28 MAC Leod, The Place of Science in History. 



one season to another, things one would be unable to use 

 were it not for the method (sterilisation or pasteurisation) 

 introduced by Pasteur. 



But the above only constitutes a part of Pasteur's 

 work. His influence on the progress of the science of 

 medicine was equally great, and was exercised in different 

 lines. 



One of the greatest obstacles which at one time 

 hindered the progress of surgery was the mortification of 

 the wound which took place after a surgical operation, 

 and which was often more dangerous than the operation 

 itself. Pasteur's discovery explains this phenomenon. 

 Normally the flesh is protected from contact with the air 

 by the skin. When this is removed the germs which are 

 floating in the air fall into the wound, multiply in the flesh, 

 and set up decomposition (fermentation, mortification). 

 It is obviously impossible to exclude the oxygen of the 

 air from wounds, but it is practicable to protect them 

 from the microbes {bacteria, bacils, spirils, etc.) by the use 

 of antiseptic substances which hinder their development. 

 It was the English doctor JOSEPH LISTER 10 who applied 

 this principle to surgery. The first substance he employed 

 for this purpose was carbolic acid. Lister's invention had 

 the happiest results and brought about a veritable 

 revolution in surgical practice. 



In an address which he delivered in Paris on the 

 occasion of the 13th International Medical Congress, 

 Lord Lister declared that his method was in reality a 

 practical application of the scientific discoveries of 

 Pasteur. 



We know to-day that, just as each kind of fermenta- 

 tion corresponds to a microbe of a definite species, so a 

 great number of the illnesses of men and animals, the 



10 Joseph Lister was born on the 5th of April, 1827. He died in 1912. 



