Within the legal profession Purves showed a flair for spectacular cases that were widely reported in the press. By the 1880s he was briefed to appear in almost every important jury case, and was retained as standing counsel by a large number of public and private institutions, including the Victorian railways. In 1886 he was appointed Q.C. and acknowledged as a leader of the Victorian bar. His success depended less on abstract legalities than on a ready grasp of technical skills and an ability to easily make disputed points clear to a jury. His significant contribution to forensic law in Victoria was the development of a new style of cross-examination, a persistent and focussed questioning by which a defensive witness could be led to trip up and prejudice his own case.
