Syn. Turpeth Mineral.

Preparation

This is prepared by boiling mercury and sulphuric acid together to dryness, and throwing the resulting mass into boiling water. The sulphate of deutoxide of mercury, obtained in the first step of the process, is decomposed by the hot water into a supersulphate, which remains dissolved, and the yellow subsulphate, which is deposited.

Properties

This mercurial is in the form of a lemon-yellow powder, inodorous, of an acrid taste, and nearly insoluble in water, requiring 2000 parts of cold, and about 600 of hot water, for solution. At a red heat, it is entirely dissipated.

Medical Effects and Uses

Turpeth mineral has long been used as an emetic, formerly much more than at present. Though operating with great promptness, and with little of the secondary prostrating influence of the antimonials, it has been considered as uncertain, sometimes failing to act, and sometimes acting harshly; and is liable to the disadvantage that, if not wholly rejected by the stomach, it is apt to salivate. These qualities unfit it for ordinary use as an emetic; but it is occasionally employed, repeated two or three times a week, in cases of obstinate swelling of the testicle, in which its mercurial influence may be desirable; and has, moreover, been strongly recommended by Dr. Hubbard, of Maine, in the treatment of croup. Dr. Hubbard states that it is prompt and certain, that it is little disposed to act on the bowels, and prostrates less than other emetics used in the treatment of that disease. in the pseudomembranous variety, its disposition to affect the system would be rather in its favour than otherwise.

The ordinary emetic dose is five grains. For a child two years old, with croup, the dose is two or three grains, to be repeated, if necessary, in fifteen minutes. in over-doses, turpeth mineral acts as a corrosive poison. in a case recorded in Guy's Hospital Reports (x. 180, a.d. 1864), death resulted from the accidental swallowing of forty grains. The symptoms were violent vomiting and purging, severe abdominal pains, excessive salivation with soreness of the mouth and fauces, great prostration followed by some febrile reaction, and a series of distressing phenomena dependent on the inflammation and disorganization of the mucous membrane of the whole alimentary canal. Death took place on the eleventh day. Throughout the intestinal canal, the mucous mem- brane was softened and easily torn, with dark patches here and there. The stomach towards the pylorus and on the lower surface was congested and softened, with inflamed patches elsewhere. The inner surface of the mouth and fauces was covered with black sloughs.

Besides the mineral substances mentioned, there are many others which possess emetic properties; as, for example, alum, the precipitated sulphuret and chloride of antimony, the acetates of copper and zinc, corrosive chloride of mercury, etc.; and, in fact, almost all highly irritating or corrosive substances will occasionally provoke vomiting; but, with the single exception of alum, which is used in the treatment of croup, and of which sufficient has been said under the head of the astringents, not one of them, so far as I know, is at present habitually employed in this capacity. They are generally more or less uncertain, are liable to do serious injury in over-doses, and are susceptible of no useful application as emetics, for which those generally employed are not as well or better adapted.