360 



SCIENCE 



[Vol. LV, No. 1423 



in the Great Lakes region. Figure 2 (taken 

 from Davenport and Love^^) shows a map of 

 GOITRE. SIMPLE 



I m torn MCN 



TOTAL, CAMPS AMI kOCAk BOAROS 



the goiter as reported by the Draft Board and 

 we have more or less the same distribution in 

 the opposite direction and see more goiter 

 towards the lake region and less toward the 

 coast. Owing to the fact that no chlorine maps 

 have been made for the rest of the country, it 

 is not possible to extend this comparison. It 

 is reported, however, from various sources (and 

 is my personal observation in Minnesota) that 

 the whole Great Lakes region is quite goiterous, 

 and this is necessarily a region in which very 

 little sea salt falls upon the land since the air 

 blowing over it has already been washed free 

 from sea salt by previous rains. Besides this 

 goiterous region, various mountainous regions 

 in the country have been reported to be goi- 

 terous and this is also true of Europe. These 

 mountainous regions may be relatively near 

 or far in relation to the sea. We often speak, 

 however, of the clear mountain air free from 

 dust, and it seems very probable that sea salt, 

 being very heavy, would tend to remain in the 

 lower strata of air rather than rise to mountaiji 

 heights. Volcanic dust when thrown to great 

 heights may remain in the upper air for a con- 

 siderable time, but this is true only of the very 

 finer particles of dust. The larger particles 

 settle very rapidly. In fact, so rapidly as to 

 sometimes bury towns. We may suppose the 

 same things are true of the sea salt in the air. 



J3 Davenport, C. B., and Love, A. G., 1920. 

 Scientific Monihly. 



The very finest particles may be carried to 

 greater heights than the larger ones, provided 

 they can escape the rain long enough to reach 

 that height in the fli-st place. The volcanic 

 dust is thrown rapidly to the great height. The 

 sea salt is thrown into the air at the sea level 

 and its reaching a great height is very for- 

 tuitous. Therefore, we may suppose that the 

 occurrence of goiter in mountainous regions 

 fits in with the deficiency hypothesis. The ab- 

 sence of iodine from the rain water and soil 

 in a region would necessitate its absence from 

 the plants growing in the region and the ani- 

 mals subsisting entirely upon the plants and 

 rain water. Man, however, may receive con- 

 siderable food from some distance. Food rich 

 in iodine, such as fish, oysters, squid, sea- 

 hares, sea urchin ovaries and sea weed, is con- 

 sumed to a much greater extent along the sea 

 coast than in inland regions. Sea weed is not 

 a general article of diet and is only eaten 

 habitually by the Japanese and certain other 

 peoples living close to the sea. Sea food, 

 owing to its perishable nature, is largely con- 

 sumed close to the sea. Therefore, even with 

 considerable means of food distribution, the 

 relation of goiter to distance from the sea 

 might still be maintained. Water might hold 

 the same relations. Water flows toward the 

 sea and therefore does not bring iodine from 

 regions richer in it. Water courses rise either 

 in mountainous regions or in inland lakes 

 which are goiterous regions. Certain mineral 

 springs may be exceptions but the consump- 

 tion of such mineral water is rather limited. 

 The principal other factor in the diet is salt. 

 Salt was first obtained by the evaporation of 

 sea water. The process used reduces the 

 amount of iodine, but the extent of reduction 

 may depend upon the amount of refining that 

 the salt undergoes. The sea water is evap- 

 orated in shallow ponds until the calcium car- 

 bonate precipitates. It is then further evap- 

 orated in other ponds until the sodium chloride 

 crystallizes out. The mother liquor from the 

 sodium chloride crystals, known by geologists 

 as the bittern, contains most of the iodine 

 along with magnesium chloride and other salts. 

 This crude sodium chloride, which may have 

 some iodine clinging to it, was formerly con- 



