■ Diseases of the Urinary Organs. 303 



Treatment. Wash with milk-warm water containing 

 laudanum, and return, pressing the centre of the mass in- 

 ward so as to correct the eversion. The main difficulty 

 will be miet in returning it through the contracted neck of 

 the bladder, and if the eversion has lasted long encugh to 

 determine inflammation and softening great care will be 

 requisite to avoid tearing the coats. Should straining be 

 so violent as to threaten renewal of the eversion a truss 

 }iiay be apphed as advised for eversion of the womb. 



UEINAEY CALCULI AND GRAVEL. STONE. 



These vary in chemical composition with the genus of 

 animal and especially with the nature of the food. In 

 herbivora the urine normally contains a large amount of 

 the carbonates of lime and magnesia and of oxalate of lime, 

 a small quantity of silica, sulphate and phosphate of lime, 

 ammonio-magnesian phosphate, hippuric acid and some- 

 times uric acid, besides the more soluble alkaline salts. 

 Carnivora, on the other hand, have an excess of phosphate 

 of hme and magnesia, of sulphates and chlorides, more 

 uric acid than the vegetable feeders but a minimum amount 

 of carbonate and oxalate of hme and silica. The omnivora 

 occupy an intermedials position, the salts of the urine va- 

 rying with the frequent changes in the food. 



The nature of the food determines the excess of particular 

 salts in the urine and their precipitation in the form of 

 crystals. 



These carhonates of lime and magnesia which make up 

 t]ie bulk of most urinary calculi in horses and ruminants 

 are due to the large amount of vegetable acids (citrates, 

 taiirates, malates, acetates, etc.,) in plants. These becom- 

 ing further oxidized are transformed into carbonic acid 

 which unites with the magnesia or lime present in the 

 blood. 



Oxalate of lime is due to imperfect oxidation of the veg- 

 etable acids, oxalic acid containing an equivalent less of 

 oxygen than carbonic acid. It appears in excess in cer 



