38 



curable, we may burn sulphur, tobacco, or pyrethrum. 

 The sulphur is put in a strong pot, placed in a basin of 

 water, and lighted. Tobacco mixed with shreds of coarse, 

 damp, brown paper is put in a large tin standing in a bath 

 and lighted. The pyrethrum has to be obtained from 

 chemists, and burnt. After the experiment the mosquitoes 

 found on the window-sills must be examined to see whether 

 they are really dead. 



In the majority of the houses of natives these opera- 

 tions are quite impossible, because such houses frequently 

 possess no glass windows, and cannot therefore be effec- 

 tively closed. In short, where general measures against 

 mosquitoes are contemplated, I advise that no time and 

 money be wasted in killing the winged insects. 



Since my researches of 1898 were published, much 

 nonsense has been written by people who have sat down to 

 make books on the subject without any previous practical 

 knowledge of the habits of mosquitoes. This is particularly 

 the case with certain Italian writers who have a custom of 

 imagining facts when they cannot discover them in the 

 works of other persons. Thus it is hopeless to attempt to 

 destroy mosquitoes by attracting them by means of a 

 bright light, because, as a matter of fact, mosquitoes are 

 repelled and not attracted by light.* We see photographs 

 of philosophers going forth to hunt mosquitoes in the 

 Campagna, armed cap-a-pie with green veils round their 

 hats and thick gloves on their hands ; and we read sage 

 advice given to generals to caparison in the same heroic 

 attire whole armies when on the march in the tropics. The 

 fact is that, in the tropics at least, mosquitoes rarely bite 



* See for example CELLI'S Malaria According to the New Researches 

 (EYRE'S translation), pages 203, 210, and 212. 



