TRANSFORMATION OF ORGANIC MATTER 



675 



disappear more rapidly than the celluloses, as has been observed in the 

 numerous studies on the composting of manure. It is sufficient to cite 

 the results obtained 22 * in composting horse manure at 35° to 37°C, 

 under various conditions: 





WUat Strew 



J)ayS 



Fig. 52. Course of decomposition of different organic materials in the soil, 

 as indicated by the evolution of carbon dioxide (after Dvorak). 



The protein content of the manure increased as a result of composting. 

 Another result of the composting of natural organic materials, or of their 

 decomposition in the soil, is an increase in the carbon content of the re- 

 sidual material, due to the fact that the pentosans and celluloses with 

 a low carbon content (42 to 44 per cent) disappear and the liginins 



22a Jegorow, M. Report of commission on decomposition of manure for 1910 

 (Russian). Moskau Agr. Inst., 17: 1-59. 1911. 



