A Mercury Mirror

This stone combines within itself all the colors. It is white, red yellow, sky-blue, and green. 

The Chinese believed that artiliciai gold was endowed with great magical powers. The masters of the Orient attempted to prepare alloys resembling gold from cinnabar (the naturally occurring form of mercury(II) sulfide) and other metals. They assumed one should eat regularly only from vessels made of such alloys in order to achieve immortality. 

Mercury and its compounds are highly toxic. Air saturated with mercury vapor contains about 15 mg Hg per in In badly ventilated laboratories the amounts of Hg vapor derived from spilt mercury In the air may suffice to induce chronic mercury poisoning. The inhaled mercuiy is only very slowly excreted via the urine. I )imethylniercury (CHj)2Hg is extremely toxic and can cause irreversible damage to the central nervous system. Ozone is a strong oxidising agent and very toxic. 

Approximately 5 mL of mercury are placed in the round-bottomed flask. The flask is rotated slowly to show that the mercury does not stick to the walls. Ozone is now allowed to flow into the flask for about 1 minute and the flask is stoppered. If the flask is now again rotated slowly the mercury adheres to the glass and forms a mirror. 

If the flask is left open for a while on completion of the experiment, the mirror disappears and the mercury runs together to form a globule. 

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