Useful things to do with mercury:
1. Use a mercury pool as a cathode, to form amalgams with ions of any metal which dissolves in mercury. These amalgams are good for reductions, in acid medium.
2. As above, using salt water as the electrolyte to form sodium amalgam. The mercury is distilled away to leave metallic sodium. (Potassium, calcium, barium, cesium, lithium...)
3. Show off your glassblowing skills. Make a mercury manometer. The vertical tube needs over 76 cm, 760 mm, which can bee graduated when you have performed the calibration. Then you can always read the exact strength of your vacuum in real time, directly read as its definition.
4. Speaking of vacuum, give yourself a real (lifetime) project. Make a high vacuum system. Use a mercury diffusion pump as the basis of your design. It works only when you have made a preliminary evacuation with your regular vacuum pump, which you now call your "roughing" pump. If you build it in the old style, with glass, you will have a treasure of beauty and true value.
These last couple things don't mess up your mercury; they don't lose it, nor convert it to toxic soluble salts.
turning science fact into <<science fiction>>