SPASM OF THE DIAPHRAGM. 185 



its action could not be clearly felt/^ Venesection — which 

 it became necessary to repeat — aperient medicines and 

 opiates, recovered her. 



The SYMPTOMS, collected from the foregoing cases, are — 

 violent palpitations against the ribs, loud enough to be 

 heard at a distance of some yards, producing a convulsive 

 motion or jerking of the whole body, unconnected with the 

 pulsation of the heart, sounding posterior to that organ, in 

 the region of the diaphragm. Indeed, the pulse at the heart 

 is rarely perceptible, nor is it often to be distinctly felt at 

 the jaw. The horse is in great distress for breath. From 

 time to time he breaks into a profuse sweat ; and, in some 

 cases, a harassing cough is an accompaniment. 



Causes. — Over-fatigue and exhaustion, especially of the 

 kind caused by hunting or hard work, on a full stomach. 

 In some instances it has come on at, or after being at, grass. 

 In one case it proved an attendant on locked jaw. 



Pathology. — That the seat of the disorder is the dia- 

 phragm, both its locality and peculiarity of symptom appears 

 to render highly probable ; while that the affection is in its 

 nature "spasmodic,^^ I think is forcibly argued, as well from 

 the character of the symptoms, as from the sudden manner 

 in which the disease attacks and quits the patient. After 

 all, however, it appears, Mr. Apperley was not running into 

 vast pathological error when he pronounced the disorder to 

 be in the abdominal muscles. For, supposing the diaphragm 

 to be in a state of spasm or convulsion, how could the 

 breathing be carried on if it were not for '^ the excessive 

 motion of the abdominal muscles ?" Upon the action of 

 the diaphragm, ordinary tranquil respiration almost entirely 

 depends; and when this agent is incapacitated or deranged, 

 but for those necessary and powerful auxiliaries — the 

 abdominal muscles — the breathing must become suspended, 

 and the animal die. The '^ distress^^ of the patient is occa- 

 sioned by this dread of suspension ; "the jerkings of his 

 body,^' by the efforts he is making with his abdominal 

 auxiliary powers to counteract it. We know that one of the 

 ordinary causes of spasm is over-action ; we need, therefore, 



