ESSENTIAL OILS, ETC. 193 



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 a short time, and also disinfected tuberculous sputum. 

 Behring has shown that in albuminous liquids creolin is less effective 

 than carbolic acid. In blood serum 1 : 175 was required to restrain 

 the development of staphylococci, and I : 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 

 to 1 : 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 



13 



