280 



Anniversary Meeting. 



[Nov. 30, 



decomposed ; at least tlie spectra they offered were the spectra of their 

 constituents. 



In a recent memoir, which has only just been published in the Philoso- 

 phical Transactions, Professor Pliicker has investigated the two totally dif- 

 ferent spectra frequently afforded by the same elementary substance accord- 

 ing as it is submitted to the instantaneous discharge of a Ley den jar charged 

 by an induction-coil, or rendered incandescent by the simple discharge of 

 the coil, or else, in some cases, by ordinary flames. The two spectra show 

 a remarkable difference in character, and are not merely different in the 

 number and position of the lines which they show. Some phenomena 

 which he had previously noticed receive their explanation by this twofold 

 spectrum. 



This difference of spectra is attributed by Professor Pliicker, with the 

 greatest probability, to a difference in the temperature of the flowing gas 

 when the two are respectively produced. The discovery opens up a new 

 field of research, the exploration of which may throw much light on the 

 correct interpretation of celestial phenomena, especially in relation to the 

 physical condition of nebular and cornetary matter. 



Professor Miller, 

 As we have not the pleasure of the presence of Professor Pliicker, I 

 must request you, as our Foreign Secretary, to transmit to him this 

 Medal. He will see in it the strongest evidence of the high estimation in 

 which his labours in various lines of scientific research are held in this 

 country ; and I trust you will also express to him the great pleasure which 

 this award gives to his numerous friends here, some of whom have been 

 his fellow-labourers in the same researches. 



A Royal Medal has been awarded to Mr. William Huggins for his 

 "Researches on the Spectra of some of the Chemical Elements, and on the 

 Spectra of certain of the Heavenly Bodies ; and especially for his Re- 

 searches on the Spectra of the Nebula, published in the Philosophical 

 Transactions. 



The researches on the stellar spectra referred to in this award were made 

 by Mr. Huggins conjointly with our highly valued Treasurer and senior 

 Vice-President, Dr. "William Allen Miller. The position of the latter as 

 one of the ofiicers of the Society and a member of its Council has forbidden 

 tlie consideration of his claims to share in the honours which the Society 

 can bestow ; and in conformity with the spirit of this, our " self-denying 

 ordinance," it v/ould be my duty to dwell altogether on the merits of our 

 Medallist, if, indeed, it were possible in this case to separate between the 

 merits of the two authors of the conjoint research. This is scarcely 

 possible, and I must be excused, therefore, if I sometimes speak of them 

 together. 



