A Cyclopædia of Practical Receipts, Processes, and Collateral Information (part 1)

A—ABBREVIATION

A-, ab-, abs-. [L.] In composition, from, denoting distance, departure, separation, or opposition; as in aberration, abstraction, abnormal, &c.

A-, an-. [Gr.] In composition, no, not, without, denoting the absence or loss of some quality or thing; as in achromatic, anhydrous, amorphous, &c.

AB′ACA (kăh). A species of vegetable fibre, of several varieties, obtained in the Philippine Islands, and remarkable for its brilliancy, strength, and durability. The finer kinds are woven into muslins, and other delicate fabrics; the coarser are formed into mats, cordage, and sail-cloth. It has been recently employed in Paris for the manufacture of various articles of furniture and dress; including bonnets, tapestry, carpets, network, hammocks, &c. The fibre, and fabrics made of it, may be bleached and dyed in a similar manner to flax and linen.

ABATTOIR. A public slaughter-house for cattle, &c., usually erected within the walls or precincts of a continental town or city.

ABBREVIATION. One or more of the earlier letters of a word used to express the whole.

1. Abbreviations in general use:—

A.B., Bachelor of Arts.

A.D., In the year of our Lord.

A.I.C., Associate of the Institute of Chemistry.

A.I.C.E., Associate of the Institute of Civil Engineers.

A.M., Master of Arts.—Before noon.

A.R.A., Associate of the Royal Academy.

B.A., Bachelor of Arts.

Bart., Baronet.

B.C., Before Christ.

B.D., Bachelor of Divinity.

B.Sc., Bachelor of Science.

C.B., Companion of the Bath.

C.E., Civil Engineer.

C.S., Civil Service.

D.C.L., Doctor of Civil Laws.

D.D., Doctor of Divinity.

D.G., By the Grace of God.

Dr., Doctor.—Debtor.

D.Sc., Doctor of Science.

D.V., God willing.

Ed., Editor, or Edition.

e.g., for example.

F.C.P., Fellow of the College of Preceptors.

F.C.S., Fellow of the Chemical Society.

F.G.S., Fellow of the Geological Society.

F.I.C., Fellow of the Institute of Chemistry.

F.L.S., Fellow of the Linnean Society.

F.R.A.S., Fellow of the Royal Astronomical Society.

F.R.C.P., Fellow of the Royal College of Physicians.

F.R.C.S., Fellow of the Royal College of Surgeons.

F.R.G.S., Fellow of the Royal Geographical Society.

F.R.S., Fellow of the Royal Society.

F.R.S.E., Fellow of the Royal Society of Edinburgh.

H.M.S., Her Majesty’s Ship.

H.R.H., His (or Her) Royal Highness.

i.e., That is.

Inst., Instant (the present month).

I.H.S., Jesus the Saviour of Man.

K.B., Knight of the Bath.

K.C.B., Knight Commander of the Bath.

K.G., Knight of the Garter.

Knt., Knight.

K.St.P., Knight of St. Patrick.

K.T., Knight of the Thistle.

L.A.C., Licentiate of the Apothecaries’ Company.

Lat., Latitude.

L.D., Licentiate in Dentistry.

LL.D., Doctor of Laws.

L.M., Licentiate in Midwifery.

Loc. cit., The part referred to.

Lon. or Long., Longitude.

M.A., Master of Arts.

M.B., Bachelor of Medicine.

M.C., Master of Surgery.—Master of the Ceremonies.

M.C.P., Member of the College of Preceptors.

M.D., Doctor of Medicine.

M.I.B.A., Member of the Institute of British Architects.

M.R.C.P., Member of the Royal College of Physicians.

M.R.C.S., Member of the Royal College of Surgeons.

M.R.C.V.S., Member of the Royal College of Veterinary Surgeons.

M.R.I., Member of the Royal Institution.

M.R.I.A., Member of the Royal Irish Academy.

MS., Manuscript.

MSS., Manuscripts.

Mus. Doc., Doctor of Music.

N.B., Mark well.

Nem. con., Without opposition.

O.H.M.S., On Her Majesty’s service.

Op. cit., The work quoted.

Per cent. (often expressed by the sign %), By the hundred.

Ph.D., Doctor of Philosophy.

P.M., Afternoon.

Prox., The next (month).

P.S., Postscript.

Q.C., Queen’s Counsel.

Qy. (?), Query, Question.

R.A., Royal Academician—Royal Artillery.

R.E., Royal Engineers.

R.H.A., Royal Horse Artillery.

R.M., Royal Marines.

R.N., Royal Navy.

Tr., Translator.

Ult., The last (month).

v. or vide, See.

W.S., Writer to the Signet.

&, ampersand, and.

&c., et cetera, And so on.

2. Abbreviations used in Prescriptions:—

A. aa., ana (Greek), of each. Equally by weight or measure.

Abdom., abdomen, the abdomen, the belly.

Abs. febr., absente febre, fever being absent.

Ad 2 vic., ad secundum vicem, to the second time; or ad duas vices, for two times.

Ad gr. acid., ad gratam aciditatem, to an agreeable acidity.

Ad def. animi, ad defectionem animi, to fainting.

Ad del. an., ad deliquium animi, to fainting.

Ad libit., ad libitum, at pleasure.

Add., adde, or addantur, add, or let them be added; addendus, to be added.

Adjac., adjacens, adjacent.

Admov., admove, admoveatur, admoveantur, apply, let it be applied, let them be applied.

Ads. febre, adstante febre, while the fever is present.

Alter. hor., alternis horis, every other hour.

Alvo adstr., alvo adstrictâ, when the bowels are confined.

Aq. astr., aqua astricta, frozen water.

Aq. bull., aqua bulliens, boiling water.

Aq. com., aqua communis, common water.

Aq. fluv., aqua fluviatilis, river water.

Aq. mar., aqua marina, sea water.

Aq. niv., aqua nivalis, snow water.

Aq. pluv., aqua pluviatilis, or pluvialis, rain water.

Aq. ferv., aqua fervens, hot water.

Aq. font., aqua fontana, or aqua fontis, spring water.

Bis ind., bis in dies, twice a day.

Bib., bibe, drink.

BB., Bbds., Barbadensis, Barbadoes, as aloë Barbadensis.

B.M., balneum mariæ, or balneum maris, a warm-water bath.

B. P., or B. Ph., British Pharmacopœia.

But., butyrum, butter.

B.V., balneum vaporis, a vapour bath.

Cærul., cæruleus, blue.

Cap., capiat, let him (or her) take.

Calom., calomelas, calomel, subchloride of mercury.

C. C., cornu cervi, hartshorn; it may also signify cucurbitula cruenta, the cupping-glass with scarificator.

C.C.U., cornu cervi ustum, burnt hartshorn.

Cochleat., cochleatim, by spoonfuls.

Coch. ampl., cochleare amplum, a large (or table) spoonful; about half a fluid ounce.

Coch. infant., cochleare infantis, a child’s (or tea) spoonful.

Coch. magn., cochleare magnum, a large spoonful.

Coch. med., cochleare medium, } a middling or moderate spoonful; that is,

Coch. mod., cochleare modicum,} a dessert-spoonful—about two fluid drachms.

Coch. parv., cochleare parvum, a small (or tea) spoonful; it contains about one fluid drachm.

Col., cola, strain.

Col., colatus, strained.

Colet., coletur, colat., colatur, let it be strained; colaturæ, to the strained liquor.

Colent., colentur, let them be strained.

Color., coloretur, let it be coloured.

Comp., compositus, compounded.

Cong., congius, a gallon.

Cons., conserva, conserve; also (imperat. of conservo) keep.

Cont. rem., or med., continuentur remedia, or medicamenta, let the remedies, or the medicines, be continued.

Coq., coque, boil; coquantur, let them be boiled.

Coq. ad med. consumpt., coque or coquatur ad medietatis consumptionem, boil, or let it be boiled to the consumption of one half.

Coq. S. A., coque secundum artem, boil according to art.

Coq. in S. A., coque in sufficiente quantitate aquæ, boil in a sufficient quantity of water.

Cort., cortex, bark.

C. v., cras vespere, to-morrow evening.

C. m. s., cras mane sumendus, to be taken to-morrow morning.

C. n., cras nocte, to-morrow night.

Crast., crastinus, for to-morrow.

Cuj., cujus, of which.

Cujusl., cujuslibet, of any.

Cyath. theæ, cyatho theæ, in a cup of tea.

Cyath., cyathus, vel, a wine-glass; from an ounce and half...

C. vinar., cyathus vinarius; to two ounces and half.

Deaur. pil., deaurentur pilulæ, let the pills be gilt.

Deb. spiss., debitur spissitudo, due consistence.

Dec., decanta, pour off.

Decub. hor., decubitûs horâ, at the hour of going to bed, or at bedtime.

De d. in d., de die in diem, from day to day.

Deglut., deglutiatur, let it be swallowed.

Dej. alv., dejectiones alvi, stools.

Det., detur, let it be given.

Dieb. alt., diebus alternis, every other day.

Dieb. tert., diebus tertiis, every third day.

Dil., dilue, dilutus, dilute (thin), diluted.

Diluc., diluculo, at break of day.

Dim., dimidius, one half.

D. in 2 plo., deter in duplo, let it be given in twice the quantity.

D. in p. æq., dividatur in partes æquales, let it be divided in equal parts.

D. P., directione propria, with a proper direction.

Donec alv. bis dej., donec alvus bis dejecerit, until the bowels have been twice opened.

Donec alv. sol. fuer., donec alvus soluta fuerit, until the bowels have been loosened.

Donec dol. neph. exulav., donec dolor nephriticus exulaverit, until the nephritic pain has been removed.

D., dosis, a dose.

Eburn., eburneus, made of ivory.

Ed., edulcorata, edulcorated.

Ejusd., ejusdem, of the same.

Elect., electuarium, an electuary.

Enem., enema, a clyster.

Exhib., exhibeatur, let it be administered.

Ext. sup. alut. moll., extende super alutam mollem, spread upon soft leather.

F., fac, make; fiat, fiant, let it be made, let them be made.

F. pil., fiant pilulæ, let pills be made.

Fasc., fasciculus, a bundle.

Feb. dur., febre durante, during the fever.

Fem. intern., femoribus internis, to the inside of the thighs.

F. venæs., fiat venæsectio, let venesection be performed.

F. H., fiat haustus, let a draught be made.

Fict., fictilis, earthen.

Fil., filtrum, a filter.

Fist. arm., fistula armata, a clyster-pipe and bladder fitted for use.

Fl., fluidus, fluid.

F. L. A., fiat lege artis, let it be made by the rules of art.

F. M., fiat mistura, let a mixture be made.

F. S. A., fiat secundum artem, let it be made according to art.

Gel. quav., gelatina quavis, in any jelly.

G. G. G., gummi guttæ gambæ, gamboge.

Gr., granum, a grain; grana, grains.

Gr. vj pond., grana sex pondere, six grains by weight.

Gtt., gutta, a drop; guttæ, drops.

Gtt. quibusd., guttis quibusdam, with some drops.

Guttat., guttatim, by drops.

Har. pil. sum. iij, harum pilularum sumantur tres, of these pills let three be taken.

H. D., or hor. decub., horâ decubitûs, at bedtime.

H. P., haustus purgans, purging draught.

H. S., horâ somni, at the hour of going to sleep.

Hor. un. spætio, horæ unius spatio, at the expiration of one hour.

Hor. interm., horis intermediis, in the intermediate hours.

Hor. 11mâ mat., horâ undecimâ matutinâ, at 11 o’clock in the morning.

Ind., indies, daily.

In pulm., in pulmento, in gruel.

Ind. Ph., Indian Pharmacopœia.

Inf., infunde, infuse.

Inj. enem., injiciatur enema, let a clyster be thrown up.

Jul., julepus, julapium, a julep.

Kal. ppt., kali præparatum, prepared kali (potassæ carbonas).

Lat. dol., lateri dolenti, to the affected side.

M., misce, mix; mensurâ, by measure; manipulus, a handful; minimum, a minim.

Mane pr., mane primo, early in the morning.

Man., manipulus, a handful.

Min., minimum, a minim, the 60th part of a drachm measure.

M. P., massa pilularum, a pill mass.

M.R., mistura, a mixture.

Mic. pan., mica panis, crumb of bread.

Mitt., mitte, send; mittantur, let them be sent.

Mitt. sang. ad ℥xij, mitte sanguinem ad ℥xij, take blood to twelve ounces.

Mod. præscr., modo præscripto, in the manner directed.

Mor. dict., more dicto, in the way ordered.

Mor. sol., more solito, in the usual way.

Ne tr. s. num., ne tradas sine nummo, do not deliver it without the money.

No., numero, in number.

N. M., nux moschata, a nutmeg.

O., octarius, a pint.

Ol. lini s. i., oleum lini sine ligné, cold-drawn linseed oil.

Omn. hor., omni horâ, every hour.

Omn. bid., omni biduo, every two days.

Omn. bih., omni bihorio, every two hours.

O. M., or omn. man., omni mane, every morning.

O. N., or omn. noct., omni nocte, every night.

Omn. quadr. hor., omni quadrante horæ, every quarter of an hour.

O. O. O., oleum olivæ optimum, best olive oil.

Ov., ovum, an egg.

Oz., the ounce avoirdupois.

P. æ., part. æqual., partes æquales, equal parts.

P. d., per deliquium, by deliquescence.

Past., pastillus, a pastil, or ball of paste.

P., pondere, by weight.

Ph. D., Pharmacopœia Dubliniensis.

Ph. E., Pharmacopœia Edinensis.

Ph. L., Pharmacopœia Londinensis.

Ph. U. S., Pharmacopœia of the United States.

Part. vic., partitis vicibus, in divided doses.

Per. op. emet., peractâ operatione emetici, the operation of the emetic being over.

Pocul., poculum, a cup.

Pocill., pocillum, a small cup.

Post sing. sed. liq., post singulas sedes liquidas, after every loose stool.

Ppt., præparata, prepared.

P. r. n., pro re nata, occasionally.

P. rat. ætat., pro ratione ætatis, according to the age.

Pug., pugillus, a pinch, a gripe between the thumb and the two first fingers.

Pulv., pulvis, pulverizatus, a powder, pulverised.

Q. l., quantum lubet, } as much as you

Q. p., quantum placet,} please.

Q. s., quantum sufficiat, as much as may suffice.

Quor., quorum, of which.

Q. V., quantum vis, as much as you will.

Red. in pulv., redactus in pulverem, reduced to powder.

Redig. in pulv., redigatur in pulverem, let it be reduced into powder.

Reg. umbil., regio umbilici, the umbilical region.

Repet., repetatur, or repetantur, let it, or them, be repeated.

S. A., secundum artem, according to art.

Scat., scatula, a box.

S. N., secundum naturam, according to nature.

Semidr., semidrachma, half a drachm.

Semih., semihora, half an hour.

Sesunc., sesuncia, half an ounce.

Sesquih., sesquihora, an hour and a half.

Si n. val., si non valeat, if it does not answer.

Si op. sit, si opus sit, if it be necessary.

Si vir. perm., si vires permittant, if the strength allow it.

Signat., signatura, a label.

Sign. n. pr., signetur nomine proprio, let it be written upon, let it be signed with the proper name (not the trade name).

Sing., singulorum, of each.

S. S. S., stratum super stratum, layer upon layer.

Ss., semi, a half.

St., stet, let it stand; stent, let them stand.

Sub fin. coct., sub finem coctionis, towards the end of boiling, when the boiling is nearly finished.

Sum. tal., sumat talem, let the patient take one such as this.

Summ., summitates, the summits or tops.

Sum., sume, sumat, sumatur, sumantur, take, let him or her take, let it be taken, let them be taken.

S. V., spiritus vini, spirit of wine.

S. V. R., spiritus vini rectificatus, rectified spirit of wine.

S. V. T., spiritus vini tenuis, proof spirit.

Tabel., tabella, a lozenge.

Temp. dext., tempori dextro, to the right temple.

T. O., tinctura opii, tincture of opium.

T. O. C., tinctura opii camphorata, camphorated tincture of opium.

Tra., tinctura, tincture.

Ult. præscr., ultimo præscriptus, last prescribed.

U. S. Ph., United States’ Pharmacopœia.

V. O. S., vitello ovi solutus, dissolved in the yolk of an egg.

Vom. urg., vomitione urgente, the vomiting being troublesome.

V. S. B., venæsectio brachii, bleeding from the arm.

Zz., zingiber, ginger.

See Formula, Prescriptions, Symbols, &c.

ABDO′MEN. [Eng., Fr., L.] In anatomy, the belly, or lower belly; the great cavity of the body extending from the thorax, or chest, to the bottom of the pelvis. It contains the stomach, intestines, liver, spleen, kidneys, bladder, &c.; and in the female, the uterus, ovaria. &c.

AB′ERNE′THY MEDICINES. These originally consisted of a calomel pill, and subsequently of a mercurial or ‘blue’ pill, to be taken over-night, followed by an aromatised black draught in the morning. The quantity of either of the former, for an adult, was about 3 gr. to 3⁄2 gr., increased a little in bulk by the addition of some liquorice powder; that of the latter, from 1 to 1⁄2 fl. oz. As, however, when frequently taken, these pills sometimes occasioned salivation, which proved prejudicial to their sale, a little compound extract of colocynth (Ph. L., 1836) was introduced into their composition, by which this objection was obviated. Ultimately, their composition was settled at 3 gr. of mercurial pill, and 2 gr. of compound extract of colocynth; and these proportions are still followed as the best by those who prepare and sell them. Persons who object to black draught, will find a dose of castor oil, or of any other mild purgative medicine that may be more agreeable to them, equally efficacious.

The occasional use of these medicines seldom fails to prove highly beneficial to the plethoric, bilious, and dyspeptic. In ordinary cases of constipation, headache, &c., arising from deranged stomach or liver, wherein the administration of mercurials is not contra-indicated, they will be found of great service. It need scarcely be added that these medicines are named after Mr Abernethy, the celebrated surgeon, who is said to have frequently employed them in his practice.

ABERRA′TION. [Eng., Fr.] Syn. Aberra′tio, L. A wandering or deviation from the usual course, or from the normal condition. In optics, the deviation of the rays of light from the true focus, when inflected by a lens or speculum. This arises from a difference in the physical nature of the rays, from the figure of the lenses or specula, or from the nature of the materials of which the media traversed are composed. See Achromatism, Lens, &c.

Aberration of mind. Mental alienation or wandering; insanity. A term frequently applied, in familiar language, to a mild form of incipient insanity or dementia, which is more or less occasional or continued, trifling or severe, according to circumstances. The studious, nervous, slothful, and those who are engaged in sedentary occupations and spend much of their time in ill-ventilated apartments, or who indulge in irregular or vicious habits, as well as ‘fast livers,’ are the most liable to this affection. It also frequently arises from disordered physical health.

Treat., &c. Change of scene, out-door exercise, agreeable company, pleasing and continued mental occupation, and due attention to diet, clothing, ventilation, &c., with the judicious use of some mild aperient medicine and tepid bathing, will generally alleviate, and frequently effect a cure. For the prevention of its accession, or its recurrence, care should be taken to promote the general health, and also, where necessary, to elevate the spirits and to divert the mind.

ABLU′TION. [Eng., Fr.] Syn. Ablu′tio, L. In a general sense, washing, cleansing, or purification by water.

Ablution. In hygiène and the toilet, a washing of the whole body, or any part of it. The value of frequent and copious affusions of pure water to the surface of the body is well known. During life, the skin is continually subjected to abrasion, and the processes of reproduction and decay, by which the cuticle, its exterior portion, is being constantly thrown off as effete and useless matter, in the shape of very minute scales or dust. This, mingling with the oily and saline products of the skin, acquires sufficient adhesiveness to attach itself to the surface of the body and clothing, as well as to attract the waste particles of the dress, and the dust and soot floating in the atmosphere. In this way, if occasional ablutions be not had recourse to, the channels of perspiration will become choked, and the clothing itself rendered unwholesome and unfit for use. The consequence of the pores of the skin being obstructed is impeded transpiration, by which its functions, as a respiratory organ, are interfered with or suspended. This adhering pellicle of refuse matter also acts as an irritant, and forms a favorable medium for the absorption, and the transmission into the body, of effluvia, miasmata, poisonous gases, and the infectious and contagious matters of disease. “The greater part of (contagious) poisons are conveyed to us through the external surface of our bodies; and it is fully proved that poison, already communicated, has been by cleanliness removed, before it could actually produce any bad effects. I here allude, in particular, to frequent washing, bathing, rinsing the mouth, combing and brushing the hair, and often changing the linen, clothing, and bedding.” (Hufeland.) Such are the immediate effects of neglected ablution of the skin; the further consequences are of an equally serious character. The blood being deprived of one of its sources of oxygen, and one of the outlets for its carbon, the functions of nutrition become imperfect, and the animal temperature lessened. The matters which would be thrown out of the system in the form of perspiration are retained, and must be eliminated by other channels. The lungs, the kidneys, the liver, and the bowels, are each, in their turn, overtasked to perform the functions of another organ. The oppressed viscera suffer from exhaustion, and incipient disease soon follows. Their particular offices are languidly performed, the equilibrium of health is disturbed, and skin diseases, or consumption, diarrhœa, dropsy, liver-complaints, visceral obesity, or some other serious diseases of the vital organs, ensue. When it is added, that no dirty or imperfectly washed skin can long continue healthy, and ceasing to be healthy must also cease to be agreeable and beautiful, the argument in favour of the daily use of water of good quality to the whole surface of the body, when possible, will surely be complete. The inculcation of habits of personal cleanliness cannot be too forcibly emphasized. The fact, however, cannot be overlooked, that in order to introduce habits of cleanliness amongst the poorer classes, a plentiful supply of water, combined with cheap baths, are requisite. Every officer of health should inquire into the amount as well as the character of the water supply in the district over which he has supervision. The body should be washed all over every morning with either cold or lukewarm water and soap. This custom is more necessary for workmen employed in laborious and dirty occupations than for those who live sedentary lives; but all people perspire, and from every drop of perspiration the water evaporates, and leaves a fraction of solid matter on and around the pores that excrete the perspiration. If this solid matter be not washed off, it accumulates and may derange the health. Instances have occurred in which persons suffering from extensive bodily burns have died, not from the effect of the injury, but from the destruction of the pores or excreting vessels, with which the skin is covered. It is well, therefore, to bear in mind that a dirty skin does not always come from without, but also from within. Cold ablution, that has been so indiscriminately recommended, is not half so efficacious, nor so safe, as lukewarm. The German aurists ascribe the presence of the large amount of deafness in England to our habit of washing the head and ears each morning with cold water.

Ablution. In medicine, the washing the body, externally, as by bathing; or internally, by diluting drinks. In ancient medicine, according to Galen, internal ablution was accomplished by the use of profuse libations of milk-whey; an object now aimed at, by the hydropathists, by the copious administration of pure cold water. To neglect the daily ablution of an infant is to discard one of the greatest aids to its healthy development and physical wellbeing. That disregard of this precaution is a fertile source of most of the skin diseases that affect infants and children there seems little question about amongst medical men. Water at a temperature ranging from 80° to 90° F. should always be used. Mr Chevasse, in his ‘Counsel to a Mother,’ is emphatic in his advocacy of rain water. He also advises the employment of Castile soap, and of glycerine soap, should there be any excoriation of the skin. Of course the same remarks apply to children as to infants, with this difference, that the ablution is to be performed with water a few degrees colder; and both infants and children should be rubbed dry with a dry soft towel. There are doubtless many persons who deem themselves cleanly washed, if in addition to their hands and arms, neck and face, undergoing duly daily ablution, they wash their feet once a week. These individuals cannot reflect that, because of their less exposure to the depurating influence of the atmosphere, the feet require to be more frequently washed than either the hands or face. See Bathing, Baths, Hydropathy, &c.

ABNORM′AL. [Eng., Fr.] Syn. Abnor′mis, L. In medicine and the collateral sciences, contrary to, or without system or rule; irregular; deformed; unnatural. In a diseased or unhealthy state.

ABORTION IN COWS. Abortion is the expulsion of the contents of the pregnant womb before the full period of gestation is complete, and occurs much more frequently in cows than in any other of the lower animals. Abortion is often induced by shocks and injuries, feeding on ergotised grasses, but more commonly by causes which are less obvious. Thus, bad smells, pasturing on flooded meadows, rich and stimulating food, and even association with other cows while aborting, are among the exciting causes of this malady. The premonitory signs are an irritable excited state of the animal, a discharge from the vagina, looseness and fulness of the external organs of generation, and, occasionally, sudden enlargement of the udder. These symptoms may continue for several days, and, if noticed before straining or other signs of calving have appeared, the animal should be copiously bled and placed in a comfortable loose-box, kept as quiet as possible, moderately supplied with soft laxative food, and, if the bowels be costive, with a pound or two of treacle daily. Powerful purgatives are too irritant, and must, therefore, be studiously avoided. Two ounces of laudanum, with the same quantity of sweet spirits of nitre, should be given twice a day until all danger is over. To prevent the continuance and spread of the evil, place the cow by herself as soon as she aborts; remove and bury the fœtus beyond the reach of other cows; feed off the cow, if practicable, but if she be again bulled, it ought not to be for several weeks, and until the period of heat is passing off; remove all disagreeable smells, and see that the remainder of the herd are moderately fed and carefully watched, so that the earliest symptoms of abortion may be noticed.

ABRA′SION. [Eng., Fr.] Syn. Abra′sio, L. The rubbing or wearing down of surfaces by friction. In the arts, the reduction or figuration of materials by the use of an abrasive tool, or grinder, of which the effective portion is an exact counterpart of the form to be produced.

Abrasion. In numismatics, the ‘wear and tear,’ or waste of the substance of coins, in the pocket and circulation. It forms a large item in the expense of a metallic currency. The means employed to obviate, or to reduce it, consist in either alloying the metal to render it tougher and harder, or raising the borders so as to lessen the surface exposed to friction. In well-formed coin both methods are adopted.

Abrasion. In pathology and surgery—1. A superficial removal or injury of the skin by fretting or friction.

Treat., &c. When the injured surface is large, or exposed, it should be protected from dirt and further injury, by applying a piece of lint or soft linen rag, covered with spermaceti cerate, or some other simple ointment; over which a piece of strapping, or bandage of any sort, may be placed to keep it on. In many cases, a piece of common sticking-plaster will be found quite sufficient.

2. A very superficial ulceration or excoriation of the intestinal or other mucous membrane. Treat. Aperients of castor oil, demulcents, and a light nutritious diet. See Excoriations.

ABRUS PRECATORIUS. (Ind. Ph.) Indian Liquorice Plant. Habitat. Tropical portions of both hemispheres, Officinal part. The root (Abri Radix, Indian Liquorice). Occurs in pieces of various lengths, from ⁄2 to 1 inch in diameter; pale brown externally, yellowish internally; inodorous, taste sweetish and mucilaginous, much resembling officinal liquorice root. Properties and uses. Similar to those of liquorice, for which it forms an excellent substitute. Preparation. Extract of Abrus (Extractum Abri). Prepared as Extractum Glycyrrhizæ.

ABSCESS. A formation of matter or pus, resulting from inflammation, either acute or chronic. The symptoms are pain, swelling, heat, and redness, a conical projection on the swelling, often with a white point at the apex. Abscess or suppuration may come on any part of the body. When the local inflammation does not yield to cold lotions, apply poultices; a pledget of lint dipped in cold water and kept moist by means of oil-silk; a slice of bread softened with boiling water or milk, or linseed meal, make the best poultices. Should the pain be severe add laudanum, and additionally rub it round the swelling. Or apply common white paint by laying it on gently with a brush, or else tincture of marigold or arnica in the same manner. Chronic abscesses in the glands in the neck are usually scrofulous, and should be opened. Abscesses in the breast should not be opened too early, or others are formed. Those in the gums may be cut early, not so if in the tonsils. After opening with a needle or lancet-point external abscesses, continue to poultice till the hardness disappears, then dress with spermaceti ointment spread on lint. When the abscess is of a dangerous nature, lose no time in consulting a medical practitioner.

Treatment for horses and cattle. Mr Finlay Dun prescribes fomentations, poultices, counter-irritants, the knife, cauterisation, carbolic-acid dressing, stimulating injections, and the administration of sulphites and chlorate of potash.

ABSINTHE. [Fr.] Absinthium, L.; Wormwood, E.; Wermuth, G. This article is met with in commerce in the form of the dried herb with the flowers of Artemisia Absinthium, having a whitish-grey appearance, a soft feel, an aromatic and unpleasant odour, and an extremely bitter and aromatic flavour. The plant is indigenous, and grows in thickets, in mountainous districts, and on waste ground. Its odour is due to its containing an essential oil; its bitterness is referable to absinthin, a crystallisable principle which may be extracted from the herb by water or spirit. The name absinthe is also given to an intoxicating liqueur which is extensively drunk on the Continent, and which unfortunately appears to be rapidly attracting consumers in this country. The remarks on this subject by Blyth in his admirable ‘Dictionary of Hygiène’ are so pregnant with important facts that they will be here produced verbatim et literatim. “An analysis recently made at the Conservatoire des Arts shows that absinthe now contains a large quantity of antimony, a poison which cannot fail to add largely to the irritant effects necessarily produced on the alimentary canal and liver by constant doses of a concentrated alcoholic liquid. And we have recently received the results of some experiments made by M. Magnan, of Paris. By means of successive distillations he has been able to isolate various products—(1) a blue oil; (2) a yellowish oil; (3) an oxygenated substance. There was besides a yellowish residue left in the glass. These various substances were tried on animals; ten grammes of the yellow sediment given to a small dog produced no effect; thirty centigrammes of the blue oil produced from eight to ten epileptiform attacks. The oxygenated product proved, however, the most powerful toxic agent. Fifteen centigrammes of it, injected into the veins of a large dog, caused the most violent epileptic attacks, which followed in rapid succession, and ended in death. There was an extraordinary rise of temperature, from 39° to 42° Centigrade, and the post mortem showed various apoplectic centres. Dr Decaisne regards the terrible evil of this almost universal absinthe-drinking as the greatest national calamity that has ever befallen France, and has made an eloquent appeal to the Government to strike at once a decisive blow at the trade in this liqueur. Originally the only important ingredient in its composition besides alcohol was the essential oil of absinthium or wormwood; and though this without doubt added something to the mischievous effects of the liqueur, it would be impossible to trace to it, or to the other comparatively trivial ingredients, the more serious of the special results which are now observed to occur to victims of absinthe, though the habitual drinking even in small doses of good absinthe is believed by Dr Decaisne, sooner or later, to produce disorders in the animal economy. Now various deleterious substances are added, the most important of these being antimony. As at present constituted, therefore, and especially when drunk in the disastrous excess now common in Paris, and taken, as it frequently is, on an empty stomach, absinthe forms a chronic poison of almost unequalled virulence, both as an irritant to the stomach and bowels, and also as a destroyer of the nervous system. The effect of absinthe is to produce a superabundant activity of the brain, a cerebral excitement, which at first is agreeable; intoxication comes on rapidly; the head swims, and the effect produced is nearly the same as that of poisoning by a narcotic, which certainly does not occur with an equal dose of brandy. With the absinthe-drinker, as with the opium-eater, the excitement the spirit produces diminishes daily in intensity. Each day he is obliged to augment the dose in order to bring himself up to the right pitch. The diseases brought on by the excessive drinking of ardent spirits are produced with greater rapidity by the use of absinthe.” The amount of absinthe consumed in London has during the last few years been enormously on the increase. See Liqueurs.

