51 



partial and probably much more expensive in the long run. 

 They possess, moreover, one almost fatal defect : while the 

 extirpation of mosquitoes can be undertaken by the 

 authorities without reference to the wishes, convictions, or 

 prejudices of the public, the other methods must depend 

 upon these very quantities. Mosquito nets, quinine, and 

 segregation will not be generally resorted to until the public 

 generally believes that mosquitoes cause disease. Now I 

 think that I am right in saying that at present, in spite of 

 the overwhelming proofs that have been given against the 

 insects, not five per cent, even of Europeans in our tropical 

 colonies believe in any such thing. As for natives, probably 

 not one per mille has ever heard of the subject.* The 

 complete ignorance which prevails regarding pathology, 

 even among people who imagine themselves to be well 

 educated, and that peculiar apathy which leads thousands of 

 people to prefer " taking the risk " to " taking the trouble," 

 will surely prevent any general personal prophylaxis against 

 mosquito-borne diseases, probably for scores of years. Let 

 us take for example the case of vaccination, and remember 

 that even now, more than a century after jENNER's dis- 

 covery, perhaps a tenth of the so-called civilized people of the 

 world disbelieve in it, while cranks still write against it in 

 the press of the day. No ; if we wish to clear out mosquito- 

 borne disease on a large scale, we must not wait for the 

 conversion of the public ; we must adopt general measures 

 which can be executed without deference to private 

 opinions. 



Of course where operations are not likely to be profit- 

 able (paragraphs 20 and 21), we must fall back on other 

 measures. Wire-gauze window-screens will be specially 



* Such at least is my experience in West Africa. 



