GRAHAM  LECTURES:
ON THIE
POWER, WISDOM, AND GOODNESS
OF GOD,
AS MANIFESTEDI) IN HIS WORKS.
VOLUME III.
PUBLISHED BY
THE BROOKLYN INSTITUTE.  
REILIGION AND  CHPEMI STRY; 
OR,        ~    /, 01I,? t- P
~~2> I'!,
PROOFS OF GOD'S PLAN IN THE ATMOSPHERE
AND ITS ELEMENTS.
TEN LECTURES
DELIVERED AT THE BROOKLYN INSTITUTE, BROOKLYN, N.Y.
ON THE GRAHAM FOUNDATION.
BY,:
JOSIAH P.COOKE, JR.,
ERVING PROFESSOR OF CHEMISTRY AND  MINERALOGY
IN IIARVARD UNIVERSITY.
"Duo sunt qua in cognitionem Dei ducunt; Creatura et Scriptura."
ST. AUGUSTINE.
SECOND EDITION.
NEW YORK:
CHARLES SCRIBNER & CO.,
124 GRAND STREET.
1865. 
Entered according to Act of Congress, in the year 1864, by
PETER G. TAYLOR,
President of the Brooklyn Institute,
in the Clerk's Office of the District Court of the United States for the Southern District of
New York.
UNIVERSITY PRESS:
WELCH, BIGELOW, AND COMPANY,
CAMBRIDGE. 
TO
MY FATHER,
THIS BOOK
IS AFFECTIONATELY AND GRATEFULLY
DEDICATED. 
N
t 
PREFACE.
THE Lectures now published were first delivered
before the Brooklyn Institute on Sunday evenings
of January and February, 1861, and the larger
part of them were subsequently repeated, during
the same winter, before the Lowell Institute in
Boston, and before the Mechanics' Association of
Lowell. The progress of science since that time
has rendered necessary many additions, and in revising the Lectures for publication, the material
has been thus so greatly increased that what was
originally prepared and delivered as six Lectures is
now distributed over ten. At the time when the_
Lectures were written, Mr. Darwin's book on the
Origin of Species, then recently published, was exciting great attention, and was thought by many
to have an injurious bearing on the argument
for design. It was, therefore, made the chief aim
of these Lectures to show that there is abundant
evidence of design in the properties of the chemical elements alone, and hence that the great argu
-.-. — 
PREFACE.
ment of Natural Theology rests upon a basis which
no theories of organic development can shake. In
illustrating his subject, the author has used freely
all the materials at his command, and if, in any
case, he has failed to give due acknowledgment, it
has been because by long dwelling on the subject
the thoughts of others have become blended with
his own. He would here acknowledge his repeated
indebtedness to Professor Guyot's work on "Earth
and Man," to Professor Faraday's published Courses
of Elementary Lectures, and to Professor Tyndall's Lectures on "Heat considered as a Mode of
Motion." He would also express his especial obligations to the author of "In Memoriam," in whose
verses he has discovered a truer appreciation of
the difficulties which beset the questions discussed
in this volume, than he has ever found in the philosophy of the schools.
CAMBRIDGE, May 3d, 1864.
viii 
CONTENTS.
STATEMENT OF THE CASE..
TESTIMONY OF THE ATMOSPHERE
TESTIMONY OF OXYGEN..
TESTIMONY OF WATER...
TESTIMONY OF CARBONIC ACID.
TESTIMONY OF NITROGEN..  
ARGUMENT FROM SPECIAL ADAPTATIONS
ARGUMENT FROM GENERAL PLAN.
NECESSARY LIMITATIONS OF SCIENTIFIC
RELIGIOUS THOUGHT...
1
PASs
1- 15
16- 72
73-124
125-170
171-211
212-238
239-266
267-341
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
AND
341-348  
GRAHAM LECTURES.
RELIGION AND CHEMISTRY.
LECTURE I.
STATEMENT OF THE CASE.-TESTIMONY OF THE ATMOSPHERE.
THE time has been when the Christian Church
was an active antagonist of physical science;
when the whole hierarchy of Rome unit- The relation of
ed t condemn.  i     ts  results andtoresithe Church to
ed to condemn its results and to resst physical sciits progress; when the immediate reward e-.
of great discoveries was obloquy and persecution.
But all this has passed. The age of dogmatism
has gone, and an age of general scepticism has
succeeded.  The power of traditional authority has
given place to the power of ideas, and physical
science, which before hardly dared to assert its
birthright, and could even be forced to recant, on
its knees, its demonstrated truths, has now become
one of the rulers of society. By its rapid growth,
by its conquests over brute matter, and by its
wonderful revelations, it has deservedly gained the
highest respect of man, while by multiplying and
diffusing the comforts of life it has become his 
RELIGION AND CHEMISTRY.
acknowledged friend. Every effort is now made
to further its progress. Its great discoveries win
the applause of nations, and its fortunate students
are remembered when the princes and nobles of
the earth are forgotten.
All this is well. But unfortunately, elated by
his success, the stripling has been at times proud
and arrogant, usurping authority not his due. Forgetting his early faith, he has approached with
irreverent thoughts the holy temple of our religion, and, not content to worship in the outer court,
has dared to penetrate into  the very Holy of
Holies, and apply his material tests even to the
vessels of the altar. No wonder that the Church
should become alarmed, that many of her best men,
holding fast to the sacred dogmas of our religion
as the only sure anchor of their faith in this world,
and their sole ground of hope for the next, should
join in a general cry against the whole tendency
of science and its results.
But this is a great mistake. Judging of the
real character of physical science from the pretensions of a few, and not possessing the power
or opportunity of investigating for themselves,
these good men are unnecessarily alarmed: the
phantom they fear is purely of their own creation, and, could they but know the whole truth,
they themselves would see that to ignore the
well-established results of science, and to denounce
its legitimate tendency, is a policy as short-sighted
as it is illiberal and unchristian.
2
[LEcr. I. 
STATEMENT OF THE CASE.
Fortunately, such fearful souls constitute but a
small party in the Christian Church. There is a
far nobler and more  courageous  faith Theattitudeof
than theirs, -a faith so strong in its a brave Chris
convictions  that it fears no  criticism,     fith.
however searching, and no scientific analysis, however rigorous it may be, - a faith which finds in
the Bible, not a series of dead formulas, but a
mass of living truth,- a faith which really believes that the God of nature is the God of grace,
and that man was created in the image of this
one and only God, -a faith which wells up from
the depths of the soul, which speaks because it
believes, which believes because it feels,- a faith
whose sources are as hidden as those of the fountain, but whose reality is as living as the verdant
landscape which the fountain waters.
It is the men with a faith like this who are
the really brave Christians. They are not alarmed
at the apparent contradictions between science
and revelation.   By  the very imperfections of
their own faculties, which they so keenly feel,
they have been taught that mysteries exist; nay,
they find in these very mysteries the strongest
bulwarks of their faith; for they feel, with Robert
Hall, that "a religion without its mysteries would
be a temple without its God." They are fulily
assured that our minds were framed after the
likeness of their Divine original, in order that
we, creatures of the dust though we are, might
nevertheless in our feeble measure comprehend
LECT. I.]
3 
RELIGION AND CHEMISTRY.
God's workmanship and sympathize with his divine thoughts; and they reject as absurd the doctrine that man, thus created an intelligent and
sympathizing observer of God's universe, should
have been permitted, in the legitimate exercise
of the very powers which God has given him, to
build up a connected system of science in direct
contradiction with those higher and spiritual truths
which the Father has been mercifully pleased to
reveal to his sinning children through his prophets
and his Son.
May the foundation of these lectures ever stand
as a monument of this brave Christian faith. He
who provided in his last testament that the wisdom, power, and goodness of his God should at
short intervals be illustrated in this place from
the varied stores of knowledge which the investigator of nature might collect, could not have
feared that there was any essential contradiction
between science and revelation. On the contrary,
he must have felt that science would become the
great champion of the Christian faith; and may
the result fully prove his wisdom and his foresight.
