and Oxygen Gas ly Respiration. B&f 



more than appears by the average ; that is, more than Q/'5 

 per cent. 



It now appeared to us of consequence to ascertain exactly 

 what happened to a given volume of atmospheric air, when 

 it was inspired and expired as often as possible. 

 Fourteenth Experiment *. 



Three hundred cubic inches of atmospheric air were ad- 

 mitted into the mercurial gasometer G. 1. ; the other, G. 2, 

 was empty. The nose being properly secured, and the mouth 

 applied to the tube A, as usual, air was drawn from G. -2^ 

 and by half turning the cock, 2, was expired into G. 2. ThSs 

 was repeated until the contents of G. 1. had been made to 

 pass through the lungs, and transmitted to G. 2. The air 

 was then inspired from G. 2, and expired into G. I, .until 

 G. 2 was nearly empty. This was repeated about eight or 

 ten times during three minutes, until respiration became ex- 

 tremely laborious, and the operator desisted. 



The whole 300 cubic inches must have passed eis;ht or ten 

 times through the lungs; and we confidently expected, that 

 on examining the air we should have found an unusual pro- 

 portion of carbonic acid. 

 But 100 parts gave only Q'5 carbonic acid. 

 -5*5 oxygen. 

 85* azote. 



100 



Here was an increase of six parts in 100 of something which 

 the tests for oxygen would not take up, and also a loss of six 

 per cent, oxygen. This seemed to convince us, that under 

 certain circumstances, as during some peculiar alteration in 

 the vital functions, gaseous oxide of carbon, carburetted 

 hydrogen, or some other gas not absorbable by lime-water 

 or the tests for oxygen, might be given off from the lungs, 

 and we accordingly determined to repeat Cruikshank's ex- 

 periments with hyperoxygenized muriatic acid gas. 



* In this experiment there was obviously no occasion to make allowance for 

 the air contained in the tubes and sockets. We find its volume to be eighteen 

 ■cubic inches. 



We 



