Note 448 — Chapter II · DOMESTIC AFFAIRS OF SPAIN.
Reading edition
Examples equally ancient, of both forms of spelling the name, may be found; though Escorial, now universal in the Castilian, seems to have been also the more common from the first. The word is derived from scoriæ, the dross of iron-mines, found near the spot.—See Ford, Handbook for Spain (3rd edition), p. 751.