ON THE FOOD OF PLANTS. 



** with a pump, by which any fluid matter may 

 " be collected for the use of the land. It too 

 ** often happens that a dense mucilaginous and 

 " extractive fluid is suffered to drain away from 

 " the dunghill, so as to be entirely lost to the 

 farm." 



My previous objections to the application of 

 Sir Humphry's ideas, must be equally strong 

 against the mode here recommended. 



Those who are in the habit of making hot- 

 beds for vegetables, know that fresh dung from 

 the stable, packed together without a sufficient 

 degree of moisture, to modify its fermentation ; 

 will very speedily acquire a high degree of 

 heat, and throw off* a quantity of elastic vapour ; 

 either carburetted hydrogene, or ammonia, and 

 that as the moisture declines, the heat will also : 

 and the dung will then be overrun with moul- 

 diness, or fungii, and thus during such ferment- 

 ation, the exclusion of moisture or rain, by 

 a shed being placed over it, must facilitate and 

 increase the loss by such evaporation, and by the 

 evolution of the gases ; and the earth covering 

 dung in this state, will not afterwards support 

 vegetation. As the chief supply of manure is 

 derived from the stable and farm yard, the ar- 

 rangement and management of these is a matter 

 of no trivial importance. 



