark or disreputable deeds of those who fill our gaols, and fully an equal proportion of the poverty and wretchedness which pauperises our population and crowds our workhouses, are traceable to this damning vice of the Anglo-Saxon race—intemperance.

To cure HABITUAL DRUNKENNESS various means have been proposed, most of which are more ingenious than useful. The following, however, deserves respectful notice:—

Dr Kain, an eminent American physician, recommends tartar emetic, given in alterative and slightly nauseating doses, for the cure of habitual drunkenness. “Possessing,” he observes, “no positive taste itself, it communicates a disgusting quality to those fluids in which it is dissolved. These liquors, with the addition of a very small quantity of emetic tartar, instead of relieving, increase the sensation of loathing of food, and quickly produce in the patient an indomitable repugnance to the vehicle of its administration. My method of prescribing it has varied according to the habits, age, and constitution of the patient. A convenient preparation of the medicine is 8 gr., dissolved in 4 oz. of boiling water; ⁄2 an oz. (say a table-spoonful) of the solution to be put into half a pint, pint, or quart of the patient’s favorite liquor, and to be taken daily in divided portions. If vomiting and purging ensue” (which is seldom the case), “I should direct laudanum to allay the irritation, and diminish the dose. In some cases the change suddenly produced in the patient’s habits has brought on considerable lassitude and debility, which, however, were of short duration. In a majority of cases no other effect has been perceptible than slight nausea, some diarrhœa, and a gradual but very uniform distaste to the menstruum.”

Dr W. Marcet has described the more or less disordered state of the brain, nerves, muscles, and stomach, brought on by the continual use of alcohol, even without intoxication being produced. The symptoms of this state, which he terms CHRONIC ALCOHOLISM, are quite distinct from those of DELIRIUM TREMENS, which is an acute and violent disturbance of the nervous system. From experiments on a large number of patients, Dr Marcet has arrived at the important conclusion, that oxide of zinc is the true antidote in cases of slow alcoholic poisoning. It seems to act as a strong tonic on the nerves, being at the same time a powerful sedative and antispasmodic.

The symptoms of actual intoxication, or the disordered condition of the intellectual functions and volition, produced by taking excessive quantities of alcoholic liquors, need not be described.

Among the remedies employed to remove the ‘fit of drunkenness,’ the preparations of ammonia, and the vegetable acids, are the most common and important. About 2 or 3 fl. dr. of aromatic spirits of ammonia (spirits of sal volatile), or a like quantity of solution of acetate of ammonia (mindererus spirit), mixed with a wine-glassful of water, will in general neutralise or greatly lessen the action of intoxicating liquors. In some cases these fluids produced vomiting, which is, however, a good symptom, as nothing tends to restore an inebriated person so soon as the removal of the liquor from the stomach. Hence tickling the fauces with the finger or a feather, until sickness comes on, is a method very commonly adopted by drunkards to restore themselves to a sober state. The use of aromatic water of ammonia was first suggested by Mr Bromly. With a like intention, some persons have recourse to soda water, which acts by the free carbonic acid it contains, and also as a diluent and, from its coldness, as a tonic on the coats of the stomach. The carbonates and bicarbonates of soda and potassa are also favourite remedies with habitual drunkards. Among the vegetable acids, acetic acid is the one that appears to possess the greatest power of removing intoxication; and after this follow the citric, tartaric, malic, and carbonic acids. These substances are commonly taken by soldiers before going to parade. The usual dose of vinegar is a small teacupful. In the West Indies lime juice and lemon juice are had recourse to. Both these juices act from the citric acid they contain. The use of bitter almonds, as a means of lessening or retarding the effects of fermented liquors was known to antiquity, and is still common among heavy drinkers at the present day. Even small doses of medicinal prussic acid have been foolishly taken with a like intention. See Abstinence, Alcohol, effects of, Delirium tremens, &c.

INTERMIT′TENT FEVER. Syn. Ague. A disease consisting of paroxysms or periods of fever with perfect intermissions or periods without fever. Marsh miasmata, or the effluvia arising from stagnant water or marshy ground, when acted upon by heat, are the most frequent causes of this malady. For the prevention of ague in situations where it prevails endemically, small doses of quinine should be taken two or three times a day, and flannel clothing should be constantly worn.

Symp. Each febrile paroxysm is of three periods or stages—the cold, the hot, and the sweating stage, and these occur in regular succession. The cold stage commences with great languor and aversion to motion; a sense of coldness down the back soon follows; then the extremities become cold, the fingers shrunken, and the nails blue; the skin assumes that peculiar condition which is commonly known as ‘goose-skin,’ the patient shivers, his teeth chatter, and he is glad to draw close to the fire or envelop himself in blankets. After this state of things has continued for a greater or less time, the heat of the surface begins to return, the patient has flushings and becomes warmer and warmer, and ultimately the whole surface is of a dry burning heat; intense thirst, restlessness, severe headache, and sometimes delirium, characterise this second or hot stage. After this stage has continued for some time, another change comes over the patient; moisture appears on the face and forehead, the harsh and hot skin becomes soft, and at last a copious sweat breaks out over the whole surface. This is the third or sweating stage, and after it has passed, the several functions of the system return to their ordinary condition. The paroxysm may return daily (QUOTIDIAN AGUE); or every other day (TERTIAN A.); or every fourth day, including that of the first attack (QUARTAN A.).

Treatm. During the cold stage everything should be done to bring on the hot; the patient should be placed in a warm bed, with warm pans or bottles of water; he may be allowed the free use of warm diluent drinks. In the hot stage the opposite course should be adopted; the coverings must be diminished and lemonade and other cooling drink administered. In the sweating stage there is no occasion for any treatment beyond care to avoid checking the perspiration by premature exposure. During the intermission the disease must be fought with the tonics, Peruvian bark, or its chief alkaloid, quinine. The most effective form of this remedy is the sulphate, which may be given in doses of from 2 to 4 gr. every three hours, the dose being greater for a quartan than for a quotidian. See Ague-cake, Fever, &c.

INTOXICA′TION. See Intemperance.

IN′ULIN. Syn. Inuline, Alantine, Dahline. A peculiar starch-like substance, first obtained by Rose from the root of Inula Helenium or elecampane. It has been found in several other vegetables.

Prep. From the rasped root, by the same method that is adopted for arrow-root or potato farina; or by boiling the sliced root in 7 or 8 times its weight of water, and after filtration, whilst hot, allowing the decoction to repose for a short time.

Prop., &c. Only very slightly soluble in cold water; very soluble in boiling water, but is nearly all deposited as the solution cools; it is precipitated by alcohol.

Inulin is distinguished from starch by giving a yellow or yellowish-brown instead of a blue colour with iodine; in the decoction not being precipitated by either acetate of lead or infusion of galls; and by the precipitate formed in the cold decoction by an infusion of gall-nuts not disappearing until the liquid is heated to above 212°, whilst the precipitate from starch redissolves at 122° Fahr. It appears to be a substance intermediate between starch and gum.

I′ODATE′. Syn. Iodas, L. A salt of iodic acid. The iodates closely resemble the chlorates of the corresponding metals. They are recognised by the development of free iodine when their solutions are treated with reducing agents; thus, sulphuretted hydrogen passed into a solution of iodate of potassium reduces this salt to an iodide, iodine being liberated and sulphuric acid and water formed. They deflagrate like the chlorates when heated with combustibles. They are all of sparing solubility, and many are quite insoluble in water. They may be made by adding iodine to soluble hydrates or carbonates, and crystallising the sparingly soluble iodate from the very soluble iodide. See Iodic acid, Iodine, and Potassium.

IODHY′DRIC ACID. See Hydriodic acid.

IOD′IC ACID. HIO3. Syn. Acidum iodicum, L.

Prep. 1. Iodate of sodium is dissolved in sulphuric acid in considerable excess, the solution boiled for 15 minutes, and then set aside to crystallise.

2. Decompose iodate of barium by dilute sulphuric acid.

3. (Boursen.) Iodine, 1 part; nitric acid (sp. gr. 1·5), 40 parts; mix, keep them at nearly the boiling temperature for several hours, or until the iodine is dissolved, then evaporate to dryness, and leave the residuum in the open air at a temperature of about 59° Fahr.; when, by attracting moisture, it has acquired the consistence of a syrup, put it into a place where the temperature is higher and the air drier, when in a few days very fine white crystals of a rhomboidal shape will form.

Prop., &c. Iodic acid is a crystalline solid, white or yellowish-white; it is decomposed into oxygen and iodine by a heat of about 450° to 500° Fahr.—a property of which we avail ourselves for the conversion of the salts of this acid (iodates) into iodides. It is very soluble in water, and is rapidly decomposed when heated with inflammable bodies. Iodic acid is used as a test for morphia and sulphurous acid. It has been employed as a tonic, stimulant, and alterative, in catarrhal hoarseness, strumous cases, incipient phthisis, &c.—Dose, 3 to 6 gr.

Test. When iodic acid is mixed with an equal quantity of an alkaloid (preferably quinine), on a capsule or watch-glass, and a drop or two of water added, several distinct explosions occur, accompanied by the copious evolution of gas. No other substance exhibits a similar reaction. See Iodate.

I′ODIDE. Syn. Ioduret*, Hydriodate*, Iodidum, Ioduretum, Hydriodas, L. A compound of iodine with a metal or other basic radical. The iodides belong to the same class of bodies as the bromides and chlorides, and may be, for the most part, made in the same manner. All the principal iodides are noticed under the names of their respective bases. See Iodine, &c.

I′ODINE. I. Syn. Iodum, B. P.; Iodinium (Ph. L. & D.), Iodineum (Ph. E.), L.; Iode, Fr.; Iod, Ger. An elementary substance accidentally discovered in 1812, by De Courtois, a saltpetre manufacturer at Paris. It was first examined and described by M. Clement, in 1813, and its precise nature was soon afterwards determined by Sir H. Davy and M. Gay-Lussac. In 1819, some six years after its discovery, iodine was first employed in pharmacy. The merit of the introduction of this powerful curative agent into medicine is due to Dr Coindet, a physician of Geneva, who in that year commenced a series of experiments upon it as a remedy for bronchocele or goitre. It is found in each of the three kingdoms of nature, but exists in greatest abundance in the vegetable family Algæ (Seaweeds).

Prep. Iodine is principally manufactured in the neighbourhood of Glasgow, from the mother-waters of kelp known as iodine lye.

1. Kelp, the half vitrified ashes of seaweed, is exhausted with water, and the solution filtered; the liquid is then concentrated by evaporation until it is reduced to a very small volume, the chloride of sodium, carbonate of sodium, chloride of potassium, and other salts, being removed as they successively assume the crystalline form; oil of vitriol is now added, in excess, to the residual dark-brown mother-liquor (iodine-lye), and the evolved gases are either kindled or allowed to escape by a flue; the liquid, after standing some time, is decanted or filtered, heated to about 140° Fahr., and mixed with as much binoxide of manganese as there was oil of vitriol employed; the whole is then introduced into a cylindrical leaden still, furnished with a very short head and connected with 2 or 3 large globular glass receivers, and heat is applied, when fumes of iodine are evolved and condensed in the receivers. During the distillation very great care is taken to watch the process, and prevent the neck of the still becoming choked with condensed iodine. For this purpose the head of the still is usually furnished with a movable stopper, by which the process may be watched, and additions of manganese or sulphuric acid made, if required. To render the product pure, it should be pressed between blotting paper, and then resublimed in glass or stoneware.

2. A solution of sulphate of copper, 4 parts, and protosulphate of iron, 9 parts, are added to the mother-liquid of the soda-works, as long as a white precipitate is thrown down; this precipitate (iodide of copper) is collected, dried, and mixed with its own weight of finely powdered black oxide of manganese, and distilled by a strong heat in a retort, when dry iodine passes over. By the addition of sulphuric acid with the manganese, a less heat is required, but the product is wet with water, like that of the last formula.

3. The residual liquor of the manufacture of soap from kelp (or other iodine lye), of the sp. gr. of 1·374, is heated to 230° Fahr., with sulphuric acid diluted with half its weight of water, after which the liquor is allowed to cool, and is either decanted or filtered; to every 12 fl. oz. of the filtrate 1000 gr. of black oxide of manganese, in powder, are added; the mixture is put into a glass globe or matrass with a wide neck, over which is inverted another glass globe, and heat is applied by means of a charcoal chauffer, when iodine sublimes very copiously, and condenses in the upper vessel; as soon as the latter is warm, it is replaced by another, and the two globes are thus applied in succession, as long as violet fumes are evolved. The iodine is washed out of the globes with a little cold water. A thin disc of wood, having a hole in its centre, is placed over the shoulder of the matrass, to prevent the heat from acting on the globular receiver. On the large scale, a leaden still, as before described, may be employed, and receivers of either stoneware or glass; and the addition of the sulphuric acid is made in a basin or trough of stoneware or wood. Prod. 12 oz. yield 80 to 100 gr.

4. Another method of preparing iodine has been patented by a Mr Stanford, which consists of compressing the wet weed, drying in an oven, and distilling at a high temperature. The inventor claims that double the usual amount of iodine is obtained besides other useful products.

5. Considerable quantities of iodine are now obtained from the mother-liquor of Chilian saltpetre or nitre (nitrate of soda). In 1873, a nitre refinery in Peru which separates the iodine in combination with copper, as cuprous iodide, by means of bisulphide of soda and sulphate of copper, produced 15,000 kilos of cuprous iodide, corresponding to 9000 kilos of iodine.

Other methods of obtaining it from Chilian nitre consist in treating the mother-liquors left after the salt has been crystallised out with sulphurous acid, until the separated iodine begins to redissolve. Nitrous acid has also been substituted for sulphurous. The iodine so procured is purified by sublimation, whilst that which remains in the residual saline matter is removed by treatment with chlorine.

Prop. Iodine is usually met with under the form of semi-crystalline lumps having a semi-metallic lustre, or in micaceous, friable scales, somewhat resembling plumbago or gunpowder. By carefully conducted sublimation, or by the slow evaporation of its solution in hydriodic acid, it may be obtained in rhombic plates an inch long. It has a greyish-black colour, a hot acrid taste, and a disagreeable odour not much unlike that of chlorine. It fuses at 225° into a deep-brown liquid, volatilises slowly at ordinary temperatures, boils at 347°, forming a magnificent violet-coloured vapour, when mixed with water it rapidly rises with the steam at 212° Fahr. It dissolves in about 7000 parts of water, and freely in alcohol, ether, solutions of the iodides, liquid hydriodic acid, chloroform, petroleum, bisulphide of carbon, &c. Most of these solutions have the brown colour of liquid iodine, but some (particularly those formed by the last three solvents named above) have the beautiful violet colour of the vapour. It bleaches like chlorine, only more feebly. Iodine has an extensive range of affinity; with the metals it forms compounds termed iodides, of which several are used in medicine. Its principal compounds with oxygen are the iodic and periodic anhydrides. Sp. gr. 4·946 to 4·948. According to Debaugne, the addition of syrup of orange peel or tannin to water greatly increases its power of dissolving iodine. 2 gr. of the latter will enable 6 fl. oz. of water to take 10 gr. of iodine. A knowledge of these facts may prove useful to the pharmaceutist.

Pur. It is entirely soluble in rectified spirit, and in a solution of iodide of potassium. On applying heat to it, it first liquefies, and then (wholly) sublimes in violet-coloured vapour. The iodine of commerce is usually that of the first sublimation, and generally contains from 12% to 20% of water. Some of the foreign iodine, prepared by precipitation with chlorine, without subsequent sublimation, even contains 1-4th part of water, and has a dead leaden-grey colour, and evolves a sensible odour of chlorine. Coal, plumbago, oxide of manganese, crude antimony, and charcoal, are also frequently mixed with iodine to increase its weight. Water may be detected by the loss of weight it suffers when exposed to strong pressure between bibulous paper; or more accurately by drying it in the manner directed below,—chlorine may be detected by the odour, and the other substances mentioned above, by their insolubility in rectified spirit and in a solution of iodide of potassium. Before use as a medicine it should be dried by being placed in a shallow basin, of earthenware, in a small confined space of air, with 10 or 12 times its weight of fresh-burnt lime, till it scarcely adheres to the side of a dry bottle, or else prepared from the commercial iodine as follows:—Place it in a deep circular porcelain capsule, and having covered it accurately with a glass matrass filled with cold water, apply a water heat to the capsule for 20 minutes, and then allow the whole to cool; should the sublimate attached to the bottom of the matrass include acicular prism of a white colour, and a pungent odour, it must be scraped off with a glass rod, and rejected; the apparatus is then to be again exposed to a gentle and steady heat until the whole of the iodine has sublimed; the sublimate is, lastly, to be collected from the bottom of the matrass, and at once enclosed in a stoppered bottle.

Tests. Free iodine may be recognised by the violet colour of its vapour, by its imparting a violet colour to bisulphide of carbon, and by its striking a blue colour with starch. The latter test is so delicate, that water containing only ⁄450000th part of iodine acquires a perceptible blue tinge on the addition of starch. Free iodine may be eliminated from solutions of iodides by chlorine, nitric acid, concentrated sulphuric acid and peroxide of manganese, and may be made evident by adding starch-paste. This reagent serves to detect minute traces of iodine in insoluble as well as in soluble compounds of that element. The substance under examination is mixed in a retort with concentrated nitric acid, and a strip of white cotton cloth moistened with a solution of starch suspended from the stopper; in a few hours the cloth will become coloured blue if the most minute trace of iodine be present. By mixing the liquid containing the iodine with the starch and acid, and lightly pouring thereon a small quantity of aqueous chlorine, a very visible blue zone will be developed at the line of contact, even in very dilute solutions.

Iodides give a pale yellowish precipitate with nitrate of silver, scarcely soluble in ammonia, and insoluble in dilute nitric acid; a bright yellow one with acetate of lead; and a scarlet one with bichloride of mercury. This distinguishes them from the iodates which give white precipitates with the same reagents. In solutions of alkaline iodides, chloride of palladium produces a black precipitate.

Estim. The proportion of free iodine in a mixture may be estimated: by separating it by heat, and collecting and weighing the sublimate; by solution in rectified spirit, adding water, and collecting the resulting precipitate, which must then be dried and weighed; by dissolving it in a solution of iodide of potassium, and then adding a standard solution of hyposulphite of sodium, until the whole of the free iodine is taken up, and the mixture no longer strikes a blue colour with starch. 24·8 gr. of the hyposulphite are necessary to absorb 12·7 gr. of free iodine; by comparing the tint of a solution prepared by chloroform with that of a standard solution containing a known quantity of iodine, as in Crum’s process for estimating chlorine.

Uses, &c. Iodine is chiefly used as a medicine, a chemical test, and in photography. Until within the last year it was largely used in the manufacture of the green coal-tar colours; these latter are now chiefly made from anthracene. In small doses it appears to be both alterative and tonic, rapidly diffusing itself through the body, and exerting a stimulating action on the organs of secretion. It is also said to be diuretic, and in some cases to have produced diaphoresis and salivation. Iodine has been exhibited in the following diseases, as well as in most others depending on an imperfect action of the absorbents, or accompanied by induration or enlargement of individual glands or organs:—Internally, in bronchocele, goitre, Derbyshire neck, scrofula, ovarian tumours, enlargement or induration of the lymphatic, prostate, and parotid glands, amenorrhœa, leucorrhœa, diseases of the muco-genital tissues, phthisis, chronic nervous diseases, lepra, psoriasis, chronic rheumatism, dropsies, hydrocele, &c.:—Externally, in scrofula, numerous skin diseases, (especially the scaly), erysipelas, diseased joints, chilblains, burns, scalds, various wounds, to check ulceration, to promote absorption, &c.—Dose, ⁄2 gr. dissolved in spirit, or in water by means of an equal weight of iodide of potassium. It is seldom exhibited alone, being usually combined with the last-named substance, which, in fact, is now generally preferred by practitioners. It is applied externally in the form of ointment, solution, or tincture.

Iodine, Bro′mides of. Bromine and iodine unite rapidly by mere mixture. By careful distillation a red vapour is obtained, which, on cooling, condenses into red crystals, of a form resembling fern leaves. This is said to be the protobromide (IBr). By adding more bromine, these crystals are converted into a fluid, said to be a pentabromide (IBr5).

Iodine, Chlo′′rides of. When dry chlorine is passed over dry iodine, at common temperatures, heat is evolved, and a yellow solid terchloride (ICl3) results when the iodine is fully saturated, and an orange-red liquid protochloride (ICl) when the iodine is in excess. They both absorb moisture in the air, are volatile, and very soluble in water.

Iodine and Hydrogen. Hydriodic acid, HI. Syn. Iodhydric acid; Acidum Hydriodicum, L. An acid compound of iodine and hydrogen. Prep. 1. (Gaseous).—a. Into a glass tube, closed at one end, introduce a little iodine, then a small quantity of roughly powdered glass moistened with water, next a few small fragments of phosphorus, and upon this some more glass; this order (iodine, glass, phosphorus, glass) is to be repeated until the tube is one half or two thirds filled; a cork and delivery tube are then to be fitted, a gentle heat applied, and the gas collected by ‘downward displacement’ or over mercury. If the gas be passed into water a solution of hydriodic acid will be obtained.

Obs. Hydriodic acid gas can only be retained a short time over mercury, owing to its action on that metal.

b. Pour a little water over some pentiodide of phosphorus, previously put into a glass retort, apply a gentle heat, and collect the gas as before.

c. Heat together in a retort water, iodide of potassium, iodine, and phosphorus, and collect the gas as in b.

d. Place pure iodide of barium in a retort, and decompose it with sulphuric acid.

2. (Solution of Hydriodic acid.)—a. The gas prepared by either of the above methods passed into cold distilled water.

b. Iodine, in fine powder, is suspended in water, and a stream of sulphuretted hydrogen passed through the mixture as long as sulphur is deposited, or until it becomes colourless. The liquid is then gently heated, to expel the excess of sulphuretted hydrogen, and either decanted or filtered. A cheap and excellent process.

c. (Medicinal Hydriodic acid.) Dr Buchanan.—Tartaric acid, 264 gr.; pure iodide of potassium, 330 gr.; dissolve each separately in 1⁄2 fl. oz. of water; mix the solutions, and when the precipitate has settled decant the clear liquid, and add a sufficiency of water to make it up to 6⁄4 fl. oz. The liquid retains a little acid tartrate of potassium in solution, but this does not interfere with its medicinal properties. This preparation “possesses all the therapeutic powers of iodine without its irritating properties.” (Pereira.)—Dose, ⁄2 to 1 fl. dr., gradually increased to 2 or 3 fl. dr., twice or thrice daily.

Prop., &c. Gaseous hydriodic acid is colourless, fumes in the air, is very soluble in water, and has a density of about 4·4. Liquid hydriodic acid, when strong, is very liable to decompose, and should be kept in well-stoppered bottles. Both the gas and the solution are decomposed by potassium, zinc, iron, and other metals, with the evolution of hydrogen and the formation of salts called iodides.

Iodized Cotton wool. (Mehu.) Prep. Finely powdered iodine (5 to 10 per cent.) is strewn upon loose cotton wool in such a manner that the glass jar in which this operation is performed contains alternate layers of cotton wool and iodine. The mixture is gently heated in the open jar on a water bath to expel the air; when this is accomplished the jar is closed and the application of heat continued for about two hours, during which the iodine vapour thoroughly penetrates the wool, imparting to it a yellow colour.

IODO′FORM. CHI3. Syn. Iodoformum, L. A solid, yellow, crystallisable substance, obtained by the action of iodine on alcohol.

Prep. 1. An alcoholic solution of potash is added to tincture of iodine, carefully avoiding excess; the whole is then gently evaporated to dryness, the residuum is washed with water, and then dissolved in alcohol; the alcoholic solution yields crystals by evaporation.

2. (Paris Pharmaceutical Society.) Pure carbonate of potash, 2 parts; alcohol (84°) 5 parts; distilled water, 15 parts. The potash, water, alcohol, and the iodine reduced to powder are placed together in a flask, and the whole heated in a water bath until the decoloration of the liquid. Another ⁄2 part of iodine is then added and heat again applied, and the addition of the element is repeated until the liquid remains slightly brown coloured. It is then decolorised by the addition of one or two drops of caustic potash solution, and upon cooling crystals of iodoform are obtained.

These are collected upon a filter, washed lightly with cold distilled water, then dried upon blotting paper and enclosed in well-stoppered bottle.

By the evaporation of the mother liquor iodide of potassium is obtained.

Prop., &c. Nearly insoluble in water; freely soluble in alcohol; the solution is decomposed by caustic potassa into formic acid and iodide of potassa.—Dose, ⁄2 gr. to 3 gr. Medicinal applications, the same as those of iodine itself.

IPECACUAN′HA. Syn. (Ipecacuanha, L.; Ipecacuhan, E., B. P.) Radix ipecacuanhæ, Ipecacuanha (Ph. L. E. & D.), L. The dried root of Cephaëlis Ipecacuanha, or the true ipecacuanha plant, one of the Cinchonaceæ. “Ashy coloured, tortuous, very much cracked, and marked in rings with deep fissures, having an acrid, aromatic, bitterish taste.” (Ph. L.) It occurs in pieces 3 or 4 inches long, and about the size of a writing quill.—Dose. As an emetic, 10 to 20 gr., assisted by the copious use of warm water; as a nauseant, 1 to 3 gr.; as an expectorant and sudorific, ⁄2 to 1 gr. It is undoubtedly the safest and most useful medicine of its class. It has recently been highly recommended in dyspepsia, combined with other bitters or aperients. Almond meal is sometimes used as an adulterant in ipecacuanha powder.

The following is Bucholz’s analysis of ipecacuanha root:—

Emetic extractive (emetina) 4·13

Soft resin 2·43

Wax 0·75

Gum 25·17

Starch 9·00

Woody fibre 10·80

Bitter extractive 10·12

Sugar 2·00

Extractive, gum and starch extracted by potash 34·80

Loss 0·80

100·00

The annexed process for the determination of the emetina in ipecacuanha is by Zenoffsky:—Take 15 grammes of the root, mix with 15 drops of dilute sulphuric acid, and so much of 85 per cent. alcohol that the volume shall be 155 c.c. Digest 24 hours, filter, measure 100 c.c. of the filtrate, evaporate the alcohol, and add a deci-normal solution of iodo-hydrargyrate of potassium until no more reaction takes place. The number of c.c. of the reagent used multiplied by 0·0189 (⁄10000th of an equivalent of emetine) gives the amount of emetine in the 10 grammes of root to which the 100 c.c. of liquid corresponds. The deci-normal solution of iodo-hydrargyrate of potassium is made by dissolving 13·546 grammes of mercuric chloride and 49·8 grammes of potassium iodide in water, and making up to 1 litre.

Quantitative determination showed that one c.c. of such a solution corresponds to 0·0189 gramme of emetine. To perform the volumetric estimation, the standard solution is added to the liquid containing the alkaloid, until no more turbidity is produced. To determine the end of the reaction, filter a few drops on to a watch-glass (placed on black glazed paper) and touch with a glass rod previously moistened with the standard solution. To prevent loss both filter and filtrate should be returned to the liquor.

IRID′IUM. Ir. A rare metal discovered by Descotils in 1803, and by Tennant in 1804, in the black powder left in dissolving crude platinum. This powder is an alloy of iridium with osmium. The metal is also found native and nearly pure amongst the Uralian platinum ores.

Prep. The native alloy of iridium and osmium remaining after dissolving crude platinum in aqua regia is reduced to powder, mixed with an equal weight of dry chloride of sodium, and heated to redness in a glass tube, through which a stream of moist chloride gas is transmitted. The further extremity of the tube is connected with a receiver containing liquor of ammonia. Chloride of iridium and chloride of osmium are produced; the former remains in combination with the chloride of sodium; the latter, being volatile, is carried forward into the receiver, where it is decomposed into osmic and hydrochloric acids, which combine with the ammonia. The contents of the tube, when cold, are treated with water to dissolve out the double chloride of iridium and sodium; the solution thus formed is mixed with an excess of carbonate of sodium, and evaporated to dryness. The residue is ignited in a crucible, boiled with water, and dried; it then consists of a mixture of sesquioxide of iron and a combination of oxide of iridium with sodium hydrate. It is reduced by hydrogen at a high temperature, and treated successively with water and strong hydrochloric acid, which remove the alkali and the iron, leaving metallic iridium in a divided state. By strong pressure and exposure to a welding heat, a certain degree of compactness may be given to the product.

Prop., &c. Brittle, white, very hard, only fusible by the strongest heat of Deville’s gas furnace. In its pure state it is not acted upon by any of the acids, but it is oxidised by fusion and nitre, and by ignition to redness in the air. An ingot of iridium, weighing 27⁄4 oz., melted by Deville’s process, was displayed in Messrs Johnson and Matthey’s case at the International Exhibition of 1862. An alloy of iridium and osmium (artificial or native) has been employed for tipping the nibs of gold pens (everlasting pens).

Iridium, Chlo′rides of. Dichloride. IrCl2. An olive-green powder formed by transmitting chlorine over powdered iridium, heated to a dull red, or by digesting the hydrated protoxide in hydrochloric acid. Sesquichloride, Ir2Cl6, obtained by calcining iridium with nitrate of potassium, digesting in nitric acid, washing with water, and solution in hydrochloric acid. Tetrachloride, IrCl4, obtained in solution by adding hydrofluosilicic acid to the tetrachloride of iridium and potassium (formed when chloride is passed over a heated mixture of iridium and chloride of potassium). Hexachloride, IrCl6, obtained in combination with potassium by heating iridium with nitrate of potassium, dissolving in aqua regia, and evaporating to dryness.

Iridium, Ox′ides of. Monoxide, IrO, prepared by adding potassium hydrate to the hexachloride of iridium, and digesting the precipitate in an acid. It is a heavy black powder, insoluble in acid. Sesquioxide, Ir2O3, is best prepared by fusing in a silver crucible a mixture of carbonate of potassium and the double chloride of iridium and potassium, and boiling the product in water. Bluish-black TRIOXIDE, IrO3, is produced when carbonate of potassium is gently heated with hexachloride of iridium. A greyish-yellow hydrate, containing alkali.

