ANATOMY'. 
part ; the other small and soft, called the lobe, 
which makes the lower part. We may like- 
wise consider two sides in the outward ear, 
one turned obliquely forward, and irregularly 
concave; the other turned obliquely back- 
ward, and unequally convex. 
The foreside is divided into eminences and 
cavities. The eminences are four in number, 
called helix, antihelix, tragus, and antitra- 
gus. The helix is the large folded border, or 
circumference of the great portion of the ear. 
The antihelix is the large oblong eminence, 
or rising, surrounded by the helix. The tra- 
gus is the small anterior protuberance below 
the anterior extremity of the helix, which, in 
an advanced age, is covered with hairs. The 
antitragus is the posterior tubercle, below 
the inferior extremity of the antihelix. 
The cavities on the fore side are four in 
number ; the hollow of the helix, the depres- 
sion at the superior extremity of the antihelix, 
called fossa auricularis ; the concha?, or great 
double cavity, that lies under the rising term- 
ed antihelix, the upper bottom of which is dis- 
tinguished from the lower by a continuation of 
the helix, in form of a transverse crista ; and 
lastly, the meatus of the external ear, situated 
at the lower part of the bottom of the concha. 
The other parts of the external ear are 
ligaments, muscles, integuments, sebaceous 
and ceruminous glands, vessels, and nerves. 
'Fhe bony part of the organ of hearing may 
be divided into four general parts. 1. The 
meatus auditories externus. 2. The tympa- 
num. 3. The labyrinth. 4. The meatus audi- 
torius intern us. It may likewise be divided 
into immoveable or containing parts, which 
take in all the four already mentioned ; and 
moveable or contained parts, which are four 
little bones lodged in the tympanum, called 
incus, malleus, stapes, and os orbiculare or 
lenticulare. 
The meatus externus is somewhat more 
than half an inch in length, running obliquely 
from behind forward in a curved direction. 
It terminates inwardly by an even circular 
edge, which is grooved quite round, for the 
attachment of the membrana tympani. 
The tympanum, or drum of the ear, is a 
cavity somewhat spherical, or rather hemi- 
spherical, the bottom of which is turned in- 
ward, and the mouth joined to the circular 
groove already mentioned. The remarkable 
eminences are three in number ; a large tu- 
berosity, lying in the very bottom of the 
tympanum, a little toward the back part, and 
a small irregular pyramid, situated above the 
tuberosity, and a little more backward, the 
apex of which is perforated by a small hole. 
In the third eminence is a cavity situated at 
Ihq upper end, a little toward the anterior 
part of the bottom of the tympanum. This 
cavity is part of a halt-canal, which, in a na- 
tural state, has one of the muscles of the mal- 
leus lodged in it. 
The principal cavities in the tympanum 
are, the opening of the mastoid cells, the 
opening of the Eustachian tube, the bony half- 
canal, the fenestra ovalis and rotunda; and 
to these may be added the small hole in the 
pyramid. 
The labyrinth is divided into three parts; 
the anterior, middle, and posterior ; the mid- 
dle portion is termed vestibulum, the anterior 
cochlea, and the posterior labyrinth in parti- 
cular, which comprehends the three semi- 
circular canals. 
Yol. I. 
The cochlea lies forward and inward, to- 
ward the extremity of the pars petrosa; the 
semicircular canals backward and outward, 
toward the basis of the process, and the vesti- 
bulum between the other two. 
The meatus auditorius internus, is on the 
back side of the pars petrosa, in some mea- 
sure behind the vestibule and basis of the 
cochlea fossula- ; one large and the other 
small. 
The ductus auris palatinus, or Eustachian 
tube, is a canal or duct, which goes from the 
tympanum to the posterior openings of tire 
nares, and toward the arch of the palate. 
The membrana tympani is a thin, transpa- 
rent, ilattish pellicle, the edge of which is 
round, and strongly fixed in the orbicular 
groove which divides the bony meatus of the 
external ear from the tympanum, or barrel. 
The whole internal cavity of the labyrinth is 
filled with a watery fluid, secreted from the 
vessels, which are dispersed upon the perios- 
teum. This fluid transmits to the nerves the 
vibrations it receives front the membrane situ- 
ated between the tympanum and labyrinth. 
The superfluous part of this fluid is suppos- 
ed to pass off through two small canals, called 
aqueducts of Cotunnius. 
The portio mollis of the auditory nerve 
ends, by its trunk, at the great fossula of the 
internal auditory hole, whence the filaments 
pass through the cochlea, the vestibule, and 
the semicircular canals, upon membranous 
canals, and bags disposed within them. 
Of the mouth . , and organ of taste. 
