DISEASES OP THE XJEHiTARY OEGANS. 137 



looked for: (1) Colm^: White from deposited salts of lime; brown 

 or red from blood clots or coloring matter; yellow or orange from 

 bile or blood pigment ; pale from excess of water ; or variously 

 colored from vegetable ingredients (santonin makes it red; rhubarb 

 or senna, brown; tar or carbolic acid, green). (2) Density: The 

 horse's urine may be 1.030 or 1.050, but it may greatly exceed this in 

 diabetes and may sink to 1.007 in diuresis. (3) Cherrdcal reaction, &s 

 ascertained by blue litmus or red test papers. The horse on vegetable 

 diet has alkaline urine turning red test papers blue, while in the 

 sucking colt and the horse fed on flesh or on his own tissue (in 

 starvation or abstinence during disease) it is acid, turning blue litmus- 

 red. (4) Organic constituents, as when glairy from albtimen co- 

 agulable by strong nitric acid and boiling, when charged with micro- 

 scopic casts of the urinif erous tubes, with the eggs or bodies of worms, 

 with sugar, blood, or bile. (5) /ti its salts, which may crystallize out 

 spontaneously, or on boiling, or on the addition of chemical reagents. 



Albuminous urine in the horse is usually glairy, so that it may be 

 drawn out in threads, but its presence can always be tested as follows : 

 If the liquid is opaque, it may be first passed through filter paper; 

 if very dense and already precipitating its salts, it may be diluted 

 with distilled water ; add to the suspected liquid acetic acid drop by 

 drop until it reddens the blue litmus paper; then boil gently in a 

 test tube ; if a precipitate is thrown down, set the tube aside to cool 

 and then add strong nitric acid. If the precipitate is not dissolved, it 

 is albumen; if dissolved it is probably urate or hippurate of am- 

 monia. Albumen is normally present in advanced gestation ; abnor- 

 mally it is seen in diseases in which there occurs destriiction of blood 

 globules (anthrax, loW fevers, watery states of the blood, dropsies), in 

 diseases of the heart and liver which prevent the free escape of blood 

 from the veins and throw back venous pressure on the- kidneys, in 

 inflammation of the lungs and pleurae, and even tympany (bloat- 

 ing) , doubtless from the same cause, and in all congestive or inflam- 

 matory diseases of the kidneys, acute or chronic. 



Casts of the uriniferous tubes can be seen only by placing the sus- 

 pected urine under the microscope. They are usually very elastic and 

 mobile, waving about in the liquid when the cover glass is touched, 

 and showing a uniform, clear transparency (waxy) or entangled cir- 

 cular epithelial cells or opaque granules or flattened, red-blood glob- 

 ules or clear, refrangent oil globules. They may be even densely 

 opaque from crystals of earthy salts. 



Pus cells may be found in the urine associated with albumen, and 

 are recognized by clearing up, when treated with acetic acid, so that 

 each cell shows two or three nuclei. 



