John Joly

“ Whether the organism stands at rest and life comes to it on the
material currents of the winds and waters, or in the vibratory
energy of the æther; or, again, whether with restless craving it
hurries hither and thither in search of it, matters nothing. The
one principle—the accelerative law which is the law of the
organic—urges all alike onward to development, reproduction and
death. But although the individual dies death is not the end; for
life is a rhythmic phenomenon. ”

“ Thus, the sum of passing events constituting the present universe
should long ago have been accomplished and passed away. If we
consider alternative hypotheses not involving this difficulty, we
are at once struck by the fact that the future of material
development is free of the objection. For the eternity of
unprogressive events involved in the future on Kant's hypothesis,
is not only thinkable, but any change is, as observed,
irreconcilable with our ideas of energy. ”

“ That the geological age of the Earth is very great appears from
what we have already reviewed. The sediments of the past are many
miles in collective thickness: yet the feeble silt of the rivers
built them all from base to summit. They have been uplifted from
the seas and piled into mountains by movements so slow that
during all the time man has been upon the Earth but little change
would have been visible. The mountains have again been worn down
into the ocean by denudation and again younger mountains built
out of their redeposited materials. ”

“ It follows, in fact, from the
second law of thermodynamics, that whenever work is derived from
heat, a certain quantity of heat falls in potential without doing
work or, in short, is dissipated. On the other hand, work may be
entirely converted into heat. The result is the heat-tendency of
the universe. Heat, being an undirected form of energy, seeks, as
it were, its own level, so that the result of this heat-tendency
is continual approach to uniformity of potential. ”

“ Although some particles be
burnt up before others become alight, and some linger yet a
little longer than the others, in our day's work the
scintillation of the iron dust is the work of a single instant,
and so in the long night of eternity the scintillation of the
mightiest suns of space is over in a moment. A little longer,
indeed, in duration than the life which stirs a moment in
response to the diffusion of the energy, but only very little. ”

“ It can be shown that a primitive
and more rapid solution of the original crust of the Earth by the
slowly cooling ocean would have given rise to relatively small
salinity. The fact is, the quantity of salts in the ocean is
enormous. We are only now concerned with the sodium; but if we
could extract all the rock-salt (the chloride of sodium) from the
ocean we should have enough to cover the entire dry land of the
Earth to a depth of 400 feet. It is this gigantic quantity which
is going to enter into our estimate of the Earth's age. ”

“ The heat of the
earth is not internal only, but rather a heat-source exists at
the surface, which, as we have seen, cannot prevail to the same
degree within; and when the conditions become favourable for the
aggregation of the energy, the crust, heated both from beneath
and from above, assumes properties more akin to those of its
earlier stages of development, the secular heat-loss being
restored in the radioactive supplies. ”

“ What is the actual dynamic attitude of the primary organic
engine—the vegetable organism? We consider, here, in the first
place, not intervening, but resulting phenomena.
The young leaf exposed to solar radiation is small at first, and
the quantity of radiant energy it receives in unit of time cannot
exceed that which falls upon its surface. But what is the effect
of this energy? Not to produce a retardative reaction, but an
accelerative response: for, in the enlarging of the leaf by
growth, the plant opens for itself new channels of supply. ”

“ Earth's history or the history of the radioactive elements. With
this necessary admission we leave our study of the Birth-Time of
the World.
It has led us a long way from Lucretius. We do not ask if other
Iliads have perished; or if poets before Homer have vainly sung,
becoming a prey to all-consuming time. We move in a greater
history, the landmarks of which are not the birth and death of
kings and poets, but of species, genera, orders. And we set out
these organic events not according to the passing generations of
man, but over scores or hundreds of millions of years. ”

“ Weismann points out that natural selection favours
early and abundant reproduction. But whether the qualifications
of the "fittest" be strength, fertility, cunning, fleetness,
imitation, or concealment, we are safe in concluding that growth
and reproduction must be the primary qualities which at once
determine selection and are fostered by it. Inherent in the
nature of the organism is accelerated absorption of energy, but
the qualifications of the "fittest" are various, for the supply
of energy is limited, and there are many competitors for it. ”

