Tartris Antimonii. E. Tartarum Antimoniatum. D.
Tartar Emetic.[[377]]
Qualities. Form, crystals whose primitive form is the regular tetrahedron, although it assumes a variety of secondary forms. Colour, white. Odour, none. Taste, slightly styptic and metallic; on exposure to the air, the crystals slightly effloresce and become opaque; thrown upon burning coals, they become black and afford metallic antimony. Chemical Composition. This is involved in much doubt and obscurity; it is stated in the various dispensatories to be a triple salt, consisting of tartaric acid, oxide of antimony,[[378]] and potass, and which therefore, says Mr. Thomson, on the principles of the reformed nomenclature, ought to be termed a tartrate of antimony and potass. The truth of these views, however, is extremely questionable. I am inclined to believe with Gay Lussac, that in the various metalline compounds, of which super-tartrate of potass is an ingredient, this latter substance acts the part of a simple acid; an opinion which receives much support from the great solvent property of cream of tartar, and from the striking fact that it is even capable of dissolving various oxides which are insoluble in tartaric acid, of which the protoxide of antimony is an example. According then to this view, tartar emetic is a salt composed of bi-tartrate (super-tartrate) of potass, which acts the part of an acid, and protoxide of antimony: from the experiments of Mr. Phillips, it would appear that 100 parts of the bi-tartrate will dissolve 70 of the protoxide. In this state of doubt it must be admitted that no name can be more appropriate than Antimonium Tartarizatum, and the London College have therefore properly disregarded the suggestions which have been offered for changing its name. Solubility. Much discrepancy of opinion exists upon this subject, owing probably to the variations and incidental impurities to which the salt is liable. Dr. Duncan, who selected very pure specimens for examination, states that it is soluble in three times its weight of water at 212°, and in fifteen at 60°. This solution, when the salt is pure, is perfectly clear and transparent, but if long kept, unless a portion of spirit be added, it undergoes decomposition; a precipitate indeed sometimes takes place very rapidly, but this is generally tartrate of lime, an incidental impurity, derived from the super-tartrate of potass. Incompatible Substances. Mineral Acids, Alkalies, and their Carbonates, most of the Metals, Soaps, Hydro-Sulphurets, and many infusions and decoctions of bitter and astringent Vegetables, e. g. f℥j. of the decoction of yellow bark is capable of completely decomposing ℈j of this salt, and of rendering it inert.[[379]] Berthollet has accordingly recommended the immediate exhibition of this decoction when an overdose of the salt has been taken; and Orfila has given a very satisfactory case in which this antidote succeeded. Infusion and tincture of galls throw down curdled and inert precipitates of a dirty white colour, inclining to yellow. Rhubarb is equally incompatible: the extract of this substance therefore never ought to be employed in forming pills of tartar emetic: but it deserves notice that this salt is not decomposed by the infusions of gentian or wormwood. The Alkaline Sulphates, provided they be perfectly neutral, produce no disturbance in solutions of tartar emetic, and therefore cannot be considered incompatible with them; if there be any excess of acid, as in alum, bi-sulphate of potass, &c. then its decomposition is effected, and a white insoluble sulphate of antimony is precipitated. It appears therefore that the famous “Emeto-purgative” of the French school, consisting of sulphate of soda, and tartarized antimony in solution, is by no means the unchemical mixture which some have considered it to be, and that it really produces its effects from the operation of its original ingredients, and not from that of the compounds (Sulphate of Antimony, Tartrate of Soda, and Sulphate of Potass) which have been erroneously supposed to result. Forms of Exhibition. Solution is its best form, see Liquor Antimonii Tartarizati. Dose. It either vomits, purges, or sweats, according to the quantity exhibited; thus gr. 1/4 will, if the skin be kept warm, promote a diaphoresis; gr. ½ will procure some stools first, and sweating afterwards; and gr. j will generally vomit and then purge, and lastly sweat the patient; in very minute doses, as gr. 1/10 or 1/12 combined with squill and ammoniacum, it acts as an expectorant, see Formulæ 1, 2, 3, 8, 60. It is decidedly the most manageable, and the least uncertain of all the antimonial preparations, and the practitioner would probably have but little to regret, were all the other combinations of this metal discarded from our pharmacopœias. Some authors have considered this substance as possessing sedative powers, independent of its nauseating and diaphoretic effects. It undoubtedly acts upon the heart, and controls the force of the circulation in fevers, without occasioning any other sensible effect. Mr. Brodie, after having given large doses of this salt to animals, found that the heart beat very feebly, and although artificial respiration was kept up, it soon ceased to act altogether. Lenthois of Montpellier advises small doses of it in incipient phthisis, and it would on some occasions appear to diminish the febrile excitement. The following is the form in which Dr. Lenthois recommends it to be exhibited upon such occasions. He directs a grain of Tartarized Antimony to be dissolved in eight table spoonsful of distilled water, which are to be added to six or eight pints of water, and to be taken as common drink. Tartar emetic, when triturated with lard, in the proportion of ʒiss or ʒij to ℥j of the latter, forms a very powerful rubefacient, occasioning a pustular eruption on the skin, and proving very serviceable in deep-seated inflammation; or the application may be made by dusting a piece of adhesive plaster with tartarized antimony, taking care to leave a margin untouched that it may more firmly adhere. Dr. Jenner, in a late Essay on the influence of artificial eruptions on certain diseases, recommends the following formula for such a purpose.