1 4 Prof. Pictet on the Ice-caves of the Jura and ike Alps. 
The cold caves called Cantines , at Chiavenna, in Italian 
Switzerland, rest against a rock from whence issues a cold wind, 
which Saussure ascertained, August 5. 1777, at noon, to be at 
45° Fahr., while the external air was at 70°. 
Those which he had observed with the greatest attention, 
says he, and where he found the air the coldest, were those of 
Caprino on the edge of the lake of Lugano, at the foot of a 
calcareous mountain, the very rapid declivity of which termi- 
nated close to the foot of the lake. 
In the first visit which Saussure made to these caves, in June 
29. 1775, the external air was at 79° in the shade, and the 
thermometer suspended at the extremity of the caves fell to 
37V 
In the second visit (August 1. 1777), the air without being 
at 72°J, the thermometer fell only to 42° in the cave. These 
caves are not deep, their bottom is level with the ground, and 
the cold air comes out from between the pieces of rock against 
which they are placed, and only at certain points opposite to 
which they have made holes in the wall of the inner end. 
The last caves of this sort, which our learned and indefati- 
gable philosopher has visited, are those of Hergisweil, on the 
banks of the Lake of Lucerne, in the territory of Underwald, 
and at the foot of the mountain called Reny, which forms one 
of the bases of Mount Pilatus. The cold caves are simply 
little wooden huts, except the back wall, which is built of dry 
stones, against the accumulation of rubbish at the foot of the 
rock. 
On the 31st July 1783, the thermometer was at 73°.2 in the 
shade, and at 39° J in the interior of the hut. The proprietor 
affirmed to Saussure, that milk could be preserved in it for 
three weeks, meat for a month, and cherries from one season to 
another. Near this hut, there was another similar, where they 
preserved snow, which was sold in summer at Lucerne. This 
last fact connects very closely the series of phenomena, of which 
I have just given an account, with those which the natural ice- 
caves have presented to us. 
There is another circumstance which must not be omitted, 
that in winter congelation takes place a little later in these huts 
than in the open air, but it afterwardsjTreezes harder in the huts: 
