Page:On the various forces of nature and their relations to each other.djvu/136

132 bar and balance it carefully on a point, so that it will be free to move round, I can try what action this piece of iron has on it. Well, it attracts one end, and it also attracts the other end, just as you saw the shell-lac and the glass did, with the exception of its not attracting in the middle. But if now, instead of a piece of iron, I take a magnet', and examine it in a similar way, you see that one of its ends repels the suspended magnet—the force then is no longer attraction, but repulsion; but if I take the other end of the magnet and bring it near, it shews attraction again.

You will see this better, perhaps, by another kind of experiment. Here (fig. 38) is a little magnet, and I have coloured the ends differently, so that you may distinguish one from the other. Now this end (S) of the magnet (fig. 37)