Researches on the light manifested in the combustion 
of inflammable substances , by Count Rumfo&d, 
F. R. S. and Foreign Associate of the National 
Institute ; read at the sitting of the first class of 
the Institute, October 14 , 1811 . Translated by 
James Low, M. D. and Secretary to the Socie¬ 
ty of Arts. 
When an inflammable substance, in a state of purity, 
such for example as wax, fat, or purified oils, is burnt en¬ 
tirely, or without leaving any residuum, and with a transpa¬ 
rent, lively, white flame, and without smoke or odour, its 
combustion is regarded as complete, and its products (water 
in the state of vapour, and carbonic acid gas) are always 
identical, and in the same proportions for each substance. 
Those who consider light as a particular substance ema¬ 
nated from luminous bodies, have been obliged to seek the 
source of that which is manifested in combustion, among 
the different substances which unite in this process. Some 
suppose that the inflammable substance furnishes it, others 
that it proceeds from the air which supports the combus¬ 
tion; and some have imagined that it is furnished partly by 
the air, and partly by the inflammable substance which is 
burnt. 
If this light was in reality one of the chemical products 
of combustion, as has been supposed, we ought, without 
doubt, to find it fire-existing in these bodies, and we are au¬ 
thorized by every analogy, to conclude, that in this case, the 
quantity of light developed in the perfect combustion of a 
given quantity of any inflammable substance, ought neces¬ 
sarily to be limited, and as uniform as the other chemical 
products of the process. 
