The Romance of Modern Chemistry

THE ADULTERATION OF FOOD are found to be surprisingly different in shape and size. The granules of wheat starch are circular, those of potato starch are oval, while those of rice starch are many-sided; the granules from maize starch, as found, for example, in cornflour, are also many-sided, but are uniformly much larger than rice-starch granules. It is therefore possible for a skilled analyst to determine with the microscope whether any starch, and, if so, what kind of starch, has been used in adulterating a given food-stuff. He can also discover at once whether a certain kind of starch is pure or is contaminated with another kind. Obviously there is a temptation for the adulterator to add a cheap starch to a more expensive one, say potato starch to arrowroot, keeping the price the same. The microscope, however, soon exposes such a fraud. Substances which in some cases are to be regarded as regular adulterants are those used as preservatives. It is now generally agreed that a dairyman who knows his business does not require to add preservatives such as boric acid and formaldehyde, even in the hottest weather. Moreover, the passage of these substances into the digestive organs is not to edification. The amount of formaldehyde which must be added to milk in order to preserve it is certainly exceedingly small—1 part in 10,000 of milk will keep the latter sweet for five or six days—but it must be remembered that in the case of children who consume considerable quantities of milk, the total amount of preservative taken into the system be- comes appreciable. Similar objection may be taken to the employment of boric (or boracic) acid. This is used as a preservative of milk less frequently than formaldehyde, and it is generally mixed with borax, its sodium salt Boric acid, by the 266