PULSE DURING MENTAL AND PHYSICAL WORK. 231 



less than on normal days, just as it was in the association experiments. 

 In the wide variety of mental and muscular activities which are repre- 

 sented by these measurements, making very different demands on the 

 heart, the effect of alcohol is always in the same direction. Individual 

 exceptions to the rule are more numerous than in the association 

 experiments, but they are negligible in view of the uniform tendency 

 in the averages. 



The greatest average relative acceleration effect of alcohol appears 

 in the rest-pulse, where it is 5.3 per cent of the average length of the 

 pulse-cycles. 1 After standing quietly for 60" subsequent to the double 

 genuflection experiment, the average accelerating effect of alcohol is 

 least, being 0.8 per cent. Between these two extremes the order of 

 effect is 4.1 per cent for the double genuflections; 3.2 per cent for the 

 finger-movements; 3.1 per cent for the standing rest subsequent to the 

 rising; 2.4 per cent for the word-reactions; and 2.2 per cent for the 

 rising. The average effect of alcohol in all these experiments is 3 per 

 cent of the normal pulse-cycles. 



An indication of the relative demands of the various experimental 

 processes on the pulse is shown in the summary of the normals of the 

 day for each of the experiments. (See table 43.) 



From a comparison of the averages of table 43, it appears that the 

 word-reactions accelerate the pulse 1.1 per cent; finger-movements 9.3 

 per cent; rising 21.6 per cent; two double genuflections, 18.5 per cent; 

 while 60" after rising and the genuflections the acceleration is slightly 

 less than 1 1 per cent in both cases. The word-reaction acceleration is 

 conspicuously less than that of muscular work; it appears to be less 

 also than the acceleration of the association measurements. These 

 latter values are, however, not strictly comparable, since the word- 

 reaction pulse was not correlated with the process of reacting, as was 

 the association acceleration. We were content in the former case with 

 the average pulse of the experimental process. 



The amount of experimental acceleration bears no fixed relation to 

 the percentile effect of alcohol in the several instances. The dispro- 

 portion is greatest and probably also the most significant in the pulse- 

 accleration 60" after the more violent muscular activities of rising and 

 the double genuflections. We would not imply that our data in this 

 respect are numerous enough or sufficiently followed up by related 

 experiments to be conclusive, but taken together with other data the}' 

 form part of the cumulative evidence that the effect of alcohol on the 

 pulse-changes incident to physical as well as to mental work manifests 

 itself in a slowness or sluggishness of response. In the association 



l The percentile average relative acceleration of the pulse effected by alcohol is calculated from 

 the data of tables 42 and 43. For example: the normal rest retardation of the pulse during the 

 three hours experiment averages 0.062" (table 42) ; the alcohol retardation under similar circum- 

 stances averages 0.0175", giving a relative acceleration of 0.0445", or 5.3 per cent of the average 

 normal of the day pulse during rest as given in table 43. 