ABSINTHIN. C16H22O5. The bitter principle of wormwood (Artemisia absinthium). A hard crystalline solid, having an intensely bitter taste; slightly soluble in water, very soluble in alcohol, less so in ether. Its physiological effects resemble those of extract of wormwood. Dose. ⁄2 gr. to 2 gr., or more; in dyspepsia; as a stomachic, to promote the appetite, &c.; as a substitute for quinine in intermittents; and in worms.

ABSINTH′IUM. [L.] See Absinthe.

ABSOLUTE. Syns. Absolutus, L.; Absolu, Fr.; Undebingt, G. In chemistry, pure, unmixed; as absolute alcohol, pure spirit of wine, i.e. free from water.

ABSORBED′ (-sorbd′). Syn. Chilled; Absorbé, Fr. In painting, a term among French connoisseurs, to represent that state of a picture in which the oil has sunk into the canvas or ground, leaving the colours ‘flat,’ and the touches indistinct. The remedy consists in rubbing the surface of the picture, previously well cleaned, with a soft sponge dipped in a little drying oil, and after some days varnishing it; when it should be kept in a warm room until perfectly dry.

ABSORB′ENT. Syn. Absorb′ens, L.; Absorbant, Fr.; Absorbirend, Ger. Imbibing; that imbibes or sucks up; variously applied in science and art. (See below.)

Absorbent Ground. In painting, a picture-ground prepared wholly or chiefly in distemper or water colour, in order that the redundant oil in the colours subsequently applied may be immediately ‘absorbed,’ by which expedition is permitted, and brilliancy imparted to them.

Absorbent Surfaces. In the arts, these are usually rendered non-absorbent, preliminary to their being bronzed, gilded, painted, or varnished, by giving them one, or more, coats of thin size, so as to destroy their porosity; care being taken to allow each coat to become thoroughly dry before the application of the next one; and also, finally, to remove any unabsorbed excess of size from the surface, by means of a sponge dipped in warm water. This applies to ALABASTER, PAPER, WOOD, PLASTER CASTS, &c.; and to WALLS and CEILINGS which are not exposed to the weather, and which there is not time to prepare with drying oil. See Bronzing, Maps, Varnishing, &c.

Absorption and consequent adherence in porous moulds, as those of plaster, are usually prevented by thoroughly saturating the pores of the mould with melted tallow, or a mixture of tallow and bees’ wax; or for delicate objects or the electrotype, with white wax. The ‘dry moulds’ are either heated before the application of these substances, or they are boiled in them; any portion that may finally remain unabsorbed, being carefully removed with cotton-wool or a soft rag. Another method is to wash the moulds over two or three times with drying oil, or to boil them in it; after which they must be exposed to the air for some days, to dry and harden. Before being used for plaster, composition, &c., the surface of these prepared moulds require to be slightly moistened with sweet oil.

Plaster moulds are generally prepared for sulphur, wax, and gutta percha casts, by simply placing them (upright) with the back immersed in a little water, contained in any shallow vessel, as a saucer or plate; and letting them remain there until moisture begins to appear on the surface. The materials to be cast, or moulded, should then be used at the lowest possible temperature, to prevent the formation of air-bubbles.

The adherence of wax or mixtures containing it, and of gutta percha, is best prevented by moistening the surface of the mould (whether of plaster, metal, or gutta percha), immediately before use, with soft soap reduced to the consistence of thin cream with water. See Casts, Moulds, Electrotype, &c.

ABSORB′ENTS. In anatomy and physiology, two distinct sets of small, delicate, transparent vessels, which imbibe or suck up fluid substances, and convey them to the blood. They are termed lacteals or lymphatics; the former take up the chyme from the alimentary canal, the latter pervade almost every part of the body in which they absorb lymph.

Absorbents. In botany and vegetable physiology, the origins of the different vessels constituting the vascular tissue, as they are found in the root, where they imbibe or suck up the nutritive fluids from the soil. See Plants and Vegetables.

Absorbents. In agriculture and chemistry, substances which possess the power of withdrawing moisture from the atmosphere; as soils, argillaceous earths, &c. Also (but less frequently) substances which neutralise acids; as chalk, lime, and magnesia. Absorbents differ from ‘deliquescent salts’; the latter attract moisture and dissolve in it; whilst the former merely suck it into their pores, as a sponge does water. See Absorption.

Absorbents. Syn. Absorben′tia, L. In medicine and pharmacy, substances which remove acidity from the stomach and bowels. Of these the principal are—magnesia, carbonate and bicarbonate of magnesia, prepared chalk, and the carbonates and bicarbonates of potash, soda, and ammonia. The first four are popularly called earthy absorbents; and the others, alkaline absorbents. See Antacids.

The following absorbent mixtures are taken from Dr Kirby’s valuable work, ‘Selected Remedies’:

1. Infusion of rhubarb, 1⁄2 oz.; compound spirit of ammonia, 1⁄2 dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

2. Bicarbonate of potash, 1⁄2 dr.; syrup, 2 drs.; compound spirit ammonia, 1⁄2 dr.; compound infusion of gentian to 6 oz. Two tablespoonfuls to be taken 3 times a day.

3. Bicarbonate of soda, 1⁄2 dr.; spirits of chloroform, 1⁄2 dr.; infusion of calumba to 6 oz. Two tablespoonfuls to be taken 3 times a day.

ABSORP′TION. [Eng., Fr.] Syn. Absorp′tio, L.; Einsaugung, Ger. The act or the power of absorbing, in various applications. (See below.)

Absorption. In agriculture, the power possessed by soils of absorbing moisture from the atmosphere. The more a soil is divided by labour and vegetation, the greater is its absorbent power, and, consequently, its fertility. Indeed, the latter chiefly depends on its capacity for imbibing moisture, and may be illustrated by reference to recent and disintegrated lava. (Leslie.) The finely divided state, most penetrable by the delicate fibres of plants, appears to derive its superior power of acting on atmospheric vapour from the augmentation of its surface and the multiplication of its points of contact. (Ure.) This method of increasing the fertility of a soil is well known to scientific farmers, and seldom neglected by them. (Loudon.) That soil must be regarded as the most fertile which possesses this power in the greatest degree. Garden-mould has the highest absorbent power of any mineral substance. (Leslie.)

Process of ascertaining the ABSORBENT POWER OF SOILS, and other substances. Thoroughly dry the article by the suitable application of a heat not exceeding 212° Fahr., continued for several hours, and transfer it, while still warm, into a clean dry phial furnished with a perfectly tight ground-glass stopper. When cold, quickly and cautiously introduce it, along with a delicate hygrometer, into a large wide-mouthed glass bottle, the atmosphere of which has been previously rendered as damp as possible, by suspending a piece of moistened rag or filtering paper in it. It must now be kept closed for some hours, when the hygrometer will indicate the degree of dryness of the enclosed air, and, consequently, the absorbent power of the substance examined.

Obs. Experiments of this nature are only relatively correct, and must be performed under exactly similar circumstances, to furnish reliable comparative results. The whole process, in each case, must be as similar as careful manipulation can possibly make them. With this reserve, they will be found invaluable to the agriculturist.

Absorption. In chemistry the passage of gases and vapours into liquid and solid substances. Thus, water absorbs the oxygen of the air, lime absorbs water, charcoal absorbs ammoniacal and other gases.

Absorption. In medicine and toxicology, see Medicines and Poisons.

Absorption. In perfumery, see Enfleurage.

Absorption. In physics, see Heat, Light, Refrigeration, &c.

Absorption. In physiology (animal and vegetable), the function of sucking, or taking up, of appropriate substances, by the ‘absorbent vessels.’ It is one of the chief vital functions, the primary object of which is to convey to the circulatory organs the proper supply of the materials necessary for the support and growth of the body; and subsequently, to remove and convey to these organs its effete and useless portions, in order to their ultimate elimination from the system.

Absorption. In surgery, the natural process by which tumours and their contents, morbid growths, and, sometimes, even healthy glands, &c., are gradually taken up and disappear, by the action of the ‘absorbents.’

Absorption (of Surfaces, Moulds, &c). See Absorbent Surfaces.

ABSTERG′ENTS. Syn. Abstergen′tia, L. In medicine and pharmacy, substances which cleanse or clear away foulness from the surface of the body or sores; as soap, lotions, &c. See Detergent, which has a nearly similar meaning, and is in more general use.

AC′ARI (-rī). [L.; prim. Gr.] Syn. Acar′idans; Acar′ides (dēz); Acarid′iæ. (-e-ē). In entomology, a division of arachnidans, including the mite and tick. All the species are either microscopic or extremely minute, and possess such tenacity of life as to resist for some time the action of boiling water, and to live with comparative impunity in alcohol. Leuwenhoek had one that lived eleven weeks glued on its back to the point of a needle, without food. The following are well known—ACARUS AUTUMNA′LIS, the harvest-bug or wheal-worm; A. DOMES′TICUS, the domestic tick; A. DYSENTE′RIÆ, the dysentery-tick; A. FARI′NÆ, the meal mite (fig. a); A. RI′′CINUS (rĭc-), the dog-tick; A. SAC′CHARI, the sugar-mite (fig. b); A. SI′′RO, the cheese-mite (fig. c); A. SCABIE′I, the itch-insect (fig. d).

The irritation of the skin, caused by these vermin, may be relieved by a lotion of equal parts of sal volatile and water; and they may be destroyed by tobacco water, or a lotion or ointment of stavesacre. See Itch, Mange, Parasites, Pediculi, Scab, &c.

Acarus Farinæ, or meal-mite (fig. a). This insect is found only in damaged flour, and is more frequently met with in the flour of the leguminosæ (beans, peas) than in that of the gramineæ (wheat, rye, oat).

Now and then a single acarus may occasionally be found in good flour, but even one should be regarded with suspicion, and the flour should afterwards be frequently examined to see if they are increasing.

Acarus Sacchari, or sugar-mite (fig. b).

Most of the brown sugars of commerce are infested by this pest, which is of a size sufficiently large to be visible to the naked eye. The following method of proceeding will lead to its detection:

Dissolve 2 or 3 teaspoonfuls of sugar in a large wineglass of tepid water, and let the solution remain for an hour or so, at the expiration of which time the acari may be found, some on the surface of the liquid, some attaching themselves to the sides of the glass, and some at the bottom, mixed up with the copious and dark sediment, made up of fragments of cane, woody fibre, grit, dirt, and starch granules, which usually subside on dissolving even a small quantity of sugar in hot water. When first hatched this acarus is hardly visible.

Acari of all sizes—that is, in all stages of growth—may be met with in most samples of sugar.

Dr Hassall, in seventy-two samples of sugar which he examined, found sixty-nine containing them.

Acarus Siro, the cheese-mite (fig. c). The dry and powdery parts of decayed cheese, which by careful watching may very frequently be seen in movement, consist almost wholly of this insect and their eggs in different stages of development. The cheese-mite can hardly be seen without the aid of the microscope. They are very tenacious of life, even when kept without food. Mr Blyth says that under these circumstances “it is no uncommon sight to see them killing and devouring each other; and that cheese is rapidly destroyed by them; they crumble it into minute pieces, and emit a liquid substance which causes the decayed parts to spread speedily.” They may be destroyed by being exposed to a strong heat, or by putting the cheese for a short time in whisky.

Acarus Scabiei, the itch-insect (fig. d). The parasitic character of the disease known as the itch was first demonstrated by Dr Bononio, who on turning out the contents of one of the little bladders that show themselves between the fingers of those affected with the complaint, and placing the fluid under the microscope, discovered a minute animal, very nimble in its movements, covered with short hairs, having a short head, a pair of strong mandibles or cutting-jaws, and eight legs, terminating in remarkable appendages, each provided with a sucker and setæ.

It has no eyes; but when disturbed it quickly draws in its head and feet, and then somewhat resembles the tortoise in appearance, its march being precisely the same. It usually lays sixteen eggs, which are carefully deposited in furrows under the skin, and ranged in pairs; these are hatched in about ten days.

“To find the itch-insect,” says Mr Jabez Hogg, “the operator must carefully examine the parts surrounding each pustule; he will then see a red line or spot communicating with it; this part, and not the pustule, must be probed with a fine-pointed instrument. The operator must not be disappointed by repeated failures.”

ACCIDENT′AL COLOURS. See Colours (Complementary).

ACCIDENTS. Black eye. Bathe the eye frequently with a soft piece of linen rag dipped in a lotion composed of one part of tincture of arnica and seven parts of water.

Burns and Scalds. Refer to Burns and Scalds.

Charcoal, combustion of, poisoning by. Refer to Carbonic Anhydride.

Choking, or suffocation from substances sticking in the throat. Refer to Choking.

Cut Finger. Refer to Cuts.

Precautions against Fires. Refer to Fires.

Precautions against Lightning. To take refuge under a tree during a thunderstorm accompanied by lightning is to expose oneself to a double danger—firstly, because by keeping the clothes dry these are prevented becoming the non-conductors they would be if damp; and secondly, because the tree, serving as a point of attraction for the lightning, conducts it to the ground, and in doing so frequently rends the trunks or branches, and kills any person or animal who happens to be close to, or in contact with, it at the time.

Never, therefore, if overtaken by a storm of thunder and lightning fly to the dangerous cover of a tree, pillar, hay-rick, wall, or hedge, but seek shelter in the nearest dwelling; or if this is not at hand, get to a part of the road or field where there is no object to attract the lightning, and there remain till the storm has expended itself. Also avoid particularly the proximity of iron gates, palisades, bronze statues, bell wires, iron railings, and such like. When in the house, do not sit or stand near the windows, doors, or walls, but place yourself in the middle of the room, unless there should be a lamp or chandelier hanging from the ceiling. Franklin recommends persons to keep away from the neighbourhood of fireplaces.

Treatment of persons struck by lightning. In case of any person being struck by lightning, immediately strip the body and throw bucketsful of cold water over it for ten or fifteen minutes; continued frictions and inhalations of the lungs must also be employed, and electricity should be tried if it be possible.

Accidents by Poison. The means to be adopted in cases where poison is taken, if the poison be known, are embodied in the antidotes, which will be found given in this volume under the respective poisons.

Under all circumstances, however, medical aid should be sought as expeditiously as possible, since many of the antidotes themselves being of a dangerous, if not poisonous, character, should only be administered under medical supervision. Pending the arrival of the doctor, no time should be lost in giving an emetic, consisting of a teaspoonful of flour of mustard in half a pint of warm water, supplemented by copious draughts of warm water, and tickling the throat with the finger if necessary.

Fish poisoning. It is a not unfrequent occurrence to find fish when eaten giving rise to a species of poisoning of a more or less violent form, such as a sense of weight at the stomach, accompanied with nausea, vertigo, headache, heat about the head and eyes, pains in the stomach, thirst, and often an eruption of the skin resembling nettle-rash. These symptoms may be sometimes due to the nature of the fish itself; sometimes to its being in a state unfit to be taken as food, as, for instance, when it is in a stale or decomposing condition; and occasionally to the peculiarity of constitution of those who partake of it, even if in a perfectly fresh condition. Whenever any of the symptoms above described follow from eating fish, an emetic of mustard and water (a teaspoonful of mustard in half a pint of water) should be administered. If subsequently a rash should appear, it would be well to take a dose of brisk purgative medicine, and, if necessary, a few doses of carbonate of soda 3 or 4 times during the day.

Poisonous Mushrooms. The same treatment should be followed as for fish. With some people the edible mushroom acts as a poison.

Sinks. See that these be securely trapped, and in the event of any unpleasant smell from them, pour down some disinfectant, such as chloride of lime, carbolic acid, or Condy’s fluid. The foul emanations from a sink ought to be regarded as of a most dangerous and pestilential nature.

Accidents to Children. Many, if not most, of the casualties to which children are exposed are given above, together with the best course to be pursued in the event of their being overtaken by any of them. There are, however, a few forms of disaster which seem more especially peculiar to children. Of these we may select—

Swallowing a piece of broken glass. In this case avoid giving purgatives, but give solid farinaceous food, so as to envelope the glass and enable it to pass through the bowels without causing injury by coming in contact with them.

Swallowing a coin. Give a dose or two of castor oil, and examine the stools until the coin is perceived.

A small coin sticking in the windpipe. Seize the child by the legs, letting his head hang downwards, then administer several brisk blows on the back with the palm of the hand, when very frequently the coin will be coughed out of the mouth and on to the floor. If this plan do not succeed, send immediately for medical aid.

ACCLI′MATE, or ACCLI′MATISE. In botany and zoology, to inure a plant or animal to a climate to which it is not indigenous. When so inured it is said to be ACCLIMATED. In medicine, to habituate the body to a foreign climate, so that it may not be peculiarly liable to its endemic diseases; or to become so habituated. Thus, a person who has resided several years at New Orleans without an attack of yellow fever, or having had an attack has satisfactorily recovered, is said to be ACCLI′MATISED.

ACCOM′PANIMENTS. In cookery and housekeeping, see Trimmings.

ACCUMULA′TION. [Eng., Fr.] Syn. Accumula′tio, L. In medicine, a term applied when the effects of the first dose of any substance still continue when the second is administered (accumulation of action); or when several doses of insoluble substances remain inactive in the system until their energy is developed by chemical influence (accumulation of doses). See Medicines, Poisons, &c.

ACEPH′ALANS. Syn. Aceph′ala, Cuv. In malacology, a class of aquatic mollusca, having no apparent head, but a mouth between the folds of their mantle. Several of them, as the oyster, cockle, mussel, scallop, &c., are consumed for food.

ACERB′ITY. Syn. Acerb′itas, L.; Acerbité, Fr.; Herbigkeit, Ger. In chemistry, &c., sourness, with bitterness and astringency, or harshness. See Cider, Fruit, Wine, &c.

ACERBO’S ANTI-RHEUMATIC AND ANTI-CATARRH OIL. For various horse diseases. Gum euphorbium, 10 parts; absolute alcohol, 10 parts; olive oil, 80 parts. Digest in a warm-water bath for 24 hours, then boil until all the spirit has evaporated, and, when cold, strain through cotton. (Hager.)

ACER′IDES. Plasters that do not contain wax.

ACES′CENT. Syns. Aces′cens, L.; Acescent, Aigrelet, Fr.; Säurlich, Ger. In chemistry, &c., growing sour; slightly tart or acid; having a tendency to sourness, or to run into the acetic fermentation, as wine, beer, malt-wort, &c. Hence, ACES′CENCE or ACES′CENCY (acescen′tia, L.; acescense, aigreur, Fr.; säurlichkeit, Ger.), the tendency to become slightly acid, or the quality of being so. See Acetification, Malt-liquors, Wine, Wort, &c.

ACETA′′RIOUS (-tāre′-e-ŭs). Used for salads (as plants); relating to salads (which see).

AC′ETATE (ăs′-). Syn. Ace′tas, L.; Acetate, Fr.; Essigsäure salze, Ger. In chemistry, a salt consisting of C2H3O2 (sometimes called the acid-radical of the acetates) with hydrogen, a metal, or a compound basic radical; e.g.,

Hydrogen acetate (acetic acid) HC2H3O2

Potassium acetate KC2H3O2

Lead (plumbic) acetate Pb(C2H3O2)2

Ammonium acetate NH4C2H3O2

Salts of acetic acid (HC2H3O2) with the alkaloids are likewise termed acetates; e.g.,

Morphia acetate . C17H19NO3 . C2H4O2

Prep. That of the commercial acetates, and of many others, is noticed under the respective metals. In general, they may all be formed by direct solution of the carbonate, hydrate or oxide of the metal whose acetate it is desired to form, in dilute acetic acid; or from a solution of an acetate and of another salt of the metal, by double decomposition. In either case, the resulting solution must be carefully evaporated by a gentle heat, and, where possible, crystallised.

Prop., &c. All the neutral acetates, except those of molybdenum and tungsten, are more or less soluble in water, several so much so as to be uncrystallizable; many dissolve in alcohol; they suffer decomposition at a dull red heat, and by distillation, at that temperature, yield acetone and water, or acetone and acetic acid, and leave a carbonaceous residuum; at a full red-heat, those of potassium, sodium, barium, strontium, calcium, and magnesium, are converted into carbonates, whilst the other metallic acetates leave behind the pure metal, or its oxide. The aqueous solutions of the alkaline acetates soon turn mouldy and suffer decomposition. No more of them should, therefore, be dissolved at once than is required for immediate use.

Char., tests, &c. The acetates are known—1. By evolving fumes of acetic acid, recognisable by its peculiar and characteristic odour, on the addition of strong sulphuric acid:—2. By evolving the vapour of acetic ether (known by its peculiar and agreeable odour) when heated with a mixture of about equal parts of concentrated sulphuric acid and alcohol.

AC′ETATED (ăs′-). In chemistry and pharmacy, combined or impregnated with acetic acid or vinegar.

ACE′TIC. Syn. Ace′ticus, L.; Acétique, Fr. Of or relating to vinegar; made with acetic acid, as perfumes, &c. (See below.)

ACETIC ACID. HC2H3O2. Syn. Pyrolig′neous acid (pure); Acid of vinegar; Acidum ace′ticum, L.; Acide acetique, Fr.; Acido acetico, It.; Essigsäure, Ger.; Azynzuur, Dut.; Eisel, Sax. When free from water it crystallises on cooling, and is distinguished as—Acetic hydrate, Hy′drated acetic acid, Monohy′drated a. a., Gla′cial a. a., Monohydrated a. a., Ace′tum glacia′le, Acidum ace′ticum G., L., &c. the sour principle of vinegar.

Var. Commercial acetic acid is found under the form of the pure acid of the chemist and pharmaceutist (glacial and dilute), and of vinegar, of which there are several varieties, which are noticed under their respective heads.

Sources. Fermented liquors; the vinegars of commerce; alcoholic liquors; wood, from which it is obtained, as pyroligneous acid, by distillation; the commercial acetates of soda, potassa, lime, lead, copper, &c. The pure acetic acid of the chemist and of commerce is almost wholly obtained from the acetates, either by the action of a strong acid, which seizes on the base, setting the acid free; or, by dry distillation, in which the high degree of heat employed separates the acetic acid from the base in the form of vapour. It is also obtained by the oxidation of alcohol.

Prep. The following are the principal processes at present adopted to obtain pure acetic acid:—

1. From the Acetates in the moist way:—

a. From ACETATE OF SODA:—

1. Commercial acetate of soda (i.e., the ‘pure acetate’ of the pyroligneous acid works), in crystals, is put into the body of a stout copper still, and a deep cavity being made in the centre of the mass, about 35% of sulphuric acid of a sp. gr. of not less than 1·84 is poured in; the walls of the cavity are then thrown in upon the acid, and the whole briskly agitated, for a very short time, with a large wooden spatula; the head of the still is next luted on, and the distillation conducted at a gentle heat, the receiver being changed as soon as the distillate begins to acquire a slight empyreumatic odour. The product, when the process is well managed, is an almost colourless acid of the sp. gr. of fully 1·05, containing about 40% of glacial acid, or between 34% and 35% of anhydrous acid. Any trace of colour or empyreuma is removed by agitation with some well-washed and recently ignited vegetable charcoal, or with a very small quantity of recently ignited purified animal charcoal, and subsequently passing it through a prepared calico bag-filter; or by allowing it to stand, for about a fortnight, in barrels containing some beech-wood chips; after which it is ready for sale, either as the ordinary acetic acid or pure pyroligneous acid of commerce, or (on dilution, &c.) as vinegar.

2. The acid of sp. gr. 1·05 (obtained as above) is distilled with fused chloride of calcium, the distillate being run into a refrigerator; the crystals that form are drained at a temperature below 40° or 45° Fahr., and after removal to a warmer temperature, where they liquefy, and agitation with a little peroxide of lead, are submitted to a second distillation, as before; and this is repeated until the whole of the acid crystallises at 51° Fahr. The product is the glacial acetic acid of commerce.

Obs. The above are the processes usually adopted, on the large scale, in this country.

3. (M. Mollerat’s process—without distillation.) Pure commercial acetate of soda, in coarse powder, is placed in a hard glazed stoneware or glass pan or receiver set in a cool situation, and 35% or 36% of concentrated sulphuric acid, of the sp. gr. 1·843, added, in such a manner that the acid may flow under the powder, and little heat be generated by the operation; the whole is then allowed to remain in contact (covered) for some hours, when crystalline grains of sulphate of soda are found covering the bottom and sides of the vessel, and hydrated acetic acid, partly liquid and partly in crystals, the upper portion. The temperature being now slightly raised to a point just sufficient to cause the liquefaction of the crystals of acetic acid (i.e., to from 62° to 65° Fahr.), the fluid is poured off, and a very small quantity of pure acetate of lime added to it gradually, until it ceases to yield any trace of free sulphuric acid on evaporation. After sufficient repose it is carefully decanted for use. An excellent commercial strong acetic acid is thus obtained, without distillation, owing to the insolubility of sulphate of soda in acetic acid; and from which glacial acid may be procured by refrigeration. If, however, the process be badly managed, or the proportions of the ingredients be not carefully observed, the product will be contaminated with either a little sulphuric acid or saline matter. It is also important to the success of this process that it be performed in a cool apartment, and in well-cooled vessels. Perfectly pure acetic acid may easily be obtained by rectification from this acid. The above plan of superseding a troublesome distillation is one of the greatest improvements yet introduced into the manufacture of acetic acid.

4. (Liebig’s process.) Pure acetate of soda, thoroughly dried and finely powdered, 3 parts, is placed in a capacious retort, and pure concentrated sulphuric acid, 9·7 parts, poured over it through the tubulature. One eighth of the acetic acid passes over by the heat developed by the reaction of the ingredients. The heat of a sand bath is next applied and continued until the contents of the retort become quite liquid. The distillate, carefully rectified, yields two parts of pure acid, containing only 20 per cent. of water. On exposing the latter portion which comes over in a closed vessel to a temperature below 40° Fahr., crystals of hydrated acetic acid are deposited. The weaker, or liquid portion, being poured off, the crystals are again melted and re-crystallised by cooling. The crystals of the last operation, separated from the liquid, and carefully drained in a cool and closed vessel, are perfectly pure hydrated acetic acid.

Obs. The above is an excellent process for obtaining a chemically pure acid. The excess of sulphuric acid left from the process may be recovered by distillation; or the whole residuum may be employed in a second distillation with fresh acetate.

Although a retort is recommended by Liebig for the distillation, and is usually adopted, on the small scale, for the purpose, a flask closed by a cork perforated by two tubes, as exhibited by the engr., will be found more convenient and safe; as the product is then less likely to be contaminated by the ‘spirting’ of the ingredients over the brim of the vessel. The heat of a diffused gas-flame may also be often advantageously substituted for a sand bath.

b. From ACETATE OF POTASH:—

1. Acetate of potash (fused and powdered) is placed in a still, or other suitable vessel, and 50% of the strongest sulphuric acid (‘oil of vitriol’ of fully 1·84 sp. gr.) being added, the mixture is distilled to dryness, as before. The product is 50 to 51% of the weight of the acetate employed, with a sp. gr. of about 1·0735 to 1·074, containing about 66% of anhydrous acetic acid, or nearly 80% of ordinary glacial acid. By rectification from a little dried acetate of lead a perfectly pure acid of almost any strength may be obtained. The ingredients are nearly in equiv. proportions.

c. From ACETATE OF LEAD:—

1. (Ure.) Take of dried acetate of lead, 4 parts; strongest oil of vitriol, 1 part. Distil slowly to dryness. Nearly equal to the last.

2. (Liebig.) Acetate of lead, 3 parts; sulphuric acid, 8 parts; as before.

3. (Dollfuss’ Concentrated Acetic Acid.) Take of dried acetate of lead, 12 oz.; sulphuric acid, 6 oz.; distil 7 ounces.

d. From ACETATE OF LIME:—

1. (Christl.) Raw acetate or pyrolignate of lime (prepared by Völckel’s process), 100 parts, is mixed with hydrochloric acid (20° Baumé, or sp. gr. 1·1515), 120 parts; and after 12 hours, distilled in a copper vessel, with a gradually applied heat. The product is 100 parts or lbs. of acetic acid of 8° Baumé (sp. gr. 1·0556), containing about 47% of hydrated acid, only slightly coloured and empyreumatic, fit for various manufacturing purposes. The advantage of this process is the low price of hydrochloric acid, and the product not being contaminated with sulphuric or sulphurous acid.

Obs. It will be found that pyrolignate of lime generally contains 60% to 70% of neutral acetate; but should it contain either more or less, a proportionate quantity must be employed. When the proper proportions are used the distillate gives only a scarcely perceptible turbid cloud when tested with nitrate of silver. If the hydrochloric acid used has the sp. gr. 1·16, a less quantity being employed, the product will have the sp. gr. of 1·058 to 1·061, and will then contain from 48 to 51% of the monohydrate, or 41 or 42% of anhydrous acetic acid. The resin sometimes found floating on the mixed ingredients should be carefully removed, by skimming, before distillation.

As acid of the above strength is rarely required, and as the distillation is more easily conducted when the ingredients are less concentrated, a little water may be conveniently added either before or towards the end of the distillation. Hence the following proportions have been recommended:—

2. (Völckel.) Acetate of lime (as last), 100 parts; hydrochloric acid (sp. gr. 1·16), 90 to 95 parts; water, 25 parts; mix, and proceed as before. Prod. 96 to 98 parts of an excellent acid, well adapted to trading purposes, having a sp. gr. about 1·050, and containing nearly 40% of hydrated acetic acid. It has been correctly remarked, that the acetic acid produced with hydrochloric acid is always of better quality than that produced with sulphuric acid; being not only less coloured, but also entirely free from sulphurous acid. The distillation uniformly proceeds with ease and regularity, and the whole of the acetic acid passes over between 212° and 248° Fahr.; by which the danger of contamination with other products, resulting from a high degree of heat, is obviated.

3. An Acetic acid sufficiently strong and pure for many ordinary purposes may be obtained without distillation, by pouring strong sulphuric acid, 60 parts, diluted with water, 5 parts, on well-dried acetate of lime, 100 parts; digesting, with occasional agitation in a close vessel, decanting the clear liquid, and straining the remainder.

II. From the Acetates by dry distillation with a sulphate:—

a. From ACETATE OF LEAD:—

1. Acetate of lead (dried), 5 parts; and sulphate of iron (gently calcined), 2 parts; are separately powdered; and after thorough mixture, carefully distilled, by the heat of a sand bath, into a well-cooled receiver. An economical process for a strong acid, under certain circumstances; but one now seldom adopted.

2. (Bardollier’s Strong Acetous acid.) Dried acetate of lead, 10 oz.; calcined green vitriol, 12 oz.; as the last.

b. From the ACETATES OF COPPER:—By substituting acetate or diacetate of copper, in equiv. proportions, or better with excess of the sulphate. Seldom used.

c. From ACETATE OF POTASH, as the last.

