368 yfnulijih of Scientific Books. 



covered by a shower of ashes, which must have been cold, as 

 they fell at a distance of seven or eight miles from the crater of 

 Vesuvius. Among the Neapolitan manuscript's there are some 

 covered with a glossy substance resembling varnish, arising. 

 Sir Humphry suggests, from the decomposition of the skin used 

 to infold them, and now converted into a brilliant animal 

 charcoal, leaving phosphate of lime when burned, but produc- 

 ing at the same time no inconsiderable quantity of ammonia. 



One method only has been adopted for. unrolling these fragile 

 coils of carbonized papyrus ; it consists in applying thin animal 

 membrane (gold-beaters' skin), by a solution of glue to the back 

 of the manuscript, and carefully elevating the layers by a silk 

 thread,when the glue is dry. Alcohol and ether were found 

 useful auxiliaries in this operation, and great advantage was also 

 derived from throwing warm air upon the surface of the leaves, 

 with precautions which are pointed out in the paper before us. 

 The different MSS., however, required very different treatment. 



During the two months that Sir H. Davy was employed in 

 these experiments at Naples, he succeeded, with the assistance 

 of the persons attached to the Museum, in partially unrolling 

 twenty-three MSS., from which fragments of writing were 

 obtained, and in examining about 120 others which gave no 

 hopes of success : 



And I should gladly have gone on with the undertaking, from the mere 

 prospect of a possil))lity of discovering some better results, had not the 

 labour, in itself difficult and unpleasant, been made more so, by the con- 

 duct of the persons at the head of this department in the Museum. At 

 first every disposition was shewn to promote my researches ; for the papyri 

 remaining unrolled were considered by them as incapable of affording any 

 thing legible by the former methods, or, to use their own word, dhperati ; 

 and the efficacy and use of the new processes were fully allowed by the 

 Svolgatori or unroUers of the Museum : and I was for some time permitted 

 to choose and operate upon the specimens at my own pleasure. When, 

 however, the Reverend Peter Elmsley, whose zeal for tlie promotion of 

 ancient literature brought him to Naples for the purpose of assisting in 

 tiie undertaking, began to examine the fragments unrolled, a jealousy, with 

 regard to his assistance, was immediately manifested ; and obstacles, which 

 the kind interference of Sir William A'Court was not always capable of 

 removing, were soon opposed to the progress of our inquiries ; and these 

 obstacles were so multiplied, and made so vexatious towards the end of 

 February, that we conceived it would be both a waste of the public money, 

 and a compromise of our own characters, to proceed. 



In respect to the date of these MSS., Sir Humphry remarks 

 that, from the mixture of Greek and Roman characters, it is 

 probable some of them were very ancient when buried. The 

 ink with which they were written was a mixture of charcoal and 

 glue, and from the omission of any mention by Pliny of an ink 

 of galls and iron, it is not probable that it was used up to his 

 period, but that parchment and our present writing ink were 

 adopted together, " for a mixture of charcoal and solution of 



