Fuller's earth from near Dry Branch, Georgia, is shown by X-ray analysis to contain comparable amounts of montmorillonite and cristobalite, and only minor amounts of other minerals. The cristobalite resembles the high form, but may be a very disordered low form. Electron micrographs show the montmorillonite to be lath-like, and the cristobalite globular in form.

The features required in a calorimeter for studying clay mineral systems are discussed and a suitable calorimeter of high sensitivity is described in detail.

The mineralogical nature of clays from the Catalan coastal range corresponding to Bunter, Muschelkalk and Keuper in stratigraphic sequence has been investigated. The predominant minerals present are illite, quartz, carbonate (calcium and/or magnesium) and chlorite in the Keuper and Muschelkalk and in the Bunter kaolinite is found in addition. Attention is drawn to the occurrence of interstratified chlorite and swelling chlorite, which association may be typical of clays deposited during Triassic time.

The major and minor elements for Pugu D, a rock containing a well-crystallised but disordered form of kaolinite are presented, The concentrations in the various fractions are discussed and reasons adduced for element behaviour. Relationships between element distribution and Sedimentation conditions are considered.

A study was made of five clays used for brickmaking to determine the reason why certain clays crumbled on firing. Partially weathered biotite was found to be a constituent of the clays which crumbled and the crumbling was due to this mineral exfoliating and so disrupting the bricks at a comparatively low temperature. Fresh biotite and highly weathered biotite do not have this adverse effect.

Four ice advances have been recognised in East Anglia but only two of these, the Lowestoft and the Gipping, have deposited till in the Cambridge area. The clay fractions of these tills have been investigated and compared with those of the Oxford, Ampthill, Kimeridge and Gault Clays, the Lower Greensand and the Chalk, all of which outcrop in the district and could be expected to contribute material to the tills.

The value of clay mineralogical analysis as a means of measuring directions of ice-movement is critically discussed.

An outline account is given of the more important processes of weathering and soil-formation which occur on the Gipping till in the Breckland area.