saw it was the Nigger, and perceived at the same instant that he was almost beside himself with terror. His eyes rolled, his teeth chattered, his frame contracted in a strong convulsion, and the black of his complexion had faded to a washed-out dirty grey, revolting to contemplate. He felt my touch and sprang to his feet, clutching me by the shoulder as a man clutching rescue.
"My Gawd!" he shivered. "Look! Dar it is again!"
He fell to pattering in a tongue unknown to me—charms, spells, undoubtedly, to exorcise the devils that had hold of him. I followed the direction of his gaze, and myself cried out.
The doctor's laboratory stood in plain sight between the two columns of steam blown straight upward through the stillness of the evening. It seemed bursting with light. Every little crack leaked it in generous streams, while the main illumination appeared fairly to bulge the walls outward. This was in itself nothing extraordinary, and indicated only the activity of those within, but while I looked an irregular patch of incandescence suddenly splashed the cliff opposite. For a single instant the very substance of the rock glowed white hot; then from the spot a shower of spiteful flakes shot as from a pyrotechnic, and the light was blotted out as suddenly as it came. At the same moment it appeared at another point, exhibited the same phenomena, died, flashed out at still a third place, and so was repeated here and there with bewildering rapidity until the walls of the valley crackled and spat sparks. Abruptly the darkness fell.
