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.
Whiting or chalk contains about 40 per cent. of its weight in carbonic acid, also frequently oxide of iron, magnesia, silex, etc., in varying proportions. Animal and bituminous matters are also very frequent components of natural whiting, and if not thoroughly purified the carbonic acid gas produced thereof will be of a bad odor, as those impurities give cause to rise of inferior gases, that adhere to the carbonic acid, and if not most carefully purified, will contaminate the beverage.
Only the finer and purified grades of whiting ought, therefore, to be used in the manufacture of mineral waters, or it will, like impure marble dust, be a source of endless trouble, and a low-graded carbonated drink will be the result. Whiting is used by a few in this country, and almost only where English machinery is employed. It is decomposed by the action of sulphuric acid almost exclusively in the United States. Muriatic acid also decomposes whiting readily, even in diluted form, but it should be used only when peculiar circumstances command it, and then not in a powdered, but rather coarse state, as with its use many inconveniences arise which are sometimes difficult to overcome, especially if the gas is not most carefully purified. The residue is sulphate of lime when sulphuric acid is used, and chlorcalcium when muriatic acid has been employed.
From the National Bottlers' Gazette we extract the following: "The main source of supply of commercial chalk is from the cliff-hills along the shores of the North Sea and the banks of the English Channel, where it is found in deposits of vast extent, through which are occasionally distributed more or less rounded nodules of flint, together with, very rarely, a specimen of petrified fish. Chemically, it is almost wholly calcium carbonate, with small and varying traces of ferric oxide, alumina, magnesia and silica. The so-called ' French chalk' does not contain any calcium carbonate, but is a hydra ted magnesium silicate, used for ' filling' soaps. Next, and of far less importance than the common, white variety, is the 'black chalk,' a soft carbon-like schist that may be used in writing or drawing; 'brown chalk,' an umber-like body, and 'red chalk' or 'riddle,' an impure earthy variety of haematite. The red varieties in general may contain as much as 9.28 per cent silica, 9.6 per cent, ferric oxide, and 1.43 per cent, alumina, and the Norfolk red chalks, in particular, leave, on treatment with acids and subsequent drying, 9.3 per cent, argillaceous residue, consisting of water, ferric oxide and alumina, with a small proportion of magnesium and potassium.
"Chalk is brought from Hull or London, England, on board ships as ballast, in the form of yellowish-white or white (with occasional traces of red from traces of ferric oxide), insoluble, soft and friable earth-like masses, irregular in shape and size, variable in weight, and having a rough, irregular fracture, and insipid taste; specific gravity varying about from 2.4 to 2.6; absorbent of moisture; containing 5, 10, 20 or more per cent. of water. ' Cliffstone' is the name given to a variety of chalk, from which it differs mainly in being much more hard and stone-like. The source of supply is not necessarily limited to England, since France exports from her shores a much finer crude product; the only objection to whose employment, in certain cases, being its lack of body, yet, if desired, the English and French articles may be mixed with the best of results. In our country an inferior quality, and apparently limited supply, is furnished by the States of North Carolina, Colorado, and the interior of Dakota, which has, as yet, failed to receive any special attention, or whose development has not been deemed of sufficient importance to prosecute".