cannot better convey, or more forcibly impress, the necessity of being able to recognize the earliest marks of iritis, and the ignorance and inattention that prevails in detecting the primary stage of the disease, than by reciting the following case.

A young gentleman about thirty, complained of general uneasiness of one eye, pain of the ball, and lacramation. These symptoms were first experienced towards evening, and abated much before morning. The next day about the same hour they recurred with increased severity, the pain extending to the orbit and temple. The medical attendant to the family now saw the person, and found the vascularity so slight as to lead him to consider the attack as one of rheumatism of the sclerotic. Four days elapsed with progressive aggravation, the pain towards evening becoming intolerable, with great intolerance of light. The violence of his sufferings, and not any apprehension of the deprivation of sight, induced the patient to have additional advice. Iritis was then detected, barely in time to preserve vision under the most decisive treatment.

The necessity of being able to recognize the complaint or its invasion is too apparent to dwell on. This is the leading difficulty to be encountered. If the disease be ascertained sufficiently soon, the treatment is simple and successful. What symptoms, then, characterize it? On looking at an affected eye, a peculiar arrangement of red vessels is observable. Towards the circumference of the globe they become distinctly visible, running forward in lines without lateral communications; as they approach the cornea, a free anastomoses takes place, and a plexus is formed, a little external to the cornea, of a pretty deep colour in general. This is a diagnostic mark of importance. The vessels being covered by the conjunctiva, exhibit a purplish tinge; and the lustre or clearness of the cornea will be diminished. But these signs, of course, vary in intensity. If the inflammation be acute, these marks are very apparent, in cases of an opposite nature, they are nearly imperceptible. When the inflammation is violent and the red zone marked, on close inspection a greyish line will be observable, which Mr Howard has aptly called the ash-coloured zone; "the edge, or circle, he observes, formed by the junction of the conjunctiva and cornea appears thickened, of an ash-colour, slightly tinted with red." It is most distinct towards the cornea.

These characters, are, I have said, subject to much variation, either from the degree of the inflammatory action, or from inflammation co-existing, or arising in the conjunctiva or sclerotica, or deeper tissues of the eye. The general appearance will point out in which texture the complication exists, although, when high action is going on, the distinguishing features are

lost in the general redness. The pain is often urgent, and in cases where syphilis has given rise to it, the patient's sufferings become aggravated towards evening; the most distressing feelings are caused by the intolerance of light; this is most severe during the first stage of an acute attack, before muddiness of the aqueous humour, and dulness of the cornea have veiled the retina; it is often as great as in strumous ophthalmia. "The venereal ophthalmia," says Mr Howard," is most likely to be confounded with that arising from scrofula, to which it bears a very strong resemblance."

In very severe cases, there will be diffuse redness; the zone and white line are not discernible; the cornea is opaque, with red vessels shooting over its surface; depositions of lymph take place between its lamina; and the patient's sufferings are commensurate. Such an attack ends in disorganization. A train of symptoms similar to those now detailed, should lead us to investigate the appearance of the iris, however slight these indications, or the person's sufferings may be. It is by examining the appearance and condition of the iris, that we can alone judge of the absence or presence of this disease. Impressed with this conviction, I called the attention of the reader to the imperative necessity of acquiring a familiarity with the diversified aspect of the iris. He ought to be conversant also with its contractionsthe extent, rapidity, and duration of these under different degrees of light. Without possessing himself of these, a practitioner will be often baffled in forming a decision, and will act from erroneous and detrimental conclusions.

On inspecting the iris, its colour if inflamed will be altered; this discoloration will depend on the natural colour, the degree and duration of the inflammation. As the change is produced by deposition of fibrine, an admixture of yellow with its colour in health may be anticipated, with a tinge of red. If the colour approached to that of green, it will become lighter mingled with yellow; if blue it assumes a greenish hue-if dark, it will exhibit a reddish tint. In cases where the tone of the inflammation is high, globules of lymph will be deposited of a yellow or amber-colour, usually three or four in number, and occupying in general the papillary margin; they may, however, form in the ciliary border, or on the surface. There is sometimes seen likewise a detached substance in the lower part of the anterior chamber, of different magnitudes, varying in bulk from a pin's head to that of a small pea, called hypopion. The earliest deviation in the motion of the iris, is that of sluggishness, unaccompanied by irregularity. This diminution in the brisk action of the iris may be partly owing to the injected condition of the part. This tardiness, and even a minor degree of irregular

ity, was ascribed to a state of turgescence of its vessels by Professor Graham, in a clinical lecture, and the opinion supported with much ingenuity. He conceived that its mobility may be impaired, and contraction rendered irregular from a loaded state of the vessels, before any change in the organization has occurred. Subsequently, it becomes irregular, contracts imperfectly or not at all; the pupillary margin becomes thickened, irregular, contracted, and drawn backwards; at times the aperture of the pupil is dilated, at others contracted; it is in the generality of cases diminished. The pupil may be divided by a band of lymph, a net-work may obstruct the opening, or a complete closure of the pupil may happen. Under any of these conditions, especially the latter, restoration of vision by medical treatment is very ambiguous, and the prognostication ought consequently to be guarded.

An interesting question as to the origin of the affection, and not devoid of importance to a practical inquirer, has received different solutions by different authors,-whether the disease ever exist in a sound state of the system, or is idiopathic; or follows or arises from a general morbid state of the body, specific or constitutional? I cannot assent to the opinion, notwithstanding the high authority that Mr Lawrence's name attaches to it, that iritis is never simple or idiopathic. It is seldom so; but the weight of medical testimony is in favour of the possibility of the existence of the uncomplicated form of the complaint. In the summer of last year, a case corroborative of the correctness of this opinion came under my observation.

