312 ON THE NATURAL HISTORY 



year 1838, whereupon the price of brimstone became so hip^h 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 coniains 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, coppevas-stone. Silas Taylor, 



in his well-known " History of Harwich,"'' tells us that — 



" Upon this Shore also within the Flow of the Sea, are gathered as they are 

 common! V call d Coppe/as-stoties and carried to certai'n Copperas -Ho uses 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 performed 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 Shells that 

 I can observe. Dr. Plot in his LList. of Oxfordshire, p. 52, takes notice that it 

 was common in the blew Clays of that County to have the Pyrites aureus or 

 Brass-luni[>s (which are Sorts of Copperas-Stones) mixed with it. And I have seen 

 them among Tile-Earth at Booking, 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.^ The Copperas-Stones mentioned by 



our Author, are found upon all this Shore not only where the Cliff \% gravelly, 



7 The History and Anfiquifia of Harwich and Dov'eicourt, in the County of Easex." By 

 Silas Taylor, Gent. To ichich 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 

 cj English IVords, 1674. 



