rly unprepared for the truth.

"When I approached the table I found, sure enough, that the bar of metal
had vanished, and that the clamp was empty. Having noted the fact, I was
about to turn away to something else, when my attention was attracted to
the fact that the table upon which the clamp stood was starred over with
little patches of some liquid silvery matter, which lay in single drops
or coalesced into little pools. I had a very distinct recollection of
having thoroughly cleared the table before beginning my experiment,
so that this substance had been deposited there since I had left for
London. Much interested, I very carefully collected it all into one
vessel, and examined it minutely. There could be no question as to what
it was. It was the purest mercury, and gave no response to any test for
bismuth.

"I at once grasped the fact that chance had placed in my hands a
chemical discovery of the very first importance. If bismuth were, under
certain conditions, to be subjected to the action of electricity, it
would begin by losing weight, and would finally be transformed into
mercury. I had broken down the partition which separated two elements.

"But the process would be a constant one. It would presumably prove
to be a general law, and not an isolated fact. If bismuth turned into
mercury, what would mercury turn into? There would be no rest for me
until I had solved the question. I renewed the exhausted batteries and
passed the current through the bowl of quicksilver. For sixteen hours I
sat watching the metal, marking how it slowly seemed to curdle, to grow
firmer, to lose its silvery glitter and to take a dull yellow hue. When
I at last picked it up in a forceps, and threw it upon the table, it had
lost every characteristic of mercury, and had obviously become another
metal. A few simple tests were enough to show me that this other metal
was platinum.

"Now, to a chemist, there was something very suggestive in the order in
which these changes had been effected. Perhaps you can see the relation,
Robert, which they bear to each other?"

"No, I cannot say that I do."

Robert had sat listening to this strange statement with parted lips and
staring eyes.

"I will show you. Speaking atomically, bismuth is the heaviest of the
metals. Its atomic weight is 210. The next in weight is lead, 207, and
then comes mercury at 200. Possibly the long period during which the
current had acted in my absence had reduced the