he hesitates to determine as to the variety of the cataract; or, in effect, whether it be a cataract at all. The shadow cast by the iris constitutes his leading clue. If the lens in an opake state maintain the size it possest when transparent, there is a manifest shadow thrown back upon the surface of the cataract by the iris. If the cataract be less than the natural lens, this shadow is broader than usual. If the opake lens be swollen, no shadow is present, as the capsule is pushed forward into contact with the iris, and the posterior chamber is abolished. And by carefully comparing all the signs that lie before him, he is able to indicate with certainty, in every instance, the seat, the size, and the consistence of the cataract. "We have already observed that a cataract is occasionally the result of an hereditary taint; in other instances it originates spontaneously, or from causes we cannot trace. It has, however, often followed upon convulsions, chronic head-ache, syphilis, rheumatism, suppressed perspiration, and in a few instances. TRICHOSIS Plica, or matted hair.* It has also appeared as an effect of inflammation produced by a thunder-storm.+ "The siliquose or bean-shaped cataract, is usually the result of a wound or rupture of the capsule, through which the aqueous humour is admitted to the lens. In children this mischief is occasionally produced by those fits of convulsion to which they are subject as soon as born, and during which the muscles of the eye-ball are affected with violent spasms. At this age the opacity is a light gray, and evidently has its seat in the anterior capsule, which is shrivelled and wrinkled. In adults the opacity is chalky, when the capsule has been wounded; otherwise it is dusky or yellowish; and the kernel of the lens usually remains, while its surface and circumference are dissolved. The opacity is flat; and the shadow of the iris broad. From its occurring occasionally in infants soon after birth, it is often confounded with a genuine congenital cataract. * De la Fontaine, Chirurg. Med. Beer, ut suprà. "Like PAROPSIS Glaucosis, or humoral opacity, it has sometimes ceased spontaneously, or without any manifest cause ;* and Helwig gives an instance in which the cessation was not only spontaneous, but sudden. It has also, at times, been carried off by a fever.‡ "There is hence specious ground for conceiving that some medicine might be discovered capable, by some general or specific action, of producing a like change, and proving a remedy for the disease; and the more so, as we find ganglions and other accidental deformities frequently removed from the extreme part of the system by external or internal applications. But no such remedy has hitherto been descried, or at least none that can be in any degree relied upon, excepting in those cases of supposed, but miscalled, cataracts, which have consisted in a deposition of lymph from an inflammation of the iris and ciliary processes: for recourse has been had to mercurial preparations, both external and internal, as well as almost every other metallic salt, aconite, the pasqueflower, or pulsatilla, to protracted vomiting, electricity, and puncturing the tunics of the eyes, but without any certain advantage. This is the more to be lamented, because whatever surgical operation may be determined upon as most advisable, there is no guarding, on all occasions, against the mischievous effects which may result, I do not mean from the complication or severity of the operation, for this, under every modification, is simpler and less formidable than the uninitiated can readily imagine; but from the tendency which is sometimes met with, from idiosyncrasy, habit, some peculiar acrimony, or other irritable principle, to run rapidly into a state of ulcerative inflammation, and in a single night, or even a few hours, in spite of the *Haggendorn, Observ. Med. Cent. i. Obs. 50. Franc. 1698. 8vo. Ludolf, Miscell. Berol. tom. iv. 258. Walker, on the Theory and Cure of a Cataract. + Observ. Physico. Med. 23, Aug. Vind. 1680, 4to. Velschius, Episagm. 20. § Beytrage zur Chirurgie und Augenheilkunst. Von Franz Reisinger, &c. Göttingen, 1814. wisest precautions that can be adopted, to endanger a total and permanent loss of vision. I speak from personal knowledge, and have, in one or two instances, seen such an effect follow, after the operation had been performed with the utmost dexterity, and with every promise of success; and where a total blindness has taken place in both eyes, the operation having been performed on both; neither of them being quite opake antecedently, and one of them in nothing more than an incipient state of the disease, and the patient capable of writing and reading with it. And hence it is far better, in the author's opinion, to have a trial made on one eye only at a time, and that the worst, where both are affected and one is still useful, than to subject both to the same risk; for the sympathy between them is so considerable, that if an inflammatory process, from any constitutional or accidental cause, should shew itself in either, the other would be sure to associate in the morbid action. "The usual modes of operating for the cure of a cataract are three that of couching or depression; that of extraction; and that of what is called, absorption.