1493.  These results, though indicative of very striking and peculiar relations of the electric force or forces, do not show the relative degrees of charge which the small ball acquires before discharge occurs, i.e. they do not tell whether it acquires a higher condition in the negative, or in the positive state, immediately preceding that discharge.  To illustrate this important point I arranged two places of discharge as represented, fig 130.  A and D are brass balls 2 inches diameter, B and C are smaller brass balls 0.25 of an inch in diameter; the forks L and R supporting them were of brass wire 0.2 of an inch in diameter; the space between the large and small ball on the same fork was 5 inches, that the two places of discharge n and o might be sufficiently removed from each other’s influence.  The fork L was connected with a projecting cylindrical conductor, which could be rendered positive or negative at pleasure, by an electrical machine, and the fork R was attached to another conductor, but thrown into an uninsulated state by connection with a discharging train (292.).  The two intervals or places of discharge n and o could be varied at pleasure, their extent being measured by the occasional introduction of a diagonal scale.  It is evident, that, as the balls A and B connected with the same conductor are always charged at once, and that discharge may take place to either of the balls connected with the discharging train, the intervals of discharge n and o may be properly compared to each other, as respects the influence of large and small balls when charged positively and negatively in air.

1494.  When the intervals n and o were each made = 0.9 of an inch, and the balls A and B inductric positively, the discharge was all at n from the small ball of the conductor to the large ball of the discharging train, and mostly by positive brush, though once by a spark.  When the balls A and B were made inductric negatively, the discharge was still from the same small ball, at n, by a constant negative brush.

1495.  I diminished the intervals n and o to 0.6 of an inch.  When A and B were inductric positively, all the discharge was at n as a positive brush:  when A and B were inductric negatively, still all the discharge was at n, as a negative brush.

1496.  The facility of discharge at the positive and negative small balls, therefore, did not appear to be very different.  If a difference had existed, there were always two small balls, one in each state, that the discharge might happen at that most favourable to the effect.  The only difference was, that one was in the inductric, and the other in the inducteous state, but whichsoever happened for the time to be in that state, whether positive or negative, had the advantage.

1497.  To counteract this interfering influence, I made the interval n = 0.79 and interval o = 0.58 of an inch.  Then, when the balls A and B were inductric positive, the discharge was about equal at both intervals.  When, on the other hand, the balls A and B were inductric negative, there was discharge, still at both, but most at n, as if the small ball negative could discharge a little easier than the same ball positive.