So for Duncan's apologist, the best proof that melancholy was brought on by melancholic liquor was that the essential qualities of the disease were to be found there: The melancholic liquor has far more of the conditions necessary to produce melancholy than any burnt anger, as by its coldness it diminishes the quantity of the spirits, and by its dryness it enables them to sustain the form of a strong and stubborn imagination for much longer; and by its blackness, it deprives them of their clarity and natural subtlety.