PLATE 1. * 
PETRIFIED WOOD. WOODSTONE, 
PHYTOLITHUS Lythoxylon C^luercus) texturi 
ligni querni. S. t. 
Petrified wood ; the original apparently oak. 
Not very common in Derbyshire ; specimens occur now 
and then in our gravel pits, and in the water-courses of our 
lead-mines, &c. but they are by no means frequent — ^They 
have also been found bedded in clay, near Eyem, at a 
considerable depth in the limestone strata — It should be 
remarked, however, that the clay, in this instance, did not 
form a regular stratum; it was merely lodged in perpen- 
dicular cavities or fissures communicating with the surface, 
through which the adventitious vegetable matter had, in all 
probability, been introduced. 
The specimen represented in the adjoining plate was 
sawn from a large trunk-like body of petrified wood dis- 
covered several years ago, near Ashford, on clearing an 
old level where the original seemingly had been placed 
as a prop for the support of some part of the roof. Its 
The figures, In each plate, the size of the specimens, except where the 
contrary is noted. 
t An horizontal Perforation through the side of a hill. See. for the pur- 
pose of carrying olF the water from the neighbouring mines. 
A 
