From a recent Lewes History Group Newsletter Dec 2016
The 30 January 1826 Sussex Advertiser included a petition against various aspects of slavery in the British Colonies signed by 79 householders of the borough of Lewes. The signatories included the non-conformist ministers of Westgate Chapel (Thomas W. Horsfield) and Tabernacle (Evan Jones), the Unitarian gentleman William Boys, Baptist attorney John Webb Woolgar, banker Thomas Whitfeld, surgeon Gideon Mantell, ironmonger Nehemiah Wimble of The Friars, printers William Lee and John Baxter, butcher Benjamin Morris, auctioneer Plumer Verrall, bookseller R. W. Lower, draper William Crosskey and shepherd-schoolmaster John Dudeney. Many of the signatories were non-conformist Liberals but Anglican Conservatives were also represented.
Gideon’s father Thomas Mantell was a Methodist and had the first Methodist chapel built in Lewes in St Mary’s Lane next to the current Chapel Hill Antiques. He was close to the fellow members of the non-conformist community of Lewes listed above but died age 57 in 1807. He would no doubt have approved of Gideon’s presence amongst these signatories.
More on Gideon’s parents can be found here
More information about non-conformism in Lewes in the early 1800s, the time of Thomas Mantell, can be found here http://home.btconnect.com/christchurchlewes/CC2015/files/Tabernacle_vol1.pdf