In 1840 Grove invented one of the first incandescent electric lights, which was later perfected by Thomas Edison. William Robert Grove (July 11, 1811 - August 1, 1896) was a judge and physical scientist. He anticipated the general theory of the conservation of energy, and was a pioneer of fuel cell technology. In 1842, Grove developed the first fuel cell (which he called the gas voltaic battery), which produced electrical energy by combining hydrogen and oxygen, and described it using his correlation theory. In developing the cell and showing that steam could be disassociated into oxygen and hydrogen, and the process reversed, he was the first person to demonstrate the thermal dissociation of molecules into their constituent atoms. Grove became a Fellow of the Royal Society in 1840, and received their Royal Medal in 1847. He was Vice-President of the Royal Institution in 1844. Receiving a knighthood in 1872, he was given an honorary degree by Cambridge University in 1879. He died in 1896 at the age of 85. This image has been color-enhanced.