IRITIS. A very dangerous disease of the eye, producing inflammation in the iris or coloured circle which surrounds the pupil. Iritis is frequently produced by rheumatism, as well as by scrofula and gout, and often places the sight in great peril.

The symptoms are pains around the ball of the eye and on the brow, which increase at night, cloudiness of the cornea, difficulty, and inequality of contraction in the pupil, change of colour in the iris, frequently disturbed vision, and much pain in and watering from the eye when the patient is placed in the light, particularly a strong light.

We have described the principal symptoms of this serious disorder in order that any one affected by them may at once seek the assistance of a skilful surgeon or oculist.

I′RON. Fe. Syn. Ferrum, L.; Fer, Fr.; Eisen, Ger. The history of this most important metal extends to the remote past. The discovery of an iron rod in one of the Assyrian bronzes brought to England by Mr Layard established the interesting fact that this metal was known and commonly employed, where strength was required, nearly 3000 years ago. Rust of iron and scales of iron were used as medicines at a period equally remote.

Sources. Iron in a metallic state (native iron) is of very rare occurrence; but it invariably enters into the composition of meteorites. Combined with oxygen and other elements, as iron ores, it occurs in nearly every part of the earth. These ores may be divided into the oxides and the carbonates. The oxides may be again divided into four distinct classes, viz.—(1) Magnetic iron ore, consisting of 31% protoxide and 69% sesquioxide, with an insignificant proportion of silica; (2) specular iron, or iron glance, composed of the sesquioxide, with a small admixture of magnetic oxide; (3) red hæmatite, consisting of the sesquioxide nearly in a state of purity; and (4) brown hæmatite, the hydrated sesquioxide of iron. The carbonates are principally two, viz.—(5) spathose iron, the protocarbonate of iron in a sparry condition, and (6) clay ironstone or black band ironstone, which consists of the protocarbonates associated with clay and carbonaceous matter.

Swedish iron is made almost entirely from No. 1, which occurs in massive beds at Arendahl and Dannemora, in Sweden. This iron is of great purity, being perfectly free from sulphur and phosphorus. The titaniferous iron sand found at Taranaki, in New Zealand, consists almost entirely of No. 1 and the metal titanium. No. 2 found principally in the island of Elba, in the form of rhombohedral crystals. The micaceous iron ore found in small quantities in Wales and Lancashire has nearly the same composition, but crystallises in brilliant plates. No. 3 occurs in radiated fibrous masses in different parts of the world. It is found in large quantities in Wales and Lancashire, some of the specimens from the latter locality containing nearly 99% of the sesquioxide. It makes excellent iron. No. 4 occurs in reddish-brown masses of a botryoidal form. It is a valuable ore, and is found in England, Wales, and Scotland. No. 5 is found chiefly at Siegen, in Prussia. No. 6 is the principal ore of the Staffordshire and Scotch iron districts, where it occurs in great abundance, associated with the fuel and the flux required for smelting it. Iron is contained in plants, and forms an essential component of the blood of the higher animals.

Prep., &c. Iron is only prepared on the large scale, and an account of the manufacture would be out of place here. Those requiring detailed information must consult the elaborate works of Percy, Hunt, Fairbairn, Phillips, and other metallurgists.

Pure iron may be prepared by introducing fine iron wire, cut small, 4 parts, and black oxide of iron, 1 part, into a Hessian crucible; covering with a mixture of white sand, lime, and carbonate of potassium (in the proportions used for glass-making); and, after applying a closely fitting cover, exposing the crucible to a very high degree of heat. A button of pure metal is thus obtained, the traces of carbon and silicon present in the wire having been removed by the oxygen of the black oxide.

Prop., &c. The properties and uses of iron are too well known to require description. Its applications are almost universal. It is remarkably ductile, and possesses great tenacity, but is less malleable than many of the other metals. Its sp. gr. is 7·844. It is the hardest of all the malleable and ductile metals, and when combined with carbon (steel) admits of being tempered to almost any degree of hardness or elasticity. In dry air it does not oxidise at common temperatures; but at a red heat it soon becomes covered with a scaly coating of black oxide, and at an intense white heat burns brilliantly with the production of the same substance. Pure water, free from air or carbonic acid, does not tarnish the surface of polished iron, but the combined action of air and moisture, especially when a little acid vapour is present, causes its surface to be soon covered with rust, which is hydrated sesquioxide of iron (ferric hydrate). Nearly all acids attack iron; dilute sulphuric and hydrochloric acid do so with considerable energy and the evolution of hydrogen gas. At a red heat iron decomposes water rapidly, hydrogen being evolved, and the black oxide of iron formed. Iron is magnetic up to a dull-red heat, at which point it loses all traces of that property. It melts at about 3300° Fahr. With oxygen, chlorine, iodine, the acids, &c., it forms numerous important compounds. As a remedial agent, when properly exhibited, iron acts as a genial stimulant and tonic, and generally proves beneficial in cases of chronic debility, unaccompanied with organic congestion or inflammation. The carbonate (ferrous carbonate), as it exists in mineral waters, held in solution by carbonic acid in excess, appears to be the form most congenial to the human body; and from its state of dilution is rapidly absorbed by the lacteals, and speedily imparts a ruddy hue to the wan countenance. Iron is undoubtedly one of the most valuable articles of the materia medica, and appears from the antiquity of its introduction into medicine, and the number of its preparations, to have been deservedly appreciated.

Tests. Iron forms two classes of salts, namely, ferrous or proto salts, in which iron exhibits a power of combining with two atoms of any monad element, and the ferric or persalts in which iron has a capacity of uniting with three atoms of any monad element.

The ferrous or proto salts have generally a greenish colour, but yield nearly colourless solutions, except when concentrated. Their solutions are known by the following reactions:—They are not precipitated by hydrosulphuric acid when acid, and but incompletely when neutral. Sulphide of ammonium produces a black precipitate, becoming brown on exposure to the air, insoluble in alkalies, but easily soluble in the mineral acids. Ammonia and potassa give a greenish-white precipitate, gradually becoming green and then brown in the air. This precipitate occasionally is of a bluish-black if excess of potassa is used. The presence of ammoniacal salts interferes with the action of these tests. Ferrocyanide of potassium gives a nearly white precipitate, becoming gradually blue in the air, and immediately so on the addition of a little weak nitric acid or chlorine water. Ferricyanide of potassium produces a rich deep-blue precipitate, insoluble in hydrochloric acid. In highly dilute solutions the effect is only a deep bluish-green coloration. Phosphate of sodium produces a white precipitate, which after a time becomes green.

The ferric salts, which are also called the sesqui or persalts of iron, have for the most part a reddish-yellow colour, yielding deep-coloured solutions, which exhibit the following reactions:—They redden litmus paper. Hydrosulphuric acid in acid solutions reduces ferric to ferrous salts, giving a white or yellow precipitate of sulphur only. In alkaline solutions it yields a blackish precipitate, consisting of sulphur and ferrous sulphide. Sulphide of ammonium gives similar reaction. Ammonia and potassa produce bulky reddish-brown precipitates insoluble in excess. Ferrocyanide of potassium gives a rich blue precipitate, insoluble in hydrochloric acid, and readily decomposed by potassa. Ferricyanide of potassium deepens the colour, but does not give a blue precipitate, as it does with ferrous salts (proto salts). Sulphocyanide of potassium gives an intense ruby-red colour to neutral or acid solutions. Tincture and infusion of galls strike a black colour. Phosphate of sodium gives a white precipitate, which becomes brown, and finally dissolves on the addition of ammonia.

Estim. The iron may be thrown down in the state of ferric hydrate or hydrated sesquioxide, washed, dried, ignited, and weighed. The weight, in grains, multiplied by ·7, indicates the weight of metallic iron.

Fifty gr. of the ore are reduced to powder, dissolved in aqua regia, with the aid of heat, and the solution filtered in order to separate the silica and a little alumina which sometimes is left in an insoluble state; an excess of ammonia is then added to the filtered liquor, which produces a reddish-brown precipitate of ferric hydrate mixed with alumina which is collected on a filter, washed, and boiled with a solution of potassa, in order to dissolve the alumina; the whole is next thrown upon a filter, washed, dried, carefully ignited, and weighed. The above is well adapted to determine the quantity of iron in clay ironstone, the most common ferruginous ore in England.

The sulphur in cast and wrought iron, and steel, may be estimated by the following process, invented by M. Koppmayer:—10 grammes of iron, finely produced and sifted, are introduced into a bottle holding from ⁄2 to ⁄3rd litre. The stopper has three holes. Through one of these passes a funnel with a ground-glass tap, its neck reaching to the bottom of the bottle. Through the second passes the tube at right angles, fitted with a tap and reaching also to the bottom of the bottle.

Through the third hole passes a delivery tube, connecting the bottle to the condensing apparatus.

This latter consists of a series of bulbs arranged like a staircase, so as to permit the gas to come into the greatest possible contact with the standard solution of iodine in iodide of potassium, with which the condenser is filled, this solution ought not to be exposed to light.

When the apparatus is arranged as above, the atmospheric air is first driven out of the bottle by means of a current of hydrogen gas, introduced by the tube bent at right angles. When it is considered that the air is entirely expelled, the tap of this tube is closed. The funnel is now filled with hydrochloric acid, its tap is opened, and by means of the application of heat the acid is allowed to run down upon the iron without allowing any common air to enter. Hydrogen and sulphuretted hydrogen are formed which pass into the condenser.

Acid is thus added until all disengagement of gas ceases. The bottle is then heated till its contents boil, a little water having been first added by means of the funnel. After these operations, hydrogen is allowed to enter anew to sweep out all remaining gases. The iodised solution is then poured out, care being taken to rinse the bulb-tube thoroughly, and titrated with hyposulphite of soda, so as to find the remaining proportion of free iodine. The difference between the original amount of free iodine present in the solution, and the amount thus found, shows the proportion of iodine which has been converted into hydriodic acid, and which is proportional to the sulphur contained in the sample under examination.

Iron, Preparations of:—

Ferric Acetate. Fe2(C2H3O2)6. Syn. Peracetate of iron; Ferri sesquiacetas, L. Prep. Ferric carbonate, 1 part; acetic acid, 6 parts; digest three days and filter. A dark brownish-red, uncrystallisable liquid, very soluble and powerfully astringent. The calcined sesquioxide of iron of the shops, commonly sold as carbonate of iron, does not answer well for this or any of the sesqui-compounds, owing to its being with difficulty dissolved by acids, especially by the weaker ones.—Dose. (Of the last) 10 to 25 drops, in water or wine.

Ferric Albuminate. Syn. Ferri albuminas, L. Prep.

Precipitate a filtered solution of white of egg with another of ferric sulphate or persulphate of iron, wash the deposit in water, and dissolve it in alcohol holding potassium hydrate in solution.

This preparation is highly spoken of by M. Lassaigne as especially adapted by its nature, on theoretical grounds, for combining with the tissues of the body.

Ferric Citrate. Fe2(C6H5O7)2. Syn. Percitrate of iron, Citrate of Sesquioxide of i., Citrate of i.; Ferri citras.

Prep. By saturating a solution of citric acid in an equal weight of water with freshly precipitated moist hydrated ferric hydrate, evaporating at 150° Fahr. to the consistence of a syrup, and spreading on glass plates to dry.

By either of the methods adopted for the AMMONIO-CITRATE, merely omitting the addition of the ammonia. It much resembles the ammonio-citrate, but is only slightly soluble in water, and has a rather less agreeable taste.—Dose, 3 to 5 gr.

Ferric and Ammonium Citrate. Syn. Ammonio-citrate of iron: Ammonio ferric citrate; Ferri ammonio citras. L. There are several preparations in which the term ‘citrate of iron’ has been applied. That commonly known under this name is really a double citrate of iron and ammonia, and appears to be correctly called ‘ammonio-citrate of iron.’

B. P. Liquor Ferric Persulphatis (B. P.), 8; liquor ammonia, 19⁄2; citric acid (in crystals) 4; distilled water, a sufficiency, mix 14 of the solution of ammonia, with 40 of water, and all gradually; the solution of ferric sulphate stir constantly and briskly; let the mixture stand two hours, and put into a calico filter and allow to drain. Wash well the precipitate until it no longer gives a precipitate with barium chloride. Dissolve the citric acid in 8 oz. of the water, and having applied the heat of a water bath add the precipitate of ferric hydrate previously well drained, stir them together until the whole or nearly the whole of the hydrate has dissolved. Let the solution cool, then add 5⁄2 of the ammonia, filter through flannel, evaporate to the consistency of syrup, and dry it in thin layers on flat porcelain or glass plates at a temperature not exceeding 100°.

Prep. (Ph. L.) Ferrous sulphate, 12 oz.; carbonate of sodium, 12⁄2 oz.; dissolve each separately in boiling distilled water, 6 pints; mix the solutions whilst still hot, and allow the precipitate to subside; after a time decant the supernatant liquor, wash the precipitate frequently with water (drain it), add of citric acid (in powder), 6 oz., and dissolve by the aid of a gentle heat; when the whole has cooled, add of liquor of ammonia, Ph. L., 9 fl. oz., and gently evaporate to the consistence of a syrup; in this state spread it very thinly on flat earthenware dishes (or sheets of glass), dry by a gentle heat, and when dry keep it in well-stoppered bottles.

(Ph. D.) Citric acid, 4 oz.; distilled water, 16 fl. oz.; hydrated ferric oxide, obtained from the sulphate, 5 oz.; liquor of ammonia, 4 fl. oz., or q. s.

(Wholesale.) A mixture of iron filings and citric acid, in powder, with barely sufficient water to cover it, is kept in a warm situation for some days, occasionally stirring the mass, and replacing the water as it evaporates. A saturated solution is next made in distilled water, there being previously added more citric acid (about half the weight of the acid first used), as required; it is then neutralised with liquor of ammonia (about 1⁄4 oz. of liquor of ammonia, sp. gr. ·882, to every gallon of the solution of sp. gr. 1·025), and the solution is concentrated by evaporation; the process is then completed as in No. 1. The first part of this process produces a salt of the protoxide of iron, or ferrous citrate, which is afterwards converted, by exposure to the atmosphere, into a citrate of the magnetic acid, or ferri, ferro-citrate, and, lastly, into citrate of peroxide of iron, or ferric citrate.

B. P. Liquor Ferri Persulphatis 8. Liquor ammoniæ 19⁄2. Citric acid (in crystals) 4. Distilled water, a sufficiency. Mix 14 of the solution of ammonia with 40 of water, and add gradually the solution of ferric sulphate. Stir constantly, let the mixture stand 2 hours and filter through calico, and allow to drain. Wash until the washing ceases to precipitate barium chloride, dissolve the citric acid in 8 of water, add the precipitated ferric hydrate, and heat in a water bath until dissolved. Let the solution cool, add 5⁄2 of the ammonia, filter through flannel, evaporate to the consistency of syrup, and dry on flat porcelain plates in thin layers at a temperature below 100° F.

Obs. Pharmaceutical writers have been so diffuse in their disquisitions on the preparation of this salt, as would lead to the inference that there is some difficulty attending it. The contrary is, however, the case. The only care necessary is to spread the syrup solution very thinly on warm sheets of glass to dry, which it will rapidly do if they are placed in an atmosphere of warm dry air, for which purpose a ‘drying closet’ is the most convenient. The dry salt may then be easily detached from the glass, and will form thin scales, or lamellæ, of great brilliancy and beauty. It is also better to use a little more oxide than the acid will dissolve, as the remainder will be employed in a future operation. Less water may be used, or even a larger quantity than that mentioned; but in the first case the liquid will become difficult to filter—in the latter it will require more evaporation. Boiling water dissolves about twice its weight of citric acid, and there remains ⁄20ths of this quantity in solution when cold, and it takes rather more than twice the weight of the citric acid in moist hydrated protoxide of iron to produce saturation.

Prop., &c. This beautiful salt is of a rich ruby colour, and forms glistening transparent scales, very soluble in aqueous menstrua, and the resulting solution is less easily decomposed by reagents than the solutions of most of the other salts of iron. It is ‘compatible’ with the alkaline of carbonates and bicarbonates, and several other salts, and is nearly tasteless, advantages which have been perhaps overrated by both prescriber and patient. It is doubtful whether this article has not obtained a larger sale from its pleasing appearance than from its medicinal virtues. Several persons who have prepared it in lumps or powder, by the simple evaporation of the solution to dryness, have been unable to sell it under that form, even at a lower price.

Ammonio-citrate of iron is soluble in water; the solution neither changes the colour of litmus nor turmeric; nor is it turned blue by ferrocyanide of potassium; but either potassium hydrate or lime water being added, it throws down ferric hydrate, and ammonia is evolved. From 100 gr. dissolved in water, potassium hydrate precipitates about 34 gr. of ferric hydrate.—Dose, 3 to 10 gr., in water, wine, or bitter infusions.

Ferric and Strychnine Citrate. (U. S.) Syn. Ferri et strychniæ citras. Prep. Citrate of iron and ammonia, 500 gr.; strychnia, 5 gr.; citric acid, 5 gr.; distilled water, 9 fl. dr. Dissolve the citrate of iron and ammonia in 1 oz. of the water, and the strychnia and nitric acid in 1 dr. of distilled water. Mix the two solutions, evaporate the mixture over a water bath, at 140° Fahr., to the thickness of a syrup, and spread on glass plates, so that the salt, when dry, may be obtained in scales.

Ferric and Magnesium Citrate. Syn. Citric of iron and magnesia; Ferri magnesio citras; Ferri et magnesiæ citras, L. Prep. As the last, but using carbonate of magnesium instead of ammonia to neutralise the solution.—Dose, 2 to 10 gr. It has been recommended as a chalybeate in the dyspepsia of gouty and debilitated habits.

Ferric and Quinine Citrate. Syn. Citrate of quinine and iron; Ferri-quinio-citras, L. As the ammonio-citrate, but using quinine, recently precipitated, instead of ammonia, to neutralise the acid.

B. P. Pure ferric hydrate is prepared from liquor ferri persulphatis, 4⁄2 pints, and liquor ammoniæ, 8 pints, as in the ferric and ammonium citrate. Sulphate of quinine 1 is mixed with water 8, and sulphuric acid 1⁄2, and when dissolved, ammonia added until the quinine is precipitated. The precipitate is collected and washed with 30 of water. Citric acid 3 is dissolved in 8 of water by the aid of a water bath, and the ferric hydrate, well drained, added; stir together until dissolved, and add the quinine, stirring well until all is dissolved, and allow to cool; add 1⁄2 of solution of ammonia diluted with 2 of water, stirring the solution briskly until the quinine at first thrown down by the ammonia is redissolved; filter and evaporate to a syrup, drying in thin layers on flat porcelain or glass plates at a temperature of 100°.

Ferric citrate, 4 parts; citrate of quinine, 1 part; distilled water, q. s.; dissolve, gently evaporate, and proceed as directed for ammonio-citrate of iron. Greenish golden-yellow scales when prepared by the B. P. process, soluble in 2 parts of water, and somewhat deliquescent; entirely soluble in ether; taste bitter as well as chalybeate.—Dose, 2 to 6 dr.; in cases where the use of both iron and quinine is indicated.

Ferric and Sodium Citrate. Syn. Ferri sodio-citras, Ferri et sodæ citras, L. Prep. From citric acid, carbonate of sodium, and iron or the hydrate, as the ammonio-citrate or potassio-citrate.

Ferric Chlo′ride. Fe2Cl6. Syn. Sesquichloride of iron, Perchloride of iron, PERMURIATE OF I.; Ferri sesquichloridum, L. Prep. 1. (Anhydrous.) By passing dry chlorine over heated iron filings. Brown scales.

(Hydrated.) Dissolve ferric hydrate in hydrochloric acid, evaporate to the consistence of a syrup, and crystallise. Yellow or red scaly crystals. The impure solution of this salt has been greatly used as a sewage deodoriser. See Tincture.

Ferric and Ammonium Chloride (Fe2Cl6NH4Cl.Aq). Syn. Double chlorides of iron and ammonium, Ammonio-chloride of iron; Ferri ammonium chloridum.

Ferric oxide, 3 oz.; hydrochloric acid, ⁄2 pint; digest in a sand bath until dissolved, then add of ammonium 2⁄2 lbs., dissolved in water, 3 pints; filter the liquid, evaporate to dryness, and reduce the mass to coarse powder. Orange-coloured crystalline grains readily soluble in water.

Ammonio-chloride of iron is tonic, emmenagogue, and aperient.—Dose, 5 to 15 gr.; in glandular swellings, obstructions, &c.

Ferric Ferrocy′anide. (Fe4(FeCy6)3. 18Aq). Syn. Sesquiferrocyanide of iron, Prussian blue; Ferri ferrocyanidum, F. sesquiferrocyanidum, L. Prep. Ferrous sulphate, 4 oz.; water, 1 pint; dissolve, add to the solution of nitric acid, 6 fl. dr., in small portions at a time, boiling for a few moments after each addition; next dissolve ferrocyanide of potassium, 4⁄2 oz., in water, 1 pint, and add this last solution, by degrees, to the first liquid, stirring well each time; lastly, collect the precipitate, wash it with boiling water, drain, and dry it.—Dose, 3 to 5 gr., three or four times daily, as an alterative, febrifuge, and tonic, gradually increasing the quantity until some obvious effect is produced; in agues, epilepsy, and neuralgia. See Prussian blue.

Ferric Hydrate. Fe2(HO)6. See under Ferric Oxide.

Ferric Iodide. Fe2I6. Syn. Ferri periodidum, L. Prep. Freely expose a solution of ferrous iodide to the air; or digest iodine, in excess, on iron, under water, gently evaporate, and sublime. A deliquescent, volatile red compound, soluble in water and alcohol. It is rarely employed in medicine.

Ferric Oxide. Fe2O3. Syn. Sesquioxide of iron, Peroxide of iron, Red oxide of i.; Ferri sesquioxydum, F. peroxydum, F. oxydum rubrum, L. This substance is found native under several forms, but that employed in the arts is prepared by one or other of the following methods:—

From metallic iron. From iron wire or clean iron filings cut into pieces, moistened with water, and exposed to the air until completely converted into rust; it is then ground with water, elutriated, and dried, in a similar way to that adopted for chalk. For sale, it is usually made up into small conical loaves or lumps.

By calcination:—(Brown-red colcothar, Crocus, Indian red, Rouge, Jewellers’ r.; Ferri oxydum rubrum, L.)—Calcine ferrous sulphate until the water of crystallisation is expelled, then roast it with a strong fire until acid vapours cease to rise; cool, wash the residuum with water until the latter ceases to affect litmus, and dry it.

Ferrous sulphate, 100 parts; common salt, 42 parts; calcine, wash well with water, dry, and levigate the residuum. This process yields a cheap and beautiful product, which is frequently sold for the ferri sesquioxydum; but it is less soluble, and therefore unfitted for a substitute for that preparation.

By precipitation;—Ferri sesquioxydum—B. P., Ferri oxydum rubrum—Ph. E. L. By precipitating a solution of ferric sulphate or chloride with ammonia, in excess, and washing, drying, and igniting in the resulting hydrate. Pure; anhydrous.

Ferrous sulphate, 4 lbs.; sodium carbonate, 4 lbs. 2 oz.; dissolve each separately in water, 3 galls.; mix the solution whilst hot, set the mixture aside, that the precipitate may subside, and subsequently wash and dry it as before. Contains water, and a trace of alkali.

Ferric hydrate, Ferri peroxydum hydratum—(Ph. D., Ferrugo—Ph. E.)—a. (Ph. E.) Ferrous sulphate, 4 oz.; sulphuric acid, 3⁄2 fl. dr.; water, 1 quart; mix, dissolve, boil, and gradually add of nitric acid, 9 fl. dr.; stirring well and boiling for a minute or two after each addition, until the liquor yields a yellowish-brown precipitate with ammonia; it must then be filtered and precipitated with liquor of ammonia (fort.), 3⁄2 fl. oz.; rapidly added and well mixed in; collect the precipitate, wash it well with water, drain it on a calico filter, and dry it at a heat not exceeding 180° Fahr. When intended as an antidote for arsenic it should not be dried, but kept in the moist or gelatinous state.

Ferric peroxide, moist (B. P.) Syn. Ferri peroxidum humidum. Prep. Mix solution of persulphate of iron (B. P.), 4 fl. oz., with 1 pint of distilled water, and add it gradually to 33 fl. oz. of solution of soda (B. P.), stirring constantly and briskly. Let them stand for two hours, stirring occasionally; then put on a calico filter, and when the liquid has drained away, wash the precipitate with distilled water till what passes through ceases to give a precipitate with chloride of barium. Lastly, enclose the precipitate without drying it in a stoppered bottle, or other vessel, from which evaporation cannot take place.

Dry hydrate of peroxide of iron (B. P.). Ferri peroxidum hydratum. Dry the moist peroxide, 1 lb., at a temperature not exceeding 212° Fahr., till it ceases to lose weight. Reduce to a fine powder.—Dose, 5 to 30 grains.

Prop. Ferric oxide, prepared by precipitation (1, c), is an impalpable powder, of a brownish-red colour, odourless, insoluble in water, freely soluble in acids, and possessing a slightly styptic taste, especially when recently prepared. When exposed to heat its colour is brightened, its sp. gr. increased, and it is rendered less easily soluble in acids. The oxide prepared by calcination is darker and brighter coloured, less soluble, and quite tasteless. It has either a scarlet or purplish cast, according to the heat to which it has been exposed. The finest Indian red, or crocus, usually undergoes a second calcination, in which it is exposed to a very intense heat. It is then known as ‘purple brown.’ The best jeweller’s rouge is prepared by calcining the precipitated oxide until it becomes scarlet.

The hydrate is of a yellowish-brown colour, and though it can be dried without decomposition, it requires to be kept in a moist state. It is best preserved in a well-stoppered bottle, filled with recently distilled or boiled water.

Pur. Medicinal ferric oxide or sesquioxide of iron (FERRI SESQUIOXYDUM, Ph. L. & D.) is soluble in dilute hydrochloric acid, scarcely effervescing, and is again thrown down by potassa. The strained liquor is free from colour, and is not discoloured by the addition of either sulphuretted hydrogen or ferrocyanide of potassium.

The hydrate (FERRI PEROXYDUM HYDRATUM—Ph. D., FERRUGO—Ph. E.) is entirely and very easily soluble in hydrochloric acid, without effervescence; if previously dried at 180° Fahr., a stronger heat drives off about 18% of water.

Uses, &c. The precipitated oxide is employed in medicine as a tonic and emmenagogue, in doses of 10 to 30 gr.; and as an anthelmintic and in tic douloureux, in doses of 1 to 4 dr., mixed up with honey. It is also employed to make some preparations of iron. The calcined oxide is employed as a pigment, as an ingredient in a plaster, &c. The hydrate is used medicinally as a tonic in doses of 10 to 30 gr.; and in much larger, as an antidote in cases of arsenical poisoning.

We are indebted to Bunsen and Berthold for the introduction of this substance as an antidote to arsenic. A table-spoonful of the moist oxide may be given every 5 or 10 minutes, or as often as the patient can swallow it. (Pereira.) When this preparation cannot be obtained, rust of iron or even the dry so-called carbonate (sesquioxide) may be given along with water instead. According to Dr Maclagan, 12 parts, and to Devergie, 32 parts, of the hydrate are required to neutralise 1 part of arsenious acid. Fehling says that the value of this substance as an antidote to arsenic is materially impaired by age, even when kept in the moist state. The presence of potassium, sodium, ammonium, hydrates, sulphates, chlorides or carbonates, is not of consequence, and, therefore, in cases of emergency, time need not be lost in washing the precipitate, which, in such cases, need only be drained and squeezed in a calico filter. The magma obtained by precipitating ferrous sulphate with magnesia, in excess, and which contains free magnesia and magnesium sulphate, besides ferric hydrate, precipitates arsenious acid not only more quickly, but in larger quantity, than ferric hydrate does when alone. It will even render inert Fowler’s solution, and precipitate both the copper and arsenic from solutions of Schweinfurt green in vinegar, which the pure gelatinous oxide alone will not do.

Soluble Saccharated Oxide of Iron. (G.) Syn. Ferrum oxydatum saccharatum solubile. Prep. Solution or perchloride of iron (sp. gr. 1·480), 2 oz. (by weight); syrup, 2 oz. (by weight); mix, and add gradually, solution of caustic soda (sp. gr. 1·330); 4 oz. (by weight); and set aside for 24 hours; then add to the clear liquid 30 fl. oz. of distilled hot water; agitate and set aside. Pour off the supernatant liquid from the precipitate which will have formed, and pour on fresh distilled water; then collect the precipitate on a filter and wash thoroughly with distilled water.

Put the drained precipitate into a porcelain vessel, and mix with it 9 oz. of sugar in powder, and evaporate to dryness with constant stirring over a water bath, then mix in enough sugar in powder to make up 10 oz. by weight; reduce to powder and keep in a closed vessel. One hundred parts contain three of metallic iron.

Ferric Nitrate. Fe2(NO3)6. Syn. Proto nitrate of iron, Nitrate of sesquioxide of iron; Ferri pernitras, L. By digesting nitric acid (diluted with about half its weight of water) on iron or ferric hydrate. A deep-red liquid, apt to deposit a basic salt. It is used in dyeing, and has been recommended in dyspepsia, calculous affections, and chronic diarrhœa.—Dose, 5 to 10 or 12 drops.

Ferric Phosphate. Fe2H3(PO4)3. Syn. Ferric orthophosphate (Odling); Ferri sesquiphosphas, Phosphas ferricus, L. A white powder obtained by precipitating ferric chloride by sodium phosphate.—Uses and dose. As the last.

Ferric pyrophosphate. Fe6(P2O7)3. A salt containing ferric iron combined with the radical of pyrophosphoric acid.

