definite conception of an atom is met by regarding 

 an atom, not necessarily as something which cannot 

 be divided, but as "a particle of matter which under- 

 goes no further division in chemical metamorphoses. 



THE CHEMICAL FORCE. What power binds the 

 atoms of a chemical compound together in such 

 marvelous closeness of union that in the couple or 

 group they lose all individuality? Clearly an 

 attractive force of enormous powder, a force re- 

 motely resembling, perhaps, that which attracts a 

 piece of iron to a magnet. Were not this force thus 

 all-powerful, the carbon in wood would show its 

 blackness and other qualities, and the hydrogen and 

 oxygen give indications of their gaseous and other 

 characters. This attractive force is commonly 

 termed the chemical force, sometimes chemical affinity. 



MOLECULES. An atom free and uncombined cannot 

 exist in a state of isolation, at common temperatures, 

 for any appreciable length of time. For we must re- 

 gard an atom as the home of an attractive force of 

 great intensity, and the moment such an atom is liber- 

 ated from a state of combination, it finds itself in 

 proximity to another atom having similiar desires for 

 union, so to speak; the result is an impetuous rush- 

 ing together and formation of either couples, trios, 

 or groups, according to the nature of the atoms. It 

 is doubtless possible to keep some pairs of atoms 

 apart by the aid of heat, just as the magnet and steel 

 may be parted by a superior amount of force, but 

 such a condition of things is probably abnormal. 

 These pairs and other groups of atoms are conven- 

 iently designated by the one word molecule. Dis- 

 similar kinds of atoms seem to have greater attrac- 

 tion to each other than similar kinds; for, first, the 

 masses of matter met with in nature in the great 

 majority of cases contain two or more dissimilar ele- 



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