THE BREATH OF LIFE 



which is so radically different from a mechanical 

 mixture. In a chemical union the atoms are not 

 simply in juxtaposition; they are, so to speak, inside 

 of one another each has swallowed another and 

 lost its identity, an impossible feat, surely, viewed 

 in the light of our experiences with tangible bodies. 

 In the visible, mechanical world no two bodies can 

 occupy the same place at the same time, but appar- 

 ently in chemistry they can and do. An atom of 

 oxygen and one of carbon, or of hydrogen, unite 

 and are lost in each other; it is a marriage wherein 

 the two or three become one. In dealing with the 

 molecules and atoms of matter we are in a world 

 wherein the laws of solid bodies do not apply; fric- 

 tion is abolished, elasticity is perfect, and place and 

 form play no part. We have escaped from matter 

 as we know it, the solid, fluid, or gaseous forms, and 

 are dealing with it in its fourth or ethereal estate. 

 In breathing, the oxygen goes into the blood, not to 

 stay there, but to unite with and bring away the 

 waste of the system in the shape of carbon, and re- 

 enter the air again as one of the elements of carbon- 

 ic-acid gas, CO 2 . Then the reverse process takes 

 place in the vegetable world, the leaves breathe this 

 poisonous gas, release the oxygen under the chem- 

 istry of the sun's rays, and appropriate and store up 

 the carbon. Thus do the animal and vegetable 

 worlds play into each other's hands. The animal is 

 dependent upon the vegetable for its carbon, which 

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