206 ACTION OF COAL-TAR PRODUCTS, 



Alpha-naphthol and beta-naplitliol have about the same antiseptic and 

 germicidal value. In the proportion of 1 : 16,000 both prevent the develop- 

 ment of the cholera spirillum in peptonized beef -tea, while 1 : 24, 000 fails to 

 prevent development. In the proportion of 1 : 3,000 both destroy the vital- 

 ity of the cholera spirillum in bouillon cultures, twenty-four hours old, 

 after two hours' contact, while 1 : 4,000 fails to destroy this microorganism 

 in the time mentioned two hours. 



In experiments made with a solution of 1:1,000, added to an equal 

 quantity of a twenty-four hours old bouillon culture making- 1 : 2,000 after 

 mixture and in which the time of contact varied from five to thirty minutes, 

 alpha-, beta-, and hydronaphthol were found to destroy the cholera germ by 

 fifteen minutes' exposure, but to fail after ten minutes' contact, so that the 

 germicidal value of each of these is similar, or nearly so. 



In all these experiments the line was sharply drawn between success and 

 failure. No development occurred and the bouillon remained transparent 

 in those experiments in which the germicidal action was complete, and a 

 characteristic development occurred within twenty -four hours in those ex- 

 periments in which there was a failure to destroy the spirillum. 



Benzo-naphthol has no germicidal power, probably because it is insoluble 

 in water. At least this is my inference from the experiments made. One 

 gamme was added to one thousand cubic centimetres of distilled water, and 

 after vigorous shaking was placed in the steam sterilizer for half an hour. 

 At the end of this time the greater portion, at least, of the benzo-naphthol re- 

 mained undissolved at the bottom of the flask. The saturated solution (?) 

 was then filtered and added to recent bouillon cultures of the cholera spiril- 

 lum in the proportion of 1 : 1, 1:2, 1 : 4, and 2:1. At the end of two hours 

 sterile bouillon in test tubes was inoculated from each of these and placed in 

 the incubating oven. At the end of forty-eight hours a characteristic devel- 

 opment of the cholera spirillum had occurred in all of the tubes. 



Olive Oil. Anthrax spores germinate after having been im- 

 mersed for ninety days in pure olive oil (Koch). 



Oil of Mustard. Koch found that the development of anthrax 

 spores is prevented by 1 : 33,000. 



Oil of Peppermint. A five-per-cent solution in alcohol failed in 

 twelve days to destroy anthrax spores, but the development of these 

 spores is restrained by 1 : 33,000 (Koch). 



Oil of Turpentine destroys anthrax spores in five days, but failed 

 to do so in one day (Koch). The development of anthrax spores is 

 prevented by 1: 75,000 (Koch). The addition of 1 : 200 to nutrient 

 gelatin prevents the development of bacteria (Riedlin) . An excess 

 of oil of turpentine added to a liquefied gelatin culture of Staphylo- 

 coccus aureus does not destroy this micrococcus in five hours (v. 

 Christmas-Dirckinck-Holmfeld). 



Saprol. Laser (189*2) recommends tbis agent for the disinfection 

 of the excreta of cholera and typhoid patients. He reports that in the 

 proportion of 1 : 100 it sterilizes liquid fa3ces in twenty-four hours. 



Skatol in excess in water has no germicidal power, as tested upon 

 anthrax spores (Koch). 



Smoke. The researches of Beu show that meats which have been 

 preserved by smoking commonly contain living bacteria capable of 

 growing in culture media; and Petri has shown that pork which has 



