BACTERIAL CELLULAR SUBSTANCE 93 



with form and properties as already given, was obtained 

 from both fraction 3 and 4, containing 11.935 per cent, of 

 nitrogen, and showing a melting-point of 282 to 286.4 in 

 an open tube, and of 279 to 283 in a closed tube. Like- 

 wise from fraction 5 the heavy oil of phenylalanin ethyl 

 ester was obtained, and from this as in the other cases the 

 qualitative test for phenylalanin by the production of 

 phenylacetaldehyde. The remaining portion of fraction 5 

 yielded the same rhombic plates and prisms as described 

 under the colon fractions, and which are like those of aspartic 

 acid .properly obtained at this point if present. The copper 

 salt was again formed, the same needles, very difficultly 

 soluble in cold water, difficultly in hot, being obtained. 

 The amount of crystals was too small for further identi- 

 fication. 



From this it will be seen that mono-amino-acids are 

 obtained from the protein poisons after hydrolysis with 

 strong acid. It is not claimed that these are the only 

 mono-amino-acids present, or that all of these have been 

 sufficiently identified, but in consideration of the fact that 

 those discussed were found in the proper fraction according 

 to Fischer's separation and according to the boiling-points 

 of their esters, that the crystalline form and qualitative 

 properties corresponded, and that, when it could be deter- 

 mined, the percentage of nitrogen was close to the theo- 

 retical, it seems fair to conclude that the following tabulation 

 is not far from correct: 



MONO-AMINO-ACIDS OF THE PROTEIN POISONS 



Aspartic acid aspartic acid 



Leucinimide 



This is sufficient to establish the point for the proof of 

 which the method was employed, that is, the protein nature 



