Artificial alloys of gallium have even lower melting points and are used in applications such as thermometers, as a non-toxic liquid metal substitute for mercury.
Gallium was predicted before it was discovered. Mendeleev, who first formulated the periodic table more or less as we know it, identified a gap that would be filled by “eka-aluminium” and deduced some of its properties. In less than five years Lecoqde Boisbaudran had proved it by spectroscopy, from two characteristic violet bands in the spectrum, and shortly afterwards isolated the metal itself; a scientific triumph.
Although gallium is not toxic to humans, it's highly corrosive to aluminium. So I was careful to keep it away from my iPhone and took the photograph above with the other hand, a bit tricky.