THE CENTURY'S PROGRESS IN CHEMISTRY 



Here, then, was what might be termed direct experi- 

 mental evidence for the hypothesis of Prout. Unfortu- 

 nately, however, it is evidence of a kind which only a 

 few experts are competent to discuss so very delicate a 

 matter is the spectral analysis of the stars. What is 

 still more unfortunate, the experts do not agree among 

 themselves as to the validity of Mr. Lockyer's conclu- 

 sions. 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 unique form 

 of primordial matter. But it should not be forgotten 

 that this view, whatever its attractiveness, still lurks in 

 the domain of theory. There is no proof that the Dal- 

 tonian atom has yet been divided in the laboratory. 



