1102.5 Jan Frederick HELVETIUS. Vitulus Aureus, Quem Mundus adorat et orat, In quo tractatur de Rarissimo Naturæ Miraculo transmutandi Metalla, Nempe Quomodo Tota Plumbi substantia vel intra momentum ex quavis minima Lapidis veri Philosophici particula in Aurum obryzum commutata fuerit Hagæ-Comitis. Editio secunda auctior, et emendatior. 8° Hagæ-Comitis, Apud Johannem Kitto, Bibliopolam 1702 Ferguson Wolfenbuttel [Illustration:- Engraving inserted after page 6. 95x135mm. Depiction of medal struck to commemorate a transmutation performed at Prague on the 15th January 1648 in the presence of Emperor Ferdinand III. See Becher, 'Institutiones chimicae prodromae', 1664.]