20 HOKSE-MANURE. 



large quantity of cold sour humic acid formed, which 

 seriously impairs the value of the manure. 1 



Having now considered the composition of the three 

 separate ingredients of farmyard manure viz., 'the 

 dung or solid excreta, the urine, and the litter we are 

 in a position to consider the composition of farm- 

 yard manure. In this connection it will be well to 

 consider separately the manures produced by the dif- 

 ferent farm animals. 



1. Horse-manure. The composition of horse-manure is 

 perhaps the most uniform of all the manures produced 

 by the different farm animals. This is due to the fact 

 that the food of the horse is generally of the same 

 kind, consisting of oats, hay, and straw. 



The total excrements voided by a horse in a day 

 have been calculated, according to the average of 

 experiments by Boussingault and Hofmeister, at 

 28.11 lb., of which only 6.37 Ib. consisted of dry 

 matter. 2 These 28.11 lb. contained .18 lb. of nitrogen 

 and .92 lb. of mineral matter. The amount of straw 

 necessary to absorb this amount of excrement may be 

 stated at from 4 to 6 lb. The amounts of nitrogen 



1 According to Storer, in a ton of autumn leaves of the best quality 

 there would be 6 lb. of potash, less than 3 lb. of phosphoric acid, 

 and 10 or 15 lb. of nitrogen. 



2 Heiden's Diingerlehre, vol. ii. pp. 34, 66. In Boussingault's 

 experiments the food consisted of 15 lb. hay, 4.54 lb. oats, and 32 lb. 

 water; the total excrements amounting to 31.16 lb., containing 

 7.42 lb. dry matter. In Hofmeister's experiments the food consisted 

 of 5.23 lb. hay, 6.18 lb. oats, 1 lb. chopped straw, and 25.57 lb. water ; 

 the excrements amounting to 25.07 lb., containing 5.32 lb. dry matter. 



