Observations on Combustion. 147 
vided for furnishing light and heat for the use of man. But for a 
long time, although one of the easiest things possible to produce flame 
and heat, yet how it was effected seemed a perfect mystery, the so- 
lution of which appeared altogether hopeless, as somany able and em- 
inent chemists, with every possible advantage that had been or could 
be devised, had not succeeded ;—-still it was impossible for me to 
withdraw my mind from it. : 
When I began to reason as follows, I saw a gleam of hope that 
this mysterious process might be explained. It is well known that 
when the two electricities combine or unite, they always produce 
light and heat ;—light and heat must therefore exist in them as a con- 
stituent part, or be combined with them in a latent or dormant state ; 
it is quite immaterial which. For, as a given quantity of the elec- 
tricities will decompose a given quantity of water, the result is al- 
ways a given volume and weight of the gases known as oxygen and 
hydrogen. 
It is also well known, that these gases by their own combustion al- 
ways give out much heat and light, and reproduce the same quantity 
of water, that had been decomposed when the gases were evolved. It 
therefore appeared to me very evident, that in the decomposition of 
the water, light and heat had been imparted to the gases, solely by - 
the electricities. — sig 
gain, if a given volume of those gases, while in an aérial state, 
will weigh say four grains, and if by their own combustion they pro- 
duce four grains of water, it appeared to follow conclusively that the 
base of those gases was the elements of water combined with the 
* electricities in a gaseous form; and if their weight was the same as 
that of the water produced by their combustion, it seems to prove that 
those gases have no other base whatever.. Now, if a given volume of 
those gases, thus formed, will produce the same number of grains of 
water, can there be a doubt that the elements of combustion, and the 
base are the same in each? 
Once more—take a given volume of oxygen and hydrogen gases 
weighing say twelve grains—inflame them; and if by their own com- 
bustion, much heat and light are given out and they produce twelve 
grains of water, can there be a doubt left, that water was the base 
those gases and that they had no other? — 
That base must necessarily, as it does, greatly change the nature 
and operations of the electricities. Before, they had no sensible ory 
ity ; now they have acquired weight, and are subject to mechanjcal 
