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;
Cinchonidine (alkaloid), 128 grains.
Simple elixir, phosphoric acid (U. S. P., 1872), of each a sufficient quantity.
Powder the cinchonidine, and triturate it in a mortar with two fluidounces of simple elixir. When a smooth, creamy mixture results, continue the trituration, and gradually add of phosphoric acid an amount sufficient to dissolve the cinchonidine; then mix this solution with a sufficient amount of simple elixir to make the whole measure sixteen fluidounces, and filter if necessary.
Each fluidrachm (teaspoonful) of the finished elixir contains of phosphate of cinchonidine an amount which is equivalent to one grain of cinchonidine.