XII.—HYDROCHLORIC ACID
Hydrochloric Acid, muriatic acid, or spirit of salt, is not uncommonly used for suicidal purposes, being fifth in the list.
Method of Extraction from the Stomach.—The same as for sulphuric acid. As hydrochloric acid is a constituent of the gastric juice, the signs of the acid must be looked for.
Post-Mortem Appearances.—The mucous membranes are dry, white, and shrivelled, and often eroded.
Tests.—The concentrated acid yields dense white fumes with ammonia. When warmed with black oxide of manganese and strong sulphuric acid it gives off chlorine, recognized by its smell and bleaching properties. Diluted it gives with nitrate of silver, a white precipitate, which is insoluble in nitric acid and in caustic potash, but is soluble in ammonia, and when dried and heated melts, and forms a horny mass. Stains on clothing are reddish-brown in colour.
Fatal Dose.—Half an ounce.
Fatal Period.—Shortest, two hours; average, twenty-four hours. Death may occur after an interval of some weeks from destruction of the gastric glands and inability to digest food.
XIII.—OXALIC ACID
Oxalic Acid is used by suicides, though not often by murderers. The crystals closely resemble those of Epsom salts or sulphate of zinc; oxalic acid has been taken in mistake for the former. It is in common use for cleansing brass, in laundry work, for dyeing purposes, and especially for bleaching straw hats.