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Combating Lousiness 
should be suspended on hooks or wires so that they are freely exposed 
to the dry circulating air. 
III. DESTRUCTION OF LICE. 
GENERAL CONSIDERATIONS. 
Sham Death of Lice. 
A Source of fallacious Conclusions regarding the Effects of Insecticides 
and Heat. 
The reports of various authors upon the effects of insecticides on lice 
have convinced me that many have been led into error through the 
occurrence of sham death in the insects under experiment. I have 
already referred to the subject and stated what constitute the unequi¬ 
vocal signs of death that should be accepted in practice (see pp. 183 4), 
and would add here merely that the phenomenon of “turning red” is 
observable in lice killed by exposure to moderate dry heat (70°C.); dry 
heat, therefore, may be added to the list of causes of this condition. 
The authors who exclude sham death as a source of error from their 
experiments are Pregl, Felix, Knaffl-Lenz, and Heymann in 1915, and 
Seitz, Swellengrebel, and Peacock in 1916. 
Some of the results recorded by the following authors are fallacious 
because they obviously assumed that merely immobilized lice were dead: 
Jeanneret-Minkine, Legendre, Prowazek, Galewsky, Zupnik, Kulka, 
Busson, Sergent and Foley, Widmann, Castellani and Jackson, Musselius, 
Vishnjakov in 1915, and Kinloch in 1916. These authors, as a rule, 
state that various remedies kill lice in an impossibly short time, other 
more carefully conducted experiments proving the contrary. For 
example Prowazek states that ether kills Ph. pubis “instantly”; Sergent 
and Foley state that oil of eucalyptus dropped on verminous cloth kills 
clothes-lice “in a few moments”; Castellani and Jackson assert that 
petroleum (kerosene) kills lice “almost instantaneously” and that 
vaseline kills them “instantaneously,” etc., etc. Busson mentions that 
sham death occurs, but his experimental results prove that he did not 
apply his knowledge in practice, and the like holds for Galewsky (hi. 
and v. 1915). Widmann placed reliance upon the totally inadequate 
evidence of the cessation of intestinal peristalsis in lice as a sign of death, 
whilst he experimented with so few nits that the chance of some being 
sterile was not excluded at the start. The positive results given by the 
foregoing authors are therefore largely excluded from my tables, because 
they are clearly fallacious. On the other hand I record their negative 