III. From the Acetates per se:—

a. From ACETATE OF COPPER:—Aromatic v.†; Spirit of verdigris†; Spiritus ven′eris†, L.; Esprit de venus, Fr.; Acidum ace′ticum, (Ph. L. 1787.) Process. Carefully dry crystallised verdigris (diacetate of copper) by a very gentle heat, and introduce it into a large stoneware retort (see engr.), the bottom of which has been previously coated with a mixture of clay and horse-dung, to render it more capable of standing the fire. Next place it in a suitable furnace, and connect it, by an adapter, with 3 or 4 double tubulated globes, the last of which must be furnished with a vertical tubulature, to which a double Welter’s safety-tube should be adapted; the other end being immersed in a basin half-filled with distilled vinegar or water, while the funnel portion communicates with the atmosphere. Then place each globe in a basin of water, kept cool by a stream constantly passing through it; and cover the upper portion with cloths kept continually wet with cold water. After 15 or 20 hours, fire may be applied, and must be so regulated that the drops follow each other with considerable rapidity from the end of the adapter, whilst the bubbles of air cause no inconvenience at the other end of the apparatus. If otherwise, the fire must be damped a little. The operation should be continued, and the fire gradually increased, until vapour ceases to come over, known by the globes gradually cooling, notwithstanding the heat of the furnace. The operation being concluded, the whole may be allowed to cool, and the acid collected preparatory to rectification. This may be effected in a similarly arranged apparatus, except that it must be wholly of glass; and the retort should not be much more than half-filled. The operation must now be very carefully conducted, and discontinued before barely the whole of the acid has distilled over; as the last portion is apt to injure the flavour and colour of the rest. The first portions which come over are very weak, and should be kept separate, until the sp. gr. reaches to about 1·372, when the receiver should be changed, and the product collected in separate portions, as noticed below.

Obs. Good diacetate of copper yields, by careful management, at a temperature of 400° to 560° Fahr., fully one half its weight of a greenish-coloured acid, of the sp. gr. of about 1·061, containing above 50% of hydrated acetic acid, or 43% of anhydrous acid. 20 lbs. of the ordinary acetate yields 9⁄4 lbs. of this rough acid, leaving a residuum of about 6⁄2 lbs. of metallic copper mixed with a little charcoal, in the retort; the remainder (nearly ⁄10ths of the acid in the acetate) being decomposed by the heat, and lost. This 9⁄4 lbs. of crude acid yields by rectification, and dividing the products, ⁄2 lb. of acid of the sp. gr. 1·023; 3 lbs. of the sp. gr. 1·042; and 6 lbs. of the sp. gr. 1·065; exclusive of a little acetone which comes over with it. In the first distillation, the strongest acid is found in the third receiver, and the weakest in the first. The acid obtained in this way is always accompanied with a little fragrant pyro-acetic spirit; which renders it preferable for aromatic vinegar and perfumery. It dissolves camphor, resins, and essential oils with facility. This is one of the oldest methods of obtaining glacial acetic acid, and the product is still preferred for some purposes. It is the RADICAL VINEGAR of the alchemists, and it is that which is preferred by the perfumers. Well-dried acetate of lead, or of iron, as well as several other acetates, may be substituted for acetate of copper in the above process; but are less economical and convenient. In all cases, great care must be taken to avoid over-firing, as thereby the quantity obtained is lessened, and the quality injured. The residuum of the distillation is pyrophoric and frequently inflames spontaneously, on exposure to the air. Due caution must be therefore observed regarding it.

IV. From Wood, by dry distillation. See Pyroligneous Acid. The preparation of the purified acid, by converting it into an acetate, and subsequent distillation with a strong acid, is noticed above.

V. From Alcohol. (Alcohol vinegar, German acetic acid.) In a bell-glass, or an oblong glass case, perforated shelves are arranged, a few inches apart, one above another, on which are placed a number of small flat dishes of porcelain, earthenware, or wood. These dishes are filled with spirit of wine or dilute alcohol; and over each is suspended a watch-glass or capsule containing a portion of platinum-black; the whole being arranged so that the platinum-black and the surface of the alcohol are not more than 1⁄2 to 2 inches apart. Strips of porous paper are next so hung in the case, that their bottom edges are immersed in the spirit, to promote evaporation; and lastly, the apparatus, loosely covered, is set in a light place at a temperature of from 70° to 90° Fahr.—the sunshine, when convenient. In a short time the temperature of the platinum rises, and the formation of acetic acid begins; and the condensed vapour trickles down the sides of the glass and collects at the bottom of the case, whence it is removed once or twice a day. (See engr.) The product of a case of twelve cubic feet content, with 7 or 8 oz. of platinum-powder, is capable of producing daily, if well managed, nearly 1·31 lb. of hydrated acetic acid from 1 lb. of absolute alcohol; 25 lbs. of platinum-powder and 300 lbs. of alcohol will, in like manner, furnish a daily supply of nearly 350 lbs. of pure acid, and of other strengths in proportion. Theoretically, the product should be 130 parts of the hydrated acid for every 100 parts of alcohol consumed; but this is never quite obtained in practice, owing to a small portion of the alcohol mixing with the newly formed acid, and escaping decomposition; and from another small portion of both the alcohol, and of the newly formed aldehyd, being carried off by the air that permeates the apparatus. The platinum-powder does not waste, and the most inferior spirit may generally be employed.

Rationale. In this process, the alcohol (as in other cases of acetification) is first converted into aldehyd; and this, as rapidly as formed, absorbs oxygen and passes into hydrated acetic acid. The simultaneous formation of aldehyd during the oxygenation of that already formed, may be detected by its odour.

Obs. During the mutual action of the platinum-black and the vapour of alcohol, the temperature increases, and continues to do so until all the oxygen contained in the air enclosed in the case is consumed, when the acetification stops. On opening the case for a short time, to admit of a fresh supply of air, the operation recommences, thus showing its dependence on the oxygen of the atmosphere. For this transmutation, 100 grains of alcohol require 71 grains (equal to 200 cubic inches) of oxygen, or about 1000 cubic inches of atmospheric air. To render the process continuous and rapid, a fresh supply of air must, therefore, be constantly provided. This may be effected by either having a loosely covered opening at the top of the case, and several much smaller ones near its lower part; or (and preferably) by means of two small glass tubes passing through the lid or cover, one of which terminates just below the point of insertion, whilst the other divides into branches which reach to within a short distance from the bottom, as shown in the engraving. In this way a very slow current of fresh air will always be kept up in the apparatus.

In practice, we find, that by loosely spreading the platinum-black on pieces of platinum-gauze, and supporting these on small tripods or bars of glass or porcelain (or even wood), the watch-glasses and their troublesome suspension may be dispensed with; as also may be the strip of porous paper, provided a temperature of not less than 90° Fahr. be maintained in the case or acetifier, which may easily be done by the application of artificial heat in the absence of sunshine. On the large scale, a case of wood with a glass roof, or even a well-seasoned cask or vat may be employed, in which case the temperature of the apparatus must be kept up either by means of steam-pipes or flues, or by the supply of warm air. On the small scale, a hand bell-glass placed on a dish, with a single watch-glass or piece of platinum-gauze, and a single capsule containing alcohol, may be used, provided the bell-glass be supported on three very small wedges, to admit of a supply of air. A modification of this is sometimes employed, in which the alcohol is supplied, in drops, to the platinum-black, by means of a long, tubular funnel passing through the mouth of the bell-glass, and having its lower extremity drawn to a very fine point, as shown in the engr. To ensure success, the platinum-black should be either fresh-prepared, or recently washed and very gently heated, before placing it in the acetifier. Spongy platinum, though ordered by many chemical compilers, does not answer well for this process.

By the above elegant and economical process, perfectly pure acetic acid of considerable strength may be produced from even impure alcohol; but it is impossible in this way to obtain a concentrated acid without a subsequent operation, because the action of platinum-black on absolute alcohol, or even on strong alcohol, is so violent that the platinum soon begins to glow, and inflammation ensues. Unfortunately the revenue laws of this country, until lately, stood in the way of the adoption of this beautiful process, unless duty-paid alcohol or methylated spirit be employed; but there is no statute that prevents an individual employing pure spirit, of any strength, on the small scale, for private consumption. In Germany, and in the United States of America, vinegar is manufactured on this plan, and from the low price of crude alcohol there, it will no doubt prove ultimately to be the cheapest source of both pure acetic acid and culinary vinegars.

VI. Miscellaneous Formulæ:—

1. An excellent acetic acid, of considerable strength, may be made by soaking fresh-burnt and perfectly dry charcoal in common vinegar, and then subjecting it to distillation. The water comes over first, and on increasing the heat, the acid follows. Vinegar-bottoms and waste vinegar may be used.

2. By exposing vinegar, or dilute acetic acid, to the air in very cold weather, or to freezing mixtures, the water separates in the form of ice, and the strong acetic acid may be obtained by draining it into suitable glass vessels, observing to do so at a temperature sufficiently low to keep the water solid. Said to answer well in cold climates.

3. Acetic acid containing 20% of water may be deprived of a good deal of its superfluous water by standing over dry sulphate of soda. (Liebig.) It may then be used either with or without distillation.

4. Acetic acid, of ordinary strength, may be concentrated to any degree, by rectification once, or oftener, from dry acetate of potash or soda, rejecting the first and last portions. The same acetate may be used repeatedly. The temperature need not exceed 400°, and must not rise above 570° Fahr.

Acetic acid. (B. P.) Syn. Acidum aceticum. Water mixed with 33% of hydrated acetic acid. Prepared by distilling acetate of soda with sulphuric acid. Colourless sour liquid. Sp. gr. 1·044.

Prop. Pure hydrated acetic acid is a thin, colourless liquid above 62 Fahr.; at 50° to 55° it crystallises in large, brilliant, colourless, transparent needles and plates, and even at 60° if a crystal of the acid be dropped in; at 40° it is a solid crystalline mass. Sp. gr.—liquid, 1·063 (Mollerat) to 1·0635 (Mohr);—crystallised, 1·135 at 55° Fahr. (Ure). Odour, intensely pungent when concentrated, but grateful, fragrant, and refreshing, when diffused; taste, intensely sour and acrid, becoming agreeable and refreshing, on sufficient dilution with water; volatile; inflammable, burning with a white flame; vapour of boiling acid highly combustible; dissolves camphor, resins, gum resins, volatile oils, gelatin, gliadin, coagulated albumen, and fibrin (as muscle or the crassamentum of the blood); it coagulates casein, but not liquid albumen (as the serum of the blood and white of egg): miscible with alcohol, ether, and water in all proportions; boils at 248° Fahr.; and is decomposed at a red heat. Its salts are called ACETATES (which see).

Char., Tests, &c.—1. Free acetic acid reddens litmus paper, like the other acids; and may be readily recognised by its odour and volatility:—2. Sesquichloride of iron being added, and the acid then nearly saturated with ammonia, the fluid acquires a deep dark-red colour.

Estim. See Acetimetry. Organic mixtures that cannot be thus tested, or from which the acid cannot be obtained by simple distillation, may be neutralised, if acid, with carbonate of lime, boiled for a few minutes, cooled, filtered, the lime precipitated with dilute sulphuric acid, and the whole submitted to distillation, when the acid contents of the distillate may be estimated as above.

Pur. By heat, it escapes (entirely) in vapour; nothing is precipitated on the addition of either hydrosulphuric acid, nitrate of silver, or chloride of barium. Sometimes it is contaminated with sulphurous acid, which may be recognised by putting a fluid drachm of the acid, mixed with an ounce of distilled water and half a drachm of pure hydrochloric acid, also a few pieces of granulated zinc, into a flask. While effervescence continues suspend a slip of white blotting-paper, moistened with solution of sub-acetate of lead, in the upper part of the flask above the liquid, for about five minutes. The paper should not be discoloured, and thus indicate the absence of sulphurous acid.

Adult. The acetic acid of the shops is chiefly adulterated with water. Sulphurous acid and lead are accidental contaminations; that of the latter often reaches 2%, making the acid poisonous.

Phys. eff., &c. In its concentrated state it is a corrosive and an acrid poison. Taken internally, it acts by dissolving the animal tissues, and by thus destroying the organisation causes death, like the other acids. In the dilute form it acts as a stimulant, rubefacient, alterative, refrigerant, and escharotic.

Uses. Acetic acid is much employed by the chemist and pharmaceutist, in the manufacture of various preparations, and in analysis; by the perfumer, in the composition of several of his most refreshing and agreeable scents; and in medicine, as an antiseptic, stimulant, rubefacient, alterative, refrigerant, and escharotic. Acetic acid (B. P.) applied by means of a piece of rag tied to the end of a small stick, is a nearly certain cure for ring-worm and scaldhead—one or two applications generally effecting a cure, and the severe smarting it causes is only of short duration; as a caustic, it removes warts and corns; a piece of lint or blotting-paper wetted with it and applied to the skin (evaporation being prevented), forms a useful extemporaneous blister. It was once employed as a disinfectant; but is now only used as a fumigation, to disguise the unpleasant smell of the sickroom and crowded assemblies. It is a popular refreshing scent in faintings, asphyxia, and nervous headache; and is a valuable rubefacient, astringent, and local stimulant. It is also used as a rubefacient and caustic in veterinary practice.

In the arts, the commercial acid (pure pyroligneous acid) is used by the engraver to etch his plates; as an antiseptic in pickling and preserving animal and vegetable substances used as food, and anatomical preparations; in dyeing and calico printing, and in the manufacture of medicated vinegars and other pharmaceutical preparations.

In the dilute state, its properties and applications are similar to those of ordinary vinegar, and are noticed under that head.

Poisoning from acetic acid is rare. When concentrated, it is capable, by its corrosive and solvent action, of perforating the coats of the stomach and digestive canal; and it colours the mucus of these organs by the chemical action it exerts upon the blood. Vinegar in an excessive quantity acts in a similar way, but in a slighter degree. The treatment and antidotes are similar to those directed in cases of poisoning by the other acids. See Poisons.

Duty, Excise, &c. See Vinegar.

Gen. commentary. Acetic acid, on the large scale, is principally prepared from acetate of soda, which yields by a comparatively inexpensive, and not a difficult operation, an acid sufficiently strong and pure for commercial purposes, without the necessity of rectification. In this process shallow vessels of wood or of copper formed without rivets or solder (except silver solder) in those parts exposed to the action of the acid, are generally employed for the purpose of the distillation. A coil of drawn copper pipe, heated by steam having a pressure of 30 to 40 lbs. to the inch, traverses the bottom of the apparatus, to impart the necessary heat. The refrigerator consists of well-cooled earthenware, Berlin ware, or glass vessels; and the adopter pipe is also of the same materials. Another common form, which is even still more convenient, is a stout copper still, furnished with a cast-iron jacket to hold high-pressure steam, the usual refrigeratory being employed. In a few instances the space between the still and jacket is filled with sand, oil, tallow, or fusible metal; in which case the apparatus is set in brickwork, and heated by a naked fire. Stills of earthenware are also frequently employed; and even worms and condensers of silver, or silvered copper, are sometimes used, and with advantage. With a leaden worm the product is always contaminated with a little of that metal; the efforts of the manufacturer to the contrary, by the exclusion of air, and by rejecting the first and last portions of the distillate, only lessening and not preventing this evil. A lute (if any) composed of linseed meal and water, with or without a little powdered plaster of paris, may be employed; but flat bands and short tubes of well-seasoned vulcanised india rubber are infinitely more convenient and efficacious. The ingredients being placed in the still, and well but hastily stirred together with a wooden spatula, the head is luted on, and the distillation soon afterwards commenced. The chief care now should be to increase the heat gradually as the distillation proceeds; and when a steam-heat is not used, to carefully avoid over-firing, particularly towards the close of the operation. A little acetic ether is added by some manufacturers. In this way 4 lbs. of acid of the sp. gr. 1·050, is obtained for every 3 lbs. of acetate of soda employed. Should rectification be had recourse to, the addition of about 2 or 3% of bichromate of potash, peroxide of manganese, or red oxide of lead, will remove empyreuma, if present. The first of these substances is the most effective; the power of the others being in the order in which they are printed. In distilling the weaker acids and vinegars, it is found useful to add from 25 to 30% of chloride of sodium, which, by raising the boiling-point of the liquid, allows the acid the more freely to pass over (Stein); but this addition proves disadvantageous when any sulphuric acid is present, in which case sulphate of soda may be employed instead. If this addition be not made, the whole of the acid cannot be obtained without distillation to dryness, and the generation of empyreuma.

On the small scale, glass retorts are usually directed to be used, but glass alembics or flasks are more convenient and safe, as already noticed. In the preparation of the pure acid, care should be taken that the acetate of soda does not contain common salt, as the carbonate of soda prepared by calcination, and frequently used to form the acetate, is generally contaminated with it, and yields up its hydrochloric acid or chlorine during the process of distillation, thus vitiating the product. In all the methods given the product becomes more concentrated in proportion to the dryness of the acetate and the strength of the oil of vitriol or muriatic acid employed. By using the one dry, and the other concentrated, glacial acid may always be obtained by collecting separately the last two fifths that come over, and submitting this to refrigeration.

According to Melsens, pure GLACIAL ACETIC ACID is most advantageously obtained by distilling pure and dry acetate of potash with an excess of strong and moderately pure acetic acid, rejecting that which first passes over.

Acetate of soda may be safely dried at a temperature of 400° to 450°, provided care be taken to avoid ignition from contact with sparks. A less heat is, however, quite sufficient to drive off the whole of its water of crystallisation. It is known to be dry by its assuming the appearance of a smooth oily liquid whilst hot. If, whilst heated, it emits fumes, it is suffering decomposition. The same applies to the other commercial acetates. Crystallised acetate of soda loses about ⁄5ths of its weight by thorough drying.

When acetate of soda and sulphuric acid are the ingredients employed in the production of acetic acid, sulphate of soda is formed, which, in the large way, the chemist returns to the manufacturer of acetate of soda (i. e. to the pyroligneous acid maker), who employs it in the decomposition of fresh acetate or pyrolignite of lime. In this way the same soda-salt is employed over and over again, acting merely as the vehicle for the separation of the crude acetic acid in the solid form, and its easy and cheap transportation from one point to another. This ingenious method of mutual assistance resulting from the application of chemical science to provide for the wants of everyday life, offers some explanation of the extraordinarily low price at which acetic acid may now be purchased.

The acetic acid of commerce (pure pyroligneous acid) is almost wholly obtained from the acetates of soda and lime. The principal supply of crude acetate (pyrolignite) of soda is from America, Norway, and Sweden; but much is also obtained from our home manufactories. See Acetification, Acetimetry, Fermentation, Pyroligneous Acid, Sodium, (Acetate of), Vinegar, &c.

More recently, acetic acid has been obtained by decomposing with hydrochloric acid the double salt of chloride of calcium and acetate of lime, mentioned by Fritzsche (‘Ann. de Poggend,’ xxviii, 123). For this purpose, solutions of acetate of lime and chloride of calcium are mixed and evaporated, the combined salts readily crystallising in large needles. These are freed from the mother-liquor and distilled with common muriatic acid.

The acid furnished by this method requires redistillation, and is, moreover, contaminated with some of the fatty products always present in the crude pyrolignite.

Anhydrous Acetic Acid.

Syn.

Acetic Anhydride.

Acetic acid deprived of the elements of water.

Acetic Acid. Water. Acetic Anhydride.

2C2H4O2 - H2O = C4H6O3.

Aromat′ic Acetic Acid. Syn. Aromatic vinegar; A. spirit of v.; Acidum Ace′ticum aromat′icum, L.—Prep. 1. (Ph. E. 1839.) Dried rosemary and origanum, of each 1 oz.; lavender flowers, ⁄2 oz.; bruised cloves, ⁄2 dr.; acetic acid (sp. gr. 1·068), 1⁄2 pint; macerate for 7 days, express, and filter. A fragrant and refreshing perfume. Omitted in Ph. E. 1841 and P. B. 1867.

2. (Ph. E. 1817.) As the last, but using distilled vinegar instead of the strong acid of the Pharmacopœia. Inferior.

3. (P. Cod. 1839) Camphor, 2 oz.; oil of lavender, 10 gr.; oil of cinnamon, 20 gr.; oil of cloves, 30 gr.; concentrated acetic acid, 1 pint. Very fragrant and refreshing.

4. (Ph. Bor. 1847; Cod. Med. Hamb. 1845.) Oil of cloves, 1 dr.; oils of lavender and citron, of each 2 scrup.; oils of bergamot and thyme, of each 1 scrup.; oil of cinnamon, 10 drops; strongest acetic acid, 1 oz.; mix. Limpid; yellow-brown; highly fragrant and refreshing. See Acetic Acid (Camphorated), and Vinegar (Aromatic).

Beaufoy’s Acetic Acid. A superior commercial acetic acid (i. e. purified pyroligneous acid), having a sp. gr. of about 1·044; or containing about 28% of real acetic acid, or 32 to 33% of the hydrated acid. Same strength, &c., as Acetic Acid P. B.

Cam′phorated Acetic Acid. Syn. Camphorated vinegar; Acidum ace′ticum camphora′tum, L.—Prep. 1. (Ph. E. 1841.) Camphor, ⁄2 oz.; pulverise it by means of a few drops of spirit of wine, and then dissolve it in acetic acid (Ph. E.), 6⁄2 fl. oz.

2. (Ph. D. 1850.) Camphor, 1 oz.; rectified spirit, 1 fl. dr.; pulverise, and dissolve in strong acetic acid (acid. acet. fort. Ph. D.), 10 fl. oz.

Obs. This preparation is intended as a substitute for the aromatic acetic acid of the shops and previous pharmacopœias. It is also useful as an embrocation, in rheumatism and neuralgia; as an extemporaneous vesicant and counter-irritant; and as a fumigation in fevers, &c.

Dilute′ Acetic Acid. Syn. Acidum aceticum dilu′tum, L. Acetic acid, 1 pint; distilled water, 7 pints; mix, Sp. gr. 1·006. One fluid ounce corresponds to 16 grains of anhydrous acid (3·63 per cent.).

Glacial Acetic Acid. Syn. Acidum aceticum glaciale. Acetate of soda, 20 oz., is liquefied by a gentle heat, stirred till it becomes pulverulent, and then further heated until it fuses; it is at once removed from the fire, and, when cool, the mass is broken up, placed in a 3-pint stoppered retort connected with a Liebig’s condenser, and then treated with sulphuric acid, 8 fl. oz. When the distillation slackens heat is to be applied, and the process continued until 6 fl. oz. of acetic acid have passed over. If a little of the product strikes a blue colour when mixed with a solution of iodate of potassium containing mucilage of starch, the whole product must be agitated with perfectly dry black oxide of manganese, ⁄4 oz., and redistilled. Sp. gr. 1·065; contains 85% of anhydrous acid.

ACETIC ANHYDRIDE. See Anhydrous Acetic Acid.

ACETICA. [L.] Medicated vinegars.

ACETIDUX, Dr DELFER’S. Made by Döllinger, of Berlin. For the radical and painless removal of warts, corns, hard skin, &c. A solution of 5 grms. of chromic acid in 15 grms. of water. (Schädler.)

ACETIFICATION. Syn. Acetifacio, L.; Acetification, Fr.; Essigmachen, Einsaüern, Ger. In chemistry, the act or process of converting into vinegar; also the state of undergoing such conversion.

Acetic acid is produced either by the partial dehydrogenation and subsequent oxidation of bodies containing its elements, or by their destructive distillation. The first is effected—by their exposure, in a finely divided state, to the action of air or atmospheric oxygen, as in the quick process of making vinegar; or—by submitting them, in combination with ferments, to contact with a free supply of atmospheric air, as in the old field process of making vinegar; or—by exposure to the direct action of chemical or mechanical oxidizing agents, as condensed air (platinum-black process), chromic and nitric acid, &c. In general, it is alcohol more or less dilute, particularly as it exists in fermented liquors, which is thus converted into acetic acid. In the second process (destructive distillation), wood is the substance usually employed, and heat is the agent which develops the acid.

The conversion of alcohol into acetic acid is not immediate and direct. The atmospheric oxygen first oxidises two atoms of its hydrogen, aldehyd and water being formed; and this aldehyd uniting with one atom of oxygen produces one molecule of ACETIC ACID. The changes are represented in the following equations:—

Alcohol. Oxygen. Aldehyd. Water.

1. C2H6O + O = C2H4O + H2O

Aldehyd. Oxygen. Acetic Acid.

2. C2H4O + O = HC2H3O2

After the first formation of aldehyd, the two processes, unless artificially checked, go on simultaneously, as long as any undecomposed alcohol is present.

The conversion of alcohol into acetic acid, although greatly accelerated by the presence of nitrogenised organic matter (according to Mulder, of a fungus—the Mycoderma Vini or Vinegar Plant), is rather a case of eremacausis (slow combustion) than of fermentation. Acetification effects combination, as shown by the foregoing equations, whereas fermentation resolves complex bodies into simpler ones, e.g. sugar into alcohol and carbonic anhydride. Moreover, the presence of ferments is not essential to the change, since pure alcohol becomes acetified when exposed to the oxidising agents already named.

Another remarkable distinction between acetification and fermentation is, that the former requires the continued presence of atmospheric oxygen; whilst the vinous fermentation after being once established, proceeds perfectly without it.

During the oxidation of the alcohol of vegetable solutions, some of the other organic matters present also suffer change. A white gelatinous mass (mother of vinegar) is commonly deposited; but this is a secondary result of the process, and not, as formerly supposed, one essential to it. In ordinary cases acetification occurs only at or near the surface of the liquid; which accounts for the length of time required for the operation under the old process of ‘fielding,’ and the shorter time in which it is accomplished by the improved process of Mr Ham. It proceeds favorably at temperatures ranging from 60° to 90° Fahr.; and most rapidly at 95° Fahr. (Liebig). In the ‘quick process’ of making vinegar a temperature of 90° to 92° is generally aimed at; but it often rises to 100°, or even to 105°, Fahr. As the temperature falls acetification proceeds more slowly, and at 46 to 50° Fahr. it ceases altogether (Liebig).

Aldehyd (see above) is an exceedingly volatile substance, and easily dissipated by a slight heat. It is, therefore, of the highest importance to duly regulate the temperature, as well as the supply of air, during acetification. In the ‘quick process’ of making vinegar the loss from this cause is always considerable, and often very great. This loss may be diminished by passing the heated air, as it escapes from the acetifier, through a porcelain or silvered copper worm or refrigerator, set in a chamber containing water of a temperature not higher than 40° to 45° Fahr.; the connection being made at the lower end of the worm, whilst the upper end is open to the air. On the small scale, as in the platinum-black process, the loss may be almost entirely prevented by causing the upper air tube to pass through a vessel containing ice or a freezing mixture; or by uniting it with the lower end of a Liebig’s condenser.

In liquors undergoing the vinous fermentation, a portion of the newly formed alcohol is invariably acetified whenever the temperature rises above 51° Fahr.; and at a higher temperature, this proceeds with a rapidity often highly injurious to the quality of the liquor. In this way there is frequently a useless loss of the alcohol, which is rendered more apparent by the incipient, and sometimes the actual, souring of the liquor.

ACETIM′ETRY. Syn. Acetom′etry; Acétométrie, Fr.; Acetime′tria, &c., L. The art or process of determining the quantity of pure acetic acid in vinegar, or in any other liquid. The plans generally adopted for this purpose are—

I. From the saturating power of the acid, as in the common methods of acidimetry:—

1. The molecular weight of commercially pure bicarbonate of potash, in crystals, being 100, whilst that of absolute acetic acid is 60, it is evident that every ten grains of the bicarbonate will exactly equal 6 grains of the acid. To apply this practically, we have only to exactly neutralise 100 gr. of the vinegar or solution under examination with the bicarbonate, observing the usual precautions; then, as 10 is to 6, so is the number of grains used, to the per-centage strength required. In this, as in other like cases, it is convenient to form a test-solution with the bicarbonate, by dissolving it in sufficient water to fill the 100 divisions of any simple form of ‘acidimeter,’ as a, b, or c; when the quantity of the solution, and, consequently, of the salt used, may be read off at once from the graduated portion of the tube. Still greater accuracy may be obtained by dissolving the bicarbonate in exactly 1000 gr. of distilled water contained in a ‘Schuster’s alkalimeter,’ previously very carefully weighed; in which case each grain of the test-solution will indicate ⁄10th of a grain, or 0·1% of absolute acetic acid, whilst every 10 grains will be equal to 1 grain, or 1%.

The test-solution may also be prepared from bicarbonate of soda, or from the carbonates of soda or potash, care being taken that the quantity of the salt dissolved be in proportion to its molecular weight.

2. (Brande.) A small piece of white marble, clean and dry, is weighed, and then suspended by a silk thread in a weighed sample (say 100 or 1000 grs.) of the vinegar or acid under examination; the action being promoted by occasionally stirring the liquid with a glass rod, until the whole of the acid is saturated, as shown by no further action on the marble being observable on close inspection. The marble is then withdrawn, washed in distilled water, dried and weighed. The loss in weight which it has sustained will be nearly equal to the acetic acid present, or strictly, as 50 (marble) to 60 (absolute acetic acid). The only precautions required are, to avoid striking the piece of marble with the rod whilst stirring the solution, or causing loss of substance in it after its withdrawal; and to allow ample time for the action of the acid on it. If the sample consists of strong acid, it should be diluted with twice or thrice its weight of water before suspending the marble in it.

3. (Ure.) 100 grains of the sample under examination is slightly reddened with tincture of litmus, and ammonia of the sp. gr. 0·992 is added drop by drop (from an acetimeter holding 1000 water-gr. measure, divided into 100 divisions) until precise neutralisation is effected, indicated by the blue colour of the litmus being restored. The number of the divisions of the acetimeter used, multiplied by 60, and the first two right-hand figures of the product cut off as decimals, gives a number which represents the exact quantity of absolute acetic acid in the sample. In practice, it is found more convenient to keep the test-ammonia ready tinged with litmus.

The mode of estimating the per-centage of acetic acid in beers, when finding their original gravities, is a slight modification of the above. A test-solution of ammonia is prepared of such a strength that a given bulk of it will exactly neutralise one per cent. of absolute acetic acid in an equal bulk of beer, so that, if 100 fluid grains of the solution are sufficient to neutralise the acid in 1000 fluid grains of beer, such beer contains one tenth per cent. of acid. A solution of ammonia, diluted with distilled water until it has the sp. gr. ·9986 at 60°, is of the exact strength required.

An acetimeter holding 1000 grains, and graduated downwards to 100 equal divisions, is filled to 0 of the scale with the test-ammonia, which is then added, drop by drop, to 1000 measured grains of the beer, until neutralisation takes place. Every division of the acetimeter (corresponding to ten fluid grains), so emptied, indicates ·01 per cent. of acetic acid in the beer. The progress of the neutralisation is tested from time to time with a slip of reddened litmus paper, which should be suffered to become faintly blue before ceasing to add the ammonia. By this method the exact per-centage of absolute acetic acid in any sample may be accurately determined. The only precaution necessary is to be certain that the ‘test-ammonia’ has the required sp. gr. (·9986). Test-solutions may also be prepared with pure potash or pure soda.

