Definition of "amalgam"

This was the Ambergate, Nottingham & Boston & Eastern Junction Railway, an amalgam of a number of separate schemes put forward in 1845, which secured its Act on July 16, 1846.

1960 March, J. P. Wilson, E. N. C. Haywood, “The route through the Peak - Derby to Manchester: Part One”, in Trains Illustrated, page 149

gold t’amalgam with some six of mercury

1610 (first performance), Ben[jamin] Jonson, The Alchemist, London: […] Thomas Snodham, for Walter Burre, and are to be sold by Iohn Stepneth, […], published 1612; reprinted Menston, Yorkshire: The Scolar Press, 1970, (please specify the GB page), (please specify the scene number in lowercase Roman numerals)

[…] I had once occaſion to diſtil in a ſmall Retort ſome Gold amalgamed vvith ſuch a fine and ſubtile Mercury, that being (vvithout the addition of any Salt) put to the Gold in the cold, they preſently grevv hot together.

1684, Robert Boyle, “An Essay on the Porousness of Solid Bodies. Chapter VIII.”, in Experiments and Considerations about the Porosity of Bodies, in Two Essays, London: […] Sam[uel] Smith […], page 143