In group 5 the lithium carbonate is dissolved in the acids (see also group 2), the iron and manganese salts are dissolved in 5 parts of boiling, or 10 parts of cold, water, the solution quickly filtered, the acids added to it, and the whole mixture added to the fountain already charged with gas, the cap being quickly taken off, and the solution poured in. The iron and manganese salts easily oxidize and produce turbidity, therefore the atmospheric air should be carefully {740} blown off under high pressure several times while charging fountains. The substances mentioned in group 7 are never put into the fountain, except the arseniate of sodium in the case of Vichy water, which contains but a trifling amount of this compound.
Most of the solutions may be prepared beforehand and be used when required, thus saving considerable time.
Formulas for various waters will be given at the end of this article.
A question which arises in preparing mineral waters is: What is the best charging pressure? As a general rule, they are charged to a lower pressure than plain soda; good authorities even recommend charging certain mineral waters as low as 30 pounds pressure to the square inch, but this seems much too low a pressure for the dispensing counter. From 50 to 120 pounds pressure would be a good limit, while plain soda may be served out as high as 180 pounds. There must be enough pressure completely to empty the fountain, while enabling sufficient gas to be retained by the water to give it a thorough pungency. Moreover, a high pressure to the mineral water enables a druggist at a pinch, when he runs out of plain soda, to use his Vichy water, instead, with the syruped drinks. The taste of the Vichy is not very perceptible when covered by the syrup, and most customers will not notice it.
Apollinaris Water.—
| Sodium carbonate | 2,835 grains |
| Sodium sulphate | 335 grains |
| Sodium silicate | 10 grains |
| Magnesium chloride | 198 grains |
| Calcium chloride | 40 grains |
| Potassa alum | 57 grains |
| Magnesium carbonate hydrate | 158 grains |
| Iron sulphate | 21 grains |
Hunyadi Water.—
| Magnesium sulphate | 400 parts |
| Sodium sulphate | 400 parts |
| Potassium sulphate | 2 parts |
| Sodium chloride | 31 parts |
| Sodium bicarbonate | 12 parts |
| Water | 1 quart |
Lithia Water.—
| Lithium carbonate | 120 grains |
| Sodium bicarbonate | 1,100 grains |
| Carbonated water | 10 gallons |