134 soils: PB0PEBTIE8 AND MANAGEMENT 



1. Nitric nitrogen 3. Diamine acids 



2. Ammoniacal nitrogen 4. Acid amides 



5. Monamino acids 



The two latter constituents were found to make up the 

 bulk of the organic nitrogen, but quantitative determina- 

 tions proved uncertain. These compounds produced 

 ammonia readily, the rate depending on their chemical 

 structure. 



92. The work of Oswald Schreiner. — Of the chemists 

 who have been most active and most successful, Schreiner ^ 

 deserves especial mention. Our present knowledge of the 

 chemical constitution of the organic matter of the soil is 

 very largely due to his efforts. While he realized that 

 the isolation of specific compounds from the soil was likely 

 to present insurmountable problems, and that the iden- 

 tification of such compounds after they were obtained 

 might be very difficult, he undertook a systematic ex- 

 traction of the soil. As a result of several years of work 

 he was able to isolate and identify a number of com- 

 pounds. The complexity and varied character of these 

 eompomids is revealed bv the following list of the more 

 important bodies isolated :- 



List of Compounds isolated from Soil Organic 

 Matter by Schreiner, Shorey, Skinner, Reed, 



AND others, of THE U, S. BUREAU OP SOILS 



Hentriacontane, C31H64 Picoline carboxylic acid, 



Dihydroxystearic acid, C^HAN 



C18H36O4 Histidine, C6H9O2N3 



1 Scliremer, 0., and Shorey, E. C. The Isolation of Harm- 

 ful Organic Substances from Soils. U. S. D. A., Bur. Soils, 

 BuL 53, 1909 ; also, Buls. 47, 70, 74, 77, 80, 83, 87, 88, and 90. 



