Question: 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?

Related documents: [0]  [DOC] Christian Friedrich Schönbein (18 October 1799 – 29 August 1868) was a German-Swiss chemist who is best known for inventing the fuel cell (1838) at the same time as William Robert Grove, Robert Cumming and his discoveries of guncotton and ozone. [END] 
[1]  [DOC] Sir William Robert Grove, PC, FRS FRSE (11 July 1811 – 1 August 1896) was a Welsh judge and physical scientist. He anticipated the general theory of the conservation of energy, and was a pioneer of fuel cell technology. He invented the Grove voltaic cell. [END]  
Answer: fuel cell
fuel cell