VH 



so perfectly arranged and coloured, with so little disturb- 

 ance, that the very cracks and broken parts are detected 

 with the utmost precision. Possibly the Oxide of Iron, or 

 colouring substance, does not evaporate with the other prin- 

 ciples : thus the colour of the parts is identically preserved. 

 The specimen is externally somewhat granular, with the 

 appearance of a fine-grained compact Sandstone, more 

 dense in the centre, resembling Flint, and in some parts 

 almost Opal*. 



I have received specimens of this nature from Ireland, 

 through the kindness of Dr. Scott and Mr. Templeton, 

 and from Warwickshire by favour of Lady Aylesford, 

 variously stained, and otherwise acted upon in the same 

 piece, showing that the Wood had been more or less de- 

 composed, or was decomposing in different parts, before 

 the metamorphosis had taken place. Since the above was 

 written His Grace the Duke of Bedford has favoured me 

 with a curious and interesting piece of Petrified Wood, 

 from Aspley, which has the hollows left by some insect 

 very perfect. A most remarkable specimen of this kind, is 

 described in Dr. Smith's Tour on the Continent, v. 3. 113. 



* Wood wholly opalized is sometimes found. 



TAB. CLXIV. 



The former specimen is externally very much allied to a 

 Sandstone, although somewhat more condensed in the 

 middle dt centre ; which often happens. The upper speci- 

 men in this plate is part of a piece found in Fleet-street in 



