But it is not in all cases that this tolerance of the medicine can be established. Probably, so far as concerns its direct relations with the gastric nervous centre, the result might be uniform; but, in some instances, the susceptibility of the stomach to the irritant influence of the antimonial is such, that vascular irritation if not inflammation of the mucous membrane is induced, which causes nausea, vomiting, and purging through the relation of the membrane itself with the nervous centres, which is not impaired by repetition in the same manner as that between these centres and the medicine. Consequently vomiting and purging are incessantly maintained, and it is not possible to persevere with the large doses without great danger. Again, should these phenomena return after having once disappeared, an irritability of membrane is induced, which renders the further use of the medicine hazardous. it not unfrequently, however, happens that the tolerance is sustained, after having been established, for many days and even for weeks. Rasori supposed that it was diminished, in cases of disease, as convales-. cence became established; but Dr. Pereira states that, though he has seen the medicine extensively employed, he has never known this supposition to be satisfactorily confirmed. (Mat. Med., 3d ed., p. 697.)

Occasionally, after tartar emetic has been used largely for some time, there is a peculiar effect experienced in the mouth and fauces; a feeling of tension, with otherwise disagreeable sensations, and a metallic taste; and occasionally also an inflammation of these parts, with redness and pain, and an aphthous eruption on the mucous membrane. Some suppose these effects to result from the irritative action of the medicine, as it comes in contact with the parts affected when swallowed; others ascribe them to its operation through the circulation. But, whatever view may be entertained of the origin of this antimonial stomatitis, it should serve as a warning, as soon as perceived, to cease immediately with the use of the medicine, for fear that a similar susceptibility to be inflamed by it should extend to the stomach and bowels.

It has been already stated that tartar emetic does not evince any signs of a direct action upon the nervous centres of animal life. Sensibility is not affected, and the mind generally remains perfectly clear in the midst of the most violent disturbance of the organic functions. When nausea is not produced, even the command of the will over the muscles is not impaired. Secondarily, however, the proper cerebral functions are often more or less disturbed. in excessive nausea, all mental energy is lost, and the power of voluntary motion greatly diminished; and, in sympathy with the irritated stomach and bowels, the mind is sometimes more or less disordered, and convulsive movements induced.

Local Effects

The local effects of tartar emetic are those of a powerful irritant. This is abundantly proved by its action upon the stomach and bowels already referred to. Applied in powder or concentrated solution to a mucous, ulcerated, or freshly cut surface, or to the skin deprived of the cuticle, it produces speedy and violent inflammation, not unfrequently attended with mortification. Upon the sound skin it operates more slowly, but in the end causes redness and a peculiar painful eruption, consisting of flat pustules, which cover themselves with scabs, and, if the application be continued, are apt to be followed by deep ulceration, and even sloughing. Of this effect of the salt more will be said under the rubefacients.

Poisoning by Tartar Emetic. Though tartar emetic may, by a proper management of the dose, in reference to amount and succession, be given to a very great extent without causing any serious consequences, it is nevertheless capable of acting as a powerful poison, and has frequently caused death. I believe that its fatal effects are to be ascribed mainly to its irritant action upon the alimentary mucous membrane, whether that action be direct or indirect; at least I have neither witnessed its poisonous influence, nor seen any well authenticated account of it, in any case, without evidences of high irritation or inflammation of the stomach and bowels; and, when this is avoided by the mode of its administration, enormous quantities have been taken without serious injury. Probably the reason why death has not more frequently resulted from tartar emetic is, that it is so promptly rejected by the stomach, or carried off through the bowels. Magendie found that half an ounce of it might be given to dogs with impunity, if they were allowed to vomit; but if, after it had been swallowed, the oesophagus was tied, from four to eight grains were sufficient to cause death in a few hours.* From five to twenty grains, given at one dose, have frequently produced alarming effects in man; and Dr. Beck mentions the case of a child in which fifteen grains caused death in two weeks, preceded by vomiting, purging, and convulsions.* Orfila gives the particulars of a case in which forty grains proved fatal; and several others are on record, in which quantities varying from one to three drachms have had the same effect. The symptoms usually resulting from a poisonous dose of tartar emetic are excessive nausea, violent vomiting and purging, spasmodic pains in the stomach and bowels, burning pain in the throat and epigastrium, sometimes a sense of stricture of the throat and difficult deglutition, tenesmus, great prostration, faintness, a feeble vanishing pulse, cold or hot skin, painful cramps in the extremities sometimes amounting to tetanic spasms, and occasionally convulsions and delirium before death. Sometimes there is inflammation of the mouth and throat, followed by desquamation of the epithelium, or the formation of whitish incrustations, which afterwards darken.

* These reports of death in dogs from tartar emetic, after the tying of the oesophagus, must be received with some allowance; as it. has been ascertained that, under similar circumstances, the animal may die in a day or two, though but a small quantity of common salt may have been given instead of tartar emetic. (Journ. de Pharm. et de Chim., Nov. 1858, p. 362.) - Note to the second edition.