20 Nature of Humus [Oct. 



etc. Thus, the Splitting off of carbon dioxid from the diamino 

 acids as well as of the NHj group from the monoamino acids, leads 

 to the formation of amins and acids respectively, as illustrated by 

 the following equations : 



NH2-CH2-CH2-CH2-CH2-CH-NH2-COOH -^ CO2 + 



NH2-CH2-CH2-CH2-CH2-CH2-NH2 

 Lysin Cadaverin 



CH CH 



CH^\C C-CH,-CH-NH,-COOH CH^\C C-CH.-CH^-COOH 



CH 



CH ^'H CH NH 



CH 



Tryptophan Indolpropionic acid 



In the case of nucleoprotelns there result, in addition to protein 

 products, purin derivatives and pyrimidin bases. 



When carbohydrates are subjected to the influence of enzymes 

 and bacteria, they also, as the result of primary hydrolysis, are first 

 split into smaller carbohydrate molecules, which then may be further 

 decomposed to alcohol, organic acids, etc. 



In the same manner, f ats, under the influence of similar agencies, 

 are split into fatty acids and glycerol. 



There is no reason to assume that the proteins, nucleoprotelns, 

 carbohydrates and fats in vegetable and animal remains, when sub- 

 jected to the action of such agencies in soil, would not yield decom- 

 position products similar to those that result in the case of pure 

 proteins, nucleoprotelns, carbohydrates and fats. 



Recent investigations show that humus, using this word in its 

 widest sense, is very complex, consisting of a large number of Com- 

 pounds. Contrary to the findings of earlier writers (see p. 17) 

 humus contains, in addition to carbon, hydrogen and oxygen, also 

 nitrogen, sulfur and phosphorus. It contains acids of well known 

 composition and Constitution, e. g., monohydroxystearic,^^ dihydrox- 

 ystearic, oxalic, succinic, acrylic, saccharic. It contains basic sub- 



1* Schreiner and Shorey: Bul. Nos. 53 and 74, Bureau of Solls, U. S. Dept. 

 Agr.; Jour. Amer. Chem. Soc, 32, 1674 (1910) ; Proc. Eighth Intern. Congr. 

 Appl. Chem., 15, 247 (1912). 



