Unfortunately, the atomic ideas of Democritus had no lasting effects on other Greek philosophers, including Aristotle. In fact, Aristotle dismissed the atomic idea as worthless. Aristotle's opinions were considered very important and if Aristotle said the atomic idea is wrong then everybody else thought it was wrong also.
For more than 2000 years nobody did anything to continue the explorations that the Greeks had started into the nature of matter. It wasn't until the early 1800's that people began to question the structure of matter.
In the 1800's an English chemist, John Dalton performed experiments with various chemicals that showed that matter, indeed, was made out of elementary lumpy particles (atoms). Although he did not know about their structure, he knew that they were, somehow, fundamental.
