BILE. 71 



tion of HC1; then wash twice with water and dry the paper 

 in the funnel. 



When dry pass through the filter again and again about 

 10 c.c. of chloroform until this assumes a yellowish color, 

 caused by its solvent action on the bilirubin. Finally allow 

 a few c.c. of fresh chloroform to flow through the funnel, and 

 uniting this with the previous extract, let it evaporate in the 

 air. 



Treat the residue of the calculus still on the filter-paper 

 with about 10 c.c. of alcohol. What does this extract? 

 Evaporate off the alcohol on the water-bath. Notice the 

 color of the residue and compare it with that of bilirubin. 



What was the necessity for the use of the hydrochloric 

 acid in the analysis? 



Perform the following tests with the residue of bilirubin: 



(a) Gmelin's test. 



(6) Dissolve some of the substance in a few c.c. of chloro- 

 form and shake it with a dilute solution of Na 2 C0 3 . Notice 

 the changes which occur in the aqueous solution. 



