Adulterants in Wheat Flour as Commonly Used

Rice meal, rye flour, potato starch, cornstarch, meal from leguminous plants, as peas or beans, and corn flour; also the following mineral bodies are sometimes used as adulterants: Alum, borax, chalk, carbonate of magnesia, and bone ash.

The tests for these must be mostly made by the chemist and microscopist, as the adulterations are fine, like flour.