Difficult choices as death nears. As the changes described in this article develop in the final days or hours of a progressive terminal illness, difficult choices may arise. There may be questions about whether to provide food and fluids, receive blood transfusions, or treat infections.
The use of mercury in thermometers dates back hundreds of years. It was widely used because it reliably expands and contracts with changes in temperatures. It is highly poisonous, however, and can enter the body through the respiratory or digestive tracts, or directly through the skin.
Mercury is a naturally-occurring chemical element found in rock in the earth's crust, including in deposits of coal. On the periodic table, it has the symbol Hg and its atomic number is 80. It exists in several forms: methylmercury and other organic compounds, elemental (metallic) mercury, and; inorganic mercury compounds. Methylmercury and other organic mercury compounds are formed when mercury combines with carbon. Microscopic organisms convert mercury into methylmercury, which is the most common organic mercury compound found in the environment. Elemental or metallic mercury is a shiny, silver-white metal and is liquid at room temperature. It is used in older thermometers, fluorescent light bulbs and some electrical switches.