never actually still for a second. A sort of internal bubbling
seemed to work in its centre, and curious specks and lines of
crimson and gold flashed through it from time to time.

"What is it?" I asked; adding with a half-smile, "Are you the
possessor of a specimen of the far-famed Aqua Tofana?"

Cellini placed the decanter carefully on a shelf, and I noticed that
he chose a particular spot for it, where the rays of the sun could
fall perpendicularly upon the vessel containing it. Then turning to
me, he replied:

"Aqua Tofana, mademoiselle, is a deadly poison, known to the
ancients and also to many learned chemists of our day. It is a clear
and colourless liquid, but it is absolutely still--as still as a
stagnant pool. What I have just shown you is not poison, but quite
the reverse. I will prove this to you at once." And taking a tiny
liqueur glass from a side table, he filled it with the strange fluid
and drank it off, carefully replacing the stopper in the decanter.

"But, Signor Cellini," I urged, "if it is so harmless, why did you
forbid my tasting it? Why did you say there was danger for me when I
was about to drink it?"

"Because, mademoiselle, for YOU it would be dangerous. Your health
is weak, your nerves unstrung. That elixir is a powerful vivifying
tonic, acting with great rapidity on the entire system, and rushing
through the veins with the swiftness of ELECTRICITY. I am accustomed
to it; it is my daily medicine. But I was brought to it by slow, and
almost imperceptible degrees. A single teaspoonful of that fluid,