It will be my object, in the present course of
lectures, to aid in carrying out the noble purThewholema- poses of the founder by developing beterial creation fore you the illustrations of the wisdom,
illustrates
aod's at-i  goodness, and power of God, which have
butes.   been discovered in the constitution of
matter.  The material of this universe, by which
4
[LECT. I. 
STATEMENT OF THE CASE.
we are surrounded and in which we live and
move, is full of the evidences of these attributes of the Creator. They crowd upon us from
every side. Wherever we turn our eyes there
we read them, on the blue dome of heaven, and
on the gorgeous cloud-turrets of the western sky;
they are inscribed on the rocky cliffs which record the memory of long-buried ages, and on the
green sods which cover the last-made grave; they
are heard in the crackling of the conflagration no
less than in the roaring of the tempest, in the
pattering of the rain-drop as well as in the rolling of the thunder.
"The heavens declare the glory of God, and
"the firmament showeth his handywork. Day
"unto day uttereth speech, and night unto night
"showeth knowledge.  There is no speech nor lan"guage where their voice is not heard. Their line
"is gone out through all the earth, and their words
"to the end of the world."
It is the privilege and duty of the student of
nature to interpret the characters in which these
evidences are written, and the language which
nature speaks; but the best translation gives only
an inadequate idea even of a work of human
genius, and far less can my imperfect rendering
convey to you the full force of that impression
which the devout student receives while studying
the perfect works of God.
The illustrations of the attributes of God, which
may be drawn from the constitution of matter, are
5
LECT. I.] 
RELIGION AND CHEMISTRY.
conveniently divided into two classes, —first, those
Twoclasses of which appear in the adaptation of varimustrations.  ous  means  to  a  particular  end, and,
second, those which are to be found in the unity
of plan according to which the whole frame of
nature has been constructed. The first class are
exhibited by the properties of matter, the second
by the so-called physical laws and forces.
There are probably no forms of matter in which,
even with our present imperfect knowledge, a combination of means conspiring to some beneficent
end cannot be traced; but such adaptations are
more especially to be seen in the properties of
those substances which are the most intimately
associated with man, and on which his existence
and happiness depend. We shall not, therefore, be
obliged to search the recondite facts of science, or
to investigate the rarities of nature, to find our
illustrations of the Divine attributes; they lie all
around us, in the air we breathe, in the water we
drink, and in the coal we burn; and what more
convincing evidence could we have of the beneficence of our Heavenly Father than the very fact
that these familiar substances are of all others
most vocal with his praise?
In following out, then, the order which seems to
be so obviously indicated by the nature of the
The plan of this case, I shall ask you, in the first place, to
courseoflec- study with me the physical condition of
tures.
our atmosphere, and the properties of the
various materials of which it consists; and I am
6
[LECT. I. 
STATEMENT OF THE CASE.
sure we shall not fail to find in one and all abundant evidence of the wisdom, goodness, and power
of God. Having thus made you acquainted with
some of the more important scientific facts required for my argument, I shall next direct your
attention to those grander demonstrations of God's
wisdom and power which appear in the great laws
and forces, by which the whole material universe
is upheld, and lastly an examination of the relative
limits of scientific and religious thought will form
an appropriate termination for the course.
The argument from special adaptations which lies
at the basis of all works on natural theology is
admirably condensed by Dugald Stewart The  ent
The argument
into two simple propositions.   The  one fromr specil
is, "that everything which begins to exist must have a cause"; the other, "that a combination of means conspiring to a particular end
implies intelligence." To these might be added the
two equally clear propositions stated by Dr. Reid:
first, " that design may be traced from its effects";
second, "that there are evidences of design in the
universe."   I do not intend to discuss at length
the logical validity of this argument, or the general value of analogical reasoning which it implies.
Such discussions belong particularly to the province of metaphysics, and I willingly leave them
to abler hands. It will be my chief object in
these lectures to bring to your notice a few of the
numberless indications of adaptation in the materials of our atmosphere, assuming for the present
7
LaCT. I.] 
RELIGION AND CHEMISTRY.
that these adaptations are evidences of design, and
therefore evidences of the existence of a personal
God, infinite in wisdom, absolute in power.  When
we have thus become acquainted with some of the
facts on which the argument rests, we may then
profitably consider the validity of the reasoning, at
least so far as to weigh the objections, which modern materialism has urged against it.
I am well aware that great prejudice is entertained in many religious minds against the whole
Prejudice   scheme of natural theology, originating
against natural in a vague idea that its study is in some
theology.
theology measure unfavorable to the growth of
Christian faith. That such an impression should
be produced by a class of modern writers, who
think to supersede Christianity by a sort of pantheistic naturalism, is not surprising; but certainly
natural theology is no more chargeable with the
presumption of such speculations than is Christianity with the excesses of Jesuitism. Let me not
be misunderstood. I have no desire to press the
argument of natural theology too far.
For myself, I believe that the facts of human
nature themselves all tend to prove that a divine
Natu  theol- revelation is the only legitimate basis for
ogyno ubti- a system of religion, and that an histortute for an historical faith. ical faith based on a supernatural revelation is the only religion possible for imperfect
humanity. Indeed, I am led to think we find evidence of the goodness of our Heavenly Father in
the very circumstance that the foundations of all
8
[LECT. I. 
STATEMENT OF THE CASE.
knowledge have been laid in such obscurity that
no unaided human intellect can wholly dispel the
cloud which hides the Creator from our sight,
"To feel, although no tongue can prove,
That every cloud that spreads above
And veileth love, itself is love."
This very obscurity humbles the pride of human
learning, and raises its constant warning against
that intellectual idolatry which would substitute
its shallow philosophy for the simple truth as it
is in Jesus. The Bible once received, science can
furnish abundant illustrations of the attributes of
the Being therein revealed; but even with all
the illumination which has been the immediate
or secondary result of Christianity, man is hopeless without its authority, and I would not give
the slightest shadow of support to that irreverent
presumption which, guided by what it calls the
unaided light of nature, would construct a system
of religion out of passions, intuitions, and I know
not what absurdity.
But still it must be remembered that the Christian revelation does not prove the existence of
G     o     d;       on the contrary, it is based on   a Naturaltheol                                           ogy the logical
belief in his being that already exists in bagyithe of Chricthe mind of man.  The Bible opens with tianity.
this assumption. The first line asserts that
"In the beginning God created the heaven and
"the earth."
And the Hebrew name of God, Jehovah (I am that
Ilam), is itself a declaration of his self-existent being.
9
LECT. I.] 
RELIGION AND CHEMISTRY.
With all men a belief in some Almighty Power
overshadowing their being grows up spontaneously
in the heart, thev know not how; but the educated and the intelligent seek further to find its
logical grounds in the evidences of nature.
Here, then, is the first great office of natural
theology. It furnishes the logical basis on which
the whole scheme of revealed religion given us
in the Bible rests.
I have no desire to over-estimate the importance
of my subject. For myself, I believe, with Paley
and the other eminent writers of the same class,
that the fundamental truths of our religion can
be inferred from the constitution of the human
mind and from the course of nature with as much
oertainty as analogical reasoning can ever give.
But still I know that the evidence is not demonstrative and not likely to convince the sceptic;
for in the last analysis it rests on certain assumptions which he will not admit. And it is in vain
to urge that these assumptions are really intuitive truths and tacitly admitted by the whole
human race; for he easily replies, that they are
not intuitive to his mind.
Nevertheless, the evidences of God in nature
are the only proof we have or can have of his
existence, and they are therefore the only logical
basis of the Christian revelation. Nature and revelation are parts of one and the same system, and,
however much our prejudices may obscure the
fact, Christianity rests on natural religion, and
.0
LLECT. I. 
