462 cALciFKwnow coscinrnoxs. .\\i> i\Ch'rsT.[Ti<)\^< 



Cholesterol 7.69 



Pifrnients and soaj) 40.01 



Uiuletormiiied 6.01 



rsually. liowc'ver, pancreas stones consist chiefly of inorganic sub- 

 stances. .Johnson and Wollaston report analyses of two stones, one 

 containing 72.30 per cent, calcium phosphate and but 8.80 per cent. 

 organic matter; the other 91.65 per cent, calcium carbonate, 4.15 per 

 cent, magnesium carbonate, and but 3 per cent, organic matter. 

 Legrand ^ found only 0.7 per cent, organic matter i)i another concre- 

 tion which contained 93.1 per cent, calcium carbonate. Pancreatic 

 juice, being strongly alkaline, can hold but a small quantity of calcium 

 salts in solution (normally but 0.22 part per thousand — C. Schmidt) ; 

 presumably the little normally present is held in the form of a colloidal 

 suspension by the proteins. Possibly when stasis occurs, digestion of 

 the proteins leads to the precipitation of the calcium salts, or, more 

 probably, the excessive calcium is largely derived from the exudate 

 from the inflamed ducts, as seems to be the case with the calcium of 

 biliary calculi. 



Salivary Calculi.- — These have a similar composition, in the main, 

 to the concretions of the pancreatic duct, except that they generally 

 contain more organic matter, resembling in this respect the "tar- 

 tar" of the teeth. Bessanez found in one 81.3 per cent, of calcium 

 carbonate and 4.1 per cent, of calcium phosphate, whereas in an- 

 other the carbonate was but 2 per cent, and the phosphate 75 per 

 cent. Potties has described a calculus with a central portion com- 

 posed chiefly of uric acid and a peripheral portion containing 69 per 

 cent, of calcium pliospliate and 20.1 per cent, of calcium carbonate. 

 Harlay ^ found in one specimen 15.9 per cent, organic matter, 75.3 

 per cent, calcium phosphate, 6.1 per cent, calcium carbonate. Ro- 

 berg believes that bacteria alone do not usually cause salivary calculi 

 to form, but that a foreign body entering the duct is the chief factor. 

 Increased alkalinity nuiy also favor ]irecipitation of calcium from the 

 saliva. In Roberg's case of sialolitliiasis the saliva was of normal 

 composition. 



Intestinal Concretions. — These always have a nuclens of some 

 indigestible foreign su])stance. most often hair, but sometimes eellu- 

 lose structures or solid indigestible j^articles, including gall-stones. 

 fruit-stones, bone, etc. The bulk of the eoiu'retions is usually made 

 U]i chiefly of ammonio-magnesium ))hosj)hate, with some calcium 

 ])hos])hate, carbonate, and sulphate, |)rotein matter, and occasionally 

 calcium and magnesium soa])s. Two iulestiual coiu'retions analyzed 

 by Scliuberg ^ had the following percentage com{)osition when dried: 



1 .Idiir. I'lianii. ct Cliiiii.. I'.IOI (14), 21. 



- I.iteratiire, see KoIht'.', Annals of Siiruerw l!>(»4 (."!!»), (Itl!). 



a.Ioiir. I'liarm. et Cliiin., l'.Mt:{ (IS), 11. 



■• \'irclio\v's .Arcii., ISSii (!l(l|, ~:i. 



