EXCREMENTS AND URINE. 77 



tions are discussed in such a manner as to enable us 

 to deduce sure and certain rules for practical guid- 

 ance ; but it is the only one that will conduct to a 

 knowledge of the truth. 



That the excrements of our live stock are derived 

 from the food which is given to these animals, every- 

 one is aware ; as also that a large part of this prov- 

 ender, that, namely, which was appropriated to the 

 nourishment and preservation of the animal, and, 

 besides this, the surplus devoted to its fattening 

 (that is, to the formation of flesh and fat), or to the 

 production of milk, disappears during its passage 

 through the living organism. Which, then, are the 

 ingredients of the food that are converted into flesh 

 and fat ? which are removed by breathing and per- 

 spiration ? and which, finally, are voided in the urine 

 and excrements from the body ? Is it not obvious 

 that a clear insight into the nutritive processes, and 

 a trustworthy opinion upon the proportion of the 

 food to the faeces, can only be attained when their 

 individual constituents are known, and the altera- 

 tions can be learnt from them which the provender 

 has undergone in the body of the animal? How 

 will it be possible to form an accurate judgment re- 

 specting the differences of animal excrement and its 

 effect upon the various plants in cultivation, if the 

 first elements essential to this judgment, the constit- 

 uents of the plant, the manure, and the soil are not 

 known ? Questions of this character can be solved 

 by chemistry alone ; this science must constitute the 

 7* 



