400 PATHOLOGICAL PIGMENTATION 



with the lipochromes. It commonly fades on exposure to air, 

 and also when in the usual preservative fluids, to which it does 

 not impart its color. It contains no iron, is soluble in absolute 

 alcohol and in ether, and is usually, but not always (v. Reck- 

 linghausen), stained black with osmic acid. The pigment of 

 xanthdasma multiplex also seems to be a fatty substance (Poens- 

 gen x ). 



Chromophile cells may be considered in this connection. Kohn 2 has 

 described certain cells with a decided affinity for chromic acid and its 

 salts, found abundantly in the sympathetic nervous system, in the carotid 

 gland, and in the medulla of the adrenal. They are also present in 

 tumors derived from these organs. Extracts from such organs have a 

 marked effect in raising blood pressure, and, according to Wiesel, 3 they 

 are greatly involved in Addison's disease. The nature of the chromo- 

 phile substance is unknown, but it can only be fixed by chromic acid 

 or chromates ; cells hardened by other means show merely spaces in the 

 places occupied by this substance. Mulon 4 believes it to be the same 

 as the adrenalin. 



BLOOD PIGMENTS 5 



Red corpuscles behave much as do other non-nucleated frag- 

 ments of cells, undergoing disintegration rapidly and constantly 

 when under normal conditions, as well as when subjected to 

 various harmful influences (see " Hemolysis "), or when outside 

 of the vessels in extravasations of blood. The processes and 

 products of their disintegration are, therefore, much the same 

 whether occurring under normal or pathological conditions. 

 The hemoglobin molecule is large and complex, and from it are 

 derived many substances of the nature of pigments ; indeed, 

 hemoglobin itself may appear free as a pigment. 



Hemoglobin is a compound proteid, consisting of a proteid 

 group (globin) and a coloring-matter (hematin or hemochromogen). 

 The proteid globin is of a basic nature, and seems allied to 

 the histons. The hematin is, therefore, presumably acid, and 

 the compound proteid, hemoglobin, is strikingly like the nucleo- 

 proteids in nature. Hemoglobin ordinarily does not crystallize 

 readily, especially the hemoglobin of man, and it is doubtful if 

 it ever does so in the living tissues, although possibly this may 

 occur in the center of large hematomas. In bodies that 

 have undergone postmortem decomposition, and occasionally in 



1 Virchow's Arch., 1883 (91), 354. 

 2 Prag. med. Woch., 1902 (27), 325. 

 3 Zeit. f. Heilk., Path. Abt, 1903 (24), 257. 

 *Compt. Kend. Soc. BioL, 1904 (56), 113. 



5 Literature by Schmidt, Ergebnisse der PathoL, 1894 (I 2 ), 101 ; and 1896 

 (III!), 542; Schulz, Ergebnisse der Physiol., 1902 (1^, 505. 



