BY JAMES M. PKTRIE. 131 



to a strength of 85% spirit. After heating to 70", then 

 allowing to stand till cold, the precipitated proteins were 

 filtered off. From an aliquot portion of the filtrate, the 

 alcohol was distilled off, and the nitrogen of the residue 

 estimated by Kjeldahl's process. This is designated the 

 non-protein nitrogen. 



It is not assumed that this separation of proteins is com- 

 plete, indeed it is almost certain that the simpler polypeptides 

 remain unprecipitated, and are included in the nonprotein 

 nitrogen solution. The complete separation of proteins from 

 such mixtures, is a matter of very great difficulty. 



The results of the determinations are here tabulated : — 



Tablk i. 



100 gms. of fresh seeds of Vicia saliva contain : — 



Stage Protein-N. Nonprot.-N. Total N. 



1 1-088 gms. 0-702 gni. 1-790 gms. 



2 1-129 0-541 1-670 



3 4-345 1085 5 430 



The results here show that, in 100 gms. of the very young 

 seeds, containing 1-79 gms. of total nitrogen, the protein- 

 nitrogen is 1-088 gms., and the nonprotein-nitrogen 0-702 gm. 

 In the second stage of their development, the protein - 

 nitrogen has increased to 1129 gms. ; the nonprotein-nitrogen 

 is 0-541 gm. ; and the total nitrogen is slightly less than in 

 Stage 1. In the perfectly ripe seeds, the total nitrogen has 

 increased to 5-43 gms., and consists of 4-345 gms. of pro- 

 tein- and 1-085 gms. of nonprotein-nitrogen. 



By comparing the same number of seeds in each case, the 

 absolute amount of nitrogen, in the two different forms, be- 

 comes at once apparent. Table ii. shows the contents of 100 

 seeds in the same three stages of development. 



'I'ABr.K ii. 



100 seeds of Vicia saliva contain : — 



Stage Weight Protein-N. Nonprot.-N. Total N. 



1 0-9 gms. 0010 gm. OOOKgm. 0016 gm. 



2 31 0036 0-017 0-053 



3 1-7 076 0-019 095 



