IT IS VERY EVIDENT that the mineral content of our food-stuffs is a matter of some concern, and any misgivings we may have regarding its sufficiency are due to the fact that there is in this century an ever-increasing tendency on the part of manufacturers and traders to tamper with, and affect prejudicially, many of our staple food-stuffs. On account of the introduction, nearly a quarter of a century ago, of the roller process of milling wheat, and of a growing demand for white flour, a very large percentage of the mineral constituents of wheat are now eliminated from marketable flour. Within recent years even the wholesomeness of this has been lowered by the injudicious exposure of much of the flour on the market to the influence of some bleaching reagent like nitrogen peroxide.