The almond tree, growing somewhat larger than the peach and living longer, is strikingly beautiful when in flower. The gro....

The almond tree, growing somewhat larger than the peach and living longer, is strikingly beautiful when in flower. Sweet almonds mature only occasionally in climates like that of southern England. The Old World almond cultivation was characterized by small plantings mainly for family use; trees interplanted with other crops; variability in age, condition, and bearing capacity of individual trees; and hand labour, often with crude implements. Bitter almonds, as inedible as peach kernels, contain about 50 percent of a fixed oil that also occurs in the sweet almond, together with an enzyme called emulsin, which in the presence of water yields glucose, prussic (hydrocyanic) acid, and the essential oil of bitter almonds called benzaldehyde. When the prussic acid has been removed, the oil of bitter almonds is used in the manufacture of flavouring extracts for foods and liqueurs.