STATEMENT OF THE CASE.
cannot be logically defended if the authority of
the last is denied.*
But however great the value of natural theology, considered as the basis on which revelation
rests, this is not its only or most impor- Natural theoltant office.  In the present age of the ogycofirm
and illustrates
world it confers a still more inestimable thetruths of
benefit on mankind by confirming, illus- revelation.
trating, and enforcing the admitted truths of revelation.
If it be asked of what value are further illustrations of admitted truths, I answer, that there
is an important class of nominal Christians who
are more open to impressions from the study of
nature than to direct appeals to the heart. It
is true that the great mass of mankind must be
Christianized, if at all, through the affections and
by the hard discipline of sorrow; but there are
some who, not yet tried in the fiery furnace of
affliction, have first felt their Father's hand and
recognized his love while contemplating his works.
I do not say that persons so touched are already
Christians, but I do say that the first step has
been taken, and that is a great deal. It may
require many years of sad experience and many
a bitter pang of disappointment before they come
to kneel humbly at their Saviour's feet; but, like
the great Apostle, they will always look back to
the time when the Divine presence first visibly
* See a recent work by the Rev. A. P. Peabody, D. D., entitled,
"Christianity the Religion of Nature," for a development of this idea.
11
LEc'r. I.] 
RELIGION AND CHEMISTRY.
shone before them as the turning period of their
life.
While, therefore, I should be the first to condemn
that hollow naturalism which would substitute a
Importance of system of natural theism for the simple
this office. doctrines of the Bible, I must also deprecate that prejudice which prevents many clergymen, through fear of this tendency of the age, from
availing themselves of the aid of science in enforcing the fundamental truths of our religion. I assure them they thus neglect a most important
means of influence over educated and thinking
men, - a means of influence always important, but
never more so than in an age which is marked
by its cultivation of practical science, and in a
country where so large a portion of the active
energy of the community has taken this practical
direction. The danger of our time is not so much
a philosophical scepticism as a practical materialism.
The fear is, not that men should reason themselves
into unbelief, but that, spending their whole lives
in developing the powers of nature, they should
practically worship the dead matter, rather than
the living God. If, however, you can make such
persons feel that the material is but a form of the
spiritual, and that in fact the spiritual- is nowhere
more manifest than in those very laws and forces
which they so much idolize, you will not change,
it is true, the tendency of the age, but you will
ennoble and sanctify it. The whole material universe will become transfigured, and nature will no
12
[LEc'r. L 
STATEMENT OF THE CASE.
longer be seen as a wonderful mechanical application of blind forces, but as a living embodiment
of the Eternal One. Nature-worship may continue,
but it will have lost its idolatry; for it will be
no longer the machine that is worshipped, but that
same Living Spirit which spoke in tones of thunder
from the clouds of Sinai and in accents of mercy at
the baptism of Christ.
I know it is said that nature conceals rather than
reveals God, and in a certain sense it is undoubtedly
true that He is hidden from us behind the veil of
his works; but since it is permitted to man by the
exercise of his intelligence to lift in part this veil,
it is certainly the duty, as it should be the privilege, of the ministers of religion to show forth the
unspeakable glory which lies behind these material
forms.
But why multiply arguments when we have the
authority of the Great Teacher himself, who frequently appealed to nature to illustrate and Example of
enforce the divine truths which he came Christ.
on earth to reveal? We have indeed the whole
summary of Natural Theology in His simple words.
"Wherefore, if God so clothe the grass of the
"field, which to-day is, and to-morrow is cast into
"the oven, shall he not much more clothe you, 0
"ye of little faith?"
With, then, such authority as this, let us not despise the beginnings because they are not the end,
or undervalue the means by which many a noble
soul has been led to the foot of the Cross.
13
LECT. I.] 
RELIGION AND CHEMISTRY.
Without seeking, therefore, to vindicate further
the claims of my subject, I will at once enter upon
the plan already proposed for this course of lec tures, and will first ask your attention to the illustrations of the wisdom, goodness, and power of God,
which may be discovered in the constitution of our
atmosphere. In endeavoring to carry out this plan,
I shall require all your indulgence and all your
kind forbearance.   From  the very nature of the
case, it will be necessary to start from first principles, and much of the way we are to travel together
will be uninteresting and dull. If, however, the path
shall lead us to the summit of that holy mountain
from which we can gain a clearer vision of spiritual
things, we shall soon forget the toil and difficulty
of the ascent. We have no extravagant expectations of the result. We do not hope to convince
the sceptic, or to arouse the indifferent from their
practical unbelief. Our only hope is,- and this we
entertain in all humility, - that, by pointing out a
few of the footprints of the Creator which lie thickly
along our daily path, we may encourage some earnest student toiling forward on his journey of life.
May God grant to us all the richest blessings of
Hiis grace; for though man may plant and water,
Hie only giveth the increase.
The illustrations of the attributes of God  presented to us by the atmosphere are especially
manifest in those adaptations of properties by
which it has been made to subserve the welfare
and happiness of mankind. Here, however, as
14
[LECT. L 
STATEMENT OF THE CASE.
always in the study of nature, we must be careful
to avoid the error of considering man as
Adaptations in
the sole end of creation, and of interpret- the atmosphere
ing all phenomena with reference to him to be stdiea
with especial
alone. The material universe is the mani- reference to
festation of one grand creative thought, as
comprehensive in the diversity of the parts, as it is
grand in the unity of the whole. These parts have
been so wondrously joined and skilfully wrought
together, that each is linked with each, and one
with all. In this Divine economy nothing is wanting, nothing is superfluous, and what seems to our
feeble vision least important is as essential to complete the unity of the plan as our own glorious
manhood:
"Nothing useless is or low,
Each thing in its place is best,
And what seems but idle show
Strengthens and supports the rest."
Amidst all this wonderful variety in unity, man
stands the culminating glory of the whole. Made
in the image of his Creator, and but "a little lower
than the angels," he has been intrusted with dominion and power over all the brute matter which
surrounds him. Through the long ages of geological history the earth was preparing for his dwelling,
and in the earliest forms of animal life his coming
was prefigured and foretold. It will be natural,
therefore, to consider the adaptations of the atmosphere with special reference to him; and this we
may do legitimately, without losing sight of the
2
15
LECT. I.] 
RELIGION AND CHEMISTRY.
grand idea which underlies the whole, and of which
man is only the nobler part.
The atmosphere is a vast ocean of aeriform
matter, enveloping the earth like a mantle, and
]esriton  rising to the height of many miles above
theatmos- our heads, but constantly diminishing in
phere.   density as the elevation increases.  At
the height of about three miles and a half (3.43)
the density is only one half as great as at the
level of the sea; and at the height of forty miles
it is less than in the exhausted receiver of the
best air-pumps. How much higher than this the
atmosphere extends, it is impossible to determine
with accuracy. In this ocean of air all bodies on
the surface of the globe are immersed. It is so
subtile that it penetrates into the minute pores
of matter, and fills the cavities of all organized
being. It is the medium in which all vital processes both of plants and animals take place, and
in which all human activity has its seat. Let us
see now with what wisdom its properties have
been adapted to the important ends which it is
appointed to subserve.
Consider, in the first place, the physical state of
the atmosphere, its very aeriform condition. This
air is as truly matter as the solid planks
Physical state
of the atmos- on which we are treading, or the granite
phere.   rocks on which this building rests.  It is
far less dense, it is true, but then it has all the
essential properties of matter. It fills space. It
16
[LECT. L 
LECT. I.]   TESTLMONY OF THE ATMOSPHERE.
resists with an ever-increasing force all attempts
to condense it; and, moreover, it has weight. But
how different in condition from the solid rock!
so different that to the uneducated it hardly seems
material; and in our common language we speak
of a space which is filled only with air as empty.
Its particles are endowed with such perfect freedom of motion, and yield so readily to the slightest
pressure, that we move through it without feeling
its presence.   It is firm enough  to support the
wings of the lark as he mounts thie sky, and yet
so yielding as not to detain the tiniest insect in
its rapid flight.
