Gallium was a relatively unheard of metal until the internet marketed it as a non-toxic alternative to mercury. Now you can get it at mom-and-pop rock shops and if you don't have one near Google's happy to pull up dozens of internet shops that are happy to sell you some. The only downside is that as it melts in your hand gallium smears all over it turning it into a glittery mess. Which asides from wasting a not-so-cheap metal makes for quite a mess. Well, you win some, you lose some!

In this version we encapsulate a highly-pretreated glass ampule containing a gram or two of very pure gallium metal. The combination allows for the metal to flow in its molten state from one end to another much as mercury would. Because gallium tends to supercool, that is, it resists freezing at its normal melting point without a nucleation site (usually a foreign body), it should remain liquid at room temperature. If it freezes solid, gentle heating such as leaving it in a sunlit spot for a few minutes, it will melt and the effect can be resumed.