Since the medical profession is unable to determine just what rheumatism is, it is difficult to prescribe a diet. The theory so long believed that it is caused by an excess of uric acid in the system is no longer held by most of the advanced physicians. Uric acid, however, sometimes accompanies the disease. Some authorities hold that it is a nerve difficulty; others that it is caused by an excess of lactic acid; others hold that it is caused by infection from the tonsils and the gums. Assuming that it is due to the failure of the system to promptly eliminate its waste, whether this failure to eliminate be through a weakened condition of the nerves, and the consequent failure to properly direct the body activities, the correction of the difficulty must lie in building up the general vitality and in aiding the system in its elimination. Hot sweat baths, a free use of water, and a free use of fruits and fruit juices, particularly the citrus fruits, such as lemons, oranges, limes, etc., are desirable in moderation, because they increase the alkalinity of the blood, and because of their diuretic effect. Lemonade, orangeade, and all fresh fruits and vegetables are diuretic. The diet should be cut down in quantity. If an excess of uric acid exists, meat may be eliminated and the suggestions given in the diet for Gout may be followed. The food must be plain and well cooked, not highly seasoned, and the amount must be confined to the needs of the system as shown by the general condition. Regular exercise, until the body is thoroughly heated, deep breathing of pure air day and night, and a copious drinking of water are necessary. * * * * * [Sidenote: Leanness] No definite diet can be given here for flesh building, because a lack of sufficient fat to round out the figure is due to faulty digestion or assimilation. It may be that the strength of the muscles and nerves of the stomach, liver, and intestines should be built up by exercises and deep breathing, and it may be that the habit of nerve relaxation must be established. When the nerves are tense much nourishment is consumed in nervous energy and the nerves to the digestive organs and muscles being disordered, they interfere with digestion and assimilation. It is apparent that the cause of the lack of flesh must first be corrected. Merely to give a fat-building diet may overload deranged digestive organs with sugars, starches, and fats, further weakening them.