TISSOT AND BENEDICT METHODS. 



159 



TABLE 23. Respiratory exchange in comparison experiments with the Tissot apparatus and the 

 Benedict respiration apparatus (spirometer unit). (Without food.) Continued. 



If the individual comparisons are considered, it will be seen from 

 table 24, in which the values for the spirometer unit are used as a base- 

 line, that the averages are not truly representative of the individual 

 experiments, since some of the values show large variations. With 

 K. H. A. the comparisons give, on the whole, fairly good results. 

 With P. F. J. the second experiment shows a higher metabolism with 

 the Tissot apparatus, but it will be noted that the periods with that 

 apparatus were in the early part of the morning, while the periods with 

 the spirometer unit were in the last part, so that the differences may 

 be partly accounted for by the difference in the time of day. With 

 J. B. T. the first experiment shows a marked difference in the carbon- 

 dioxide production; from a comparison of the figures obtained in this 

 experiment for the total ventilation of the lungs and the volume of 

 respiration, it is apparent that the subject over- ventilated the lungs in 

 the periods with the spirometer unit. An average value of 698 c.c. 

 per respiration is distinctly abnormal for most subjects. The other 

 two comparisons with the same subject gave on the whole very good 

 results. With J. W. P. the values for the Tissot apparatus are usually 

 higher than those for the spirometer unit; in one of the experiments 

 with this subject, the periods with the Tissot apparatus preceded those 

 with the spirometer unit. With J. K. M. the differences are not large 

 and on the whole the comparisons gave very fair results. In the second 



