1906.] The Pharmacology of Ethyl Chloride. 403 



Fig. 10. — i size of original. 



considerably longer than that of the average (see the former table) required 

 to bring on marked slowing of the heart rate and great fall of blood-pressure. 

 In the fifth experiment (second table), in which 30 per cent, of ethyl 

 chloride was administered in the inspired air, the blood-pressure fell from 

 102 to 38 mm. Hg in 7' without alteration in the heart rate. In this 

 experiment the fall of blood-pressure was due to the paralytic effect of 

 the anaesthetic upon the heart and vessels. 



From these results it is evident that great and sudden falls of blood- 

 pressure may occur from the administration of ethyl chloride in strength of 

 10 per cent, and upwards, and that when the strength of the vapour does not 



