2i6 Transactions of the Canadian Institute. [Vol. VII. 



have been successful in restoring life," and apart from this probable 

 reflex action, the pressure of the finger assures the operator that the 

 cords are swung apart. 



One soon learns to tell whether artificial respiration will be success- 

 ful or not in a given case by the "feeling" of the chest. If this feel 

 elastic, and it be easy to make the air pass in and out, all is well ; but 

 if this be not the case, even although the air passages be free, it is bad. 

 Why this should be I am not quite certain, but certainly artificial 

 respiration on a dead dog will not produce the amount of respiratory 

 tide in such that it will do in a living animal. It must be remembered 

 that when one compresses the chest the air is not thus directly pressed 

 out, but the compression lessens the cubic capacity of the thorax and 

 then the elasticit}' of the lungs drives the air out. If this elasticity be 

 lessened then compression of the chest will not so readily cause the air 

 to pass out. This is observed in cases of Emphysema, where the 

 elasticity of the lungs is more or less lost^ and expiration in con- 

 sequence becomes difficult. 



As the animal recovers under the influence of artificial respiration it 

 becomes progressively easier to make a good flow of air in and out of 

 the chest, until at last this occurs spontaneously, and when once this 

 stage has been reached I have not seen the respiration fail again. The 

 Hyderabad Commission report such cases, however. 



Tracing XXXII.— 9/40— Dog poisoned with Chloroform. 4 Respiration ceased but heart could be 

 heard on anscultation. 5 Artificial respiration. 6 Pulse appeared and pressure rose. 7 Artificial 

 respiration stopped at 6 and pulse here failed and pressure fell again. 8 Artificial respiration again. 9 

 Pulse started again and soon after natural respiration commenced and animal recovered. 



Tracing 32 illustrates the beneficial efi"ect of artificial respiration on 

 the pulse and blood pressure. At 4 the animal was very deeply poisoned 

 with chloroform, the pressure was almost zero, and the respiration 

 had stopped, and the pulse was absent from the chart though the heart 

 could be heard to be beating. The chloroform had been removed. At 

 5 artificial respiration was started, and the waves produced b)' it are 

 visible on the tracing. At 6 the pressure suddenly rose, and with it the 

 pulse appeared. At 7 artificial respiration was stopped, and at once the 

 pressure fell again and the pulse disappeared. At 8 artificial respiration 

 was resumed, and at 9 the pressure rose again and the pulse reappeared. 



I Diseases of the Lungs. Sir Douglas Powell. 



