14 MANUAL OF BACTERIOLOGY. 



number of failures. Such failures it was shown were due to the 

 presence of the resistant forms of the organisms called spores 

 previously alluded to which some bacteria assume. The true 

 nature of spores was recognized later by Cohn. Pasteur found 

 that exposure to steam at temperatures sufiSciently high above 

 the boiling point would destroy the most resistant microbes and 

 their spores. 



The controversies over fermentation and putrefaction lasted 

 almost until the present day. They have been productive of nu- 

 merous benefits to the arts and manufactures. But, what is of 

 more importance to our subject, they led to a vastly better 

 understanding of diseases producing microorganisms. The 

 study of bacteria has been pursued with such vigor in the last 

 twenty-five years in fact that most of what we know concerning 

 the bacteria of disease has been learned during this period, and 

 advances are still constantly being made. 



The discussions concerning fermentation and putrefaction 

 were still going on when Lister made his brilliant deduction that 

 suppuration and septic processes in wounds were a species of 

 fermentation (1867). From this came the antiseptic and aseptic 

 methods of operating and of dressing wounds, which have 

 made possible the wonderful results of modern operative 

 surgery.* 



In 1834 the parasite of itch {Acarus scabiei, the itch mite, an 

 arachnid, related to the insects) was discovered, and the cause 

 of one contagious malady determined. 



Quite early in the nineteenth century also the relatively 

 large fungi of thrush and some of the parasitic skin diseases 

 were discovered. The bacilli of anthrax, which are also rela- 

 tively large, were seen in the blood of animals by Pollender 

 in 1855 and Davaine in 1863. 



Davaine produced anthrax in animals by injecting into them 



* See Dr. Roswell Park. History of Medicine. 



