434 



Histon and its Preparation 



[April 



vievv. The data for the amide fractions also tend to show that the 

 difference in nitrogen content cannot be due to combination of the 

 ammonia nitrogen vvith the ammonia-precipitated histon. 



TABLE 6 

 Data pertaining to percentage elementary composition 



TABLE 7 



Data in duplicate pertaining to nitrogen partition 



Aside from the difference in nitrogen content the only other 

 striking difference shown by these results is the presence of chlorin 

 in the sodium chlorid-precipitated product and its absence from the 

 ammonia-precipitated substance. That this is not due to failure to 

 sufficiently purify the sodium chlorid-precipitated material was 

 shown qualitatively in the f ollowing experiments : 



A portion of the water-solution of the sodium chlorid-precipi- 

 tated product was treated with a few drops of ammonium hydroxid. 



^ Nitrogen calculations on an ash-f ree basis — Histon A, preparation 2 : 16.20 

 per Cent, and 16.28 per cent. ; Histon B, preparation 2: 17.00 per cent. and 16.88 

 per cent. ; Histon C, preparation 2 : 17.52 per cent. and 17.41 per cent. 



