A revelation dawned on Nicholl's mind. That intensity of light, the physiological troubles which had arisen in him, the overexcitement of all his moral and quarrelsome faculties—he understood all.
"The oxygen!" he exclaimed.
And leaning over the air apparatus, he saw that the tap was allowing the colorless gas to escape freely,life-giving, but in its pure state producing the gravest disorders in the system. Michel had blunderingly opened the tap of the apparatus to the full.