VEGETABLE MANURES. 35 



insects. It drives these off and its ammonia also promotes 

 the growth of the plants. 



Among the vegetable matters which may add to the 

 stock of manures for the garden, the very best is cotton 

 seed where it can be obtained. If the husk were removed 

 and the remainder reduced to an equally dried state, it 

 would scarcely be inferior in strength to guano itself. It 

 may be applied with advantage to any crop. 



Charcoal renders the soil light and friable, gives it a 

 dark color and additional warmth for early crops. The 

 bed whereon charcoal has been burnt is always marked 

 by a more vigorous growth of plants when it becomes 

 sufficiently mixed with earth. It contains also small 

 quantities of silicate of potash and other fertilizing salts. 



It absorbs both carbonic acid and ammonia from the 

 air, and yields them to the roots of plants. It is most 

 marked in its effects on plants which require abundant 

 nitrogen. As it is indestructible, its beneficial effects last 

 as long as it remains in the soil, supplying the spongioles 

 or rootlets of plants with an atmosphere of carbonic acid 

 which is renewed as fast as abstracted. Its good effects 

 begin to be seen when the dust is applied at the rate of 

 forty bushels per acre. Charcoal is invaluable for destroy- 

 ing the odor of decaying animal matter, retaining all the 

 gases in its own substance ready to yield them up for the 

 use of plants. Hence, the best application of this sub- 

 stance is not directly to the soil, but to compost it with 

 putrescent animal matters, urine or night soil, of which it 

 will absorb all the odor and fertilizing gases given off 

 during their decomposition. Composted with the last 

 named substance, it becomes poudrette, and is second only 

 to guano as a fertilizer. 



In striking cuttings or potting plants, charcoal is a 

 valuable substitute for sand, plants rooting in with greater 



