258 



waves will be possible, the corresponding vibrations of the 

 molecules being in three directions, at right angles to each 

 other, though not, in general, parallel or normal to the wave- 

 plane. Mr, Haughton 'investigates the possibility of the 

 vibrations being normal and transversal, and finds that for 

 particular directions of wave (given in the paper), the vibra- 

 tions are, two in the wave-plane, and the third perpendicular 

 to it. He discusses also at length the other two cases, toge- 

 ther with the equations of condition which hold in general at 

 the limits, and the geometrical interpretation of these condi- 

 tions by means of the fixed ellipsoids (10). 



The President read a note from Edward Cooper, Esq., 

 giving the place of the new Comet, as observed at Markree, 

 May 18d. 12h. 6m. Greenwich mean time. 



DONATIONS. 



Report of the Commissioners appointed to take the Census 

 of Ireland for the Year 1841. Presented by W. R. Wilde, 

 Esq. 



Transactions of the Botanical Society of Edinburgh. 

 Vol. II. Parts 1 & 2. Presented by the Society. 



Lettres a S. A. R. le Due Regnant de Saxe Coburg et 

 Gotha, sur la Theorie des Prohabilites appliquee aux Sciences 

 morales et politiques. Par A. Quetelet. Presented by the 

 Author. 



Annates des Sciences Physiques et Naturelles, d' Agricul- 

 ture et d' Industrie, publiees par la Societe Royale d Agricul- 

 ture, SfC, de Lyon. Tome VII. Annee 1844. Presented by 

 the Society. 



Popery unmasked. By John Ryan, Esq. Presented by 

 the Author. 



The thirteenth Annual Report of the Royal Cornwall 

 Polytechnic Society. 1845. Presented by the Society. 



