HELMHOLTZ, HERMANN VON. ber die Erhaltung der Kraft, eine physikalische Abhandlung, vorgetragen in der Sitzung der physikalischen Gesellschaft zu Berlin am 23sten Juli 1847. Berlin: G. Reimer, 1847. 8vo, modern half calf, a few slight stains. FIRST EDITION. Dibner, Heralds 159; Norman 1039; PMM 323 ("...the first comprehensive statement of the first law of thermodynamics: that all modes of energy, heat, light, electricity, and all chemical phenomena, are capable of transformation from one to the other but are indestructible and cannot be created.)