480 PATIIOLOaiCAL PIGMEXTATIOX 



class. Iron pigments may be transformed from one class to another, 

 e. g., in corpus lutenm scars, whose age can be estimated, class three 

 may be replaced by class two. We may have in the sputum and lungs 

 " Herzf ehlerzellen " that either do or do not stain with ferrocyanide. 

 In morbus macidosus, Kunkel found the pigment of the internal or- 

 gans to be pure iron oxide. Hueck also hohls that hemosiderin is an 

 inorganic iron compound, loosely bound to proteins and fats, and 

 that it never forms an iron-free pigment, as has been stated. He be- 

 lieves that there is very little iron in the tissues in a firm union like 

 hemoglobin, and that by proper technic some iron can be stained in 

 every organ which contains iron chemicallj' demonstrable. Ischida '^^ 

 believes that an iron-containing pigment may be formed in striated 

 muscles from the iron normally there, w^ithout requiring a hematoge- 

 nous origin. 



Hematoporphyrin."- — There are several closely related pigments de- 

 rived from hematin that are appropriately grouped under the desig- 

 nation of porphyrins, for they are not all identical with the pigments 

 prepared artificially from hematin b}^ Nencki and called by him 

 heniatoporphyrin and mesoporphyrin, the former apparently repre- 

 senting a reduction, the latter an oxidation product. ''^ The porphy- 

 rins found in the urine and feces are different from each other and 

 from those prepared by Nencki.*'* Physiologically, these pigments are 

 of great interest, because of the close chemical relation they have been 

 found to bear to chlorophyll,^'^ with which hemoglobin is so closely re- 

 lated functionally. It is also interesting to consider that whereas car- 

 nivora obtain much hemoglobin in their food, herbivora obtain much 

 chlorophyll. Pathologically, porphyrin is of interest as a urinary 

 pigment, being found normally in the urine in traces, but present in 

 considerable quantities in many diseases,'^*' such as rheumatism, tuber- 

 culosis, various liver diseases, and, most strikingly, after the admin- 

 istration of sulphonal, veronal or trional. When in abundance it 

 may color the urine a rich Burgundy red, and it is sometimes accom- 

 panied by a precursor, vro-fuscin. It is present in the bones of animals 

 showing hemochromatosis and in the bones of persons *""' exhibiting a 

 congenital form of "hematoporphyria, " described by Giinther, which 

 is accompanied by severe skin lesions that are ascribed to the action of 

 light upon the skin sensitized by the hematoporphyrin. Hausmann •'^ 

 and others have studied extensively the photosensitizing action ex- 



«i Virehow's Arch., 1012 (210), 67. 



"s Literature and full review bv Giintlier, Deut. Arcli. kiiu. :\[ed., 1012 (105), 

 80; and by Jesionek, Erjreb. inn. Med., 1013 (11), .52"). 



«■■! Fischer and Meyer-Bet/, Zeit. physiol. Chem., 1912 (82). 06. 



04 11. Fischer, Miiiich. nied. Woch.. 1016 (63). 377; Zeit. phvsiol. Chem., 1016 

 (97), 100 and 148; Schumni, ibid., 1015 (06). 183. 



«5 For literature see Aliderhalfh'ii, "Lehrbucli der plivsiol. C'lieniie." 1000. 



«<■■ See Carnid, .lour, of Phvsiol., 1802 (1:5), .'"jOS. 



O'iallegler ct a/., J)eut. iiied. Wodi., 1013 (30), 842. 



07 Biochcm. Zeit., 1010 (3(1), 27(;; 1014 (67), 300. 



