Castration by clams. 



191 



an interval of twenty-four to forty-eight hours or longer the clam 

 is removed. 



In the second method, which is known as the " covered operation," 

 the coverings of the testicle — skin, dartos, and fascial layers — outside 

 the tunica vaginalis reflexa (or tunica vaginalis scroti) are carefully 

 divided, and then separated by stripping from the testis and cord 

 as high as may be required. The clam is applied to the cord above 

 the epididymis and over the parietal serous covering (tunica vaginalis 

 reflexa), and secured as above described. The testicle with the lower end 

 of the cord is removed with scissors or a knife ; the clam is left in 

 position for twenty -four to forty-eight hours, and in cases of hernia 

 it is advisable to allow the clam to fall off. 



The clams should be made of 

 hard, tough, light wood (elm, 

 boxwood, oak, ash, or hickory), 

 and their edges should be well 

 rounded to prevent injury to the 

 surface of the cord. The internal 

 or pressure surfaces may be flat 

 or grooved, and either undressed, 

 or medicated with caustic or anti- 

 septic pomade, containing copper 

 sulphate, arsenious oxide, zinc 

 chloride, or corrosive sublimate. 

 Sometimes the pressure surfaces are 

 coated with oil of tar and sprinkled 

 with finely powdered mercuric 

 chloride. 



Moller recommends a concen- 

 trated solution of sublimate in gum 



arabic mucilage, painted two or three times over the pressure surfaces 

 of the clams. Schlammp applies to the clams a strip of gauze 

 saturated with sublimate solution ; the gauze adheres firmly on drying 

 and greatly facilitates removal of the clams after operation. 



The furrow on the pressure surfaces of the clams was probably 

 first used with the idea of preventing the clams slipping off, an object 

 which, without doubt, it fulfils. It also facilitates the application of 

 disinfectants, however, and increases the intensity of the pressure, 

 inasmuch as it concentrates it on a narrower surface. 



Various forceps and screws have been constructed for closing 

 the clams, but the instrument most commonly used is shown 

 in Fig. 236. 



Fig. 238. — Iron clams. 