Prep. By precipitating a solution of ferric sulphate with one of pyrophosphate of sodium, taking care to operate at a temperature below 59° Fahr.

Prop., &c. A gelatinous precipitate which dissolves with facility in excess of pyrophosphate of sodium. The citrate of ammonium is the most eligible solvent according to M. Robiquet, who first called attention to this salt as a remedial agent.—Dose, 5 to 10 gr.

Ferric Sulphate. Fe2(SO4)3. Syn. Persulphate of iron, Sulphate of sesquioxide of iron; Ferri persulphas, L. Prep. By adding to a solution of ferrous sulphate exactly half as much sulphuric acid as it already contains, raising the liquid to the boiling-point, and then dropping in nitric acid, until the liquid ceases to blacken by such addition. The solution evaporated to dryness furnishes a buff-coloured mass, slowly soluble in water.

Prop., &c. With the sulphates of ammonium and potassium it unites to form compounds to which the name ‘iron alums’ has been given. It forms the active ingredient in the ‘liquor oxysulphatis ferri’ of Mr Tyson, and is said by Dr Osborne to be a constituent of ‘Widow Welch’s pills.’ This salt is also formed when ferrous sulphate is calcined with free exposure to the air. Dissolved in water, it is used as a test for hydrocyanic, gallic, and tannic acids.

Ferric Sulphide. Syn. Persulphide of iron. This compound is prepared in the hydrated state (FERRI PERSULPHURETUM HYDRATUM) by adding, very gradually, a neutral solution of ferric sulphate to a dilute solution of potassium sulphide, and collecting, &c., the precipitate, as in the case of the hydrated ferrous sulphide. Proposed by Bouchardat and Sandras as a substitute for ferrous sulphide, to which they say it is preferable.

Ferric Tan′nate. Syn. Ferri tannas, Ferrum tannicum, L. Prep. From tannin, 1 part; boiling water, 150 parts; dissolve, add of freshly precipitated ferric hydrate (dried at 212° Fahr.), 9 parts; evaporate by a gentle heat to one half, filter, add of sugar 1 part, complete the evaporation, and at once put it into bottles.—Dose, 3 to 5 gr., thrice daily; in chlorosis, internal hæmorrhages, &c.

Double Ferric and Ammonium Tartrate. Syn. Ammonio tartrate of iron, Double tartrate of iron and ammonium; Ammonio ferric tartrate, Ferri ammonio tartrate; Ferri ammonio tartras.

Prep. (Aikin.) Tartaric acid, 1 part; iron filings, 3 parts; digest in a sufficient quantity of hot water to barely cover the mixture for 2 or 3 days, observing to stir it frequently, and to add just enough water to allow the evolved gas to escape freely; next add ammonia, in slight excess, stir well, dilute with water, decant, wash the undissolved portion of iron, filter the mixed liquors, and evaporate to dryness; dissolve the residuum in water, add a little more ammonia, filter, and again gently evaporate to dryness, or to the consistence of a thick syrup, when it may be spread upon hot plates of glass or on earthenware dishes and dried in a stove-room, as directed for the corresponding citrate.

Tartaric acid, 6⁄2 oz.; water, 7 pints; dissolve, neutralise the selection with sesquicarbonate of ammonium, and add 6⁄4 oz. more tartaric acid; to the solution heated in a water bath, further add moist hydrated oxide of iron (obtained from sesquioxide of iron, 53⁄2 dr., dissolved in hydrochloric acid, and precipitated by ammonia); when dissolved, filter, and evaporate, &c., as before.

Prop., &c. Glossy, brittle lamellæ, or irregular pieces, of a deep garnet colour, almost black, very soluble in water, and possessing a sweetish and slightly ferruginous taste. By repeated re-solution and evaporation its sweetness is increased, probably from the conversion of a part of its acid into sugar. It contains more iron than a given weight of the sulphate of the same base. It is the most pleasant-tasted of all the preparations of iron except the ammonio-citrate, last noticed.—Dose, 3 to 10 gr.

Ferric and Potassium Tartrate. Syn. Tartrate of potassa and iron, Ferro-tartrate of potassa; Ferric tartrate of p.; Ferri tartaratum (B. P.), Ferri potassio-tartras (Ph. L.), Ferrum tartarizatum (Ph. E.), Ferri tartarum (Ph. D.), Ferri et potassæ tartras (Ph. U. S.), L. Prep. (B. P.) Prepare ferric hydrate from 4 fl. oz. of liq. ferri persulphas, B. P., as in making the double citrate, and add it to 2 oz. of the acid tartrate of potassium, dissolved in 30 oz. of water. Digest for 6 hours at 140°, allow to cool, and decant off the clear solution, which is to be evaporated down and dried on glass plates.—(Ph. L.) Ferrous sulphate, 4 oz., is dissolved in water, 1 pint, previously mixed with sulphuric acid, ⁄2 fl. oz.; heat is applied to the solution, and nitric acid, 1 fl. oz., gradually added; the solution is boiled to the consistence of a syrup, and then diluted with water, 4 galls. (less the pint already used); liquor of ammonia, 10 fl. oz., is next added, and the precipitate washed, and set aside for 24 hours; at the end of this time, the water being decanted, the still moist precipitate is added, gradually, to a mixture of bitartrate of potassium, 2 oz., and water, ⁄2 pint, heated to 140° Fahr.; after a time the undissolved oxide is separated by a linen cloth, and the clear solution either gently evaporated to dryness or treated in the same manner as the citrate (lastly, preserve it in well-stoppered bottles). The formulæ of the Ph. E., D., & U. S., are essentially the same. The Ph. D. orders a heat not beyond 150° Fahr. to be applied to the mixture of the oxide and bitartrate, with occasional stirring for 6 hours, and the desiccation to be conducted at the same temperature.

Obs. This preparation is a double salt of potassium and iron; it is therefore wrongly called ‘tartrate of iron’ as is commonly heard. It is totally soluble in water; the solution is neutral to litmus and turmeric, unaffected by ferrocyanide of potassium, and not precipitated by acids nor alkalies, nor acted on by the magnet. Heated with potassa, 100 gr. throws down about 34 gr. of sesquioxide of iron. Entirely soluble in cold water; taste freely chalybeate. That of commerce has generally a feebly inky taste a slight alkaline reaction, is slightly deliquescent, dissolves in 4 parts of water, and is nearly insoluble in alcohol.

Potassio-tartrate of iron is an excellent ferruginous tonic.—Dose, 10 to 20 gr., made into a bolus with aromatics, or dissolved in water or other convenient menstruum.

Ferric Valerianate. Syn. Valerianate of sesquioxide of iron, Valeriate of iron; Ferri valerianas (Ph. D.), L. Prep. (Ph. D.) By adding a solution of sodium valerianate to another of ferric sulphate, and collecting and washing the precipitate, which is to be dried by placing it for some days folded in bibulous paper, on a porous brick; after which it is to be carefully kept from the air.

Prop., &c. A reddish-brown amorphous powder; nearly insoluble in water; soluble in rectified spirit, and in the dilute acids with decomposition. Citrate or tartrate, flavoured with oil of valerian, is frequently sold for it.—Dose, 1 to 3 gr.; in anæmia and chlorosis complicated with hysteria.

Ferroso-Ferric Hydrate. Fe3(HO)6. Syn. Hydrated ferroso-ferric oxide, Hydrated magnetic oxide. (B. P.) Liquor ferri persulphas, 5⁄2; ferri sulphas, 2; solution of soda, 80; distilled water, a sufficiency. Dissolve the ferrous sulphate in 40 of water, add the solution of soda, stirring them well, boil the mixture, let it stand for two hours, put in a calico filter, wash with distilled water until the washing gives no precipitate with barium chloride, and dry at a temperature not exceeding 120.

Ferrous sulphate, 6 oz.; sulphuric acid, 160 minims; nitric acid, 4 fl. dr.; stronger solution of ammonia, 4⁄2 fl. oz.; boiling water, 3 pints; dissolve half of the sulphate in half of the water, add the oil of vitriol, boil, add the nitric acid gradually, boiling after each addition for a few minutes; dissolve the remaining half of the sulphate in the rest of the boiling water; mix the two solutions, add the ammonia, stirring well (and boil for a short time); collect the precipitate on a calico filter, wash it with water until it ceases to precipitate a solution of nitrate of barium, and dry at a heat not exceeding 183° Fahr. The formulæ of Gregory and Dr Jephson are similar.

Ferrous sulphate, 8 oz., dissolved in a mixture of water, 10 fl. oz., and sulphuric acid, 6 fl. dr., is converted by means of nitric acid, 4 fl. dr., diluted with water, 2 fl. oz., into ferric sulphates; this solution is then added to another, formed by dissolving ferrous sulphate, 4 oz., in water, ⁄2 pint; the whole is then mixed with liquor of potassium hydrate, 2⁄4 pints, and after being boiled for 5 minutes is collected on a calico filter, and washed, &c., as before; and is to be preserved in a well-stoppered bottle.

Prop., &c. The hydrate is a black sand-like substance, consisting of very minute crystals. When pure it is attracted by the magnet, and is entirely soluble in hydrochloric acid; and ammonia added to the solution throws down a black precipitate. The oxide is the chief product of the oxidation of iron at a high temperature in the air and in aqueous vapour. It is more permanent than ferrous oxide, but incapable of forming salts.—Dose, 5 to 20 gr. two or three times a day.

Ferroso-ferric Oxide. Fe3O4. Syn. Magnetic o. of i.; Ferri oxydum nigrum, F. o. magneticum (Ph. D.), Oxydum ferroso-ferricum, L. This occurs native, but that used in medicine is prepared artificially.

From the black scales of iron that fall around the smith’s anvil, by washing, drying, detaching them from impurities by means of a magnet, and then treating them by grinding and elutriation, as directed for prepared chalk. The product of this process is inferior as a medicine to the hydrate obtained as below, being less easily soluble in the juices of the stomach.

Ferroso-ferric Oxide. Fe3O4. Syn. Magnetic oxide. See Ferroso-ferric oxide.

Iron, Black Oxide of. (B. P.) Syn. Ferri oxydum magneticum; Ferri oxydum nigrum; Martial æthiops. Prep. Dissolve sulphate of iron, 2 oz., in 2 pints of distilled water, and add solution of persulphate of iron (B. P.), 5⁄2 fl. oz., then mix with solution of soda, 4 pints (B. P.), stirring well together. Boil the mixture, let it stand for 2 hours, stirring occasionally, then put it on a calico filter, and when the liquid has drained away wash the precipitate with distilled water till what passes through ceases to precipitate chloride of barium. Finally, dry the precipitate at a temperature not exceeding 120° Fahr.—Dose, 5 to 10 gr.

Ferrous Acetate. Fe(C2H3O2)2. Syn. Ferri acetas, L. Prep. 1. From freshly precipitated ferrous carbonate dissolved in dilute acetic acid.

2. By adding a solution of calcium acetate to another of ferrous sulphate, and evaporating the filtered liquid, out of contact with the air. Small, colourless, or pale-greenish needles or prisms, very soluble and prone to oxidation.

Ferrous Arsenate. Fe3(AsO4)2. Syn. Ferri arsenias, L. Prep. 1. From a solution of sodium arseniate, added to a solution of ferrous sulphate, the precipitate being collected, washed in a little cold water, and dried.—Dose, ⁄20 to ⁄12 gr., made into a pill; in lupus, psoriasis, cancerous affections, &c. Externally, combined with 4 times its weight of ferrous phosphate and a little water, as a paint to destroy the vitality of cancerous formations. An ointment (20 to 30 gr. to the oz.) is also used for the same purpose. They are all dangerous remedies in non-professional hands.

2. (B. P.) Prep. Sulphate of iron, 9 oz.; arseniate of soda dried at 300° F., 4 oz.; acetate of soda, 3 oz. Dissolve the arseniate and the acetate of soda in 2 pints, and the sulphate of iron in 3 pints, of boiling distilled water, mix the two solutions, collect the white precipitate which forms on a calico filter, and wash until the washings cease to be affected by a dilute solution of chloride of barium. Squeeze the washed precipitate between folds of strong linen in a screw-press, and dry it on porous bricks in a warm air-chamber whose temperature shall not exceed 100° F.—Dose, ⁄16th of a gr.

Ferrous Arsenite. Fe(AsO2)2. Syn. Ferri arsenis, L. From the potassium arsenite, and ferrous sulphate, as the last. A yellowish-brown powder, occasionally used in medicine as a tonic, alterative, and febrifuge.—Dose, ⁄16 to ⁄12 gr.

Ferrous Bromide. FeBr2. Syn. Ferri bromidum, L. Prep. (Moir.) Bromine and iron filings, of each 1 part; water, 3 parts; mix in a stoppered phial, set it aside, occasionally shaking it, for 2 or 3 days, and when the colour of the bromine has disappeared, and the liquid becomes greenish, filter and evaporate to dryness.—Dose, 1 to 6 gr., as a tonic, diuretic, and resolvent, in similar cases to those in which iodide of iron is given.

Ferrous Carbonate. Fe(CO3). Syn. Protocarbonate of iron; Ferri carbonas, F. subcarbonas, L. This occurs in nature as SPATHOSE ORE, the chief constituent as of CLAY IRONSTONE, and in many CHALYBEATE WATERS.

Prep. (B. P.) Ferrous sulphate (sulphate of iron), 2; ammonium carbonate, 1⁄4; boiling distilled water, 320; refined sugar, 1. Dissolve the sulphate and ammonium carbonate each in ⁄4 of the water, and mix; allow to stand for 24 hours and decant, of the clear solution, add the remainder of the water to the precipitate, stir well, allow to settle, and decant off. Collect the deposit in a calico filter, press, rub in the sugar in a porcelain mortar, and dry at a temperature not exceeding 212° Fahr. Small coherent grey lumps. Precipitate a solution of ferrous sulphate with a solution of sodium carbonate, well wash the green powder with water which has been boiled, and dry it out of contact with the air. On the slightest exposure to air it is converted into ferrous hydrate or oxide. This change is for the most part prevented by combining it with sugar, as in the following preparation.

With sugar: Ferri carbonas saccharata, B. P.; SACCHARINE C. OF I.; FERRUM CARBONICUM SACCHARATUM, FERRI CARBONAS CUM SACCHARO—Ph. L., FERRI CARBONAS SACCHARATUM—Ph. E. & D. L.—(Ph. L.) Ferrous sulphate, 4 oz.; sodium carbonate, 4⁄4 oz.; dissolve each separately in quart of boiling water, and mix the solutions whilst hot; after a time collect the precipitate, wash it frequently with water, and add of sugar, 2 oz., previously dissolved in water, 2 fl. oz.; lastly, evaporate the mixture over a water bath to dryness, and keep it in a well-closed bottle.

Prop., &c. A sweet-tasted greenish mass or powder, consisting chiefly of carbonate of iron. It is one of the best of the chalybeates.—Dose, 5 to 10 gr. When pure, it should be easily soluble in hydrochloric acid with brisk effervescence.

Ferrous Chloride. FeCl2. Syn. Protochloride of iron; Muriate of iron; Ferri chloridum, L. Prep. 1. (Anhydrous.) By passing dry hydrochloric acid gas over ignited metallic iron. The chloride sublimes in yellowish crystals.

2. (Hydrated.) Dissolve iron filings or scale in hydrochloric acid, evaporate and crystallise. Soluble green crystals.

Ferrous Citrate. Fe3(C6H5O7)2. Syn. Protocitrate of iron, Citrate of protoxide of iron. This salt is easily formed by digesting iron filings or wire with citric acid, and evaporating the solution as quickly as possible out of contact with the air. It presents the appearance of a white powder, nearly insoluble in water, and rapidly passing to a higher state of oxidation by exposure to the air. Its taste is very metallic. It is exhibited under the form of pills, mixed with gum or syrup, to prevent it from being prematurely decomposed.

Ferrous Ferricy′anide. Syn. Ferridcyanide of iron. Prep. By adding a solution of potassium ferricyanide (‘red prussiate of potash’) to a solution of ferrous sulphate (or any other soluble ferrous salt), and collecting and drying and precipitate. A bright-blue powder. (See Turnbull’s blue.)

Ferrous Hydrate. Fe2(HO)2. See under Ferrous oxide.

Ferrous Hydrate. Fe(HO)2. May be precipitated from ferrous solutions as a white powder, by alkaline hydrates. It rapidly absorbs oxygen, and turns first green, and then red, by exposure to the air. Both the oxide and hydrate are very powerful bases, neutralising the acids and forming stable salts, which, when soluble, have commonly a pale green colour, and a nauseous metallic taste.

Ferrous Hypophosphite. Syn. Ferri hypophosphis. From the double decomposition of hypophosphite of lime and sulphate of iron, as hypophosphite of potash.

Ferrous Iodide. FeI2. Syn. Protoiodide of iron, Iodide of iron; F. iodidum, Ferri hydriodas, F. ioduretum, L. Prep. (B. P.) Fine iron wire, 1; iodine, 2; distilled water, 10. Introduce the iron, iodine, and 8 of water into a flask, heat it about ten minutes, and boil until all the red colour is gone. Filter through paper into a polished iron dish, washing with the rest of the water, and boil until a drop of the solution taken out on iron wire solidifies on cooling. Pour on porcelain and cool. (Ph. L. 1836.) Iodine, 6 oz.; iron filings, 2 oz.; water, 4⁄2 pints; mix, boil in a sand bath until the liquid turns to a pale green, filter, wash the residuum with a little water, evaporate the mixed liquors in an iron vessel at 212° Fahr. to dryness, and immediately put the iodide into well-stoppered bottles.

Iodine, 1 oz., and clean iron filings or turnings, ⁄2 oz., are put into a Florence flask with distilled water, 4 fl. oz., and having applied a gentle heat for 10 minutes, the liquid is boiled until it loses its red colour; it is then at once filtered into a second flask, the filter washed with water, 1 fl. oz., and the mixed liquid is boiled down, until it solidifies on cooling.

With sugar: Saccharine iodide of iron, Saccharum ferri iodidi, Ferri iodidum saccharatum, L. Iron (in powder), 1 dr.; water, 5 dr.; iodine, 4 dr.; obtain a solution of iodide of iron, as above, and add to it of sugar of milk (in powder), 1⁄4 oz.; evaporate at a temperature not exceeding 122° Fahr., until the mass has a tenacious consistence, then further add of sugar of milk, 1 oz., reduce the mixture to powder, and preserve it in a well-stoppered bottle. Every 6 gr. contains 1 gr. of iodide of iron.

From “syrup of iodide of iron” exposed in a shallow vessel, in a warm place, until it crystallises; the crystals are collected, dried, and powdered. A simpler plan is to gently evaporate the whole to dryness, and to powder the residuum. The saccharine iodide may be kept for some time in a corked bottle without undergoing decomposition.

Obs. The preparation of the above compound, like that of the citrates, has formed a fertile subject during some years for pharmaceutical amateurs to dilate upon. There is in reality not the least difficulty in the process. As soon as iodine and iron are mixed together under water much heat is evolved, and if too much water be not used the combination is soon complete, and the liquor merely requires to be evaporated to dryness, out of contact with the air, at a heat not exceeding 212° Fahr. This is most cheaply and easily performed by employing a glass flask, with a thin broad bottom and a narrow mouth, by which means the evolved steam excludes air from the vessel. The whole of the uncombined water may be known to be evaporated when vapour ceases to condense on a piece of cold glass held over the mouth of the flask. A piece of moistened starch paper occasionally applied in the same way will indicate whether free iodine is evolved; should such be the case, the heat should be immediately lessened. When the evaporation is completed, the mouth of the flask should be stopped up by laying a piece of sheet india rubber on it, and over that a flat weight; the flask must be then removed, and when cold broken to pieces, the iodide weighed, and put into dry and warm stoppered wide-mouth glass phials, which must be immediately closed, tied over with bladder, and the stoppers dipped into melted wax.

Prop., &c. Ferrous iodide evolves violet vapours by heat, and ferric oxide remains. When freshly made it is totally soluble in water, and from this solution, when kept in a badly stoppered vessel, ferric hydrate is very soon precipitated; but with iron wire immersed in it, it may be kept clear in a well-stoppered bottle.—Dose, 1 to 3 gr., or more, as a tonic, stimulant, and resolvent. It has been given with advantage in anæmia, chlorosis, debility, scrofula, and various glandular affections.

Ferrous Lactate. Fe(C3H5O3)2. Syn. Protolactate of iron; Ferri lactas, Ferrum lacticum, L. Prep. Boil iron filings in lactic acid diluted with water, until gas ceases to be evolved, and filter whilst hot into a suitable vessel, which must be at once closely stopped; as the solution cools, crystals will be deposited, which after being washed, first with a little cold water, and then with alcohol, are to be carefully dried. The mother liquor, on being digested, as before, with fresh iron, will yield more crystals.

Into sour whey, 2 lbs., sprinkle sugar of milk and iron filings, of each, in fine powder, 1 oz.; digest at about 100° Fahr., until the sugar of milk is dissolved, then add a second portion, and as soon as a white crystalline powder begins to form, boil the whole gently, and filter into a clean vessel; lastly, collect, wash, and dry the crystals as before.

Prop., &c. Ferrous lactate is a greenish-white salt; and when pure, forms small acicular or prismatic crystals, which have a sweetish ferruginous taste, and are soluble in about 48 parts of cold and in 12 parts of boiling water. It has been regarded by many high authorities as superior to every other preparation of iron for internal use, as being at once miscible with the lactic acid of the gastric juice, instead of having to be converted into a lactate at the expense of that fluid, as it is asserted is the case with the other preparations of iron.—Dose, 2 to 6 gr., frequently, in any form most convenient.

Ferrous Ma′late (Impure). Syn. Ferri malas impurus, L. Prep. (P. Cod., 1839.) Porphyrised iron filings, 1 part; juice of sour apples, 8 parts; digest for 3 days in an iron vessel, evaporate to one half, strain through linen whilst hot, further evaporate to the consistence of an extract, and preserve it from the air.—Dose, 5 to 20 gr., where the use of iron is indicated.

Ferrous Nitrate. (FeNO3)2. Syn. Protonitrate of iron, Nitrate of protoxide of iron; Ferri nitras, L. By dissolving ferrous sulphide in dilute sulphuric acid, in the cold, and evaporating the solution in vacuo. Small green crystals, very soluble, and prone to oxidation.

Ferrous Oxalate. (U. S.) Syn. Ferri oxalas. Prep. Sulphate of iron, 2 oz.; oxalic acid, 396 gr.; distilled water, q. s. Dissolve the sulphate in 30 oz. (old measure), and the acid in 15 oz. (old measure) of distilled water. Filter the solutions, mix them, shake together, and set aside until the precipitate is formed. Decant the clear liquid, wash the precipitate thoroughly, and dry it with a gentle heat.

Ferrous Oxide. FeO. Syn. Protoxide of iron, Ferri protoxydum, L. This substance is almost unknown in a pure state, from its extreme proneness to absorb oxygen and pass into the sesquioxide.

Ferrous Phosphate. Syn. Phosphate of iron, Neutral p. of protoxide of iron, Bimetallic ferrous orthophosphate (Odling); Ferri phosphas (Ph. U. S.), L. A salt formed from ordinary or tribasic phosphoric acid.

Prep. (B. P.) Ferrous sulphate, 3; sodium phosphate, 2⁄2; sodium acetate, 1; boiling distilled water, 80; dissolve the sulphate and sodium salts, each in half the water, mix, and stir carefully, filter through calico, wash with hot distilled water until it ceases to give a precipitate with barium chloride, dry at a heat not exceeding 120° Fahr. (Ph. U. S.) Ferrous sulphate, 5 oz.; sodium phosphate, 6 oz.; dissolve each separate in 2 quarts of water, mix the solutions, and after repose for a short time wash and dry the precipitate.

Prop., &c. A slate-coloured powder; insoluble in water; soluble in dilute nitric and hydrochloric acid.—Dose, 5 to 10 gr.; in amenorrhœa, diabetes, dyspepsia, scrofula, &c.; and externally, as an application to cancerous ulcers.

Ferrous Sulphate. FeSO4.7Aq. Syn. Protosulphate of iron, Sulphate of iron, Copperas, Green vitriol, Shoemaker’s black; Ferri sulphas (B. P., Ph. L. E. & D.), Vitriolum ferri. The crude sulphate of iron or green vitriol of commerce (FERRI SULPHAS VENALIS, Ph. L.) is prepared by exposing heaps of moistened iron pyrites or native bisulphuret of iron to the air for several months, either in its unprepared state or after it has been roasted. When decomposition is sufficiently advanced, the newly formed salt is dissolved out with water, and the solution crystallised by evaporation. In this state it is very impure. The ferrous sulphate or sulphate of iron employed in medicine is prepared as follows:—

Prep. (B. P.) Iron wire, 4; sulphuric acid, 4; distilled water, 30. Pour the water on the iron, add the acid, and when the disengagement of gas has nearly ceased, boil for ten minutes. Filter through paper. Allow to stand twenty-four hours, and collect the crystals. Sulphuric acid, 1 fl. oz.; water, 4 pints; mix, and add of commercial sulphate of iron, 4 lbs.; iron wire, 1 oz.; digest with heat and occasional agitation until the sulphate is dissolved, strain whilst hot, and set aside the liquor that crystals may form; evaporate the mother-liquor for more crystals, and dry the whole.

Dissolve the transparent green crystals of the impure sulphate of iron in their own weight of water, acidulated with sulphuric acid, and re-crystallise.

The formula of the Ph. U. S. is similar.

Dried; Ferri sulphas exsiccata, B. P.; Ferri sulphas exsiccatum—Ph. E., F. s. siccatum—Ph. D. From ferrous sulphate, heated in a shallow porcelain or earthen vessel, not glazed with lead, till it becomes a greenish-grey mass, and then reduced to powder. The heat should be that of an oven, or not exceeding 400° Fahr. Five parts of the crystallised sulphate lose very nearly 2 parts by drying.

Granulated; Ferri sulphas granulata, L. (B. P.) A solution of iron wire, 4 oz., in sulphuric acid, 4 fl. oz., diluted with water, 1⁄2 pint, after being boiled for a few minutes, is filtered into a vessel containing rectified spirit, 8 fl. oz., and the whole stirred until cold, when the granular crystals are collected on a filter, washed with rectified spirit, 2 fl. oz., and dried, first by pressure between bibulous paper, and next beneath a bell-glass over sulphuric acid, after which they are put into a stoppered bottle, to preserve them from the air.

Prop., &c. Ferrous sulphate forms pale bluish-green rhombic prisms, having an acid, styptic taste, and acid reaction; it dissolves in two parts of cold and less than one part of boiling water; at a dull-red heat it suffers decomposition; sp. gr. 1·82. It is perfectly soluble in water; a piece of iron put into the solution should not be covered with metallic copper. By exposure to the air it effloresces slightly, and is partly converted into a basic ferric sulphate.—Dose, ⁄2 to 4 gr., in pills or solution; externally, as an astringent or styptic. In the arts, as sulphate of iron (copperas), it is extensively used in dyeing, and for various other purposes. The dried sulphate (ferri sulphus exsiccatum) is chiefly used to make pills.

Crude sulphate of iron is frequently contaminated with the sulphates of copper, zinc, manganese, aluminium, magnesium, and calcium, which, with the exception of the first, are removed with difficulty. It also contains variable proportions of the neutral and basic ferric sulphates. The preparation obtained by direct solution of iron in dilute sulphuric acid should, therefore, be alone used in medicine.

In commerce there are four varieties of crude sulphate of iron or copperas known,—greenish-blue, obtained from acid liquors,—pale green, from neutral liquors,—emerald green, from liquors containing ferric sulphate,—and ochrey brown, which arises from age and exposure of the other varieties to the air. Even the first two of these contain traces of ferric sulphate, and hence give a bluish precipitate with ferrocyanide of potassium; whereas the pure sulphate gives one which is at first nearly white.

Ferrous Sulphide. FeS. Syn. Sulphuret of iron, Sulphide of i., Protosulphide of i.; Ferri sulphuretum (Ph. E. & D.), L. Prep. (Ph. E. & D.) Expose a bar of iron to a full white heat, and instantly apply a solid mass of sulphur to it, observing to let the melted product fall into water; afterwards separate the sulphide from the sulphur, dry, and preserve it in a closed vessel.

From sublimed sulphur, 4 parts; iron filings, 7 parts; mixed together and heated in a common fire till the mixture begins to glow, and then removing the crucible from the heat, and covering it up, until the reaction is at an end, and the whole has become cold.

Hydrated; Ferri protosulphuretum hydratum, L. By adding a solution of ammonium sulphide or of potassium sulphide to a neutral solution of ferrous sulphate made with recently distilled or boiled water; the precipitate is collected on a filter, washed as quickly as possible with recently boiled water, squeezed in a linen cloth, and preserved in the pasty state, under water, as directed under ferric hydrate.

Prop., &c. The sulphide prepared in the dry way is a blackish brittle substance, attracted by the magnet. It is largely used in the laboratory as a source of sulphuretted hydrogen. The hydrated sulphide is a black, insoluble substance, rapidly decomposed by exposure to the air. Proposed by Mialhe as an antidote to the salts of arsenic, antimony, bismuth, lead, mercury, silver, and tin, and to arsenious acid; more especially to white arsenic and corrosive sublimate. A gargle containing a little hydrated sulphide of iron will instantly remove the metallic taste caused by putting a little corrosive sublimate into the mouth. (Mialhe.) On contact with the latter substance it is instantly converted into ferrous chloride and mercurous sulphide, two comparatively inert substances. It is administered in the same way as ferrous hydrate. When taken immediately after the ingestion of corrosive sublimate, it instantly renders it innocuous; but when the administration is delayed until 15 or 20 minutes after the poison has been swallowed, it is almost useless.

