PHYSICO-CHE.MK \I. BASIS OF TRAXSMIssK ,.n ^ ^^^ 



area, we have a transmission of slinuilalin^; c! 

 through three centimeters in .001 of a sccon<l 

 equivalent to thirty meters per Miond, ihc usual 

 transmission- velocity at tliis temperature. The rcsulli 

 of this simple calculation are thus in agreement with 

 observation and support the view that transr " ' 11 is in 

 reality a case of secondary stimulation by tlu- cuf 



TTTTr^W^ 





> 



Fig. 5. — Diagram of the momentary conditions in a -« 



at 20°. The shaded region markeci A, between /fj and K,. ; I 



under consideration by the excitation-wave, which is rcgardctl as .. v 



tion of the large arrow at the rate of 30 meters per second. It> Icnicth, ■Mumint tfat 

 total duration of the local process (as indicated by the dumlidn nf the local biockctric 

 variation) to be .cx>2 second, is cm. The excitation-priKos is just berinnini sT *,. 



has reached its maximum at A 10, and has just subsided at Rt. The curvr 4 



variation from the resting potential at different points in the activt n 

 P.D., at Aio, is ca. 40 millivolts. The regions marked K arr •• 

 small arrows indicate the direction of the bioelectric current 

 tion of the active-resting circuit. Between R, and R, ila intensity it 



the nerve; excitation is thus always being initiate*! at •. 4 



the wave front (i.e., up to R,). For a somewhat simiUr i!. « 



excitation-wave the nerve is refractory to stimulation. 



of the local bioelectric circuit. Fi«;urc 5 p;\ves a diagram- 

 matic representation of the conditions in a nerve during 

 transmission. 



The course of the current in the bioelectric circuit 

 should be noted; this course is partly cxtra-ccllular, 

 i.e., through the medium,' and j)artly inlra-ccllular, 



» Part of this current passes throuRh the galvanomrtrr »hrn ihc 

 action-current is recorded by such an instrument, the rcn »ugh 



the medium or other extracelluhir conducting |>alh. 



