258 AN UNDISCOVERED GAS. 



a partial regularity. It is undoubtedly one of the main problems of 

 pbysics and chemistry to solve this mystery. What the solution will 

 be is beyond my power of prophecy; whether it is to be found in the 

 influence of some circumstance on the atomic weights hitherto regarded 

 as among the most certain "constants of Nature" or whether it will 

 turn out that mass and gravitational attraction are influenced by tem- 

 perature or by electrical charge I can not tell; but that some means 

 will ultimately be found of reconciling these apparent discrepancies I 

 firmly believe. Such a reconciliation is necessary, whatever view be 

 taken of the nature of the universe and of its mode of action; what- 

 ever units we may choose to regard as fundamental among those which 

 lie at our disposal. 



In this address 1 have endeavored to fulfill my promise to combine a 

 little history, a little actuality, and a little prophecy. The history 

 belongs to the Old World. I have endeavored to share passing- events 

 with the New, and I will ask you to join with me in the hope that much 

 of the prophecy may meet with its fulfillment on this side of the ocean. 



