The first chapter covers thoughts about atoms, from the ancient Greeks to Robert Boyle's demonstrating that air is compressed. The second chapter discusses early experiments about the ways atoms combined w/ other atoms to form molecules. These experiments were all done by considering mass, and lead to some incorrect and some correct conclusions about the relative weights of the atoms. The third chapter discusses more work on figuring out the relative weights of atoms, taking into account Avogadro's observations about volumes of gases. The fourth chapter discusses how bonds are formed between atoms and the notion of isomers. The fifth chapter discusses proofs that atoms actually exist and therefore aren't just a useful construct for understanding chemical behavior. Special reference is made to Brownian motion and the fact that Einstein's equations made it possible to determine the size of a water molecule. ( )