PART I. THE RELATION BETWEEN THE PERCENTAGE OF IODIN AND THE PHYSIOLOGIC ACTIVITY OF THE THYROID.
The question of the relation of iodin to the thyroid had been a subject of active discussion for many years, even before the discovery by Baumann (in 1895) that iodin is usually present in this gland; this interest resulted from the fact that iodin had been in constant use in the treatment of goiter since about 1820. In fact, substances containing iodin had been used in the treatment of this condition for many centuries before the discovery of iodin itself. With Baumann's discovery, however, a new era in the physiology of the thyroid began. The view that the function of the thyroid consists, in part at least, in the production of an internal secretion and that this secretion contains iodin, rapidly gained favor.Apparently the earlier workers in this field had no doubt about