STONE, OR GRAVEL. 99 



pealike calculi. These are smoother, but on the surface crystals of 

 oxalate of lime may be detected with a lens. Some renal calculi are 

 formed of more distinct layers, more loosely adherent to each other, 

 and contain an excess of mucus, but no oxalate of lime. Finally, a 

 loose aggregation of small masses, forming a very friable calculus, 

 is found of all sizes within the limits of the pelvis of the kidney. 

 These, too, are in the main carbonate of lime (84 to 88 per cent) and 

 without oxalate. 



Symptoms of renal calculi are violent colicky pains, appearing sud- 

 denly, very often in connection with exhausting work or the drawing 

 of specially heavy loads, and in certain cases disappearing with equal 

 suddenness. The nature of the colic becomes more manifest if it is 

 associated with stiffness of the back and hind limbs, frequent passage 

 of urine, and, above all, the passage of gravel with the urine, espe- 

 cially at the time of the access of relief. The passage of blood and 

 pus in the urine is equally significant. If the irritation of the kid- 

 ney goes on to active inflammation, then the symptoms of nephritis 

 are added. 



Uretral calcidi. — These are so called because they are found in the 

 i:)assage leading from the kidney to the bladder. They are simply 

 small renal calculi which have escaped from the pelvis of the kidney 

 and have become arrested in the ureter. They give rise to symptoms 

 almost identical with those of renal calculi, with this difference, that 

 the colicky pains, caused by the obstruction of the ureter by the 

 impacted calculus, are more violent, and if the calculus passes on 

 into the bladder the relief is instantaneous and complete. If the 

 ureter is completely blocked for a length of time, the retained urine 

 may give rise to destructive inflammation in the kidney, which may 

 end in the entire absorption of that organ, leaving only a fibrous 

 capsule containing an urinous fluid. If both the ureters are similarly 

 blocked, the animal will die of uremic poisoning. 



Treatment of renal and uretral calculi. — Treatment is unsatisfac- 

 tory; as it is only the small calculi that can pass through the ureters 

 and escape into the bladder. This may be favored by agents which 

 will relax the walls of the ureters by counteracting their spasm and 

 even lessening their tone, and by a liberal use of water and watery 

 fluids to increase the urine and the pressure upon the calculus from 

 behind. One or 2 ounces of laudanum, or 2 drams of extract of bella- 

 donna, may be given and repeated as it may be necessary, the relief of 

 the pain being a fair criterion of the abating of the spasm. To the 

 same end use warm fomentations across the loins, and these should be 

 kept up persistently until relief is obtained. These act not alone by 

 soothing and relieving the spasm and inflammation, but they also 

 favor the freer secretion of a more waterj^ urine, and thus tend to 

 carry off the smaller calculi. To further secure this object give cool 



