44 A FEW CHEMICAL CHANCJES 



Liebic and Wuhler prepared amvii'dalie acid or c'lncoman- 

 delie acid, C H O iroia amvo-dalin, bv boiliii<>- it with 



' 20 28 13 . t" ' . .^ 



barvta water, the change taking ])hice in this way: — 

 C H NO + 2H O = C H () + NH 



20 27 11 2 20 28 13 3 



Tlii< acid is a wliite crvstallinc siiljstancc which readily 

 foriiis auiiirphons siih.<. 



Tt i< probalilc ihar the change taking ]dace with Fehling'- 

 sdlutidii is (ine similar to tliis. Tlie action of the potassimn 

 hy<h"oxid<» is to foi'in amygdalic acid and auinionia, 'and at the 

 same time a.i insohiblc salt of the former is formed with the 

 co})per, which is held in solution by the s(»i!iiim and ])otassiniii 

 tartrate in the Fehling's solution. 



The (h'Coni])osition of aniygdalin by Fehling's sohuion d<x^s 

 not take ])lace unless the solution is boiled. However, if the 

 solution of aniygdalin is boiled with potassium hydroxide, 

 cooled, and then a few drojis of Fehling's solution added to it 

 the bluish ])reci])itate is formed. 



A quantity (d" this precipitate was foi-nied and washed free 

 from aniygdalin and Fehliiig's s(dution. When some of it was 

 heated on a ])iece of platinum foil it charred, showing that it 

 contained organic matter, and a greyish residue containing a 

 carbonate and copjxn-, but no sodium nor jiotassium was left 

 ])ehind. 



From The foreg<»ing facts it would seem tliat, on adding 

 Fehling's s()luti<ni to a sdhition of amygdalin and b:»ilin<>'. we 

 have a change taking ])lace like that ol)serve{l bv Liebig and 

 Wcihler, resulting in the break down of the amygdalin. As a 

 result of this decomposition the nitrogen of the amygdalin is 

 changed to ammonia, and a bluish white precipitate, which is 

 probably a cf>])]ier salt of amygdalic acid, is formed. It is 

 believed that the evolution of ammonia and the formation of the 

 precipitate noted above, might be used for the detection of 

 amygdalin. When the amygdalin has been under the influence 

 of radium for a time, it is found this change is more complete. 



