344 Drs. V. H. Veley and A. D. Waller. Action of [Feb. 22, 



Note 1. — A. V. Hill,* working in Langley's laboratory and according to his 

 method, used extremely dilute nicotine solution, viz., 0"00003 per cent., i.e. 

 approximately %/50000() (we generally used solutions of 1000 to 500 times 

 this strength, viz. 7;/1000 and n/500). 



For the antagonism of nicotine by curare. Hill, working with the redics 

 abdominis muscle, gives O'OOOOG per cent. {i.e. «,/25000) nicotine as antagonised 

 by a 0-05-per-cent. solution of curare, and O-QOOOl per cent. {i.e. 7i/15O0O0) as 

 antagonised by a 0'005-per-cent. solution of curare. 



"We used in our antagonism an n/500 (0"03 per cent.) of nicotine with 

 curarine amounting to it/10000 (0 0026 per cent.) and 7i,/85000 (0-0005 per 

 cent.). 



Following the same method, he determines by Arrhenius' formula the 

 temperature constant for nicotine = 17,340, which corresponds with the 

 constant m = 31*4 by Esson's formula. 



Note 2. — Several years ago, one of us (A. D. W.) made a considerable 

 number of experiments on the isolated frog's heart, for the purpose of 

 comparing the activity of nicotine with that of pyridine. The comparison 

 failed by reason of the irregular effects exhibited by the heart. The failure 

 is worth mention in the present connection in illustration of our opinion that 

 isolated muscle ahords a gootl physiological reagent for the comparison of 

 toxicity. Thus, e.g., the relative power of ether and chloroform can be 

 estimated with far greater accuracy and unifoiiiiity of results on isolated 

 muscle than on the isolated heart. 



In a recent paper we have given the temperature constants by Esson's 

 formula for 



Alcohol //(, = 20-8, 



Chloroform m = 14-3, 



Quinine m = 2G'7 ; 



these correspond with tlic Arrlicnius constants: — 11,550,7930, and 14,820 

 respectively. 



But Hill's paper does not contain any data or records by which it would 

 be possible to compare his I'esults witli our own. His conclusion is, liowever, 

 the same as ours, viz. that the high value of the constant is evidence of a 

 chemical combination between drug and muscle. 



Arrhenius' formula, as expressing variation of rate of chemical cliangc wit h 

 temperature, has l)e(Mi generally adopted hy writers on I'liysical and on 

 Physiological Chemistry. 



* 'Journal of IMiyHiolof^y,' vol. 39, ]). 361. 