—℞. Antimonii Tartarizati (in pulverem subtilem trit.) ʒij—Unguenti Cetacei ʒix;—Sacchari albi[[380]] ʒj;—Hydrargyri Sulphureti Rubri gr. v. M. ut fiat Unguentum. The Pustules which are produced by the inunction have been generally compared to variolous pustules, they are, however, in general much smaller, not so red at the base, nor so tense and white when fully suppurated. They are very painful. In Hooping cough, frictions with this ointment upon the region of the stomach have been greatly extolled. By this application, says Dr. Jenner, we can not only create vesicles, but we can do more,—we have at our command an application which will at the same time both vesicate and produce diseased action on the skin itself, by deeply deranging its structure beneath the surface. This is probably one cause why the sympathetic affection excited by the use of Cantharides, and those changes produced by Tartar Emetic are very different. The eruption should be kept up for some time, either by the re-application of small portions of the diluted tartaremetic ointment, to the affected part, or by other gently stimulating ointments. Should they become much irritated and very painful, a soft bread and milk poultice will in general afford relief, without interfering with the progress of the eruption. Officinal Preparations. gr. j. is contained in f℥ss of Liquor Antimonii Tart: L. and Vinum Tartratis Antimonii. E.[[381]] Adulterations. It should be always purchased in its crystalline form; and a solution of it in distilled water ought to furnish a copious gold coloured precipitate with sulphuret of ammonia; a precipitate soluble in nitric acid, with acetate of lead; and a white and extremely thick precipitate, dissolving with facility in pure nitric acid, with lime water. If the crystals deliquesce, the presence of other salts may be inferred. M. Sexullas, in a memoir of which there is a copious extract in the Journal de Pharmacie for 1821, has shewn that all the antimonial preparations used in medicine, except carefully crystallized Tartar Emetic, contain more or less arsenic, which metal was originally combined with the antimony in the ore, and has continued pertinaciously associated with it through all its modifications.
AQUA. Water.
Water, from its extensive powers as a solvent, never occurs in a state of absolute purity, although the nature and degree of its contamination must necessarily vary according to circumstances and situation. It is generally found holding earthy matter in a state of mechanical suspension, or saline and other bodies in chemical solution. The usual varieties of common water are classed and defined by Celsus; and modern chemists have not found any reason to reject the arrangement. “Aqua levissima pluvialis est; deinde fontana, tum ex flumine, tum ex puteo; posthæc ex nive, aut glacie; gravior his ex lacu; gravissima ex palude.”
1. Rain Water. Aqua Pluvialis, when collected in the open fields, is certainly the purest natural water, and consequently of the least specific gravity; the bodies which it holds in solution are, carbonic acid, a minute portion of carbonate of lime, with traces of muriate of lime. Dew is said to be water saturated with air. Rain water ought, however, to be boiled and strained whenever it is collected near large towns; Hippocrates gives this advice, and M. Margraaf of Berlin has shewn the wisdom of the precaution by a satisfactory series of experiments.
2. Spring Water. Aqua Fontana, in addition to the substances detected in rain water, generally contains a small portion of muriate of soda, and frequently other salts; but the larger springs are purer than smaller ones, and those which occur in primitive countries, and in siliceous rocks, or beds of gravel, necessarily contain the least impregnation. An important practical distinction has been founded upon the fact, that the water of some springs dissolves soap, whilst that of others decomposes, and curdles it; the former has been termed soft, the latter hard water; soft water is a more powerful solvent of all vegetable matters, and is consequently to be preferred for domestic as well as medicinal purposes; the brewer knows well from experience how much more readily and copiously soft water will dissolve the extractive matter of his malt. Horses by an instinctive sagacity always prefer soft water, and when by necessity or inattention they are confined to that which is hard, their coats become rough and ill-conditioned, and they are frequently attacked with the gripes. Pigeons also refuse hard water when they have been accustomed to that which is soft.[[382]]
3. River Water. Aqua ex Flumine, being derived from the conflux of numerous springs and rain water, generally possesses considerable purity; that the proportion of its saline ingredients should be small, is easily explained by the precipitation which must necessarily take place from the union of different solutions; it is, however, liable to hold in suspension particles of earthy matter, which impair its transparency, and sometimes its salubrity; this is particularly observed of the Seine, the Ganges, and the Nile.[[383]]
4. Well Water. Aqua ex Puteo, is essentially the same as spring water, being derived from the same source; it is, however, more liable to impurity from its stagnation, or slow infiltration;[[384]] hence our old wells furnish much purer water than those which are more recent, as the soluble particles are gradually washed away. Mr. Dalton observes that the more any spring is drawn from, the softer the water becomes.
5. Snow Water. Aqua ex Nive, has been supposed[[385]] to be unwholesome, and in particular to produce bronchocele, from the prevalence of that disease in the Alps, but it does not appear upon what principle its insalubrity can depend; the prejudice however is a very ancient one, for Hippocrates observes that snow or ice water is unwholesome, in consequence of its finer particles being evaporated and lost during its solution: it appears to differ only from rain water in being destitute of air, to which water is certainly indebted for its briskness, and perhaps for many of its good effects upon animals and vegetables. The same observations apply to Ice Water.