476 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



in the last column which were obtained with the subject standing after 

 walking ceased. The actual number of respiratory cycles counted 

 were usually not far from 6 to 9, but occasionally there were no more 

 than 4 and rarely but 2. Special attention will be called to those 

 values lower than 4 in discussing the table, particularly if the count 

 seems in any sense abnormal, for it is obvious that these few respira- 

 tory cycles should not be accorded the significance of the longer 

 counts. 



The most important point in studying the respiration rate under 

 these conditions is the transition from the standing position to walk- 

 ing. With practically all of these subjects we have the standing 

 respiration rate which was determined in connection with the experi- 

 ments on the portable respiration apparatus. It seemed best, however, 

 to attempt to obtain the standing respiration rate immediately prior 

 to the beginning of the walking on the treadmill and under the same 

 conditions. Unfortunately, owing to difficulty of instrumental ad- 

 justment, but few of these values could be obtained (see first column 

 of table). While from the standpoint of a study of the respiration 

 rate this is of course a serious omission, the exigencies of experimenta- 

 tion demanded that the walking begin immediately. On the other 

 hand, when legible records were obtained, the rates after 1, 6, 12, 24, 

 and 26 minutes show clearly the influence of the continued walking 

 upon the respiratory rhythm. 



The respiration in this chamber was not under strictly normal con- 

 ditions, for after the first minute the percentage of carbon dioxide in 

 the air inside the chamber was perceptibly higher than that of the 

 room air. In the first 2| minutes that the subject walked on the 

 treadmill the cover of the respiration chamber was not closed down 

 (see p. 132)^; hence the respiration rate recorded for the first minute 

 was obtained under normal conditions. The subsequent records, and 

 particularly those for the twenty-fourth minute, were obtained with 

 the subject breathing air in which the percentage of carbon dioxide 

 was gradually increasing; rarely, however, did it exceed 0.9 per cent; 

 the average proportion was not far from 0.6 to 0.7 per cent. The 

 relatively few records obtained after 26 minutes of walking were 

 secured when the subject was still walking upon the treadmill, but 

 the cover of the respiration apparatus had been raised and he was 

 breathing essentially normal, outdoor air. 



With these preliminary statements regarding the actual conditions 

 obtaining during the experiment, the data in the table may be analyzed. 



The observations were first made for Squad B on January 6, 1918. 

 Such records as were obtained were for the most part unsatisfactory. 

 In the three cases in which standing records were obtained, the effect 

 of walking was, in the case of How and Sc h, to raise the rate from 



lOn January 6 the cover was lowered directly after the subject entered the chamber. 