“ Only mountains can beget mountains. Great accumulations of
sediment are a necessary condition for the localisation of
crust-flexure. The earliest mountains arose as purely igneous or
volcanic elevations, but the generations of the hills soon
originated in the collection of the _débris_, under the law of
gravity, in the hollow places. And if a foundered range is
exposed now to our view encumbered with thousands of feet of
overlying sediments we know that while the one range was sinking,
another, from which the sediments were derived, surely existed. ”

“ In fact, regelation will confer upon it all the
appearance of viscosity.
Let us picture to ourselves a glacier pressing its enormous mass
down a Swiss valley. At any point suppose it to be hindered in
its downward path by a rocky obstacle. At that point the ice
turns to water just as it does beneath the skate. The cold water
escapes and solidifies elsewhere. But note this, only where there
is freedom from pressure. In escaping, it carries away its latent
heat of liquefaction, and this we must assume, is lost to the
region of ice lately under pressure. ”

“ Only within narrow
limits of temperature and in presence of certain of the elements,
can life like ours exist, and outside these conditions life, if
such there be, must be different from ours. Once originated it is
so constituted as to assail the energies around it and to advance
from less to greater. Do we know more than these vague facts?
Yes, we have in our experience one other fact and one involving
much.
We know that our world is very old; that life has been for many
millions of years upon it; and that Man as a thinking being is
but of yesterday. ”

“ The planet is supposed to show its
solid crust in cross section, which may be a few miles in
thickness. Below this is such a hot plastic magma as we have
reason to believe underlies much of the solid crust of our own
Earth. Now there is an attraction between the satellite and the
crust of the planet; the same gravitational attraction which
exists between every particle of matter in the universe. Let us
consider how this attraction will affect the planet's crust. ”

“ A study of the rocks shows us that the world was not always what
it now is and long has been. We live in an epoch of denudation.
The rains and frosts disintegrate the hills; and the rivers roll
to the sea the finely divided particles into which they have been
resolved; as well as the salts which have been leached from them.
The sediments collect near the coasts of the continents; the
dissolved matter mingles with the general ocean. The geologist
has measured and mapped these deposits and traced them back into
the past, layer by layer. He finds them ever the same ”

“ On these grounds I contend that the present gravitational
properties of matter cannot be supposed to have acted for all
past duration. Universal equilibrium of gravitating particles
would have been indestructible by internal causes. Perpetual
instability or evolution is alike unthinkable and contrary to the
phenomena of the universe of which we are cognisant. We therefore
turn from gravitating matter as affording no rational account of
the past. We do so of necessity, however much we feel our
ignorance of the nature of the unknown actions to which we have
recourse. ”

“ Nevertheless, on the scratched and
torn ice-surface skating is still quite possible; on the smooth
plate glass we know we could not skate.
Some little time after this discussion, the connection between
skating and a somewhat abstruse fact in physical science occurred
to me. As the fact itself is one which has played a part in the
geological history of the earth,
[1] A lecture delivered before the Royal Dublin Society in 1905.
260
and a part of no little importance, the subject of skating,
whereby it is perhaps best brought home to every one, is
deserving of our careful attention. ”

“ When an alpha ray is discharged from the transforming element
into a gaseous medium its velocity is rapidly checked and its
energy absorbed. A certain amount of energy is thus transferred
from the transforming atom to the gas. We recognise this energy
in the gas by the altered properties of the latter; chiefly by
the fact that it becomes a conductor of electricity. The
mechanism by which this change is effected is in part known. The
atoms of the gas, which appear to be freely penetrated by the
alpha ray, are so far dismembered as to yield charged electrons
or ions ”

“ Thus, development
along lines of large growth will tend to a slow rate of
reproduction from the simple fact that unlimited energy to supply
abundant reproduction is not procurable, whatever we may assume
as to the strength or cunning exerted by the individual in its
efforts to obtain its supplies. On the other hand, development
along lines of small growth, in that reproduction is less costly,
will probably lead to increased rate of reproduction. ”

