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 §. A. R. le Duc Regnant de Saxe Coburg et 
Gotha, sur la Theorie des Probabilites appliquée aux Sciences 
morales et politiques. Par A. Quetelet. Presented by the 
Author. 
Annales des Sciences Physiques et Naturelles, d Agricul- 
ture et d’ Industrie, publieés par la Société Royale d Agricul- 
ture, &c., 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. 
