CHEMICAL BASIS OF T1IK ANIMAL linDV. 



13. Haematoidin. 1 C u H u N a O,. 



This substance is found as reddish or orange rhomboh- 

 crystals in old blood-clots as of cerebral haemorrhages, 8 in corpora 

 lutea, iii the urine in cases of transfusion of blood 3 and in cases 

 of luematuria. 4 There is no doubt that as occurring in the above 

 cases it is directly derived from some metamorphosis of haemo- 

 globin. Apart from the .similarity of crystalline form and colour 

 it was further found that ha-matoidin crystals readily ^ive the 

 characteristic (Umelin's; reaction for bilirubin by treatment with 

 nitric acid, and thus its identity with bilirubin was at once asserted 

 and supported by very convincing evidence. 6 The identity was 

 however for some time disputed, notably by Stadeler, and by 



*?/ * 



40. H.KMATOIUIV CRYSTALS. (Frey after Funke.) 



others largely on the basis of inconclusive spectroscopic im 

 Cation of the two substances. There is however no doubt that 

 nfematoidin is really identical with bilirubin, so that imw the 

 nuinf is of interest rather from a historical point of vi.-\v and 

 physiuluu'iriiiiy aa indicating lu- undoubted genetio reUtioDBbip 

 of the pigments of bile to those of blood. 



I, ILK-PIGMENTS AND TIIKIK DERIVATIVES* 



The bile is in all animals a characteristically . 



secreti. >n. The colour of the fresh bile is as a general rale 



i The litoratnre of this ul>.tance is very fully quoted in Hermann 1 ! lldbch. d. 



fully closrril.o.1 it -TS ol.taino.l frmn tins ..ource. ai 

 hamatoidin t.. indirat.- iti iind..nl.t-d .lrriv.iti..n fr-.m the colouring matter o 



\'in-h..w^ .I-/,. l',.| 



ii ..;.;.. Eteyter, I'fln^or's .l/w,. Bi. \ -Mi. 



i I <rA. Arch. f. Klin. M ' ' "' 



6 See among others K. 'Salkowski, Hoppe-Seyh-r'n Mtd.-cktm. DM 



| Qlvfi tt *l*lf* 



I MeUh Malv it, H-nnam.-- I/'I'^h. ,1. /'A v .o'. Hd. r. Th. 2 J-l. 

 AN.. f..r hit..rv aud literature. Heyusiu* u. Campbell, Pfliiger Arch. 

 8. 497. 