A country man, æt. 24, of very robust frame, was attacked, after several hours exposure to wet, while his face was exposed to a penetrating wind, by inflammation of the iris, ushered in by the usual symptoms, and uncomplicated by inflammatory action in any other texture. It showed the characteristic marks of iritis in the most indisputable manner, and although measures were promptly and vigorously used, it ended in adhesion, and slightly permanent attraction of colour. This young man had not, I can attest, been the subject of syphilis, or rheumatism, nor had he any marks of strumous diathesis.

That syphilis, rheumatism, gout, scrofula, and mercurialism predispose in a peculiar degree, and in frequency in the order of their enumeration, to the affection, must, I think, be admitted. That it is a sequence of fever among the poor of Dublin, I have heard observed by a practitioner in that city. It may occur from punctured wound, or after extraction of cataract. The disease is, however, induced by secondary syphilitic action generally, and often co-exists with the syphilitic papular eruption, or the scaly eruption, sore throat, superficial ulcerations on the

soft palate of a venereal nature, in cases where mercury was administered ineffectually, or acted deleteriously during its exhibition. Mercury may be the sole exciting cause; in particular where the body has been under the severer influence of the mineral frequently. I have known it attributed to the use of the warm bath during mercurialism.

Having said so much relative to the nature and symptoms of this affection, I shall now detail the treatment. In this as in every other affection, we must be governed by circumstances, adopting means with a due attention to the character, the violence, and duration, of the inflammation, and the consequences that have already taken place; and attending in an especial manner to the state of the patient's health both during and previous to an attack. Observance of this caution is more deinanded in this than many other affections, being often the concomitant, or more correctly perhaps, the product of such an unsound and broken up state of body, as to call for the closest circumspection in the choice of measures; so as to control the disease by the least possible exhaustion of strength. The sovereign power of mercury in every case in which its administration is admissible is well known. The first step in the treatment is the free abstraction of blood, if the inflammation be acute, and the strength of the patient do not contraindicate its adoption. The intention should be that of producing a decided impression on the constitution; and the quantity of blood drawn must be proportioned to the accomplishment of this design. Any course of treatment without this preparatory step will be uncertain and injudicious. It lessens the local action, mitigates the general disturbance, and facilitates the curative operation of mercury. An acute attack may be destructive of vision in four or five days; and no time is to be lost in palliating means. The use of mercury is to follow immediately the abstraction of blood; it checks the action in the minute vessels, and prevents the inflammation from ending in adhesion. The sooner its effect is manifest of course the better.

Calomel and opium is in general use. The calomel and opium are to be given every third, fourth, and fifth hour; the calomel in doses of from three to five grains, until its constitutional influence is unequivocal. As soon as the mercurial action is established, the pain and intolerance of light abate, the red vessels disappear, the motion of the iris is restored, the absorption of lymph is set up, the clearness of the cornea is restored in cases in which it had participated, and the aqueous humour becomes transparent. Whilst this crisis is being brought on, the extract of belladonna is to be smeared over the superciliary region and round the orbit, night and morning. Many other

substances answer this end. Henbane is used by some; but the belladonna, either in form of extract round the eye, or in solution to the globe, has superseded every other. It dilates the pupil, and prevents the adhesion of the iris to the crystalline capsule; or if adhesions have formed they are elongated. It is supposed also to alleviate the pain, and with this view has been combined with opium; but this benefit is by no means certain. Topical applications are unavailing; local depletion by leeches or cupping may be highly advantageous in the course of the treatment. This treatment is applicable to an acute attack.

In the subacute cases there is not the imperative call for the full effect of bleeding, nor the very rapid introduction of mercury into the system. Leeching or cupping may be substituted for the general bleeding, if debility is apprehended, and the calomel apportioned in smaller doses, and given at longer intervals. In the chronic form of the complaint a month or six weeks is not an unusual period for its duration; when it assumes this moderate and protracted state of action, there is consequently less necessity for the adoption of the vigorous and prompt measures already specified. These, however, are to be followed at the discretion of the practitioner, and may be relied on as bringing about a favourable issue.

Cases will occasionally occur in which this treatment would be injudicious or even hazardous. They are rare, but too frequent to be overlooked. There are individuals who cannot bear mercury in any quantity or form. Where this idiosyncracy is known, or found to exist, mercury must not be given, or its use must be discontinued on the manifestation of any untoward symptoms. The mercurial rash may be excited by a few grains of the mineral. If this state of the system were likely to be produced, it would be very inconsiderate to run the risk of calling it into action, and to continue its use on the appearance of this affection would be highly culpable. Iritis now and then comes on in conjunction with syphilis, where mercury would, if given in efficient doses, be unsafe. The sort of cases to which I allude will be met in the persons of young men, of dissipated habits and broken up constitutions, with a tendency to tubercular deposition in the lungs, or strong evidence of its having already taken place. If mercury be given to check the iritis, it will be at the risk of exciting a fatal action in the chest. In those cases where it is accompanied by syphilitic eruptions, the blotches may degenerate into scabs, or phagedenic ulceration may ensue. The spirit of turpentine, as recommended by Mr Carmichael, I have seen used in cases such as I have described with entire success. Given to the extent of one or two drachms three times daily, I have witnessed a perfect cure. An alleviation was generally ex