368 Royal Irish Academy, 



lations ; and also to elucidate the general method, so as to render it 

 more easily applicable to other cases which may arise in the further 

 prosecution of the determination of specific indices. For this pur- 

 pose a general statement is given of Mr. Kelland's method, in whose 

 formulae, it is easy, knowing the value of the wave-length in air, 

 and taking the indices as given by observation for that particular 

 medium, to introduce the values of the wave-length in the medium. 

 Two of the constants are then determined for that medium ; and by 

 the aid of these, combined with the indices given by observation, 

 a value of the third constant is deduced for each ray : and the veri- 

 fication of the theory will result from the equality of the respective 

 values of this latter constant thus obtained. 



The author then gives tables exhibiting the comparison of observed 

 refractive indices with the results of Mr. Kelland's theory ; first, in 

 the case of sulphuret of carbon, at a temperature of 12° (centigrade) ; 

 next, of the same substance at 22° ; and lastly, of oil of Cassia : 

 from which it appears, that the accordance between the results of 

 observation and of theory is sufficiently within the limits of the 

 errors in the experimental data to satisfy all reasonable expectation. 



A paper was also in part read, entitled, " Experimental Re- 

 searches in Electricity." Twelfth Series. By Michael Faraday, Esq., 

 D.C.L., F.R.S., &c. 



A letter was read from Dr. Marshall Hall, in reply to a note con- 

 tained in the paper of Mr. Newport, published in the last volume of 

 the Philosophical Transactions. 



[To be continued.] 



ROYAL IRISH ACADEMY. 



Inaugural Address delivered by the President, Sir W. Rowan 

 Hamilton, ^.ikf., F.R.S., Astronomer Royal of Ireland, 

 December 11, 1837. 

 My Lords and Gentlemen of the Royal Irish Academy, 



The position in which your kindness has placed me, entitles me, 

 perhaps, to address to you a few remarks. Called by your choice 

 to fill a chair, which Charlemont and Kirwan, and others, not less 

 illustrious, have occupied, I cannot suffer this first occasion of pub- 

 licly accepting that high trust to pass in silence by, as if it were to 

 me a thing of course. Nor ought I to forego this natural opportu- 

 nity of submitting to you some views respecting the objects and 

 prospects of this Academy, which, if they shall be held to have no 

 other interest, may yet be properly put forward now, as views, by 

 the spirit at least of which I hope that my own conduct will be re- 

 gulated, so long as your continuing approbation shall confirm your 

 recent choice, and shall retain me in the office of your President. 



First, then, you will permit me to thank you for having con- 

 ferred on me an honour, to my feelings the most agreeable of any 

 that could have been conferred, by the unsolicited suffrages of any 

 body of men. Gladly, indeed, do I acknowledge a belief which it 

 would pain me not to entertain, that friendship had, in influencing 



