This section is from the book "Monograph on Flavoring Extracts With Essences, Syrups, and Colorings", by Joseph Harrop . Also available from Amazon: Monograph On Flavoring Extracts With Essences, Syrups And Colorings.
It has been stated that any harmless mucilaginous substance will answer to hold the foam on soda water. Gum Arabic, Gelatin, the White of Egg, and more recently the Mucilage of Irish Moss, have been recommended and used for such purposes.
Of all the articles used for causing soda water to froth or foam, we find nothing that will answer the purpose to the entire satisfaction of the public taste, half so well as albumen in the form of white of egg.
It is also guaranteed to fill up a drain pipe much more rapidly than any other known substance.