This consists in crushing the spermatic cord with a hammer, the vessel continuing, meanwhile, to be covered with its envelopes. It was first described in the year 1826, and is most commonly practised in some French districts. The instruments used are two cylindrical pieces of wood, each about one yard in length and two inches in diameter; and a hammer or mallet formed of hard and heavy wood. The animal being properly secured in the standing position, the testicles being drawn well down into the bottom of the envelopes, the sticks are placed, one behind and one in front of the cord, close to the upper extremity of the gland. When in that position they are moved in such a manner that instead of remaining, one in front of the other, one becomes so superimposed upon the other that the spermatic cord becomes twisted in the form of the letter S (Fig. 15). While held together in this position by an assistant, the operator, placing himself in front of one side of the hind quarter, with repeated blows of the hammer or mallet, crushes the cord at the point where it rests upon the wood which occupies the inferior position, of course guaging the force and frequency of the blows by the effect observed, until the crushing of the organ is satisfactorily accomplished. As a measure of caution, it will be well, upon the completion of the process of crushing, to surround the cord with a ligature moderately tightened, in order to guard against the drawing up of the cord into the inguinal canal, an accident not likely to occur, however, if the operation has been well performed. [Illustration: FIG. 15. CASTRATION BY CRUSHING OF THE CORD.] DOUBLE SUBCUTANEOUS TORSION; BISTOURNAGE. In this mode of operating, principally in vogue in the southern parts of France, the position of the testicle is so changed that its lower extremity is made to take the place of the upper, the cord is subjected to a certain degree of torsion, and then the testicle is restored to its normal position, to undergo a process of atrophy which destroys its power of secretion by a physiological action. The great length of the cord and the greater laxity of the cellular tissue situated between the dartos and the fibrous coat, render this operation much easier in the ruminants than in the solipeds. Simple in its manipulations, although still involving a certain degree of dexterity, and followed by comparatively no symptoms of reactive fever, the only instrument necessary for its performance is a piece of cord, twine, or rubber, sufficiently strong to secure the testicular envelopes when the gland has been subjected to the double displacement, and the cord to the torsion it has undergone. In this operation, no special preparation being demanded, the animal is usually treated on his feet.