theories were to be admitted that did not bear
the test of experiment and varied observation.
A wise humility took the place of the old
mischievous and aggressive dogmatism. Even
Newton, when he was vouchsafed glimpses of
the divine secrets, confessed that his theory of
gravitation was only the locum tenens for some
greater and more central truth yet to be
discovered. In every nation the new philosophy
was coloured by the national character: in
France it became sceptical and mathematical;
in Germany, more abstract and generalising; in
England, more practical and energetic. As the
new science had always special topics on which
it was engaged, it often happened that, with so
many thousand observers, many of its most useful
discoveries were made simultaneously in several
countries. A long range of semi-discoveries in
England, France, and Germany led slowly up to
the great results of Watt and his steam-engine.
In older times such secrets were sought for by
fewer miners. The field of knowledge was indeed
but a small spot then.

As it was with steam, so it was with gas.
Van Helmont's discoveries lay apparently
dormant for many years, but they were not
forgotten. Scientific curiosity was approaching
them by analysis, and already the first truths had
grown and put forth branches in that vast
collection of observations, at first so often
timid and puerile, the Philosophical Transactions.
In 1667, a Mr. Shirley, a gentleman
living at Wigan, wrote to describe a series of
experiments he had commenced in 1659 on the
waters of a burning spring on the Warrington
road. This water burnt like oil when a candle
was applied to its surface, being impregnated
with carburetted hydrogen gas from the coal
seams that underlaid it. Shirley, a thoughtful
man, saw at once that it was not the water
that burned, but only some emanation from the
coaly earth. This he proved by draining the place
and then setting fire to the dry earth, which
threw up a cone of flame as wide as a hat and a
foot and a half high. This flame he proved
he could extinguish by water.

Boyle carried further and gave more
popularity to Van Helmont's experiments. He
proved that fixed air and inflammable air are
elastic fluids capable of being exhibited
unmixed with common air. In 1726, Dr. Hefler
Hales distilled coal, obtained gas, and observed
and noted down its elasticity. In 1733, the
Philosophical Transactions record some valuable
and suggestive experiments made in a coal-pit
belonging to Sir James Lowther, near Whitehaven,
in Cumberland. The pit was near the
full sea-mark, and intended to drain a
neighbouring colliery. When the pit was sunk forty-
two fathoms from the surface, the workers came
on a six-inch bed of black stone, full of clefts,
under which lay a seam of coal. When this
black stone was pierced, a quantity of damp
corrupted air came bubbling through the water
with a hissing noise. On a startled workman
putting a candle towards it, the water caught
fire and rose in a wave of flame two yards high.
This frightened the men so much that they beat
out the fire with their hats, then ran to the
rope and escaped up the pit. The steward of
the works then came down, and again lit the
gas, which soon rose and covered the bottom
of the pit a yard deep. Extinguishing the
flame, the men, who had returned, opened a
larger aperture in the bed of black stone. This
time the gas flared three yards high, and
almost stifled them. Unable to flap it out with
their hats, they got down a spout from a
cistern and so extinguished it. After this, no
candles were allowed in the pit till the coal was
reached, and a tube carried into the open air
to carry off the gas. This stream of gas
continued unabated in strength or quantity for
several years. Many savans came to collect
this strange form of air in bladders. Some of
it was taken to the Royal Society, and there
burnt, to the delight of the wigged philosophers.
A small pipe was first put into the
bladder, and the gas pressed through that into
the flame of a candle. Still no glimmering of
its vast capabilities of usefulness broke upon
the savans. They were not quite ripe for that
discovery yet. It was observed that sparks
would not light it; so the workmen used flint
and steel in the dark passages, and toiled on
by the miserable and momentary twinklings.
After the tube was fixed, the pit was no more
troubled with the mysterious " damp and
corrupted air," which would burn after being kept
a whole month in a bladder. In 1726, " the
ingenious" Dr. Stephen Hales first obtained
gas by distilling coal; but his experiments were
rather with a view to observe the elasticity
than the inflammability of the new vapour.

In 1739, the Rev. Dr. John Clayton, Dean
of Kildare and brother of one of Boyle's
correspondents, came a step or two nearer to the
bright secret. He went to see a ditch near
Wigan (probably Mr. Shirley's spring), because
he heard that the water there would burn like
brandy, would boil eggs, and thirty years before
had actually boiled a piece of beef; but was
now much less fierce, especially after rain.

Some experiments, not unlike Shirley's, soon
convinced Mr. Clayton that it was not water
that really fed the fire. Digging down half
a yard, he found a shaly coal, which yielded
an inflammable vapour. To prove the vapour
came from the coal, Mr. Clayton distilled some
coal. From this he obtained, first, a black oil
(tar), and, lastly, a spirit so intractable as to
force the luting of his vessels, break the glasses,
and eventually catch fire when a candle came
near it. He repeated the experiments with
a bladder; but they attracted but little notice.
They harmonised with no fashionable and popular
theory of the day, and were therefore disregarded;
but still the secret was unravelling. Van
Helmont had decomposed air. Shirley had observed
that certain air rising from the earth would
burn; the Whitehaven men had shown that
inflammable air could be kept in bladders;
and now the learned Dean proved that it could
be obtained by distillation from coal.