II. From the specific gravity of the liquid after it has been neutralised with hydrate of lime:—

Common hydrate of lime (freshly slaked lime), in powder, is added gradually to the sample under examination, until it is saturated, when the sp. gr. of the resulting clear solution of acetate of lime is taken by Taylor’s ACETIMETER. This instrument is so adjusted and graduated as to float at the mark on the stem called ‘proof,’ in a solution containing 5% of absolute acetic acid (No. 24 vinegar). For vinegars stronger than proof small weights are provided, each of which indicates an additional 5 per cent. To ascertain the per-centage of real acid, 5% must therefore be added to the acetimeter number. Thus, without being loaded, the instrument, floating at the ‘proof mark,’ indicates a vinegar of 5%; with one weight, a vinegar of 10%; with two weights, 15%, and so on. According to this system of notation, each 5% is called a ‘vinegar.’ An acid of 10% is said to contain two vinegars; one of 15%, three vinegars, &c. It is also common to speak of the degrees of the acetimeter as proof or over-proof. Thus, No. 24 vinegar is said to be proof; one of 5 acetimeter degrees, 5 over-proof; one of 10 degrees, 10 over-proof, &c. For malt and wine vinegars, which contain gluten and mucilage, this method is not strictly accurate, as a portion of these substances escapes precipitation by the lime, and consequently alters the specific gravity. A small weight marked ‘M’ is generally supplied with the acetimeters for trying such vinegars.

III. From the specific gravity:—

The sp. gr. of the sample (carefully determined by any of the usual methods) is sought in one of the following Tables, when the corresponding per-centage content of acetic acid is at once seen.

This method furnishes reliable results only with pure, or nearly pure solutions which do not contain much above 50% of glacial acid, or which have a sp. gr. not higher than 1·062. It is also more to be depended on for weak solutions than strong ones. By carefully diluting a strong acid with an equal weight, or twice or thrice its weight of water, and allowing the mixture to again acquire its normal temperature, the sp. gr. may be taken as a guide in all cases in which great accuracy is not required. When such dilution is made it only becomes necessary to multiply the indication furnished in the Tables by 2, 3, or 4, as the case may be. As, however, authorities are not agreed as to the precise sp. gr. of the monohydrate or glacial acid, and of its solutions, extreme accuracy must not be expected by this method.

Table I.—Adapted to the Specific Gravities of common vinegar. By Messrs J. and P. Taylor.

sp. gr. per
cent.

1·0085 contains of anhydrous or real acetic acid 5

1·0170 ” ” 10

1·0257 ” ” 15

1·0320 ” ” 20

1·0470 ” ” 30

1·0580 ” ” 40

Table II.—Exhibiting the quantity of ABSOLUTE or GLACIAL ACETIC ACID (HC2H3O2), in acetic acid of successive strengths. By Mr Cooley.

Absolute Acetic Acid, per cent. Sp. Gr. Absolute Acetic Acid, per cent. Sp. Gr. Absolute Acetic Acid, per cent. Sp. Gr. Absolute Acetic Acid, per cent. Sp. Gr.

Pure acid
or

100 1·0630 74 1·0732 48 1·0582 22 1·0311

99 1·0648 73 1·0728 47 1·0568 21 1·0292

98 1·0663 72 1·0721 46 1·0557 20 1·0275

97 1·0677 71 1·0718 45 1·0553 19 1·0264

96 1·0685 70 1·0713 44 1·0544 18 1·0253

95 1·0696 69 1·0711 43 1·0535 17 1·0241

94 1·0704 68 1·0708 42 1·0525 16 1·0229

93 1·0708 67 1·0702 41 1·0518 15 1·0218

92 1·0715 66 1·0701 40 1·0513 14 1·0200

91 1·0721 65 1·0693 39 1·0502 13 1·0173

90 1·0726 64 1·0692 38 1·0492 12 1·0172

89 1·0729 63 1·0685 37 1·0482 11 1·0161

88 1·0730 62 1·0679 36 1·0473 10 1·0150

87 1·0731 61 1·0675 35 1·0460 09 1·0131

86 1·0732 60 1·0672 34 1·0449 08 1·0121

85 1·0733 59 1·0665 33 1·0439 07 1·0102

84 1·0734 58 1·0662 32 1·0425 06 1·0085

83 1·07343 57 1·0653 31 1·0413 05 1·0071

82 1·0735 56 1·0645 30 1·0402 04 1·0057

81 1·0738 55 1·0641 29 1·0392 03 1·0042

80 1·0743 54 1·0632 28 1·0380 02 1·0025

79 1·0742 53 1·0628 27 1·0364 01 1·0012

78 1·0740 52 1·0616 26 1·0352 00 1·0000

77 1·0739 51 1·0610 25 1·0341 or Pure water.

76 1·0736 50 1·0602 24 1·0330

75 1·0731 49 1·0593 23 1·0320

Concluding remarks. Before applying the above processes, account should be taken of any mineral acid which may be present in the sample, such being not unfrequently added to vinegar to impart artificial strength; and in those depending on the sp. gr., gum, gluten, &c., must also be allowed for. The methods depending on the saturating power of the acid will be found appropriate to acetic acid of all strengths, when unadulterated with the mineral acid. The method based on the sp. gr. is also very convenient, and is sufficiently accurate for distilled vinegars and for pure acids of moderate strength.

It is found that the decimal fraction of the sp. gr. of pure or nearly pure vinegar is doubled by its conversion into acetate of lime. Thus, 1·0085 in vinegar becomes 1·0170 when converted into a solution of acetate of lime. In malt vinegar, however, 0·005 may be deducted from the sp. gr. for mucilage and gluten. The quantity of foreign matter present in vinegar may therefore be approximatively ascertained, by deducting the decimal of the sp. gr. of the solution of acetate of lime from double that of the decimal part of the sp. gr. of the vinegar. Thus:—the sp. gr. of a sample of vinegar being 1·014, and after saturation with hydrate of calcium 1·023, the sp. gr. of the pure vinegar would be 1·009, and that due to foreign matter ·005. For—

·028 - ·023 = ·005

and—

1·014 - ·005 = 1·009

The reason why proof-vinegar is called, in commerce, No. 24, is that 1 fl. oz. of it requires exactly 24 gr. of pure anhydrous carbonate of soda to neutralise it. Weaker vinegars are represented in the same ‘notation’ by the Nos. 22, 20, 18, &c., according to their respective strengths estimated by their saturating power.

ACETINE. An essence for the removal of corns. Concentrated vinegar (1·04 sp. gr.) slightly tinged with fuchsine, 15 grms. (Hager.)

ACETINE, HOCHSTETTER’S. Prepared by J. C. F. Witte, Berlin. A remedy for corns, warts, and hard skin. Diluted vinegar, coloured with blue carmine, 16 grms. (Schälder.)

ACETOLATS. [Fr.] Syn. Esprits acétiques. In French pharmacy, medicated vinegars obtained by distillation.

ACETOLES. [Fr.] In French pharmacy, medicated vinegars obtained by maceration.

ACETOUS FERMENTATION. See Acetification.

ACETUM. [L.] Vinegar.

ACETYL. Syn. Acetyle. A name originally given to a hypothetical body, having the formula C2H3, and regarded by Berzelius as the radical of the acetates and their congeners. The acetyl of Gerhardt (C2H3O) is, however, according to that chemist, the true radical of the acetates. Williamson, in order to remove the confusion of terms occasioned by the application of the same name to compounds of different composition, proposed the title of othyl for the radical C2H3O.

ACHAR. See Pickles.

ACEIILE′INE (-kĭl-). A peculiar bitter principle obtained from achillé a millefolium (Linn.), or yarrow.

A′CHOR, (-kŏr). [Gr.] See Scald-head.

ACHROMAT′IC (ăk-ro-). Syn. Achromatique, Fr. In optics, devoid of colour; bodies that transmit light without decomposition, and consequently, without the formation of coloured rings or fringes; applied to compound lenses, prisms, &c., and to instruments fitted with them.

ACRO′MATISM. Syn. Achromatisme, Fr. In optics, the state of being achromatic; the absence of coloured fringes in the images of objects seen through a lens or prism.

Light is not homogeneous, but decomposable by refraction, absorption, or reflection, into coloured rays of unequal refrangibility. A ray of white light, in passing through a glass prism, is entirely separated into the coloured rays forming the ‘prismatic spectrum,’ and when it passes through a lens, an analogous resolution into coloured rays still occurs, though not so readily observed, and that to an extent often incompatible with distinct vision. Now, if a convex lens be regarded as a number of prisms united by their bases round a common centre, and a concave lens, as a similar number of prisms with their apices in contact, the action of lenticular and prismatic glasses on light will be reduced to a common principle. A beam of light thrown on a simple converging lens not only suffers refraction at the spherical surface (SPHERICAL ABERRATION), but the different coloured rays of which it is composed, from the causes mentioned, being unequally bent or refracted, diverge from their original course (CHROMATIC ABERRATION), forming as many foci on the axis of the lens as there are colours, and fall separately, instead of together, on the eye or object which receives them. Hence arise the coloured fringes or halos that surround objects viewed through ordinary glasses, and which form the great impediments to the construction of perfect lenses. This effect, like the refractive power and focal distance, varies in degree in different diaphanous substances.

The correction of the chromatic aberration of lenses is commonly effected by combining two, or more, made of materials possessing different ‘dispersive’ powers. Thus, the spectrum formed by flint glass is longer than that formed by crown glass, for the same deviation. When the two are combined, so as to form a compound lens, the one tends to correct the ‘dispersion’ of the other. On this principle ACHROMATIC GLASSES are generally formed in this country. A convex lens of crown glass is combined with a weaker concave lens of flint glass, the latter counteracting the dispersion of the former, without materially interfering with its refractive power. The resulting combination is not absolutely achromatic, but is sufficiently so for all ordinary purposes. According to Dr Blair, a compound lens perfectly achromatic for the intermediate, as well as for the extreme rays, may be made by confining certain fluids, as hydrochloric acid, between two lenses of crown glass. In order to produce nearly perfect achromatism in the object-glasses of telescopes, microscopes, cameras, &c., a concave lens of flint glass is commonly placed between two convex lenses of crown or plate glass, the adjacent surfaces being cemented with the purest Canada balsam, to prevent the loss of light by reflection from so many surfaces.

Obs. The production of perfect achromatism in lenses is a subject not less fraught with difficulty than with practical importance to the astronomer, the mariner, the microscopist, and the photographer; and it has hence engaged the attention of the leading mathematicians and artists of Europe up to the present time. All the larger object-glasses lately manufactured are said to consist of only two lenses; the resulting achromatism proving sufficiently exact for all useful purposes. Those of recent production have come chiefly from the workshops of Dollond, of London, and the opticians of Bavaria and Switzerland. The achromatism of prisms depends upon the same principles, and it is effected in the same way as that of lenses.

ACIC′ULAR. Needle-shaped; slender or sharp pointed; spicular; in botany, applied to leaves, and in chemistry, to crystals. The last are also sometimes termed ACIC′ULÆ.

ACID, Syn. Acidum, L.; Acide, Fr.; Acido, Ital.; Säure, G. In familiar language, any substance possessing a sour taste. In chemistry, substances are said to be acid, or to have an acid reaction, when they are capable of turning blue litmus red. In chemistry, also, the term acid is applied to a very large class of compounds containing hydrogen (hydrogen salts), and in which one or more atoms of that element may be replaced by an equivalent quantity of a metal or other basic radical; e.g.—

1. The one atom of hydrogen in hydrochloric acid (HCl) may be replaced by sodium, producing the salt sodium chloride (NaCl).

2. The one atom of hydrogen in nitric acid (HNO3) may be replaced by silver, producing the salt silver nitrate (AgNO3).

3. One atom of hydrogen in acetic acid (HC2H3O2) may be replaced by the basic radical ammonium (NH4), producing the salt ammonium acetate (NH4C2H3O2).

Acids which, like those mentioned in the foregoing examples, contain one atom of replaceable hydrogen are called monobasic; those which contain two such atoms (e.g. sulphuric acid, H2SO4; tartaric acid, H2C4H4O6), dibasic; those which contain three such atoms (e.g. phosphoric acid, H3PO4; citric acid, H3C6H5O7), tribasic; and so on with acids of higher basicity. Acids of greater basicity than unity are frequently termed polybasic.

Besides containing replaceable or basic hydrogen, acids are further characterised by the property of combining with alkaloids to form salts; e.g.—

Sulphuric Acid. Quinia.

H2SO4 + 2C24H24N2O2 =

Quinia Sulphate.

(C20H24N2O2)2 . H2SO4

Acetic Acid. Morphia.

HC2H3O2 + C17H19NO3 =

Morphia Acetate.

C17H19NO3 . HC2H3O2

Dibasic Acids. See Acid.

Fatty Acids. Acids separable from fats or oils; e.g. stearic acid, oleic acid, butyric acid, &c.

Inorganic Acids. Same as Mineral Acids (which see).

Mineral Acids. Acids chiefly or wholly derived from the mineral kingdom. In medicine, sulphuric, hydrochloric, and nitric acids, are commonly so called.

Monobasic Acids. See Acid.

Organic Acids. Acids formed by, or derived from organic substances; e.g. acetic acid, tartaric acid, uric acid, &c.

Polybasic Acids. See Acid.

Pyro-acids. Acids resulting from the decomposition by heat of other acids, e.g. gallic acid, when heated, yields pyro-gallic acid.

Tribasic Acids. See Acid.

ACIDIFICA′TION. [Eng., Fr.] Syn. Acidifica′tio, L. In chemistry, the act, process, or state of acidifying, or of making, becoming, or impregnated with acid.

ACIDIM′ETER. Syn. Acidom′eter; Acidime′trum, &c., L.; Acidimètre, Fr. An instrument or apparatus employed in acidimetry.

The ordinary acidimeters of the chemist are small tubes, constructed to hold exactly 1000 grains of distilled water, at 60° Fahr., within the limits of their scale, which is accurately graduated into 100 divisions. They are used to contain the alkaline solutions (TEST-LIQUORS, NORMAL or STANDARD SOLUTIONS) employed in the following processes.

Beaumé’s Acidimeter, and others of the same class, are HYDROMETERS, and are described under that ‘head.’

ACIDIM′ETRY. Syn. Acidom′etry; Acidime′tria, &c., L.; Acidimétrie, Fr. The estimation of the strength or quantity of acid, in a free state, contained in any liquid. It is the reverse of ‘alkalimetry.’ Acidimetrical assays are understood to refer to the relative strengths of the same acids (i. e., the quantity of real acid of the same kind contained in the solutions examined), and not to the comparative strengths of acids of different composition or names.

Acidimetrical processes. These are founded chiefly on the capacity of the acids to saturate the bases; and, in some of the liquid acids, on the specific gravity.

a. Volumetrically:—

1. The sample of the acid to be examined (100 gr., or any convenient aliquot part thereof) is placed in a suitable glass vessel, and if it be one of the stronger acids, diluted with six or eight times its weight of water, or if solid (as oxalic, or citric acid), dissolved in a like quantity. This liquid is then exactly neutralised with an alkali.

This point is usually determined, by the addition of a small quantity of litmus solution, which turns just blue when the solution is neutralised, but when a carbonate is used for the alkaline solution, the acid must be boiled a short time after each addition to expel the carbonic acid. The quantity of the alkaline solution consumed for this purpose represents an equivalent quantity of acid, and thus gives us the acid content of the sample under examination. The common practice is to dissolve one equivalent of the alkaline test in grains or grammes in water, and to make up the solution to exactly 1000 parts by measure (i. e., 1000 ‘water-grains’ or grammes), so as to accurately fill the 100 divisions of an acidimeter; when the quantity, in grains or grammes, of the sample tested, bears the same proportion to the equivalent number of the acid under examination, that the number of acidimeter divisions of the test-liquor consumed bear to the per-centage of acid sought. Thus:—suppose 50 gr. of a sample of sulphuric acid take 25 acidimeter divisions (300 parts or water-grains measure) of the test-liquid to neutralise it, what is its content of real acid?

The equivalent of sulphuric acid is 49 (half its atomic weight); so, by the rule of proportion,

50 : 49 :: 25 : 24⁄2

It therefore contains 24⁄2 parts of real sulphuric acid, in 50.

If the 1000 parts or grain-measures, instead of the number of the acidimeter divisions, be taken for the calculation, it will, of course, be necessary to point off the first right-hand figure of the result as a decimal. Thus; repeating the above example—

50 : 49 :: 250 : 24·5

Or, since the equivalent of the test-liquid is 100, it will bear the same proportion to the equiv. of the acid examined as the number of the acidimeter divisions of the test-liquid consumed in neutralising 100 gr., do to the per-centage sought. Thus:—50 gr. of hydrochloric acid take 45 acidimeter divisions to effect neutralisation, what is its real strength?—The equiv. of hydrochloric acid is 36·5: therefore—

100 : 36·5 :: 45 : 16·425%

and, since only 50 gr. (instead of 100 gr.) were examined—

16·425 × 2 = 32·85%

Some operators prefer employing 100 gr. instead of the equivalent weights of the given tests in making their test-solutions, in which case each gr. or 1000th part represents ⁄10th, and each acidimeter degree 1 gr. of the alkali or carbonate employed; when a similar proportion will obtain to that first above given.

In technical analysis it is more convenient if the number of acidimeter divisions of the ‘test-liquid’ consumed express the per-centage strength of the acid, without further calculation. For this purpose the number of grains of the acid taken for the assay should correspond to the equivalent number of such acid (see Table I, below); or to some convenient aliquot part of it, as the ⁄2, ⁄4, ⁄5, or ⁄10th; the per-centage answer, in the last case, being doubled, quadrupled, &c., according to the aliquot part taken. The reason of this is obvious.

For the test-solutions, ammonia, and the dry and crystallised carbonates and bicarbonates of potash and soda, are used, and are made by dissolving in water their constituents except ammonia, of which 1000 grains, or one litre, of solution of specific gravity 0·992 contains exactly one equivalent.

53 grains (or grammes) of pure anhydrous carbonate of soda, prepared by gradually heating to redness the crystallised salt, constitute one equivalent (half the atomic weight), and 69 grains (or grammes) of pure dry carbonate of potash. Of the crystallised salt 143 grains of carbonate of soda will be required, and 84 grains (grammes) of the crystallised bicarbonate of soda, and 100 of the crystallised bicarbonate of potash. Occasionally solutions containing in one thousand parts, 50 of pure carbonate of lime or chalk, or 28 of pure caustic lime, are used.

Besides these, a process known as Kiefer’s is practised, and an ammoniacal solution of oxide of copper is employed as the ‘test-liquor,’ and the ‘point of neutralisation’ is known by the turbidity observed as soon as the free acid present is completely saturated.

The normal solution or test-liquor is prepared by adding to an aqueous solution of sulphate of copper, pure ammonia water, until the precipitate, which at first forms, is just redissolved, carefully avoiding excess. Or better, by adding a rather strong solution of sulphate of copper, to a quantity of a rather strong solution of ammonia containing exactly 17 gr., or one equiv. of pure ammonia, as long as the precipitate which forms is redissolved on agitation; the resulting liquid being afterwards diluted with pure distilled water, until it accurately measures 1000 water-grains, or fills 100 divisions of an acidimeter, at 60° Fahr. In either case, the strength of the resulting ‘test-solution’ must be carefully determined by means of standard sulphuric acid, and adjusted, if necessary.

This method answers well with all the stronger acids (excepting oxalic acid), even when dilute; and it has the advantage of not being affected by the presence of a neutral metallic salt with an acid reaction, as sulphate of copper, or of zinc.

Besides this process a solution of lime in sugar may be used, as proposed by M. Peligot, and made as follows:—

Pure caustic lime is carefully slaked by sprinkling with water, and 50 grains (or grammes), made up by water to a milky solution, and 100 grains of pure sugar candy dissolved in 1000 grains of water, are added, and the whole well shaken. It is allowed to settle in a closed bottle, and the clear solution poured off and diluted, until 1000 grains neutralise exactly 100 grains of pure hydrochloric acid of sp. gr. 1·1812. Of course it only answers with acids whose calcium salts are readily soluble in water.

b. Gravermetrically:—

The test-liquors or standard solutions of the above methods are made up so as to weigh exactly 1000 grains, instead of to ‘measure’ 100 acidimeter divisions. Every grain of the test-liquor thus represents ⁄10th gr. of alkali; and every 10 gr., 1 gr. of alkali; or respectively, ⁄10th per cent. and 1 per cent. The vessel used for containing the solutions is carefully weighed whilst empty, and 1000 gr. being placed in the opposite scale, the test-solution, containing exactly one equivalent of base, is poured in, and the whole made up with distilled water (if necessary) so as to restore the balance to an equilibrium. After the process of neutralisation, the acidimeter, with its contents, is again placed in the scales; its previous weight still remaining there. The number of grains required to restore the equilibrium of the balance (i.e., the loss of weight), gives the exact weight of the test-liquor consumed. In all other respects the process is the same as in the ‘volumetrical method’ already described.

Another method for estimating the strength of the sample of acid is by weighing the amount of carbonic acid expelled during saturation. (Method of Fresenius and Will.) This depends on the weight of gaseous carbonic acid which a given weight of the acid-sample under examination is capable of expelling from pure bicarbonate of soda (or of potash), which is estimated by the loss of weight in the acidimeter, or apparatus, after the gas, rendered perfectly dry by passing through sulphuric acid, has escaped into the air.

Table I.—Weights of the respective acids equivalent to the given weight of the principal bases, hydrogen being taken as unity.

17 gr. of pure ammonia. are exactly neutralised by 51 Acetic acid (anhydrous).

31 ” anhydrous soda. 60 Acetic acid (crystallised or glacial).

40 ” hydrate of soda. 99 Arsenious acid (dry).

53 ” dry carbonate of soda. 35 Boracic acid (anhydrous).

143 ” crystallised carbonate of soda. 62 Boracic acid (crystallised).

84 ” crystallised bicarbonate of soda. 22 Carbonic acid (dry).

47 ” anhydrous potassa. 67 Citric acid (crystallised).

56 ” hydrate of potassa. 85 Gallic acid (dried at 212°).

69 ” dry carbonate of potassa. 94 Gallic acid (crystallised).

100 ” crystallised bicarbonate of potassa. 127⁄2 Hydriodic acid (dry or gaseous).

50 ” pure chalk or pure marble. 27 Hydrocyanic acid (anhydrous).

28 ” pure caustic lime. 36⁄2 Hydrochloric acid (dry or gaseous).

37 ” hydrate of lime (fresh). 109⁄2 Hydrochloric acid (liquid, sp. gr. 1·162).

44 ” dry carbonic acid (when the bicarbonate of potassa or soda is used for testing in the process of Fresenius and Will). 166⁄2 Iodic acid.

22 ” dry carbonic acid (when a dry carbonate is used). 54 Nitric acid (anhydrous).

67⁄2 Nitric acid (liquid, sesquihydrated, sp. gr. 1·5033 to 1·504).

72 Nitric acid (liquid, binhydrated, sp. gr. 1·486).

90 Nitric acid (liquid, sp. gr 1·42).

36 Oxalic acid (anhydrous).

63 Oxalic acid (crystallised).

72 Phosphoric acid (anhydrous).

81 Phosphoric acid (glacial).

50 Succinic acid (dry or anhydrous crystals).

59 Succinic acid (ordinary crystals).

40 Sulphuric acid (anhydrous).

49 Sulphuric acid (liquid, monohydrated, sp. gr. 1·8485).

75 Tartaric acid (crystallised).

12 Tannic acid (carefully dried).

Oper. A determined amount of the acid under examination is accurately weighed into the flask A (see engr.); and if it be a concentrated acid, or a solid, it is mixed with or dissolved in 6 or 8 times its weight of water. The little glass tube (e) is then nearly filled to the brim with pure bicarbonate of soda, in powder, and a fine silken thread is tied round the neck of the tube, by means of which it can be lowered down into the flask (A), so as to remain perpendicularly suspended when the cork is placed in the latter; the cord being held between the cork and the mouth of the flask. The flask (B) is next about half filled with oil of vitriol, and the tubes being arranged in their places, as represented in the engr.; and time having been allowed for the mixture of acid and water to cool completely, after the increase of heat caused by mixing, the whole apparatus is very accurately weighed. The cork in the flask (A) is then slightly loosened, so as to allow the little tube containing the bicarbonate of soda to fall into the acid, and is again instantly fixed AIR-TIGHT in its place. The evolution of carbonic acid now commences, and continues until the acid in the flask (A) is neutralised. When this takes place, which is easily seen by no bubbles being emitted on shaking the apparatus, the flask (A) is put into hot water (120° to 130° Fahr.), and kept there, with occasional agitation, until the renewed evolution of gas has completely ceased. The little wax stopper is then taken off the tube (a), the apparatus taken out of the hot water, wiped dry, and suction applied, by means of a perforated cork, or a small india-rubber tube, and the mouth, to the end of the tube (d), until the sucked air no longer tastes of carbonic acid. The whole is then allowed to become quite cold, when it is replaced in the balance (the other scale still containing the original weights), and weights added to restore the equilibrium.

(A) A wide-mouthed flask, capable of holding 2⁄2 to 8 oz., containing sample for trial (f).

(B) Ditto, capable of holding 1⁄2 to 2 oz., partly filled with oil of vitriol (g).

(a, c, d) Tubes fitting air-tight in the flasks by means of the corks (i) and (j).

(b) Piece of wax fitting air-tight on the end of a.

(e) Small tube capable of holding about 1 drachm of powdered bicarbonate of soda or potash.

(h) Open end of the tube (d).

(k) Silk cord fastened to the tube (e).

The loss of weight represents the exact quantity of dry carbonic anhydride, or anhydrous carbonic acid gas, that has been expelled from the bicarbonate of soda, by the action of the acid in the sample examined.

The quantity of real acid it contained is then deduced by the following calculation:—One equivalent of gaseous carbonic anhydride, or anhydrous carbonic acid (= 44) bears the same proportion to one equivalent of the acid in question, as the amount of the carbonic anhydride expelled does to the amount of the acid sought. Thus, suppose a dilute sulphuric acid expels 3 gr. of carbonic anhydride, the arrangement is—

44 : 49 :: 3 : 3·349

Consequently the sample operated on contained 3·5 (nearly) grains of true sulphuric acid.

Instead of the above calculation, we may multiply the weights of the respective acids required to expel 1 gr. of carbonic acid (as exhibited in the following table) by the number of gr. of dry carbonic acid evolved during the above operation. The product represents the per-centage strength, when 100 gr. of the acid have been examined. When only 50, 25, 20, or 10 gr. have been tested, this product must, of course, be doubled, quadrupled, &c., as the case may be.

Table II.

Multipliers.

Acetic acid (anhydrous) 1·159

Acetic acid (hydrated or glacial) 1·364

Citric acid (crystallised) 1·523

Hydrochloric acid (dry or gaseous) ·829

Hydrochloric acid (sp. gr. 1·16) 2·478

Nitric acid (anhydrous) 1·227

Nitric acid (sp. gr. 1·5) 1·523

Nitric acid (sp. gr. 1·42) 2·045

Oxalic acid (crystallised) 1·432

Sulphuric acid (anhydrous) ·909

Sulphuric acid (sp. gr. 1·8485) 1·114

Tartaric acid (anhydrous) 1·500

Tartaric acid (crystallised) 1·705

Even this easy calculation may be avoided, in technical analysis, by simply taking for the assay such a weight of the respective acids as is capable of disengaging exactly 10 gr. of dry carbonic acid from the bicarbonate. In this case, the loss of weight in grains, from the operation, multiplied by 10, at once indicates the exact per-centage strength sought. The proper weight of any acid to be taken to give per-centage results is found by simply dividing ten times the equiv. of that acid by 44. For, taking sulphuric acid as an example,

as— 44: 49 :: 10 : 11·1318

or 11·13 nearly.

On this principle are obtained the weights to be taken, as given in—

Table III.

Grains.

Acetic acid (anhydrous) 11·59

Acetic acid (hydrated or glacial) 13·64

Citric acid (crystallised) 15·23

Hydrochloric acid (dry or gaseous) 8·29

Hydrochloric acid (sp. gr. 1·16) 24·78

Nitric acid (anhydrous) 12·27

Nitric acid (sp. gr. 1·5) 15·23

Nitric acid (sp. gr. 1·42) 20·45

Oxalic acid (crystallised) 14·32

Sulphuric acid (anhydrous) 9·09

Sulphuric acid (sp. gr. 1·845) 11·14

Tartaric acid (anhydrous) 15·00

Tartaric acid (crystallised) 17·05

2. A convenient modification of the preceding method of acidimetry consists in using the common apparatus figured in the margin and employing fused chloride of calcium to dry the evolved carbonic acid gas, instead of concentrated sulphuric acid. The mode of conducting the process and obtaining the results is precisely the same as in that last explained, and need not, therefore, be repeated. In this case, however, suction must be applied to the small tube (g), instead of (d) in the accompanying engraving.

Obs. These methods, though apparently complicated, are not difficult to perform, when once well understood. The application of heat after the completion of the operation is indispensable, as, if it were neglected, from 0·3 to 0·4 of a gr. of carbonic acid would be retained in the liquid. The bicarbonate of soda must be pure, and perfectly free from any neutral carbonate or sesquicarbonate of soda. To ensure this, the bicarbonate of commerce is reduced to a uniform powder, put into a glass jar, and covered with its own weight of cold distilled or rain water, and allowed to stand for twenty-four hours, with frequent stirring. It is then placed upon a funnel, the tube of which is stopped with loose cotton, so as to allow the lye to drain off. It is next washed several times with small quantities of cold distilled or rain water, and after being dried by pressure between some sheets of blotting-paper, without the aid of heat, is kept for use in a well-closed glass bottle. Before use, it may be tested to ascertain its purity. If pure, it neither reddens turmeric paper, nor gives a brick-red precipitate with a solution of bichloride of mercury. Pure bicarbonate of potassa may be used instead of bicarbonate of soda; but in either case it is always proper to use an excess, so as to leave some undecomposed carbonate after the operation has ended. The presence of a little sodium chloride or sulphate in the bicarbonate will not interfere in the least, but the absence of every trace of neutral carbonate is a sine quâ non.

(a) Wide-mouthed flask, containing the sample for examination, hermetically stopped by the cork (e) and supporting the tubes (b) and (c).

(b) Bulbous tube, containing fragments of fused chloride of calcium, terminating in a capillary tube (g).

(c) Bent tube, reaching nearly to the bottom of the flask (a).

(d) Small tube containing bicarbonate of soda.

(e) Cork fitting bottle (a), and the tubes (b) and (c), hermetically.

(f) Silken thread, suspending the small tube (d).

The two above methods of estimating the amount of acid are only superior to the generally used methods first described, when the presence of colouring matter interferes with the reaction of the litmus used to show the point of neutralisation.

