In a discussion of the composition of glauconite, it was shown that the analyses of this substance can be represented in terms of simple molecular proportions, provided that the mineral is regarded as a mixture of a silicate containing the group R2O3 with a similar compound in which one equivalent of R2O8 is replaced with one equivalent of RO; the general formula being R2O. 4(R2O3, RO). 10SiO2. nH2O.

Work on the sedimentary iron ores collected during the preparation of the ‘Special Reports on Mineral Resources’, recently issued by the Geological Survey, made it necessary to review the composition of some of the chlorites ; but no evidence of similar replacement was found among the better-known minerals of that group.

On the basis of field relationships, the main types of the Dartmoor granite can be referred to four stages of intrusion, the sequence being from relatively basic to thoroughly acid.

To this sequence is closely related an increase in the content of tourmaline and in the extent to which autopneumatolysis (with tourmalinization) was effective before solidification of the rock was complete.

Autopneumatolysis is well displayed by many minor intrusions referred to the latest stage. Such an intrusive rock is reddened more or less uniformly throughout its entire mass, and volatile constituents exhaled from its margin have reddened a contact-zone of the grey granite into which it is intrusive.

A Fine set of loose crystals of felspar from Mt. Erebus was collected by Mr. F. Debenham on the British Antarctic (‘Terra Nova’) Expedition in 1910, and was acquired by the British Museum (Natural History) with the collection of rocks obtained on that voyage. These crystals are found in great profusion on the crater slopes, and their occurrence has been briefly described by David and Priestley, who referred to them as anorthoclase. On ascending the inclined floor of the second crater they saw ‘that the covering of snow became thinner until it almost entirely disappeared, being replaced by a surface formed of crystals of anorthoclase felspar from half an inch to four inches in length’.

Pentaerythritol tetranitrate, C(CH2ONO2)4, is an interesting compound structurally, since there is, in the molecule, a carbon atom with foul' like groups (–CH2ONO2) attached to it. The molecule is therefore of the type CX4. It was hoped that an examination of the crystals by means of X-rays would show how far the molecule retains its form and symmetry in the crystalline state ; also that some light would be thrown on the configuration of the nitro- (–NO2) group, especially the equivalence or otherwise of the two oxygen atoms of the group—a question which it has not yet been found possible to settle by chemical methods.

A Committee on Nomenclature and Classification of Minerals was appointed at the first annual meeting of the Mineralogical Society of America in December 1920, and two of its reports have been recently issued in the ‘American Mineralogist’. Such a committee for standardizing nomenclature is clearly needed, but it must take a far wider view. If the recommendations can be, or are likely to be, adopted only in their country of origin then the result will be still further confusion in the nomenclature of the science. It is especially important in this connexion to bear in mind that science is world-wide, and its language should, as far as possible, be adapted to meet international needs. The tendency to adapt names to particular languages should rather be discouraged.