Sir Humphry Davy. : 239 
those pigments which have retained their freshness and brilliancy 
through so: many centuries. By such means, the artist is taught how 
to prepare for himself the azure of Egypt and the purple of Tyre. 
The manuscripts found in the ruins of Herculaneum, originally 1696 
in number,* excited the hopes of the scholar, that could some 
method be devised for unrolling them, we should find many of those 
works of the ancients, (as the deficient parts of Aristotle or of Livy) 
the loss of which is so deeply deplored. Sir Humphry had made a 
few experiments on certain fragments of papyri while in England: in 
1818, which encouraged the belief that chemical agents might be 
found, which could be so applied to the manuscripts, as to separate 
their folds without destroying their texture. Lord Liverpool, Lord 
Castlereagh, and even the Prince Regent, afforded ample means for 
defraying the expenses of such an undertaking ; and the experiments 
were prosecuted for two months upon the MSS. belonging to the 
Museum at Naples. During this period he succeeded in partially 
unrolling twenty-three MSS., and he examined about one hundre¢ 
and twenty more which afforded no hopes of success. In addition 
to the labor, in itself difficult and unpleasant, he had to encounter un+ 
expected obstacles thrown in his way by the jealous superintendants 
of the Museum; and he was therefore induced to abandon the un- 
dertaking, before he had fulfilled the anticipations he had inspired. 
The enterprize, however, does not appear to have been entirely abor- 
tive. Its results threw some light upon the charaeter of this collec- 
tion of manuscripts, and upon the modes of writing employed by the 
ancients, : 9 fos | 
The volcano of Vesuvius presented an object to his curiosity 
unembarrassed by any impediments of human jealousy. It was 
the more interesting to our philosophic observer; because at af- 
forded peculiar facilities for comparing its phenomena with a conjec- 
ture he had thrown out in a paper on the decomposition of the earths, 
published in the Philosophical Transactions in 1812, that the metals 
of the alkalies and earths might exist in the interior of the globe ; 
and on being exposed to the action of air and water, give rise to vol- 
canic fires. .'The facts as observed at Vesuvius, appeared to strength- 
en this supposition, and the opinion is evidently gaining ground amon 
geologists. + 
"SU Piaee 2081. = oe et at ge 
t See * Outline of the Course of Geological Lectures” of Professor Silliman, p. 
415. 
