LEE 
i\\e aperture of the Hps and the bottom of the 
mouth; and, on differing it, and drawing the 
finger gently over this part, a roughnefs is percep- 
tible like that of a fine file, which evidendy arifes 
from the afperity of fome fubftance of the hardnefs 
of bone. This is, in fad, a number of fine fliarp 
teeth; which, when microfcopically examined, are 
found to be compofed of three feries, on three ribs 
or jaws, each of which is placed along the middle 
of a ftrong mufcle, regularly correfponding to a tri- 
angular opening, which the creature has in it's 
mouth : when that has fixed on a proper part for 
the extraction of blood, thefe mufcles exert their 
aftion, and force the teeth through the fkin. 
Such are the inftruments which penetrate the 
blood-veffel. For the reception of the fluid into 
the body of the animal, there is a fmall aperture 
between thefe rows of teeth; and within this a 
fmall fubftance is perceptible, which by it's mo- 
tions appears to be a tongue, and probably a£ts as 
a pifton to take up the blood flowing from die tri- 
ple wound, in the centre of which it naturally 
ftands; while the larger circle of the lips, and the 
other appendages, perform the office of the body 
of the pump. Laftly, between the root of the 
tongue and the beginning of the ftomach, there is 
a fpace, about two lines long, in which may be 
difcovered two different arrangements of fibres, 
one fet flat, and the other circular : thefe evidently 
poflefs the power of widening or contrafting the 
cavity of the pump, and by that means facilitate 
it's office; the plane ones contradling it's length, 
in order to enlarge the capacity; and the circular 
ones determining the blood towards the ftomach, 
by their power of contracting the cavity, when 
the blood is received. The blood from hence en- 
ters into a membranaceous kind of receptacle, 
ferving the animal for ftomach and inteftines, and 
occupying the grcateft part of the body. If the 
air is admitted into the body by the mouth, it may 
be feen permeating a longitudinal canal, and fill- 
ing, as it proceeds, a number of veficles on each 
fide : thefe receive the blood, and becoming re- 
plete, inflate the body to a confiderable fize. 
But the moft extraordinary circumftance relative 
to the conformation of this animal is, that though 
it admits fuch a large quantity of food. It has no 
anus, or paflage to eje£l it from the body, after it 
is digefted : on the contrary, the blood which the 
.Leech has thus abforbed, remains for feveral 
months clotted within it's body, blackened a litde 
by the change, but in no refpedt putrified, and 
very little altered either in texture or confiftence. 
In what manner it pafles through the animal's 
body, or how it contributes to it's nouriftiment, is, 
perhaps, not eafily accounted for. The water in 
which it is kept is very little difcoloured ; it cannot 
be fuppofed to return the blood by the fame paf- 
fage through which it was admitted; it therefore 
only remains, that it muft go off^ through the 
pores of it's body, and that thefe muft be fuffi- 
ciently large to permit it's exclufion. 
Leeches are capable of exifting in oil; and, 
when removed out of that liquid into water, they 
fhed tender flcins, or films, of the regtilar fliape of 
their bodies, and refembling the pellicles of eels in 
miniature. Their living in oil feems to be a proof 
that the organs of refpiration are not placed on 
the external parts of their bodies, as in many fmall 
animals, fuch as the wafp, the bee, and the worm, 
which would quickly be fuffbcated if the refpira- 
tory duCts were oiled. Hence it appears that the 
LEE 
Leech breathes through the mouth ; and in faCl it 
has a motion which feems to relemble the a6l of 
refpiration in more perfefl animals. 
When Leeches are to be applied for medicinal 
purpofes, it is generally thought expedient to take 
them from the water in which they are contained 
about an hour before ; for thus they become more 
voracious, and faften more readily. When fa- 
turated with blood, they often voluntarily quit 
their hold; but if it be indeed necefl^ary to feparate 
them from the wound, care fliould be taken to pull 
them very gendy, or even to fprinkle them with 
fait if they continue to adhere; for, if rudely- 
plucked away, they frequently leave their teeth in 
the wound, which excites a moft troublefome in- 
flammation, often attended with danger. If they 
feem averfe to fix on the fl<;in, they may be allured 
by rubbing it with milk or blood, or water mixed 
with fugar. As fait proves fatal to moft infedls, rt 
is commonly thrown on' Leeches when they have 
dropped from wounds, by which means they dif- 
gorge the blood they have fwallowed, and are then 
kept for repeated applications: however, they fel- 
dom adhere after this operation, or recover their 
former vivacity. 
The Leech, which Is a viviparous animal, pro- 
duces it's young, one after another, to the number 
of forty or fifty at a birth. It is probable that, 
like the fnail, each infed contains the two fexes ; 
and that it impregnates, and is impregnated, in a 
fimilar manner. The young ones are chiefly 
found, in the month of July, in fliallow running 
waters, and particularly where they are tepified by 
the rays of the fun. The large ones are chiefly 
fought after; and, being put into glafs vefl^els 
filled with frefh water, remain there for months, 
and even years, without any vifible means of fub- 
fiftence: but they never breed in fuch confined 
fituations; and, confequendy, what regards this 
part of their hiftory is ftill enveloped in obfcurity. 
The Leeches of this climate feldom exceed four 
inches in length ; but, in America and the Eaft, 
they are found from fix to feven : there they are lb 
extremely numerous, that bathing in the lakes is 
dangerous, and walking through the marfliy 
grounds is by no means fafe. Even in Ibme parts 
of Europe, they increafe fo as to become formxi- 
dable; and Sedelius, a German phyfician, relates, 
that a girl of the age of nine years, who was tend- 
ing flieep near the city of Bornft in Poland, per- 
ceiving a foldier making up to her, attempted to 
hide herfelf among fomebuflies in a neighbouring 
marfh; but the Leeches in that place, v/hich hap-- 
pened to be very numerous, adhered fo clofely to 
her body, that fhe foon expired from the quantity 
of blood which ftie loft by their united efforts. 
Leech, Horse; the Hirudo Sanguifuga of 
Linnfeus, The body of this fpecies is deprefled; 
and In the bottom of the mouth there are certain 
great fliarp tubercles, or whitlfh caruncles. The 
mouth and tail are flender; the body is pretty 
thick; the belly is of a yellowifli green colour; 
and the back is dufl<:y. This animal is very com- 
mon in ftagnant waters. 
Leech, Mechanical; the Hirudo Geometrst 
of Linnseus. This fpecies frequents the fame 
places with the reft of the kind; and is found on 
trout and fome other fifties after the fpawning fea- 
fon. It's motions are performed by a particular 
expanfion of the head and tail, as if meafuring like 
a compafs; and hence it receives it's name. Th6 
body, which k filiform^ is greenifh, fpotted with 
' white- 
