P R O C E E D I N G S OF T H E CLAY MINERALS GROUP JOINT MEETING with the International Geological Congress (18th Session), held in the Chemistry Lecture Theatre, Royal College Of Science, South Kensington, on 26th, 27th and 30th August, 1948. The subject for discussion at these meetings was "Geology and Mineralogy of Clays." At each session in accordance with the procedure usual at the Congress, two Chairmen were appointed, each of whom officiated for half the session. The following papers were read and discussed : Thursday, 26th August, 2-5 p.m. Dr G. W. BRINDLEY,then Mr S. HENINin the Chair. 1. The Illite Clay Minerals: by R. E. Grim and W. F. Bradley. 2. Illite occurring in decomposed granite at Ballater, Aberdeenshire: by R. C. Mackenzie, G. F. Walker and R. Hart. 3. The principal clay minerals in certain refractory and bond clays: by A. L. Roberts and R. W. Grimshaw. 4. Changes produced in kaolin minerals by grinding: by A. Westerman and A. L. Roberts. 5. Structural relationships in the kaolin group of minerals : by G. W. Brindley.
Friday, 27th August, 9.30-12.30 a.m. Prof R. E. GRIM, then Dr J. J. DE LANGEin the Chair. 6. Transformation des mineraux de la famille des montmorillonites en pbyllite a 10 ~: by S. Henin. 7. Experience sur la formation et l'evolution des chlorites et des vermiculites: by S. Caillere. 8. Alteration of the properties of bentonite by reaction with amines: by John W. Jordan, presented by R. E. Grim. Monday, 30th August, 2-5 p.m. Dr W. CAMPBFLLSMITH,then Dr J. S. HOSKINGin the Chair. 9. Sui rapporti fra diabasi ed argille delia formazione argilloscistosa appenninica. Esperienze ed osservazioni: by Prof. P. Gallitelli. )0. Nuovo tipo di illite-idromica in giacimento idrotermale di bassa temperatura: by Prof. C. Andreatta, presented by Prof P. Gal!itclli. ll. A tfioctahedral montmorillonite derived from biotite: by D. M. C. MacEwan. 196
PROCEEDINGS OF THE CLAY MINERALS GROUP
197
MEETING HeM in the Physics Department, University of Leeds, on 8th and 9th April, 1949. This was the first of our meetfngs to be divided into two scientific sessions--one held on Friday afternoon at 2.30 p.m., and the other on Saturday morning at 9.30 a.m. On the Friday morning there was an organised visit to the laboratories of the Physics Department and the Department of Coal Gas and Fuel Industries. The subject chosen for discussion at the scientific sessions was "Clay Minerals and Colloid Chemistry." The third Annual General Meeting was held on the Friday afternoon at 6 p.m., and thereafter members and guests joined in dinner at the University Staff House. About .60 members and guests were present. At the Business Meeting, officers elected for the ensuing year were: Chairman Professor A. L. Roberts; Secretary--Dr R. C. Mackenzie. The following papers were read and discussed: Fri6