* The first was well known to the practitioners of Greece and Rome; and is ably described by Celsus, who advises, in cases where the lens cannot be kept down, to cut it into pieces with the sharpedged acus or needle, by which mean it will be the more readily absorbed. And, from this last remark, we have some reason for believing that even the third of the above methods, that of absorption, was also known at the same time; as it is probable, indeed, that the second, or the operation by extraction, was likewise; since we find Pliny recommending the process of simple removal or depression, in preference to that of extraction or drawing it forth; squammam in oculis emovendam potius quàm extrahendam,'t which Holland has * Guthrie, Lect. on the Operative Surgery of the Eye, p. 184. 8vo. 1823. + Nat. Hist. lib. xxix. cap. 1. thus honestly, though paraphrastically, translated, 'a cataract or pearl in the eye is to be couched rather, and driven down by the needle, than quite to be plucked forth.' "In the East, however, both these plans appear to have been pursued through a much longer period. Both are noticed by the Arabian writers in general, and especially by Avicenna and Rhazes; and both seem to have been practised from time immemorial in India, and, according to the account of the cabirajas, with wonderful success. Dr. Scot was informed by one of the travelling operators, who, however, spoke without a register, that in the operation of depression this success was in the proportion of a hundred who were benefited, to five who obtained no advantage whatever. "Upon the ordinary operation of depression, M. Willburg seems to have made a considerable improvement, by pressing the cataract backwards and downwards into a particular position, where it is less likely to ascend or touch the retina; and to this mode of operation is given the name of RECLINATION. "The operation of extraction seems to have derived no small improvement from the method of Sir William Adams, who, after detaching the cataract, first passes it through the opening of the pupil into the interior chamber by means of his needle, and then extracts it by an opening on the outer side of the cornea, instead of by one in its interior part. "The simplest and least irritating of these operations, however, is that by absorption, as it is now commonly called, as it was named precipitation by Maître-jan,‡ on his first noticing the disappearance of portions of the opake lens; but which in effect is neither absorption nor precipitation, but SOLUTION, or dissolution, as Mr. Pott correctly described it. But it should be known to the operator, that while the solvent power of the aqueous humour is wonderfully active, that of the vitreous is weak and inconsiderable: and hence the solvent or absorbent Traité des Maladies de l'Oeil. edit. sec. Troyes. 1711. plan, first practised by Buckhorn, and since in our own country by Sir William Adams, consists in dividing the cataract, after its separation, into small fragments, and passing them with the needle, by which they are thus divided, through the pupil into the anterior chamber, which constitutes the seat of the aqueous humour, apparently in perfect coincidence with the method first practised by Gleize, and since recommended by Richter.* The fragments thus deposited are usually dissolved in a few weeks; and where the cataract is fluid, they have often been dissolved and absorbed in a few seconds; and sometimes even before the needle has been withdrawn. The division is here made through the cornea, previously illined with belladonna to dilate the pupil, and it is to this method of operating that M. Buckhorn gave the name of CERATONYXIS.† The first inventor, however, of the plan in its simplest state was Conradi of Norheim." vol. iv. pp. 221-229. I have already (p. 111.) alluded to letters from several of the most distinguished physicians, and others, at home and abroad, expressive of their high sense of the value of Dr. Good's "Study of Medicine," and of its tendency "to support and increase the reputation he had so deservedly acquired, as one of the most learned and most philosophical members of the medical profession." It was once my intention to solicit the permission of these gentlemen to publish their respective letters, as honourable to themselves for their frank and kind expressions of esteem, as to the individual whom they panegyrize for the rich diversity of his talents and attainments. But on farther meditation, I feel it preferable to adduce the testimonies supplied by * Chirurgische Bibliothek, band. x. + Buckhorn de Keratonyxide. Halâè, 1806. |