The Tumbling Egg
Fill a quill with quicksilver, seal it at both ends with good hard wax; then have an egg boiled, take a tiny piece of shell off the small end, and thrust in the quill with the quicksilver; lay it on the floor, and it will not cease tumbling so long as any heat remains in it; or if you put quicksilver into a small bladder, and then blow it up, upon warming the bladder it will skip about as long as heat remains in it.
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