AND GEOLOGICAL RELATIONS OF CERTAIN HOT SPRINGS. 
595 
of Europe were affected by the same event*. What shows that these springs are 
much connected with the sources of ordinary springs, is a curious fact mentioned to 
me by M. Barrau, one of the Inspecting Physicians of Luchon. In 1835, after great 
rains (in the month of May if my memory serves me rightly), the same spring, La 
Reine, delivered four times as much water as usual, and its temperature fell 16° 
Reaumur. This continued for twenty-five days, when it resumed its former state. 
The following Table contains: 1. The observations of Camperdon in 1761 ; 2. Those 
of M. Barrau in 1818 ; 3. Two sets of observations by M. Boisgiraud, Professor of 
Chemistry at Toulouse, made at two different periods. I have reduced the whole to 
Fahrenheit’s scale. 
Cajiperdon, 1761. 
Baruai;, 1818. 
Boisgiraud. 
1832, Sept. 16. 
1833, Aug. 19. 
Reaum. 
Fahk. 
Reaum. Fakr. 
Cent. Fahr. 
Cent. Fahr. 
O 
o 
o o 
o o 
o o 
La R.eine 
41 = 
124-2 
39 = 119-7 
50-45 = 122-8 
50-45 = 122-8 
La Grotte Superieure . . 
51 = 
146-7 
50 = 144-5 
58-75 = 137-8 
61-25 = 142-3 
Source aux Yeux 
22 = 
81-5 
39 = 119-7 
45-5 =113-9 
46-3 = 115-3 
La Blanche 
18 = 
72-5 
23 = 83-7 
34-75 = 94-6 
22-65 = 72-8 
La Froide 
22-25 = 72-1 
21-1 = 70-0 
M. Boisgiraud’s observations were made with great care ; I had an opportunity 
of verifying the accuracy of the copy I obtained of them by the originals. M. Bois- 
giraud informed me that he had verified the zero of his thermometer by frequently 
plunging it in melting snow. The obvious conclusion is that the springs of Bagneres 
de Luchon are quite useless for the solution of the problem in which we are engaged. 
For the reasons already mentioned I confined my observations to the two first. 
Troughton. Reduced. 
1835, August 14. — La Reine HO’7 110 6 
La Grotte Superieure . . 139‘1 1 39* 1 
Hence it would appear that the Source de la Reine has by no means recovered its 
former temperature, since the derangement of the year 1835, above noticed. 
IX. Lez. V alUe d' Aran, in Spain. 
A. Geological Position . — This trifling thermal site, of which, from being little 
known, I had heard exaggerated accounts, is chiefly interesting from the conformity 
of its geological position with that of more important springs. The springs of Lez 
rise near the boundary of a patch of granite on which the Spanish town of Bososte 
* See Gairdner on Mineral Springs, p. 211. A most extraordinary effect of an earthquake which occurred 
in the Pyrenees since my visit, has been stated to the Academie des Sciences ; namely, that on that occasion 
a strong sulphureous smell was perceptible in the air in the environs of Gavarnie. It is not in the least unlikely 
that some of the springs I have noticed have already changed their temperature. See L’lnstitut (Journal), 
Decembre 1835. 
4 G 2 
