150 MUSCULAR WORK 
it would be expected that the carbon dioxide in the alveolar air would also 
be relatively increased. Accordingly in a number of experiments with the 
subject M. A. M., samples of the alveolar air were taken at the beginning 
and end of some of the resting periods following the muscular work and 
analyzed by Mr. H. L. Higgins for carbon dioxide, the Haldane method 
being used." The results are summarized in table 131, together with the 
respiratory quotients which were obtained at approximately the same time. 
By reference to the table, it will be seen that the data are given for six 
periods following work, these being lettered A to F. The only period in which 
there is a marked difference shown between the alveolar carbon dioxide found 
at the beginning and that found at the end of the period is B, but this differ- 
ence is not seen in A or C for the same day, although the respiratory quotients 
for these two periods are much lower. The data for D and E, and especially 
F, also show clearly that the low respiratory quotient following work was not 
due to a storage of carbon dioxide in the body. Consequently one must look 
elsewhere for an explanation of these low quotients after work. 
COLLAPSE FROM EXCESS OF CARBON DIOXIDE IN THE VENTILATING CURRENT. 
During the first few experiments with this apparatus, two or three sub- 
jects shortly after the beginning of the severe riding utterly collapsed. At 
first we were at a loss to account for this, but it was soon found to be due to 
an excessive accumulation of carbon dioxide in the system, and the re- 
breathing by the subject of the carbon-dioxide rich air; measures were there- 
fore immediately taken to remedy this defect. 
One of the experiments in which this collapse occurred was that of No- 
vember 22, 1911, with the subject J. E. F. The first three rest periods were 
uneventful, the pulse-rate averaging 59 per minute. The subject then rode 
the bicycle ergometer for some 20 minutes before the pulse-rate became rea- 
sonably regular at 122 per minute. After the mouth was placed to the mouth- 
piece and the valve was turned, he collapsed within 2 minutes. His face 
became pallid, almost cyanotic; he broke out into a cold sweat, and the pulse- 
rate rose suddenly from 124 to 184 per minute. The subject was neither 
able to retain the mouthpiece in the mouth nor to keep his feet on the pedals, 
having completely lost muscular control. As quickly as possible he was re- 
moved from the ergometer, placed upon the couch and allowed to rest. 
Twenty minutes later, the pulse-rate had almost returned to the normal and 
he reported himself as being quite comfortable. Indeed, somewhat later he 
was ready for a work experiment which was carried out without inconvenience. 
Two days later, November 24, 1911, the same subject attempted another 
experiment. As in the first experiment, the three resting-periods were un- 
eventful. After 10 minutes of preliminary work upon the bicycle ergometer, 
with an average per minute of 59 revolutions, it was found that the pulse-rate 
was regular at about 124. The first work experiment was then begun and 
lasted approximately 10 minutes, the work being done at the rate of 57 revolu- 
tions per minute. The pulse-rate rose to 146 and the respiration-rate to 24, 
but no abnormalities were noted. Ten minutes after the conclusion of the first 
period, a second period was begun, but within 4 minutes the subject showed 
all the symptoms of collapse, including pallor, gasping, lack of muscular con- 
■ Haldane and Priestley, Journ. Physiol., 1905, 32, p. 225. 
