Alan Stewart (ed.), The Oxford Francis Bacon, Vol. 1: Early Writings 1584-1596
The only known witness to the epistle is
TNA, SP 12/242 item 18 (fos. 45v–47r)
tna, sp 12/242, item 18 (fos. 45v–47v) (N)
Item 18 is a tract of three leaves (a bifolium, letter-size). The body-text runs from fo. 45v to 47r; it is written in a regular, upright, professional mixed hand, with Latin tags and one marginal note in italic. The piece is titled on fo. 45v and endorsed on fo. 47v in a different hand. The paper was folded for archiving, and discoloration on fo. 47v suggests that the third quarter of this page was the outside cover when folded.
This item has been preserved probably throughout its existence in the Paper Office, subsequently the Public Record Office, and now the National Archives. Many of the papers of this period were once in the possession of William Cecil, Lord Burghley. N's current location in State Papers 12/242 is as a result of the calendar drawn up by Mary Anne Everett Green, and almost certainly is misrepresentative of the date of its copying (Bacon's response to Verstegan's Declaration dates from early 1593 rather than May 1592). It seems likely that it was archived with item 17, a manuscript copy of Verstegan's Declaration.