THE BREATH OF LIFE 



The physical history of the universe is written in 

 terms of heat and motion. Astronomy is the story 

 of cooling suns and worlds. At a low enough tem- 

 perature all chemical activity ceases. In our own 

 experience we find that frost will blister like flame. 

 In the one case heat passes into the tissues so quickly 

 and in such quantity that a blister ensues; in the 

 other, heat is abstracted so quickly and in such 

 quantity that a like effect is produced. In one sense, 

 life is a thermal phenomenon; so are all conditions 

 of fluids and solids thermal phenomena. 



Great wonders Nature seems to achieve by vary- 

 ing the arrangement of the same particles. Arrange 

 or unite the atoms of carbon in one way and you 

 have charcoal; assemble the same atoms in another 

 order, and you have the diamond. The difference 

 between the pearl and the oyster-shell that holds it 

 is one of structure or arrangement of the same par- 

 ticles of matter. Arrange the atoms of silica in one 

 way and you have a quartz pebble, in another way 

 and you have a precious stone. The chemical con- 

 stituents of alcohol and ether are the same; the dif- 

 ference in their qualities and properties arises from 

 the way the elements are compounded the way 

 they take hold of hands, so to speak, in that marriage 

 ceremony which constitutes a chemical compound. 

 Compounds identical in composition and in molecu- 

 lar formulae may yet differ widely in physical prop- 

 erties; the elements are probably grouped in dif- 

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