This section is from the "Elixirs And Flavoring Extracts. Their History, Formulae, & Methods of Preparation" book, by John Uri Lloyd. Also available from Amazon: Elixirs and flavoring extracts,: Their history, formulae, and methods of preparation;
We cannot too strongly condemn the indiscriminate use of nervines in the form of beverages. Perhaps there may be an excuse for the affixing of a name only to a fanciful, harmless syrup, the name reminding one of a remedy, and yet it seems as though the use or imaginary use of medicines should be left to the discretion of physicians.
Such "tonics" even as solution of phosphate of calcium in acid water, so fashionable in some instances at present, may better be left to the discretion of physician prescribers who understand the systemic condition of the "debilitated." It seems to us as though much injury may result in the continued drinking of phosphoric acid and other medicines by persons who do not need such substances, and who simply imagine that they should " take a tonic."
The same remarks apply to "iron tonics" and "calisaya tonics," and other similar syrups; and while "syrup of beef extract" may do no harm, it seems to us enough out of place as a beverage to give even a man in health the horrors and a dislike for beef tea in its proper place. We may, with our views of this matter expressed, be pardoned for omitting formulae for such compounds
Throughout this work various substances for coloring are occasionally commended. They are, or should be, harmless, and are necessary adjuncts, for the public taste must be pampered in the way of bringing certain syrups to resemble the colors of the fruits that they are designed to imitate. It is important that these colors should be innocuous, and luckily the shades desired can be easily obtained. At the present time beautiful, concentrated red, yellow, green, and other colors can be purchased of dealers in essential oils, and are warranted free from any poison or objectionable impurity, and may be substituted for those we commend. The colors we direct may be made as follows (natural fruit syrups do not demand artificial colors).