126 ESSAYS BIOGRAPHICAL AND CHEMICAL 



We are getting on rather slowly, however, in the hunt 

 for an explanation of flame. A great step in advance was 

 made by the discovery of radium by Madame Curie. 



Radium is a metal, the salts of which continually give 

 out ' Lenard rays/ or ' Crookes's rays.' And it is certain 

 that it is losing substance during their emission. 



Mr. Soddy and I have actually trapped and measured 

 one of the products which is being thrown off by radium 

 while these rays are being shot out; it is a gas called 

 ' radium emanation.' And it in its turn decomposes and is 

 changed to some extent into the gaseous element helium, 

 which I discovered in 1895. 



All the while that these changes are taking place, what 

 are called ' /3-rays ' (beta-rays) are being evolved, and the 

 opinion is now generally held that these so-called rays are 

 really negative electricity, and are identical with the 

 ' cathode-rays ' of Lenard. 



I have been frequently asked : ' But is not electricity a 

 vibration ? How can wireless telegraphy be explained by 

 the passage of little particles or corpuscles ? ' The answer 

 is 'Electricity is a thing', it is these minute corpuscles, 

 but when they leave any object, a wave, like a wave of 

 light, spreads through the ether, and this wave is used for 

 wireless telegraphy.' 



It has been found that flames are capable of conducting 

 electricity, while gases, under the usual atmospheric 

 pressure, are very good insulators, and sparks can pass 

 through air only when the current is one of very high 

 tension. Now, in flames rapid chemical action is taking 

 place; compounds are burning that is, their constituents 

 are in the act of uniting with oxygen. 



Although it is not certain that /3-rays or, to give their 

 other name, corpuscles of electricity are being shot out 

 during such changes, it is not improbable that they are. 

 No doubt they impinge on the neighbouring atoms and 



