CHAPTER VIII. 



METHODS FOR THE ANALYSIS OF THE BILE AND 

 BILIARY CALCULI. 



WE have in the preceding Chapters treated so fully of the 

 properties and methods of separating the normal constituents of the 

 bile, that it only remains to describe the methods which are employed 

 in the systematic analysis of bile and biliary calculi, and which are 

 of special importance to the physician and the pathologist. 



SECT. 1. EXAMINATION OF THE BILE FOR ALBUMIN, OXYH^MO- 

 GLOBIN AND ITS DERIVATIVES, SUGAR, UREA, LEUCINE AND 

 TYROSINE. 



Albumin. 



Sugar. 



* 

 derivatives. 



The bile is cautiously neutralised by means of dilute 

 acetic acid and then boiled, when the production of a 

 coagulum will indicate the presence of albumin. 



The bile is decolourised by means of animal char- 

 coal, filtered, and the filtrate is tested for sugar, (1) by 

 Fehling's test, (2) by the fermentation test. 



oxy-hsemo- l n the case of the presence of sufficient blood- 



its colouring matter, a red colour and the characteristic 



& \ , , . , , ._., 



spectrum ot oxy haemoglobin may be observed. Ine 



bile, however, readily decomposes this body, throwing down a pre- 

 cipitate which contains both hsematin and albuminous substances 

 (Hoppe-Seyler). This precipitate should be dissolved in dilute 

 solution of sodium hydrate when the spectrum of hsematin in 

 alkaline solution is observed ; on treating the solution with ammo- 

 nium sulphide the spectrum of haernochromogen (reduced haematin) 

 is obtained (see Vol. I. 1st ed. p. 110). 



In examining the bile of the ox and of the sheep, when two bands 

 alone are visible, their position should be carefully determined and 

 compared with that of the oxyhsemoglobin bands, before the con- 

 clusion is arrived at that this substance is present ; the necessity for 

 caution arises from the fact that the two central bands of the 



