300 THE BLOOD. 



An alcoholic solution of hsematoporphyrin, acidulated with hydro- 

 chloric or sulphuric acid, shows two absorption-bands (spectrum Plate, 

 7), one of which is fainter and narrower and lies between C and D, near 

 D. The other is much darker, sharper, and broader, and lies midway 

 between D and E. An absorption extends from these bands toward 

 the red, terminating with a dark edge, which may be considered as a 

 third band between the other two. 



'> A dilute alkaline solution shows four bands, namely, a band between 

 C and D; a second, broader band surrounding D and with the greater 

 part between D and E', a third, between D and E, nearly at E; and 

 lastly, a fourth, broad and dark band between b and F. On the addi- 

 tion of an alkaline zinc-chloride solution the spectrum changes more 

 or less rapidly, 1 and finally a spectrum is obtained with only two bands, 

 one of which surrounds D and the other lies between D and E. If an 

 acid hsematoporphyrin solution is shaken with chloroform, a part of the 

 pigment is taken up by the chloroform, and this solution often shows a 

 five-banded spectrum with two bands between C and D. The position 

 of the hsematoporphyrin bands in the spectrum differ with the various 

 methods of preparation and other conditions, so that they do not cor- 

 respond to the same wave length. These facts coincide well with the 

 recent investigations of A. ScnuLz; 2 according to which the appearance 

 of the spectrum is not only dependent upon the reaction but also upon 

 the character of the solvent and the method of preparation. 



In regard to the preparation of hsematoporphyrin, see HOPPE-SEYLER- 

 THIERFELDER'S Handbuch, 8. Aufl., and the works cited on page 294. 



Mesoporphyrin, CsJIssN^, has the same spectrum as haematoporphyrin. 

 It has two oxygen atoms less, and further differs from it in that on oxidation it yields 

 hsematinic acid as well as methylethylmaleic imide, and does not show the 

 above-mentioned biological action of hsematoporphyrin. 



Hsematinogen is a ferruginous pigment so named by FREUND, S which he 

 obtained by carefully extracting blood with alcohol containing hydrochloric 

 acid. It is closely related to hsematin, but is not sufficiently characteristic and is 

 not considered as a cleavage product. 



A question of great interest is whether it is possible to produce the 

 blood-pigment from its cleavage products. In this respect certain recent 

 investigations are interesting. ZALESKI obtained from mesoporphyrin 

 hydrocloride dissolved in 80 per cent acetic acid saturated with NaCl 

 and heated to 50-70, a hsemin-like pigment by the addition of a solu- 

 tion of iron in acetic acid, and this pigment had a spectrum in acid 

 solution very similar to that of hsematin, although not identical with it. 



1 See Hammarsten, Skand. Arch. f. Physiol., 3, and Garrod, Journ. of Physiol., 13. 



2 Arch. f. (Anat. u.) Physiol., 1904, Suppl. 



3 Wien. klin. Wochenschr., 1903. 



