On the other hand the farmer was asking him : 



" What shall I use to produce profitable crops — how much and in 

 what form? " 



Starting then from the crop, with the farmer's question ever spur- 

 ring him on and with such data as he could find, he worked out his 

 well known formulas, which were published broadcast in 1876. And 

 let me say here that besides being published in many agricultural 

 papers and reports more than half a million pamphlets containing 

 them were distributed. 



He did not claim that his formulas were infallible, for he antici- 

 pated and announced, what we soon discovered in practice, that they 

 would need to be modified, as experience should point the way. 

 They served, however, a greater purpose even than Stockbridge 

 dreamed at the time — they centered our thought and our study on 

 the crop. From that time on we discussed plant food and not soil 

 food — plant feeding instead of soil manuring. " Feed the crop 

 rather than the soil," was a frequent expression at this time. 



It is well to observe here that crop formulas were not new. Ville 

 and others had published various sets. The Stockbridge formulas, 

 however, were unique in this : that they were based not alone on the 

 analysis of the crop, but on its power of absorption from all the 

 sources of fertility — from soil, air and water. Thus Stockbridge 

 boldly prescribed : 



"To produce fifty bushels of shelled corn per acre (without any 

 stable manure) and its natural proportion of stover, more than the 

 natural yield of the land, apply so many pounds each of nitrogen, 

 potash and phosphoric acid. Or to produce a stated quantity of 

 tobacco leaf of the desired color and texture, apply a stated quantity 

 of plant food elements, preferably in the form of sulphates and 

 nitrates." 



Here then, for the first time, a definite way was prescribed to at- 

 tain a definite object. It was a startling proposition, and, as might 

 be expected, it brought ridicule from many quarters, but Stockbridge 

 did not allow that to disturb him. He knew that the commercial 

 farmer needed a tangible starting point. He knew that to consider 

 the needs of the crop, the living thing, both as to amount and kind 

 of plant food, rather than the needs of the soil, an unknown and un- 

 knowable quantity, was not only a common sense way of meeting the 

 problem of plant nutrition, but a very direct way of helping the farmer 



