MIRACLES OF SCIENCE 



occupied by 'matter' contains very much less than 

 the space where no 'matter* exists." 



I shall not attempt here to detail the reasoning by 

 which this paradoxical view is sustained and made 

 to seem plausible. Suffice it that spherical .bodies of 

 tangible size, say shot or marbles, can be piled to- 

 gether in various ways, and that accordingly as they 

 are piled in so-called dilated or in close order, they 

 occupy more or less space. From the experiments 

 with such tangible spheres, it is shown that a shift 

 in the mutual positions of the hypothetical granules 

 making up the ether will account theoretically for 

 the production of rifts or bubbles which our crude 

 senses interpret as solid matter, and that an exten- 

 sion of the same reasoning makes possible an ex- 

 planation of the world-old mystery of gravitation 

 itself. 



The observations that led Reynolds to his explana- 

 tion of gravitation are based on tests made with 

 masses of small granules, such as shot or sand grains, 

 and have to do with the phenomenon which Reynolds 

 describes as dilatancy. This "consists in a definite 

 change of bulk, whenever there is a definite change 

 of shape or distortional strain, any disturbances what- 

 ever causing a change of volume and general .dila- 

 tion." 



Professor Mackenzie illustrates the meaning of ; 

 this by saying that when shot or sand or other 

 spherical grains are put into a bag or other closed 

 surface and shaken, they settle into a very close 

 position, in which the spaces or interstices between 

 the grains are about the smallest possible. This 



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