Manly Palmer Hall [P.R.S.] MS. 214. 165 folios. 206 x 162mm. 18th Century. [This is included in the Bacstrom Collection MS. 102, Vol. 4.] Letters of Michael Sendivogius to the Rosey Crucian Society. Copied from an old Manuscript. [Illustrated with four circular symbolic daigrams on two pages titled 'The Hieroglyphical Seal of the Society of Unknown Philosophers' and one extra-long watercolour illustration of alchemical equipment.] [Edited by Ebenezar Sibley, translation anonymous.]