288 THE POPULAR SCIENCE MONTHLY 



put a mouse in a dish of water and then give this water to the patient 

 to drink, not to mention washing his forehead and feet in it. As with 

 drinking Postum instead of coffee, " There is a reason." It is this, 



Inasmuch as the mouse runs away from everything, therefore it drives away 

 the falling disease. 



Marbod and Hildegard were twelfth-century writers, and some- 

 what nai've and undiscriminating in their acceptance of marvels. The 

 thirteenth-century encyclopedias and works on medicine do not contain 

 so much chaff in proportion to their wheat; but they still contain a 

 great deal. Even Eoger Bacon, who declared false and disproved by 

 experiment several such notions as that only goat's blood can break 

 adamant and that hot water freezes faster than cold, — even Bacon still 

 speaks of the "almost miraculous" powers of "herbs and stones and 

 metals." However, the writers come to recognize that there is some- 

 thing peculiar and requiring explanation in these strange properties 

 ascribed to the things of nature. In the thirteenth century they are 

 distinguished as occult virtues and are regarded as marvelous. It is 

 admitted that reason can not account for them, but their existence is 

 declared to be attested by experience. 



Thus Albertus Magnus admits that it is difficult to explain the 

 strange virtues of gems, and says that many students of nature seem to 

 doubt whether stones possess any such attributes as to cure ulcers, 

 counteract magic potions, conciliate human hearts, and win battles. 

 But he insists that these occult virtues are well-established facts, and 

 gives two examples attested by his own experience, namely, the mag- 

 net's power to attract iron and a sapphire which he saw cure ulcers. 

 Some plants, too, Albert declares, have "divine effects which students 

 of magic especially investigate." 



On the other hand, Vincent of Beauvais, while he still agrees with 

 Marbod that the virtues of gems are so marvellous that they can be ac- 

 counted for only as the result of direct divine influence, thinks that 

 plants possess only natural powers, which are chiefly medicinal. Nor 

 does either Albert or Vincent usually recommend fantastic or irrelevant 

 methods of using herbs medicinally. Many, however, of the medicinal 

 virtues which they ascribe to plants are probably false, and they also 

 show a tendency to make each plant a panacea for a long list of very 

 miscellaneous and unrelated diseases. This may be illustrated by a 

 passage taken quite at random and which happens to be about the nas- 

 turtium : 



It is acid and hot and dry. It is a gentle purgative and laxative, and 

 dries up the gases of an empty stomach. Used as a potion or liniment, it keeps 

 one's hair from falling out. It is beneficial for abscesses and carbuncles, if 

 taken with salt and water. ... It is good for softening of the muscles, puri- 



