GEN. I.

SPEC. VII.

Paropsis

it with success upon an extensive field of practice*. Gleize employed it with equal success alone †, and Hufeland as satisfactorily in combination with warm bathing, Caligo. and the internal use of millepedes: the last of which, Opake however, may be spared without any serious risk. The disease has sometimes disappeared spontaneously, or without any known cause.

cornea.

How distinfrom cataguishable

Where the disease has become permanent, it may be distinguished from a cataract, and hence a useless operation be avoided, by a greenish hue of the iris if previously ract. blue or grey, or a reddish, if previously brown. The iris moreover remains immoveable, as the debility has now extended to itself, and from an irregular contraction of its fringe, the pupil acquires a broken, and for the most part angular or elliptic shape.

the cornea

In newly-born infants spots on the cornea are occa- Spots on sionally met with, which soon vanish spontaneously §: probably the rays of light acting as a salutary stimulus upon the occasion.

born infants: soon vanish, and why.

greenish-tinted," from the common colour of the obscu

GEN. I. SPEC. VIII. Specific

rity. It was also called by the Greeks glaucoma, and name, its by the Romans glaucédo. Glaucosis is here preferred to termination.

• On the Principal Diseases of the Eyes.

+ Nouvelles Observations, &c.

§ Farr. Med. Commun. 11. 30.

Von Blathern. p. 159.

origin and

GEN. I.

SPEC. VIII.
Paropsis
Glaucosis.
Humoral
opacity.

Probable proximate

cause.

Caligo of Sennert.

Glaucoma

of Guthrie.

Carried off spontaneously or by a fever.

How distinguishable from caligo. Treatment.

glaucoma, because the final oma imports usually, and, for the sake of simplicity and consistency, ought always to import, external protuberance, as in staphyloma, sarcoma, and various others noticed in detail in the volume of Nosology.

This species is probably produced in most instances by a torpitude of action in the absorbents that carry off the waste fluid of the humours, similar to that described under the last species; and is sometimes benefited by a like stimulant and tonic plan of treatment. Sennert calls it indeed a calígo, and distinguishes it by its proceeding from a defect of the aqueous humour-calígo à defectu humoris aquei; by which he seems to mean that the torpitude belongs rather to the excretory than the absorbent vessels; but, in this case, the cornea would appear depressed or flattened, which is rarely if ever a symptom.

Mr. Guthrie has united the two diseases in the same manner as Sennert, describing both under the name of Glaucoma, which he defines " an alteration of the component parts of the vitreous humour, accompanied by derangement of structure of the hyaloid membrane of the retina, and tunica choroidea, the vessels of which are always more or less in a varicose state." *

Both this and the preceding species have sometimes ceased spontaneously †, without any apparent cause; and Helwig gives an instance in which the cessation was not only spontaneous but sudden. They have also been carried off by fever. In the caligo there is often a sense of fulness, stiffness, or other uneasiness, and occasionally of pain. In the present affection little disquiet of any kind is complained of. Collyriums of the astringent minerals or metallic earths, or other stimulants are often serviceable, when persevered in §.

* Lectures on the operative Surgery of the Eye, p. 214.

Hagendorn, Observ. Med. Cent. I. Obs. 56. Franc. 1698, 8vo. Eph. Nat. Cur. Dec. 1. Art. 11. Obs. 166.

Obs. 23.

$ Collezione d'Osservazioni e Riflessioni di Chirurgia di Giuseppe Flajani, Dottore in Medicina e Chirurgia, &c. Tomi 1v. Roma, 1803.

SPECIES IX.

PAROPSIS CATARRACTA.

Cataract.

DIMNESS OR ABOLITION OF SIGHT FROM OPACITY OF
THE CRYSTALLINE LENS.

66

GEN. I. SPEC. IX.

The pearl

eye

of old

writers.

THE cataract as it is now called, was by old English
writers named PEARL-EYE or PEARL IN THE EYE, and is
so denominated by Holland, the faithful translator of
Pliny. Catarracta, as a Greek term, is usually derived English
from καταρράσσω, to disturb, destroy, or abolish". Catarracta
καταρράκτης οι καταράκτης, however, was employed by whence de-
the Greek writers themselves to signify a gate, door, or rived.
loop-hole, and the bar which fastens it, and becomes the Primary
meaning of
impediment to its being opened. And it is probably the term.
from this last sense that the term cataract was first ap-
plied to the disease in question, as forming a bar to the
eyes which were called the loop-holes or windows of the
mind by various philosophers, as we learn from Lucretius,
who thus closes his opposition to their view:

Dicere porro oculos nullam rem cernere posse,
Sed per eos animum ut foribus spectare reclusis
Difficile est *.

