$i [AN 
congeners. "Thc extraneous parasites are the lar- 
vz of different lepidopterous insects, beetles, flies, 
butterflies, gad-flies and others, infecting intes- 
tines. nares &c. &c. Inquiries into the manner of — 
their introduction, whether by food or otherwise: 
cases detailed of those whose mode of life exposes 
them to these larvee: hair worm of Laplanders, 
from marshy water, &c. &c. These larvae not so 
common to human species but every where infect- 
ing horses, sheep and other cattle, and those chief 
parasites may be added the Guinea worm — 
insinuates itself into the fles 
jy who attend on them. To the head of extrancous __ 
in all its varieties fas attracted much attention 
with physicians, because of the annoying and even 
fatal disease they prodace—intestinal and stomach 
worms. For their destruction, various are the 
medicaments of reputed power: as these have been 
supposed endued with a specific noxious property, 
they have been denominated anthelmintics. An en- 
quiry whether there be any such specific property 
inherent in any of the remedies usually employed, 
or whether they do not act by their common evac- 
want property, and in many instances by the in- 
vigorating effect of their bitter tonic quality. 
Different opinions are entertained respecting the : 
pristine formation within our bodies, or extraneous — 
erigin from without, of these parasites. ede 
hoth opinions are correct, the reasons why. As 
the different anthelmintic medicines possess very 
different powers, (according to the commonly re- 
ceived opinions of practitioners,) in disgorging or 
destroying the different kinds of worms, it is highly 
requisite that all the genera and species, with the 
concomitant morbid deran, nt they induce, ~ 
_ should be well known by students, that they may 
/ 
Sir oP UeRean bole 
A third kind of parasites infests our bodies, which 
eet 
