Due to concerns about the element's toxicity levels, the use of mercury is slowly being phased out. However, being the only metal that possesses the property of maintaining a liquid state at room temperature, it is not surprising that mercury has found a number of special applications throughout past decades.
Mercury has a very large thermal expansion which remains constant over a considerable temperature range. As such, mercury has often been used in thermometers to indicate changes in temperature.
Though the method is not practiced as much today, in the past, mercury has been used to form dental amalgams for tooth fillings. By mixing it with silver and tin, mercury forms a malleable material that can be inserted into tooth cavities where it will cool and expand to fill the hole.
In the form of thiomersal, mercury has been widely used in the production of commercial mascara products.
In neon and fluorescent lights, gaseous mercury is often added to the tubes so the light produced is consistent. In some argon lamps, gaseous mercury is added to increase ionization and electrical conductivity.
In some countries, mercury chloride is still used as a topical disinfectant to treat minor scrapes and cuts. Many industrial countries now prohibit the use of mercury in medicine. Merbromin or mercurochrome is a mercury compound that was once used as a topical antiseptic to treat minor scrapes and cuts.
In hydraulic gold mining, mercury was frequently used because it would bind to gold and help it sink through the water-gravel mixture, thereby helping to increase recovery rates. For the most part, large-scale use of mercury in gold mining was halted in the 1960s.
- Photo Credit thermometer image by Dusan Radivojevic from Fotolia.com