How did Peter Jacob Hjelm produce the first metallic molybdenum?

In 1781, the Swedish chemist Peter Jacob Hjelm successfully produced the first sample of metallic molybdenum by reducing molybdic oxide.1

Following a suggestion from Carl Wilhelm Scheele, who had previously isolated the oxide from the mineral molybdenite, Hjelm created a paste using the molybdic oxide and linseed oil. He then heated this mixture at high temperatures within a crucible, using the carbon from the oil to reduce the oxide into its metallic form.12