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.
| B | C | D | E | |||||
| Current in 1/105 amp. | Resist in ohms. | c | r | c | r | c | r | |
| 0·10 | 9·0 | 1,136 | 12·0 | 830 | 25 | 400 | 43 | 232 |
| 0·15 | 14·2 | 1,060 | 18·0 | 830 | 40 | 375 | 69 | 217 |
| 0·20 | 20·5 | 970 | 26·0 | 770 | 59 | 340 | 102 | 196 |
| 0·25 | 29·5 | 850 | 40·0 | 625 | 83 | 300 | … | … |
| 0·30 | 40·0 | 750 | 63·5 | 472 | 118 | 254 | … | … |
| 0·35 | 56·0 | 620 | 105·0 | 333 | … | … | … | … |
| 0·40 | 85·0 | 470 | … | … | … | … | … | … |
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.
