Of course, at that time the members of the expedition did not understand
the conditions of Mercury as they are now known. They had to depend upon
the general impression they got from their first-hand investigations;
and it is remarkable that the doctor should have guessed so close to the
truth.

"He must have made up his mind to outlast everybody else," was the way
he put it as he kicked off his suit. He stepped up to the cabinet and
felt of the glass. "I wish it were possible, without breaking the case,
to see how he was embalmed."

His fingers still rested on the glass. Suddenly his eyes narrowed; he
ran his fingers over the entire surface of the pane, and then whirled to
stare at a thermometer.

"That's mighty curious!" he ejaculated. "This thing was bitter cold when
we brought it in! Now it's already as warm as this car!"

Smith's eyes lit up. "It may be," he offered, "that the case doesn't
contain a vacuum, but some gas which has an electrical affinity for our
atmosphere."

"Or," exclaimed the geologist suddenly, "the glass itself may be totally
different from ours. It may be made of--"

"GOD!" shouted the doctor, jerking his hand from the cabinet and leaping
straight backward. At the same instant, with a grinding crash, all three
sides of the case collapsed and fell in splinters to the floor.