Encyclopaedia Britannica, or, a Dictionary of arts, sciences, and miscellaneous literature : enlarged and improved. Illustrated with nearly six hundred engravings > Volume 20, SUI-ZYM

Chap. X. ' . . S U R
Of the Dif-pair of fciffars *, and then carefully dktfe&ing it off to _iti
ealeb of theapex> jf any portion of it has been allowed to remain,
, £>'e or if the wound thews any tendency to form a fungus,
lunar cauftxc ought to be applied to it, and the appli¬
cation repeated "as often as may appear neceflary. Any
flight inflammation or weaknefs in the eye which may
continue after the operation, may be fpeedily removed
by the application of the vinous tindlure of opium.
Sect. III. Of PuJIules (Ophthalmia puflulofa).
Symptoms. Puftules are fmall tumors which are formed both on the
cornea and fclerotic coat, but they occur moft frequent¬
ly near the jun&ion of thefe membranes. A puftule
commonly firfl: appears like a dulky yellow or reddifli
fpot, a little elevated above the furfaee of the cornea
or fclerotic coat *, and in a fliort time it becomes a di-
ftinct conical tumor. The adjacent part of the cornea
is always more or lefs dim-, and a confiderable degree of
inflammation accompanies it, which is either confined
to the white of the eye contiguous to the puftule, or is
fpread over the whole eyeball. Whilft the puftule is
forming, the inflammation is generally confined to that
part of the white of the eye which is in its immediate
vicinity. The blood veffels are of a pale livid hue j
they appear fuperficial, and can be readily elevated by a
pointed inftrument; each trunk can be diftinguifhed,
for they are never fo numerous as to appear confufed, or
like one red mafs. They fometimes run in various di¬
rections, anaftomofe freely with one another, forming
net-works upon the wdiite of the eye.
If the inflammation and puftule remain for fometime,
the puftule generally advances to fuppuration. When
fuppuration takes place, the apex of the puftule ulce¬
rates, and frequently a chalky white fpot appears at the
centre of the ulceration ; and the opacity of the cornea
at the fame time daily inereafes around it. In other
cafes, the opaque matter feparates, and leaves behind it
a deep ulcerous excavation.
Sometimes the fuppuration proceeds more like a com¬
mon pimple or phlegmon of the fkin ; a fmall quantity
of a thick matter colleCls within the puftule, and when
it is difeharged, a conical tumor remains, which has a
depreflion at the apex. When the puftule contains a
Avatery fluid, the fluid is moft frequently abforbed in a
, gradual manner ; but at other times the paflule breaks,
and an ulcer is formed.
If, in either of thefe cafes, the contents are artificially
difeharged, all the accompanying inflammatory fymp-
toms are jrmch increafed.
Moft frequently there is only one puftule, and only
one eye affe&ed ; but in fome cafes there are feveral
both on the cornea and fclerotic coat of each eye.
The difeafe, at its commencement, is almoft inva¬
riably accompanied with the fenfation of a mote in the
eye, and the whole conjunctiva covering the fclerotic
coat has often a yellowith and fhining glaffy colour be¬
fore the rednefs appears. There is often alfo a degree
of rednefs and fAvelling, chiefly of the upper eyelid j and
the tarfi are found adhering together in the morning,
from the exudation of a yelloAv matter among the ciliae.
There is frequently an unufual drynefs felt in the eye ;
but if it be expofed to a bright light, or if an attempt
be made to ufe it, the fecretion of tears is increafed.
This fpecies of inflammation is always accompanied
Vol. XX. Part I.
G E R Y.
89
with a much greater degree of general fever, in proper-Of the Dif-
tion to the feverity of the local fymptoms, than any ot the
other ophthalmia. The pain is rarely acute till the pu- ^e' ,
ftule ulcerates ; but, if that takes place, it is commonly
very fevere.
An eye which has been once affeCted with puflule, is
very fubjeCt to repeated attacks of the difeale. Puflules
of the cornea are met with in people of all ages ; but
they are more common in young people than in thofe
advanced in life.
Treatment.—Sudorific medicines, cooling diluent
drinks, and purgatives, ought to be employed in the firft
ftage of the difeafe \ and given according to the vio¬
lence of the conftitutional fymptoms. The eye, and
parts around it, fliould be fomented three or four times
a-day, with a deeo£tion of poppy heads to which may
be added a fmall quantity of fpirits. When the fymp-
tomatic fever abates, and the rednejs affumes a more
purple hue, the vinous tindlure of opium may be applied
to the eye once or twice a-day ; and this will be found
equally ufeful whether the puflule is in a ftate of fup¬
puration or not •, and it ought to be continued as long
as there are any remains of the difeafe.
Sect. IV. Of Matter colleSled between the Larnel/ce 10*
of the Cornea.
Purulent matter is fometimes collefted between the
lamellge of the cornea, Avhen the difeafe is termed unguis
or onix; or in the anterior chamber, when it is called
hijpopion.
When the matter is collected between the lamellae of
the cornea, it appears in the form of a yelloAv fpot j and
as the quantity increafes, the fpot becomes larger, but
does not alter its fituation from the pofition of the head.
When the matter is colle&ed in the anterior cham¬
ber, it generally appears like a fmall yellow globule be¬
tween the iris and cornea, occupying the inferior part of
the cavity. Thefe abfeeffes are commonly the effedfl of
violent ophthalmia, oecafioned by a blow, or injuries of
the eyeball 5 they are alfo formed, though rarely, with¬
out any accompanying inflammatory fymptoms.
Treatment.—Though the purulent matter may be
more or lefs abforbed on the abatement of the accom¬
panying inflammatory fymptoms 5 yet it would be found
a good general praftice to evacuate the matter when¬
ever it appears, by making an incifion through the cor¬
nea. The difeharge of the aqueous humour along with
the matter, never fails to diminifh the inflammation ;
and this perhaps may be the reafon why the pradlice is
fo ufeful. Befides this, fomentations, brifk purges, and
cupping at the temples, may be neceffary if the inflam¬
matory fymptoms are fevere.
Sect. V. Of Ulcers of the Cornea.
Ulcers of the cornea have been divided by fome au¬
thors into a number of fpecies, from differences in their
fize, in their duration, in the degree of the feverity of the
accompanying fymptoms, and from the various caufes
from Avhich they have been fuppofed to originate.
The moft frequent variety of ulcer is that which re¬
mains after the cornea has fuppurated and burft j either
in confequence of a puftule or of an abfeefs.
When a puftule fuppurates, the central part of it ge-
M nerally