378 The Microscope. 



Name of Organism. Centigrade. Fahrenheit. 



Sarcina Lutea 64 1 47.2 



Sarcina axirantiaca 62 143.6 



Vaccine vinis (Carstens and Coert) 54 129.2 



Rinderpest virus (Semmer and Raupach) 55 131 • 



Sheep-pox virus (Semmer and Raupach) 55 131 



Hydrophobia virus 60 140 



No attempt has been made to fix the thermal death-point within 

 narrower limits than 2" C, and in the above table the lowest 

 temperature is given which has been found in the experiments 

 made, to destroy all of the organisms in the material subjected to 

 the test. No doubt more extended experiments would result, in 

 some instances, in a reduction of the temperature given as the 

 thermal death -point for a degree or moi'e. 



But the results as stated are sufficiently accurate for all 

 practical purposes, and permit us to draw some general conclusions: 



(a.) The temperature required to destroy the vitality of 

 pathogenic organisms varies for different organisms. 



(&.) In the absence of spores, the limits of variation are 

 about 10° centigrade (18" F.) 



(c). A temperature of 56'^ C. (132.8° F.) is fatal to the 

 bacillus of anthrax, the bacillus of typhoid fever, the bacillus of 

 glanders, the spirillum of Asiatic cholera, the erysipelas coccus, to 

 the virus of vaccinia, of rinderpest, of sheep-pox, and probably of 

 several other infectious diseases. 



(d.) A temperature of 56° C. (132.8° F.) is fatal to all of the 

 pathogenic and non-pathogenic organisms tested, in the absence of 

 spores (with the single exception of sarcina lutea, which, in one 

 experiment, grew after exposure to this temperature). 



(e.) A temperature of 100° C. (212° F.) maintained for five 

 minutes destroys the spores of all pathogenic organisms tested. 



(/.) It is probable that some of the Bacilli which are 

 destroyed by a temperatiu-e of 60° C. form endologenous spores 

 which are also destroyed at this temperature. 



Bacteria in Ear-Furuncles.— Lowenberg of Paris, has under- 

 taken bacteriological researches, in a certain number of cases of still 

 unopened boils of the meatus. In each case he first syringed this 

 canal and then tilled it for ten minutes Avith a luke-warm solution of 

 bichloride of mercury ( 2Thu)- ^ small portion of the pus was innocu- 



