Factitious Mineral Waters. These are the imitations of different celebrated springs, whose waters have more or less medicinal properties; they are prepared by adding to pure water the ingredients which the original spring water is found, by chemical analysis, to contain. Under this class are also included tho ordinary aerated or carbonated waters, which are known as soda waters. The majority, whether plain or medical, are charged with carbonic acid gas by the powerful apparatus employed by manufacturers of soda waters (see No. 718 (To Charge Champagne with Gas)); the gas being evolved by tho action of weak sulphuric acid on marble chalk, whiting, etc.. Some few obtain their carbonic acid gas by the action of an acid and an alkali introduced into tho bottle, and instantly corked. Tho quantity of gas introduced is usually about 5 times tho volume of tho liquid. In making chalybeate and sulphuretted water, tho water should bo previously boiled, to expel all air from it.

4431. Simple Aerated Water

4431. Simple Aerated Water. Carbonic acid gas water. Water charged with five or more volumes of carbonic acid gas, by means of a suitable apparatus. (See No. 718 (To Charge Champagne with Gas).)

4432. Alkaline Aerated Waters

4432.     Alkaline Aerated Waters.

Aerated soda and potash waters should be made by dissolving 1 drachm of the carbonated alkali in each pint of water, and charging it strongly with carbonic acid gas. The soda water usually offered for sale contains little or no soda.

4433. Aerated Magnesia Water

4433.      Aerated Magnesia Water. This is a solution of magnesia of various strengths, charged with carbonic acid gas in the same manner as other aerated waters.

4434. Murray's Fluid Magnesia

4434.    Murray's Fluid Magnesia may be thus made: To a boiling solution of 16 ounces sulphate of magnesia in 6 pints water, add a solution of 19 ounces crystallized carbonate of soda in the same quantity of water; boil the mixture till gas ceases to escape, stirring constantly; then set it aside to settle; pour off the liquid, and wash the precipitate on a cotton or linen cloth, with warm water, till the latter passes tasteless. Mix the precipitate, without drying it, with a gallon of water, and force carbonic acid gas into it under strong pressure, till a complete solution is effected. The Eau Magnesienne of the French Codex is about a third of this strength; and some fluid magnesias prepared in this country are not much stronger. Dinneford's preparation is similar to the above.

4435. Carbonated Lime-Water - Carrara Water

4435.   Carbonated Lime-Water - Carrara Water. Lime-water (prepared from lime made by calcining Carrara marble) is supersaturated, by strong pressure, with carbonic acid, so that the carbonate of lime at first thrown down is redissolved. It contains 8 grains carbonate of lime in 10 fluid ounces water.