INFLAMMATION. 185 



A weak pulse, when the arterial stream flows slowly, is caused by the feeble action 

 of the heart. It is the reverse of fever, and expressive of debility. 



The oppressed pulse is when the arteries seem to be fully distended with blood. 

 There is obstruction somewhere, and the action of the heart can hardly force the 

 stream along, or communicate pulsation to the current. It is the case in sudden 

 inflammation of the lungs. They are overloaded and gorged with blood, which can- 

 not find its way through their minute vessels. This accounts for the well-known faci 

 of a copious bleeding increasing a pulse previously oppressed. A portion being 

 removed from the distended and choked vessels, the remainder is able to flow on. 



There are many other varieties of the pulse, which it would be tedious here to par- 

 ticularise ; it must, however, be observed, that during the act of bleeding, its state 

 should be carefully observed. Many veterinary surgeons, and gentlemen too, are apt 

 to order a certain quantity of blood to be taken away, but do not condescend to super- 

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

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

 state of disease, indicated by a peculiar quality of the pulse, which we are endeavour- 

 ing to alter. The most experienced practitioner cannot tell what quantity of blood 

 must be abstracted in order to produce the desired eflect. The ciiange 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 take blood, until, in inflammation of the lungs, the op- 

 pressed pulse becomes 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 innu- 

 merable 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 wound- 

 ing some of them. 



In these little tubes, the nourishment of the body and the separation of all the vari- 

 ous secretions is performed, and in consequence of this, the blood is changed. When 

 these capillaries unite together, and begin to enlarge, it is found to be no longer arte- 

 rial, 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 red arterial blood, having dis- 

 charged its function by depositing the nutritious parts, is changed to venous or black 

 blood. 



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, injiamnm- 

 iion is produced. If this disturbed action is confined to a small space or a sino-le 

 organ, it is said to be htcal, as inflammation of the eye, or of the lungs ; but when 

 this inordinate action spreads from its original seat, and embraces the whole of the 

 arterial system, /eyer is said to be present, and this usually increases in proportion as 

 the local disturbance is observable, and subsides with it 



INFLAMMATION. 



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

 redness proceeds from the greater quantity of blood flowing through the part, occa- 

 sioned by the increased action of the vessels. The swelling arises from the same 

 cause, and from the deposit of fluid in the neighbouring 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 is driven through the capil- 

 laries of an inflamed part, and in which this change is effected, more heat will neces- 

 sarily 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 disturb- 

 ance of the surrounding parts. 



If inflammation consists of an increased flow of blood to and through the part, the 

 ready way to abate it is to lessen the quantity of blood. If we take away the fuel, 

 the fire will go out. All other means are comparatively unimportant, contrasted with 

 bleeding. Blood is generally abstracted from the jugular vein, and so the general 

 quantity may be lessened ; but if it can be taken from the neighbourhood of the dis- 

 eased part, it will be productive of tenfold benefit. One quart of blood abstracted from 

 16* Y 



