i9i 2] SCH REINER & SKINNER— FERTILIZER SALTS 33 



mixtures of P 7 e and K 



the 



mixtures 



NH 3 . The cultures in the interior of the triangle contain mixtures 

 of all constituents, differing in io per cent stages one from the other, 

 the composition depending upon its position in the triangle; those 

 nearer the P 2 s apex consisting chiefly of phosphate fertilizer, 



NH 



K 



more 



scheme 



reader is referred to an earlier paper. 4 



Two sets of these 66 culture solutions were prepared, one of 

 them containing in every culture io ppm. of cumarin. The total 

 concentration of the nutrient elements P 2 O s +NH 3 +K 2 was in 

 all cases 8o ppm. The culture solutions were contained in wide- 



mouth bottl 

 the manner 



The culture solutions 

 hnnp-es beiner made in 



each experiment. The culture solutions were analyzed imme- 

 diately after each change for nitrates, but the phosphate and 

 potassium were determined on a composite of the four changes. 

 The green weight of the nlants was determined at the termination 



: experiment. The first experiment with 

 December o and discontinued December 2 



ppm 



was strikingly noticeable in the difference between the plants grow- 

 ing in the two sets of cultures. The appearance of plants growing 



ns containing cumarin is very characteristic dnu 1 

 from the effect on wheat of anv other toxic com 



rked 



The leaves are shorter and broader 



normal 



remaining 



swollen sheath; such leaves as do break forth are usually distorted 

 and curled or twisted. The appearance is so characteristic that 

 the investigator can pick out the cumarin-affected plants from 

 those affected by any other toxic body in the same experiment by 



4 Schreinek, O., and Skinner, J. J., Ratio of phosphate, nitrate, and potassium 

 on absorption and growth. Bot. Gaz. 50: 1. 1910. 



