Or Michael Faraday's masterpiece "the chemical history of a candle", which deep-dives not only into what every part of the fire is, but also how we know what it is.

https://www.gutenberg.org/cache/epub/14474/pg14474.txt

The whole book is a delight to read, but I really like this part:

> And now I want you to follow me in this explanation. You would hardly
think that all those substances which fly about London, in the form of
soots and blacks, are the very beauty and life of the flame, and which are
burned in it as those iron filings were burned here...

> I want you now to follow me in this point,--that whenever a substance
burns, as the iron filings burnt in the flame of gunpowder, without
assuming the vaporous state (whether it becomes liquid or remains solid),
it becomes exceedingly luminous. I have here taken three or four examples
apart from the candle, on purpose to illustrate this point to you; because
what I have to say is applicable to all substances, whether they burn or
whether they do not burn,--that they are exceedingly bright if they retain
their solid state, and that it is to this presence of solid particles in
the candle-flame that it owes its brilliancy.

>... This flame has carbon in it; but I will take
one that has no carbon in it. There is a material, a kind of fuel--a
vapour, or gas, whichever you like to call it--in that vessel, and it has
no solid particles in it; so I take that because it is an example of flame
itself burning without any solid matter whatever; and if I now put this
solid substance in it, you see what an intense heat it has, and how
brightly it causes the solid body to glow. This is the pipe through which
we convey this particular gas, which we call hydrogen, and which you shall
know all about next time we meet. And here is a substance called oxygen,
by means of which this hydrogen can burn; and although we produce, by
their mixture, far greater heat[8] than you can obtain from the candle,
yet there is very little light. If, however, I take a solid substance, and
put that into it, we produce an intense light If I take a piece of lime, a
substance which will not burn, and which will not vaporise by the heat
(and because it does not vaporise, remains solid, and remains heated), you
will soon observe what happens as to its glowing. I have here a most
intense heat, produced by the burning of hydrogen in contact with the
oxygen; but there is as yet very little light--not for want of heat, but
for want of particles which can retain their solid state; but when I hold
this piece of lime in the flame of the hydrogen as it burns in the oxygen,
see how it glows! This is the glorious lime-light, which rivals the
voltaic-light, and which is almost equal to sunlight. I have here a piece
of carbon or charcoal, which will burn and give us light exactly in the
same manner as if it were burnt as part of a candle. The heat that is in
the flame of a candle decomposes the vapour of the wax, and sets free the
carbon particles--they rise up heated and glowing as this now glows, and
then enter into the air. But the particles when burnt never pass off from
a candle in the form of carbon. They go off into the air as a perfectly
invisible substance, about which we shall know hereafter.

> Is it not beautiful to think that such a process is going on, and that
such a dirty thing as charcoal can become so incandescent? You see it
comes to this--that all bright flames contain these solid particles; all
things that burn and produce solid particles, either during the time they
are burning, as in the candle, or immediately after being burnt, as in the
case of the gunpowder and iron-filings,--all these things give us this
glorious and beautiful light.

>... That, however, is not
the only thing I wish to mention. If I take a flame sufficiently large, it
does not keep that homogeneous, that uniform condition of shape, but it
breaks out with a power of life which is quite wonderful. I am about to
use another kind of fuel, but one which is truly and fairly a
representative of the wax or tallow of a candle. I have here a large ball
of cotton, which will serve as a wick. And, now that I have immersed it in
spirit and applied a light to it, in what way does it differ from an
ordinary candle? Why, it differs very much in one respect, that we have a
vivacity and power about it, a beauty and a life entirely different from
the light presented by a candle. You see those fine tongues of flame
rising up. You have the same general disposition of the mass of the flame
from below upwards; but, in addition to that, you have this remarkable
breaking out into tongues which you do not perceive in the case of a
candle. Now, why is this? I must explain it to you...