7 o MALARIA 



Cisterns, fire buckets, and other water receptacles 

 need to be kept properly screened or securely covered. 



Repellents. — Night laborers, watchmen, pickets, and 

 others compelled to be on duty at night are, of course, 

 exposed to the bites of mosquitoes and should exercise 

 some precaution at least against these pests. Repel- 

 lents of several kinds have been used with more or less 

 success. The writer has found oil of citronella to be 

 one of the most reliable deterrents when simply rubbed 

 on the hands and face, a dozen drops or thereabouts 

 being placed in the hollow of the palm and thus applied. 



To this oil may be added various other ingredients ; 

 for example, Howard has found the following mixture 

 most effective, viz. : I ounce of citronella, I ounce 

 spirits of camphor, and \ ounce oil of cedar. 

 This Howard found very satisfactory against Culex 

 pipiens by applying a few drops on a bath towel hung 

 on the head of the bed. He, however, adds that it is 

 not effective against the yellow fever mosquito, which 

 begins biting at daybreak when the oil has lost most 

 of its strength. 



Other deterrents used and recommended by various 

 authors are a mixture of castor oil, alcohol, and oil of 

 lavender, equal parts ; or a few drops of peppermint 

 or pennyroyal, oil of tar, oil of cassia, or simply pure 

 kerosene. 



Repellent Plants.- Much has been written about 

 deterrent trees and plants, but few if any have stood 

 the test of accurate observation. The writer's own 



