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BOARD OF AGRICULTURE 



handsome profit. If he makes no profit by its use, he would bet- 

 ter let it alone. I think he should reasonably expect not T 3-10 

 per cent., but rather 73 per cent, and upwards; for experience 

 shows that when judiciously employed, several times its cost is 

 frequently realized. 



It is certain that he cannot afford to pay the price demanded for 

 chemically pure potash, nor for pure phosphoric acid, nor for pure 

 ammonia. But he is not shut up to these resources, for he can 

 find them constituting a part of various substances occuring in 

 nafiire, as for instance, potash in wood ashes, phosphoric acid in 

 bones and minerals, and nitrogen in organic substances. Wood 

 ashes will give up its potash to plants without difficulty, for it 

 exists in them in a readily soluble condition, very unlike the con- 

 dition in which it exists in feldspar, or granite. Bones require, at 

 least, to be finely ground before plants can get good of the phos- 

 phoric acid which the}'- contain ; and if they be dissolved in acid 

 so much the better. Mineral and fossil phosphates- must be both 

 finely ground and also chemically treated before they will yield 

 up their virtues, and some organic substances may be improved 

 hj either mechanical or chemical treatment. 



To the celebrated Saxon chemist, Dr. Stockhardt we are in- 

 <debted for the earliest suggestions whereby approximately to 

 d-etermine the money value of commercial manures. He reasons 

 as follows : 



" The inquiry, what is the money value of manures? is one of great moment 

 'to the farmer, especially in times when he is in danger of buying a manure for 

 twice, nay three or four times as much as, compared with others, it is actually 

 worth. How then is the farmer to protect himself against losses of this des- 

 cription? We answer, by interrogating chemistry. In deciding upon the 

 value of artificial manures, external signs and evidences are wholly insuffi- 

 cient and insecure; they must be subjected to a keener and more thorough 

 scrutiny ; to wit, a chemical analysis. ■* * * * 



The chief difficulty consists in finding a trustworthy and accurate criterion 

 by which the price of the inditidval chemical substances tliat form the con- 

 stituents of mj^nures may be determined. Many of these substances (for 

 example nitrogen) are not met with as articles of commerce and have, accord- 

 ingly no definite market value. Other substances (for example potash, soda, 

 sulpluiric acid, etc.) occtir, indeed, in commerce, but only in the more or less 

 purified state in which they are used in the arts. The commercial value they 

 possess, when so refined, cannot be assumed as a basis of our calculations, in- 

 asmtwh as it would be greatly too high. Finally, most substances, recognized 

 as manuring agents, even wlien they form an article of trade, are commonly 

 united witli each other, whence a distribution of the money value between two, 



