I20 ORGANIC NITROGENO US MANURES 



influence of bacteria of the type of Micrococcus urece^ 

 ammonium carbonate being formed intermediately : 



QOC +2H20 = C03< = 2NH3 + CO2+H2O. 



Urea. Ammonium 



Carbonate. 



103. Uric Acid. 



Uric acid is normally present in small quantity in 

 the urine of carnivora and of man, and separates from 

 urine on allowing to stand for some time. It may be 

 detected by the murexide reaction : a small quantity of 

 uric acid is evaporated to dryness with a few drops of 

 nitric acid. On moistening the residue with ammonia, 

 a purple colour is produced, due to the formation of 

 murexide. 



104. Hippuric Acid. 



This material takes the place of uric acid in the 

 urine of herbivora, and particularly in that of the horse, 

 in which it exists to the extent of 2 per cent. It may 

 be tested for by evaporating the urine nearly to dryness 

 and boiling for some time with caustic soda until 

 no more ammonia is liberated. The solution will 

 now contain benzoic acid, formed by hydrolysis of 

 the hippuric acid. The solution is acidified with 

 sulphuric acid, boiled with animal charcoal, and 

 filtered hot. 



On testing the concentrated filtrate with ferric 

 chloride a buff-coloured precipitate of ferric benzoate 

 should be obtained. 



Shoddies, Wool Wastes, etc. 



Numerous waste products containing nitrogenous material are 

 largely used as manures, particularly for fruit and hops. These 



