126 



CIRCULATING FLUIDS: 



The quantity of carbonic acid formed in the process of re- 

 spiration in twenty- four hours in adults^ and the amount of 

 carbon contained therein, have been calculated as follows : 



Lavoisier and Seguin 



Menzies 



Davy . 



Allen and Pepys . 



Expired Carbonic Acid 



Cubic in. 

 14930 



31680 

 39600 



Grains. 

 8584 



17811 

 18612 



Carbon. 



Grains. 

 2820 



4853 

 5148 



Consumed Oxygen. 



Cubic in. 

 46037 

 51480 

 45504 

 39600 



Grains. 



15661 French. 

 17625 EngUsh. 

 15751 „ 

 13464 „ 



The large amount of carbon, from 11 to 13 ounces, (Davy, 

 Allen, and Pepys,) that is thus carried off by the lungs in the 

 twenty-four hours, does not accord with the other phenomena 

 of nutrition ; and Berzelius has calculated that it woidd require 

 6i pounds of solid food daily to make up for the carbon that is 

 separated by the lungs alone, without taking into consider- 

 ation the very considerable amount that is also removed by 

 the urinary secretion. And further : when we consider that in 

 most sorts of food the portion which is converted into chyle is 

 much less than that Avliich is carried off by the intestinal 

 canal in the form of faeces, it becomes the more wonderful how 

 so many persons can exist on a few pounds of daily food, the 

 solid constituents of which must be very small, and of which 

 only a still smaller part admits of assimilation ; and we cannot 

 help agreeing with Berzelius, that so large an excretion of 

 carbon is inconceivable, and that in all probability there is 

 some fallacy in the experiments. 



Prout has made some interesting observations respecting 

 the development of carbonic acid from the lungs at different 