Observations. When great accuracy is required in conducting the neutralisation of the solution in estimating volumetrically with litmus as an indicator, it is proper to prepare and keep standard solutions of sulphuric acid and oxalic acid, with which occasionally to try the alkaline test-liquor. The only difficulty in the process is to avoid over-saturation of the acid-sample. Great care must be taken not to exceed the precise point of neutralisation of the acid. After adding each portion of the test-liquor, the solution should be well stirred up, and as soon as the effervescence becomes languid the greatest caution must be observed in adding more. The proper point is arrived at when the liquor ceases to redden litmus, and does not alter the colour of turmeric paper; if it turns the latter brown, too much of the test-liquid has been added, and the operation becomes useless. Towards the end of the experiment, when great precision is required, a gentle heat may be applied, in order to expel the free carbonic acid in the liquor; but otherwise this is unnecessary. The peculiar soapy odour gradually acquired by the liquor as it nears saturation will materially assist the operator when testing vinegars, and some of the other vegetable acids. A good method is to tint either the acid-sample or the test-liquid with a few drops of litmus, as noticed under Acetimetry; when the reddish shade will gradually deepen into ‘purple,’ or the purple into ‘red,’ as the point of saturation is approached; and the blue colour will be perfectly restored as soon as this point is reached. Dr Ure recommends keeping the ammonia-test ready tinged with litmus, and the same applies to other test-liquors.

In commerce, the strength of acids is frequently reckoned with reference to a standard, termed 100 acidimetric degrees. This is taken from the circumstance that 91 gr. of commercial oil of vitriol, of a sp. gr. of 1·845, exactly saturate 100 gr. of dried carbonate of soda. An acid requiring only 35, 50, or any other number of grains of the carbonate to saturate it, is in like manner termed of so many degrees strong; the number of grains representing in each case an equal number of degrees. This method originated with the French chemists, and though only conventional, and principally confined to commercial purposes, is especially adapted to practical men but little conversant with chemistry, yet very ready in retaining or calculating anything on the centesimal scale, from its similarity to monetary language and reckoning.

ACID′ITY. Syn. Acid′itas, L.; Acidité, Fr.; Säure, Ger. In chemistry, the state of being acid. In physiology, &c., the impression given to the organs of taste by tart or acid substances. Sourness. See Fermentation, Malt-liquors, Wines, &c.

Gas′tric Acidity. Acidity of the stomach; a common and well-known symptom of weak or disordered digestion.

Treat., &c. Small doses of absorbents or antacids, three or four times daily, to which some tonic bitter, as calumba, cascarilla, chamomile, gentian, or orange-peel, may be added. Stomachic stimulants, as capsicum, ginger, mustard, or wine, &c., taken with, or after, meals, are also useful. The diet should be light and nutritious; and acescent vegetables, over-ripe fruit, and weak new beer or other liquors avoided as much as possible. The bowels should be kept regular, but not open, by the occasional use of mild aperients, as rhubarb, aloes, castor oil, senna, or mercurial pill, or compounds containing them. Excessive looseness or diarrhœa may be checked by a few doses of carbonate of soda, chalk-mixture, or astringents.

In INFANCY this affection is usually accompanied by restlessness, continual crying, drawing up of the legs forcibly towards the body, hiccups, vomiting, diarrhœa, sour eructations, griping pains, green stools, and debility; often followed, when the irritation is considerable, by convulsions. The treatment consists in relieving the bowels of all offending matter by a few doses of rhubarb-and-magnesia. The looseness or diarrhœa may be checked by a few small doses of carbonate of soda or chalk mixture; or better, in an infant which is fed by lime-water (1 or 2 fl. oz.) mixed with as much milk. Two or three drops of caraway, cinnamon, dill, or peppermint water, on sugar (not with the food) will tend to promote the expulsion, and prevent the undue generation of gases. The flatulence usually disappears with the acidity. The occasional administration of 1 to 3 gr. of quicksilver-with-chalk (‘grey powder’), will frequently remove the complaint, and prevent its recurrence, when all other means fail. The diet of both nurse and infant should be carefully regulated.

See Antacids, Dyspepsia, &c.

Treatment for Horses. Alkalies, their carbonates and bicarbonates; alterative doses of aloes with alkalies; chalk, carbonate of magnesia; mineral acids; bismuth, arsenic, nux vomica, or strychnia.

ACIDS, EFFECTS OF, ON VEGETATION. This subject has been ably investigated of recent years by Dr Angus Smith and Mr Rothwell, and the practical importance of their labours is shown by the circumstance that an Act of Parliament passed in 1875 renders it penal for the proprietors of alkali works to condense not less than 95 per cent. of the hydrochloric acid evolved in the process of manufacturing ‘soda,’ also to allow air, smoke, or chimney gases to escape into the atmosphere containing more than one fifth of a grain of hydrochloric acid per cubic foot. Every owner of an alkali work is likewise required to ‘use the best practical means of preventing the discharge into the atmosphere of all other noxious gases arising from such work, or of rendering such gases harmless when discharged.’

The injurious effects of acids on vegetation are indicated chiefly by the shrivelled-up appearance which the leaves of herbage, trees, &c., exhibit in the vicinity of chemical works in which the condensation of noxious gases (hydrochloric acid, sulphurous acid, sulphuric acid, sulphuretted hydrogen, nitric acid, and oxides of nitrogen and chlorine) is not effectually carried out. According to Mr Rothwell, ‘in fields exposed to acid vapours handfuls of dead grass may be pulled up in the spring, smelling strongly of the vapour, and that trees, under similar influences, become bark-bound.’

The following is a list of trees arranged in the order of their susceptibility. (Rothwell.)

Forest Trees. Larch, spruce fir, Scotch fir, black Italian poplar, Lombardy poplar, ash, oak, elm, birch, alder, sycamore.

Fruit Trees. Damson, greengage, Halewood plum, Jacob plum, pears, apples, cherries.

Shrubs, Evergreens, and Wild Plants. British laurels, Portugal laurels, Aucuba Japonica, Barberry evergreen, hazel, guelder rose, sloe thorn, hawthorn, raspberries, gooseberries, blackberries, gorse, hollies.

Farm Crops. Potatoes, mangel, white clover and rhubarb, red clover, trefoil, rye-grass, wheat, oats, barley, common turnips, swedes.

Second list of Plants affected by Noxious Vapours, mixing the classes according to the effects produced on each.

I. Fern—only in the summer.

Scotch firs, spruce, and larches—a little in winter.

Clover (white and red), trefoil, rye-grass, poplars, hawthorn, potatoes—receive damage in winter to roots.

II. Wheat receives some damage in winter.

Oats in May, when in the grass state, soon receive damage.

Barley, mangel, common turnips, rhubarb.

III. Laurels (British and Portugal), aucubas, yews, holly, gorse—receive damage in winter, but more in summer.

Old grass meadows and pastures receive much damage in winter.

IV. Ashes, oaks, hazels, horse-chestnuts, walnuts, Spanish chestnuts, sloe thorn.

V. Swedish turnip and cabbages, damson, other fruit trees, beech, elm, birch, alder, sycamores.

ACIDULÆ. [L. pl.] In medicine, mineral waters rich in carbonic acid.

ACIDULATED. Syn. Acidulatus, L.; Acidulé, Fr. Blended or flavoured with an acid; made slightly sour. See Kali (Acidulated), Drops, Lozenges, &c. In chemistry, the addition of an acid to a neutral or alkaline liquid until it reddens blue litmus paper.

ACIDUM. [L.] An acid.

ACNE. [Syn. Pimpled Face.] There are two forms of this affection. 1st. In young persons of both sexes; generally in phlegmatic habits. The disease shows itself by hard pimples, with a small black spot on the apex, unaccompanied with redness or inflammation at first, but after a while they become red and inflamed, and sometimes suppurate, with a greasy look of the skin between them. In this form of acne the black spots should be picked out with a needle or a small pair of tweezers. A long piece of thick matter, like a worm, is extracted; but is no worm. Afterwards wash the face with water in which a small piece of Quillar bark has been steeped, or with bitter almond emulsion, or borax, one drachm, water 4 oz. When there is no inflammation, use Eau de Cologne, or a few drops of oil of rosemary dissolved in spirit of wine, taking a small dose of magnesia in the morning, or milk of sulphur daily. When the pimples are very sluggish the cautious application of tincture of iodine, or of ointment of nitrate of mercury, will be found serviceable.

2nd. Arises from intemperance. In this case a gradual change of habits is essential. The use of soap should be avoided, and recourse had to warm fomentations of slippery elm, or thin oat gruel. The following should be applied to the pimples:—Cold cream, 1 oz., Goulard’s extract 20 drops, mixed together; or lemon juice diluted, or solution of borax in water. The internal administration of the mineral acids combined with bitter tonics, or small doses of iodide of potassium, will be found effectual.

Treatment. Fomentations, poultices, chloride of zinc solution externally; sulphur and alteratives internally.

ACOLOGY. Syn. In medicine, the doctrine of, or a discourse on, remedies or the materia medica.

ACONITE. (-nite). Syn. Acon′itum, L.; Aconit, Fr.: Akonitum, Eisenhut, Sturmhut, Ger. Monkshood; wolfsbane. In botany, a genus of exogenous plants. Nat. ord., Ranunculaceæ; Sex. syst., Polyandria Trigynia. They are characterised by showy purple or yellow helmet-shaped flowers growing in panicles, deeply cut leaves, and perennial (usually) tap-shaped or tapering roots. The whole plant is highly poisonous, the roots being more poisonous than the leaves. In medicine and materia medica, the plant Aconitum Napellus (which see).

Symptoms. Numbness and tingling in the mouth and throat, which are parched; followed by giddiness, dimness of sight, and (sometimes) delirium, but seldom complete coma; there is numbness and tingling of the limbs, a loss of power in the legs, (in some cases) frothing at the mouth, severe abdominal pains, nausea, vomiting, and diarrhœa; tremors or twitchings of the voluntary muscles, (sometimes) convulsions (in animals, but not in man); sharp cries; pupil (generally) dilated, very rarely contracted; pulse fitful and sinking; skin cold and livid; difficulty of breathing; general prostration; loss of sensation or feeling, insensibility, general trembling, fainting, and sudden death. The eyes are often glaring; and, in some cases, the patient is completely paralysed, yet retains consciousness to the last. The case generally proves fatal in from 1 to 8 hours. If it last beyond this period there is hope of recovery. (Fleming.)

Antidotes. Ammonia, or brandy, with artificial respiration if necessary: cold affusion and friction, with warm towels to the back and limbs. See Alkaloids.

ACONITE LEAVES (B. Ph.). Syn. Aconiti folia, L. The fresh leaves and flowering tops of aconitum napellus, Linn., gathered when about one third of the flowers are expanded, from plants cultivated in Britain.

Char. Leaves smooth, palmate, divided into five deeply cut wedge-shaped segments; excizing slowly, when chewed, a sensation of tingling. Flowers numerous, irregular, deep blue, in dense racemes.

Prep. Extractum aconiti.

ACONITE ROOT. (B. Ph.). Syn. Aconiti radix, L. The dried root of aconitum napellus. Imported from Germany, or cultivated in Britain, and collected in the winter or early spring before the leaves have appeared.

Prep. Aconitia, the active principle; Linimentum Aconiti, 1 ounce to 1 fluid ounce; Tinctura Aconiti, 54⁄2 grains to 1 fluid ounce.

Char. Usually from one to three inches long, not thicker than the finger at the crown, tapering, blackish-brown, internally whitish. A minute portion, cautiously chewed, causes prolonged tingling and numbness.

ACONITI FOLIA. See Aconite Leaves.

ACONITI RADIX. See Aconite Root.

ACONITIA. C30H47O7N. (B. P.) Syn. Aconitia, L. An alkaloid obtained from aconite.

Take of

Aconite root, in coarse powder, 14 pounds.

Rectified spirit of each a sufficiency.

Distilled water

Solution or ammonia

Pure ether

Diluted sulphuric acid

Pour upon the aconite root three gallons of the spirit, mix them well, and heat until ebullition commences; then cool and macerate for four days. Transfer the whole to a displacement apparatus, and percolate, adding more spirit, when requisite, until the root is exhausted. Distil off the greater part of the spirit from the tincture, and evaporate the remainder over a water bath until the whole of the alcohol has been dissipated. Mix the residual extract thoroughly with twice its weight of boiling distilled water, and when it has cooled to the temperature of the atmosphere, filter through paper. To the filtered liquid add solution of ammonia in slight excess, and heat them gently over a water bath. Separate the precipitate on a filter, and dry it. Reduce this to coarse powder, and macerate it in successive portions of the pure ether with frequent agitation. Decant the several products, mix and distil off the ether until the extract is dry. Dissolve the dry extract in warm distilled water acidulated with the sulphuric acid; and, when the solution is cold, precipitate it by the cautious addition of solution of ammonia diluted with four times its bulk of distilled water. Wash the precipitate on a filter with a small quantity of cold distilled water, and dry it by slight pressure between folds of filtering paper.

Characters and Tests. A white, usually amorphous, solid, soluble in 150 parts of cold, and 50 of hot water, and much more soluble in alcohol and in ether; strongly alkaline to reddened litmus, neutralising acids, and precipitated from them by the caustic alkalies, but not by carbonate of ammonia or the bicarbonates of soda or potash. It melts with heat, and burns with a smoky flame, leaving no residue when burned with free access of air. When rubbed on the skin it causes a tingling sensation, followed by prolonged numbness. It is a very active poison.

ACONITIA, CRYSTALLISED. C27H40NO10. Exhaust the root of wild aconite, carefully picked and powdered, with very strong alcohol, to which 1 per cent. of tartaric acid has been added. Distil at a gentle heat, and sheltered from the air, to recover the alcohol. Treat the extract with water to separate all the fatty and resinous matters. The solution which contains the aconite in the state of acid tartrate is first shaken with ether to remove colouring matters, and then the alkaloid is set free by the addition of alkaline bicarbonate, until the cessation of effervescence. A fresh treatment with ether of this alkaline solution removes the alkaloid, which crystallizes upon the concentration of the ethereal liquid, with an addition of petroleum spirit. The crystals are colourless tables, rhombic or hexagonal, according to the modifications produced principally in the acute angles. Crystallized aconitia is soluble in alcohol, ether, benzine, and chloroform; insoluble in petroleum oils and glycerine.

Aconitia Nitrate, Crystallised. Crystallised aconitine q. s.; nitric acid, sp. gr. 1·442, q. s. Saturate the nitric acid with the aconitine and evaporate. Voluminous crystals are easily obtained (from ‘Formulæ for New Medicaments adopted by the Paris Pharmaceutical Society’).—‘Pharm. Journal.’ Owing to the decomposition which this alkaloid undergoes in the animal organism, as well as to its liability to decompose during the process of evaporation, and exposure to the air, it often becomes extremely difficult, if not impossible, to obtain it in a separate state in conducting a post-mortem examination. The physiological effects seem to furnish the most prominent and characteristic evidence of its presence in such cases, or at any rate these may serve as a valuable guide to the toxicologist.

Uncrystallised aconitia is sometimes contaminated with delphinia, as well as with aconella, another constituent of aconite root. For the dissection of these see Alkaloids. One fiftieth of a grain of aconitia is stated to have killed a dog.

Antidotes. See Aconite.

ACONITIC ACID. (Identical with Pyrocitric Acid.) An acid extracted by Peschier from aconitum napellus, and by Bracconnot from equisetum fluviatile. It exists in these plants chiefly in the form of aconitate of calcium.

Properties. A white, colourless, semi-crystalline mass.

ACONITINA. See Aconitia.

ACONITINE. See Aconitia.

ACONI′TUM. [L.] Aconite. The pharmacopœial name of aconitum napellus(see below).

Aconitum Ferox. (Ind. P.) Habitat. Temperate and sub-Alpine Himalaya, at 10,000 to 14,000 feet elevation, from Gurhwal to Sikkim.

Officinal part. The dried root (Aconiti ferocis Radix), in common with those of other Himalayan species, viz., aconitum napellus, a. palmatum, and a. luridum, constitutes the drug well known in the bazaars of Upper India under the Hindostani name of Bish or Bikh.

It occurs in the form of tuberous roots of a more or less conical form, from two to three inches in length, and from half an inch to one inch in thickness at their upper end. They have usually a shrunken appearance, and are covered with a dark shrivelled bark; fracture shining and resinous; sometimes waxy, varying in colour from pale to deep brown. Some specimens are white and spongy; and these, it is asserted, are superior in activity to the more compact kinds. Inodorous; taste at first slightly bitter, leaving a peculiar sense of numbness on the tongue and fauces. Active principle, aconitia.

Medical Properties and Uses. Similar to those of aconitum napellus of Europe. Preparations. This root may be advantageously used for the manufacture of aconitia, the proportion of this alkaloid being much larger than in the European drug; and also for the preparation of Linimentum Aconiti. From its greater activity, however, it is unsuited for the preparation of this tincture, which is intended for external use.

Aconitum Hetorophyllum. (Ind. P.) Habitat. Western temperate Himalaya, at 8000 to 13,000 feet elevation; from Indus to Kumaon. Officinal part. The dried root (Aconiti heterophylli Radix). Ovoid tuberous roots, tapering downwards to a point, from one to one and a half inches or more in length, and from three eighths to half an inch in thickness. The surface, which is covered with a thin greyish epidermis, is slightly wrinkled longitudinally, and marked here and there with root scars. It is inodorous, and of a bitter taste, devoid of acridity. Does not contain aconitia. It may be readily distinguished from other roots sold in the bazaars under the same vernacular name (Atis) by its characteristic bitterness. Properties. Tonic and antiperiodic. It may be administered internally with safety, as it contains no poisonous principle. Therapeutic uses. In convalescence after debilitating diseases, and in intermittent and other paroxysmal fevers, it has been found an efficient remedy. Doses. Tonic, 5 to 10 grains thrice daily; antiperiodic, 20 to 30 grains of the powdered root every three or four hours, irrespective of the presence of pyrexia.

Aconitum Napell′us. [Linn.] Syn. Aconi′tum, Ph. L., E., & D.; Aconitnapèl, chaperon de moine, Fr.; Eisenhut, Blauersturmhut, Ger. Early blue wolfsbane, or deadly aconite. Hab. Various parts of Europe; grows wild in England, flowering in June and July. The fresh and dried leaves (ACONITI FO′′LIUM), Ph. L. & E. The root (ACONITI ra′dix), Ph. L. & D. This is the species of aconite ordered in the pharmacopœias, and commonly used in medicine. When chewed it imparts a sensation of acrimony, followed by a pungent heat of the lips, gums, palate, and fauces, which is succeeded by a general tremor and chilliness. The juice applied to a wound or the unsound skin affects the whole nervous system. Even by remaining long in the hand, or on the bosom, it produces unpleasant symptoms. Fatal cases of poisoning, by eating the root in mistake for horseradish, have been common of late years. The two roots may be, however, easily distinguished from one another; when scraped aconite emits an earthy, and horseradish its well-known pungent odour. Moreover, the shape of the roots is very different. In the accompanying figure a represents aconite root, and b horseradish root.

The leaves should be gathered as soon as the flowers appear. The root should be taken up in autumn. When the whole plant is employed, it should be gathered as soon as the flowers begin to open. The strength (richness in aconitia) varies considerably with the time of the year. 1 oz. of the fresh root contains ⁄4 to ⁄4 gr. of aconitia; 1 lb. of the dried English root contains from 12 to 36 gr. (Herapath). The leaves possess the greatest activity just before flowering; the root, after it. The root is at all times fully six times as strong as the leaves or herb. The wild plant contains much more aconitia than that which is cultivated. The herb, and all its preparations, lose their efficacy if long kept. The powder, more particularly, cannot be relied on. Mr Holmes says it is difficult to find in a commercial sample of aconite root one root in a dozen, which upon fracture appears sound and in good condition.

Properties, Antidotes, &c. See Aconite.

Tests, &c. See Aconite.

Uses, &c. In small doses aconite is narcotic, powerfully diaphoretic, and sometimes diuretic; in larger ones, the symptoms are similar to those produced by aconitia. It acts as a powerful sedative on the heart’s action, and destroys sensibility without disturbing the mental faculties. It has been given in chronic rheumatism, gout, paralysis, scirrhus, scrofula, cancers, venereal nodes, epilepsy, amaurosis, intermittents, &c.; but its exhibition requires the greatest possible caution. As a topical benumber it has been used with great advantage in painful affections depending on increased sensibility of the nerves. Externally it “is most valuable for the cure of neuralgic and rheumatic pains. In neuralgia, no remedy, I believe, will be found equal to it. One application of the tincture produces some amelioration; and after a few times’ use, it frequently happens that the patient is cured. In some cases, the benefit appears almost magical. In others, however, it entirely fails to give permanent relief.” “I do not think that in any (case) it proves injurious.” “When it succeeds, it gives more or less relief at the first application. When the disease depends on inflammation, aconite will be found, I think, an unavailing remedy.” “In rheumatic pains, unaccompanied with local swelling or redness, aconite is frequently of very great service.” (Pereira, iii, 691.) Dose, of the powder, 1 to 2 gr., gradually increased to 6 or 8. Dr Stocrk was the first who gave wolfsbane internally, about the year 1762. It has since been successfully employed in Germany in cases of chronic rheumatism, gout, &c., some of which were of long standing and had resisted every other remedy. In England it has been less extensively used.

Aconitum Panicula′tum. Panicled wolfsbane; a species formerly ordered in the Ph. L.; and, with a. napellus, also in the Ph. U. S. It is less active than the officinal species.

A′CORN. Syn. Glans. quer′cus, L. The seed or fruit of the oak. In the early ages of the world, acorns probably formed one of the principal articles of the food of man. (Ovid, Met., i, 106; Virgil, Georg., i, 8; &c.) In modern times, during periods of scarcity, they have been consumed as food on the Continent. Besides starch, they contain a peculiar species of sugar, which crystallises in prisms, and is unfermentable; they also contain tannic and gallic acids. Mannite and dulcose are the substances which it most nearly resembles. (M. Dessaignes.) During the autumn, acorns are said to be sometimes poisonous to cattle and sheep. Supposed cases of so-called acorn poisoning are best treated by withdrawing the supply of acorns, or removing the animals from the pastures on which the acorns fall, and by the administration of aperients, alkalies, and stimulants.

AC′ORUS CAL′AMUS. See Sweet Flag.

ACOTYLE′DONS (-ko-te-lē′-). Syn. Acotyle′dones (dŏn-ēz; L., prim. Gr.), Jussieu; Acotylédons, Fr.; Ohne samenlappen, Ger. In botany, plants whose seeds are not furnished with distinct cotyledons or seed-lobes. Acotyledonous plants form one of the two great divisions of the vegetable kingdom, according to the natural system. They are remarkable by increasing chiefly in length, by additions to their end; and not by addition to the outside, as in Exogens; nor to the inside, as in Endogens. They are also termed Asex′ual and Flowerless Plants, and answer to the Cryptogamia of the Linnean system. See Acrogens, Cellulares, Thallogens, &c.

ACOUS′TICS (-kow′-). The science of audition and sound; that branch of physics which treats of their cause, nature, and phenomena. The doctrine of the production and transmission of sound is termed Diacous′tics; that of reflected sound Catacous′tics.

Acoustics. In medicine, remedies employed to relieve deafness. See Deafness and Drops, Acoustic.

ACQUETTA. [It., Little Water.] Syn. Aqua Toffana; A. Toffania; Acquetta di napoli della Toffana, It. A celebrated poison, prepared by an Italian woman named Toffano, or Tophana, and in great request in Rome about the middle of the 17th century. The composition of this poison has been a matter of frequent controversy. Pope Alexander VII, in his proclamation, described it as “aquafortis distilled into arsenic.” This would produce a concentrated solution of arsenic acid. The Emperor Charles VI, who was governor of Naples during Toffano’s trial, declared to his physician, Garelli, that it was arsenic (arsenious acid) dissolved in aqua cymbalariá. According to Gerarde this cymbalarià was an aquatic species of pennywort, highly poisonous. The only objection to the latter statement is the smallness of the dose, regard being had to the comparative insolubility of arsenious acid; but if the woman Toffano prepared two poisons, as is probable from history—one, a single dose of which was fatal, and another, of which the dose required repetition, and which was more gradual in its activity—the discrepancy will be at once removed.

AC′RID. Syn. Ac′er, Ac′ris, L.; Acre (âcre), Fr.; Beissend, Scharf, Ger. In chemistry and medicine, sharp, pungent, acrimonious. Acrid substances are such as excite a sensation of pungency and heat when tasted, and which irritate and inflame the skin; as mustard, turpentine, cantharides, &c.

ACRIDITY. Syn. AcretÉ, Fr.; Acritudo, L. The quality of being acrid.

AC′RIMONY. Syn. Acrimo′nia, L.; Acrimonié, Acreté, Fr.; Scharfe, Ger. In medicine and chemistry, the quality or property of inflaming, irritating, corroding, dissolving, or destroying other bodies.

ACROGENS. Syn. Acrogenæ, L.; Acrogènes, Fr. In botany, acotyledonous or cryptogamic plants, in which stems and leaves, or an organisation approaching leaves, are distinguishable; which have stomates or breathing spores on their surface, are propagated by spores, and increase by the growth of the stem at the point only. Ferns and club-mosses are examples of this class of plants.

ACROLEIN. Syn. Acrylic Alcohol. This substance occurs amongst the products of decomposition when glycerine or any of its compounds is subjected to ordinary distillation. It derives its name from its violently irritant effect upon the mucous membranes of the eyes and respiratory organs. It is best prepared by the process of Redtenbacher (see ‘Leibig’s Ann.,’ xlvii, 114), by distilling in a capacious retort, a mixture of glycerine with phosphoric anhydride, or with hydric-potassic sulphate (the acid sulphate or bisulphate of potash); the vapours must be condensed in a properly cooled receiver, which is luted on to the retort and provided with a tube opening into a chimney having a good draught. The distilled liquid separates into two layers, the upper one consisting of acrolein, and the lower one of an aqueous solution of the same substance mixed with a quantity of acrylic acid. This distillate, after digestion with finely powdered litharge, with the object of neutralising the acid, must be rectified by the heat of a water bath: the acrolein so obtained must be submitted to a second rectification from calcic chloride. All these operations must be conducted in vessels filled with carbonic anhydride (carbonic acid) because acrolein becomes rapidly oxidized when exposed to the air.

Acrolein is a clear colourless liquid, lighter than water, boiling at about 125° F. It has great refracting power and a burning taste; when pure it is neutral to test paper.

AC′ROSPIRE (-spire). Syn. Acrospi′ra, L.; Plumule, Fr.; Blattkeim, Ger. The shoot or sprout of a seed, when it begins to grow; the part of a germinating seed termed the plume, or plumula.

When the growth of a seed begins to be developed, the germ, from which the stem originates, shoots forth under the form of a delicate curved fibre, which, gradually bursting its covering, makes its appearance at the end of the seed. The fibrils of the radicle first sprout forth from the tip of the grain; a white elevation appears, that soon divides into three or more radicles, which rapidly grow larger, and are succeeded by the plumula, which peeps forth at the same point, in the form of a pale green leaflet, which, twisting thence beneath the husk to the other end of the seed, ultimately bursts its prison-house, and becomes a perfect leaf. See Germination and Malting.

ACTINIC RAYS. See Actinism.

ACTINISM. Syn. Actinic Rays; Chemical Rays. A term given to a supposed principle accompanying the heat and light of the sunbeam. Actinic rays chiefly exist beyond the violet extremity of the solar spectrum, and are characterised by the power of exciting chemical change, e.g., the decomposition of certain silver salts (in photography); the combination of a mixture of chlorine and hydrogen, &c. The so-called vital functions of animals and plants are also greatly influenced by the actinic or chemical rays.

ACTINOGRAPH. An instrument for registering the intensity of the chemical influence (actinism) of the sun’s rays.

ACT, TOWNS IMPROVEMENT CLAUSES, 1847 (10 & 11 Vict., c. 34), The following provisions of this Act are incorporated in the Public Health Act, 1875, and refer exclusively to urban districts:—

1. With respect to naming the streets and numbering the houses.

2. With respect to improving the line of the streets and removing the obstructions.

3. With respect to ruinous or dangerous buildings.

4. With respect to precautions during the construction and repair of sewers, streets, and houses.

5. With respect to the regulation of slaughter houses.

Notices for alterations under the 69th, 70th, and 71st sections, directions under the 73rd section, and orders under the 74th section of the said Towns Improvement Clauses Act, may, at the option of the urban authority, be served on owners instead of occupiers, or on owners as well as occupiers, and the cost of works done under any of these sections may, when notices have been so served on owners, be recovered from owners instead of occupiers; and when such cost is recovered from occupiers, so much thereof may be deducted from the rent of the premises where the work is done as is allowed in the case of private rates under the Act.

AC′TUAL. Real, effectual, absolute; as opposed to that which is merely virtual or potential. In surgery, a red-hot iron, or any other heated body, used as a cautery, is termed the ACTUAL CAUTERY; whilst a caustic or escharotic so employed is called the POTENTIAL CAUTERY.

ACTUAL CAUTERY. See Actual.

ACUTE′. Syn. Acut′us, L.; Aigu, Fr.; Heftig, Hitzig, Spitzig, Ger. Sharp, pointed, sensitive. Applied to the senses, as acute hearing, eyesight, &c. In pathology, diseases exhibiting violent symptoms, and whose course is short, are said to be acute diseases.

ADAPTER. In chemistry, a tube placed between two vessels (commonly a retort and receiver) for the purpose of uniting them or increasing the distance between them, so as to facilitate the condensation of vapour in distillation. (See figure.)

ADDER’S TONGUE. Syn. Common adder’s tongue; Ophioglos′sum vulga′tum, Linn. A perennial plant, of the natural order Filices (DC.), growing wild in England. It is found in our woods and pastures, and flowers in May and June. It was once used to form a celebrated traumatic or vulnerary ointment and is still highly esteemed among rustic herbalists.

ADEPS. Syn. Lard. See Adeps præparatus, Fat, and Lard.

ADEPS BENZOATUS. Syn. Benzoated Lard.

ADEPS PRÆPARATUS. Syn. Axunge; Prepared Lard.

ADHE′SION (-hē-zhün). Syn. Adhæ′sio, L.; Adhesion, Fr.; Anhängung, Arxlebung, Ger. The act or state of sticking or being united.

Adhesion. In physics, the force with which bodies remain attached to each other when brought into contact; e.g., ink adheres to paper, paint adheres to wood, &c. It differs from ‘cohesion’ in representing the force with which different bodies cling together; whereas cohesion is the force which unites the particles of a homogeneous body with each other, e.g., particles of iron cohere and form a mass of iron; particles of water cohere and form a mass of water, &c.

Adhesion. In pathology, the morbid union, from inflammation, of parts normally contiguous but not adherent.

Adhesion. In surgery, the reunion of divided parts, by the adhesive inflammation; as when incised wounds heal by what is termed the ‘first intention.’

ADHE′SIVE. Syn. Adhæsi′vus, L.; Adhésif, Fr.; Adhäsive, Verwachsend, Ger. In pharmacy, &c., having the quality or property of sticking or adhering. Hence adhe′siveness.

AD′IPOCERE (-sēre). Syn. Grave-wax‡; Adipoce′′ra, L.; Adipocire, Fr.; Fetewachs, Ger. A substance resembling a mixture of fat and wax, resulting from the decomposition of the flesh of animals in moist situations, or under water. It is chiefly margarate of ammonium. Lavoisier proposed to produce this substance artificially, for the purposes of the arts. Attempts have since been made to convert the dead bodies of cattle (carrion) into adipocere, for the purposes of the candle-maker and the soap-boiler, but without success. Besides, dead animal matter can be worked up more profitably than in making artificial adipocere.

