BARIUM SALTS.—Two preparations of barium have caused death, viz., the chloride and the carbonate. These may also give rise to specific nervous symptoms, as cramps and convulsions. _Chloride of Barium_ is found crystallized in irregular plates or tables, which are permanent in the air, soluble in water, and of a disagreeable bitter taste. Half an ounce has proved fatal in two hours, after causing symptoms of irritation, with vertigo, paralysis and convulsions. _Carbonate of Baryta_ or _Barium Carbonate_, in its native state, occurs in massive radiated crystals, very heavy, and nearly colorless. Artificially prepared, as sold in the shops, it is a fine, tasteless, odorless powder, almost insoluble in hot or cold water. One drachm is said to have destroyed life, but recovery has taken place after a much larger dose. _Treatment._—The sulphate of soda or sulphate of magnesia, or some earthy sulphate, should be speedily administered, by which the poison will be converted into an inert insoluble sulphate of baryta. Emetics should also be given, or the stomach-pump used. CHAPTER X. SALTS OF THE METALS: ZINC—SILVER—TIN—BISMUTH—CHROME—IRON. Two preparations of ZINC must be noticed: SULPHATE OF ZINC (_White Vitriol_, _White Copperas_.)—This is a very mild irritant, resembling in its appearance Epsom salts and oxalic acid. It is very useful as an emetic in scruple or half-drachm doses, dissolved in any thin fluid. In one case an ounce was accidentally taken. Great pain in the stomach, vomiting, and prostration, soon set in. Subsequently there was gastritis, and recovery only occurred after a prolonged convalescence. _Treatment._—Vomiting is to be encouraged by milk or albuminous fluids; after which remedies containing tannin (strong tea, decoction of oak bark, or tincture of Peruvian bark) are to be given. CHLORIDE OF ZINC.—A solution of chloride of zinc forms a valuable disinfectant, but is also a dangerous irritant, or, if sufficiently strong, a corrosive poison. Sir William Burnett’s Fluid consists of gr. xxv of this salt to the drachm of water. It has been taken in mistake for fluid magnesia, pale ale, &c., and has caused death. _Symptoms._—A burning sensation in the mouth and throat is immediately produced. This is followed by nausea, vomiting, and signs of collapse. Death has occurred in less than four hours. _Post-mortem Appearances._—The mucous membrane of the throat and stomach has been found corrugated, hard, and leathery. In the case of a sailor who died from about half a pint of Burnett’s solution, the body was livid, the neck swollen, the cerebral vessels were engorged, and the lungs were congested. The mucous coat of the stomach was of a purple red, and partially corroded, while the pyloric orifice looked as if caustic had been applied to it. There were patches of congestion in different parts of the small intestines. _Treatment._—Albuminous drinks, followed by some preparation of tannin, will be needed.