CATARACTS AND INUNDATIONS. 183 



cording to the best chemists ; and that we shall not speak of bi- 

 tuminous \vaters, because none such have been yet found. 



It appears to us, that all mineral waters may be arranged in four 

 classes, viz. acidulous, saline, sulphureous, and ferruginous wa- 

 ters. 



Acidulous Waters. Gaseous waters, which may with more 

 propriety be called acidulous waters, are those in which the carbo- 

 nic acid predominates ; they are known by their sharp taste, and 

 the facility with which they boil and afford bubbles by simple agi- 

 tation : they redden the tincture of turnsole, precipitate lime water 

 and alkaline sulpliures. As no waters have yet been discovered 

 which contain this acid pure and alone, we think this class may be 

 divided into several orders, according to the other principles con- 

 tained in them, or the modifications they exhibit. They all appear 

 to contain more or less alkali and calcareous earth ; but their dif- 

 ferent degrees of heat afford a good criterion for dividing them into 

 two orders; the first might comprehend cold, acidulous, and alka- 

 line waters, such as those of Seltzer, Saint-Myon, Bard, Langeac, 

 Chateldon, Vals, &c. in the second might be placed, hot, or ther- 

 mal, acidulous, and alkaline waters, as those of Mount D'Or, 

 Vichy, Cliatelguyon, &c. 



Saline or Salt ll'aters. By the name of saline waters, we un- 

 derstand such as contain a sufficient quantity of natural salt to act 

 strongly on the animal economy, so as most commonly to purge. 

 The theory and nature of these waters are easily discovered ; they 

 perfectly resemble the solutions of salt made in our laboratories ; 

 but they almost always contain two or three different species of 

 salts. The sulphat of soda is very rare ; sulphat of magnesia, 

 Epsom salt, marine salt, or muriat of soda, calcareous and mag 

 nesian muriats, or the saline principles which mineralize them, either 

 together or separate. The waters of Sedliz, of Scydschutz, and of 

 Egra, abound with Epsom salt, frequently mixed \\ith muriat of 

 niagnesfa. Those of Balaruc contain uwriat of soda, chalk, and 

 the calcareous and magnesian muriats ; those of Bourbonne, mnriat 

 of soda, sulphat of lime and chalk ; and those of la Motbe contain 

 muriat of soda, sulphat of lime, chalk, sulphat of magnesia, muriat 

 of magnesia, and an extractive matter. It must be here observed 



O 



that salts, with base of magnesia, are much more common in waters 

 than has hitherto been supposed ; and that few analyses have \e$ 



$ 4 



