warning to him, but
Ballard either did not hear it or else paid no attention.

The form of the prospector, leaping and plunging onward, sprang from one
row of vats to another. Each row was a little lower than the row to the
north, so that the tiers took on the form of a flight of giant steps.

Porter gained the top tier, and stood for a moment on a plank spanning a
vat that was three or four times as large as any of the others. Ballard
climbed to the same plank. Porter dropped down with a savage, snarling
cry. Clinging for a moment to the edge of the tank, he twisted the plank
from under Ballard's feet. Ballard dropped with a splash.

"Merciful powers!" yelled a voice in wild alarm. "Get him out, quick!
That's the solution tank and is filled with cyanide!"

Merriwell's heart almost stopped beating. In a gleam of light from the
mill he saw the white, drawn face of Pardo peering toward the spot where
Ballard was splashing in the deadly cyanide solution. An instant later
he bounded to the rescue.

CHAPTER IV.

A CLOSE CALL.

Just one thing saved Ballard from going over his head into the cyanide
solution, and that was this: Porter had not twisted the plank off the
rim of the tank, but had manipulated it in such a way as to cause
Ballard to lose his footing and drop into the poisonous liquid beneath.
As Ballard dropped, he flung out his arms, seized the plank, and so kept
head and shoulders out of the cyanide. Had he gone under or swallowed
even a few drops of the deadly stuff, that pursuit of the savage
prospector would have had a tragic termination. Ballard, kicking around
in the solution, was trying to drag himself up on the plank as Merry
crept toward him.

"Steady there, Pink!" called Frank. "Don't splash the stuff around, and
keep out of it as much as you can. It's a deadly poison."

"Never mind me," cried, Ballard. "Keep after that confounded prospector
He'll get away if you don't."

"You first, old chap," Frank answered. "It has a scurvy trick Porter
played on you, and--and it might have resulted fatally. Now, then!"

Gripping his chum by the arms, Frank heaved him upward until he was on
his knees on the plank.

"Want any help?" came the agitated voice of Clancy, from just below the
solution tank.

"No," answered Merriwell, "we're making it all right."

"Drop him over the side," called Pardo, "here, over in this direction.
There's a tank of clear water next to the solution vat, and the quicker