Ferrous Tar′trate. Syn. Ferri tartras, Ferri prototartras, L. Prep. 1. From iron filings, 2 parts; tartaric acid, 1 part; hot water, q. s.; digest together until reaction ceases, agitate the liquid, pour off the turbid solution, and collect, wash, and dry the powder as quickly as possible, and keep it out of contact with the air.

2. Crystallised potassium tartrate, 132 parts; ferrous sulphate, 139 parts; dissolve each separately, mix the solutions, and collect the precipitate as before. A nearly insoluble powder; seldom used.

Obs. By dissolving the corresponding hydrates in a solution of tartaric acid, employing the former in slight excess, and evaporating, both the ferrous and ferric tartrate are easily obtained.

IRON AL′UM. See Alums.

IRON CEMENT′. See Cements.

IRON, DIALYSED. (Paris Pharmaceutical Society.) Syn. Ferrum dialysatum. Oxide de fer dialysé. Prep. Solution of ferric chloride (sp. gr. 1·245), 100 grams; solution of ammonia (sp. gr. 1·169), 35 grams; add the ammonia in small quantities to the ferric chloride; at first the precipitate formed is redissolved very rapidly, but afterwards disappears more slowly. When the liquor has again become transparent, it is introduced into the dialyser; the distilled water in which the vessel containing the ferruginous solution is placed, must be frequently renewed. After a time the highly coloured solution is no longer precipitated by silver nitrate, and gives no acid reaction. It is then absolutely free from the disagreeable taste of certain ferruginous preparations. A small quantity of hydrochloric acid always remains in the liquor, which may be shown by precipitating the oxide of iron by a slight excess of ammonia, filtering, adding an excess of nitric acid, and then silver nitrate. Ten c.c. are evaporated, and from the residue must be calculated how much distilled water is required to be added to produce a 10 per cent. solution.

2. (‘American Journal of Pharmacy.’) Take 10 parts of liq. ferri perchlor. (B. P.), precipitate by liquor ammoniæ, and wash the precipitate thoroughly. Mix this with 12 parts of liq. ferri perchlor. (B. P.), and place in a dialyser. The dialyser is placed in a suitable vessel with distilled water, the water under it renewed every 24 hours. The operation is continued until no trace of chlorine exists, at which time the preparation is found to be neutral. It usually takes from twelve to fifteen days to complete the process.

The resulting preparation, which should be of a deep dark red colour, contains about 5 per cent. of the oxide of iron. If the solution after completion of the operation should contain more than 5 per cent. of iron, it may be diluted with dialysed water till it reaches that point.

The above formula is said to furnish an article precisely similar to the original Bravais’ dialysed iron.

3. (E. B. Shuttleworth.) Add ammonia to a solution of perchloride of iron as long as the precipitate formed is redissolved. A solution is produced which contains ferric hydrate dissolved in ferric chloride, with free chloride of ammonium. Either the liquor ferri perchlor. fort. (B. P.), or the liquor ferri chloridi (U. S.), may be conveniently used, and the liquor ammoniæ, sp. gr. ·959 or ·960, of either Pharmacopœia will be found a convenient strength. If the ammonia be added to the strong solution of iron, considerable heat is evolved, and, on cooling, the preparation becomes gelatinised—often so much so that the vessel containing it may be inverted. It is better to avoid this result, and to such end the solution of perchloride must be diluted until of a sp. gr. of about 1·300. This degree may be nearly enough approached by diluting two measures of the B. P. liquor with one of water; or adding one measure of water to five of the U. S. preparation. This solution will generally remain permanently bright and fluid. The amount of liquor ammoniæ required will of course vary with the acidity of the perchloride. The liquor ferri B. P. will sometimes bear as much as an equal volume. A gelatinised solution, even when made from the undiluted liquor, will often become fluid when put upon the dialyser, but, as I have said before, it is better to work with bright solutions.

4. (Dr Pile.) Dr Pile, noticing the fact that chloride of sodium is one of the most rapid crystalloids to dialyse, used a solution of carbonate of sodium to add to the solution of ferric chloride in place of the ammonia so generally recommended, and with great success. The solution of ferric chloride (U. S.) which has been neutralised by a cold solution of carbonate of sodium is poured into a floating dialyser. Starting with 1 pint of solution of ferric chloride, which on being treated with the sodium solution and ready to dialyse, had a sp. gr. of 1·175, it had in 5 days increased to 5 pints. The water in which the dialyser floated was changed daily. At the end of five days it had passed through the membrane all the crystalloids, was free from taste of foreign substances, and owing to increase of bulk had now the sp. gr. of 1·0295, and on evaporation yielded 5 per cent. dry oxide of iron. Too long dialysation will cause the solution of iron to become gelatinous.

Mr Shuttleworth says that an efficient dialyser may be made out of one of the flat hoops of an ordinary flour barrel, a bell jar, or even an inverted glass funnel. He gives the preference to the former, and limits its diameter to ten or twelve inches; if it exceeds this, the septum is liable to bulge in the centre, and to make the layer of liquid too deep at that point.

The parchment paper employed for the septum must be entirely free from holes; this is an essential condition, and if any should be discovered—by the simple process of sponging the upper surface of the paper with water, and then carefully examining the under surface,—they must be stopped by means of a little white of egg, applied and coagulated by heat, or by a drop of collodion.

The parchment paper is not the kind ordinarily known under that name, but a less porous description, which has been made by previous immersion in dilute sulphuric acid.

Well-washed bladder, deprived of its outer coat, also makes a good septum.

The septum should be tied around the hoop with twine, but not too tightly, and should be so arranged that its edges shall be left standing up around the hoop, so as to absorb any liquid escaping from the hoop at its junction with the septum. The dialyser being ready for use, the liquid intended for dialysis is poured into it to a depth of not more than half an inch, and the dialyser with its contents is then floated on the surface of some distilled water, contained in a suitable receptacle.

The hoop must only be allowed to sink just below the level of the water; if it gets below this point, it will be necessary to keep it up by some support or the other.

It is necessary to change the water in the outer vessel daily. For the first two or three days distilled water should always be used. When this is not obtainable rain water should be employed. When the water shows the absence of chlorides, and the preparation ceases to have a ferruginous taste, the operation may be regarded as finished. The process generally occupies one or two weeks.

“A pig’s bladder, completely filled with the iron solution, securely tied, and immersed in water frequently changed, answers well for making this preparation. The process requires a longer time than with a carefully regulated and properly conducted dialysis, but it entails considerably less trouble. I consider it an advantage to procure the bladder perfectly fresh, as it is then easily cleaned by pure water, and alkaline ley need not be used. Great care is necessary in tying the neck carefully. This can be best accomplished by a few turns of iron wire. Above this may be secured a piece of twine, to suspend the bladder, by means of a stick, or rod, placed on the edge of the vessel containing the water. The bladder should be perfectly full, and immersed altogether in water. The attraction of the solution for the water is so great, that considerable pressure is manifested, and should any parts or holes be in the bladder, the liquid will be forced out, water will take its place, and failure result.”

Pretty general consent appears to have fixed the strength of the solution of dialysed iron at five per cent. Where it exceeds this, the solution must be diluted with distilled water; and where it falls short of the amount, it will have to be reduced to the required volume by standing it in a warm and dry situation. The employment of much heat must be particularly avoided as it very frequently leads to the destruction of the compound; hence every care should be taken to render the evaporation of the fluid unnecessary.

There seems little doubt that the so-called “dialysed iron” is an oxychloride of the metal. Prof. Maisch believes it to be a very basic oxychloride of iron. On the supposition that the oxychloride and chloride of iron are both present in the liquid put into the dialyser, the origin of the oxychloride admits of easy explanation:—The chloride being a crystalloid, diffuses through the septum into the outer water, and thus becomes separated from the oxychloride, which being a colloid, and incapable of a passage through the membrane, remains in solution in the dialyser.

The comparative freedom from taste and easy assimilation of the oxychloride of iron render it a valuable therapeutic agent. The dose of the five per cent. solution is 15 to 50 drops daily, in divided doses. Syrup forms a pleasant vehicle for its administration.

Dialysed iron has been successfully employed in a case of arsenical poisoning. The ‘American Journal of Pharmacy’ for January, 1878, contains an interesting paper by Dr Mattison detailing a series of experiments, which conclusively prove its value as an antidote to arsenic. Dr Mattison recommends the administration of the iron to be immediately followed by a teaspoonful or more of common salt.

IRON FI′′LINGS. Syn. Ferri ramenta (Ph. L. 1836). Ferri limatura (Ph. E.), Ferri scobs (Ph. D.). The usual method of preparing iron filings for medical purposes has been already noticed; the only way, however, to obtain them pure, is to act on a piece of soft iron with a clean file. The Fr. Cod. orders them to be forcibly beaten in an iron mortar, and to be separated from oxide and dust by means of a fine sieve, and from the grosser parts by means of a coarse hair-sieve.—Dose, 10 to 30 gr., in sugar or honey, as a chalybeate; in larger doses it is an excellent vermifuge, especially for ascarides or the small thread-worm.

IRON LIQ′UOR. Syn. Pyrolignite of iron, Dyer’s acetate of i., Black liquor, Tar iron L.; Ferri acetas venalis, L. This article, so extensively used in dyeing, is a crude mixed acetate of the protoxide and sesquioxide of iron. It is usually prepared by one or other of the following methods:—

1. Old scraps of iron (hoops, worn-out tin-plate, &c.) are left in a cask of pyroligneous acid, occasional agitation being had recourse to, until a sufficiently strong solution is obtained. By keeping the acid moderately warm in suitable vessels it will become saturated with the iron in a few days. With cold acid, on a large scale, forty days or more are required to complete the process.

2. A solution of pyrolignite or crude acetate of lime, is added to another of green copperas, as long as a precipitate is formed; after repose, the clear liquor is decanted.

IRON, REDUCED. Syn. Quevenne iron; Ferrum redactum (B. P.), Ferri pulvis, L.; Fer reduit, F. Prep. This preparation, which consists of metallic iron in a fine state of division mixed with a variable amount of magnetic oxide of iron, is made by passing perfectly dry hydrogen over peroxide of iron heated to redness in a gun-barrel.

Prop. A greyish-black powder, attracted by the magnet, and exhibiting metallic streaks when rubbed with firm pressure in a mortar. Rapidly absorbs oxygen, and must, therefore, be preserved from the air in well-stoppered bottles. It dissolves in hydrochloric acid with the evolution of hydrogen. 10 grains added to an aqueous solution of 50 grains of iodine and 50 grains of iodide of potassium, and digested with them in a small flask at a gentle heat, should leave not more than 5 grains undissolved, which should be entirely soluble in hydrochloric acid.

Uses. In medicine it is chiefly given to restore the condition of the blood in all anæmic states of the system. There is no pulverulent state of iron so convenient as this for children, as it has no taste, and only a very small dose is required.—Dose, 1 to 5 grains (children, ⁄4 to 1 grain), in powder, pill, or between bread and butter.

Iron reduced by Electricity. See Electricity, Iron reduced by.

Iron, to remove Rust from Polished. Rust of iron may be removed from a polished grate by means of emery paper, or by scraping some Bath-brick to a fine powder, mixing it with a little oil and rubbing the spots well with a piece of flannel dipped in this mixture; after which some whiting should be applied by diligent friction. This operation requires daily repetition until the rust has disappeared. Steel fire-irons, fenders, &c., when put aside in the summer, should be previously smeared thinly over with a species of paraffin, known to druggists by the name of ‘vaseline’ or ‘cosmoline,’ or with grease, mercurial ointment, &c.

Iron, to remove the Stains of, from Marble. Rub on very cautiously (confining it to the surface only occupied by the spot) some strong hydrochloric acid, removing it directly the spot disappears. Should this cause any diminution in the polish, this may be restored by means of emery paper.

IRON WIRE. Syn. Ferrum in fila tractum (Ph. L.), Ferri filum (Ph. E.), Ferri fila (Ph. D.), L. This is the only form of metallic iron retained in the Ph. L. It is used to make preparations of iron.

ISATINE. C16H10N2O4. A yellow crystalline body obtained by the oxidation of indigo. When acted upon by potash it becomes converted into aniline. Isatine may be formed by heating indigo in a dilute solution of dichromate of potash and sulphuric acid, or by treating indigo under proper conditions with nitric acid.

ISCHU′RIA. In pathology, retention, stoppage, or suppression of the urine.

I′′SINGLASS. Syn. Ichthyocolla, L. The finest kinds of isinglass are obtained from various species of the genus Acipenser, or sturgeon, that from the great sturgeon being perhaps the most esteemed. It is the air-bag, swimming bladder, or sound, dried without any other preparation than opening, folding, or twisting it. The picked or cut isinglass of the shops consists of the lamps of staple isinglass picked in shreds by women and children, or cut by machines.

Prop., &c. Good isinglass is the purest natural gelatin known. Its quality is determined by its whiteness, absence of the least fishy odour, and ready and almost entire solubility in boiling water; the solution forming a nearly white, scentless, semi-transparent, solid jelly, when cold. It is soluble in weak acids, and this solution is precipitated by alkalies. The aqueous solution is not precipitated by spirit of the common strengths. 1 part of good isinglass dissolved in 25 parts of hot water forms a rich, tremulous jelly. It is very commonly adulterated. Of the different varieties of isinglass, the Russian is the best and most soluble. See Gelatin.

ISOM′ERISM. In chemistry, identity of composition, with dissimilarity of properties. Isomeric compounds (isomerides) are such as contain the same elements in the same proportions, but which differ from each other in their chemical properties; thus, formate of ethyl and acetate of methyl are isomeric, having precisely the same ultimate composition, though differing in the arrangement of their elements.

ISOMOR′PHISM. In chemistry, the quality possessed by bodies differently composed of assuming the same crystalline form. Isomorphous substances are found to be closely allied in their chemical nature; and the fact of two bodies crystallising in the same form has often led to the discovery of other points of similarity between them. The alums, for instance, no matter what their components, all crystallise in octahedra, and a crystal of potassium-alum, if transferred to a solution of chrome-alum, will continue to increase with perfect regularity from the deposition of the latter salt.

IS′SUE. Syn. Foniculus, L. In surgery, a small artificial ulcer formed on any part of the body by means of caustic or the lancet, and kept open by daily introducing an ISSUE PEA covered with some digestive or stimulating ointment; the whole being duly secured by an appropriate bandage.

ISSUE PEAS. Syn. Pisæ pro fonticulis, L. Those of the shops are the immature fruit of the orange tree (ORANGE BERRIES). They are usually smoothed in a lathe. Issue peas are also ‘turned’ from orris root. The following compound issue peas are occasionally employed:—

1. Orris root (in powder) and Venice turpentine, of each 1 part; turmeric, 2 parts; beeswax, 3 parts; melted together and made into peas whilst warm.

2. Beeswax, 3 parts; melt, add of Venice turpentine, 1 part; mix, and further add, of turmeric, 2 parts; orris root (in powder), 1 part; mix well, and form the mass into peas whilst warm. More irritating than the common pea.

3. (Dr Gray.) Beeswax, 12 parts; verdigris and white hellebore, of each 4 parts; orris root, 3 parts; cantharides, 2 parts; Venice turpentine, q. s. Used to open issues instead of caustic, but their employment requires care.

ISSUE PLAS′TERS. See Plasters.

ITCH. Syn. Youk‡, Scotch Fiddle‡; Psora, Scabies, L.; Gale, Fr. In pathology, a cutaneous disease, caused by a minute insect lodging under the skin, and readily communicated by contact. There are four varieties of itch, distinguished by nosologists by the names—scabies papuliformis, or rank itch;—scabies lymphatica, or watery itch; scabies purulenta, or pocky itch; scabies cachectica, a species exhibiting appearances resembling each of the previous varieties. Our space will not permit more than a general notice of the common symptoms, and the mode of cure which is equally applicable to each species, and will not prove injurious to other skin diseases simulating the itch.

The common itch consists of an eruption of minute vesicles, principally between the fingers, bend of the wrist, &c., accompanied by intense itching of the parts, which is only aggravated by scratching. The usual treatment is repeated applications of sulphur ointment (simple or compound), well rubbed in once or twice a day, until a cure is effected; accompanying its use by the internal exhibition of a spoonful or more of flowers of sulphur, mixed with treacle or milk night and morning. Where the use of sulphur ointment is objectionable, a sulphur bath, or a lotion or bath of sulphurated potash, or of chloride of lime, may be employed instead.

In the ‘Canadian Pharmaceutical Journal’ for 1872 is a paper by Professor Rothmund recommending the employment of balsam of Peru in this objectionable disease. The writer states that one application generally effects a cure, and that its use does away with the necessity of baths. He recommends the balsam being rubbed all over the naked body. Carbolic acid is another and much cheaper remedy proposed by the same author. To obviate its caustic action he advises the acid to be mixed with glycerin or linseed oil, in the proportion of one scruple of the acid to two ounces of either excipient. He considers the objection to this remedy may be that it enters too rapidly into the circulation. Another agent employed by Professor Rothmund is a lotion composed of one part of carbolate of sodium dissolved in 12 parts of water. The affected parts of the skin are to be rubbed with this three times a day.

It is further recommended to continue this treatment 8 or 10 days after the cure, in order to kill any acari or their eggs that may have lurked among the clothes or bed-linen. See Bath, Lotion (Itch), Ointment, Psoriasis, &c.

I′VORY. The osseous portion of the tusks and teeth of the male elephant, the hippopotamus, wild boar, &c. That of the narwhal or seahorse is the most esteemed, on account of its superior hardness, toughness, translucency, and whiteness. The dust or shavings (IVORY DUST, IVORY SHAVINGS) of the turner form a beautiful size or jelly when boiled in water. Vegetable ivory is the hard albumen of the seed of the Phytelephas macrocarpa, one of the Palm family.

Ivory may be dyed or stained by any of the ordinary methods employed for woollen, after being freed from dirt and grease; but more quickly as follows:—

1. Black. The ivory, well washed in an alkaline lye, is steeped in a weak neutral solution of nitrate of silver, and then exposed to the light, or dried and dipped into a weak solution of sulphide of ammonium.

2. Blue. Steep it in a weak solution of sulphate of indigo which has been nearly neutralised with salt of tartar, or in a solution of soluble Prussian blue. A still better plan is to steep it in the dyer’s green indigo-vat.

3. Brown. As for black, but using a weaker solution of silver.

4. Green. Dissolve verdigris in vinegar, and steep the pieces therein for a short time, observing to use a glass or stoneware vessel; or, in a solution of verdigris, 2 parts; and sal ammoniac, 1 part, in soft water.

5. Purple. Steep it in a weak neutral solution of terchloride of gold, and then expose it to the light.

6. Red. Make an infusion of cochineal in liquor of ammonia, then immerse the pieces therein, having previously soaked them for a few minutes in water very slightly acidulated with aquafortis.

7. Yellow. a. Steep the pieces for some hours in a solution of sugar of lead, then take them out, and when dry, immerse them in a solution of chromate of potassa.

b. Dissolve as much of the best orpiment in solution of ammonia as it will take up, then steep the pieces therein for some hours; lastly, take them out and dry them in a warm place, when they will turn yellow.

Ivory is etched or engraved by covering it with an etching ground or wax, and employing oil of vitriol as the etching fluid.

Ivory is rendered flexible by immersion in a solution of pure phosphoric acid (sp. gr. 1·13), until it loses, or partially loses, its opacity, when it is washed in clean cold soft water, and dried. In this state it is as flexible as leather, but gradually hardens by exposure to dry air. Immersion in hot water, however, restores its softness and pliancy. According to Dr Ure, the necks of some descriptions of INFANTS’ FEEDING BOTTLES are thus made.

Ivory is whitened or bleached by rubbing it with finely powdered pumice-stone and water, and exposing it to the sun whilst still moist, under a glass shade, to prevent desiccation and the occurrence of fissures; observing to repeat the process until a proper effect is produced. Ivory may also be bleached by immersion for a short time in water holding a little sulphurous acid, chloride of lime, or chlorine, in solution; or by exposure in the moist state to the fumes of burning sulphur, largely diluted with air. Cloez recommends the ivory or bones to be immersed in turpentine and exposed for three or four days to sunlight. The object to be bleached should be kept an eighth or a fourth of an inch above the bottom of the bath by means of zinc supports. For the preparation of ivory intended for miniature painting Mr Ernest Spon in his useful work, ‘Workshop Receipts,’ says: “The bleaching of ivory may be more expeditiously performed by placing the ivory before a good fire, which will dispel the wavy lines if they are not very strongly marked, that frequently destroy the uniformity of surface.”

Ivory may be gilded by immersing it in a fresh solution of proto-sulphate of iron, and afterwards in solution of chloride of gold.

Ivory is wrought, turned, and fashioned in a similar manner and with similar tools to those used for bone and soft brass.

Obs. Bone for ornamental purposes is treated in a similar way to ivory, but less carefully, owing to its inferior value. The bones of living animals may be dyed by mixing madder with their food. The bones of young pigeons may thus be tinged of a rose colour in 24 hours, and of a deep scarlet in 3 or 4 days; but the bones of adult animals take fully a fortnight to acquire a rose colour. The bones nearest the heart become tinged the soonest. In the same way logwood and extract of logwood will tinge the bones of young pigeons purple. (Gibson.)

1. Ivory, Artificial. Let a paste be made of isinglass, egg-shell in very fine powder, and brandy. Give it the desired colour, and pour it while warm into oiled moulds. Leave the paste in the moulds until it becomes hard.

2. (L’Union Pharmaceutique.) Two parts of caoutchouc are dissolved in 36 parts of chloroform, and the solution is saturated with pure gaseous ammonia. The chloroform is then distilled off at a temperature of 85° C. The residue is mixed with phosphate of lime or carbonate of zinc, pressed into moulds and dried. When phosphate of lime is used the product possesses to a considerable degree the nature and composition of ivory.

IVORY BLACK. See Black pigments.

JABORANDI. Syn. Iaborandi, Jamborandi. The above names are given by the natives of Brazil, Paraguay, and other parts of South America to any indigenous plants possessing strongly stimulant, diaphoretic, and sialagogue properties, which are principally employed in those countries as antidotes for the bites and stings of venomous snakes and insects.

As far as they have been examined, all the plants known under the generic name ‘jaborandi’ have been traced to the two natural orders, Rutaceæ and Piperaceæ. Those exercising the most marked physiological effects appear to belong to the former or the rutaceous division, and are very probably different species of Pilocarpus. The drug was first introduced into Europe by Dr Coutinho, of Pernambuco, who some four years since sent a sample of it to Dr Gubler, of Paris, by whom it was administered to some of the patients of the Beaujon Hospital there. The jaborandi with which these experiments were made was identified by Professor Baillon, of Paris, as belonging to the Pilocarpus pinnatus (pinnatifolius). Four to six grams of the bruised leaves and twigs were infused in a cup of water, and the patient being put to bed, in ten minutes after taking the draught, finds himself bathed in a perspiration lasting for four or five hours, this being so profuse as to render several changes of linen necessary during the time. Accompanying the diaphoresis are great salivary and bronchial secretions, which sometimes will not permit the patient to speak without his mouth becoming filled with water.

The quantity of saliva is stated to have sometimes equalled a litre in measure. These experiments have been repeated in this country with analogous effects; in one case reported with jaborandi obtained from the Beaujon Hospital, and in another from London; results the similarity of which strongly point to a corresponding composition in the two specimens of the plant used, if, as seems not improbable, they may have belonged to different species. A case of impaired vision following the administration of jaborandi is also recorded; but this seems evidently to have been the effect of an overdose of the drug.

When jaborandi is administered in divided doses instead of producing salivation or sweating, it acts as an active diuretic only, increasing the flow of urine to nearly double the usual amount. M. Albert Robins says:—“The effect of jaborandi on animals is very marked; guinea-pigs are seized with salivation, weeping and diarrhœa, true ecchymoses being found in the intestines, and dogs become instantly salivated, their gastric secretion being also much increased.”

Drs Coutinho and Gubler affirm they have employed jaborandi in dropsy, bronchitis, diabetes, and various other diseases, and that they have found it fully answer their expectations; and in one case of albuminuria it is narrated that a permanent diminution of albumen from 14·40 to 12 grammes followed its use.

An alkaloid has been obtained from the piperaceous jaborandi by Parodi, and named by him jaborandine. Some short time afterwards Mr A. W. Gerrard succeeded in separating the alkaloid from the rutaceous jaborandi, to which, in accordance with Mr Holmes’ suggestion, and because Parodi had anticipated him in the adoption of the previous title, he gave the name pilocarpine.

Mr Gerrard recommends the following process for the preparation of pilocarpine:—“Prepare a soft extract either with leaf or bark, with 50 per cent. alcohol. Digest this with water, filter and wash. Evaporate the filtrate to a short extract, cautiously add ammonia in slight excess, shake well with chloroform, separate the chloroform solution, and allow it to evaporate; the residue is the alkaloidal pilocarpine with probably a small amount of impurity.” Mr Gerrard has also succeeded in preparing a crystalline nitrate and hydrochlorate of the alkaloid, both of which possess the medicinal powers of the jaborandi.

The abridged description of a sample of jaborandi from Pernambuco is from Mr Holmes’ paper in the ‘Pharmaceutical Journal.’ The cut is from the last edition of Royle’s ‘Materia Medica.’ “The specimens of the plant examined appear to belong to a shrub about 5 feet high. The root is cylindrical, hardly tapering at all, nearly ⁄4 inch in diameter for the first 12 inches, and very sparingly branched. Bark of root of a pale yellowish brown, about a line in thickness, and has a short fracture. The root has an odour like a mixture of bruised pea-pods and orange-peel. Its taste is first like that of green peas; this soon disappears, and gives rise to a tingling sensation. The stem is ⁄2 inch in diameter near the root, narrowing to ⁄4 inch in the upper branches. The bark is thin, greyish-brown, longitudinally striated, and in some specimens sprinkled over with a number of white dots. The wood of the stem is yellowish-white and remarkably fibrous. The leaves (one of which is represented in the drawing) are imparipinnate, about 9 inches long, with from 3 to 5 pairs of opposite leaflets, which are articulated to the rachis, and have very short, slightly swollen petiolates. The rachis of the leaf is swollen at the base.

The pairs of leaflets are usually about 1⁄4 inch apart, the lowest pair being about 4 inches from the base of the rachis. The leaflets are very variable in size, even on the same leaf. Their general outline is oblong-lanceolate. They are entire, with an emarginate or even retuse apex and an unequal base, and texture coriaceous. The veins are prominent on both sides of the leaf, and branch from the midrib at an obtuse angle in a pinnate manner. When held up to the light the leaflets are seen to be densely pellucidly punctate. These pellucid dots, which are receptacles of secretion, are not arranged, as in another kind of jaborandi, in lines along the veinlets, but are irregularly scattered all over the leaf, and appear equally numerous in every part. The whole plant is glabrous.”

Mr Holmes says there appear to be two varieties, if not species, of this Pilocarpus, the one being perfectly smooth in every part, as above described, and the other having the stems, petioles, and under surface of the leaves covered with a dense velvety pubescence composed of simple hairs.

JAG′GERY. Syn. Palm sugar. A coarse brown sugar made in India by the evaporation of the juice of several species of palms. The following are the principal varieties of this product:—

1. Cocoa jaggery. From the juice of the Cocoa-nut palm (Cocos nucifera).

2. Malabar jaggery. From the juice of the Gummuti palm (Saguerus saccherifer).

3. Mysore jaggery. From the juice of the wild Date-palm (Phœnix sylvestris); 17 galls. yields 46 lbs.

4. Palmyra jaggery. From the juice of the Palmyra palm (Borassus flabelliformis); 6 pints yield 1 lb.

JA′LAP. Syn. Jalapæ radix, Jalapa, B. P. (Ph. L. & D.) Convolvuli jalapæ radix (Ph. E.), L. The dried tubercles of the Exogonium purga, I. jalapa—(Royle.) Jalap is a powerful stimulant and drastic purgative, producing copious liquid stools; but when judiciously administered, both safe and efficacious. It appears to be intermediate in its action between aloes and scammony.—Dose, 10 to 30 gr., in powder; in constipation, cerebral affections, dropsies, obstructed menstruation, worms, &c. Owing to its irritant properties, its use is contra-indicated in inflammatory affections of the alimentary canal, and after surgical operations connected with the abdomen and pelvis. It is usually administered in combination with sulphate of potassa or bitartrate of potassa and ginger; with mercurials, as the case may indicate. The powder is very generally adulterated.

Jalap Biscuits. 1. An ounce of jalap mixed with 16 ounces of the materials for gingerbread or other kind of cake.

2. Pure resin of jalap, 56 grams, powdered sugar and flour, 1000 grams; tincture of vanilla, 10 grams, white of egg, No. 20, yolk of egg, No. 40.

Let the resin be emulsified with the yolks of the egg, add successively the sugar, tincture, and flour, and mix thoroughly into a paste, with which thoroughly incorporate the whites of eggs, previously beaten up. Let the mass be divided into 144 biscuits, and bake.

Jalap, Res′in of. Syn. Resina jalapæ, L. Prep. 1. (Ph. E.) See Extract of Jalap.

2. (Nativelle.) Jalap root is digested in boiling water for 24 hours, and after being reduced to thin slices more water is added, and the whole boiled for 10 minutes, with occasional agitation; the liquid is then expressed in a tincture press, and the boiling and pressing repeated a second and third time (these decoctions by evaporation yield AQUEOUS EXTRACT OF JALAP); the pressed root is next treated with rectified spirit, q. s., and boiled for 10 minutes, and then allowed to cool; the tincture is then pressed out, and the boiling with fresh alcohol and expression is repeated twice; a little animal charcoal is added to the mixed tinctures, and, after thorough agitation, the latter are filtered; the liquid is now distilled until nothing passes over, the supernatant fluid is poured off the fluid resin, and the latter dried by spreading it over the surface of the capsule, and continuing the heat. The product is a friable and nearly colourless resin, which forms a white powder resembling starch. Prod. Fully 10% of pure resin.

3. (Planche.) Resinous extract of jalap is dissolved in rectified spirit, the tincture agitated with animal charcoal, and after filtration gently evaporated to dryness.

