DISEASES OF THE URINARY ORGANS. 135 
favor the formation of stone, of taurocholic acid, and other bodies 
that tend when in excess to destroy the blood globules and to cause 
irritation of the kidneys by the resulting hemoglobin excreted in the 
urine, and of glycogen too abundant to be burned up in the system, 
which induces saccharine urine (diabetes). Any disorder leading to 
impaired functional activity of the lungs is causative of an excess of 
hippuric acid and allied bodies, of oxalic acid, of sugar, etc., in the 
urine, which irritate the kidneys, even if they do not produce solid 
deposits in the urinary passages. Diseases of the nervous system, 
and notably of the base of the brain and of the spinal cord, induce 
various urinary disorders, prominent among which are diabetes, 
chylous urine, and albuminuria. Certain affections, with imperfect 
nutrition or destructive waste of the bony tissues, tend to charge the 
urine with phosphates of lime and magnesia and endanger the 
formation of stone and gravel, In all extensive inflammations and 
acute fevers the liquids of the urine are diminished, while the solids 
(waste products), which should form the urinary secretion, are 
increased, and the surcharged urine proves irritant to the urinary 
organs or the retained waste products poison the system at large. 
Diseases or the heart and lungs, by interfering with the free, 
onward flow of the blood from the right side of the heart, tend to 
throw that liquid back on the veins, and this backward pressure 
of venous blood strongly tends to disorders of the kidneys. Certain 
poisons taken with the feed and water, notably that found in mag- 
nesian limestone and those found in irritant, diuretic plants, are 
especially injurious to the kidneys, as are also various cryptogams, 
whether in musty hay or oats. The kidneys may be irritated by 
feeding green vegetables covered with hoar frost or by furnishing 
an excess of feed rich in phosphates (wheat bran, beans, peas, vetches, 
lentils, rape cake, cottonseed cake) or by a privation of water, which 
entails a concentrated condition and high density of the urine. Ex- 
posure in cold rain or snow storms, cold drafts of air, and damp 
beds are liable to further disorder an already overworked or irritable 
kidney. Finally, sprains of the back and loins may cause bleeding 
from the kidneys or inflammation. ° 
The right kidney, weighing 233 ounces, is shaped like a French 
bean, and extends from the loins forward to beneath the heads of 
the last two ribs. The left kidney (Pl. VIII) resembles a heart 
of cards, and extends from the loins forward beneath the head of 
the last rib only. Each consists of three distinct parts—(a) the 
external (cortical), or vascular part, in which the blood vessels form 
elaborate capillary networks within the dilated globular sacs which 
form the beginnings of the secreting (uriniferous) tubes and on the 
surface of the sinuous, secreting tubes leading from the sacs inward 
toward the second, or medullary, part of the organ; (6) the in- 
