V. GLUCOSIDES. 



A NUMBER of natural substances possess the common 

 property of breaking up into sugar and other bodies by 

 the action of certain agents (ferments, acids, alkalies). 

 Neither the sugar nor the other bodies exist ready 

 formed in them, but are formed during the process of 

 decomposition, water being assimilated. "With very 

 few exceptions, the variety of sugar that results from 

 the glucosides is grape-sugar; the other bodies, how- 

 ever, which make their appearance, are of very various 

 character. The glucosides are to be considered as 

 complicated ether-like compounds of grape-sugar. 

 They still contain a number of hydroxyl-groups, the 

 hydrogen of which is readily displaced by acid radicles. 



1. Amygdalin. 



Occurrence. In bitter almonds; in the leaves and 

 berries of Prunus laurocerasus ; in the blossoms, bark, 

 and fruit kernels of Prunus padus ; in the bark and 

 young shoots and leaves of Sorbus aucuparia ; in the 

 fruit kernels of cherries, apricots, peaches, and in a 

 great many other plants of the orders Amygdalece, and 

 Pomacece. 



Preparation. The fatty oil is pressed from the paste 

 of bitter almonds, and the mass then boiled repeatedly 

 with fresh quantities of alcohol, the liquid being 

 filtered each time boiling hot; and then about three- 

 fourths of the alcohol distilled off from the mixed 

 solutions. The amygdalin separates from the residue 

 after being allowed to stand for several days in a cool 



