This was the special claim set up by Aveling for his Sigmoid forceps. Tarnier also, in introducing his axis traction forceps to the profession in 1877 (for an account of which see _British Medical Journal_, May 26, 1878), proves by means of diagrams and figures that, “in pulling on the classical forceps, it is impossible to make the traction exactly in the line of the pelvic curve,” and that two forces are actually exerted—one in the direction of the inferior straight, and the other at right angles to this in the direction of the pubes, while the head tends downward in the pelvic curve—the resultant of these two forces. This “vicious pressure” upon the pubes represents not only so much force lost, but also tends to injure the maternal soft parts, and can only be overcome by using the axis traction forceps. As the head descends, the pelvic curves of the blades become less and less, until, as the head arrives on the floor of the pelvis, the forceps are nearly straight. At the moment the head sweeps over the perineum the blades are still further deflected, until they form an angle with the shafts, as shown in the dotted lines of Fig. 1, thus forming the perineal curve of Herman's, Aveling's and Tarnier's forceps. 2. These forceps give the greatest permissible freedom of movement to the head during traction. By the loose connection of the blades each possess a degree of independent movement, but always in a plane parallel to the other, so that the head may rotate during traction. The carrying out of this important principle is the chief advantage of this instrument over all other axis traction forceps. 3. An index is supplied by the arms and pin, which serves to indicate the advance and position of the head. The application of Breus' forceps is in no wise more difficult than that of the ordinary instrument. Having disinfected, warmed and lubricated the blades, and the patient being prepared by an irrigation of a solution of bichloride, one part in 2,000, and placed in the lithotomy position, the handle of the left blade is taken up by the thumb and three fingers of the left hand (as one would hold a fiddle bow), the index finger pressing the projecting arm firmly against the shaft, as the thumb of the right hand guides the blade forward in the groove between the index and middle fingers introduced into the vagina. The right blade is then introduced in a similar manner and locked, and the pin inserted in the eyes of the projecting arms. The traction is made upon the handles in the axis of the brim, without changing its direction until the head presses on the perineum. Prof. Braun prefers, at this point, to remove the forceps and complete the delivery in the ordinary way.