174 THE HORSE. 



Many veterinary surgeons, and gentlemen too, are apt to order a certain 

 quantity of blood to be taken away, but do not condescend to superintend 

 the operation. This is unpardonable in the surgeon, and censurable in the 

 owner of the horse. The horse is bled for some particular purpose. There 

 is some state of disease, indicated by a peculiar quality of the pulse, which 

 we are endeavouring to alter. The most experienced practitioner cannot 

 tell what quantity of blood must be abstracted to produce the desired effect. 

 The change of the pulse can alone indicate when the object is accom- 

 plished ; therefore, the operator should have his finger on the artery during 

 the act of bleeding, and, comparatively regardless of the quantity, continue 

 to take blood, until, in inflammation of the lungs, the oppressed pulse be- 

 comes fuller and more distinct, or the strong pulse of considerable fever is 

 evidently softer, or the animal exhibits symptoms of faintness. 



The arteries divide as they proceed through the frame, and branch out 

 into innumerable minute tubes, termed capillaries (hair-like tubes), and they 

 even become so small as to elude the sight. The slightest puncture cannot 

 be inflicted without wounding some of them. 



In these little tubes, the nourishment of the body, and the separation of 

 all the various secretions is performed, and, in consequence of this, the 

 blood is changed ; and when these capillaries unite together, and begin 

 to enlarge, it is found to be no longer arterial, or of a florid red colour, 

 but venous, or of a blacker hue. Therefore, the principal termination 

 of the arteries is in veins. The point where the one ends, and the other 

 commences, cannot be ascertained ; it is when the red arterial blood, 

 having discharged its function, is changed to venous or black blood ; but 

 this is a process gradually performed, and therefore the vessel is gradually 

 changing its character. 



Branches from the ganglial or sympathetic nerves wind round these 

 vessels, and endue them with energy to discharge their functions. When 

 the nerves communicate too much energy and these vessels consequently 

 act with too much power, iujlammation is produced. If this -disturbed 

 action be confined to a small space, or a single organ, it is said to be local,, 

 as inflammation of the eye, or of the lungs ; when this inordinate action 

 spreads from its original seat, and embraces the whole of the arterial system, 

 fever is said to be present, and which usually increases in proportion as 

 the local disturbance increases, and subsides with it. 



INFLAMMATION. 



Local inflammation is characterised by redness, swelling, heat, and pain. 

 The redness proceeds from the increased quantity of blood flowing through 

 the part, occasioned by the increased action of the vessels. The swelling 

 arises from the same cause, and from the deposit of fluid in the neigh- 

 bouring substance. The natural heat of the body is produced by the gra- 

 dual change which takes place in the blood, in passing from an arterial to 

 a venous state. If more blood be driven through the capillaries of an in- 

 flamed part, and in which this change is effected, more heat will necessarily 

 be produced there; and the pain is easily accounted for, by the distention 

 and pressure which must be produced, and the participation of the nerves 

 in the disturbance of the surrounding parts. 



We have spoken of some of these local inflammations, and shall 

 speak of others when describing the structure of the parts that are occa- 

 sionally attacked by them. The treatment will in some degree vary with 

 the part attacked, and the degree of the inflammation ; but it will necessa- 

 rily include the following particulars. 



