402 BOTANICAL GAZETTE | DECEMBER 
28. At the concentrations inhibiting fungus spores mono- 
and dichloracetic acids are more influenced by the increased 
toxic properties of the molecule, and trichloracetic by the ioniza- 
F i. ee n ; ‘ 
tion. The former in —— and — concentration are respectively 
increased in toxicity 40 per cent. and 30 per cent. over the origi- 
nal acetic. Trichloracetic, on the contrary, at ae suffers a 
reduction of 10 per cent. in toxic properties as compared with 
the original acetic. 
29. The anions of the mineral acids, HCl, HNO,, and 
—fi,SO,, have a low toxic value for fungi, having less than one 
thirty-second that of ionic H. 
In conclusion I wish to acknowledge my indebtedness to Dr. 
B. M. Duggar, instructor ian plant physiology, and Professor 
George F. Atkinson, professor of botany in Cornell University, . 
for much valuable advice and assistance, and constant encourage- 
ment. My best thanks are also due to Professor W. D. Bancroft 
and Mr. A. L. Knisely of the chemical department for much 
help and information on the chemical aspects of the work. 
BOTANICAL LABORATORY, CORNELL UNIVERSITY. 
BIBLIOGRAPHY. 
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ARRHENIUS ('83): Recherches sur la conductivité galvanique des électrolytes: 
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ARTHUR, J.C. (’97): Formalin for prevention of potato scab. Bull. of Purdue 
Univ. Exp. Stn. 65 : 1897. 
“Boxorny, T. (’86): Das Wasserstoffsuperoxyd und die Silberabscheidung 
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(’88): Uber die Einwirkung basischer Stoffe auf dasle bende Prote- 
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* CvarK, J. F. (’99): Electrolytic dissociation and toxic effect. 
Chem. 3: 263-316. 1899. 
Jour. Physical 
