THE STRUCTURE OF THE WORLD-STUFF 269 



THE STRUCTURE OF THE WORLD-STUFF 1 



By Professor HORACE CLARK RICHARDS 



UNIVERSITY OF PENNSYLVANIA 



SCIENCE, and the humanities. How often are they placed in 

 opposition. There is doubtless a utilitarian aspect of science 

 which though admirable in itself tends to foster a spirit antagonistic 

 to culture. But science is many-sided. And in the single-minded 

 seeking for the truth amidst clouding obscurities, in the searching out 

 the laws of the development be it of an atom, a tree, a man or a star, 

 in the aim to express that unity which we instinctively feel is the key 

 to the interpretation of nature's marvelous complex, I feel that she 

 earns an honored seat among the immortals. And so I need make no 

 apology for speaking to you upon a scientific subject, one which lies 

 at the very basis of natural science, one whose development has de- 

 manded not only zealous, strenuous research but calm judicial, wise 

 speculation, — the subject of the constitution of matter, the stuff of 

 which the physical world is made. 



The ultimate structure of the material world around us must always 

 have been a problem of deep interest to thoughtful minds, and has 

 formed a fruitful subject of speculation from the time of Thales to 

 the present day. But it is not of the philosophical aspect of the ques- 

 tion that I venture to speak. I can not claim to be a philosopher — 

 save such a one as is characterized by Touchstone as a " natural 

 philosopher " — but only a student of physics ; and it is therefore to 

 the physical side of the problem that I shall confine myself. The 

 substance and the form of Aristotle, the monad of Leibnitz, the strife 

 between idea and thing-in-itself, and other metaphysical contributions 

 toward the interpretation of the universe, important though they be in 

 the history of thought, are beyond the limitations of the present speaker 

 and of the present occasion. Our attention is rather to be directed to 

 the physical theories which have been framed as to the constitution of 

 matter, especially to the one which has won almost universal acceptance, 

 that known as the atomic theory; its development from the past, its 

 modern form, and its promise for the future. 



For the hypothesis of atoms is not a product of modern science. 



Indeed the question of the divisibility of matter must necessarily arise 



in the early stages of scientific thought. In our youth when we inquire 



as to the structure of things we are told that 



Little drops of water, 

 Little grains of sand, 



1 Address delivered before the joint meeting of Phi Beta Kappa and Sigma 

 Xi, University of Pennsylvania, June 16, 1909. 



