CASE II. Vincent Grenier, aged thirty-eight, making a false step, fell on the rotula, and fractured it, on the 6th of June, 1791: he was brought to the Hotel-Dieu, where Desault demonstrated to his pupils, by the usual signs the existence of the disease: a considerable swelling had already taken place. The bandage formerly described was applied: the same precaution as in the preceding case; apparatus examined every day; renewed as often as relaxed; extension maintained with great exactness. On the forty-fifth day, the consolidation was nearly effected; on the fifty-second it was complete, the joint was exercised for some time, and on the seventy-seventh day the cure being in all respects complete, the patient was discharged. MEMOIR XIV. ON THE FORMATION OF FOREIGN BODIES IN THE JOINT OF THE KNEE. 1. The history of foreign bodies divides itself naturally into two great sections; the one includes those that are introduced from without; the other such as are formed within our own systems. This latter section may be again divided into two classes; to the first class belong bodies altogether inorganic, such as the different kinds of stones; to the second, those which are truly organic, and become foreign only by being situated in places where they impede the functions, such as cartilaginous or bony productions, existing accidentally within the joints. On the subject of the latter class, art is much more deficient than she is with regard to the former. Let us endeavour to assist her a little, by giving a sketch of the opinions and practice of Desault with respect to these productions. 2. Before his time, the surgery of France appears to have contained scarcely a record of this affection. Described only in some ancient works, such as the writings of Pare, it had been forgotten by the moderns, when numerous instances of it were suddenly met with by English and German surgeons, and soon afterwards by Desault, who illustrated and confirmed the practice of his predecessors in it, and even added something of his own. 3. All the joints may become the seat of these concretions; Haller found many of them in that of the lower jaw; Bell mentions, as a very rare occurrence, their existence at the junction of the foot with the leg. Some authors have met with them in the wrist; but none are more common, or merit more particular attention, than those that exist in the joint of the knee. To these alone shall the following observations be confined, because these alone have fallen under the notice of Desault. § II. OF THE VARIETIES.