| dc.description.abstract | U7. mechanical acttm may he derivei] from heat, and heat may be generated
by mechanical action, by means of forces either acting between contiguous parts
of bodies, or due to electric excitation : but in no other way known, or even conceivable,
in the present state' of science. hence thcrmo-dvnamies falls naturallv
*■ *.
into two divisions, of which the subjects art1 respectively, the relation of heat
to the forces actina hrtireen cnnt'njuoas /ends of t>odies, and the relation if heat to
*■ *
electrical <i(jenc/i. the investigations of tin* conditions under which thermodynamic
(‘fleets arc1 produced, in operations of any fluid or fluids, whether
gaseous or liquid, or passing from one state to the other, or to or from the
solid statt1, and tin1 establishment of universal relations between the physical
properties of all substances in these different states, which have been given
in parts i.-v. of the1 present series of papers, belong to that first great division
of thermodynamics—to be completed as is intended fob future communications
to the royal society) by the extension of similar researches to the thermoelastic
properties of solids. the second division, or thermo electricity, which
may include many kinds of action as yet undiscovered, has hitherto been investigated
only as far as regards the agency of heat in producing electrical effects in
non-crystalline metals. in a mechanical theory of electric currents, communicated
to the royal society, dec. lõ, us51.* the application of the general laws
of the dynamical theory of heat to this kind of agency was made, and certain
universal relations precisely analogous to the thermo-elastic properties of fluids
established in the previous treatment of the first division of the subject, were
established between the thermo-electric properties of non-crystalline metals. the
object of the present communication is to extend the theory to the phenomena of
thermo-electricity in crystalline metals ; but as recent experimental researches on
air have pointed out an absolute therniometric scale,f the use of which in express- | pt_BR |
