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