G. H. F. Nuttall 
529 
Ref. 
No. 
unaffected. Expts 246-247: lice survived 2 hrs and nits 24 hrs 
exposure to strong vapour when on clothes in a box. Expt 277: 
spraying the clothes recommended after 2 months’ practical ex¬ 
perience. Since the seams of clothing may have to be ripped open 
and the vapour is ineffective, the method scarcely commends itself. 
400. Hellebore, white, decoction for corporis and capitis. 
An old remedy advocated for use on man and animals (mentioned 
by Sennertus, 1572-1637; James, 1743; and Linnaeus, 1767). 
Expt 362: pubis recovered and lively after 5 minutes’ immersion. 
401. Hexachlorethane. Expt 304 too volatile and but moderately 
efficient. Mixed with other ingredients and tested on corporis. 
402. Hydrocyanic acid gas, for corporis in clothing, etc. 
Recommended by Lebedeff in the Caucasus, it having been used 
extensively for destruction of plant-pests in N. America, against 
plague fleas and vermin on shipboard (see Roberts, 1914, U.S. 
Publ. Health Reports, xxix. No. 50). Corlette writes that it is used 
on Australian coasting steamers and railways against vermin, 
water 1 pint, strong H 2 S0 4 12 oz. and coarsely ground Pot. ferro- 
cyanide (or P. cyanide) being used per 1000 cubic feet space. 
Lebedeff describes an apparatus consisting of a chamber built of 
iron pipes or bamboos, planted in the ground, covered with waxed 
cloth, and provided with a vertically sliding door operated by a 
string from a distance. The dampened clothes are hung up inside. 
An earthenware bowl containing H 2 S0 4 is placed on the floor and 
Pot. cyanide q.s. in a filter paper bag is dropped into the bowl and 
the door slammed. The reaction is over in about 10 minutes. The 
exposure lasts 20-30 minutes in practice. The chamber is now 
ventilated by pulling open the door with the string from a distance 
and similarly opening a ventilator flap at the top of the chamber. 
Needless to say the personnel must be carefully instructed regarding 
the dangerous qualities of the gas. The method scarcely appears 
suited for disinfestation in war times. 
Teichmann (1917) states that lice and nits were killed by 1 % 
of the gas in 2 hrs and 2 % gas in 1 hr in a sealed room (2120 cb. ft), 
the gas penetrating through bedclothes and cotton wool in which 
the insects in glass vessels were wrapped. Hydrocyanic acid gas 
has therefore great penetrating power. After 2 hrs fumigation the 
room was aired for 15 minutes and could then be safely entered. 
403. Illuminating gas, does not kill corporis (Zucker). 
