BLOOD PIGMENTS 403 



much chlorophyll. Pathologically, hematoporphyrin is of 

 interest as a urinary pigment, being found normally in the urine 

 in traces, but present in considerable quantities in many diseases, 1 

 such as rheumatism, tuberculosis, various liver diseases, and, 

 most strikingly, after the administration of sulphonal or trional. 

 When in abundance it may color the urine a rich Burgundy red. 



Psetldomelanosis. When loosely bound iron is present 

 in the tissues, and in the same tissues sulphides are produced 

 through bacterial action, a discoloration with sulphide of iron 

 will result, which is called pseudomelanosis, because the pigment 

 resembles true melanin in its blackness. This is most frequently 

 observed as a postmortem phenomenon in and about the 

 abdominal cavity, and in the ordinary postmortem discoloration 

 both the liberation of the iron from its firm organic combination, 

 and the production of hydrogen sulphide, are the work of 

 bacteria. Pseudomelanosis may also occur intra vitam, particu- 

 larly in the margins of infected areas, and it may also be 

 observed in the liver and spleen, and about the peritoneum, in 

 bodies examined immediately after death, before any evident 

 postmortem decomposition has set in. This seems to depend 

 upon the previous intra vitam formation of hemosiderin, which 

 is then combined by sulphur liberated from tissue proteids 

 through bacterial action. 2 If hydrogen sulphide acts upon 

 hemoglobin that has not been decomposed, a greenish compound 

 of sulphur-methemoglobin is formed (Harnack 3 ), which is the 

 cause of the greenish color seen in the abdominal walls and 

 along the vessels of cadavers. This union of hemoglobin and 

 hydrogen sulphide occurs only when oxygen is present (oxyhemo- 

 globin). The sulphur-hemoglobin compound is readily decom- 

 posed by weak acids, even by CO 2 , with the formation of 

 methemoglobin, which in turn readily becomes decomposed to 

 form hematin. 



Hetnofuscin is the name given by von Recklinghausen to 

 the brownish pigment found in involuntary muscle-fibers, par- 

 ticularly in the wall of the intestine. It does not react for 

 iron, and is insoluble in alcohol, ether, chloroform, or acids ; 

 therefore it is not a lipochrome. von Recklinghausen, and also 

 Goebel, 4 ascribe this pigment to an alteration of hemoglobin 

 which enters the cells in dissolved form, but Rosenfeld, 5 who 

 has submitted the material to analysis after isolation, found 



1 See Garrod, Jour, of Physiol., 1892 (13), 598. 



2 Ernst, Virchow's Arch., 1898 (152), 418. Literature. 

 3 Zeit. physiol. Chem., 1899 (26), 558. 



4 Virchow's Arch., 1894 (136), 482. 



5 Arch. exp. Path. u. Pharm., 1900 (45), 46. 



