76 BOARD OF AGRICULTURE. 



supplied to the plants those materials which they consume in 

 maximum quantities, he would develop, the next year, out of 

 the materials in the soil, those elements which the plant con- 

 sumes in minimum quantity, and thus the farmer be relieved 

 from the expense of supplying anything for the growth of the 

 plants but those larger elements which the plant consumes in 

 greatest quantity? That was the first question we asked 

 nature in our experiments, and that question we put in 1869. 

 I come now, gentlemen, to the experiments. We com- 

 menced, as I say, in 1869. We took from various parts of 

 the College farm, and from surrounding farms, far and near, 

 specimens of soil, carefully avoiding all rich lands, and put 

 them into pots in the plant-house. Into those pots we put 

 the different agricultural crops or plants which we produce. 

 To those plants we gave various materials, and, of course, 

 we had Dr. Goessmann to tell us what we should use ; there 

 was no guess about it. We fed those plants with nitrogen, 

 with phosphoric acid, with potash, with all the different 

 elements, — soda, magnesia, carbon, and everything else. I 

 will not stop to detail minutely the experiments during the 

 first four years. Year after year we went on — feeling, feel- 

 ing, feeling — to see what stimulated the growth, and what 

 did not stimulate the growth; two years in the pots in the 

 plant-house, and two years in large boxes out in the garden, 

 near my own residence ; carefully observing the effects pro- 

 duced upon the plants by these different elements which we 

 used. The result was this : that, if I interpreted the answer 

 I got aright, nature said, "In practical operations on the 

 land, for crops, one year, two years, three years, four years 

 consecutively, for such crops as you have used, the farmer 

 need not use any carbon, to make carbonic acid, sugar, 

 starch, etc. He need not use any oxygen or hydrogen, any 

 soda, or any chlorine. He need not use any sulphuric acid ; 

 he need not use any magnesia, except, perhaps, for the 

 tobacco crop. He need not apply anything to grow crops 

 upon the farm, but nitrogen, potash and phosphoric acid." 

 That is what nature seemed to say to us : "If you want to 

 grow plants, take nitrogen, potash and phosphoric acid, on 

 such soils, for such plants, and you can make them." We 

 accepted the answer; supposed, perhaps, we were right, 



