10 Prof. W. Gr. Adams on the Forms of 



point taken in this curve are 80, 10, and the battery-electrodes are at 

 the same point as before, 2 ( - — - J for each point. 



•0316 



•0310 



•0313 



•0314 



•0311 



•0312 



•0314 



•0309 



•0315 



•0312 



•0311 



•0316 



•0311 



•0311 



•0319 



The mean value of 2 (- - - J = -0313, neglecting all the images but 



one of the more distant electrode. 



These images would diminish the potential at each point, but by very 

 nearly the same amount, as they are so far away from every point of 

 the curve. 



Another curve is drawn on this Plate through the point (100, 10). 

 These three curves were drawn with the battery-poles in the same 

 positions. 



Case 8. In a curve (see Plate 2. fig. 10) drawn through the point (120, 

 20), with the electrodes at a distance of 80 millims. from the ends of the 

 box, only the nearest electrical image was taken into account : the values of 



[-— ~-f- — ) f° r the several points are : — 



•0183 -C183 -0173 



•0181 -0183 -0170 



•0183 0182 -0166 



•0182 -0182 -0167 



•0183 -0178 -0163 



•0182 -0177 -0160 



•0183 -0172 



In this case all the images except one are neglected. When the curve 

 approaches near the side of the box, as at these latter points, it becomes 

 necessary to take account of the effect due to the side of the box ; and 

 the forms of the curves are completely altered. 



Case 9. In the experiments with sulphate of zinc (Plate 1. fig, 11), the 

 zinc electrodes were not immersed to any considerable depth in the liquid, 

 as in the other experiments already described, but were rounded off and 

 immersed to a depth of about 3 or 4 millims., in order to make good contact, 

 the galvanometer-electrodes being somewhat smaller than the others 

 and only just dipping into the liquid. The other arrangements were the 

 same as before. No electrical images were taken into account, as the 

 battery-electrodes were at a distance of 102 millims. from the ends of 



the box. Taking the first curve described, the values of ( - — J for the 



several points are: — 



