And the Madman seized nervously on his pestle and mortar, to show the Doctor the harmlessness of his pursuits, and went on pounding--click, click, click.

He hadn't given six clicks before, puff! up went the whole into a great blaze, away went the pestle and mortar across the study, and back we tumbled into the passage.

The magpie fluttered down into the court, swearing, and the Madman danced out, howling, with his fingers in his mouth.

The Doctor caught hold of him, and called to us to fetch some water.

'There, you silly fellow,' said he, quite pleased, though, to find he wasn't much hurt, 'you see you don't know the least what you're doing with all these things; and now, mind, you must give up practising chemistry by yourself.' Then he took hold of his arm and looked at it, and I saw he had to bite his lip, and his eyes twinkled; but he said, quite grave, 'Here, you see, you've been making all these foolish marks on yourself, which you can never get out, and you'll be very sorry for it in a year or two.