Societies and Academies

Abstract

EDINBURGH Mineralogical Society, June 24.—This meeting was held at the Museum of Science and Art, Edinburgh.—Prof. Jas. Geikie, F. R. S., in the chair.—The following papers were read:—On forms of silica, by Prof. John Ruskin, D.C.L. The Chairman and Dr. Dudgeon made some remarks.—On the application of the periodical law to mineralogy, by Prof. Thos. Carnelley of Dundee.—On the origin of the Andalusite schists of Aberdeenshire, by Mr. John Horne, F.G.S.—On the occurrence of Prehnite and other zeolites in the rocks of Samson's Ribs and Salisbury Crags, by Mr. Andrew Taylor.—On a new locality for zoisite at Loch Garve, Ross-shire, by Mr. Hamilton-Bell.—On diatomaceous deposits in Scotland, by Prof. W. Ivison Macadam. The author drew attention to the vast extent of some of these beds, and gave particulars as to the proportions of silica, &c., contained in them. The deposits were being worked up to yield an absorbent for dynamite manufacture, and gave a material having double the liquid retaining power of samples of “kieselguhr” experimented on.—On the albertite beds of Strathpeffer, Ross-shire, by Mr. Wm. Morrison. Mr. J. Stuart Thomson referred to the fact that an allied jet mineral was found embedded in the oil-yielding bituminous shales of Midlothian. The substance only occurred in small quantities, the largest pieces not exceeding a pound in weight. It is capable of taking a fine polish, being similar to jet. In fact a jet-worker pronounced it at first to be Spanish jet.—On new localities for kyanite in Glen Urquhart, Drumlach Glen, Inverness-shire, and for staurolite at Presholme, Enzie, Banffshire, by Mr. Thomas Walker.—On the crystallography of Bournonite, by Mr. H. R. Miers, British Museum. The paper criticised the history of the subject, and corrected various errors which have crept into the earlier literature. To those crystallographic forms hitherto recorded twenty-nine new forms are added as determined without doubt, and twenty-one as probable. A list of over 1000 angles, calculated from the elements of Miller, is given. The twinning (twin-plate the prism 110) is discussed; the observations of Hessenberg are supported, and it is concluded that the twinning is always by juxtaposition, not by interpenetration, but that Cornish crystals afford an example of composition perpendicular to, as well as parallel to, the plane of composition.—On a peculiar development of tourmaline from Lockport, New York County, by Mr. R. H. Solly, F.G.S.—Notes on the metallic veins of the Upper Hartz, Germany, by Mr. H. M. Cadell.—Scottish localities for actinolites, by Mr. Peyton.—On Welsh gold, by Mr. T. A. Readwin. A specimen weighing 160 grains, from the Mawddach Valley, Merionethshire, was exhibited.