350 OCCURRENCE OF IODINE IN THE 



employed, since they may occasion loss of iodine owing to the 

 formation of insoluble silver iodide. The reagents used were 

 repeatedly examined for iodine with negative results. In test- 

 ing the efficiency of the method when applied to large quan- 

 tities of material, I have found no difficulty in recovering at 

 least T^ mgr. iodine when ^ mgr. iodine as KI were added to 

 about 15 grams of dried serum-proteids or fibrin. 



A summary of a few analyses of thymus and thyroid glands 

 from infants follow. The weight of each thymus varied from 

 three-quarters to three grams, dried ; the thyroids were some- 

 what smaller. 



The thymus and thyroid glands of four infants at full term 

 were examined for iodine with negative results. In the same 

 glands from two infants about 24 days old, the thymus contained 

 no iodine, while the thyroid contained 0.07 mgr. iodine. The 

 thymus from the following individuals likewise showed no iodine 

 whatsoever. 



Infant 26 days old ; cause of death : gastritis. 

 " 48 " " " " inanition. 



" 2 months " " " ileo-colitis. 



4i " " " pneumonia. 



g ( It U 



" 8 " " " colitis. 



" 20 " " " " ileo-colitis. 



As regards the thyroid, these results correspond with the 

 observations of Baumann * and of Miwa and Stolzner,f who 

 likewise examined the thyroids of young infants without find- 

 ing iodine in the great majority of cases. H. G. Wells, J how- 

 ever, has reported the finding of traces of iodine in thyroids 

 of infants at full term. With reference to the thymus it is 

 evident that the absence of iodine is noticeable even in older 

 individuals in which a considerable accumulation of iodine in 

 the thyroid has already taken place. I have made similar ob- 

 servations in the case of a dog of ten kilos. The thyroids, 



* Baumann, Zeitschrift fur physiol. Chemie, 1896, xxii, p. 11. 



t Miwa und Stoltzner, Jahrbuch fur Kinderheilkunde, 1897, xlv, p. 87. 



J H. G. Wells, loc. cit., reprint, p. 25. 



