BACTERIAL CELLULAR SUBSTANCE 83 



Calculated per cent, of Cu in Cu-leucin . . . . 19 . 66 

 Calculated per cent, of Cu in Cu-valin . . . .25.52 

 Calculated per cent, of Cu in Cu-leucin-valin . . 20.48 



The more soluble copper salt was freed from its copper 

 with hydrogen sulphide. The filtrate furnished, on treating 

 it with 80 per cent, alcohol and allowing it to stand in the 

 ice-box, 0.5 gram of alanin. 



Fraction III. After saponification by boiling for five 

 hours under reflux condenser with five times its weight of 

 water, this fraction yielded 7.3 grams of solid. The absence 

 of prolin was demonstrated by the fact that hot absolute 

 alcohol dissolved nothing. The solution was boiled with 

 copper oxide which took up all the substance. The per- 

 centage of copper was found to be 20.38, thus showing the 

 compound to be the double salt of copper with leucin and 

 valin. 



Fractions IV and V. When these were mixed with 

 water a brownish oil separated. This was filtered off and 

 saponified by heating for several hours on the water-bath 

 with an excess of baryta. When the barium had been 

 removed there was obtained 0.5 gram of phenylalanin. It 

 was found difficult to purify this, but finally we did so, and 

 found the melting-point to be 262.5. The filtrate from the 

 oily ester of phenylalanin was also saponified by heating 

 on the water-bath with an excess of baryta. The absence 

 of aspartic acid was shown by failure to obtain an insoluble 

 barium asparaginate. When the barium was removed a 

 small amount of glutamic acid was found in the filtrate. 



The pasty mass left after the extraction of the esters 

 was neutralized with hydrochloric acid and prepared for a 

 second esterification, but owing to an accident this was 

 not completed. No ultimate analyses were made in this 

 or the subsequent hydrolyses, and we have relied for the 

 recognition of the amino-acids on (1) the boiling-point of 

 the esters, (2) crystalline form, (3) melting-point, and (4) the 

 percentage of copper in the copper compounds. 



In this hydrolysis we have accounted for only a little 

 more than 10 per cent, of the nitrogen, distributed as 





