Ignition plug

An ignition plug intended for use in association with a cylinder of an internal combustion engine, comprising a plug body, a first electrode, means to support said first electrode by said body, a second electrode disposed on said body in spaced relationship to said first electrode, a porous annular member in said body, a chamber having a wall which is at least in part a circumferential surface defined by the inner surface of said porous annular member in a position with respect to said electrodes so that firing of said plug produces a spark in said chamber between said electrodes, a conduit in said body communicating with the outer surface of said porous annular member for supplying plasma medium in liquid form to said chamber, said porous annular member distributing said plasma medium to said wall of said chamber so that between successive firings of the plug at least a part of said circumferential surface of the wall of said chamber between said electrodes is wetted with liquid plasma medium, and means to provide communication between said chamber and said cylinder.