11th August 1999.
By the 1870s a few mines in Cornwall produced half of the world’s arsenic.
Visiting Cornwall has been popular for the last century, and no more so than Today in 1999 when it was the best place, in Britain, to see a full eclipse of the sun. One of the two constituent elements of the sun is Helium, but here we are looking at another element and one specifically relating to Cornwall: Arsenic (As).
Re-tracking to the 19thc we find a peninsula, surviving on fishing and metal mining, mainly for tin and copper, but also for this semi metal (metalloid) element and long synonymous with poison.
Appearing in the same ore as tin, its contamination by arsenic, as well as sulfur, had to be removed, otherwise the tin abstracted was brittle and less valuable.(1)
The Gwennap Mining District was the first commercial arsenic producer in 1812, followed by Bissoe 1834 in the Carnon Valley, at a time of growing demand for white arsenious oxide by the Lancashire cotton industry, for use in pigments and dyes.(2)
The English Arsenic Company at Roseworthy, Gwithian and Greenhill near Gunnislake was the largest.
Owners included John Williams and John Taylor’s Redruth ‘Consolidated Mines’ which was making profits of £50 million, even minting its own penny for the workers to spend in its shop.
Baron Bassett’s operation at Redruth must have been a ‘happy ship’, as through subscription, a public monument was built in his memory.
The size of mining operations in 19thc Cornwall was colossal, with 50,000 working in the valley, until overseas competition resulted in closure.
Holman Bros of Camborne closed in 2001 after two centuries serving Cornish mining with rock and pneumatic drills. It once had three factories and the biggest employers in Cornwall with 3,000 workers.
Arsenic has long been known as the ‘poudre-succession’, a powder used to achieve illicitly an inheritance and many cases have been recorded.
However in the 1930s there was an unusual case of supposed poisoning where three women had died in mysterious circumstances, but the defence by Norman Birkett Q.C., managed to persuade the jury that an exhumed body had been contaminated with natural arsenic in the soil.(3)
The risks to public health are still a concern today in Cornwall, from a private water supplies used by 9,000 people using local bores and wells. Also the dust thrown up by off-road vehicles is said to be causing chest complaints.(4)
(1) The most common mineral in which arsenic is found, is arsenopyrite composed of iron, arsenic and sulfur.
Allotropes of Arsenic appear in grey, yellow and black colours.
(2) Other industrial uses of arsenic, were sheep-dips, leather tanning, glass, lead shot making and pharmaceuticals with wallpaper requiring the green and yellow tints from arsenic.
The principal arsenic insecticides used Paris Green of 1869 and London Purple of 1878. In the 1870s the influx of the Colorado Beetle was controlled by arsenic
(3) Daily Telegraph article Roger Wilkes, 10.10.2001. Mysterious Case of Arsenic Poisoning.