Measurements Employed. 27 



which the heart recovered approximately its normal relaxation rate. 

 Two similar tracings, designated as pulse records Nos. 10 and 11, were 

 taken as outlined. The time interval between the tetanus signal for 

 No. 10 and that for No. 11 was 1 minute. The actual taking of these 

 two records after the subject was in position and had relaxed required 

 approximately 2 minutes. 



In the Dodge and Benedict observations, 1 the pulse records taken 

 with the purpose of showing the change in heart rate with muscular 

 activity were with the subject sitting in position, immediately after 

 standing, 60 seconds after standing, immediately after two double 

 genuflections, and 60 seconds thereafter. In our series this group of 

 five records was, at the suggestion of Professor Dodge, shortened to the 

 three-part continuous record described. 



(7) Memory. — A series of twelve 4-letter words, carefully printed on 

 a strip of white paper, was made to encircle the kymograph drum. 2 A 

 circular screen hid the words from view, except as they could be seen 

 through a window 15 mm. wide, which permitted a view corresponding 

 to the width of two of the letters used in the words. When the word 

 series had been placed upon the kymograph and properly covered, the 

 subject was disconnected from the string galvanometer and the respira- 

 tion recorder, and changed chairs to the position previously occupied 

 during the reactions to isolated words (measurement No. 3). The 

 drum rotated at a rate of 10 mm. per second in a clock-wise direction, 

 i. e., from left to right of the subject. Hence the latt letter of a word 

 appeared first in the window, which limited the subject's view, and not 

 until the first letter of the word had appeared could the subject pro- 

 nounce it correctly in the voice key, which recorded the reaction. The 

 instructions were as follows: 



"There are twelve words; each is composed of four letters; watch carefully 

 and at the first exposure speak each word as soon as you are sure of its identity, 

 also try to remember each word in its order that at the second revolution of the 

 drum you may speak each particular word immediately before any part of it 

 has appeared in the window. If you can not recall a word to speak it before 

 it has partly appeared, let as little as possible of it appear before you do speak 

 it. If you speak the wrong word correct yourself immediately by speaking 

 the right one." 



The distance on the kymograph record between the first and second 

 reactions to a particular word was taken as the measurement of the 

 residual memory for that word. For the twelve such values an average 

 was found. Dodge and Benedict 3 had used different sets of word series 

 for the different experimental days, but came to the conclusion "that 

 for purposes of determining the effect of a drug we would have done 

 better to use only one group for all days alike." This method was 

 employed here. The same series of twelve words was used for period 1 



1 Dodge and Benedict's report, p. 223. 2 Ibid., p. 129, and fig. 26. 3 Ibid., p. 130. 



