GRAVITY AND MAGNETISM. 293 



globe, by its own virtues, attracts them. Otherwise, the 

 dissipation of the universe would necessarily follow. 



Now this, he avers, is not an appetite or inclination to 

 position, or to space, or to a boundary, but is to the body, 

 the source, the mother, the beginning where all are united 

 and safely kept. Thus the earth attracts all magnetic 

 bodies, besides all others in which by reason of material, 

 the primary magnetic force is absent ; and this inclination 

 to the earth in terrene substances is commonly called 

 gravity. The gravity of a body then is inclination to its 

 source, and all things which come of the earth return to it. 



Thus, repeating himself in many ways, not uninfluenced, 

 perhaps, by the recollection of the return of all flesh to the 

 dust, he suggests the correlation of gravity and magnetism 

 a thought still burning, a question still unsolved. More 

 than two centuries afterwards another great student of 

 nature, facing like problems, conceived of the same rela- 

 tionship; and it was while endeavoring to penetrate into its 

 mysteries, the one by speculation, the other by experi- 

 ment, that both William Gilbert and Michael Faraday 

 each reached the ultima thule of his life-work. 



The amber phenomenon had begun to detach itself in 

 men's minds from that of the lodestone, as Cardan's differ- 

 entiation plainly shows. Gilbert now made the separation 

 complete, and not only brought electricity so termed as 

 distinguished from magnetism into the sphere of human 

 thought of his times, but gave to its intellectual progress 

 an impetus which has ever since continued, and with 

 growing force. 



"Those unobvious, delicate and often cumbrous and 

 tedious processes of experiments which have thrown most 

 light upon the general constitution of nature," says Mill, 1 

 "would hardly ever have been undertaken by the persons, 

 or at the time they were, unless it had seemed to depend 

 upon them whether some general doctrine or theory which 



'Mill: System of Logic, ii, 18. 



