On the Production of Light by Chemical Action. 169 
the flame, corresponding to the two great groups of fixed lines. 
Perhaps through all these inactive parts, the incombustible nitro- 
gen chiefly escapes. 
VI. Effects of the introduction of air into the interior of a 
flame, producing the destruction of the red and orange strata, 
and converting them into violet. 
It now becomes a curious subject of enquiry to determine what 
must take place when an ordinary flame is disturbed by the intro- 
duction of air into its interior. When a blowpipe jet is thrown 
through the flame of an oil lamp, the sharp blue cone which 
forms, indicates, on the principles here set forth, that the combus- 
tion is much more active. But if the colors of a common flame 
come from different depths, the red being the innermost, it is clear 
that the introduction of a jet of air by a blowpipe should make 
the combustion rapid where before it was slowest, and the less re- 
frangible colors ought to be destroyed. A prismatic analysis 
should exhibit the spectrum of a blowpipe flame without any red 
or orange. : 
In this examination no slit is required, as in the former experi- 
ments, for the cone itself when at a distance of six or eight feet, 
is narrow enough for the purpose. It yields a very extraordinary 
Spectrum. As was anticipated, I found that all the red rays were 
gone, and not a vestige of either them or the orange could be 
seen. But the spectrum was divided into five well marked re- 
gions, separated from one another by inactive spaces. In short I 
ve distinct images of the blue cone; one yellow, two green, 
one blue, and one violet. In fig. 1, No. 10, this result is repre- 
ted. 
This experiment may, be verified without a telescope. On 
looking through a prism set horizontally, at its angle of minimum 
deviation, at the blowpipe cone some six or eight feet distant, 
there will be scen a spectrum of that part of the flame whic 
Ses not join in the production of the Fig. 2. 
blue cone. It contains of course re 
green, one blue and one violet. They 
are entirely distinct from one another, 
and parted by dark spaces as seen Air in the interior of a flame. 
in fig. 2. 
Such is the effect of introducing air into the interior of a flame, 
destroying those strata that yield the red and orange colors. 
The effect of a blowpipe is to produce a double stratum of blue 
light, one being external and the other internal; also two strata 
of green, one azain external and the other internal ; and the es- 
caping products of combustion, steam and carbonic acid, mingled 
e 
