Q. Why will not iron cinders burn?
A. Iron cinders are cinders saturated with oxygen; they are unfit for fuel, because they can imbibe no more oxygen, being saturated already.
Q. Why are cinders lighter than coals?
A. Because their vapour, gases, and volatile parts, have been driven off by previous combustion.
Q. Why will not stones do for fuel, as well as coals?
A. Because they contain no hydrogen (or inflammable gas) like coals.
Q. Why will not wet kindling light a fire?
A. 1st—Because the moisture of the wet kindling prevents the oxygen of the air from getting to the fuel to form it into carbonic acid gas: and
2ndly—The heat of the fire is perpetually drawn off, by the conversion of water into steam.