G. Williams 197 



A third fraction was obtained after treating the mother liquor with a 

 little animal charcoal. This also was impure, and w^as recrystallised 

 from water. Finally 14-5 gi'ms. of pvire hydrochloride was obtained, 

 a large refractory mother liquor residue weighing 25 grms. being left. 



0-1282 grm. phenylalanine hydrochloride gave NHg equal to 6'32c.c. 

 N/10 acid = 0-008848 grm. N 



= 6-90 per cent. N. 



Calculated for CgHnOaN . HCl - 6-94 per cent. N. 



14-5 grms. phenylalanine hydrochloride correspond to 11-87 grms. 

 of free phenylalanine. 



A further quantity of 1-03 grms. of phenylalanine was obtained 

 during the subsequent treatment of Fraction 3 (see page 208), making 

 a total weight of phenylalanine of 12-90 grms., equal to 4-47 per cent, 

 in the protein. 



Fractional crystallisation of Fraction 1 from water. 

 {After extraction of proline.) 



The acids of Fraction 1 were fractionally crystalhsed from water, 

 and the melting point and nitrogen content of each fraction determined 

 in order to obtain some indication as to their constituents. 



The melting point of glycine is 240° C. (Van Rostand gives 

 232° C- — ^236° C.) wdth decomposition, d-alanine melts with decomposi- 

 tion at 297° C, d-vahne at 315° C, 1-leucine at 297° C, and d-isoleucine 

 at 280° C. Glycine contains 18-67 % nitrogen, alanine 15-73 %, vahne 

 11-97 %, and the leucines 10-69 %. 



The analysis of crop 1 indicates the presence of much vahne. Crops 

 2 and 3 seem to be largely made up of alanine. The residue should 

 contain nearly all the glycine. 



Glycine. 



The picrate method of Levene and Van Slyke^ was used to isolate 

 the glycine from the residue from the fractional crystallisation of 



^ J own. Biol. Chem. xii, p. 285, 1912. 



