280 ON THE DISEASES OF FARM HORSES. 
becoming mixed wiih the hepatic and pancreatic secretions, is 
converted into chyle , which is passed onwards by the muscular 
creeping action of the small intestines into the larger ones; and 
during this passage it is acted on by the agency of a set of 
vessels termed lacleals, whose orifices are abundantly spread 
over their villous surfaces, for the purpose of absorbing the 
nutritious parts., The same absorption takes place in the large 
intestines, only the chylous mass is retained in the colon for a 
longer period, by which its nutritious parts are finally separated 
and absorbed, and the excrementitious portions are afterwards 
expelled per rectum. 
Now, in this process we observe that the united pancreatic 
and biliary fluids poured on the chyme, penetrate it, render 
it fluid, animalize it, separate the nutritious from the excre¬ 
mentitious, which is finally carried into the circulation. 
It sometimes happens, however, that serious disturbances 
occur during this process. Horses are frequently fed with 
imperfect or indigestible articles of food, which, accumulating 
either in the small or large intestines, prove sources of irritation 
and disease. It is a very common case to find the colon, or 
big gut, as it is frequently called, packed with indigestible 
fibrous matters, which, on being evacuated by the use of 
medicines and injections, prove to be unmasticated and un- 
chvmified chaff of straw and husks of oats: the refuse of the 
barn, consisting of the husks of various grain, half rotted frosted 
clover, weather beaten dusty hay, or hay mouldy and rusty 
and covered with parasitical growths, musty pea haulm, and 
sapless fibrous turnips; these are articles that frequently oc¬ 
casion visceral complaints. 
But amongst all these, the use of chaffed straw, sometimes of 
wheat, but more frequently of barley, proves the most common 
cause, and consequently should never be given alone, but 
mixed with hay in the proportion of one-third of the former to 
two of the latter. Some horses are in the habit of bolting their 
corn, which passes into the intestines intact. This is also a 
cause of indigestion, and its consequences; and hence the 
bruising of oats is not only an economical practice, but lessens 
a tendency to visceral disease. 
In colic cases of this kind we do not find the rolling, 
agonising pain of spasmodic colic; but the animal lies and 
rises at short intervals, frequently points his muzzle round to 
the flank, the seat of pain, and when standing, either paws the 
litter with one of its fore feet, or strikes at its belly with its 
hinder ones. The pain, in cases of this kind, arises from the 
indigested food impacked in the colon; and the symptoms are 
