EXPERIMENTS WITH SUBJECT STANDING. 



105 



March 13), with no tendency for the ventilation to change in any one 

 direction as the season advanced in the period from February 26 to 

 June 1. During this time the man was walking almost daily on the 

 treadmill at considerable grades and speeds. On many days the ven- 

 tilation in the first period of the day was greater than that in succeed- 

 ing periods, but there are a sufficient number of exceptions to prevent 

 the making of any categorical statement. 



E. D. B. has the largest number of periods and days from which 

 comparisons may be made. The pulmonary ventilation varied with 

 this subject from 6.1 liters per minute in the first periods of November 

 18 and 19 to 10.3 liters per minute in the third period of December 31, 

 while the daily average varied from 6.2 liters per minute on November 

 18 to 10.1 liters per minute on February 15. The figure for February 

 15 was, however, the record of but one period. The low averages of 6.2 

 liters for November 18 and of 6.3 liters on the day following are 

 exceptional, as aside from these two days the lowest daily average is 8.0 

 liters on December 22. The figures for the lung ventilation on Novem- 

 ber 18 and 19 are, however, believed to be correct, as the tracings on 

 the kymograph have beeii measured and agree with the record of the 

 ventilation adder. They are accordingly included in the general aver- 

 age for the lung ventilation of E. D. B., which is 9.1 liters per minute. 



The data for the ventilation of the lungs do not indicate that it was 

 larger at any particular period of the day than at another. Though 

 there are variations, they are no greater than might be expected and 

 appear to be as much in one direction as in the other. On the whole, 

 the ventilation seems to be fairly uniform for each day's series. If the 

 daily average ventilation is compared by periods of 10 days or 2 weeks 

 we have the following results for liters per minute: 



The two exceptionally low values obtained on November 18 and 19, 

 1915, were omitted from these averages. It would appear from this 

 grouping of the values that after the first 10 days the lung ventilation 

 of the subject while standing did not materially alter as a result of his 

 daily exercise in walking. 



The lung ventilation of J. H. G. showed an increase for each suc- 

 ceeding period on the three days that he was a subject, with a variation 

 in the daily average from 10.1 to 11.3 liters per minute and an average 

 for the three days of 10.6 liters per minute. With E. L. F. the venti- 

 lation increased considerably on January 24 over that of the preceding 

 days, the pulse-rate also showing an increase on that day; but this high 



