Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/62

52 The breadth of the main metallic vein at Foxdale, the partings being included, was computed to be full six yards.

In all the three places the vein appears adherent to the contiguous rock, whether it be greywacke or small grained granite.

At Foxdale a cross metallic vein of lead also was found running a few points from the North and South, that is to say, intersecting the main vein at a great angle; at the junction or counter, the ore grew richer, and many knockings, shods, or balls occurred. The cross course was as fertile as the main vein itself, if the information I received be correct. Its inclination likewise, with respect to the horizon, was fully as considerable.

According to Mr. Wood's statement, it would appear that the ore at Brada-head was chiefly sulphuret of copper.

I shall now enter into a more minute examination of the several substances which accompany the lead-ore at those three places.

Laxey-Mine.

The galena of Laxey, when pure, is possessed of the lustre characteristic of common lead-ore. Its specific gravity is 7.652.

Sex octagonal carbonat of lead, along with efflorescent and fibrous carbonat of copper, are the various minerals attending the lead-ore. A button of copper may be easily obtained by exposing the carbonat of copper with borax to the heat of the blowpipe.

The vein-stone or Rider, is a greywacke breccia, composed of pieces of silky-greywacke, quartz, and bitterspath, with much brown blende.