The earliest systematic catalogue of meteorite collections is that of Otto Buchner in 1863, in which he listed 264 meteorites preserved in 89 collections. Thirty years later E. A. Wülfing, after circularizing 350 mineralogical and other collections, gave preliminary results for more than 500 meteorites with a total weight of 18,514 kilograms (18½ metric tons) preserved in 105 collections. This information was further elaborated in his valuable book in 1897, in which is given the weight in grams of individual meteorites in each collection.

At that time Wülfing recognized 536 known meteorites. Now there are very many more–1347 according to the latest published list (C. F. Leonard, 1946, below) and 46 others have been noticed in ‘Mineralogical Abstracts’ since 1940. Wülfing's data, compiled for July 1893, is now, after more than half a century, much more out of date than he found Buchner's data after an interval of thirty years. To digest all the information now available would be an enormous task.

Of the results which have so far been achieved by study of the packing of equal spheres one of the most remarkable, both by reason of its simplicity and of its fundamental importance, was that announced by Barlow in 1883. He called attention to the fact that equal spheres can be most densely packed in two ways, one possessing cubic symmetry and the other hexagonal (fig. 1).

Already in 1862 Tait had investigated the piling of marbles of equal size and had noticed that ‘there are two obvious ways of constructing the layers, and two of applying layer to layer’: nevertheless his two densest arrangements are in fact identical. He saw that the cubic structure could be begun either upon a square base or a triangular base but failed to perceive the possibility of the hexagonal arrangement.

The separation and analysis of the olivine phenocrysts from the Spiegel river and Klaasvoogds melilite-basalts was undertaken in order to ascertain whether the olivines contain significant amounts of Ca2SiO4 in their constitution in view of the fact that the closely allied rock-types, alnöite (Bowen, 1922) and the basalt from Shannon Tier, Tasmania (Tilley, 1928), are known to contain monticellite, and that Taljaard (1936) has tentatively identified monticellite in one of the melilite-basalts from the Sutherland district, Cape Province.

The Spiegel river melilite-basalt from the Riversdale district of the Cape Province was first described by Corstorphine (1898). Petrographic descriptions of the rock have been given by Rogers and Schwarz (1898), Rogers and du Toit (1903), Rogers (1905), Wagner (1914), du Toit (1926), Taljaard (1936), and Holmes (1936).

It has been shown recently by Brindley and Robinson that anatase could be recognized by X-ray diffraction technique in fireclays from Scotland and Yorkshire which contained from one to two per cent. of titanium dioxide. These authors remark that the anatase appeared to be of a fineness comparable to the kaolin mineral which was the main constituent, and although kaolinites from various sources throughout the world were examined, in no case was either anatase or rutile detected.

The object of this note is to draw attention to the presence of anatase in the sedimentary kaolins of Georgia and perhaps South Carolina, U.S.A. According to Smith 115 kaolin samples from Georgia had on an average 1·13 % of TiO2 by chemical analysis. The values ranged from 0·5 to 2·2 % of TiO2. This is in marked contrast to most primary kaolins; those of Cornwall and Devon, for instance, have as a rule below 0·2 % of TiO2.

Blue pleochroic crystals obtained from basic slag were first described by Carnot and Richard. They published a chemical analysis, some of the optical properties, and a brief description of the forms they observed. The crystals were stated to be orthorhombic, with a composition of 5CaO.P205.SiO2. Several authors later described similar crystals. None, however, gave a thorough account of the optical properties. These various papers were summarized and discussed by Kroll, who accepted Carnot's formula, but concluded, from Bücking and Linck's examination, that the material was monoclinic. Kroll applied the rather unfortunate term ‘silico-carnotite’ to these crystals.

The present work shows that silicocarnotite occurs in only one modification–orthorhombic. The crystals drawn by Bricking and Linck and described as monoclinic are, in fact, identical with our orthorhombie crystals.

The clinozoisite to be described is found in veins traversing a metamorphosed basic intrusion exposed at the top of Camaderry Mountain, Glendalough, Co. Wicklow. This intrusion is a small boss of Lower Palaeozoic age which has been metamorphosed both by earth movement and by the intrusion of the Leinster granite. The rock exposed is now an amphibolite (fig. 1) within which are found the veins carrying clinozoisite with albite and a little prehnite, sphene, and tremolite. These veins, which are up to an inch in width, were probably introduced during the late stages of the basic intrusion as veins of lime-rich plagioclase.

Preliminary examination under the microscope shows that the clinozoisite is well crystallized, fresh, and free from inclusions. The colour in the hand-specimen is grey-white; in thin section it is colourless. Individual crystals are found up to 5 mm. in length. Twinning and intricate zoning are common.