350 



sultants, and the pulsations seen in many aurorse may be real lu- 

 minosities. 



It is hazardous, in the present ill-arranged state of auroral obser- 

 vation, to offer so rude a sketch of a new hypothesis, although we 

 may suffer a considerable defeat in very good company. 



Since the previous note was written, I find that M. Morlet has 

 published a theory of the auroral arch (Ann. de Ch., t. xxvii., 3me 

 Serie). The ideas above were stated by me two years ago, to differ- 

 ent persons. 



The following Donations to the Library were announced : 



Transactions of the Royal Scottish Society of Arts. Vol. III., 



Part 4. 8vo. — By the Society. 

 Journal of the Asiatic Society of Bengal. Edited by the Secretaries. 



N. S. No. 32. 8vo. — By the Society. 

 Annali di Fisica dell' Abbate Francesco Car. Zantedeschi. Fasci- 



colo 4. 8vo. — By the Author. 

 Quarterly Journal of the Chemical Society. Xo. 9. Bvo. — By the 



Society. 

 Scheikundige Onderzoekingen gedaan in het Laboratorium der 



Utrechtsche Hoogeschool. 5''« Deel. 6th Stuk. 8vo. — By the 



University. 

 Bulletin de la Societe de Geographie. 3""^ Serie. Tom. 12'°e. 1849. 



Bvo. — By the Society. 



ERRATUM, 

 Vol. II., No. 33, page 205, line 12 from bottom, 

 For " These data are (1.)," &c., read '■ These data are (1.), The known expan- 

 sion of water in freezing ; (2.), The known quantity of heat which 

 becomes latent in the melting of ice ; and (3.). The quantity of work 

 given out.'" &c. 



