78 NORTH AMERICAN INSECTS. 
that hair-powder, pomatum, and hair-oil were chiefly in- 
vented, and generally used, because every kind of grease 
destroys these insects, by stopping up their air-holes or 
breathing organs, and they immediately fall into convul- 
sions and die—an experiment that may be repeated at 
pleasure on caterpillars. 
These disgusting creatures make their abode principally 
upon the heads of human beings, as may be seen, for in- 
stance, in the haunts of the filthy poor every where, or the 
poor, oppressed Jews and peasants of Poland, or the down- 
trodden and degraded countrymen of Italy, and the innu- 
merable host of beggars with which all her churches 
swarm. . 
According to the observations made in the year 1687 by 
the celebrated Dutch philosopher, Leuwenhoeck, the female 
Louse, in the course of six days, lays fifty white eggs, which 
are called Nits, and from which, after six days more, pro- 
ceed the young ones, which are perfected in eighteen days. 
In this manner such a female may have the satisfaction of 
being grandmother to a progeny of five thousand individuals 
around her in the short space of eight weeks. This species 
is called the Hrap-LovuseE (Pediculus capitis). 
Another species, also a nuisance to the human family, is 
the Bopy-Lovuse (Pediculus vestimentorum), whose favorite 
dwelling is in the folds of the shirt-collar, and which prob- 
ably produces that generally incurable disease called phthi- 
riasis. It is humbling to human pride and the high con- 
ceit of mortal man to think that the poor and the rich, the 
ignorant and the wise, princes, kings, and emperors, have 
been and are alike subject to this misfortune. Examples 
are not wanting: the Dictator Sylla, the two Herods of 
Judea, the Roman Emperor Maximian, and the mighty 
Philip IL., King of Spain, and many others, have been car- 
ried off by this disgusting, incurable malady, in which the 
whole human body becomes covered with sores, and is lit- 
