THE CONTROL OF HUMAN LICE 315 



themselves are given thorough spraying with kerosene or gasoline emul- 

 sion, and then baths with warm water, and if lice are present, the hair 

 of the men and boys is clipped and burned. The women have a mixture 

 of equal parts of kerosene and acetic acid applied to the hair for half an 

 hour with a towel covering the head. The acetic acid loosens the eggs 

 from the hair and the kerosene kills or stupefies the lice. Before enter- 

 ing the bath, liquid soap is spra3'ed on each person. The soap is made 

 by boiling one part of soap chips in four parts of water and then adding 

 two parts of kerosene oil, or four parts of gasoline. This jellies when 

 cold, and one part of this soap jelly is added to four parts of warm 

 water, making a good liquid soap at very small cost. The clothing is 

 disinfected by being placed in bundles in the steam chamber, in which a 

 vacuum of 10 to 15 inches is created, and live steam is then introduced 

 until the gauge shows 20 pounds, which gives a temperature of 259° F. 

 This is maintained for 10 minutes to insure penetration. The creation 

 of a second vacuum of 10 inches and holding it for 10 minutes will dry 

 the clothing completely. (Pierce, C. C, 1917.) 



Recent studies have shown the inadequacy of gasoline and gasoline 

 emulsion as an insecticide, and it is therefore our recommendation that 

 only kerosene emulsion be used in delousing. (See Hutchison and Pierce 

 1919.) 



There are certain general methods by which much of value in insect 

 control can be gained, and many of these can be classed as educational. 

 An educational propagandum has been conducted in practically ever}^ 

 one of the nations most seriously affected and also in the United States. 

 Press statements, magazine articles, bulletins and lectures, posters, and 

 personal demonstrations have done much to reduce louse incidence, and 

 finally, the moving pictures used by the War Department to educate 

 the American troops, have vividly brought to their minds the dangers and 

 the means of control. 



Personal prophylaxis, when one is subject to louse infection, may be 

 regarded as one of the best means of keeping free of them. This should 

 consist of daily or weekly baths, according to convenience; frequent 

 change and laundering of underclothing, and dry-cleaning of outer gar- 

 ments ; frequent personal inspection of clothing, especially along the 

 seams. Li military commands where practicable, there should be weekly 

 official inspection of a very thorough nature. Many inspectors make the 

 mistake of looking at the man for body lice, instead of in his clothing. 

 For crab or head lice an inspection of the person is of course the only 

 means of detection. 



Inspection for lice must not be considered essentially an arm}'^ prac- 

 tice. Any jail, hospital, lodging house, poorhouse, orphanage, or other 

 chantable institution, is more than likely to receive many lousy inmates. 



