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found in the ruins of Herculaneum. 
years that they have been exposed to the atmosphere. I 
found that a fragment of a brown MS. kept for a few weeks 
in a portion of air confined by mercury, had caused the dis- 
appearance of a considerable part of the oxygene, and the 
formation of much carbonic acid. 
Plate XI. 
Fig. 1. represents a papyrus partly unrolled, with the 
ink-stand and reed for writing used by the ancients. 
Fig. 2. represents a box of papyri ; both copied from the 
“ Pitture antiche d’Ercolano." 
Plate XII. 
Fig. l. is a specimen of an unrolled papyrus, which is so 
destroyed, that the letters of different columns appear through 
the folds, as if they formed one column. 
Figs. 2 and 3. are specimens of fragments, in which the 
lines begin with Greek capitals. 
Plate XIII. 
Contains a specimen of a fragment of a Roman MS. of 
which the characters are partly Greek. 
