190 Hydrolysis of the Soluble Protein of Swede Turnips 



0-3746 grm. gave NHg equal to 13-3 c.c. N/10 acid. 

 1 grm. would give NHg equal to 35-6 c.c. N/10 acid 



= 0-0498 grm. N. 

 Total N in humin bodies is 0-68 grm. 

 It also contained 6-6 per cent, of ash. 



An attempt to isolate glutaminic acid as hydrochloride. 



The hydrolytic liquid and washings were now concentrated in vacuo 

 down to about 750 c.c. The thick liquid was poured into an enamel pot, 

 and saturated with dry hydrochloric acid gas at 0° C. and placed in 

 the ice chest. It was kept at 0° C. for twelve days with occasional 

 cooling below 0° C. by means of a freezing mixture. The liquid was 

 seeded with a few crystals of glutaminic acid hydrochloride, but no 

 indication of a separation could be detected. 500 c.c. of ice-cold 

 absolute alcohol were added, and the mixture filtered through a pad 

 of asbestos. A jelly- Hke black residue was obtained which, however, 

 gave no glutaminic acid hydrochloride on recrystallisation. This was 

 put back with the filtrate. 



Esterif cation of the amino-acids. 



Foreman^ has described a new method of converting the amino- 

 acids into their esters, for which he claims greater efficiency than the 

 older methods. He has carried out a hydrolysis of casein using this 

 method, and obtained higher results for the mon-amino-acids than any 

 previous worker. This method has been employed in this hydrolysis. 



Preparation of the lead salts of the amino-acids. 



The hydrolytic liquid containing the alcohol was concentrated to a 

 syrup under reduced pressure at 40° C. Steam was now passed through 

 this syrup to get rid of some more of the hydrochloric acid. The liquid 

 was made up to about 1700 c.c, placed in an enamel pot, and heated 

 up to boiling point. Steam was passed through, and a suspension of 

 150 grms. of freshly prepared lead hydroxide added slowly. After 

 about twenty minutes the dark residue of undissolved lead hydroxide 

 containing humin bodies was filtered off and thoroughly washed. 



The combined filtrate and washings were poured back into the 

 vessel, steam passed in, and lead oxide added in 50 grm. lots. About 

 550 grms. of lead oxide were thus added, steam being passed in all 



^ J own. of Agric. Sci. iv, 481, 1911. 



