198 COMPOSITION OF GALL-STONES. 



9. Cholate of lime, found in the gall-stones of many 

 ruminants, as well as man. 



10. Free fatty acids, a compound of fatty acids and 

 lime, mucus, epithelium, and uric acid. 



11. Inorganic Metallic Matters. Iron, manganese, 

 copper, and earthy matters, such as the carbonates, 

 phosphates, potass, and soda have been found in varied 

 quantities in the human gall-stone. 



Ordinary gall-stones are composed, as we have seen, 

 of cholesterine, which, with variable proportions of 

 colouring matter, is deposited around a nucleus which 

 generally consists of biliary matter, more or less altered 

 with other properties. The chnlrstcrine < r\ >tallizes so 

 as to form rays converging from all points of the 

 circumference of the stone to r ; but when 



it is mixed with, or stained by, the colouring matters 

 of bile, which, as usual, are in ditterent proportioned 

 layers successively deposited, tin- stone, while it still 

 exhibits the convei-m^ rays, appears to b '<!' ot 



distinct concentric lamina-. Two eireumstancesthen seem 

 generally to concur in the formation of these cl. 

 t-rinc stones : the presence of a small mass of concrete 

 biliary matter, or of some other substance, to serve as a 

 nucleus; and the presence of cholesterine in cryst;i 

 make up the body of th< The first step then, 



is the formation of ti 08, which probably results 



in most cases, especially when many gall-stones are 

 formed together, from the peculiar principles of the bile 

 being in an abnormal condition, and more than un- 

 usually insoluble. The second step is the formation of 

 crystals of cholesterine, which, like the former, re 

 from faulty assimilation, and which is frequently asso- 



