80 MASSACHUSETTS HORTICULTURAL SOCIETY. 



The important fact, however, is this : The corn plant has in 

 these trials shown itself capable of getting on and bringing fair 

 3'ields with small amounts of the less costly mineral fertilizers, 

 even in the worn-out soils of the Eastern States. With this help 

 it has gathered its nitrogen from natural sources, and holds it 

 readily to be fed out on the farm and returned in the form of 

 manure for other crops. In other words, the experiments thus far 

 impl}" that corn has, somehow or other, the power to gather a 

 great deal of nitrogen from soil or air, or both ; that in this 

 respect it comes nearer to the legumes than the cereals ; that, in 

 short, corn may be classed with the '' renovating" crops. If this 

 is really so — and this can be settled only by continued experi- 

 menting — then our great cereal, instead of simply being a con- 

 sumer of the fertilitj' of our soils, may be used as an agent for their 

 restoration. 



Ville laid stress on the " dominant ingredient," and divided 

 plants into two groups, one of which responds especially to 

 potash. No writings on the subject have been so much read as his, 

 but chemists do not always believe all that he has said. 



In some experiments to determine this point, corn treated with 

 phosphoric acid gave an increase of less than four bushels per 

 acre. Phosphoric acid was set down as inefficient. When the 

 crop pays attention to nitrogen or potash, phosphoric acid is the 

 regulating ingredient. Out of eighty experiments with corn, phos- 

 phoric acid proved the regulating ingredient in twenty-seven, 

 potash in eleven, and nitrogen in four. In twenty-seven experi- 

 ments with potatoes, phosphoric acid proved the regulating 

 ingredient in three, potash in one, and nitrogen in none. But 

 these experiments are subject to the manifold vicissitudes of field 

 experiments. Certain ones which seemed most reliable were 

 selected for -tabulation. In twenty-four of these with corn, phos- 

 phoric acid proved the regulating ingredient in six, potash in 

 three, and nitrogen in one. In twelve selected experiments with 

 potatoes, neither of these substances showed such efficiency' that 

 it could be deemed a regulating ingredient. When the differences 

 in experiments are all alike the results are reliable. 



In man}' cases, Ville's theory applies ; in many it does not. 

 We can find abundance of facts to favor any theory. Phosphoric 

 acid was most efficient with corn, and potash next; nitrogen had 

 scarcely any efficiency. If we omit the experiments afTecled by 



