H^EMATOPORPHYRIN. 289 



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 L); 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 addition 

 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 

 hsematoporphyriii solution is shaken with chloroform, a part of the pig- 

 ment 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 haematoporphyrin bands in the spectrum differ with the various 

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

 spond 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 char- 

 acter of the solvent and the method of preparation. 



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

 THIERFELDER'S Handbuch, 8. AufL, and the works cited on page 288. 



Haematinogen is a ferruginous pigment so named by FREUND, $ 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 

 hydrochloride dissolved in 80 per cent acetic acid saturated with NaCl 

 and heated to 50-70, a haBmin-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 haamatin, although not identical with it. 

 ZALESKI considers this pigment as a hydrogenized haBmin. A regenera- 

 tion of ha?matin from haBmatoporphyrin has been performed by LAIDLAW. 

 If haBmatoporphyrin is 1 dissolved in dilute ammonia and warmed with 

 STOKES' solution and hydrazine hydrate, iron is taken up again and hamo- 

 chromogen is produced, which is changed into haBmatin by shaking with 

 air. According to HAM and BALEAN, 4 it is possible to produce haBmo- 



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. 



4 Zaleski, Zeitschr. f. pkysiol. Chem., 43; Laidlaw, Journ. of Physiol., 31; Ham 

 and Balean, ibid., 32. 



