The production was performed by roasting tin ore and guiding the fumes through a tunnel to the chimney, making arsenic to condensate in the tunnel. Workers were scraping off the heavily poisonous substance without wearing any kind of protection, so most of them died before their 30th birthday. But in those days, having a job was vital - no matter how short one’s life then had to be.

The arsenic was sold mainly to America, where its was used as an insecticide in cotton fields.

Arsenic contamination in Cornwall is widespread due to the historic mining of polymetallic ores and the calcination of ores, it seems however not to reach a dangerous level. The American cotton fields are probably polluted in a similar way.