He finds that the so-called _flame-bud_, a globular blue flaminule,
is first produced at the summit of the wick: this is the result
of the combustion of carbonic oxide, hydrogen, and carbon, and is
surrounded by a reddish-violet halo, the _veil_. The increased
heat now gives rise to the actual flame, which shoots forth from
the expanding bud, and is then surrounded at its inferior portion
only by the latter. The interior consists of a dark gaseous cone,
containing the immediate products of the decomposition of the fatty
acids, and surrounded by another dark hollow cone, the _inner
cap_. Here we already meet with carbon and hydrogen, which have
resulted from the process of decomposition; and we distinguish
this cone from the inner one by its yielding soot. The _external
cap_ constitutes the most luminous portion of the flame, in which
the hydrogen is consumed and the carbon rendered incandescent. The
surrounding portion is but slightly luminous, deposits no soot,
and in it the carbon and hydrogen are consumed.--_Liebig’s Annual
Report._