BILE, BILIN. 1045 



tuents of bile are remarkably prone to assume new forms under 

 the influence of re-agents. 



Bilin, the principal constituent of bile, may be isolated by the 

 following processes, (a) The bile of the ox, after the separation of 

 its mucus, is mixed with a little acetic acid, then filtered and pre- 

 cipitated by acetate of lead. The yellow precipitate, consisting 

 of a combination of biliverdin, oleic and margaric acids with 

 oxide of lead, is filtered, and the filtered liquid precipitated by a 

 solution of the basic acetate of lead. The last precipitate, at 

 first white, then yellow and plaster-like, contains fellinic acid in 

 combination with a portion of the bile. Most of the bilin 

 remains undissolved. The lead in the same solution is precipi- 

 tated by sulphuretted hydrogen, and the solution remaining of 

 bilin is evaporated carefully to dryness. The bilin so procured 

 contains acetate of soda, and is likewise somewhat altered by 

 the action of the free acetic acid during the evaporation. It is 

 in this condition that bilin has been distinguished by the name 

 of bile-sugar orpicromel. 



(b) Ox-bile is evaporated to perfect dryness on a water-bath, 

 reduced to powder and digested with anhydrous ether, which 

 dissolves out all the fatty bodies not in combination with bases. 

 The mass is then dissolved in alcohol, by which, mucus, common 

 salt, &c. are left undissolved. To the filtered liquid a solution 

 of chloride of barium is added, by small portions at a time, so 

 long as a dark green precipitate is formed. The last contains 

 the biliverdin or colouring principle. The liquid filtered from 

 it is then treated with barytes-water, added gradually, so long as 

 a precipitate falls. The colour of different portions of the pre- 

 cipitate, as they are successively produced, is dark grey, soon 

 becoming green, then brownish yellow, and at last yellow. It 

 contains, besides biliverdin, an orange-coloured matter, not yet 

 investigated, and margaric acid. 



The liquid filtered from the last precipitate, after the pre- 

 cipitation of the free barytes it contains by carbonic acid, is 

 evaporated to dryness, and the mass dissolved again in anhy- 

 drous alcohol, which leaves common salt and chloride of barium 

 undissolved. Sulphuric acid mixed with an equal bulk of water, 

 and then diluted by alcohol, is added gradually to the alcoholic 

 solution to precipitate the bases it contains, in the form of sul- 

 phates. The liquid again filtered is mixed with freshly precipi- 



