It is often observed that patients affected by exophthalmic goiter have a decreased vital capacity, and in taking the vital capacity of a number of such patients we noted that in several instances patients with the high basal metabolic rates had a relatively lower vital capacity than those with low metabolic rates. These observations prompted investigation to determine whether there is any fixed relationship between basal metabolism and vital capacity, and whether the thyroid secretion which causes the variations in metabolic rates likewise has an indirect compensatory action causing parallel fluctuations in the vital capacity. If this should be true, there would be at our disposal an easy method for determining thyroid activity.
With this purpose in mind, eighty-five subjects with goiter were examined. The diagnosis as to the type of goiter in each instance was based on the clinical findings, basal metabolic rates and postoperative histologic diagnosis in the