He laughed when this thought struck him and drove his spurs sharply against Mustard's flanks, riding forward past the cottonwood at which he had been staring.
"Hell!" he ejaculated, as he passed the tree, "what a fool notion." But he could not banish the "notion" from his mind, and five minutes later, when he tried again to sit steadily, he found the swaying more pronounced.

The saddle seemed to rock with him, and even by jamming his uninjured foot tightly into the ox-bow stirrup he could not stop swaying.
"Mebbe I won't get very far," he said, realizing that the poison had entered his system, and that presently it would riot in his veins, "but I'm goin' on until I stop.

I wouldn't want that damned rattler to know that he'd made me quit so soon." He urged Mustard to a faster pace, even while realizing that speed was hopeless.

He could never reach the Two Diamond.

Convinced of this, he halted the pony again, swaying in the saddle and holding, for the first time, to the pommel in an effort to steady himself.