Coherer

[Sarah]

Any device in which an imperfectly conducting contact betweenpieces of metal or other conductors loosely resting against eachother is materially improved in conductivity by the influence ofHertzian waves; -- so called by Sir O. J. Lodge in 1894 on theassumption that the impact of the electic waves caused the looselyconnected parts to cohere, or weld together, a condition easilydestroyed by tapping. A common form of coherer as used in wirelesstelegraphy consists of a tube containing filings (usually a pinch ofnickel and silver filings in equal parts) between terminal wires orplugs (called conductor plugs).