 He did however spend a number of years on the continent, and after his return to England he wrote his work "The Compound of Alchemy; or, the Twelve Gates leading to the Discovery of the Philosopher's Stone" ("Liber Duodecim Portarum") in 1471.The "Cantilena Riplaei" is one of the very first poetic compositions on the subject of alchemy.Most of Ripley's work is based on the work of pseudo-Ramon Lull, although "The Compound of Alchemy" is based largely on the work of a little-known alchemist of the fifteenth century, named Guido de Montanor.