60. If the luxation be consecutive, then the first extension made in the direction of the displaced bone, is intended to bring its head into the place where it was primitively lodged, in order that it may be afterwards acted on as if it were a case of primitive luxation. It is oftentimes only at the moment of reduction, that it is practicable to ascertain to which kind of luxation the accident belongs. Indeed, as in most cases, the reduction takes place of itself when the extensions are well executed, if the head be consecutively drawn inward, it is seen to descend along the internal part of the scapula, till it arrives near to the inferior part of that bone, and then to reascend towards the rupture in the capsule through which it passes into its natural situation. 61. I have said that when the extension is properly made, the reduction takes place almost spontaneously. Indeed whatever may be the kind of primitive luxation, it is evident, that the muscles surrounding the articulation must be stretched on one side, while they are relaxed on the other; whence there will necessarily arise a change both in their contractions, and in the direction of these contractions, and such is the nature of this change, that, in case the muscles act, instead of bringing the head towards the rupture in the capsule, they will draw it in another direction, and by that means produce a consecutive luxation. 62. But, if the extensions render the muscles straight, and restore to them their primitive direction, then, obeying their natural irritability, which is still further increased, by means of the extension, they will draw the head to the rupture in the capsule, and force it to re-enter it, with much more certainty than this can be done by the efforts of the surgeon, who is always ignorant of the precise situation of this rupture. On the other hand, if the extension be not judiciously made how can it restore to the muscles their natural direction? In such a case, the head of the bone will be drawn towards some other part of the capsule than that where the rupture exists, and hence, the difficulties that so frequently occur, in reducing luxations of the humerus. 63. From these circumstances it follows; 1st, that the whole art in the treatment of luxations, consists in giving to the extending powers a proper direction; 2dly, that, in general, the process of conformation is unnecessary and useless; 3dly, that to reduce a luxation is not to replace the head of the bone in its cavity, by force, but to restore the muscles to such a state, as to enable them to replace it. Here, therefore, as in every other case, art is only the minister and handmaid of nature.