10 Professor Hughes on the Theory of Magnetism. [Feb. 29, 



what direction ; again the same north pole appears. Thus these forces 

 must be very similar in nature, and may be fairly presumed to be 

 vibrations, or modes of motion, having no directive tendency except a 

 slight one, as in the case of electricity. For the same three forces 

 render the rod perfectly neutral, even when previously magnetised, 

 when placed in a longitudinally neutral field, as east and west. 



Motion of the molecules gives rise to external magnetism to a rod 

 previously neutral, or renders it neutral when previously magnetised ; 

 in other words, it simply allows the molecules to obey an external 

 directing influence; the only motion, therefore, is during a change 

 of state or polarity. If there is constant polarity, there is no con- 

 sequent motion of the molecules : in fact, the less motion of any kind 

 that it can receive, the more perfect its retention of its previous 

 position ; consequently, constant magnetism cannot be looked upon 

 as a mode of motion, neither vibratory nor rotatory ; it is an inherent 

 quality of each molecule, similar in its action to its chemical affinity, 

 cohesion, or its polar power of crystallisation. A molecule of all 

 kinds of matter has numerous endowed qualities ; they are inherent, 

 and special in degree to the molecule itself. I regard the magnetic 

 endowed qualities of all matter or ether to be inherent, and that they 

 are rendered evident by rotation to a symmetrical arrangement in 

 which their complete polar attractions are not satisfied. 



Time will not allow me to show how completely this view explains 

 all the phenomena of electro-magnetism, diamagnetism, earth cur- 

 rents — in fact, all the known efi'ects of magnetism — up to the original 

 cause of the direction of the molecules of the earth. To explain the 

 first cause of the direction of the molecules of the earth would rest 

 altogether upon assumption as the first cause of the earth's rotation, 

 and of all things down to the inherent qualities of the molecule itself. 



The mechanical theory of magnetism which I have advocated 

 seems to me as fairly demonstrable as the mechanical theory of heat, 

 and it gives me great pleasure to have been allowed to present you 

 with my views on the theory of magnetism. 



[D. E. H.] 



