is the type.

Unusual constituents of the urine are _albumen, sugar_, and _bile_. When
albumen is present in urine, it often indicates some disease of the
kidneys, to which the term _albuminuria_ or Bright's Disease is applied.
The presence of grape sugar or glucose indicates the disease known as
diabetes. Bile is another unusual constituent of the urine, appearing in
_jaundice_.

The bladder is situated in the pelvic cavity or in the lowest part of
the abdomen. When full, the bladder is pear-shaped; when empty, it is
collapsed and lies low in the pelvis. The functions of the bladder are to
collect and retain the urine, which has reached it drop by drop from the
kidneys through the ureters, until a certain quantity accumulates, and
then to expel it from the body.

[Illustration: Fig. 109.--Vertical Section of the Back. (Showing kidneys
_in situ_ and the relative position of adjacent organs and vessels.)
[Posterior view.]

A, 12th dorsal vertebra;
B, diaphragm;
C, receptaculum chyli;
D, small intestines
]

In the kidneys, as elsewhere, the vaso-motor nerves are distributed
to the walls of the blood-vessels, and modify the quantity and the
pressure of blood in these organs. Thus, some strong emotion, like fear or
undue anxiety, increases the blood-pressure, drives more blood to the
kidneys, and causes a larger flow of watery secretion. When the atmosphere
is hot, there is a relaxation of the vessels of the skin, with a more
than ordinary flow of blood, which is thus withdrawn from the deeper
organs. The blood-pressure in the kidneys is not only diminished, but the
total quantity passing through them in a given time is much lessened. As a
result, the secretion of the kidneys is scanty, but it contains an unusual
percentage of solids.

When the atmosphere is cold, the reverse is true. The cutaneous vessels
contract, the blood is driven to the deeper organs with increased
pressure, and there is a less amount of sweat, but an increased renal
secretion, containing a smaller proportion of solids. Certain drugs have
the power of increasing or diminishing the renal secretion. As the waste
matters eliminated by the kidneys are being constantly produced in the
tissues, the action of the renal organs is continuous, in marked contrast
with the intermittent flow of most of the secretions proper, as
distinguished from the excretions.

258. Effects of Alcoholic Drinks upon the Kidneys. The kidneys differ
from some of