DISEASES OF THE URINARY ORGANS. 137 
looked for: (1) Color: 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) Chemical reaction, as 
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 albumen co- 
agulable by strong nitric acid and boiling, when charged with micro- 
scopic casts of the uriniferous tubes, with the eggs or bodies of worms, 
with sugar, blood, or bile. (5) Jn tts 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 destruction 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 pleure, 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. 
