amputation, Baron Larrey has directed an incision to be previously made into the part, and to this there can be no objection. When a large shot or other solid substance has injured a limb to such an extent only as admits of the hope of its being possible to save it, this hope is sometimes found to be futile, at the end of three or four days, from a failure of power, in the part below the injury, to maintain its life for a longer time: mortification is obviously impending. In military warfare, uncontrollable events often render amputation unavoidable in such a case. Under more favorable circumstances, the surgeon should be guided by the principle laid down of _constitutional_ and _local_ mortification; and, although the line cannot perhaps be distinctly drawn between them at the end of three, four, or more days, it will be better to err on the side of amputation than of delay. If the limb should be swollen or inflamed to any distance, with some constitutional symptoms, in a doubtful habit of body, the termination will in general be unfavorable, whichever course be adopted, more particularly if the amputation must be done above the knee. The consideration of the circumstances in which the patient is placed, his age, and habit of body, should have great weight in forming a decision in the first instance, as to the propriety of attempting to save the limb, which ought only to be done in persons of good constitution and apparent strength. 28. Whenever the main artery of a limb is injured by a musket-ball, mortification of the extremity will frequently be the result, particularly if it be the femoral artery; it will be of certain occurrence if both artery and vein are injured, although they may not be either torn or divided. There may not then be such a sudden loss of blood, in considerable quantity, as to lead to the suspicion of the vessel being injured. The fact is known from the patient’s soon complaining of coldness in the toes and foot, accompanied by pain, felt especially in the back part or calf of the leg, or in the heel, or across the instep, together with an alteration of the appearance of the skin of the toes and instep, which, when once seen, can never be mistaken. It assumes the color of a _tallow candle_, and soon the appearance of _mottled soap_. Although there may be little loss of temperature under ordinary circumstances of comfort, there is a feeling of numbness, but it is only at a later period that the foot becomes insensible. This change marks the extent of present mischief. The temperature of the limb above is somewhat higher than natural, and some slight indications of inflammatory action may be observed as high as the ham, and the upper part of the tibia in front; it is at these parts that the mortification usually stops when it is arrested. The general state of the patient, during the first three or four days, is but little affected, and there is not that appearance of countenance which