This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
In cases of this kind it becomes necessary for the bottler to have resort to a chemical purification of the carbonic acid gas, for which we recommend the use of the following chemicals in connection with the purifiers:
The soda being an alkali, all traces of sulphuric, sulphurous or hydrochloric acid that are caused to be carried through the liquid in the purifier, will neutralize it immediately when coming in contact with the soda from gas, and consequently purify the carbonic acid.
As stated on another page, chunks of marble have the same neutralizing effect, and where they are used, soda can be dispensed with.
It neutralizes bad odors that arise from bituminous or animalic matters contained in the carbonate, with the eliminated gas.
This also disinfects the carbonic acid from contaminating gases.
It is a salt chiefly composed of sulphuric acid, with iron as a base.
On account of the latter, it may appear to some as not being very practical for application, because iron is not a very commendable ingredient to have in connection with mineral waters, for it has a tendency of giving mineral waters mixed with wine or similar mixtures a dark hue when exposed to the atmospheric air for a short time; but for the purpose it is here intended, its actions are entirely to the contrary; it keeps the water of the purifier in a good and healthy state for a time, and disinfects or destroys all impurities embodied within the carbonic acid or which it may perchance carry along with itself. These are not mere suggestions, but are facts based upon numerous experiments and many years of practical experience. Its employment is also recommended by high authorities, and its purifying action upon the liberated gas and consequently upon the beverage will, when applied, soon be noticed.
The chemicals heretofore mentioned are within easy reach of all who desire to make use of them. They are inexpensive and can be had from all dealers in bottlers' supply or from wholesale drug-houses, where they are usually kept in stock. They come in solid form, and must therefore be dissolved in some water previously to being used and the solution filtered and then added to water in purifier. Salicylic acid is used in the form of a solution as described later on.