“ The ice under the increased pressure would melt a little
everywhere throughout its mass, taking the requisite latent heat
from itself at the expense of its sensible heat, and the
temperature of the ice would fall to the new melting point.
Could we melt the whole of the ice in this manner? Again the
answer is "yes." But the pressure must be very great. If we
assume that all the heat is obtained at the expense of the
sensible heat of the ice, the cooling must be such as to supply
the latent heat of the whole mass of water produced. ”

“ On the other hand, measurements have been
made of the accumulation in minerals of radioactive _débris_—the
helium and lead—and results obtained which, although they do not
agree very well among themselves, are concordant in assigning a
very much greater age to the rocks. If the radioactive estimate
is correct, then we are now living in a time when the denudative
forces of the Earth are about eight or nine times as active as
they have been on the average over the past. Such a state of
things is absolutely unaccountable. ”

“ Geddes and Thomson, The Evolution of Sex, chap. xviii.
85
of its mortality, the body remains a striking manifestation of
the progressiveness of the organism, for to this it must be
ascribed. To it energy is available which is denied to the
protozoon. Ingenious adaptations to environment are more
especially its privilege. A higher manifestation, however, was
possible, and was found in the development of mind. This, too, is
a servant of the cell, as the genii of the lamp. Through it
energy is available which is denied to the body. This is the
masterpiece of the cell. ”

“ I need not
illustrate so well-known a principle by experiment. Solid
friction disappears when the liquid intervenes. In its place we
substitute the lesser difficulty of shearing one layer of the
liquid over the other; and if we keep up the supply of oil the
work required to do this is not very different, no matter how
great we make the pressure upon the bearings. Compared with the
resistance of solid friction, the resistance of fluid friction is
trifling. Here under the skate the lubrication is perhaps the
most perfect which it is possible to conceive. ”

“ There is
seemingly a principle at work, leading to the increase of organic
activity.
Many other examples might be adduced. The gastrula stage in the
development of embryos, where by invagination such an arrangement
of the multiplying cells is secured as to offer the greatest
possible surface consistent with a first division of labour; the
provision of cilia for drawing upon the energy supplies of the
medium; and more generally the specialisation of organs in the
higher developments of life, may alike be regarded as efforts of
the organism directed to the absorption of energy. ”

“ The downward
deflection of the crust is of course an outcome of the same
compressive stresses which elevate the mountain.
The fact that the yielding of the crust is always situated where
the sediments have accumulated to the greatest depth, has led to
attempts from time to time of establishing a physical connexion
between the one and the other. The best-known of these theories
is that of Babbage and Herschel. This seeks the connexion in the
rise of the
123
geotherms into the sinking mass of sediment and the consequent
increase of temperature of the earth-crust beneath. ”

“ The heat-tendency of the universe is also revealed in the
far-reaching "law of maximum work," which defines that chemical
change, accomplished without the intervention of external energy,
tends to the production of the body, or system of bodies, which
disengage the greatest quantity of heat. [1] And, again, vast
numbers of actions going on throughout nature are attended by
dissipatory thermal effects, as those arising from the motions of
proximate molecules (friction, viscosity) , and from the fall of
electrical potential. ”

“ In inanimate
actions throughout nature, as we know it, the availability is
continually diminishing. The change is all the one way. As,
however, the supply of available energy in the universe is
(probably) limited in amount, we must look upon the two as simply
effecting the final dissipation of potential in very different
ways. The animate system is aggressive on the energy available to
it, spends with economy, and invests at interest till death
finally deprives it of all. ”

“ In short, the facts and generalisations concerning evolution must
presuppose an organism endowed with the quality of progressive
absorption of energy, and retentive of it. The continuity of
organic activity in a world where supplies are intermittent is
evidently only possible upon the latter condition. Thus it
appears that the dynamic attitude of the organism, considered in
these pages, occupies a fundamental position regarding its
evolution. ”