U\ JAMES M. PETRIE. 121 



B. — Amniuiiia is obtained fioui all the extracts by distil- 

 ling with magnesia in a current of steam. Zymolysis during 

 the extraction of the seeds, with its consequent liberation of 

 ammonia, is entirely excluded in method (b) by boiling. 

 That this ammonia is actually free in the extracts, is doubt- 

 ful, since the desaniidising enzymes of seeds do not become 

 active till germination begins. There remains then the 

 probability that compounds are present, which decompose 

 with great ease by distilling with magnesia. In support of 

 this, we have (in Table vii., iv.) the result of a distillation, 

 following the removal of all pre-existing ammonia, and other 

 basic compounds, with phosphotungstic acid : ammonia is 

 formed as before. Again, when distilled directly (Table 

 vii., ii.), and after hydrolysis with dilute acid (Table x., i.) 

 practically equal quantities are obtained in the same time. 



C. — By hydrolysing with dilute acids, amides split off 

 ammonia with great readiness, which distils off rapidly with 

 magnesia. In Tables viii. and xi.a, the minimum figures are 

 obtained under conditions well known to yield the whole of 

 amide-ammonia. These are about 8-10% of the non-protein 

 nitrogen, and would represent about 2% of asparagin in the 

 seeds. On the other hand, when the attempt is made to 

 isolate amides by Schulze's method with mercuric nitrate, 

 only a syrupy residue is left, which shows no crystallisation 

 on long standing. Again, the magnesia distillations, instead 

 of coming to a sharp finish, apparently go on for some con- 

 siderable time, evolving ammonia (Table xi.), as if it were 

 gradually formed by the slow decomposition of substances 

 other than amides. In consequence, the invariable pro- 

 cedure of ascribing to amides, this ammonia obtained by 

 Sachsse's process, can certainly not be applied here. 



D. — By increasing the duration of hydrolysis, and strength 

 of acid, the decomposition is accelerated, with an increased 

 liberation of ammonia. Boiling with 25% sulphuric acid, for 

 15 hours, results in the formation of 31°/ of ammonia- 



