66 AMERICAN AGRICULTURE. 



manures, is a practice attended with no benefit, but with the 

 certainty of the escape of much of its valuable properties. 



Many farmers assign a distinct or peculiar merit to the 

 different manures. Much of this opinion is fanciful ; for 

 there is frequently more difference in the comparative value 

 of that from the same species, and even the same individual, 

 at different times and under different circumstances, than 

 from those of different species. 



The diversity in manures may arise from several causes. 

 The more thoroughly the food is digested and its nutritive 

 qualities extracted, the less is the value of the manure. 

 Thus, on the same quantity and quality of food, a growing 

 animal, or a cow in calf or giving milk, yields a poorer qual- 

 ity of feces and urine, than such as are not increasing in 

 weight ; and if the animal be actually losing condition, the 

 richness of the manure is very much increased. 



The quality of food adds materially to this difference, the 

 richest giving by far the most valuable manure. Those 

 animals which are kept on a scanty supply of straw or refuse 

 hay, yield manure little better than good turf, and far infe- 

 rior to the droppings of such as are highly fed. The imper- 

 fect mastication and digestion of the horse and mule, in 

 comparison with the ruminating animals, the ox and sheep, 

 their generally better quality of food, and the fact, that for 

 the greater part of their lives they are not adding to their 

 carcass, is the cause of the increased value of their manure. 

 Their solid feces are also much richer than those of the cow, 

 as they void less urine and this is of an indifferent character. 

 In a long series of careful experiments, made at Dresden 

 and Berlin by order of the Saxon and Prussian governments, 

 it was ascertained, that unmanured soil which would yield 

 three for one sown, when dressed with cow dung, would 

 give seven ; with horse dung, ten ; and with human, fourteen. 



For the purpose of showing the proportions of the various 

 elements which compose the farmer's manure heap, an analy- 

 sis from Mr. Richardson is subjoined, of some taken from 

 the farm yard in the condition usually applied to the field. 



Fresh. Dried at 212. 



Water 64.96 Carbon 37.40 



Organic matter . 24.71 Hydrogen . 



Inorganic salts . 10.33 Oxygen . 



Nitrogen . 

 100.00 Ashes 



5.27 

 25.52 



1.76 

 30.05 



100.00 



