June 25, 1897.] 



SCIENCE. 



975 



i-^i^ - ^i per gram of fresh tissue. Iodine has 

 likewise been detected in the human hy- 

 pophesis.* 



In human thyroids, on the other hand, 

 as well as in the thyroids of sheep, oxen 

 and pigs, iodine is most generally present 

 in quite appreciable amount, and pure 

 iodothyrin may contain as much as 10 per 

 cent, of the element. In iodothyrin the 

 iodine is in close combination with the rest 

 of the molecule and is not easilj'^ split off 

 even by the action of alkalies. It is notice- 

 able that the thyroids of sheep (and of other 

 -animals) vary greatly in their content of 

 iodine. Thus in sheep coming from Frei- 

 burg 1 gram of dry thyroid gland contained 

 on an average 0.9-1. .3 milligrams of iodine, 

 while the thyroids from Paris sheep con- 

 tained 1.15-1.2 milligrams of iodine per 

 gram of dry gland, and those from Elberfeld 

 1.5-5. milligrams per gram of dry tissue. As 

 judged by the rate and intensity of physio- 

 logical action 0.25-0.3 milligram of iodine 

 in the form of iodothyrin is equal to 1 gram 

 of fresh thyroid gland. Further, according 

 to Baumann, doses of 1 milligram of iodo- 

 thyrin which contain only yty milligam of 

 iodine will produce a decided effect upon 

 goitre after 3-4 applications, thus clearly 

 indicating that it is not the iodine per se 

 that is effective, but rather the iodine com- 

 pound. 



The content of iodine in human thyroids 

 is likewise variable, the determining factor 

 being apparently the locality in which the 

 individual lived. Thus, in 26 adults dying 

 from various causes in Freiburg the aver- 

 age amount of iodine in the thyroid was 

 0.33 milligram per gram of dry tissue, while 

 in Hamburg the average from 30 adults 

 was 0.83 milligi'am per gram of drj^ tissue. 

 In Berlin, average of 11 adults, 1 gram of 

 dry thyroid contained 0.9 milligram of 



*Sclinitzler unci K. Ewald; Ueberdas Vorkommen 

 des Tbyrojodins im mensclilicben Kcirper. Wiener 

 klin. Woohensohr., 1396, p. 657. 



iodine. It should be noted, however, that 

 in the Freiburg cases the average weight 

 of the gland was 8.2 grams with a total 

 content of 2.5 milligrams of iodine. In 

 Berlin, on the other hand, the average 

 weight of the dry gland was 7.4 grams with 

 a total content of 6.6 milligrams of iodine 

 per gland, and in Hamburg the dried gland 

 weighed only 4.6 grams, with 3.83 milli- 

 grams of iodine. 



Eecently "Weiss* has reported the results 

 from fifty analyses of thyroids of adults and 

 children in Silesia, the average weight of 

 the dried gland being 7.2 grams and with 

 an average content of 4.04 milligrams of 

 iodine. 



From a large number of observations 

 among children and adults in different 

 localities in Germany, Baumann concludes 

 that in Freiburg, where goitre is endemic, 

 the weight of the thyroid is the largest and 

 its content of iodine the lowest, while in 

 Hamburg and Berlin, where goitre is not 

 endemic, the reverse holds good. As a rule, 

 in cases of goitre only minimal and almost 

 always relatively small amounts of iodine 

 are to be found, from which Baumann 

 draws the conclusion that between the 

 iodine-content of the thyroid and the oc- 

 currence of goitre there is a certain definite 

 relationship. 



I understand, however, that additional 

 results, not yet published, tend to show 

 that in some cases of goitre the content of 

 iodine is far beyond the normal, thus im- 

 plying the existence of two abnormal con- 

 ditions : one in which the iodine- content 

 is below, and another in which it is far 

 above the normal. In old age the content 

 of iodine frequentlj' falls to a minimum, ap- 

 parently in harmony with the degeneration 

 of the gland. The largest amount of iodine 

 is found between the ages of twentj^-five 



*Ueber den Jodgehalt von Solulddriisen in Sehlesien 

 Chemisclies Central-Blatt, 1897. Baud 1, p. 298. 