To deem the eyes, then, of themselves survey
Nought in existence, while th' interior mind
Looks at all nature through them, as alone,
Through windows, is to trifle—

Whence, perhaps, Shakspeare in the speech of Rich-
mond :-

To thee I do commend my wakeful soul
Ere I let fall the windows of mine eyes.

De Rer. Nat. I. 360.

GEN. I. SPEC. IX. Paropsis Catarracta. Cataract.

Called by

the Greeks hypochyma, apochysis, and hypochysis.

Cataracta

probably first used by Avicenna: though the

common

Arabian term was gutta ob

scura.

Origin and meaning of

gutta obscura and

gutta serena.

Onyx and ceratonyx of modern

Germans.

The Greeks themselves, however, called this disease indifferently hypochyma, apochysis, and hypochysis. The earlier Latins, suffusio: while catarracta seems first to have been made use of by the Arabian writers, and was probably introduced into the medical nomenclature by Avicenna. Yet the more common name among the Arabians was gutta obscura, as that for amaurosis was gutta serena; the pupil, in this last species, being serene or transparent.

The Arabians, who had adopted generally the humoral pathology of Galen, conceived both these diseases to be the result of a morbid rheum or defluxion falling on a particular part of the visual orb, in the one case producing blindness with obscurity, whence the name of an obscure rheum or gutta; and in the other without obscurity, whence the contrary name of a transparent or serene rheum or gutta. But as various other diseases, and particularly of the joints, were also supposed to flow from a like cause, and were far more common, the terms gutta and rheuma were afterwards emphatically applied, and at length altogether limited, to these last complaints: whence the terms gout and rheumatism which have descended to the present day, as the author has already had occasion to observe under ARTHRODIA PODAGRA. For gutta the Arabian writers sometimes employed aqua; and hence, cataract and amaurosis are described by many of them under the names of aqua obscura, and aqua serena; and the former, by way of emphasis, sometimes under the name of aqua or arqua alone. For gutta obscura the modern Germans have revived the terms ONYX and CERATONYX where the lens is peculiarly hard or horny *.

The opacity producing a cataract may exist in the lens alone, the capsule alone, or in both; thus laying a foundation for the three following varieties :

⚫ See Langenbeck's Prufung der Keratonyxis, einer nener Methode, &c. Götting, 1811, 8vo.

the humour

of Morgagni, what.

We are told moreover by Richter* of a cataract of Cataract of the humour of Morgagni, or the interstitial fluid which lies between the capsule and the lens: whence this has also been copied by Plenck, Professor Beer, and Sir William Adams into the list of modifications; but rather as a possible than an actual case; for none of these practitioners give a single example of such a variety ever having occurred to them with certainty, though Beer suspected it in one caset.

It is sometimes accompanied with a sac inclosing a small body of pus or ichor, and is probably the result of the inflammation that produced it. In this case it forms the cataracta capsulo-lenticularis cum bursa ichorem continente of Schmidt ‡. Beer affirms that this sac is commonly seated between the lens and posterior part of the capsule, and very rarely between the former and the anterior part §. Professor Beer seems to have refined a little too much in his divisions and subdivisions of cataract, for he not only assigns a distinct place to the Morgagnian, and this pustular cystic, but to a cystic form without pus, to a siliquose, and a trabecular; while he further partitions the capsular into two separate forms, according as it is before or behind in the capsular chamber; thus giving us a catalogue of nine distinct forms of what he calls the true cataract; while he allots four other subdivisions to what he denominates the spurious cataract: meaning hereby some other obstacle to vision, the seat of which is

• Von der Ausziehung des grauen Staars. Gött. 1773. 8vo. + Lehre von den Augenkrankheiter, Band II. Sect. 56. Ueber Nachstaar und Iritis, &c. Wien 1801.

§ Lehre von der Augenkrankheiter, Band 11. p. 301. 1813.

Sometimes accompani

ed with a sac, containing pus, and particu larly named Beer's seat of the sao. Multipli

by Schmidt.

cated subdi

visions of Beer;

being nine for his true, and four for his spurious cataract,