Letter concerning the loss, by 'Chance (or which is more likely) Fraud', of 'the Manuscript about the Examen & Improvement of the Materia Medica' Some overlap with `Previous Hydrostatical Way of Estimating Ores' ('Medicina Hydrostatica'), section I, opening paragraph; however, it could relate to a different, otherwise unpublished work.\r\nHand: Greg, correc by Boyle c 1680