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BactcrioloQical IDalue of Corrosive Sublimate 



a£5 a (Bermicibe^ 



By Prof. V. A. Latham, D.D.S., Chicago Univ. 



^'^HE following is from an abstract Of a Thesis by Charles T. 

 McClintock, A.M., candidate for the degree of Ph.D. 

 (Univ. of Mich.) : — 



"In 1 88 1 Koch recommended corrosive sublimate as the most 

 efficient of all known substances for disinfecting purposes. Since 

 then it has been universally used. After making some hundreds 

 of experiments, the author finds that Koch and those who have 

 confirmed his work based their conclusions on faulty experiments, 

 the most important of which was the failure to notice that the 

 sublimate formed, with the gelatinous coat of bacteria, a compound 

 insoluble in water, but soluble in salines, and readily removed by 

 the blood. When bacteria treated with sublimate were transferred 

 to gelatine or agar, the capsule of mercury compound prevented 

 the growth of the germ, and the false conclusion was drawn that it 

 was dead. In the author's experiments this capsule of mercury 

 was removed by precipitation with hydrogen sulphide ; while Koch 

 states that all bacteria are killed in a few minutes by solutions of 

 sublimate, i : looo, the experiments show the bacteria — such as 

 Staphylococcus pyogeneus aureus — may grow after having been in 

 the I : I GOO solution ninety-three hours; i : loo, eleven hours; 

 saturated solution, one hour. 



Bacillus subtilis gxQy^ diiXQX lying in i : looo forty-one hours; 

 saturated solution, eighty-five minutes; typhoid germs, after 

 I : looo, one hour; germs in faeces, after twenty-four hours in a 

 saturated solution. Several experiments comparing strong vinegar 

 with I : looo sublimate indicated that they have the same germi- 

 cidal power. The experiments also indicate that the larger number 

 of bacteria in a given culture are comparatively easily killed, and 

 that the ratio of those killed by a germicide to those that survive 

 is of no value. The conclusions drawn from the experiments are : 



(i) That the high rank heretofore given corrosive sublimate as 

 a germicide is without warrant and was based on faulty experi- 

 ments. 



