identity of the nervous principle with electricity

[Noha Shehata]

Hello,

I'm translating a book called models of mind  Models of the Mind: How Physics, Engineering and Mathematics Have Shaped Our Understanding of the Brain , and have some questions:

1. What is meant by  identity of the nervous principle with electricity and what is meant by nervous principle? does it mean the electrical nature of the nervous system?

With his glimpsing of current changes coming from the nerve, du Bois-Reymond wrote: 
‘If I do not greatly deceive myself, I have succeeded in realising [...] the hundred years’ dream of physicists and physiologists, to wit, the identity of the nervous principle with electricity.’

 

2. what is meant by electrical disturbance in the following?

Neurons have action potentials.
Certain other excitable cells, like those in the muscles or heart, do as well.
This electrical disturbance travels across a cell’s membrane like a wave.
In this way, action potentials help a cell carry a signal from one end of itself to the other.