122 



comj)oun(ls themselves. Asparaginc contains no phos- 

 phorus, while the nucleic acid does; and the phos- 

 phoric acid of the nucleic acid is set free during the 

 decomposition of the compound in the soil. Since 

 this is true, the absence of phosphorus in the treat- 

 ment given would be more noticeable in the aspara- 

 ginc treated pots than in the nucleic acid treated pots. 

 Corn was planted in a number of the pots after the 

 oats were harvested. The pots were treated as fol- 

 lows for the corn: the check pot remained untreated; 

 the pot which had received a complete fertilizer for 

 the oats was given a complete fertilizer for the corn. 

 the same quantities of phosphate, kainit and nitrate 

 being used in each case; while all of the remaining pots 

 received 4.5 grams each of kainit and acid phosphate. 

 It is very interesting to note the effect of the addition 

 of potassium and phosphorus to those pots which had 

 previously received nitrogenous compounds alone to 

 oats. Without the minerals, the oat plants could not 

 make use of the nitrogenous materials, and hence, there 

 was an accumulation of nitrogen in those pots in which 

 the minerals were lacking. Now, when these pots were 

 treated with potassium and phosphorus and planted to 

 corn, the limiting factor was removed, and there result- 

 ed enormous growth of the corn plants. Without excep- 

 tion, the high yielding oat pots proved to be the low 

 yielding corn pots, and vice versa. No evidence is ob- 

 tained from this w^ork to show that pyridine or quino- 

 line is toxic to plants, when it is added to the soil in 

 which the plants are grown. On the contrary, it is defi- 

 nitely shown that these two compounds are useful 

 sources of nitrogen, when used in connection with min- 

 eral fertilizers. 



The effect of dihydroxystearic acid on plant growth 

 when it is added to soil is of special interest in view 

 of the great amount of work that has been done with 

 it in water cultures, and the conclusions that have been 

 drawn from these water cultures. The presence of 

 even minute quantities of dihydroxystearic acid in 

 water cultures greatly reduced the growth of wheat 

 seedlings; and since this toxic compound has been 

 isolated from soils, the conclusions were drawn that 

 the infertility of the soils from which this compound 

 vras isolated, was due to its presence. If this be true, 

 then it should be possible to increase the infertility of a 