The physical condition of the atmosphere will
still further excite our admiration, when we consider the wonderful play of forces by Twoopposing
which  it is upheld.   It may  not  be in the atmoi
ein the atmosknown  to you all that upon this mass phere.
of air, outwardly so calm and passive, there are
constantly acting two mighty forces, the force
of gravitation and the force of heat. In virtue
of the force of heat the particles of the atmosphere mutually repel each other, and the whole
mass, like a great bent spring, tends to break
from its confinement and to expand into the surrounding space; but this it cannot do, for by the
power of gravitation it is held with a firm grasp
to the surface of the globe. Were this grasp for
a moment relaxed, the atmosphere would dash
off with explosive violence and be lost in the
immensity which surrounds us. How great the
17 
RELIGION AND CHEMISTRY.
force is which is required to restrain the expansive tendency of the atmosphere few persons
have an adequate conception, because the two
opposing forces are so perfectly balanced that we
are obliged to call in the aid of experiment in
order to render their effects evident. So true is
this, that the world never even dreamed of their
existence until within two hundred years, and the
story of the discovery is one of the most remarkable in the history of inductive philosophy. This
story is well known; but as it is short, and
teaches us an important truth, you will pardon
its repetition.
Every one who has seen a common pump is
familiar with the fact that it is the pressure of
"Natureabhors the air which causes the water to rise
a vacuum." in the suction-pipe, and this suction is
one manifestation of that force by which the
atmosphere is held so firmly to the  surface of
the globe.  The  pump, however, was  used  long
before the discovery of the pressure of the atmosphere, and its action was explained by a principle which seemed perfectly satisfactory then,
but which sounds strange enough to modern ears.
The principle appears first to have originated with
the Aristotelians, and was expressed in the phrase,
"Nature abhors a vacuum."  These ancient phi losophers noticed that space was always filled with
some material substance, and that the moment a
solid body was removed air or water always
rushed in to fill the empty space. Hence they
18
[LECT. I. 
LETr. I.]    TESTIMONY OF THE ATMOSPHERE.
concluded that it was a universal law of nature
that space could not exist unoccupied by matter,
and the phrase just quoted was merely their
figurative expression of this philosophical idea.
When, for example, the piston of a common pump
was drawn up, the rise of the water was explained
by declaring, that, as from the nature of things
a vacuum could not exist, the water necessarily
filled the space deserted by the piston.
This physical dogma served the purpose of natural philosophy for two thousand years, and it was
not until the seventeenth century that Florentine
Florentine
men discovered any limit to nature's ab- pump-makers
horrence of a vacuum.  Near the middle  and Galeo.
of the century some engineers were employed by
the Duke of Tuscany to sink a well in the neighborhood of Florence to an unusual depth. They
finished their work, but on adjusting the pump
they found to their surprise that it would not work.
With all their efforts the water would rise only a
little more than thirty feet, and by no ingenuity or
skill could they raise it an inch higher. More disgusted with nature than nature was with the vacuum in their pump, they applied to Galileo, then an
old man, living in his villa on the brow of Fiesole.
He could not aid them, but he is said to have
replied, half in jest, half in earnest, that nature did
not abhor a vacuum above ten metres. Had this
incident occurred earlier in his career, Galileo would
undoubtedly have added to the 6ther jewels of his
crown a brighter gem than all, but now the vigor
19 
RELIGION AND CHEMISTRY.
of his manhood was spent; he had done his work,
and, worn out by the persecution of a bigoted
priesthood, he was peacefully resting from his life's
labor, and calmly awaiting the close.
But the key which the incident had furnished
was not lost. It passed into able hands, and it was
the fortune of Torricelli, Galileo's best pupil, to
unlock the secret. This young Italian philosopher,
whose clear intellect had been trained in the mechanical philosophy of his great master, saw at
once that a column of water thirty-three feet high,
and no higher, could not be sustained in a cylindrical tube by a mere metaphysical abstraction.
This effect, he said, must be the result of some
mechanical force equivalent to the weight of the
mass of water sustained. It was not difficult to
prove the correctness of this reasoning, for it was
evident that if a column of water was sustained at
the height of thirty-three feet in the suction-pipe
of a pump by a constant force, the same force could
only sustain a column of a heavier liquid at a proportionally less height. So Torricelli tried mercury, a liquid thirteen and a half times heavier
than water, and the result was as he had anticipated. The force which raised the column of
water thirty-three feet could only raise a column
of mercury to the height of thirty inches, which is
thirteen and a half times less than thirty-three feet.
Torricelli did not, however, make this experiment
with a pump, but with an apparatus of his own,
much simpler and equally effective.
20
[LEc,r. I. 
LECT. I.]  TESTIMONY OF THE ATMOSPHERE.
He took a long glass tube, open at one end,
filled it with mercury, and,.having closed the opening with his thumb, inverted the tube, xperient of
and plunged the open end in a basin of Torricel.
mercury; on removing his thumb the mercury,
instead of remaining in the tube, and thus satisfying nature's abhorrence of a vacuum, fell, as he
expected, and, after a few oscillations, came to rest
at a height of about thirty inches above the level
of the mercury in the basin. The correctness of
his induction having been thus verified, Torricelli
at once concluded that it must be the pressure of
the air which sustained both the water in the
pump and the mercury in his tube.
This experiment excited a great sensation in Europe; but, as might naturally have been expected,
the old physical dogma was not easily Demonstration
laid aside, and Torricelli did not live to of Pascal.
see his opinion generally received. It was left to
the celebrated Blaise Pascal to convince the world
that Torricelli was right, and this he did by one
of those master strokes of genius which at once
silence controversy.
"If," said Pascal, "it be really the weight of the
atmosphere under which we live that supports the
column of mercury in Torricelli's tube, we shall
find, by transporting this tube upwards in the
atmosphere, that in proportion as it leaves below
it more and more of the air, and has consequently
less and less above it, there will be a less column
sustained in the tube, inasmuch as the weight of
21 
RELIGION AND -CHEMISTRY.
the air above the tube, which is declared by Torricelli to be the force which sustains it, will be diminished by the increased elevation of the tube."
Accordingly Pascal carried the tube to the top
of a church-steeple in Paris, and observed that the
mercury fell slightly, but not satisfied with this
result, he wrote to his brother-in-law, who lived
near the high mountain of Puy de Dome, in
Auvergne, to make the experiment there, where
the result would be more decisive.
"You see," he writes, "that if it happens that
the height of the mercury at the top of the hill
be less than at the bottom, (which I have many
reasons to believe, though all those who have
thought about it are of a different opinion,) it will
follow that the weight and pressure of the air are
the sole cause of this suspension, and not the
horror of a vacuum; since it is very certain that
there is more air to weigh on it at the bottom than
at the top; while we cannot say that nature abhors a vacuum at the foot of a mountain more than
on its summit." M. Perrier, Pascal's correspondent,
made the observation as he desired, and found a
difference of about three inches, "which," as he replies, "ravished us with admiration and astonishment."
Thus it was that man first learned to recognize
the existence of that power, which retains the atmosphere on the surface of the globe, and the history of the discovery should humble our intellectual pride and teach us to hold our knowledge with
22
[LECT. L 
LECT. I.]  TESTIMONY OF THE ATMOSPHERE.
reverence and humility. This old scientific dogma
of the seventeenth century never fails Theold dogma
to excite a smile, and  we  are inclined a partial truth.
to wonder how man could ever have believed
what now appears so absurd; but if, like an antiquary, we imbue our minds with the spirit of that
age, it will be seen, not only that the dogma was
not essentially absurd, but also that the philosophical idea, clothed in those quaint terms, appeared to the scientific men of the period as truly
a legitimate induction from observed facts, as the
law of gravitation seems to us.   And the induction was legitimate; but since the known facts did
not cover the whole ground, they gave only a
very partial truth. The Grand Duke's pump was
the first failing case, and proved, not that the old
principle was absolutely false, but only that its
application was very limited.
