On Sep 7 2004, 23:08, William Donzelli wrote: the It readily reacts with even dilute nitric acid to form nitrates, or with aqua regia (a mixture of nitric and hydrochloric acids) to form mercuric chloride, also known as corrosive sublimate. It reacts slowly with sulphur, chlorine, or oxygen (cinnabar is mercury sulphide). Pure mercury sulphide used to be used as vermilion pigment (which may explain something about some artists). It reacts dangerously rapidly with bromine, and reacts with ammonia (don't try this at home!). The oxide reacts with quite a lot of things; it's used to make mercuric sulphate which is (was?) used as for some organic reactions. BTW, the reactions with oxygen and sulphur are very slow, which is why mercury vapour is, well, mercury vapour (rather than mercury oxide); and why the advice that used to be given to use flowers of sulphur (finely powdered sulphur) to mop up mercury spills is not very good (use zinc powder instead, to make a non-volatile amalgam). Some of the compounds are very toxic, and some can react with organic materials to produce organo-mercuric compounds (some list members are old enough to remember the Japanese fishermen who were poisoned by consuming them in fish over a long period). Lots of these are liquids with high toxic vapours. -- Pete Peter Turnbull Network Manager University of York