230 PRINCIPLES OF VETERINARY SURGERY 



tion of the cornea now reveals its insensitiveness, the mus- 

 cles are limp and immobile, the knife can be applied with im- 

 punity, the respirations rather suddenly become soft and 

 shallow, the pulse slow and somewhat weak, although not 

 markedly so, in fact; 



3. The Stage of Anaesthesia has begun. This period is 

 recognized from the preceding stage by the symptoms just 

 enumerated. It is the surgical, stage. The subject is ready 

 for the waiting surgeon. The cornea no longer responds 

 to the touch, the respirations are slow, soft, shallow and 

 sometimes almost imperceptible, especially the exhalations. 

 The heart beats are regular but rather weak and the arteries 

 compressible. The entire body can be cut to pieces without 

 provoking the least sign of pain or reflex action on part of 

 either the voluntary or involuntary muscles. The cere- 

 brum, the pons, and the excito-motor apparatus have 

 yielded to the so-called dehydration of their cellular ele- 

 ments. The medulla and' the sympathetic system, upon 

 which the few remaining movements of the body are de- 

 pending, are exhibiting evidences of yielding to the same 

 modifications. If the administration continues they, too, 

 suspend their activity, and death ensues. 



Chloroform and ether are irritants. They blister the in- 

 tegument, and irritate the mucous membranes to no small 

 degree. As a result of this action the bronchial secretion 

 is always greatly augmented. Expectoration is profuse. 

 The mucus can be heard in the bronchial tubes by auscul- 

 tation, and it frequently produces a clicking in the throat. 

 In the dog and in the ox there is also a marked increased 

 flow of saliva, due evidently to increased secretion from 

 irritation and to arrested deglutition. This feature is gen- 

 erally absent in the horse, but is not always wanting. 



DURATION OF ANAESTHESIA.— Anaesthesia can 

 be prolonged at will by continuing the administration. The 



