SPONTANEOUS GENERATION 317 



wound and abscess which so frequently converted our 

 hospitals into charnel-houses, and it is their destruction 

 by the antiseptic system that now renders justifiable opera- 

 tions which no surgeon would have attempted a few years 

 ago. The gain is immense to the practicing surgeon as 

 well as to the patient practiced upon. Contrast the anx- 

 iety of never feeling sure whether the most brilliant opera- 

 tion might not be rendered nugatory by the access of a 

 few particles of unseen hospital dust, with the comfort 

 derived from the knowledge that all power of mischief on 

 the part of such dust has been surely and certainly anni- 

 hilated. But the action of living contagia extends beyond 

 the domain of the surgeon. The power of reproduction 

 and indefinite self-multiplication which is characteristic of 

 living things, coupled with the undeviating fact of con- 

 tagia " breeding true," has given strength and consistency 

 to a belief long entertained by penetrating minds, that 

 epidemic diseases generally are the concomitants of para- 

 sitic life. "There begins to be faintly visible to us a 

 vast and destructive laboratory of nature wherein the dis- 

 eases which are most fatal to animal life, and the changes 

 to which dead organic matter is passively liable, appear 

 bound together by what must at least be called a very 

 close analogy of causation.'* 1 According to this view, 

 which, as I have said, is daily gaining converts, a con- 

 tagious disease may be defined as a conflict between the 

 person smitten by it and a specific organism which multi- 

 plies at his expense, appropriating his air and moisture, 



die Balken zur Stiitze seiner Faulnisstheorie zu zimmern versucht, hat zueret 

 den Satz 'keine Faulniss ohne Bacterium Terrao' zu widerlegen. " 

 1 Report of the Medical Officer of the Privy Council, 1874, p. 5. 



