334 CHOLOILEMATIN. [BOOK II. 



connected with putrefaction, but commences as soon as the bile is 

 brought in contact with the atmospheric oxygen. 



From these observations it is obvious that we have no more 

 right to say that cholohsematin exists in the bile of the ox or sheep 

 than to assert that fibrin exists in the living blood. The bile of these 

 animals at the time of death contains a chromogen, or chromogens, 

 which under the influence of oxygen gives rise to a body, or bodies, 

 which confer upon the bile the spectroscopic characters studied in 

 the first instance by Hoppe-Seyler and by Heynsius and Campbell, 

 and afterwards by MacMunn. There is no evidence that the four- 

 banded spectrum is due to one substance. It may be, and probably 

 is, due to more than one substance ; this view is at least rendered 

 probable by the fact, already referred to, that at one stage in the 

 development of the final product, or products, the spectrum presents 

 only the two central bands, and that the others are superadded as 

 the process of change proceeds. 



The Author wishes it to be understood that he does not assert 

 that the so-called cholohaematin is necessarily a product of oxidation 

 of chromogen or chromogens, in the same sense in which biliverdin 

 is a product of oxidation of bilirubin ; it may be a mere product of a 

 decomposition which is initiated by oxidation. 



MacMunn's Ox-bile is treated with absolute alcohol, a few drops 



method of of acetic acid are added, the liquid is filtered and 

 separating shaken with chloroform. The orange-coloured chloro- 

 namatin 1 ^ orm so ^ u ^ on * s separated, filtered and evaporated to 



dryness. On dissolving the chloroform extract in ether, 

 a greenish solution is obtained ; this is evaporated to dryness, the 

 residue dissolved in chloroform and washed again in a separating 

 funnel with water. " On separating off the chloroform, filtering and 

 evaporating the solution, an amorphous-looking residue of a dark 

 sap-green colour was obtained, which still had a peculiar musky odour. 

 On dissolving some of this residue in alcohol and adding ether no 

 precipitate formed, shewing that bile salts could not have been 

 present." 



It is obvious that such a process could yield no pure substance, 

 and that the question whether any individual body exists to which 

 the name choloha3matin can be applied remains an entirely open 

 one, to be settled by future researches. 



MacMunn's The spectrum of cholohaematin is shewn in Spect. I. 



description of o f p| ate jj MacMunn has given the following data 

 of cholo 5 -* as to the approximate position of the four bands of 



nsematin. cholohsematin, expressed in wave-lengths. 



1st band centre at X649. 

 2nd band from X613 to 585. 

 3rd band from X577'5 to 561 '5. 

 4th band from X537 to 521-5. 



1 MacMunn, op. cit., Journal of Phys., Vol. vi. pp. 25 and 26. 



