XXV 



adit water had already carried with it into the sea at Restronguet, 

 from £150,000 to £200,000 worth of copper. 



It is well known that precipitation takes place more rapidly 

 in warm than in cold weather; that the precipitates are both 

 richer and more plentiful in winter than in summer ; that at all 

 seasons they are of better quality in the upper than in the lower 

 part of the works ; and that Avhen tinned-iron is used as a precip- 

 itant, the precipitate obtained affords metal of much the same 

 kind as that smelted from tinny copper-ore.* 



The foregoing statements make no pretension to minute accu- 

 racy ; they show, however, the remarkable means by which many 

 industrious families earn a comfortable livelihood. 



Similar operations are now conducted with equal success, 

 although on a smaller scale, in several other parts of Cornwall 

 and Devon ; and it may not be unworthy of remark, that in many 

 of these mineral waters the (Alga) Mugeotia flourishes. t 



I should like to have said something on the relations of various 

 rocks to the lodes and cross-veins which traverse them ; and on the 

 manner in which practical Miners and Geologists may instruct 

 and benefit each other. Such an enquiry, however, could scarcely 

 have been dismissed very briefly; and, although the ofiicers and 

 council, when conferring this honour on me, kindly gave me as 

 long a notice as it was in their power to give, even that time 

 would have been insufiicient for the discussion of so long and so 

 important a subject. 



In larger Societies, which hold weekly or fortnightly meetings, 

 an entire sitting is commonly given once a year to a review of 

 their proceedings, and to tracing the relations they bear to the 

 general knowledge of the subjects they embrace. With us, who 

 meet so much less frequently, however, such summaries must of 

 necessity be much shorter, in order that we may hear, from the 

 gentlemen who honour us with their support, the communications 

 which will hereafter enrich our Journal. 



* This information was given me by Mr. Henry Williams, of Alma, 

 whose kindness has aided me in another part of this enquiry. — Ante, p. xxiv, 

 Note «i[. 



f Eels thrive as well in pools (sinks) underground as in the stream 

 pumped out of Botallack mine into the Engine-tank at the surface ; in both 

 cases, however, the watejr may be supposed to be more highly charged with sea 

 than with mineral salt. — Mr. Stephen Harvey James, Purser of the Mine, MS. 



