"And all these door keys that the magnet didn't pull," he continued, "are brass, too. Perhaps it can't pull brass things."
"Suppose you try. But first see if there are any brass things that the magnet pulled."
Charlie looked them over. Then we tried the casters of my chair, and all the other brass things we could find, none of which the magnet would pull.
"There's no use in trying any longer," said Charlie. "It won't pull brass."
"Then, there's another matter settled," I said. "The magnet does not pull brass. Is there any thing else it does not pull?"
"Wood," said Charlie. "I tried lots of pieces."
"Any thing else?"
"Stones," said Charlie, eagerly.
"What are these?" I asked, holding up a couple of heavy stones he had put among the things the magnet pulled.
"I guess I put those there by mistake," said Charlie, testing with, the magnet a number of stones in the other pile.