Page:The American Cyclopædia (1879) Volume XI.djvu/614

596 MINERAL WATERS Berzelius and the German physician Struve; but the latter, who proved the practical value of the invention, and founded, as Berzelius did in Stockholm, the first manufactories or spas in Dresden (1818-'20), Leipsic, Hamburg, Ber- lin, St. Petersburg, and Brighton, is deservedly called the father of artificial mineral waters. By powdering the clinkstone of Bilin and sub- jecting it to the action of carbonic acid water, under a slight hydrostatic pressure, he pro- duced a mineral water identical with that of the natural spring of Bilin. Faraday and Lie- big pronounced his artificial Carlsbad and Friedrichshall bitter waters to be identical in chemical composition and physiological action with the natural waters which they represented. Artificial mineral waters have some advantages over natural waters. The supply of the latter exported from the springs of continental Eu- rope is inadequate for the demand, and most natural waters lose materially by bottling. The springs too are subject to many changes, and frequently vary in the quantity or the relative proportion of their mineral ingredients. Arti- ficial waters, on the contrary, are prepared according to analyses which represent the natural mineral waters when in their best con- dition. They are always the same in compo- sition, in consequence of the technical perfec- tion of their manufacture, and they produce the same general effect as the natural waters. They are more highly charged with carbonic acid gas than the latter, which insures their keeping in any climate and renders them more pleasant to the taste. The manufacture of mineral waters also embraces composition waters, devised for special medical purposes, and the beverages soda water, seltzer water, &o. The most important constituent of all these waters is carbonic acid gas, which is pre- pared by decomposing carbonates of lime and bicarbonates of soda with acids, especially sul- phuric acid, in a vessel called the generator. Carbonates of lime contain from 41 to 52 per cent, of carbonic acid ; bicarbonates of soda, 47'62 of soda and 52*38 of carbonic acid. Dis- tilled water is used in making mineral waters, pure well or spring water for soda water, &c. Water absorbs nearly its own volume of car- bonic acid gas at 60 F., and the absorption is increased by reduction of temperature, increase of pressure, or both. The principal substances or salts used in the manufacture of mineral waters are comprised in the following groups : 1, chlorides of magnesium, calcium, strontium, and lithium, carbonate of lime and of magne- sia, and sulphate of magnesia ; 2, the alkaline salts; 3, the salts of iron and of manganese. Waters containing sulphuretted hydrogen gas can never be perfectly imitated, because the for- mation of this gas is a continual process of decomposition, originating from the reaction of organic matter upon the sulphates. In the construction of the manufacturing apparatus two different systems are followed: 1. The Geneva system, an improvement of Struve's ' original apparatus. In this the carbonic acid gas passes from the generator through purify- ing vessels or bottles containing partly water, partly certain solutions of salts, and thence into the gasometer, out of which it is pressed by a pump into the mixing cylinder, where the water is impregnated with it. Between the pump and the cylinder is placed the repurgator, a cylindrical tube of strong sheet copper con- taining fine charcoal, in which the gas under- goes a final purification. The water is then impregnated with the gas by revolving a pad- dling shaft which passes through the middle of the mixing cylinder. The latter is nrovi- ded with a manometer which indicates the pres- sure of the gas, tubes through which the wa- ter enters, a safety valve, and a water gauge. Bramah's apparatus is of similar construction, but has some improvements. In it the water to be aerated and the expanded carbonic acid gas are pumped in the proper proportions into the receiving vessel, where they are mixed and the aeration completed. This system is more generally in use in England and France than in Germany. 2. The self-generator system, after which the apparatus of Ozouf, Gappard, and Savaresse are constructed. It dispenses with the pump and gasometer, the water being impregnated by the pressure of the gas itself. The generator which contains the carbonates is filled with hot water to a certain height, and a square cooling apparatus is therefore applied between the washing vessels and the cylinder. This apparatus is not so expensive as the for- mer, but is less recommended on account of the imperfect purification of the gas and its liabil- ity to explosion. The apparatus of Mr. John Matthews of New York, which is now widely introduced in Europe, is a combination of the Bramah and the self-generator systems, the mechanical devices of the former being greatly simplified, and the lia- bility to explosion of the latter being obvi- ated by a safety cap. This cap consists of a duplex disk, a, a nut, J, screwed firmly against it, a lead wash- er, c, to close joint on the generator bung, and an aperture, d, through which the gas escapes when the disk is ruptured by Matthews's Apparatus, undue pressure. Af- ter the mineral water is made, it is drawn from the apparatus into fountains (portable cylinders), siphons, or bottles, the faucets and filling and corking apparatus being so con- structed as to prevent the loss of carbonic acid. For use, the fountains, which resemble the mixing cylinder in construction, are placed as reservoirs under or behind the marble case on the counter. The case contains ice in a cooling chamber, through which the connecting pipes