Medusa--Phenomena of recurrence--The Brood of Echidna and their survival--Behemoth and Leviathan--The Mouth of Hell--The Lambton Worm--Ragnar--The Lambton Doom--The Worm's Orthodoxy--The Serpent, Superstition, and Science. Asura has already been mentioned as the most ancient Aryan name for deity. The meaning of it is, the Breather. It has also been remarked that in the course of time the word came to signify both the good and the evil spirit. What this evil breath meant in nature is told in Leonardo da Vinci's picture of the expiring Medusa, referred to on p. 386, from whose breath noxious creatures are produced. It may have been that the artist meant only to interpret the Gorgon as a personification of the malarious vapours of nature and their organic kindred; if so, he painted better than he knew, and has suggested that fatal vitality of the evil power which raised it to its throne as a principle coeternal with good. The phenomena of recurrence in things evil made for man the mystery of iniquity. The darkness may be dispersed, but it returns; the storm may clear away, but it gathers again; inundations, sickly seasons, dog-days, Cain-winds, they go and return; the cancer is cut out and grows again; the tyrant may be slain, tyranny survives. The serpent slipping from one skin to another coils steadily into the symbol of endlessness. In another expression it is the poisonous breath of the Dragon. It is this breath that cannot be killed; the special incarnations of it, any temporary brood of it, may be destroyed, but the principle in nature which produces them cannot be exterminated.