Pur. The jalap resin of commerce is generally adulterated with scammony, gum, guaiacum or resin. When in a state of purity, it does not form an emulsion with milk, like scammony resin, but runs into a solid mass. It is insoluble in fixed oils and turpentine, whilst the common resins are freely soluble in those menstrua. Its alcoholic solution, dropped on a piece of absorbent white paper, and exposed to the action of nitrous gas, does not acquire a green or blue colour; if it does, guaiacum resin is present. 2% of this adulteration may be thus detected. (Gobley.) It is insoluble in ether; but guaiacum resin, common resin, and some others, are so; the decanted ether should not become opalescent when mixed with water, and should evaporate without leaving any residuum. Powdered jalap resin placed in cold water does not dissolve, but forms a semi-fluid, transparent mass, as if it had been melted. Dissolved in a watch-glass with a little oil of vitriol, a rich crimson-coloured solution is obtained, from which, in a few hours, a brown viscid resin separates. These last two characteristics distinguish it from other resins.

Obs. Earthenware or well-tinned copper vessels must alone be used in the above processes, as contact with copper or iron turns the resin black, and this tinge can only be removed by redissolving the resin in alcohol, the addition of animal charcoal, and re-evaporation.

Jalap resin is an energetic cathartic.—Dose, 1 to 5 gr. See Jalapin.

Jalap, Factitious Resin of. Syn. Resinæ jalapæ factitia, L. A substance frequently sold for jalap resin is made by fusing a mixture of pale yellow resin and scammony resin, and adding, when it has cooled a little, but still semi-fluid, a few drops of balsam of Peru or tolu; the mixture is then poured into small paper capsules or tin moulds. Its effects resemble those of jalap resin, but it inflames less. (Landerer.)

Jalap, Soap of. Syn. Sapo jalapæ, Sapo jalapinus, L. Prep. (Ph. Bor.) Resin of jalap and Castile soap, of each 1 part; rectified spirit, 2 parts, or q. s. to dissolve the ingredients softened by a gentle heat; subsequently evaporate the mixture by the heat of a water bath until reduced to 4⁄2 oz., or it has acquired the consistence of a pill-mass.

Prop., &c. A greyish-brown mass, soluble in rectified spirit. Said to be milder in its action than the resin alone.—Dose, 5 to 15 oz.

JALAP′IC ACID. Syn. Odorous principle of jalap.—Pereira. Prep. Add an alcoholic solution of acetate of lead to a similar solution of jalap resin, collect the precipitate (jalapate of lead), and throw down the lead by means of sulphuretted hydrogen. (See Absinthic acid.) A brownish, soft, greasy substance, smelling strongly of jalap, soluble in alcohol and alkali, and slightly so in ether. Jalap resin contains about 13% of this substance.

JAL′APIN. C34H56O16. Syn. Jalapina. Jalap resin is commonly sold under this name, but pure jalapin is prepared by one or other of the following formulæ:—

Prep. 1. The liquid filtered from the jalapate of lead in preparing jalapic acid is a solution of acetate of jalapin, which, after any trace of lead is removed, by adding a few drops of dilute sulphuric acid, and filtration, yields the whole of its jalapin, as a precipitate, on the addition of 5 or 6 times its volume of water; this is collected, washed with a little cold distilled water, and dried by exposure to a current of warm dry air.

2. (Hume.) Coarsely powdered jalap is digested in strong acetic acid for 14 days, the tincture filtered ammonia added in excess, and the whole agitated strongly; the mixture is then filtered, the deposit washed in cold water, redissolved in acetic acid, reprecipitated by ammonia, and again washed and dried.

3. (Kayser.) Pure jalap resin, in powder, is digested for some time in boiling ether, by which means the jalapic acid is removed, and pure jalapin remains undissolved.

Prop., &c. A transparent, colourless, scentless, insipid resin, very soluble in alcohol, but insoluble in ether. It is the active purgative principle of crude jalap resin.

JAMAI′CINE. Syn. Jamaicina. A peculiar alkaloid obtained by Huttenschmidt from the bark of the Cabbage-tree (Andira inermis).

Prep. The aqueous solution of cabbage-tree bark, treated with sulphuretted hydrogen and evaporated.

Prop. Yellow crystals soluble in water and, to a limited extent, in alcohol; fusible, and very bitter tasted. It forms salts with the acids, which, in small doses, produce restlessness and trembling; and in larger ones, purging. It is said to be vermifuge.

JAMES’S POWDER. See Powders.

JAMS. Syn. Preserves. Conserves of fruit with sugar, prepared by boiling. In the latter respect they differ from the conserves of the apothecary.

Prep. The pulped or bruised fruit is boiled along with ⁄2 to ⁄3 of its weight of loaf sugar, until the mixture jellies, when a little is placed on a cold plate; the semi-fluid mass is then passed through a coarse hair sieve whilst hot, to remove the stones and skins of the fruit, and as soon as it has cooled a little is poured into pots or glasses. It is usual to tie these over, when cold, with paper which has been dipped in brandy. The pots must then be placed aside in a dry and rather cold situation.

The following fruits are those from which jams are commonly prepared:—Apricots, cherries (various), cranberries, currants (black, red, and white), gooseberries (ripe and green), mulberries, Orleans plums, raspberries, and strawberries. Red currants are commonly added to the last, to remove insipidity.

JAPAN′. See Varnish, and below.

JAPAN′NING. The art of covering paper, wood, or metal, with a coating of hard, brilliant, and durable varnish. The varnishes or lacquers employed for this purpose in Japan, China, and the Indian Archipelago, are resinous juices derived from various trees belonging to the natural order Anacardiaceæ, especially Stagmaria verniciflua, Holigarna longifolia, Semecarpus Anacardium, and species of Rus (Sumach). For use, they are purified by a defecation and straining, and are afterwards mixed with a little oil, and with colouring matter, as required. In this country varnishes of amber, asphaltum, or copal, or mixtures of them, pass under the names of ‘JAPAN’ and ‘JAPAN VARNISH,’

Proc. The surface is coloured or painted with devices, &c., as desired, next covered with a highly transparent varnish (amber or copal), then dried at a high temperature (135° to 165° Fahr.), and, lastly, polished. Wood and paper are first sized, polished, and varnished. For plain surfaces, asphaltum, varnish or japan is used. See Varnishing.

JAPON′IC ACID. C12H10O5. When catechu is exposed to the air in contact with caustic alkalies, black solutions (alkaline japonates) are formed; with carbonated alkalies, red solutions (alkaline rubates); the acid of the former may be separated. It is a black powder, insoluble in water, soluble in alkalies, and precipitated by acids. Buric acid forms red insoluble compounds with the earths and some other metallic oxides.

JARAVE. The Spanish name for SARSAPARILLA BEER. See Beers (in pharmacy).

JASPER. Syn. Iaspis, L. A mineral of the quartz family, occurring in rocky masses. It takes various shades of red, yellow, brown, and green, and is occasionally banded, spotted, or variegated. It was formerly used as an amulet against hæmorrhages and fluxes. It is now extensively worked up into rings, seals, snuff-boxes, vases, &c., for which it is well calculated from its extreme hardness and susceptibility of receiving a fine polish.

JATRO′PHIC ACID. Syn. Crotonic acid, Iatrophic a. A peculiar fatty acid discovered by Pelletier and Caventon, and originally regarded by them as the cathartic principle of croton oil and croton seeds, but since shown by Redwood and Pereira to be nearly inert.

Prep. The oil is saponified by caustic potassa, and the resulting soap is decomposed by tartaric acid; the fatty matter which floats on the surface of the liquid is then skimmed off the aqueous portion, and the latter submitted to distillation; the liquid in the receiver is a solution of jatrophic acid.

Prop., &c. Volatile; very acid; has a nauseous odour; is solid at 23°, and vaporizes at 35° Fahr. It forms salts with the bases, none of which possess any practical importance.

JAU′MANGE. Prep. From isinglass, 1 oz.; boiling water, 12 oz.; dissolve, add of any sweet white wine, ⁄2 pint; the yolks of 2 eggs beaten to a froth, and the grated yellow peel of two lemons; mix well, and heat the whole over the fire until sufficiently thickened, stirring all the time; lastly, serve it up or pour it into moulds.

JAUN′DICE. Syn. Icterus, Morbus luteolus, L. A disease characterised by a yellow colour of the eyes and skin, deep-coloured urine, and pale alvine evacuations. It appears to arise from a disordered action of the biliary organs. The treatment consists of the administration of saline aperients, and small doses of blue-pill, followed by tonics and diaphoretics. The action of these remedies should be promoted by the copious use of diluents (particularly saline water), and exertion in the open air, when possible. When there is much pain and vomiting, anodynes (or opium, morphia, &c.) may be administered. Jaundice is not in itself a dangerous disease, but it sometimes lays the patient open to attacks of others which are so.

Animals.—Jaundice affects cattle, giving rise to a tawny hue of the skin and membranes. Pleuro-pneumonia is frequently followed by jaundice. The best remedies are large doses of Epsom salts combined with ginger; and if these fail to remove the costiveness, a drachm of calomel should be added. If necessary, the above purge must be repeated next day, the action being assisted by giving the animal warm fluids.

Tonics and stimulants are also sometimes superadded to the above treatment.

JEL′LY. Syn. Gelatina, L. A term now very loosely applied to various substances which are liquid or semi-liquid whilst warm, and become gelatinous on cooling.

Jellies are coloured by the addition of the usual stains used by confectioners, and are rendered transparent by clarification with white of egg.

Jelly, Almond. Syn. Gelatina amygdalarum, L. Prep. From rich almond milk, ⁄4 pint; thick hartshorn jelly, ⁄2 pint; sugar, 2 oz.; with 2 or 3 bitter almonds and a little lemon peel, to flavour, heated together, strained, and moulded.

Jelly, Ar′row-root. Syn. Gelatina marantæ, L. From arrow-root, 1⁄2 oz., to water, 1 pint. Tous les mois jelly is made in the same way.

Jelly, Bis′cuit. Prep. From white biscuit (crushed beneath the rolling-pin), 4 oz.; cold water, 2 quarts; soak for some hours, boil to one half, strain, evaporate to 1 pint, and add, of white sugar, ⁄4 lb., red wine, 4 oz., and cinnamon, 1 teaspoonful. In weakness of the stomach, and in dysentery and diarrhœa, and in convalescence combined with rich beef gravy or soup.

Jelly, Bladder-wrack. (Dr Russell.) Syn. Gelatina fuci. Prep. Bladder-wrack (Fucus vesiculosus), 2 lbs.; sea water, 2 lbs.; macerate for 15 days. Applied to glandular tumours.

Jelly, Bread. Syn. Panada; Gelatina panis, L. Prep. Cut a French roll into slices, toast them on each side, and boil in water, 1 quart, until the whole forms a jelly, adding more water if required; strain, and add sugar, milk, &c., to palate. It may be made with broth from which the fat has been skimmed, instead of water. Used as the last.

Jelly, Broth. Syn. Soup-jelly. From broth or soup from which the fat has been skimmed, evaporated until it becomes gelatinous on cooling. A few shreds of isinglass are commonly added. See Soup (Portable).

Jelly, Calves’ Feet. Prep. For each foot take of water 3 pints, and boil to one half; cool, skim off the fat, and again boil for 2 or 3 minutes with the peel of a lemon and a little spice; remove it from the fire, strain through a jelly bag (see Filtration), add the juice of a lemon and a glass of wine, and when it has cooled a little put it into glasses or ‘forms.’

Obs. If this jelly is required to be very transparent it must be treated as follows:—After the fat is removed it should be gently warmed, just enough to melt it, next well beaten with the white of an egg and the seasoning, and then brought to a boil for a minute or two, when it will be ready for straining, &c. The calves’ feet should not be bought ready boiled, but only scalded. Cows’ feet (‘COW HEELS’) make nearly as good jelly as that from calves’ feet, and are much more economical.

Jelly, Ceylon Moss. Syn. Gelatina gracilariæ, L. Prep. (Dr Sigmond.) Boil Ceylon moss (Granularia lichenoides), ⁄2 oz. in water, 1 quart, for 25 minutes, or till the liquid jellies on cooling; strain and flavour. Very nutritious; recommended in irritation of the mucous membranes and phthisis.

Jelly, Copaiba. (M. Caillot.) Syn. Gelatina copaiba. Prep. Isinglass, 4 parts; water, 40 parts; dissolve in a water bath, and add 20 parts of sugar; pour the clear liquid jelly into a warm mortar, and add copaiba, 60 parts; triturate, and pour in a vessel to jelly. Flavour with some aromatic essential oil or balsam of tolu.

Jelly, Cor′sican Moss. Syn. Gelatina helminthocorti, L. Prep. (P. Cod.) Corsican moss (Gracilaria Helminthocorton), 1 oz.; water, q. s.; boil 1 hour, and strain 8 fl. oz.; to this add of isinglass (previously soaked in a little water), 1 dr.; refined sugar, 2 oz.; white wine, a wine-glassful. Vermifuge. See Decoction.

Jelly, Fruit. Under this head we include those jellies made from the juices of fruits.

Prep. The strained juice mixed with ⁄3 to ⁄2 its weight of refined sugar, until it ‘jellies’ on cooling, observing to carefully remove the scum as it rises. The process should be conducted by a gentle heat, and it is preferable not to add the sugar until the juice is somewhat concentrated, as by lengthened boiling the quality of the sugar is injured.

Obs. Jellies are sold in pots or glasses, like JAMS. Both jams and fruit jellies are refrigerant and laxative; they are, however, mostly employed as relishes, especially during fevers and convalescences. The principal fruit jellies are:—Apple, BARBERRY, CHERRY (from either Cornelian or Kentish cherries), CURRANT (black, white, and red), ELDERBERRY, GOOSEBERRY, PLUM, QUINCE, RASPBERRY. See Lemon and Orange jelly.

Jelly, Glycerin. Syn. Gelatina glycerini. Mix glycerin to the required consistence with compound tragacanth powder. Or take powdered gum Arabic, ⁄2 oz.; syrup, 4 oz. (3 oz. of sugar to 1 oz. of water); the yolks of 3 eggs; olive oil, 4 oz.; glycerin, 2 oz. Rub the gum and syrup well together, add the yolks, and when mixed add the oil and glycerine, previously triturated together. Applied to chapped hands, abrasions, &c. See Glycerin of Starch.

Jelly, Gra′′vy. By evaporating meat gravies.

Jelly, Harts′horn. Syn. Gelatina cornu cervi, L. Prep. (P. Cod.) Hartshorn shavings, 8 oz.; wash it in water, then boil in clean water, 3 pints, till reduced to one half; strain, press, add of sugar, 4 oz., the juice of one lemon, and the white of an egg beaten up with a little cold water; mix well, clarify by heat, evaporate till it jellies on cooling, then add the peel of the lemon, and set it in a cool place. It may be flavoured with wine, spices, &c. Very nutritious.

Jelly, Ice′land Moss. Syn. Gelatina lichenis, L. Prep. (P. Cod.) Iceland moss, 2 oz.; soak for 1 or 2 days in cold water, then boil for 1 hour in water, q. s. to yield a strong solution; strain, decant the clear after repose, apply heat, and dissolve therein of isinglass, 1 dr.; evaporate the whole to a proper consistence, put it into pots, and set them in a cool place. Nutritious. Recommended in phthisis. The jelly of Iceland moss and cinchona (GELATINA LICHENIS CUM CINCHONA—P. Cod.) is made by adding to the above syrup of cinchona, 6 fl. oz.

Jelly, Iceland Moss (Sweetened). (P. C.) Syn. Gelatina lichenis saccharata. Prep. Saccharated Iceland moss (see Iceland moss, Saccharated), 7⁄2 oz.; sugar, 7⁄2 oz.; water, 15 oz.; orange-flower water, 1 oz. Boil the first three substances and remove the scum which forms, and then let the jelly flow into a vessel which contains the orange-flower water.

Jelly, I′′rish Moss. Syn. Gelatina chondri, L. Prep. From Irish or carrageen moss. See Decoction.

Jelly, I′′singlass. Syn. Confectioners’ jelly; Gelatina ichthyocollæ, L. Prep. From isinglass dissolved in water by boiling, and evaporated till it ‘jellies’ on cooling, adding flavouring, as desired. 1⁄2 oz. of good isinglass makes fully a pint of very strong jelly. See Blancmange, Isinglass, Calves-feet Jelly, &c.

Jelly, Lem′on. From isinglass, 2 oz.; water, 1 quart; boil, add of sugar 1 lb., clarify, and when nearly cold add the juice of 5 lemons, and the grated yellow rinds of 2 oranges and of 2 lemons; mix well, strain off the peel, and put it into glasses.

Jelly No′yeau. As Punch jelly, but strongly flavoured with bitter almonds.

Jelly, Or′ange. From orange juice, 1 pint; let it stand over the grated yellow rind of 3 or 4 of the oranges for a few hours, then strain, and add, of loaf sugar, ⁄2 lb., or more, isinglass ⁄2 oz., dissolved in water, 1 pint; mix, and put it into glasses before it cools.

Jelly, Punch. From isinglass, 2 oz.; sugar, 1⁄4 lb.; water, 1 pint; dissolve, add of lemon juice, ⁄2 pint; the peels of 2 lemons and of 2 oranges; rum and brandy, of each ⁄4 pint; keep it in a covered vessel until cold, then liquefy it by a very gentle heat, strain, and pour it into moulds. A pleasant and deceptive way of swallowing alcohol.

Jelly, Quince. (E. P., 1744.) Syn. Gelatina cydoniorum. Prep. Juice of quinces, 3 lbs.; sugar, 1 lb.; boil to a jelly.

Jelly, Rice. Syn. Crême de Riz. From rice boiled in water, sweetened, and flavoured.

Jelly, Sago. Prep. Soak sago in cold water for 1 hour, strain, and boil in fresh soft water until it becomes transparent; then add wine, sugar, clear broth, milk, or spices, to flavour. 1 oz. of sugar makes a pint of good jelly.

Jelly, Salep. (Soubeiran). Syn. Gelatina salepæ. Prep. Ground salep, 4 dr.; sugar, 4 oz.; water, a sufficient quantity. Boil to 12 oz., and flavour to the taste.

Jelly, Ta′pioca. As Sago jelly, but using tapioca in lieu of sago.

JERVINE. C60H5N2O5 An alkaloid discovered in 1837, by Simon, in the root of the Veratrum album, and by Mitchell, in 1874, in the root of the Veratrum viride. Dr H. C. Wood, jun., describing the physiological effects of jervine, says they consist “in general weakness, lowering of arterial pressure, a slow pulse, profuse salivation, and finally convulsions.” Jervine was analysed by Will, who ascribed to it the above composition.

JES′UIT’S BARK. See Cinchona.

JESUIT’S DROPS. See Drops.

JESUIT’S POWDER. Powdered cinchona bark.

JET. A variety of mineral bituminous carbon, very hard, and susceptible of a fine polish.

JEW′ELS. See Diamond, Emerald, Gems, &c.

JEWEL′RY. The gold in articles of jewelry, whether solid or plated, which are not intended to be exposed to very rough usage, is generally ‘coloured,’ as it is called in the trade. This is done as follows:—

1. (Red gold colour.) The article, after being coated with the amalgam, is gently heated, and, whilst hot, is covered with gilder’s wax; it is then ‘flamed’ over a wood fire, and strongly heated, during which time it is kept in a state of continual motion, to equalise the action of the fire on the surface. When all the composition has burned away, the piece is plunged into water, cleansed with the ‘scratch-brush’ and vinegar, and then washed and burnished. To bring up the beauty of the colour, the piece is sometimes washed with a strong solution of verdigris in vinegar, next gently heated, plunged whilst hot into water, and then washed, first in vinegar, or water soured with nitric acid, and then in pure water; it is, lastly, burnished, and again washed and dried.

2. (Or-molu colour.) This is given by covering the parts with a mixture of powdered hematite, alum, common salt, and vinegar, and applying heat until the coating blackens, when the piece is plunged into cold water, rubbed with a brush dipped in vinegar, or in water strongly soured with nitric acid, again washed in pure water, and dried. During this process, the parts not to be dried in ‘or-molu colour’ should be carefully protected.

The frauds practised in reference to the ‘fineness’ of the metal used in jewelry is noticed under Gold (Jeweller’s). See also Assaying, Diamond, Gems, Gilding liquor, Gilding wax, &c.

JEW’S PITCH. See Asphaltum.

JOURNAL BOXES, Alloy for. Copper, 24 parts; tin 24 parts; antimony, 8 parts. First melt the copper, then add the tin, and lastly the antimony.

JUICE (Spanish). See Extract and Liquorice.

JU′JUBE. A fruit resembling a small plum, produced by various species of Zizyphus. Combined with sugar, it forms the JUJUBE PASTE of the shops, when genuine; but that now almost always sold under the name is a mixture of gum and sugar, slightly coloured and flavoured.

JU′LEP. Syn. Julap; Julepum, Julepus, Julapium, L. A term usually regarded as synonymous with ‘MIXTURE’; but according to the best authorities, implying a medicine which is used as a vehicle for other forms of medicine. The word comes through the French, from a Persian expression, which signifies ‘sweet drink.’ A julep, according to Continental writers, is a drink of little activity, generally composed of distilled waters, infusions, and syrups, to which mucilages and acids are sometimes added; “but never powders or oily substances, which could interfere with its transparency.” In England the juleps of old pharmacy are now classed under ‘MIXTURES,’

JU′′NIPER BERRIES. Syn. Juniperi baccæ, J. communis baccæ (Ph. E.), JUNIPERUS (Ph. L.), L. The fruit of the Juniperus communis, or common juniper tree. In the old Ph. L. & D. both the tops and berries (JUNIPERI FRUCTUS ET CACUMINA—Ph. L. 1836; JUNIPERUS—BACCÆ, CACUMINA—Ph. D. 1862) were ordered. The berries are stomachic and diuretic, and have been long employed in dropsies, either alone or combined with foxglove and squills. The tops (SUMMITATES) have been highly praised in scurvy and certain cutaneous affections.—Dose, 1 to 2 dr., made into a conserve with sugar, or in the form of infusion or tea.

Douath found 100 parts of the berries to contain—

Water 29·44

Volatile oil ·91

Formic acid 1·86

Acetic acid ·94

Malic acid (combined) ·21

Oxalic acid traces

Wax-like fatty matter ·64

Green resin (from ethereal solution) 8·46

Hard brown resin (from alcoholic solution) 1·29

Bitter principle (called juniperin) ·37

Pectin ·73

Albuminous substances 4·45

Sugar 29·65

Cellulose 15·83

Mineral substances 2·33

97·11

JUN′KET. Syn. Devonshire junket, Curd jelly. From warm milk put into a bowl, and then turned with a little rennet; some scalded cream and sugar are next added with a sprinkling of cinnamon on the top, without breaking the curd. Much esteemed by holiday folk in the western counties during the hot weather of summer. Sometimes, very strangely, a little brandy finds its way into these trifles.

JUTE. This is the fibre yielded by the Corchorus capsularis, a lime tree growing in India and China. It is the material of which sacks, gunny bags, and coarse thread are made. It mixes even with linen or cotton, and hence may not improbably be employed as a sophisticant of these substances.

The plates on page 930 exhibit the different microscopic appearances of the three substances.

KALEIDOSCOPE. Syn. Flower-glass. A pleasing philosophical toy invented by Sir David Brewster, which presents to the eye a series of symmetrical changing views. It is formed as follows:—Two slips of silvered glass, from 6 to 10 inches long, and from 1 to 1⁄2 inch wide, and rather narrower at one end than the other, are joined together lengthwise, by one of their edges, by means of a piece of silk or cloth glued on their backs; they are then placed in a tube of tin or pasteboard, blackened inside, and a little longer than is necessary to contain them, and are fixed by means of small pieces of cork, with their faces at an angle to each other that is an even aliquot part of 4 right angles (as the ⁄6, ⁄8, ⁄10, &c.). The other end of the tube is then closed with an opaque screen or cover, through which a small eyehole is made in the centre; and the other end is fitted, first with a plate of common glass, and at the distance of about ⁄8th of an inch, with a plain piece of slightly ground glass, parallel to the former; in the intermediate place or cell are placed the objects to form the images. These consist of coloured pieces of glass, glass beads, or any other coloured diaphanous bodies, sufficiently small to move freely in the cell, and to assume new positions when the tube is shaken or turned round. A tube so prepared presents an infinite number of changing and symmetrical pictures, no one of which can be exactly reproduced. This toy is so easily constructed, is so very inexpensive, and at the same time so capable of affording an almost inexhaustible fund of amusement to the young, that we advise our juvenile friends to try their hands at its construction. Any common tube of tin or pasteboard may be used, and strips of glass smoked on one side will answer for mirrors.

KA′LI. The name formerly applied to a species of Salsola employed for making BARILLA. It is sometimes used as a designation for the crude alkalies, and is the German synonym for ‘potassa.’

Kali, Acid′ulated. Syn. Lemon and kali, Lemonated k. A common preparation of the shops for making a pleasant effervescing draught. It is sometimes incorrectly styled ‘citrate of potash.’ Prep. 1. Carbonate of soda and tartaric acid, of each 5 oz.; lump sugar, 1 lb.; all in the state of fine powder, and separately dried by a very gentle heat, after which they are mixed together, flavoured with essence of lemon, 1 dr., rubbed through a gauze sieve in a warm dry situation, put into bottles, and corked down immediately.

2. Finely powdered white sugar, 16 lbs.; tartaric acid, 4⁄4 lbs.; carbonate of soda, 4 lbs.; essence of lemon, 1 oz.; as the last. Keeps well. A dessert-spoonful of either thrown into a glassful of water makes a pleasant effervescing draught.

KA′LIUM. [L.] Potassium.

KAL′YDOR. A cosmetic lotion; it resembles ‘Gowland’s Lotion,’ but is got up in a rather more pleasing style. See Lotion.

KAMALA. A powder consisting of the minute glands obtained from the capsules of the Rottlera tinctoria, a plant belonging to the nat. ord. Euphorbiaceæ. Kamala is imported from India, where it is known under the name of kameela. The rottlera, from which it is obtained, is a tree from 15 to 20 feet in height, indigenous to India and to many of the East Indian Islands.

Kamala has long been employed in India as a remedy for tapeworm, and within the last few years has been given for the same purpose in this country with very general success. It may be administered in doses of from thirty grains to three drachms, suspended in water, rubbed up with mucilage, or mixed with syrup. In large doses, such as three drachms, it sometimes purges violently. After the third or fourth motion the worm is generally evacuated dead. A second dose may be taken in about four hours should the first fail to act; or instead of a second dose, some castor oil may be given. Kamala is also used externally by the natives of India in various skin complaints, particularly in scabies. It is also said to have proved useful in herpetic ringworm.

Dr Anderson obtained from the resinous colouring matter, which is the principal constituent of kamala, a yellow crystalline substance, to which he gave the name rottlerin. The existence of rottlerin has since been confirmed by Mr Groves, who found that it becomes changed by exposure, a circumstance to which he attributes its non-detection in old specimens of the drug, and to which may very reasonably be attributed Leube’s failure to find it.

The ‘British Pharmacopœia’ ascribes the following ‘characters’ to kamala:—“A fine granular mobile powder, of a brick-red colour; it is with difficulty mixed with water, but when boiled with alcohol the greater part is dissolved, forming a red solution. Ether dissolves most of it, the residue consisting principally of tufted hairs. It should be free from sand or earthy impurities.”

Kamala forms a very considerable article of export from India, it being a valuable dye.

KA′OLIN. Syn. China clay, Porcelain c. A fine white clay, derived from the decomposition of the felspar of granitic rocks. The potteries and porcelain works of this country are chiefly supplied with this substance from extensive tracts of it which occur near St Austie, Cornwall. See Clay.

Elsner gives the following process for distinguishing kaolin from ordinary clay:—He agitates it in a test-tube with pure strong sulphuric acid till a uniform mixture is produced, decants the acid after subsidence, dilutes it carefully with six volumes of water, and supersaturates the cooled solution with ammonia.

Kaolin thus treated separates but slowly from the strong acid, and the diluted acid solution gives an immediate white precipitate with ammonia, whereas ordinary clay is but slightly attacked by the acid, separates quickly from it, and the acid after dilution gives but an insignificant precipitate with ammonia.

KAP′NOMOR. Syn. Capnomor. A colourless oil obtained from crude kreasote by distillation with potassa. It boils at 360° Fahr., has a peculiar odour, and is insoluble in water, but readily soluble in an alkaline solution of kreasote.

KATAL′YSIS. Syn. Catalysis, Contact action. Terms applied to a class of chemical actions in which the decompositions, and the recombination of the elements of compound bodies, is apparently excited by the mere presence of, or contact with, other bodies, which do not themselves suffer such a change.

KAVA-KAVA. See Ava.

KELP. The alkaline ashes obtained by burning various species of sea-weed, formerly much used for the preparation of carbonate of soda. The weeds most valued for the purpose are the Fucus vesiculosus, nodosus, and serratus, and the Laminaria bulbosa and digitata.

Of late years the manufacture of kelp, like that of barilla, has been almost abandoned except as a source of iodine. Mr E. C. C. Stanford, by carefully collecting and compressing the weed, and afterwards submitting it to dry distillation, doubles the yield of iodine and bromine, and obtains in addition various valuable hydrocarbons. See Barilla, Iodine, Soda, &c.

KER′MES. Syn. Kermes-grains, Alkermes; Granum tinctorium, L. The dried bodies of the female Coccus Ilicis of Linnæus, a small insect of the order Hemiptera, which flourishes on the Ilex oak. It has been used as a red and scarlet dye-stuff ever since the time of Moses; but is now superseded in this country by cochineal, which gives colours of much greater brilliancy.

