66 Sir H. Davy's researches on flame. 
It is probable that with certain heated mixtures of gases, 
where the non-supporting or non-inflammable elastic fluids 
are in great quantities, combination with oxvgene will take 
place, as in the instance mentioned, page 63, of hydrogene 
and chlorine, without any light, for the temperature produced 
will not be sufficient to render elastic media luminous ; and 
there are no combustions, except those of the compounds of 
phosphorus and the metals, in which solid matters are the 
result of combinations with oxygene. I have shown in the 
paper referred to in the introduction, that the light of common 
flames depends almost entirely upon the deposition, ignition 
and combustion of solid charcoal; but to produce this deposi- 
tion from gaseous substances demands a high temperature. 
Phosphorus, which rises in vapour at common temperatures, 
and the vapour of which combines with oxygene at those tem- 
peratures, as I have mentioned before, is always luminous, for 
each particle of acid formed must, there is every reason to 
believe, be white hot; but so few of these particles exist in a 
given space that they scarcely raise the temperature of a solid 
body exposed to them, though, as in the rapid combustion of 
phosphorus, where immense numbers are existing in a small 
space, they produce a most intense heat. 
In all cases the quantity of heat communicated by com- 
bustion, will be in proportion to the quantity of burning matter 
coming in contact with the body to be heated. Thus, the 
blow-pipe and currents of air operate. In the atmosphere, 
the effect is impeded by the mixture of azote, though still it 
is very great: with pure oxygene compression produces an 
immense effect, and with currents of oxygene and, hydrogene, 
there is every reason to believe, that solid matters are made 
to attain the temperature of the flame. This temperature, 
