At Cambridge, Ray spent much of his time in the study of natural history, a subject which would occupy him for most of his life, from 1660 to the beginning of the eighteenth century. When Ray found himself unable to subscribe as required by the ‘Bartholomew Act’ of 1662 he, along with 13 other college fellows, resigned his fellowship on 24 August 1662 rather than swear to the declaration that the Solemn League and Covenant was not binding on those who had taken it. Tobias Smollett quoted the reasoning given in the biography of Ray by William Derham: