HELMHOLTZ, HERMANN VON. Populäre wissenschaftliche Vorträge.<> Wood-engraved text illustrations. Half-titles. 3 volumes in 2. 8vo, sizes not uniform, Volume 1/2 in contemporary cloth, spine faded, Volume 3 in contemporary 1/4 sheep, portion missing from bottom of spine. Braunschweig, 1865-71-76
