628 DISEASES OF THE BLADDER, ETC. 



purpose very well ; tliey should, however, he provided with a 

 lohalebone stillet, the wire ones usually provided heing apt to 

 hend upon themselves, and remain in the hent position when 

 the point of the catheter reaches the ischiatic arch. When the 

 instrument has reached the symphysis pubis, the stillet must be 

 withdrawn, in order to allow the catheter to pass easily along 

 the pehdc floor. 



The catheter having reached its destination, an incision is to 

 be made upon it, at the perinseum, so as to freely expose the 

 interior of the urethra, and to bring the catheter fairly and 

 clearly into view. The catheter being withdrawn, the smaller 

 forceps is to be introduced into the urethra, and by a ghding 

 motion pushed into the bladder. Some little difficulty is 

 generally experienced in doing this, from the fact that the 

 sphincter vesicae contracts pretty firmly upon the instrument ; 

 the operator must therefore exercise a little patience, or the 

 parts may be torn by a forcible introduction. 



Many writers describe lithotomy as a very complicated opera- 

 tion, and that it must be performed by various cuttings with 

 long-bladed bistouries, guided by " directors," &c., and Professor 

 Dick used to say that it was necessary to take up the pudic 

 artery ; but none of these are requisite, one free incision, suffi- 

 ciently large to admit the forceps, is all that is required. I 

 have operated in this manner, both for the stone, and experi- 

 mentally, before my class repeatedly, and always successfully. 

 It is advisable that the forceps be warmed and dipped in oil 

 before it is introduced, as the sensation of cold causes the 

 sphincter of the bladder to contract with some force, and its 

 introduction to be a matter of difficulty. 



The operation of cutting for the stone is called lithotomy; 

 that of crushing the stone without cutting, lithotripsy ; and that 

 of boring or rubbing the calculus, in order to reduce it to powder, 

 lithotrity. These two latter methods are inapplicable, except in 

 the mare ; but it may be necessary to crush the stone in the 

 hors3 before removal, and, in such a case, the operation would be 

 a combination of lithotomy and lithotripsy. 



Provided the stone cannot be grasped whilst the horse is upon 

 his side, he must be placed upon his back, care being always 

 taken that the hand in the rectum sliall guide the stone into the 

 forceps. 



