PHYSIOLOGICAL ACTION OF NITROBENZENE VAPOR ON ANIMALS 453 
from the tank after the fumigation of Hen V (fumigated for six and one- 
half hours at 30° C.). The lice were all apparently dead, showing no 
signs of life, at the end of twelve hours. At the end of eighteen hours, 
however, some of them were seen to be moving their legs. In Goniocotes 
these movements were rapid, and were very similar in character to the 
movements of the legs of poisoned guinea pigs. 
Approximately three hundred biting lice, representing six species, 
were recovered from the tank after the fumigation of a chicken for a 
period of one and one-half hours at 20° C. Some of these insects showed 
signs of life when removed from the tank, and nearly all of them recovered 
entirely during the next few hours. 
Nineteen specimens of biting lice were recovered from the bottom of 
the tank after the fumigation of Hen VI (fumigated for eleven hours at 
27-28° C.). None of these showed signs of life when taken from the tank, 
and none recovered. 
THE FOLLICULAR MITE 
(Demodex folliculorum) 
Two or three cases of mild infection of demodecic scabies in dogs 
apparently cleared up after fumigations for long periods at low tem- 
peratures. One of these cases was Dog V, which was fumigated twice — 
once for twelve hours at 20° C., and once for five hours at 20° C. These 
observations led to the following experiments for the purpose of determining 
the value of nitrobenzene in controlling demodecic scabies. 
A special fumigation chamber was constructed in such a way that 
the animal’s nose passed thru a rubber collar and remained on the outside 
of the chamber, and an attempt was made to fumigate the body of the 
animal without permitting it to inhale a large amount of the vapor. 
Morphine and chloral hydrate were given in order to cause the animal 
to remain quiet during the fumigation. A six-hour fumigation under 
these special conditions had no effect on the mites, nor was it possible 
to induce dogs to remain quiet without giving them large doses of the 
narcotics. The method was therefore abandoned. 
Small pieces of skin heavily infected with D. folliculorum var. canis 
were placed in a petri dish in which there was a drop or so of nitrobenzene. 
The dish was then kept at a temperature of 30° C. for six hours. At the 
end of that time the mites were still alive. 
