"Well, then, I am going to tell you."
[CHAPTER XXIV.]
THE AIR AND THE LUNGS.
"In order to live," continued Monsieur Roger, "you must breathe. You don't doubt that?"
"No," said Miss Miette, seriously.
"Now, respiration consists in the absorption by the blood of some of the oxygen of the air and in breathing out carbonic acid. The oxygen, in combining with the carbon and hydrogen of the blood, excites a real combustion in the lungs, which results in the production of heat and in the exhalation of vapor and carbonic acid."
Monsieur Roger was going to continue in the same scientific tone, when Monsieur Dalize remarked to him that his explanation did not seem to be at all understood by the children.
The latter, a little embarrassed, held their tongues.