Letter, from Antoni van Leeuwenhoek to the Royal Society, dated at Delft Signed letter Concerning the difference in the growth of wood felled in different seasons, and also differences in wood grown in different countries; discussion on the durability of wood; an account of the annual growth rings of oak; discussion of wood for cooperage; causes for different ring widths; explains how wooden barrels can be watertight Leeuwenhoek adds a postscript about prawns Two figures attached (not by Leeuwenhoek) Partial English translation see EL/L2/7 Transcribed and translated in 'Alle de brieven van Antoni van Leeuwenhoek', edited, illustrated and annotated by Committee of Dutch Scientists, vol 6, p 125 English extract printed in 'Philosophical Transactions', vol 18, no 213, p 224 10 July 1686