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An Exposition of some of the Laws and Phenomena of Mao-- 

 NETic Induction, with original Illustrative Experiments, 

 By the Rev. William Scoresby, F.R.S. Lond. & Edin., 

 Correspondent of the Institute of France, &c. &c. &c. Com- 

 municated by the Author. 



,X,K£ magnetic principle, like the electric, to which it is nearly 

 a|iied, is. (lot a. mere attribute of a particular class of bodies, 

 but a principle or influence pervading, doubtless, the whole 

 of the terrestrial creation. For it is not likely that such an 

 influeoce has been ordained by Infinite Wisdom for the com- 

 paratively minor purposes to which men are able to apply it ; 

 but rather that it is an essential constituent in the economy of 

 the globe, — and not of this globe only, but of the entire system, 

 perhaps, of created nature. Wherever the exploring traveller 

 has urged his way, there its influences have been marked; 

 wherever the adventurous mariner has traversed the ocean, there 

 its agency has availed him ; wherever the laborious miner has 

 penetrated the earth, there its energy has been found undi- 

 minished ; and wherever the daring aeronaut has ascended into 

 the atmosphere, thence its power has been extended. 



Though a universal agent, however, and a part of the consti- 

 tution of our globe, it is chiefly in ferruginous bodies, and in 

 bodies in a peculiar electric condition, where its phenomena be- 

 come sensible, and its influences capable of being controlled. 

 In ferruginous bodies, its strongest and most permanent energies 

 are exhibited. 



In iron, the magnetic principle has evidently permanent re- 

 sidence, — capable, indeed, of exerting external influences, but 

 not capable of being abstracted or increased. Each portion and 

 description of iron has its own constant and unalterable quan- 

 tity, abiding apparently in its individual particles, — the two 

 qualities possessing northern and southern polarity existing in 

 every particle. The usual condition of the magnetisms is ge- 

 nerally neutral, or nearly so, so that but a shght and imperfect 

 energy is naturally evinced. Yet the latent energies, especially 

 in the softest kinds of iron and steel, are readily developed by 

 electric influence, or by the touch, or even the mere juxta-posi- 



VOL. XIII. NO. XXVI. OCTOBER 1832. R 



