182 PHYSIOLOGY OF MUSCLES AND NERVES. 



cylinder a, somewhat flattened, is attached to the stand 

 A, The socket e and the motor apparatus on the 

 column h allow the glass cylinder to be placed in any 

 desired position. Within the cylinder is a strip of 

 amalgamated sheet zinc h, which can he connected 

 with the multiplier by means of a wire. The glass 

 cylinder is closed below . w ith a stopper of plastic clay 

 moistened with a solution of common salt, the project- 

 ing ends of which can be moulded into a point which 

 touches the smallest possible point on the conductor 

 to be examined. The space within the glass cylinder 

 is filled with a concentrated solution of sulphate of 

 zinc, and thus forms an unj)olari sable and homogene- 

 ous conductor between the strip of zinc and the clay 

 point. A second and exactly similar apparatus, which 

 is only partly represented in the figure, provides for 

 the diversion from the other point of the conductor. 



Whatever form of diverting apparatus is employed, 

 the determination of the fact whether the two points 

 touched by the feet of the diverting arch have like or 

 unlike tension will be more accurate the more sensi- 

 tive is the multiplier which is inserted in the diverting 

 arch. By placing the body to be examined in such a 

 way that the various points in its surface successively 

 lie on the pads of the above-described diverting vessel 

 (see ch. ix. § 5), or by touching them with the ends of 

 the diverting cylinder just mentioned, it may be dis- 

 covered which points have equal tension (for in such 

 cases the multiplier will indicate no deflection), or, if the 

 points touched are unequal in tension, it may be dis- 

 covered at which the positive tension is greatest. For, 

 from this latter point a current must pass through the 

 multiplier to the point at which the positive tension is 



