DUST AND DISEASE. 303 



he showers upon his exposed surfaces the spray of diluted 

 carbolic acid, which is particularly deadly to the germs, 

 and he surrounds the wound in the most careful manner 

 with antiseptic bandages. To those accustomed to strict 

 experiment it is manifest that we have a strict experimenter 

 here a man with a perfectly distinct object in view, which 

 he pursues with never-tiring patience and unwavering faith. 

 And the result, in his hospital practice, as described by him- 

 self, has been, that even in the midst of abominations too 

 shocking to be mentioned here, and in the neighborhood 

 of wards where death was rampant from pyaemia, erysipe- 

 las, and hospital gangrene, he was able to keep his patients 

 absolutely free from these terrible scourges. Let me here 

 recommend to your attention Professor Lister's "Intro- 

 ductory Lecture before the University of Edinburgh," which 

 I have already quoted ; his paper on "The Effect of the 

 Antiseptic System of Treatment on the Salubrity of a Sur- 

 gical Hospital ; " and the article in the British Medical 

 Journal, to which I have just referred. 



If, instead of using carbolic-acid spray, he could sur- 

 round his wounds with properly-filtered air, the result 

 would, he contends, be the same. In a room where the 

 germs not only float but cling to clothes and walls, this 

 would be difficult if not impossible. But surgery is ac- 

 quainted with a class of wounds in which the blood is freely 

 mixed with air that has passed through the lungs, and it is a 

 most remarkable fact that such air does not produce putre- 

 faction. Professor Lister, as far as I know, was the first to 

 give a philosophical interpretation of this fact, which he 

 decribes and comments upon thus : 



I have explained to my own mind the remarkable fact that in simple 

 fracture of the ribs, if the lung be punctured by a fragment, the blood 

 effused into the pleural cavity, though freely mixed with air, undergoes 

 no decomposition. The air is sometimes pumped into the pleural cavity 

 in such abundance that, making its way through the wound in the pleura 



