YELLOW FEVER. 417 



The writer has italicized the sentence in which 

 the editor of the "Medical Record" has inciden- 

 tally remarked that the death of the animal gen- 

 erally ensues, and would respectfully call attention 

 to his experiments relating to a fatal form of septi- 

 caemia in rabbits resulting from the subcutaneous 

 injection of the saliva of healthy individuals. 



YELLOW FEVER. In a paper contributed to 

 the American Journal of the Medical Sciences 

 (April, 1873), the writer has stated the a priori 

 argument in favor of the germ theory as regards 

 the etiology of yellow fever in the following 

 language : 



" There are three agents, to one of which we must (in 

 the present state of our knowledge) refer the poison, 

 which, by its action upon the human system, produces 

 yellow fever, viz. : 



" (a) A volatile inorganic matter. 



" (&) A lifeless organic matter of the nature of a fer- 

 ment, which, by catalytic action, is capable of trans- 

 forming otherwise (comparatively) harmless substances, 

 present in the earth or in the atmosphere, into the ma- 

 teiies morbi of yellow fever. 



" (c) A living germ, capable, under favorable con- 

 ditions as to heat, moisture, etc., of rapid self-multi- 

 plication, and acting, either directly, or indirectly by 

 catalytically transforming other substances into the 

 efficient cause of the disease. 



" That the poison is of the latter nature, is, I con- 

 ceive, the only theory consistent with the observed facts 

 in regard to the origin and propagation of the disease, 

 :md upon it all the otherwise contradictory facts are 



