Treatment.—As for hydrocyanic acid.
PREPARATIONS CONTAINING
HYDROCYANIC ACID
The following plants contain prussic acid, and are therefore more or less poisonous in proportion to the quantity of the acid which they severally contain:
- Nat. Ord. Rosaceæ
- Amygdalus Communis.—The Almond and its varieties.
- Prunus Domestica.—The Plum and its varieties.
- Cerasus.—The Cherry and its varieties.
- Pyrus Aria, or White Bean Tree.—The seeds are poisonous.
- Nat. Ord. Euphorbiaceæ
- Jatropha Manihot, or Bitter Cassava.
Bitter Almonds
The essential oil of bitter almonds is very poisonous. “The oil does not, like common essential oils, exist ready formed in the almond, but it is only produced when the almond pulp comes in contact with water. It cannot be separated by any process whatever from the almond without the co-operation of water—neither, for example, by pressing out the fixed oil, nor by the action of ether, nor by the action of absolute alcohol. After the almond is exhausted by ether, the remaining pulp gives the essential oil as soon as it is moistened; but if it is also exhausted by alcohol, the essential oil is entirely lost. The reason is, that alcohol dissolves out a peculiar crystalline principle named Amygdalin, which, with the co-operation of water, forms the essential oil by reacting on a variety of the albuminous principle in the almond, called Emulsin, or Synaptase.
The essential oil of bitter almonds may contain from 6.0 to 14.33 per cent. of hydrocyanic acid. Deaths from the incautious use of this oil for flavouring articles of confectionery are not infrequent. As the flavour is not in the least injured, it has been suggested to subject the oil to repeated distillation with caustic potassæ, by which means the oil is purified from prussic acid.
Symptoms in Man.—Nausea, vomiting, and diarrhœa, due to gastric irritation, have occurred when the dose has been small, as is the case when confectionery owes its flavour to the use of the essential oil. Idiosyncrasy may have something to do with these effects, for cases are on record where a single almond has produced a state resembling intoxication, followed by an eruption not unlike urticaria or nettle-rash. Taken in large doses, the symptoms produced are identical with those described under poisoning by prussic acid. The breath is usually strongly impregnated with the odour of bitter almonds.
Symptoms in Animals.—Vomiting, trembling, weakness, paralysis, tetanic convulsions, and coma.
Post-mortem Appearances.—These are identical with those seen in poisoning by the pure acid.