OF THE OCCURRENCE OF IODINE IN THE 

 THYMUS AND THYROID GLANDS.* 



BY LAFAYETTE B. MENDEL. 



THE announcement of Baumann's discovery of iodine as a 

 normal constituent of the thyroid gland directed attention to 

 the possible occurrence of this element in other organs of the 

 body. For the most part, the investigations in this direction 

 have yielded negative results. In the case of the ovaries, the 

 occurrence of iodine in very minute quantities has been 

 reported by several investigators.f The presence of minimal 

 quantities of iodine in the hypophysis has been asserted by 

 some writers,^ while others, have failed to detect it. In the 

 adrenals, || spleen, || and salivary glands^]" also, iodine has been 

 detected. When the almost constant presence of iodine com- 

 pounds in the thyroids of fully developed animals is considered, 

 it cannot seem remarkable that iodine in some form should 

 pass into the circulation and occasionally be found in various 

 organs. In all the instances cited, however, the quantities 

 actually found have been so small that renewed investigation 

 is needed before any serious significance can be attached to 

 existing statements. That iodine is by no means a constant 

 constituent of some of these glands, my own experience has 

 shown ; thus I have examined relatively large quantities of 



* Reprinted from the Amer. Jour, of Physiol., vol. iii. 



t Barell, Chemisches Centralblatt, 1897, i, p. 608; Seyda, ibid., 1897; ii, 

 p. 806 ; Lanz, Berliner klinische Wochenschrift, 1898, pp. 371-372. 



t Schnitzler und Ewald, Chemisches Centralblatt, 1896, ii. p. 548 ; H. G. 

 Wells, Journal American Medical Association, October-November, 1897. 

 Reprint, p. 57. 



Baumann, Miinchner medicinische Wochenschrift, 1896, No. 14; v. Ro- 

 sitzky, Wiener klinische Wochenschrift, 1897, pp. 823-824. 



|| Barell, loc. cit. 



T Cunningham, Journal of Experimental Medicine, 1898, iii, p. 231 note. 



