44 ORGANIC CONSTITUENTS. 



All attempts to isolate tliis substance from tlie bile, by 

 chemical means, have failed ; it is apparently decomposed by 

 the processes that are adopted in the analysis of this compli- 

 cated fluid. We sometimes, hoAvever, find it deposited in the 

 form of a yellow powder, in the gall-bladder, or concreted, with 

 a little mucus, constituting a biliary calculus. 



In this manner we have an opportunity of examining its che- 

 mical reactions. Biliphsein is of a bright reddish-yellow colour, 

 and is only slightly soluble in most fluids ; it is devoid of taste 

 and odour, and yields ammonia on dry distillation. Water 

 takes up an extremely minute trace of biliphsein, just sufficient 

 to communicate a faint yellow tinge. Alcohol dissolves more 

 than water, but only a very inconsiderable quantity. Its best 

 solvent is a solution of caustic potash or soda, both of which 

 are more eflScient than ammonia. On exposing this solution 

 to the atmosphere, oxygen is absorljed, and the yellow colour 

 becomes gradually green. On the addition of an acid to this 

 yelloAV or green solution, there is a precipitation of green flocculi 

 which possess all the properties of chlorophyll, or the green 

 colouring matter of leaves. In this state it is termed bi liver din 

 by Berzelius. It is no longer biliphsein (or cholepyrrin), but a 

 product of its metamorphosis. 



The colouring matter of the bile may be separated from a 

 composite animal fluid, by evaporation to dryness; by successive 

 extractions with alcohol of "845, ether, and water; by dissolving 

 the colouring matter in a solution of potash, and then precipi- 

 tating it, as biliverdin, by hydrochloric acid. 



Diagnosis. The action of nitric acid afl'ords a certain test 

 of the presence of biliphsein. 



b. After the separation of the biliphsein, by conversion into 

 biliverdin, another colouring matter remains, to which Berzelius 

 has given the name of bilifulvin. It is a double salt of lime 

 aud soda, combined with an organic nitrogenous acid, to which 

 the term bilifulvic acid has been applied. When isolated, this 

 acid is insoluble in water and in alcohol, and separates in pale 

 yeUow flocculi when it is precipitated from an aqueous solution 

 of its salts by a stronger acid. Whether bilifulvin is an actual 

 constituent of the bile, or whether it is a mere product of meta- 

 morphosis, is unknown. 



