Wiktionary
n. (context philosophy English) The postulate that all physical bodies possess an inner and outer layer of minute particles or corpuscles.(reference-book last = Levere first = Trevor, H. title= Transforming Matter – A History of Chemistry from Alchemy to the Buckyball publisher=The Johns Hopkins University Press year=2001 isbn=0-8018-6610-3)
Wikipedia
Corpuscularianism is a physical theory that supposes all matter to be composed of minute particles. The theory became important in the seventeenth century; amongst the leading corpuscularians were Rene Descartes, Pierre Gassendi, Isaac Newton, Robert Boyle, and John Locke.
Corpuscularianism is similar to the theory of atomism, except that where atoms were supposed to be indivisible, corpuscles could in principle be divided. In this manner, for example, it was theorized that mercury could penetrate into metals and modify their inner structure, a step on the way towards the production of gold by transmutation. Corpuscularianism was associated by its leading proponents with the idea that some of the properties that objects appear to have are artifacts of the perceiving mind: "secondary" qualities as distinguished from "primary" qualities. Corpuscularianism stayed a dominant theory for centuries and was blended with alchemy by early scientists such as Robert Boyle and Isaac Newton in the 17th century.
In his work, The Sceptical Chymist (1661) Boyle abandoned the Aristotelian ideas of the classical elements—earth, water, air, and fire in favor of corpuscularianism. In his later work, The Origin of Forms and Qualities (1666), Boyle used corpuscularianism to explain all of the major Aristotelian concepts, marking a departure from traditional Aristotelianism.
The philosopher Thomas Hobbes used corpuscularianism to justify his political theories in Leviathan. It was used by Newton in his development of the corpuscular theory of light, while Boyle used it to develop his mechanical corpuscular philosophy, which laid the foundations for the Chemical Revolution.