Aerated Saline Water.—In the preparation of waters of the second class, namely, those which contain carbonic acid gas and different saline ingredients in solution, it is necessary only to imitate as carefully as possible the composition of the natural waters. By so doing, artificial waters may be produced which far more closely resemble these than by adopting any of the numerous recipes and formulas which are published for the purpose. The mixtures of the salts, as determined by analysis, may generally be made directly, especially if they are all soluble ; but if they are in soluble, they may often be dissolved by carbonic acid. Some makers obtain by double decomposition certain salts which they require the water to possess. Distilled or filtered rain water should be used in preparing these saline waters ; and for the chalybeate waters, it should be boiled and allowed to cool out of contact with the air. Solutions are generally made and stored in slate tanks, in which the drawing-off pipe is carried up a few inches from the bottom to allow room for the sediment. When small quantities only are required, the bottles are dosed with the exact amount before the carbonated water is let in. Those who wish to avoid the trouble of preparing them, and require only small quantities, can purchase the concentrated solutions ready made.
Many natural waters contain minute traces of bromides and iodides, of manganese, and of phos phoric and fluoric acids. It may be well to remark that it is the opinion of many high authorities that the medicinal virtues of these waters are due rather to the presence of the above substances, and to the high state of dilution in which they are held, than to those salts which are present in far more abundant quantities.
There are also a few saline waters which are not made in imitation of any of the natural springs, bnt which, nevertheless, have many valuable properties, and are widely consumed. The e,ommon recipes for beverages of this kind are given bPlow.
Carrara Water.—Lime water. made from lime made by calcining Carrara marble, supersaturated with carbonic acid under a strong pressure, so that the carbonate of lime at first precipitated is redissolved. It should contain 8 or 10 grm. of carbonate of lime per half-pint bottle.
Chalybeato Water.—Ferrous sulphate, 3 grm.; bicarbonate of potash, 61 grin.; cold rain or distilled water, 1 quart ; mixed and agitated in a corked bottle. This water is equal in tonic pro perties to that of the springs, and rnay be rendered refreshing by aeration at a low pressure.
Lithia Water.—A solution of carbonate of litbia, of any required strength, in aerated water ; or 3 to 5 grains may be placed in the bottle and filled np with highly charged water, and well shaken. Lithia water and potass water are often mixed together.
Magnesia Water.—About 1 oz. of fluid magnesia to a bottle of water ; or carbonate of magnesia may be dissolved in aerated water, under a slight continued pressure, in about the proportion of 1 oz. to 10 quarts of water.
Potass Water.—About oz. of bicarbonate of potash to the gallon is the usual quantity, pro ceeding as described below for soda water.
Seidlitz Water.—Ncarly oz. of tasteless salta of Rochelle, diseolvod in warm water, per gallon of spring water.
Soda Water.—The amount of soda varies with the purpose for which it is required. If it is for medicinal use, as much as 15 grains to the bottle is sometimes employed, or about oz. of bicar bonate of soda per gallon. If sold as a refreshing beverage instead of plain carbonated water, which is often erroneously called soda water, 2 grains, or less, to the bottle is sufficient, or about 1 oz. of bicarbonate of soda to 12 gallons. After mixing, the solution is allowed to settle, and the clear portion filtered through lawn before being passed through the machine.
Aerated Sacch,arine Waters.—The third class, or saccharine aerated waters, consist, as we have remarked, simply of gaseous water sweetened, flavoured, and sometimes coloured with various ingredients; they are coueurned only as refreshing and pleasant drinks. The sugar and flavouring matter are mixed together and dissolvi d in water, e,onstituting what are called syrups ; of these there are many varieties ; their general preparation and a few recipes for the most common, aro given below.
Syrups aro formed by making concentrated solutions of sugar in pure water, or in water con taining the principles of various flavouring substances; the former are called simple, and the latter compound syrups.
There are many precautions to be taken in order to ensure the production of good syrups, the most important being, perhaps, the selection of the sugar. Canc-sugar only should be used, and that should be perfectly refined. The least shade of colour in tho sugar is duo to tho presence of impurities, and syrup prepared from such sugar not only has an unpleasant flavour, but is also very difficult to keep. The use of common or brown augar may be regarded, in many cases, as an adul teration.
Syrups aro very easily prepared. A hemispherical copper basin, not tinned, but well polished, and kept scrupulously clean, is the apparatus en3ployed. This basin stands on three legs, and is furnished with a false bottom, which is also hemispherical. The two hemiTheres are surrounded by a copper oylinder, fitted with a licl; the three parts of the apparatus are fixed together by means of two circular iron rings, which are fitted to tho circumference of the hemispheres and to the bottom of the cylinder, the whole being well pinned or bolted together. A stop-cock in the outer hernisphere communicates hy means of a short pipe with the inner one, and serves to with draw the contents. Another cock, placed almost at tho top, serves for the admission of steam between the two bottoms ; and the condensed water is drawn off by means of a third cock com municating only with the outer bottom, and placed at a short distance from the first. The whole apparatus may be of any convenient size. Its chief advantage is that the syrup can be heated to the required degree with the utmost nicety ; the steam is admitted until this degree is reached, and the supply may then be stopped in a moment, thus ensuring perfect regularity of working.