402 LICE 



remedy reported by Frankel, and is said to stun lice in four 

 minutes and to kill them in ten minutes. Soaking for one hour 

 in a 1 J per cent cresol solution is said to destroy all lice on clothing. 

 The eggs are not so easily destroyed as are the adults, but they 

 succumb to heating, to exposure to carbon bisulphide (100 grams 

 per cubic meter), or to immersion in any of the oils mentioned 

 above. Ammonia gas destroys the eggs on clothing in a closed 

 receptacle. On the Mexican border of the United States a mix- 

 ture of vinegar and kerosene is used for dipping louse-infested 

 clothing. The French soldiers are said to have kept largely free 

 of lice by the simple expedient of having a hot iron run along the 

 seams of the underwear when laundered, to kill nits. 



Preventive measures against lice, simple as they are under 

 ordinary conditions, often constitute a very difficult problem, 

 especially in army camps. Common methods employed are the 

 treatment of the clothes with odorous or poisonous substances, 

 the use of underclothes with smooth inner surface, such as silk 

 or oil cloth, to which lice cannot attach their eggs, or the dusting 

 of naphthaline powder into the shoes, stockings and underwear. 

 A substance which has been found most efficient by the British, 

 and has been used extensively on the western front in France is 

 the now famous NCI, a powder consisting of 96 per cent com- 

 mercial naphthaline with two per cent creosote added to increase 

 the toxicity and to give lasting qualities and two per cent iodoform 

 to increase the adhesiveness of the powder when dusted on the 

 inside of the clothing. The shepherd people of the Carpathians 

 are said to protect themselves against lice by saturating their 

 underclothes in melted butter which prevents the lice from 

 fastening their eggs to the fibers of the clothes, and probably the 

 fatty acids of rancid butter are also directly deleterious to the 

 pests. 



When louse prevention is undertaken on a large scale, as it 

 has been as never before in the present war, enormous difficulties.^ 

 are encountered, largely due to the fact that the soldiers, es- 

 pecially of the less enlightened nations, do not cooperate with 

 the officials. Germany, menaced by louse-borne diseases more, 

 perhaps, than any others of the principal warring nations, due to 

 the constant contact of her troops with the less efficiently cared- 

 for troops of Russia and of the Baltic nations, has largely solved 

 the problem by the erection of " disinfection stations." In 



