1902.] 



On Skin Currents. 



385 



mortem room, more or less doubtful results may be obtained, and 

 unless due regard is paid to possible sources of fallacy, wrong conclu- 

 sions may be drawn. 



A principal source of fallacy lies in the electrodes ; it is less liable to 

 be of disturbing effect in the simple case of excitation by single 

 shocks ; it is more liable to give rise to ambiguous results in the more 

 doubtful cases where alternating currents are required, the resulting 

 polarisation in such case being less easy to recognise as such than in 

 the case of single shocks. In such cases, when single shocks produce 

 only polarisation effects, the voltage of any true response that may 

 co-exist is low, and although alternating currents may then bring it 

 into evidence, still we are not wholly free from a polarisation 

 resultant which is of complicated origin and of inconstant direc- 

 tion. 



Currents of a Berne Coil, supplied by 8 Leclanche Cells (11*5 volts). 





alternating currents. 















Conduc- 



Kesist- 











tivity. 



ance. 







10000. 















(Not corrected for gal- 











vanometer and elec- 







C make + ~) 



("make + > 



trode resistance.) 







(.break — j 



(.break — J 









■ — 



>+o*oioo 



> + 0-0100 



60 



166667 



Ingoing effects — 0'0020 and —0*0015 with weak tetan. 





+0-0350 



+ 0-0180 



75 



133333 



Another piece. 





+ 0-0015 



-0-0002 



■ 300 



33333 



Same piece, boiled. 





+0-0500 



+ 0-0200 



30 



333333 



Another piece. 









110 



90909 



Another piece. 









210 



476i9 



Another piece. Doubtful state. 





+ 0-0006 



-0-0006 



210 



47619 



Same piece, boiled. 









70 



142857 



Another piece. 









200 



50000 



Ditto, boiled. 





+ 0-0007 



+ 0-0005 



210 



47619 



Another piece. Doubtful. 









210 



47619 



Ditto, boiled. 







- 



150 



66667 



Another piece. Doubtful. 





+ small 



— small 



250 



40000 



Ditto, boiled. 









10 



1000000 



Good response. Cond. x 2 by tetanisation. 





+ 0*0005 



-0-0005 



200 



50000 



Same piece, boiled. Cond. x 10 by boiling. 









5 



560000 



Another piece. Gal v. shunted 1/3. Cond. x 5. 









25 



112000 



Same piece. Cond. x 7. 









115 



24348 



Ditto, boiled. Cond. raised to 115, and not further altered 













by tetanisation. 









40 



250000 



Another piece. Galv. unshunted. 





+ 0-0002 



-0-0003 



200 



50000 



Ditto, boiled. 









7 



500000 



Another piece. Galv. shunted 1/3. Cond. x 2*5 by tetan. 









15 



186667 



Same piece. Series at +1000. Cond. x 35/15 by tetan. 









35 



80000 



Ditto, ditto. 









20 



140000 



Ditto, ditto, half dry. 





+ 0-0550 



+0-0160 



7 



500000 



Another piece, half dry. 





+ small 



— small 



90 



31111 



Ditto, boiled. 





+ 0-0060 



+ 0-0020 



15 



186667 



Another piece. Galv. 1/3. Cond. x 85/15 by tetan. 









36 



277778 



Skin of nipple. Galv. unshunted. Cond. x 44/36. The 













surrounding skin is inactive. 









180 



55555 



Ditto, boiled. 





>+o-oioo 



> + 0-0100 



70 



142857 



Normal current = —0*0050. 









60 



166667 



Another piece. B.M. discharge at —6°. 





+ small 



—small 



150 



66667 



Same piece at +14° after h hour at —6°. 









80 



125000 



Another piece. 





+ 0-0160 





70 



142857 



Another piece. 



