THE THYROID 29 



that develop, and by the ready response to treat- 

 ment with thyroid extract. Poultices of burnt sea- 

 weed a fruitful source of iodine and iodine itself 

 painted on the skin, were used for this disease long 

 before it was known that the thyroid contained this 

 element. 



Iodine an essential element. Now as to the io- 

 dine itself, is it really essential to the body? An 

 element can neither be synthesized in the labora- 

 tory nor in the body ; it can merely be obtained from 

 nature or from compounds that already contain it. 

 If we deprive our food of all iodine we deprive the 

 thyroid of what seems to be its essential element. 

 Yet the situation is not as clear as it seems; for 

 though many experiments have shown that thyroid 

 activity and the iodine content of the gland go hand 

 in hand, yet cases are known of animals, it is 

 true where the thyroid contains no iodine at all, 

 and yet the animal seems quite normal. On the 

 other hand, in endemic goiter some remarkable 

 cures have been obtained by the administration of 

 simple inorganic iodides. Marine and Kimball, of 

 the Western Keserve University, Cleveland, started 

 in 1917 with a survey of the incidents and types of 

 thyroid enlargement in the schoolgirls of Akron, 

 Ohio, from the fifth to the twelfth grades inclusive. 

 For treatment they used sodium iodide, which was 

 taken in doses of three grains daily for ten consecu- 

 tive school days, repeated each spring and autumn. 



