Chemical Antidotes.—The administration of a solution of carbonate of potash, followed by a solution of the mixed sulphates of iron, has been suggested. The formation of Prussian blue is the result. The only objection to this treatment is, that prussic acid is so rapidly absorbed that death may result from the already absorbed acid before the antidote can be given.
Atropine.—This should be given hypodermically.
Peroxide of hydrogen should be given freely by means of the stomach tube.
Cobalt nitrate 0.5 to 1 per cent. solution has been advocated hypodermically.
Sodium thiosulphate, in 10 per cent. solution, repeated hypodermically.
Cyanide of Potassium
This substance is used largely by photographers and electro-platers. It acts as a poison in a similar manner to hydrocyanic acid, and the symptoms are the same. As a commercial preparation it frequently contains undecomposed potassium carbonate, and may exert a corrosive action on the mucous membranes of the mouth and stomach, leading to the production of blood-stained mucus in the stomach.
Post-mortem Appearances.—These are the same as those described under hydrocyanic acid, with the addition of the corrosive effects.
Fatal Dose.—Five grains have proved fatal in a quarter of an hour; recovery has taken place after forty grains.
Chemical Analysis.—Same as for hydrocyanic acid.