Transactions of the Canadian Institute. 



[Vol. VII. 



leSs, and as surely lowers it immediately afterwards. This after lowering 

 may be partly of the nature of compensation, but it is most probably 

 due, in part at least, to the struggling causing a greater inhalation of 

 the drug, and hence poisoning by it. 



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Tracing XIX. — q/31. — Chloroform poisoning. 

 Struggling. 5 Pressure falling and pulse slowing 

 8 Pulse very slow, g Artificial respirations. 



Animal Horizontal. 3 CliK^roform pushed. 4 

 6 Chloroform removed. 7 Respiration ceased. 



Tracing 19 shows a very typical tracing of chloroform poisoning. 

 The animal was horizontal when the chloroform was pushed at 3. He 

 had not had any morphia. A slight temporary fall, with slowing of the 

 pulse occurred, which is very frequently the case, followed by struggling 

 at 4, with a consequent rise and hastening of the pulse. Then about 

 forty seconds after the commencement of the chloroform, a rapid fall 

 with slowing of the pulse, set in. The chloroform was removed at 6, but 

 several seconds later, the respiration ceased, and the pressure fell more, 

 with great slowing of the pulse. Artificial respiration was commenced 

 twenty seconds after the respiration failed, and the animal recovered. 

 Even though the chloroform towel be removed as soon as ever the 

 struggling sets in, the temporary rise followed by a fall occurs, sufficient 

 chloroform vapour being present in the air passages to produce this 

 train of events. Conclusion 19 of the Anesthetic Committee of the 

 British Medical ^Association is that " struggling must be regarded as a 

 source of very grave danger under chloroform," and Lieut.-Col. Lawrie's 

 rule, as given in his recent book on chloroform (p. 1 1 1) is " never to give 

 chloroform while there is struggling or irregular breathing." With this 

 clinical rule my experiments on dogs entirely agree. 



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Tracing XX.— 3/1 i.— Chloroform poisoning. S Struggling, i Chloroform pushed. 2 Pressure 

 began to fall quickly. 3 Chloroform removed as pulse slowing. 4 Respiration stopped. 



