Page:Collected Physical Papers.djvu/257

Rh In the curves C, D, and E the initial currents were increased with resulting increase of steepness of the curves.

In order to test further the accuracy of the adjustments, I have taken on the same chart, the curve for a constant resistance. In C, the resistance of the receiver at 0·15 volt was found to be 830 ohms. A resistance box having the above resistance was substituted for the receiver, and a curve traced in the usual manner. This curve C′ is seen to be a straight line.

I give below a table showing the results of four sets of experiments on the variation of the resistance r and of conductivity c of the receiver under increasing E. M. F.

Table II.—Showing the Diminution of Resistance of the Receiver, with increasing E. M. F.

It will be seen that in all the above cases the resistance undergoes a continuous diminution with the increase of E. M. F., and that the diminution of resistance due to electromotive variation is not an abrupt, but essentially a continuous process.