488 
Combating Lo usiness 
prevent the decomposition of the oil or grease and influence the diseased 
condition of the skin or ( b ) aromatic principles added merely to render 
an ointment agreeable. 
In view of this statement it would be of practical interest to determine, 
for instance, in cases of uncomplicated Phthirus pubis infestation, if 
simple ointment liberally applied is not perhaps almost as efficacious 
as the mercurial ointment so generally employed, having regard to the 
frequent objections there are to the use of mercury. This remark also 
applies to the use of similar remedies in simple cases of infestation with 
head-lice and body-lice. 
The asphyxiating effect of oil and grease upon lice is assumed to be 
due to a film of grease formed over the respiratory orifices of the active 
stages or the opercular pores of the nit, thus preventing respiration in 
a manner comparable to what is observed when mosquito larvae and 
pupae are asphyxiated by a film of petroleum spread on the water 
which they inhabit. In addition the greasing of the hair may perhaps 
render it more slippery and difficult for the louse to grasp, or it may to 
some extent mat the hair and thus impede the formation of the chitin 
tube in the act of oviposition. Single hairs when smeared with olive 
oil (droplets of oil being excluded) do not impede normal oviposition, as 
I have found by experiment. 
“Repellants.” 
A great deal has been assumed regarding the supposed repellant 
effect of various substances on lice, it being repeatedly stated that lice 
are kept away from a person by their application to the skin or clothing. 
A survey of the literature, however, affords scarcely any positive 
information on the subject, most of the evidence being negative. 
Positive evidence. Teske (1915, p. 346) states that lice scatter away 
from oil of anise dropped upon cloth infested with insects. Sergent and 
Foley (vi. 1915, p. 378) state that oil of eucalyptus repels lice; they 
placed lice in a dish between two pieces of cloth 4 cm. apart, the 
one was oiled, the other not; after about three hrs 3 lice were found 
to have approached the eucalyptus cloth and died, whereas 17 lice w~ere 
found on the untreated cloth. Jeanneret-Minkine (1915, p. 136) put 
a ring of glue upon a board placed near a stove; concentrated tobacco 
infusion was placed in the ring, and two layers of cloth laid upon it 
with the lice between the cloth layers; the lice fled outward and became 
stuck in the glue. 
