The pseudonym for W.(illiam) Yworth [Y-Worth], a spagyrick
physician, chemist and "Philosopher by Fire" from Rotterdam;
an associate of Isacc Newton who acted as a patron.
published works where written under the pen-name Mystagogus:
"Mercury's Caducean rod." The second edition. London,
"Trifertes sangani, or immortal dissolvent." London,
his other published works are a six-chapter version of 'Processus
Mysterii Magni Philosophicus', in English; Prefaced by 'A short
Epistle to my Children'. Dated 1702, and signed 'Wiliam Yarworth
V.D.' 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
Whole Art of Distillation", 1692, later became titled as
the second edition printed in London, 1705 by J. Taylor as "The
compleat distiller "
used the surname Y-Worth.