Can you imagine anything more horrifying for a curator at a museum to open a show with priceless examples of an art that is no longer practiced to find that the materials are deteriorating as you watch? Daniel Grushkin in his Dec. 12, 2012 article [full article is behind a paywall, link to preview] for Scientific American magazine sporting two titles: The Case of the Disappearing Daguerreotypes or Nano-Scientists Attempt to Save Disintegrating Artworks describes just what happened at the International Center of Photography’s (based in New York City) “Young America” exhibit of dageurreotypes in 2005 and the aftermath,

… These were the works of Albert Sands Southworth and Josiah Johnson Hawes, the Rembrandts of daguerreotypy — the first practical form of photography. A demure bride in white silk crepe fingered her ribbons; the stern and haughty statesman Daniel Webster glared from behind his brow. When the “Young America” exhibit opened in 2005, its 150-year-old images captured American icons at a time when the nation was transitioning from adolescence into a world power. “Each picture glows on the wall like a stone in a mood ring,” the New York Times raved in its review.

Yet after a month on exhibit, the silver plate-bound images began to degrade. … By the end of the two-and-a-half-month show, 25 daguerreotypes had been damaged, five of them critically.

Where daguerreotypes are concerned there is only an original as copying the image is not possible,

The vanishing images suggested that any daguerreotype could spontaneously crumble. Collectors feared they would lose their million-dollar collections. Conservators feared these windows into the 19th century might simply cloud over.

Taking action led to some unexpected places,

“I’ve been a conservator for nearly 30 years, and this object stands apart,” he [Ralph Wiegandt, a conservator at Eastman House who had designed the lighting and cases for the “Young America” exhibit] says. “Its entire meaning is in a molecular layer or two.” Because of the complex physics on the silver surface of daguerreotypes, the crisis called for an unlikely collaboration.

Wiegandt needed to partner with physicists. And in the course of their quest to understand the fading images, he and his partners would uncover surprising new molecular effects at the nanoscale. In doing so, the accidental relics of a 150-year-old technology may perhaps inspire the future of engineering.

Here’s what the researchers (Wiegandt and Nicholas Bigelow, physics and astronomy department chair at the University of Rochester) discovered,

Louis-Jacques-Mandé Daguerre, a Parisian artist and showman, introduced the medium in 1839, after a decade of searching for a way to fix an image on a silver plate. One day, the story goes, he accidentally broke a thermometer and absently put it in a cabinet with his silver plates. The following day he found that the mercury vapor had somehow made the image permanent. Daguerre had discovered the chemistry of image making. “What was really going on was self-assembling nano-structures,” Bigelow says. “Whether or not he meant to, he was doing nanoengineering.”

As noted in Grushkin’s article there are many reasons why daguerreotypes are fragile from above and, surprisingly, below,

… In collaboration with researchers at Kodak, Wiegandt’s team punched a 30-micron-long rectangle through the surface of sample daguerreotypes using a focused ion beam. They then examined the layers in cross section. To their surprise, they saw 300-nanometer-wide voids just under the surface — a network of tunnels running just beneath the image.

…

The voids could explain why some of the daguerreotypes in the exhibit showed damage. Over the course of 150 years chlorine or other contaminants might have seeped into these voids. When the pictures went on display, light may have triggered subsurface reactions between the chlorine and silver, causing the images to sprout spots from below.

Unfortunately, the damage cannot be repaired but Wiegandt and his colleagues will be able to use the information to help preserve remaining daguerreotypes. Grushkin’s article does not speculate about how these discoveries might be applied to nanoscale engineering but I imagine that would entail another article.

*’Dageurreotypes’ corrected to ‘Daguerreotypes’ on Nov. 16, 2015.