N. P. Bigelow
The University of Rochester
R. Wiegandt
George Eastman House
Daguerreotypes are the first photographic images, formed by a process Louis-Jacques-Mandé Daguerre invented in 1839. It was the mode of photography in the United States from that year until about the time of the US Civil War. Daguerreotypes are unique, nonreproducible images of almost unbelievable clarity— yet in many cases they are deteriorating before our eyes. At the University of Rochester and George Eastman House / International Center of Photography, we are using a range of techniques centered around tools in the University’s nanocenter to address the understanding and conservation of these invaluable cultural heritage items.
Scientific advances in the chemistry and physics of nano-scale materials, especially silver and gold, require reconsideration of our material understanding of the daguerreotype and will be a central theme of the talk.
Our research on the daguerreotype image exhibits predominately nanoscale physical properties. As molecular structures approach discrete dimensions of several hundred nanometers and below, elemental surface properties become increasingly dominant and do not conform to the general properties of the bulk material. This paper presents a nanometer scale perspective on the daguerreotype and itshas profound conservation implications.
Micron scale and macro properties of metals have been the basis for commonly held explanations of image formation, tarnish, oxidation, and environmental deterioration. Consequently, daguerreotype restorative treatments and preservation methods, both historically and currently, appear to alter the original structure in the former, and are inadequate for preventing progressive deterioration in the latter.
Taking into account the expanding body of research on the unique physical and optical properties of silver and gold, and to a lesser extent copper and mercury, we apply this recent research to our investigation of the daguerreotype. This paper proposes new insight into the extraordinary bio-receptivity of the daguerreotype surface, the optical effects that occur when gold and silver nanoparticles have dimensions considerably smaller than the wavelength of the visible light spectrum and the step-by-step impact of the image formation on nanoscale material science.