> as lemmas

1626 F. Bacon Sylua Syluarum §99 It is certaine, that of all Powers in Nature, Heat is the chiefe.

1665 R. Hooke Micrographia 37 Heat is a property of a body arising from the motion or agitation of its parts; and therefore whatever body is thereby toucht must necessarily receive some part of that motion, whereby its parts will be shaken.

1665 R. Hooke Micrographia Table 248 Experiments to shew, that bodies expand by heat.

1695 J. Woodward Ess. Nat. Hist. Earth 121 Heat and Fire differ but in degree: and Heat is Fire only in lesser quantity. Fire I shall shew to be a Fluid consisting of Parts extremely small and light, and consequently very subtile, active, and susceptive of Motion.

a1704 J. Locke Elem. Nat. Philos. (?1750) xi. 43 Heat, is a very brisk agitation of the insensible parts of the object, which produces in us that sensation, from whence we denominate the object hot; so what in our sensation is heat; in the object is nothing but motion.

1760 J. Black Inq. Nat. Heat 529 But heat is evidently not passive; it is an expansive fluid, which dilates in consequence of the repulsion subsisting among its own particles.

1833 N. Arnott Elements Physics (ed. 5) II. 10 Heat cannot be exhibited apart, nor proved to have weight or inertia.

c1860 M. Faraday Var. Forces Nature iii. 79 Whenever we diminish the attraction of cohesion we absorb heat.

1862 H. Spencer First Princ. ii. viii. §66 That mode of force which we distinguish as Heat, is now generally regarded by physicists as molecular motion.

1879 W. Thomson & P. G. Tait Treat. Nat. Philos. (new ed.) I: Pt. i. §385 The Dynamical Theory of Heat..is based upon the conclusion from experiment that heat is a form of energy.