The cocoa bean, which was mentioned as the source of chocolate and cocoa-butter, is also the source of the beverage known as breakfast cocoa. The cocoa bean contains caffein, though the per cent is considerably less than in coffee or tea. Cocoa is practically free from tannic acid. For these reasons, and because of its food value, it is decidedly the least harmful of the narcotic beverages. Cocoa, though being in reality more tasteful and nutritious than either coffee or tea, is less used because it lacks the stimulating effect.

The various alkaloid poisons thus far discussed form but an infinitesimal part of the great group of articles used by old school physicians in the treatment of disease, and by civilized people as stimulating and sedative beverages.