Suspend a bullet of antimony in a jar of chlorine gas, in which, after
the lapse of many minutes, it will acquire a red heat, and slowly burn
away. Then pour finely-divided metallic antimony into a tall jar
containing chlorine; the metal instantly ignites, and falls to the
bottom as a fiery shower; yet the nature of the chemical action in both
these experiments is the same. Make a piece of thick iron wire white
hot, and insert it in a large tube containing vapour of sulphur, made by
boiling some brimstone in the bottom of the tube; the white-hot iron
will catch fire, and burn away like wax, and with intense brilliancy, in
the sulphur vapour. The iron must first be raised to an intensely white
heat, or it will not burn under these conditions.