30 HAXDY-BOOK OP HUSBANDRY. 



NITROGEN. 



Nitrogen is an element not only of all plants, but of every part 

 of the plant. Root, stem, branch, and leaves, at some period of 

 their growth, contain it in every minutest part of their structure. 

 Its quantity, in comparison w^ith the other elements, is extremely 

 small ; but, in vegetable growth, the importance of any constitu- 

 ent of the tissues is not to be measured by its quantity. It may 

 play the smallest possible part in the building up of the plant, but 

 so much of it as is necessary must be at the right spot at the right 

 time. If the sap lacks the atom of nitrogen that is required, all 

 the other atoms in the sap go for nothing. 



It generally forms from lo to 40 parts of every 1,000 parts of 

 the dry weight of the whole plant — by far the largest proportion 

 being lodged in the grain. 



The experiments of Boussingault showed that 1,000 lbs. of 

 each of the following articles contain the amount of nitrogen 

 stated in the table. (The substances were thoroughly dried at a 

 high temperature). 



Wheat 23 lbs. 



" Straw , , . . , . 4 " 



Rye 17 " 



" Straw 3 " 



Oats 22 «< 



" Straw 4 « 



Peas 42 " 



" Straw 23 «< 



Potatoes I c « 



Beets 



'7 



Turnips 17 «< 



Red Clover hay 21 " 



This, like all other tables based on vegetable analysis, is to 

 be regarded as indicating the general proportion which the different 

 elements bear to each other, rather than the positive amount of 

 each. They vary a little, according to the conditions of growth, 

 but not very materially. 



