848 AMYGDALIC ACID. 



tity of sugar which prevents the amygdalin from crystallizing, 

 the residue is diluted with water, a little yeast added to it, and 

 it is left to ferment in a warm place. After the fermentation 

 ceases., the liquid is filtered and evaporated again by a water- 

 bath to a syrupy consistence. On mixing the syrup with a 

 portion of strong alcohol of 94 per cent, all the amygdalin pre- 

 cipitates in the form of a white crystalline powder, which is 

 pressed in folds of filter paper, and afterwards purified by new 

 crystallizations from alcohol. (Liebig). 



As crystallized from alcohol, amygdalin retains a portion of 

 that substance in combination, which it loses when exposed to 

 air. At the ordinary temperature it is scarcely soluble in anhy- 

 drous alcohol, but is more easily dissolved by boiling *alcohol. 

 It is very soluble in water, and crystallizes from a solution 

 saturated at 104 in large transparent prisms, of a silky lustre 

 which contain 10.57 per cent of water, or 6 atoms ; dried in 

 vacuo over sulphuric acid the crystals lose 3.52 per cent of 

 water, equivalent to 2 atoms. The crystals are not volatile, but 

 are decomposed Iry a high temperature, diffusing the odour of 

 hawthorn, and leaving a bulky charcoal. 



Dry chlorine has no effect upon amygdalin ; humid chlorine 

 converts it into a bulky white powder, insoluble in water and 

 alcohol, which has not been examined. Heated with dilute 

 nitric acid, or with peroxide of manganese and dilute sulphuric 

 acid, amygdalin produces ammonia, volatile oil of bitter almonds, 

 benzoic acid, formic and carbonic acids. Hypermanganate of 

 potash in decomposing amygdalin gives rise to cyanate and ben- 

 zoate of potash. Caustic alkalies convert amygdalin into ammonia, 

 which is disengaged, and amygdalic acid, a peculiar acid, which 

 remains in combination with the alkali. 



AMYGDALIC ACID. 



Formula : HO + C 40 H 26 O 24 . This acid was first obtained by 

 Liebig and Woehler, by the action of alkalies upon amygdalin. 

 It is best prepared by dissolving amygdalin in barytes-water, 

 and maintaining the mixture in a state of ebullition, so long as 

 ammonia is disengaged ; the barytes is then removed by sul- 

 phuric acid, and the liquid evaporated by a water-bath. In the 

 formation of this acid, 1 atom of amygdalin and 2 atoms of 



