In " Notes on some Minerals of the Mawddach Valley, Merionethshire," Min. Mag, Vol. III. p. 122, I referred to their general auriferous character; and to the occasional occurrence of flee or native Gold in workable quantity, often in states of Electrum, &c.

Since then I have been experimenting rather large!y with the auriferous lode-stuff and its enclosing Silurian slate-rock, just at its junction with the coarse Cambrian (or, it may be, pre-Cambrian) sandstone, about 1,000 feet up the Gwynfynydd or white mountain, ascending from the beautiful waterfalls known to tourists as Pistyll-y-Cain and Rhiadr Mawddach.