128 



COMPARISONS OF RESPIRATORY EXCHANGE. 



with a tendency for the results with the tension-equalizer unit to be the 

 more nearly uniform. The differences in the uniformity of the pulse- 

 rate are somewhat marked; this again tends to confirm the belief that 

 the cause for the differences in the respiratory exchange is due to the 

 differences in muscular repose. It must be noted in this connection 

 that, at the time this comparison was made, the necessity for absolute 

 muscular repose and a uniform degree of wakefulness was not so well 

 known as it was in the comparison of the Zuntz-Geppert apparatus with 



10 I I 12 I 2 3 4 



PER CENT OF VARIATION 



10 II 12 13 14 15 l« 



Fig. 38. — Probability curves for the series of comparison experiments with the tension-equalizer 

 unit and the Zuntz-Geppert apparatus. 



The ordinates indicate the percentage of the total number of periods and the abscissae the 

 percentage of variation from the average. 



the spirometer unit, and that no graphic method of recording the degree 

 of muscular repose was used. 



The general conclusion from the results obtained in the comparison 

 of the tension-equalizer unit and the Zuntz-Geppert apparatus is that 

 the two forms of apparatus give practically the same results in the 

 measurement of the respiratory exchange. 



