CASTRATION BY CLAMS. 



209 



apt to occur in consequence of the sharp edges. The clams are 

 either half round in section, or the flattened crushing surface is 

 exxavated, allowing greater pressure to be exerted on the narrower 

 surfaces left. The latter form deserves preference. The central ex- 

 cavation is often filled with some 

 caustic, like sulphate of copper, red 

 precipitate, or sublimate and flour 

 paste. The reason for using caustics 

 was to ensure complete necrosis of 

 the portions enclosed within the 

 clams, but it is better to use a dis- 

 infectant, which prevents decompo- 

 sition in the necrotic portion of the 

 cord, and infection of the neighbour- 

 hood. 



Moller recommends a concen- 

 trated solution of sublimate in gum 

 arable mucilage, painted two or three 

 times over the pressure surfaces of 

 the clams. Schlammp first applies 

 to the clams a strip of gauze, satu- 

 rated with sublimate solution, which adheres firmly on dr3'ing 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 dis- 

 infectants, however, and increases the intensity of the pressure, inas- 

 much 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. 240. 



Fig. 239. — Iron clams. 



Fig. 240. —Forceps for closing wooden clams. 



Should no reliable assistant be available for holding the forceps 

 whilst the operator ties the clams, the forceps may be provided with a 

 catch near the base, in which case they may also, in case of emergency, 

 be used as "bull-dogs." The screw instrument (Fig. 241) permits 

 the operator to dispense with assistants. Iron clams (Fig. 239) are 



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