Thanks to Galileo, Torricelli, Pascal, and Newton,
-  noble line of genies,-  nature's abhorrence of
a vacuum gave place to the law of gravitation,
and two centuries of unparalleled scientific activity
have only served to confirm the truth, and extend
the domain of Newton's grand generalization; but
even after this signal triumph, who now feels fully
assured that the law of gravitation may not find
its failing case? and when, two centuries hence, the
future historian comes to write the history of inductive philosophy, who can feel certain that Aristotle's dogma and Newton's law may not both be
condescendingly noticed among the partial truths
23 
RELIGION AND CHEMISTRY.
which served the purposes of science in its infancy
and childhood?
Let me not be understood to imply a belief that
man cannot attain to any absolute scientific truth,
for I believe that he can, and I feel that
Distinction
between fact every great generalization brings him a
ndtheory. step nearer to the promised goal; but I
wish here at the outset most strongly to impress
the distinction between the undoubted facts of sci  ence, and the laws and principles which have grown
up around themn, and by which they have been em  bodied in our systems of philosophy, - the distinc  tion, in a word, between the observed phenomena
of nature, and man's interpretation of the phe  nomena.
This distinction, so obvious when stated, is too
often forgotten, and is necessarily overlooked in our
scientific text-books. It is the sole aim of these
elementary treatises to teach the present state of
knowledge, and they would fail in their object if
they attempted by a critical analysis to separate the
phenomena from the laws or systems by which alone
the facts of nature are correlated and rendered
intelligible. But although while studying science
itself, We may for the time waive the distinction
between fact and theory, the moment we come to
* compare the results of science with the eternal
truths of religion, the distinction here enforced be comes of paramount importance, and it must be
our chief aim to separate that which is absolute
and eternal truth from that which, even in its high
24
[LECT. I. 
LECT. I.]  TESTIMONY OF THE ATMOSPHERE.
est development, is the result of human thought,
and, like all things human, subject to limitations and
liable to change.
Had this distinction been always borne in mind,
the controversies between the philosophers and the
churchmen would have been less bitter and more
fruitful in truth; the philosophers would have been
willing to waive their theories, and the churchmen
would have been led to respect the results of
science, and conform their theology to the indisputable truths which God has been pleased to reveal through nature no less plainly than in his
written word; and if the trite anecdote of Galileo
and the pump-makers will serve to impress the distinction on our minds, this digression will not have
been made in vain.
You must all have recognized in Torricelli's
tube our modern barometer. By means of this
well-known instrument we  can  readily Pressureothe
estimate the pressure of the atmosphere, atmosphere.
and determine the amount in our human standards of measurement. It can be readily proved
that the pressure of the atmosphere is about fifteen pounds on every square inch of the earth's
surfaoe, and if, starting from this well-known fact,
you calculate the amount of pressure on any extended surface, you will be astonished at the result.
For example, the pressure exerted by the atmosphere on the area on which this building stands
is vastly greater than the whole weight of the
building itself. The pressure on a man of ordi
25 
RELIGION AND CHEMISTRY.
nary stature is about sixteen tons; that on one
square mile of surface is equal to over twenty-six
million tons.
How great, then, must be the pressure on the
whole surface of the globe, or, what is the same
thing, how great is the intensity of that ever-acting power, which holds the atmosphere in its appointed place! It would not be difficult to calculate the amount and to express it in numbers; but
these numbers would convey to you no definite
idea, for our minds are incapable of forming an
adequate conception of such immensity. The attempt to grasp it only exposes our weakness, and
yet this force, immense as it is, is so delicately
balanced by the sweet influences of the sunbeam,
that it does not so much as shake the aspen-leaf or
break the gossamer. If we believe no more than
this, that the world was once created by God, what
must be the power and wisdom of a being who
could appoint these mighty forces and adjust them
with such perfect precision! But if we also believe that these forces are direct emanations of
Divine Power,- that it is God himself who with
His own right hand holds the atmosphere in its
place, and appoints its bounds, -then all nature
assumes a more glorious aspect, and we feel that
we are indeed surrounded by the Divine Presence.
Yet this force, which we find so far beyond our
powers of conception, is but a secondary phase of
that immeasurably greater power which "brings
forth Mazzaroth in his season, and guides Arcturus
26
[LECT. I. 
LECT. I.]   TESTIMONY OF THE ATMOSPHERE.
with his sons." How futile all attempts to measure
Divine power! We select some one of the feeble
forces acting around us, and succeed in reducing
its value to our human standards of comparison,
and expressing this value in numbers; but the
numbers, when obtained, are beyond our grasp,
and we find that we have merely mounted to a
little higher platform, from which we discover
numberless other forces immeasurably greater
than the first. Something, however, has been
gained. We have attained to the idea of the infinite; and to thoroughly apprehend the existence
of the infinite, is to take the first step towards
recognizing the existence of a God.
I know it will be said that man cannot comprehend the infinite, and if by this statement it is
only meant to affirm the declaration of Theidea ofthe
the Bible, that man cannot "find out the incte.
Almighty unto perfection," not even the most visionary dreamer would question the position. But
there is a class of philosophers at the present day
who think to enforce the authority of revelation
by maintaining the doctrine that man can know
absolutely nothing of the infinite, -nothing more
than he now knows of the facts or principles bf
science to be hereafter discovered; that, indeed,
the very term infinite implies a negation of all
cognizable qualities.
To me, this position seems fatal to the very
cause it is intended to defend, and surrenders all
the approaches of the citadel to the infidel. For
27 
RELIGION AND CHEMISTRY.
if there is in man no possibility of apprehending
the infinite, even to the smallest degree, I can see
nothing to which revelation can appeal. He has
then no power to distinguish between the Divine
and the human.
But it is not so. Revelation implies, and all ex perience shows, that man can recognize the pres ence of the infinite by attributes as clear and
unmistakable as those which mark the presence
of the finite matter around him. He may npt be
able to comprehend a single attribute of the infi nite in its essence, but as the mathematician, deal ing with infinitesimal quantities, which he cannot
fully understand, arrives at truths of the material
world with all the certainty of demonstration, so
the mental philosopher may attain to moral truths
in regard to the Infinite Being, although the very
terms he employs may be veiled in impenetrable
mystery.
And what is the true human criterion of the
infinite? It is not merely something which we
feel to be very great indeed, but it is something
which we feel surpasses our utmost conceptions of
the great, - something which, let us account it as
great as we please, yet, wherever the inability of
our mental power fixes the limit of our conception,
will still be felt to be greater than the greatest.
We cannot gaze into the heavens without awe; we
cannot examine the wonders of the dew-drop without reverence; we cannot look into our own souls
without trembling. It is the same invisible Pres
28
[LECT. 1. 
L )C. I.]  TESTIMONY OF THE ATMOSPHERE.
ence everywhere, and however long false philosophy may conceal the vision, or material cares and
pleasures blind the senses, when man once recognizes its existence he instinctively worships and
adores.
The evidence of design which we are now studying is still further enforced when we consider how
exactly the density of the atmosphere Density of the
has been adjusted to the human organ- atmosphere.
ism. By density is meant, I need not state, the
quantity of matter which the atmosphere contains in a given volume; for example, in a cubic
yard. This quantity is capable of exact measurement, and although to a certain extent variable, it
is constant in the same place, under the same conditions of temperature and pressure.
In this latitude, at the level of the sea, one cubic
yard of the atmosphere when dry, and under the
normal conditions of temperature and pressure,
contains about two pounds of air, and this weight
is the measure of its density. Now we find that
the organization of plants and animals, including
man, has been most skilfully adjusted to the density of the air, and many illustrations of this adaptation will be met with as we proceed. But
accepting the fact for the present as universally
conceded, let us consider the conditions on which
this exact adaptation of the air to our physical
organization rests.
