In this method of castration the cord is twisted with sufficient force to cause it to break of itself at the point of the greatest violence. Its design is to accomplish the removal of the testicle without dragging or excessive traction upon the cord, and thus to avoid the hemorrhage following the torsion of the spermatic artery, as a mode of hemostasis sufficient to prevent the flow of blood attendant upon the rupture of the cord. The operation may be performed either above or below the epididymis, or may consist simply in the torsion of the artery alone. At first the hands only were called upon to act in the manipulations, and the operation was from this cause known as _free torsion_, until about fifty years ago, when instruments were introduced into general practice, and gave rise to the plan of _limited torsion_. FREE TORSION. _Free torsion_, or that in which the hands alone are employed in the operation, may be performed, as before stated, either above or below the epididymis. _Above the Epididymis._--The first is one of the oldest modes of castration known; one which must have been practiced contemporaneously with the use of clamps, or in the first age of surgery. The first steps of the operation required for the exposure of the testicles are the same as have already been detailed. When this is accomplished the steps of torsion and rupture are then performed in the following manner: The operator, grasping the testicle, carefully draws out the spermatic cord, and with a pointed bistoury makes a transverse incision, above the tail of the epididymis, through the posterior septum of the cord, involving what we know as the white muscle of Bouley, the efferent canal, and the small testicular artery. He then seizes the anterior fasciculus of the cord between the thumb and index finger of the left hand, squeezing it as tightly as possible, and having with the other hand secured the cord at a short distance below the point where the left hand has already been placed, performs the torsion by a rotatory movement given to the testicle itself, the motion having for its result the twisting and tearing of the cord when long enough continued to overcome the tenacity of its fibres. Fifteen or twenty turns of the organ will usually be found sufficient to effect the rupture. A considerable degree of strength in the fingers is required in this movement, and for this reason the torsion may take effect further up than may be desired, and beyond the point designed, which may result in an unnecessary amount of irritation and injury. When the torsion has gone so far that the rupture of the cord has been effected, the stump is released, and retracts in the inguinal canal to a certain height limited by the presence of the posterior septum, which holds it in place, and to a great extent prevents its return through the superior orifice of the inguinal canal.