74 ON THE POISONOUS ACTION OF THE HYDROXYL-DERIVATIVES 
It seemed to be of interest to compare these different 
phenols in relation to yeast and bacteria as it has been recently 
asserted by Biernacki (Pflüg. Arch. 49, 112) that phenol is a 
stronger poison for yeast than pyrogallol which would be an 
exceptional case, the alcoholic fermentation being prevented by 
the following solutions :— 
# • • 
Phenol.i : 200 
Resorcin.1 : 100 
Pyrogallol. 1 : 50. 
For this purpose, equivalent quantities of different phenols 
were dissolved in Pasteur solution, and yeast added. The results 
are shown in the following table :— 
Phenol 0,5% no fermentation. 
Pyrocatechin 0,585 ,, ,, 
Resorcin 0*585 fermentation. 
Hydrochinon 0,585 ,, 
Pyrogallol 0,670 ,, 
Phloroglucin 0,670 ,, 
0,4% no fermentation. 
0,468 ,, feeble fermen¬ 
tation. 
In a second experiment, yeast was shaken first with the 
solutions of these phenols and left to stand for 70 hours. After 
decantation of the liquid, the yeast was put in Pasteur solution 
with the following results : 
Phenol 0,3 % fermentation 
Pyrocatechin 0,351 ,, 
1 ) 
5* 
J J 
Resorcin 0,351 
Hydrochinon 0,351 
Pyrogallol 0,402 
Phloroglucin 0,402 
Phenol 
Pyrocatechin 0,527 
Resorcin 0,5 27 
Hydrochinon 0,527 
Pyrogallol 0,603 
Phloroglucin 0,603 
0,4% no fermentation. 
0,468 feeble fermenta¬ 
tion. 
0,468 fermentation. 
0,468 
°> 53 6 
0.536 
0,45% no fermentation. 
* * 
; * 
fermentation, 
feeble fermentation. 
55 
fermentation. 
The same experiment has been carried out with bacteria. 
A drop of putrid peptone solution was mixed with 50 c. c. of the 