The density of the atmosphere may be said to
depend upon four conditions: first, on the inherent
29 
RELIGION AND CHEMISTRY.
nature of the substance which we call air itself;
secondly, on the intensity of gravity; thirdly, on
the total quantity of air on the globe; and, lastly,
on the temperature.   The influence of the first
condition is not understood, but that of the last
three we can readily trace. If the intensity of the
force of gravity at the surface of the earth were to
change, other circumstances remaining the same,
the density of the atmosphere would change in the
same proportion. Thus, for example, if the intensity of gravity on the earth were as great as it is
on the surface of the sun, the density of the atmosphere would be twenty-eight times as great as at
present; or if this intensity were reduced to that
which exists on the surface of the moon, the density would be diminished to one sixth of the existing density.
But, assuming that the intensity of the force
of gravity on the surface of the earth remained
constant, precisely the same effect would result
from any variation in the total quantity of the
atmosphere. Were the whole amount of air on
the earth increased or diminished, the density
of the atmosphere at its surface would also be
increased or diminished in the same proportion.
Still flirther, assuming that, while the intensity
of gravity and the mass of the atmosphere remained fixed, the temperature were changed, then
also the density of the atmosphere would vary,
and by a quantity which can be easily determined.
By accurate experiments it has been ascertained
30
[LECT. I.
1. 
LECT. I.]    TESTIMONY OF THE ATMOSPHERE.
that an elevation of temperature equivalent to
about five hundred degrees of our Fahrenheit
thermometer would reduce the density to one
half, and, on the other hand,. that a reduction of
temperature would increase the density in the
same proportion.
Consider next what these relations imply. Reflect that the intensity of the force of gravity
depends upon the mass of the earth. Evidenceof
Remember that the mean temperature unity in the
depends upon the distance of the earth design.
from the sun, and you will see that not only the
actual size of the earth, but also its distance from
the sun, and the quantity of air on its surface,
were all necessary conditions, in order that the
atmosphere should have its present density, and
thus become the fit abode for man. If any one
of these conditions had been neglected, the result
would not have been attained, and man, as he exists, could not have lived on this globe.
It must then have been He "who hath meted
"out heaven with the span, and comprehended
"the dust of the earth in a measure, and weighed
"the mountains in scales, and the hills in a bal"ance," who  "formed man  of the dust of the
"ground, and breathed into his nostrils the breath
"of life."
The unity of the design implies the oneness of
the designer, and, although the adaptations just
considered may not exclude every possible atheistic theory of cosmogony, yet they show conclu             3
31 
RELIGION AND CHEMISTRY.
sively that, if there is design anywhere, there
is design everywhere; if there s design in the
least, there is desigyn also in the greatest, and design
in the atom may thus confirm  the evidence of design in
man.
32
[LECT. I. 
LECTURE II.
TESTIMONY OF THE ATMOSPHERE.- Concluded.
DURING a recent journey in Switzerland, at the
close of a delightful summer's day, in the early
part of July, I arrived at Interlachen, in Relation ofthe
company with a number of fellow-trav- atmosphereto
ellers. We had been sailing on the beau- lght.
tiful lake of Brienz, and some minutes before we
reached our destination the sun had set, and the
mountains had already cast their long shadows
across the lake. Early in the afternoon the clouds
had settled on the nearer hills, and we had been
disappointed at not obtaining a view of the distant summits of the Bernese Oberland; but suddenly, as the boat neared the shore, the magnificent peak of the Jungfrau appeared from behind
the veil of clouds, clothed in her white mantle of
everlasting snow, and bathed with a flood of rosy
light. The effect thus heightened by the contrast
was grand beyond description, and as beautiful as
it was grand. It seemed like a vision of the Heavenly Kingdom, -as if the glory of God had rested
on the mountain. The scene completely filled the
soul, and the heart overflowed with gratitude for
the blessing it enjoyed. It was felt to be one of 
RELIGION AND CHEMISTRY.
the great privileges of a lifetime, and his would
have been a dull understanding, and a duller heart,
which did not recognize the Giver in the gift. The
view so riveted the attention that we hardly noticed our arrival, and as we walked to the hotel we
watched the successive shades of crimson and purple as they flitted up the mountain, until the last
blended in the gray of the twilight.
It may not be permitted to many to behold
the Jungfrau blushing before her retiring lord, but
all have witnessed the same effect on even a
grander scale, when the white clouds, piled up on
the western horizon like  vast mountain chains,
become, at evening, resplendent with the rays of
the setting sun; and many have watched their
varying tints of gold and purple, until at last
their ghostly forms vanished in the dusk of the
evening, and the stars came out to take up with
their measured twinkling the silent song of praise.
Perhaps, also, there may be some who, after anxiously watching through the night, have felt their
hearts strengthened and their hopes revived when
the blush of morning reassured them of their Father's providence, and all nature smiled in the
floods of returning light.
All these glorious visions, all this beauty, and
all the pure emotions of our hearts which they
excite, we owe, my friends, to the skill with which
the physical qualities of the atmosphere have been
adjusted to the wants of our physical and moral
natures, and they all thus become the silent wit
34
[LECT. II. 
LeCr. II.]    TESTIMONY OF THE ATMOSPHERE.
nesses not only of the wisdom, but also of the
goodness of our God.
We have already, in the first lecture, discussed
some of the adaptations of the physical condition
of the atmosphere to the purposes which it subserves on the globe, and I wish this evening to develop still further the same subject, by considering
a few additional examples; and first I will ask your
attention to those evidences of design which are to
be found in the relations of the atmosphere to
light and heat. Here, however, I am met by a difficulty.  In order to explain fully these relations it
would be necessary to develop from first principles the sciences of optics and thermotics, and to
do this in a popular manner would require several
lectures. These sciences furnish some of the most
wonderful evidences of design which are to be
found in nature, and I have no doubt will be given
their appropriate place in this series of lectures.
Without, therefore, attempting any detailed explanations, I will merely bring before you a few facts,
drawn from these departments of knowledge, which
illustrate the adaptations of the density of the atmosphere to its appointed ends.
The atmosphere, although very much more pervious to light than any kind of solid or liquid matter, is far from being perfectly transparent. Transparency
Indeed, the reverse is sufficiently evident oftheatmosfrom our daily experience. Every one phere.
has noticed that distant objects appear less distinct
in proportion as they are removed, their colors
35 
RELIGION AND CHEMISTRY.
become fainter, the contrast between light and
shade less marked, and that they seem as if cov ered with a pale blue veil.  This effect, always noticed on distant mountains, is owing to a partial
absorption of the light while passing through the
atmosphere; for, were the passage of the rays
wholly unimpeded, all objects, although reduced in
size in proportion to their distance, would appear
equally distinct, and their colors equally brilliant.
The transparency of the atmosphere differs very
greatly munder different circumstances, but it has
been estimated, that under the most favorable conditions, at least thirty per cent of all the light
coming from the heavenly bodies is absorbed before reaching the surface of the earth, and in our
latitude at this season, even when the sun is on the
meridian and the sky clear, fully one half of his
rays are thus spent. Do not suppose, however,
that all the light so expended is lost. Quite the
contrary, for every particle of the atmosphere, illuminated by the sunbeam, becomes itself a new
centre of emission, radiating the light in every
direction.
This diffusion of the sun's rays is the cause of
that wonderful effect which we term daylight. I
Diffusion of the say wonderful effect, for although so fasun's rays.  miliar, it is one of the most remarkable
results of skilful adaptation and infinite wisdom.
The very daylight which streams in at the open
windows of our houses, filling them with cheerfulness, and penetrating to their inmost recesses,
36
[LEcT. II. 
LECT. 11.]    TESTIMONY OF THE ATMOSPHERE.
which enlivens the whole landscape, and which
bars and bolts cannot wholly exclude even from
the prisoner's dungeon, is another evidence of the
adjustment of the density of the atmosphere to the
constitution of man.
