1. Few kinds of luxation of the os femoris occur in practice more rarely than this. Practitioners who have seen it, and those who, on the authority of others, have described it, without having seen it, have all given an unfavourable prognosis respecting it, for the following reasons: 1st, on account of the inevitable rupture of the round ligament: 2dly, on account of the distension, and even laceration of the capsule, and of the compression and overstretching of the nerves and blood-vessels: 3dly, on account of the great difficulty of reduction. The following case will prove, that in all these respects, the apprehensions of authors have been exaggerated, that the obstacles to reduction arise less from the nature of the displacement, than from the nature of the means employed to remedy it; and that, if properly directed, art would here be as successful as in other cases. CASE. (Collected by C***). About the close of the winter which preceded the death of Desault, a porter was brought to the Hotel-Dieu, in consequence of a fall which he had received about two hours before, in the following manner. As he was carrying on his shoulders a heavy burden, his foot slipped, while his leg and thigh were directed backwards: he fell on his knee, his thigh maintaining still the same direction; so that the conjoined weight of his own body and of the burden which he carried, aided by the velocity of the fall, forcing the head of the os femoris, which pointed at the time forward and upward, against the distended capsule, lacerated it and drove the articulating end through the opening. Continuing still to act, it ruptured the ligament, which connects the extremity of the bone to the articulating cavity, and forced the head in front of the os pubis, where it could be easily felt. At the moment of the fall, an acute pain was felt in the part; and the power of moving the limb was suddenly lost; the patient was carried home, where a surgeon who visited him, considered the accident as a fracture of the neck of the os femoris, and sent him to the Hotel-Dieu, to undergo the necessary treatment. Desault having examined the parts, discovered, from the following appearances, not a fracture, but a luxation upward and forward. The limb was nearly an inch shorter[31] than natural; the point of the foot was turned outwards; the thigh being in a state of painful extension, could not be flexed on the body; adduction and abduction were alike painful; the great trochanter, being more approximated than usual to the anterior and superior spine of the os ilium, was also too far forward; finally, the projecting head of the bone could be felt, as I have already said, in the groin.