GERMICIDES AND ANTISEPTICS. 22 5 



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Hydrogen. Bacteria may develop in an atmos- 

 phere of hydrogen (Hamlet). 



Iodine (in aqueous solution with potassium 

 iodide) destroys the septic micrococcus in the 

 proportion of 1 : 1,000 ; the micrococcus of pus 

 and B. tenno in 1 : 500. It prevents the develop- 

 ment of these organisms when present in a culture- 

 solution in the proportion of 1 : 4,000 (S). The 

 development of bacteria in tobacco-infusion is 

 prevented by 1 : 5,714 (Bucholz); in boiled beef- 

 infusion, 1 : 2,010; in unboiled, 1:10,020 (de la 

 Croix). One part in 1,000 destroys the bacteria 

 which produce the acid fermentation of milk 

 (Molke) ; and 1 : 410 the bacteria of broken-down 

 beef-tea (de la Croix). 



Mercuric Bichloride. All experimenters agree in 

 placing this in the front rank as a germicide and 

 antiseptic agent. One part in 40,000 prevents 

 the development of the septic micrococcus, and 

 but little less is required in the case of the micro- 

 coccus of gonorrhoeal pus and of B. termo. To 

 destroy the vitality of bacteria in broken-down 

 beef-tea (old stock) required 1 : 10,000, while the 

 above-mentioned micrococci were killed by 1 : 20,- 

 000 (S). The activity of the virus of sympto- 

 matic anthrax (dried virus) is destroyed by 1: 5,000 

 (Arloing, Cornevin, and Thomas). The bacteria 

 of broken-down beef-infusion are destroyed by 1 : 

 6,500, and their development in beef-tea prevented 

 by 1 : 10,250 (de la Croix). One part in 20,000 

 prevents the development of bacteria in sterilized 



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