274 



Dr. N. H. Alcock. 



[Nov. 9, 



If the small final values under 20 be disregarded, these experiments show 

 that : — 



(1) Ether vapour of 51 to 54 per cent, and CHC1 3 of 16 to 12-3 per cent, 

 are identical in their final effects. 



(2) CHC1 3 of 8 per cent, has a less effect. < CHC1 3 vapour of about 

 12 per cent, has, therefore, a maximum action. 



(3) Ether acts more quickly than CHC1 3 (fig. 5). 



70 



50 



1 





\t 1 1 1 

 /( Vy hole| nerjve 











IP 



jb 2 o tjo dis 



Gal 













c 



fiCljjfcop 



ox. 



























rt 

















\ 



! 

















































v 

































\ 



























++++ 













































+ + ■»-+ 



Fig. 5.— Series IV. 



Control Experiments. 



In order to exclude any possible source of current from electrodes or any 

 unexpected physical cause, control experiments were made with threads 

 moistened with (a) salt solution, (6) egg albumen, (c) egg yolk, and (d) fresh 

 blood. These were treated in an exactly similar manner to the nerves in 

 Series II. No electromotive phenomena followed the application of CHCI3 

 vapour. So also nerves kept in salt solution until they gave no injury 

 current showed no results witli amesthetic vapours. HC1 and NH 4 OH gave 

 electromotive effects when applied either to threads or nerves, HC1 with the 

 same sign as CHCI3, NH 4 OH with the reverse. The similarity is therefore 

 only apparent and probably due to diffusion into the electrodes. 



