Times Independent | 1955-02-24 | Page 49 | Selenium on Job

Selenium On Job I The element selenium one of the products by-products obtained during the smelting and refining of nickle copper ores of the Sudbury district district district dis dis- of nf Ontario has unusual pro pro- They are neither those of a atrue atrue atrue true metal like nickle or copper copper cop cop- per nor those of non-metallic non materials materials materials ma ma- such as sulphur Selenium is a semi-metal semi and this makes possible many of its unique One of these Is in photoelectric photoelectric photoelectric photo photo- electric cells The operation of these cells depends depends depends de de- upon the fact that selenium when in contact with a noble metal usually gold develops a slight electric current when exposed to light Selenium photo-electric photo cells are employed in burglar alarms industrial industrial industrial in in- safety devices automatic door opening mechanisms and more recently to control the ventilating ventilating ven ven- systems of mines and tunnels tunnels tun tun- nels were dust or fumes are liable to be present