The medicines which help to promote the oxidation of the food-elements, especially the carbohydrates, are alkalies and iron. Clinical observation establishes this fact as strongly in the treatment of gout as in that of glycosuria. The relative power of the salts of potassium and sodium in augmenting oxidation is not clearly determined. The salts of sodium appear to be most useful in aiding the process of primary digestion, and the potassium salts in improving the process of sanguification. It is well known that potash predominates in the corpuscles and soda in the serum of the blood. The efficacy of the combinations of iron with the salts of potassium, as in Blaud's pills and in the citrate and tartrate of iron and potassium, in the treatment of anæmia, is well known. In the most renowned ferruginous springs, however, such as those of Schwalbach, Spa, Pyrmont, and St. Moritz, the iron is combined with salts of sodium, calcium, and magnesium. It would appear, therefore, that the increased energy of iron in augmenting hæmatosis, when combined with alkalies, is not relatively greater with potash than with either of the other alkaline bases. 4. The promotion of the elimination of the waste products of nutrition is to be accomplished by remedies which act as solvents of uric acid and as diuretics. As solvents of uric acid the salts of lithia and potash have been shown to be superior to those of soda. The urate of lithia is the most soluble of the uric-acid salts, and the low chemical equivalent of the metal lithium makes the neutralizing power of the oxide much greater than that of equal proportions of the other alkalies. It is used in the forms of carbonate and citrate, and is generally combined with potash and soda. It exists in some of the mineral springs of Europe and of this country, but in such minute proportion as probably to be of little value. In administering the salts of potash and soda it is generally admitted that the carbonates and the neutral salts of the organic acids are to be preferred to solutions of the caustic alkalies. They have less power in neutralizing the acid of the gastric juice, and enter the circulation as neutral salts, where they are decomposed into alkaline carbonates by the oxidation of the organic acids, increasing the alkalinity of the serum and acting as diuretics. The combinations of the alkalies with sulphur, with iodine, and with mineral acids, as in the alkaline springs, are frequently used in the treatment of gouty lesions of the subacute variety. The sulphur salts probably owe their chief value to their alkaline bases when they are used internally; and in sulphuretted baths, as before remarked, the good effects are probably due to the high temperature at which the bath is usually administered.