134

OXYGEN AND NITROGEN.

of cohesion between its particles will not be suf-ficiently overcome—

CAROLINE.

It has actually taken fire, and yet I did not letit touch the coals ; but I held it so very close,that I suppose it caught fire merely from the in-tensity of the heat.

MRS. B.

Or you might say, in other words, that theheat so far overcame the attraction of cohesion ofthe wood, that it was enabled to absorb oxygenvery rapidly from the atmosphere.

EMILY.

Does the wood absorb oxygen while it is burn-ing ?

MRS. B.

Yes; and the heat and light are produced bythe caloric of the oxygen gas, which being set atliberty by the oxygen uniting with the wood, ap-pears in its sensible form.

CAROLINE.

You'astonish me! Is it possible that the heatof a burning body should be produced by the at-mosphere, and not by the body itself?

MRS. B.

It is not precisely ascertained whether any por-