GAEL STONES IN CATTLE. 



Characters. The biliary calculi of cattle are characterized by 

 a faint odor of musk, which becomes stronger on the addition of 

 potassa and the consequent disengagement of ammonia. 



They are distinguished according to their color as dark green, 

 yellowish green, and orange, brownish or white. There are also 

 the sedimentary deposits (biliary sand). 



The dark green calculi are the most frequent, and being found 

 in the gall bladder and larger bile ducts, they attain a larger size 

 than the others. Those in the gall bladder may be pear-shaped, 

 and those in the ducts, round, ovoid or cylindroid. They are 

 often rough and uneven on the surface with deep cracks and 

 holes penetrating deeply into their substance and often filled 

 with cholesterin. The pigments may change to a blood red 

 when dried. The consistency of these calculi varies, some being 

 hard, resistant and heavy, while others are soft and friable. All 

 are composed of concentric layers around a central nucleus as in 

 those of the horse. They vary in weight up to seven ounces in 

 exceptional cases. They contain cholesterin, fat, resin, pig- 

 ments, and lime and magnesia salts. 



The yellowish green calculi are usually spherical unless moulded 

 into polygonal shapes by mutual contact. In the last case they 

 have flattened surfaces. These have a firm consistency and are 

 composed of successive layers of nearly equal color and density 

 surrounding the central nucleus. They are on an average 

 smaller than the dark green variety but individual calculi have 

 been found of three ounces. 



The whitish or orange calculi are usually in the form of hollow 

 casts of the bile ducts having a dull white color externally and a 

 yellowish brown internally. They are usually thin, fragile and 

 crystalline and contain relatively more earthy salts than the two 

 first named varieties. From this cause also they have a higher 

 specific gravity. One specimen weighed 8 ounces. 



The biliary sand or pulp, is made up of granules of a yellowish, 

 dark green or black color, forming with the bile a pultaceous 

 mass but drying into a consistent mass. It may be firmly adher- 

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