236 THE UNIVERSE 



microscope to be made up of a thousand or more 

 still smaller particles. 



There are living creatures so small it would take 

 a million of them to equal the size of a mustard 

 seed. Millions of them float unseen in the air around 

 us, and swim in the drops of water we drink. Mil- 

 lions more float through the blood in our veins, 

 which to them are vast, surging seas of life. They 

 are so very small, a thousand of them might fly 

 side by side through the eye of a needle. Yet each 

 little creature must be made of still smaller parts, 

 else they could not move or devour their food ; they 

 are too infinitesimal for the grasp of our imagina- 

 tion. 



If we keep on dividing a body into smaller and 

 smaller pieces, we at last get a piece so very small 

 it cannot be divided again without changing into 

 some other kind of matter. These smaller pieces are 

 called molecules, which are particles of matter which 

 cannot be divided without changing their nature. All 

 bodies are porous and have spaces between their 

 molecules. This was proven of gold a long time ago 

 at Florence, where a hollow globe of gold was filled 

 with water and shut up tight, then put under im- 

 mense pressure. The water was forced by the pressure 

 through the pores of the gold as a fine dewy mois- 

 ture or perspiration. The same result would have 

 occurred had it been iron, copper or any other 

 metal, as there is a space between all molecules in 

 all bodies. 



All molecules in all bodies revolve around each 

 other without touching. You can stand a man be- 

 fore the Crookes tube or Roentgen rays and look 

 through him and take pictures of his bones, and 



