59 
meter sank 3° or 4° lower, but this was the general tempera- 
ture). After leaving it here for some time we examined it 
carefully ; the prismatic structure was entirely obliterated, the 
only traces of it being the slight surface depressions here and 
there which marked the edges of the prisms, and certain vertical 
chains of small air-bubbles which had formed in the interstices 
at their angles. ‘The ice was very hard, and, when broken, ex- 
hibited the usual conchoidal fracture. I was anxious to see 
whether the prisinatic structure would return as the ice thawed 
again, but unfortunately the fragment laid aside for this pur- 
pose got in contact with some of the melted salt and snow of 
the bath, and was dissolved too rapidly.” 
The author then expresses his opinion, derived from the 
examination of this case and of the ice in some of the glaciéres 
of Savoy, that the axes of the prisms are always perpendicular 
to the ice-surface, whatever its form may be; that the structure 
is only developed under peculiar conditions, viz. when thawing 
takes place slowly and without disturbance in a place sheltered 
from wind and sun. The following table, from the register kept 
by Mr Pain, Sidney Street, shews the temperature in the neigh- 
bourhood during the days of thaw preceding Jan. 26. 
Jan. 22. | Jan. 23. | Jan. 24. | Jan. 25. | Jan. 26. 
At 9 A.M. 282 44°5 51°5 46 40 
During past 24th. 
maximum ... 30 44 53 55 50 
minimum ... 26 22 43°5 42 34. 
March 18, 1867. 
G. KE. Pacer, M.D., ViczE-PREsIDENT, in the Chair. 
The following new Fellows were elected : 
G. H. Evans, M.A., King’s College. 
K. Carver, M.A., St John’s College. 
J. B. Brappury, B.A. and M.B., Downing College. 
R. K. Mitier, B.A., St Peter’s College. 
