In French. Short description: Euler, Leonhard. Lettres a une princesse d'Allemagne sur divers sujets de physique et de philosophie. [Letters To a Princess of Germany on Various Subjects of Physics and Philosophy]. Volume 2. St. Petersburg, Imperial Printing House, 1768. Letters to a German Princess on Various Physical and Philosophical Matters occupy a special place in the scientific heritage of Leonhard Euler. The essay is written in an epistolary form unusual for Euler and is a presentation of the foundations of natural science and philosophy of that time in its interpretation; it bears a bright imprint of the author's personality, his many years of searching and thinking about the nature of physical phenomena, his ideas about the structure of the Universe, about the philosophical and physical picture of the world. This very serious and complex scientific material is presented in the form of letters-conversations, in which scientific rigor is combined with clarity and accessibility of presentation, designed for an unprepared reader. The Letters were published anonymously, but Euler's authorship was no secret to anyone. For the first time Letters were published in St. Petersburg in French and in Russian translation. Please feel free to contact us for a detailed description of the copies available. SKUMS002189 kn_nat