Letter, from Armand de Gerard to Henry Oldenburg Sends a figure of the philosophical tree of Raymond Lull (c 1235-1315) which he describes (figure not attached). The tree was used to analyse the problems and concepts of medicine. Lists the names of authors of alchemical works and discusses the door of his cathedral at Sarlat in the Dordogne because it has the figures of ten pagan gods 22 October 1673