Anti-Monii et Potassae Tartras. U.S. - Antimonium Tartara-tum. Br. - Antimonii Potassio-Tartras. Loud. - Antimo-nium Tartarizatum. Ed., Dub. - Tartarated Antimony. - Potassio-tartrate of Antimony. - Tartarized Antimony. - Tartar Emetic.

This is prepared by saturating the excess of tartaric acid in bitartrate of potassa with oxide of antimony. I would here observe that, in using the term oxide of antimony instead of the chemical name of teroxide, I am incurring no risk of being misunderstood, as this is the only well-defined oxide of the metal; the compounds containing larger proportions of oxygen being acids, and called antimonious and antimonic acid. it is, besides, the officinal name. in different processes, different forms of the oxide are used; but it was generally admitted, till of late, that the most convenient was the powder of Algaroth, which contains the oxide of antimony combined with a little chloride. At present, however, the pure oxide of antimony is used in our national Pharmacopoeia, which gives a distinct process for its preparation. This is boiled with bitartrate of potassa in distilled water, and the solution, having been filtered while hot, is set aside to crystallize. The crystals thus obtained are the salt in question, containing two equivalents of tartaric acid, one of potassa, and one of oxide of antimony, besides water of crystallization. These constituents are probably combined in the form of a double salt, composed of one equivalent of tartrate of antimony, one of tartrate of potassa, and two or three of water. With this view of its nature, it is properly designated as tartrate of antimony and potassa. it should always be procured in the form of crystals, as the possibility of accidental admixture of impurities, or purposed sophistication, is thus provided against; and arsenic, which is stated by Serullas to accompany antimony in its other preparations, is entirely excluded from this, being left behind when it crystallizes.

Properties

The crystals of tartar emetic, when recently prepared, are transparent, but on exposure become white and opaque by efflorescence. Their characteristic form is that of rhombic octohedra, though, as usually existing in commerce, the crystals are seldom perfect, presenting in general the shape of a four-sided pyramid with a broken irregular base. The salt is commonly in the form of a white powder in the shops. Tartar emetic is inodorous, of a slightly sweetish, somewhat styptic, and metallic taste, readily soluble in water, and soluble in dilute alcohol, but insoluble in alcohol when concentrated. its aqueous solution is decomposed on exposure to the air, with the production of a microscopic fungus, which gives it a mouldy appearance.

The salt is charred by heat, with the odour of burning tartaric acid. With sulphuretted hydrogen it forms in solution an orange-red precipitate of sulphuret of antimony, which is dissolved by hot muriatic acid; and the solution thus formed, if poured into water, is decomposed, with the formation of a white powder.

Incompatibles. Sulphuric, nitric, and muriatic acids produce precipitates with the solution, which are soluble in an excess of the acid. Precipitates are also caused by the alkalies and their carbonates, lime-water, chloride of calcium, acetate and Subacetate of lead, corrosive chloride of mercury, hydrosulphuric acid and the soluble sulphurets, and the vegetable astringents through their tannic acid.

1. Effects On The System

In general terms, tartar emetic may be said to be sedative to the circulation and respiration, stimulant to most of the secretions, and, in large doses, emetic, and often cathartic.

Given in minute doses, such as produce no observable effect in health, it is thought to modify the system in some unknown way, so as to be serviceable in certain diseases. in other words, it is supposed to act as an alterative.

When given so largely as to occasion obvious effects, its sedative influence is evinced by a diminution in the frequency, force, and fulness of the pulse, in the frequency of respiration, and in the temperature of the surface. if, at the same time, the heart be examined by the ear, it will be found to act less forcibly.*

Along with these sedative effects, there is very often an increase of one or more of the secretions; that one of the secretory functions being most affected, towards which circumstances especially direct the agency of the medicine. Thus, when the patient is covered warmly in bed, and warm drinks or diaphoretic medicines are given at the same time, perspiration is specially promoted. if, on the contrary, the surface of the body be kept cool, and cold or diuretic drinks are exhibited, the action of the medicine is directed to the kidneys, and the urine is sometimes greatly increased. Should the bronchial tubes be in a state of vascular irritation or inflammation, the antimonial has a tendency to increase the mucous secretion, and not unfrequently acts as a very efficient expectorant. in somewhat larger doses than necessary to affect the secretions above mentioned, and sometimes even in the same dose, it operates as a laxative, producing liquid discharges, which may be bilious, mucous, or watery, showing that the secretions of the liver, the intestinal mucous membrane, and possibly the pancreas, are promoted. When it affects the bowels, it is less apt to act upon the skin and kidneys, partly because it is carried out of the system without being absorbed, and partly also because, when any one of the secretions is increased, from any cause, it is apt to be so at the expense of the others. The medicine is said sometimes also to increase the saliva.

* Dr. Theodore Ackerman states positively, as the result of often repeated experiments, that, instead of diminished frequency of the pulse, which is generally affirmed to be one of the effects of tartar emetic, that medicine, given in moderate doses, uniformly increases the frequency of the pulse when it begins to nauseate. After a time the frequency diminishes, but not to the normal standard, and then rises again before it ultimately settles down to the usual state. He never saw a diminution in the frequency of the pulse from medium doses in less than eight hours. But at the same time that it is thus accelerated, it is weakened; and the heart's impulse is lessened both in force and extent. Respiration increases and falls in frequency with the pulse. The temperature is reduced in proportion to the frequency and weakness of the pulse. The amount of the excretions and secretions is on the whole increased. The saliva and perspiration are augmented; and. as to the urine, though the proportion of water is lessened, as also of chloride of sodium, yet the urea is considerably augmented, generally as much as one-eighth and sometimes to one-quarter. (B. and F. Medico-chir. Rev., Am. ed., April, 1859, p. 260.) - Note to the third edition.