British Library MS. Sloane 3721. Paper. Small Quarto. 103 folios. Beginning of 17th Century. 1. Extracts 'taken out of the Rose yarde of Philosophers'. ff.1,45. 2. 'The true coppie of a booke that was written and made by Trevisonn earle of Marche, touching the Philosophers' Stone'. ff.2-47. Printed in Latin in the Theatrum Chemicum, Vol I, p.748. The following note occurs at the end of the treatise; 'For Francis Archer this booke was written by Willam Burghe, ended the 8th daie of Marche, 1601'. 3. 'Ripley his Medulla or Marrrowe of Alkamie'. ff.48-71. Printed in Latin, (but with some variation from the present copy, at the commencement and end), among 'Georgii Riplaei Opera omnia Chemica'; ed. Cassellis, 8 vo, 1649, p.123. At the end occurs the following note: 'Heare endeth the treatis called the Marrowe of Alkamie, compiled by George Ripley, the yeare of our Lorde God 1476. Hee died in anno 1490. Soe that this booke was written 14 yeares before his death'. 4. 'Of the generation of animals; taken out of Artefius'; a part of the third chapter of his 'Clavis Majoris sapientiae'. ff.77-86. Printed in Latin, in the Theatrum Chemicum. ed Argentorati, tom IV. p.236. 6. An extract from Marsilius Ficinus, relating to the generation of mettals. f.87. 7. Translation of the second, third and fourth canons of the treatise 'De consideratione Quintae Essentiae omnium rerum' by Johannes de Rupescissa. ff.88-101. They vary considerably from the printed Latin copy. 8. Fragment of an Alchemical treatise. f.102.