UROCHROME. 703 



by the action of light (SAILLET) and air (JAFFE, DISQUE l and others). 

 Besides this chromogen, urine contains various other bodies from which 

 coloring matters may be produced by the action of chemical agents. 

 Humin substances (perhaps in part from the carbohydrates of the urine) 

 may be formed by the action of acids (v. UDRANSZKY) without regard 

 to the fact that such substances may sometimes originate from the rea- 

 gents used, as from impure amyl alcohol (v. UDRANSZKY 2 ). To these 

 humin bodies developed - by the action of acid in normal urine when 

 exposed to the air must be added the urophain of HELLER, the various 

 uromelanins and other bodies described by different investigators (PLOSZ, 

 THUDICHUM, SCHUNCK^). Indigo blue (uroglaucin of HELLER, urocyanin, 

 cyanurin, and other coloring matters of earlier investigators 4 ) is split 

 off from the indoxyl-sulphuric acid or indoxyl-glucuronic acid. Red 

 coloring matter may be formed from the conjugated indoxyl and skatoxyl 

 acids, and urohodin (HELLER), urorubin (PLOSZ), urohcematin (HARLEY), 

 and perhaps also urorosein (NENCKI and SIEBER 5 ) probably j^ave such an 

 origin. 



We cannot discuss more in detail the different coloring matters obtained 

 as decomposition products from normal urine. HaBmatoporphyrin has 

 already been referred to in a previous chapter (VI) and will best be described 

 in connection with the pathological pigments. It only remains to describe 

 urochrome, urobilin, and uroerythrin. 



Urochrome is the name given by GARROD to the yellow pigment of 

 the urine. THUDICHUM had previously given the same name to a less 

 pure pigment isolated by himself. The accounts as to the composi- 

 tion and properties of urochrome differ so considerably that it is 

 questionable whether anybody has ever had this pigment in a pure 

 form. Urochrome is free from iron, but contains nitrogen. DOMBROW- 

 SKY found 11.15 per cent nitrogen, HOHLWEG found 9.89 per cent nitrogen, 

 and KLEMPERER found only 4.2 per cent nitrogen. According to 

 DOMBROWSKY urochrome contains about 5 per cent sulphur, while 

 other investigators like HOHLWEG, SALOMONSEN, and MANCINI found 

 that is was free from sulphur. 7 According to GARROD it. stands in 



1 Jaffe, Centralbl. f. d. med. Wissensch., 1868 and 1869, and Virchow's Arch., 47; 

 Bisque, Zeitschr. f. physiol. Chem., 2; Saillet, Revue de me"decine, 17, 1897. 



2 v. Udranszky, Zeitschr. f. physiol. Chem., 11, 12, and 13. 



3 P16sz, Zeitschr. f. physiol. Chem., 8; Thudichum, Brit. Med. Journ., 201, and 

 Journ. f. prakt. Chem., 104; Schunck, cited from Huppert-Neubauer, 10. Aufl., 509. 



4 See Huppert-Neubauer, 161. 



5 In regard to this and other red pigments, see Huppert-Neubauer, 593 and 597 ; 

 Nencki and Sieber, Journ. f. prakt. Chem. (2), 26. 



6 Garrod, Proc. Roy. Soc., 55; Thudichum, 1. c. 



7 Dombrowsky, Zeitschr. f. physiol. Chem., 54; Hohlweg, Bioch. Zeitschr., 13; 

 Salomonsen, ibid., 13; Mancini, ibid., 13; Klemperer, Berl. klin. Wochenschr., 40. 



