TRANSMUTATION OF THE METALS 89 



copper, etc., are elements and cannot be changed, is merely 

 to say that we have not been able to decompose them. 

 Water, potash, soda, and other substances, were at one 

 time considered elements, and resisted all the efforts of 

 the older chemists to resolve them into their components, 

 but with the advent of more powerful means of analysis 

 they were shown to be compounds, and it is not impossible 

 that the so-called elements into which they were resolved 

 may themselves be found to be compounds. This has 

 happened in regard to some substances which were at one 

 time announced as elements, and it is not impossible that 

 it may happen in regard to others. The ablest chemists 

 of the present day recognize this fully and are prepared 

 for radical changes in our knowledge of the nature and 

 constitution of matter. Amongst the new views is the 

 hypothesis of Rutherford and Soddy, which, as given by 

 Sir William Ramsay, in a recent article contributed by him 

 to " Harper's Magazine," is that, 



" atoms of elements of high atomic weight, such as radium, 

 uranium, thorium, and the suspected elements polonium 

 and actinium, are unstable ; that they undergo spontaneous 

 change into other forms of matter, themselves radioactive 

 and themselves unstable; and that finally elements are 

 produced, which, on account of their non-radioactivity, are 

 as a rule, impossible to recognize, for their minute amount 

 precludes the application of any ordinary test with success. 

 Tie recognition of helium however, which is compara- 

 tively easy of detection, lends great support to this hypo- 

 thesis." 



At the same time we must not lose sight of the fact 

 that the substances which we now recognize as elements 

 have not only resisted the most powerful analytical agencies 

 and dissociating forces, but have maintained their ele- 



