Egypt – Investigating whether Egyptians modified for electrical purposes, I came across this blog post.

“I purchased an electrical device from an electrical supply store called a Proof Plane, It is a metal disk with a non-conducting plastic handle.

By holding the device by the plastic handle, and touching the metal disk to the electronic equipment excess electricity will jump to the metal disk. The disk then becomes portable and can be moved to a different location. The accumulated electricity can be discharged at will by touching the metal disk to anything grounded.

The unique thing about the Egyptian metal disk then becomes a , capable of capturing and holding an electrical charge that can only be released by touching something that is grounded to the earth. The ancient Egyptians had disks that ranged in size from 1 to in diameter.”

Come to find out the some mirrors were made as alloys, combining and silver. Silver has a higher conductivity ability than , where as any other metal combined with would lower the ‘s conductivity due to its impurities.