52 Mr. W. Sturgeon on the Theory of Magnetic Electricity. 



tish Almanac to point out those days, and the position in 

 which it will be visible. 

 Dec. 14, 1832. 



VIII. On the Theory of Magnetic Electricity. By Mr. William 

 Sturgeon, Member of the British Association for the Pro- 

 motion of Science : Lecturer at the Hon. East India Com- 

 pany's Military Academy, Addiscombe, Sfc. fyc. * 

 [With Figures : Plate I.] 

 r T , HE original plan which I had prescribed to myself for 

 -■- the publication of my investigations on the distribution 

 of magnetic polarity in metallic bodies, was that of first de- 

 scribing all those experiments which appeared to me to be the 

 most interesting, with such explanatory remarks and practical 

 rules for their exhibition as were necessary to their being pro- 

 perly and easily understood ; and afterwards to offer such the- 

 oretical inferences, with observations, as naturally presented 

 themselves to my mind whilst contemplating the curious and 

 novel phaenomena which these inquiries elicited : and in order 

 that the arrangement might be the more regular, uniform, and 

 intelligible, I placed the experiments on iron in the earliest 

 part of the detail. According to that plan, there would have 

 been another communication previous to that which I am now 

 writing, which would have continued, and perhaps completed 

 the detail of my former original experiments. Since sending 

 my last communication to the press -j-, however, I have had an 

 opportunity of perusing a paper containing the detail of the 

 more recent experiments of Mr. Faraday, published in the Phi- 

 losophical Transactions for the present year ; and finding that 

 several of the experiments there detailed, although performed 

 with somewhat different arrangements of apparatus, are inti- 

 mately connected with those of mine already published, and 

 consequently with those also which I have not yet described, I 

 have been induced to deviate from my original plan, and to 

 offer more early in the series than I had intended, those theo- 

 retical elements of this new branch of physics, of which all the 

 rides hitherto advanced for the exhibition of the phaenomena, 

 however important they may appear in a practical point of 

 view, are but the mere consequent subordinate results. 



Before proceeding further, however, with the principal object 

 of this communication, I must beg permission to observe, that 

 notwithstanding the title under which I have hitherto published 

 my investigations on this subject is perfectly unobjectionable, 

 and also sufficiently comprehensive and explanatory for all 



* Communicated by the Author. 



f Phil. Mag. and Journ. of Science, vol. i. p. 31. 



