Note 159 — Chapter IX

In the lead lodes of Lagylas and Frongoch, electrical currents were detected by Mr. Fox, but none in those of South Mold and Milwr, in Flintshire: Cornwall Geological Transactions, vol. iv. In the lead veins of Coldberry and Skeers, in Teasdale, Durham, the currents detected were very feeble: Reports of the Bristol Association, 1838. Von Strombeck could detect no electric currents in the veins worked in the clay slate near Saint Goar, on the Rhine: Archiv. für Mineralogie, Geognosie, &c., von Dr. C. J. B Karsten, 1833. Professor Reich, however, obtained very decided results at Frisch Glück, Neue Hoffnung, Gottlob, and in other mineral veins in the mining districts of Saxony: Edinburgh New Philosophical Journal, vol. xxviii. 1839. The irregularities are all to be explained by the presence or absence of chemical excitation.