vari-colored brightness that filled
the cage with a golden splendor and seemed to rim each one of the
watching men with fire.

"See you, Kashtanov," came Istafiev's voice. "The refractive index,
lowered to that of air to produce invisibility, iss being raised
again--all through a simple adaptation of Roentgen's theories! The
substance above, mark, in the dome, which this morning you saw affect
Zenalishin's blood and the pigment of his hair so that the vibrations
would render his colorless tissues transparent, iss now reversing.
Soon--see!--already he becomes visible!"

Something was growing in the heart of the ribbons of color, and Chris
strained his shrouded eyes to discern what it was.

Black lines, standing out in the dazzling welter of light--lines that
grew and became more solid as he peered at them--lines that were
shaping into a recognizable form, the form of a man's skeleton!

The effect was that of an X-ray. A skeleton hung in the cage, held
steady by the cords around its arms, its naked skull with yawning
eye-pits grinning out at the four men in the room. Soon other details
became visible: black lumps that were organs, the web of fine thin
lines that were veins; and then a hazy, ghostly outline of flesh that
quickly assumed solidity, burying the bones and veins and organs which
had been first apparent.

* * * * *

And all the time the dynamo was filling the hut with its sweeping
drone, and the million points of light flung from the intercrossing
flame-tongues inside the cage were dancing madly on the walls and
floor and ceiling, making the whole scene unreal, fantastic, as from a
dream....

"There! That iss enough," said Istafiev.

The lever went back. The streaks of blue-white that threaded the cage
died; the grayish vapor in the dome above faded away, leaving more of
the creamy, bleaching substance than had been there originally; the
dynamo was shut off, and silence fell in the room. A naked man with a
very white, peaked face and a blotch of blood encrimsoning his neck
hung inside the cage, his head pitched over lifelessly to one side.

Chris stared, almost forgetting the pose of unconsciousness in his
bewilderment. A queer mechanism shaped in the form of a cylinder from
some oddly sparkling, almost transparent material, was clasped to the
nude body's chest: over the nose and mouth was another small
attachment of the same substance. A nozzle midway in the large
cyl