British Library MS. Sloane 689. Paper. Quarto. 42 folios. 17th Century. 1. f2 'Opus aureum verum, authore Georgio Ripleio, cannonico Bridlingtoniensi, de lapide minerali.' Begins: 'Fili, oportet te intelligere'. [This forms no part of Ripley's printed works.] 2. f20 'Liber secretissimus Georgii Riplei; the whole worke of the composition of the philosophicall stone and grand elixir, and of the first solution of the gross bodies.' Begins: 'Take our antificiall antimony'. [Not in Ripley's printed writings.] 3. f32 'De aquae chaoicalis operationibus miris.' Begins: 'Principium primum et praecipuum'. 4. f37 'De Mercurio philosophorum, et de quibus rebus compositus est.' Begins: 'Arcanum mercurii philosophici'.