XI. 
ACTION OF COAL-TAR PRODUCTS, ESSENTIAL 
OILS, ETC. 
In the present section we shall consider the action upon bacteria 
of a variety of organic products, and for convenience will arrange 
them alphabetically. 
Acetone.—Anthrax spores grow freely after two days’ exposure 
to the action of this agent; at the end of five days their development 
is feeble (Koch). 
Alcohol.—In the writer’s experiments ninety-five-per-cent alco- 
hol did not destroy the bacteria (spores) in broken-down beef tea in 
forty-eight hours. Micrococcus Pasteuri was destroyed by two hours’ 
exposure in a twenty-four-per-cent solution ; pus cocci required a 
forty-per-cent solution. Koch found that absolute alcohol had no 
effect upon anthrax spores exposed to its action for one hundred and 
ten days. Schill and Fischer found that when tuberculous sputum 
was mixed with an equal amount of absolute alcohol its infecting 
power was not destroyed in twenty-four hours, but that in the pro- 
portion of five parts to one of sputum it was effective in destroying 
the tubercle bacillus, as proved by inoculation experiments. Yersin 
found that in pure cultures the tubercle bacillus is killed by five 
minutes’ exposure to the action of absolute alcohol. 
Aniline Dyes.—Recent researches have shown that some of the 
aniline colors possess very decided germicidal power. Stilling found 
that solutions of methyl violet containing 1:30,000 exercise a re- 
straining influence upon the development of putrefactive bacteria 
and pus cocci, and that these microérganisms are destroyed by solu- 
tions containing 1 :2,000 to 1:1,000. Methyl violet has been placed 
in the market by Merck under the name of pyoktanin. Jianicke re- 
ports the following results with pyoktanin : Staphylococcus pyogenes 
aureus was restrained in its development by solutions containing 
1: 2,000,000, Bacillus anthracis by 1: 1,000,000, Staphylococcus pyo- 
genes by 1: 333,300, Spirillum cholerze Asiaticze by 1 : 62,500, Bacil- 
lus typhi abdominalis by 1:5,000. In blood serum stronger solutions 
were required (1:500,000 for Staphylococcus pyogenes aureus). Sta- 
phylococcus pyogenes aureus, Streptococcus pyogenes, and Bacillus 
anthracis were killed in thirty seconds by 1 : 1,000, the typhoid bacil- 
