October ijth, ipo/.] PROCEEDINGS. iii 



Demonstrator in Geology in the University of Manchester ; 

 Mr. F. H. Gravely, B.Sc, Assistant-Lecturer and Demonstrator 

 in Zoology in the University of Manchester ; Mr. J. L. Simonsen, 

 M.Sc, Assistant-Lecturer in Chemistry in the University of 

 Manchester, IJ2, Barlow Moor Road, West Didsbury, Man- 

 chester ; and Mr. Julius Hubner, Lecturer in the Faculty of 

 Technology in the University of Manchester, were elected 

 ordinary members of the Society. 



Ordinary Meeting, October isth, 1907. 

 Professor PL B. Dixon, M.A., F.R.S., President, in the Chair. 



The thanks of the members were voted to the donors of the 

 books upon the table. 



Professor William J. Pope, P\R.S., read a paper, written in 

 conjunction with Mr. William Barlow, P".C.S., F.G.S., entitled 

 " The Relation between the Crystalline Form and 

 the Chemical Constitution of Simple Inorganic 

 Substances." 



The authors have applied the methods employed in their 

 paper of October i6th, 1906, to the study of the crystalline 

 structure and molecular condition of a number of simple inor- 

 ganic substances such as the crystalline elements, binary com- 

 pounds like silver iodide, potassium chloride, &:c., ammonium 

 halogen salts and compounds of the type of rubidium tri-iodide, 

 Rblg. In connection with the known, but hitherto unexplained 

 fact, that the greater number of the ciystallographically examined 

 elements crystallise in the cubic system (50 per cent.) or the 

 hexagonal system (35 per cent.), it is pointed out that only 

 two simple homogeneous closest-packed assemblages of equal 

 spheres exist, and that these possess holohedral cubic and 

 hexagonal symmetry respectively. Further, the hexagonal 

 closest-packed assemblage of equal spheres exhibits axial ratios 

 of the form, a : f= i : o'8i65, or a: c=\ \ i"4i42, and the 



