542 THE THIRD HUXLEY LECTURE 



I am, of course, aware of the great importance of the emigration of leuco- 

 cytes, discovered by Cohnheim, and rendered immeasurably' more interesting by 

 Metchnikoff's observation of their phagocytic powers ; and I know that collec- 

 tions of pus have often such an origin. But I am quite satisfied that this is 

 not the exclusive mode of pus-formation, and that it is often produced by the 

 prohferation of cells, as was first taught by my illustrious predecessor in this 

 chair of two years ago (Professor Virchow), in the Cellular Pathologic. 



While these investigations into the nature of pyaemia were proceeding, 

 I was doing m}- utmost against that deadly scourge. Professor Polli, of Milan, 

 having recommended the internal administration of sulphite of potash on account 

 of its anti-putrescent properties, I gave that drug a very full trial as a prophy- 

 lactic. I have notes of a case in 1864, in which, after amputating the thigh 

 for disease of the knee-joint, I gave ten grains of the sulphite ever};- two hours 

 from the time of the amputation ; and when, on the sixth day, an ominous 

 rigor occurred, I doubled the frequency of the administration. Death, however, 

 took place nevertheless, and this was by no means my only experience of such 

 disappointment. 



At the same time, I did my best by local measures to diminish the risk 

 of communicating contagion from one wound to another. I freely used antiseptic 

 washes, and I had on the tables of my wards piles of clean towels to be used 

 for drying my hands and those of my assistants after washing them, as I insisted 

 should invariably be done in passing from one dressing to another. But all 

 m}^ efforts proved abortive, as I could hardly wonder when I believed, with 

 chemists generally, that putrefaction was caused by the oxygen of the air. 



It will thus be seen that I was prepared to welcome Pasteur's demon- 

 stration that putrefaction, like other true fermentations, is caused by microbes 

 growing in the putrescible substance. Thus was presented a new problem : 

 not to exclude oxygen from wounds, which was impossible, but to protect them 

 from the living causes of decomposition by means which should disturb the 

 tissues as little as is consistent with the attainment of the essential object. 



It has been since shown that putrefaction, though a most serious cause of 

 mischief in wounds, is not its only cause. In other words, it has been proved 

 that there are microbes which produce septic effects without occasioning un- 

 pleasant smell. But the principle that first guided me, still retains, I believe, 

 its full value, and the endeavour to appty that principle so as to ensure the 

 greatest safety with the least attendant disadvantage has been my chief life- 

 w^ork. 



