484 PATHOLOGICAL PIGMENTATION^ 



or yellowish-brown granules, and not as crystals. After a time it is 

 taken up and deposited to a large extent in the liver, spleen, bone- 

 jnarrow, and kidney, either as hemosiderin or possibly as some other 

 iron compound of similar nature. From these sites it seems to be 

 later taken up to be utilized in the manufacture of new red corpuscles. 

 Whenever there is hemosiderin deposition in the kidney, granules 

 of, the pigment may be found in the urine, free or in cells (Rous).^^ 



All told the average human body contains about 3.2 grams of iron, 

 of which 2.4 to 2.7 grams is in the blood. According to ]\Ieyer^^ 

 iron is present in the body in three forms: 1. Not demonstrable by 

 reagents because so firmly bound (hemoglobin). 2. Loosely bound 

 iron, colored by (NHJaS acting for a long time (ferratin). 3. Salt- 

 like compounds with proteins, and inorganic compounds, reacting at 

 once with reagents. Ferratin is the iron compound in the liver, con- 

 taining 6 per cent. iron. He believes that probably hemosiderin is 

 not a definite substance, but merely indicates compounds of the third 

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

 e. g., in corpus luteum 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 maculosus, Kunkel found the pigment of the internal organs 

 to be pure iron oxide. Hueck also holds that hemosiderin is an in- 

 organic iron compound, loosely bound to proteins and fats, and that 

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

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

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

 organ which contains iron chemically demonstrable. Ischida''* be- 

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

 muscles from the iron normally there, without 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 by Nenclci and called by him hema- 

 topoi'phyrin and mesoporphyrin , the former apparently representing a 

 reduction, the latter an oxidation product. "'' The porphj-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 



" Jour. Exp. Med., 1918 (28), 645. 



" Ergel). der Physiol., 190.5 (5), 698; literature. 



»^ Virchow's Arch., 1912 (210), 67. 



*' Literature and full review by Giinther, Deut. Arch. klin. I\Icd., 1912 (105), 

 89; and by Jcsionek, Ergeb. inn. Med., 1913 (II), 525. 



»• Fischer and Meyer-Betz, Zeit. physiol. Chem., 1912 (82), 96. 



•7 H. Fischer, Munch, med. Woch., 1916 (63), 377; Zeit. physiol. Chem., 1916 

 (97), 109 and 148; Schuinin, ibid., 1915 (96), 183. 



