Etymology Dictionary

ALLOY,  a due proportion in mixing metals.  (F.,—L.)   [The verb to alloy is made from the substantive, which is frequently spelt alay or allay, though wholly unconnected with the verb allay, to assuage.]   M.E. sb. alay; Chaucer has the pl. alayes, C. T. 9043.   The sing. alay is in P. Plowman. B. xv. 342; the pp. alayed, alloyed, is in P. Plowman, C. xviii. 79.—O.F. a lai, a lei, according to law or rule.—Lat. ad legem, according to rule, a phrase used with reference to the mixing of metals in coinage.   'Unusquisque denarius cudatur et fiat ad legem undecim denariorum;' Ducange.   See Law.   ¶ In Spanish, the same word ley means both 'law' and 'alloy;' á la ley means 'neatly;' á toda ley means 'according to rule;' and alear is 'to alloy.' [※]

ERRATA

To combine metals, to mix gold and silver with metals of less value.  (F.,—L.)   The etymology given above is the popular one, and is adopted by Diez, Scheler, and Littré, though the last of these expresses doubt.   But it is certainly wrong, and due to a misunderstanding of early date, since even Cotgrave gives aloy with one l, as if it were compounded of a and loy, law.   The truth is that the sb. is a derivative of the verb.   We already find the pp. alayed in P. Plowman, B. xv. 346.   This is from an Anglo-F. alayer*, equivalent to O.F. aleier, aloier, old spelling of F. allier; see allier in Littré; and cf. s’aleier in Chanson de Roland, l. 990.   Cotgrave gives alier, allier, 'to stiffen, or imbase gold, &c, by mingling it with other metals.'—Lat. alligare, to bind fast.—Lat. al-, for ad, to; ligare, to bind.   Thus alloy is a doublet of Ally, q.v.   β. The etymology is proved by Ital. legare, 'to solder or combine mettals,' Florio; whence the sb. lega, 'aloy,' id.; for lega can only be derived from legare, and could not have come from Lat. acc. legem (which gave Ital. legge).   Cf. also Port. ligar, 'to allay metals;' whence liga, sb., 'allaying of metals;' Vieyra.   Even Spanish has ligar, to alloy, liga, alloy, as well as the comp. alear, to alloy.   The derivation from ligare thus becomes irrefutable.   The Anglo-F. alay, sb., occurs in the Stat. of the Realm, i. 140, an. 1300.   Godefroy, s.v. aloier, cites several examples of the spelling allayer.