24 ANIMAL ELECTRICITY. LECTURE I. 



The action of ether you have just witnessed ; the 

 effect was quite typical — an aboHtion of excitability 

 consummated in about three minutes, and lasting 

 another five minutes. 



But how about chloroform ? I applied it in strong 

 vapour for one minute nearly half-an-hour ago, and you 

 then saw that the "excitability" was promptly abol- 

 ished; on testing it now, you see that nothing happens; 

 the nerve has definitively lost its excitability — you have 

 witnessed its "death by chloroform." 



Those are the facts in the rough — no slight differ- 

 ence of degree, but a striking contrast. There are 

 many accessory considerations to be weighed ; ob- 

 viously a question of this moment is not settled by a 

 single experiment. How about quantity? The nerve 

 has had in each case a maximum dose, i.e., for a period 

 of one minute, air saturated with the drug, i.e., with 

 about 50 per cent, of ether and about 1 2 per cent, of 

 chloroform. And to what extent may you argue from 

 a naked tag of nerve to the complex human organisa- 

 tion ? We shall not settle these matters offhand. We 

 have seen that there is a similarity between the 

 effects of anaesthetics on a living nerve and on a 

 living organism ; our next task will be to examine 

 some of the cases in which their effects differ. 



