EFFECT OF ALKALI ON GE1NE. 71 



pointed out, sufficiently for all practical purposes. 

 The chemical proportion of the elements of geine is 

 unconnected with the practical question, how far it 

 is essential to plants. The fact, that the most bar- 

 ren soil contains these elements in vast quantity, that 

 exhausted land is nearly equally rich in these, as is 

 the highly productive, has been overlooked. The 

 amount of nitrogen in geine, even in exhausted soil, 

 is sufficient to supply that element, to several crops 

 of grain. The amount of carbon, oxygen, hydrogen, 

 and nitrogen, in a poor, sandy, barren soil, has been 

 proved, by chemical analysis, to be not less than 34 

 tons per acre, taking the soil at only a foot in depth. 

 If the light of modern chemistry, shall hereafter 

 teach, that these are never taken from the geine of 

 soil, it will teach also, what the true action of geine 

 is. If no approach to the solution of this impor- 

 tant question, has yet been made, still the absolute 

 necessity of geine in soil, is admitted by all practi- 

 cal men. Some attempt to explain this fact, will be 

 presented in the next chapter ; and the following 

 appendix may be omitted by those to whom practi- 

 cal results are of more value than speculations of 

 philosophy. 



