On Skin Currents. 485 



Some Data regarding Magnitudes of Effects of Direct Electrical 

 Excitation of Frog's Skin. 



(Interval between Excitation and Galvanometer Closure = 2 Sees.) 



Excitation. 



Response. 



1. 



Break induction current. . . . 100 + 







+ -0050 volo 







100- 







+ 0-0010 „ 







1 AAA _j_ 

 1UUU + 













1UUJ 







4- • 0850 







1 A AAH _L 







+ o -o^oo 







1 A AAA 



I u,uuu — 







+ 0-0900 „ 



2. 



T> 1 



Ureals 



1 AAA -l 

 , , .... X UUU + 







4- "0330 







1 AAA 







4- -0420 







5000 + 







4 -0260 







^AAA _ 

 OUUU 







+ -0320 



Q 



o. 



IVJ-diliC , 



1 AAA j- 



, , .... J.UUU T 







+ -0045 







1000- 







+ 0-0015 „ 





Break ,, 



„ ... 1000 + 







+ 0-0140 „ 







1000- 







+ 0-0160 



4. 



Make 



„ .... 500 + 







nil 







500- 







nil 





Break ,, 



„ .... 500 + 







+ -0035 „ 







500- 







+ 0-0135 „ 





Make 



.... 1000 + 







+ 0-0150 „ 







1000- 







-1-0-0065 „ 





Break ,, 



,, .... 1000 + 







+ 0-0370 „ 







1000- 







+ 0-0500 „ 



5. 



Condenser dis- 



8 volts 1 mP. + 



( = 



640 ergs) 



+ -0100 „ 





charge 





+ -oioo „ 







8 volts 0-1 mf. + 



( = 



64 ergs) 



+ 0-0015 „ 









+ -0008 „ 



N.B.— The + sign signifies outgoing direction, the — sign ingoing direction. 



3. The electrical response to indirect excitation of the nerve of a 

 nerve-skin preparation is of three types — 



I. Positive or outgoing. 



II Mixed I ( CL ^ P° s ^ ve interrupted by negative. 



L (b.) Negative followed by positive. 

 III. Negative or ingoing. 



I have in no one instance witnessed the three types upon the same 

 preparation, and may not therefore definitely say that they form three 

 progressive stages. Nevertheless, I regard a positive response of 

 type I as being the most normal, it having presented itself with the 

 best preparations ; and type III as the most enduring, it having 

 exhibited least decline in consequence of repeated stimulation. I 



