A HISTORY OF SCIENCE 



who knows anything of the subject has some concep- 

 tion, but those alone can have full comprehension who 

 have themselves attempted to follow the devious and 

 delicate pathways of bacteriology. But the goals to 

 which these pathways lead have a tangibility that give 

 them a vital interest for all the world. The hopes and 

 expectations of bacteriology halt at nothing short of the 

 ultimate extirpation of contagious diseases. The way 

 to that goal is long and hard, yet in time it will be made 

 passable. And in our generation there is no company 

 of men who are doing more towards that end than the 

 staff of that most famous of bacteriological laboratories 

 the Pasteur Institute. 



THE VIRCHOW INSTITUTE OF PATHOLOGY 



Even were the contagious diseases well in hand, 

 there would still remain a sufficient coterie of maladies 

 whose origin is not due to the influence of living germs. 

 There are, for example, many diseases of the digestive, 

 nutritive, and excretory systems, of the heart and 

 arteries, of the brain and nerves, and various less 

 clearly localized abnormal conditions, that owe their 

 origin to inherent defects of the organism, or to various 

 indiscretions of food or drink, to unhygienic surround- 

 ings, to material injuries, or to other forms of environ- 

 mental stress quite dissociated from the action of bac- 

 teria. It is true that one would need to use extreme 

 care nowadays in defining more exactly the diseases 

 that thus lie without the field of the bacteriologist, as 

 that prying individual seems prone to claim almost 

 everything within sight, and to justify his claim with 

 the microscope ; but after that instrument has done its 



1 86 



