gold series--not the group--reads gold, mercury,
thallium, lead, bismuth, and other elements known only to myself. For
the known elements, however, these groups and series are now perfectly
recognized by all scientists; they are determined by the fixed weight
of the atom, and there is a close approximation to regularity.

"This twelfth series is interesting. So far only radium, thorium, and
uranium are generally known. We know that the radioactive elements are
constantly breaking down, and one often hears uranium, for instance,
called the 'parent' of radium. Radium also gives off an emanation,
and among its products is helium, quite another element. Thus the
transmutation of matter is well known within certain bounds to all
scientists to-day like yourself, Professor Kennedy. It has even
been rumored but never proved that copper has been transformed into
lithium--both members of the hydrogen-gold group, you will observe.
Copper to lithium is going backward, so to speak. It has remained for
me to devise this protodyne apparatus by which I can reverse that
process of decay and go forward in the table, so to put it--can change
lithium into copper and copper into gold. I can create and destroy
matter by protodyne."

He had been fingering a switch as he spoke. Now he turned it on
triumphantly. A curious snapping and crackling noise followed,
becoming more rapid, and as it mounted in intensity I could smell a
pungent odor of ozone which told of an electric discharge. On went
the machine until we could feel heat radiating from it. Then came a
piercing burst of greenish-blue light from a long tube which looked
like a curious mercury vapor lamp.

After a few minutes of this Prescott took a small crucible of black
lead. "Now we are ready to try it," he cried in great excitement.
"Here I have a crucible containing some copper. Any substance in the
group would do, even hydrogen if there was any way I could handle the
gas. I place it in the machine--so. Now, if you could watch inside you
would see it change; it is now rubidium, now silver, now caesium. Now
it is a hitherto unknown element which I have named after myself,
presium, now a second unknown element, cottium--ah! there we have
gold."

He drew forth the crucible, and there glowed in it a little bead or
globule of molten gold.

"I could have taken lead or mercury and by varying the process done
the same thing with the gold series as well as the gold group," he
said, reg