ORGANIC MANURES. 53 



(in an intense degree) in the gradual rusting which tuke* 

 phiee in tlie air at its ordinary temperature ; or the more 

 rapid format ion of the scales under the heat of the black- 

 smith's forgo. Ail are simple oxidations of the metal, or the 

 combination of oxygen with iron ; and we see in the com- 

 parison, the immensely accelerated effect produced by the 

 absence of nitrogen. 



Xitric acid is another compound of great importance to 

 vegetation. It is simply nitrogen and oxygen ; the identical 

 materials which compose the atmosphere, combined in differ- 

 ent proportions, 20.15 parts by weight of the former, and 

 73.85 of the latter in every 100. This acid in union with 

 potash, forms nitrate of potash, or saltpetre ; and with soda 

 ionns nitrate of soda. The last is found in immense beds and lies 

 upon and immediately under the surface of the earth in Chili, 

 India and Spain. From Chili it is exported in large quanti- 

 ties, and has been extensively used in England of late years, 

 as a manure. 



It has been deemed relevant to our subject to say thus much 

 respecting some of the most striking characteristics of those 

 four simple principles, which make up an average of more 

 than 98 per cent, of all living vegetables. And heje a mo- 

 ment's reflection irresistibly forces from us an expression of 

 wonder and admiration at that Wisdom and Omnipotence, 

 which, out of such limited means, has wrought such varied 

 nnd beautiful results. Every plant that exists, from the 

 obscure sea-weed 100 fathoms below the surface of the ocean, 

 to the lofty pines that shoot up 300 feet in mid-air; and 

 from the clinging moss that seems almost a part of the rock 

 on which it grows, to the expanded banyan tree of India, with 

 its innumerably connected trunks, overshadowing acres ; 

 every thing that is pleasant to the taste, delightful to the eye, 

 and grateful to the smell, equally with whatever is nauseous, 

 revolting and loathsome, are only products of the same 

 materials, slightly differing in association and arrangement. 



BARN- YARD MANURE. 



The first consideration in the management of manures, is 

 to secure them against, all waste. The bulk, solubility and 

 peculiar tendency to fermentation of barn-yard manure, ren = 

 ders it a matter of no little study so to arrange it as to pre- 

 serve all its good qualities and apply it undiminished to the 

 soil. A part of the droppings of the cattle are neces- 



