eath the inner angle of the eye.
The duct leading from the sac to the nose may be compressed or
obliterated by fractures of the bones of the face, and in disease of
these bones (osteosarcoma, so-called osteoporosis, diseased teeth,
glanders of the nasal sinuses, abscess of the same cavities).

The narrowed or obstructed ducts may be made pervious by a fine, silver
probe passed down to the lacrimal sac, and any existing inflammation of
the passages may be counteracted by the use of steaming mashes of wheat
bran, by fomentations or wet cloths over the face, and even by the use
of astringent eyewashes and the injection of similar liquids into the
lacrimal canal from its nasal opening. The ordinary eyewash may be used
for this purpose, or it may be injected after dilution to half its
strength. The fractures and diseases of the bones and teeth must be
treated according to their special demands when, if the canal is still
left pervious, it may be again rendered useful.

EXTERNAL OPHTHALMIA, OR CONJUNCTIVITIS.

In inflammation of the outer parts of the eyeball the exposed vascular
and sensitive mucous membrane (conjunctiva) which covers the ball, the
eyelids, the haw, and the lacrimal apparatus, is usually the most deeply
involved, yet adjacent parts are more or less implicated, and when
disease is concentrated on these contiguous parts it constitutes a
phase of external opththalmia which demands a special notice. These have
accordingly been already treated of.

_Causes._--The causes of external opththalmia are mainly those that act
locally--blows with whips, clubs, and twigs, the presence of foreign
bodies, like hayseed, chaff, dust, lime, sand, snuff, pollen of plants,
flies attracted by the brilliancy of the eye, wounds of the bridle, the
migration of the scabies (mange) insect into the eye, smoke, ammonia
arising from the excretions, irritant emanations from drying marshes,
etc. Road dust containing infecting microbes is a common factor. A very
dry air is alleged to act injuriously by drying the eye as well as by
favoring the production of irritant dust; the undue exposure to bright
sunshine through a window in front of the stall, or to the reflection
from snow or water, also is undoubtedly injurious. The unprotected
exposure of the eyes to sunshine through the use of a very short
overdraw check is to be condemned, and the keeping of the horse in a
very dark stall, from which it is habitually led into the glare of ful