296 THE BLOOD. 



subcutaneously and then exposed to bright light die very quickly with character- 

 istic symptoms, while control animals kept in the dark show no symptoms of disease. 

 H. FISCHER and MEYER-BETZ l have also shown that in this regard a certain 

 difference exists between the hsematoporphyrin and the mesoporphyrin. The 

 perfectly pure crystalline mesoporphyrin does not show the photobiological 

 action which occurs with crystalline hsematoporphyrin. 



Of especial interest is the close relationship of the hsematoporphyrin 

 to certain chlorophyll derivatives, especially to phylloporphyrin,. 

 Cs2H36N402. Phylloporphyrin is similar to the above-mentioned meso- 

 porphyrin, C34H3gN4O4, and the absorption spectrum of the brom- 

 porphyrins, bromphylloporphyrin and brommesoporphyrin as prepared 

 by SCHUNCK and MARCHLEWSKI, seems to be almost identical. Just as 

 from mesoporphyrin, with sodium chloride, glacial acetic acid and an 

 iron salt we can regenerate a product very similar to hsemin (ZALESKI) 

 so MARCHLEWSKI 2 has been able under similar conditions to prepare from 

 phylloporphyrin a pigment, phyllohcemin, which contained iron and was 

 similar to hsemin. A comparison of the cleavage products gives still 

 more conclusive and important proofs of the close relationship of the 

 blood and leaf pigments. 



We have important investigations of KUSTER, S PILOTY, WILLSTATTER, 

 H. FISCHER 4 and their collaborators upon the constitution of hsBmin and 

 hsematoporphyrin. The constitution of chlorophyll has been explained 

 by the pioneering researches of WILLSTATTER. 



On the oxidation of hsematin in glacial acetic acid by potassium 

 dichromate or chromium trioxide KUSTER obtained the imide of the 



/CO C.CH 2 .CH 2 .COOH 

 tribasic hcematinic add, HN< , which is a deriva- 



X CO C.CH 3 

 tive of maleic acid, and from which methylethylmaleic acid anhydride, 



xCO C.CH 2 CH 3 



O\ , can be readily obtained. The same hsematinic 



X CO C.CH 3 



1 Hausmann, Bioch. Zeitschr., 30; Hans Fischer and Meyer-Betz. Zeitschr. f, 

 physiol. Chem., 82. 



2 The pertinent literature will be found in L. Marchlewski, Die Chemie der Chlor- 

 ophylle und ihre Beziehung zur Chemie des Blutfarbstoffes, 1909 and Ber. d. d. chem. 

 Gesellsch., 45. 



3 Beitrage zur Kenntnis. des Hamatins, Tubingen, 1896; Ber. d. d. chem. Gesellsch. r 

 27, 30, 32, 35, 43, and 45, Annal. d. Chem. u. Pharm., 315, and Zeitschr. f. physiol. 

 Chem., 28, 40, 44, 54, 55, 61, 62, and 82. 



4 The work of Piloty and collaborators may be found in Annal. d. Chem. u. Pharm. r 

 366, 37?, 388, 390, and 392 and Ber. d. d. chem. Gesellsch., 42, 43, and 45. In regard 

 to the work of Willstatter and the literature on chlorophyll (to 1911) see Willstatter 

 in Abderhalden's Bioch. Handlexicon, Bd. VI and Annal. d. Chem. u. Pharm., 378, 

 380, 382, and 385. Hans Fischer and collaborators, Zeitschr. f. physiol. Chem., 82, 

 and footnote 2, p. 297, and the literature on bilirubin Chapter VII. 



