Pulse-Bate. 129 



PULSE-RATE IN EXPERIMENTS. 



A long series of experiments made with the respiration chamber at Wesleyan 

 University has furnished data regarding the pulse-rate which have been so 

 obtained that they throw definite light upon the normal pulse-rate of indi- 

 viduals. The experiments here discussed are only the so-called rest experiments, 

 t. e., experiments in which no external muscular work was performed, and 

 were both with and without food. The narrow confines of the chamber, and 

 the regularity of the routine from day to day, insure a very even muscular 

 activity. This may be considerable so far as minor muscular movements are 

 concerned, and may vary with different subjects, but under no circumstances 

 was there direct muscular effort exercised other than that required to dress 

 and undress and arrange the bed and bedding night and morning. 



In a number of instances where the subjects were to be used for only one 

 experiment and it seemed undesirable to complicate the details of the experi- 

 ment by the addition of the pneumograph, we have relied upon the observations 

 made by the subject himself. 



IX EXPERIMENTS WITHOUT FOOD. 



In a previous publication 1 the influence of inanition on the pulse-rate was 

 discussed in some detail. In addition to the results considered in that discus- 

 sion, there were other pulse data obtained in earlier published experiments or 

 accumulated in later unpublished experiments. These data have been sum- 

 marized and are combined with those previously discussed in table 50. The 

 table shows the minimum and maximum pulse-rate, the average daily range, 

 and the average daily pulse-rate for each experiment and for each individual. 

 To give some idea of the value of the different experiments, the number of 

 observations is likewise recorded in the table. The individual averages have 

 been obtained in every instance by giving due value to the average in each 

 experiment, in that the average pulse-rate for each experiment has been multi- 

 plied by the number of days, before being included in the grand average. All 

 measurements subsequent to June 2-1, 1905, were secured from the pneumograph. 



Table 50 is of particular value for indicating the average daily rate and 

 the fluctuations in the pulse-rate of the same individual under like conditions 

 of muscular activity. With the same individual, J. C. W., for example, we 

 find in 4 experiments a daily average ranging from 48 to 69, while the grand 

 average of all experiments without food with this subject shows that his normal 

 pulse is 60 per minute. All the observations were made by the subject himself. 



Even in experiments where the pneumograph was used such variations occur 

 in the daily average, for with H. C. K. on November 24-26, 142 observations 

 give the average pulse as 65, while 5 months later 35 observations in an 8-hour 

 experiment show the average as 50. This is all the more surprising when it 



1 Benedict, loc. cit., p. 31S. 



