There is, however, proof that lodes are actually re-forming and the action observed is very interesting as showing how the stratification in some lodes has come about. The growth of silica on the sides of the drives has occurred in some of the mines on the Thames gold-fields, New Zealand (p. 36), where in some cases the deposition was so rapid as to be noticeable from day to day, whilst the big pump, which drained all the mines in the vicinity, was actually choked by siliceous deposits. In old auriferous workings which have been under water for years, in many parts of the world, formations of iron and silica have been found on the walls and roof, while in mining tunnels which have been long unused stalactites composed of silica and calcite have formed. Then, again, experiments made by the late Professor Cosmo Newbery, in Victoria, showed that a distinctly appreciable amount of gold, iron, and silica (the latter in granular form) could be extracted from solid mine timber, which had been submerged for a considerable time. This reaction then must be in progress at the present time, and doubtless under certain conditions pyrites would eventually take the place of the timber, as is the case with some of the long buried driftwood found in Victorian deep leads. Again, we know that the water from some copper mines is so charged with copper sulphate that if scrap iron be thrown into it, the iron will be taken up by the sulphuric acid, and metallic copper deposited in its place. All this tends to prove that the deposition of metals from their salts, though probably not now as rapid as formerly, is still ceaselessly going on in some place or another where the necessary conditions are favourable. Quite unexpectedly I lately came across these lines in Dryden’s _Annus Mirabilis_, verse cxxxix.:-- “As those who unripe veins in mines explore, On the rich bed again the warm turf lay, Till time digests the yet imperfect ore, And know it will be gold another day.” _Is_ there “any new thing under the sun?” With regard to auriferous pyritous lodes, it does not appear even now to be clear, as some scientists assert, that their gold is never found in chemical combination with the sulphides of the base metals. On the contrary, I think much of the evidence points in the other direction.