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Civilisation
would have been impossible without the discovery, taming and use of fire.
Some historians would consider evidence of the use of fire as the mark
of civilisation. The cooking of food widened food supplies and made food
more nutritious; fire enabled the making of the first 'chemical' products
- such as soap, and enabled metals to be obtained from rocks, as were
glass and pottery. These developments are the hallmarks of civilisation
and without fire they were and are impossible. Fire was also used for
heating, enabling people to survive hard winters and to colonise more
extreme climates, and to keep off predators. Thus the making of fire and
keeping the fire in became vital tasks, without which vulnerable early
societies would have perished. Starting a fire was a skilled and non-trivial
task right up until the beginning of the 19th. century, and yet today
we give it no thought. Why not? Because we expect to be able to 'strike
a light' anywhere at any time using a match or nowadays, a butane gas
lighter.
Put
21st. century man on an island or in a jungle without matches or a lighter
and watch them struggle to create fire! We have lost the traditional skills
of flint and tinder, of a friction stick, or one of the other time-honoured
methods. It would now take us a long time, much experimentation (and even
then we might well fail) to produce a flame. We would give anything for
a simple box of matches, that humble, unsung product of the chemist and
the chemical industry that has revolutionised everyday life around the
world. How many times have you needed a light today - for the fire, the
cooker or (unfortunately) a cigarette? We would be lost without a box
of matches or a lighter, and none of us could make either of them from
scratch! In this series of articles I want to trace the history of phosphorus
and the friction match, and the contribution the chemical match has made
to our comfort. Sadly, no matches are made any longer in the United Kingdom
or Ireland - in Ireland Maguire & Patterson stopped manufacture in
1982 and in the U.K. Bryant & May closed its last match factory in
1997. The matches we buy now are made in Sweden or perhaps China (who
seem to make almost everything these days). The match factories closed
because of the competition from the disposable lighter, that awkward creation
of plastic, metal and butane which as often as not burns one's fingers
as one tries to light something. But its convenience has almost killed
off the humble match, that matchless triumph of applied chemistry.
The burning brand - Brand discovers phosphorus!
The story of the match goes back to the discovery of phosphorus by Hennig
Brand (or Brandt) in 1669, immortalised in the painting by Joseph Wright
of Derby (see page 58) and is one of the many legacies to civilisation
of that despised domestic product, urine.
"More than 300 years ago, in 1669, Hennig Brand, a Hamburg alchemist,
like most chemists of his day, was trying to make gold. He let urine stand
for days in a tub until it putrified. Then he boiled it down to a paste,
heated this paste to a high temperature, and drew the vapours into water
where they could condense - to gold. To his surprise and disappointment,
however, he obtained instead a white, waxy substance that glowed in the
dark.
Brand had discovered phosphorus, the first element isolated other than
the metals and non-metals, such as gold, lead and sulphur, that were known
to the ancient civilisations. The word phosphorus comes from the Greek
and means light bearer."1
Brand
(also known as Dr. Teutonicus) evaporated urine and so produced ammonium
sodium hydrogenphosphate (microcosmic salt), which on heating produces
sodium phosphite. When heated with carbon (charcoal) this decomposed to
produce white phosphorus and sodium pyrophosphate.
1. (NH4)NaHPO4
NaPO3 + NH3 + H2O
2. 8NaPO3
+ 10C 2Na4P2O7 + 10CO +
P4
Brand's
discovery was an accident but his discovery of phosphorus mirabile would
turn out to be more valuable than gold in the future, for this 'cold fire'
would enable inventors to produce fire on demand, an unimaginable achievement
to Brand's contemporaries. Brand had tried to keep the method secret but
he had sold the 'secret' to the German chemist, Krafft, who showed off
the new wonder substance around the courts of Europe where Robert Boyle
saw it in London. The secret that it was made from urine leaked out and
first Johann Kunckel in Sweden (1678) and later Boyle in London (1680)
also managed to make phosphorus.
Robert
Boyle had seen samples of Brand's phosphorus exhibited in London and he
eventually worked out a method to make phosphorus from urine in 1680,
improving on Brand's process by using sand.
3. 4NaPO3
+ 2SiO2 + 10C 2Na2SiO3 +
10CO + P4
Notice that
Boyle's improved method (eqn. 3) liberates all the phosphorus in the sodium
phosphite. One of Boyle's assistants, Ambrose Godfrey Hankewitz, later
set up in business making the new, wonder material. He charged 50/- an
ounce for this new scientific curiosity. Robert Boyle was the first to
use phosphorus to ignite sulphur-tipped wooden splints, forerunners of
our modern matches, in 1680.
Boyle
called the material 'icy noctiluca' (cold light) and examined its properties
in a systematic way, which Brand and co-workers had not. To them it was
just an interesting and profitable curiosity. Interestingly white phosphorus
became known as English or Boyle's phosphorus to distinguish it from other
luminescent materials, which were all called 'phosphorus'. Over the years
these other names have vanished leaving only elemental phosphorus.
