SOME EXPERIMENTS WITH DISINFECTANTS 



23 



disinfectants used in this series of experiments were the same as those 

 employed by Klein in certain of his more crucial experiments. They 

 were the same for formaline and phenol, as in my first series, but the 

 dilutions of cyllin and corrosive sublimate were about twice the strength 

 of those used in the first series. Agar cultures were used instead of 

 bouillon cultures. 



1. Emulsions of the different cultures were made in sterile distilled 



water, using one loopful of the culture in each case. 



2. 5 c.c. of the different strengths of the disinfectant were put into 



sterile tubes. 



3. To each tube of disinfectant was added 'i c.c. of the emulsion of 



the organism, and the mixture was then shaken thoroughly. 



4. At end of intervals of 5, 10, and 15 minutes, 3 loopfuls of the 



mixture were smeared over the surface of an agar tube, and 

 incubated for 8 days at 37° C. The following results were 

 obtained. 



FORMALINE (32 %). 



(+=Growth; — = No Growth). 



Growth was present in all tubes, except those of B. typhosus, where the dilutions were 

 1-20 and 1-25, and the exposures 10 and 15 minutes; and Staph, pyog. aureus, 

 where the dilutions were 1-15 and 1-20, and the exposures were 10 and 15 minutes. 



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S I 



