GENERAL MEETING. 63 
cause, and least cause. Such is the power of conception of the un- 
known in endeavor to explain the inconceivable known. 
If the dynamic hypothesis of perpetual transformation of energy 
could be established as a universal induction, with as much gen- 
erality, e. g., as the statement of the law of gravitation, it would 
establish and confirm that law, by Mr. Browne’s demonstration, as 
something more than a law, to wit, the necessary constitution of 
matter as a system of central forces and nothing more, substan- 
tially as conceived by Newton and elaborated by Boscovich. At 
present it is but a dynamic induction, but the theory of gravity is 
no more. Our appliances are material, and we can deal with mo- 
lar forces, but only indirectly and inferentially with those which 
are atomic. Conservation is indubitably true of energy in the me- 
chanical and molar sense, under the laws of dynamics and the per- 
sistence of force. It is, also, experimentally true, so far as we can 
trace it, of those less understood forms of energy which are mole- 
cular or atomic, the establishment of which was the great glory of 
Benjamin Thompson, Clausius, and Joule as to heat, and of a mul- 
titude of observers as to electrical energy. We infer it as a gen- 
eral truth of these energies (formerly known as imponderables, 
since they are not manifestations of matter in the concrete), from 
the fact of their convertibility with other modes of energy which 
are undoubtedly dynamical, and also from the intimate connection 
of electrical energy with one of the specific exhibitions of central 
atomic force—magnetism. Such clews create a warrantable pre- 
sumption that the phenomena in question will all ultimately be 
classified among the modes of atomic mass and motion, inductively 
as well as hypothetically. Possibly in the investigation of these 
evanescent modes of energy the missing simple particle may come 
to light. Provisionally, we are entitled to rank them among the 
mechanical modes of energy, as products of the same material 
forces, assuming, until the contrary is proved, that some form of 
matter is concerned in manifestations so correlated by conservation 
with undoubted material activities. 
In including the imponderables within the general dynamical 
law of conservation, we have to take account of the phenomenon 
of dissipation, first pointed out by Sir William Thompson. It is 
true that heat (as well as electrical energy) is strictly correlated 
with and interconvertible with energy of mass motion, as before 
