AMERICAN AGRICULTURE. 



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of substances requiring different constituents, and on this the 

 system of alternation of crops is founded. 



The principal source from which the soil is to be supplied with 

 the inorganic constituents of plants, is the urine and excrements of 

 animals and different animal remains. Urine contains a large 

 proportion of alkaline and earthy phosphates, and on them depends 

 its value as a manure, more than on the nitrogen it furnishes. 

 The same is true of bones, which have been found to be so valua- 

 ble as manures. After being buried a few years they contain no 

 animal matter, and furnish only food for the inorganic constituents 

 of the plant. 



Guano is a substance which has recently been brought into use 

 as manure. It consists of the excrements of birds which has 

 accumulated for a great length of time, and it furnishes to plants 

 both nitrogen, and alkaline and earthy phosphates. 



These matters must not only be present in the soil, but must 

 also be soluble in water, and several substances are employed as 

 manures, the efficacy of which depends on their capacity of forming 

 soluble combinations of the silex, alumina, &c. 



WHAT IS TO BE DONE FOR AMERICAN AGRICULTURE ? 



Ever since the attention of agriculturists in England was awa- 

 kened to the immense benefits to be derived to their noblest of 

 arts, by the aid offered by science, there has been a vast amount 

 of speculation afloat in this country upon the same subjects. If, 

 instead of speculation, it had been the well grounded result of in- 

 vestigation and careful experiment, it would have been, even at 

 this time, amply sufficient to have redeemed American farming, and 

 placed it upon a secure and profitable footing. If the activity and 

 zeal displayed, instead of being set to work loosely and without 

 any definite object, had been first enlightened and then cautious — 

 slow and prudent, and directed to particular results — if instead of 

 being distributed over the whole broad field of agriculture at once, 

 it had been guided with discretion to the improvement of some 

 single branch of husbandry — the effects at this day would have 

 been incalculable. Great revolutions, such as are necessary in 



