October ijtii, igo-j'.\ Proceedings. v 



the spheres by which the alkaH metals and the halogens are 

 represented in the assemblages differ slightly in size, the sphere 

 increasing in magnitude with an increase of atomic weight in the 

 case of each of these classes of elements. 



General Meeting, October 29th, 1907. 

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



Captain Arthur Doggett, Works Secretary, Vulcan Loco- 

 motive Works, Newton-le-Willows, 48, Gilda Brook Road, 

 Eccles ; Mr. Harold Shawcross Leigh, Brentiuood, IVors/ey ; 

 Mr. Theodore George Bentley Osborn, Wellbury, Richmond 

 Road, East Jzvickenhain, Middlesex, Reginald Francis 

 GwYTHEi^, M.A., Secretary to the Joint Matriculation Board, 

 and Mr. Thomas Whitehead, B.Sc, Chemist to the Manchester 

 Steam Users' Association, were elected ordinary members of 

 the Society. 



Ordinary Meeting, October 29th, 1907. 

 Professor H. 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. 



Dr. Henry Wilde, F.R.S., read a paper entitled, "On the 

 Atomic Weight of Radium." 



Professor E. Rutherford, D.Sc, F.R.S. , read a paper 

 entitled, " The Production and Origin of Radium." An 

 account was given of the historical development of our ideas in 

 regard to radium. On the disintegration theory, radium is 

 regarded as a substance undergoing slow spontaneous trans- 

 formation with a period of about 2,000 years. In order to 

 account for the existence of radium in minerals of great age, it 



