152 BOTANICAL GAZETTE [AUGUST 
For the P. sativum seedlings growth occurred in the first two 
dilutions for the first twenty-four hours only. In the next dilu- 
tions growth. continued for the entire period. For Zea Mais 
growth was noted in the first dilution for the first twenty-four 
hours, but not afterwards, while in the following dilutions growth 
continued for the entire period. Those roots which were killed 
remained rigid. : 
The solutions were mixed upon Ag as a base, and the fol 
lowing action will show what the solutions contain: 
AgNO, + 3KCN = KNO, + K(AgCN,) + KCN. 
At the dilutions used the KNO, is without effect. The K(Ag 
CN,) will dissociate to form K* ions and AgCN; ions; the 
KCN to K* ions and CN°- ions. 
The above experiments show that more silver is required to 
produce poisoning when present in the form of AgCN7 ions, bee 
when present as the simple Ag ion: four times as much fot the P. 
sativum seedlings and eight times as much for Zea Mais seedlings: 
A comparison of the results obtained by myself with oe of 
True and Kahlenberg* is given in the following table. The 
dilutions given just allowed growth. 
——— 
Name of Compound P, sativum gen ee 
HCl 
Cems ce ee Mette esse cece eel Tohop. eq. 
ee re a 
PG oe Me “ 
Pe a a ¥ 
C,H,0, vou . 
oe Re ad A tee Waele: sitoe 
CHO er a : 
Cu(C,H30,), Wt eee Gorm Ne ea kee oe 6 co a eo “s 
: J, ee ORAM ee ce os eg S srést . 
NENG coe Ce 
ODO rtou 
CONG soos 
AgNO eee 
— CO ee chee ee zorseu “ 
$2 APRN ee ede ele gg Le re: es 
H C] i tas ee ek Botsoo 
g FOO he PA go eS sueeT 2 
BRON ere Trt00 
RFHCN) ae a . 
KiFCCN . 
*S Bor. Gaz. 22:81, 1896. 
