PIERCE AND EVANS. — CAPACITY OF CARBORUNDUM. 



811 



charge currents (Table IV.) differ by about 5 per cent, at the highest 

 voltage, 1.2 volts. At .9 volts, and lower, this difiference is one per 

 cent or less. With the point negative the steady current at 1.2 volts 

 amounts to 1.79 X 10 "^ amperes as is seen in Table V. Therefore 

 the crystal with the point charged negative is not non-leaky as with the 

 opposite direction of charging, but the leak is so small as to make the 

 analysis of the problem much more satisfactory than with Specimen I. 



Figure 11. Point positive. Discharge current vs. n, for various applied 

 voltages V. 



Figures 11 and 10 show the discharge current plotted against n, the 

 number of discharges per second, obtained with point positive and 

 point negative respectively. The corresponding charge curves depart 

 so slightly from the discharge curves that they are not here reproduced. 



AU of the charge and discharge curves for this specimen pass 

 through the origin. This is a result such as one obtains with an 

 ordinary condenser possessing no leakage. 



The curves all droop at higher values of n, but are nearly straight 

 for small values of n. Now this fact is in agreement with results 

 obtained with good condensers provided they possess such high resist- 

 ance in the charge or discharge circuit that the charge and discharge 

 are incomplete. It is interesting that the treatment of the experimen- 

 tal curves of Figures 10 and 11 as due to a condenser with incomplete 



