282 FKAGMENTS OF SCIENCE. 



the laws and phenomena of inorganic nature ; but that 

 one great advance made by modern science was ia the 

 direction of biology, or the science of life ; and that in 

 this new direction scientific enquiry, though at the out- 

 set pursued at the cost of some temporary suffering, 

 would in the end prove a thousand times more benefi- 

 cent than it had ever hitherto been. I said this because 

 I saw that the very researches which the lady depre- 

 cated were leading us to such a knowledge of epidemic 

 diseases as will enable us finally to sweep these scourges 

 of the human race from the face of the earth. 



This is a point of such capital importance that I 

 should like to bring it home to your intelligence by a 

 single trustworthy illustration. In 1850, two distin- 

 guished French observers, MM. Davainne and Kayer, 

 noticed in the blood of animals which had died of the 

 virulent disease called splenic fever, small microscopic 

 organisms resembling transparent rods, but neither of 

 them at that time attached any significance to the 

 observation. In 1861, Pasteur published a memoir on 

 the fermentation of butyric acid, wherein he described 

 the organism which provoked it ; and after reading this 

 memoir it occurred to Davainne that splenic fever might 

 be a case of fermentation set up within the animal 

 body, by the organisms which had been observed by him 

 and Eayer. This idea has been placed beyond all doubt 

 by subsequent research. 



Observations of the highest importance have also 

 been made on splenic fever by Pollender and Brauell. 

 Two years ago, Dr. Burdon Sanderson gave us a very 

 clear account of what was known up to that time of 

 this disorder. With regard to the permanence of the 

 contagium, it had been proved to hang for years about 

 localities where it had once prevailed ; and this seemed 

 to show that the rod-like organisms could not con- 



