102 



Insects and Disease 



get too insistent during the day the bed makes a 

 safe and comfortable retreat. All the mosquitoes in 

 a room may be killed by fumigating with sulphur at 

 the rate of two pounds to the thousand cubic feet of 

 air-space. Pyrethrum is also used largely, but it 

 only stupefies the mosquitoes temporarily instead of 

 killing them. While in that condition they may be 

 swept up and destroyed. 



Various substances are sometimes used as re- 

 pellants by those who must be in regions where the 

 mosquitoes are abundant. With many of these, 

 however, "the cure is worse than the disease." 

 Smudges are often built to the windward of a house 

 or barn-yard and the smoke from a good smoldering 

 fire will keep a considerable area quite free from 

 mosquitoes. The man who can keep himself en- 

 veloped in a cloud of tobacco smoke will not be 

 bothered by mosquitoes. Oil of pennyroyal, oil of 

 tar or a mixture of these with olive oil, and various 

 other concoctions are sometimes smeared over the 

 face and hands. These will furnish protection as 

 long as they last. Dr. Smith says that he has 

 found oil of citronella quite effective and of course 

 less objectionable than the other things usually 

 used. Care should be taken not to get it in the 

 eyes. An ointment made of cedar oil, one ounce; 

 oil of citronella, two ounces; spirits of camphor, 



