336 The Modern Aspects of Physical Science. [July, 
only when in motion, is an established fact. That Heat may re- 
quire one mode of motion, and Light another, can scarcely be denied. 
But we have still to inquire what is it that is moved, and where is 
the Mover. It is not enough to say it is the Ether that is put into 
undulation; we cannot rest satisfied with the idea, in many cases 
much too dogmatically put, that the vibration of material atoms 
produces, according to its degree, one or the other kind of physical 
energy. However positively these scientific dogmas may be as- 
serted, it should never be forgotten that they are but hypotheses, 
and that notwithstanding the appeal which is constantly made to 
mathematical analysis in support of them, the evidence is yet want- 
ing to establish their first principles. Faraday long since showed 
us that a dew-drop held within it a quantity of Electricity which 
would, if suddenly liberated, be sufficient to destroy the life of a 
small animal. He also proved that this great quantity of electri- 
city was necessary to the combination of the gases, oxygen and 
hydrogen, into that drop of water. Beyond this, we know that 
water is the fluid which we find it, by virtue of a given equivalent 
of heat, and by the simple process of chemical decomposition we 
may burn this water—strictly, its elements—and produce heat and 
light of the highest intensity. Are those phenomena explained in 
any way by the dynamical theory? We think not. 
At the same time that we are advancing to those metaphysical 
conclusions, we find ourselves in blind ignorance respecting the most 
simple conditions which rule the molecular condition of matter, 
whether inorganic or organic. We have firmly established the Law 
of Gravitation; but we know not what force it is that pushes or 
pulls mass towards mass. We speak of Cohesion, but we can only 
speculate on the power which compels molecule to cohere to mole- 
cule. We have supposed ourselves familiar with capillarity ; but since 
M. E. Becquerel has shown us that the surface-attraction which 
compels the rise of fluids within a tube is sufficient to separate 
metals from their combinations with acids, and deposit them in films 
upon the attracting surface,* we discover that we have to study the 
indications of some occult power. The Osmose forces, again, have 
been so fully investigated by Professor Graham, that we begin to 
see that they involve all the phenomena of condensation which are 
exhibited by porous bodies, and that solution, diffusion, transpira- 
tion, and probably chemical attraction are but modified manifest- 
ations of some undeveloped force capable of producing new forms 
of energy. , 
Residing upon the surface of material atoms there is a power 
equal, if not superior, to the known physical forces, probably 
* As long since as the Meeting of the British Association at Southampton, 
Professor Oersted called attention to phenomena of this class. 
