BLOOD-PIGMENTS. 



277 



chromogen (about 4 per cent), containing iron, which in the presence of 

 oxygen is easily oxidized into hcematin. 



As first shown by SCHUNCK and MARCHLEWSKI, and especially by the 

 work of the latter, a close relation exists between chlorophyll and the 

 blood-pigment, because a derivative of the first, phylloporphyrin, 

 stands very close in certain respects to a derivative of the blood-pigment 

 hsematoporphyrin. By the investigations of NENCKI in conjunction 

 with MARCHLEWSKI and ZALESKI, x it was shown that haemopyrrol could 

 be prepared from the derivatives of both the leaf-pigment and the blood- 

 pigments by reduction, and also the investigations of PILOTY and WILL- 

 STATTER on chlorophyll and blood pigments have further developed 

 the interesting biological fact that the chlorophyll and blood pigments 

 are closely related bodies. 



The haemoglobin prepared from different kinds of blood has not 

 exactly the same composition, which seems to indicate the presence 

 of different haemoglobins. The analyses by different investigators of 

 the haemoglobin from the same kind of blood do not always agree with 

 one another, which probably depends upon the somewhat varying methods, 

 of preparation. The following analyses are given as examples of the 

 constitution of different haemoglobins: 



Haemoglobin from the C 



Dog 53.85 



" 54.57 



Horse 54.87 



" 51.15 



Ox 54.66 



Pig 54.17 



" 54.71 



Guinea-pig 54 . 12 



Squirrel 54 . 09 



Goose 54.26 



Hen 52.47 



That the repeatedly observed quantity of phosphorus in the haemo- 

 globin of birds (Inoko and others) is due to a contamination has been 

 proved by ABDERHALDEN and MEDIGRECEANU. In the haemoglobin 

 from the horse (ZINOFFSKY), the pig, and the ox (HUFNER), we have 

 1 atom of iron to 2 atoms of sulphur, while in the haemoglobin from the 

 dog (JAQTJET) the relation is 1 to 3. From the data of the elementary 

 analysis, as also from the amount of loosely combined oxygen, HUFNER 1 

 has calculated the molecular weight of dog-haemoglobin as 14,129, and 



'Schunck and Marchlewski, Annal. d. Chem. u. Pharm., 278, 284, 288, 290; 

 Nencki, Ber. d. deutsch. chem. Gesellsch., 29; Marchlewski, and Nencki, Ber. d. d. 

 chem., Gesellsch., 34; Nencki and Zaleski, ibid., Marchlewski, Chem. Centralbl., 

 1902, I, 1016; Zaleski, Zeitschr. f. physiol. Chem., 37. The literature and the works 

 of Willstatter and Piloty will be given under haemopyrrol, page 297. 



