Isaac Newton didn't specifically say anything about the atom in the modern sense. While he was a brilliant physicist and mathematician, the concept of the atom as a fundamental unit of matter was not widely accepted during his lifetime.

Here's why:

* Ancient Greek Philosophers: The idea of atoms was first proposed by ancient Greek philosophers like Democritus and Leucippus. However, this idea was largely dismissed by the scientific community until the 19th century.

* Newton's Focus: Newton focused on developing laws of motion, gravity, and optics. He didn't delve into the nature of matter at the atomic level.

* Rise of Atomic Theory: The modern atomic theory, which describes atoms as the building blocks of matter, emerged much later with the work of John Dalton in the early 1800s.

It's important to note that Newton did believe in the concept of "corpuscles," tiny particles that made up matter. While this concept is similar to the atom, it lacked the specific properties and structure we now associate with atoms.

So, while Newton didn't talk about the atom in the way we understand it today, his work on the laws of nature paved the way for the development of modern atomic theory.