MELAN^EMIA. 733 



granules, but also as enclosed in colorless cells. This observer saw 

 that, in dissolving the hematin in a drop of blood by adding water, 

 the hematin became most distinct in the colorless blood-corpuscles, 

 and hence it is probable that, in the extensive destruction of blood- 

 cells in the spleen, the hematin enters the colorless elements of the 

 spleen-pulp, and with these reaches the blood. It is more difficult to 

 explain the occurrence of pigment in the blood in the form of irregular 

 flakes. It is possible that these flakes consist of fibrin that has pre- 

 cipitated on the angular granules ; but it is more probable that the 

 substance adherent to the pigment-granules, surrounding them like a 

 bright border, consists of the protein substance that was combined 

 with the fibrin in the blood-corpuscles that were destroyed ( Virchow). 



ANATOMICAL APPEARANCES. In melanaemia the pigment found in 

 the blood of the heart and vessels is black ; more rarely besides the 

 black we find brown or yellowish-brown, rarely yellowish-red pigment. 

 With acids and caustic alkalies it shows the following conditions, which 

 Virchow has found peculiarly characteristic of pathological pigment : 

 the more recent formations become pale and finally lose their color en- 

 tirely, while the older ones resist the reaction of these reagents a long 

 time (Frerichs). The small pigment-granules have an irregularly 

 roundish form. As Meckel, the first observer of pigment in the blood, 

 saw, a larger or smaller number of these is almost always united, by a 

 colorless substance, to roundish, spindle-shaped, or irregular flakes. 

 The cells containing pigment sometimes have the size and form of the 

 white corpuscles of the blood ; sometimes they are larger, and club or 

 or spindle shaped ; the latter resemble the spindle-shaped cells in the 

 spleen-pulp, which Kolliker considers the epithelium of the splenic 

 vein. Besides these forms, Frerichs observed large clumps of pig- 

 ment of irregular shape, as well as cylindrical bodies that looked like 

 small vessels. 



With the blood the pigment enters all the organs of the body, and, 

 according to the amount collecting in the capillaries, colors them more 

 or less. According to Planer and Frerichs, we almost always find 

 the most pigment in the spleen, so that it appears slate-gray and often 

 almost black. Next to the spleen, the greatest amount of pigment i* 

 found in the liver and brain, particularly in the cortical substance. 

 The liver is often steel-gray or blackish ; the cortical substance of the 

 brain chocolate or graphite color. Not unfrequently there is also a con- 

 siderable collection of pigment in the kidneys, as a result of which 

 usually the cortical substance has gray points in it. In the pulmonary 

 vessels, particularly in the smaller ones, there is occasionally a large 

 amount of pigment. In the vessels of the other tissues and organs it 

 is never accumulated tc any great extent ; but the skin, mucous mem- 



