508 CHEMISTRY OF THE PROTEIDS CHAP. 



Gamgee l has noticed an electrolytic dissociation of haemoglobin, but 

 was unable to exclude secondary action due to formation of acids. 



Haematin and its Derivatives 



Haematin is the non-proteid constituent of haemoglobin and con- 

 tains the iron as a ferri-compound. It is a pyrrol derivative, as has 

 been shown by Kiister 2 and Nencki 3 and their pupils. All investiga- 

 tions into the chemical structure of the noncrystalline hsematin start 

 with haemin, which may be readily obtained in crystals. According 

 to Nencki, haemin is formed from haematin by one OH group of the 

 latter becoming replaced by Cl. 



Krister's 4 latest investigations (see p. 517) having shown that 

 haematin has the formula 



C 34 H M N 4 ClFe0 6 , 



the conversion of haematin into haemin would be expressed by the 

 formula 



C 34 H 34 N 4 Fe0 5 + HC1 - C 34 H 33 ClN 4 Fe0 4 + H 2 0. 



The analyses of Nencki and Sieber, 5 Cloetta, 6 Rosenfeld, 7 Bialobrzeski, 8 

 Morner, 9 v. Zeynek, 10 and the older ones of Kiister n give a somewhat 

 different composition. For a long time the formula C 32 H 31 ClN 4 Fe0 3 

 has been in use. 12 The chief reason for these differences is not that 



1 A. Gamgee, Proc. Roy. Soc. 68. 503 (1901) ; 70. 79 (1902). 



2 W. Kiister, Uber das Hamatin, Habilitationsschr., Tiibingen, 1896 ; Ber. d- 

 deutsch. chem. Oes. 29. I. 821 (1896) ; 30. I. 105 (1897) ; Zeitschr. f. physioL 

 Chem. 28. 1 (1899) ; G. Hiifner and M. Kolle, ibid. 28. 34 (1899) ; ibid. 29. 1.85 

 (1900) ; Ber. d. deutsch. chem. Oes. 32. I. 678 (1899) ; 33. III. 3021 (1900) ; 35. 

 II. 1268 (1902) ; 35. III. 2948 (1902) ; Liebig's Annalen, 315. 174 (1901) ; Zeitschr. 

 f. physioL Chem. 40. 391 and 423 (1903) ; M. Kolle, Dissertation, Tiibingen, 1898. 



3 M. Nencki and N. Sieber, Archiv f. experiment. Pathol. u. Pharm. 24. 430 

 (1888) ; M. Nencki and J. Zaleski, Zeitschr. f. physioL Chem. 30. 384 (1900) ; M. 

 Nencki and J. Zaleski, Ber. d. deutsch. chem. Ges. 34. I. 997 (1901) ; M. Nencki and 

 L. Marchlewski, ibid. 34. II. 1687 (1901) ; J. Zaleski, Zeitschr. /. physioL Chem. 37. 

 54 (1902). -Compare also the reports by H. Steudel, Chem. Zeitschr, I. Nr. 15 (1902) ; 

 N. Sieber- Schumoff, Munch, med. Wochenschr. 1902, Nr. 45. 



4 William Kiister, Zeitschr. f. physioL Chem. 40. 391 (1903). 



5 M. Nencki and N. Sieber, Ber. d. deutsch. chem. Ges. 17. II. 2270 (1884) ; Arch, 

 f. exper. Path. u. Pharm. 18. 401 (1884) ; 20. 325 (1885) ; 24. 430 (1888). 



6 M. Cloetta, ibid. 36. 349 (1895). 7 M. Eosenfeld, ibid. 40. 137 (1898). 



8 M. Bialobrzeski, Ber. d. deutsch. chem. Ges. 29. III. 2842 (1896). 



9 K. A. H. Morner, MalysJahresber.f. Tierchemie, 27. 145 (1897). 

 X^ 10 E. v. Zeynek, Zeitschr. f. physioL Chem. 25. 492 (1898). 



11 W. Kiister, Ber. d. deutsch. chem. Ges. 29. I. 821 (1896). 



12 M. Nencki and N. Sieber, Ber. d. deutsch. chem. Ges. 17. II. 2270 (1884) ; Arch, 

 f. exper. Path. u. Pharm. 18. 401 (1884) ; 20. 325 (1885) ; 24. 430 (1888) ; E. v. 

 Zeynek, Zeitschr. f. physioL Chem. 25. 492 (1898) ; W. Kiister, Ber. d. deutsch. chem. 

 Ges. 29. L 821 (1896). 



