CH. XVI] SYNAPTASE. 311 



volurnetrically with Fehling's solution, but it is not neces- 

 sary to remove the dextrins present in these experiments, 

 as rough results are sufficient to give the chemical evidence 

 in a perfectly conclusive form. 



Decomposition of a glucoside (salicin) by a 

 ferment (synaptase) from another plant. 



Add to a 5 p.c. solution of salicin (which gives no 

 reaction with dilute ferric chloride), some paste of bitter 

 almonds ground up with water and sand. Digest for a few 

 hours on the water bath at 40 50C., filter clear and test 

 a portion of the filtrate with dilute ferric chloride, a deep 

 purple colour is produced (destroyed by acids or alkalies) 

 due to saligenol, formed by hydrolysis of salicin. 



C 13 H 18 7 + H 2 = C 6 H 4 . OH . CH 2 . OH + C 6 H 12 O 6 . 

 Salicin Saligenol Glucose. 



