292 MANUAL OF BACTERIOLOGY. 



temperatures was shown by Liibert* was shown to depend 

 upon the manner of application. Suspensions in water were 

 killed in 30 minutes at 50 C. On dried threads it resisted 60 C. 

 for one hour. Aside from the variation shown by different strains 

 of the staphylococcus, the medium in which it is exposed to 

 heat has decided influence upon the effect of the heat, the num- 

 ber of cocci used in the test also has a decided influence. But 

 one-half to one hour at 80 C. appears to kill the organism 

 under all conditions. Cold appears to have no effect. Very 

 variable results have been observed by different authorities on 

 the effect of different chemical agents as well as of electricity and 

 the Rontgen rays. Corrosive sublimate in the strength of 2-1000 

 requires two or three hours. The many statements in regard to 

 the use of germicides in this connection are confusing. In prac- 

 tice everything contaminated with pus containing the organism 

 should be burned or sterilized in the autoclave for safety. It is 

 not killed by drying alone. In the same specimen the micro- 

 cocci may have quite different resisting powers to chemical 

 germicides. Some of the individual cells are destroyed by 

 i- 1 ooo solution of bichloride of mercury in five minutes; others 

 survive exposure to this solution for from ten to thirty minutes. 



Sterilized cultures introduced into animals may produce 

 local suppuration. The cells contain intracellular toxic sub- 

 stances.f 



As has already been mentioned, the Staphylococcus pyo- 

 genes aureus is the commonest of the pyogenic bacteria in man. 

 It has been obtained from a great variety of sources, and ap- 

 pears to be able to exist as a saprophyte. It has been found 

 on the skin, in the mouth, in the nasal and pharyngeal mucus, 

 and also in the alimentary canal. It has furthermore been de- 

 tected in the air and in dust. It appears to find the conditions 

 necessary for its existence in the vicinity of human habitations. 



*Cited in Kolle and Wassermann. Vol. III., 1903. p. 112. 

 fMorse. Journal. Experimental Medicine. Vol. I., p. 263. 



