The following is an extract from the Reports of Inspectors of Mines 1878:
"The precipitation of copper from mineral water, which until recently has only been in operation above ground at certain mines, has during last year been introduced below ground in the Cronebane Mine, county Wicklow. It might, however, have proved a very serious affair, as but for the watchfulness of those acting in mamagement, who noticed the flame of the candles lengthening, the gas emitted might have occasioned a very destructive explosion"
What gas would be emitted by the Cu precipitation process?
Has anyone come across this elsewhere, particularly as the process can occur in old workings containing much old ironwork?.