354 HEALTH AND DISEASE 



The sediment obtained after the fluid has been allowed to rest is 



shown by three analyses to consist of organic and inorganic matter in 



the following proportions: 



i ii in 



Carbonate of lime ... 8O9 87'2 87'5 



Carbonate of magnesia ... 12'1 7'5 8*5 



Organic matter 7'0 5'3 4'3 



100-0 100-0 100-3 



It will be seen from the above that urine is a highly complex fluid, 

 comprising organic and inorganic constituents in a state of watery solution. 



Origin Of Stone. On the origin of vesicular calculus there is very 

 little of a definite nature to be advanced. It is a well-established truth 

 that under certain local as well as general conditions of the body the renal 

 secretion undergoes various modifications and changes both in its physical 

 state and chemical constitution. Thus, normal constituents may be in- 

 creased or diminished, or altogether disappear, while others foreign to the 

 secretion are sometimes found entering into its composition. 



These departures from the general standard are in some cases doubtless 

 connected with physiological deviations in the complex processes of assimi- 

 lation, and in some measure also with chemical alterations which the urine 

 undergoes after its departure from the kidneys. 



In diseased conditions of the system peculiar compounds are not un- 

 frequently formed which are rarely or never produced in the healthy 

 organism, and, being feebly soluble in urine, are immediately deposited in 

 a solid form from that fluid. In this manner oxalate of lime comes to form 

 a part, and in some very rare cases the whole, of the vesicular calculus in 

 the horse. 



To what extent the superabundant formation of lime-salts in the 

 economy is referable to food, water, climate, and assimilative disturbance, 

 separately or together, we have at present but little to guide us to a satis- 

 factory conclusion. The fact remains, nevertheless, that some horses 

 eliminate from their systems an amount of calcic carbonate that is simply 

 astonishing. The writer's attention was recently called to a case in which 

 a considerable amount of this salt w T as periodically removed from the 

 bladder of a mare in addition to that which escaped with the urine in 

 the act of micturition. 



On this subject the late Professor Morton remarks: "The water drunk 

 by animals has generally been considered as the source of calculi, but it is 

 by no means proved that in those localities where lime is more abundantly 

 met with in water, as Matlock, Scarborough, Carlsbad, and other limestone 

 districts, that in these, calculous affections are most prevalent; whereas 



