Konigsberg & Leipzig: Grafe & Unzer; L. Voss, 1854 - 1855. 8vo. 2 vols. in one. 47, ; 42,  pp. I: SECOND EDITION II: FIRST EDITION. Contemporary cloth-backed marbled boards; an excellent copy with browning to a few leaves. Item #4909
I: Second edition (printed the same year as the first). This extremely rare paper (On the Interaction of Natural Forces, and Recent Physical Discoveries Bearing on the Same), considered Helmholtz's most brilliant scientific lecture, was given in direct response to Clausius' assault of his landmark work, Über die Erhaltung der Kraft (On the Conservation of Energy), first read in 1847 before the Berlin Physical Society. Helmholtz here refutes the attack, using a facile style to give a more concise account of the principle. In a masterly exposition intelligible to all, he communicates his theory of the sun's heat based on his first law of thermodynamics, and noting Robert Mayer's contributions, presents the historical development of the mechanical principles that became the foundation of future scientific endeavors.
II: First edition of this lecture on "human vision," given on the occasion of the unveiling of a Kant memorial in Königsberg. According to Koenigsberger, Helmholtz treats "the subjectivity of the sensations, and of their analogy with Kant's theory, and the psychical processes that underlie the interpretation of our sensations." Being close to Kant in his own philosophy, Helmholtz here correlates the empirical facts of the physiology of the sense organs and the philosophical attitude of Kant, though he states that "I was somewhat hindered in my philosophical exposition by the need of making it popular." (Koenigsberger).
Helmholtz (1821-94) was one of the most versatile scientists of the modern era. He made epic contributions not only to the science of physiological optics but to the fields of acoustics, mathematics, and natural philosophy. A student of Müller at Berlin, he in turn became one of the most influential teachers of the nineteenth century.