FARADAY AND HIS INFLUENCE ON OUR EVERYDAY LIFE. 213
The first production of liquid chlorine by Faraday is of interest.
On March 5th, 1823, he was heating chlorine hydrate in a sealed
tube. Dr. Paris called on him and noticed some oily matter
in this tube. He upbraided Faraday for the "carelessness
of employing soiled vessels." Faraday started to open the
tube by filing the scaled end. It exploded, and the "oil"
disappeared. Faradayrepeated the experiment. Next day
Dr. Paris received this brief note :—"Dear Sir, The oil you
"noticed yesterday turned out to be liquid chlorine. Yours
"faithfully, Michael Faraday."
Faraday also made experiments on "Regelation." This has a
bearing on theories of glacier movement. A glacier takes a
winding course like a stream. Cracks occur as it turns a bend,
but they heal up by the process of regelation—water vapour
condenses more easily in a crack than on an open surface of
ice. This is not Faraday's only association with geology.
In 1844 ninety-five lives were lost in a disaster at Haswell
Colliery in Durham. The Prime Minister, Sir Robert Peel,
decided that a chemist and geologist should visit Haswell. So
Faraday and Sir Chas. Lyell attended the inquest. They
examined the Davy lamps and found some were damaged.
They discovered that men could light a pipe from them, and,
though smoking was forbidden in the mine, cases of smoking
had been known. Faraday asked how they measured the rate
at which air flowed in the mine. An inspector demonstrated
by taking a pinch of gunpowder and allowing it to fall through
a candle flame. A colleague measured the time taken by the
smoke to travel a known distance. Faraday asked where they
kept the powder. They replied, "In a bag, the neck of which
was tied up." "But where," asked Faraday, "do you keep
"the bag?" "You are sitting on it," was the reply. They had
given him the most comfortable seat available.
Faraday was often consulted by Government Departments
and was generally willing to assist them, but "not for pay."
This condition allowed him a certain freedom—to refuse his
services if due politeness had not been accorded him. In April,
1825, he was sent a crystal, alleged to have been taken from a
piece of chalk. His report follows : "Specimen is a piece of
"borax. Has not come from the chalk, but has either acci-
"dentally been supposed to do so, or has been mischievously
"described as having such a source, with intent to deceive."