ENTOMOLOGY

THE CONTROL OF HUMAN LICE 819bathing and cleaning the clothing, the only means left is to use somekind of vennicide or repellent. Nuttall has described experiments withmany chemicals, b~t Moore has gone into the subject much more exhaustively.Both reported unfavorably regarding sachets, although the followingsubstances have been found to exert repellent action on the lice:oils of anise, cloves, eucalyptus, naphthalene and carbolic acid. Insecticidalpowders are frequently favored. Moore (191So.) lists manyeffective powders but reports the most effective to be made of:Creosote .................................. 1 cc.Sulphur .................................. ~ gr.Talc ...•................................. ~O gr.Naphthalene is very commonly used and is effective, but its continuoususe may injure the eyes. One of the commonest powders in generaluse is known as N. C. I. powder and is made of:Naphthalene ........................... 96 per centCreosote ............................... ~ per centIodofonn .............................. ~ per centThe specialists of all the nations have sought to find a substancewith which clothing could be impregnated and rendered vennicidal.Moore has suggested wearing a cheesecloth suit impregnated with saturatedsolution of sulphur in creosote on the outside of the underwear, buton the whole he reports (Moore, 1915b) after testing many substances,that the cost of application is too high for the results obtained, andnone are effective longer than a. week. Moore and Hirschfelder subsequentlyreported more hope- of success from naphthalene and cresol compoundsthan from anything else.CONTROL OF LICE IN CLOTHINGIn order to properly delouse a unit~ the cleansing of the clothing isof utmost importance. There are many satisfactory systems of treatmentand "it is therefore a question of choosing the one which is mostpracticable l.mder the existing conditions.1. LawndryThe laundry method of disinsection as described by Pierce, Hutchison,and Moscowitz, is the best and most efficient, given sufficient :timeand the necessary equipment. In this process the clothes are deloused,disinfected, cleaned, and pressed. Every step in, the laundry is in-