Conversations on Chemistry, V. 1-2 / In Which the Elements of that Science Are Familiarly Explained and Illustrated by Experiments

by Mrs. Marcet

But if nitrogen gas is unfit for respiration, how does it happen that the large proportion of it which enters into the composition of the atmosphere is not a great impediment to breathing?

MRS. B.

We should breathe more freely than our lungs could bear, if we respired oxygen gas alone. The nitrogen is no impediment to respiration, and probably, on the contrary, answers some useful purpose, though we do not know in what manner it acts in that process.

EMILY.

And by what means can the two gasses, which compose the atmospheric air, be separated?

MRS. B.

There are many ways of analysing the atmosphere: the two gasses may be separated first by combustion.

EMILY.

You surprise me! how is it possible that combustion should separate them?

MRS. B.