230 Mr Blackadder on the Constitution of' Flame. 



vestigation. When a jet of it is projected above the apex, 

 or on the opaline brush of a blue spirit flame, streaks of reddish 

 brown light make their appearance, if projected through the 

 brush, so as to come into contact with the bright blue part of 

 the flame, light of a golden yellow is extricated ; but, when the 

 jet is forced into the interior, so as to strike on the inner surface 

 of the blue flame, the light that is given out is similar to the 

 yellowish- white light of a candle. There cannot be a doubt 

 that these appearances depend on the presence of minute parti- 

 cles of charcoal, which are brought to various degrees of igni- 

 tion in different parts of the flame ; but the relation which the 

 carbon has to the vapour has not been accurately determined. 

 Between the point of the tube, and the place where the yellow 

 light is extricated, there is sometimes observed an attenuated 

 blue flame, and some of the charcoal, is merely in a state of sus- 

 pension. When projected from a wide orifice at the base of a 

 blue spirit flame, almost the whole surface of the latter appears 

 as if spotted with minute spangles of a brilliant golden colour. 

 In this case, none of the vapour enters at the base of the flame, 

 so as to mix with the cone of alcoholic vapour in the interior ; 

 for, in that case, streaks of yellow light would appear at its apex, 

 similar to what was stated to take place with the flame of the 

 white vapour, after a puff' of air had been directed against the 

 circular wick. The vapour, however, may be made to enter at 

 the base of a spirit flame, by directing a jet from a small orifice 

 between it and the glass burner. The vapour then rises through 

 the centre of the cone, and streaks of yellow light appear at its 

 apex. To produce this effect, the jet must be small, and urged 

 with considerable force ; and we may therefore conclude, that, 

 on ordinary occasions, atmospheric air is not mixed with the va- 

 pour in the interior of a flame. This, however, may be other- 

 wise and more accurately determined. A flame is extinguished 

 in the interior of another flame. This may readily be deter- 

 mined by means of a glass burner : thus, pass the glass burner 

 of a lamp through a cork in the bottom of a glass or porcelain 

 vessel, the diameter of which may be one inch, or several inches, 

 but whose depth does not necessarily exceed the fourth of an 

 inch. Fill the vessel with alcohol, or strong ardent spirits, and 

 having lighted the lamp, raise the vessel on the glass burner to 

 about the fourth of an inch from its orifice, when the alcohol 



