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LXX. Remarks on M. Mossotti's Theory of Physics, suggest- 

 ed by Mr. Babbage's notice of the same. By Mr. Thomas 

 Exley, M.A.* 



T^HERE is most certainly one theory of physics, and only 

 -*- one ; to determine this has always been the aim of philoso- 

 phers. Innumerable have been the theories proposed, and as 

 often have they been refuted, or at least rendered doubtful, 

 till Newton unfolded the laws of gravitation ; his doctrine has 

 stood every test, and cannot be overthrown : but his theory of 

 gravitation does not embrace molecular action. Many have at- 

 tempted the generalization without success; and this paper is 

 intended to show that even the theory lately proposed by 

 Mossottif, or any similar theory, which continues the direction 

 of the forces the same to the centres of atoms, cannot be true. 

 This so far clears the way for my own, which the more I ex- 

 amine the more I am convinced is the true one; which also it 

 is desirable to corroborate. Because my theory is in conformity 

 with received principles, with the single difference of a change 

 of direction of the force, near the centre, and because no phae- 

 nomenon can be found in contradiction to its doctrines, it has 

 everything in its favour which, previously to its adoption, 

 any theory can have. But since Mossotti's theory has excited 

 much attention, and he has endeavoured to support it bj r ma- 

 thematical reasonings, I have considered it incumbent on me 

 to investigate its merits, especially as it has been particularly 

 noticed by so great a name as Mr. Babbage. 



While reading note A in Mr. Babbage's Ninth Bridgewater 

 Treatise, it was gratifying to observe, that a train of thoughts 

 had occupied my own mind, while writing my New Theory of 

 Physics eight years ago, very similar to that which runs 

 through the note mentioned. 



Mr. Babbage has given a clear and concise statement of 

 Mossotti's theory, and several judicious observations on what a 

 physical theory ought to comprehend ; and as I wish to make 

 some remarks on that theory, with notices respecting my own, 

 I beg to present some corresponding sentences from that note 

 and my own treatise, as the reasons of such remarks; first 

 stating that Mossotti has, in behalf of his theory, introduced 

 some profound mathematical investigations: but we must be 

 aware that such abstruse processes are not to be regarded as 



* Communicated by the Author. 



t A notice of M. Mossotti's views will be found in Lond. & Edinb. Phil. 

 Mag , vol. x. p 320 ; and a translation of his entire paper in Scientific Me- 

 moirs, vol. i. p. 448. — Edit. 



