ENTOMOLOGY

SANITARY ENTOMOLOGYpowder are not obnoxious to most persons and are very effective in freeinga room of mosquitoes. The powder slightly moistened and moulded intoa candle will burn s~owly lik~ punk. The essential oil of the powder maybe volatilized by placing on a metal screen above a lamp chimney. Theodor is only slightly perceptible and not unpleasant.For protection of the body, camphor, oil of citronella, oil of cassia,and other essential oils are found efficacious. Howard, Dyar, and Knabrecommend as the best in their experience:Oil of citronellaSpirits 'of camphorOil of cedar1 oz.1 oz.lh oz.This may be rubbed on the clothes or body. A few drops on a bathtowel hung over the bed will keep Culex pipiena away for a whole night.Graybill lists many repellents against flies which have been tried onanimals. The most successful substances tried by him were 50 per centpine tar in cotton seed oil, or 10 per cent oil of tar in cotton seed oil,when applied lightly. Fish oil is a very effective repellent. Bishopp'sfish oil repellent is very effective in keeping flies from livestock whenapplied lightly. It consists of:Fish oilOil of tarOil of pennyroyalKerosene'1 gallon! ounces! ounces% pintMosquito nets for the bed are used in many parts of the South wherethe buildings are unscreened. Campers who sleep in hammocks mayeasily arrange a good sleeping net by tying a rope to the hammock supportsand .hanging from this a tent-shaped net which can be fastened atthe ends and tucked in beneath the blankets.Hegh illustrates mosquit.o bars for tent coverings, for tent doors,and soldiers' cots, and also a mosquito bar fastened inside a soldier'ssmall field-tent so that the sides of the tent can be raised to give air.Various type of protective headgear have been described for trQops intropical count.ries, two of which are illustrated by Hegh. Simpson illustratesa new headgear invented by his wife, which can be worn by dayand at night.The references cited below are worthy of study in conncction withthis lecture. There are many other works in all languages on thespecial problems of different countries, most of which are listed byHoward, Dyar and Knab.