_c._ These two flaps are united over the vertical meridian of the cornea by sutures, three generally being sufficient. This entirely hides the cornea for a time, but eventually shrivels and contracts, and the remnants are to be cut off with scissors three weeks after the operation. PUNCTURE OF THE CORNEA.--_Paracentesis of the Anterior Chamber._--_Tapping of the Aqueous Humour._--This very simple operation is in many cases extremely useful. In cases of corneal ulcer, the result either of injury or disease, where there is much pain in the bone, and evidence of tension of the globe, it gives great relief, and when repeated at short intervals greatly hastens a cure. Sperino of Turin recommends its frequent use in cases of chronic glaucoma. _Operation._--The surgeon stands behind the patient, who is seated; the lids being fixed, the upper by the surgeon's left hand, and the lower by an assistant, the cornea is punctured a little in front of the sclerotic margin, either with a broad needle, or, what is as good, a well-worn Beer's knife. Care must be taken on entering the knife, on the one hand, not to wound the iris, which is sometimes arched forwards in the cases of commencing glaucoma, and, on the other, fairly to enter the anterior chamber, not merely split up the layers of the cornea. On withdrawing the cataract knife, the aqueous humour gets out by its side, aided by a slight turn of the knife, sometimes with great force, and in much larger quantity than usual. If the operation has been done by a needle, a blunt probe requires to be introduced on the removal of the needle. Once punctured, the remarkable fact is that the same wound suffices for many succeeding tappings, which are effected by pressing the probe into the wound day after day, sometimes several times a day, with great relief to the symptoms. If the probe is to be used for succeeding evacuations, the operator must be careful to remember the exact spot at which the needle or knife was entered. To facilitate remembering it, it is best, when nothing prevents it, to operate always in the same spot. Sperino chooses the horizontal meridian of the cornea at the temporal side, at the junction of the cornea and sclerotic. CATARACT OPERATIONS.--Here we cannot enter into any discussion of the pathology of cataract and the varieties of it. Enough for our purpose to know that the lens is in some cases hard, in others soft, and that thus in the latter it may be removed piecemeal, and by a small incision, while in the former, removal must be almost entire, and by a larger opening. In cataract, the lens, which should be transparent, has become opaque, and the object of treatment is to get it out of the line of sight, to prevent it from obstructing, now that it can no longer assist sight. The operations used for this end may be classed under three heads:--