78 THE THYROID AND 



of observations that in goitre the thyroid colloid is 

 exceedingly deficient in iodine, both in calves and 

 man. Thus we get a clue to the successful treatment 

 of the affection either by iodiferous compounds 

 or by thyroid extract. It is well known that either 

 of these remedies will cure early cases of goitre, 

 before the enlargement becomes chronic. The 

 success of the iodiferous rock-salt on the American 

 farms may be accounted for in the same way. An 

 explanation is also offered of the fact, noticed 

 previously, that the whelps of bitches from whom 

 a good part of the thyroid has been removed are 

 all goitrous, the plasma supphed to the foetal glands 

 evidently containing a deficiency of iodine derived 

 from the maternal thyroid. Of 2,333 cases of con- 

 genital goitre collected by Fabre and Thevenot,* the 

 mother was almost invariably goitrous. The foetal 

 thyroid enlarges in order to obtain as much iodine 

 as it can. 



It was natural to suggest that the waters of the 

 Kropfbrunnen were deficient in iodine, but this 

 theory would overlook the fact that the bulk of our 

 iodine is derived from vegetables, not from drinking- 

 water, and as a matter of fact these wells show no 

 constant deficiency or excess of iodine. It is more 

 probable that they contain minute traces of some 

 metal having a great affinity for iodine, and forming 

 with it an insoluble compound. It is quite conceiv- 

 able that boihng the water might precipitate such 

 a metal. There are probably many metals, known 



* Revue de Chirurgie, June 10, 1908. 



