102 



applying the lateral disruptive force of the electrical discharge to the 

 disintegration of calculi in the bladder. There can be no difficulty 

 in bringing the end of a gutta percha catheter, conveying two cop- 

 per wires, in contact with the surface of a stone in the bladder, and 

 a very simple mechanical contrivance will enable the extremities of 

 the platinum wires to be protruded when the end of the catheter 

 touches the calculus. By employing two wires, one connected with 

 the positive, the other with the negative, portion of the jar or ma- 

 chine, not only is the intensity of the discharge increased, but the 

 body is also prevented from forming any part of the circuit, and the 

 risk of injury thereby materially diminished. The bladder used in 

 the above-mentioned experiments was not at all injured, and on re- 

 taining a portion of it between the platinum wires so that the dis- 

 charge passed through it, no perforation or other destructive effect 

 took place. The gutta percha tubes, having the projecting platinum 

 wires, were placed in the mouth without being in contact with the 

 lips, and a discharge sent through the wires, but there was no per- 

 ceptible shock. When, however, the bladder containing the stone 

 rested upon the hand, during the act of disintegration a smart im- 

 pulse was felt. 



On the whole, I am of opinion that the electrical force applied in 

 the manner indicated, will be found quite as efficient for the disin- 

 tegration of calculi in the bladder as the more formidable analogous 

 operation of lithotrity, occasionally practised. And, as regards sim- 

 plicity and security, the electrical apparatus certainly appears pre- 

 ferable to the instruments used for crushing the stone by ordinary 

 mechanical force. 



Communications also were read from Mr. Forrester, Mr. Huxley, 

 Mr. Joule and Prof. Thomson, Dr. Hassall, Dr. Hooker, Dr. Marcet, 

 Mr. Brooke, Dr. Scoresby, Sir J. C. Ross, Mr. Wheatstone, 

 Dr. Williamson and Mr. Collins*. 



* Notices of these will appear in succeeding Numbers. 



