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.
The popular notion seems to demand so-called "nerve food beverages" at the soda fountain or in bottled goods. These nerve food beverages, phosphate beverages, or others claiming the same results, appear with the most mystifying names, and all assert the same positive properties, and all pretend to restore every individual case to the soundest health, energize the brain, invigorate the system, strengthen the body and so on. All sorts of melodious names are given to those beverages or extracts, etc. We do not intend to cast any discriminating remarks on the valued compounds; they may all be serviceable; but we claim that those compounds should be definite in composition, appropriate in application, and specific in effect. Most of the nerve foods are about alike; a little different flavor and more or less syrup constitute the measure of their variety and service.
There are phosphate syrups and phosphate and cream phosphate extracts in the market, also phosphate and iron compounds, which are well spoken of, and if prepared with absolutely pure phosphoric acid (which see later on) may serve as a mild tonic in carbonated beverages. Phos-pho-citric acid is another compound that made its appearance, and it is claimed should serve as a tonic.
The National Bottlers' Gazette, New York, properly remarks: "It is a serious problem for the physiological chemist to discover the best method of supplying the human system, especially an exhausted one, with the requisite amount of phosphatic food for the organism to remain in health. The phosphatic salts are never wanting in the most nourishing varieties of food, whether vegetable or animal. They are closely allied to all the vital functions, are constantly being eliminated from the body, and must be replaced by a fresh supply. The testimony of thousands goes to show that, under the prevalent conditions and habits of American life, there are few who are not greatly benefited when they partake of these same phosphates as restorative agents. The sales of phosphatic preparations for medicinal use, or as a mild tonic in carbonated beverage form, have assumed enormous proportions".This is very true; however, if we think of the deplorable compounds flourishing amongst the public, and swallowed in the hope of restoring vital functions, doing more harm than good, we think humanity rather suffers than benefits. Suits at law have exposed the fact that some nerve foods are only solutions of volatile oils; in one case the components were oil of sassafras and wintergreen. This is rather favorable for humanity, except for the fraud practiced.
We have seen formulae published directing strychnine as well as nux vomica tinctures to be used for carbonated beverages, and we wonder at their publication, as we are convinced of their unfitness and dangerous consequences. Think of a customer swallowing, on a hot day of much exercise, many bottles of carbonated water, admixed with that dangerous stuff. It might result fatally. And the manufacturer could and should be held lawfully responsible. Where an absolute necessity for "nerve food" exists, we recommend the use of the " phosphate syrups" with the addition of phosphoric acid or phosphates, the formulae of which are appended later on under "Compound Syrups". No special phosphate ex-tract or essence whatever is required for the bottler's purpose, as any flavor desired may be added to the syrup. Syrups mixed with wine, liquors, flavors, and with a small portion of phosphoric acid or phosphates, as the trade may require, tinctures of iron, for phosphate iron compounds (see Compound Syrups), may even enter, but all those liquids must be kept from any contact with metal. We refer to and append under the heading of " Phosphoric Acid," later on, the proportions which may be used per gallon of syrup.