Natural History, fyc.. 417 



3. ON THE THERMAL WATERS OF CHAUDES AIGUES, IN THE 

 DEPARTMENT DU CANTAL. (M. Chevalier.') 



The little village of Chaudes Aigues is situated to the south of St. 

 Flour, on the border of a stream in a pleasant valley, surrounded by 

 high mountains. Its mineral waters have long enjoyed some cele- 

 brity, but have fallen into medical disuse. At present establishments 

 are forming for the reception of patients, and many circumstances 

 combine to render the place agreeable and tempting, and so to favour 

 the enterprise. The sources of the Par, which is the largest of all, 

 yield 230 cubic metres and 4 decalitres every twenty-four hours ; its 

 temperature is at 80 C. (170 F.) It is this water which the inhabi- 

 tants employ by means of ingeniously contrived conduits, which 

 conduct it to the houses, to give warmth during the winter: in the 

 summer they turn it away towards the river, that they may not be 

 inconvenienced by its heat. This practice should be followed at 

 other towns where there are sources of hot water, as at Plombieres, 

 Aix, &c. M. Berthier has calculated, that the water of the Par is equi- 

 valent, as a heating agent, to the wood which would be furnished by a 

 forest of oaks 540 hectares (1334 acres) in area. The water of this 

 spring is clear, limpid, and almost tasteless ; it leaves a slight ochra- 

 ceous film upon stones ; it becomes spontaneously covered with a 

 thin oily film, but may be retained a long time unaltered. It issues 

 from massive sulphuret of iron, and its channels are obstructed by a 

 deposit of the same substance. 



The second spring is that of the mill of Ban. It flows over 

 quartz, serving as the gangue for sulphuret of iron. This water is 

 conducted to the hospital and several private houses, in the same 

 manner, and for the same purpose, as the preceding water. 



The third spring, that of the Grotto of the mill, is particular in 

 this circumstance, that, though less hot than the others, it follows 

 exactly the same changes of temperature. At its source it disen- 

 gages carbonic acid mixed with oxygen and azote. 



The Maison Felgere is in possession of four springs, one of 

 which is at the temperature of 70 C. (158 F.) The water of the 

 river, heated by all these streams, is said to be more favourable in 

 exciting vegetation than other rivers. 



These waters, besides being applied to heat apartments, are used 

 also to cleanse wool, and M, Felgere has formed an establishment for 

 the hatcliing of eggs, in imitation of that arranged by M. d'Arcet, at 

 Yichey. 



M. Chevalier has obtained, by chemical analysis, from 20 litres 

 (1220 cubic inches) of the Par water : i. A trace of hydrosulphuret 

 of ammonia, which appears to be formed by the action of heat. ii. An 

 organic animaiizcd matter, which appears as flocculi, when the water 

 is evaporated, and sometimes occurs united to carbonate of lime, 

 iii. 18.86 grammes (291 grs.) of a light solid substance, more than 

 half composed of subcarbonate of soda. These waters, by their heat 



