312
ON THE NATURAL HISTORY
year 1838, whereupon the price of brimstone became so high that
chemists cast about for some other source of sulphur, and found
it at hand in the widely-distributed mineral—iron-pyrites. But
as nothing is wasted now-a-days, much of the pyrites, after
having yielded up its sulphur, is utilized for sake of its iron. If
other metals are present so much the better. Thus, the vast
deposits of pyrites in parts of Spain and Portugal contain a small
proportion of copper, which is extracted by a wet process from
the calcined pyrites; and then the residue, which contains the
iron in the form of an oxide, passes to the iron-master, who
knows it as "purple ore" or "blue billy."
The pyrites found in Essex was formerly employed in the
manufacture of copperas, and was therefore often called, as in the
passage already cited from Morant, copperas-stone. Silas Taylor,
in his well-known "History of Harwich,"7 tells us that—
" Upon this Shore also within the Flow of the Sea, are gathered as they are
commonly called Copperas-stones and carried to certain Copperas-Houses not far
distant from hence. Where being mixed with Earth and disposed into light Beds,
it dissolves by the Rain from the Sky, which Water being by Trunks guided
into a great Cistern made of Lead, from thence is conveyed into a Boiler of Lead,
which having perform"d its Operation upon it, produceth Copperas, which is a
sort of Vitriol."
In an engraving (here reproduced, Plate XII.) showing the
shore at Harwich, boys are seen busily engaged in collecting the
copperas-stones ; and the editor, Samuel Dale, in describing
what we should now call the London clay of Harwich, remarks
that :—
" This Clay hath Pyrites or Copperas-stones sticking in it, but no Skills that
I can observe. Dr. Plot in his Hist. of Oxfordshire, p. 52, takes notice that it
was common in the blew Clays of that County to have the Pyrites aureus or
Brass-lumps (which are Sorts of Copperas-Stones) mixed with it. And I have seen
them among Tile-Earth at Bocking, in Essex ; without doubt it is so in other
Places."
Referring to the copperas-houses, Dale informs us that in his
day there were :—
" Divers in this County as at Ramsey three miles from hence. Also at
Walton, Anno 1696, there were two, but one of them I hear since demolished by
the Sea. There is also one at Bricklesey.8 The Copperas-Stones mentioned by
our Author, are found upon all this Shore not only where the Cliff is gravelly,
7 The History and Antiquities of Harwich and Dovercourt, in the County of Essex." By
Silas Taylor, Gent. To which is added an Appendix containing the Natural History of the
Sea Coast and Country about Harwich, particularly the Cliff, the Fossils, Plants, Trees,
Birds, and Fishes, etc. By Samuel Dale. 2nd ed. London, 1782.
8 The manufacture of Copperas in Essex is described by John Ray in his Collection
cf English Words, 1674.