KER′MES MIN′ERAL. Syn. Kermes minerale, K. mineralis, L. An amorphous tersulphide of antimony, containing a small admixture of teroxide of antimony and sulphuride of potassium. Prep. 1. In the humid way.—a. (P. Cod.) Carbonate of soda (cryst.), 128 parts (say 21 parts), is dissolved in water, 1280 parts (say 210 parts), contained in a cast-iron pan; tersulphide of antimony (in fine powder), 6 parts (say 1 part), is next added, and the whole boiled for an hour, with constant agitation with a wooden spatula; the boiling liquid is then filtered into a heated earthen pan containing a small quantity of very hot water, and the solution is allowed to cool as slowly as possible; the red powder which is deposited is collected on a cloth, on which it is well washed with cold water, and the superfluous water being removed by pressure, the powder is dried by a gentle heat, and is, lastly, passed through a fine silk-gauze sieve, and preserved from light and air.

b. (Wholesale.) From black sulphuride of antimony, 4 lbs.; carbonate of potassa, 1 lb.; boil in water, 2 galls., for half an hour, filter, &c., as before. The undissolved portion of sesquisulphuret of antimony may be boiled again several times with fresh potassa and water, until the whole is dissolved. Inferior to the last.

c. (Cluzell’s kermes.) From tersulphide of antimony, 4 parts; crystallised carbonate of soda, 90 parts; water, 1000 parts; boil, &c., as in 1, a, and dry the powder, folded up in paper, at a heat not exceeding 90° Fahr.

2. In the dry way.—a. (P. Cod.) Carbonate of potassa, 100 parts; tersulphide of antimony, 50 parts; sulphur, 3 parts; mix, fuse in a Hessian crucible, pour the melted mass into an iron mortar, and when cold reduce it to powder; next boil it in water, 1000 parts, contained in an iron vessel, filter the solution, and otherwise proceed as before. Product: large, but of inferior quality.

b. (Fownes.) From tersulphide of antimony, 5 parts; carbonate of soda (dry), 3 parts; water, 80 parts; fuse, &c., as before. Nearly equal to 1, a.

c. (Berzelius.) Carbonate of potassa (pure), 3 parts, tersulphide of antimony, 8 parts; water, q. s. Resembles the last.

Prop., &c. An odourless, tasteless powder, insoluble in both water and alcohol, and, when pure and carefully prepared, entirely soluble in hydrosulphate of ammonia. As prepared by the formulæ 1, a, and 1, c, it is a very dark crimson powder, of a velvety smoothness; but that from the other formulæ has a brownish-red colour, more or less deep. The secret of preparing this compound of a fine and velvety quality, like that imported from the Continent, consists simply in filtering the solution whilst boiling hot, and allowing it to cool very slowly, by placing the vessel in an appropriate situation for that purpose. Another important point, according to Rose, is to employ sufficient alkali to keep the whole of the teroxide of antimony in solution as the liquid cools, instead of allowing a part of it to be deposited with the kermes. This is the reason of the superior quality and mildness of that prepared according to the directions of the French Codex. The liquor decanted from the ‘kermes mineral’ yields the golden sulphide of antimony on the addition of an acid, for which purpose the acetic is generally employed.

Dose, ⁄2 gr. to 3 or 4 gr., as a diaphoretic, cathartic, or emetic. It occupies in foreign practice the place of our James’s Powder.

KETCH′UP. Syn. Catchup, Catsup, Katchup. The juice of certain vegetables strongly salted and spiced, so as to be used as sauce; or a simple sauce made without the natural juice as a substitute for the true ketchup. The following are the principal varieties:—

Ketchup, Camp. Prep. Take of good old beer, 2 quarts; white wine, 1 quart; anchovies, 4 oz.; mix, heat it to the boiling-point, remove it from the fire, and add of peeled shalots, 3 oz.; mace, nutmegs, ginger, and black pepper, of each, bruised, ⁄2 oz.; macerate for 14 days, with frequent agitation, then allow it to settle, and decant and bottle the clear portion.

Ketchup, Cu′cumber. Prep. From ripe cucumbers, in the same way as mushroom ketchup. Very luscious. Mixed with cream, or melted butter, it forms an excellent white sauce for fowls, &c.

Ketchup, Marine′. Prep. Take of strong old beer, 1 gall.; anchovies, 1⁄2 lb.; peeled shalots (crushed), 1 lb.; bruised mace, mustard seed, and cloves, of each ⁄2 oz.; bruised pepper and ginger, of each ⁄4 oz.; mushroom ketchup and vinegar, of each 1 quart; beat the mixture to the boiling point, put it into a bottle, and macerate for 14 days, frequently shaking; then strain through flannel, and bottle it for use. Excellent with anything; like the last, it makes good white sauce, and keeps well.

Ketchup, Mush′room. Prep. 1. Sprinkle mushroom flaps, gathered in September, with common salt, stir them occasionally for 2 or 3 days, then lightly squeeze out the juice, and add to each gallon cloves and mustard seed, of each, bruised, ⁄2 oz.; allspice, black pepper, and ginger, of each, bruised, 1 oz.; gently heat to the boiling-point in a covered vessel, macerate for 14 days, and decant or strain. Should it exhibit any indications of change in a few weeks, bring it again to the boiling-point, with a little more spice, and a table-spoonful more salt.

2. Take of mushroom juice, 2 galls.; pimento, 2 oz.; cloves, black pepper, mustard seed, and ginger, of each, bruised, 1 oz.; salt, 1 lb. (or to taste); shalots, 3 oz.; gently simmer for 1 hour in a covered vessel, cool, strain, and bottle.

3. Take of mushroom juice, 100 galls.; black pepper, 9 lbs.; allspice, 7 lbs.; ginger, 5 lbs.; cloves, 1 lb. (all bruised); salt, q. s.; gently simmer in a covered tin boiler for 1 hour.

Ketchup, Oys′ter. Prep. Pulp the oysters, and to each pint add, of sherry wine, or very strong old ale, 1 pint; salt, 1 oz.; mace, ⁄4 oz.; black pepper, 1 dr.; simmer very gently for 10 minutes, strain, cool, bottle, and to each bottle add a spoonful or two of brandy, and keep them in a cool situation. Cockle ketchup and MUSSEL KETCHUP are made in the same way. Used to flavour sauces when the fish are out of season; excellent with rump steak, &c.

Ketchup, Pon′tac. Prep. Take of the juice of elderberries and strong vinegar, of each 1 pint; anchovies, ⁄2 lb.; shalots and spice, q. s. to flavour; boil for 5 minutes, cool, strain, and bottle. Used to make fish sauces.

Ketchup, Toma′to. Prep. Prepared from tomatoes or love apples, like mushroom ketchup, except that a little very strong Chili vinegar is commonly added. An admirable relish for ‘high’ or rich flavoured viands.

Ketchup, Wal′nut. Prep. 1. Take of the expressed juice of young walnuts, when tender, 1 gall.; boil 10 minutes, skim, add of anchovies, 2 lbs.; shalots, 1 lb.; cloves and mace, of each 1 oz.; 1 clove of garlic, sliced; simmer in a covered vessel for 15 minutes, strain, cool, and bottle, adding a little fresh spice to each bottle, and salt, q. s. Will keep good in a cool place for 20 years.

2. Take of green walnut shells, 16 galls.; salt, 5 lbs.; mix and beat together for a week, press out the liquor, and to every gallon add, of allspice, 4 oz.; ginger, 3 oz.; pepper and cloves, of each 2 oz.; all bruised; simmer for half an hour, and set aside in a closed vessel and in a cool situation until sufficiently clear.

3. Take of walnut juice, 1 gall.; vinegar, 1 quart; British anchovies (sprats), 3 or 4 lbs.; pimento, 3 oz.; ginger, ⁄4 oz.; long pepper, ⁄2 oz.; cloves, 1 oz.; shalots, 2 oz.; boil and bottle, as before.

4. From the juice of walnut shells, 30 galls.; salt, 1 bushel; allspice and shalots, of each 6 lbs.; ginger, garlic, and horse-radish, of each 3 lbs.; essence of anchovies, 3 galls.; as before.

Ketchup, Wine. Prep. Take of mushroom or walnut ketchup, 1 quart; chopped anchovies, ⁄2 lb.; 20 shalots; scraped horse-radish, 2 oz.; spice, q. s.; simmer for 15 minutes, cool, and add of white and red wine, of each 1 pint; macerate for 1 week, strain, and bottle.

General Remarks. In preparing the above articles, vessels of glazed earthenware, or stoneware, or well-tinned copper pans, should alone be used to contain them whilst being boiled or heated, as salt and vegetable juices rapidly corrode copper, and render the ketchup poisonous. Nothing in the shape of copper, lead or pewter should be allowed to touch them. Even a plated copper spoon left in a bottle of ketchup for some time will render its contents poisonous. Unpleasant and even dangerous fits of vomiting, colic, and diarrhœa have resulted from the neglect of this precaution. See Sauce, &c.

KIBES. The vulgar name for ulcerated chilblains.

KID′NEYS. Syn. Renes, L. (In anatomy.) The kidneys, as almost every one knows, are abdominal viscera which secrete the urine, and form the great channels by which the effete nitrogenous matter is removed from the blood. They are subject to various affections, both functional and organic, chronic and acute, of which some are imperfectly understood, and others only admit of alleviation, but not of being cured. See Urine and Urinary affections.

Kidneys. (In cookery.) Soyer recommends kidneys to be dressed by gently broiling them, having previously split them, “so as nearly to divide them, leaving the fat in the middle,” and “run a skewer through them, that they may remain open.” After being rubbed with a little butter, and seasoned with salt and pepper, “they may be served on toast, or with any sauce.” “You may also egg and bread-crumb them.” “Five minutes suffice for a sheep or lamb’s kidney of common size.” (Soyer.) One or two lamb’s kidneys, plainly broiled and served up with the gravy in them, eaten along with a little dry-toasted bread, form a most excellent and appropriate luncheon or dinner for a dyspeptic or convalescent.

KIESERITE. A sulphate of magnesia found in the refuse salt (abraumsalz) of Stassfurth, near Magdeburg. It forms about 12% of the abraumsalz. It is employed for washing wool and for the manufacture of ‘permanent white’ by treatment with chloride of barium; also for the preparation of Glauber salts, and of hypochlorite of magnesia for bleaching linen. See Linen.

KING’S CUP. Prep. Yellow peel of 1 lemon; lump sugar, 1⁄2 oz.; cold water, 1 pint; infuse 8 or 10 hours, and strain. The addition of a teaspoonful of orange-flower water is a great improvement. Used as a diluent in cases where acid liquors are inadmissible. See Lemonade.

KING’S EVIL. See Scrofula.

KING’S YELLOW. See Yellow pigments.

KI′NIC ACID. HC7H11O6. Syn. Quinic acid, Cinchonic acid. A peculiar monobasic acid occurring in the cinchona barks, in which it exists associated with the alkaloids.

Kinic acid is somewhat extensively diffused throughout the vegetable kingdom, being found in the bark of every species of the true cinchonas, as well as in the leaves of the oak, the elm, the ash, the ivy, the privet, and the coffee plant and berries. It occurs in the cinchona barks most probably combined with the alkaloids, which therefore exist in the plant as kinates.

It is readily obtained from kinate of lime by the action of dilute sulphuric acid; the filtered solution evaporated to the consistence of a syrup, gradually deposits large crystals resembling those of tartaric acid.

Henry and Plisson give the following directions for the preparation of kinic acid:—Make a decoction of cinchona bark with water containing some sulphuric acid, and filter whilst hot, and to the filtrate add gradually freshly precipitated oxide of lead, until the liquid becomes neutral, and changes from a red to a pale yellow colour; care must be taken to add sufficient oxide. The filtrate is freed from lead by passing sulphuretted hydrogen through it, and filtered milk of lime is then added to precipitate the quinine and cinchonine; and the filtered liquid is evaporated to a syrup, which yields on cooling crystalline calcic kinate. To separate the acid from the calcic salt, Berzelius directs an aqueous solution of the salt to be made and to be precipitated by basic acetate of lead; the washed precipitate, suspended in water, is then decomposed by sulphuretted hydrogen, and the solution filtered and evaporated. Or the calcium kinate may be decomposed by an aqueous or alcoholic solution of sulphuric acid.

Kinic acid is, in the form of large tubular crystals, fusible at 161° C. These crystals dissolve in two parts of water; they are also soluble in spirits of wine, but scarcely, if at all, in ether.

It forms salts called kinates. Kinate of calcium is obtained from an acidulated infusion of cinchona bark, by adding an excess of lime, filtering, evaporating to a syrup, and setting the liquid aside to crystallise. These crystals are purified by re-dissolving them, treating the solution with a little animal charcoal, and crystallising the salt as before. The liquid from which the bark-alkaloids have been precipitated by hydrate of lime affords an almost inexhaustible supply of this salt. See Kinone.

KI′NO. Syn. Gum kino; Kino (B. P., Ph. L. E. & D.) The juice flowing from the incised bark of the Pterocarpus Marsupium or Indian, hardened in the sun.—Dose, 10 to 30 gr., in powder; as an astringent in chronic diarrhœa, &c.

Kino, Factitious, met with in the shops, is made as follows:—Logwood, 48 lbs.; tormentil root, 16 lbs.; madder root, 12 lbs.; exhaust by coction with water, q. s.; to the liquor add of catechu, 16 lbs.; dissolve, strain, and evaporate to dryness. Prod. 24 lbs. Extract of mahogany is also commonly sold for kino.

KIRSCH′WASSER (-văs ser) [Ger.]. Syn. Kirschenwasser. A spirituous liquor distilled in Germany and Switzerland from bruised cherries. From the rude manner in which it is obtained, and from the distillation of the cherry-stones (which contain prussic acid) with the liquor, it has often a nauseous taste, and is frequently poisonous. When properly made and sweetened, it resembles noyeau.

KISH. An artificial graphite occasionally produced in iron-smelting furnaces. It occurs in brilliant scales, and is said to possess peculiar efficacy in certain forms of anæmia and chlorosis.

KITCH′EN. The late Alexis Soyer set down as one of the crying faults of our countrymen the employment of an apartment for the kitchen which is either too small or inconveniently situated, and which, in general, is not sufficiently provided with ‘kitchen requisites.’ “As a workman cannot work properly without the requisite tools, or the painter produce the proper shade without the necessary colours, in like manner does every person wishing to economise his food and to cook it properly require the proper furniture wherewith to do it.” The neglect of these matters, which is so general, is, undoubtedly, a mischievous and deceptive economy.

KNIVES, to Clean. After being used all knives should be wiped on a coarse cloth, so as to ensure their freedom from grease previous to being cleaned. The practice of dipping the blades in hot water not only fails to remove any grease that may be on them, but is almost sure to loosen the handles. It is very essential to remove any grease from them, since if this remain it will spoil the knife-board.

For cleaning knives, a proper knife-cleaning machine, purchased of a good maker, is best. But where this is not used, the knife-board ought to be covered with very thick leather, upon which emery powder should be placed. The emery gives a good polish to the knives, and does not wear them out so quickly as Bath-brick. When the points of the knives become worn very thin, they should be rounded by the knife-grinder. Where the handles are good it will sometimes be worth while to fit them to new blades.

KNOX’S POW′DER. Prep. From common salt, 8 parts; chloride of lime, 3 parts; mixed together. An ounce of it dissolved in a tumblerful of water furnishes a solution which is similar to Labarraque’s disinfecting fluid.

KŒCHLIN’S LIQUID. Prep. From copper filings, 96 gr.; liquor of ammonia, 2 fl. oz.; digested together until it turns of a full blue colour, and then mixed with hydrochloric acid, 5 fl. dr.; distilled water, 5 lbs.—Dose, 1 to 2 teaspoonfuls daily; in scrofula. It is poisonous in large doses.

KOOCH′LA NUT. See Nux vomica.

KOU′MISS. A liquor prepared by the Calmucs, by fermenting mare’s milk, previously kept until sour, and then skimmed. By distillation it yields a spirit called rack, racky, or araka. 21 lbs. of fermented milk yield about ⁄4 pint of low wines, and this, by rectification, gives fully ⁄4 pint of strong alcohol. It has lately come into use as a remedy for phthisis and general debility.

The following formula from the Zeitschrift des Oesterr. Apoth. Ver. (1876, 526), for the preparation of so-called Koumiss Extract, is said to be a good one:—

Powdered sugar of milk 100 parts

Glucose (prepared from starch) 100 ”

Cane sugar 300 ”

Bicarbonate of potassium 36 ”

Common salt 33 ”

Dissolve these ingredients in 600 parts of boiling fresh whey of milk, allow the solution to cool, then add 100 parts of rectified spirit, and afterwards 100 parts of strained fresh beer yeast. Stir the mixture well and put into bottles containing a quarter of a litre each. The bottles must be well corked and kept in a cool place.

For the preparation of Koumiss add 5 to 6 tablespoonfuls of this extract to a litre of skimmed, lukewarm milk, contained in a bottle of thick glass; cork well, keep the bottle for half a day in a moderately warm room (at 16°-20° C.), and afterwards in a cool cellar, shaking occasionally. The bottle should be filled to within 3-4 centimètres of the cork. After two days the Koumiss is ready for use.

KOUS′SO. Syn. Cusso, Kosso. This substance is the dried flowers of the Brayera anthelmintica, an Abyssinian tree which grows to the height of about 20 feet, and belongs to the natural order Rosaceæ. It is one of the most effective remedies known for both varieties of tapeworm. The dose for an adult is 3 to 5 dr., in powder, mixed with about half a pint of warm water, and allowed to macerate for 15 or 20 minutes. The method prescribed for its successful administration is as follows:—The patient is to be prepared by a purgative or a lavement, and the use of a very slight diet the day before. The next morning, fasting, a little lemon juice is to be swallowed, or a portion of a lemon sucked, followed by the dose of kousso (both liquid and powder), at 3 or 4 draughts, at short intervals of each other, each of which is to be washed down with cold water acidulated with lemon juice. The action of the medicine is subsequently promoted by drinking weak tea without either milk or sugar, or water flavoured with lemon juice or toasted bread; and if it does not operate in the course of 3 or 4 hours, a dose of castor oil or a saline purgative is taken.

The flavour of kousso is rather disagreeable and nauseating. Its operation is speedy and effectual; but at the same time it is apt to produce, in large doses, great prostration of strength, and other severe symptoms, which unfit it for administration to the delicate of both sexes, or during pregnancy or affections of the lower viscera. Care should be taken not to purchase it in powder, as, owing to its high price, it is uniformly adulterated. The powdered kousso of the shops is, in general, nothing more than the root-bark of pomegranate, coloured and scented.

KRE′ASOTE. Syn. Creasote, Creosote, Kreosote; Creasotum (B. P., Ph. L. & D.), Creazotum (Ph. E.), L. A peculiar substance, discovered by Reichenbach, and so named on account of its powerful antiseptic property. It is a product of the dry distillation of organic bodies, and is the preservative principle of wood smoke and pyroligneous acid.

Prep. Kreasote is manufactured from wood-tar, in which it is sometimes contained to the amount of 20% to 35%, and from crude pyroligneous acid and pyroxilic oil.

1. (P. Cod.) Wood-tar is distilled in a wrought-iron retort until white vapours of paraffin appear; the heavy oily matter which forms the lower layer of the product is collected, washed with water slightly acidulated with sulphuric acid, and then distilled in a glass retort, rejecting the first portions, which are chiefly eupion; the distillate is treated with a solution of potassa (sp. gr. 1·12), the mixed liquids being shaken strongly together; after it is settled, the layer of eupion which forms is removed from the surface, and the potash-solution of kreasote exposed to the air until it becomes black; it is then saturated with dilute sulphuric acid, the water liquid rejected, and the remainder (consisting of crude kreasote) submitted to distillation in glass; the treatment by exposure, potassa, sulphuric acid, and distillation is repeated three times or oftener, until the combination of kreasote and potassa ceases to become coloured by the action of the air; it is, lastly, saturated with concentrated phosphoric acid, and again distilled, rejecting the first portion that comes over.

2. (M. Simon.) A copper still, capable of containing 80 Berlin quarts, is filled to one third with the oil of wood-tar, and heat is applied; first, the more volatile matters pass over; these do not contain kreasote, and are, therefore, rejected; but when, by gradually increasing the temperature, there passes over a very acid liquid, which becomes turbid, and at the same time an oil separates from it when mixed with water, the product is collected, and the distillation continued until the operator notices a squirting in the still, when this part of the process is complete; the distilled product is then nearly saturated with potassa and returned to the still, which, in the meantime, has been well cleaned out, and about half filled with water, and the distillation is recommenced; at first an oil comes over, which floats on water, and which consists chiefly of eupion, and is, therefore, rejected; as soon, however, as the oil begins to sink in the water which comes over with it, it is charged with kreasote, and is carefully collected; the distilling aqueous fluid being reintroduced from time to time into the still, and the distillation continued so long as any oil continues to come over with it; the heavy oily distillate is now agitated with liquor of potassa, sp. gr. 1·120; the portion which remains undissolved is eupion, and is skimmed off; the potassa-solution of kreasote still, however, contains a considerable quantity of eupion, the greater portion of which may be separated by dilution and distillation with an equal quantity, or with at least ⁄5ths of its volume of water, fresh water being added from time to time, as long as any eupion comes over with the distilled liquor; when this has ceased to pass over, sulphuric acid is poured into the still in quantity exactly sufficient to saturate ⁄3rd only of the potassa formerly employed, and the distillation is again renewed; kreasote now distils over, the first portions of which, however, still contain eupion, after which pure kreasote follows; that is to say, “a kreasote which, when mixed with 6 or 8 times its quantity of a solution of pure potassa, furnishes a mixture which, by the addition of any further quantity whatever of water, does not become turbid.” The combination of kreasote remaining in the still is now mixed with sulphuric acid in slight excess, and the distillation renewed, the water coming over with it being from time to time returned into the still; and when no further oil passes over with the water, the process is complete. The kreasote thus obtained is redistilled with the water which has passed over with it, whilst the distilled water, as before, is allowed from time to time to run back into the still. The kreasote thus obtained is then colourless; but it contains a considerable quantity of water in solution, which is separated by distillation in a glass retort. The water distils first, and then kreasote, which, after cleaning the neck of the retort from the water, must be received in another dry receiver. If the kreasote assumes a red colour after being exposed for some time to the air, it must be re-distilled, and then it keeps very well. Korne found that tar prepared from turf furnishes much more kreasote than that from fir-wood, &c.

3. (Ure.) In operating upon pyroligneous acid, if we dissolve effloresced sulphate of soda in it to saturation, at the temperature of 267° Fahr., the kreasote separates, and floats upon the surface; it is then decanted, and left in repose for some days, during which it deposits a fresh portion of salt and vinegar; it is next saturated whilst hot with carbonate of potassa, and distilled along with water; a pale yellow oily liquid passes over, which is rectified with phosphoric acid, &c., like the crude product of kreasote from tar.

Prop. Kreasote is a colourless, transparent liquid, heavier than water, of a peculiar unpleasant penetrating odour resembling that of smoked meat, and a very pungent and caustic taste; its vapour irritates the eyes; it boils at 400° Fahr., and is still fluid at -16·6° Fahr.; it produces on white filter paper greasy spots, which disappear if exposed to a heat of 212° Fahr.; dissolves in 80 parts of water, and mixes in all proportions with spirit of wine, the essential and fatty oils, acetic acid, naphtha, disulphide of carbon, ammonia, and potassa; it dissolves iodine, phosphorus, sulphur, resins, the alkaloids, indigo blue, several salts (especially the acetates and the chlorides of calcium and tin); reduces the nitrate and acetate of silver; is resinified by chlorine, and decomposed by the stronger acids. The aqueous solution is neutral, and precipitates solutions of gum and the white of eggs. It kindles with difficulty, and burns with a smoky flame. When quite pure, it is unaltered by exposure to the air. Sp. gr. 1·071, at 68° Fahr. A slip of deal dipped into it, and afterwards in hydrochloric acid, and then allowed to dry in the air, acquires a greenish-blue colour. It turns a ray of polarised light to the right, whereas carbolic acid does not affect polarisation.

Pur. The fluid commonly sold in the shops for kreasote is a mixture of kreasote, picamar, and light oil of tar; in many cases it is little else than impure carbolic acid, with scarcely a trace of kreasote. Pure kreasote is perfectly soluble in both acetic acid and solution of potassa; shaken with an equal volume of water in a narrow test-tube, not more than the 1-80th part disappears; otherwise it contains water, of which kreasote is able to assume 1-10th without becoming turbid. If it can be dissolved completely in 80 parts by weight of water, at a medium temperature, it then forms a perfectly neutral liquid. An oily residue floating on the surface betrays the presence of other foreign products (EUPION, KAPNOMOR, PICAMAR), which are obtained at the same time with the kreasote during the dry distillation of organic substances.

Kreasote is “devoid of colour, has a peculiar odour, and is soluble in acetic acid. When it is dropped on bibulous paper, and a boiling heat is applied for a short time, it entirely escapes, leaving no transparent stain.” (Ph. L.) “Entirely and easily soluble in its own weight of acetic acid.” (Ph. E.) Sp. gr. 1·046 (Ph. L.), 1·066 (Ph. E. & D.). The density and boiling point of absolutely pure kreasote is given above. When prescribed in pills with oxide of silver, the mass will take fire unless the oxide be first mixed with liquorice or other powder. (Squire.)

Uses. Kreasote has been recommended in several diseases of the organs of digestion and respiration, in rheumatism, gout, torpid nervous fever, spasms, diabetes, tapeworm, &c.; but its use has not, in general, been attended with satisfactory results. It is given in the form of pills, emulsion, or an ethereal or spirituous solution. Externally it has been employed in various chronic diseases of the skin, sores of different kinds, mortifications, scalds, burns, wounds (as a styptic), caries of the teeth, &c.; mostly in the form of an aqueous solution (1 to 80); or mixed with lard (5 drops to 1 dr.), as an ointment; dissolved in rectified spirit, it forms a useful and a popular remedy for toothache arising from decay or rottenness. In the arts, kreasote is extensively employed to preserve animal substances, either by washing it over them, or by immersing them in its aqueous solution. A few drops in a saucer, or on a piece of spongy paper, if placed in a larder, will effectually drive away insects, and make the meat keep several days longer than it otherwise would. A small quantity added to brine or vinegar is commonly employed to impart a smoky flavour to meat and fish, and its solution in acetic acid is used to give the flavour of whisky to malt spirit. See Carbolic acid.

KRE′ATIN. C4H9N3O2·Aq. Syn. Creatin. A crystallisable substance obtained from the juice of the muscular fibre of animals. It was first obtained by Chevreul, but has recently been carefully studied by Liebig.

Prep. (Liebig.) Lean flesh is reduced to shreds, and then exhausted with successive portions of cold water, employing pressure; the mixed liquid is heated to coagulate the albumen and colouring matter of the blood, and is then strained through a cloth; pure baryta water is next added as long as a precipitate forms, the liquid is filtered, and the filtrate is gently evaporated to the consistence of a syrup; after repose for some days in a warm situation, crystals of kreatin are deposited; these are purified by redissolving them in water, agitating the solution with animal charcoal, and evaporating, &c., so that crystals may form.

Prop., &c. Brilliant, colourless, prismatic crystals; readily soluble in boiling water, sparingly so in cold water and in alcohol; the aqueous solution is neutral, bitter tasted, and soon putrefies.

KREAT′ININ. C4H7N3O. This substance exists in small quantities, both in the juice of flesh and in conjunction with kreatin in urine. It is also produced by the action of the stronger acids on kreatin. It forms colourless prismatic crystals, which are soluble in water, and the solution has a strongly alkaline reaction. It is a powerful organic base, and produces crystallisable salts with the acids.

KRE′NIC ACID. See Crenic acid.

KRYSTAL′LINE. The name originally applied by Unverdorben to ANILINE.

KUSTITIEN’S METAL. Prep. Take of malleable iron, 3 parts; beat it to whiteness, and add of antimony, 1 part; Molucca tin, 72 parts; mix under charcoal, and cool. Used to coat iron and other metals with a surface of tin; it polishes without a blue tint, is hard, and has the advantage of being free from lead and arsenic.

KYANI′ZING. A method of preserving wood and cordage from decay, long known and practised; patented by Mr Kyan many years since. It consists in immersing the materials in a solution of corrosive sublimate, 1 part, and water, 50 or 60 parts, either under strong pressure or the contrary, as the urgency of the case or the dimensions of the articles operated on may require. See Dry rot.

KY′ANOL. A substance obtained from coal-tar oil, and at first thought to be an independent principle, but since shown to be identical with ANILINE.

LABARRAQUE’S FLUID. See Solution of Chloride of Soda.

LAB′DANUM. Syn. Ladanum. An odorous, resinous substance found on the leaves and twigs of the Cystus creticus, a plant growing in the island of Candia and in Syria. It was formerly much used for making stimulating plasters. The following compound is often vended for it:—

Labdanum, Facti′′tious. Prep. From gum anime, resin, Venetian turpentine, and sand, of each 6 parts; Spanish juice and gum Arabic, of each (dissolved in a little water), 3 parts; Canada balsam, 2 parts; ivory black, 1 part; balsam of Peru, q. s. to give a faint odour.

LA′BELS capable of resisting the action of OILS, SPIRITS, WATER, SYRUPS and DILUTE ACIDS, may be obtained as follows:—Lay a coat of strained white of egg over the label (an ordinary paper one), and immediately put the vessel into the upper portion of a common steam-pan, or otherwise expose it to a gentle heat till the albumen coagulates and turns opaque, then take it out and dry it before the fire, or in an oven, at a white heat of about 212° Fahr.; the opaque white film will then become hard and transparent. The labels on bottles containing STRONG ACIDS or ALKALINE SOLUTIONS should be either etched upon the glass by means of hydrofluoric acid, or be written with incorrodible ink. See Etching and Ink.

