Jean-Jacques Rousseau. Letters on the Elements of Botany Addressed to a Lady. Translated into English, with Notes, And Twenty-Four Additional Letters Fully Explaining the System of Linnaeus, by Thomas Martyn. Fifth Edition with Corrections and Improvements. London: Printed for B. And J. White, 1796. (220 x 135 mm) pp. 503 + 28 p. index + single foldout. Blue pastedown and fly leaves. Half title. Owner inscription along top of dedication, Frances Amelia Rundell 1799. Bound in rustic pasteboard to resemble leather with leather spine and green label with gilt title. Some minor discolouration to front board. Top endband a little chipped. Overall VERY GOOD condition. In addition to being one of the most influential philosophers in the Age of Enlightenment, Jean Jaques-Rousseau was also an accomplished botanist. While living in Grenoble, he wrote Letters on the Elements of Botany for the daughter of Madame Delessert in Lyon. The letters were intended to help her learn, so he avoided using the Latin names and created a pedagogy behind his explanations to guide the young lady. The letters were eventually published posthumously to great acclaim. Thomas Martyn, Regius Professor of Botany at the University of Cambridge, took it upon himself to translate the letters from French into English to further their accessibility to an Anglophone audience. He said of the letters that they were intended to be studied not in an armchair, but with a plant in hand to be examined. Frances Amelia Rundell (1780-18550 is fairly obscure in history; however, it appears her name also appears in a 1809 edition of Voltaire’s Historic de l’Empire de Russia sous Pierre le Grand.