THE ODOUR OF BITTER ALMOND. 177 
changed to benzoic aldehyde, and is now known by the name of 
benzaldehyde (C,;H;CHO). 
The action of the ferment is destroyed by boiling water and by 
heating with alcohol, so that when dried and powdered bitter 
almonds are shaken up with boiling water and distilled, none of 
the essential oil is obtained, and the same result occurs when, as 
in Robiquet and Boutron-Charlard’s process, they are treated with 
boiling alcohol. 
Amygdalin, which is the first example of a glucoside (a large 
number of which bodies are now known), occurs in many plants, 
chiefly the Amygdalacee, Drupacez, and Pomacez, which all 
yield benzaldehyde and prussic acid when distilled with water*. 
The kernel of the peach also yields an oil resembling the oil of 
bitter almonds in every respect}; while that obtained from the 
leaves, flowers, seeds, and bark of the cherry contains both oil of 
bitter almonds and another oil which has a penetrating, repulsive 
odour}. According to Winkler, the fresh leaves of the cherry- 
laurel (Prunus Laurocerasus), the cherry (Prunus Padus), and the 
peach contain a small quantity of free oil of bitter almonds, 
varying in amount with the water present$, which can be ex- 
tracted by ether. Of Syrian peach and apricot kernels consider- 
ably over a million pounds weight are annually exported from 
Damascus, which is the principal locality of the production. The 
cracking of the shells and removal of the kernels is done partly by 
hand and partly by machinery. 
In the distillation of oil of bitter almonds a difficulty is expe- 
rienced by the formation of large quantities of froth, by reason of 
* To prepare amygdalin, bitter almonds are freed as far as possible from 
fatty oil by pressing, and the mass repeatedly extracted with boiling alcohol ; 
the alcohol is then distilled off, and the residue recrystallized from boiling 
alcohol. It erystallizes in lustrous plates or scales, or from water in trans- 
parent, rhombic prisms, which become anhydrous at 120°, solidifying to an 
amorphous mass on cooling. At 8°-]2° it dissolves in 12 parts of water, while 
it is soluble in every proportion in boiling water. It is slightly soluble in cold, 
more readily in boiling alcohol, and insoluble in ether. On the addition of 
emulsin to its aqueous solution, it decomposes into grape-sugar and phenyl- 
hydroxyacetonitril, which is partially decomposed by distillation into benz- 
aldehyde and hydrocyanic acid. The same decomposition takes place on 
boiling with dilute hydrochloric acid. (Roscoe and Schorlemmer.) 
+ Righini, Ann. Chem. Pharm. x. p. 359; Geissler, ibid. xxxvi. p. 331. 
¢t Winkler, Repert. Pharm. Ixvii. i. p. 56. 
§ Jahresb. Chem. iv. p. 519. 
