514 INTERDEPENDENCE OF SCIENCE AND THE HEALING ART 



microbes must at last be got rid of by phagocytosis, and some recent observations 

 would seem to indicate that the useful elements of the serum may be, in part at 

 least, derived from the digestive juices of the phagocytes. If ever there was a 

 romantic chapter in pathology, it has surely been that of the story of phagocytosis. 



I was myself peculiarly interested by these observations of Metchnikoff's, 

 because they seemed to me to afford clear explanation of the healing of wounds 

 by first intention under circumstances before incomprehensible. Complete 

 primary union was sometimes seen to take place in wounds treated with water 

 dressing, that is to say, a piece of wet lint covered with a layer of oiled silk to 

 keep it moist. This, though cleanly when applied, was invariably putrid within 

 twenty-four hours. The layer of blood between the cut surfaces was thus 

 exposed at the outlet of the wound to a most potent septic focus. How was it 

 prevented from putrefying, as it would have done under such influence if, instead 

 of being between divided living tissues, it had been between plates of glass or 

 other indifferent material ? Pasteur's observations pushed the question a step 

 further. It now was. How were the bacteria of putrefaction kept from propa- 

 gating in the decomposable film ? Metchnikoff's phagocytosis supplied the answer. 

 The blood between the lips of the wound became rapidly peopled with phagocytes, 

 which kept guard against the putrefactive microbes and seized them as they 

 endeavoured to enter. 



If phagocytosis was ever able to cope with septic microbes in so concentrated 

 and intense a form, it could hardly fail to deal effectually with them in the very 

 mitigated condition in which they are present in the air. We are thus strongly 

 confirmed in our conclusion that the atmospheric dust may safely be disregarded 

 in our operations ; and Metchnikoff's researches, while they have illumined the 

 whole pathology of infective diseases, have beautifully completed the theory of 

 antiseptic treatment in surgery. 



I might have taken equally striking illustrations of my theme from other 

 departments in which microbes play no part. In fact any attempt to speak of 

 all that the art of healing has borrowed from science and contributed to it during 

 the past half-century would involve a very extensive dissertation on pathology 

 and therapeutics. I have culled specimens from a wide field ; and I only hope 

 that in bringing them before you I have not overstepped the bounds of what is 

 fitting before a mixed company. For many of you my remarks can have had 

 little if any novelty : for others they may perhaps possess some interest as 

 showing that Medicine is no unworthy aUy of the British Association — that, 

 while her practice is ever more and more based on science, the ceaseless efforts 

 of her votaries to improve what have been fittingly designated Quae prosiint 

 omnibus artes, are ever adding largely to the sum of abstract knowledge. 



