Letter, from Martin Lister to Henry Oldenburg, dated at York Signed autograph Sends a list of people who are believed to be elderly; outlining an experiment to extract sap from different trees and fruit bushes Read to the Royal Society on 30 March 1670 Transcription in 'The correspondence of Henry Oldenburg', ed and trans by A Rupert Hall & Marie Boas Hall, vol 7, p 521 Partially printed in 'Philosophical Transactions', vol 6, no 70, p 2123 17 March 1670