THE TRANSFORMATION OF ELEMENTS 227 



deposit of copper from the accumulated waters ; copper could 

 be changed into white or yellow alloys by admixture with 

 various earths. The transformations into copper, and into 

 silver or gold, were apparent 



The early history of chemistry is largely the history of such 

 attempts at transmutation, with various discoveries incident 

 thereon. As chemical knowledge grew, the evidence of these 

 changes became more and more capable of disproof, and belief 

 in them was only upheld by deception and self-deception. 



With the acceptance of Boyle's definition of an element, 

 the belief in transmutation in great part vanished. Dalton's 

 hypothesis of definite indivisible atoms peculiar to each element 

 made it appear still less likely. Not until the development of 

 the subject of radio-activity, and in particular till Ramsay and 

 Soddy showed that radium is transformed into helium, could 

 any support be given to the belief. 



It is necessary at this stage to distinguish between the terms 

 " transformation " and " transmutation." The element-changes 

 so far dealt with, which take place in nature under normal 

 conditions, are examples of transformation. Transmutation con- 

 tains the idea of active human intervention, and it is convenient 

 to ascribe it to changes so brought about where they differ 

 from those which would have occurred without such inter- 

 vention. 



The old and new ideas of transmutation differ greatly. The 

 alchemist sought to transmute large quantities of material, and 

 made the attempt for personal gain. The modern chemist 

 knows that such transmutations, if possible, can only be carried 

 out in extremely small quantity, by the expenditure in some 

 form or other of a relatively enormous amount of energy. The 

 product of transmutation will be probably of less value than 

 the original element. Thus the idea of gain is eliminated, and 

 the study of these changes can have no commercial application. 



As an example of these ideas the recently published ex- 

 periments of Th. Gross may be cited. An alternating current of 

 high voltage was passed for several hours through a platinum 

 crucible containing fused potassium carbonate at a red heat ; 

 potassium nitrate was added at intervals. The electrodes con- 

 sisted of stout platinum wire, and it was found that an appreci- 

 able quantity of platinum dissolved, both from the electrodes 

 and from the crucible. The melt, when examined, gave an 



