70 W. Sturgeon, Esq., on the 



useful pm*poses discovered — or that novel and more exact 

 views for the explanation of those facts be developed, an ad- 

 ditional step in the advancement of science would thus be 

 securely established ; and it is solely from a hope that by 

 some of these means the present memoir will contribute to 

 the progress of scientific knowledge, that I have ventured to 

 offer it to the consideration of this Society. 



3. The superlative degree of magnetic action displayed by 

 metallic iron, above that of all other known bodies, has been 

 a theme of almost continuous contemplation and philosophi- 

 cal speculation from remote periods in the history of science 

 till the present day, and continues to be a subject of interest 

 and admiration throughout every part of the scientific worldi 

 The ordinary laws of the magnetic action of metallic iron, 

 especially when in masses, are, however, now so satisfactorily 

 established, and the phenomena so well known, that any fur- 

 ther notice of them in this place would be foreign to the ob- 

 ject of this memoir ; more especially as it alludes to the 

 simple magnetic attractions only, whilst illustrating the 

 novel facts it contains, and the mode by which they were de- 

 veloped. 



4. Nickel is a metallic body, which, next to iron, stands 

 most distinguished for the display of magnetic action : and in- 

 deed, notwithstanding the number of inquiries that have been 

 made respecting the magnetic action of other bodies, and the 

 talent and expedients that have been employed in the pur- 

 suit, little or nothing has been satisfactorily ascertained be- 

 yond that which is so conspicuously displayed by those two 

 metals, — iron and nickel. (7-13.) 



5. There is something very remarkable, however, respect- 

 ing the magnetism of these two distinguished metals when 

 in combination with other bodies. Nickel, for instance, is 

 said to lose all its magnetic action when combined with even 

 a small dose of arsenic, and iron has long been understood 

 to sufi^er the same fate when alloyed with antimony. Be- 

 yond these two alloys of nickel and iron, I am not aware that 

 any other have been magnetically investigated, although, as 

 will appear in the sequel, some of the most extraordinary 

 facts that have hitherto appeared in the magnetism of me- 



