In Hutchinson’s list of eye diseases which occur in association with rheumatism and gout there is a history of gonorrhœa in twenty-six cases, syphilis in seventeen, of both gonorrhœa and syphilis in six. Herpes occurred in two, pustular acne in one, eczema in one, albuminuria in one, ague in one. Bad teeth are reported in two. In all the total was fifty-seven cases out of 117 (48·7 per cent.) in which there was a possible source of infection. It is probable that this percentage would have been materially increased if at that time it had been recognised how great is the influence of pyorrhœa and other sources of infection in the etiology of irido-cyclitis. With regard to all infections it is only in the present day that full advantage is taken of bio-chemical and bacteriological methods of differentiation. How frequently the true origin of disease must have been overlooked when the pallid spirochæte was unknown, when the Wassermann test was not applied, and when the complement fixation test for gonorrhœa was not recognised. With regard to a combined cause it has been maintained that gonorrhœa is always more severe in the gouty than in other people, and it may be that the more intense the gonorrhœa the more likely may it be to produce constitutional symptoms, of which iritis is one. In all such the combination of gout and iritis would indelibly impress upon the mind of the surgeon the intimate association of joint and eye. It was long ago recognised that many forms of joint disorder were associated with iritis, and, as the cause of the arthritis was not always gout, Mackenzie introduced the generalisation “arthritic iritis.” “Not being able,” he tells us,[50] “to determine the diathesis which predisposes to this ophthalmia” (iritis), “I use _arthritic_ as a conventional term, without adopting it in the strict sense of gouty.” The expression is well worthy of retention for the reason that it warns us to be prepared for an attack of iritis in many forms of arthritis and arthralgia. In the following articular diseases the triad joint, muscle and nerve disorders is not uncommonly linked with iritis:— Tuberculous arthritis; Syphilitic arthritis; Gonococcal arthritis; Certain forms of specific arthritis: malarial, dysenteric, etc.; Infective arthritis of undifferentiated type, as yet unaffiliated to specific germs. In the following forms of arthritis iritis is less common:— Acute articular rheumatism; Acute gout; Osteoarthritis (hypertrophic); Rheumatoid arthritis (atrophic). Iritis occurring in these last suggests the possibility of error in the diagnosis of the putative parent disease. Especially is the clinical similarity of gonorrhœal (polyarticular) rheumatism to rheumatoid arthritis to be borne in mind.