Manchester Memoirs, Vol. li. (1907), No. %. 



II. On some Points of Chemical Philosophy involved 

 in the Discovery of Radium and the Properties 

 of its Combinations. 



By Henry Wilde, D.Sc, D.C.L., F.R.S. 



Received and Read November 27th , igob. 



The discovery of no elementary substance has created 

 such profound and general interest as that of Radium. 

 This is abundantly evident from various scientific pub- 

 lications and from magazine articles on " The Wonders 

 of Radium," " The Revelations of Radium," " The Miracle 

 of Radium," and other titles equally striking. Although 

 the new element has not yet been isolated, the fact that 

 it has a well defined spectrum, and that its chemical 

 reactions agree closely with those of barium, leave no 

 room for doubt of its existence, and that it is one of the 

 alkaline-earth family of metals. 



Radium, as I have already shown, 1 has a definite 

 position, atomic weight, and specific gravity in my tables 

 of atomic weights (1878, 1894, 1903), and is the next 

 member higher to barium, as well as. the highest of the 

 series of alkaline-earth metals. 



Operating with less than two grains of radium 

 chloride, Mme. Curie deduced for the element an atomic 

 weight of 225, and places it in the column of alkaline- 

 earth metals, the member next above barium. 



From spectroscopic observations, Runge and Precht, 2 

 while agreeing that radium belongs to the barium group, 



1 Manchester Memoirs, vol. 48, 1 903 — 1 904. 



2 Journ. Chem. Soc, vol. 84, p. 346, 1903. 

 Phil. Mag., April, 1903, p. 476. 



December igth, igo6. 



