Plants take in carbonic-acid gas through their leaves, and send the oxygen back into the air ready for us to use again.
This is carbonic-acid gas, which is a poison and will destroy life.
It is highly inflammable, burning with a pale-blue flame, and giving off sulphurous and carbonic-acid gases.
Here it combines with the carbonic-acid gas taken from the air.
There are two reasons then why we breathe: (a) to obtain oxygen; (b) to get rid of carbonic-acid gas.
Suitable drinks are—plain water, Seltzer and Apollinaris water, carbonic-acid water, lemonade.
The "Valley of Death," in the island of Java, is simply the crater of an extinct volcano, filled with carbonic-acid gas.
If the dough be baked during the alcoholic and carbonic-acid stage of fermentation, the gas will render the loaf light and porous.
What would have escaped up a chimney as carbonic-acid gas is confined here as a solid, and fire can yet liberate it.
Then, after due consideration, it was decided to make the test with carbonic-acid gas instead.