LAB′ORATORY. Syn. Laboratorium, L. A place fitted up for the performance of experimental or manufacturing operations in chemistry, pharmacy, and pyrotechny. For full information respecting the best mode of fitting up a chemical laboratory, the reader is referred to works especially devoted to chemical manipulation. Almost any well-lighted spare room may be fitted up as a small laboratory at very little expense. The gas-furnaces and improved lamps introduced of later years have to a certain extent rendered chemists independent of brick furnaces. A strong working bench, fitted with drawers and cupboards, and having gas-pipes at intervals for attaching different kinds of jets, is an indispensable fixture. A close cupboard or closet, which is connected by a pipe with the chimney or the external air, is required to receive vessels emitting corrosive or evil-smelling vapours; the door of this closet should be of glass. A sink, with a copious supply of water, must be at hand, for washing apparatus. A glass, a stoneware barrel, with a tap of the same material, is required for holding distilled water. Shelves, supports for apparatus, and drawers, should be provided in abundance. The fine balances and other delicate instruments should be kept in a separate apartment. With regard to apparatus, we may state that the articles most frequently required in a laboratory are the gas or alcohol lamps; iron pans for sand bath and water bath; evaporating dishes; precipitating jars, funnels, and wash-bottles; retorts, flasks, and test-tubes; mortars and pestles; retort- and filtering-stands; rat-tail and triangular files, and glass rod and tubing.

The principal philosophical instrument-makers sell chests or cabinets filled with apparatus and chemicals, under the name of ‘PORTABLE LABORATORIES,’ Those sold by Mr J. J. Griffin and by Messrs Jackson and Townson are, perhaps, the most complete. They are well adapted for illustrating all the more valuable facts of chemical science, and performing all the ordinary operations of qualitative analysis.

LABURNINE. A poisonous alkaloid, found in the unripe seeds of the laburnum plant, associated with another poisonous alkaloid called Cytisine.

LAC. Syn. Lacca, L. A resinous substance combined with much colouring matter, produced by the puncture of the female of a small insect, called the Coccus lacca or ficus, upon the young branches of several tropical trees, especially the Ficus Indica, Ficus religiosa, and Croton lacciferum. The crude resinous exudation constitutes the STICK-LAC of commerce. Shell-lac or SHELLAC is prepared by spreading the resin into thin plates after being melted and strained. Seed-lac is the residue obtained after dissolving out most of the colouring matter contained in the resin.

Shell-lac is the kind most commonly employed in the arts. The palest is the best, and is known as ‘orange-lac.’ The darker varieties—‘liver-coloured,’ ‘ruby,’ ‘garnet,’ &c.—respectively diminish in value in proportion to the depth of their colour.

Uses, &c. Lac was formerly much used in medicine; its action, if any, is probably that of a very mild diuretic. It is now chiefly used in DENTIFRICES, VARNISHES, LACQUERS, and SEALING-WAX.

Lac, Bleached. Syn. White lac; Lacca alba, L. By dissolving lac in a boiling lye of pearlash or caustic potassa, filtering and passing chlorine through the solution until all the lac is precipitated; this is collected, well washed and pulled in hot water, and, finally, twisted into sticks, and thrown into cold water to harden. Used to make pale varnishes and the more delicate coloured sealing-wax.

LAC DYE. Syn. Lac, Lac-lake, Indian cochineal. A colouring substance used to dye scarlet, imported from India.

Prep. By dissolving out the colour of ground stick-lac by means of a weak alkaline solution, and then precipitating it along with alumina by adding a solution of alum.

Obs. To prepare the lac for dyeing, it is ground and mixed with diluted ‘lac spirit,’ and the whole allowed to stand for about a week. The ‘cloth’ is first mordanted with a mixture of tartar and ‘lac spirit,’ and afterwards kept near the boil for three quarters of an hour, in a bath formed by adding a proportion of the prepared lac dye to the mixture used for mordanting. Lac dye is only applicable to woollen and silk. The colours it yields are similar to those obtained from cochineal, but less brilliant.

LAC SPIRIT. See Tin mordants.

LACE. This decorative fabric is made by interweaving threads of linen, cotton, or silk, into various patterns and designs. Although in some instances lace is made by hand, the greater part is now manufactured by machinery worked by steam or water. The hand-made lace was called bone, pillow, or bobbin lace, these two latter names having been given it from its having been woven upon a pillow or cushion by means of a bobbin. The manufactured article is bobbin net. Lace and the machinery by which it is produced is of so complex a nature that Dr Ure says of one particular form of it “it is as much beyond the most curious chronometer in the multiplicity of mechanical device as that is beyond a common roasting jack.”

Owing to the improvements in machinery introduced of late years, it may be mentioned that a piece of lace which twenty years since could only be produced at a cost of 3s. 6d. for labour, may now be turned out for 1d., and a quantity of the fabric which sold for £17, now realizes only 7s. A pair of curtains, each four yards long, may be made in one frame in two hours.

The following statistics relating to the British lace industry are of interest:—“In 1843 there were 3200 twist net and 800 warp frames, returning £2,740,000 that year; in 1851, 3200 bobbin net and 800 warp, giving a return of £3,846,000; and in 1866, 3552 bobbin and 400 warp, returning £5,130,000. There has since been no actual census, but about the same number is now at work, and the returns and profits are greatly increased by improved quality and patterns of goods produced. The returns of 1872 were certainly £6,000,000 at least; and from advancing wages and demand for Lever’s laces, must still rapidly increase. Men are now earning by making them from £4 to £6 for 56 hours’ weekly labour.”

Lace, Gold and Silver, to Clean. Reduce to fine crumbs the interior of a 2-lb. stale loaf, and mix with them ⁄4 lb. of powder blue. Sprinkle some of this mixture plentifully on the lace, afterwards rubbing it on with a piece of flannel. After brushing off the crumbs rub the lace with a piece of crimson velvet.

Lace, to Scour. Take a perfectly clean wine bottle; wind the lace smoothly and carefully round it; then gently sponge it in tepid soap and water; and when clean, and before it becomes dry, pass it through a weak solution of gum and water. Next pick it out and place it in the sun to dry. If it be desired to bleach the lace, it should be rinsed in some very weak solution of chloride of lime, after removal from which it must be rinsed in cold water. Starch and expose it; then boil and starch, and again expose it if it has not become sufficiently white.

The following method is also said to whiten lace:—It is first ironed slightly, then folded and sewn into a clean linen bag, which is then placed for 24 hours in pure olive oil. Afterwards the bag, with the lace in it, is to be boiled in a solution of soap and water for 15 minutes, then well rinsed in lukewarm water, and finally dipped in water containing a small quantity of starch. The lace is then to be taken from the bag, and stretched on pins to dry.

To scour point lace proceed as follows:—“Fix the lace in a prepared tent, draw it tight and straight, make a warm lather of Castile soap, and with a fine brush dipped in rub over the lace gently, and when clean on one side do the same on the other; then throw some clean water on it, in which a little alum has been dissolved, to take off the suds; and, having some thin starch, go over with it on the wrong side, and iron it on the same side when dry; then open with a bodkin and set it in order. To clean the same, if not very dirty, without washing, fix it as before, and go over with fine bread, the crust being pared off, and when done, dust out the crumbs.” (Ernest Spon.)

Black lace may be cleaned by passing it through warm water containing some ox-gall, rinsing it in cold water, and then passing it through water in which a small quantity of glue has been previously dissolved by means of heat; it should then be taken out, clapped between the hands, and dried on a frame.

LAC′QUER. A solution of shell-lac in alcohol, tinged with saffron, annotta, aloes, or other colouring substances. It is applied to wood and metals to impart a golden colour. See Varnish.

LACTALBU′MEN. See Casein.

LAC′TATE. Syn. Lactas, L. A salt of lactic acid. The lactates are characterised by yielding an enormous quantity of perfectly pure carbonic oxide gas when heated with 5 or 6 parts of oil of vitriol. Most of these salts may be directly formed by dissolving the hydrate or carbonate of the metal in the dilute acid.

LACTA′TION. See Infancy, Nursing, &c.

LACTIC ACID. H2C6H10O6. Syn. Acid of milk; Acidum lacticum, L. A sour, syrupy liquid, discovered by Scheele in whey. It is also found in some other animal fluids, and in several vegetable juices, especially in that of beet-root.

Lactic acid is by no means an unimportant constituent of the human organism. It is contained in the gastric juice, and is frequently formed in the sweat. It has also been detected in the saliva of persons suffering from diabetes. A modification of the acid, termed sarkolactic acid, occurs in the fluids of the muscular tissue.

It is likewise a product of the fermentation of many vegetable juices, such as turnips, carrots, beet-root, and cabbage, which latter vegetable, after undergoing the lactic fermentation, becomes converted into the sauer kraut of the Germans.

In the form of calcic lactate it occurs in nux vomica.

Prep. 1. Dissolve lactate of barium in water, precipitate the barium with dilute sulphuric acid, carefully avoiding excess, and gently evaporate to the consistence of a syrup, or until it acquires the density 1·215. Lactate of calcium may be used instead of lactate of barium, in which case a solution of oxalic acid must be employed as the precipitant. Pure. (See No. 5.)

2. Milk (skimmed or stale), 1 gall.; bicarbonate of sodium, ⁄2 lb.; dissolve and expose the liquid to the air for some days, until it becomes sour, then saturate the excess of acid with some more bicarbonate of sodium, and again expose it to the air; repeat this as often as the liquid becomes sour; next heat the liquid to the boiling point, filter, evaporate to dryness (or nearly), and exhaust the residuum with rectified spirit; filter the alcoholic solution, which contains lactate of sodium, add sulphuric acid as long as it causes a precipitate to form, again filter, and concentrate the clear liquid by evaporation.

3. (Boutron and Fremy.) Milk, 3 or 4 quarts; sugar of milk, 200 to 300 gr.; mix, and expose for 2 or 3 days in an open vessel at 70° to 80° Fahr., then saturate with bicarbonate of sodium, again expose at a moderate temperature, saturate with more bicarbonate of sodium, and repeat the process until the whole of the sugar of milk is decomposed; then coagulate the casein by heat, filter, evaporate, extract the acid lactate of sodium by alcohol of sp. gr. ·810, and decompose it by the cautious addition of dilute sulphuric acid; again filter, distil off the alcohol, and evaporate as before.

4. (Scheele.) Evaporate sour whey to ⁄8th of its bulk, saturate with slaked lime, filter, add 3 or 4 times the quantity of water, cautiously precipitate the lime with a solution of oxalic acid, filter, and gently evaporate to dryness in a warm bath; digest the residuum in strong rectified spirit, and again filter and evaporate.

5. (Wackenroder.) Sugar of lead, 25 parts; finely powdered chalk, 20 parts; skimmed milk, 100 parts; water, 200 parts; digested together at about 75° Fahr. In six weeks the chalk will be dissolved; the whole is then heated, but not to boiling; the cheese is strained off, pressed, and the decanted liquid is clarified by albumen and evaporated, to let the lactate of calcium crystallise; the salt is recrystallised and decomposed, either by sulphuric acid or by the exact quantity of oxalic acid. This is, perhaps, the most effective mode of preparing lactic acid.

6. (Wholesale.)—a. Good raw cane-sugar, 7 lbs., is dissolved in milk (skimmed or stale), 2 galls., and cheese (in a moist or putrescent state), ⁄2 lb., and chalk, 4 lbs., previously rubbed to a cream with water, 1⁄2 gall., is then added; the mixture is then exposed in a loosely covered jar, at a temperature of 80° to 86° Fahr., with occasional stirring, for 2 or 3 weeks, or until the whole is converted into a semi-solid mass of crystals of lactate of calcium; this is purified either by draining off and expressing the liquid portion, dissolving the residue in water, and evaporating the solution for crystals; or the whole is put into a stoneware vessel and heated to the boiling-point, by which the casein is coagulated, and the lactate of calcium is dissolved; the solution filtered whilst hot, furnishes the salt in crystals on cooling; these crystals are subsequently dissolved in water, and the filtered solution decomposed by oxalic acid, as before.

b. From cane-sugar, 4 parts; moist cheese, 1 part; chalk, 3 parts; water, 20 parts; as the last.

Obs. Lactic acid prepared by any of the used formulæ may be rendered quite pure by dilution with water, saturation with baryta, evaporation, crystallisation, re-solution in water, and the careful addition of dilute sulphuric acid, as in No. 1; the liquid is, lastly, again filtered and evaporated. Another plan is to convert the acid into lactate of zinc, by the addition of commercial zinc-white, and to redissolve the new salt in water, and then decompose the solution with a stream of sulphuretted hydrogen. In all cases the evaporation should be conducted at a very gentle heat, and, when possible, finished over sulphuric acid, or in vacuo. For particular purposes this last product must be dissolved in ether, filtered, and the ether removed by a very gentle heat. Care must also be taken to remove the solid lactate of calcium at the proper period from the fermenting liquid, as otherwise it will gradually redissolve and disappear, and on examination the liquid will be found to consist chiefly of a solution of butyrate of calcium.

Prop. The product of the above formulæ is a solution of lactic acid. It may be concentrated in vacuo over a surface of oil of vitriol until it appears as a syrupy liquid of sp. gr. 1·215; soluble in water, alcohol, and ether; exhibiting the usual acid properties, and forming salts with the metals, called LACTATES. Heated in a retort to 266° Fahr.; a small portion distils over, and the residuum on cooling concretes into a yellowish, solid, fusible mass, very bitter, and nearly insoluble in water. This is lactic acid, which has lost half (1 equiv.) of its basic water. By long boiling in water this substance is reconverted into lactic acid. Heated to 480° Fahr., it suffers decomposition, lactide (the anhydrous, concrete, or sublimed lactic acid of former writers) and other products being formed. This new substance may be purified by pressure between bibulous paper and solution in boiling alcohol from which it separates in dazzling white crystals on cooling. By solution in hot water and evaporation to a syrup, it furnishes common lactic acid.

Uses. Lactic acid has been given in dyspepsia, gout, phosphatic urinary deposits, &c. From its being one of the natural constituents of the gastric juice, and from its power of dissolving a considerable quantity of phosphate of calcium, it appears very probable that it may prove beneficial in the above complaints.—Dose, 1 to 5 gr.; in the form of lozenges, or solution in sweetened water.

LAC′TIC FERMENTA′TION. The peculiar change by which saccharine matter is converted into lactic acid. Nitrogenous substances, which in an advanced state of putrefactive change act as alcohol-ferments, often possess, at certain periods of their decay, the property of inducing an acid fermentation in sugar, by which that substance is changed into lactic acid. Thus, the nitrogenised matter of malt, when suffered to putrefy in water for a few days only, acquires the power of acidifying the sugar which accompanies it; whilst in a more advanced state of decomposition it converts, under similar circumstances, the sugar into alcohol. The gluten of grain behaves in the same manner. Wheat flour, made into a paste with water, and left for four or five days in a warm situation, becomes a true lactic acid ferment; but if left a day or two longer, it changes its character, and then acts like common yeast, occasioning the ordinary panary or vinous fermentation. Moist animal membranes, in a slightly decaying condition, often act energetically in developing lactic acid. The rennet employed in the manufacture of cheese furnishes a well-known example of this class of substances.

In preparing lactic acid from milk, the acid formed, after a time, coagulates and renders insoluble the casein, and the production of the acid ceases. By carefully neutralising the free acid by carbonate of sodium, the casein becomes soluble, and resuming its activity, changes a fresh quantity of sugar into lactic acid, which may be also neutralised, and by a sufficient number of repetitions of this process all the sugar of milk present may, in time, be acidified. This is the rationale of the common process by which lactic acid is obtained. Cane-sugar (probably by previously becoming grape-sugar) and the sugar of milk both yield lactic acid; the latter, however, most readily, the grape-sugar having a strong tendency towards the alcoholic fermentation. If the lactic fermentation be allowed to proceed too far, the second stage of the process of transmutation commences, hydrogen gas and carbonic acid gas are evolved, and the butyric fermentation, by which oily acids are formed, is established.

Pasteur ascribes the lactic fermentation to the agency of a specific kind of ferment, which occurs in the form of a greyish layer deposited upon the surface of the sediment formed during the fermentation of the sugar, casein, and chalk (see Lactic acid, b), in the manufacture of lactic acid.

If to a mixture of yeast, or any nitrogenous substance, and water, sugar, and then chalk, be added, and finally a very small quantity of this greyish substance, taken from a portion of a liquid undergoing active lactic fermentation, lactic acid fermentation is almost immediately set up, the chalk disappears owing to the formation of calcic lactate, and the greyish substance is copiously deposited. When placed under the microscope this ferment is seen to be composed of “little globules, or very short articulations, either isolated or in threads, constituting irregular flocculent particles, much smaller than those of beer yeast, and exhibiting a rapid gyratory motion.” If these little particles be washed thoroughly in pure water, and then placed in a solution of sugar, lactic acidification immediately commences in the saccharine liquid, and goes on steadily until stopped by the excess of free acid.

LAC′TIDE. See Lactic acid.

LAC′TIN. See Sugar of Milk.

LAC′TOMETER. Syn. Galactometer. An instrument for ascertaining the quality of milk. Milk may be roughly tested by placing it in a long graduated tube sold for the purpose, and allowing it to remain until all the cream has separated and measured, then decanting off the clear whey, and taking its specific gravity; the result of the two operations, when compared with the known quantity of cream and the density of the whey of an average sample of milk, gives the value of the sample tested. See Milk.

A little instrument called a ‘milk-tester’ is sold in London at a low price. It is essentially a hydrometer which sinks to a given mark on the stem in pure water, and floats at another mark at the opposite end of the scale in pure milk. The intermediate space indicates the quantity of water (if any) employed to adulterate the article. As the sp. gr. of pure milk varies, the indications of the ‘tester’ cannot be depended on.

LAC′TOSE. See Sugar of Milk.

LAC′TUCA. (B. P.) Syn. Lettuce. The leaves and flowering tops of the wild indigenous plant Lactuca virosa. They are sedative, narcotic, and powerfully diuretic; also mildly laxative and diaphoretic. Given in dropsy and visceral obstructions. See Lettuce, Extract of.

LACTUCA′′RIUM. Syn. Lettuce opium. Thridace; Lactucarium (Ph. E. & D.). The inspissated milky juice of the Lactuca sativa (common garden lettuce), or the Lactuca virosa (strong-scented wild lettuce), obtained, by incision, from the flowering stems, and dried in the air. The latter species yields by far the greatest quantity. M. Arnaud, of Nancy, adopts the following method of procuring this substance, which appears to be the most productive and simple of any yet published:—Before the development of the lateral branches, the stems of twelve plants are cut, one after another, a little below the commencement of these branches; returning to the first one, a milky exudation is found on the cut portion, and on that which remains fixed in the earth; this milky exudation is adroitly collected with the end of the finger (or with a bone knife), which is afterwards scraped on the edge of a small glass; the same operation is performed on twelve other heads, and so on; on the third day it is repeated on every portion of the plant remaining in the ground, a thin slice being first cut off the top; this is done every day until the root is reached. As soon as the lactucarium is collected it coagulates; the harvest of each day is divided into small pieces, which are placed on plates, very near each other, but without touching, and allowed to dry for two days, after which they are set aside in a bottle. In this way 15 or 20 times the ordinary product is obtained.

Prop., &c. Lactucarium is anodyne, hypnotic, antispasmodic, and sedative, allaying pain and diminishing the force of the circulation. It has been recommended in cases in which opium is inadmissible, and has been administered with advantage in chronic rheumatism, colic, diarrhœa, asthma, and troublesome cough of phthisis, the irritability and watchfulness in febrile disorders, &c.—Dose, 2 to 5 gr.; made into pills, lozenges, or tincture.

LACTU′CIN. Syn. Lactucinum, L. This is the active principle of lactucarium, and is found in the juice of several species of lettuce.

Prep. Exhaust lactucarium with hot rectified spirit, agitate the tincture with a little animal charcoal, filter, add a little milk of lime, and evaporate to dryness; digest the residuum in hot rectified spirit; filter, and evaporate by a gentle heat, so that crystals may form.

Prop., &c. A nearly colourless, odourless, fusible, neutral, bitter substance; sparingly soluble in cold water and in ether, but freely soluble in alcohol. It possesses feeble basic properties. Good lactucarium contains fully 20% of this substance.

LAD′ANUM. See Labdanum.

LAENNEC’S CONTRA-STIMULANT. See Draught.

LAKE. Syn. Lacca, L. Animal or vegetable colouring matter, precipitated in combination with oxide of tin or alumina; usually the latter. The term was formerly restricted to red preparations of this kind, but is now indiscriminately applied to all compounds of alumina and colouring matter. The term ‘LAKE,’ when unqualified by an adjective, is, however, understood to apply exclusively to that prepared from cochineal.

Prep. Lakes are made—1. By adding a solution of alum, either alone or partly saturated with carbonate of potassa, to a filtered infusion or decoction of the colouring substance, and after agitation precipitating the mixture with a solution of carbonate of potash.—2. By precipitating a decoction or infusion of the colouring substance made with a weak alkaline lye, by adding a solution of alum.—3. By agitating recently precipitated alumina with a solution of the colouring matter, prepared as before, until the liquid is nearly decoloured, or the alumina acquires a sufficiently dark tint. The first method is usually employed for acidulous solutions of colouring matter, or for those whose tint is injured by alkalies; the second, for those that are brightened, or at least uninjured, by alkalies; the third, for those colouring matters that have a great affinity for gelatinous alumina, and readily combine with it by mere agitation. By attention to these general rules, lakes may be prepared from almost all animal and vegetable colouring substances that yield their colour to water, many of which will be found to possess great beauty and permanence. The precise process adapted to each particular substance may be easily ascertained by taking a few drops of its infusion or decoction, and observing the effects of alkalies and acids on the colour. The quantity of alum or of alumina employed should be nearly sufficient to decolour the dye liquor; and the quantity of carbonate of potassa should be so proportioned to the alum as to exactly precipitate the alumina without leaving free or carbonated alkali in the liquid. The first portion of the precipitate has the deepest colour, and the shade gradually becomes paler as the operation proceeds. A beautiful ‘tone’ of violet, red, and even purple, may be communicated to the colouring matter of cochineal by the addition of perchloride of tin; the addition of arseniate of potassa (neutral arsenical salt) in like manner gives shades which may be sought for in vain with alum or alumina. After the lake is precipitated, it must be carefully collected, washed with cold distilled water, or the purest rain water, until it ceases to give out colour, and then carefully dried in the shade. In this state it forms a soft velvety powder. That of the shops is generally made up into conical or pyramidal drops (drop lake), which is done by dropping the moist lake through a small funnel on a clean board or slab, and drying it by a gentle heat as before. A very little clear gum water is commonly added to the paste to give the drops consistence when dry.

Lake, Blue. Syn. Lacca cœrulea, L. Prepared from some of the blue-coloured flowers; fugitive. The name is also applied to lump archil (lacca cœrulea), to moist alumina coloured with indigo, and to mixed solutions of pearlash and prussiate of potash, precipitated with another solution of sulphate of iron and alum. These are permanent and beautiful, but are seldom used, in consequence of indigo and Prussian blue supplying all that is wanted in this class of colours.

Lake, Brazil-wood. Syn. Drop lake; Lacca in globulis, L. Prep. 1. Take of ground Brazil-wood, 1 lb.; water, 4 galls.; digest for 24 hours, then boil for 30 or 40 minutes, and add of alum, 1⁄2 lb., dissolved in a little water; mix, decant, strain, and add of solution of tin, ⁄2 lb.; again mix well and filter; to the clear liquid add, cautiously, a solution of salt of tartar or carbonate of soda, as long as a deep-coloured precipitate forms, carefully avoiding excess; collect, wash, dry, &c., as directed above.

Obs. The product is deep red. By collecting the precipitate in separate portions, lakes varying in richness and depth of colour may be obtained. The first portion of the precipitated lake has the brightest colour. An excess of alkali turns it on the violet, and the addition of cream of tartar, on the brownish red. The tint turns more on the violet red when the solution of tin is omitted. Some persons use less, others more, alum.

2. Add washed and recently precipitated alumina to a strong and filtered decoction of Brazil wood. Inferior to the last.

Lake, Carminated. Syn. Cochineal lake, Florence l., Florentine l., Paris l., Vienna l.; Lacca Florentina, L. Prep. 1. The residuum of the cochineal left in making carmine is boiled with repeated portions of water, until it is exhausted of colour; the resulting liquor is mixed with that decanted off the carmine, and at once filtered; some recently precipitated alumina is then added, and the whole gently heated, and well agitated for a short time; as soon as the alumina has absorbed sufficient colour, the mixture is allowed to settle, after which the clear portion is decanted, the lake collected on a filter, washed, and dried, as before. The decanted liquor, if still coloured, is now treated with fresh alumina until exhausted, and thus a lake of a second quality is obtained. Very fine.

2. To the coloured liquor obtained from the carmine and cochineal as above, a solution of alum is added, the filtered liquor precipitated with a solution of carbonate of potassa, and the alum or alumina; this brightens the lake collected and treated as before. Scarcely so good as the last.

Obs. Some makers mix a little solution of tin with the coloured liquor before adding colour. The above lake is a good glazing colour with oil, but has little body. It may be made directly from a decoction of cochineal. (See below.)

Lake, Cochineal. Prep. 1. Cochineal (in coarse powder), 1 oz.; water and rectified spirit, of each 2⁄2 oz.; digest for a week, filter, and precipitate the tincture with a few drops of solution of tin, added every two hours, until the whole of the colouring matter is thrown down; lastly, wash the precipitate in distilled water, and dry it. Very fine.

2. Digest powdered cochineal in ammonia water for a week, dilute the solution with a little water, and add the liquid to a solution of alum, as long as a precipitate falls, which is the lake. Equal to the last.

3. Coarsely powdered cochineal, 1 lb.; water, 2 galls.; boil 1 hour, decant, strain, add a solution of salt of tartar, 1 lb., and precipitate with a solution of alum. By adding the alum first, and precipitating the lake with the alkali, the colour will be slightly varied. All the above are sold as CARMINATED or Florence lake, to which they are often superior.

Lake, Green. Made by mixing blue and yellow lake together. Seldom kept in the shops, being generally prepared extemporaneously by the artist on his palette.

Lake, Lac. Prep. Boil fresh stick-lac in a solution of carbonate of soda, filter the solution, precipitate with a solution of alum, and proceed as before.

Lake, Lichen. See Orcein.

Lake, Madder. Syn. Lacca rubiæ, L. columbina, L. Prep. 1. (Sir H. C. Inglefield.) Take of Dutch grappe or crop madder, 2 oz.; tie it in a cloth, beat it well in a pint of water in a stone mortar, and repeat the process with fresh water (about 5 pints) until it ceases to yield colour; next boil the mixed liquor in an earthen vessel, pour it into a large basin, and add of alum 1 oz., previously dissolved in boiling water, 1 pint; stir well, and while stirring, pour in gradually of a strong solution of carbonate of potassa (‘oil of tartar’), 1⁄2 oz.; let the whole stand until cold, then pour off the supernatant yellow liquor, drain, agitate the residue with boiling water, 1 quart (in separate portions), decant, drain, and dry. Product, ⁄2 oz. The Society of Arts voted their gold medal to the author of the above formula.

2. Add a little solution of acetate of lead to a decoction of madder, to throw down the brown colouring matter, filter, add a solution of tin or alum, precipitate with a solution of carbonate of soda or of potassa, and otherwise proceed as before.

3. (Ure.) Ground madder, 2 lbs.; water, 1 gall.; macerate with agitation for 10 minutes, strain off the water, and press the remainder quite dry; repeat the process a second and a third time; then add to the mixed liquors, alum ⁄2 lb., dissolved in water, 3 quarts; and heat in a water bath for 3 or 4 hours, adding water as it evaporates; next filter, first through flannel, and, when sufficiently cold, through paper; then add a solution of carbonate of potassa as long as a precipitate falls, which must be washed until the water comes off colourless, and, lastly, dried. If the alkali be added in 3 successive doses, 3 different lakes will be obtained, successively diminishing in beauty. See Madder, Madder, Red, &c.

Lake, Or′ange. Prep. Take of the best Spanish annotta, 4 oz.; pearlash, ⁄4 lb.; water, 1 gall.; boil for half an hour, strain, precipitate with alum, 1 lb., dissolved in water, 1 gall., observing not to add the latter solution when it ceases to produce an effervescence or a precipitate; strain, and dry the sediment in small squares, lozenges, or drops. The addition of some solution of tin turns this lake on the LEMON YELLOW; acids redden it. See Lake, Yellow.

Lake, Red. Prep. Take of pearlash, 1 lb.; clean shreds of scarlet cloth, 3⁄2 lbs.; water, 5 galls.; boil till the cloth is decoloured, filter the decoction, and precipitate with a solution of alum, as before. See the Lakes noticed above (Brazil-wood, Carminated, Cochineal, and Madder).

Lake, Yellow. Prep. 1. Boil French berries, quercitron bark, or turmeric, 1 lb., and salt of tartar, 1 oz., in water, 1 gall., until reduced to one half, then strain the decoction, and precipitate with a solution of alum.

2. Boil 1 lb. of the dye-stuff with alum, ⁄2 lb.; water, 1 gall., as before, and precipitate the decoction with a solution of carbonate of potash. See Lake, Orange (above).

LAMB in its general qualities closely resembles mutton, of which, indeed, it is merely a younger and more delicate kind. It is well adapted as an occasional article of food for the convalescent and dyspeptic; but it is unequal for frequent use, more especially for the healthy and robust, to the flesh of the adult animal.

LAMBS, DISEASES OF. Among other diseases, these animals are particularly prone to one affecting the lungs, in consequence of the existence of parasites (Strongylus bronchialis) in the air-passages. See Parasites.

LAMP. A contrivance for producing artificial light or heat by the combustion of inflammable liquids. The term ‘lamp’ is also applied to a portable gas-burner (GAS-LAMP), and to a tubular candle-holder, which, by the aid of a simple mechanical device, keeps the flame at one height (CANDLE-LAMP).

