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 so many 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. 



Again, if a given volume of those gases, while in an aerial 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 of 

 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 grav- 

 ity ; now they have acquired weight, and are subject to mechanical 



