REMEDIES AGAINST MOSQUITOES 171 



bottles, empt}- cans, or discarded vessels of any kind. 

 About houses, the greatest care must be taken to examine 

 every possible spot where still water may occur ; cisterns 

 must be covered tightly, with, however, a sufficient aper- 

 ture covered with wire gauze to admit of a plentiful aera- 

 tion of the water ; rain-water barrels should be either 

 covered or treated with kerosene. In the surrounding 

 ground every permanent pool and every swamp-area 

 should be charted and the method of treatment determined 

 upon ; permanent pools not used for Avatering- stock 

 should be treated with kerosene ; swamp-areas should 

 be drained ; and small depressions should be filled with 

 earth. All such work must be thorough and practically 

 perfect, else it is hardly worth while to undertake it. 



The Use of Kerosene on Breeding Pools. 



As long ago as 1812, the writer of a Avork pul)lished in 

 London, entitled, "Omniana or Hor?e Otiosiores," sug- 

 g-ested that by pouring oil upon water the number of 

 mosquitoes may be diminished. Delboeuf, in the Revue 

 Scientifqiie, 1895, says that he used kerosene in this way 

 fifty years before. H. E. Weed, in 1895, stated that in the 

 French quarter of New Orleans it has been a common 

 practice for many 3^ears to place kerosene in the water 

 tanks to lessen the number of mosquitoes in a given 

 locality. Suggestions as to the use of kerosene were 

 made by Mrs. Aaron, and by Beutenmiiller, in the Lam- 

 born Prize Essays, " Dragon-flies versus Mosquitoes " (D. 

 Appleton & Co., 1890). In 18G7 the present writer used 



