30 SOUECES OF INFECTION. 



isms," American Journal Med. Sciences, vol. 94, p. 146) has found 

 by a series of very interesting experiments that different pathogenic 

 germs possess varying degrees of resistance to heat. The following 

 were his results in studying the microorganisms which more par- 

 ticularly interest the surgeon. The time of exposure was ten 

 minutes, unless otherwise indicated by figures in parentheses : 



Fahrenheit. 



Bacillus anthracis (Chaveau) . . . 129.2 



Bacillus anthracis spores . . . . . 212.0 



Bacillus tuberculosis (Schill and Fischer) . . 212.0 (4 m.) 



Staphylococcus pyogenes aureus . . . 136.4 



Staphylococcus pyogenes albus . . . 143.6 



Staphylococcus pyogenes citreus . . . 143.6 



Streptococcus erysipelatosus .... 129.2 



Gonococcus ....... 140.0 



Of course, the same difference of resistance to cold and other 

 destructive influences must exist among them. 



The spores possess still greater resisting powers, and conse- 

 quently, in places where the destructive influences are sufficiently 

 severe to destroy microbes, infection may still take place from this 

 source. 



J. Geppert (" Zur Lehre von den Antisepticis," Berl. klin. 

 Wochenschrift, Sept. 9, 1889) while making the experiments for the 

 purpose of verifying the statements of Woronzoff and others, that 

 the spores of the bacillus anthracis are rendered harmless by im- 

 mersion in a 1 to 10,000 solution of sublimate for fifteen minutes, 

 and by a 1 to 2000 solution in one minute, found a source of fal- 

 lacy in their method. This consists in impregnating a thread with 

 the spores and immersing it in the antiseptic solution for the desired 

 time, and after washing it in alcohol or water, using it to inoculate 

 nutrient media or animals, the extreme difficulty of removing all 

 traces of the chemical used becomes apparent, while its importance 

 is shown by the statement of Koch, that the presence of sublimate 

 in the strength of 1 to 100,000 will retard the growth of anthrax 

 spores. Geppert's method consists in using a suspension of spores 

 in distilled water, which is then filtered through glass wool until 

 the liquid is perfectly clear. After subjecting the spores for a defi- 

 nite length of time to the action of the antiseptic he used some 

 indifferent chemical to precipitate the antiseptic. In the case of 

 sublimate he used ammonium sulphide. He made inoculations with 

 spores exposed to the action of the sublimate before and after pre- 

 cipitation. When he used spores exposed to the action of a subli- 

 mate solution 1 to 1000, without precipitation, he obtained cultures 

 in all cases after an exposure for three minutes, once after seven 

 minutes, also after ten minutes. In using spores of solutions where 



