 Along with Walter Illingworth he promulgated the Hammick-Illingworth rule, which predicts the order of substitution in benzene derivatives.He also developed the Hammick reaction which generates ortho-substituted pyridines.The son of L. S. H. Hammick, Dalziel Hammick was educated at Whitgift School, Magdalen College, Oxford (where he was a demy), and at the University of Munich.