1906.] 



The Pharmacology of Ethyl Chloride. 



413 



Fig. 8 (size of original). — Vagus inhibition. Dog. Weight, 4*2 kilogrammes. Morphine, 

 - 2 gramme. Blood-pressure tracing. Air containing 10 per cent, of ethyl 

 chloride vapour administered by artificial respiration. Blood-pressure at 

 starting 83 mm. After 1' 45" administration the blood-pressure fell to 

 10 mm. from vagus inhibition. Recovery. 



Fig. 9 (size of original). — Vagus inhibition from central stimulation. Dog. Weight, 

 9'4 kilogrammes. Morphine, 0"4 gramme. Curare, - 02 gramme. Artificial 

 respiration. Artificial arterial brain circulation prepared as in experiment 

 for fig. 6, but with the vagi intact. Blood-pressure figure. Artificially 

 circulating blood contained ethyl chloride equal to 30 per cent, of the vapour. 

 Blood-pressure at starting 126 mm. Artificial circulation started at "on" 

 and continued for 49'', ceasing at " off." Blood-pressure fell to 10 mm. 

 The heart ceased from vagus inhibition. Recovery by vagotomy. 



Fig. 10 (i size of original). — Interdependence of respiration and blood-pressure. Dog. 



Weight, 7'8 kilogrammes. Morphine, 03 gramme. Respiration (Resp.) and 

 blood-pressure (B.P.) figure. Air containing 30 per cent, ethyl chloride 

 vapour started at "on" and administered continuously. Blood-pressure at 

 starting 103 mm. Hg. In 3' 54" the blood-pressure fell to 10 mm. The 

 respiration quickened after the commencement of the administration and 

 slowed with the onset of heart slowing and ceased in 3' 14" with blood- 

 pressure 35 '5 mm. Hg. 



Fig. 11 (I size of original). — Respiration and blood-pressure. Dog. Weight, 7 kilogrammes. 



Morphine, 0'25 gramme. Blood-pressure figure. Ethyl chloride of unknown 

 but large percentage administered by spraying the liquid into the mouth 

 until the respiration ceased. Blood-pressure at starting "on," 118 mm. 

 Some slowing from vagus inhibition occurred after 35" of administration 

 and lasted 1' 26", at which period the respiration, after slowing, ceased. 

 Respiration continued in abeyance for 6' 56". Blood-pressure was 99 mm. 

 at cessation of respiration and 98 mm. on its return. 



