cooling, but a gas, a permanent air, which may be washed, purified,
conducted, distributed, and afterwards turned into flame at any
distance from the hearth.

"It is almost needless," continued he, "to point out the formation of
verdigrise, white lead, and a quantity of other operations, in which
acetous acid is employed. I shall only remark that it is this
pyroligneous acid which penetrates smoked meat and fish, that it has
an effect on leather which it hardens, and that _thermolampes_ are
likely to render tanning-mills unnecessary, by furnishing the tan
without further trouble. But to return to the aeriform principle.

"This aliment of flame is deprived of those humid vapours, so
perceptible and so disagreeable to the organs of sight and smell.
Purified to a perfect transparency, it floats in the state of cold
air, and suffers itself to be directed by the smallest and most
fragil pipes. Chimnies of an inch square, made in the thickness of
the plaster of ceilings or walls, tubes even of gummed silk would
answer this purpose. The end alone of the tube, which, by bringing
the inflammable gas into contact with the atmospheric air, allows it
to catch fire, and on which the flame reposes, ought to be of metal.

"By a distribution so easy to be established, a single stove may
supply the place of all the chimnies of a house. Every where
inflammable air is ready to diffuse immediately heat and light of the
most glowing or most mild nature, simultaneously or separately,
according to your wishes. In the twinkling of an eye, you may conduct
the flame from one room to another; an advantage equally convenient
and economical, and which can never be obtained with our common
stoves and chimnies. No sparks, no charcoal, no soot, to trouble you;