AND GEOLOGICAL RELATIONS OF CERTAIN HOT SPRINGS. 
605 
however, I was not able to approach nearer than at one of the cocks in a small esta- 
blishment (belonging to the same proprietor, and also on the left bank of the stream,) 
erected to receive it. I was informed that it was conveyed by thirty or forty yards 
of baked earthen tube, so that the observation is of little value. This may be called 
“ Source Nouvelle de 1835.” The springs of Vernet are sulphureous. 
On the right bank of the river is a new establishment, that of the Bains Mercader. 
A very trifling spring was materially enlarged by judicious boring. As it is received 
by a large covered reservoir, I was unable to ascertain its temperature. 
C. Temperature. — On the subject of the early observations of Carrere, I refer to 
what has been said in the introduction to this paper. Anglada, speaking of the tem- 
perature of the spring A, or Source Intdrieure, expresses regret at a discrepancy of 
1°*4 cent, between his observations and those of M. Arago in 1826. I am enabled, 
however, by the kindness of that philosopher to correct this statement, and to show 
that the coincidence between their observations, and also with mine, is as satisfactory 
as could be expected ; 
Spring A. — Arago, 1826, 55°*8 c. ; Anglada, 55°*62 ; J. D. F., 1835, 55°*7. 
Anglada also informs us that he frequently took the temperature of these springs 
without finding any variation. The following are the particulars of my observations. 
1835, August 29. Elevation of Vernet not known, but may be about 1700 or 1800 
feet above the sea. 
Troughton. Reduced. 
Spring A (Source Interieure) .... 132*3 132*2 
Spring B 124*2 124*1 
“ Source Nouvelle de 1835” 118*9 118*8 
Some other thermal sites occur in the Valley of the Tet, particularly those of Vin§a 
and Molitg ; but being anxious to visit the Valley of the Tech, the extreme southern 
limit of France (in lat. 42° 10'), and the Roman thermal establishment of Arles, I 
crossed the western shoulder of the highly picturesque mountain of Canigou to Prats 
de Mollo, and thence proceeded to Arles, which closes our list of Pyrenean waters. 
XVII. Bains pres d' Arles. 
A. Geological Position. — The situation of the springs near the town of Arles in the 
Valley of the Tech, is perfectly in unison with our general statement of the subject. 
They issue from granite almost close to its junction with limestone*. This is the 
* I have some recollection of having noticed slate rocks between the granite and the limestone just men- 
tioned ; and this is confirmed by the circumstance of M. Arago, in the observations which will presently be 
adverted to, having characterized the principal spring as “ sortant de la roche schisteuse.” This may, how- 
ever, be the slaty granite which so remarkably characterizes the southern side of the Canigou, and my notes 
expressly state that the bed of the torrent issuing from the defile is composed of granite. 