In 1769
J.G. Gahn and C.W. Scheele2 showed that calcium
phosphate (Ca3(PO4)2) is found in bones
and obtained phosphorus from bone ash. Lavoisier recognised phosphorus
as an element in 1777. Bone ash became the major source of phosphorus
until the 1840s. Phosphate rock, a mineral containing calcium phosphate,
was first used in 1850 and following the introduction of the electric
arc furnace in 1890 this became the only source of phosphorus. Phosphorus,
phosphates and phosphoric acid are still obtained from phosphate rock.
A major use for phosphate rock is for making phosphate fertilizers (but
that's another story.)
Albright and Wilson
Albright & Sturges started making phosphorus in the UK in 1844 and
are still one of the major world producers of phosphorus chemicals3.
The company, located at Oldbury in the 'Black Country', was founded by
Arthur Albright (1811-1900), a Quaker. The Quakers, a nonconformist Christian
group, became very influential in business and industry in the 18th. and
19th. century, partly because they were prevented from entering traditional
occupations4. At 16 Arthur was apprenticed
to a chemist-and-druggist uncle in Bristol, the start of many a chemical
career in the 19th. century. In 1840 he became a partner in the firm of
John & Edmund Sturges of Birmingham, manufacturing chemists, and in
1844 he persuaded his partner to start making phosphorus, then coming
into use for making matches. It cost 5/- a pound and most of it was imported.
The raw material was bone ash, imported from South America and later from
eastern Europe. The first factory was in Selly Oak, Birmingham. The company
moved to Oldbury and erected a new factory in 1850, and the first phosphorus
was made at Oldbury in 1851. Oldbury was already a centre of chemicals,
with local supplies of coal and a good canal and rail transport system.
A contemporary writer, Walter White, wrote in 1860 of a visit to Oldbury:
"Among the chimneys rise those of a phosphorus factory, where,
at some risk, and at a fierce temperature, phosphorus is extracted from
bones, in such quantities that England, which used to import, now exports
the article, sending many tons to Vienna and receiving it back on the
end of matches by hundreds and millions every week. One pound of phosphorus,
worth about two-and-nine-pence, suffices to charge a million of matches."5
Albright
said that he thought of making phosphorus because Sturges was already
supplying the 'twin sister' of phosphorus used in matches, namely chlorate
of potash (KClO3). He thought he could make it cheaper than
on the Continent because of the good supplies of cheap coal in the Black
Country. At first the price of phosphorus was 7s.6d. a lb, but this came
down to 6d. a lb. by the 1880s, as the economies of scale started to produce
fruit. England became by 1860 a net exporter of phosphorus. The partnership
with Sturges was dissolved in 1855 and in 1856 John Edward Wilson (another
Quaker) joined Albright in partnership and the firm was incorporated as
Albright & Wilson in 1856. He supplied the administrative acumen to
support Albright's chemical genius: "if Arthur struck the spark,
John Edward blew it to a flame; and it was his wise and constant tending
that kept it burning ever more brightly."6
Wilson ensured that the new company was run profitably with as little
waste as possible, so that it survived and prospered while 25 other phosphorus
works opened and closed in Oldbury in as many years.
Initially
the raw material for phosphorus production was animal bones, later replaced
by mineral phosphates. The bones or rock were dissolved in sulphuric acid
to give phosphoric acid and calcium sulphate as a by-product. The acid
was concentrated, mixed with 25% of its mass with carbon, dried in iron
pots to a black powder and then distilled in clay retorts. Phosphorus
distilled over and was condensed into 25-30 lb. blocks called 'cheeses'.
After refining and casting into sticks (all under water to prevent it
catching fire), the product was shipped, again under water, to the end
users. In the 1890s this original batch process was superseded by the
continuous electrothermic process. Cheap electricity rather than coal
was now the key to cheap phosphorus and by 1920 production had ceased
at Oldbury and Albright & Wilson transferred their production to Niagara
Falls, in the USA and Canada.
As soon
as Albright heard of Schrtter's discovery of the safer red phosphorus
in 1844 he bought the patent and started to develop a safe production
process. He was successful and the Oldbury works started making red (or
amorphous) phosphorus in 1851 by heating white phosphorus at a controlled
temperature in a closed iron pot. The problem of making reliable matches
using red phosphorus was yet to be solved, but eventually Albright's efforts
to make a safer form of phosphorus was to protect to health of match makers
around the world. Production of red phosphorus did not expand until a
successful safety match was invented (see part 2).
White, red and black: allotropes of phosphorus
Phosphorus is one of the non-metals that shows distinctive allotropy:
different forms of the same element but with different physical and chemical
properties. There are three common forms of phosphorus: white (or yellow),
red and black. In all of them the P atoms are joined together by three
single bonds, but in different ways. White P is a molecular solid composed
of P4 tetrahedral molecules (tetraphosphorus), with highly
strained single bonds. These molecules are held together by only weak
intermolecular bonds and this white P has a low mpt. and bpt. and is very
reactive. It catches fire spontaneously in air (and must therefore be
stored under water) and its vapour causes the dreaded 'phossy jaw' which
bedevilled early matchmakers. White P turns yellow due to the slow formation
of red phosphorus.
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