174 THE HORSE. 



Many \3.t. iiiary surgeons, and gentlemen too, are apt to order a certain 

 quantity oi 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, whici 

 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 accomplished ; 

 therefore the operator should have his finger on the artery during the act 

 of bleeding, and, comparatively regardless of the quantity, continue to tak« 

 blood, until, in inflammation of the lungs, the oppressed pulse becomes fuUei 

 and more distinct, or the strong pulse of considerable fever is evide^itly 

 softer, or the animal exhibits symptoms of faintness. 



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

 into in)mmerable minute tubes, termed capillaries (hair-like tubes), and ihoy 

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

 be inflicted without wounding some of them. 



In these little tubes, the nourislmient of the body, and tht 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 /ed 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 com- 

 mences, cannot be ascertained ; it is when the red artei-ial blood, havmg 

 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 wmd round these ves 

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

 nerves communicate too much energy, and these vesstls consequently act 

 with too much power, injiammation is produced. If this disturbed action be 

 confined to a small space, or a single organ, it is said to be local, as inflam- 

 mation of the eye, or of the lungs ; when this inordinate action spreads 

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

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

 disturbance increases, and subsides with it. 



INFLAIklMATION. 



Local inflammation is characterized 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 neighbour, 

 mg substance. The natural heat of the body is produced by the gradual 

 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 inflamed 

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

 produced there ; and the pain is easily accounted for by the distension 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 occasional!} 

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

 attacked and the degree of the inflammation ; but it will necessarily include 

 the following particulars. 



