GENEKAL SYMPTOMS OF DISEASE. 29 



probaLility such an one is bordering on disease. A persistently 

 staring coat, without any other symptom of disease, often in- 

 dicates the incubative stage of glanders or farcy, and recurrent 

 rigors are generally the fore-runners of strangles or other sup- 

 purative diseases. The premonitory stage of lymphangitis is 

 marked by a fit of rigor or shivering, and in one case which 

 came under my notice, acute glanders was ushered in by a con- 

 tinuous shiverincf fit of three davs' duration. 



THE PULSE. 



The pulse is the beating of the arteries, and is usually felt at 

 the jaw — the submaxillary artery, or on the inner side of the 

 arm — the brachial artery. In the cow, whilst recumbent, the 

 pulse may be very distinctly felt on the posterior part of the 

 fore fetlock, and in the dog it is best felt at the femoral, on the 

 inner surface of the thigh. 



The pulsations felt by the finger are principally due to the 

 fact that the artery expands during the contraction of the heart, 

 and returns to its previous condition during the relaxation of 

 that organ. 



The arterial movements, as indicated by the sphygmograph, 

 constituting the pulse, are described as follows by Dr. Burdon 

 Sanderson : — 



" 1. At the moment that the heart begins to contract, a vibratory 

 movement of the blood contained in the aorta is produced, in 

 which the molecules of liquid are projected forwards in the axis 

 of the vessel. A similar vibratory movement occurs the 

 moment the ventricles cease to contract. These two move- 

 ments differ only in this respect, that in the former the 

 primary shock is directed towards the perij)hery, in the latter 

 towards the heart. 



" 2. Each of these movements is propagated in the direction of 

 the stream at a rate of about ninety feet per minute, — the one 

 expressing itself at the radial artery by a sudden expansion of 

 the arterial tube, the other by a sudden collapse. 



" 3. The exact moment at which each movement occurs is 

 indicated by the sphygmograph, — the former by a sudden vertical 

 ascent of the lever, the latter by a descent. In either case the 

 primary movement is followed by a succession of smaller raove-r 



