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HANDBOOK OF PHYSIOLOGY. 



saturated solution of zinc sulphate into which dips a well amalgamated piece 

 of zinc connected by means of a wire with the galvanometer. In this way 

 the zinc sulphate forms a homogeneous and non-polarizable conductor between 

 the zinc and the china clay. A second electrode of the same kind is, of course, 

 necessary. 



Fig. 818. Diagram of Du Bois Reymond's non-polarizable electrodes, a. Glass tube filled 

 with a saturated solution of zinc sulphate, in the end, c, of which is china clay drawn out to a 

 point; in the solution a well amalgamated zinc rod is immersed and connected, by means of the 

 wire which passes through A, with the galvanometer. The remainder of the apparatus is simply 

 for convenience of application. The muscle and the end of the second electrode are to the 

 right of the figure. 



In a regular muscle prism the currents are found to be as follows: 



If from a point in the surface aline the equator be drawn across the 



muscle prism equally dividing it, currents pass from this point to points 



away from it, which are weak if the points are near, and increased in 



J 



Fig. 319. Diagram of the currents in a muscle prism. (Du Bois Reymond.) 



strength as the points are further and further away from the equator; 

 the strongest passing from the equator to a point representing the middle 

 of the cut ends (fig. 319, 2) ; currents also pass from points nearer the 

 equator to those more remote (fig. 319, 1, 3, 4), but not from points 



