SOOT A VALUABLE MANURE. 125 



vary greatly with the fuel, and with the circumstances 

 of its combustion. In very dry seasons, soot, like 

 some other of the powerful manures we have men- 

 tioned, sometimes does injury. From 30 to 60 bushels 

 per acre are applied, commonly as a top dressing. It 

 gives a beautiful dark green color to grass or grain, 

 and on many soils increases the yield very largely. 

 If a little exertion were made, there are few places 

 where considerable quantities of this strong manure 

 could not be obtained. 



In Great Britain it has been proposed to crush de- 

 caying granites, to mix them in heaps with quick- 

 lime, and then allow the whole to stand for some 

 months. Granite contains much potash, and it is sup- 

 posed that by the prolonged action of the caustic lime, 

 a part of this would become soluble, and fit for the 

 nourishment of plants. In some parts of this country, 

 masses of decayed rock exist, which it would be well 

 to examine with reference to their economical value 

 for applying to the land. 



