There are many meanings for the word mercury, and there are mercury quotes that include a variety of them. Mercury is a silvery element that is used in thermometers and for other purposes, and it is also the name of a planet in space. As an element mercury is the only metal element that has a liquid form, and it can be absorbed through the skin and is toxic to humans and animals both in larger amounts. Mercury may also be called quick silver, and it has uses in the medical and manufacturing industries. Many fish contain small amounts of mercury and this has caused the US government to issue guidelines about consuming these fish too often. The amount allowed for pregnant women, small children, and anyone with a compromised immune system is smaller and may not be allowed at all with some fish species and bodies of water.