19 



THE AMMONIFICATION OF MEAT-EXTRACT 



As a comparison between the availability of meat-extract 

 and peptone nitrogen for ammonification experiments, a 

 medium consisting of 19.85 grams Liebig's extract of meat 

 per liter of distilled water, was used. The meat-extract as- 

 sayed 7.94% nitrogen, which was approximately the peptone- 

 nitrogen content. 



TABLE SHOWING COMPARATIVE WEIGHTS 

 NITROGEN EVOLVED AS AMMONIA IN PEP- 

 TONE AND MEAT-EXTRACT MEDIA 

 HAVING SAME NITROGEN CONTENT 



TABLE V 



OF 



The ammonification in the meat-extract medium appears 

 to be uniformly lower than in the peptone solution, and the 

 difference in per cent in soils 9, 43 and 49 is constant. An 

 attempt was made to use lecithin as a culture medium for sim- 

 ilar experiments, but the nitrogen content being low (1.80)%, 

 and the insolubility so great, the attempt was finally aban- 

 doned. 



THE DEVIATION OF NASCENT HYDROGEN FROM 



THE PROTEIN NITROGEN EFFECTED BY THE 



PRESENCE OF NITRATES AND NITRITES 



Fifteen flasks each containing 100 cc of the 1% peptone 

 solution, were inoculated with one gram of soil as indicated: 

 To each of the second set of five, was added one gram of potas- 

 sium nitrate. Similarly to the third set of five, was added 



