272 VEGETABLE FOOD. 



every kind of soil ; so that were it possible to collect 

 them in such a shape as to be tangible and distri- 

 butable the attempt would be superfluous ; except 

 only as regards carbon, which, as it exists in the 

 excrement of animals, is a powerful assistant to 

 vegetation wherever obtained and used. 



But by far the greater part of our knowledge rela- 

 tive to the food of plants, has been derived from 

 experience. Chemistry, with all its powers of ana- 

 lysation, c., has hitherto done but little, and that 

 little seldom attended to as it deserves, especially in 

 the management of farm and stable yard dung, and 

 composition of mixings or composts. Every culti- 

 vator is aware that all recent or decomposed vegetable 

 matter is a useful pabulum of living plants ; as well 

 as all animal substances whether recent or rotten. 

 Farm-yard, fold, and stable dung, wood ashes, bone 

 dust, and horn shavings ; the refuse and sweepings 

 of butchers', curriers', and fellmongers' yards and 

 workshops ; linseed and rape seed cake ; woollen, 

 linen, silk, and cotton rags: in short the offal of 

 every employment, where either animal or vegetable 

 substances are manufactured are all found valuable 

 manures. 



Mineral substances, as salt, lime, chalk, marl, coal, 

 culm, soot, and ashes, are all used on land as direct 

 or indirect stimulants thereto. These combined with 

 some of the components of the staple, promote it is 

 said the solution of effete matter, and prepare it for 

 the sustentation of plants. 



