PhUoiopkiad Tninsaciious. 



307 



caith, deduced from the preceding observations by Captain 

 Katcrs method, described in the Philosophical Transactions tor 

 1819. 



2. Some Observations and Expcmnents on the Papyri, foiaid in 



the Ruins of Herculaneum. By Sir Humphry Davy, Bart. 



P.R.S. 



In this paper Sir Humphry Davy gives an accoimt of his first 

 experiments upon fragments of papyri, which mduced hira to 

 hope that chemistry might afford assistance towards unrolimg 

 the MSS. He then describes those in the Museum at Naples, 

 and the processes caiTied on there, and concludes with some 

 general observations on the manuscripts of the ancients. The 

 following is a brief outline of the interesting contents of this 

 communication : . ,. i i i 



The papyri in question appear to consist of leaves reduced 

 to the state of cinder, cemented by a matter soluble in certain 

 liquids, and especially in muriatic and nitnc ether ; now, as 

 chlorine, while it has a strong attraction for hydrogen, exerts 

 no action upon carbonaceous substances, and as charcoal lorms 

 the basis of ancient writing-ink, it occurred to Sir Humphry 

 that that gas might be usefully applied to destroy the adhe- 

 siveness of the layers ; he therefore tried it and some other 

 agents, possessed of analogous properties, and his attempts were 

 to a certain extent successful. , •. 



The state of the Neapolitan specimens, and the general exist- 

 ence in them of undecomposed vegetable matter, suggest some 

 curious remarks respecting the origin of the changes which they 

 have suffered, and which have conmionly been referred to the ac- 

 tion of fire ; the part of 1 lerculaneum, however, in which they were 

 found was not inundated by lava, but covered by sand and ashes, 

 cemented together by the operation of water ; and again, that 

 fire is not necessary for the carbonization displayed by the ma- 

 nuscripts, is inferred from the state of the wood in the houses 

 at Pompeii, which is always converted into charcoal, tlimi^jli 



