As it has an historical interest, and as this operation (defective as it is) had been the means of saving many legs prior to the invention of amputation at the ankle-joint, a brief description may be appended:-- Chopart's own manner of operation was briefly somewhat as follows:-- The tourniquet having been applied, the surgeon is to make a transverse incision through the skin which covers the instep, two inches from the ankle-joint. He is to divide the skin, and the extensor tendons, and the muscles in that situation, so as to expose the convexity of the tarsus. He is next to make on each side a small longitudinal incision, which is to begin below and a little in front of the malleolus, and is to end at one of the extremities of the first incision. After having formed in this way a flap of integuments, he is to let it be drawn upwards by the assistant who holds the leg. There is no occasion to dissect and reflect the flap, for the cellular substance connecting the skin with the subjacent aponeurosis is so loose, that it can easily be drawn up above the place where the joint of the calcaneum with the cuboides and that between the astragalus and scaphoides ought to be opened. The surgeon will penetrate the last the most easily, particularly by taking for his guide the eminence which indicates the attachment of the tibialis anticus muscle to the inside of the os naviculare. The joint of the os cuboides and os calcis lies pretty nearly in the same transverse line, but rather obliquely forwards. The ligaments having been cut, the foot falls back. The bistoury is then to be put down, and the straight knife used, with which a flap of the soft parts is to be formed under the tarsus and metatarsus, long enough to admit of being applied to the naked bones, so as entirely to cover them. It is to be maintained in position with three or four straps of adhesive plaster, etc.[37]