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A TEXT-BOOK OF BOTANY. 



always associated in the plant cell with the special ferments 

 which are capable of decomposing them. There are other sub- 

 stances which have the property of breaking up the glycosides, 

 viz., dilute acids and alkalies. Of the mineral acids, dilute 

 sulphuric acid and dilute hydrochloric acid are the most effective. 

 They do not, however, always produce the same results on the 

 same glucoside, as sometimes one acid works better than the 

 other. Some glucosides are hydrolyzed by the use of strong 



FIG. 98. Microphotograph of the rhombic prisms of Asparagine (amido-succinamic 

 acid), which is rather widely distributed in the vegetable kingdom. From aqueous solution 

 the smaller crystals are combinations of base and prism (a) ; one or both of the acute angles 

 may be truncated on the faces of the brachydorhe (b) ; in the larger crystals (c) the brachy- 

 dome is more developed and is either equi dimensional or elongated on the a -axis. 



organic acids, as oxalic acid and citric acid. In view of the fact 

 that most glucosides require the presence of water in addition 

 to the presence of the ferment to produce an interaction, they 

 are looked upon as ether or ester derivatives. This view is 

 strengthened by a careful study of the glucosides which have 

 been prepared synthetically, but it is not known in what manner 

 the glucoside is united with the. other compounds making up the 

 natural glucosides, 



