DISEASES OF THE HORSE. 95 



off in solution in the urine in disease. In this connection it is impor- 

 tant to observe the following- analysis of the horse's urine in health: 



Water , 918.5 



Urea 13.4 



Uric acid and urates 1 



Hippuric acid 26. 4 



Lactic acid and lactates 1.2 



Mucus and organic matter 22. 



Sulphates (alkaline) 1. 2 



Phosi^hates (lime and soda) , 2 



Chlorides (sodium) 1.0 



Carbonates (potash, magnesia, lime) 16. 



1000. 

 The carbonate of lime, which is present in large amount in the urine 

 of horses fed on green fodder, is practically insoluble, and therefore 

 forms in the passages after secretion, and its microscopic rounded 

 crj^stals give the urine of such horses a milky Avhiteness. It is this 

 material which constitutes the soft, w^hite, puitaceous mass that some- 

 times fills the bladder to repletion and requires to be washed out. In 

 haj^-fed horses carbonates are still abundant, while in those mainly 

 grain-fed they are rej)laced by hippurates and phosphates — the prod- 

 ucts of the wear of tissues — the carbonates being the result of oxida- 

 tion of the vegetable acids in the food. Carbonate of lime, therefore, 

 is a very common constituent of urinar}^ calculi in herbivora, and in 

 many cases is the most abundant constituent. 



Oxalate of lime, like carbonate of lime, is derived from the burning 

 up of the carbonaceous matter of the food in the system, one important 

 factor being the less perfect oxidation of the carbon. Indeed, Fiisten- 

 berg and Schmidt have demonstrated on man, horse, ox, and rabbit, 

 that under the full play of the breathing (oxidizing) forces, oxalic acid, 

 like other org-anic acids, is resolved into carbonic acid. In keeping 

 with this is tlie observation of Lelimann that in all cases in which man 

 suffered from interference with the breathing, oxalate of lime appeared 

 in the urine. An excess of oxalate of lime in the urine may, however, 

 claim a different origin. Uric and hippuric acids are found in the 

 urine of carnivora and herbivora, respectively, as the result of the 

 healthy wear (disassimilation) of nitrogenous tissues. But if these 

 products are fully oxidized they- are thrown out in the form of the 

 more soluble urea rather than as these acids. When uric acid out of 

 the body is treated with peroxide of lead it is resolved into urea 

 allantoine, and oxalic acid, and Woehler and Frerrichs found that the 

 administration of uric acid not only increased the excretion of urea, 

 but also of oxalic acid. It may therefore be inferred that oxalic acid 

 is not produced from the carbonaceous food alone, but also from the 

 disintegration of the nitrogenous tissues of the body. An important 



