1906.] The Action of Ancesthetics on Living Tissues. 169 



It would appear therefore that this action of chloroform, namely, the 

 breaking down of a semipermeable apparatus, is the characteristic action of an 

 anaesthetic on living tissue. 



The additional possibility just mentioned remains to be considered. The 

 view of Moore and Pioaf * is that CHCI3 combines with proteid, forming 

 " unstable compounds or aggregates," and in doing so splits off inorganic 

 ions, further, that " anaesthesia is due to a paralysis of the chemical activities 

 of the protoplasm as a result of the formation of such aggregates." The 

 present experiments (Parts I and II) give no direct information on these 

 subjects, all that can be deduced with certainty is the conclusion given 

 above. Moore and Eoaf's theory may be adopted as an addition to this, or 

 it may not. Whether or no this addition is justified by the experimental 

 evidence adduced by these authors is a debatable point. 



It is to be remarked that the observations (Part I, Series Y and VI, 

 Part II, Series III) on the electrical resistance of the tissues cannot be taken 

 as proving or disproving an ion formation — they show that what is equivalent 

 to a diminution of viscosity takes place (much in skin, little in nerve) and 

 that in the latter case this diminution causes less than 2 per cent, alteration 

 in conductivity, obviously a small production of ions would be masked 

 by these other changes, f As the resistance and freezing-point determina- 

 tions of Moore and Eoaf were made with solutions, there were no membranes 

 to cause this ambiguity, but from inspection of their figures it would appear 

 that the mean differences, which they use in support of their argument, are 

 less than the error of their experiments ; it is only a matter of accident what 

 values are obtained in such a case. The question is one that merits further 

 study before a definite conclusion is arrived at. 



I have again much pleasure in acknowledging the assistance of Dr. "Waller, 

 and I also wish to thank Professor Ayrton for his kindness in examining 

 the electrical data and conclusions. Dr. Collingwood and Mr. Shapiro have 

 again given me much help. 



* Moore and Eoaf, ' Eoy. Soc. Proc.,' vol. 73, p. 382, and vol. 77, B, p. 86. 



+ Using the apparatus mentioned in the text, it was found that any alteration in the 

 resistance of serum was not detectable after CHC1 3 , but that there was a diminution of 

 approximately 15 per cent, in the case of blood (laked or simply defibrinated) ; it would 

 seem that the effect of CHC1 3 on haemoglobin would be worth investigating. 



VOL. LXXVIII. — B. 



P 