Hatchettine or rock-fat is sometimes called ‘adipocere’; and bog-butter is a substance nearly similar to it.

AD′JECTIVE. Syn. Adjecti′vus, L.; Adjectif, Fr. In dyeing, depending on another, or on something else; applied to those colours which require a base or mordant to render them permanent. See Dyeing.

AD′JUVANT. [Eng., Fr.] Syn. Ad′juvans, L.; Aidant, &c., Fr. Assistant; helping. (As a substantive—) In prescriptions, see Prescribing (Art of).

ADULTERATION. Strictly speaking, this term ought only to be applied to the practice of adding substances to articles of commerce, food or drink, for the purposes of deception or gain, but a wider interpretation is frequently placed on the word than the definition given by magistrates and analysts, these latter often regarding accidental impurity, or even, in some instances, actual substitution as acts of adulteration.

The following definition of an adulterated substance has been adopted by the Society of Public Analysts—

A substance shall be deemed to be adulterated—

A. In the ease of food or drink:

1. If it contain any ingredient which may render such article injurious to the health of a consumer.

2. If it contain any substance that sensibly increases its weight, bulk, or strength, or gives it a fictitious value, unless the amount of such substance present be due to circumstances necessarily appertaining to its collection or manufacture, or be necessary for its preservation, or unless the presence thereof be acknowledged at the time of sale.

3. If any important constituent has been wholly or in part abstracted or omitted, unless acknowledgment of such abstraction or omission be made at the time of sale.

4. If it be an imitation of or sold under the name of another article.

B. In the case of drugs:

1. If when retailed for medical purposes under a name recognised in the ‘British Pharmacopœia’ it be not equal in strength and purity to the standard laid down in that work.

2. If when sold under a name not recognised in the ‘British Pharmacopœia’ it differs materially from the standard laid down in approved works on materia medica, or the professed standard under which it is sold.

Limits. The following shall be deemed limits for the respective articles referred to:

Milk shall contain not less than 9·0 per cent., by weight, of milk solids, not fat, and not less than 2·5 per cent. of butter fat.

Skim Milk shall contain not less than 9·0 per cent. by weight, of milk solids not butter fat.

Butter shall contain not less than 80 per cent. of butter fat.

Tea shall not contain more than 8·0 per cent. of mineral matter, calculated on the tea dried at 100° C., of which at least 3·0 per cent. shall be soluble in water, and the tea as sold shall yield at least 30 per cent. of extract.

Cocoa shall contain at least 20 per cent. of cocoa fat.

Vinegar shall contain not less than 3 per cent. of acetic acid.

The practice of fraudulent adulteration has been indulged in for centuries. In every civilised state there have been enactments against it. The Romans had their inspectors of meat and corn. In England an Act to prohibit adulteration was passed as early as 1267, and penalties against it were in force in 1581, 1604, 1836, 1851. In 1822, Accum published a work having the sensational title of ‘Death in the Pot,’ and in 1855 appeared Dr Hassall’s book, ‘Food and its Adulterations.’ The information conveyed in these works, added to the revelations of the ‘Lancet’ Sanitary Commission, and the contributions to scientific literature on the subject of food by Letheby, Pavy, Parkes, Blyth, and others, together with the published evidence given before the House of Commons Commission appointed to carry out an inquiry into the subject, roused public attention to such a degree as to lead to the passing by the legislature of the Adulteration Acts.

The sophistications may be divided into several distinct classes:

1. To give weight or volume, such as water added to butter, plaster of paris to flour, &c.; red earths to annatto, sand to tea-leaves, &c.; water to milk, &c.; all these, therefore, are substitutions of worthless or very cheap articles which take the place of the real.

2. To give a colour which either makes the article more pleasing to the eye, or else disguises an inferior one, e.g., Prussian blue, black lead, &c., to green teas; annatto to cheese, &c.; arsenite of copper to sweetmeats, &c.

3. Substitutions of a cheaper form of the article, or the same substance from which the strength has been extracted put in the place of the real, e.g., tea mixed with spent leaves, &c.

4. A very small class where the adulteration is really added with no fraudulent intent, but to enhance the quality of the goods sold—alum to bread in small quantities.

The following, according to Blyth (‘Dic. of Hygiène’), is a list of articles most commonly adulterated, with the names of the substances used in their sophistication:—

Aconitia with other alkaloids, e.g., delphinia, aconella, &c.

Ale, common salt, Cocculus indicus, grains of paradise, quassia, and other bitters, sulphate of iron, alum, &c.

Allspice, mustard husks.

Anchovies, other fish, and colouring matters, e.g., Armenian bole, Venetian red, &c.

Annatto, all sorts of starch, soap, red ferruginous earths, carbonate and sulphate of lime, salts, &c.

Arrowroot, various other fecula, such as sago, tapioca, potato, and others.

Balsam of Copaiba, turpentine and fixed oils.

Beef (Potted), Armenian bole.

Bismuth, carbonate of lead, sometimes arsenic (this latter is an impurity not intentional).

Bloaters (Potted), Armenian bole.

Brandy, water, burnt sugar, &c.

Bread, potatoes (mashed), alum, inferior flour, &c., &c.

Butter, water, salt, colouring matter, lard, tallow, and other fats.

Cajuput Oil, copper, camphor dissolved in oil of rosemary, and coloured with copper as a substitute.

Calamine, coloured sulphate of baryta.

Calomel, sulphate of baryta, chalk, white precipitate, white lead, pipe-clay, &c., &c.

Calumba, tinged bryony root, root of Frasera Walteri, and others.

Camboge, starch, &c.

Camphor, a substitution of Borneo camphor has been made.

Cantharides, golden beetle, artificially coloured glass, &c.

Carbonate of Lead, sulphate of baryta, sulphate of lead, chalk, &c., &c.

Carmine (Cochineal), sulphate of baryta, bone black, &c.

Cassia (Senna), leaves of Solenostemma argel, and other foreign leaves.

Castor Oil, other oils, often small quantities of croton oil.

Cayenne, ground rice, vermilion, Venetian red, turmeric.

Champagne, gooseberry and other wines as substitutes, different colouring matters, &c.

Cheese, annatto, bole (Armenian), and other colouring matters.

Chicory, colouring matters, such as ferruginous earths, and burnt sugar, Venetian red, &c., and different flours, such as wheat, rye, beans, &c., and sometimes sawdust.

Cider, lead (as an impurity, not intentional).

Cigars, substitutions of hay and other rubbish, inferior tobacco, leaves sometimes darkened by some brown vegetable dye.

Cinnamon, cassia, clove stalks, and different flowers.

Claret, brandy, and substitution of inferior wines.

Cloves, clove stalks.

Cocoa and Chocolate, cheaper kinds of arrow-root, such as Tous les mois and East Indian, animal matter, corn, sago, tapioca, &c.

Coffee, chicory, roasted wheat, rye flowers, and colouring matters, such as burnt sugar, &c.

Cod-liver Oil, other oils mixed with it.

Colocynth (Compound Extract of), the extract is not unfrequently made with the pulp and seeds.

Confectionery, injurious colouring matters, such as arsenite of copper, chromate of lead, &c.

Confection, Aromatic (Aromatic Chalk Powder), expensive ingredients omitted, turmeric substituted for saffron, &c., &c.

Copal, gum dammar, resin, &c.

Curry-powder, red lead, ground rice, salt.

Cusparia Bark, the bark of Strychnos Nux Vomica is said to have been substituted.

Custard and Egg Powder, turmeric, chrome yellow, and different flours.

Elaterium, starch, flour, chalk, &c.

Epsom Salts, chloride magnesium, chalk, &c.

Ether, alcohol.

Flour, other and inferior flours, as the flour from rice, bean, Indian corn, potato, &c., sulphate of lime, alum.

Gelatine, salt and sugar.

Gin, water, sugar, capsicum, flavouring matters of different kinds, turpentine, alum, tartar.

Ginger, turmeric, and husks of mustard, flour from wheat, sago, &c.

Guaiacum Resin, other resins.

Honey, flour, cane sugar, &c.

Hops, Cocculus indicus, grains of paradise, &c., &c.

Iodide of Potassium, water, carbonate of potash, chlorides of soda and potash, iodate of potash, iodine, &c.

Iodine, water, plumbago, charcoal, black oxide of manganese, &c.

Ipecaquanha, other roots, extraneous woody fibre; when in powder, chalk, flour, &c., have been added.

Isinglass, gelatine.

Jalap, raspings of guaiacum, false jalap root, &c.

Lard, carbonate of soda, salt, potato, flour, and lime.

Lemon Juice, a mixture of sugar and water, acidulated with sulphuric acid, has been substituted.

Liquorice, rice, chalk, gelatine, and different flours.

Magnesia, Magnesia Sulphate, lime, carbonate of magnesia.

Magnesia, Carbonate, lime, sulphate, &c., &c.

Marmalade, apple, or turnip pulp.

Mercury, lead, tin, zinc, bismuth, &c.

Mercury Green Iodide of, red iodide of

Mercury Red Oxide of, brick-dust, red lead, &c.

Mercury Ammoniated (WHITE PRECIPITATE), chalk, carbonate of lead, plaster of Paris, &c., &c.

Milk, water.

Mustard, turmeric, wheat flour.

Myrrh, gum bdellium, and other gum resins.

Oatmeal, barley flour, rubble.

Opium, stones, sand, clay, vegetable extracts, sugar, treacle, water, &c.

Pareira Root, different roots substituted.

Pepper, linseed meal, different flours, mustard husks, &c.

Pickles, salts of copper, acetate of copper.

Porter and Stout, sugar, treacle, water and salt.

Potash, carbonate, sulphate, and chloride of potash, lime, iron, and alumina.

Potash, Acetate of, sulphates, and chlorides of potash.

Potash, Carbonate of, sulphates, and chlorides of potash.

Potash, Bicarbonate of, carbonate of potash.

Potash, Citrate of, sulphates of potash.

Potash, Chlorate of, chloride of potassium.

Potash, Tartrate of, tartrate of lime.

Potash, Nitrate of, sulphate or chloride of potassium.

Preserves, salts of copper.

Quinine, sulphate of lime, chalk, magnesia, cane-sugar, sulphate of cinchonine, &c.

Rhubarb, turmeric, and inferior varieties substituted for Turkey.

Rum, water, cayenne, burnt sugar.

Sago, potato flour.

Sauce, treacle, salt, cochineal, Armenian bole, and other colouring matters.

Scammony, chalk, starch, guaiacum, jalap, dextrin, &c.

Senega, guiseng, gillenia.

Senna, leaves of cynanchum argel.

Sherry, sulphates of potash, soda, brandy, burnt sugar, &c.

Snuff, carbonate of ammonia, glass, sand, colouring matter, &c.

Soda, Bicarbonate, carbonate and sulphate of soda.

Soda, Carbonate, sulphate of soda.

Soda, Phosphate of, phosphate of lime.

Spices, colouring materials, substitutions, and different flours.

Squills (Powdered), wheat flour.

Sugar (Moist), sand, flour, &c.

Sulphur, sulphurous acid (as an impurity).

Sulphuric Acid, lead, water, arsenic, hydrochloric acid, &c.

Tapioca, mixing inferior starches with the pure tapioca.

Tea, sand, iron filings, exhausted tea leaves, foreign leaves; and in green teas, black lead, Prussian blue, China clay.

Tobacco, inferior tobacco, water.

Turmeric, yellow ochre, carbonate of soda, or potash.

Uva Ursi (Bearberry Leaves), leaves of red whortleberry, and others.

Vinegar, sulphuric acid, and metallic impurities.

Wines, water, jerupiga, bitartrate of potash, substitution of inferior wines, brandy, spirits, and various other matters.

Zinc, Oxide of, chalk, carbonate of magnesia.

“The Sale of Food and Drugs Act” has now supplemented several Acts which were passed during the present century for the prevention of adulteration. An Act prohibiting the mixture of injurious ingredients with intoxicating liquors remains unrepealed, as do also one or two statutes relating to trade frauds as for example the Adulteration of Seeds Act, 1809. These latter have not been incorporated in “the Sale of Food and Drugs” Act.

Æ (ē). [L.] For words sometimes written with this initial diphthong, and not found below, look under E.

ÆGI′RINON (-jī′-). [Gr.] See Ointment.

ÆGYPTI′ACUM† (-jĭp-tī′-). [Lat.] Syn. Unguen′tum Ægyptiacum, L. Oxymel or liniment of verdigris. The name originated with Hippocrates, who is said to have learned its composition in Egypt.

ÆOL′IPILE (-pĭle). A hollow ball of metal, having a slender neck with a very small orifice, contrived to exhibit the conversion of water into steam by the action of heat, and to account for the natural production of winds. It was known to the ancients, is mentioned by Vitruvius, and was studied by Descartes and others. It has been used in surgery to produce eschars, in the same cases as moxas; the effect of the steam being limited by means of a piece of perforated pasteboard. When filled with alcohol, and the jet of vapour inflamed, it is sometimes employed as a blowpipe. M. Soyer used an apparatus of this kind to supply the heat in his portable furnace. The liquid, however, which he employed was camphine.

A′ER, (ā′-ĕr). [L. prim. Gr.] Air.

A′ERATED (ā′-ĕr-rāte-ĕd). In chemistry, &c., impregnated with carbonic acid. See Alkali, Lemonade, Waters, Mineral.

AE′′RIAL (ā-ēre′-e-ăl). Belonging to the air or atmosphere; produced by, consisting of, depending on, or partaking of the nature of the air.

AERIFICA′TION (ā-ĕr-e-). Syn. Aërifica′tio, L.; Aérification, Gazéification, Fr. In chemistry, the conversion of a body into gas.

A′ERIFORM (ā′-ĕr-). Syn. Aëriform′is, L.; Aériforme, Gazéiforme, Fr. Luftformig, &c., Ger. In chemistry, air-like, gaseous.

AEROL′OGY. Syn. Aërolo′gia, L.; Aérologie, Fr., Ger. In physics, a discourse or treatise of the air. In physiology and hygiène, the doctrine of the air, more especially with regard to its salubrity and action on organised beings.

AEROM′ETER. Syn. Aërome′trum, L.; Aéromètre, Fr. An instrument used in aërometry.

AEROM′ETRY. Syn. Aërome′tria, L.; Aérométrie, Fr.; Luftmesskunst, &c., Ger. In chemistry and physics, the art of measuring gases, and of determining their densities.

AERONAUT′ICS. Syn. Aéronautique, Fr. The art of sailing in, or of navigating the air. See Balloons.

AEROPHO′BIA. [L.] Syn. Aérophobie, Fr. In pathology, a dread of air (wind); a common symptom in hydrophobia, and occasionally present in hysteria and phrenitis.

AEROSTAT′ICS. Syn. Aérostat′ica, L.; Aérostatique, Fr. That branch of pneumatics which treats of air, and other elastic fluids, in a state of rest.

AEROSTA′TION. [Eng., Fr.] Syn. Aërosta′tio, L. The art of weighing the air; aërial suspension and navigation. See Balloons.

ÆRU′GO (ē-). [L.] The rust of brass, bronze, or copper; verdigris.

ÆSCULIN. C21H24O13. A crystalline fluorescent substance existing in the bark of the horse-chestnut (æsculus hippocastanum) and of other trees of the genera Æsculus and Paria. In the above-named sources Æsculin is associated with another fluorescent body called Pariin.

Æ′′THER. See Ether.

ÆITHE′′REA (-thēré-). [L. pl.] Ethers.

ÆSTHET′ICS (ēz-). Syn. Æsthet′ica, L. Medicines or agents which affect sensation. See Anæsthetics and Hyperæsthetics.

ÆTHIOPS. See Ethiops.

AFFEC′TION. [Eng., Fr.] Syn. Affec′tio, L. In pathology, a term nearly synonymous with disease.

AFFINITY. Syn. Chemical affinity; Affinitas, L.; Affinité, Fr.; Verwandtschaft, Ger. If oil and water be shaken together they produce no change upon one another, as is proved by their separating into two layers with their properties unaltered, when the mixture is allowed to remain at rest for a short time. Such bodies are said, in chemical language, to have no affinity for one another. If iodine and metallic mercury be rubbed together in a mortar they will unite in definite proportions by weight, and form a combination possessing properties totally distinct from those of its constituents. Thus, iodine is a greyish, metallic-looking solid, convertible into a violet vapour by heat, perceptibly soluble in water, and capable of producing a blue compound with starch. Mercury is a metallic, silvery-looking liquid. The product of their union (biniodide of mercury) is a scarlet powder, destitute of metallic lustre, convertible into vapour by heat, without the production of violet fumes, insoluble in water, and incapable of developing a blue colour with starch. Again, the greenish-yellow and intensely poisonous gas, chlorine, unites in definite proportions by weight with the soft, wax-like, and highly poisonous metal sodium to produce the white crystalline solid chloride of sodium (common salt), a compound which, except in very large quantities, is not only not poisonous, but actually beneficial to health.

Such combinations are called chemical compounds, and the force which binds their constituents together is distinguished from all other attractive forces by the term affinity or chemical affinity. Bodies united by affinity are also said to have united chemically.

Affinity is in most cases exerted between different substances, in which respect it resembles adhesion; but bodies united by adhesion, e.g. ink to paper, paint to wood, &c., unlike those united by affinity, suffer no change of properties.

Affinity is exerted at immeasurable distances, therefore substances to be submitted to its influence must be brought into (apparently) actual contact. This condition is frequently fulfilled by the vaporisation, fusion, or solution of one or more of the bodies to be submitted to its action.

In many instances substances which have no affinity for one another at ordinary temperatures manifest this power when heated.

Whenever chemical union takes place, heat is invariably evolved; conversely, the decomposition of a chemical compound is always accompanied by an apparent loss of heat or reduction of temperature.

Finally, the most striking phenomena characteristic of, and accompanying, chemical affinity are, development of heat, change of properties, and union in definite or constant proportions by weight.

AFFUSION. In chemistry, the washing of a precipitate, &c., for the purpose of removing soluble matters. In medicine, affusion is of three kinds:—

1. Lotions, which consist in washing a part of the body with a sponge or rag soaked in a liquid.

2. Aspersions, which consist in throwing a liquid drop by drop, like rain, upon the body.

3. Shower baths, which consist in allowing a number of small streams of water to fall from a height upon the surface of the body. If the water fall from a considerable height, affusion is then termed douche by the French.

AFT′ER-DAMP. Syn. Choke-damp. Carbonic acid gas resulting from explosion of air and fire-damp (light carbonetted hydrogen) in coal mines.

AFT′ER-PAINS. Those following childbirth. The only remedy is patience; they may, however, be frequently alleviated by small doses of morphia or liquor opii sedativus. Heated cloths and warm fomentations are sometimes useful, particularly if assisted by moderate but sufficient pressure on the abdomen, by means of a broad bandage. They seldom follow with severity the first birth.

Treatment for Animals. Remove clots from parts, raise the hind-quarters. Give clysters of linseed tea, lukewarm, and laudanum or belladonna extract. Syringe out parts with Condy’s fluid considerably diluted. Give internally belladonna, opium, or chloroform. Draw away milk.

AFT′ER-WASH (wŏsh). In the art of the distiller, the liquor in the still after the spirit has been drawn over.

AG′ARIC. [Eng., Fr.] Syn. Agar′icum, Agar′icus, L.; Blätterschwamm, Pilz, Schwamm, Ger. In botany, a genus of fungi, of numerous species, embracing the mushrooms and champignons. Of these plants, some are edible; others poisonous. The term is also commonly applied to the boletus found on oaks (TOUCHWOOD), and on larches (MALE AGARIC). See Mushrooms.

Fly-agaric. Syn. Fly mush′room; Agar′icus musca′′ria, Linn.; Amani′ta m. One of the most narcotic and poisonous of our fungi, producing, in small doses, intoxication and a pleasing species of delirium; for which purpose it is commonly employed in Kamschatka. (Hooker.) It possesses the singular property of imparting an intoxicating quality to the urine, which continues for a long time after taking it. This secretion is, therefore, commonly saved by the natives during a scarcity of the fungus. “Thus, with a few amanitæ, a party of drunkards may keep up their debauch for a week;” and the intoxication so produced is capable of “being propagated through five or six individuals.” (Langsdorff.) Water in which it has been boiled is poisonous; but the boiled fungus itself is inert. The liquid from it is used as a fly-poison; whence the name mushroom is derived. It may be known by its rich orange-red colour in autumn.

AG′ATE (-āte, -ĕt‡). [Eng., Fr.] Syn. Acha′tes (-kā′-tēz), L. A semi-pellucid uncrystallised species of quartz, remarkable for its hardness, variety of colour, and susceptibility of receiving a high polish. It is an aggregate of various siliceous minerals, of which chalcedony appears generally to be the base. Carnelian, jasper, amethyst, and other similar minerals, often enter into its composition. The colours are often delicately arranged in stripes, bands, or clouds. Those which take an angular form, as the Scotch pebble, are called FORTIFICATION AGATES. It is the least valuable of the precious stones, and is chiefly made into rings, seals, beads, burnishers, &c., on account of its hardness. Its powder is used for cleansing and polishing iron, brass, &c., and to sharpen edge-tools.

AGEING LIQUOR. Dissolve 3 lbs. of chlorate of potash in 4 galls. of boiling water. Add 20 lbs. of powdered white arsenic to 20 lbs. of solution of caustic soda at 60° Tw., and boil until the arsenic is completely dissolved. Add the latter solution to the former, with stirring, until the mixture stands at 28° Tw.

AG′NAIL. See Whitlow.

AGRYPNOT′ICS (-grĭp-). Syn. Anthypnot′ics (-hĭp-); Agrypnot′ica, Anthypnot′ica, L. In medicine and pharmacology, agents or substances which prevent sleep; as tea, coffee, digitalis, vinegar, &c.

A′GUE (-gŭ). Ague may be defined as febrile phenomena occurring in paroxysms, and observing a certain regular succession, characterised by chill, abnormal heat, and unnatural cutaneous discharge, which prove to be a temporary crisis and usher in a remission. These phenomena are developed in an uninterrupted series or succession more or less regular, which pass into each other by insensible stages. Ague is paludal fever, and has always been observed to prevail in marshy moist districts, and in low, swampy humid countries, in which seasons of considerable heat occur.

The neighbourhood of marshes, or of a district which has been at some recent time under water; the banks of extensive lakes, and the shores of rivers and seas where the water flows sluggishly, and in some places stagnates; shallow rivers; extensive level tracts of forest land, where moisture is always present; and the surface of the land constantly covered with excavation from the ground,—these are the terrestrial physical conditions, in which marsh and littoral fevers are almost universally to be found, although it must be admitted that there are some marshy districts in which the disease does not show itself.

In these latter localities the effects of the miasmatic poison, show themselves in cholera or typhus. No precise knowledge of the nature and source of this subtle poison which, in default of a better name we call malaria, has yet been acquired; indeed it has yet to be proved that malaria has a distinct existence. Science has as yet been unable to discover the presence of any poisonous principle in the air of ague on other regions.

Ague may exist without any alteration of structure being set up; but in the milder forms of this fever a greater number of organs and tissues are morbidly altered than perhaps in any other form of disease. The parts so affected are the liver, spleen, lungs, heart, brain, and the serous and mucous membranes of the body generally. Within certain limits, the specific action of the malarial poison may be said to be in the inverse ratio of the intensity of the fever which attends its action. The affections of the liver and spleen also vary greatly according to the locality in which the patient is attacked; for instance, whilst in some parts of India the spleen is the organ principally involved, in other districts of the same continent it is the liver. In England, under proper medical treatment, the patient usually recovers without any manifest derangement either of structure or impairment of function of any organ or tissue. The liver may, however, become affected if the patient suffering from the disease has been neglected for any length of time.

Notwithstanding the opinions of Finke and Professor Colin, there appears to be considerable ground for the supposition that ague may be caused by drinking marsh and surface water. In an interesting paper on the ‘Indian Annals’ for 1856, Mr Bettington, of the Madras Civil Service, says:—“It is notorious that the water produces fever and affections of the spleen.” In confirmation of this assertion, he brings forward what seems to be some remarkably strong evidence. He cites cases of villages placed under the same conditions as to marsh-air in some of which fevers were prevalent, whilst in others they were absent; and he found on inquiry that whilst the latter villages were supplied with pure water, the inhabitants of the former had to drink marsh or mullah water, full of vegetable débris. In one village there were two sources of supply—a spring and a tank, the first fed by surface, and the other by marsh water. Those only who partook of the tank water were attacked by fever. Again, in Tulliwaree the fever was so universal that scarcely any inhabitant escaped it. In this village Mr Bettington caused a well to be dug, and the result was that the fever disappeared. Similar cases have occurred in this country. Twenty years ago Mr Blower, of Bedford, directed the attention of medical men to a case that occurred in a village, in which ague had nearly disappeared when a well was dug; and to another instance which occurred in the village of Houghton. In this parish almost the only family which escaped ague was that of a farmer; the members of this family partook of well water; whilst those who did not escape the disease drank ditch water.

In the ‘Indian Annals’ for 1867 is a paper by Dr Moore, confirming the opinion that ague may be produced by the causes already stated, and M. Commaille (‘Rec. de Mêm. de Med. Mil.,’ Nov., 1868) states that in Marseilles, paroxysmal fevers, formerly unknown, have made their appearance, since the water supply to that city has been drawn from the Marseilles Canal.

In his report for 1870 Dr Townsend, the Sanitary Commissioner for the central provinces of India, states that the natives of India hold an opinion that the use of river and tank water during rainy seasons (when the water always contains an increased quantity of vegetable matter) will almost always cause ague. Boudin (‘Traité de Géographie et de Statistiques Médicale,’ 1857, t. i, p. 142), records an extraordinary case. Eight hundred soldiers, in good health, embarked in three vessels to pass from Bona, in Algiers, to Marseilles, in the year 1834. They all arrived at Marseilles the same day. In two vessels there were 680 men, without a single sick one amongst them. In the third vessel, the Argo, there had been 120 soldiers; 13 died during the short passage, and of the 107 survivors no less than 98 were disembarked suffering from all forms of paludal fevers. We may presume that the diagnosis was correct, since Boudin himself examined the men. When the vessels started the crew of the Argo had not a single sick man aboard. The crew and soldiers of all the boats were exposed to the same atmospheric conditions. The influence of air must, therefore, be excluded. There is no mention of food, but it has never been suggested that food has ever been concerned in the production of malarious fever. It was a very different matter, however, with the water supply. In two of the vessels the water was good, whilst the Argo had been supplied with marsh water, which was offensive to the smell, as well as unpalatable. This latter was supplied to the soldiers, whilst the crew drank uncontaminated water. Amongst those who deny that marsh water is the cause of ague must be quoted Professor Colin. The professor, who is regarded as an authority on intermittent fever, in his work De l’Ingestion des Eaux Marécageuse comme cause de la Dysenterie et des Fièvres intermittentes,’ instances numerous cases in Algiers and Italy in which impure marsh water gives rise to indigestion, diarrhœa, and dysentery, but in no case to intermittent fever; and he states that in all his observations he has never met with an instance of ague having such an origin. Without contesting the case of the Argo, he views it with considerable suspicion, and doubts whether Boudin is correct in his details. Finke also states that, in Hungary and Holland, marsh-water is daily drank without causing any ill-effects. The inhalation of the fumes of oxide of zinc appears to produce in workers of this metal a variety of ague termed by Shackrah “brass ague,” and by Dr Greenhow, “brass-founder’s ague.” The symptoms of the malady are tightness and oppression of the chest; with indefinite nervous sensations, followed by shivering, an indistinct hot stage, and profuse perspiration. These attacks, however, are not periodical.

It is open to doubt whether the malarious poison exists in the form of a gas, for the observations of microscopists go to show the extreme minuteness of the germs of disease, which are probably not more than ⁄70000th of an inch in size, and it is regarded as probable that the real cause of ague is the entry into the circulation of some low forms of spores of fungi, or of some minute animalcules. Ague is always to be met with in places where fungi grow, and is always associated with what Pettenkofer calls “the ground air”—that is, the air contained in the interstices of the soil, no inconsiderable volume of which is drawn into every house which has a fire on the floor which rests on the earth. That animalcules (?) may exist in the blood is evidenced by the discovery of Dr Lewis, who found hair-like worms in the circulation; and whilst considering this point, we must bear in mind that the remedial agents employed to check ague, quinine, arsenic, &c., are drugs capable of destroying animal life, and it is not impossible that they may exercise a beneficial effect in destroying the spores or animalcules to which the disease may be due.

The best means to be employed to combat malarial fevers in any district are thorough and efficient drainage (and it must be remembered that drainage purifies both the ground-air and the ground water) and a supply of wholesome water free from decomposing vegetable matter.

That the adoption of the above means cannot fail to succeed is incontestably proved by the fact, that during the last 200 years, ague in England has diminished to a wonderful extent, in short, as good drainage and a pure water supply have prevailed, there has been a proportionate diminution of paludal poisoning.

During the protectorate of Cromwell great mortality prevailed in London, from the ravages of ague; at that time London was as swampy as the fens of Lincolnshire. See Fever (Intermittent).

Ague-cake. The popular name of a tumour felt under the false ribs on the left side, formed by enlargement and induration of the spleen, following protracted ague; also, sometimes, of indurations of the liver following ague.

Ague-drop. See Drops.

Ague-salt (sŏlt). Disulphate of quinine.

Ague-tree. Sassafras.

Ague-weed. The herb thorough-wort (‘Eupato′′rium perfolia′tum,’ Linn.).

AIG′REMORE (ĕg′r-mor). [Fr.] Pulverised charcoal in the state it is used to make gunpowder.

AIGUILLETTE (Attelette). [Fr.] In cookery, a term applied to several small dishes, from the articles of which they consist being mounted on silver needles, or skewers, with ornamental handles or tops. (See engr.) They form one of the varieties of the ‘hors-d’œuvres’ of Soyer; and are commonly served on a napkin. The skewers should be about four inches long, and of the thickness of an ordinary packing needle. The person eating what is served on them takes the head of the skewer between the thumb and fingers of the left hand, and picks it off with his fork. Those noticed by Soyer are—

Aiguillettes à l’Éperlan (smelts);

Aiguillettes aux Huitres (oysters);

Aiguillettes de Filets de Sole (soles);

Aiguillettes de Homard (lobsters);

Aiguillettes de Langue de Bœuf (ox-tongue);

Aiguillettes de Ris de Veau (sweetbread of veal);

Aiguillettes de Volaille à la Jolie Fille (fowl);—

all of which are prepared in a nearly similar manner, merely varying the sauces, &c., to suit the article and palate. See Attelettes, Hors-d’œuvres, &c.

AHORNZUCKER (genuine American maple sugar). For coughs, hoarseness, and all affections of the throat and chest caused by cold. The raw maple sugar as imported. (Hager.)

AILANTHUS. The inner bark of the ailanthus glandulosa, a common tree growing in northern China, said by Dr Dudgeon to have proved very successful in dysentery.

The ailanthus glandulosa is also well known throughout the United States. Professor Hétet, of Toulon, tried the effect of the powdered bark, leaves, and various preparations of the bark or drugs, with the result of their administration being attended with purgative effect—and the discharge of worms.

