Arsenic had to be removed as a waste product from the tin and copper ore.
By the early 19th century there was a growing demand for arsenic – it was used in:
- glass making
- dyes for fashionable carpets
Furnaces began to be modified - long flues were built to collect the arsenic as a fine white dust. Young boys were often sent in, covered with a protective layer of clay, to scrape the arsenic from the walls of the flues.
During the 19th century arsenic had many uses. Some arsenic compounds are highly coloured and were used as pigments to colour dyes and paints etc, though these readily decomposed in the sulphur laden smogs common in cities during the 19th century releasing deadly poisonous arsine gas.
Because of its poisonous properties arsenic was much used to make pesticides. From 1890-1930 thousands of tonnes of arsenic were exported from Cornwall and West Devon to America to control Colorado beetle and Boll Weevil infestations. Devon Great Consols mine near Tavistock was for a time the largest arsenic producer in the world. The introduction of synthetic pesticides such as DDT, and increasing legislation banning the use of arsenic caused demand to fall.
One of the last major uses of arsenic was as a decolouriser in the manufacture of glass but since the 1950’s demand has steadily fallen.
Photograph reproduced with the kind permission of the Royal Institution of Cornwall