220 PRESENT PROBLEMS OF INORGANIC CHEMISTRY. 



ex])eriments, and I suggest this hypothesis (in the words of Dr. John- 

 stone Stoney, a hypotliesis is *■" a supjiosition which we hope may be 

 useful "") to serve as a guide for future endeavor. 



In the light of such facts, speculation on the periodii- arrangement 

 of the elements is surely premature. It is open to anyone to make 

 suggestions; they are self-evident. Most of you Avill agree with the 

 saying, " It is easy to prophesy after the cA^ent.'' I jjrefer to wait 

 until prophecy becomes easy. 



I must ask your indulgence for having merely selected a few out of 

 the many possible views as regards the problems of inorganic chcni 

 istry. I can only plead in excuse that ni}' task is not an easy one; 

 and I venture to express the hope that some light has been thrown on 

 the shady paths which penetrate that dark region which we term the 

 future. 



