20. In making incisions for the removal of balls in the vicinity of large vessels, particularly in the neck, the hand should always be unsupported, in order to prevent an accident from any sudden movement of the patient. This caution is the more necessary on the field of battle, where many things may give rise to sudden alarm. At the affair of Saca Parte, near Alfaiates, in Portugal, I stationed myself behind a small watch-tower, and the wounded were first brought to this spot for assistance. A howitzer had also been placed upon it, being rising ground, and at the moment I was extracting a ball situated immediately over the carotid artery, the gun was fired, to the inexpressible alarm of surgeon, patient, and orderly, who bolted in all directions. From my hand being unsupported, no mischief ensued, and the operation was completed as soon as all had recovered their usual serenity. When a ball is discovered on the opposite side of a limb, through which it has nearly penetrated, but has not had sufficient power to overcome the resistance and elasticity of the skin, it should be removed by incision. An opening is thus obtained for the evacuation of any matter which may be formed in the long track of such a wound, and any other extraneous bodies are more readily extracted. When a ball has penetrated half through the thick part of the thigh, in such a direction that it cannot readily be removed by the opening at which it entered; or, from the vicinity of the great vessels, it may be considered unadvisable to cut for it in that direction; or if the ball cannot be distinctly felt by the finger through the soft parts, it ought not to be sought for at the moment, for an incision of considerable extent will be required to enable the surgeon to extract it. Much pain will be caused, and higher inflammation may follow than would ensue if the wound were left to the efforts of nature alone, by which, in time, the ball would in all probability be brought much nearer to the surface, and might be more safely extracted. It frequently happens, that after a few days or weeks, a ball will be distinctly felt in a spot where the surgeon had before searched for it in vain. A wound will frequently close without further trouble, the ball remaining without inconvenience in its new situation; and the patient not being annoyed by it, does not feel disposed to submit to pain or inconvenience for its removal. A very strong reason for the extraction of balls during the first period of treatment, if it can be safely accomplished, is, that they do not always remain harmless, but frequently give rise to distressing or harassing pains in or about the part, which often oblige the sufferer to submit to their extraction at a later period, when their removal is infinitely more difficult; and may be more distressing than at the moment of injury.