After some 25 years of work , his Theory of the Earth was read to meetings of the Royal Society of Edinburgh in 1785 . After some 25 years of work , his Theory of the Earth ; or an Investigation of the Laws observable in the Composition , Dissolution , and Restoration of Land upon the Globe was read to meetings of the Royal Society of Edinburgh in two parts , the first by his friend Joseph Black on 7 March 1785 , and the second by himself on 4 April 1785 .