CASE 540.—Private G. W. Perkins, Co. G, 1st Massachusetts Cavalry, aged 22, was wounded at Beverly Ford, June 9, 1863, by a pistol ball, which entered the left knee at the lower outer edge of the patella, passed downward, and came out over the head of the fibula. Three days after the reception of the injury he was admitted to Douglas Hospital, Washington, where he was etherized and an incision made to examine the wound, when the head of the tibia was found to be grazed and the joint opened, allowing synovia to escape on motion of the limb. Ice-water dressings were applied for a couple of days. It was then resolved by Assistant Surgeon W. Thomson, U. S. A., in charge of the hospital, to lay the knee joint freely open by means of liberal incisions on either side of the patella and through the original track of the wound. By this means it was hoped to give free exit to pus, which was already filling the joint, and to save the limb with anchylosis, the operation being adopted as the only alternative to amputating the thigh. A large quantity of bloody pus and synovia escaped when the lateral incisions were made; two or three cutaneous vessels were tied, and by means of a syphon the limb was kept constantly under the effect of ice water. The patient, though having some fever and retention of urine, had very little pain in the knee and felt comfortable. Morphia and sweet spirits of nitre were prescribed. On June 17th, there was some fluctuation along the base of the internal condyle, for which a free horizontal incision was made, and flaxseed poultices were applied. All the incisions about the knee continued to discharge freely. About one week later an erysipelatous swelling was noticed, a deep-seated abscess having apparently formed and fluctuation being detected below the head of the tibia. A large quantity of pus was then liberated by a careful dissection, and the painful tension of the leg was thereby relieved. On June 26th, the patient had a severe chill for the first time, and his stimulants were at once increased and quinine and capsicum added to the prescription of morphia. On the following day the fever had disappeared, but pneumonic symptoms were detected, and a mustard plaster was applied over the left chest. Suppuration still continued freely from all the openings. On the morning of July 1st, a large amount of arterial blood was found to have escaped through the incision along the gastrocnemius muscle, and compression was at once made in the groin and the wound was cleaned out carefully, the source of the bleeding being apparently the anterior or posterior tibial artery near the bifurcation, and too deeply seated to be reached without careful dissection. Meanwhile the patient, already moribund, was stimulated, but without avail. He died within a half hour, from the immediate effects of the hæmorrhage. At the autopsy a diffused abscess was found following the course of the vessels in the popliteal space into Hunter's canal but not otherwise involving the thigh; all the connecting tissue in the ham was in a sloughing condition. When the artery was dissected out the perforation was found in the anterior tibial, about three-fourths of an inch from its origin, the vessel being much thickened, soft, and tough, though not materially diseased. The left lung was found firmly adherent and much congested. The bones comprising the injured knee joint were contributed by Dr. Thomson (Cat. Surg. Sect., 1866, p. 323, Spec. 1339), and the history of the case was furnished by Assistant Surgeon C. C. Lee, U. S. A.