How did Matthew Arnold Hunter first produce pure metallic titanium?

In 1910, the metallurgist Matthew A. Hunter successfully produced pure metallic titanium for the first time at the Rensselaer Polytechnic Institute in New York, working in cooperation with the General Electric Company.12

Hunter achieved this by reacting titanium tetrachloride (${\text{TiCl}}_4$) with sodium inside an airtight steel cylinder under a vacuum. Although his initial research was driven by the mistaken belief that titanium could serve as a high-temperature filament for incandescent lamps, his method demonstrated that the metal possessed some ductility. This technique, now known as the Hunter process, was later commercialized and remains a foundational method for reducing titanium metal.123