Such adulteration is rendered possible by the presence in the bean of a large proportion of fatty matter or cocoa-butter, which renders it too rich for most digestions. To overcome this difficulty one or other of two methods is available: (1) Lowering the percentage of fat by the addition of starch, sugar, etc.; or (2) removing a large proportion of the fat by some extractive process; this latter method being in every respect preferable to that first mentioned. [Illustration--Drawing: COCOA ADULTERATED WITH ARROWROOT OR POTATO STARCH.] In order to avoid the expense and trouble consequent on the latter process, some manufacturers add alkali, by which means the free fatty acids are saponified, and the fat is held in a state of emulsion, thus giving the cocoa a false appearance of solubility. Another effect of the alkali is to impart to the beverage a much darker colour, from its action on the natural red colouring matter of the cocoa, this darkening being often taken, unfortunately, as indicative of increased strength. On this account the presence of added alkali should be regarded as an adulteration, unless notified on the package in which the cocoa is contained. A more subtle treatment with alkali for the same purpose is the addition to the pulverized bean of carbonate of ammonia, or caustic ammonia. This is afterwards volatilized by the application of heat. Scents and flavourings are then added to disguise their smell and taste. Besides these combinations of cocoa with starch, sugar, etc., and cocoa treated with alkali, there are now found on the market mixtures of cocoa with such substances as kola, malt, hops, etc., sold under strange-sounding names, reminding one of the many mixtures that are made up as medicines rather than food. While the substances thus incorporated are of value in their place, they possess no virtues which are absent from the pure cocoa, and cannot be in any way considered an improvement of cocoa as food. The sooner this practice of drug taking under cover of diet comes to an end the better it will be for the national health.