[3] These beverages appeared in the 1870s, following the advent of development by Harvard professor Eben N. Horsford of a process for "acid phosphates of lime" (patented 1868, later voided), and began promoting it as a health product.
Some businesses realized that the taste of it was quite palatable to consumers when combined with sugar and water, and some innovator came up with the idea of combining it with fruit syrup and soda water, creating a new soda fountain drink.
[4] Its popularity continued into the 1930s, when the trend shifted to ice cream-based parlor drinks.
[3] The original acid phosphate, made by Horsford's chemical company,[3][5] and was a mixture of calcium, magnesium and potassium phosphate salts with a small amount of phosphoric acid producing a liquid mixture with a pH of around 2 to 3, the same as freshly squeezed lime juice.
In the 21st century, bone ash is used primarily in the ceramics industry, and is rarely available as food grade stock.