If tachycardia is the only serious symptom present in a patient who is considered to have hyperthyroidism, it may generally be successfully treated by insistence on quiet, cessation of all physical and exciting mental activities, more or less complete rest, the absolute interdiction of all tear coffee or other caffein- bearing preparations, total abstinence from alcohol, the restriction to a cereal and fruit diet (the withdrawal of all meat from the diet), the administration of calcium, as the calcium glycerophospate in dose of 0.3 gm. (5 grains) in powder three times a day, and for a time, perhaps, the administration of bromids. If the depressing action of bromids on the heart is counteracted by the coincident administration of digitalis, they will act only for good by quieting the nervous system and more or less inhibiting the secretion of the thyroid gland. If a patient has exophthalmic goiter fully developed, absolute rest in bed, with the treatment outlined above, should soon cause improvement. If it does not, the operative treatment as advised above should be considered. If myocarditis has been diagnosed, the minor operations should be done if the patient does not soon improve. The prolongation of the treatment depends on the condition and the amount of improvement. If the physician is in doubt as to whether or not this particular tachycardia is caused by hyperthyroidism, the administration of sodium iodid in doses of 0.25 gm. (4 grains) three times a day will make the diagnosis positive within a few days. If the trouble is due to hyperthyroidism, all of the symptoms will be aggravated; there will be more palpitation, more nervousness, more restlessness, more sweating and more sleeplessness. In such cases the iodid should be stopped immediately, of course, and the proper treatment begun. TOXIC DISTURBANCES AND HEART RATE Under this head it is not proposed to consider disturbances of the heart due to infections, to cardiac disease, or to localized or general acute or chronic disease, but to discuss disturbances due to the absorption of irritants froth the intestines, and to alcohol, tobacco and caffein. It is hardly necessary to repeat that various toxins which may seriously irritate the heart may be absorbed from the intestines during fermentation or putrefactives processes in either the small or the large intestines. The heart may be slowed by some, made rapid by others, and it is often made irregular. The relation of the absorption of intestinal toxins to increased blood pressure has already been described, and the necessity of removing from the diet anything which perpetuates or increases intestinal indigestion in all cases of high blood pressure has already been referred to several times. The indications that such a condition of the intestines is present are irregular action of the bowels, a large amount of intestinal gas, sometimes watery stools, often a coated tongue, and the presence of indican in the urine.