Photogravure of a photo portrait of German physician and physicist Hermann von Helmhotz in his later years; most famous for his work on acoustics and the conversion of energy. His signature reproduced below the portrait. Verlag von Wilhelm Engelmann in Leipzig. Photogravure Meisenbach Riffarth & Co. Berlin
Photo includes Linus Pauling, Robert Corey, George Beadle and Albert Tyler. Biochemistry and Chemistry [incl. Individuals; Pasadena Conf. on the Structure of Proteins. 21-25 Sept., 1953]
Photograph of an etched portrait of Alessandro Volta; engraving done by Raffaello Morghen (1758-1833), after a drawing by Italian artist Luigi Sabatelli (1772-1850).