PULSE DURING MENTAL AND PHYSICAL WORK. 



207 



age decrease in the length of post-stimulation pulse-cycles. For illus- 

 tration, the post-stimulation pulse-acceleration of Subject II on the 

 first normal day is 0.043" for the first period (see table 36), 0.023" for 

 the second, 0.026" for the third, etc. The average of all periods of the 

 first and second normal day for Subject II is 0.023." (See table 37.) 

 From the averages of table 37 it appears that alcohol tends to de- 

 crease the post-stimulation acceleration, though not directly in propor- 

 tion to the dose. This disproportion depends on two cases, Subjects 

 VI and IX. Unfortunately, the lack of records for Subject VI after 

 dose A unbalances the data here and elsewhere in the association-pulse 

 records. Inspection of the individual records shows that the dispro- 

 portionate effect of the doses is not general. Doubtless in these, as in 



TABLE 37. Summary of the post-stimulation acceleration as shown by decreased 



length of post-stimulation pulse-cycles. 



[Values in hundredths of a second.] 



other measurements, the " differences" between the normal of the day 

 and subsequent periods is a better expression of the effect of alcohol 

 than the averages. Both expressions agree in their clear indication of 

 a falling-off in the post-stimulation pulse-acceleration after the ingestion 

 of alcohol. 



As a contribution to the general theory of association, as well as to 

 the knowledge of the effect of alcohol on the association process, it 

 seemed desirable, if possible, to use our extensive pulse data for a 

 comparison of the other characteristics of the association experiments 

 with the post-stimulation pulse-acceleration. Such a comparison de- 

 manded a measure of the experimental acceleration in each association 

 reaction. In view of the previous discussion of the intercurrent pulse- 

 rhythms, and the statistical treatment of our pulse data in the effort 

 to eliminate these rhythms from the average results, the sources of error 

 which are involved in the attempt to isolate the true experimental 

 changes in each experiment need no new emphasis. 



While the averages of 50 measurements at each homologous moment 

 in the experiment should give a fairly satisfactory indication of the 



