i 



215 



pear as unexpectedly as they come : hence the inference is drawn, 

 that the true cause of this phenomenon is atmospheric, and that it is 

 perhaps connected with some highly rarefied material, disseminated 

 in cloud-like, though invisible, masses in the very highest regions of 

 our atmosphere, and possibly the same with that which, when ignited 

 by the passage of electric currents, gives rise to many, if not all, the 

 phenomena of the aurora borealis. Frequent instances occur of the 

 proximity of minute stars to nebulas j an appearance which naturally 

 suggests the idea of their composing planetary systems : for the enor- 

 mous magnitude of the nebulae, and its consequent probable mass, 

 may, notwithstanding the rarity of its material, give it a gravitating 

 energy, capable of retaining, in orbits three or four times their own 

 diameter, and in periods of great length, small bodies of a star-like 

 character. 



Lastly, the author offers some temarks on the constitution of ne- 

 bulae which have an elongated or elliptical form, of those which are 

 double, and of those to which the epithets of hairy or filamentous have 

 been applied ; and considers their relations to ordinary physical laws. 



Anniversary Meeting, Nov. 30th, 1S33. 



HIS ROYAL HIGHNESS THE DUKE OF SUSSEX, K.G., 

 President, in the Chair. 



The President delivered the following Address: 



Gentlemen, 



The third anniversary of my election to this Chair affords me 

 asrain the opportunity of expressing my grateful thanks for the kind- 

 ness which I have continued to receive from you. I would willins-ly 

 enlarge upon a topic which is so grateful to my feelings, -were I 

 not conscious that by so doing I should merely vary the form of 

 phrases which the natural expression of my sentiments prompted me 

 to use when I have before had the pleasure of addressing you, whilst 

 the sentiments themselves remain not merely unchanged, but, I 

 trust, likewise unchangeable. If I am thus brief, therefore, Gentle- 

 men, in the public declaration of my acknowledgements, from a fear 

 of being tedious by their too frequent repetition, I hope that you will 

 not upon that account consider them the less sincere, or that the 

 long experience which I have had of your support and co-operation 

 has made me less sensible of their value. 



When I last had the honour of addressing you, it was a source of 

 pride and happiness to me to be empowered to announce to you the 

 gracious intentions of His Majesty to continue to the Royal Society 

 the Annual Grant of two Gold Medals, which had been previously 

 conferred on the Royal Society by his Royal Predecessor. 



It must be well known to you. Gentlemen, that these Royal 

 Medals were not adjudged during the two first years that I presided 

 over the Roval Societv ; and as there exist manv circumstances con- 



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