50 J. W, SLATER, ESQ., F.C.S., F.E.S,, ON 



80 also in respect of the spinal cord and brain the same result 

 follows, e.g., in blushing and flushing reflex conditions arising out 

 of some temporary alteration of the normal quantity of vital force 

 conveyed by the vasomotor nerves. 



Light is produced as a display of electrical force, under the usual 

 conditions of interrupted current, etc. So also is light, or that 

 condition of force wliicli gives rise to it, produced when force is 

 suddenly and abruptly applied to the organ of vision, e.g., by a 

 blow; or, wben the eyes are closed, by pi'essing the fingers upon 

 the eyelids so as to cause pi'essure upon the eyeballs, assuming, 

 with regard to the blow, the appearance of a flash of light, or a 

 myriad of bright sparks ; and from pressure by the finger that of 

 a ring of light; such efforts, as in the case of the battery being 

 obviously due to interruption of a current of force. 



Shock results also fi'om interruption of an electrical force curi-ent. 



So also as to the brain and spinal cord similar consequences 

 follow, e.g., a blow over the ulnar nerve gives rise to shock from 

 sudden stoppage of vital force current. 



Small shocks producing pin and needle sensations are experienced 

 by the use of the battery and coil, etc. The same sensations ate 

 the sequence of partial pressure upon a nerve trunk. 



Complete hindrance to electrical force current and vital force 

 flow entail the same results : cessation of all manifest effects of 

 the former; and abolition of functions of parts supplied by the 

 latter. 



In connection with a battery, we see under certain conditions — 

 mechanical effects of electrical force — or so-called conversion of 

 the former into the latter, these effects being, however, neither 

 more nor less than qualities of primary force rendered evident by 

 the conditions under which it is placed. In like manner we find 

 the mechanical effects of vital force in connection with the brain 

 and .spina! coi'd rendered evident by the contlitions with which it 

 is associated, and under Avhich it is placed ; giving rise to 

 mechanical motion in the body wherever needed, e.g., sucking, 

 mastication, deglutition, evacuation, heart and artery movements, 

 respiratory, limb and general movements of the body through the 

 agency of the muscular system. 



The ball and socket joint of the scapula and humerus Avitli its 

 associated muscles affords an example of adaptation and con- 

 struction, such as jDcrmits of a display of every form of 



