mation of one of its eyes and puriform secretion from the conjunctiva. From under the edge of the upper lid there projected a black roundish body, which at first view he thought might be a protrusion of part of the iris through an ulcer in the cornea great was his surprise, when on cautiously raising the upper lid he found this was a case, not of figurative but of real myocephalon. A common house-fly was fairly lodged and had been so for eight days between the eyeball and the upper eyelid; its head only projecting in the manner described, and producing an appearance as if the eye were disorganized.

Should the particle be retained near the margin of the lid so as to play over the cornea, it will not only cause much suffering, but opacity, and even suppuration and destructive ulceration of the cornea, may ensue.

A blacksmith's apprentice, whilst paring a horse's hoof, received a piece of horn beneath the left upper eyelid. He applied to a druggist, who gave him a lotion. Seven days after the accident the foreign body was removed. After the further lapse of four weeks he presented himself to Mr. Vose Solomon, with symptoms of disorganizing inflammation of the internal tunics, and although he improved somewhat under treatment, the eye remained incapable of discerning light and somewhat diminished in size.

It was formerly a common practice to blow into the eye powdered sugar as a remedy for opacities of the cornea, and both in this country and on the Continent the lower orders use it for this purpose. Cunier met with the following curious cases: A young woman had had this remedy employed for catarrhal ophthalmia; the sugar had been coarsely pounded, and nearly twenty little crystals remained fixed in each cornea, where they had continued undissolved for more than twenty-four hours; Cunier used lotions, which

cleared away the lymph enveloping them, and they were speedily dissolved. The two corneæ recovered much of their transparency, which had been greatly impaired, but several small opacities remained in the right. Cunier saw another case, where an incrustation of sugar-candy remained eight days in the eye of a young woman who had been subjected to these insufflations.

CHAPTER II.

THE penetration of the eyeball by a foreign body is always attended with risk, and this is increased or diminished by a variety of circumstances. In the eye, as elsewhere, our prognosis is occasionally at fault, for unexpected recoveries under unfavorable circumstances are met with, whilst eyes are lost by trivial accidents. Who would imagine that a touch from the end of a spectacle-branch, so slight as to be scarcely felt, would destroy sight; whilst a fragment of stoneware, the size of a pea, could remain in the anterior chamber eight days, without producing any severe effects?1

A man came to Dr. Mackenzie with a thorn in his eye; the point of it was fixed in the iris, and its thicker extremity in the cornea. The accident had happened three weeks before, and the wound of the cornea, by which the thorn had entered, was healed over; during these three weeks the presence of the thorn had caused no inflammation, and very little irritation.2

The toughness and form of the cornea and sclerotica are alike calculated to resist penetration; hence, if they be pierced, the foreign body must either possess considerable momentum, as in the case of a shot, or be of such a form and size as to facilitate its entrance. Perhaps the commonest substances that do pierce the eye are chips of metal, thrown

off from turning lathes, fragments of percussion caps, and small pieces of stone driven off by heavy hammers. But very unlikely substances may find their way into the eye. Dr. Bader informed me that dissecting an eye excised at Moorfields, he was greatly surprised to find a piece of bee's wax between the sclerotic and choroid. Its presence there greatly puzzled him, till he found that the injury rendering necessary the removal of the eye had been explosion of a cartridge, and that bee's wax is used to close one end of cartridges.

Extraneous substances present themselves under many conditions; the cornea may be pierced through, and the foreign body remain fixed in it, projecting into the anterior chamber, as in the case of the thorn before mentioned; or it may lie loose in the anterior chamber; may be fixed in the iris, or pass through it or the pupil, resting in the posterior chamber behind the iris, or lodging in the capsule of the crystalline, or in the lens itself; or, finally, it may be driven with sufficient force to reach the vitreous cavity, and there remain to the destruction of the eye.

The gravity of the injury will vary with the size and situation of the foreign body. It is singular how tolerant some eyes are of substances which enter the anterior chamber. I have seen a shot rest there for two days without causing pain or inflammation; and Dr. Jacob, in a valuable paper,1 mentions cases even more striking.

Indeed, the number of recorded instances is great in which bodies have entered the anterior chamber, and there become encysted, without material injury to the eye. On the other hand, I have seen most violent inflammation follow the presence of a small portion of cataract there; and Cunier mentions a case in which an eye was very nearly lost, in

''Dublin Medical Press,' Dec. 9th, 1846.

consequence of a minute particle broken off from the point of a cataract needle accidentally resting in the anterior chamber.

Escape of the aqueous humour is a common consequence of penetration of the cornea, but a chip of metal may be driven with such force and velocity as to pass through the cornea, the wound closing behind it so instantaneously as to retain the aqueous humour.

The peculiar texture and varying density of the lens seem well adapted for checking the course of a foreign body; that it does so is proved by a case of Mr. Critchett's, hereafter related, in which a chip of metal, driven cleanly through the cornea and iris, was, in its passage through the lens, deprived of so much of its velocity as to fail to rupture the delicate hyaloid membrane.

In turning over the pages of ophthalmic periodicals, especially the foreign journals, it is remarkable how common are accidents from percussion caps; those in use on the Continent are made of inferior metal, and are more brittle than those supplied by English gunmakers; they break in pieces. when struck by the hammer of the lock, and the fragments, driven off with force, frequently penetrate the eye. Another source of accidents is exploding caps for amusement, either by striking them or holding them to a candle; the sharp angular fragments cut through the coats of the eye, leaving an exceedingly small wound, bearing no proportion to the magnitude of the foreign body.

Mr. Walton states: "I have seen not less than five eyes destroyed by percussion caps during the last year, and not in a single instance were the caps used in shooting; but two persons received their injury by exploding the caps between

1 'Operative Ophthalmic Surgery,' p. 107.