"Try them," I said.
"O!" he said, as the magnet lifted them; "I forgot. It does lift some stones."
"Well, what else have you in that pile of things the magnet did not pull?"
"Glass, leather, lead, bone, cloth, tin, zinc, corn, and a lot of things."
"Very well. Now let us see what the magnet does pull."
"Iron keys," said Charlie, "and nails."
"Here's a nail in this other pile."
"That's a brass nail. The magnet pulls only iron nails."
"What else have we in this pile?"
"Needles, hair-pins, screws, wire—iron wire," he added quickly. "Brass wire doesn't stick, you know."