Oil lamps were employed for illumination among the nations of antiquity, at the earliest period of which any record exists. The Assyrian, Greek, and Roman lamps preserved in our museums are generally noble specimens of art-workmanship. Though elegant in form, and rich in external embellishment, the ancient lamp was simply a vessel to contain the oil, with a short depression or spout on the one side, in which the wick is laid. Lamps of this rude construction are still in common use in many countries.

No important improvement in the principle and construction of lamps as a source of light occurred until a comparatively recent date; the smoke, dirt, and disagreeable odour of the common lamp having previously led to its disuse among the superior classes in favour of candles. At length, in 1789, M. Argand made a revolution in illumination by the invention and introduction of the well-known lamp which bears his name. In the Argand lamp a hollow tubular wick of woven cotton replaces the solid bundles of fibres, and is so arranged that air passes through it into the interior of the flame. Over the burner is placed a cylindrical glass chimney, open at the bottom, and surrounding the flame at a short distance from it, by which another current of air is made to act on the exterior portion of the flame. In this way a due supply of oxygen is secured, and sufficient heat generated for the perfect combustion of the gaseous products of the oil, and the smoke and soot which escape from the ordinary lamp are converted into a brilliant and smokeless flame.

The earliest table-lamps constructed on Argand’s principle had one serious defect—the oil vessels had to be placed almost on a level with the burners, in a position which caused them to cast objectionable shadows. This defect was almost entirely removed by making the oil vessel in the form of a flattish ring, connected by slender tubes with the burner. The more elegant contrivances, known as the MODERATOR LAMP and Carcel lamp, which are now so much used for burning colza and similar oils, cast no shadow. In these the oil, instead of being sucked up by the wick, or descending to it by the force of gravity, is driven up by mechanical means from the oil-reservoir contained in the foot or pedestal. A spiral spring, acting upon a piston, elevates the oil in the ‘moderator,’ while a little pump worked by clockwork does the same duty in the ‘Carcel.’ The burner and wick in each are formed on Argand’s principle.

For burning the hydrocarbon oils distilled from coal and petroleum, lamps of very simple construction are used. These oils, in consequence of their diffusive character, rise to a considerable height up a wick, and therefore do not require mechanical lamps. The wicks of HYDRO-CARBON LAMPS are usually flat, but sometimes circular. To cause perfect combustion, a strong draught of air is created by placing over the flame a tall glass chimney, usually much contracted above the flame. A metallic cap, with an orifice the shape of the flame, is placed over the burner, its use being to deflect the currents of air upon the flame. The reservoirs of hydro-carbon lamps ought always to be constructed of some bad conductor of heat, as glass or porcelain.

For chemical operations, many forms of lamp are used. The ordinary glass SPIRIT-LAMP, fitted with a ground-glass cap, is quite indispensable for minor experiments. (See engr. 1.) Stoneware wick-holders are preferable to those of brass, which become greatly heated, and endanger the splitting of the glass. “An effective spirit-lamp may at any time be constructed out of a vial having a glass tube passing through the cork, a cover being formed from a test-tube inverted over the wick, and fitting with moderate tightness on the superior extremity of the cork” (Greville Williams). Alcohol or wood spirit is the fuel used.

The Argand lamp, when intended as a source of heat for chemical purposes, is so modified as to adapt it to burn either oil, spirit of wine, or wood-spirit, and the combustion is greatly aided by the chimney, which in this case is made of copper. (See engr. 2 and 3.) The lamp itself is also made of metal, and furnished with ground caps to the wick-holder and aperture by which the spirit is introduced, in order to prevent loss of spirit by evaporation when the lamp is not in use. When in use this aperture must always be left open, otherwise an accident is sure to happen, as the heat expands the air in the lamp, and the spirit is forcibly expelled.

In those situations in which coal-gas is cheap, it may be used with great economy and advantage as a source of heat in most chemical operations. Retorts, flasks, capsules, and other vessels, can be thus exposed to an easily regulated and constant temperature for many successive hours. Small platinum crucibles may be ignited to redness by placing them over the flame on a little wire triangle. Of the various gas-lamps now used in the laboratory, the first and most simple consists of a common Argand gas-burner fixed on a heavy and low foot, and connected with a flexible gas-tube of caoutchouc or other material. (See engr. 4.) With this arrangement it is possible to obtain any degree of heat, from that of the smallest blue flame to that which is sufficient to raise a moderately large platinum crucible to dull redness. When gas mixed with a certain proportion of air is burnt, a pale blue flame, free from smoke, and possessing great heating power, is obtained. A lamp for burning the mixture may easily be made by fitting a close cover of fine wire gauze over the top of the chimney of the last-mentioned contrivance. The gas is turned on, and after a few minutes ignited above the wire gauze. (See page 946). The ingenious and useful burners of Bunsen and Griffin are so constructed that gas and air mixed in any proportions, or gas alone, may be burnt at pleasure. Bunsen’s is a most efficient and convenient form of burner. (See illustration on next page.) It consists of a gas jet, surrounded by a metal tube, about 6 to 9 inches high and about ⁄2 inch in diameter; having at the bottom four large holes. On the admission of air, when the gas is turned on, the air rushes in by these orifices, and mingling with the gas, the mixture ascends to the top of the tube and is there ignited, giving rise to a flame of great heat, but without luminosity, owing to the simultaneous combustion of the carbon and the hydrogen. The burner, however, is so contrived that by shutting off the supply of air entirely, or limiting it, the flame may be made more or less luminous at pleasure. To distribute the flame, a rosette burner is placed on the top of the tube.

An improved variety of this burner has been designed by Bunsen, and is figured below.

It is so contrived as to give a flame that is a very much better substitute for the flame of the blowpipe, than the ordinary Bunsen’s burner, and may hence be employed for reducing, oxidising, fusing, and volatilising, as well as for the observation of coloured flames. Fig. 1 is a sheath which, by turning round, regulates the admission of air. When it is used the conical chimney, d d d d, is placed in e e; it is of a size sufficient to allow of the flame burning tranquilly. In fig. 1 the flame is represented of half its natural size. This flame it will be seen consists of three divisions, viz.—1, a a a a the dark zone, which is composed of cold gas mixed with about 62 per cent. of air. 2, a c a b the mantle formed by the burning mixture of gas and air. 3, a b a, the luminous tip of the dark cone, which only appears when the orifices for the air are partially closed. Reductions may be performed in this part of the flame.

Bunsen, however, divides the flame into six parts, to which he attributes as many functions. These six divisions of the flame he names as follows:—

1. The base at α has a relatively low temperature, because the burning gas is here cooled by the constant current of fresh air, and also because the lamp itself conducts the heat away. This part of the flame serves for discovering the colours produced by readily volatile bodies, when less volatile matters which colour the flame are also present. At the relatively low temperature of this part of the flame, the former vaporises alone instantaneously, and the resulting colour imparted to the flame is for a moment visible unmixed with other colours.

2. The Fusing Zone. This lies at β, at a distance from the bottom of somewhat more than one third of the height of the flame, equidistant from the outside and the inside of the mantle, which is broadest at this part. This is the hottest part of the flame, viz., about 2300°, and it therefore serves for testing substances, as to their fusibility, volatility, emission of light, and for all processes of fusion at a high temperature.

3. The lower Oxidising Zone lies in the outer border of the fusing zone at γ, and is especially suitable for the oxidation of oxides dissolved in vitreous fluxes.

4. The upper Oxidising Flame at ε consists of the non-luminous tip of the flame. Its action is strongest when the air holes of the lamp are fully open. It is used for the roasting away of volatile products of oxidation, and generally for all processes of oxidation, when the highest temperature is not required.

5. The lower Reducing Zone lies at δ, in the inner border of the fusing zone next to the dark cone. The reducing gases are here mixed with oxygen, and, therefore, do not possess their full power, hence they are without action on many substances which are deoxidised in the upper reducing flame. This part of the flame is especially suited for reduction on charcoal or in vitreous fluxes.

6. The upper Reducing Flame lies at η, in the luminous tip of the dark inner cone, which, as already explained, may be produced by diminishing the supply of air. This part of the flame must not be allowed to get large enough to blacken a test tube filled with water and held in it. It contains no free oxygen, is rich in separated incandescent carbon, and therefore has a much stronger action than the lower reducing zone. It is used more particularly for the reduction of metals collected in the form of incrustations.

The subjoined is a drawing of the gauze burner, which is an open cylinder with wire gauze at the top.

When this is placed over the gas burner, a supply of air is drawn in at the bottom by the ascending current of gas, and the mixture burns above the gauze, with a very hot flame, quite free from smoke, the metallic meshes preventing the flame from passing down to the gas below. See Illumination, Fuel, Furnace, Gas, Laboratory, &c.

Lamp, Flame′less. Syn. Glow lamp. A coil of fine platinum wire is slipped over the wick of a spirit lamp, the greater part being raised above the cotton; the lamp is supplied with ether or alcohol, lighted for a moment and then blown out. The coil continues to glow in the mixed atmosphere of air and combustible vapour, until the liquid in the lamp is exhausted.

Lamp, Monochromat′ic. A lamp fed with a mixture of a solution of common salt and spirit of wine. It gives a yellow light, and makes every object illuminated by it appear either yellow or black. The human features are changed in a remarkable degree; the countenance appearing truly ghastly and unearthly.

Lamp, Safety. Syn. Miner’s lamp, Davy, Geordy. The safety lamp of Sir H. Davy and George Stephenson are similar in principle, and were independently invented about the same time. That of Sir H. Davy consists of a common oil lamp, surmounted with a cylinder of wire gauze, the apertures of which are not greater than the ⁄20th of an inch square, and the wire of which it is made to the ⁄40th to the ⁄60th of an inch in diameter. (See engr.) The fire-damp (carbonetted hydrogen) along with air passes through the meshes into the interior of the gauze cylinder. Here it ignites, but the flame which is produced by its combustion cannot explode a mixture of fire-damp and air by which the lamp may be surrounded. The flame is prevented from passing to the exterior of the gauze by the cooling action of the metal of which it is constructed. When this lamp is taken into an explosive atmosphere, although the fire-damp may burn within the cage with such energy as sometimes to heat the metallic tissue to dull redness, the flame is not communicated to the mixture on the outside. These appearances are so remarkable, that the lamp becomes an admirable indicator of the state of the air in different parts of the mine, and if its admonitions are attended to, gives the miner time to withdraw before an explosion takes place.

Lamp, Telescope. This ingenious contrivance, invented by Messrs Murray and Heath, is intended for microscopic illumination. It consists of three brass tubes, sliding one within the other, the oil vessel being contained in the inner tube. The height of the lamp is regulated to the greatest nicety by simply turning one tube in the other, interior spiral guides preventing all chance of slipping. The great advantage of this arrangement is absence of the stand and bar usually employed for raising and lowering the lamp, which enables it to be used on all sides, and to be brought much closer to the microscope than other lamps. See engr., below.

LAMP BLACK. See Black pigments.

LAMP′REY. Syn. Great lamprey, Seal. This fish is the Petromizon marinus of Linnæus. It generally quits the sea in the spring, for the purpose of spawning, and remains in our rivers for a few months. Its flesh is soft and glutinous, and though esteemed a delicacy, is extremely difficult of digestion, if not otherwise unwholesome. Potted lampreys are usually so highly seasoned as to become a dangerous article of food. Henry I is said to have lost his life from the effects of a surfeit of lampreys.

LAUDANINE. C20H25NO3. An alkaloid obtained by Hesse from the aqueous extract of opium. It is homologous with morphine and codeine. It dissolves in strong sulphuric acid with a rose-red colour, in strong nitric acid with an orange red colour, and in ferric chloride with emerald green colour.

LANTHA′NIUM. La92. A rare metal, discovered by Mosander, associated with oxide of cerium. Oxide of lanthanium is a pale salmon-coloured powder, unaffected by ignition in open vessels. According to Zschiesche the atomic weight of lanthanium is 90·18. See Cerium.

LANTHOPINE. C23H25NO4. A base obtained by Hesse in small quantity, associated with other bases from the aqueous extract of opium. It is homologous with papaverine. Strong nitric acid dissolves it, giving rise to an orange red colour. Strong sulphuric acid gives with it a faint violet colour.

LA′PIS. [L.] A stone. The term was much employed by the old chemists, and is still commonly applied to several preparations used in medicine.

Lapis Causticus. See Potassium.

Lapis Divi′nus. Syn. Divine Stone; Lapis ophthalmicus, L.; Pierre divine, Fr. Prep. 1. (Beer.) Verdigris, nitre, and alum, equal parts, melted together.

2. (P. Cod.) Alum, nitre, and blue vitriol, of each 3 oz.; camphor, 1 dr.; as last.

3. (Woolfuss.) Blue vitriol, nitre, alum, and camphor, equal parts, melted together, adding the camphor last. Astringent and detergent. 1 oz., dissolved in water, 1 pint, formed a once celebrated lotion. 1 dr. in water, 1 pint, is still used as a collyrium.

Lapis Inferna′lis. See Nitrate of Silver.

Lapis Lazu′li. See Ultramarine.

Lapis Lydius. Syn. Lydian stone. A siliceous slate, used as a touchstone by jewellers.

Lapis Medicamento′sus. Syn. Medicinal stone; Lapis mirabilis, L. Prep. (Ph. L. 1746.) Alum, litharge, and Armenian bole, of each 6 oz.; colcothar of green vitriol, 3 oz.; vinegar, 4 fl. oz.; mix, and evaporate to dryness. Formerly used to make an astringent and detergent lotion:—1 oz. to water, 1 pint. Once a popular application to ulcers, and in other cases; now disused.

Lapis Vulnerar′ius. Very similar to Lapis divinus.

LARCH BARK. The inner bark of the Larix Europœa, the common larch, has been lately introduced, under the form of a tincture, into the British Pharmacopœia.

Dr Stenhouse obtained from the bark a peculiar volatile constituent, possessed of acid properties for which the name of lariximic acid has been proposed. The other trees of the pine family are deficient in this acid. The young bark abounds most in it. Gum, starch, resin, and that variety of tannic acid, which forms olive green precipitates with the salts of iron, have also been found, in addition to other substances, in larch bark.

The inner bark, employed internally, has a special action on the mucous membranes, and acts as an astringent and mild stimulant. It is said to have been given with excellent results in hæmoptysis, as well as in bronchitis attended with copious expectoration, and in diseases of the urinary passages. Externally has been found serviceable in psoriasis, chronic eczema, and some other skin diseases. It is best to combine its extract or tincture with glycerin when it is to be used outwardly. See Tincture of larch bark.

LARD. Syn. Hog’s lard, AXUNGE; Adeps (Ph. L.), Axungia (Ph. E.), A. suillus (Ph. D.), A. porci, A. præparatus (B. P.), L. The fat of the pig (Sus scrofa—Linn.) melted by a gentle heat, and strained through flannel or a hair sieve. The fat about the loins yields the whitest and hardest lard. “That which has been cured with chloride of sodium is not to be employed.” (Ph. L.) “It is not to be used without being first carefully washed with water.” (Ph. L. 1866.) Used chiefly to make ointments, and in cookery. See Adeps.

LARD′ING. By many this is regarded as belonging to the higher style of cookery only, and too troublesome and extravagant to be adapted to the kitchens of the middle classes and the poor. This, we are assured, is not the case. On the contrary, “it is an economical process, and will make lean meat go much farther than without it.” The process of larding is as follows:—“Get what is called a larding needle, that is, a piece of steel from 6 to 9 inches long, pointed at one end, and having four slits at the other to hold a small strip of bacon when put between them. It will, perhaps, cost tenpence. Cut the bacon into pieces 2 or 3 inches long, and ⁄4 to ⁄2 an inch square; put each one after the other in the pin, insert it in the meat, and leave only about half an inch out; using 8 pieces to each pound.” (Soyer.)

LARK. The Alauda arvensis (SKYLARK) and the Alauda cristata (FIELD-LARK), with several other species of the same genus, form a light and nutritious article of food, by many esteemed a delicacy. The last, according to Galen and Dioscorides, eaten either roasted or boiled, ‘helps the colic.’ The heart, applied to the thigh, was also regarded to possess the same virtue.

LARYNGITIS. Inflammation of the larynx, or upper part of the windpipe. The symptoms that indicate this most dangerous malady are sore throat, accompanied with considerable pain in front of the throat, difficulty in breathing and swallowing, considerable hoarseness, change or loss of voice, a sense of suffocation, fever, restlessness, flushing of the face, and an eager desire for fresh air. We have described the accompaniments of this dread disease, in order that any one seized with an attack may know its nature, and at once send for his medical attendant. Should circumstances prevent his doing so immediately, as many leeches as possible should be applied to the centre of the throat.

LAUD′ANUM. This name is now understood to denote, exclusively, the common tincture of opium of the Pharmacopœia; but formerly the term was applied to several preparations of opium differing greatly from each other, both in their strength and mode of preparation. (See below.)

Laudanum, Dutchman’s. From the flowers of bull’s hoof or Dutchman’s laudanum (Passiflora merucuja—Linn.) infused in rum. Narcotic. Used as a substitute for tincture of opium in the West Indies.

Laudanum, Ford’s. This is merely the common tincture of opium aromatised with a little cloves and cinnamon.

Laudanum, Houlton’s. Prep. From opium 2⁄2 oz.; distilled vinegar, 1⁄2 pint; digested together for a week, the filtered tincture gently evaporated nearly to dryness, and then redissolved in weak spirit (1 of rectified spirit to 7 of water), 1 quart.—Dose, 10 to 60 drops.

Laudanum, Neumann’s. A fermented infusion of opium evaporated to the consistence of honey.

Laudanum, Quince. Syn. Extractum opii cydoniatum, Laudanum cydoniatum, L. Prep. 1. Extract of opium made with quince juice; a few drops of the oils of cinnamon, cloves, and mace being added before the mass cools. Now seldom used.

2. Laudanum, liquid-quince; (Laudanum liquidum cydoniatum, L.) (L. c. paratum fermentatione, L.) A fermented infusion of opium prepared with quince juice, aromatised with cloves, cinnamon, aloes wood, and yellow sandal wood, and evaporated so as to possess about twice the strength of the ordinary tincture. Now obsolete.

Laudanum, Rousseau’s. Wine of opium prepared by fermentation. See Wine.

Laudanum, Smith’s Concentrated. Resembles Battley’s LIQUOR OPII SEDATIVUS, but possesses about 6 times its strength.

Laudanum, Swediaur’s. Prep. From extract of opium, 2 parts, dissolved in a mixture of alcohol, 1 part, distilled water, 8 parts. Every 5 drops contain 1 gr. of opium.

Laudanum, Sydenham’s Liquid. Syn. Laudanum liquidum Sydenhami, L. Similar to Wine of Opium—Ph. L., but rather stronger, and aromatised with a little cloves and cinnamon. Wine of opium is now always sold for it.

Laudanum, Tartarised. Syn. Laudanum liquidum tartarizatum, L. A tincture of opium prepared with spirit alkalised with salt of tartar, and flavoured with aromatics. Obsolete.

LAUGH′ING GAS. See Nitrous oxide.

LAUR′EL. See Cherry laurel, Sweet bay, Oil, &c.

LA′VA. The matter thrown out by volcanoes. The beautiful ornamental vases, jugs, and other objects sold under the name, are a superior sort of unglazed coloured porcelain.

LAVE′MENT. See Enema.

LAV′ENDER. The flowers or flowering tops of Lavandula vera or common garden lavender. An essential oil, spirit, and tincture, prepared from it, are officinal in the Pharmacopœias.

Lavender Dye (for COTTON). For 100 yards of material. Take 1 lb. of logwood, and 2 lbs. of sumach, and scald them separately. Then decant them into a proper sized tub, let them cool to 150° Fahr., and add 2 gills of vitriol. Winch the goods in this 20 minutes; lift, and run them slightly through acetate of iron; wash them in two waters; then give 1 lb. of logwood as before, raise with a pint of chloride of tin, wash in two waters; then in a tub of cold water put 4 oz. extract of indigo, enter and winch in this 15 minutes, lift; give one water, and dry.

Lavender Dye (for WOOL). Boil 5⁄2 lbs. of logwood with 2 lbs. of alum. Then add 10 oz. of extract of indigo. When cold put in the goods, and gradually raise to the boiling point. For 50 lbs.

Lavender, Red. See Tincture.

Lavender, Smith’s British. Prep. From English oil of lavender, 2 oz.; essence of ambergris, 1 oz.; eau de Cologne, 1 pint; rectified spirit, 1 quart. Very fragrant. See Water (Lavender).

Lavender, to Dye Silk. (Mustpratt.) Into a vessel with warm water, as hot as the hand can bear, dissolve a little white soap, enough to raise a lather; then add one gill of archil liquor, and work the goods in this for fifteen minutes; ring out and dry.

Boil one ounce of cudbear, and add the solution to the soap and water instead of archil, which will give a lavender having a redder tint than with the archil. If a still redder shade of lavender be required the soap may be dispensed with.

Lavender Water. See Spirits, Perfumed.

LAX′ATIVES. Syn. Lenitives; Laxativa, Laxantia, Lenitiva, L. Mild purgatives or cathartics. The principal of these are—almond oil, cassia pulp, castor oil, confection of senna, cream of tartar, figs, grapes, honey, phosphate of soda, prunes, salad oil, tamarinds, &c.

LAY′ERS. Among gardeners, a mode of propagating plants, by laying down the shoots of young twigs, and covering a portion of them with the soil, without detaching them from the parent plant. To facilitate the rooting of such layers, the part beneath the soil is fractured by twisting or bruising it, or it is partly cut through with a sharp knife, immediately under a bud. When the layer has taken root, it is divided from the parent stem, and transplanted or potted. In this way, with a little care, nearly all plants may be multiplied.

LEAD. Pb. Eq. 207. Syn. Plumbum. This metal, like gold, silver, and iron, appears to have been known in the most remote ages of antiquity. The ore from which it is almost exclusively extracted, as being the only one found in abundance, is the native sulphide or sulphuret of lead, called by mineralogists galena.

Prep. On the large scale lead is obtained by roasting galena in a reverberatory furnace, and smelting the residue along with coal and lime. The lead thus obtained generally contains small quantities of both silver and gold, which it often pays to extract, by a method termed ‘Pattinson’s process.’ This process is founded on the circumstance that, when melted, lead containing silver is allowed to cool. The lead crystallises out first, leaving an alloy of lead and silver still fused. By removing the crystals of lead, as formed, until about four fifths are removed, the residue is an alloy of lead and silver much richer than the original. Repeated several times, this yields a rich alloy of silver and lead that is expelled and the silver obtained.

Another method for the removal of silver from lead is one employed in Glasgow, and known as the ‘Flack-Guillim’ process. It is thus described in ‘Dingler’s Polytechnic Journal,’ ccxxxv, 67-70, and in ‘Engineering’ for September 15th, 1876. “Eighteen tons of rich lead are melted, and one per cent. of zinc added. The molten mass then allowed to cool, the crust which forms is removed, and the lead sweated out in a small pot. The lead in the large pot is then treated with another half per cent. of zinc in the same way. A third addition of a quarter per cent. of zinc suffices to remove the greater part of the remaining silver, 5 dwts. being left in the lead per ton. This lead is then run into the improving pan, and the last traces of zinc oxidised out.”

Pure lead for chemical purposes may be obtained as follows, although the lead of commerce is nearly pure:

By reducing nitrate of lead with charcoal.

By heating the oxide left by igniting pure acetate of lead with black flux.

Prop., &c. The general properties of lead are too well known to require notice here. The sp. gr. of that of commerce is about 11·35; but in a state of absolute purity its greatest density is 11·45. It melts at about 600° Fahr., and when very slowly cooled, crystallises in octahedrons. At a white heat it boils, and is volatilised. When exposed to moist air, it soon becomes covered with a grey film. It is scarcely acted on by hydrochloric or sulphuric acids, although after some time both coat it with a film of chloride or sulphate. It is rapidly acted on by nitric acid, with formation of the nitrate. Pure water put into a leaden vessel and exposed to the air soon corrodes it, and dissolves the newly formed oxide; but river and spring water have little action upon lead, provided there is no free carbonic acid present, the carbonates and sulphates in such water destroying their solvent powers. It has been found that a very small amount of phosphate of sodium or of iodide of potassium, dissolved in distilled water, prevents its corrosive action on this metal. The lead in contact with such water gradually becomes covered with a superficial film of an insoluble salt of lead, which adheres tenaciously, and prevents further change. From this it appears that ordinary water (‘hard water’), which abounds in mineral salts, may be more or less safely kept in leaden cisterns; but distilled water and rain water, and all other varieties that contain scarcely any saline matter, speedily corrode, and dissolve a portion of lead, when kept in vessels of that metal. When, however, leaden cisterns have iron or zinc fastenings or braces, a galvanic action is set up, the preservative power of saline matter ceases, and the water speedily becomes contaminated with lead, and unfit for consumption as a beverage. Water containing carbonic anhydride also acts on lead, and this is the reason why the water of some springs (although loaded with saline matter), when kept in leaden cisterns, or raised by leaden pumps, possesses unwholesome properties.

M. Fordos, in a communication to the ‘Journal de Pharmacie et de Chimie,’ xix, 20, states that in the course of some experiments on the applicability of lead for water pipes and cisterns he could not detect a trace of lead in ten litres of river water taken from the leaden cistern of one of the Paris hospitals. But upon shaking pure water with shot and air, a coating of carbonate of lead was formed on the sides of the bottle, which almost rendered the glass opaque. On dissolving the film in nitric acid, and estimating the lead, it was found that one litre of water had produced five milligrammes of the carbonate. Wine and vinegar would also dissolve that film; and as shot is commonly used for cleaning wine bottles, lead frequently finds its way into wines, a fact which may account for many of the cases of chronic poisoning by lead which occur in large towns. The detection of small quantities of lead in forensic investigation would afford, therefore, no proof of any intentional poisoning.

Orfila’s erroneous statement that lead is a normal constituent of the human organism may also be accounted for in this way.

Free carbonic acid is evolved during the fermentation or decay of vegetable matter, and hence the absolute necessity of preventing the leaves of trees falling into water-cisterns formed of lead. The ‘eau de rose’ and the ‘eau d’orange’ of commerce, which are pure distilled water holding in solution small quantities of essential oil, and are imported in leaden canisters, always contain a small quantity of lead, and deposit a sediment, which is not the case when they are kept in glass or incorrodible vessels.

Lead and all its preparations are highly poisonous; and whether imbibed in almost infinitesimal quantities with our daily beverages and food, or swallowed in larger and appreciable doses, is productive of the most disastrous consequences, the real cause being unfortunately seldom suspected.

Mr G. Bischof writes:—Some eight months ago a tube was passed in my laboratory, which is supplied with water by the New River Company, into the slate cistern so as to act as a syphon to supply some apparatus with water. The external surface of the tube inside the cistern was therefore alternately exposed to the action of air and water, according to the level of water in the cistern.

Recently I noticed a white efflorescence on the greater part of the tube inside the cistern. An adjoining cistern of sheet lead, with a lead overflow pipe fixed into the bottom, shows nowhere any such corrosion.

On cutting the tube it became evident that it is a composition tube, that is to say, a lead tube, containing some antimony. On analysis it was found to be composed of—

Lead 98·3

Antimony 1·7

100·0

Although the external diameter of the tube is only half an inch, 0·29 gram of efflorescence was obtained per foot by gentle rubbing. This dried at 100° C. contained 1·02 per cent. of sulphuric acid, corresponding with 4·1 per cent. of sulphate of lead. The remainder, except 1·13 per cent. of a residue insoluble in nitric acid, is carbonate of lead.

The alternate exposure to air and water appears not essential to the corrosion, as I have observed a similar effect when the same tubing remained constantly under water. The interior of the tube has also been corroded, although of course no permanent efflorescence could be formed, owing to the rapid flow of the water.

The frequent practice of plumbers of using composition tubing in connection with water supplies is therefore highly reprehensible, being fraught with considerable danger to the health of those using the water for drinking or cooking.

Mr Louis Siebold detected lead in eight out of ten samples of concentrated solution of acetate of ammonia as well as in a sample of the ordinary solution of the British Pharmacopœia. In pursuing his investigations Mr Siebold found that solutions of acetate of ammonium are capable of dissolving lead from glass. He therefore advises that all forms of the solution, more particularly the concentrated liquor employed by many chemists for making the weaker solutions, should be kept in bottles free from lead.

With the acids lead or its oxides form salts, usually white in colour, and in the majority nearly insoluble in water, but readily soluble in acids.

Tests. The oxides and salts of lead, mixed with a little carbonate of soda, and exposed on a charcoal support to the reducing flame of the blowpipe, readily yield a soft and ductile globule of metallic lead, and the charcoal, at the same time, becomes covered with a yellowish incrustation of oxide of lead. Both metallic lead and its oxides are soluble in nitric acid, furnishing a solution which may be examined with ease.

Solution of lead salts may be recognised by the following reactions:—Sulphuretted hydrogen, sulphydrate of ammonium, and the alkaline sulphides, give black precipitates, insoluble in the cold dilute acids, alkalies, alkaline sulphides, and cyanide of potassium. Potassium and sodium hydrates give a white precipitate, soluble in excess. Ammonia (except with the acetate) gives a white precipitate, insoluble in excess. The carbonates of potassium, sodium, and ammonium, give a white precipitate, insoluble in excess. Dilute sulphuric acid (in excess), and solutions of the sulphates give a white precipitate, sparingly soluble in dilute acids, but soluble in a hot boiling solution of potassium carbonate. Chromate and bichromate of potassium give yellow precipitates insoluble in dilute nitric acid, and soluble in solution of potassium hydrate. Iodide of potassium gives a yellow precipitate, soluble in great excess by heat, and separating in small, brilliant, golden-yellow scales, as the liquid cools. A piece of polished zinc precipitates metallic lead in an arborescent form, hence called the lead tree. To prepare for these tests, a solid supposed to contain lead should be digested in nitric acid, when the solution, evaporated to dryness and redissolved in water, may be tested as above.