I40 AGRICULTURAL EXPERIMENT STATION. 



ingredients, and both of these are of some effect. A friend who 

 Hved in a Florida town during one of the yellow fever epidemics 

 assured me that he took no precautions save to have his pockets 

 constantly filled with napthaline crystals and his rooms reeking 

 with the odor of napthaline. This was before a mosquito was 

 recognized as the carrier of the disease, and the explanation that 

 occurs at this day is that the odor of napthaline kept mosquitoes 

 from biting. 



After learning of the effectiveness of the Datura smoke, some 

 preparation forming a smoldering mass may be produced that 

 will be more effective than anything heretofore used. 



Of decoctions to be smeared upon face and hands Avhen going- 

 fishing along shore or in the north woods there used to be a 

 great number, each a little worse than the others and nearly all 

 of them worse than the disease. Twenty-five years ago oil of 

 tar mixed with a little olive oil was the favorite in the Adiron- 

 dack region. Then came oil of pennyroyal, which was hardly 

 less offensive, and then a mixture of the three, oil of tar, oil of 

 pennyroyal and olive oil, which I used for years. 



In 1896 or 1897 a correspondent who saw this formula in my 

 "Economic Entomology," suggested that I try oil of citronello 

 as a substitute. I did so, found it satisfactory, published the fact 

 whenever I had a cliance and now its use is almost universal. 

 Along the boardwalks at night and on hotel porches along shore 

 everywhere, the odor of citronello is noticeable. 



Oil of citronello is an extract from a grass, Andropogon 

 nardiis, primarily used in the manufacture of a cheap grade of 

 perfumery. The odor is not unpleasant to most persons, is quite 

 lasting and absolutely keeps off all kinds of mosquitoes. Pro- 

 tected by this material I have slept comfortably for an hour on 

 an Anglesea piazza on an evening when everyone else was driven 

 indoors. I have used it since 1897 on all my collecting trips, and 

 no matter how large the swarm of mosquitoes surrounding me in 

 the salt or other marshes or in the woods, none ever alighted on 

 any protected part of the body. It may be liberally applied to 

 hands, face or other exposed parts of the body, but should be 

 kept- out of and well away from the eyes. When the tempera- 

 ture is not excessive and there is little or no perspiration the 

 material retains its effect an hour or more and causes no un- 

 pleasant skin sensation. When the temperature is high and per- 

 spiration is free, necessitating the use of a handkerchief, half an 

 hour is the limit, and there is a more or less well marked burning 

 sensation. At such times care should be taken to prevent the per- 

 spiration from getting into the eye, as the smarting caused by 

 citronello in that organ is intense. It can be readily relieved by 



