Manchester Memoirs, Vol. li. (1906), No. % 7 



in vacuo. Reference is made by Langley to the experi- 

 ments of H. Muraoka in 1896, on lampyrid beetles 

 collected in Kyoto in Japan, who found that these insects 

 emitted both actinic and Rontgen rays, which acted 

 through cardboard and could also be deflected ( Wied. 

 Aim. Phys., vol. 59, pp. 773 — 781). 



Radium bears the same relation in its combinations 

 with the halogen and oxygen elements as calcium and 

 thorium in their combinations with the same elements. 

 Now no chemist will be found to affirm that elementary 

 calcium and thorium are the principal agents in the pro- 

 duction of the oxyhydrogen (lime) light, or the same light 

 from Welsbach thoria mantles. The conclusion may 

 therefore be justly drawn that elementary radium plays 

 the like subordinate part when in combination with the 

 negative elements, and that these elements are the prin- 

 cipal, if not the sole cause of the phenomena of radio- 

 activity manifested in radium combinations. 



Considering the fact that, when positive and negative 

 elements of the series Hn and H2n enter into active com- 

 bination, the resultant compounds possess but few of the 

 chemical and physical properties which characterize their 

 components, the persistency with which the properties of 

 radium compounds have been attributed to elementary 

 radium is as interesting, psychologically, as the physio- 

 logical effects of its compounds on the human body and 

 on other living structures. 



The incidence of the discovery of these properties, 

 prior to the isolation of the element, has doubtless largely 

 contributed to the illusion that they are wholly inherent 

 in radium itself. 



The announcement made three years since by Sir W. 

 Ramsay and Mr. Soddy of the transmutation of radium, 



