184 METABOLISM DURING WALKING. 



EFFECT WITH SUBJECT STANDING. 



In table 50 the data for the respiration and ventilation rates ob- 

 tained with the subject standing are given for E. D. B. for March 2 

 and 3, 1916. In the first test in each comparison the subject had been 

 standing with the mouthpiece inserted for at least 15 minutes previous 

 to the beginning of the measurements. In this test the values were 

 measured in minute intervals. In the second test of each comparison 

 the mouthpiece was inserted but a few seconds before the measurements 

 began. The measurements were made in quarter minutes and the per 

 minute rate calculated from the results. These quarter-minute rates 

 are also averaged for comparison with the measurement for the cor- 

 responding full minute in the preceding test, when the mouthpiece was 

 inserted 15 minutes. 



Three comparisons were obtained with the subject standing on both 

 March 2 and 3, with intervals of rest of 30 minutes or more between 

 the first and second and the second and third comparisons. The 

 respiration-rate in the periods when the mouthpiece had been used for 

 approximately 15 minutes does not, on the whole, appear to be different 

 from the rate when the mouthpiece was inserted immediately before 

 the experiment. There seems to be a slight tendency for the respira- 

 tion-rate to increase with the time, but this is as apparent with the long 

 preliminary breathing as with the short. 



In most cases, when the pulmonary ventilation was calculated on the 

 quarter-minute basis, a slightly larger ventilation was found for the 

 first quarter-minute during the periods when the mouthpiece had been 

 but briefly inserted. There are, however, several exceptions to this. 

 No greater variation was found under one condition than under the 

 other, if we take the per minute averages for comparison. With the 

 exception of a slight disturbance for the first one-quarter minute, it 

 appears that the ventilation was as constant under one condition as 

 under the other, and that both the respiration and ventilation with the 

 subject standing were unaffected by the presence of the mouthpiece 

 during a short or a long preliminary breathing. 



The oxygen consumption per minute for the first 7 or 8 minutes of 

 each period was computed as outlined on page 182. Considerable varia- 

 tions actually occur in single minutes, the range being, with the subject 

 standing, from 186 to 418 c. c. per minute. Little, if any, regularity 

 can be observed on any day, although it is worthy of note that both 

 the extreme values occurred in the first minute. The inherent errors 

 in the method of measurement outlined above make its use questionable 

 when such small per minute amounts of oxygen were obtained, and 

 hence we do not tabulate them. 



EFFECT DURING GRADE WALKING. 



On March 4, 6, 7, and 8, the usual grade-walking experiments were 

 varied to the extent that in each alternate period the subject breathed 



