PULSE : WOUNDS OF ARTERIES. 237 



purpose is the radial artery (fig. 124) at the wrist ; but the 

 carotid artery in the neck, and the temporal artery in the 

 temple, may be felt, when it is desired to know the force of 

 the circulation in the head; as may the arteries supplying 

 other parts, when we wish to gain information respecting 

 the organs they supply. An increased action in the organ, 

 whether this be due to inflammation, or to a state of unusual 

 activity of its function, causes an increase of size in the artery 

 which supplies it ; and thus the pulsation may be unusually 

 strong in a particular trunk, when the heart's action and the 

 general circulation are not in a state of excitement. For 

 instance, a whitlow on the thumb will occasion its artery to 

 beat almost as powerfully as the radial artery usually does ; 

 and excessive activity of the mind, prolonged for some hours, 

 greatly increases the force of the pulsations in the carotid 

 arteries, from which the brain is chiefly supplied. 



277. When an artery is wounded, there is often great 

 difficulty in controlling the flow of blood ; for pressure can 

 seldom be effectually applied in the situation of the wound ; 

 and the surgeon is generally obliged to tie the vessel above 

 the orifice. As a temporary expedient, the loss of blood may 

 be prevented by making firm pressure upon the artery above 

 the wounded part, that is, nearer the heart ; and many valu- 

 able lives have been saved by the exercise of presence of 

 mind, guided by a little knowledge. The best means of 

 keeping-up the requisite pressure, until the proper instrument 

 (the tourniquet) can be applied, is to lay over the artery (the 

 place of which may be found by its pulsation) a hard pad, 

 made by tightly rolling or folding a piece of cloth ; this pad 

 and the limb are then to be encircled by a bandage, by which 

 the pressure is maintained ; and this bandage may be tightened 

 to any required degree, by twisting it with a ruler or a piece 

 of stick. Thus a constant pressure may be exercised upon 

 the artery, which will be generally sufficient to control the 

 bleeding from it. But there are, unfortunately, many cases 

 in which pressure of this kind cannot be applied ; as for 

 instance when the femoral artery is wounded high up in the 

 thigh, or the carotid artery in the neck. And nothing else 

 can then be done, but to compress the artery with the thumb, 

 or with some round hard substance (such as the handle of an 

 awl), until proper assistance can be obtained. 



