abstracts: chemistry 125 



tenance of a good greensward are explained. The presence of harmful 

 compounds in certain soils is considered, as is also the influence of trees 

 on lawns. 



The best methods of building up grounds artificially by the hauling 

 in of suitable material, both for subsoil fillings and for surface layering, 

 are fully described, a list of soil types adapted to grass growing being 

 given for this purpose. 



While the bulletin is mainly for the purpose of aiding in the improve- 

 ment of large tracts, the individual owner of a small plot in town or 

 city has also been kept in mind. J. S. S. 



AGRICULTURAL CHEMISTRY.— Soil organic matter as material 

 for biochemical investigation. Oswald Schreiner and Edmund 

 C. Shorey. Journal of the Franklin Institute, 171: 295. 1911. 



Attention is called to the complexity of the organic matter of soils and 

 the fruitful field of research that it offers for biochemical investigation. 

 The importance of the chemical character of the organic matter of the 

 soil is considered under four heads : its effect on crops ; its effect on the 

 bacteria and fungi of the soil; its influence on the physical properties of 

 the soil; and its relation chemically to the mineral ingredients of the 

 soil. B\ the application of the biochemical methods there have been 

 isolated in this research twenty definite organic compounds thus far from 

 that portion of soil organic matter included in the term humus. A 

 chart shows the classification of these compounds, as well as methods 

 of separation. The compounds comprise paraffin hydrocarbons, acids 

 alcohols, esters, carbohydrates, hexone bases, pyrimidine derivatives 

 and purine bases. M. X. Sullivan. 



AGRICULTURAL CHEMISTRY.— Studies in soil oxidation. 0. 

 Schreiner, M. X. Sullivan, and F. R. Reid. Bulletin Bureau 

 of Soils, No. 73. 1910. 



The fact that roots possess the power of reduction is shown by the 

 precipitation of tellurium and selenium from sodium tellurite and selen- 

 ite, respectively. The oxidative power of the roots is shown by means 

 of organic compounds, which, on oxidation, yield dyes that either color 

 the solution or are deposited on the root surface. These two opposite 

 properties may occur separately or concurrently, depending upon the 

 reaction of the medium. Oxidation within the soil itself is demonstrated 

 by the same reagents as those showing oxidation by the roots. The 



