_Of Inflammation and Abscess of the Lachrymal Passages._—In former times, all affections of the lachrymal passages, and of the parts in the neighbourhood, were denominated fistula lachrymalis, and were all treated nearly in the same manner, by opening the sac, and inserting probes, knives, terebræ, scalpra, caustics, and red-hot irons; the anatomy of the various parts being then ill understood, and the opinions as to the origin and nature of the diseases being founded on erroneous theories regarding the defluxion of acrid humours, formation of imposthumes, fungous growths, &c. The term, however, which was indiscriminately applied to all diseases in the inner corner of the eye, accompanied with derangement of the lachrymal secretion, is now confined to a distinct form of disease, as will afterwards be mentioned. Inflammation sometimes occurs in the loose cellular tissue covering the lachrymal sac,—whilst that cavity remains free of all disease,—and is attended with some obstructions to the passage of the tears in their natural course, on account of the eyelids becoming swollen, from an extension of the inflammation. The morbid action resembles erysipelas in its nature, and usually terminates in unhealthy suppurations; thin purulent matter lodges in the opened out cellular membrane, a soft boggy tumour is formed, and the superimposed integuments become of a bluish colour, as in the case of other scrofulous collections. Though the affection is at first unconnected with the lachrymal sac, this organ may ultimately be involved. It may become the seat of a like unhealthy inflammation, and matter may consequently form within its cavity; or, on account of the pressure of interstitial deposit around, the parietes of the sac may ulcerate before the abscess of the cellular tissue in front has discharged externally. Thus, the cavities of the lachrymal sac, and of the external abscess, will communicate with each other. If, after an external aperture has been made either by nature or by art, any doubt exist as to whether the sac is involved or not, such doubt will soon be removed by dexterous use of the probe.