Prof. Pictet on the Ice-caves of- the Jura and the Alps. 9 
height above the village of Brezon, that is 462 toises above the 
lake. 
“ The discharge of cold air was not confined to the orifice 
mentioned above. There issued a stream more or less cold and 
rapid, from all the natural and irregular openings in the verti- 
cal rock, of which I have been speaking. The direction of the 
canal, by which it issued, was downwards, and plunged into the 
mass of rock at an angle of 15° or 20°. 
“ It is impossible to estimate either the thickness of the ice 
contained in this cavern, or its surface, which is very irregular. 
A part of it was evidently a remnant of the winter’s snow ; the re- 
mainder derived its origin from the local congelation of the wa- 
ter operating as in the cavern of St George’s. The guide as- 
serted that the process of congelation took place in summer also.” 
After descending to the plain, we passed the night at Bonne- 
ville. The next morning, at three quarters past five o’clock, we 
set out for Scionzier, a village situated at the entrance of the 
valley of Reposoir, by which we were to ascend to the Ice Cave 
of the Vergy Mountains. We arrived at the village at a quar- 
ter past seven o’clock. Weakened by the illness of the evening 
before, I took a horse for part of the ascent from the village. 
Our guide had, in 1807, accompanied two of our countrymen 
(MM. Necker and Colladon), in the same excursion we in- 
tended to make ; and he believed, that since that period,- no 
one had, from curiosity, visited the cavern, which is much less 
known than it deserves to be. We skirted along the side of a 
narrow and wooded valley, in the bottom of which rolled the 
foaming torrent called Foron. In this region, entirely calca- 
reous, we frequently met with enormous rounded blocks of gra- 
nite, deposited on the steep side of the valley, at the epoch of 
the grand convulsion, which brought them from the central 
chain of the Alps. It is difficult to conceive how these blocks 
could reach this height, in a narrow and steep pass, shut up at 
the highest extremity by a circle of very lofty peaks. 
In skirting along the southern face of the Vergy Mountains, 
which we did during the whole route, we remarked that the 
calcareous beds which compose them, are, on this side, almost 
vertical, resting against the chain, in the same manner as we see 
them in looking from the north side, on the road from Bonne- 
