EXPERIMENTS WITH HORIZONTAL WALKING. 169 



two periods no record was available. On March 17 the standing rate 

 of 74.8 to 77.6 was followed by a rate of 72.8 after 17 minutes of walk- 

 ing, which rose in 10 minutes to 76.5. A more pronounced change is 

 seen in the records for March 18, in which case the pulse-rate after the 

 subject had walked 7 minutes was 73.6 as compared with a standing 

 rate of 85.6 at the end of the standing period. 



With E. D. B. similar cases were found. The records for February 

 1 have been included in the table to show that while the standing 

 pulse was abnormally high, the pulse in the preliminary period of 

 walking was also high, although no higher than that for standing. 

 The rates of March 29 and 30 show that though the first walking rate 

 was higher than the first standing rate, it was nevertheless lower than 

 the final standing rate, even though the subject had walked 30 and 

 46 minutes at a speed of 58 and 69 meters per minute, respectively, 

 between the two sets of pulse-records. 



It is thus evident that these records confirm the earlier observations 

 of Benedict and Murschhauser. This fall is so pronounced as to justify 

 the statement that a change from standing to walking at moderate 

 speeds, i. e., 35 to 75 meters per minute, is in many instances accom- 

 panied by a decrease in pulse-rate, although the metabolism may si- 

 multaneously be doubled or more. In many of the records in table 46, 

 a pulse-rate after a considerable period of forced quiescence is compared 

 with that found early in a period of walking. It may be suggested 

 that the change in walking was possibly agreeable to the subject 

 and thus in part account for the apparent anomaly. This does not, 

 however, explain such definite records as, for instance, those for E. D. B. 

 on March 31, when all of the walking-rates were clearly lower than 

 the standing rates. The fact that these lower rates were found after 

 the subject had been walking in some cases from 15 to 20 minutes 

 precludes the suggestion put forth by Benedict, Miles, Roth, and Smith 1 

 that possibly the low pulse-rates found by Benedict and Murschhauser 

 had been counted during a moment of pulse-reaction from the first 

 stimulus of walking. The fact that the pulse-rates for walking on a 

 level at a moderate speed can be maintained at a lower rate than when 

 the subject is standing is of prime physiological interest and warrants 

 further study. 



RELATIONSHIP OP OXYGEN CONSUMPTION, PULSE-RATE, AND PULMONARY VENTILATION 



DURING HORIZONTAL WALKING. 



The relationship between the oxygen consumption and the heat-out- 

 put of the body is so close that the oxygen consumption may, to a 

 certain extent, be taken as a measure of the heat-output. It has also 

 been shown by Boothby 2 that the oxygen consumption and the ven- 



^enedict, Miles, Roth, and Smith, Carnegie Inst. Wash. Pub. No. 280, 1919, p. 451. 

 2 Boothby, Am. Journ. Physiol., 1915, 37, p. 383. 



