INFLUENCE OF THE FREQUENCY OF THE RESPIRATIONS. 337 



maxima and minima, for the respiratory function for one minute 

 during a state of perfect bodily repose. 



After having obtained these fundamental values, Vierordt tried 

 the experiment of breathing with double the rapidity without 

 diminishing the normal depth of the inspiration, and he then 

 obtained the result that the relative quantity of carbonic acid was 

 on an average about 0*907^ less than in normal undisturbed respi- 

 ration ; when the number of inspirations were increased three 

 times their former amount this diminution was about 1'125-g- ; when 

 the number was increased fourfold it was l'292{f; and finally, when 

 they were increased eightfold it was about 1'600. When the 

 number of the inspirations was diminished by one-half, (when only 

 6 instead of 12 inspirations were made in a minute, which occa- 

 sioned considerable difficulty of breathing, and hence could not 

 yield a perfectly pure result,) the difference in the quantity of car- 

 bonic acid in the expired air was found to be 1'316^. This rela- 

 tion will be rendered more clear by the following comprehensive 

 arrangement of mean values found by Vierordt, in which the mean 

 quantities of the carbonic acid obtained during respirations of dif- 

 ferent rapidity, are calculated for one and the same normal quan- 

 titv of carbonic acid. 



Acts of respiration in one minute. 



6 

 12 

 24 

 48 

 96 



Carbonic acid in 100 vols. of expired air. 

 5-628 

 4-262 

 3-355 

 2-984 

 2-662 



Vierordt was able, after a few corrections made in the numbers 

 thus obtained, to show that the numbers of the respirations are 

 VOL. III. Z 



