478 PArilOLOCIVAL PIGMEXTATIOX 



and generalh- with acute toxic heiiioh'sis, including patients infected 

 with B. c))iphi/scmatosus, when the hematin may be accompanied by 

 methemogk)biu without a corresponding- urinary excretion of these pig- 

 ments. Brown *^ found that solutions of hematin cause chills and 

 fever, and suggests tliat his pigment may be at least partially respon- 

 sible for the symptoms of malaria/"" Hematin has been believed to 

 split up gradually into an iron-free pigment {hematoidin) and an 

 iron-containing pigment (hemosiderin). This change may be repre- 

 sented by the following equation, according to Nencki and Sieber : ^'^ 



C3=H3,N,0,Fe + 2H,0 = 2C,„H,,K.03 + Fe. 

 (homatin) (liematoidin) 



However, finding that the pigment in the malarial spleen is hem- 

 atin, Brown ^^ suggests that hematin cannot well be an intermediary 

 ])roduct in hemoglobin disintegration, since this malarial pigment 

 ])ersists a very long time in the tissues without change. He has made 

 other observations that led him to conclude that hematin is not an 

 intermediary substance between hemoglobin and hemosiderin, but that 

 when once formed it is destroyed very slowly, by oxidation rather 

 than hydrolysis. Injected into rabbits it produces vascular lesions in 

 the kidneys ^^^ and in large doses causes a marked fall in blood pres- 



g^^pp r,ib 



Hematoidin may be found in old, large extravasations, as orange- 

 colored or red rhombic plates, first described bj' Virchow\ Some- 

 times, however, hematoidin occurs in the form of yellowish granular 

 masses, and it may be associated with lipoids; it is also found in crys- 

 talline form in icterus (Dunzelt).^- It seems to be nearly or quite 

 identical with the bile-pigment, bilirubin, and it is probably the 

 source of this substance under nornuil conditions. When formed in 

 excessive amounts, either through increased destruction of corpuscles 

 in the vessels or in extravasations, the amount of bile-pigment is in- 

 creased (see "Icterus"). Possibly some of the hematoidin becomes 

 transformed directly into urobilin, and is tlien eliminated in the 

 urine. 



Hemosiderin ■'^' is relatively insoluble, and, therefore, is more 

 slowly removed when formed in hemorrhages, and more abundantly 

 deposited in the tissues when formed after excessive hemolysis. In 

 acute hemolytic anemia a third of the total iron of the blood may be 



49 Jour. Exppr. Med.. 1012 (1.5), ;i80; 191.3 (18), 96. 



4»a Disputed by Butterfiold and Bciipdict, Prof. Soc. Exp. Biol.. 1914 (11), 80. 



no Arch. cxp. Patli. \\. Pharm.. ISSS (24), 440; Pruf^scli and Yoshimoto, Zeit. 

 cxp. Path.. 1911 (8), 039. 



niJour. Expor. Mod., 1911 (1.-?), 290; 1911 (14), (;12. 



.-.laArdi. Int. M.d., 1913 (12), 315. 



51b Brown and T>o('V(>nliart, Jour. Exp. ^Nlcd., 1913 (IS), 107. 



52 Cent. f. Path.. 1909 (20). 900. 



5.3SPO Xeun.ann, Vircliow's Arch., 1888 (111), 25; 1900 (101), 422; 1904 

 (177), 401; also Arnold, ihid., 1900 (ICl), 284; Leupold, Beitr. path. Anat., 1914 

 (59), 501. 



