From the 1902 second edition (first English edition) of Dr. Paul Zipperer’s The Manufacture of Chocolate and Other Cacao Preparations:
"Cacao husks are the only byproduct in the cacao industry, which has developed to such a considerable extent, with corresponding increase in the byproduct, that a rational use for the husks has become a matter of urgent necessity. The husks are not used in our industry, for an admixture of husk is not permissible, even in the inferior kinds of chocolate or cacao powder, but must be regarded as an adulteration" (71).
"One of the most objectionable forms of adulteration of cacao powder is the admixture of husk" (205).
"Chocolate, cacao mass and cacao powder (de-fatted, soluble cacao) should contain no foreign vegetable admixtures, such as starch, meal, earth-nut-cake, hazel nut or walnut pulp, no cacao husk or waste, nor any foreign mineral ingredients or foreign fat" (232).
"The following are to be considered as adulterations: the addition of cacao husk, foreign husks, saw dust" (241).