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BOARD OF AGRICULTURE. 



reputation for its fitness to cure root-sick and clover-sick 

 lands. Since we have learned that magnesia and sulphuric 

 acid count among those few substances which are essential for 

 a complete development of plants, it is but reasonable to 

 assume that the presence of magnesia sulphate must add an 

 increased value to a potash fertilizer, which contains that 

 compound in considerable proportion. 



Professor Ville, in his important experiments at Vincennes, 

 with the growth of wheat, found in case the magnesia was not 

 added to his so-called complete fertilizer, that the latter 

 proved as inefficient as if phosphoric acid had been excluded. 

 The ash of wheat-grain contains 12 per cent, of magnesia to 

 23 per cent, of potassa. Potash fertilizers containing sulphates 

 of magnesia, are therefore considered of particular value for 

 the cultivation of grain-crops. 



From the preceding short exposition, we can draw at 

 least some good hints regarding the particular kinds of potash 

 salts we ought to import. 



Our dealers act in the best interest of their customers by 

 importing none but 80 per cent, containing muriate of potash, 

 and 40 to 50 per cent, containing sulphate of potassa ; the 

 former being equal to 50 per cent, of potassium oxide, the 

 latter to 25 per cent.* These compounds are the cheapest 

 of their kind, and answer the requirements of both general 

 and special farming. 



The subsequent statements show what price farmers have 

 been paying during the past year, for one pound of potassium 

 oxide, when buying by the ton. 



Note. — The nitrogen contained in the latter, is equal to 13 per cent., 

 and counts 30 cents per pound, or $78 per ton of nitre. 



* Our farmers do best, as a general rale, to ask for the higher grades of these fer- 

 tilizers, and to use the lower grades, if cheap, only for forage crops. 



