[20] Klinische Monatsblätter für Augenheilkunde, 1869, p. 431. Galezowski,[21] in 1875, published a somewhat similar method in which he used his falciform knife, _aiguille-a-serpette_ (Fig. 16), which he introduced through the cornea and iris-membrane, making either a horizontal or a vertical incision, with a “go-and-come” (sawing) movement, after the suggestion of Adams. If this single cut was not sufficient, he made a linear incision of the cornea with a Graefe knife, drew out the iris and cut it off with scissors. By a process of evolution, however, he perfected the former procedure and eliminated the scissors. This latter method was published in the third edition of his book in 1888. He punctured the cornea and iris-membrane with the sickle-shaped knife, making first a horizontal incision by the sawing movement of Adams, and finishing with a second cut in the vertical direction, thus forming a T-shaped incision. In actual practice, however, he almost always prolonged this second cut, thus making a crucial incision after the manner of Guérin.[11] [21] Galezowski, Xavier: Maladies des Yeux, 2d. ed., Paris, 1875, p. 401, and 3rd. ed., Paris, 1888, p. 384. The writer,[22] in 1888, was led to devise an operation with a modified Hays knife-needle, in which through a corneal puncture he made a converging incision in the iris-membrane which resembled an inverted V. The resulting pupil opened up and formed either a triangular or an oval-shaped pupil depending on the degree of stiffness or resiliency of the iris-membrane. This method will be described in detail later on. [22] A brief description of the author’s method, written by him, was first published in de Schweinitz on Diseases of the Eye, Philadelphia, 2nd. ed., 1896, p. 607. II. SCISSORS METHOD. We will now return to the consideration of the second school in which scissors were introduced through a previously made corneal section and a free incision was made in the iris-membrane, or a portion of the membrane excised. [Illustration: Fig. 17.--Wenzel’s cataract knife, and method of incision (after Mackenzie).] Janin,[10] in 1768, having abandoned the procedure of Cheselden, proposed a new method. He incised the cornea below as for cataract extraction, and raised the corneal lip with a spatula while he introduced a pair of curved scissors, the lower blade of which was pointed. He plunged this sharp blade through the iris-membrane, and with a single vertical cut made a crescentic pupil which gaped sufficiently for visual purposes. As this is the first known description of iridotomy by the scissors method it is probable that Janin was the originator of this procedure.