Heavy metals is improved with the addition of thorium. Tellurium is added to copper and steel alloys to improve their machinability; and to lead to make it harder and more acid-resistant. The biocidal effects of some heavy metals have been known since antiquity. Platinum, osmium, copper, ruthenium, and other heavy metals, including arsenic, are used in anti-cancer treatments, or have shown potential. Antimony (anti-protozoal), bismuth (anti-ulcer), gold (anti-arthritic), and iron (anti-malarial) are also important in medicine. Copper, zinc, silver, gold, or mercury are used in antiseptic formulations; small amounts of some heavy metals are used to control algal growth in, for example,
British Non-Ferrous Metals Research Association British Non-Ferrous Metals Research Association The British Non-Ferrous Metals Research Association was a research group in the United Kingdom during the 20th century, bringing together public and privately funded research into metallurgy. The name was abbreviated officially to B.N.F.M.R.A. (the organisation was normally known as ‘The BNF’ during its life). It was formed in 1920 by members of the British Non-Ferrous Metals Federation which represented the commercial interests of British manufacturers of coppers and copper alloys, lead, zinc and other non-ferrous metals and their alloys, latterly including titanium. Robert Hutton was appointed director in 1921. The 600 or so subscribing