GROUP II  . Alkalis.—This includes caustic potash, caustic soda, solution of ammonia, their carbonates and bicarbonates, borax, soaps, lithium carbonate and citrate, quicklime, slaked lime, chalk, magnesia and magnesium carbonate . All these substances, apart from any other actions, exert a similar effect upon the body in virtue of their alkalinity . When they are taken internally in small amounts they neutralize the acids in the stomach and other parts of the alimentary canal, and at the same time they increase the normal acid secretion of the stomach . After absorption into the blood, which they make somewhat more alkaline, they are excreted chiefly in the urine, to which they impart an alkaline reaction if given in sufficient quantity . Some of them by stimulating the kidney cells act as diuretics, but others apparently lack this action . Caustic potash and caustic soda are locally very irritating, and destroy the tissues, but lose this quality when combined with acids as in the case of their carbonates, bicarbonates and borax . Quicklime is also caustic, but magnesia is bland and unirritating . Weak solutions applied locally saponify fats, soften the epidermis, and thus act as slight stimulants and cleansers of the skin . Calcium salts form insoluble soaps with fats, and combine with albumen in a manner which makes them soothing and astringent rather than irritating . Apart from alkaline effects, these metals differ considerably pharmacologically . Potassium and lithium have a depressing action upon the nervous system, ammonium salts have a stimulating action, while sodium practically speaking is indifferent .

Calcium and magnesium have actions somewhat similar to that of potassium . Most of these substances are normal constituents of the body, and indispensable for healthy existence . They are contained in sufficient amount in our

ordinary dietary to supply the needs of the organism .