806 THE POPULAR SCIENCE MONTHLY. 



for the superior microbe a vaccine that is to say, a virus capable of 

 producing a milder disease. Here, then, we have a method of prepar- 

 ing the vaccine of splenic fever. You will see presently the practical 

 importance of this result, but what interests us more particularly is to 

 observe that we' have here a proof that we are in possession of a gen- 

 eral method of preparing virus vaccine based upon the action of the 

 oxygen and the air that is to say, of a cosmic force existing every- 

 where on the surface of the globe. I regret to be unable, from want 

 of time, to show you that all these attenuated forms of virus may very 

 easily, by a physiological artifice, be made to recover their original max- 

 imum virulence. The method I have just explained of obtaining the 

 vaccine of splenic fever was no sooner made known, than it was very ex- 

 tensively employed to prevent the splenic affection. In France we lose 

 every year by splenic fever animals of the value of 20,000,000 francs. 

 I was asked to give a public demonstration of the results already men- 

 tioned. This experiment I may relate in a few words. Fifty sheep 

 were placed at my disposition, of which twenty-five were vaccinated. 

 A fortnight afterward the fifty sheep were inoculated with the most 

 virulent anthracoid microbe. The twenty-five vaccinated sheep re- 

 sisted the infection ; the twenty-five unvaccinated died of splenic fever 

 within fifty hours. Since that time my energies have been taxed to 

 meet the demands of farmers for supplies of this vaccine. In the 

 space of fifteen days we have vaccinated, in the departments surround- 

 ing Paris, more than 20,000 sheep, and a large number of cattle and 

 horses. If I were not pressed for time, I should bring to your notice 

 two other kinds of virus attenuated by similar means. These experi- 

 ments will be communicated by-and-by to the public. I can not con- 

 clude, gentlemen, without expressing the great pleasure I feel at the 

 thought that it is as a member of an international medical congress, 

 assembled in England, that I make known the most recent results of 

 vaccination upon a disease more terrible, perhaps, for domestic ani- 

 mals than small-pox is for man. I have given to vaccination an ex- 

 tension which science, I hope, will accept as a homage paid to the 

 merit and to the immense services rendered by one of the greatest 

 men of England, Jenner. What a pleasure for me to do honor to 

 this immortal name in this noble and hospitable city of London ! 



DEAN SWIFT'S DISEASE. 



By Dr. BUCKN1LL, F. E. S. 



DURING the past autumn I received a letter from a gentleman 

 engaged in literary work, requesting my opinion on the " mys- 

 terious disease " of the great author and wit whose name distinguishes 

 this paper. My interlocutor particularly wished to know whether the 



