materia subtilisn.

1665 R. Hooke Micrographia 94 The pores which Des Cartes allow his materia subtilis between the æthereal globules.

1700 J. Locke Ess. Humane Understanding (new ed.) ii. xxiii. 166 The parts, that make up every the least corpuscle of that materia subtilis.

1741 Mem. Martinus Scriblerus xvii. 72 in A. Pope Wks. (1797) II He it was, that first taught the right use sometimes of the Fuga Vacui, and sometimes of the Materia Subtilis, in resolving the grand Phænomena of Nature.

1759 Voltaire Candide xxviii. 123 The pre-established harmony [of Leibniz] is the finest thing in the world, and so is the plenum and materia subtilis.

1805 Philos. Mag. 21 139 The materia subtilis is thus assumed to be compressible.

1865 All Year Round 25 Mar. 208/2 Light, therefore, consists not in a conatus—an effort or inclination of the materia subtilis to recede from the centre of the luminous body..—but in a real motion of those particles, darting away from the luminous body.

1978 Jrnl. Hist. Ideas 39 210 Hobbes had employed a technical mechanistic concept, ‘corpus subtile’, which he took to be essentially the same as Descartes' ‘materia subtilis’.

2007 L. M. Principe New Narr. 18th-cent. Chem. 6 It would be a strange sort of Cartesian who believes that light is an emitted stream of material particles, who invokes the materia subtilis only rarely in his early career—and even then in modified form—before discarding it.