HEMATOIDIN. 63 



hematoporphyrin results. This is a bluish-black, amorphous powder, becoming 

 brown when rubbed. Its solutions in caustic alkalies are dichroic: that is brownish- 

 red in reflected light, garnet-red in a thick layer with transmitted light and olive- 

 green in a thin layer. The acid solutions are monochromatic brown. 



For the preparation of hemin-crystals in large amount, it is advisable to heat 

 dry horses' blood with 10 parts of formic acid until bubbles form. If the hemin- 

 crystals are suspended in methyl-alcohol, they dissolve after addition of iodin 

 and application of heat, with the development of a purple color, which becomes 

 brown after addition of bromin and green after the passage of chlorin-gas. All 

 of these exhibit a characteristic appearance in the spectroscope. The glacial acetic 

 acid may be replaced by an alcoholic solution of oxalic or tartaric acid, and the 

 sodium chlorid by salts of iodin or bromin. In the latter event bromin-hematin 

 or iodin-hematin is formed. 



HEMATOIDIN. 



An important derivative of hemoglobin is sorrel-colored hematoidin- 

 C3 2 H 36 N 4 O 6 (Fig. 19), which forms in the body from hematin through 

 loss of iron and taking up of water when- 

 ever blood stagnates [outside of the circula- 

 tion and undergoes decomposition, as, for 

 instance, in apoplectic extravasations of 

 blood, in coagulated plugs in blood-vessels 

 (thrombi). It develops regularly in every 

 Graafian follicle from the drop of blood 

 poured out at the menstrual rupture of the 

 follicle. It is free from iron, crystallizes in 

 clinorhombic prisms, and is soluble in FIG. 19. Hematoidin-crystais. 

 chloroform and in warm alkalies. Probably 

 it is identical with the biliary coloring-matter, bilirubin. 



Pathological. After extensive dissolution of blood in the vessels, as, for 

 instance, after transfusion with foreign blood, hematoidin-crystals have been ob- 

 served in the urine. 



THE COLORLESS PROTEID OF HEMOGLOBIN. 



This is designated globin and is closely related to histon. 



Demonstration. A solution of hemoglobin is made feebly acid with hydro- 

 chloric acid, then one-fifth volume of alcohol is added and the mixture is shaken with 

 ether. The coloring-matter is taken up by the ether and the globin is precipitated 

 by the ammonia. Hydrochloric or nitric acid likewise precipitates the globin, 

 which, however, is redissolved on boiling. Hematin and globin are probably not 

 the sole products of the decomposition of hemoglobin. As hemoglobin-crystals 

 can be decolorized under special conditions, it is most probable that they owe their 

 form to the proteid body. On introducing hemoglobin-crystals with alcohol in a 

 dialyzer surrounded by ether acidulated with sulphuric acid Landois succeeded 

 in decolorizing the crystals. 



PROTEID BODIES IN THE STROMA. 



These constitute from 5.10 to 12.24 per cent, of the dry red 

 blood-corpuscles of man, including a globulin participating in fibrin- 

 formation and possible traces of a sugar-forming ferment. Under 

 special conditions it has been observed that the stromata, coherent 

 in masses, form a substance stroma-fibrin resembling fibrin. 



L. Brunton has found in the nuclei of nucleated red blood-corpuscles a mucin- 

 containing body, Miescher nuclein and Kossel histon united with the latter. 



