the importance of the experiment that he had just performed, and
resolved to work it further. He had just found that wood and other
combustibles were, under the action of heat, capable of disengaging a
gas fit for lighting and heating. He had seen that the gas which is
disengaged from wood is accompanied with blackish vapors of an acrid
and empyreumatic odor. In order that it might serve for the production
of light, it was necessary to free it from these foreign products.

Lebon passed the vapor through a tube into a flask of water, which
condensed the tarry and acid substances, and the gas escaped in a
state of purity. This modest apparatus was the first image of the gas
works; and it comprised the three essential parts thereof--the
generating apparatus, the purifying apparatus, and the receiver for
collecting the gas.

One year afterward, the inventor had seen Fourcroy, Prony, and the
great scientists of his epoch. On the 28th of September, 1799, he took
out a patent in which he gives a complete description of his thermo
lamp, by means of which he produced a luminous gas, while at the same
time manufacturing wood tar and pyroligneous or acetic acid. In this
patent he mentions coal as proper to replace wood, and he explains his
system with a visible emotion and singular ardor. In reading what he
has written we are struck with that form of persuasion that does not
permit of doubting that he foresaw the future in reserve for his
system.

Unfortunately, Lebon could not devote all his time to his discovery.
Being a government engineer, without money and fortune, he had to
attend to his duties. He went as an ordinary engineer to Angouleme,
but he did not forget his illuminating gas, and he strongly regretted