Cooley's Cyclopaedia of Practical Receipts Volume I Part 11

_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 03 to 04 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 gla.s.s 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 quant.i.ties 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 gla.s.s 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 pota.s.sa 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 qua non_.

[Ill.u.s.tration:

(_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 a.s.sist 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 circ.u.mstance that 91 gr. of commercial oil of vitriol, of a sp. gr. of 1845, 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 princ.i.p.ally 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.; ACIDITe, Fr.; SaURE, 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 capsic.u.m, 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 diarrha 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, diarrha, 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 diarrha 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; bis.m.u.th, a.r.s.enic, 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 circ.u.mstance that an Act of Parliament pa.s.sed 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 gra.s.s 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_ _j.a.ponica_, 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-gra.s.s, wheat, oats, barley, common turnips, swedes.

_Second list of Plants affected by Noxious Vapours, mixing the cla.s.ses 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-gra.s.s, poplars, hawthorn, potatoes--receive damage in winter to roots.

II. Wheat receives some damage in winter.

Oats in May, when in the gra.s.s 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 gra.s.s 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.

=ACIDULae.= [L. pl.] In _medicine_, mineral waters rich in carbonic acid.

=ACIDULATED=. _Syn_. ACIDULATUS, L.; ACIDULe, 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 s.e.xes; 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 pota.s.sium, 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._, Ranunculaceae; _s.e.x. 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 diarrha; 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, 54-1/2 grains to 1 fluid ounce.