1867.] Dr. TliudicliuirL on the Colour inc/ -matters of Bile. 215 



III. Researches conducted for the Medical Department of the 

 Privy Council ac the Pathological Laboratory of St. Thomas''s 

 Hospital.^^ By J. L. Vi. Thudichum^ M.D. Communicated by 

 John Simon, Esq._, Medical Officer of the Privy Council. Pn-st 

 Series. — The Chemical Nature and Composition, Combinations, 

 and Metamorphoses of the Colouring-matters of Bile. Received 

 November 14, 1867. 



(Abstract.) 



I. On Cholophceine or Bilirubine and its Compounds. 

 Sect. 1 . The paper commences with a short historical retrospect on the lite- 

 ratureof the subject under consideration, in which the researches ofBerzelius, 

 Scherer, Hein, Marchand, Heiutz, Maly, and Stadeler are mentioned. 

 Sect. 2. The author then describes the mode of obtaining a red colouring- 

 matter from ox-gallstones. These concretions have to be extracted with 

 water, alcohol, ether, dilute hydrochloric acid, and ultimately, after re- 

 peated extraction with boiling alcohol and ether, with chloroform. This 

 agent dissolves bilirubine or cJioloph<xin€, and deposits it, on concentration 

 and the addition of absolute alcohol, in an amorphous condition, or in a 

 crystallized state. Sect. 3. The crystals are dark brown, and have a 

 splendid blue lustre. They are rhombic plates, as represented by a draw- 

 ing in outline taken from a specimen magnified about iwenty times. The 

 amorphous or only crystaUine modification is a powder of a splendid red, 

 nearly orange-colour. Sect. 4. The elementary analysis of several speci- 

 mens yielded results which led to the formula Hg N O.,. Sect. 5. Bili- 

 rubine dissolves in ammonia, but does not form any permanent compound 

 with it. Its combinations with fixed caustic alkalies are insoluble in an 

 excess of lye. The neutral alkali solution, mostly the one in ammonia, 

 yields neutral salts with monodynamic metals, half-acid salts with didy- 

 namic ones. 



The neutral monoJujdrated cholophceinate of silver^ H^^ Ag N03, 

 Ag = 37"5 per cent., is a reddish-brown precipitate, which does not lose the 

 atom of water at 110° C. As a hydrated silver-salt it is anomalous ; but a 

 few other animal products, such as hippuric acid, are known also to form 

 such hydrated silver-salts. By means of this compound, the formula of 

 bihrubine, or cholophseine, above given, is shov/n to express its atomic 

 weight. 



The basic anhydrous cholophceinate of silver, Cg H. Ag,, NO^, Ag 

 = 57*29 per cent., is obtained from an alkaline solution of cholophaeine 

 and silver nitrate in ammonia, by cautiously reducing the amount of free 

 alkali by means of nitric acid. The compound is analogous to a lead-salt, 

 Pb described lower down. 



The neutral cholophceinate of barium is ])recipitated from an alkaline 

 solution, and has the composition C^, H^^BaN^Og, Ba=27'o6 })er cent. 



The half -acid cholophceinate or sesquicholophceinate is €.,^ H.,9 Ba 



