"Get another tumbler," said Jonas, "and let us see."
So Dorothy brought another tumbler, and Jonas put the burning end of the paper down into it, with about as rapid a motion as that with which he had put it before into the tumbler he had at first. The paper continued to burn.
"There," said he to Dorothy, "when I put it down into common air, it burns on the same as ever; so it can't be that the wind puts it out." Jonas repeated the experiment a number of times; the effect was always the same. Whenever he put it into the tumbler of common air, it burned on without any change; but whenever he put it into the choke damp, it immediately went out. Even Dorothy was satisfied that there was a difference in the kind of air contained in the two tumblers.
That evening, when Rollo gave his mother a full account of their attempts,—describing particularly their failure at first, and their subsequent successes,—his mother seemed much interested. When he had finished, she said,—
"Well, Rollo, I don't see but that you have learned two lessons in philosophy."
"Two lessons?" said Rollo.
"Yes," replied his mother. "The first is, that fire will not burn in choke damp; and the second is, that it requires nice attention and care to verify philosophical truths by experiment."
"Yes," said Rollo, "we missed the first time, just because we had too big a paper."