In order that you may see the force of this evidence, let us inquire what would be the effect of
the sun's light if there were no atmosphere, assuming, for the sake of illustration, that man could exist under such conditions. The known principles
of optics will furnish an answer to our question.
They inform us that while all objects directly illuminated by the sun would shine so brilliantly as to
dazzle the eye, everything else would be in complete darkness. The interior of our dwellings would
be at midday as dark as during the darkest night;
and the contrast between light and shadow would
be stronger than that between the most brilliant
sunlight and the blackest darkness now known.
Our eyes, as little fitted to such conditions as our
lungs, would be blinded by the sudden alternations,
and distinct vision would be rendered impossible.
Thus it appears that the atmosphere is as much
an essential condition of our seeing as of our breathing.  But more than this, the immeasur- Effetonthe
able pleasure which we derive from our ladsoape.
sense of vision depends upon the exact adaptation
of the density of the atmosphere to the organization
of the eye. Similar effects to those just noticed,
although of course on a greatly diminished scale,
would result, were the density of the atmosphere
37 
RELIGION AND CHEMISTRY.
materially diminished. This is not a matter of
theory, for such effects have been frequently noticed on the summits of high mountains, where
the air is much rarer than at the sea level. On
the top of Mont Blanc the sky has a blackish
hue, and the stars are seen at midday. The glare
of the direct light is unsupportable to the eye,
and even the reflection from the snow blisters
the unprotected skin, while at the same time
the contrast between light and shade, unnaturally
increased, gives to all near objects a peculiar and
ghastly aspect. This effect results, it is true, from
a very great diminution in the density of the air;
but when you reflect upon what delicate contrasts
of light and shade the beauty of a landscape depends,- the clearness of the foreground, the gray
of the middle distance, and the tender purple of
the distant hills all blending into one harmonious
whole, - you can appreciate how slight a change
would disturb the result, and deprive the sense
of beauty of its purest enjoyment.
I have thus far spoken only of the influence of
the atmosphere in softening the intensity of the
rays of light, and in diffusing their action; but
the atmosphere has also, under certain conditions,
the power of decomposing the sun's rays, and thus
producing, not only those displays of gorgeous
tints which we witness in the sunset clouds,
but also the pure blue which colors the dome of
heaven.
In regard to the precise means which are em
38
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
ployed by nature to produce these results, scientific men are not agreed.  It has been Bluecolor of
proved that the blue color of the sky is the sky.
seen by reflected light, and it is probable that the
color is caused by repeated reflections of the sun's
rays from the surfaces of the innumerable small
water-bubbles which are constantly floating in the
atmosphere. You have all noticed the blue color
of the soap-bubble shortly before it breaks. This
color is caused by the action of the very thin film
of water in decomposing the light reflected from
its surface, and it is supposed to be an action of
the same sort, only very much increased by repeated reflections, which gives to the sky its azure
hue.
While the blue color of the sky appears to
result from changes in the white light of the sun
caused by reflection, it is equally probable Snset tints.
that the sunset tints arise from changes
in the same white light caused by an unequal
absorption of its different colored rays during their
transmission through the atmosphere. Here, again,
the vapor in the air is supposed to be the active
agent; and the theory is, that the tints are produced while the vapor is condensing into clouds,a change which naturally occurs at sunset. But
this is a mere theory, and our whole knowledge
on these subjects is very imperfect.
So far, however, as our present argument is
concerned, it is not essential that we should understand exactly how these glorious results are
39 
RELIGION AND CHEMISTRY.
obtained. It is sufficient that we are constantly
enjoying their beauty, and that we know they
are owing to the peculiar constitution of the atmosphere. When future discoveries shall bring
to light the methods, at present secret, by which
nature gilds the sunset clouds and covers our
beautiful dwelling-place with its canopy of blue,
we shall unquestionably fined fresh evidences of
God's wisdom; but even now, when ignorant, perhaps, of these hidden causes, we have that which
is far more excellent, the most conclusive evidence of His goodness and love. Our Father has
not only adapted the atmosphere to the wants of
our bodies and made it conducive to our physical
enjoyment, but he has also made it the scene
of the highest beauty,- a beauty which fills the
longings of our souls and calls forth their noblest
and purest aspirations. Man, sinful as he is, cannot look up into the pure blue of heaven without
a sense of reproach, and the feeling that it is a
fit emblem of the kingdom of purity and peace.
And when the setting sun lights up the evening
altar in the west, who can repress the rising prayer
of devotion, and hesitate to believe, with the child,
that his Heavenly Father is smiling behind the
clouds? There is a depth to the beauty of nature
which man cannot fathom. Poetry cannot describe
it, and the highest art only displays its weakness
when it attempts to copy it. The savage feels
that it is immeasurably above him, and worships
it. The artist seeks to attain it, but the more he
40
[LECT. IL 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
strives, the more it surpasses his power, and he
dies disappointed, unless, happily, he finds that
the perfect ideal has been realized only in Christ,
and thus through nature is led up to nature's
God. Yes! the beauty of nature is in the Infinite
Presence it conceals, and, unconsciously though it
may be, it is the spirit, not the matter, which
the artist loves.
Such are some of the evidences of design which
we discover in the relations of the atmosphere to
light.  Let us now examine some of its
Relations of the
relations to heat, which we shall find not atmosphere to
less instructive.   It was formerly sup- heat
posed that the rays of heat, although accompanying the luminous rays in the sunbeam, were essentially different from those of light. But it is now
almost universally believed that the rays of heat
differ from those of light only, at most, as one color
differs from another, and that even the same rays,
which, falling on the retina of the eye, excite the
sensation of light, when falling on the nerves of
feeling may excite heat. But what, you may ask,
is the difference between the different colors? The
subject is somewhat abstruse, but if you will follow
me attentively for a few minutes I will try to make
it intelligible.
Every one who has dropped a stone into the
water of a still lake has noticed the system of
waves which, with its ever-increasing cir- Wave moon,
Wave motion,
cles, spreads in every direction from the illustrated by
stone; but all may not know that when wavesofound
41 
RELIGION AND CHEMISTRY.
two stones are struck together in the air a similar
system of aerial waves spreads, in ever-widening
spheres, through the atmosphere, and that it is
these waves breaking on the tympanum of our
ears, like the waves of water on a sand-beach, which
produce the sensation we call sound. Two stones
thus struck together give rise to waves of unequal
size, following one another at irregular intervals;
and such waves produce an unpleasant sensation
on our auditory nerves, which we call noise. But
if, instead of striking together two stones, we set
in vibration the string of a piano-forte or the reed
of an organ-pipe, we excite a system of waves, all
of equal size, and succeeding one another with perfect regularity, and these breaking on the ear produce by their regular beats what we call a musical
note. If the waves follow one another with such
rapidity that one hundred and twenty-eight break
on the tympanum every second, the note has a
fixed pitch, called in music C natural. If the
waves come faster than this, the pitch is higher,
and if less rapidly the pitch is lower. What you
are all familiar with as the pitch of a musical note
depends, then, on the rapidity with which the
waves of sound strike the ear, and may evidently
be measured by the number of waves breaking on
the tympanum in a second.
Our ears are so constituted that they can hear
a musical note only when within certain fixed limits of pitch, differing to a slight extent with different individuals. The deepest bass note, which can
42
[LECT. II. 
LECT. II.1    TESTIMONY OF THE ATMOSPHERE.
be heard, as such, by a good ear, is produced by
about eight waves in a second. If the waves
strike less rapidly than this, they are perceived as
distinct beats, and beginning at this note the musical scale ascends to a note caused by twenty-four
thousand waves a second, which is the highest note
perceptible by human sense. The range of a piano
generally extends from a note produced by sixteen
waves in a second, to one caused by one thousand
and twenty-four waves in a second, as is shown by
the accompanying table.
Number of waves
striking the ear
in one second.
