abstracts: chemistry 127 



the conditions which decrease growth, and the factors which favor oxi- 

 dation are the factors which favor soil productivity. 



O.S.,M.X. S.,andF. R. R. 



AGRICULTURAL CHEMISTRY.— Enzymotic activities in soils. Os- 

 wald Schreixer and M. X. Sullivan. Science, 33:339, 1911. 



Within the bodies of micro-organisms in plant roots and plant debris* 

 in worms and animalcules, enzymes of various kinds must exist. Evi- 

 dence of various enzymotic activities, proteolytic, amylolytic, inverting, 

 cytolytic, lipolytic, etc., may be seen in many soils. Starches, sugars, 

 cellulose, fat, and protein are speedily changed or disappear, and in 

 many cases especially of proteins, some of the products of digestion may 

 be found in the soil. As yet no satisfactory means have been obtained 

 of extracting enzymes from soil to any great extent, though in those 

 recently cropped there is some slight evidence of the presence of enzyme- 

 like substances in the glycerine extract of the soil. M. X. S. 



AGRICULTURAL CHEMISTRY.— The chemical nature of soil or- 

 ganic matter. Oswald Schreiner and Edmund C. Shorey. Bul- 

 letin Bureau of Soils, No. 74. 1910. 



This bulletin discusses the chemical nature of the organic compounds 

 in the soil, and methods are described by which a number of organic 

 compounds have been isolated from soils. These compounds, 16 in 

 number, are described, the manner in which they have been identified 

 pointed out, the possible sources of the compounds suggested, and their 

 relation to other compounds stated. They belong to eight classes of 

 chemical compounds, some containing carbon and hydrogen only, some 

 containing carbon, hydrogen, and oxygen, and some containing carbon, 

 hydrogen, oxygen, and nitrogen. Paraffin hydrocarbons, acids, alcohol 

 esters, carbohydrates, hexone bases, pyrimidine derivatives, and purine 

 bases are represented. The list of isolated and identified compounds com- 

 prises: Hentriacontane, C 3 iH 64 ; monohydroxystearic acid, Ci8H 36 3 ; 

 paraffinic acid, C24H48O2; lignoceric acid, C24H48O2; phytosterol, C 26 

 H44O.H2O; pentosan, C 5 H 8 4 ; histidine, C 6 H 9 02N 3 ; arginine, CsHi40 2 N 4 ; 

 cytosine, C 4 H50N 3 .H 2 0; xanthine, C5H4O2N4; hypoxanthine,C 5 H40N 4 ; 

 fatty glycerides and several resin acids and esters. 



This work shows that the complexity of the organic matter of soils 

 is not so great but that the chemical nature of all of the organic matter 

 of soils can be determined by modern methods. E. C. S. 



