Definition of "hydrargyrum"

Hydrargyrum, Quick-ſilver, a Mineral, of a ſtrange piercing Quality, ſo as to eat thro' Gold, Silver, &c.

1706, Edward Phillips, compiler, J, column 2

‘There is a channel in the spine of her blade, and in it runs a river of hydrargyrum—a metal heavier than iron, though it flows like water.’

1980, Gene Wolfe, chapter XIV, in The Shadow of the Torturer (The Book of the New Sun; 1), New York: Simon & Schuster, page 129