POTASH. SODA. AMMONIA
Poisoning by the use of the alkalies is very rare. For the sake of convenience, and as the symptoms produced by the caustic preparations of soda and potash, taken in large doses, do not greatly differ, one description will do for both:
Potash is found in commerce as (1) caustic potash, either solid or in solution; (2) carbonate and bicarbonate; (3) pearl-ash and soap-lees.
Soda is found as (1) caustic soda; (2) carbonate (washing soda) and bicarbonate; (3) soap-lees, carbonate of soda mixed with caustic alkali.
General Characters.—Like the inorganic acids, the alkalies destroy the animal tissues with which they come in contact. Their action is local, no specific remote effects being produced. They are seldom, if ever, used for the purpose of homicide; the deaths caused by them are in most cases the result of accident or suicide. When injected directly into the veins of animals, the toxic action of potash and soda appears to differ, the former arresting the action of the heart in diastole, whereas the latter, according to Podocaepow and Guttman, does not, even in large doses, affect the heart or temperature—Guttman, moreover, asserting that soda has no influence upon the nerve centres, the peripheral nerves, or the muscles. It is difficult to understand how, with this asserted negative action, soda, like potash, causes death.
Symptoms.—During the act of swallowing, the patient complains of a caustic taste, accompanied with a sensation of burning in the mouth and throat, extending into the stomach. Vomiting may or may not be present; but in severe cases, when it does occur, the vomited matters may be mixed with blood. The surface of the body is cold, and bathed in a cold sweat. Purging is generally present, accompanied with intense pain and straining. The pulse is weak and quick, and the countenance anxious.
The post-mortem appearances are inflammation and softening of the mucous membrane of the mouth, gullet, and stomach, which may also be covered with chocolate-coloured or black spots. When life has been prolonged for some months the stomach may become contracted, the pyloric orifice scarcely admitting the passage of a fine probe.
Chemical Analysis.—The caustic alkalies are known from their carbonates by giving a brown precipitate with nitrate of silver; whereas their carbonates give a white, and also effervesce on the addition of an acid.
The following table will show the reaction of these alkalies with reagents:
To distinguish Caustic Potash from Caustic Soda