164 Dr. N. H. Alcock. [Apr. 9, 



Experiment 507. Experiment 508. 



AB. 



BC. 



(A + C)B. 





AB. 



BC. 



(A + C)B. 



TOlt. 



volt. 



volt. 





volt. 



volt. 



volt. 



0299 



0349 



-0338 





-0450 



+ -0157 



+ 0-0248 



355 



350 



354 





497 



173 



261 



370 



361 



369 





512 



180 



270 



382 



354 



366 





525 



189 



280 



390 



357 



369 





535 



197 



288 



396 



358 



372 





550 



210 



300 











560 



218 



308 



CHC1, to BO. 











410 



+ 282 



312 





CHCI3 to BC. 



410 



200 



230 





645 



120 



230 



. 415 



120 



190 





648 



60 



100? 



420 



60 



150 





670 



30 



180 



420 



30 



130 





683 



13 



167 



423 



15 



115 





687 



+ 3 



159 



424 



+ 5 



110 





780 



- 3 



154 



426 



— 2 



102 





















CHCI3 off. 







CHC1 3 off. 







720 



8 



153 



434 



- 8 



95 











437 



10 



93 









437 



- 11 



91 









The sign + indicates that the current was directed from outer to inner in the skin. 



Conclusions. — Chloroform applied to electrode BC — 



(i) Causes no change in the potential between A B (as in Series I). 



(ii) Abolishes the p.d. between B C. 



(iii) Diminishes the p.d. between A+C and B. 

 For further observations see below. 



Series III. 



Determinations were made of the electrical resistance of skin before and 

 after chloroformisation, in the same manner as the parallel series in nerve, 

 the skin resting by its external on two non-polarisable electrodes in a 

 chamber to which moist CHCI3 vapour- of about ] 6 per cent, or moist air 

 could be passed at will. The probable error of a single observation does not 

 exceed 2 per cent. 



Conclusions. — Chloroform causes — 



(i) A diminution of real resistance of about 24 per cent. 



(ii) A diminution of polarisation of about 10 per cent. 



The first of these conclusions contrasts markedly with the results of the 

 experiments on nerve, where there was no alteration of the real resistance (as 

 opposed to polarisation) within the limits of error of the method. 



