Benzaldehyde: Oil of Bitter Almonds by Steam Distillation

Benzaldehyde is the oil of bitter almonds. It is not in the almond as such: crushed with cold water, the almond's own ferment splits its amygdalin into benzaldehyde, hydrocyanic acid and sugar. Thorpe (1912): press out the fatty oil, cream the cake with cold water, leave it a day, and steam-distil. Hydrocyanic acid comes over with it and is deadly: work outdoors, never alone, and take it out with lime and ferrous sulphate. The picture: our own drawing.