70 On Mineral Waters* 



February 1822, Messrs. Monticelli and Govelli discovered in 

 a crater of Vesuvius, a layer of snow, of a foot in thickness, 

 and which had lain there for a couple of days ; nor did these 

 gentlemen experience the slightest inconvenience on applying 

 the hand to the margin of a canal, formed of congealed lava, 

 although a stream of red-hot lava was flowing through it at the 

 time. 



In considering the origin of thermal springs, I cannot omit 

 adverting to the warmth that prevails in the interior of the earth. 

 Observations made in the mines of Cornwall and other dis- 

 tricts have shown, that, at no great depth, the temperature is 

 augmented in no inconsiderable degree. Thus, in a mine of 

 New Spain, Von Humboldt found the temperature at a depth 

 of 1647 feet, to be 32 degrees higher than at the surface. To 

 the influence of this principle, in imparting warmth to the pene- 

 trating atmospheric fluid. Professor Berzelius and, with him, 

 M. Brognard are inclined to attribute the less ardent tem- 

 perature of springs, like those of Bath and Clifton, as the soil 

 in which they are generated has not a volcanic character. 



The next objection urged against factitious mineral waters^ is, 

 that the means which Nature employs in their formation are 

 enveloped in mystery, but that they probably differ from those 

 which are in the power of Art. 



This objection is obviously devoid of meaning. It is the 

 properties of the two products that it is our business to com- 

 pare, and not the causes that co-operated in their formation,— 

 for the cause ceases in the effect. Sufficient reasons were, 

 however, thought to have been discovered for overturning the 

 ancient Plinian doctrine : '' tales sunt aquae, qualis terra per 

 quam fluunt." 



The aggregate quantity of water flowing from the source of 

 the Sprudel, at Carlsbad, in a single year, is calculated to con- 

 tain fourteen millions of pounds of carbonate of soda, and 

 nearly twenty-two millions of pounds of Glauber's salts. This 

 quantity, multiplied by the number of years the Sprudel may 

 be supposed to have existed, (and it has flowed to our know- 

 ledge for nearly five centuries,) appears so enormous, that na- 

 ture was assumed to have fixed on the inmost recesses of the 

 earth for her laboratory, and there, aided by the powers of elec- 



