I02 Indianapolis Biochemical Meeting: Ahstracts [Sept. 



formed. B. coli behaves similarly. Not only do the products 

 Vary, but the composition of the bacteria themselves may be altered. 

 All these considerations will prove of great importance in practice. 



The Carbon-Nitrogen Ratio in the Decay of Protein 



Compounds 



JACOB G. LIPMAN AND H. C. MCLEAN 



{New Jersey Experiment Station, New Brunswick, N. J.) 



In processes of decay the oxidation of the carbon and nitrogen 

 in protein Compounds is influenced by the physical and chemical 

 make-up of the decaying substances, the prevailing moisture and 

 temperature conditions, and the prevailing micro-organic flora. 

 Some of these factors were studied by the authors by means of a 

 method especially devised for the purpose. 



Weighed quantities of soil, containing definite amounts of dried 

 blood, tankage, cottonseed meal, etc., were placed in covered 

 tumblers and kept under bell-jars of known capacity. Under each 

 bell-jar there was also placed a meastired quantity of Standard 

 baritim hydrate. The latter was renewed daily, for a period of 

 eight to ten days, and the amount of carbon dioxid absorbed was 

 determined by titration against n/io hydrochloric acid. Similar 

 quantities of soil without additions of nitrogenous materials were 

 employed as checks. It was possible, thus, to estimate the amount 

 of carbon dioxid formed from the protein substances in any given 

 length of time. The daily production of ammonia in a parallel 

 series was determined by transferring the contents of the tumblers 

 to copper flasks, adding water and calcined magnesia, distilling 

 off and titrating the ammonia formed. 



The determination of the carbon dioxid on the one band, and 

 of the ammonia on the other, furnished accurate data on the 

 relative rate of oxidation of the carbon and the nitrogen in the 

 nitrogenous materials employed. It was shown in this manner that 

 the presence of large amounts of readily decomposable non-nitrog- 

 enous organic matter lessened the amount of ammonia found. On 

 the other band, the amount of carbon dioxid produced was increased 



