TRANSFORMATION OF ONE SPECIES INTO ANOTHER 191 



of ferments in fermentation. We have seen that Pasteur 

 had come to know that the air was not that receptacle 

 for germs, that redoubtable enemy which he had hitherto 

 supposed it to be, and had convinced himself that, 

 provided the liquids were well sterilized in the auto- 

 clave and the flasks in an oven, it was possible to work 

 with some security in contact with air, and not have to 

 fear too much the entrance of germs from this source. 

 All our present technique has come from these ideas. 

 Personally Pasteur was .indifferent to perfection of 

 technique; the complexity of his apparatuses was of 

 little importance to him. He only required that they 

 should be reliable, and answer the questions he asked 

 without ambiguity. But accuracy and facility or 

 rapidity of question and answer may go hand in hand. 

 This is the role of a good technique. That which has 

 come out of the laboratory of Pasteur was the offspring of 

 the ideas and discoveries of the master; but it is only just 

 to say that it was created by the three collaborators 

 whom Pasteur had the good fortune to encounter at 

 this time Joubert, Chamberland and Roux. 



Pasteur needed another thing for approach to the 

 domain of pathology, which every circumstance invited 

 him to enter. He saw the germ theory inspire the works 

 of Davaine on the anthrax bacteridium, the startling 

 experiment of M. Chauveau on castration by sub- 

 cutaneous torsion (bistournage) , Alphonse Guerin's new 

 method of dressing wounds, the researches of M. Guyon 

 on antiseptic washings of the bladder and of the urethra. 

 He had applauded in 1871 Dr. Declat's successful 

 experiments in the antiseptic dressing of wounds; he 

 did not yet know the work of Lister in antiseptic surgery, 

 which has opened a new era, but he was not slow in 

 finding it out and admiring it. But in order to approach 

 the promised land of which he dreamed, and especially 



