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XXXII. — On the Temperature of certain Hot-Springs in the Pyrenees. By 

 R. E. ScoEESBY- Jackson, M.D., F.R.C.P., Lecturer on Materia Medica and 

 Therapeutics at Surgeons' Hall, Edinburgh. 



(Read ISth January 1864.) 



Having determined to spend my autumn holiday in the Pyrenees, it occurred 

 to me that I might add a linlc to a very interesting chain of observations which 

 was begun by one of the Vice-Presidents of this Society in the year 1835. 

 Twenty-eight years had elapsed since Principal Forbes made his careful obser- 

 vations of the temperatures of certain of the Pyrenean hot springs ; and I thought 

 that if I could repeat his experiments after so long an interval, the results might 

 not be without some interest.* 



A visit to the Pyrenees in the year 1835 was so far uncommon as to make a 

 description of the places through which the traveller passed a source of enter- 

 tainment to the general as well as the scientific reader ; but now such description 

 would be tedious. Then, too, some remarks were necessary touching the geolo- 

 gical features of the localities where the springs existed ; but it is unnecessary to 

 repeat them now, for I am not aware that the explorations into the rocks in 

 search of new springs, or of a more abundant supply of water from the older 

 springs, have altered the relations as described by Principal Forbes. Therefore, 

 respecting the natural aspect of the country, beautiful though it be, and its geo- 

 logical features, I shall have nothing to say ; and as I have no new theory of the 

 cause of thermal springs to propound, I need not repeat the speculations with 

 which we are familiar. 



The temperature of thermal springs is interesting in a variety of aspects. 

 The geologist and the chemist are alike concerned in it, and to the physician it 

 is a question of no slight importance. In the treatment of diseases by mineral 

 waters, temperature is a cardinal element ; indeed in many instances the thermal 

 feature appears to be that by which alone the water is characterised as a medi- 

 cine. Physicians who frequent the bathing places during the season when in- 

 valids resort to them, and who have unusual facilities for witnessing the ejffects of 

 mineral waters, have great confidence in the curative power of heat. In esti- 



* See Principal Forbes' paper " On tlie Temperatures and Geological Relations of certain Hot 

 Springs, pai'ticularly those of the Pyrenees" — Philosophical Transactions, Part II. for 1836. 



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