London, Wellcome Institute MS. 2592. 74 folios + 54 folios. 230x190mm. 19th Century [1857] [Grasshof, Johann.] Aperta Arca Arcani Artificiosissimi (By F. Grassius otherwise called Cortalasius). The Chest open and opened by the Great and Little Baur (Klein Baur), or the Treatise of the greatest and most secret Mysteries of Nature, together with the right and veritable Physica Naturalis Rotunda, and now made entirely intelligible by the Chemico-Cabalistical Figure. Also: Cautions or a Warning, Instructions and Proofs against all those who falsely persuade other people and themselves that they are able to prepare the Aurum Potabile without the Tincture of the Universal Lapis Philosophorum in less time by itself. Hamburgh & Stockholm. 1687. Translated by D.R.N. [?] and C.W.H. Michelser [?] 1847. Copied from the rough. Constantinople. April, 1857. [The 'Aperta Arca' seems first to have been published under the title 'Der Kleine Baur' in a slightly different version, at Frankfort in 1617. It was included in Zetzner's 'Theatrum Chemicum' Vol VI, 1661 in Latin.] [The 'Cautions' were published originally as 'Warnung' at Cologne in 1607, and were possibly written by Franz, Krelle.] [The two translators are the Rev. W.A. Ayton, and C. W. Hoyland.] [Followed by a work on heraldry.] [See MS. Wellcome 2591.]