26 Effect of Alcohol on Psycho-Physiological Functions. 



with the voice key in hand. 1 Pulse record No. 4 was then made. An 

 offset from the shaft of the kymograph momentarily opened a circuit 

 and exposed a stimulus word which remained in view. The instruc- 

 tions were to keep the voice key pressed lightly against the lips, and to 

 pronounce the words as quickly as possible after their appearance. 

 One word appeared every 10 seconds. Both exposure and reaction 

 were registered by the same signal magnet, the rate of the kymograph 

 being 100 mm. per second. The kymograph drum was visible to the 

 subject. A signal was given him before the exposure of each word, and 

 care was exercised to make sure that the correct word was pronounced. 

 The set of 24 four-letter words previously used was employed in this 

 series. The 24 small cards bearing the words were well shuffled before 

 each set of reaction measurements, in order that the subject might have 

 no tendency to anticipate the sequence of their exposure. As con- 

 nections were already made with the string galvanometer and the respi- 

 ration recorder, pulse records Nos. 5 and 6 were taken by the assistant 

 during the latter third of the reaction measurements, and occasioned 

 no interruption. After 30 seconds of quiet, following the reactions, 

 pulse record No. 7 was made, the subject sitting upright and still 

 holding the voice key. 



(5) Finger movements. — The movements were not interrupted by 

 mechanical limitation of their amplitude. The subject sat in a steamer 

 chair, leaning forward. The right arm and hand were supported by a 

 rest and in a comfortable position, suitable for the free oscillation of the 

 middle finger in a horizontal plane. A light system of levers (total 

 mass, 7 grams) attached to the finger operated in front of the cylin- 

 drical lens of the pulse-recording camera, and made possible the photo- 

 graphic registration of the oscillations reduced to one-fifth their actual 

 amplitude at the same time that pulse and respiration curves were 

 recorded. The uniform instruction was to make the movements as 

 rapidly as possible ; they were continued for about 9 seconds, a period too 

 short for development of conscious fatigue. Two records were taken, 

 with an intervening rest of 1 minute. Thus pulse records Nos. 8 and 

 9 are incorporated directly with the finger-movement records. 



(6) Voluntary tetanus pulse. — During the finger movements the sub- 

 ject sat upright in the steamer chair, leaning slightly forward. After 

 this measurement was concluded he was instructed to recline and relax 

 until a given signal, when he was expected to tetanize voluntarily the 

 muscles of arms, legs, and trunk (he sat up, both fists were clenched, and 

 arms and legs were extended directly in front) , and to retain this posi- 

 tion until the second signal, a period of 5 seconds. A continuous pulse 

 tracing was taken covering the latter part of the preliminary period of 

 relaxation, the tetanus, and the 20 seconds following, a period during 



1 For a diagram indicating the positions occupied by the subject and the general distribution 

 of the apparatus, see Dodge and Benedict's report, p. 95. The construction and sensitivity of the 

 voice-reaction key can be judged from their figures 16 and 17 to 20. 



