402 



Dr. E. H. Embley. 



[June 13, 



of 10, 10, and 30 per cent, respectively of ethyl chloride in the air 

 respired. In the above cases the vagi were intact. The varying rapidity of 

 onset of inhibition with the same or different percentages of the anaesthetic 

 denotes variations in the excitability of the vagus mechanism in these 

 experiments. 



t 1 



on Off 



• 



i 



Vag. 

 cut 



■iiiiiuiii'iniiiHiHiiiiiiiurniiiiT i ri 







Fig. 9. — Original size. 



(b) The Effect of Ethyl Chloride in varying Percentages upon the Heart 

 Rate after Section of the Vagi is seen below : — 



10 p.c. 



in 14' caused no 



change 



in heart rate and no fall in blood-pressure. 



15 , 



12 







20 , 



12 



3) 



?) >) ;J 



20 , 



13 





„ a fall in blood-pressure from 78 to 70 mm. 



30 , 



7 





» 102 „ 38 „ 



The heart rate was altered in none of these experiments. In three out of 

 the five there was no fall in pressure. In the fourth there was a fall, 

 but it was slight. The duration of the administration in these cases was 



