I interrupted in my turn. Leyden was no doubt a skilled naturalist, a close observer and a man of deep power of thought and analysis, but he was not a physician, had never made a regular study of physiological chemistry, and was, therefore, scarcely in a position to argue with a person who had.
"Such cases are not infrequent," I answered. "The ancient Greeks understood that much, as we see from their terms. 'Hypochondria'; under the ribs the liver probably poisoning the brain, if you like; then there is the condition of hysteria often accompanying a movable kidney; the action of certain drugs on special centers"
"Such as cannabis indica?" interrupted Leyden, "which affects the sense of elapsed time and makes the subject happy—or—what is that principle, Doctor, which produces xanthopsia, or yellow vision, and makes one sluggish and depressed?"
"Xanthopsia is an early symptom of santonin poisoning," I answered. "The alkaloid
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