Some new Researches on Flame. 17 
that solid matters are made to attain the temperature ofthe 
flame. This temperature, however, evidently presents the limit 
to experiments of this kind; for bodies exposed to flame can never 
be hotter than flame itself; whereas in the Voltaic apparatus 
there seems to be no limit to the heat, except the volatilization 
of the conductors. 
The temperatures of flames are probably very different. Where, 
in chemical changes, there is no change of volume, as in the 
instance of the mutual action of chlorine and hydrogen, prussi¢ 
gas (cyanogen) and oxygen, approximations to their tempera- 
tures may be gained from the expansion in explosion. 
I have made some experiments of this kind by detonating the 
gases by the electrical spark in a curved tube containing mercury 
or water; and I judged of the expansion from the quantity of 
fluid thrown out of the tube: the resistance opposed by mercury, 
and its great cooling powers, rendered the results very unsatis- 
factory in the cases in which it was used; but with water, cy- 
anogen aud oxygen being employed, they were more conclusive. 
Cyanogen and oxygen, in the proportion of one to two, detonated 
ina tube of about 2-5ths of an inch in diameter, displaced a quan- 
tity of water which demonstrated an expansion of fifteen times 
their original bulk. This would indicate a temperature of above 
50006° of Fahrenheit, and the real temperature is probably much 
higher; for heat must be lost by communication to the tube and 
the water. The heat of the gaseous carbon in combustion in this 
gas, appears more intense than that of hydrogen; for I found a 
filament of platinum was fused by a flame of cyanogen in the air 
which was not fused by a similar flame of hydrogen. 
IV. Some general Observations, and practical Inferences. 
The knowledge of the cooling power of elastic media in pre- 
venting the explosion of the fire-damp, led me to those practical 
researches which terminated in the discovery of the wire-gauze 
safe-lamp; and the general investigation of the relation and 
extent of these powers serves to elucidate the operation of wire- 
gauze and other tissues or systems of apertures permeable to 
light and air, in intercepting flame, and confirms the views I 
originally gave of the phenomenon. 
Flame is gaseous matter heated so highly as to be Juminous, 
and that to a degree of temperature beyond the white heat of 
solid bodies, as is shown by the circumstance, that air not lu- 
minous wil! communicate this degree of heat*, When an at- 
tempt is made to pass flame through a very fine mesh of wire- 
* This is proved by the simple experiment of holding a fine wire of pla- 
tinum about the 1-20th of an inch from the exterior of the middle of the 
flame of a spirit-lamp, and concealing the flame by an opaque body, The 
wire will become white hot in a space where there is no visible light. 
Vol. 50, No.231. July 1817. B gauze 
