The excellency and advantage of doing good [electronic resource] : represented in a sermon preached before the honourable trustees for establishing the colony of Georgia in America, and the associates of the late reverend Dr. Bray, on their Anniversary Meeting, March 17, 1747-8. In the Parish Church of St. Margaret, Westminster. By Ralph Thoresby, A. M. Rector of Stoke-Newington in Middlesex. Publish'd at the Desire of the Trustees and Associates. To which is annex'd, A Letter of Samuel Loyd, Esq; Concerning the Nature and Goodness of the Georgia Silk.