Page:Ballantyne--The Battery and the Boiler.djvu/409

 copper melted like wax. With silver a still brighter and purer green flame was the result. With platinum an intense white light was given off, and the molten metal fell in globules of exceeding brilliancy. With iron lovely coruscations were exhibited, the boiling vapour flying and burning in all directions; and a platinum wire three feet long was in an instant melted into thousands of minute globules. All this showed the power of electricity to produce intense heat when resistance is opposed to its passage."

"It is remarkably human-like in that respect," said Captain Rik, in an under-tone.

"Then its power to produce magnetism," continued Sam, "was shown by Lord Lindsay's huge electro-magnet. This magnet, you must know, is nothing but a bit of ordinary metal until it is electrified, when it becomes a most powerful magnet. But the instant the current is cut off from it, it ceases to be a magnet. If you understood much about electricity," said Sam, looking round on his rapt audience, "I might tell you that it is upon this power of making a piece of iron a magnet or not at pleasure that depend the Morse and Digne telegraph instruments; but as you don't understand, I won't perplex you further. Well, when a piece of sheet copper was passed between the poles of Lord Lindsay's giant magnet, it was as