Afk ELEMENTS OF 



add a further quantity of silicate of potash, and phos 

 phates, which, if the straw be aheady putrified, are 

 exactly in the same state as before ihey formed part of 

 the crop which yieided them. 



But, if we use human excrements, in addition to the 

 phosphates of hme and magnesia, we supply a larger 

 proportion of compounds of nitrogen, essential to ih^ 

 development of those parts of plants upon which human 

 beings are accustomed to feed : and, by a wise ordina- 

 tion, grain-plants are found associated with human 

 dwelhngs — in other words, the family of man having 

 selected such spots on the earth's surface, as are fitted 

 for the growth of grain, animal manure is always at 

 hand in quantity for its artificial cultivation ; thus re- 

 storing, through the feculent discharges of man and ani- 

 mals resident on the spot, precisely those materials which 

 the process of growth has removed from the soil. 



Cow-dung is not incorrectly said to be "cold;" so 

 much of the saline, nutritive, and other organic matters 

 from the cow, pass off almost exclusively with her urine, 

 that her dung does not readily heat and run into putre- 

 faction. Still, mixed with other manures, or well dif- 

 fused through the soil, its vegetable matter is not use- 

 less. It loses more than any other similar substance i^ 

 drying. The dung of pigs is soft and cold, like that of 

 the cow — containing, like it, nearly 80 per cent, of wa- 

 ter. Mixed with other manures, it may be applied to 

 any crop — but is of very variable quality, owing to the 

 variety of food of the animal. 



The horse is fed, generally, on less liquid food, less 

 succulent and watery, than that of oxen. He discharges 

 less urine ; hence his dung is richer in animalized mat- 

 ter ; or, adopting the figurative language of the farmer, 

 it is hotter, and, indeed, runs more readily into the pu- 

 trefactive fermentation. 



If the solid excrements of animals are chiefly valuable 

 for the saline, earthy, and inorganic constituents they 

 restore to the soil which has yielded them, it will hi 

 readily inferred, that instead of dung or night-soil, other 

 substances, containing their peculiar ingredients, may 



