Tractility

1673, Robert Boyle, Essays of the Strange Subtilty, Great Efficacy, Determinate Nature of Effluviums, London: M. Pitt, “If the Strange Subtilty of Effluviums,” Chapter 2, p. 8, Silver, whose Ductility and Tractility are very much inferiour to those of Gold, was, by my procuring, drawn out to so slender a Wire, that, when we measur’d it, which was somewhat troublesom to do, with a long and accurate measure, we found, that eight Yards of it did not yet fully counterpoise one Grain:

We shall not […] anticipate these chemical details […] but will confine ourselves at present to that potent talisman “Coal,” at whose bidding, and whilst in a state of combustion, the minerals are decomposed and liquefied, and their gritty, brittle, stony qualities changed to those of tractility and extensibility.