ESSENTIAL OILS, ETC. 201 
pyogenes aureus was prevented from developing by two per cent, 
and was killed in six days by a five-per-cent solution ; Streptococcus 
pyogenes was prevented from growing by one per cent, and killed by 
a ten-per-cent solution in one day ; Proteus vulgaris did not grow in 
presence of 2.5 per cent, and was killed in two days by ten per cent. 
The question as to what constituent of the infusion of roasted coffee 
was the active germicidal agent was not determined, but the authors 
referred to agree that it was not caffeine. 
Creolin.—This is a coal-tar product which resembles crude carbolic 
acid in appearance, but smells rather like tar than like phenol. It 
makes a milky emulsion with water, which has been proved by nu- 
merous experiments to possess very decided germicidal power, being 
superior to carbolic acid. The first careful test of the germicidal 
power of this agent was made by Esmarch, who found that a solu- 
tion of 1:200 killed the cholera spirillum in a minute, the typhoid 
bacillus at the end of several days. Anthrax spores were not de- 
stroyed in twenty days by a five-per-cent solution, but this solution 
killed the tubercle bacillus attached to silk threads which were im- 
mersed in it for ashort time, and also disinfected tuberculous sputum. 
Behring has shown that in albuminous liquids creolin is less etfective 
than carbolic acid. In blood serum 1:175 was required to restrain 
the development of staphylococci, and 1:100 to destroy the same in 
ten minutes. Van Ermengem, as a result of numerous experiments, 
arrived at the conclusion that creolin is a cheap and useful disinfect- 
ing agent, in a five-per-cent solution, for various pathogenic organ- 
isms. Kaupe reports that in his experiments a ten-per-cent solution 
killed anthrax spores in twenty-four hours. According to Boer, a 
solution of 1:5,000 destroys anthrax bacilli in bouillon cultures in 
two hours, 1:2,000 diphtheria bacilli, 1: 300 the glanders bacillus, 
1 : 250 the typhoid bacillus, and 1 :3,000 the cholera spirillum. 
Creosote.—This agent was found by the writer to be fatal ‘to 
micrococci in the proportion of 1: 200. In the proportion of one per 
cent it failed, after twenty hours’ exposure, to destroy tubercle ba- 
cilli in sputum (Schill and Fischer). A saturated aqueous solution 
does not destroy the tubercle bacillus in cultures in twelve hours 
(Yersin). Guttman, in extended experiments upon various patho- 
genic organisms, found that development was prevented by 1 : 3,000 
to1:4,000. A solution containing 1 :300 killed Bacillus pyocyanus 
and Bacillus anthracis in one minute, Bacillus prodigiosus in two 
minutes, and the Finkler-Prior spirillum in one minute in the pro- 
portion of 1 : 600. 
Cresol.—This is a dark, reddish-brown, transparent fluid, some- 
what thinner than creolin, and, like it, having an odor of tar. It 
forms an emulsion with water, which is not so stable as that formed 
