In an O.Henry short story, he uses "amalgam" as a figure or
speech, meaning creation of something desirable from a mixture of two ingredients. I looked up the definition to
see the etymology.

NOUN: 1. Any of various alloys of mercury with other metals, especially: a. An alloy of mercury and silver used in dental fillings. b. An alloy of mercury and tin used in silvering mirrors. 2. A combination of diverse elements; a mixture: an amalgam of strength, reputation, and commitment to ethical principles. See synonyms at mixture.
ETYMOLOGY: Middle English, from Old French amalgame, from Medieval Latin amalgama, probably ultimately from Greek malagma, soft mass.

I wonder who discovered and promoted the use of such a blessing to suffering humanity. How fortunate it is that
the mercury does not cause significant toxicity.

The American Heritage Dictionary