On the Poisonous Action of the Hydroxyl-derivatives of Benzol 
upon Yeast and Bacteria, 
BY 
K- Yabe, Nögahishi. 
The toxical action of phenol, of the dioxybenzols (resorcin, 
pyrocatechin and hydrochinon) and of the trioxybenzols (phloro¬ 
glucin, 1 2 ) pyrogallol) has been compared in regard to animals but 
not yet in regard to the lower fungi. As a general rule, it has 
been found that the poisonous character increases with the 
number of hydroxyl groups entering into the benzol ring. 
Stolnikow observed that phloroglucin is more poisonous for frogs 
than resorcin, and this is again more poisonous than phenol. 
While the lethal dose of phenol for warm-blooded animals is 
0,3-0,7 gr. per kg., 0,08 gr. resorcin is found to be sufficient 
(Zeni and Betelli). The three isomeric dioxybenzols show a very 
great difference in their toxical action. Pyrocatechin is strong¬ 
est, then follows hydrochinon and finally resorcin. Of the trioxy¬ 
benzols, phloroglucin is less poisonous than pyrogallol. Loew a ) 
observed that in i per mille phenol solution some infusoria still 
remained alive after 15 hours, and certain algæ have been found 
alive after three days, while pyrocatechin solution of the same 
strength killed infusoria and diatoms after a few minutes, spiro- 
gyra after several hours. Hydrochinon acts somewhat more 
slowly, but in resorcin solution of that strength infusoria live 
several hours, and algæ are found alive even after 18 hours. 
The phenol character is here evidently increased by the toxical 
effect caused by the capability of absorbing oxygen. Pyrocatech¬ 
in and hydrochinon will rob the cells of the dissolved molecular 
oxygen much more quickly than phloroglucin, and consequently 
we find with the former also a much more poisonous character. 
1) The third isomeride, oxyhydrochinon, has not yet been physiologically 
studied. 
2) Natürliches System der Giftwirkungen, p. 50-51. 
