14 PREVENTIVE AND REMEDIAL WORK AGAINST MOSQUITOES. 



both being present and breeding in fire buckets along the sides of the 

 vessel. The buckets were teeming with larvae. They did not seem 

 to have thought of putting kerosene on the buckets in order to stop 

 the breeding, but at the suggestion of Doctor Dade a rag was sat- 

 urated with kerosene, the face, hands, and feet were smeared with it, 

 and the rag was put where it could be conveniently reached. When 

 aroused from sleep by mosquitoes another application was made. 

 "Those who had not used these means before seemed perfectly sur- 

 prised at the splendid immunity gained. The odor and the greasy 

 feeling imparted were the only drawbacks to its use." Doctor Dade 

 continued to experiment with this remedy after his return from an 

 unsuccessful attempt to capture General Aguinaldo, and found that the 

 addition of 1 part oil of bergamot to 16 of kerosene imparted an odor 

 scarcely objectionable, and at the same time added sufficient body 

 to the kerosene to prevent evaporation in less than six to eight hours. 

 After that, when the soldiers had to leave the post, and after it became 

 impracticable to carry cans with them in the field for a long or pro- 

 tracted march, this mixture was used, with the result that the list of 

 malarial patients was noticeably shortened. The oil of bergamot 

 was hard to obtain and is too expensive to be used wholesale, but the 

 soldiers rarely objected to the odor of kerosene and the bergamot was 

 not continued. 



In moist tropical regions where one perspires profusely, the oily 

 mixtures considered under this heading applied to the skin are 

 transient in their effects. Under these circumstances they should 

 be applied rather liberally to the clothing, particularly about the 

 neck and wrists. 



SCREENS AND CANOPIES. 



Such obvious measures as the screening of houses, the use of net- 

 ting for beds, and the wearing of veils and gloves after nightfall in 

 badly infested regions, need no consideration in detail. But even in 

 such an apparently simple matter as house screening certain points 

 must be taken into consideration. It may be incidentally stated that 

 with proper treatment of breeding places screening is unnecessary. 

 The expense to which the people of the United States go for screens 

 against mosquitoes and flies is enormous, and has been estimated at 

 $10,000,000 annually. If this expense were at all necessary it should 

 surely be thoroughly done. 



In screening a house, as Dr. John B. Smith has pointed out in his 

 Bulletin No. 216 of the New Jersey Agricultural Experiment Station, 

 the attempts frequently fall far short of protection : 



Adjustable, folding, or sliding screens are never tight, and when the insects really 

 want to get indoors they work their way patiently between the two parts of the screen 

 or between its frames and the window. But even a well-fitted screen either sets tightly 

 into the frame or, running like a sash, may offer leaks when a window is only partly 



