14G 



HEALTH AND DISEASE 



attention is paid to the condition of certain organs, including those of the 

 circulatory, respiratory, and digestive systems. The state of the circulatory 

 organs is to a large extent shown by the character of the pulse, i.e. the 

 periodic expansion of the arteries, during the contraction of the heart in its 

 effort to drive the blood throughout the body. This expansion, or beat as 

 it is called, may be felt by placing the finger over any of the superficial 

 arteries. The sub-maxillary artery (a, fig. 492) in the horse, as it passes under 

 the edge of the lower jaw close to the bone, is a convenient vessel for the 

 purpose. In the popular idea the object of feeling the pulse is to discover 



the number of pulsations in a 

 minute. The pathologist, however, 

 attaches far more importance to the 

 character of the pulsation than to 

 the number of beats in a given 



time, and it may be added that the 

 character of the pulse varies under 

 different circumstances to an ex- 

 tent which it may be difficult for 

 the unprofessional mind to realize. 

 Many of these variations can be 

 recognized by the touch; their 

 complete appreciation, however, re- 

 quires the use of an instrument 

 which is known as the sphygmo- 

 graph, which enables the observer 

 to obtain tracings showing precisely 

 the condition of the circulation. 

 The varieties of pulse which can 

 be recognized by the touch are described by Sir J. S. Burdon Sanderson 

 in his hand-book of the sphygmograph under four heads: 1st, There is a 

 frequent and infrequent pulse, terms which mean the number of pulsations 

 within a given time. 2nd, The quick or slow pulse, expressions which are 

 erroneously used to define the same thing, i.e. the number of beats per 

 minute. To the pathologist the words quick and slow bear a totally different 

 signification, meaning not the number of beats in a minute, but the time occu- 

 pied by each beat of the pulse irrespective of number in a certain time; thus 

 a quick pulse may be slow so far as the number of beats in the minute is con- 

 cerned. 3rd, The large or small pulse, terms relating to the degree of dilata- 

 tion of the artery in length and breadth. 4th, A hard or soft pulse, so called 

 from the impression which the beat communicates to the touch : a soft pulse 

 is easily compressed, while a hard pulse only gives way to considerable force. 



Fig. 492. — Points for Feeling the Pulse 



a, The sub-maxillary artery, b, The zygomatic artery. 

 «•, The carotid artery (behind the jugular vein). The 

 pulse is felt at the points indicated by crosses, at a by 

 pressing against the inner side of the lower jaw with the 

 fingers, at 6 and c by pressing down upon the artery. 



