14 



to the effect of the tropical sun on rotting vegetation ; that 

 they do carry malaria and yellow fever, but in such small 

 quantities that they act beneficially as unpaid vaccinators 

 of these diseases ; and so on.* It is possible to ignore all 

 such epistles, because where they do not contradict each 

 other, someone else is sure to contradict them ; but an 

 occasional letter in reply does good, and, to speak practically 

 but rather cynically, serves to stimulate the necessary 

 public interest in the work by keeping the letter-writers at 

 such a pitch of exasperation that they give the campaign 

 a constant stream of gratuitous advertisement in the news- 

 papers. We are permitted to be cynical in a good cause. 



Fortunately, operations against mosquitoes can be con- 

 ducted on a large scale without much reference to private 

 opinions fortunately, because the inertia of the masses 

 regarding new pathological discoveries is so great that were 

 we to depend upon converting them, nothing would be 

 done for half a century. For some inscrutable reason, the 

 man in the street, though he would scarcely think of con- 

 tradicting a lawyer or an engineer on matters of law or 

 engineering, finds himself quite equal to exposing the 

 absurdities of the whole Medical Faculty on a medical 

 matter. 



These operations require no sacrifices or co-operation 

 on the part of the general public. Most householders are 

 glad enough to have their mosquito larvae destroyed, and 

 their backyards cleaned up for nothing. The reader, there- 

 fore, if he sees fit to start the work we are considering, 

 may quietly proceed in it undisturbed by criticism, and may 

 calculate upon receiving not only as much public support 



* I have seen every one of these statements, and many others equally 

 absurd, made at least half a dozen times in the British press. 



