60 THE SYNTHESIS OF PROTEINS 



and by simply boiling a solution, the dipeptide of aspartic acid 

 is formed.* 



With regard to other views concerning the synthesis of 

 proteins, Treub,f from his investigations on the distribution of, 

 the periodic variation in the amount of, and cognate observations 

 on the cyanogenetic glucosides,J concluded that hydrocyanic 

 acid is the first recognizable product of nitrogen assimilation 

 and possibly is the first organic nitrogen compound formed. 

 Whilst on purely chemical grounds it is not impossible that 

 acetone cyanhydrin, CH 3 COHCNCH 3 , may be a stage in 

 protein synthesis, Treub's conclusions are not convincing : free 

 hydrocyanic acid has not been identified in plants and its 

 compounds may equally well result from the oxidation of 

 amino acids : in other words, the known facts regarding com- 

 pounds of hydrocyanic acid in the plant neither prove nor 

 disprove Treub's hypothesis. 



* Ravenna and Bosinelli : " Rend. R. Acad. Lincei.," 1919, 28, ii. 113. 

 tTreub: "Ann. Jard. Bot. Buitenzorg," 1895, J 3 * J I 94 I9>86; 1907, 

 21, 107. 



$ See Vol. I., p. 173. 



Rosenthaler : " Schweiz. Apoth. Ztg.," 1920, 58, 137. 



