VII. The Things wherein I observed a Piece of shining Wood and a burning Coal to agree or resemble each other are principally these five:
1. Both of them are Luminaries, that is, give Light, as having it (if I may so speak) residing in them; and not like Looking-glasses, or white Bodies, which are conspicuous only by the incident Beams of the Sun, or some other luminous Body, which they reflect....
2. Both shining Wood and a burning Coal need the Presence of the Air (and that too of such a Density to make them continue shining)....
3. Both shining Wood and a burning Coal, having been deprived, for a Time, of their Light, by the withdrawing of the contiguous Air, may presently recover it by letting in fresh Air upon them....
4. Both a quick Coal and shining Wood will be easily quenched by Water and many other Liquors....
5. As a quick Coal is not to be extinguished by the Coldness of the Air, when it is greater than ordinary; so neither is a Piece of shining Wood to be deprived of its Light by the same Quality of the Air....
Differences:
1. The first Difference I observed betwixt a live Coal and a shining Wood is, that whereas the Light of the former is readily extinguishable by Compression (as is obvious in the Practice of suddenly
extinguishing a piece of Coal by treading upon it), I could not find that such a Compression as I could conveniently give without losing sight of its operation, would put out, or much injure the Light, even of small Fragments of shining Wood....
2. The next Unlikeness to be taken notice of betwixt rotten Wood and a kindled Coal is, that the latter will, in a very few Minutes, be totally extinguished by the withdrawing of the Air; whereas a Piece of shining Wood, being eclipsed by the Absence of the Air, and kept so for a Time, will immediately recover its Light if the Air be let in upon it again within half an hour after it was first withdrawn....