.STONE IN THE BLADDER 355 



we do know that animals kept on any of the lime plants for a long time, 

 or pastured where lime has recently been laid, become the subjects of these 

 accumulations. Nevertheless, excess of lime in water will readily furnish 

 the requisite calcareous matter." 



Why the salts of the urine should cease to be held in solution by the 

 urinary secretion may be conceived to arise either out of a supersaturated 

 condition of that fluid or from chemical reactions resulting in the produc- 

 tion of insoluble compounds, but it is not always so easy to comprehend 

 the reasons which in certain cases determine the aggregation of small 

 particles of salts and the development of a distinct calculous formation 

 or stone. Such a state of quiescence as is aftbrded by a paralysed bladder 

 would appear to favour the separation and aggregation of the crystallizable 

 constituents of the urine, as would also its retention for long periods in 

 the cavity of the bladder, either as the result of habit or by force of 

 stricture of the urethra, prostatic enlargement, or other like interferences 

 with its proper and due discharge, but it cannot be said that stone in 

 the bladder is specially prevalent under these circumstances. 



Experience gives no encouragement to the idea that the tendency to 

 stone formation is greater in proportion to the amount of stone-forming 

 salts secreted by the kidneys. 



Composition of Vesical Calculus.— The following table of analyses 

 of vesical calculus of the horse and ass is given by Furstenberg: — 



Calculi, it will he .seen, are compo.sed of earthy salts in combination 

 with a greater or less amount of organic matter. As shown by reference 

 to the above analyses, carbonate of lime constitutes over 80 per cent ot 



