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;
Fluid extract of ptelea, 2 fluidounces.
Elixir of pepsin, 16 fluidounces.
Powdered wood charcoal, a sufficient quantity.
Triturate the fluid extract of ptelea with powdered wood charcoal in amount sufficient to form a thick, pasty mixture, then gradually add the elixir of pepsin, and filter.
Each fluidrachm of this preparation represents such an amount of seven and one-half grains of the medicinal principles of ptelea as will dissolve in the elixir of pepsin, and two grains of saccharated pepsin. However, as the proper menstruum for extracting these principles from ptelea trifoliata is alcohol of specific gravity 0.820, the elixir is not a representative of the fluid extract of ptelea used in making it. We direct powdered wood charcoal instead of the magnesium carbonate or magnesium phosphate, as the first would neutralize the acid of the elixir of pepsin, while the last would dissolve to a considerable extent.