'Bronze disease' or the gradual decomposition of bronze when buried over a period of centuries, is one of the problems being tackled by the Oriental Art Laboratory located in the basement of the Fogg Museum, in connection with the Chemical department.
Research is being conducted on a set of Chinese mirrors sent over by James M. Plumer '21, now in the employ of the Chinese Customs Service. This 'disease' has long puzzled archeologists, and it is hoped that chemical analysis will not only disclose the cause of this metallic 'alment', but that the actual rate of decomposition will also be discovered, providing a fairly accurate test as to its age.
Another result of these experiments is doubt thrown on the probability that a mercury amalgam was used on the face of the mirrors. No effects of a mercury amalgam was used on the face of the mirrors. No effects of a mercury coating have been discovered, and it has been found that the particular alloy of which they are made will polish to a shiny, silver surface. Replicas of the same alloy are now being made for further experimentation.
The research laboratory is one of the most complete in existence. Surrounded by shelves containing over 13,000 mounted photographs, a small staff of secretaries is kept busy cataloguing the collection for convenient research purposes. theatrical producers have availed themselves of the complete files to study continuing as well as many emluent authorition on Oriental Art.
A collection of rubbings, one of the largest in existence, is perhaps the most unique treasure of this department. These 'rubbings' are outlines of Chinese reliefs stamped on specially prepared paper, and are particularly valuable because so many of the originals have been destroyed recently by bandits.
Rubbings are made by placing a large sheet of paper over the area that is to be reproduced and pushing it carefully into the interstices of the relief so that it makes a closely fitting cover. an inked pad is then rubbed lightly over the surface inking the high spots of the relief and producing an accurate impression of the figures.
Although professing to be a scientific organization members of this department will proudly profess that they own a magic mirror. Producing this flendish article the Fogg conjurer will let you examine it until you are satisfied that it contains no hidden hingos or occult openings. It appears to be very similar to the other bronze mirrors of the collection, with one surface polished and a design carved on the back. Then, with sleeves figuratively rolled, the master of magic will reflect a beam of sunlight on a wall --and, hocus poems, the design on the back is projected by the beam of light.
The explanation of this phenomenon is as follows: the surface of the mirror was polished and kept bright by generations of owners. Every time that it was polished, it was rested on its back, or carved surface. Through constant repetition of this act, the metal between the points of contact sunk, imperceptibly, but enough to allow the design on the back to be reflected from the shiny surface.