A PRACTICAL DEVICE TO SIMULATE THE WORKING 

 OF NERVOUS DISCHARGES 



S. BENT RUSSELL 

 St. Louis, Missouri 



First we shall briefly outline a theory which will reconcile 

 observed facts as to the structure of nervous systems and the 

 reactions of such systems. We will then take up the descrip- 

 tion of a practical mechanical contrivance which will represent 

 the essential elements of a nervous system and which will react 

 in the same way. We will then compare the results obtained 

 with the machine with those given by live nervous connections. 

 In this discussion we shall confine our field to the interactions 

 of the nerves. What happens in sensory endings like those of 

 smell and taste does not concern us. The reader should also 

 avoid thinking of what he knows of his own sensations and 

 have in mind only what he can observe in the nervous systems 

 of other creatures. 



A nervous system may be taken as controlling several pairs 

 of opposing muscles through a system of nervous channels 

 excited by a number of sensory terminals. A muscular move- 

 ment or response is caused by a combination of discharges from 

 several channels acting on a given muscle or muscles more than 

 on the muscle or muscles directly opposed to it or them. The 

 said combination of discharges may be excited at one or several 

 sensory points. 



As a result of individual experience changes take place in the 

 nervous channels. With the same sensations l as before we 

 observe that the responses have changed and vice versa we 

 observe the same responses when the sensations have changed. 

 The most natural explanation for this is that some of the chan- 

 nels have grown more than others, that is, that they have be- 

 come more open to the flux. 



The problem that is before us is to account for the growth 



1 Throughout this article the term sensation is used to represent the excitement 

 of a sensory terminal of a nervous channel. Of course this departure from the 

 usual subjective meaning of the word is made for the sake of brevity. 



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