PEOTECTION FKOM BITES. 13 



The oil of citronella has come into very general use in the United 

 States in the past few years. The odor is objectionable to some people, 

 but not to many, and it is efficient in keeping away mosquitoes for 

 several hours. A mixture recommended by Mr. C. A. Nash, of New 

 York, composed of 1 ounce oil of citronella, 1 ounce spirits of cam- 

 phor, and one-half ounce oil of cedar, has been the most efficacious 

 mixture tried by the writer. Ordinarily a few drops on a bath towel 

 hung over the head of the bed will keep Culex pipiens away for a 

 whole night. Where mosquitoes are very persistent, however, a few 

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

 the experience of the writer, has been effective against all mosquitoes 

 except Aedes (Stegomyia) calopus, the yellow-fever mosquito. This 

 mosquito begins to trouble the sleeper at daybreak, and by that time 

 the potency 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 daybreak and apply the mixture, retiu'ning 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 J pounds of mutton tallow and strain it. While still hot add 

 one-half pound black tar (Canadian tar), stir thoroughly, and pour 

 into the receptacle in which it is to be contained. When nearly cool 

 stir in 3 ounces of oil of citronella and IJ ounces of pennyroyal. 



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



Oil of citronella ounce . . 1 



Liquid vaseline ounces. . 4 



Apply freely to exposed parts. 



Doctor Durham, of the English Yellow Fever Commission, Rio de 

 Janeiro, 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 prevent 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 be- 

 ings 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 River on the steamer Raleigh, they were bothered greatly 

 by mosquitoes both during the day and night, Culex and Anopheles 



