The case, which was decorated with gold and niello, was much encrusted with layers of horn silver and copper corrosion products, and the metal was very thin and fragile due to intercrystalline corrosion which had produced a structure in which more or less discrete crystals of silver were held together by corrosion products. The lid was removed by local treatment of the corrosion products which cemented it in place using 15% ammonium thiosulphate solution applied with a glass fibre brush to remove horn silver and hot 30% aqueous formic acid applied sparingly on cotton wool swabs under the microscope to remove copper minerals. After the lid was removed the body was consolidated with a liner made from fibre glass impregnated with polyvinyl acetate (Grade AYAF, Bakelite Ltd.) applied as a solution in acetone with special precautions to reduce shrinkage. The remaining surface corrosion layers were then removed by repeated application of ammonium thiosulphate and hot formic acid and after washing, drying and polishing, the case was given a thin coating of lacquer. A note on the niello records that its electrical resistance is low suggesting that it was of the mixed sulphide type. -- AATA