UV JAMKS M. I'KTKIK. 



123 



I Sodium I 

 liypobrom. N. 



Nitrous 

 Acid N. 



After :— 



1. Magnesia dist. + phospiiotung. acid 



2. Hydrolysis and distillation 



3. Hydrolysis + liydrolysis and distilln... 



4. Phospholuiig. -1- hj'drolysis and distilln. 



Of the compounds known to evolve nitrogen gas with 

 sodium liypobromite, ammonia and basic compounds are 

 excluded in 1, and only certain amides are left to represent 

 the 19-3% of nitrogen. In 2, amides also are excluded and 

 no nitrogen was obtained. Although the two plant-amides, 

 asparagin and glutamin, do not evolve ammonia with hypo- 

 bromite till hydrolysed with dilute acids, yet this does not 

 exclude the existence of other compounds in which the 

 amino-group is in a less stable position, and which would 

 evolve ammonia, like urea, allantoin, etc., with this reagent. 

 It is significant that the nitrogen in 1, and that obtained by 

 Sachsse's method after prolonged hydrolysis (Table xi. d), 

 and which has been already discussed as a possible amide- 

 figure, are approximately the same. This reagent does not 

 liberate nitrogen from amino-acids. 



Nitrous acid, on the other hand, decomposes almost all 

 amino-groups with evolution of nitrogen. After hydrolysis, 

 such compounds must be present, representing the high figure 

 in 2. After a double hydrolysis, the nitrogen evolved by 

 nitrous acid is reduced to about one-half, and, following 

 phosphotungstic acid and hydrolysis, no nitrogen is obtained. 



Amino-acids. — Van Slyke* found that no nitrogen was 

 evolved from prolin or glycin anhydride which contain the 

 imino-group : also that guanidin, creatin, and the amide- 

 group of asparagin, do not react. Slyke and Hartf have 

 shown that amino-acids, boiled with magnesia, do not evolve 



* Jouin. Biol. Chem. 7, 1910, p. xxxiv, 

 1 Amer. chem. Jouin. 29, 1903, 168. 