The powdered bark has been given in small cases of tape-worm in the human subject, with marked success. The dose of the powder found sufficient for the expulsion of the tapeworm was from seven or eight to thirty grains.

AIL′MENT. Pain, indisposition; disease. Its use is generally restricted to the non-acute, and milder forms of disease.

AIR. [Eng., Fr.] Syn. Aer, L. (from αηρ Gr.); Luft, Ger.; Atmospheric Air; The Atmosphere. This name was formerly given to any aëriform body; thus, by the old chemists ammoniacal gas was called alkaline air; oxygen,—dephlogisticated, vital, or empyreal air; carbonic anhydride (carbonic acid), fixed air; hydrogen, inflammable air; heavy carbonetted hydrogen, olefiant gas, heavy inflammable air; nitrogen,—mephitic, phlogisticated, or nitrous air. At the present time the term air is usually restricted to the gaseous envelope surrounding the solid and liquid parts of our globe.

Air, Atmospheric (or simply, The Air). The air chiefly consists of a mechanical mixture of four volumes of nitrogen and one volume of oxygen, or more accurately—

By volume. By weight.

Nitrogen 79·1 76·8

Oxygen 20·9 23·2

100 100

We may premise our description of the functions of the constituents of the atmosphere by the following quotation from Mr Blyth’s ‘Dictionary of Hygiène and Public Health’:—“One of the most important properties of air is its power of penetration and its universality. Air is, indeed, present everywhere; there is scarcely a solid, however compact it may appear to be, which does not contain pores, and these pores filled with air. The soil contains no small quantity; indeed, if it were not so the numberless insects, worms, &c., which burrow in its interstices would cease to exist. The most compact mortar and walls are penetrated with it, and water of natural origin contains a large quantity of air in solution. The atmosphere is supposed to extend to a very great height, from 200 to 300 miles; it used to be considered only five (forty-five) miles high, but observations on shooting stars, &c., show that this opinion is erroneous. Owing to the force of gravity, the air is much denser near the earth, and gets more attenuated layer by layer as you ascend. If, then, the atmosphere were possessed of colour, it would be very dark just round the globe, and the tint would gradually fade into space. The air is by no means wholly gaseous; it contains, indeed, an immense amount of life, and small particles derived from the whole creation. In the air may be found animalcules, spores, seeds, pollen cells of all kind, vibriones, elements of contagion, eggs of insects, &c., and a few fungi, besides formless dust, sandy, and other particles of local origin; for example, no one can ride in a railway carriage without being accompanied with dust, a great portion of which is attracted by a magnet, and is, indeed, minute particles of iron derived from the rails. The purest air has some dust in it. There probably never fell a beam of light from the sun since the world was made which did not show, were there eyes to see it, myriads of motes; these, however, generally speaking, are quite innocuous to man—some, indeed, may possibly be beneficial. Another most important property of air is its mobility; on the calmest day and in the quietest room there are constant currents of air which rapidly dilute any noxious odours of gases.”

The chief functions of the oxygen are to maintain respiration and support combustion, while the office of the nitrogen is to dilute the oxygen and control its energy.

Besides nitrogen and oxygen, aqueous vapour, carbonic anhydride, ammonia, and nitric acid are met with in the atmosphere, the last especially during and shortly after thunder storms.

Although, doubtless owing to local conditions, trifling variations may occur in the proportion of oxygen present in the atmosphere, this variation is so trifling that the difference of the amount in air from places separated by very long distances will be found in the second decimal place only; thus, whilst a portion of air taken during a balloon ascent by Mr Green gave on analysis 20·88 per cent. by vol., Dr Frankland found in air collected by himself on the summit of Mont Blanc 20·96 per cent. by vol. A still nearer approximation in uniformity in the amount of oxygen present in atmospheric air is exhibited in the following table, which gives the results of 95 analyses by Regnault on air obtained from nine different localities:—

100 from Paris gave in 100 parts, by vol. of oxygen 20·913 to 20·999

9 from Lyons and around gave in 100 parts, by vol. of oxygen 20·918 to 20·966

30 from Berlin gave in 100 parts, by vol. of oxygen 20·908 to 20·998

10 from Madrid gave in 100 parts, by vol. of oxygen 20·916 to 20·982

23 from Geneva and Switzerland gave in 100 parts, by vol. of oxygen 20·909 to 20·993

15 from Toulon and Mediterranean gave in 100 parts, by vol. of oxygen 20·912 to 20·982

5 from Atlantic Ocean gave in 100 parts, by vol. of oxygen 20·918 to 20·965

1 from Ecuador gave in 100 parts, by vol. of oxygen 20·960

2 from Pichincha gave in 100 parts, by vol. of oxygen 20·949 to 20·981

Mean of all foregoing 20·949 20·988

Mean of the Paris specimens 20·96

Vapour of water is essential to the respiration of animals and plants, in order that the organs concerned in this operation may be kept in a soft and moist condition.

Carbonic anhydride is evolved during combustion, putrefaction, and fermentation; it is also a product of the respiration of animals, and highly poisonous to them, even when diluted with large proportions of air. This gas is, however, greedily absorbed by plants, which decompose it; they assimilate the carbon and return the oxygen to the atmosphere, ready to be again consumed in supporting the life of the animal world.

Dr Angus Smith has defined a very pure air to be one that contains with 20·99 per cent. of oxygen 0·30 of carbonic acid (anhydride).

This latter varies in amount in the atmosphere of cities, as will be seen upon inspection of the subjoined table, extracted from Dr Smith’s work ‘Air and Rain’:—

Per cent.

Air of Madrid, outside the walls, mean of 12 analyses, by Luna ·045

Mean of 12 analyses, within the walls of Madrid, by Luna ·051

Mean of 14 analyses, by Angus Smith, in Manchester suburbs ·369

In Manchester streets ·403

Usual weather ·0403

During fogs ·0679

De Saussure’s analyses show that there is more carbonic acid on the mountains than in the plains, as might be inferred from the comparative absence of vegetation in elevated positions. Dr Pietra Santa states that the air of hills or mountains, at the height of 2300 feet, is lighter than common air, contains a smaller proportion of oxygen, and is impregnated with a largely increased amount of aqueous vapour. It also contains a large quantity of ozone. He considers such a climate peculiarly soothing to persons suffering from chest diseases.

Dr Angus Smith’s analysis of the air from the mountainous districts of Scotland confirms the above statement of Dr Pietra Santa’s. The heaths and mountains of that country are remarkably healthy localities, and the air from them gave on analysis 20·94 per cent. by vol. of oxygen, and only ·033 of carbonic acid.

Ammonia is derived from the putrefaction of animal and vegetable substances. It is from atmospheric ammoniacal compounds that plants obtain much of the nitrogen which is essential to the formation of many parts of their structure.

Nitric acid, like ammonia, is absorbed, and its nitrogen assimilated, by plants.

In addition to the gases and vapours already enumerated, as well as others which exist in minute quantity, or which are of only occasional occurrence, Pasteur and other investigators have discovered in the air living germs which are capable of exciting putrefaction and fermentation, and which are competent, in some instances, to engender disease when they are injected into the blood of animals. In fact, the spread of infectious diseases, e.g., smallpox, typhus fever, cattle plague, &c., is attributed to the presence in the atmosphere of the germs of such maladies. These germs are believed to be living beings, which develope and multiply at the expense of the tissues of the larger animals into whose systems they have found entrance.

Air, Vitiated. As has been stated in the previous article, the air consists chiefly of two gases, oxygen and nitrogen. In all open places it has a similar composition, as might be concluded from the constant mingling which takes place by the agency of currents continually in movement, although sometimes to an inconsiderable extent only. Dr Angus Smith regards air as very pure when it contains not less than 20·99 per cent. by volume of oxygen, and 0·030 of carbonic anhydride (acid). According as the proportion of the former gas diminishes and that of the latter increases beyond certain limits in the air by which we are surrounded, it becomes more or less deteriorated and unfit to be breathed, particularly as the increased amount of carbonic acid is, in crowded dwellings, assembly rooms, theatres, and confined inhabited spaces, associated with deleterious and putrescent exhalations from the person.

The following tables exhibit the amount of carbonic acid in close places in London.

I.

Per-centage

by volume.

Chancery Court, closed doors, 7 feet from the ground, March 3 ·193

Same, 3 feet from ground ·203

Chancery Court, doors wide open, 4 feet from ground, 11·40, March 5 ·0507

Same, 12·40 p.m., 5 feet from ground ·045

Strand Theatre, gallery, 10 p.m. ·101

Surrey Theatre, boxes, March 7, 10·30 p.m. ·218

Olympic, 11·30 p.m. ·0817

Same, 11·55 p.m. ·1014

Victoria Theatre, boxes, March 24, 10 p.m. ·126

Haymarket Theatre, dress circle, March 18, 11·30 p.m. ·0757

Queen’s Ward, St. Thomas’s Hospital, 3·25 p.m. ·052

Edward’s Ward, St. Thomas’s Hospital, 3·30 p.m. ·052

Victoria Theatre, boxes, April 4. ·076

Effingham, 10·30 p.m., April 9, Whitechapel ·126

Pavilion, 10·11 p.m., April 9, Whitechapel ·152

City of London Theatre, pit, 11·15 p.m., April 16 ·252

Standard Theatre, pit, 11 p.m., April 16 ·320

Dr Angus Smith states that out of 339 specimens of air obtained from various mines he found 35 normal or nearly so, 81 decidedly impure, and 212 exceedingly bad; he also adds that owing to the frequent firing of charges of gunpowder within the mines, and from other causes, the atmosphere is further contaminated with sulphuretted hydrogen, sulphate, carbonate, sulphide, sulphocyanide of potassium, and nitrate of potassium, carbon, sulphur, carbonate of ammonia, organic matter, sand, and sulphurous and arsenious acids.

The air of large cities, which are the seats of manufacturing industry, is always more or less charged with the exhalations given off by chemical and other works. The sulphuric-acid works contribute sulphuric, sulphurous, nitrous, and arsenious acids; copper works, in which pyrites is employed, give off large quantities of sulphurous acid, mixed with arsenic and a little copper; manure works, in many cases, send out compounds of fluorine, besides sulphuric acid; glass works, sulphuric and hydrochloric acids; and alkali works, hydrochloric acid (although in small quantities), which very frequently contains arsenic. Of ammonia, Angus Smith remarks: “It is one measure of the ‘sewage’ of the air; it is the result of decomposition. It is not, in these small quantities, hurtful, so far as we know. The ammonia is in no case free, but combined probably with hydrosulphuric, hydrochloric, and sulphuric acid in towns. In country places it is, at all events partly, united to carbonic acid.

II. London Air.—Carbonic Acid, Metropolitan Railway, November, 1869.

Date. Place. Time of Day. Carbonic Acid, per cent. Oxygen, per cent.

1869. Nov. 12. Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage. 10 a.m. ·150 20·60

” 12. Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage. 7·30 p.m. ·078 20·79

” 12. Tunnel Praed Street; specimen taken at the open window, first-class carriage. 10·30 a.m. ... 20·71

” 15. Specimen taken during journey between Gower Street and King’s Cross, first-class carriage, window open. 10·15 a.m. ·338 20·66

” 15. Same 3 p.m. ·155 20·70

” 15. Same 11 p.m. ·150 20·74

Average ·1452 20·70

Angus Smith.

The Air of Mines (Metalliferous).

Name of Mine, and depth from surface, in fathoms. Description of place, where taken and time when taken. Thermometer, Fahr. Number of Men working in it. Oxygen, per cent. Carbonic Acid, per cent.

Hurst End, 300 ft. beyond a rise, 9 ft. high, 7 ft. wide. ... 2 ... 1·99

Old Gang End of level ... 2 20·58 ·48

” End of level ... 2 ... ·28

” (a) Rise 7 ft. high, 132 ft. from current. ... 2 20·25 ·39

Grassington (b) End of cross cut, 480 ft. from rise. ... 2 20·94 ·06

” End, 480 ft. from rise. ... 2 19·53 1·59

” Rise 60 ft. high in shale. ... 2 19·52 1·72

” End, 60 ft. from rise. ... 2 20·47 1·06

” (c)End, 840 ft. from rise. ... 2 20·08 ·94

(a) Air machine.
(b) Unusual amount of dust.
(c) Crystals were chiefly hexagons.

Angus Smith.

The following table, showing the amount of ammonia present in rain collected at the different places named, is from Dr Smith’s work, ‘Air and Rain.’

Comparative. Ammonia.

That of Valentia (Ireland) taken as 1 or 100.

Ireland, Valentia ·1

Scotland, sea-coast, country places, west 2·69

Scotland, inland, country places, west 2·96

Scotland, sea-coast, country places, average 4·10

Scotland, sea-coast, country places, east 5·51

England, inland, country places, east 5·94

England, sea-coast, country places, west 10·55

German specimens 10·61

London, 1869 19·17

Scotland, towns (Glasgow not included) 21·22

St. Helen’s 25·33

Runcorn 25·72

England, towns 28·67

Liverpool 29·89

Manchester, 1869 35·33

Manchester, 1869 and 1870, average 35·94

Manchester, 1870 36·54

Glasgow 50·55

The effects resulting from breathing an impure atmosphere are necessarily dependent upon the extent of the pollution and other conditions. When the contamination is moderate the first effect is headache, accompanied with lassitude, and a general paleness of the face and skin, owing to a diminution of the red corpuscles of the blood or to their imperfect aëration; the pulse becomes lowered, and at the same time the breathing is accelerated. When in addition to breathing such air from day to day is superadded the misfortune of an insufficiency of food, scrofula and consumption very often follow. Dr Guy has demonstrated the great mortality that is caused by consumption in those trades in which workmen pursue their calling in hot, close, gas-lit rooms, in comparison with those who pass most of their time in the open air. The amount of air required by each person in a room is no less than 2100 feet per hour; when the ventilation does not supply this amount of fresh air, the apartment smells stuffy, the furniture becomes coated with a film of organic matter, unless constantly cleaned, and the carbonic acid becomes increased beyond its normal quantity.

Dr Parkes has shown that bronchitis and consumption are more frequently than not contracted by those who live in an atmosphere of foul air. In the years 1834 to 1847 the proportion of deaths in the ill-ventilated prison of Leopoldstadt in Vienna was 86 per 1000, out of which number 51·4 per 1000 was due to phthisis or consumption; while in the well-ventilated House of Correction in the same city the deaths were 14 per 1000, of which 7·9 were from phthisis; hence 43·5 cases per 1000 of the deaths were clearly traceable to foul air and nothing else.

Mr Noel Hartley, in his valuable little manual, ‘Water, Air, and Disinfectants,’ says: “During the outbreak of cattle plague in 1866, in sheds containing twenty to thirty cows—which the owners kept closed to such an extent that all chinks in the doors and windows were stuffed with straw and matting, under an ignorant belief that thus the plague could be kept out—very frequently the entire stock died in two or three days after the first appearance of disease; while in other cases where animals were housed in a well-cleaned and tidily-kept shed, with a plentiful supply of fresh air, not only did some of them escape the disease altogether, but the deaths were reduced to one third of the number of beasts attacked.”

The large supply of fresh air necessary in hospitals for contagious diseases is fully recognised by medical men, and more especially so in America. Wounds carefully protected from contact with impure air do not suppurate, and organic fluids do not putrefy. On the other hand, in a bad atmosphere sores become unhealthy, and are difficult to heal, erysipelas and hospital gangrene frequently set in, while the best prevention and the best means of cure for such afflictions is the greatest possible exposure to fresh air.

Vitiated air, as a consequence of over-crowding, aids the spread of measles, scarlet fever, and the much to be dreaded smallpox; it brings on ophthalmia, a troublesome inflammation of the eyes, and is not unfrequently the cause of the ricketty and scrofulous condition of children. Although exposure to cold does cause such affections as bronchitis, pneumonia, cold in the head, sore throat, and other affections of the respiratory organs, it is more frequently the case that they are the result of a sudden change of temperature, such as experienced in coming out of a crowded assembly in a close, badly-ventilated building, than by actually cold weather. This is decidedly and strikingly shown by the fact which Dr de Chaumont has quoted, that the British Army when in the Crimea, when lodged in tents during extremely rigorous weather, experienced a wonderful condition of health, such a thing as a cold being an unknown complaint; but when some of the men were placed in huts which were much warmer, and into which there was a smaller circulation of fresh air, the sick rate increased, and coughs and colds began to put in an appearance. Persons who during summer and winter sleep with their windows more or less open cannot endure a night spent in the chamber with the chimney closed and the window shut. A less refreshing sleep occupies the night, and a somewhat feverish sensation is felt next morning.

If in cold weather the window be opened only one inch at the top, the difference in the air in the bedroom is something quite beyond comprehension to those who have not paid attention to these things. See Ventilation.

Air, Analysis of. Priestley’s discovery of oxygen gas in 1774 prepared the way for the knowledge of the real composition of air, which was discovered about the same time by Scheele and Lavoisier. Scheele’s method of operating was by exposing some atmospheric air to a solution of sulphide of potassium. Lavoisier effected the same object by the combustion of iron wire and phosphorus, and subsequently by heating mercury on a flask filled with air for some time, just below its boiling point.

These, however, were but elementary methods, which, however creditable to the ingenuity of the great founders of modern chemistry, not only failed in accuracy, but took no account of the presence and amount of two most important constituents in the atmosphere, viz. carbonic anhydride (acid) and ammonia.

Determination of Aqueous Vapour. To effect this an aspirator must be used (see Aspirator). This instrument is easily made, and is not expensive. The accompanying figure will illustrate the arrangement generally adopted: a is an aspirator made of galvanised iron or sheet zinc. It holds from 50 to 200 litres (from 11 to 44 gallons). By this means a known volume of air is drawn through the tubes marked b, c, d, e, which may be filled with pumice-stone moistened with strong sulphuric acid; but if the carbonic acid is to be estimated as well, b and c are filled with moist hydrate of lime (potash used to be employed, but hydrate of lime is to be preferred, as the potash absorbs oxygen), and d and e as above. Each of the tubes is accurately weighed previously to connecting them with the apparatus.

It is imperative to have each of the tubes connected by perfectly air-tight joints. The gain of weight in d and e gives the water in b and c the carbonic acid.

Determination of Carbonic Acid. A better and perhaps more exact means of determining the carbonic acid is that invented by Pettenkofer. It may be briefly described as follows:—Baryta water of definite strength is prepared and accurately standardised by a standard solution of oxalic acid. A portion of this baryta water is then made to act upon a definite quantity of air. It will absorb the whole of the carbonic acid in that air.

The alkalinity of the liquid will in consequence be diminished; it will take less of the oxalic-acid solution than before, which shows so much less caustic baryta, and from which the carbonic acid absorbed may be easily calculated.

The actual Analysis. Two kinds of baryta water may be used, the one containing 7 grammes to the litre, the other three times that strength; 1 c. c. of the stronger = 3 m. grms. of carbonic acid; 1 c. c. of the weaker = 1 m. grm. The baryta water is best kept in the bottle represented below.

The bottle (a) contains the baryta water. It has an accurately-fitting double-perforated stoppered caoutchouc. The left-hand tube is connected with the tube (b) containing pumice-stone moistened with potash, while the right-hand one is a syphon. When required for use the stop-cock (f) is opened, and suction applied by a glass tube to F. The syphon is thus filled and the stop-cock closed. If a pipette is required to be filled its nozzle is inserted at F, the stop-cock compressed, and the fluid immediately rises into the pipette.

The air entering the bottle as the fluid decreases in a is, of course, thoroughly deprived of its carbonic acid by the tubes at b.

The first thing to be done is to standardise the baryta solution by a solution of oxalic acid, containing 2·8636 grammes of crystallised oxalic acid to the litre.

Thirty c. c. of baryta solution are run into a small flask, and the oxalic acid run in from a Mohr’s burette with float, the vanishing-point of the alkaline reaction being ascertained by delicate turmeric paper. As soon as a drop placed on turmeric paper does not give a brown ring the end is attained.

The actual analysis is performed by filling a bottle of known capacity, with the aid of a pair of bellows, with the air to be analysed, then distributing over its sides 45 c. c. of the baryta water it is left for half an hour. The turbid water is poured into a cylinder, closely secured, and allowed to deposit; then take out 30 c. c. by a pipette of the clear fluid, run in the solution of oxalic acid, multiply the volume used by 1·5, and deduct the produce from the c. c. of oxalic acid used for 45 c. c. of the fresh baryta water. A different method has been suggested by Dr Angus Smith, viz. to measure the carbonic anhydride by the turbidities of the baryta water; this is, in fact, a colorimetric test. For rough approximative results Dr Smith’s process will be found a very useful and convenient one. It depends upon the fact that the amount of carbonic acid in a given quantity of air will not produce a precipitate in a given quantity of lime or baryta water unless the carbonic acid is in excess. The following is one of his tables:—Columns 1 and 2 give the rates of carbonic acid in the quantity of air which will produce no precipitate in half an ounce of lime water. Column 3 is the same as column 2; but 14·16 c. c. (half an ounce) is added to give the corresponding size of the bottle, and column 4 gives the size of the bottle in ounces.

To be used when the point of observation is “no precipitate.” Half an ounce of baryta water contains about ·08 gramme of baryta.

Air at 0° C. and 760 millims. Bar.

Carbonic Acid in the Air, per cent. Volume of Air in cubic centimètres. Size of bottle in cubic centimètres. Size of bottle in ounces Avoirdupois.

·03 185 199 7·06

·04 139 154 5·42

·05 111 125 4·44

·06 93 107 3·78

·07 79 93 3·31

·08 70 84 2·96

·09 62 76 2·69

·10 56 70 2·46

·11 51 65 2·29

·12 46 60 2·14

·13 43 57 2·01

·14 40 54 1·90

·15 37 51 1·81

·20 28 42 1·48

·25 22 36 1·29

·30 19 33 1·16

·40 14 28 1·04

·50 11 25 ·89

·60 9 23 ·89

·70 8 22 ·78

·80 6 20 ·72

1·00 5·5 19·7 ·70

Mr Wanklyn’s process for the determination of carbonic acid in the atmosphere is as follows:—A solution of carbonate of soda is first made as follows: 4·47 grammes of gently-ignited carbonate of soda are dissolved in one litre of water, giving a solution of such a strength that 1 c. c. contains exactly 1 c. c. of carbonic acid (= 1·97 milligrammes of CO2); a large quantity of baryta water (strength about 0·1 per cent.) is prepared.

If now 100 c. c. of clear baryta water be treated with 1 c. c. of carbonate of soda, just described, a certain degree of turbidity is produced.

If 2 c. c. of the solution be taken another degree of turbidity is produced, and so on. If, then, a bottle capable of holding 2000 c. c. of air, together with 100 c. c. of baryta water, be filled with the sample of air to be tested, there will be a certain depth of turbidity produced by shaking it up. Having got the air to expend itself on 100 c. c. of baryta water the degree is to be found by comparison with another 100 c. c. of baryta water, in which a like turbidity has been induced by means of the standard solution of carbonate.

Every c. c. of soda solution counts for a c. c. of carbonic acid in two litres of air. A consumption of 1 c. c. will correspond to ·05 volumes of carbonic acid per cent. Good air should accordingly not take more than 1 c. c. of soda solution, air which takes already 2 c. c. being already bad.

In order practically to carry out this method of estimating carbonic acid the following apparatus is required:—Several bottles capable of holding 2·210 c. c., and well stoppered (failing bottles of exactly the right capacity Winchester quart bottles will answer); a small pair of bellows; several colourless glass cylinders marked at 100 c. c. capacity—the Nesslerising cylinders will answer for this purpose—a graduated pipette or burette to deliver tenths of a c. c. of solution, the standard solution of carbonate of soda, and the baryta water, which may be of moderate strength.

The testing is managed thus: Winchester quart bottles having been made clean are rinsed with distilled water, and allowed to drain a little. They are then closed with their stoppers, and are ready for use. The operator having provided himself with two or three of these bottles and a small pair of bellows enters the room the air of which is to be tested. The stopper is then removed from one of the bottles, and some air of the room blown through with the bellows, and then the stopper is replaced, and the bottle carried away to be tested.

The testing is done by pouring into the bottle 100 c. c. of clear baryta water, shaking up for two or three minutes, and then pouring out into a cylinder of colourless glass, and observing the depth of the turbidity in various lights and against various backgrounds. The turbidity is to be exactly imitated by means of the standard solution of carbonate of soda. In order to imitate the turbidity produced by a Winchester quart full of good air only 1 c. c. of this solution of carbonate of soda is required.

If 2 c. c. or more than 2 are required, the air is bad and the ventilation is defective.

In place of the first c. c. of solution of carbonate of soda the carbonic acid naturally present in a Winchester quart of good average air may be used, and a little practice and intelligence will suggest the necessary precautions.

Estimation of the Oxygen.—To determine this Angus Smith has recourse to the endiometer. Five or six of Bunsen’s endiometers were used at once and the mixed gases were exploded by means of a powerful battery and a Ruhumkorff’s coil. In his ‘Inorganic Chemistry,’ Miller thus explains the principle upon which the action of the endiometer is based: “By means of the endiometer various gaseous mixtures may be analysed with great exactness. Many different forms of this instrument are in use. One of the most convenient is Hoffmann’s. It consists of a stout syphon tube. (See next figure.) Into the sides of the tube, near the sealed end, two platinum wires (a, b) are fixed for the purpose of transmitting an electric spark through the cavity of the tube. The sealed limb is accurately graduated to tenths of a c. c. or other suitable divisions. Suppose it be desired to ascertain the proportion of oxygen in atmospheric air. The instrument is first filled with mercury, after which a small quantity of air is introduced; the bulk of the air is accurately measured, taking care that the liquid metal stands at the same level in both tubes, which is easily effected by adding mercury, or by drawing off the mercury if needed, through the caoutchouc tube, which is fixed upon the small inlet tube just above the bend, and which is closed by means of a screw tap (c).

A quantity of pure hydrogen, about equal in bulk to the air, is next introduced, and the bulk of the mixture is then accurately measured. The open extremity of the tube is now closed with a cork, below which a column of atmospheric air is safely included. This portion of air acts as a spring, which gradually checks the explosive force, when the combination is effected by passing a spark across the tube by means of the platinum wires. The mixture is then exploded by the electric spark. The remaining gas now occupies a smaller volume, owing to the condensation of the steam which has been formed. Mercury is, therefore, again poured in the open limb until it stands at the same level in both tubes, and the volume of the gas is measured a third time. One third of the reduction of the bulk experienced by the gas will represent the entire volume of oxygen which the mixture contained. Liebig’s method is as follows. It is based upon the fact that an alkaline solution of pyrogallic acid absorbs oxygen:

1. A strong measuring tube holding 30 c. c., and divided into one fifth or one tenth c. c., is filled to two thirds with the air intended for analysis. The remaining part of the tube is filled with mercury, and the tube is inverted over that fluid in a tall cylinder widened at the top.

2. The volume of air confined is measured—a quantity of solution of potash of 1·4 sp. grf. (1 part of dry hydrate of potash to 2 parts of water), amounting from ⁄40th to ⁄50th of the volume of the air, is then introduced into the measuring tube by means of a pipette with the point bent upwards (see drawing), and spread over the entire inner surface of the tube by shaking the latter. When no further diminution of volume takes place the decrease is read off. The carbonic acid is thus removed.

3. A solution of pyrogallic acid containing 1 gramme of the acid in 5 or 6 c. c. of water is introduced into the same measuring tube by means of another pipette similar to the above. The mixed fluid (the pyrogallic acid and the solution of potash) is spread over the inner surface of the tube by shaking the latter, and when no further diminution of volume is observed the residuary nitrogen is measured.

4. The solution of pyrogallic acid mixing with the solution of potash of course dilutes it, causing thus an error from the diminution of its tension; but this error is so trifling that it has no appreciable influence upon the results. It may, moreover, be readily corrected by introducing into the tube, after the absorption of the oxygen, a small piece of hydrate of potash, corresponding to the amount of water in the solution of the pyrogallic acid.

There is another slight error on account of a portion of the fluid adhering to the inner surface of the tube, so that the volume of the gas is never read off with absolute accuracy.

In conducting these endiometric experiments the necessary corrections for temperature and barometric pressure must, of course, be made.

Estimation of the Nitrogen. The amount of this gas is usually determined by deducting the aqueous vapours, oxygen and carbonic acid, from the volume of air examined.

Determination of Ammonia and Organic Matter. These are best determined by drawing a known volume of air through absolutely pure water. To obtain this latter it is best to redistil distilled water, to reject the first portions, then to add an alkaline solution of permanganate of potash, and to discard any portions of the distillate which give the slightest reaction with the Nessler test. The water through which the air is drawn must be kept cool, and afterwards submitted to the proper tests, which will be found under Ammonia and Water Analysis. Mr Blyth says, “Solid bodies such as vibrionic germs, dust, fungi, &c., may be obtained by using an aspirator, and drawing the air either through a drop of glycerine or water. Organic matter may also be obtained by suspending glass vessels filled with ice water, over or in the places to be investigated, and submitted to the microscope. High powers, such as immersion lenses, are requisite for the investigation of germs,” &c.

Of these germs Dr Angus Smith says:—“They may probably be divided into many kinds—the useful and the deleterious, those which promote health and those which bring disease. The idea of any of them bringing health is not founded on anything positive, but we can scarcely imagine these numberless forms to be all useless. The idea that they bring disease is, I think, one well confirmed.” See a paper by the same author “On the Air and Rain of Manchester.” ‘Memoirs of the Literary and Scientific Society of Manchester,’ vol. x. See Air, Vitiated.

AIR-GAS. Air deprived of its carbonic acid and moisture, and then impregnated with the vapours of very volatile fluid hydrocarbons, such as benzine and benzoline, can be used as an illuminating agent. It is requisite, however, to use burners with wide openings, and to apply a low pressure, because if the current be too rapid the flame becomes too much cooled, and is readily extinguished. Apparatus for preparing air-gas have been devised and constructed by Marcus, Mille, Methei, and others.

AIR-PUMP. An instrument designed for the removal of air from closed vessels. The simplest form of air-pump is the exhausting syringe, which consists of a cylinder fitted with a stop-cock, and having a valve at the bottom opening inwards. Another valve opening outwards is attached to a piston working inside the cylinder, and by screwing the instrument on to a vessel, and alternately elevating and depressing the piston, all except a very small quantity of residual and comparatively inelastic air is pumped out of the vessel (Figs. a and b). The accompanying figures show relative positions of the valve during (a) the elevation, and (b) the depression of the piston. In the usual and more convenient form of air-pump, a brass tube passes from the bottom of the syringe and terminates in the centre of a disk of brass or glass ground accurately; the vessel from which the air is to be exhausted has its edge very accurately ground, and is mounted upon the plate as shown in the subjoined figure.

Air-pump, Bunsen’s Water. (See figure on page 53.)

