NATURAL SCIENCE IN THE MIDDLE AGES 287 



persons " that a serpent with the virgin countenance of a beardless man 

 was recently killed in an island of Germany. Another "trustworthy 

 person" told him that he saw in an eagle's nest 500 ducks, over 100 

 geese, about 40 hares, and many large fish, which were all required to 

 satisfy the hunger of the young eaglets. 



Besides miscellaneous instances of credulity, and the errors of 

 alchemy and astrology already mentioned, we find medieval books on 

 nature full of marvelous and fantastic properties attributed to plants, 

 stones, birds and beasts. Especially wonderful powers are attributed to 

 gems. A French Bishop Marbod in his book on stones tells us that the 

 sapphire nourishes the body and preserves the limbs intact. One who 

 carries it can not be injured by fraud or envy, and is impervious to fear. 

 It sets prisoners free; and is even represented as placating God and 

 rendering him favorable to prayers. It makes peace between foes. By 

 means of it the future can be predicted. It cools one off and checks 

 perspiration. Applied in a pulverized state with milk, it heals ulcers, 

 cleans the eyes, cures headache and ills of the tongue. 



But plants, too, as well as gems, have remarkable powers. The Ger- 

 man abbess Hildegard, in her work on " The Subtleties of Diverse Crea- 

 tures," mentions certain plants which fish eat, and which, if a man 

 could procure and eat, would enable him to go without food for four 

 or five months. Adam used to eat them now and then, after he had 

 been cast out of Eden, but not when he could get other food, since they 

 make one's flesh tough. As for the strange virtues possessed by birds, 

 Hildegard tells us that mistiness is marvelously removed from the 

 eyes by catching a nightingale before daybreak, adding a single drop 

 of dew found on clean grass to the bird's gall; and anointing the eye- 

 brows and lashes frequently with the mixture. 



Hildegard's chapters on quadrupeds are delightfully quaint. The 

 camel is peculiar in that its different humps possess different virtues. 

 The hump next its neck has the virtues of the lion, the second of the 

 leopard, the third of the horse. Unicorns can never be caught except 

 by means of girls, for they flee from men, but stop to gase diligently at 

 girls, because they marvel that they have human forms, yet no beards. 

 "And," adds Hildegard, 



if there are two or three girls together, the unicorn marvels so much the more 

 and is the more easily captured while its eyes are fixed upon them. 



When a weasel is sick, another weasel digs up a certain herb and 

 breathes on it for the space of an hour and then brings it to the sick 

 weasel who is cured thereby. This herb is unknown to other animals 

 and to men, and it would do them no good if they did know of it, 

 since its own virtue is not efficacious, nor would their breathing upon it 

 make it so. But the heart of a weasel, dried and placed with wax in 

 the ear, benefits deafness or headache. A fine cure for epilepsy is to 



