ve fever is an accidental
consequence of the topical phlegmon, or inflammation, and not a cause of
it; that it is often injurious, but never salutary; and should therefore
always be extinguished, as soon as may be, either by the lancet and
cathartics, and diluents, and cold air, when it is of the irritated kind;
or by the bark, opium, cool air, and nutrientia, when it is of the
inirritated kind.

SPECIES.

1. _Ophthalmia superficialis._ As the membranes, which cover the eye, are
excluded from the air about one third part of the twenty-four hours; and
are moistened by perpetual nictitation during the other sixteen; they may
be considered as internal membranes; and from the analogy of their
inflammation to that of other internal membranes, it is arranged under this
genus; whilst the tonsillitis is esteemed an inflammation of an external
membrane, because currents of air are perpetually passing both day and
night over the fauces.

The superficial ophthalmy has generally been esteemed a symptom of
scrophula, when it recurs frequently in young persons; but is probably only
a concomitant of that disease, as a symptom of general debility;
ramifications of new red vessels, and of enlarged old ones, are spread over
the white part of the eye; and it is attended with less heat, less pain,
and less intolerance of light than the ophthalmia interna, described in
Class II. 1. 2. 2. It occurs in those of feeble circulation, especially
children of a scrophulous tendency, and seems to arise from a previous
torpor of the vessels of the tunica albuginea from their being exposed to
cold air; and from this torpor being more liable to occur in habits, which
are naturally inirritable; and therefore more readily fall into quiescence
by a smaller deduction of the stimulus of heat, than would affect stronger
or more irritable habits; the consequence of this torpor is increased
action, which produces pain in the eye, and that induces inflammation by
the acquisition of the additional sensorial power of sensation.

_Ophthalmia lymphatica_ is a kind of anasarca of the tunica adnata; in this
the vessels over the sclerotica, or white part of the eye, rise
considerably above the cornea, which they surround, are less red than in
the ophthalmia superficialis, and appear to be swelled by an accumulation
of lymph rather than of blood; it is probably owing to the temporary
obstruction of a branch of the lymphatic system.

M. M. If the pain be great, ven