7 6 PHYSIC 



rence felt and seen in the experience of every observer, in 

 such affections as herpes zoster, epilepsy, and certain forms 

 of gastralgia, together with many other forms of neuralgia, 

 of particular nerve trunks or fibres, where absolutely no 

 material change can be traced in the structures implicated, 

 but where, of necessity, there must be the passage of nerve 

 energy, with its implied molecular disturbance of the 

 proper nerve and related substances. This disturbance, 

 as we have already said, consists often, if not always, of a 

 reverse current of nerve energy, i.e. the passage of an 

 efferent current along an afferent nerve trunk or fibre, 

 and, it may be, the passage of an afferent current along 

 an efferent nerve trunk or fibre. The tracing of such 

 nervine phenomena, amid the fibral intricacies of the 

 sympathetico-systemic nervature, may be possible, but is 

 transcendentally difficult ; suffice it to say, therefore, that 

 the two forms of nerve energy, afferent and efferent, being 

 different in genesis and manner of conservation, must be 

 different in their influence on the various nerve elements 

 concerned in their conveyance and distribution, the two 

 being in a sense comparable to negative and positive in 

 the kindred domain of electrical phenomena. Herpes 

 zoster, for instance, according to this view, consists in 

 efferent discharge of nerve energy through an afferent nerve 

 trunk and terminal fibres into structures not designed to 

 discharge, but to receive, hence the neuritis ; while epilepsy 

 consists in the discharge of nerve energy, efferently, it 

 may be, of the whole of both cortical and deep-seated 



nerve centres," cerebral and spinal, hence wholesale and 

 inco-ordinated character of the muscle spasm and the lapse 

 of consciousness which characterise such seizures. The 

 phenomena characterising the mixed sympathetico-systemic 

 pains and pure neuralgias are of less evident order in 

 causation and sequence, but, nevertheless, traceable to 

 some extent on these lines ; their careful study will, there- 

 fore, we are convinced, repay the expenditure of whatever 

 attention may be given to this department of the subject 

 in a more intelligent "grasp of the situation" and an 

 increased power to deal with it practically. 



The lethal discharge of nerve energy from peripheral 

 nerve endings, more especially on the sensory or afferent 



