with an accuracy greater than one-half of 1 per cent. But it is quite inconceivable that large charges such as are dealt with in commercial applications of electricity can be built up in an essentially different way from that in which the small charges whose electrons we are able to count are found to be. Furthermore, since it has been definitely proved that an electrical current is nothing but the motion of an electrical charge over or through a conductor, it is evident that the experiments under consideration furnish not only the most direct and convincing of evidence that all electrical charges are built up out of these very units which we have been dealing with as individuals in these experiments, but that all electrical currents consist merely in the transport of these electrons through the conducting bodies.
In order to show the beauty and precision with which these multiple relationships stand out in all experiments of this kind, a table corresponding to much more precise measurements than those given heretofore is here introduced ([Table VI]). The time of fall and rise shown in the first and second columns were taken with a Hipp chronoscope reading to one-thousandth of a second. The third column gives the reciprocals of these times. These are used in place of the velocities
in the field, since distance of fall and rise is always the same. The fourth column gives the successive changes in speed due to the capture of ions. These also are expressed merely as time reciprocals. For reasons which will be explained in the next section, each one of these changes may correspond to the capture of not merely one but of several distinct ions.
[TABLE VI]
Sec. | Sec. | |||||||
|---|---|---|---|---|---|---|---|---|
| 11.848 | 80.708 | .01236} | .09655 | 18 | .005366 | |||
| 11.890 | 22.366} | .03234 | 6 | |||||
| 11.908 | 22.390} | .04470} | .12887 | 24 | .005371 | |||
| 11.904 | 22.368} | .03751 | 7 | .005358 | ||||
| 11.882 | 140.565} | .007192} | 0.09138 | 17 | .005375 | |||
| 11.906 | 79.600} | .01254} | .005348 | 1 | .005348 | 4.09673 | 18 | .005374 |
| 11.838 | 34.748} | 0.01616 | 3 | .005387 | ||||
| 11.816 | 34.762} | .02870} | .011289 | 21 | .005376 | |||
| 11.776 | 34.846} | |||||||
| 11.840 | 29.286} | .11833 | 22 | .05379 | ||||
| 11.904 | 29.236} | .03414} | 0.26872 | 5 | .005375 | |||
| 11.870 | 137.308 | .007268} | .09146 | 17 | .05380 | |||
| 11.952 | 34.638 | .02884} | .021572 | 4 | .005393 | .11303 | 21 | .005382 |
| 11.860 | .01623 | 3 | .005410 | |||||
| 11.846 | 22.104} | .012926 | 24 | .005386 | ||||
| 11.912 | 22.268} | .04507} | .04307 | 8 | .005384 | |||
| 11.910 | 500.1 | .002000} | .08619 | 16 | .005387 | |||
| 11.918 | 19.704} | .04879 | 9 | .005421 | ||||
| 11.870 | 19.668 | .05079} | .13498 | 25 | .05399 | |||
| 11.888 | 77.630} | .03794 | 7 | .005420 | ||||
| 11.894 | 77.806} | .01285} | .09704 | 18 | .05399 | |||
| 11.878 | 42.302 | .02364} | .01079 | 2 | .005395 | .10783 | 20 | .05392 |
| 11.880 | Means | .005386 | .005384 |
The numbers in the fifth column represent simply the small integer by which it is found that the numbers in the fourth column must be divided in order to obtain the numbers in the sixth column. These will be seen to be exactly alike within the limits of error of the experiment. The mean value at the bottom of the sixth column represents, then, the smallest charge ever caught from the air, that is, it is the elementary ionic charge. The seventh column gives the successive values of
expressed as reciprocal times. These numbers, then, represent the successive values of the total charge carried by the droplet. The eighth column gives the integers by which the numbers in the seventh column must be divided to obtain the numbers in the last column. These also will be seen to be invariable. The mean at the bottom of the last column represents, then, the electrical unit out of which the frictional charge on the droplet was built up, and it is seen to be identical with the ionic charge represented by the number at the bottom of the sixth column.