ASSIMILATION OF NITROGEN. 65 



grain may be equally large, but it will weigh 

 lighter and be less nutritious. The agriculturist, 

 therefore, has it in his power to grow his crops, 

 his wheat especially, to suit his customers; for 

 example, if he lives in the vicinity of a starch 

 manufactory, where his wheat may be required 

 for the purpose of making that article, it will 

 be the more valuable, the less nitrogen and the 

 more carbon it contains, but if required as an 

 article of food, or for making vermicelli, the 

 very reverse of this is the case, an abundant 

 supply of nitrogen being the requisite to give 

 it that quantity of gluten on which its value as 

 an article of food entirely depends. 



These results may be obtained from the same 

 seed and the same soil, wholly by the applica- 

 tion of the proper manures, viz. of decaying 

 vegetable matter, in the one case to furnish a 

 due supply of carbon for the wheat intended for 

 the starch-maker, and of urine or the nitrates 

 of soda or potash in the other case to supply the 

 gluten for the miller. 



These subjects will again come under our 

 notice under the subject of manures. We now 

 proceed to point out other matters connected 

 with the supply of nitrogen or ammonia to the 

 soil. 



The solid excrement of animals contains com- 

 paratively very little nitrogen, especially that 

 from herbaceous animals, as almost all the ni- 

 trogen contained in vegetables which is not as- 

 similated in the passage of the food through 

 the stomach passes off through the urinary pas- 

 sages in a liquid form. And as the value of 

 7 



