156 THE INTELLECTUAL RISE IN ELECTRICITY. 



appeared, Guido delle Colonne ' of Messina expressed the 

 same thought 



" It is a secret of the lodestone, 

 That to itself the iron 'twill not draw 

 Unless the mediate air consent ; 

 Although it hath the nature of a stone, 

 Yet of its nature stones do not partake 

 For lack of this same strange capacity." 



This idea that the intervening medium takes part in the 

 phenomenon of magnetic attraction was one which did not 

 replace, but supplemented the prevailing doctrine that the 

 stone operated solely by reason of its occult virtue. It 

 was suggested in the poem of L,ucretius and favored by the 

 greatest of the Arabian philosophers, Averrhoes, 2 who also 

 explained the attraction of rubbed amber for chaff by the 

 same conception. A century later it was adopted by St. 

 Thomas Aquinas. 3 Certainly a physical hypothesis which 

 enlisted the concurring advocacy of the most eminent of 

 Christian and Pagan commentators, and which appeared, 

 ostensibly at least, to rest upon the principles of Aristotle, 

 whom the world then regarded as the fountain-head of 

 philosophy, could have had no stronger support. 



The references to the lodestone and to the compass now 

 begin to multiply rapidly in all classes of literature. 

 Oautier d'Epinois, 4 in 1245, writes amatory verses compar- 

 ing the object of his affection, not to the Pole star, as 

 William the Clerk had done, but to the magnet, and the 

 whole world to the needle which turns in response to such 

 transcendent attractions. Matthew Paris, 5 perhaps also 



1 Author's translation. Nannucci: Man. della Lett. Florence, 1856, 

 8 r. Bertelli: Mem. sopra Peregrinus, 35. 



'Colliget, V. 



8 In Phys., VII., lect. 3. See, also, Albertus Magnus : Phys., lib. VIII., 

 tract. 2. 



*D'Avezac: Aperus Hist sur la Boussole. Bull. Soc. Geog., 20 Apr., 

 1860. 



5 McPherson: Annals of Commerce. London, 1805, i. 



