A HISTORY OF SCIENCE 



still more unfortunate, the experts do not agree among 

 themselves as to the validity of Professor Lockyer's con- 

 clusions. Some, like Professor Crookes, have accepted 

 them with acclaim, hailing Lockyer as " the Darwin of 

 the inorganic world," while others have sought a differ- 

 ent explanation of the facts he brings forward. As yet 

 it cannot be said that the controversy has been brought 

 to final settlement. Still, it is hardly to be doubted 

 that now, since the periodic law has seemed to join 

 hands with the spectroscope, a belief in the compound 

 nature of the so-called elements is rapidly gaining 

 ground among chemists. More and more general be- 

 comes the belief that the Daltonian atom is really a 

 compound radical, and that back of the seeming di- 

 versity of the alleged elements is a single form of 

 primordial matter. Indeed, in very recent months, 

 direct experimental evidence for this view has at last 

 come to hand, through the study of radio-active sub- 

 stances. In a later chapter we shall have occasion to 

 inquire how this came about. 



