144 READINGS IN BIOLOGICAL SCIENCE 



times by as much as 40 per cent, and in adults there is often loss of hair. 

 The skin, especially of the face and hands, may thicken and become 

 puffy giving rise to a condition known as myxedema. Inadequate develop- 

 ment or atrophy of the thyroid in the young child produces a condition 

 known as cremiism characterized by retardation in mental, physical and 

 sexual development. The tongue and abdomen of the cretin tend to pro- 

 trude and the legs are usually bowed. Permanent dwarfism is established. 

 Such children, if treated in time with thyroxin or dried thyroid gland often 

 show remarkable improvement, both in body and mind. 



Simple goiter usually reveals itself through pathological enlargement 

 of the thyroid gland. That iodine deficiency is an important and possibly 

 the sole cause is indicated by the fact that many remarkable cures have 

 been effected in early stages through the administration of iodine in some 

 form, and by the fact that this type of goiter can be largely prevented 

 through the use of food which contains traces of iodine, or by the oc- 

 casional addition of small quantities of iodine salts, commonly sodium 

 or potassium iodide, to ordinary food. That this is an important matter, is 

 evident from the fact that in the so-called "goiter belts" some 25 per cent, 

 of the men and some 50 to 60 per cent, of the women show at least traces 

 of thyroid enlargement. Goiter is very common in the Great Lakes re- 

 gion of our own country and is usually found in glaciated regions where the 

 iodine content of soil and water is low compared with that of coastal 

 plains. The Andean plateau in South America, the Alps, Pyrenees and 

 Carpathian mountain regions of Europe, and the Himalayan plateau in 

 Asia are all characterized by a high incidence of goiter. 



The well-known experiments of Dr. Marine in Akron, Ohio, seem to 

 have been the beginning of our present-day widespread administration 

 of iodized salt to school children. He found that of 2,190 children treated 

 with iodine, only 5 had goiter at the end of the experimental period, 

 whereas of 2,305 similar children not given iodine 495 displayed goiter. 

 After eleven years of the systematic use of iodized salt on the part of 

 school children in Detroit under the supervision of the pediatric section 

 of the Michigan State Medical Society', the incidence of enlarged thyroid 

 had been cut from 35 per cent, to less than one per cent. Similar results 

 have been achieved in other states. Cleveland, Ohio, seemed to be an out- 

 standing exception at one time, inasmuch as, following the use of salt, the 

 drop in thyroid enlargement was only from 31 per cent, to 18.5 per cent. 

 When the city health department investigated the matter, however, it was 

 found that two of the local manufacturers of the iodized salt being used 

 were providing a salt that contained only one-third of the amount of 

 iodine stated on the label, and that, furthermore, a large chain store was 

 selling a brand that contained no iodine at all. In one canton of Switzer- 

 land where 50 per cent, of newborn babies had thyroid enlargement, after 

 the use of iodized salt was made compulsory for pregnant mothers, not a 



