The simplest form of manufactured water made from this pure distillate is that which is charged with pure carbonic dioxid. The carbon dioxid which is employed is usually collected from natural sources, that is, from springs which give off natural carbonic acid, or is manufactured by chemical means, usually by the action of an acid or marble or limestone.

The carbon dioxid given off naturally from springs is to be preferred, because it is the natural gas which is produced in and found with natural waters.

The carbon dioxid arising from fermentations is not desirable for this purpose, because of its carrying certain odors due to its origin.

The gas produced by chemical means may be purified, and is probably purer carbon dioxid than that derived from either of the other sources mentioned.

It is, of course, the duty of the manufacturer to see that the carbon dioxid which is used is thoroughly washed and purified so that it may enter the water under the most favorable conditions. The water being subjected under pressure to gas of this kind absorbs certain quantities of it, which convert the insipid and dead water into effervescing, pleasant and agreeable drinking water.

Waters thus charged are usually kept in syphons for use. The syphon should be made in a sanitary way, and no lead or zinc pipes or tubes should come in contact with the liquid. The proper material for making the delivery tubes of the syphon is block tin. Thus charged the waters are easily adapted to use, and are kept sparkling until the contents of the syphon are exhausted.

These carbonated waters are also put up in bottles, with corks so secured as not to be blown out by the pressure of the gas. Waters of this kind are known to the trade as carbonated waters, and sometimes simply by the word carbonic.

Kinds of Artificial Waters: - The number of artificial waters which have been offered to the public is almost as great as those of natural origin.

By means of a chemical analysis the composition of a natural mineral water at any given time can be accurately determined. Experience has shown that a natural water does not always have the same quantity of mineral constituents. Not only may the actual contents of mineral matter in natural water vary, but often the proportions of the mineral substances as related to each other may change. This is due to the fact that mineral waters are affected, more or less, by the rainfall, so that the flow of a spring is greater at one season than at another. This increased flow tends, at least in some cases, to diminish the percentage of mineral matter in the water. Then, too, the mineral matters in the water are obtained by solution of mineral substances over which the water passes. It is evident that, in the progress of solution at first, more easily soluble mineral substances are extracted, and thus these will appear in larger quantities. Thus, while it is possible to imitate the natural water by the manufacture of a product containing the same mineral ingredients, it is evident that this imitation would only be true for the analysis of the water at any given time, and not for the variations which might arise at subsequent times.

It is practically impossible to exactly imitate the natural water by any artificial means, but, it is easily possible to make artificially a water which has in general a resemblance to that of natural origin.