Fermentation. A dragon, which grows on the trunk of a tree labelled 'arbor philosophorum', forms an ouroboros, by seizing its tail in its mouth. Within the circular space is a double-headed eagle. Above its head is a planetary disc labelled 'our Mercury' which is connected by rays to six other planets arrayed around the dragon - on the left, Sun, Venus and Jupiter, on the right, Moon, Mars and Saturn.