PLANT NUTRITION. 39 



gone through with for four j'ears, and we kept correcting and 

 revising until December, 1875. Having ascertained this thing, 

 the remarkable statement was made and supposed to be justified 

 by the facts, that yoa can make plants in any given quajitity by 

 supplying to the soil nitrogen^ potash and phosphoric acid, in the 

 proper quantity and in the given proportion. In other words, if 

 you give to the soil as much of these three elements as would be 

 contained in fifty bushels of corn and the natural proportion of 

 stalks, 3'ou will get that. It is as if I were to ask you how many 

 boxes so long, so wide, and so high, you could make from such 

 and such a pile of boards. You would say so many, according to 

 the number of feet in the pile. So I said, if you give me the material 

 that is required to make fifty bushels of corn, in the form in which 

 the vital forces must have it, cannot I make the fifty bushels of 

 corn? I went to the land to find out. I will not weary your patience 

 with the details of my various experiments. Suffice it to say, 

 that in 1873, in three towns, in more than twenty different places, 

 there wasn't a failure in a single instance with corn, oats, wheat, 

 rye and tobacco. In a single instance there was a failure with 

 potatoes, but not of five bushels less than the amount pledged. 

 In the production of Indian corn we promised fifty bushels per 

 acre more than the natural production of the land, and in no case 

 did we ever run under more than two bushels. On more than 

 three hundred acres of Indian corn all over the State of Massachu- 

 setts, from the Berkshire hills to Boston, the underrun, so far as 

 we have been able to ascertain, has been on the whole less than 

 ten bushels. We got almost exactly the quantity we said we 

 would get, sometimes a little more and sometimes a little less, but 

 approximating as nearly as the mechanic would to the boxes from 

 the pile of boards, without knowing the exact number. 



Now if you believe these things (and if you don't I can't help 

 it) I have given you some practical information in respect to 

 it so that you can make plants. I will surmise that you will ask 

 certain questions that will be practical. "If you can do these 

 things what will you use to do it with ?" "You say, 'certain 

 chemical elements,' — how will you obtain them ?" For nitrogen 

 it makes no difference to the plant what you use, provided that 

 the nitrogen is available. You can provide nitrogen in the form 

 of sole leather, and it will take about ten years to render it avail- 

 able. You can provide it in the form of barn-yard manure and it 



