570 FRAGMENTS OF SCIENCE. 



ricidal media are therefore antiseptic and disinfecting."* 

 It was these organisms acting in 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 operations 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 anxiety of never feeling sure whether 

 the most brilliant operation might not be rendered 

 nugatory by the access of a few particles of unseen hospital 

 dust, with the comfort derived from knowledge that all 

 power of mischief on the part of such dust has been surely 

 and certainly annihilated. But the action of living con- 

 tagia 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 contagia "breeding true," has given 

 strength and consistency to a belief long entertained by 

 penetrating minds, that epidemic diseases generally are 

 the concomitants of parasitic life. " There begins to be 

 faintly visible to us a vast and destructive laboratory of 

 nature wherein the diseases 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." f Accord- 

 ing to this view, which, as I have said, is daily gaining 

 converts, a contagious disease may be defined as a conflict 

 between the person smitten by it and a specific organism 

 which multiplies at his expense, appropriating his air and 

 moisture, disintegrating his tissues, or poisoning him by 

 the decompositions incident to its growth. 



During the ten years extending from 1859 to 1869, 

 researches on radiant heat in its relations to the gaseous 

 form of matter occupied my continual attention. When 

 air was experimented on, I had to cleanse it effectually of 



* In his last excellent memoir Colin expresses himself thus: " Wer 

 noch heut die Faulniss von einer spontanen Dissociation der Pro- 

 teinmolecule, oder von einem unorganisirten Ferment ableitet, oder 

 gar aus ' Stickstoffsplittern ' die Balken zur Stutze seiner Fiiul- 

 nisstheorie zu zimmern versucht, hat zuerst den Satz ' keine 

 Faulniss ohne Bacterium Termo ' zu vviderlegen." 



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



