^^ 





THE 



POPULAR SCIENCE 

 MOKTHLY. 



JULY, 1901. 



THE TEAXSMISSIOX OF YELLOW EEVEE BY MOSQUITOES. 



By GEORGE M. STERNBERG, M.D., LL.D., 



SURGEON-GENERAL U. S. ARMY. 



THE discoveries which have been made during the past twenty-five 

 years with reference to the etiolog}^ of infectious diseases consti- 

 tute the greatest achievement of scientific medicine and afford a substan- 

 tial basis for the application of intelligent measures of prophylaxis. We 

 now know the specific cause ('germ') of typhoid fever, of pulmonary 

 consumption, of cholera, of diphtheria, of erysipelas, of croupous pneu- 

 monia, of the malarial fevers and of various other infectious diseases of 

 man and of the domestic animals, but, up to the present time, all efforts 

 to discover the germ of yellow fever have been without success. The 

 present writer, as a member of the Havana Yellow Fever Commission, 

 in 1879, made the first systematic attempt to solve the unsettled ques- 

 tions relating to yellow fever etiology by modern methods of research. 

 jSTaturally the first and most important question to engage my attention 

 was that relating to the specific infectious agent, or 'germ,' which there 

 was every reason to believe must be found in the bodies of infected in- 

 dividuals. Was this germ j)resent in the blood, as in the case of re- 

 lapsing fever; or was it to be found in the organs and tissues which 

 upon post mortem examination give evidence of pathological changes, 

 as in typhoid fever, pneumonia and diphtheria ; or was it to be found in 

 the alimentary canal, as in cholera and dysentery. The clinical history 

 of the disease indicated a general blood infection. As my equipment in- 

 cluded the best microscopical apparatus made, I had strong hopes that 

 in properly stained preparations of blood taken from the circulation of 

 yellow fever patients my Zeiss 1-18 oil immersion objective would re- 

 veal to me the germ I was in search of. But I was doomed to disap- 



VOL. LIX. — 15 



