1912.] PUBLIC DOCUMENT — No. 31. 31 



CHEMICAL METHODS FOR THE PRESERVA- 

 TION OF MANURE, 



BY J. B. LINDSEY. 



Barnyard manure is composed (a) of the undigested part of 

 the food, represented by the solid matter or feces; (6) the end 

 products of the protein digestion largely diluted with water, 

 namely, the urine; and (c) such materials as straw, sawdust 

 and the like, which are used for bedding. The solid part, or 

 feces, is mixed with more or less of the digestive fluids, such 

 as the bile of the liver, the intestinal juices and minute pieces 

 of the skin or lining of the intestines. The nitrogen-containing 

 matter of the urine of herbivorous or plant-eating animals is 

 composed chiefly of urea, together with such mineral matter as 

 is no longer of use in the blood (potash, soda, phosphates, etc.). 

 A considerable portion of the soluble nitrogenous part of the 

 manure is likely to be lost, both by volatilization and leaching. 

 The loss through volatilization, and in part through leaching, 

 is brought about by the action of bacteria, of which manure 

 contains an innumerable number and a great variety of species. 



Briefly stated there are four groups of bacteria which act 

 upon the nitrogenous matter of the manure : — 



1. Putrefactive hacteria, which attack both the insoluble 

 part of the nitrogenous matter and also the urea or soluble 

 part, and convert them into carbonate of ammonia, which is 

 volatile. 



2. Nitrifying hacleria, which act upon the ammonia com- 

 pounds and convert them into nitrites and nitrates. In order 

 to be active they must have plenty of oxygen, and hence act 

 near the surface of the manure pile. 



3. Denitrifying hacteria, which have the power to take the 

 oxygen from the nitrates, thus decomposing it and setting the 



