anticoherer

from The Century Dictionary.

• noun A device which, like a coherer, is a detector of electric waves, but whose resistance is increased by them.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Wireless Teleg.) A device, one form of which consists of a scratched deposit of silver on glass, used in connection with the receiving apparatus for reading wireless signals. The electric waves falling on this contrivance increase its resistance several times. The anticoherer can be used in conjunction with a telephone.