ATOMIC WEIGHTS AND ISOTOPES. 



By F. W. Aston, M. A., D. Sc, F. R. S., 

 Felloio of Trinity College, Cambridge. 



That matter is discontinuous and consists of discrete particles is 

 now an accepted fact, but it is by no means obvious to the senses. 



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Fig. 1. — Cubes 11 to 15 compared with familiar objects to scale. 



The surfaces of clean liquids, even under the most powerful micro- 

 scope, appear perfectly smooth, coherent, and continuous. The 



1 Abstract of a summary of a series of lectures given before The Franklin Institute, 

 March 6-10, 1922. Reprinted by permission from the Journal of the Franklin Institute, 

 May, 1922. 



101257—22 13 181 



