102 The Iodine Complex of Thyreoglobulin 



these per unit of iodine may determine the probable nature of the 

 iodine complex. In other words, the actual quantitative physio- 

 logical activity per unit of iodine as measured by the Reid Hunt 

 method was taken as the crucial test for the presence or absence 

 of the unaltered iodine complex. 



The historical development of the relation of thyroid activity 

 to iodine content need not be considered at this time, especially 

 in view of the thorough reviews and extensive confirmatory experi- 

 ments made by Reid Hunt and A. Seidell, 2 as well as the compara- 

 tive histological and chemical studies by Marine in cooperation 

 with Lenhardt and Williams. 3 A careful study of these papers 

 justifies the first assumption. The second assumption is also 

 well taken provided the proper precautions are observed as shown 

 by Reid Hunt and A. Seidell. 4 Other methods for testing the 

 physiological activity of thyroid substance, based on changes in 

 blood pressure, 5 on increasing the irritability of the depressor 

 nerve, 6 on changes in nitrogen metabolism 7 and on curative effects 

 in cretinism 8 have been employed, but are not applicable in a 

 quantitative study, nor are they as specific reactions. 



Of the third and fourth assumptions we had no definite proof. 

 The studies of Oswald 9 and others show that during hydrolysis 

 of thyreoglobulin only 30 per cent or less of the iodine remains 

 in organic combination. The iodine thus combined is in the vari- 

 ous fractions and qualitatively it has been determined 10 that prob- 

 ably the greater activity remains in the more complex products 



2 Bulletins 47 (1908) and 69 (1910) of the Hygienic Laboratory, U. S. Pub- 

 lic Health and Marine Hospital Service. 



3 Johns Hopkins Hospital Bull, xviii, p. 359, 1907; Journ. Inf. Dis., iv, 

 p. 417, 1907; Archives of Internal Med., i, p. 349, 1908; Ibid., iii, p. 66, 1909; 

 ibid., iv, p. 440, 1909; ibid., vii, p. 506, 1911; ibid., viii, p. 265, 1911; 

 Journ. of Exp. Med., xiii, p. 455, 1911. 



4 Loc. cit.; Journ. of Pharmacol. and Exp. Ther., ii, p. 15, 1910. 



5 von Fiirth and Schwarz: Pfluger's Archiv, cxxiv, p. 113, 1908. 



6 von Cyon and Oswald: Pfliiger's Archiv, Ixxxiii, p. 199, 1901; Asher and 

 Flack: Zeitschr. f. Biol, Iv, p. 83, 1910. 



7 Baumann: Zeitschr. f. physiol. Chem., xxi, p. 487, 1896; ibid., xxii, p. 1, 

 1896; Munch, med. Wochenschr., xl, 1896. 



8 E. Pick and F. Pineles: Zeitschr. f. exp. Path. u. Ther., vii, p. 518, 1909- 

 10. 



9 Arch.f. exp. Path. u. Pharm., Ix, p. 115, 1908. 



10 Pick and Pineles: loc. cit. 



