44 INFI.AJSIMATION OF THE STOxMACII— INTESTINES. 



Cat section 5G), the reader will be able to form a more accurate notion, neai 

 enough for his purpose, how the stomach contracts its sensible part upon it» 

 contents. This sensible coat secretes a juice which, from its strong gastric 

 nature, not only digests the food, but would also corrode the stomach itself 

 (insensible though it be), were it not supplied with another fluid for its pro- 

 tection, in the sahva or spittle that descends the gullet along with the food. 

 This saliva is also secreted, in some measure, when the animal may not be 

 feeding: but, whenever this supply fails, the gastric juice predominates so 

 much as to cause a galling pain in the stomach, and occasion in the animal a 

 ravenous desire for tilling it, if not with food, at least with some substance that 

 may keep it distended, and perhaps carry off the painful superabundance. 

 Horses so circumstanced, when in harness, gnaw the pole or shaft, or bite at 

 each other, and soon learn to become crib-biters, gnawing any thing they can 

 come near, as well as the manger ; litter, bits of old wall, and dirt, at length, 

 are found by them agreeable to their palate. See further at section 49. 



The insensible membrane I spoke of, by its loose folds, forms, at the entrance 

 of the stomach, a kind of valve, which prevents regurgitation of the food, like 

 that of ruminating animals; and a similar contrivance at its termination in the 

 lower or right oritice occasions a short obstruction until the pulp is mixed; 

 for, when the stomach is filled, the relative position of the two orifices alters 

 in a great degree. From these premises it seems apparent that any substance 

 entering an empty stomach does not act upon the sensible part of it, but being 

 soon mixed up with the gastric juice, it proceeds into the intestines, there to 

 communicate its efifects — whatever these may be. Whether nutritive or 

 medicinal, poisonous or beneficial, the intestines receive all with but little al- 

 teration.* But when it so happens that the food does not pass readily out of 

 the stomach, a fermentation commences, and the sensible part thereof being 

 then distended, the ill efifects ascend the gullet, reach the head, and cause ver- 

 tigo, staggers, &c. At times, a specific inflammation takes place, and com- 

 municates itself in four or five days to the whole of that surface, taking its 

 course downwards or upwards, according to the orifice that may be most af- 

 fected ; this being all the way down through the intestines, blocking up the 

 influx of gall (as described sect. 48), and causing yellowness of the eyes, until 

 its appearance at the anus ; or, in the other case, it ascends up to the nostrils, 

 making its appearance first about the head, and communicates either way to 

 the skin and its coat. 



47. Of the intestines, guts as they are usually called, it is miportant to keep 

 in mind, that, notwithstanding the ai)pearance of great tenacity they assume, 

 they are, nevertheless, extremely irritable, beingcomposedof two coats of fine 

 muscular fibres that cross each other, the one circularly, the other lengthwise ; 

 and having a lining which secretes a fluid for its protection, they admit in their 

 intervals an innumerable quantity of absorbent vessels, that are constantl; 

 sucking up the finer particles of their contents. This sort of conformation 



* At this place, for the information of those who would practise the veterinarjr art by com- 

 parison, it may be useful to observe, that in the human stomach is digestion prmcipally per- 

 formed, in the horse's very little ; in both, the small intestines appear to mix tlie food with tlie 

 bile and other digestive juices ; but man having no cizcum, or blind gut, like the horse, to re- 

 ceive the heavier parts of the food as they escape from the small intestines, his lactcals begin 

 higher up than those of the horse, which lie wholly on the large intestines. It follows that, 

 whatever is received into the stomach of man is felt through the system immediately ; witii the 

 horse this does not take place uniil.it has reached the intestines. One other dissimilarity in the 

 mode of digestion is worthy of notice: in man, the work of digestion is nearly finished when 

 Ihe bile is mixed with the food — say at an average of twelve hours from its being taken, whilst 

 the horse passes his feed into tlie intestines in about two hours, before it has well assumed an 

 homogeneous appearance, which the bile seems to effect for him. With us liquid reraaine in 

 (he utomach; the horse passes water immediately into the caxum. 



