found in the Ruins of Herculaneum. 423 
perature was regulated. When the fragment was too rapidly 
heated, the elastic fluid disengaged usually burst the folds of the 
MS.; and when the heat was lowered too suddenly, the layers 
~ sometimes split in irregular parts, probably from the sudden con- 
traction consequent on quick cooling. 
From the products of the distillation of these fragments, which 
were water, acetous acid, ammonia, carbonic acid, and much in- 
flammable gas, [ inferred that the papyri to which they belonged 
must contain much undecomposed vegetable matter, and could 
not be purely carbonaceous; but as there were great differences 
in the appearances even of the few papyri in England, which 
had been presented to His Majesty George IV. when Prince of 
Wales, an opinion on this subject was more likely to be correct 
when formed after an examination not only of all the MSS. found 
at Herculaneum, but likewise of the circumstances of the excava- 
tions made there; and I had an opportunity, during the time 
I remained at Naples, in two successive winters, to satisfy my 
mind on this subject, and to obtain the information which will 
be given in the next section. 
2dly. On the State of the MSS. found at Herculaneum. 
The persons who have the care of the MSS. found at Hercula- 
neum state that their original number was 1696, and that 431 have 
been operated upon or presented to foreign governments, so that 
1265 ought to remain; but amongst these, by far the larger propor- 
tion are small fragments, or specimens so injured and mutilated 
that there is not the least chance of recovering any portion of 
their contents; and when | first examined the rolls in detail in 
January 1819, it did not appear to me that more than from 80 to 
120 offered proper subjects for experiments; and this estimate, 
as my researches proceeded, appeared much too high. These 
MSS. had been objects of interest for nearly 70 years; the best 
had long ago been operated upon, and those remaining had not 
only undergone injuries from time, but likewise from other causes, 
such as transport, rude examination, and mutilations for the pur- 
pose of determining if they contained characters. 
The appearances of different rolls were extremely various. 
They were of all shades of colours from a light chesnut brown to 
a deep black ; some externally were of a glossy black, like jet, 
which the superintendants called ‘¢ varnished ;” several contained 
the umbilicns or rolling stick in the middle converted into dense 
charcoal. | saw two or three specimens of papyri which had 
the remains of characters on both sides, but in geneval one side 
only was written upon. In their texture they were as various as 
in their colours; the pale brown ones in general presented only 
a kind of skeleton of a leaf, in which the earthy matter -s 
nearly 
