battery, and bring the points in contact. See what an exhibition of force we have! We have exhausted the air so that the charcoal cannot burn; and, therefore, the light you see is really the burning of the zinc in the cells behind me—there is no disappearance of the carbon, although we have that glorious electric light; and the moment I cut off the connection, it stops. Here is a better instance to enable some of you to see the certainty with which we can convey this force, where, under ordinary circumstances, chemical affinity would not act. We may absolutely take these two charcoal poles down under water, and get our electric light there;—there they are in the water, and you observe, when I bring them into connection, we have the same light as we had in that glass vessel.
Now, besides this production of light, we have all the other effects and powers of burning zinc. I have a few wires here which are not combustible, and I am going to take one of them, a small platinum wire, and suspend it between these two rods, which are connected with the battery; and, when contact is made
