Doctor Wood. Modern Wizard of the Laboratory: The Story of an American Small Boy Who Became the Most Daring and Original Experimental Physicist of Our Day-but Never Grew Up

It wasn’t merely Howard Carter’s private vanity. If the government learned that Wood was trying to take out any of the sequins, he would be searched at the customs house until they were recovered, and Carter would raise public hell — not about “purloining”, but about the proposed unauthorized investigation.

What they did next, I’m letting Wood tell in his own way.

After Lucas had persuaded the Curator, the three of us went to the museum hall accompanied by two uniformed guards who had two separate sets of keys. While popeyed tourists stood around, they opened six separate padlocks and were then compelled to take out about a dozen screws which held down the glass. When the case was opened the Curator whispered to me to pick out what I wanted. I began picking sequins, with continual side glances at the Curator, watching for raised eyebrows. At the eighth, I saw symptoms and said, “Thank you very much, these will suffice”. I had been picking them out with my right hand and holding them in my left. The Curator said sternly and aloud, doubtless to reassure the pop- eyed tourists or perhaps his own guards, “Now give them to me”. He was a sleight-of-hand artist and slipped them back to me before we left the museum.

* * *

The archconspirator had scarcely returned to his hotel when a note was brought to him — from Howard Carter! It turned out, however, as coincidences happily often do, to be merely an invitation to visit the great Egyptologist in his laboratory headquarters in one of the old tombs, in the Valley of the Kings. Wood bearded the lion, and says, “I felt like the boy who’d almost been caught stealing the apples… but at the same time felt a temptation to tell him I had the sequins”.

How Wood found the lost secret of the purple gold, beginning there in Cairo with his wife’s nail polish and ending in the Johns Hopkins laboratories with a series of experiments as strange as any you’ll find in fictional scientific detection, is today a brilliant page in the history of Egyptology and of chemical-physical research. He not only rediscovered the ancient method and proved that the coloring was no accident due to chemical changes, burial, and time, but succeeded in reproducing, by a finally simple technique such as might easily have been known to goldsmiths three thousand years ago, all the gorgeous colors, ranging from roseate dawn pink through rich red, purple, and violet. Here in his own clear words is the story step by step.

My first problem (he explains) was to ascertain whether the colors were simple “interference” effects of thin films (soap-bubble colors) or due to some “resonance” action of minute particles covering the gold surface. This was purely a problem in physical optics. Since interference requires the cooperation of two streams of light reflected from the opposed surfaces of a thin film, the first step in the study appeared to be to destroy the reflection from the outer surface by covering it with a transparent varnish. This experiment I tried in Cairo, employing my wife’s nail polish, the only available material of the desired nature. The color was not destroyed, as it would have been in the case of an interference color, and after the celluloid had become dry, I found that it could be peeled off, carrying the film with it and leaving the underlying gold bright yellow. The film, however, now showed no color, either by transmitted or reflected light. This was as far as I could go at the time, but on my return to my laboratory in Baltimore I deposited metallic gold on the back of the film by cathodic sputtering and found that the purple reflection was restored. These two experiments appeared to show conclusively that we were dealing with something more complicated than simple thin film interference.

The next step was to ascertain the nature of the film. This was done by placing a bit of the celluloid film carrying the film from the sequin between two electrodes of pure gold and photographing the spectrum of a very brief spark discharge. Iron lines were found in the spectrum. A purple sequin was then hung on a very fine glass thread between the poles of an electromagnet, and when the current was turned on, it was drawn to one of the pole pieces. One of the yellow bars from the slipper was thrown out of the magnetic field, showing that it contained no iron, while one of the small purple rosettes was attracted. These two specimens were returned to the museum, as they were needed for the reconstruction of the slipper. They had served their purpose, however, in showing that the purple rosettes contained iron, while the yellow bars were free from it. It was now necessary to find out how the film, presumably iron oxide, had been formed, and whether it was intentionally produced or was an accidental patina resulting from time.