ORGANIC MANURES. 59 



All are simple oxidations of the metal, or the combination 

 of oxygen with iron; and we see in the comparison, the 

 immensely-accelerated effect produced by the absence of 

 nitrogen and an augmented temperature. 



Nitric 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, 26.15 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, 

 forms nitrate of soda. The last is found in immense beds, 

 and lies upon and immediately under the surface of the earth, 

 in China, India, Spain and elsewhere. From Chili it is ex- 

 ported in large quantities ; and has been of late years, exten- 

 sively used in England, 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 here, 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 

 and beautiful results. Every plant that exists, from the ob- 

 scure sea-weed 100 fathoms below the surface of the 1 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 ma- 

 terials, 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 

 preserve all its good qualities, and apply it, undiminished, to 

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

 sarily left in the pastures or about the stacks where they are 

 fed ; though it is better, for various reasons, that they should 

 never receive their food fror,i the stack. The manure thus 

 left in the fields, should be beaten up and scattered with light, 



