Vital and Physical Motion. \ 2 7 



fluence. He, himself, as is proved in the extract already 

 given, was a firm believer in animal electricity ; but he 

 failed to supply reasons for this belief which can be 

 regarded as thoroughly satisfactory at the present day. 

 Still, he did something in this direction by making out 

 first, that the agent assumed to exist, and to be 

 animal electricity, has this in common with electricity^ 

 that its action is permitted by conductors and prevented 

 by non-conductors ; and, secondly, that it is not to be 

 confounded with voltaic electricity, because the action, 

 which is permitted by conductors, is possible across a 

 gap in the circuit which would allow the passage of 

 franklinic electricity, but which would altogether prevent 

 that of voltaic electricity would allow, that is to say, 

 electricity of high tension to pass, but not electricity of 

 low tension. What Humboldt did, in fact, was to in- 

 crease the probabilities of the existence of animal 

 electricity not a little, and at the same time to make it 

 appear that this electricity would prove to be of higher 

 tension than voltaic electricity under ordinary circum- 

 stances. 



In 1803, Aldini, Galvani's nephew,* published an 

 account of certain experiments which furnish further 

 evidence in favour of the existence of animal electricity, 

 by showing that living animal tissues are capable of 

 giving rise to attractions and repulsions which seem to 

 be no other than electrical attractions and repulsions. 

 ' I held,' he says, ' the muscles of a prepared frog in 

 one of my hands, moistened with salt and water, and 

 brought a finger of the other hand, well moistened in 



* " Account of the late Improvements in Galvanism, with a series of 

 curious and interesting experiments performed before the Commissioners of 

 the French National Institute, and repeated in the Anatomical Theatres of 

 London, &c." 4to. London, 1803. 



