126 THE INTELLECTUAL RISE IN ELECTRICITY. 



and hellebore the vapors. But manifest virtue is virtue 

 that is perceptible -and here we suddenly find ourselves 

 within the borders of the particular field which we are ex- 

 ploring it is seen when the lodestone draws iron and the 

 jet chaff. 



This reference to jet is noteworthy. The ancient writers 

 spoke of "gagates," which acted like amber, and left it 

 in doubt what gagates might be. After jet had been cer- 

 tainly determined to possess the amber quality, the word 

 was so interpreted. Neckam, however, is not quoting 

 from any ancient author, but stating his own facts and be- 

 liefs; and the frequent later use of the English word "jet" 

 by English writers instead of "amber," in referring to the 

 phenomenon figuratively, renders it altogether probable 

 that the learned Abbot was speaking not of the doubtful 

 substance from Lydia, which he had never seen, but the 

 lustrous black stone which had been mined in his own 

 country ever since the Roman invasion. 1 



"If you ask its value as an ornament," he says, "jet is 

 black and brilliant: if its nature, water burns it and it is 

 extinguished by oil: if its power, being heated by rubbing, 

 it holds things applied to it, like amber: if its use, it is an 

 excellent remedy for dropsy." It was commonly found in 

 Derbyshire and Berwick, and the Romans preferred it to 

 that which was found in Germany. "The old writers," 

 says Harrison, 2 "remember few other stones of estimation 

 to be found in this Island, than that which we call 'geat,' 

 and they, in Latin, 'gegates.' " 



The explanation of "the quality of natural similitude 

 not without attractive virtue" is ushered in by an illustra- 

 tion borrowed evidently from the Arabs. A warm stomach 

 draws warm nourishment, and a cold stomach, cold nour- 

 ishment: and we are to note that, according as by friendly 



1 The value of jet and of Kitnmeridge coal for ornamental purposes was 

 then well understood, and jet ornaments have been found in graves of the 

 period. Traill: Social England, i. 92. 



2 Harrison: A Description of England. London, 1577. 



