When challenged to perform the conversion a second time in front of credible witnesses, he instead killed himself by drinking prussic acid (hydrogen cyanide).

Born in London in 1752, his original surname was Higginbottom, but he changed it to Price following the wishes of a relative who had died and left him a legacy.

In fact, he set about the distillation of laurel water (which contained hydrogen cyanide, commonly known as prussic acid).

He wrote his will at the same time, but it was another six months before he returned to London to invite members of the Royal Society to witness the experiment on 3 August in his laboratory in Guildford.

Although clearly disappointed by the poor turnout, Price welcomed the three men and then, stepping to one side, ended his life by drinking the flask of laurel water he had prepared.