POISONING BY CHLOROFORM 117 



shouting, and then without warning draws a few 

 deep breaths and dies. Here also, those who seem 

 to be under, but whose heart and respiration cease on 

 being lifted into position for the surgeon. Here, 

 again, those who have been given a mere whiff of 

 the anaesthetic for a trifling operation, and whose life 

 ebbs away at the bare touch of the knife. 



All of these may be reproduced in experimental 

 animals, and we are exactly informed as to what takes 

 place. Chloroform has the deadly power of causing 

 an undue irritability of the vagus centre, especially 

 in people of the " lymphatic " type, in whom the 

 thymus is enlarged. Later in its action, if anaesthesia 

 is gradually induced, this hyper-excitability gives 

 place to depression. During the stage of excita- 

 bility, a stimulus is likely to cause reflex stoppage of 

 the heart, just as in the frog with spinal cord and 

 vagus nucleus intact, tapping the intestines will 

 reflexly stop the heart. During the induction of 

 anaesthesia there are several possible stimuli which 

 may be sources of danger. The most important is 

 the sudden inhalation of a chloroform vapour stronger 

 than 2 per cent, which is particularly liable to occur 

 during struggling. Lifting,, or commencement of the 

 operation before the patient is under, may also 

 furnish such a stimulus, either directly or by causing 

 deep inspirations of concentrated vapour. 



An apology must be made for saying again what we 

 all know, yet never can know too well. It is courting 

 disaster to hurry the patient under. We must feel 

 the pulse all the time, as well as watch the pupil and 

 the respirations. We must withdraw the mask 



