The Struy lead mines (Six-inch ordnance Survey, Inverness-shire, sheet 17) are situated on the west side of Strath Glass, about two miles south-west of Struy village, and comprise three distinct sets of small long-abandoned workings, two of them being in the nature of trials only. All three workings are shown on the six-inch map, and are on veins traversing the Moine schists. The Geological Survey Memoir of the district says that four veins may be traced on the hill face between the Dùn south of Struy school and Crelevan; if this is correct there are two outcrops I have not seen. The mines are on what was until a few years ago part of Lord Lovat's estate. The date of their discovery is not known, but they were apparently worked about the year 1818 by Thomas Alexander Fraser (afterwards 12th Lord Lovat) at the same time as his graphite mine in Strath Farrar; most of the work seems, however, to have been done by him between 1838 and 1845, when miners were brought from England and housed in cottages specially built for them in Struy village. In 1864 the Loch na Mèine workings were cleared and prospected, but since then no further work has been done.

Loch Bruicheach (One-inch Ordnance Survey of Scotland, popular edition, sheet 37; Six-inch Inverness-shire, sheet 18) is situated 7½ miles (about 9 miles by road) south-west of Beauly and is best reached by taking the road from that town to the keeper's house at Clunevackie and thence by a track to within about half a mile of the actual locality, a low cliff bordering the north-east shore of the loch. Attention was apparently first directed to the locality about the year 1884 by a Mr. John Ross, one of Lord Lovat's gamekeepers, and Mr. Thomas D. Wallace of Inverness, having received through him specimens from there of baryte and a mineral which he, Mr. Wallace, recognized as resembling fluorite, visited the spot with Mr. Ross in May 1885. In August of the same year Mr. Wallace gave a description of the occurrence in the pages of this Magazine, and in July 1886, also in this Magazine, there appeared a note and analysis of the fluorite by Professor W. Ivison Macadam of Edinburgh, who in collaboration with Mr. Wallace proposed for the mineral, without any sort of justification, the name bruiachite. Macadam's analysis of the fluorite was very inaccurate and showed only 10% of fluorine.

The Bikita tin and tantalum field is centred about 43 miles east-north-east of Fort Victoria, in the south-eastern part of Southern Rhodesia. It forms the end of a tongue of basic and sedimentary schists surrounded on three sides by granite. Tin and tantalum minerals have been known in the area for over thirty years, and at various times attempts to work them have been made, but with indifferent success. During recent years the demand for tantalum has led to the re-opening of the field and several tons of tantalite and simpsonite concentrates have been exported to America. The area was mapped geologically by Mr. R. Tyndale-Biseoe in 1942, but the publication of the map and report have been held up during the war. The principal workings are the Mdara mine and the Al Hayat claims situated about three-quarters of a mile apart.

At two localities on the outskirts of the township of Broken Hill—near the De Bavay shear zone, and at ‘The Piggery’—W. R. Browne reported unusual rock types rich in barium. His statement is accompanied by an analysis by H. P. White (analyst to the Mines Dept.) of one of these rocks, which contains 9·23% BaO. Subsequently S. R. Nockolds and E. G. Zies examined the felspars of the rock analysed by White with a view to ascertaining whether they are barium-containing varieties.

In view of the very high barium content of some of the occurrences now being investigated, much higher than that of the rock examined by Nockolds and Zies, a further mineralogical investigation was undertaken with the results recorded below. The rocks under examination were light-coloured gneisses containing up to 15% BaO. They are distributed as lenses and streaks in an acid gneiss. A specimen of the latter rock was analysed and found to contain only 0·09% BaO. The barium was found to occur in four felspars, one being a new variety of celsian. The minerals studied were celsian, calciocelsian, hyalophane, and barium-plagioclase. A careful search was made for other barium silicate minerals such as sanbornite, but none was found.