7. When the extraction is finished, the assistant who draws the skin towards the inside of the joint, suddenly lets it go, when it returns to its natural situation. This causes the two incisions, which corresponded, at the time of the operation, to change their relative situation, the one remaining internal and the other becoming external. 8. Hence arises a twofold advantage; the entrance of air into the interior of the joint is prevented, and the external and loose portion of the capsule, being drawn inwards with the skin, unites with the condyl, if it be not brought into exact apposition with the other portion of the capsule, divided near its attachment. 9. The extraction being finished, it is then necessary to examine carefully, in order to ascertain whether or not the joint contain any more of these foreign bodies. On some occasions, when this is even the case, they cannot at the time be discovered. Desault himself was once deceived on this score, in consequence of which his patient was obliged to submit to a second operation. 10. The incision in the integuments is now united by means of adhesive plaster. Over this are laid compresses and a little lint, and the whole secured by a few turns of a roller drawn moderately tight. 11. The leg being then placed on a pillow, is kept in a state of extension, by means of a splint applied, for a few days, behind the joint. 29. If we examine but for a moment the process in this operation, we must perceive, that an incision made through the skin and capsule at a single stroke, is, in no respect, less advantageous than one made at two strokes, as recommended by all practitioners, and that, it is in the following respects greatly preferable to it: 1st, it shortens the operation very considerably: 2dly, it diminishes the pain: 3dly, it exposes the joint a much shorter time to the contact of the air. 30. The object of the operator is better answered by drawing the skin outward and towards the rotula, than by either depressing it, as Broomfield did, or raising it, as Bell does. Being more loose and more easily stretched in this direction, the opening in it is removed farther from that in the capsule, which prevents more certainly the access of air to the joint, and also favours the examination of the capsule. 31. In the mean time, the operation may succeed, even although the openings in the integuments and the capsule correspond to each other. Many English and German practitioners, without previously stretching and changing the natural situation of the skin, make a common incision, which they dress afterwards like a simple wound, and are yet no less successful than others in the result of their operations. This is a further proof of the fallacy of the ancient surgical doctrine, respecting the admission of air into the cavities of joints. Perhaps Desault might have omitted this precaution, had any operations of the kind occurred in his practice during the last years of his life.