CHEMICAL BASIS OF TUK A MM A I. I'.oDY I'll 



ami benzol, and above all in chloroform. Knun its solution in 

 the latter it may be separated out by extremely slow evaj-oratiou 

 of tin- solv.-nt in a crystalline form as rhombic plates or j.i 

 Tin- ;_reneral shape of these is shown above in Fig. 40 ; but as 

 obtained t'roiii solution in either carbon-disulphide or chloi 

 the crystal- usually exhibit somewhat blunt ends and slightly 

 envex surfaces as first pointed out by Staedeler. A.s ordinarily 



FIG. 41. BILIRDBIX CRYSTALLISED FROM CARBON-DISCLPHIDE. (Krukenberg.) 



prepared it is an amorphous powder of the colour of sulphide of 

 antimony. It readily forms compounds with bases, e.g. sodium, 

 barium, and calcium, the latter providing a convenient means 

 i"i tin- separation of bilirubin from bile, urine, or other dilute 



solution. 



/-" i-i'tion. (i) When gall-stones are not available bile may 

 lie treated as follows. 1 The bile is slightly diluted with water, 

 somw lime-water is added (avoiding excess) and after thorough 

 mixture, as by shaking, a current of carbon dioxide is passed to 

 convert all the excess lime into carbonate. The precipitate thus 

 formed contains the bilirubin as a calcium compound. This is 

 then collected on a filter, washed with water, and after suspe: 

 in a little water, decomposed by the addition of a slight excess of 

 acetic or hydrochloric acid. By this means the bilirubin is set 



UK! may now be extracted by shaking with an excess of 

 chloroform. The chloroform solution is separated by decantation. 

 and evaporated to a small bulk; the bilirubin may then finally 

 be ] precipitated by an excess of alcohol. The amount thus ob- 

 tained is not |uantitatively accurate, since all the bilirubin is not 

 precipitated by the lime at the outset and there is a further loss 

 during the subsequent operations, (ii) Since, as already stated, 

 the ^all-Mom '.s of the ox or pig may consist of nearly half their 

 weight of bilirubin combined with calcium, they provide the best 



..M Iluppcrt. Arch. d. Ileill. IM. vm 

 S-vl.T. //./'..-A. ,/. i,li,i.<i.,:.. r .,t/,. .-/,.,. Awii. I **:, s. i>:,i> Cf Hilger, Artk. </. 

 I'fiarm. (3), Bd. vi. (1875). S. 385. 



16 



