1915] on Back to Lister 385 



very freely, his results were yet more remarkable ; and in the mean- 

 time, relying on the antiseptic principle, he was doing new opera- 

 tions which, without it, he would have considered to be altogether 

 unjustifiable. 



In spite of this, as you know, Lister's treatment, though hailed 

 with acclamation abroad, met with a very ungenerous reception in this 

 country. His compatriots could not understand the great principle 

 that underlay it. They said that there was nothing new in it ; if there 

 was, it was bad. They said that their results were quite as good as 

 his, or, if they were not, it was only because he paid so much personal 

 attention to his cases. They gave the treatment silly names, showing 

 that they had not grasped the meaning of it ; at first it was the 

 "carbolic treatment," now it was the "spray and gauze treatment." 

 This last name was even adopted by Lister's disciples, and thus the 

 spray came to be regarded as a fetish to such an extent that anything 

 which cast a doubt upon its infallibility' sorely tried the tender faith 

 of the converted. 



But increasing knowledge forced Lister to alter his own l^eliefs 

 and greatly to modify his practice in the two particulars to which I 

 have especially directed your attention. Thus he more and more 

 diminished the strength of and the amount of his antiseptics ; and, 

 having become gradually convinced that infection from the air, far 

 from being the greatest source of danger, was a negligible quantity, 

 he gave up the use of the spray for good and all. 



We must now inquire how this came about. Lister always looked 

 upon an antiseptic as a necessary evil, because he saw that anything 

 strong enough to kill germs must damage the living tissues. There- 

 fore in quite early days he tried to do without antiseptics altogether, 

 or at all events to admit nothing of the sort to the wound after the 

 operation was finished. He also recognized from the first thao 

 healthy-living tissues had the mysterious power of preventitig the 

 growth of micro-organisms ; and that this protective power was 

 diminished by anything that lowered their vitality. He further 

 pointed out that the vitality of the tissues varies in different 

 individuals and in different parts of the body, as is illustrated by the 

 well-known fact that healing takes place more readily in infancy than 

 in old age, and in the face than in one of the limbs. The true 

 meaning of this power was not then known. The explanation was 

 given by the marvellous discoveries of Metchnikoff which Lister's 

 own work prepared him to receive, when they were made known 

 to the world. 



Everyone now is familiar with the word " phagocytosis," but have 

 you, ladies and gentlemen, really grasped its meaning. It is a 

 sufficiently appalling thought that each one of us, who looks upon 

 himself as a single individual, is only a huge joint stock company. 

 We carry about with us millions and millions of other individual 

 orii;anisms — micro-oro-anisms indeed — but each one endowed at least 



