CHAPTER VII 



HALOGEN -ALBUMINS AND PRODUCTS OF OXIDATION 

 ALDEHYDE- AND IRON-COMPOUNDS 



FOLLOWING up the older observations of Bohm and Berg, 1 halogen- 

 compounds of albumins have been prepared by Blum, 2 Hofmeister, 3 and 

 his pupils Kurajeff, 4 Liebrecht, 5 Hopkins, 6 Schmidt, 7 and Oswald. 8 

 Baumann, 9 Drechsel, 10 and Harnack n have shown iodine-albumins or 

 iodo-albumins to occur also in nature : in the thyroid gland of verte- 

 brates and in the supporting framework of sponges and corals. 



Halogen-albumins arise, as Blum and Hofmeister have shown, by 

 the replacement of one or of several of the hydrogen-atoms in one or 

 several of the aromatic radicals of an albumin, by fluorine, chlorine, 

 bromine, or iodine. Products formed in this way behave as do the 

 halogen-substituted benzoles : they do not give a precipitate with silver 

 nitrate, and the halogen can only be demonstrated chemically by 

 incinerating the compound. 



lodo-Albumins 



Blum and Hofmeister iodated albumins by allowing a mixture of 

 potassium iodate, KI0 3 , and potassium iodide, KI, to act on albumin 



1 R. Bohm and F. Berg, Arch.f. experiment. Pathol. u. Pharm. 5. 329 (1876). 



2 F. Blum and W. Vaubel, Journ. f.prakt. Chem. [2] 56. 398 (1897), [2] 57. 365 

 (1898) ; F. Blum, Zeitschr. f. physiol. Chem. 28. 288 (1899). 



3 F. Hofmeister, ibid. 24. 158 (1897). 



4 D. Kurajeff, ibid. 26. 462 (1899), 31. 527 (1901). 



5 A. Liebrecht, Ber. d. deutsch. chem. Ges. 30. II. 1824 (1897). 



6 F. G. Hopkins, ibid. 30. II. I860 (1897) ; F. G. Hopkins and S. N. Pinkus, ibid. 

 31. II. 1311 (1898). 



7 C. H. L. Schmidt, Zeitschr. f. physiol. Chem. 34. 55 and 194 (1901), 35. 386 

 (1902), 36. 343 (1902). 



8 A. Oswald, Hofmeister's Beitrage, 3. 391 (1903), 3. 514 (1903). 



9 E. Baumann, Zeitschr. f. physiol. Chem. 21. 319 (1895) ; E. Baumann and E. 

 Roos,*^. 21. 481 (1896) ; E. Baumann, ibid. 22. 1 (1896). 



10 Drechsel, Zeitschr. f. Biol. 33. 84 (1896). 



11 E. Harnack, Zeitschr. f. physiol. Chem. 24. 412 (1898). 



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