159 



The Action of Anaesthetics on Living Tissues. Part II. — The 



Frog's Skin. 



By N. H. Alcock, M.D. 



(Communicated by A. D. Waller, M.D., F.K.S. Eeceived April 9,— Read May 10, 



1906.) 



(From the Physiological Laboratories of the University of London arid St. Mary's 

 Hospital Medical School.; 



Contents. 



I. Introduction. 



II. Experiments — Series I. — Anaesthetics to inner and outer surfaces. 



III. Series II.— CHC1 3 to outer surfaces in parallel. 



IV. Series III. — Electrical resistance of skin after CHC1 3 . 

 V. Deductions. Kelations to Part I. Alternative theories. 



Introduction. 



The currents given by the frog's skin and their variations after excitation 

 both directly and through the nerves have already been studied by many 

 authors,* but, as far as I can determine, no one has up to the present time 

 observed the action of anaesthetics on the resting current, and as these 

 phenomena form a fitting sequel to those occurring in nerve (Part I of this 

 series),! they form the subject of this paper. It is to be observed that from 

 the nature of the object one of the possible alternative hypotheses in the 

 case of nerve is here excluded, and it is therefore now legitimate to take 

 a further step in explanation of the action of chloroform on the tissues 

 generally. 



Experiments. 

 Series I. 



A chamber was constructed of vulcanite, through the bottom of which 

 three non-polarisable electrodes projected. A movable partition of model- 

 ling wax, luted with moist china-clay, divided one electrode, A, from the 



* Most of the references to the numerous papers on the frog's skin are to be found in 

 the article by Waymouth Eeid in Schafer's 'Text-book of Physiology,' vol. 1, pp. 669 — 

 691. A criticism of the various theories is in the paper by Bayliss and Bradford, ' Journ. 

 Physiol.,' 1886, vol. 7, p. 223. See also Waller, ' Signs of Life,' 1905. 



t ' Roy. Soc. Proc.,' B, vol. 77, 1906, p. 267. 



