1902.] On Shin Currents. 379 



Skin No. VII. Second Day. 



Strength of 

 tetanisation. 

 J make — . \ 

 I break + . j 



Deflection. 



Conductivity. 

 (Deflection l>y 0*01 

 volt.) 



Voltage of 

 response. 



1000 



- 7 



50 



-0*0014 



2000 



+ 30 



70 



+ 0-0043 



4000 



+ 170 



130 



+ -0130 



6000 



+ 280 



170 



+ -0165 



8000 



+ 300 



200 



+ 0-0150 



10000 



+ 280 



230 



+ -0122 



10000 



+ 240 



240 



+ 0-0100 



8000 



+ 200 



230 



+ 0-0087 



6000 



+ 130 



220 



+ 0-0059 



4000 



+ 80 



220 



+ 0-0027 



2000 



+ 30 



200 



+ 0-0015 



1000 



+ 6 



180 



+ -0003 



From which the mean values come out — 



1000 







-0-0005 



2000 







+ -0024 



4000 







+ -0078 



6000 







+ 0-0012 



8000 







+ -oooo 



10000 







+ 0-0111 



As far as my observations have gone, decline by fatigue has exhibited 

 itself more prominently in the human skin than in the frog's skin. 

 On the other hand, summation of effects has been much less apparent. 



Locality of the Reaction. 



The blaze currents of human skin arise exclusively from its external 

 epithelial strata, not the most superficial keratinised cells, but the 

 underlying and presumably living cells of the Malpighian layer. 

 This principal fact is demonstrated in various ways : — 

 (1.) A piece of fresh skin, put up as figured, is excited through the 

 electrodes A, B, and led off to the galvanometer through A, C, and 

 then through B, C (which are previously compensated before each 

 trial). 



if 



VOL. LXX. 



