Mellon Collection, Yale University Library MS. 50. 50 folios. Paper. 146x100mm. 17th Century [c. 1620.] Johann Grasshof [Grasseus, Chortalasseus, Condeesyanus]. [Holograph alchemical notebook in Latin and German, with a later inserted leaf in English.] f19r-30r [12 coloured illustrations of the 'Donum Dei' series.] f30v-33v, f36f [Coloured drawings of furnaces and apparatus.] f41r [Coloured drawing of a crowned female figure bestride two fountains.]