120 University Geological Survey of Kansas. 
actly imitating those found in nature, and the same physician 
introduced these waters into medical use. More recently this 
business has been greatly extended all over the world, and at 
present imitations of all the famous natural mineral waters are 
prepared in the laboratory. Indeed, after a study of the com- 
position of a particular water, the bottler prepares a similar 
beverage, which is not identical, however, because certain sub- 
stances, considered of no use, are left out in compounding. 
By the use of carbon dioxid it is possible to hold in solution 
mineral substances which would otherwise be precipitated as 
soon as the water is exposed to the air. This is especially true 
of the compounds of manganese, iron, calcium, and magnesium. 
It is probable that the carbonic-acid gas is of service also in dis- 
placing the air, and so preventing oxidation and sometimes de- 
terioration of the waters. 
The manufacturer of the artificial mineral water uses, as far 
as possible, ingredients which will, when added to water and 
carbonated, give constituents similar to those in the natural 
water. These chemical salts must be of such a character that 
they will not be incompatible or precipitate each other. The 
recently precipitated hydroxids or carbonates are much more 
soluble than the ordinary dry salts, and, in the process of com- 
pounding, groups of substances in solution are added in a defi- 
nite order. Some substances, such as citric acid or sodium 
pyrophosphate, are often added as ‘‘ preservatives ’’ of these arti- 
ficial waters, the object being especially to keep iron in solution. 
THE MANUFACTURE OF CARBON-DIOXID GAS. 
Since the time of Priestley, who, in 1772, made an apparatus 
for the production of ‘‘ fixed air,’’ as he called it, from a mix- 
ture of chalk and ‘‘oil of vitriol,’’ to the present time, a great 
deal of ingenuity has been expended on apparatus for this pur- 
pose. Historically considered, the following types of appa- 
ratus have been introduced : 
The Geneva or Semi-continuous System.—This is the old form 
of generator used in Kurope. The gas was generated in a 
43, A Treatise on Beverages, or the Complete Practical Bottler, Chas. H. Sulz. 
