Iron Pyrites in petrified Wood
The upper specimen seems to have been part of a cylindrical piece of wood, and was found 260 feet below the surface of the earth in digging a well in Richmond Park in 1804, It appears to have had worm-holes, or holes of Terebellæ, perforating it in various directions, which may be presumed to have happened before the process called petrifying had taken place, f fab may more properly be called Pyritaceous Wood, as the Pyrites or Sulphuret of Iron has filled the pores of the wood so perfectly, that the shape, and somewhat of the texture of wood, was seen, but as if formed of Pyrites. The worm-holes, some lined with Pyrites, and others doubly lined. One side being nearly covered with Pyrites makes it a beautiful specimen, as well as an instructive one. The lower piece was perhaps of different wood, appearing like part of a plank. This was found 100 feet deep in digging a well for Mr. Truman’s brewhouse, Spitalfields, London, The worm-holes are lined like the other; but they seem to hive been a particular species which prefer a straight direction, crossing the fibres of the wood. It is somewhat remarkable that the woody nature remains, and being found damp and fully saturated with the Pyrites, it cracked and contracted from it, and is held together in some parts as if artificially done with wires, and is in some parts curved and warped, Thus, although these pieces of wood seem to have been many years under this process, they are not much changed, but I may say rather, preserved, as, now it is exposed to the common air, these changes which show its nature have become evident; it will soon fall to decay, in the same manner as some part has already done. The Iron and Sulphur decomposing the water of the atmosphere, the Sulphur becoming acidified dissolves the Iron, forming green vitriol or Sulphate of Iron which is very deliquescent.