higher than the minimum in the field. The relative varia- 

 tions between the extremes of phosphoric acid are greater 

 than those in the case of nitrogen, but the absolute varia- 

 tions are small, and may possibly be traceable to accidental 

 causes. It may not be amiss to state just here that a great 

 deal of time and care were spent in the analytical work, that 

 no errors might creep in to vitiate the results, and hence it 

 can be confidently affirmed that the results given may be 

 relied on. It is believed, however, that some individual 

 stalks have exhibited peculiarities of composition, and such 

 peculiarities might have been eliminated, perhaps, had a 

 larger number of plants from each plot been available for 

 analysis. 



In the second place, we note that the character of the 

 soil exercises a perceptible influence on the composition of 

 the plant, at least as far as potash and nitrogen are con- 

 cerned. Taking the means of the percentages of potash in 

 the three unfertilized plots of each soil separately, we find 

 that this mean in the garden soil is 51.4 "o higher than the 

 corresponding mean in the field soil. Making the same 

 estimates for nitrogen, we find that the garden soil exceeds 

 the field soil in this ingredient by 8.6 '-u. Here, as before; 

 we cannot affirm any positive rule concerning phosphoric 

 acid. 



The original purpose of these investigations was to find 

 out what effect, if any, the addition of fertilizing constituents 

 to the soil would have on the relative proportions of these 

 constituents in the plants themselves. With this purpose 

 before us let us examine Table I in detail. In the results 

 from the Drake field soil, we see that the highest percentage 

 of potash is in plot 3, and the next highest in plot 9, to both 

 of which plots potash was added. On the other hand, the 

 second lowest percentage is in plot 8, which also was fertil- 

 ized with potash. It will be noticed that this plot seems 

 eccentric in another particular — in that it contains the high- 



