CHAPTER III. 



HEMOGLOBIN; ITS GENERAL CHEMICAL AND PHYSICAL 

 CHARACTERS, AND ITS SPECIFICITIES. 



CONSTITUENTS AND RELATIONS TO THE OTHER CONSTITUENTS 

 OF THE ERYTHROCYTES. 



Hemoglobin, C54. 57 H 7 . 22 N 16 .3 8 So.68Feo.3360 2 o-40 (Jacquet, Zeit. f. physi- 

 olog. Chemie, 1890, xiv, 289) , is regarded as being composed of a colorless, 

 strongly basic albuminous radical, termed globin, C54. 97 H 7 . 2 N 16 . 8980-42020-52 

 (Schulz, Zeit. f. physiolog. Chemie, 1898, xxiv, 449), and a non-albuminous, 

 colored radical termed hematin, C34H3 4 N 4 FeO5 (Kiister, Zeit. f. physiolog. 

 Chemie, 1904, XL, 391). The latter constitutes 4 to 4.5 per cent of the mole- 

 cule (Schulz, loc. cit., and Lawrow, Zeit. f. physiolog. Chemie, 1898, xxvi, 

 343), and is, so far as known, probably absolutely identical in the hemo- 

 globins of all animals; but the former is in all likelihood not identical, as 

 is indicated by certain differences in chemical composition and constitu- 

 tion of the hemoglobins of different bloods; by the difference between 

 hemoglobin and myohematin; by the fact that globin may be replaced by 

 egg-white (Ham and Balean, Journal of Physiology, 1905, xxxn, 312), or 

 by albumin from the blood of another species (Bertin-Sans et Moitessier, 

 Compt. rend. soc. biologie, 1893, cxiv, 923; Bull. soc. chim., 1893, 5 Mai, 

 5 Sept.) ; and also by the fact, as stated by Schulz (loc. cit.}, that the globins 

 of the dog and horse are not identical with that of the goose. 



Globin is a histone-like body; it has been isolated by Schulz and 

 others; and its primary dissociation products have been studied by Fischer 

 and Abderhalden (Zeit. f. physiolog. Chemie, 1902, xxxv, 268) and by 

 Abderhalden (Zeit. f. physiolog. Chemie, 1903, xxxvn, 484). Only 72 per 

 cent of these products have been accounted for leucin 29, histidin 11, 

 arginin 5.4, asparaginic acid 4.4, lysin 4.3, alanin 4.2, phenylalanin 4.28, 

 prolin 2.3, glutaminic acid 1.7, tyrosin 1.3, oxyprolin 1, serin 0.6, cystin 

 0.3, ammonia 0.93 per cent. The sulphur is contained chiefly in the cystin, 

 and the iron solely in the hematin. 



The union between globin and hematin is very feeble, the addition of 

 weak acid being sufficient, as has been shown by Ham and Balean (loc. 

 cit.), to cause immediate dissociation. The nature of this linking is in 

 doubt. According to Hoppe-Seyler (Archiv f. path. Anat. u. Physiolog., 

 1864, xxix, 233; Centralbl. f. med. Wissensch., 1864, 261, and 1865, 491), 

 it is ester-like, while Hiifner (Archiv f. Anat. u. Physiolog., 1899, 491) and 

 Ham and Balean (loc. cit.) regard it as being through the agency of oxygen. 

 According to the hypothesis of Ham and Balean, the formula for oxy- 

 hemoglobinis: H NO o 



J - > " j:N ^ 



67 



