XX 111 



Coster, about one hundred and fifty years ago,* and made subject 

 of experiment at JVhexd Crofty shortly afterwards, t — seems to 

 have been lost sight of (save in a very few instances) in Cornwall, 

 until within some twelve or fifteen years since. 



Within a short time after Mr. Coster's discovery at the Chace- 

 ivater mine, however, several workmen migrated from that neigh- 

 bourhood to the county of Wicklow ; where they obtained 

 employment at the Cronebane mine, which was then superintended 

 by Captain Thomas Butler, a native of Eedruth. At his suggestion 

 the precipitation- works were established,* which, with gradually 

 diminishing produce, have been carried on there from that time 

 to this. 



About a century since an enormous deposit of copper-ore was 

 discovered at the Parys mountain in Anglesea;| and shortly 

 afterwards the water which percolated through it was found to be 

 richly charged with the sulphate of copper. By that time the 

 works at Cronebane — less than eighty miles distant — had been 

 more than fifty years in operation ; and j^ublished descriptions of 

 them II had made the treatment adopted, and the produce obtained, 

 well known. Similar proceedings, but on a much larger scale, 

 were forthwith commenced in Anglesea ; and these, although their 

 produce has gradually declined, are still carried on to great advan- 

 tage. § On the eastern slope of the Parys mountain the 3Iona 

 works were superintended for many years by the late Mr. Tre- 

 week, of Gwennap; and by his son, Mr. Treweek of Mawnan, 

 the same system was established in Cuba. 



It is a remarkable, perhajjs a characteristic, circumstance, that 

 notwithstanding the Great Adit — commenced in 1748 by Mr. 

 Williams, of Burncoose (great-grandfatli^r of Sir William Wil- 

 liams, Bart.) — had been extended, before the commencement of 

 the present century, to most of the principal mines in the Gwen- 

 nap district,^ as well as to the very (Chaceivater) mine in which 

 Mr. Coster had so long previously observed the progress of pre- 

 cipitation,* * it Avas not until some fifteen years ago that attempts 



• Pryce, Mineralogia Cornubiensis, p. 231. 

 f Ibid., p. 232. 



+ Pennant, Tours in Wales, iii, p. 60. Hawkins, Cornwall Geol. Trans., 

 iii, p. 284. Henwood, Ibid., viii, pp. .581 — 4. 



II Henry, Phil. Trans., xlvii (1752), p. 500. 



§ Mr. T. F. Evans, of Mona Lodge, Anglesea,"MS. 



% Exceptionally strdng solutions of copper oozing from the lodes, and 

 received in tanks placed underground, have yielded small quantities of rich 

 precipitate for many years past. 



♦ * Nearly thirty years ago, Mr. Treweek, of Mawnan, obtained several 

 parcels of precipitate at Wheal Falmouth, by the use of lime. 



