Catalogue Entry: ALCH00135

Incomplete copy, in (probably) the author's hand, of a six-chapter version of William Yworth's 'Processus Mysterii Magni Philosophicus' (1702).

Author: Isaac Newton

Source: Mellon Alchemical Mss Mellon Ms. 80, Beinecke Library, Yale University, New Haven, Connecticut, USA

Custodial History

Bought at the Sotheby sale by Heffers for £3.10s.

Sotheby Lot



Prefaced by 'A short Epistle to my Children'. Dated 1702 on f. 6r, and signed 'Wiliam Yarworth V.D.' on ff. 7r and 9v.


This is the only known instance of this author calling himself 'Yarworth': in all his other printed or manuscript material he appears as 'Yworth', 'Y-worth' or 'Y.worth'. This has often been taken as an abbrevation of 'Yarworth', but Figala and Petzold suggest ('Alchemy in the Newtonian circle', 181-2) that it may rather be an anglicisation of a Dutch form such as Ijvaert, as the author was by his own account Dutch by birth.

Cf. Keynes Mss. 65, 66 and 91, and Hampshire Record Office Ms. NC17. On Yworth generally and his association with Newton, see Figala and Petzold, 'Alchemy in the Newtonian circle', esp. p. 187 for this manuscript. See also 'McPhail, Alchemy and the Occult, 4: 484-6, where the manuscript is incorrectly identified as SL116 (which is in fact Hampshire Record Office Ms. NC17: Figala and Petzold are also mistaken in describing the whereabouts of SL116 as unknown (pp. 180, n. 25 and 187, n. 60)).

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Professor Rob Iliffe
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