117 



rob the land of these plant foods ; so that in some 

 respects its effect is like that of lime. Without 

 simultaneous applications of other manures it may 

 *'make the father rich and the children poor." 



The most important domestic sources of potash are 



wood ashes, cotton seed hull ashes, tobacco dust, 



and tobacco stems. The composition 



bacco ReftiBe! ^^^ values of the various ashes have 

 been given in the chapter on domestic 

 manures. Corn-cob ashes are only second to cotton 

 seed hull ashes in amount of potash. 



Tobacco dust contains about 9.05 per cent potash, 

 3.00 per cent nitrogen, and 2.25 per cent phosphoric 

 acid. Its fertilizing value is near twenty dollars per 

 ton. Tobacco stems contain about 6.50 per cent of 

 potash, 0.60 per cent phosphoric acid, and 2.25 per 

 cent nitrogen, and have a fertilizing value of about 

 twelve dollars per ton. 



Saltpetre, if pure, is almost one half potash, with 



fourteen per cent nitrogen. It is probably worth 



a hundred dollars per ton. Some of the 



andMari. ^^^ Jersey marls, (green sand marl) 



are said to contain as much as seven 



per cent of potash. This is not in an available form, 



but good results are sometimes reported from the 



use of this material. 



