Experiments with Quinidine. 



177 



TABLE I. 

 Experiment 48. 

 Male Dog — 8.0 kgm. 



Refractory Periods. 





Before 

 Quinidine. 



After 

 Quinidine. 

 0.02 gm. (Intravenous). 







.0825 







.0844 





.0560 



.0876 





.0601 



.0904 





.0605 



.091S 





.0607 



.0917 





•0653 



.0917 





.0655 



.0941 





.0663 



.0950 





.0666 



.0985 





.0678 



.0989 





.0695 



.1000 





.0699 



.1061 





.0700 



.1066 





.0708 



.1078 







.1079 





■ 



.0763 



.1099 





.0766 



.1106 





.0770 



.III4 1 





.0792 1 



•II23 1 





.0812 



.1129 





.0827 



•II35 1 





.O844 



.1138 





.0855 



•1145 





.O859 



.II6I 1 





.0861 



.1194 





.0868 



.1200 





.O892 1 



.1207 





.O96O 



.1211 





.0970 



.1219 







.1222 







.1228 







.1232 







.1234 



1 No responses. 



been discussed, an action of quinidine calculated to bring this 

 activity to an end should consist in increasing the rate of conduc- 

 tion and in lengthening the refractory period. In point of fact 

 our experiments show that quinidine affects one of these factors 

 (the refractory period) favorably, but not the other (the rate of 

 conduction). And it affects the refractory period favorably in 

 the doses we have used, in spite of the rise in rate which the drug 



