

CHEMISTRY OF GALL-STONES. 197 



CHEMICALLY. The number of substances entering 

 into the formation of gall-stones are numerous. The 

 most important are as follows : 



1. CHOLESTERINE. This substance is but seldom 

 absent, and forms the principal constituent of biliary 

 concretions. It is found in a crystalline form, and 

 mixed with fatty and saponaceous substances. It is 

 estimated that gall-stones contain from 70 to 80 per 

 cent, of this substance, which in this respect bears a 

 similar relation to these stones as uric acid does to 

 stones found in the bladder. 



-. BILE PIGMENT, which is found more or less in all 

 gall-stones. 



3. CHOLEPYRRHIN. This substance is either found in 

 a pure state or combined with lime ; it goes to form the 

 nuclei, the shell, and outer crust of the gall-stones. When 

 treated with chloroform the cholepyrrhin dissolves, and 

 separates, and on evaporation crystallizes in the form of 

 needles, prisms, and lamine, of a yellowish brown or 

 garnet-red colour. 



4. CHOLEPYKKHIN and lime. This compound is found 

 in most gall-stones ; in colour it is yellowish red, and 

 deposited in the form of layers of granules, or scales, 

 between the lamine of the stones. 



< 'HULK* iiLouiN. This is a green pigment found 

 but sparingly in gall-stones when separated from the 

 other substances, and submitted to alchohol, it presents 

 a beautiful grass-green colour. 



IJiliary ucM.s and calcareous salts. 



7. liile pigments. 



8. Glycocholute of lime, found in the ox as well as 

 man. 



n 



