366 MOSQUITOES OF NORTH AMERICA 



drops rubbed on the face and hands will suffice. This mixture in the experience 

 of the writer has been efficacious against all mosquitoes except Aedes calopus, 

 the yellow-fever mosquito. This mosquito begins to trouble the sleeper at day- 

 break and by that time the efficacy of the mixture has largely passed, and one 

 is apt to be in his soundest sleep. If, however, one could arrange to be awakened 

 just before day-break and apply the mixture, returning for the last nap, it is 

 probable that it would be efficacious. 



Fishermen and hunters in the north woods will find that a good mixture 

 against mosquitoes and black flies can be made as follows : 



Take 2^ lbs. of mutton tallow and strain it. 

 While still hot add: | lb. black tar (Canadian tar). 



Stir thoroughly and pour into the receptacle in which it is to be contained. 

 When nearly cool stir in 3 oz. of oil of citronella and 1^ oz. of pennyroyal. 



Oscar Samostz, of Austin, Tex., recommends the following formula : 



1 oz. oil citronella. 

 4 oz. liquid vaseline. 



Apply freely to exposed parts. 



Mr. B. A. Eeynolds, of the Bureau of Entomology, has used successfully in 

 New Orleans 20 minims of oil of citronella to the ounce of vaseline or lanoline, 

 preference being given to the latter. 



Doctor Durham, of the English Yellow Fever Commission to Para, Brazil, 

 told the writer that he and the late Doctor Myers found that a 5 per cent solution 

 of sulphate of potash prevented mosquitoes from biting, and that they were 

 obliged to use this mixture while at work in their laboratory in Brazil to pre- 

 vent themselves from being badly bitten. 



An anonymous correspondent of " American Medicine," who signs himself 

 F. A. H., says : 



" I would advise the use of the oil of cassia, for the odor is not offensive to 

 human beings and it is an irritant poison to all kinds of insects. Besides, its 

 power remains for a long time after it has dried." 



Pure kerosene has been used for this same purpose. An excellent example 

 of its practical use came to the writer in a letter from Dr. W. H. Dade, an 

 Army Surgeon, writing from the Philippine Islands under date of November 

 15, 1901 : 



He stated that during November, 1900, while traveling up the Cagayan 

 Eiver on the steamer Baleigli, they were bothered greatly by mosquitoes, both 

 during the day and night, Culex and Anopheles both being present and breed- 

 ing 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 in the buckets 

 in order to stop the breeding, but at the suggestion of Doctor Dade a rag was satu- 

 rated 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 surprised at the splendid immunity gained. The 

 odor and the greasy feeling imparted were the only drawbacks to its use." 



