The letters discuss practical arangements for the stay. Joseph Needham's letter stresses the need for help in the history of chemistry area. He suggests that 'it might be a great help if you would have a look at some of the alchemical books in the Tao Tsang' and mentions an 'invaluable memorandum' by Tshao Thien-Chhin [曹天欽 / Cao Tianqin] 'based on a thorough investigation of these alchemical books'. Joseph Needham's letter is also concerned with comets as 'we have been having great excitement here about the Arend-Roland comet'.