PULSE DURING MENTAL AND PHYSICAL WORK. 241 



be relatively slow, thus bringing into prominence a coincident 

 depression of the accelerator. Further support for this general rela- 

 tionship appears in the antagonism between atropin and alcohol 

 (Hascovec) . Moreover, the effect of alcohol on the pulse-rate has been 

 found to persist after the vagi are cut (Hascovec 1 and Dixon 2 ). Such 

 an event would be inexplicable if the inhibitor center alone were affected. 

 We suggest that in this probable effect of alcohol on both antagonistic 

 mechanisms, combined with the failure to differentiate absolute and 

 relative acceleration, there is ample opportunity for all the various 

 experimental results that were noted from the alcoholic tradition in 

 the first part of this chapter. Reversal of effect on the pulse-rate 

 would seem to be theoretically probable, if ether or chloroform had 

 been administered previous to alcohol or in febrile cases. 



The contention of Cushny 3 that the pulse-acceleration effected by 

 alcohol is due to increased muscular activity, and not to any direct 

 action on the regulating mechanisms, is not supported by our data. 

 One might have criticised any data that were obtained during mental 

 experiments alone, on the ground that while the subjects seemed to 

 be quieter after alcohol than on normal days, there might have been 

 increased muscular activity that we did not notice. The fact that 

 similar changes accompany definite physical tasks leaves such an objec- 

 tion improbable. We have no disproof, however, of the hypothesis that 

 without any mental or physical activity the pulse-rate might remain 

 unchanged. We would again insist that the changes in the pulse-rate 

 herein described belong to experimental conditions of moderate mental 

 or physical activity. They should not be uncritically transferred either 

 to intense activit}^ or to complete relaxation, for reasons that we have 

 already discussed. But whether the relative acceleration results or 

 not, the effect of alcohol on the cardie-inhibitory center ought to be 

 demonstrable wherever it occurs by a depression of the normal rhythms. 



In view of the large amount of our pulse data, and the thoroughness 

 with which it was read and elaborated, we believe that the accelerating 

 tendency of alcohol on the pulse-rate of normal human subjects, during 

 moderate mental and physical activity, may be regarded as certain. 

 We also believe that the evidence is sufficient to show that such relative 

 acceleration must be referred to a partial paralysis of the cardio- 

 inhibitor centers. 



But whether these generalizations be accepted or not, the experi- 

 mental fact remains that generally decreased irritability of a consider- 

 able number of related neuro-muscular processes consequent to the 

 ingestion of alcohol was regularly accompanied by a relative accelera- 

 tion of the pulse-rate. These two facts taken together we must regard 

 as a clear indication of decreased organic efficiency as a result of mod- 

 erate doses of alcohol. 



'Hascovec, Wiener med. Wchnsch., 1909, 59, p. 457. 

 2 Dixon, Joiirn. Physiol., 1907, 35, p. 346. 

 'Cushny, Pharmacology, Philadelphia, 1910. 



