XI.] THE BILE. 87 



LESSON XI. 

 BILE. 



1. Use ox-bile obtained from the butcher, and, if possible, human 

 bile. 



(a.) The colour in man is a brownish-yellow, in the ox- greenish, 

 but often it is reddish-brown when it stands for a short time. 

 ]S T ote its bitter taste, peculiar smell, and specific gravity (1010- 

 1020). 



(b.) It is alkaline or neutral to litmus paper. 



('.) Pour some ox-bile from one vessel to another, and note that 

 strings of so-called mucin connect one vessel with the other. 



(d.) Acidulate bile with acetic acid, which precipitates mucinoid 

 substance coloured with pigments. Filter off this precipitate. Test 

 the filtrate. 



(e.) It gives no reactions for albumin. 



(/.) Add hydrochloric acid and potassic ferrocyanide. A blue 

 colour indicates the presence of iron. Test for chlorides and other 

 salts 



((/.) Fresh human bile gives no spectrum, although the bile of 

 the ox, mouse, and some other animals does. 



2. Bile-Salts or Bilin (glycocholate and taurocholate of sodium). 

 (a.) Concentrate ox-bile to one-fourth of its bulk, mix with 



animal charcoal in a mortar to form a thick paste. Evaporate to 

 complete dryness over a water-bath. 



(/;.) To the dry charcoal-bile mixture, add five volumes of abso- 

 lute alcohol. Shake the mixture from time to time, and after half 

 an hour filter. To the filtrate add much ether, which gives a 

 white precipitate of the bile-salts. If no water be present, some- 

 times the bile-salts are thrown down crystalline; but not unfre- 

 quently they go down merely as a milky opalescence, which quickly 

 forms resinous masses. It is best to allow the mixture to stand 

 for a day or two, to obtain the glancing needles which constitute 

 Plattner's Crystallised Bile. 



Scheme for Bile-Salts, etc. 



200 cc. of ox-bile, dried, mixed with animal charcoal, are extracted with 

 absolute alcohol by the aid of heat ; filter. 



Residue, mucin, Alcoholic solution treated with 



pigments, salts, charcoal. ether. 



Precipitate, Solution contains 



Bile-salts. Cholesterin. 



