GENERAL SYMPTOMS OF DISEASE. 37 



Tlie feeble pulse, if associated with softness, the artery yield- 

 ing readily to tlie finger, indicates general or cardiac debility. 

 It is sometimes so weak as to give one the idea that the artery 

 is filled with air, hence it has been called the gaseous pulse, and 

 is not unfrequent in an anaemic condition of the body. 



The small pulse — -jjm/s^^s jsarvits — may result from anaemia; from 

 congestion of some important organ, as the lungs ; from feeble con- 

 traction of the heart ; or from great tonicity of the arterial coats. 



The hard pulse — pulsus durus — hardness of the pulse, is that 

 property by which the artery resists compression, and results 

 from contraction of the muscular coat of the arterial walls. Hard- 

 ness of the pulse is often associated with smallness — pulsus 

 durus et parvus ; it is then termed corded, wiry, or thready, and 

 this condition is often met with in the earlier stages of inflam- 

 matory disease, particularly during the rigor — in endocarditis, 

 and in dangerous inflammations of serous membranes — and, 

 expermientally, the thready pulse has been produced by division 

 of the pneumo-gastric nerves. 



Dr. Sanderson describes this pulse as follows : — " Wlien the 

 pulse is small and hard, as during the rigor at the outset of 

 acute diseases, and in certain dangerous forms of carditis, the 

 expansion of the radial artery is sudden and of short duration ; 

 the suddenness of the movement not depending upon the 

 rapidity with which the arteries empty themselves by the 

 capillaries, but on the violence wdth wdiich the heart itself con- 

 tracts. In this form of pulse there is no second beat. The 

 explanation is clear: the difference between the arterial and 

 venous pressure is so considerable, and the range of variation 

 in the peripheral arteries so limited, that no perceptible diastolic 

 retardation takes place in the capillaries, and consequently no 

 second expansion." 



The hard pulse is seldom associated with largeness ; the 

 nearest approach to the hard full pulse — p)ulsus magnus et durus — - 

 is the strong full pulse of laminitis. It may, however, depend 

 upon hypertrophy of the left ventricle of the heart, and be pre- 

 sent independently of any inflammatory disease. When the 

 pulse is very hard, the lateral displacement of the submaxillary 

 artery is very apparent ; it is then called by veterinarians a hard 

 rolling pulse. 



