INTRODUCTION. xli 



Surely results such as those recorded in this 

 book are calculated, not only to arouse public 

 interest, but public hope and wonder. Never before, 

 during the long period of its history, did a day like 

 the present dawn upon the science and art of medi- 

 cine. Indeed, previous to the discoveries of recent 

 times, medicine was not a science, but a collection of 

 empirical rules dependent for their interpretation and 

 application upon the sagacity of the physician. How 

 does England stand in relation to the great work now 

 going on around her ? She is, and must be, behind- 

 hand. Scientific chauvinism is not beautiful in 

 my eyes. Still one can hardly see, without depreca- 

 tion and protest, the English investigator handicapped 

 in so great a race by short-sighted and mischievous 

 legislation. 



A great scientific theory has never been accepted 

 without opposition. The theory of gravitation, the 

 theory of undulation, the theory of evolution, the 

 dynamical theory of heat all had to push their way 

 through conflict to victory. And so it has been with 

 the Germ Theory of communicable diseases. Some 

 outlying members of the medical profession dispute 

 it still. I am told they even dispute the communica- 

 bility of cholera. Such must always be the course of 

 things, as long as men are endowed with different 

 degrees of insight. Where the mind of genius dis- 

 cerns the distant truth, which it pursues, the mind 



