44 ANIMAL ELECTRICITY. LECTURE II. 



recovery within a few hours, ahiiost certainly by to- 

 morrow morning. 



Let us pause now to consider the effects of these 

 three experiments, which are chosen on purpose to 

 enforce the principle insisted upon at my last lecture, 

 that living matter in the shape of a nerve, may give 

 us some clue to the action of drugs on the living body. 

 The soda w^ater has acted evidently by reason of its 

 dissolved gas, which is carbon dioxide. The tobacco 

 smoke has very likely acted by reason of the same 

 constituent, carbon dioxide ; still I am not prepared 

 to say that no other constituent of tobacco smoke is 

 active, since I have not yet tried the effect of tobacco 

 smoke deprived of its CO^. 



Alcohol (that Is to say ethylic alcohol, EtOH ; we 

 shall on some future occasion have something to say 

 about other alcohols) has, in the way we used it, acted 

 as a profound depressant. If we had been very 

 careful, we might have witnessed on the nerve its 

 preliminary exhilarant effect. As to how it acts, I 

 do not wish to be positive, but may remark that it 

 not improbably acts by depriving the nerve of water 

 — the effects of alcohol vapour and of drying are very 

 much alike, and so indeed is that of prussic acid-^a 

 point that might perhaps be very effectively made u^e 

 of by a temperance advocate. But such a person 

 would probably omit to comment upon the effect lof 

 pure water, which very promptly puts an end to the 

 nerve. Here, however, we come to a point of diverg- 



