EXCREMENTS AND URINE. 89 



1. The urine (excepting that of swine) is far richer 

 in nitrogen than the solid excrements. A pound's 

 weight of the former will therefore readily develop 

 twice or three times stronger forcing power than the 

 same weight of the latter. The azotized constitu- 

 ents (uric acid and urea) dissolved in the urine have, 

 moreover, a greater tendency to pass into putrefac- 

 tion than the insoluble constituents of similar nature 

 contained in the faeces. Hence a very simple expla- 

 nation, at once, why the former acts far more quickly 

 than the latter. The less firmly and compactly the 

 mass of excrement hangs together, and the more 

 easily it may be distributed and diffused in the soil, 

 the more quickly can the putrefaction and decay of 

 the azotized matter take place. This is the reason 

 why many manures (horse refuse, for example) are 

 brisker and more heating in their operation than 

 others (as, for instance, cow manure). 



2. The solid excrements are indeed much richer 

 in humus-forming substances (organic matter abound- 

 ing in carbon) than the urine. Amongst all constit- 

 uents of manure, however, these are least valuable 

 to the farmer, as they are only converted into ener- 

 getic manure by the addition of azotized and min- 

 eral ingredients. 



3. Next to nitrogen, the alkalies and alkaline sails 

 form the most valuable component part of the urine, 

 and contribute importantly to its forcing power. 

 Only trifling quantities of these bodies, compara- 

 tively speaking, are contained in the faeces. 



8* 



