Amongst the rock-specimens from Co. Limerick belonging to the Allport Collection in the British Museum, a. specimen of basalt from Rathjordan, Co. Limerick, attracted attention by the fact that, in thin slices under the microscope, it showed small, round sections of isotropic material containing central and octagonally arranged, marginal inclusions, and thus resembling leucite. The rock from Rathjordan has been described by Hull and by Allport. According to Allport the rock is a columnar, fine-grained, black basalt which occurs interbedded with ashes, and consists of ‘innumerable small grains of augite and magnetite set in an amorphous glass, the whole forming a matrix in which serpentinous pseudomorphs of olivine and felspar are porphyritically imbedded’.

At the Emily coal pit, Arniston, Midlothian, a heap of shaly refuse from the workings became spontaneously ignited some time ago, the cause being presumably the evolution of heat by atmospheric oxidation of iron-pyrites. As a result of the slow combustion of the shale, accompanied as it is by liberation of sulphuric vapours, a number of uncommon mineral-species have been formed and deposited as sublimates in the cooler parts of the heap. The credit of discovering these minerals and recognizing their unusual character belongs to Mr. A. Craig Christie, F.L.S., from whom the specimens in the Royal Scottish Museum were obtained.

Although more than fifty years have passed since Guiscardi published the first description of guarinite, the true nature of this mineral has never yet been ascertained. As regards the crystalline form, Guiscardi's first idea was that the crystals of guarinite are orthorhombic (he had himself reckoned the ratio a : b = 0.9896 : 1 ; see literature, nos. 3 and 5); but, having observed crystals with a tetragonal habit, he finally decided to describe the mineral as tetragonal-hemihedral. V. v. Lang by his optical investigations appeared to place the orthorhombic symmetry of guarinite beyond doubt, and Des Cloizeaux later published a note on a combination observed by him.

When a mineral fragment is brought under the influence of an electrostatic charge, its behaviour depends chiefly upon the conductivity of the mineral and that of the surface on which it is lying. This fact can be effectively demonstrated by placing fragments of amber (sp. gr. about 1.1) and pyrite (sp. gr. about 5) on a metallic surface, such as that of a copper plate, and noting their behaviour when a rod of vulcanite, which has been electrified by rubbing with cat's skin, is brought near them. Under these conditions a small fragment of dry amber, weighing not more than one milligram, is not attracted to the rubbed rod, although the rod be brought almost in contact with it; whilst a large piece of pyrite weighing as much as 150 milligrams jumps visibly from the plate with the rod held at some distance from it.

In the course of his official work in the Lizard district, Dr. J. S. Flett collected various samples of minerals which were handed over to me for examination. Two of these specimens proved to be datolite remarkably well crystallized. As this species, now rare in Britain, had not been recorded before from Cornwall, although pseudomorphs of chalcedony after it—the well-known haytorite—are mentioned by Greg and Lettsom from North Roskear mine, Camborne, the facts of its occurrence seemed well worthy of further investigation. Accordingly, in October of last year, Dr. Flett and myself paid a visit to the locality, where we succeeded in obtaining a large amount of the material.

The history of famous diamonds has always been surrounded with mystery and uncertainty, and this is no less the case with the recently-discovered ‘Cullinan’, by far tile largest of all diamonds, which was found in the Premier diamond mine, near Pretoria, in the Transvaal, on January 25, 1905. Whilst it is now no longer possible to arrive at the exact facts respecting the earlier-found stones, it is desirable to place on record any definite information respecting the more noteworthy stones found in our own time.