192 Sir Humphry Davy on the papyri 
a description of the rolls in the Museum at Naples, and of 
some analytical experiments I made upon them. Thirdly, 
a detail of the various chemical processes carried on in the 
Museum at Naples on the MSS., and of the reasons which 
induced me to renounce my undertaking before it was corn- 
pleated. And lastly, some general observations on the MSS- 
of the ancients. 
I trust these matters will not be found wholly devoid of 
interest by the Society, and that they will excuse some repe- 
titions of what I have stated in the report before referred 
to, as they are necessary for a complete elucidation of the 
subject. 
is£. An account of some experiments made in England on frag- 
ments of papyri in 1818. 
In examining, chemically, some fragments of a roll of 
papyrus found at Herculaneum, the leaves of which adhered 
very strongly together, I found that it afforded, by exposure 
to heat, a considerable quantity of gaseous matter, which was 
principally inflammable gas, and when acted on by muriatic 
or nitric ether, it coloured them ; and when it was exposed 
to heat after the action of these fluids, there was an evident 
separation of the leaves of the MS. 
Chlorine and iodine, it is well known, have no action upon 
pure carbonaceous substances, and a strong attraction for 
hydrogen ; and it occurred to me, that these bodies might 
with propriety be used in attempting to destroy the matter 
which caused the adhesion of the leaves, without the possi- 
bility of injuring the letters on the papyri, the ink of the 
aiicients, as it is well known, being composed of charcoal. 
