88 INFLAMMATION, SUPPURATION, ETC. 



capillaries into the tissues. Everything had been 

 made ready for the fuller interpretation that was 

 coming from bacteriology : the old naked-eye de- 

 scriptions of inflammation were left behind ; men 

 set aside the definition of Celsus, that it was rubor 

 et tumor cum calore et dolor e — words that sound 

 like Moliere's jest about the vis dormitiva of opium 

 — they watched inflammation under the microscope, 

 in such transparent structures as the frog's web and 

 mesentery, the bat's wing, and the tadpole's tail. 

 It was thus that Wharton Jones discovered the 

 rhythmical contraction of the veins in the bat's 

 wing. The discovery of the escape of the white 

 blood-cells, diapedesis, through the walls of the 

 capillaries, was made by Waller and Cohnheim. 

 To those who are opposed to all experiments on 

 animals, it may seem a very small thing that a 

 blood-cell should be on one side or the other of a 

 microscopic film in a tadpole's tail ; but this diape- 

 destSy the first move of the blood in its fight against 

 disease, is now seen, in the light of Metschnikoff's 

 work, as a fact of very great importance. 



The history of this transitional period, from the 

 study of inflammation in transparent living tissues 

 to the use, in surgery, of the facts of bacteriology, 

 is told in Lord Lister's Huxley Lecture, October 

 1900. He describes how the foundations were laid 

 in surgical pathology, by microscopical and experi- 

 mental work on inflammation, coagulation, suppura- 

 tion, and pyaemia, for bacteriology to build on : 

 how his own share of the work began when he was 

 house-surgeon to Sir John Erichsen at University 



