Paper, 'Upon the office of the heart wood of trees' by T A [Thomas Andrew] Knight in a letter to the Rt Hon Sir Joseph Banks Subject: Botany Published in Philosophical Transactions as 'On the office of the heart wood of trees. By T. A. Knight, Esq. F .R . S. In a letter addressed to the Rt. Hon. Sir Joseph Banks, Bart. G. C. B. P. R. S'. Written by Knight at Downton. Read 5 February 1818. Abstract published in Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society of London], Volume 2, 1833. 24 December 1817