From _organic_ liquids, the antimony may be obtained by boiling them with tartaric acid, filtering, and then applying the tests for antimony. _Treatment_.--Milk, magnesia, and infusions containing tannin. CHLORIDE OF ZINC This substance is a powerful corrosive. It is employed as a disinfectant, and is sold to the public under the name of “Sir W. Burnett‘s Fluid.” This preparation, which is a strong solution of the chloride of zinc, has caused death by being mistaken for “fluid magnesia,” for “pale ale,” and in one case, on board one of the American steamers, for “mineral water.” Chloride of zinc is also used in the treatment of cancer and other tumours as an external application. _Symptoms._--The symptoms come on immediately after the poison is swallowed. Chloride of zinc acts as a powerful corrosive, accompanied with all the symptoms which have been before described when speaking under the head of corrosive poisons. The nervous system is also powerfully affected. _Post-mortem Appearances._--Those of corrosive poisoning in its most violent form. The mouth, throat, stomach, and intestines are often found hardened, white, opaque, and corrugated. _Chemical Analysis._--Ammonium sulphide gives a white precipitate, which is insoluble in caustic alkalies. Hydrogen sulphide gives a white precipitate in neutral solutions, but no precipitate when the free mineral acids are present. Potassium ferrocyanide gives a white precipitate. Test for chlorine with nitrate of silver. _Treatment._--White of eggs, emetics, followed by demulcent drinks. CHLORIDES OF TIN This metal requires but little notice; but the two chlorides--protochloride and the perchloride--form a mixture used in the arts, and known as _Dyer‘s Mixture_. They act as irritant poisons, but are seldom used as such. NITRATE OF SILVER The only preparation of silver requiring notice is the nitrate--_lunar caustic_, or _lapis infernalis_. It acts as a powerful corrosive. If administered for some time in small doses it is deposited in the skin, which acquires a permanent dark colour. It does not appear to be eliminated by the urine, and has been discovered in the liver five months after its administration was discontinued. The symptoms come on immediately, the vomited matters becoming blackened on exposure to light. The dark spots on the skin will also help to point to the nature of the poison. A dose of salt and water may be given by way of treatment. VULNERANT GLASS, ENAMEL, AND NEEDLES None of the above can be considered as poisons; but should they be taken, they give rise in most cases to irritation of the stomach and bowels. Pins and needles have been swallowed without doing much harm. Mixing ground-glass in food is a favourite mode of killing adopted by the West Indian negroes. CHAPTER III DIVISION II.--VITAL METALLOID IRRITANTS PHOSPHORUS