1906.] The Pharmacology of Ethyl Chloride. 401 



system, therefore, is dilatation, but the degree of paralysis is strikingly less 

 than that produced by chloroform, even when the latter is present in less than 

 one-tenth the quantity in the air inspired. 



The Effect of Ethyl Chlofjde upon the Vagus Mechanism. 

 This question was investigated by taking blood-pressure records of the 

 same and different dogs with various percentages of ethyl chloride vapour 

 in the air respired, (a) with intact vagi ; and (b) after section of the vagi. 



(a) The Effect of Ethyl Chloride in varying Percentages in the Air inspired 

 upon the rate of the heart is seen in the table below, which is compiled from 

 a number of experiments with different percentages of ethyl chloride in the air 

 inhaled : — 



3'5p.c.inl5' caused no change in the heart rate or blood- pressure. mm. Hg. 



7 p.c. in 13' caused heart rate to fall from 90 to 69 per min. and blood-press, to fall from 127 to 80 

 10 „ 14' 30" „ „ 65 „ 30 „ „ 195 „ 50 



10 „ 2' 15" „ „ 86 „ „ „ 100 „ 10 



15 „ 6' 10" „ „ 74 „ „ „ 120 „ 8 



20 „ 7' 30" „ „ 90„40 „ „ 124,, 90 



30 „ 1' 18" „ „ 80 „ 10 „ „ 120 „ 24 



30 „ 8' 40" „ „ 84„14 „ „ 116 „ 18 



30 „ 3' 20" „ „ 86 „ „ „ 100,, 10 



30 „ 2' 45" „ „ 90„10 „ „ 112 „ 50 



30 „ 4' 30" „ „ 88„16 „ „ 104 „ 30 



Figs. 8, 9, and 10 are blood -pressure curves obtained under the influence 



Ethyl Chloride 

 started, 



10% 



IlillilllllllilMIIIMlllOm^ 



Fig. 8. — Original size. 



