378 BILIARY CALCULI. [BOOK II. 



women dying in the great hospital of La Salpetriere, concretions 

 have been found in the gall-bladder 1 . 



The number of calculi which are found in the gall-bladder varies 

 greatly. Occasionally, though rarely, a single calculus is found, 

 though more commonly the number varies between 5 and 30. As 

 many as 3000 calculi were found in one gall-bladder by Morgagni, 

 and 7802 by Otto (Breslau Museum). 



Physical However few or numerous the calculi contained 



f in a g all - bladder > usually they all possess the same 

 chemical composition, the same structure, the same 

 volume, the same colour. Exceptions to this rule are rare. 



The size of biliary calculi varies greatly, the average being about 

 the size of a hazel-nut. Meckel described a biliary calculus which 

 was 15 centimetres long and 6 broad, and which only weighed 

 30'3 grms. 



When biliary calculi occur singly they are rounded or ovoid. 

 When they attain a very large size they are pyriform, as they mould 

 themselves to the shape of the cavity in which they are formed. 

 Multiple calculi usually exhibit facets. These facets are produced 

 by the mutual pressure of the concretions one against the other 

 whilst these are of yet soft consistence, and not by a process of 

 attrition* 



The colour of biliary calculi presents great varieties. Those 

 which are composed of nearly pure cholesterin are throughout white 

 and sometimes transparent. Others, which are also composed of 

 cholesterin, possess a more or less coloured and opaque exterior, 

 which is sometimes yellow and sometimes greenish. The colour 

 depends especially on the presence of particular stages of oxidation of 

 the biliary colouring matters. 



Biliary calculi have a very low specific gravity, which is, however, 

 always higher than that of water or bile. Soemmering and some 

 other authors have fallen into error in asserting that biliary calculi 

 occasionally float in water and bile. When recent, biliary calculi 

 always sink in these liquids. Sometimes, however, biliary calculi 

 are found in museums which, having become dry, float. If these are, 

 however, plunged in water or bile for some time, bubbles of air are 

 seen to rise and the calculus, acquiring its original density, sinks to 

 the bottom of the liquid. 



structure of As a rule, biliary calculi present (1) a central 

 gall-stones. nucleus: (2) a middle zone, which is in general com- 

 posed of multiple concentric lamellae, formed by radiating crystalline 



1 Charcot, 'Lecons sur les Maladies du Foie et des Keins faites a la Faculte de 

 M^decine de Paris.' Eecueillies et publiees par Bourneville et Sevestre, Eedacteurs 

 du Progres Medical, Paris, 1877. The Author has, in his descriptions of calculi, made 

 great use of the large stores of information contained in the lectures devoted to the 

 subject of biliary lithiasis. 



