Ill 



fast : and at the end of the experiment, the suffo- 

 cating uneasiness was so great as to oblige him to 

 take away the bladder from his mouth. Towards 

 the end of the minute, the bladder was become so 

 flaccid that he could not blow it above half full, 

 with the greatest expiration that he could make *. 

 When also Mr Davy respired atmospheric air in a 

 natural manner, he took in, he says, only 13 cubic 

 inches and expelled 12.7, so that only about ^ 

 part of the original bulk was retained : when he 

 made one respiration of 10O cubic inches of air, the 

 diminution was to 99, or |~ : when, after a com- 

 plete exhaustion of his lungs, he respired 141 cubic 

 inches of air, once only for one-fourth of a minute, 

 they were reduced to 1 39, or ~ nearly : and when 

 161 cubic inches were breathed for about a minute, 

 their bulk was diminished to 152, or ~t ; in every 

 case, the diminution augmenting with the repetition 

 of the respiration, and consequent impurity of the 

 air, and distress of the respiratory organs. So like- 

 wise, when Dr Henderson breathed from and into 

 the gasometer GOO cubic inches of air for four mi- 

 nutes, they were reduced to 570, or lost ^ of their 

 bulk ; and he adds, that he held on respiring until 

 the sense of oppression about the chest obliged him 

 to desist |. These distressing symptoms, brought 

 on by the repeated breathing of the same quantity 



* Statical Essays, vol. i. p. 288. 

 f Researches, p. 431, 4-32, 433. 435, 

 Nicholson's Journal, May 1 804-. 



