The Doctor arose and shut his office door. "Hark ye, Concho," he said,
"that bit of medicine I gave you just now was worth a dollar, it was
worth a dollar because the material of which it was composed was made
from the stuff you have in that can,--quicksilver or mercury. It is one
of the most valuable of metals, especially in a gold-mining country.
My good fellow, if you know where to find enough of it, your fortune is
made."

Concho rose to his feet.

"Tell me, was the rock you built your furnace of red?"

"Si, Senor."

"And brown?"

"Si, Senor."

"And crumbled under the heat?"

"As to nothing."

"And did you see much of this red rock?"

"The mountain mother is in travail with it."

"Are you sure that your comrades have not taken possession of the
mountain mother?"

"As how?"