PROCEEDINGS 



OF 



THE ROYAL SOCIETY* 



*' On the Atomic Weight of Glucinum (Beryllium)." Second 

 Paper. By T. S. Humpidge, Ph.D., B.Sc, Professor of 

 Chemistry in the University College of Wales, Aberyst- 

 wyth. Communicated by E. Franklanb, F.R.S. Received 

 February 27, 1885. Read March 5. 



In a former communication which I had the honour of making to 

 the Royal Society,* I described a method of preparing metallic 

 glucinum and of determining its specific heat. From my experiments 

 I deduced the result that the atomic weight of the metal must be 

 13*6 {circa) in order to agree with Dulong and Petit's rule. 



It is well known that the position assigned to glucinum in the 

 periodic arrangement of the elements requires an atomic weight of 

 two-thirds the above number, or approximately 9, and that with the 

 larger atomic weight it falls between carbon and nitrogen, and is 

 entirely out of place. 



Various criticisms were offered to explain this apparently anomalous 

 result. To the suggestion of Professor J. E. Reynoldsf that 

 the pure metal would have a specific heat 50 per cent, greater than 

 that of a sample containing 6 per cent, of impurities, I have already 

 replied. J Another explanation was offered by Brauner,§ who 

 thought it possible that the specific heat of the metal might increase 

 with the temperature and thus agree with D along and Petit's rule, at 

 some higher temperature-interval than — 100°. Brauner's sugges- 

 tion was based upon the position which glucinum should occupy in 

 the periodic arrangement and which would be similar to that of boron 

 and carbon. Some determinations of the specific heat of the metal up 



* " Phil. Trans.," 1883, Part II, p. 601. 

 f " Proc. Boy. Soc," vol. 35, p. 248. 

 X " Proc. Boy. Soc," vol. 35, p. 358. 

 § " Berlin Ber.," xi, 872. 



VOL. XXXIX. 



