1902.] 



On Skin Currents. 



377 



(3.) The augmented conductivity of the boiled as compared with 

 the living skin — from 35 to 115. 



(4.) The unaltered conductivity of the boiled skin — 115 before and 

 after tetanisation. 



The small deflections seen in the case of the dead skin are such as 

 may be observed with a non-living electrolyte, and are due to polar- 

 isation. They follow the direction of the break current, and are due 

 to the fact that the sum i of polarisation countercurrents by the 

 series of make currents is greater than the sum of similar effects by 

 break currents. 



The four deflections seen in the case of the living skin, do not vary 

 in direction with varying direction of the exciting currents, but 

 exhibit an inequality such that the + (outgoing) deflection after 



f make - 1 . g „ r6ater ^ an + d e fl ec ti n after { ma ^® + \ . 



I break + J I break - J 



This inequality is such as would be produced by the polarisation 

 effect witnessed alone in the dead skin. The four deflections of living 

 skin exhibit a progressive decline, attributable to fatigue. 



A similar inequality, attributable to polarisation (but possibly in 

 part due to unequal j excitation by the two poles of an exciting 

 current) is witnessed in the outgoing effects of single break induction 

 currents. The + (outgoing) response after an induction current of 



- direction is greater than the + response after an induction current 

 of + direction. (Fig. 2.) 



0-0010 

 voit 



JTTTTTT 



Dead. 



Eig-. 2 (4201). — Skin of Breast 8 hours after amputation. Living. — Two + re- 

 sponses to single break induction shocks in + and — directions. 8 L. 10,000. 

 Bead. — Several — and + effects to + and — shocks, i.e., polarisation. Re- 

 sistance diminished. 



Effect of Previous Excitation. — The response to a particular excitation 

 is greatly influenced by the previous excitation to which the skin may 

 have been subjected. In general, the second of two moderate excita- 

 tions produces a greater effect than the first, while the second of two 

 strong excitations produces a smaller effect than the first. In the case 



