THE MAGNETIC FIELD OF FORCE. 155 



"Kindles in noble heart the fire of love 



As hidden virtue in the precious stone; 

 This virtue comes not from the stars above 



Till round it the ennobling sun has shone; 

 But when his powerful blaze 



Has drawn forth what is vile, the stars impart 

 Strange virtue in their rays; 



And thus when nature doth create the heart 

 Noble and pure and high, 



Like virtue from the star, love comes from woman's eye. 1 



Even more closely knit are the facts in the following 

 stanza by the same poet, for here the traditional magnetic 

 mountains once more come to light 



In what strange regions 'neath the polar star 

 May the great hills of massy lodestone rise, 

 Virtue imparting to the ambient air 

 To draw the stubborn iron; while afar 

 From that same stone, the hidden virtue flies 

 To turn the quivering needle to the Bear, 

 In splendor blazing in the northern skies. 2 



This adds another step to William the Clerk's original 

 theory. The Pole star communicates its virtue to the 

 magnetic mountains, and from the magnetic mountains 

 comes the lodestone wherewith the needle is rubbed. But, 

 for another reason, this stanza is very curious, in that it 

 shows an early form of the hypothesis of the field of force 

 surrounding the lodestone, in which field the power or 

 strength or virtue of the stone is exerted. Note that the 

 virtue is imparted "to the ambient air to draw the stub- 

 born iron." The idea of action at a distance of the 

 magnet influencing its armature through no material 

 bond was not so thinkable to the poets and commen- 

 tators of the twelfth and thirteenth, as it afterwards 

 became to the natural philosophers of the seventeenth and 

 eighteenth centuries. Not long after Guinicelli's poem 



1 Longfellow's translation: Poets and Poetry of Europe, 511. 



2 Author's translation. Ginguene* : Hist. Litt de 1' Italic, i. 413. 



