_Inflammation of the Cornea_ supervenes on simple conjunctival inflammation, and frequently on the purulent. The vessels of the part, both veins and arteries, previously carrying single and therefore invisible blood corpuscules, become much dilated, are filled with numerous globules, and hence are rendered red and conspicuous to the unassisted eye. Writers on ophthalmic surgery, in their rage for refinement, speak of three kinds of this inflammation—inflammation of the external or conjunctival covering, of the middle tunics or cornea propria, and, lastly, of the third coat, the capsule of the aqueous humour: such distinctions, however, are found to effect no good practical end, and it is unnecessary to follow them. One particular layer of the cornea may be first attacked, but the whole structure soon becomes involved. The inflammation generally commences in the conjunctival covering. Vision is necessarily much obscured from even slight inflammatory affection of the cornea. Part only of the organ may be affected, but frequently the whole is involved. Sometimes only one or two vessels remain dilated; but still they, passing over the centre of the cornea, render vision indistinct. Opacity of the cornea, to a greater or less degree, always attends dilatation of its vessels. In inflammation of the internal and middle tunics of the cornea, most of the enlarged vessels which traverse it are seen to be continuations of those that ramify in the conjunctival covering; while the anastomotic vessels derived from the sclerotic coat are smaller and less apparent than those of the conjunctiva. The cornea, and the sclerotic immediately surrounding it, frequently appear to be almost entirely covered with meshes of their dilated capillaries. At first the whole cornea has a clouded appearance, but as the disease advances portions become distinctly opaque, and at these points either lymph or pus is effused. Sometimes matter collects between the laminæ, distends them, and, causing ulceration, discharges itself either into the anterior chamber or externally. Inflammation of the cornea arises frequently from lodgement of a foreign body in it: and ulcers of it are often produced by a similar cause. If the extraneous matter is not removed soon after its insertion, nature commences her endeavours to detach it, and the process employed is ulceration. Sometimes, however, a sac is formed around the foreign body as in other parts, and no ulcer is produced.