He was educated at Bedales School, where he became interested in biology and astronomy (he published a paper on sunspots in 1917),[citation needed] and Emmanuel College, Cambridge, where he read Natural Sciences.

He published a number of papers on haemoglobin, and in 1926 he began to work with David Keilin on the haem containing protein cytochrome c. In 1932, he commenced work on plant biochemistry, focusing on photosynthesis and the oxygen evolution of chloroplasts, leading to the discovery of the 'Hill reaction'.

In collaboration with Fay Bendall, he made his second great contribution to photosynthesis research with the discovery of the 'Z scheme' of electron transport.

[3] In the 1920s, he developed a fish-eye camera and used it to take stereoscopic whole-sky images, recording cloud patterns in three dimensions.

He discovered a new approach to the biochemical study of photosynthesis which enabled him to demonstrate and to measure the evolution of oxygen by isolated chloroplasts exposed to light in the complete absence of CO2.