Ammonia is a gaseous compound of hydrogen and nitrogen; colorless, irrespirable, highly irritant, of strong alkaline reaction and pungent odor. It is obtained in the manufacture of coal gas, and occurs as a result of the decay of organic substances.
Applied to the skin, ammonia is a powerful irritant, causing redness, blistering, and sloughing. Inhaled, it causes severe irritation of the air-passages, with sneezing, disturbed respirations, flow of water from the eyes and nose, and quickened pulse. Ammonia acts as a general stimulant to the heart and nervous system, especially the spinal cord and respiratory centre. Being rapidly diffused, its action is prompt but somewhat transitory. It is excreted by the kidneys and mucous membranes.
In large amount ammonia is a corrosive poison, producing violent abdominal pain, vomiting and purging of bloody matters, with convulsions, collapse, and death. Consciousness may remain until the last, or coma may precede death. In some cases death has taken place within five minutes, having been caused probably by oedema of the larynx. The symptoms come on at once in poisoning by ammonia.
Dilute vinegar or lemon juice is given to counteract the alkali; oils and bland liquids to soothe the mucous membrane, which is corroded. Heat favors the action of ammonia, and cold antagonizes it; therefore, in poisoning by ammonia plenty of cold fresh air should be admitted, if possible, and cold applications made to the head. The feet must be kept warm.