24 Effect of Alcohol on Psycho-Physiological Functions. 



Then the measurements, to be described in more detail in succeeding 

 paragraphs, were made. The time required to complete the group of 

 observations was approximately 50 minutes. The dose for the day con- 

 tained alcohol or was simply a control mixture, as the case might be, 

 prepared as stated on page 19. The total volume of liquid contained 

 in either case was 150 c.c. It was given the subject at this point in the 

 experimental program for the day. He drank it rather rapidly while 

 he was reclining in the steamer chair. Following the taking of the dose 

 the measurements were repeated in identical order as many times as 

 the 5-hour limit would permit. It will be convenient to term each 

 repetition of the group of measurements a " period." Thus, the dose is 

 regularly given between periods 1 and 2, and from three to five periods 

 were completed following the dose. The measurements may be de- 

 scribed in order as follows : 



(1) Pulse. — An experimental period began with the subject seated 

 in a steamer chair. He was instructed to relax as much as possible. 

 After three or four minutes the first pulse record, designated as No. 1, 

 was taken. All of the pulse records, except the count made at the 

 beginning of the session, were electro-cardiograms from body leads. 

 Eleven of these records were taken in each experimental hour. In the 

 subsequent paragraphs their order and location will be indicated by 

 numbers. The photographic paper moved 1.5 cm. per second, and the 

 records are long enough to permit the counting of 15 seconds of pulse. 

 Respiration curves were incorporated directly with the photographic 

 pulse records, to show the time relations between pulse and breathing. 

 A large tambour, buttoned under the vest of the subject, was connected 

 to a small tambour carrying a registration point so located as to cast a 

 shadow on the cylindrical lens of the camera. Connections for the 

 pulse and respiration records could be established or broken very 

 quickly. The body electrodes and respiration tambour did not hamper 

 the breathing or other body movements and produced no discomfort 

 whatever. 



(2) Patellar reflex. — Two similar stimuli, separated by an interval 

 of 0.5 second, so that the latter came within the relatively refractory 

 period of the reflex, were delivered to the tendon of the left leg by pen- 

 dulum hammers. Ten records with 30-gram stimuli were followed by 

 10 records with 50-gram stimuli. Appropriate levers with a magnifi- 

 cation of 6 times wrote directly the reflex thickening of the quadriceps 

 muscle on a kymograph rotating at a rate of 100 mm. per second. 

 From this record both the latency and amplitude were measured. The 

 subject reclined in a steamer chair. He was instructed to relax and to 

 say "Ha" immediately following each stimulus blow, that the respira- 

 tion phase might be controlled . After the patellar-reflex measurements 

 the subject remained quiet and relaxed for pulse record No. 2. 



(3) Sensory threshold for faradic stimulation. 1 — The assistant placed a 

 suitable arm-rest, bearing the non-polarizable electrodes, in a conven- 



1 Martin, The measurement of induction shocks, New York, 1912. 



