328 (EDEMA OF THE LARGE INTESTINES OF A HORSE. 
in quality,, would be quite unfit for the preservation of health; 
its effeets at first might be general, and to an extent not suffi¬ 
cient to interfere materially with the function of any particular 
organ, but unexpectedly its influence would become concen¬ 
trated upon some of the nervous centres, and thereby either 
partially or totally suspend their function. 
The nervous centres, whether belonging to the cerebro¬ 
spinal or sympathetic system of nerves, if supplied with impure 
blood, would be in a degree incapable, normally, of receiving 
impressions through the centripetal nerves, or of generating 
force to be conveyed by the centrifugal nerves to distant 
parts of the body. If such can be the condition of the nervous 
centres, we may, under such circumstances, easily imagine 
what the fate of the tissues must be whose action depends 
upon a due supply of healthy nerve stimulus; and further, 
also, of those organs which the tissues enter into the com¬ 
position of, and upon which their healthy action depends. 
Suspended action of any of the centres of the sympathetic 
nerve would result in paralysis of the muscular fibres sup¬ 
plied by the nerves connected immediately with those 
ganglia; and having in view the arteries, capillaries, and 
veins of the intestine, we cannot, I think, suppose otherwise 
than that the coats of these vessels would become relaxed, 
thinned, and weakened, and their calibre much enlarged. In 
this condition exudation of the watery parts of the blood, to a 
greater or less extent, would be favoured, and perhaps even 
an actual rupture of the vessels might take place with the 
escape of the red blood into the areolar tissue. Such we have 
found to be actually the case in this instance. 
Further, to account for these and similar phenomena, 
might not the blood not only be in a vitiated condition from 
the causes above alluded to, but have been also chemically 
altered in quality, in consequence of the animal not having 
partaken of any food for several days; as it would then be 
deficient in some of the constituents usually derived from the 
4 /_ 
food, such as albumen and certain salts ? The red cells also 
would be fewer in quantity, and there being thus proportion- 
ably a large amount of water in the composition of tlie blood, 
Ave cannot be surprised that the latter constituent should easily 
pass through an unusually porous membrane. I have before 
remarked that the symptoms very much resembled those pro¬ 
duced by some intestinal obstruction, and I have no doubt 
but such actually Avas the case in tliis instance; not, however, 
from any substance impacted in the interior of the boAvel, but 
by the abnormally SAvollcn state of the mucous membrane. If 
Ave could have diagnosed this case correctly, Ave should not 
