MELANOSIS. 
375 
tions also. The masseter muscle presented precisely the same 
appearance, only the deposits were confined more to the external 
surface. The masseter muscle is somewhat peculiar in its struc- 
ture : it is formed of layers of muscular tissue, and between two 
of these muscular layers is placed a layer of tendinous substance, 
closely similar to that investing the temporal muscles ; and it was 
between the external layers of muscular fibre and this tendinous 
structure that these globular deposits were scattered. The middle 
and lower tumours were connected with the large one by masses of 
deposit ; but the latter differed somewhat from the former. Their 
more superficial portions consisted of an immense number of the 
globular bodies, ranging from the size of a pea to a large marble ; 
the smaller of these bodies I could easily detach from the rest : 
their external investment or capsule was fine and thin, but still of 
very considerable strength. If a globule was squeezed, the invest- 
ment did not burst, as might have been expected, but the black 
matter contained within oozed through : if, on the other hand, this 
investment was cut and the melanotic matter washed away, I 
found the tissue of a fibrous character, and apparently inelastic. 
The larger globules could not be dissected away without the con- 
tents being partially liberated. Towards the base of the two 
tumours all globular character vanished, and the whole became 
agglomerated together. The inferior tumour enclosed within its 
substance the submaxillary vein of that side ; mid so closely did it 
press upon it all around , that the canal of the vein would scarcely 
allow a small probe to be passed through it ; and the vessel an- 
terior to where it was enclosed was full, almost to bursting, with 
blood . On proceeding to remove the middle and inferior tumours 
as I thought from their base, I found that they passed behind and 
underneath the maxilla: the middle tumour insinuated itself be- 
tween the jaw and the stylo-maxillaris muscle. I next removed 
the jaw and found that the whole of the parotid gland on the left 
had become melanotic, and the guttural pouch of the same side 
was filled with the melanotic fluid: altogether, the pouch contained 
more than a pint. The fluid was very black, of about the con- 
sistence of bile, and was a most excellent substitute for ink ; for, in 
fact, nearly the whole description of the dissection was written 
with it into my case book. The left branch of the jaw, between 
its curve and condyle, had nearly all disappeared: the bone was 
gone, not, I believe, from ulceration, but from the pressure to 
which it had been subject both on its internal and external sur- 
faces, thereby causing it to be absorbed. Very little of the 
internal pterygoid muscle remained, and what was left ap- 
peared to have become melanotic. The fibres of the muscle could 
be distinctly traced, but the natural colour was entirely gone, and 