This consists of a wide glass tube, a, into which another tube, b, b′, b′′, passes air-tight. c is an india-rubber tube connecting a with the water supply, d is a clamp to stop the flow of water through c. e is another clamp to regulate the flow, f is a reservoir to prevent any water which may accidentally come over from getting into j. g is a plug to let out any water from f. h is a screw for connecting a air-tight to a piece of tubing, which should pass 32 feet, if possible, below the level of a. i is a piece of strong india-rubber tubing to connect the pump with the vessel to be exhausted. The water rushes in at c and down h, carrying bubbles of air with it till the exhaustion is complete. The figure illustrates a common application of this pump to the rapid filtration of liquids which ordinarily pass through paper with difficulty. a is represented as being about half full of water. k is a funnel fixed air-tight in the india-rubber stopper of the bell-jar j. l is a small cone of platinum foil to prevent the paper filter which fits into it from being broken. m is a plate of ground glass, n is a beaker to receive the filtrate.

Air-pump, Sprengel’s. This apparatus depends on the principle of converting the space to be exhausted into a torricellian vacuum.

In the subjoined figure, c, d is a glass tube longer than a barometer, open at both ends, and connected by means of india-rubber tubing with a funnel, A, filled with mercury and supported by a stand. Mercury is allowed to fall in this tube at a rate regulated by a clamp at C; the lower end of the tube, c, d, fits in the flask B, which has a spout at the side a little higher than the lower end of c, d; the upper part has a branch at x to which a receiver R can be tightly fixed. When the clamp at C is opened, the first portions of mercury which run out close the tube and prevent air from entering below. As the mercury is allowed to run down the exhaustion begins, and the whole length of the tube from x to d is fitted with cylinders of air and mercury, having a downward motion. Air and mercury escape through the spout of the bulb B, which is above the basin H, where the mercury is collected. It is poured back from time to time into the funnel A, to be repassed through the tube until the exhaustion is complete.

AIRY’S (Dr.) NATURE’S MEDICAL TREATMENT is the title of a pamphlet which recommends four secret remedies against 166 diseases:

a. The Pain Expeller, a mixture of about 35 parts of tincture of capsicum, 20 parts of diluted spirit, and 20 parts of spirit of ammonia.

b. Sarsaparillian, a fluid extract of sarsaparilla and China root, containing 1 per cent. of iodide of potassium.

c. Pills composed of powdered iron, jalap resin, jalap powder, and marsh mallow powder, made into a mass with some bitter extract. Each pill weighs 0·1 gramme.

d. Calming Pastilles are thick, hard tablets, composed of sugar, with oil of anise, and coloured with liquorice juice. (Hager.)

AKUSTICON (an ear essence). A proved remedy for every kind of ear disease, by Pserhofer. This may be imitated by dissolving in common glycerine one fifth of its weight of fir tar, filtering, and adding a few drops of cajeput oil dissolved in spirit (Hager.)

AL-. [Ar.] An inseparable article equivalent to the English the. It is found in many chemical and other words derived from the Arabic; as alchemy, alcohol, alembic, almanac, &c.

AL′ABASTER. Syn. Albâtre, Fr.; Alabas′ter, Alabastri′tes, Alabas′trum, L. A soft, white species of calcareous and of gypseous stone, used by sculptors. There are several varieties, all of which may be ranged under two heads:—

1. Calca′′reous alabaster; Orient′al, a.; Calc-sin′ter. A sub-variety of carbonate of calcium, formed by the deposition of calcareous particles in the caverns of limestone rocks. It has a foliated, fibrous, or granular structure, and a pure, soft, rich, semi-translucent whiteness, generally agreeably variegated with undulating zones or stripes of various shades of yellow, red, or brown. This variety is that most esteemed by sculptors, and for the manufacture of alabaster ornaments. The ancients used it for ointment and perfume boxes. At the baths of San Filippo (Tuscany), the process of its formation may be examined by the observer. The natural spring of boiling water holds carbonate of lime in solution by means of sulphuretted hydrogen, which, escaping into the air, leaves the lime as a precipitate, which is gradually deposited in a concrete form. (M. Alex. Brogniart.)

2. Gyp′seous or common alabaster; Gypsum. A natural hydrated sulphate of calcium, containing a little carbonate of calcium. That from the quarries of the Paris basin contains about 12% of the latter substance. When calcined or roasted, and powdered, it forms the substance known under the name of Plaster of Paris. The more compact, fine-grained specimens of this variety are, like the preceding one, sculptured into almost numberless articles of ornament and utility, such as vases, clock-stands, statuettes, &c. The inferior kinds only are manufactured into the ‘plaster of Paris’ of the shops. The best specimens are obtained from the lower beds of the gypsum quarries, and are white, and granular, not unlike Carrara marble. It takes a high polish; but from its softness and liability to become discoloured, articles formed of it require more careful treatment than even those of ‘calcareous alabaster.’

Alabaster is wrought, turned, and fashioned, in a nearly similar manner to the softer varieties of marble. The tools resemble those employed for the like operations in ivory and brass. Machinery is now often applied to this purpose.

Alabaster is polished, first with pumice-stone, and then with a paste or pap made of whiting, soap, and milk or water; and lastly, with dry flannel. A better method, however, is to rub it first with dried shave-grass (equisetum), and afterwards with finely powdered and sifted slaked lime formed into a paste with water. The surface is then ‘finished off’ by friction with finely powdered talc or French chalk, until a satiny lustre is produced, or with putty powder, in a similar way to marble.

Alabaster is engraved with tools resembling those employed for other soft minerals. It is etched by covering every part of the surface, except that to be acted on, with a solution of white wax in oil of turpentine (1 to 4), thickened with a little finely powdered white lead, and subsequent immersion in water acidulated with acetic acid or hydrochloric acid, for the calcareous variety; and in spring water, for 20 to 50 hours (according to the effect desired), for the gypseous variety. The varnish is washed off with oil of turpentine, and the etched parts carefully brushed over with finely powdered gypsum.

Alabaster is joined and repaired by means of white of egg, or rice glue, thickened with finely powdered quicklime; or by a paste of newly baked and finely powdered gypsum, mixed up with the least possible quantity of water.

Calcareous alabaster is usually cleaned with a brush and warm soap-and-water, or with tepid water to which a few grains of carbonate of soda or of ammonia have been added; followed in either case by rinsing in clean water. If much discoloured, thoroughly cover the article with a paste of freshly slaked lime and water, and let it remain twenty-four hours; then wash off the paste with soap and water, rubbing hard the stains.

Delicate objects in gypseous alabaster can only be safely cleaned with benzol, or with pure oil of turpentine. If necessary, the surface must be repolished. Grease spots may be removed from either variety with a little benzol or oil of turpentine.

Alabaster is occasionally stained or coloured, and, for the calcareous variety, in a similar way to marble, except that heat is not employed; and for the gypseous variety, in the manner noticed under Plaster OF Paris. The gypseous variety is also bronzed and hardened in a similar way to that adopted for casts in the latter substance.

Obs. Gypseous alabaster is dissolved by water; and the beauty of both varieties is almost irrecoverably destroyed by grease, coloured oils, varnishes, smoke, &c. It is, therefore, unfitted for garden ornaments, or other objects exposed to the rain or weather, unless it be painted or bronzed; and is even then very perishable. Contact with acids, alkalies, and ammoniacal and sulphurous fumes, also injure, and, if prolonged, destroy it. Even an uncorked phial of smelling-salts placed on a mantel-piece beside an alabaster vase will soon destroy its beauty. Thus, all delicate objects in alabaster should be protected by a glass shade.

Alabaster, Orient′al (Factitious). Figures, basso relievos, &c., of considerable hardness and beauty, may be formed by imitating the process adopted at the baths of San Filippo, before referred to.

Proc., &c. Moulds of sulphur are placed either vertically or obliquely in an open tub or cistern, having a freely perforated bottom. Surmounting the whole are two or more pieces of wood in the form of a cross or star. The sulphurous calcareous water, falling on this cross, is scattered into spray or streamlets, and losing the gaseous portion which holds the lime in solution, deposits it in the form of oriental alabaster on the surface of the moulds. In from 1 to 4 months, according to the nature of the article, a sufficiently thick deposit is obtained. The object is then removed from the mould, and trimmed and polished. It is found that the more vertical the position of the mould, the finer is the grain of the resulting deposit. The water of the Spring of San Filippo may be exactly and easily imitated by the chemist; and the whole process offers a new and valuable ornamental art for the amusement and profit of the ingenious and enterprising.

Alabaster, Shand’s Chinese. Carbonate of lime. (Chandler.)

Alabaster Tablets, John Swine’s Chinese. Carbonate of lime. (Chandler.)

ALAMODE′ (ăl-ăh-mōdé). [Fr., à la mode.] According to the prevailing mode or fashion. In cookery, applied to several dishes, but more particularly to one of beef (alamode beef), commonly shortened by the lower class of Londoners into “alamode.” See Beef, Stewing, &c.

ALAN′TINE. [Eng., Fr., Ger.] Syn. Alanti′na, L. A substance identical with inulin, found in the roots of garden angelica (‘angelica archangelica,’ Linn.).

ALBA′TA. [L., Eng.] A name given to several alloys resembling silver. See Alloys, German Silver, &c.

ALBION (Parisian). “Will preserve the skin white and free from wrinkles.” An aromatic water with chloride of lead and calomel suspended in it. (Landerer.)

ALBOLITH. A cement powder prepared by W. Riemann, Breslau. Made with calcined magnesia (obtained from magnesite) and chloride of magnesium. It is recommended for painting walls, stairs, and wooden articles. (Hager.)

ALBU′MEN. [Eng., L.] Syn. Albumin; Albumine, Fr.; Eiweiss, Eiweistoff, Ger. Literally, the white of egg; a peculiar nitrogenous substance which enters largely into the composition of animal bodies. It abounds in the blood, muscles, bones, coagulable lymph, vitreous and crystalline humour of the eye, fluid of dropsy, &c. The white of egg consists of nearly pure albumen dissolved in water.

A substance identical with albumen is found in many vegetables. It enters largely into the composition of all the emulsive seeds. According to Seguin, it exists in considerable quantity in all those vegetables and fruits that afford a vinous liquor without the addition of yeast.

Prep. The white of egg and the serum of blood, when strained through muslin, furnish albumen, in solution, in a sufficiently pure state for all the ordinary purposes of the arts. Pure solid albumen may be prepared as follows:—

1. Agitate strained white of egg with 10 or 12 times its bulk of alcohol, collect the precipitated flocculi on a muslin filter, and suffer it to dry at a temperature not exceeding 120° Fahr.

2. Add a little water to white of egg, mix, filter, exactly neutralise with acetic acid, and then largely dilute with pure cold water; the precipitate which falls may be collected on a filter and washed. Strained serum of blood may be used instead of white of egg, in both the above forms.

Comp., &c. The following is the composition of albumen according to Lieberkühn:—

Carbon 53·3

Hydrogen 7·1

Nitrogen 15·7

Oxygen 22·1

Sulphur 1·8

100·0

Chatin found iodine in the white of egg; it also contains chloride, sulphate, phosphate, and carbonate of sodium, phosphate of calcium, and traces of potassium in it; but, unlike the sulphur, none of these substances form a constituent part of pure albumen, though probably always present in white of egg.

Prop. Pure solid albumen (unaltered by heat) is nearly colourless, inodorous, and tasteless; scarcely soluble in water, but readily so in water, containing an exceedingly small quantity of caustic soda or potash, and in a strong solution of nitrate of potassium. When dried by a gentle heat it shrinks into a translucent horny mass; and when exposed to a sufficient temperature, yields the usual ammoniacal odour and products of animal matter. Its solution (as white of egg) is solidified or coagulated by a heat of from 145° to 165° Fahr., forming a white, opaque mass; when very dilute, on boiling (only) it separates in fine light flocks. When thus coagulated, it is insoluble in water at a less temperature than 302° Fahr. (Wöhler and Vögel), unless alkalised. Ordinary solutions of albumen give precipitates with sulphuric, hydrochloric, nitric, and metaphosphoric acids, with tannin and astringent solutions, and with most of the metallic salts; but are not affected by either acetic acid or tribasic (common) phosphoric acid. Alcohol, in quantity, also precipitates albumen. Strong oil of vitriol turns it black in the cold, but on applying a gentle heat, a gorgeous, red-coloured liquid is produced. Strong hydrochloric acid gives a deep violet-blue solution. White of egg or serum exposed in a thin stratum to the air, dries up into a pale, yellow, gum-like substance, and in this state may be kept for any length of time, retaining its property of redissolving when immersed in slightly warm water.

Tests.—1. Both heat and alcohol (or strong spirit) coagulate it:—2. A solution of perchloride of mercury dropped into a fluid containing albumen occasions a white precipitate:—3. Subacetate of lead acts in the same way. Either of the last two will render turbid a solution containing only the 1-2000th part of fresh white of egg, or the 1-10,000th part of dry albumen:—4. Tannin and tincture of galls give yellow, pitchy precipitates:—5. If dry caustic potash or soda be triturated with either liquid or solid albumen, ammoniacal fumes are evolved, and the mixture on calcination yields ferrocyanide of potassium:—6. Its coagulability by heat, and its incoagulability by acetic acid, distinguish it from casein.

Uses, &c., Independently of its value as an alimentary substance, albumen is largely employed in photography as a glaze or varnish, for fixing colours in calico printing, as a cement, &c., and more particularly as a clarifier for wines, syrups, vegetable solutions, and other liquids. Its efficacy for the last purpose depends on its entangling the impurities in its meshes during coagulation, and either rising to the surface with them as a ‘scum,’ or sinking with them as a precipitate. In France it is prepared on an extensive scale, at the abattoirs, by being spread in thin layers to dry; the source of supply being of course the stream of the blood of the slaughtered animals. When the liquid operated on does not spontaneously coagulate albumen, it is necessary to apply heat to it. In cases of poisoning by the mineral acids, corrosive sublimate, nitrate of silver, sulphate of copper, bichloride of tin, or sugar of lead, the white of egg (or indeed the yolk as well) is one of the best antidotes that can be administered.

Albumen, Flake. Syn. Albumen in powder, Solid a., Soluble a., Planter’s a. Prep. Expose strained white of egg or serum of bullock’s blood, in a thin stratum, to a current of dry air, until it concretes into a solid transparent substance, resembling horn. In this state it may be kept any length of time, or it may be further dried until brittle, and then reduced to coarse powder.

Use. It is extensively employed as a ‘clarifier’ in the sugar plantations of the West Indies, and elsewhere. It is prepared for use by soaking and stirring it with cold water until it is dissolved, when it is whisked to a froth in the usual way, and agitated with the liquid to be clarified.

Albumen, Iodised. 1. To the white of every egg employed add 7⁄2 grains of iodide of potassium dissolved in an equal weight of distilled water. Beat the mixture to a froth, let it stand until insoluble matters have settled, pour the clear portion into a wide-mouthed bottle, and keep in a cool place. 2. Dissolve 50 grains of iodide of potassium and 10 grains of bromide of ammonium in 2⁄2 oz. of distilled water, and add 120 minims of strong liquor ammoniæ. Add this solution to 10 oz. of albumen, let the mixture stand to settle, and filter. This preparation is said to keep good for a long time.

Albumen, Solution of (B. P.). Take of white of one egg; distilled water, four fluid ounces. Mix by trituration in a mortar, and filter through clean tow, first moistened with distilled water. This solution must be recently prepared.

Albumen, Vegetable. This substance, long considered to be a distinct proximate principle peculiar to the vegetable kingdom, has been shown, by recent researches, to be identical with animal albumen. It is particularly abundant in carrots, turnips, cabbages, green stems of peas, and oleaginous seeds.

ALBU′MEN. In botany, the solid, fleshy, or horny substance found in many seeds, between the integuments and the embryo. It is the part that furnishes the flour of the ‘cereals,’ the flesh of the ‘cocoa-nut,’ and the great mass of the seeds of coffee and other vegetables. However poisonous the plants which produce it may be, this substance is never deleterious.

ALBUMENISED PAPER. A French paper highly glazed, having a fine surface, and made by Rive; a German paper having a more uniform texture, and made by Saxe; also a paper by Towgood, are recommended for the preparation of albumenised paper. Positive paper may be albumenised as follows:—Add 15 grains of finely pulverised common salt to the white of every egg used, and whisk until the mixture is entirely converted into a white froth. Allow this froth to stand in a glazed earthenware pan which must be rather larger than the sheets of paper to be albumenised, for about twelve hours. At the end of this pour the clear portion of the liquid into a flat porcelain tray. Mark the inferior side of the paper, slightly damp it, lift it by its ends, and float it carefully on the prepared albumen, keeping its inferior and dry side uppermost. Then raise the paper at each end, and if any air bubbles are seen remove them with a card or brush and replace the paper in the bath. Remove the paper from the bath and suspend it at the corners by clips. Albumenised paper should be kept dry by enclosing it in tin or zinc cases.

ALBUMENOIDS. A term applied to albumen, fibrin, casein, and similar bodies.

ALBU′MENOUS. Syn. Albumino′sus, L.; Albuminé, Abumineux, Fr.; Eiweisstoffhaltig, Ger. Formed of, containing, or having the properties of albumen.

Albuminous Plants. In botany, all plants whose seeds contain albumen in a separate state; as in the cereals, palms, &c.

Albuminous Principles or Substances. Albumen, casein, fibrin, gluten, &c.

ALBURN′UM. [L.] Syn. Alburn*; Sapwood. In botany, the white and softer parts of the wood of exogenous plants, lying between the inner bark and the heartwood. It consists of empty or nearly empty tubes or cells, which gradually acquire solidity by the deposition of resins, tannin, and other products of vegetation, and in time becomes wood. It is through the alburnum that the ascending sap chiefly flows.

ALCARAZ′ZA. [Sp.] A species of porous earthenware, or a vessel formed of it, made in Spain from a light, sandy marl, and but slightly fired. Their value as ‘coolers’ arises from the copious evaporation of the water, which gradually transudes. A similar ware and articles are made in France, under the name of HYGROCERA′MEN; and in England, under the names of POROUS WARE, WATER COOLERS, WINE COOLERS, BUTTER COOLERS, &c. The following are forms said to be used in our potteries:—

Prep. 1. Take of sandy marl, 2 parts; brine, q. s.; make a dough, and then knead in of common salt, in fine powder, 1 part. Bake the pieces slowly, and lightly.

2. Good clay, 2 parts; fine siliceous sand, 3 parts; brine, q. s.; common salt, 1 to 2 parts; as before.

3. Powdered clay, 2 parts; powdered charcoal, 3 parts (by weight); water q. s. to form a stiff dough. The kilning must be so arranged that the heat is applied gradually, and the vessels exposed to a current of hot air; and it must be continued until all the charcoal is burnt out, carefully avoiding over-firing.

AL′CHEMY (-kĭm-). Syn. Al′chymy (-kĭm-); Hermetic Art*; Alchem′ia, Alchym′ia, L.; Alchimie, Fr.; Alchemie, Ger.; Alchimia, It. The romantic forerunner of the modern science of chemistry. An imaginative art or science, having for its objects the discovery of a substance (PHILOSOPHER’S STONE) capable of transmuting the baser metals into gold—a panacea, or universal remedy (ELIXER VITÆ), by which disease and death were to be avoided by its possessor—an alkahest, or universal solvent—a universal ferment; and other like absurdities. A mixed metal formerly used for utensils was also called by this name.

AL′COHOL. C2H6O. [Eng., L.; B. P.] Syn. Al′kohol, Eng., L.; Alcoöl, Alcohol, Fr.; Alkohol, Höchst Rectifieirter Wein-geist., Ger.; Alcoöle, It. A term commonly applied to one kind of spirit—that obtained by the distillation of any fermented saccharine liquid, and forming the characteristic principle of wines, beers, spirits, and other intoxicating liquors.

Etym. Kohol, a Hebrew-Syriac word, is the name given to a preparation of powdered antimony used by Oriental ladies to paint their eyebrows. In course of time this term was applied to other fine powders, and ultimately to highly rectified spirits.

Hist., &c. Although the art of distillation was probably known at a comparatively early age of the world, the preparation of pure rectified spirit is a discovery of modern times. It was not until the 13th century that Raymond Lully first showed the way to concentrate spirit by means of carbonate of potash; after which date pure concentrated spirit gradually rose into note as an article of trade and commerce in Europe. In the 16th century its distillation was in common practice in these countries. (Burns.) By means of chloride of calcium, Dr Black obtained alcohol of sp. gr. 0·800 (about A.D. 1760); and Richter afterwards procured it of a sp. gr. so low as 0·796 at 60° Fahr. (Crell’s ‘Annals,’ 1796.) Lavoisier first demonstrated the composition of alcohol (about 1780). Its analysis was subsequently perfected by M. Saussure, jun., and confirmed by MM. Dumas and Boullay, and Gay-Lussac; and by many others since.

Nat. Hist. Alcohol is peculiar to the organic kingdom, being exclusively produced, in the natural way, by the process of fermentation.

Sources, &c. Dilute alcohol may be procured, by the ordinary process of distillation, from all fermented liquors. When drawn from wine (as in France), it constitutes BRANDY; when from the refuse juice of the sugar-cane, it is called RUM; when from malt, grain, or molasses (as in England), it is called MALT, RAW-GRAIN or MOLASSES SPIRIT; and when from rice or palm-wine, ARRACK. Brandy, rum, Hollands, and whisky, contain only about half their volume of alcohol; and gin much less. When distilled from any of these spirituous liquors, the alcohol contains, besides water, variable quantities of essential oils, ethers, and other flavouring matters, which, by one or more redistillations with charcoal or lime, it for the most part loses, and then becomes commercial spirit of wine. By a further rectification from chloride of calcium, lime, carbonate of potash, or any other substance having a strong affinity for water, the water is retained, and a strong spirit passes over containing not more than 10 per cent. of water. By repeating the process, and using the proper precautions, it may be obtained almost entirely free from water, and is then called absolute or anhydrous alcohol.

Preparation I. Of Absolute Alcohol:—

a. Alcohol (highly rectified spirit), of 85% (sp. gr. ·835 to ·822), is mixed, in a tubulated retort, with about half its weight of fresh-burnt quick-lime, in coarse powder; and the whole, after securely stopping the neck with a cork, and agitation, is allowed to repose for several days. The alcohol is then carefully distilled off, drop by drop, by the heat of a water bath, until the weight of the distillate nearly equals that of the ‘anhydrous alcohol’ in the spirit operated on. The sp. gr. of the product should be ·795 or ·796; but by carefully repeating the process with the distillate and a fresh quantity of lime, and prolonging the last digestion with the latter for several weeks, absolute alcohol of the sp. gr. ·79381 at 60° Fahr. may be easily obtained.

b. (Drinkwater; Fownes.) The strongest rectified spirit of wine is digested in a stoppered bottle for several days, with about half its weight of anhydrous carbonate of potash, in powder, frequent agitation being had recourse to; the alcohol, after repose, is then decanted, and treated with sufficient fresh-burnt quick-lime to absorb the whole of the spirit. After 48 hours’ digestion, the spirit, when distilled, will have the sp. gr. ·793 at 60° Fahr.

c. (Liebig; Ure.) Alcohol of about 90% is saturated with fused chloride of calcium, in powder, and after repose for a few hours in a stoppered bottle, is submitted to distillation as before. The product should nearly equal the quantity of dry alcohol in the sample. Ure recommends equal weights of the spirit and chloride to be taken; and the process to be stopped as soon as about half the volume of the spirit employed has passed over, or the distillate acquires a higher sp. gr. than ·791 at 68°, or ·796 at 60° Fahr.

d. (B. P. 1867.) Take of rectified spirit, 1 pint; carbonate of potash, 1⁄2 ounce; slaked lime, 10 ounces. Put the carbonate of potash and spirit into a stoppered bottle and allow them to remain in contact for two days, frequently shaking the bottle. Expose the slaked lime to a red heat in a covered crucible for half an hour, then remove it from the fire, and, when it has cooled, immediately put the lime into a flask or retort, and add to it the spirit from which the denser aqueous solution of carbonate of potash, which will have formed a distinct stratum at the bottom of the bottle, has been carefully and completely separated. Attach a condenser to the apparatus, and allow it to remain without any external application of heat for twenty-four hours; then applying a gentle heat, let the spirit distil until that which has passed over shall measure 1⁄2 fluid ounce; reject this, and continue the distillation into a fresh receiver until nothing more passes at a temperature of 200° Fahr.

e. (Poggendorff.) Saturate alcohol with caustic potash, then add half its volume of water, and distil at a low temperature.

II. Of Hydrated or Commercial Alcohol:—

a. (Alcohol, Ph. L. 1836.) Take of rectified spirit (sp. gr. 0·838), 1 gal.; chloride of calcium, 1 lb.; proceed as above, and distil 7 pints and 5 fl. oz. Sp. gr. of product 0·815. It contains about 7% of water, by weight, and 5% by volume.

b. (Alcohol, Ph. D. 1826.) Rectified spirit, 1 gal.; pearl-ashes (dried and still hot), 3⁄2 lbs.; mix, digest in a covered vessel, with frequent agitation, for seven days; then decant the clear portion, and add to it of chloride of calcium, 1 lb.; agitate to effect solution, and distil off the spirit until the mixture in the retort begins to thicken. Sp. gr. of product 0·810. It contains about 5% of water, by weight.

c. (Without distillation.) Rectified spirit is agitated, in a closed vessel, with anhydrous carbonate of potash (prepared by heating the salt to redness, and still slightly warm), until the powder sinks to the bottom undissolved; the carbonate is then added in considerable excess, and the agitation repeated at short intervals for some hours or even days; lastly, after sufficient repose, the clear upper portion is decanted.—Obs. If a clean spirit, and pure carbonate of potash (or at least one perfectly free from caustic potash or any other impurity soluble in strong spirit), be used, an alcohol sufficiently pure and free from water for many common purposes may be thus obtained; otherwise the product contains a little potassa, &c., which can only be removed by distillation. For some purposes, however, this would not be objectionable. Sp. gr. about ·812.

A, A bottle with two necks, the upper furnished with a ground-glass stopper.

B, Loop of cord to hang the apparatus up by.

C, Bladder, containing spirit, filled by means of the bottle A.

D, Neck of bladder accurately secured to the under neck of the bottle A.

III. (Soëmmering.—Varnish-maker’s alcohol.) The bladder of an ox or calf, thoroughly cleansed from fat, and washed and dried, is nearly filled with rectified spirit, and then securely fastened and suspended in any dry situation, at a temperature of about 122° Fahr. In from six to twelve hours, when the heat is properly maintained, the spirit is generally sufficiently concentrated, and in a little time longer is rendered nearly free from water (anhydrous), or of the strength of 96 to 98%.—Obs. The same bladder will serve for more than one hundred operations. If not kept very nearly full, a portion of the spirit escapes through the empty part. To prevent this accident, a bottle with a double neck, of the shape represented in the engr., may be employed; by which means the bladder may be kept constantly full during the process. After the first or second time of using, the bladder gives alcohol sufficiently pure for all ordinary purposes. Before hanging the apparatus up, it is better to enclose it in a coarse potato-netting, to prevent any accident arising from the strain on the neck of the bladder. Soëmmering recommends both the inside and outside of the dry bladder to be smeared over 2 or 3 times with a strong solution of isinglass; but this is not necessary to the success of the process.

IV. Rectified Spirit. (B. P. 1867.) Spiritus Rectificatus. Alcohol with 16 per cent. of water; obtained by the distilling of fermented saccharine fluids. Sp. gr. 0·838.

V. Proof Spirit. (B. P. 1867.) Spiritus Tenuior. Take of rectified spirit, 5 pints; distilled water, 3 pints. Mix. Sp. gr. of product 0·920.

Prop. of Alcohol. Light, transparent, colourless; highly volatile and inflammable, burning with a pale blue and smokeless flame; very mobile; odour, agreeable; taste, strong and pungent; miscible in all proportions with water, with the evolution of heat, and temporary expansion, but ultimate condensation of the mixture, some hours elapsing before the union is complete, and the normal temperature restored. The mixture has a higher sp. gr. than the mean of its constituents; and this is greatest when 54 vols. of alcohol are mixed with 49·77 vols. of water, the resulting compound measuring only 100 volumes. It absorbs water from moist air; dissolves resins, essential oils, camphor, bitumen, soaps, sugar, carbonic and boracic acid, iodine and the iodides, lime, ammonia, soda, potash, the alkaloids, wax and spermaceti (when boiling), all the deliquescent salts (except carbonate of potassa), and various other substances. It curdles milk, coagulates albumen, and (in quantity) separates both starch and gum from their mucilages. It boils, in the air, at 173° Fahr., when in the anhydrous state. When diluted with water its boiling point rises in proportion to the amount of water added. It boils, in vacuo, at 56° Fahr. Every volume of boiling alcohol yields 488·3 vols. of vapour at 212° Fahr. Its sp. gr. is 0·793811 at 60° Fahr., that of its vapour being 1·6133. It has never been frozen; when cooled to -166° Fahr., it acquired the consistence of castor oil, but did not solidify. It contracts by cold; between -15° and +99° Fahr., this occurs with great regularity, at the rate of ·00047 part of its volume for every degree of the thermometer. Its evaporation, like that of ether, produces intense cold. The products of its combustion are carbonic anhydride and water. It acts as a powerful antiseptic on organic substances immersed in it, and is in consequence extensively employed in the preservation of anatomical preparations. With the acids it forms ethers.

Phys. eff. Alcohol is a narcotico-acrid poison. In small doses it occasions excitement and intoxication; in larger ones, delirium, somnolency, coma, apoplexy, and death. It acts as a violent nervous stimulant, and, by abstracting water from the soft tissues of the stomach and primæ viæ, destroys their organisation. It is alike poisonous to all animals;—2 drs. will kill a dog. All strong spirits act in the same way, the effect being proportionate to the state of concentration and the quantity taken. On plants it acts as a rapid and fatal poison.

Ant., &c. Copious internal use of tepid water, with cold affusions to the head and spine, and injection of cold water into the ears. In the absence of vomiting, a strong emetic should be given, or the stomach-pump used. Ammonia may be used as a stimulant, and, added to water just in sufficient quantity to flavour it, is one of the best antidotes. The head should be kept elevated, and bleeding had recourse to, if cerebral congestion threatens.

Tests in cases of death. 1. The odour of the contents of the stomach and ejected matters, and their ready inflammability. 2. The spirit may be separated by digestion with water, filtration, the addition of carbonate of potash, and distillation.

Comp., &c. Its per-centage composition is—

Dumas and Boullay. Brande and Ure. Ure. sp. gr. 0·812.

Carbon 52·37 52·18 47·85

Hydrogen 13·01 13·04 12·24

Oxygen 34·61 34·78 39·91

99·99 100·00 100·00

This nearly represents 2 equivalents of carbon, 3 eq. of hydrogen, and 1 of oxygen. The atom of alcohol is now regarded as a multiple of these numbers, and formed by the breaking up of one atom of grape sugar (C13H28O11) into 4 eq. of alcohol, 8 eq. of carbonic acid, and 4 eq. of water. It was formerly regarded as a compound of 1 eq. of olefiant gas, and 1 eq. of water; but it is now generally viewed as HYDRATE OF THE OXIDE OF ETHYLE (C2H5.HO), or a compound of ethylene and water (C2H4.H2O). Grape sugar alone yields alcohol; cane sugar, before it undergoes the vinous fermentation, being first converted into this substance by contact with the ferment.

Purity. The presence of water is shown by the specific gravity (see Alcoholometry); the absence of other foreign matter by the following tests:—