A. De Schulten published a crystallographic and optical investigation of the bismuth oxyhalides in 1900. He succeeded in preparing minute square plates capped with pyramidal planes, but evidently the difficulties of manipulation prevented the measurement of interfacial angles. He did, however, record a negative uniaxial figure observed in a direction perpendicular to the plane of the square plates of all three salts BiOCl, BiOBr, and BiOI. The present work was undertaken to extend A. de Schulten's observations, to measure the axial ratios, and to determine the crystal-structure.

A small specimen (McGregor Museum, no. 4465) labelled ' Bismuth ore' was sent to me in 1932 by Miss M. Wilman, Curator of the McGregor Museum, Kimberley, for identification. It had been presented to the Museum by Mr. M. Caplan, a store-keeper of Steinkopf. The majority of bismuth-bearing minerals from Namaqualand come from a number of spots in the neighbourhood of the water-hole known as Jackals Water, which is situated 18 miles NNE. of the village of Steinkopf. Reference has already been made to this locality in a previous paper. The exact locality of this specimen is a pegmatite outcrop in granite-gneiss about a mile and a half south of the Noumaas trigonometrical beacon which is situated some 13 miles north-west of Jackals Water to the west of the Viool's Drift road. The specimen was picked up on the surface, being obviously of eluvial origin.

The first recognition of ankerite as a British mineral seems to have been made a little over fifty years ago by M. F. Heddle, who described and analysed a sample from the Ting of Norwick, Unst. The occurrence of the mineral in veins in the Carboniferous Limestone of Lilleshall, Shropshire, was recorded by C. J. Woodward, who gives analyses of two specimens. T. Crook noted the frequent occurrence of the mineral in British coal-fields and described specimens, with two analyses, from Lancashire, Yorkshire, Nottinghamshire, Leicestershire, and South Wales. F. S. Sinnatt and his collaborators, in their work on the mineral constituents of coal, devote a good deal of attention to the 'white partings' or ankerites, of which, as they say, 'no study has appeared in the literature'.

As most analysts recognize, the method generally used for the determination of carbon dioxide present as carbonate, by decomposition with acid, absorption in soda-lime or soda-asbestos, and weighing as carbon dioxide, is open to several objections; and several suggestions have been made from time to time with the object of avoiding the use of absorption tubes, but none of these have come into general use, generally because of inconvenience in manipulation.

The principal objection to the use of absorption tubes (apart from their general inconvenience and the numerous precautions their use entails) lies in the uncertainty of the blank correction; when a blank experiment is performed, under precisely the same conditions as the actual determination, a small gain in weight of the absorption tubes is almost invariably observed, but in a series of several blank experiments, this gain is frequently very variable, and by no means proportional to the volume of air drawn through the absorbers, unless many precautions are observed.

Introduction.-There are many old records of the occurrence of chondrodite in the British Isles. Greg and Lettsom mentioned Co. Donegal in Ireland and near Loch Ness in Scotland. J.H. Collins gave Wheal Druid, Redruth, and also Scotland and Ireland. The mineral is included in a list of those associated with the kyanite of Glen Urquhart, Loch Ness, Inverness-shire, given by T. Wallace. Though reference to the Loch Ness locality is made by Dana in the 6th edition of the 'System' (1892, p. 540), the existence of chondrodite at Glen Urquhart, the only likely locality near Loch Ness, had been queried by M. F. Heddle so early as 1879. Heddle failed to find chondrodite at this locality; he gave the name xantholite to a yellowish serpentinous substance that he suggested had been hitherto mistaken for chondrodite.

Introduction and mode of occurrence.-During a visit in 1929 to the well-known phonolitic laccolith of Traprain Law, East Lothian, beautiful crystals of apophyllite were discovered in drusy cavities. It was found possible to collect numerous specimens which are now in the Hunterian Museum, University of Glasgow (M 5970). There is no previous record from the locality and the following is a brief description of the rock and its associates.

Along with the apophyllite occur well-formed icositetrahedra of analcime. A thin section reveals that the apophyllite is of later crystallization than the analcime. The latter mineral lines the walls of the cavities, with which the apophyllite is seldom in contact. Radiating fibres of pectolite are occasionally seen on the surface of the analcime.

The metamorphism surrounding the granite of Carn Chuinneag in eastern Ross-shire provides the classical example of polymetamorphism in which a regional metamorphism is superimposed on a normal thermal metamorphism.

Prior to the regional alteration a pelitic facies of the Moine sediments suffered metamorphism of a purely thermal type in the vicinity of the granite. At a subsequent date the whole region was involved in fold movements with the production of crystalline schists. In this deformation the belt of rocks surrounding the granite yielded in such a way that belts of the hornfels zone moved en masse and are preserved amidst rocks which are now typical crystalline schists, and all stages of transition between genuine hornfelses and typical micaschists can be traced in the field.