120 MASSACHUSETTS HORTICULTURAL SOCIETY. 



bones, dissolved bone black, dissolved burnt bone (bone ash), 

 dissolved South Carolina rock, dissolved Canadian apatite." 



Certainly it needed no professor to tell us that Peruvian guano, 

 nitrate of soda, and wood ashes, are fertilizers, but it does need a 

 skilful chemist to give us the equivalents in these articles for the 

 constituents of the Stockbridge fertilizers. Prof. Stockbridge 

 says Mr. Judd spoiled his potatoes by using muriate of potash in- 

 stead of sulphate, and Mr. Fowler made a total failure because he 

 applied the fertilizer in a liquid form to " a coarse sand with a 

 gravel subsoil," so that the rains washed it away before it could 

 afford the crop much nutriment. In a printed statement, it 

 was said by Prof. Stockbridge himself, that he failed in an experi- 

 ment by using a quantity of the Stassfurth salts, which by a sub- 

 sequent analysis he found to be very poor in potash. These are 

 only illustrations of the difficulty of conducting experiments of this 

 kind, and of the small value of single instances, in arriving at 

 general conclusions. 



The Theory contains a Manifest Fallacy. — The difficulties 

 suggested in the way of the practical working of the Stock- 

 bridge theories, are by no means the chief objection to them. 

 The system rests upon a fallacy, which is fatal to it. It is 

 a system of exhaustion and not of compensation, and a very 

 slight examination will demonstrate the truth of this statement. 

 To produce fifty bushels more of corn than the land will yield in 

 its present condition, you should apply the quantity of nitrogen, 

 potash, and phosphoric acid, that fifty bushels of corn contain. 

 If the land would have produced fifty bushels without the fertilizer, 

 it should now produce a hundred bushels. You have applied the 

 elements of fifty bushels and removed a hundred bushels. Where 

 did the crop find the elements of the fifty bushels which you did 

 not supply? It is part of the theory of Prof. Stockbridge, that 

 the three elements in question must come from the soil. Then you 

 have exhausted the soil to the extent of fifty bushels. You have 

 treated it precisely as if you had applied no fertilizer, and taken 

 off a crop of fifty bushels. 



It seems so nearly incredible that such a system as this should 

 be gravely recommended to the public by our Agricultural College 

 that it will be proper to examine it more in detail. For conve- 

 nience, we will continue to use the formula for Indian corn. In 

 the college report it is in these words : " To produce fifty bushels 



