COAL GAS
Coal gas is composed of several hydrocarbons, the chief of which is marsh gas, together with free hydrogen, carbon monoxide and carbon dioxide, ammonia, hydrogen sulphide, and sulphides of carbon, which give to it its peculiar odour. The poisonous properties of coal gas are due to the carbon monoxide, 7.5 per cent. being present in ordinary gas as supplied for illuminating purposes. It can be detected by passing the coal gas through an acid solution of cuprous chloride, which becomes black by the formation of a compound CuCOCl. A dangerous explosive compound is formed when the gas reaches the proportion of 1 in 10 of the atmosphere. Poisoning by this gas is, as a rule, accidental.
Symptoms.—Headache, nausea, vomiting, giddiness, ending in coma. Stertorous breathing is noticed in some cases. Should the sufferer be removed from the gas, the breath smells strongly of the gas. The murderer Chantrelle tried to cover his crime by admitting gas into his wife‘s bedroom, but the attempt failed. The pupils are, as a rule, dilated before death.
Post-mortem Appearances.—Cherry-red colour of the blood, redness of the pulmonary tissue, and froth in the air-passages. The vessels of the brain are engorged, and rose-coloured patches appear on the thighs.
Treatment.—This consists in removing the patient into the fresh air, artificial respiration, oxygen inhalations, &c., as in carbon monoxide.