Essai sur l’Optique

Émilie Du Châtelet, Essai sur l’Optique

Émilie Du Châtelet worked on various scientific topics during the late 1730s, and the Essai sur l’Optique, or “essay on optics,” comes from that period. It shares much in common with her essay on the nature and propagation of fire, and serves as an important counterpoint to some aspects of her major later work, the Foundations of Physics.

Scholars have known about Du Châtelet’s Essai sur l’Optique for many years. Until recently the text has been unavailable, however, because all copies were thought to be lost. In 1947 Ira O. Wade published the first known edition of the Essai’s fourth chapter, which was held among Voltaire’s papers in Russia. Sixty years later, Fritz Nagel, Director of the Basel Research Center of the Bernoulli Edition, discovered the first complete copy of the Essai in the Bernoulli archives in Basel. Two other complete copies, which had previously gone unnoticed, were then discovered among Du Châtelet’s surviving manuscript material.

About this edition

This transcription of Émilie Du Châtelet’s Essai sur l’Optique is based on the copy located in the Universitätsbibliothek Basel (L I a 755, fo. 230–265). The text has been normalized, to reflect modern French spellings and grammar and to reduce the ambiguity of crossed-out sections, illegible markings, and errata. For information about the forthcoming translation and critical edition of this essay and updates on its progress, visit Further questions regarding the method for creating this transcription may be directed to Project Vox (

How to Cite this Text

This transcription is made available through an agreement with the Universitätsbibliothek Basel and may not be republished without permission. A recommended citation is below.