544 ScHREINER & SKINNER: EFFECT OF GUANIDIN ON PLANTS 
grams in the guanidin set. The phosphate removed was 427.3 
milligrams in the control and 287.0 milligrams in the guanidin set; 
the potash was 723.7 milligrams for the control and 496.7 milli- 
grams for the guanidin set; the nitrate was 457.9 milligrams for 
the control cultures and 304.8 milligrams for the guanidin cultures. 
Tests of guanidin carbonate in quantities of 50 parts per 
million were also made in soil cultures. The physiological effect 
of the guanidin was again apparent in the spotting and bleaching 
of the leaves and was again most evident in the soils fertilized 
with nitrate. 
EFFECT OF GUANIDIN ON OTHER PLANTS 
The effect of guanidin was further studied by using plants 
other than wheat. In FIG. 3 is shown its effect on corn growing 
= le 
€ : > 
Fic. 3. Harmful effect of guanidin on corn; no. I without guanidin, no. 2 with 
guanidin. 
in culture solution no. 41, containing 16 parts per million phos- 
phate, 32 parts per million nitrate, and 32 parts per million potash. 
Fic. 4 shows the effect of guanidin on cowpeas, the control and 
guanidin cultures being in duplicate. Fic. 5 shows its effect of 
the potato plant. In these tests guanidin was used in concentra 
