612 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



Tablb 177. — Squad A — Electrical threshold and its variability. 

 [M. and S. D. in volts; C. in per cent.] 



The average individual threshold determinations for the members of 

 Squad B demonstrate no peculiarity which differentiates them from 

 the values which have been discussed for A. The group average for 

 the 5 normal experiments is 115 volts as compared to the value of 126 

 volts for the first session. This indicates some improvement. The 

 average for the 3 low-diet experiments is 123 volts, which is fairly close 

 to the average for the first experiment. 



In connection with these threshold averages, and more particularly 

 with the variability values, a matter of experimental procedure de- 

 serves consideration. In the electrical-threshold determination it 

 was desirable to secure an average, if possible, that had statistical 

 significance. With this apparatus, stimuH could be presented about 

 every 2.5 seconds. If one began at a value which was easily felt and 

 proceeded with the series by decreasing the voltage carefully in small 

 steps to that which was the threshold value, it required about 1 minute 



