220 PRESENT PROBLEMS OF INORGANIC CHEMISTRY. 



experiments, and I suggest this hypothesis (in the words of Dr. John- 

 stone Stoney, a hypothesis is '' a supposition which we hope may be 

 useful ") to serve as a guide for future eudeaA'or. 



In the liglit of such facts. s|)ecuhi(ion on the periodic arrangement 

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

 suggestions; the}^ are self-evident. Most of you will agree with the 

 saying, '' It is easy to prophesy after the event.'' 1 ])refer to wait 

 until prophecy becomes easy. 



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

 the many possible views as regards the problems of inorganic chem- 

 istry. I can oidy plead in excuse that my 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. 



