Galileo (1564 - 1642) thought the appearance of new materials in a chemical change was due to rearrangement of parts too small to be seen.
Francis Bacon (1561 - 1626) seems to be thinking of matter in atomic terms when he says "Rapid motion of constituent particles is both a necessary and sufficient condition for something to be hot."
Robert Boyle ( 1627 - 1691) discarded the Aristotelian idea of the elements earth, air, fire and water as constituents of matter. Instead he used a ‘corpuscular or mechanical hypothesis’, explaining many physical phenomena in terms of solid bodies moving, colliding, bouncing, and having their shapes or sizes changed.
Isaac Newton (1642 - 1727) in his book Opticks wrote: "Have not the small Particles of Bodies certain Powers, Virtues, or Forces, by which they act at a distance, not only upon the Rays of Light for reflecting, refracting and inflecting them, but also upon one another for producing a great Part of the Phenomena of Nature?"