1883.] Atomic Weight of Glucinum or Beryllium. 359 



Nilson's picked 2 decigrammes, but rather with his first sample, con- 

 taining 13 per cent, of impurities. Since sending in my paper I have 

 prepared more that 3 grms. of much purer metal, and can now obtain 

 any quantity in yields of 3 to 5 decigrammes for each experiment. 

 The metal is decidedly crystalline in structure, mostly in thin plates 

 of a high metallic lustre, and of a grayish colour resembling iron. 

 No accurate analysis of these samples of the metal has been made, as 

 it has been nearly all used for the attempted preparation of organo- 

 glucinum compounds. But in my next contribution to the Society I 

 hope to be able to give accurate analyses of several samples. 



I only briefly alluded to the theoretical aspects of the question in 

 my paper, and do not intend to refer to this until I have more 

 evidence to offer than a determination of the specific heat between 10° 

 and 100° 0. ; but the very remarkable result arrived at by Professor 

 Hartley from spectroscopic evidence cannot be left unnoticed. This 

 chemist concludes from his experiments that glucinum is a dyad 

 metal, and that its homologues are calcium, strontium, and barium — 

 elements with which it has not the slightest analogy. And it seems 

 strange that Professor Hartley should consider some slight spectro- 

 scopic resemblance between glucinum and the metals of the alkaline 

 earths to outbalance all the weighty chemical and physical differences 

 between them. Glucinum differs strikingly from the metals of the 

 alkaline earths, both in the free state and combined as oxide, as 

 hydrate, carbonate, oxalate, chloride, fluoride, sulphate, &o. If 

 glucinum is really a dyad metal (which may possibly be the case), its 

 nearest homologues are decidedly magnesium and zinc ; not calcium, 

 strontium, and barium. 



XIV. " Remarks on Spectrum Photography in Relation to New- 

 Methods of Quantitative Chemical Analysis. Part I." By 

 W. N. Hartley, F.R.S.E., Professor of Chemistry, Royal 

 College of Science, Dublin. Communicated by Professor 

 Stokes, Sec. R.S. Received June 20, 1883. 



[Publication deferred.] 



XV. " On a New Standard of Illumination and the Measurement 

 of Light." By W. H. Preece, F.R.S. Received June 21, 

 1883. 



[Publication deferred.] 



The Society adjourned over the Long Vacation to Thursday, 

 ^November 15fch. 



