materialy: Manganese

Evidence: 100 • authority: 72

Manganese is a chemical element; it has the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. First isolated in the 1770s, manganese is a transition metal with many industrial alloy uses, particularly in stainless steels in which it improves strength, workability, and resistance to wear. Various manganese oxides are used as oxidising agents, as rubber additives, and in glass making, fertilizers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component…

Evidence: 47 • authority: 72

A bal maiden, from the Cornish language bal, a mine, and the English "maiden", a young or unmarried woman, was a female manual labourer working in the mining industries of Cornwall and western Devon, at the south-western extremity of Great Britain. The term has been in use since at least the early 18th century. At least 55,000 women and girls worked as bal maidens, and the actual number is likely to have been much higher. While women worked in coal mines elsewhere in Britain, either on the surface or underground, bal maidens worked only on the surface. It is likely that Cornish women had worked in metal mining since antiquity, but the first records of female mine workers date from the 13th…