400 



untouched. It could never be ascertained what it was that constituted the 

 favorable medium upon which the primary germ was supposed to acquire 

 the property of reproducing the disease ; no amount of disinfection applied 

 to the inanimate surroundings of the patient, after the sick room had been 

 vacated, having ever succeeded in stamping out the disease until the advent 

 of a cold season or a scarcity of non-immunes had brought about the 

 spontaneous cessation of Jhe epidemic. The truth of the matter, as we 

 now understand it, is that the medium which was sought for is not an 

 inanimate one, as had been supposed, but the body of a living insect 

 provided with wings. After those insects have contaminated themselves, 

 no precautions having been taken to prevent their escape, some of them 

 will have flown out of the sick room and dispersed, thus carrying with 

 them the infectious germ, before the room or house has been disinfected. 

 This was well exemplified in Havana, in 1900, in evident contrast with 

 Major Gorgas' subsequent success in 1901 and 1902. 



A few instances are quoted of epidemic outbreaks which have 

 apparently been traced to the opening of a trunk, package or closet 

 in which yellow fever fomites were believed to have been preserved during 

 such a period of time as no contaminated insect coulld have survived. I am 

 not aware, however that it has ever been proved that, at the time when the 

 said trunks, closets, etc. had been thrown open, some infected mosquitoes 

 or persons had not been introduced in the neighborhood by some other 

 channel, or that mild unrecognised cases of yellow fever had not already 

 occurred in the locality. As an offest to the above allegation, we have 

 thousands of instances to show that, at a time when disinfection was never 

 used, yellow fever fomites, so callSed, have been, year after year, conveyed 

 from the Havana yellow fever hospitals to Spain, in the summer season, 

 without propagating the disease either during the trip or at the port of 

 arrival. 



There is also the significant fact to be considered, that non-immunes 

 who become infected during their passage through Veracruz or through 

 Kio de Janeiro and develop an attack of yellow fever after their arrival 

 at Mexico (City) or Petropolis, go through the same train of symptoms as 

 if they had remained at the point of infection, but the non-immunes who 

 surround them run no risk of infection, while in Veracruz or Rio the risk 

 would have been great. Yet there would be no imaginable reason why the 

 same fomites should not have been produced within the room in the City 

 of Mexico or in Petropolis as well as in Veracruz or Rio, so that the 

 transmission of yellow fever at these ports cannot be attributed to the 

 fomites. 



Finally, the crucial experiment has been tried by the Yellow Fever 

 Military Commission, at Camp Columbia, in 1900, and also by Major 

 Ross as Director of Las Animas Hospital, in 1901, of subjecting non- 

 immunes during consecutive days, to the emanations of a large amount of 



