ACTION OF ACIDS AND ALKALIES. 183 
Benzoic Acid.—According to Miquel, this acid restrains the de- 
velopment of putrefactive bacteria when present in bouillon in the 
proportion of 1:909. In the proportion of 1 : 2,000 it retards the de- 
velopment of anthrax spores (Koch). 
Formic Acid.—The typhoid bacillus is restrained in its growth by 
0.25 per cent, and is killed in five hours by 0.35 per cent, the cholera 
spirillum by 0.22 per cent (Kitasato). 
Tannic Acid.—A solution of one per cent kills Micrococcus Pas- 
teuri in the blood of a rabbit in half an hour (Sternberg). A five- 
per-cent solution failed in ten days to destroy anthrax spores (Koch). 
A twenty-per-cent solution failed in two hours to destroy the vitality 
of spores of the anthrax bacillus or of Bacillus subtilis (Abbott). 
Micrococci are destroyed by 1:400, and 1:800 failed (Abbott). A 
twenty-per-cent solution has no effect upon the virus of symptomatic 
anthrax (Arloing, Cornevin, and Thomas). A solution of 1.66 per 
cent kills the typhoid bacillus in five hours, and 1.5 per cent the 
cholera bacillus in the same time (Kitasato). It restrains the devel- 
opment of putrefactive bacteria in the proportion of 1: 207 (Miquel). 
Tartaric Acid.—A twenty-per-cent solution of this acid fails, 
after two hours’ exposure, to destroy the spores of Bacillus anthracis 
or Bacillus subtilis. Micrococci are killed by two hours’ exposure in 
a solution containing 1 : 400 (Abbott). 
Malic Acid.—This was found by Kitasato to correspond with 
citric acid in its germicidal power. 
Valerianic Acid.—A five-per-cent solution in ether failed in five 
days to destroy anthrax spores (Koch). 
Oleic Actd.—A solution of five per cent in ether does not destroy 
anthrax spores in five days (Koch). 
Thymic Acid.—In the proportion of 1 :500 this acid prevents the 
putrefactive decomposition of beef tea (Miquel). 
Butyric Acid.—Five days’ immersion in this acid failed to de- 
stroy anthrax spores (Koch). 
Arsenious Acid.—A one-per-cent solution destroys the vitality 
of anthrax spores in ten days, but failed to do so in six days (Koch). 
In the proportion of 1 :166it prevents putrefactive changes in bouillon 
(Miquel). 
Gallic Actd.—Abbott found this acid to destroy the bacteria in 
broken-down beef tea in the proportion of 2.57 per cent, but it failed 
to destroy anthrax spores in two hours in the same proportion. Mi- 
crococci were killed in two hours by 1 : 142, while 1 : 250 failed. 
ALKALIES. 
Potassium Hydroxide, KHO.—In the writer’s experiments a ten- 
per-cent solution of caustic potash was fatal to pus cocci, and an 
