For which invention are both Christian Friedrich Schönbein, a the German-Swiss chemist and William Robert Grove, the Welsh judge and physical scientist given credit?
William Robert Grove: Sir William Robert Grove, PC, FRS FRSE (11 July 1811 – 1 August 1896) was a Welsh judge and physical scientist. William Robert Grove:  He anticipated the general theory of the conservation of energy, and was a pioneer of fuel cell technology.
i don't know