36 PATHOLOGY. 



all these respects the pulse is often irregular, and the source of 

 the irregularity is to be found in a deranged or debilitated 

 action of the heart. An intermitting pulse is that in which a 

 pulsation is occasionally omitted. This omission may be regular, 

 occurring at the end of a certain number of beats, or it may be 

 irregularly intermittent, and along with intermission of its beats 

 there may be irregularity in its tone, volume, &c. For example, 

 several beats may occur in rapid succession; these may be 

 followed by others at long intervals, or some beats may be 

 strong, others weak, some quick, others prolonged; and often 

 several run on successively of one character, to be followed by 

 more or less of another character. Occasionally all these 

 irregularities, or most of them, may occur in the same subject. 

 They are indicative of important functional or nervous disorder, 

 or of organic disease of the heart. An intermitting pulse may 

 often be observed in horses presenting all the appearances of 

 perfect health ; indeed, an intermitting pulse is very commonly 

 met with in the cart-horses of this city ; and, reasoning from the 

 frequency of indigestion, and the nature of their food, one is 

 forced to the conclusion that this irregularity of the heart's 

 action is due to some disorder of the digestive apparatus. When 

 these animals are attacked by any disease, the irregularity of 

 the pulse frequently disappears for a time, or until the animal 

 is restored to its former condition of apparent health. 



TJie volume of the pulse may be greater than usual, in which 

 case it is said to be large — pulsus magnus, or it may be less 

 than usual, when it said to be small — pulsus parvus. Largeness 

 or fulness of the pulse may depend upon general plethora, or a 

 prolonged and forcible contraction of the ventricles ; to a certain 

 extent on relaxation of the arterial coats, and on obstruction of 

 the capillaries, without diminished power of the heart. It may 

 be associated with strength or with feebleness of the pulsations. It 

 is important not to confound a fuU feeble pulse with a full strong 

 one. The feeble pulse is known by the weakness of the impulse, 

 and by the artery yielding to the pressure of the finger. In 

 pulmonary congestion of a severe character the artery is full, 

 and the pulsations feeble. This has been called the " oppressed 

 •pulse of pneumonia" by veterinarians, and depends upon ex- 

 cessive congestion of the pulmonary vessels. A pulse of this 

 character is improved in tone by a moderate abstraction of blood. 



