584 Latent Heat. (October, 
and land, and their history with the past evolution and pre- 
sent distribution and condition of organisms. 
In my theory the explanation of real and apparent changes 
of climate offers no difficulties. Climate has changed abso- 
lutely with the development and condensation of the solar 
system and of our earth. It has changed with the changing 
positions of the axis of the earth on its orbit, — that is, with 
the raising and permanency of continents and the distribution 
of sea and land, with the folding and unfolding of solid waves 
sliding, and with the whole envelope sliding in procession. 
III. LATENT HEAT. 
By Charles Morris. 
f CIENTISTS have a somewhat misleading method of 
grouping together several widely different modes of 
motion under one name, — not to their own confusion, 
perhaps, but decidedly to that of unscientific readers. Thus, 
after singling out a few forms of force under special names, 
all the rest are massed together and called heat. It is true 
the special character of the force intended is indicated by 
adjedtives. Thus we speak of Radiant Heat, Specific Heat, 
Latent Heat, Absolute Heat, and, simply, Heat. Of these 
the first phrase is most commonly used, and is most incor- 
rect. It expresses a mode of motion which is essentially 
different from Heat motion. It is readily convertible into 
Heat, but so are Light and Eledtricity, and the simple word 
Radiance would perhaps be a better term for it. 
The word Heat itself, in fadt, does not express one single 
mode of motion, since the heat motions in solids and gases 
are very different in charadter, while there is reason to be- 
lieve that liquids also possess a special mode of heat motion. 
So Specific Heat, Absolute Heat, and Latent Heat have 
special significations, which scientists have no difficulty in 
comprehending, so that the word Heat to them expresses far 
more than it does to well-informed unscientific readers. Of 
these various terms Latent Heat is the one least understood, 
