MELANINS. 793 



SCHMIEDEBERG'S sarcomelanin, and that from the melanotic sarcomata 

 of horses, the hippomelanin (NENCKI, SIEBER, and BERDEZ), which are 

 soluble with difficulty in alkalies, while others, such as the coloring mat- 

 ter of certain pathological swellings in man, the phymatorhusin (NENCKI 

 and BERDEZ), are readily soluble in alkalies. The humus-like products, 

 called melanoidic acids by SCHMIEDEBERG, obtained on boiling proteins 

 with mineral acids, are rather easily soluble in alkalies. 



Among the melanins there are a few, for. example the choroid pig- 

 ment, which are free from sulphur (LANDOLT and others) ; others, on the 

 contrary, as sarcomelanin and the pigment of the hair and of horse-hair, 

 are rather rich in sulphur (2-4 per cent), while the phymatorhusin found 

 in certain swellings and in the urine (NENCKI and BERDEZ, K. MORNER) is 

 very rich in sulphur (8-10 per cent). Whether any of these pigments, 

 especially the phymatorhusin, contains any iron or not is an important 

 though disputed point, for it leads to the question whether these pigments 

 are formed from the blood-coloring matters. According to NENCKI and 

 BERDEZ the pigment, phymatorhusin, isolated by them from a melanotic 

 sarcoma did not contain any iron, and according to -them is not a deriv- 

 ative of haemoglobin. K. MORNER and later also BRANDL and L. 

 PFEIFFER found, on the contrary, that this pigment did contain iron, 

 and they consider it as a derivative of the blood-pigments. The sarco- 

 melanin (from a sarcomatous liver) analyzed by SCHMIEDEBERG contained 

 2.7 per cent iron, which was partly in organic combination and could 

 not be completely removed by dilute hydrochloric acid. The sarcomelanic 

 acid prepared by SCHMIEDEBERG by the action of alkali on this melanin 

 contained 1.07 per cent iron. The sarcomelanin investigated by ZDAREK 

 and v. ZEYNEK also contained 0.4 per cent iron. Recently WOLFF l 

 prepared two pigments from a melanotic liver, of which one was no 

 doubt modified. The other, which was soluble in a soda solution, con- 

 tained 2.51 per cent sulphur and 2.63 per cent iron, which was in great 

 part split off by 20-per cent hydrochloric acid. From another liver he,, 

 on the contrary, obtained melanin free from iron but with 1.67 per cent 

 sulphur. From this melanin he obtained, by treatment with bromine, 

 a hydro-aromatic body which was related to xyliton (a condensation 

 product of acetone). A similar product could not be obtained from the 

 pigment of the hair (SPIEGLER) nor from hippomelanin (v. FURTH and 

 JERUSALEM 2 ). 



s 



. 



1 Zdarek and v. Zeynek, Zeitschr. f. physiol. Chem., 36; Wolff, Hofmeister's Beitrage, 

 The literature on the melanins may be found in Schmiedeberg, " Elementarformeln 



einiger Eiweisskorper, etc." Arch. f. exp. Path. u. Pharm., 39; also in Kobert, Wiener 

 Klinik, 27 (1901), and Spiegler, Hofmeister's Beitrage, 4, and especially v. Fiirth, 

 Centralbl. f. allg. Path. u. Path. Anat., 15, 1907, 617. 



2 Wolff, Hofmeister's Beitrage, 5; Spiegler, ibid., 10; v. Fiirth and Jerusalem, 

 id., 10. 



