ON NERVE FORCE 425 



transmission to higher centres, where it may be likewise 

 further stored, used up, or, it may be, spent pathologically 

 as a disease-exciting reflex, or reverse, current, or molecular 

 disturbance, as in some neuralgias, herpes zoster, or epileptic 

 " nerve storms." 



For example, the sensory impressions, conveyed by the 

 peripheral nerves to the ganglionic cells of the spinal cord, 

 in a paraplegic, are, or seem to be, reflected in the form of 

 motor impulse to the muscles of the affected limbs, which 

 points to the conversion by the sensory ganglionic and 

 connected motor cells, of the cord, of sensory molecular 

 change, impulse, or impression, into motor molecular 

 change or impulse. 



It, therefore, seems possible that peripheral impressions 

 may be thus stored in the cells of the spinal cord, and the 

 higher basal and cerebral centres, and that they may sub- 

 sequently, when necessary, be converted into motor im- 

 pulses, or be made available for higher functional, or even 

 intellectual, purposes, as memories, etc. 



Nerve energy may thus be largely derived from without, 

 and stored up for future use by the cells so plentifully 

 present in the great cerebro-spinal system, as well as in 

 the attached sympathetic system ; and so the genesis proper 

 of nerve force, by the appropriate nerve structures, may be 

 supplemented and assisted by the collection and retention 

 of unused or residual sensory nerve force. 



Another thought that has occurred to us in connection 

 with this aspect of the subject of nerve force is that a 

 recurrent molecular change, or nerve current, may be in- 

 duced in the motor nerve fibres, engaged in initiating and 

 maintaining muscular action, and transmitted in a reverse 

 manner to the higher centres as a measure, or neurometer, 

 so to speak, of the amount of nerve force expended in the 

 stimulation, or innervation, of the muscles engaged in any 

 given act, or series of acts, or movements, and that thus 

 an automatic mechanism is provided for the accomplish- 

 ment of the objects of a " muscular sense," and that, there- 

 fore, the principle of the " duplex current" is utilised in the 

 conveyance of nervine force. 



Here we might further observe that sensory nerves 

 seem to afford, in certain conditions of the bodily health, 



