Mr. Andrew Lang, in his volume entitled “Custom and Myth,” says that, in a church of a certain old Saxon town, the verger is wont to exhibit to visitors a silver mouse dedicated to Our Lady; explaining that the town was infested with mice until this now precious relic was presented by some ladies as a propitiatory offering, whereupon the creatures disappeared at once. According to the ancient Doctrine of Signatures, the therapeutic virtues of plants were indicated by certain peculiarities of their external appearance. Thus _Dracontium_, or great dragon, a plant which has a fancied resemblance to this mythical monster, was thought to be a preservative against serpents; and the scorpion-grass (_Myosotis_), whose flower-spike was not unlike a scorpion’s tail, was deemed an antidote to the stings of noxious insects. Indeed, the old herbalists of England claimed by the sole use of herbs, not only to cure all fleshly ills, but to drive away or keep at a distance wolves, leopards, and all venomous wild beasts.[486] In Tibet, according to L. Austine Waddell, M. B., ferocious mastiffs are permitted to roam at large in the night, a source of terror to wayfarers, who therefore carry about charms consisting of “the picture of a dog muzzled and fettered by a chain, terminated by the mystic and all-powerful thunderbolt sceptre,” while along the dog’s body are written certain Sanskrit magical sentences.[487] VI. WORDS USED AS CHARMS The English word “charm” is derived from the Latin _carmen_, a verse; and the magical potency of a sentence used as a charm was believed to rest in the words themselves, and not in the person who uttered them. In the opinion of the cabalistic magicians of the Middle Ages, the power of a charm of words depended upon its being unintelligible.