598 Geological Society : 



the truth for us to be able to use it as a test for the existence 

 of double molecules. The formation of liquid above the 

 boiling-point of methylether does not prove that association 

 has taken place : a somewhat high value of the mutual 

 attraction-constant a 12 in van der Waals's equation will give 

 a minimum in the vapour-pressures, and the phenomenon may 

 therefore occur with normal mixtures. The abnormal vapour- 

 density naturally suggests the formation of double molecules 

 in the vapour, and therefore a fortiori in the liquid (compare 

 the case of acetic acid), but again we need a trustworthy 

 criterion to decide between high attraction and association. 

 However probable the association in FriedePs mixtures may 

 appear, one cannot decide between the two possibilities with 

 the same sharpness as for single substances. 



University College, Dundee. 



LIX. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from p. 520.] 



November 7th, 1900.— J. J. H. Teall, Esq., M.A., F.R.S., President, 

 in the Chair. 



THE following communications were read : — 

 1. 'Additional Notes on the Drifts of the Baltic Coast of 

 Germany.' By Prof. T. G. Bonney, D.Sc, LL.D., F.R.S.. F.G.S., 

 and the Eev. E. Hill, M.A., E.G.S. 



The authors, prior to revisiting Bligen, examined sections of the 

 Drift to the west of Warnemiinde, with a view of comparing it 

 with that of the Cromer coast. Where the cliffs reach their 

 greatest elevation, 2 or 3 miles from that town, they are com- 

 posed of a stony clay, which occasionally becomes sandy. At 

 intervals, however, sand interbanded with clay occurs, filling what 

 appear to be small valleys in the Drift. A layer of grit and stones, 

 occasionally associated with a boulder, occurs once or twice between 

 these sands and clays. The valleys are excavated in the great mass of 

 stony clay which extends for 4 or 5 miles to the west of "Warnemiinde ; 

 and the synclinal slope of the layers and the contortion of the under- 

 lying bedded sands indicate that the mass filling them has been 

 let down as a whole, either by solution of the Chalk beneath the 

 Drift or by the melting of underlying ice. Of these two hypotheses 

 the authors view the latter with the more favour, but it also has its 

 difficulties. 



In Kiigen, Arkona was visited ; here Chalk occurs, apparently as 



