Page:On the various forces of nature and their relations to each other.djvu/141

know from the appearance of repulsion of the pith ball at the end of the straw, that electricity is present in those brass conductors (B B), and I want you to see the manner in which that electricity can pass away. [Touching the condutor Fig. 41. (B) with his finger, the Lecturer drew a spark from it, and the straw electrometer immediately fell.] There, it has all gone; and that I have really taken it away, you shall see by an experiment of this sort. If I hold this cylinder of brass by the glass handle, and touch the conductor with it, I take away a little of the electricity. You see the spark in which it passes, and observe that the pith-ball indicator