MINERAL WATERS. 



593 



Kubjccts or other matters of individual conscience. 

 Any attempt to inquire into the sentiments of the 

 voter is not only an abuse, but one which it is the 

 chief purpose of the ballot system to prevent. Any 

 law making party affiliations or political or religious 

 opinions attest of qualification for holding an office 

 created is unconstitutional. 



The Supreme Court of the United States has 

 decided a law of Michigan taxing traveling 

 salesmen from other States to be unconstitu- 

 tional. 



Population of Cities. The following are the 

 chief cities of the State, with their population 

 in 1880 and 1884: 



!* Incorporated after 1880. 

 The total population of the State in 1884 

 was 1,856,100. 



MINERAL WATERS. Mineral waters, in the 

 medical acceptation of the term, are waters 

 that are charged, during their filtration 

 through the earth, with certain fixed or vola- 

 tile substances which make them available in 

 the prevention or cure of disease. They are 

 thus distinguishable as medicinal waters from 

 those which contain inert or harmful constitu- 

 ents. 



Origin. Mineral waters generally flow from 



! the deeper superficial strata of the earth's crust. 



It was formerly held that their elements were 



combined in the earth under the influence of 



electricity, as in Lavoisier's experiment ; but 



, it ia now admitted that their source is the 



rainfall of the region, which penetrates the 



crust of the earth to a considerable distance, 



!, and fills subterranean reservoirs of water, often 



' under great pressure. These reservoirs become 



charged with the soluble elements of the strata 



around them, and are forced to the surface, 



i whether by the pressure of gases upon them 



I or by hydraulic pressure, as in the case of the 

 VOL. xxv. 38 A 



jet from an artesian well. At Carlsbad the sub- 

 terranean reservoirs are so near the surface that 

 borings have been made into them, the sound 

 penetrating to an immense depth through three 

 layers or roofs of accretions. After these were 

 bored through, a large reservoir of boiling 

 water was found, the bottom of which could 

 not be sounded. Water and gas rushed through 

 the opening with great violence. In many 

 cases rain or dryness influences the abundance, 

 the temperature, or the strength of mineral 

 springs. Many of the most important mineral 

 springs, and especially the warm springs, are 

 found at points where there is evidence of vol- 

 canic disturbance ; but the warmest springs, at 

 least in Europe, are those which have main- 

 tained the most remarkable uniformity of their 

 heat and of their mineral constituents during 

 the present century, a time during which they 

 have been measured, thermometrically and 

 chemically, with increasing accuracy. 



The permanence of hot springs is remarkable. 

 In Greece, says A. von Humboldt, the springs 

 of Castalia, Pirenae, Cassotis, and Erasinos still 

 flow at the same places as during the classic 

 age. Cases of considerable variability have, 

 however, been known; and, after the great 

 earthquake of Lisbon (1755), most of the warm 

 springs of Europe became warmer and flowed 

 more abundantly for a time ; for an hour and 

 a half the water of Toplitz, in Bohemia, turned 

 reddish yellow, and the springs of Clifton, Eng- 

 land, were turbid. 



Temperature. Mineral waters that are warm- 

 er than the average temperature of the air 

 whence they emerge are classified as warm or 

 thermal springs ; but the term is generally re- 

 stricted to those which have a temperature 

 above 80 Fahr. This greater heat may be 

 derived from two distinct sources ; namely, 

 from adjacent volcanic action, or from the 

 central heat of the earth. The latter agency 

 is often the more powerful. The aguas calien- 

 tes of Venezuela, which spring far from all 

 volcanoes in regular beds .of granite, have a 

 temperature of 207 Fahr., while the springs 

 near the active volcanoes of Pasto, Cotopaxi, 

 and Tunguragua range from 97 to 130 only. 

 The Calistoga hot spring, in California, ranges 

 in temperature from 150 to 195 Fahr.; the 

 Santa Barbara springs are 112. The Califor- 

 nia geysers throw out vast quantities of water 

 that is nearly at the boiling-point. The ther- 

 mal mineral springs are, as a rule, more effect- 

 ive medicinally than the cold. 



Constituents. The main bases that are found 

 in mineral waters are magnesia, soda, potassa, 

 lime, and alumina; the main acids and gases 

 are carbonic, sulphuric, and silicic acid, chlo- 

 rine and iodine. The salts are all derived by 

 solution from the strata through which the wa- 

 ter is forced or percolates. The sulphates and 

 chlorides, as Dr. Walton remarks, are readily 

 dissolved by pure water, and when water is 

 highly impregnated with carbonic acid and 

 with oxygen, its solvent power is greatly in- 



