Cyril Norman Hinshelwood was born on June 19, 1897, in London, England, to Norman MacMillan Hinshelwood, an accountant, and Ethel Smith Hinshelwood. The family moved to Canada, but because of Hinshelwood's health, he and his mother moved back to England in 1904. His father died soon afterward. Although he received a scholarship to Balliol College at Oxford in 1916, Hinshelwood delayed accepting it to work at the Queensferry Explosive Supply Factory during World War I. Promoted to assistant chief chemist in 1918, his work on solid explosives sparked a lifelong interest in chemical kinetics.

Hinshelwood entered Oxford in 1919, becoming a fellow of Balliol in 1920 and a fellow and tutor of Trinity College, Cambridge, in 1921. During the 1920s he began to apply kinetic theory, the study of bodies in motion, to the chemical reactions that occurred in gases. In 1927 he began to investigate the interaction of hydrogen and oxygen. At certain pressure thresholds, the...