The mouth may be distinguished into ex- 
ternal and internal ; and the parts of which it 
consists may likewise come under the same 
two general heads. The bony parts are the 
ossa maxillaria, ossa palati, maxilla inferior, 
and the teeth; to these we may add os hy- 
oides, and the upper vertebra of the neck. 
The external parts of the mouth are, the 
two lips, one upper the other under; the bor- 
ders, or red part of- the lips, the corners, or 
commissures of the lips ; the fossula of the up- 
per lip, the basis of the under lip; the chin, 
the basis of the chin; the skin ; the beard; and 
even the cheeks, as being the lateral parts of 
the mouth in general, and of the lips in par- 
ticular. 
The internal parts of the mouth are, the 
gums, palate, septum palati, uvula, amyg- 
dala-, the tongue, the membrane which lines 
the whole cavity, the salival duct and glands, 
and the bottom of the mouth. 
The palate is that arch or cavity of the 
mouth, surrounded anteriorly by the alveo- 
lar edge and teeth of the upper jaw, and 
reaching thence to the great opening of the 
pharynx. The arch is partly solid and im- 
moveable, and partly soft and moveable. 1 he 
solid portion is that' which is bounded by the 
teeth, being formed by the two ossa .maxilla- 
ria, and two ossa palati. The sott portion 
lies behind the other, and runs backward, 
like a veil fixed to the edge of the ossa palati, 
being formed partly by the common mem- 
brane of the whole arch, and partly by several 
muscular fasciculi, &c. 
The velum palati, terminates below by a 
loose floating edge, representing an arch, si- 
tuated transversely above the basis, or root, of 
the tongue. 'Fhe highest portion, or top, of 
this arch, sustains a small, soft, and irregularly 
conical glandular body, fixed by its basis to 
97 
the arch, and its apex hanging down, without 
adhering to any thing, which is called uvula. 
On each side of the uvula there are two mus- 
cular half-arches, called columpa? septi pa- 
lati, which contain between them the glands 
called amygdala?. 
The tongue is divided into the basis and 
point, the upper and under sides, and the 
lateral portions, or edges. The basis is the 
posterior and thickest part; the point the an- 
terior and thinnest part. The upper side is 
not quite flat, but a little convex, and divided 
into two lateral halves, by a shallow depressed 
line, called linea lingua? mediana. The edges 
are thinner than the other parts, and a little 
rounded, as well as the point. The lower side 
reaches only from tire middle of the length of 
the tongue to the point. Three sorts of pa- 
pilla? may be distinguished in the upper side 
of the tongue, capital*, semi-lenticulares, and 
villosai. 
Of the skin and organ of touch. 
The common integuments are divided into 
cuticula, rete mucosum, cutis vera, and cor- 
pus adiposum. 
The outside of the skin is covered by a thin 
transparent insensible pellicle, closely joined 
to it, which is called epidermis, cuticula, or 
scarf-skin. 
Under the cuticle, we meet with a sub- 
stance of a greyish colour, which has got the 
name of corpus cuticulare, or rete mucosum ; 
it is of a soft, mucilaginous, and viscid nature, 
and tills up the interstices of the fibres run- 
ning between the cutis vera and cuticula. 
After raising the cuticle in a negro, where it 
is thickest and most distinct, this substance 
appears of a black colour, and is composed of 
two layers. It is this that chiefly gives the 
colour to the skin, for it is black in the Afri- 
can, and white, brown, or yellowish, in the 
European. 
The cutis vera, or skin, properly so called, 
is a substance of very large - extent, made up 
of several kinds of iibres, closely connected 
together, and running in various directions, 
being composed of the extremities of nume- 
rous vessels and nerves. • 
It is not easily torn, may be elongat ed in all 
directions, and afterwards recovers itself, as 
we see In the persons, in women with child, 
and in swellings ; and it is thicker and more 
compact in some places than in others. 
In' different parts of the body, we meet 
with small glands, or follicles, of an oval form, 
and seated chiefly under the skin in the cor- 
pus adiposum. These are called sebaceous 
and miliary. 
The last universal integument of the human 
body is the membrana adiposa, or corpus adi- 
posum. 
The nails are productions of the epidermis. 
The hairs belong as much to the integu- 
ments as the nails. Their roots, or bulbs, lie 
toward that side of the skin which is next the 
membrana adiposa. 
Of the brain. 
This mass is divided into three particular 
portions; the cerebrum, or brain, properly 
so called, the cerebellum, and medulla oblon- 
gata. To these three parts, contained within 
the cranium, a fourth is added, which tills the 
great canal of the spina dorsi, by the name of 
medulla spinalis, being a continuation of the 
medulla oblongata. 
