AZOTE IN PLANTS. 255 



little azote; and, as we all know, when used alone, make much 

 poorer manure. But even among different vegetables forming 

 ordinary farm products, there are great differences in their propor- 

 tions of azote, and also in their sources of supply of this rich 

 ingredient ; and according to such differences are the respective 

 values of crops for food, and more especially their powers as im- 

 provers or exhausters of the soils on which they grow. The in- 

 vestigation and attempt at elucidation of this last branch of the 

 subject is the object of the next following pages. 



Boussingault reports (from the results of analyses by himself and 

 Pay en, in conjunction) the proportions of azote contained in nume- 

 rous vegetable and animal substances (at p. 297, Rural Economy), 

 from which the following extracts of some ordinary manuring ma- 

 terials will serve as examples : 



Ordinary farm-yard manure, 100 parts, dry, contained of 



azote 1.95 



Richer manure, from an inn-yard - . . . .- 2.08 



Wheat-straw of Alsace [presumed from ordinary soil] . 0.30 

 Do., from environs of Paris [presumed much richer soil] . 0.53 

 Rye-straw of Alsace . . .. . . .0.20 



Do., environs of Paris . . . . . . . 0.50 



Oat'-straw ' 0.36 



Barley-straw . 0.26 



Wheat-chaff 0.94 



Pea-straw [or vines, &c.] . . . . . 1.95 



Clover roots ........ 1.77 



Oilcake of flax-seed 6.00 



Do. cotton-seed . . . . . . . .4.52 



Solid cow-dung . 2.30 



Solid horse-dung . . . ... . . 2.21 



Guano 6.20 



Dried muscular flesh . . . . . . .14.25 



Woollen rags 20.26 



While I do not deem the azotic as the only fertilizing parts of 

 putrescent manures, nor concur in all that Boussingault seems to 

 claim for their preponderance of operation, still it cannot be denied 

 that the azote of all organic manures constitutes their principal and 

 greatest fertilizing quality. Hence, we may learn, that if by any 

 means, and from new or additional sources, there can be given to 

 plants an additional supply of azote, of which the absolute quantity 

 would be so small as to seem scarcely worth consideration, yet that 

 there would be added relatively as much amount of manuring value 

 as a larger dressing of ordinary manure could supply. And a due 

 'consideration of these premises will serve to increase the estimate 



