Circa 1812 Gentleman's pistol Forsyth scent bottle lock (Gold Fittings):

Percussion pistol by Forsyth, English, c1840. The pistol is fitted with the 'scent-bottle' lock designed and developed by the Reverend Alexander Forsyth at the Tower of London in 1806-1807:

Of possible interest:

http://www.gunstar.co.uk/Antique-Pistol-Hand-guns/Joseph-Egg-gun-for-sale-gs6776.aspx