122 HISTORICAL SURVEY OF YELLOW FEVER 



usually bracketed close to one another (and as we now 

 know there was a reason for so doing, for they are both 

 mosquito-carried), yet Blair recognised the very great 

 difference which existed between malaria and yellow 

 fever from the point of view of aetiology, for he states : 



" It is remarkable that some of the most destructive 

 outbreaks of yellow fever have occurred amongst the 

 troops at stations where intermittent fever is almost 

 unknown as indigenous : for instance, Brimstone Hill in 

 St. Kitts ; Fort Charlotte in St. \^incent ; St. Ann in 

 Barbados ; and vice verm, those colonies in which ague 

 are most common have been least frequently visited 

 by yellow fever — e.g. Demerara and Berbice." 



The reason for this difference is now quite clear. The 

 life-story of the anopheles and the stegomyia is quite 

 different ; the one is an earth-pool breeder, the other 

 a domestic drinking-water-barrel or odd drinking-water- 

 receptacle breeder. The one therefore is much depend- 

 ent upon the rains or upon permanent springs and 

 marshes, the other chiefly dependent upon the hand of 

 man, who provides the receptacle and fills it with 

 the drinking water necessary for the use of his house- 

 hold. 



Hist or ij. — There is every reason for supposing that 

 yellow fever is one of the very old diseases of mankind 

 in the New World. It is stated that it was knoAvn to 

 the Aztecs under the name of in(itlii::(ihunlt, and accord- 

 ing to Humboldt it existed as early as the eleventh 

 century. 



Amongst old Spanisli writers who refer to this 



