ESSENTIAL OILS, ETC. 191 



cillus and cholera spirillum were only destroyed after eight to ten 

 days' exposure to the action of camphor ("essence"). 



Carbolic Acid. Tested upon anthrax spores, Koch found a one- 

 per-cent solution to be without effect after fifteen days' exposure ; a 

 two-per-cent solution retarded development but did not completely 

 destroy vitality in seven days ; a three-per-cent solution was effec- 

 tive in two days. In the absence of spores Koch found that a one- 

 per-cent solution quickly destroys the vitality of anthrax bacilli. 

 He recommends a five-per-cent solution for the destruction of the 

 "comma bacillus" in the discharges of cholera patients, and a two- 

 per-cent solution for the disinfection of surfaces soiled with such dis- 

 charges. In the writer's experiments 1 : 200 destroyed Micrococcus 

 Pasteuri in two hours ; and pus cocci were destroyed by 1 : 125, while 

 1 : 200 failed. Davaine showed by inoculation experiments that an- 

 thrax bacilli in fresh blood are destroyed by being exposed to the 

 action of a one-per-cent solution for one hour. A two-per-cent solu- 

 tion destroys the dried virus of symptomatic anthrax in forty-eight 

 hours (Arloing, Cornevin, and Thomas). Solutions in oil or in alco- 

 hol have been shown by Koch to be less effective than aqueous solu- 

 tions. Thus a five-per-cent solution in oil failed to destroy anthrax 

 spores in one hundred and ten days, and the same solution failed to 

 kill the bacilli, in the absence of spores, in less than six days. A 

 five-per-cent solution in alcohol did not destroy anthrax spores in 

 seventy days. Schill and Fischer found that a three-per-cent solu- 

 tion destroyed the infecting power of tuberculous sputum, as shown 

 by inoculation into guinea-pigs, in twenty-four hours, while solutions 

 of one and two per cent failed. Bolton's experiments gave the fol- 

 lowing results, the test organisms being in fresh bouillon cultures 

 and the time of exposure two hours : The cholera spirillum, the 

 bacillus of typhoid fever, the bacillus of schweinerothlauf, Brieger's 

 bacillus, the bacillus of green pus, and the pus cocci (Staphylococcus 

 pyogenes aureus, albus, and citreus, and Streptococcus pyogenes) 

 were all killed by a solution of one per cent, while in a majority of 

 the experiments a one-half -per-cent (1 : 200) solution failed. Cul- 

 tures of the typhoid bacillus in flesh-peptone-gelatin gave the same 

 result (1 : 100 with two hours' exposure), and the addition of ten per 

 cent of dried egg albumin to bouillon cultures did not influence the 

 result. 



The experiments of La Place show that the addition of hydro- 

 chloric acid to a disinfecting solution containing carbolic acid greatly 

 increases its germicidal power for spores. Thus it is stated that 

 " two per cent of crude carbolic acid with one per cent of pure hydro- 

 chloric acid destroyed anthrax spores in seven days, while two per 

 cent of carbolic acid or one per cent of hydrochloric acid alone did 



