eart, diseased and nonsecreting
kidneys, or an obstruction to the flow.

The urine of the healthy horse is a pale or at times a slightly reddish
yellow. The color is less intense when the quantity is large, and is
more intense when the quantity is diminished. Dark-brown urine is seen
in azoturia and in severe acute muscular rheumatism. A brownish-green
color is seen in jaundice. Red color indicates admixture of blood from a
bleeding point at some part of the urinary tract, usually in the
kidneys.

The urine of the healthy horse is not clear and transparent. It contains
mucus, which causes it to be slightly thick and stringy, and a certain
amount of undissolved carbonates, causing it to be cloudy. A sediment
collects when the urine is allowed to stand. The urine of the horse is
normally alkaline. If it becomes acid the bodies in suspension are
dissolved and the urine is made clear. The urine may be unusually cloudy
from the addition of abnormal constituents, but to determine their
character a chemical or microscopic examination is necessary. Red or
reddish flakes or clumps in the urine are always abnormal, and denote a
hemorrhage or suppuration in the urinary tract.

The normal specific gravity of the urine of the horse is about 1.040. It
is increased when the urine is scanty and decreased when the quantity is
excessive.

Acid reaction of the urine occurs in chronic intestinal catarrh, in high
fever, and during starvation. Chemical and microscopic tests and
examinations are often of great importance in diagnosis, but require
special apparatus and skill.

Other points in the examination of a sick horse require more discussion
than can be afforded in this connection, and require special training on
the part of the examiner. Among such points may be mentioned the
examination of the organs of special sense, the examination of the
blood, the microscopic examination of the secretions and excretions,
bacteriological examinations of the secretions, excretions, and tissues,
specific reaction tests, and diagnostic inoculation.

FUNDAMENTAL PRINCIPLES OF DISEASE.

By RUSH SHIPPEN HUIDEKOPER, M. D., VET.

[Revised by Leonard Pearson, B. S., V. M. D.]

ANIMAL TISSUES.

The nonprofessional reader may regard the animal tissues, which are
subject to inflammation, as excessively simple structures, as similar,
simple, and fixed in their organization as the joists and boards which
frame a house, the bricks and iron coi