16
32
64
128
256
512
1024
Length of waves
in feet
70
35
17.5
8.75
4.375
2.178
1.093
Name of Note         C1
Number of Waves     128
Ratio of each number I 1
to that of Note C, i
Sounds of the highest pitch, like the cry of
some insects, become disagreeable, and by some
persons cannot even be distinguished. It is quite
possible to produce a sound, which, though painfully shrill to one person, shall be entirely unheard
by another. Professor Tyndall, in his very interesting work on the glaciers of the Alps, relates an
43
Notes.
C-3
C-2
C-i
C,
C2
Cs
C4
D,
144
E, F,
160 1702
Is
t   t
GI Al
192 2131
Is
3
7
B,
240
-,a,
C2
256
2 
RELIGION AND CHEMISTRY.
instructive anecdote of this sort, which I give in
his own language.
"I once crossed a Swiss mountain in company
with a friend; a donkey was in advance of us,
and the dull tramp of the animal was plainly
heard by my companion; but to me this sound
was almost masked by the shrill chirruping of
innumerable insects, which thronged the adjacent
grass; my friend heard nothing of this, it lay
quite beyond his range of hearing."
There may, therefore, be innumerable sounds in
nature to which our ears are perfectly deaf,
although they are the sweetest melody to more
refined senses. Nay, more, the very air around
us may be resounding with the hallelujahs of the
heavenly hlost, when our dull ears hear nothing
but the feeble accents of our broken prayers.
We have been studying, my friends, the nature
of sound, in order to comprehend more readily
the nature of light and heat, for the pheWaves of light.
nomena included under these names are
produced, like the phenomena of sound, by waves,
not, however, by waves in the air, but by waves
in a medium which is as much more subtile than
air as air is more subtile than water,- indeed, a
medium so exceedingly thin that it eludes all our
powers of chemical analysis; but which, as we
assume, pervades all space, and this, too, whether
the space is filled or not, at the same time, by
other forms of matter. We call this medium
ether, and through it the waves of'light speed
44
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
with  an  inconceivable rapidity.   Sound travels
1,100 feet in a second, but a wave of light spans
192,000 miles in the same time, and starting from
the sun on its journey of unnumbered years, to
Sirius or Arcturus, leaves the whole solar system
behind in a single hour.
Yet great as is the difference of velocity, the
analogy between sound on the one side and light
or heat on the other is complete. Every luminiferous body, like this candle-flame, excites in the
tenuous ether a system of waves, which spread in
ever enlarging spheres with the immense velocity
just described; and it is these little billows which,
passing through the humors of the eye, and breaking on the retina, produce the sensation we call
light, or, falling on the skin, excite the less delicate
nerves of feeling, and cause the sensation of heat.
Moreover, the difference between colors is of
precisely the same kind as the difference between
notes.  Red, yellow, green, blue, violet, Cuse of color.
n                              ~~~~~~~~~~~~~~~~~~~Cause of color.
&c., are names we give to sensations
caused by waves of ether breaking at regular intervals on the retina. Color corresponds to pitch, and
-what may seem to you incredible -we are able
to calculate from actual measurements the number
of waves of ether which must break on the retina
in a second in order to produce the sensation of a
given color. Here are some of the numbers, and,
extravagant as they appear, they are the sober
results of science, and have been as accurately determined as the magnitudes and distances of astronomy.
45 
RELIGION AND CHEMISTRY.
Length of waves *
in parts of an inch.
~.   256 ten-millionths
240                              "
227           "
211           "
196                              "
185           "
174           "cc
Number of waves
in a second.
..  477 million million.
5 06    "     "
535    "      "
577     "   "c
622    "      "
658     "     "
699   cc    cc
It is actually true, that when we are receiving
the sensation of red there are no less than 477 million millions of ether waves breaking on the retina
of our eyes every second. And more than this, we
have measured the length of these waves, and
we know that the length of a wave of red light
from crest to crest is 3 9OiOof an inch.  By examining the table you will also discover that the sensation of red, as compared with other colors, results
from the smallest number of waves, and that these
waves are comparatively large. On the other hand,
the sensation of violet is caused by the largest
number of waves, which, however, are proportionally small in size.   The red light, therefore, corresponds to low, and the violet to high notes of
* A given wave-length corresponds to each point on the line of the
solar spectrum to be described further on. The numbers given in the
table are to be regarded merely as the mean values for each color,
measured at points on the spectrum, marked by certain prominent dark
lines, called Frauenhofer's lines. The solar spectrum, when formed by
a beam of light admitted into a dark chamber through a narrow slit, is
seen crossed by thousands of these lines, which have a fixed position,
and therefore serve to mark definite points on this otherwise continuous
band of blending colors.
46
[LECT. II.
Colors.
Red.
Orange
Yellow
Green
Blue
Indigo
Violet 
LECT. H.]   TESTIMONY QF THE ATMOSPHERE.
music, and between these extremes there exists
every gradation of pitch, which is here manifested
in color.
Waves of all the dimensions given in the table,
together with waves of every possible length between certain extremes, -which are far Thesolarspecwider than those indicated above,- move trum.
together in the sunbeam, and their combined impression produces the sensation of white light.
We have a very simple way of analyzing the sunbeam and separating its different color-producing
waves. The method consists in passing the sunbeam through a glass prism. Thie prism has the
power of bending the beam from its rectilinear direction; but it does not change the direction of
the motion of all the waves to the same extent.
The longer wayes, which give the sensation of
red, are bent from their course much less than
the shorter waves, which produce the sensation of
violet, while waves of an intermediate length
take a course between  the two.   Hence, after
emerging from the prism the directions of the
different waves diverge, and if we receive the
beam of light thus analyzed, on a screen, the
various color-producing wqves strike the screen
at different points of a continuous line. A more
or less narrow band on the screen will thus be
illuminated with lights of different colors in the
order, Red, Orange, Yellow, Green, Blue, Indigo,
Violet, and this beautiful phenomenon is familiar
to almost every one under the name of the solar
spectrum.     4
47 
RELIGION AND CHEMISTRY.
Here, where we have the whole scale.of colors
spread out before us, the analogy of light to
Analogy be-  sound becomes still more evident.  As
tween colors there are persons who cannot hear the
and musical
notes.   shrill sound of some insects, so there
are many who cannot see certain colors of the
spectrum, and as there are unquestionably innumerable sounds in nature which are inaudible to
our ears, so there are innumerable waves in the
ether which are powerless to produce the sensation of light. Moreover, singular as it may seem,
we have more palpable evidence of the existence
of these non-luminiferous waves than we can obtain in the case of sound.  There are waves in
the ether far smaller, and undulating far more
rapidly, than those which produce violet light;
so small that they do not even jar the nerves of
the retina, but which, nevertheless, breaking on
the prepared plate of the photographer, leave
there an impression which, developed by his skill,
becomes a beauiful copy of nature or of art. On
the other hand, there are waves in this same ether
so large that the delicate retina cannot vibrate in
unison with their rough beats, but which, nevertheless, breaking on the surface of the skin, dis-turb the coarser nerves of feeling, and produce the
glow of heat.  Most of the waves which impress
the optic nerve will also affect the nerves of feeling; but the reverse is not true, for many of the
waves which produce the sensation of heat are
far too large, and undulate too slowly, to set in
vibration the retina of the eye.
48
[LECT. II. 
LECT. II.]    TESTIMONY OF THIE ATMOSPHERE.
I hope that I have been able to make clear two
points, -first, that light and heat are forms of
motion; second, that the differences in the phenomena which have been referred to these two
agents are simply different sensations or different
effects * produced by the same wave-motion. It
would be highly interesting in this connection
to examine the wonderfully delicate adjustments
and to follow out the peculiarly intricate motions
which concur to produce the phenomena of light
and heat; for they are in themselves most striking illustrations of the wisdom of the Creator.
But this would lead us too far from our proposed
plan, and I must content myself with the few
facts already given, which were necessary to illustrate the relations of the atmosphere to the thermal conditions of our globe.
From the principles stated, it is evident that
the atmosphere must act in diffusing heat just
as we have seen that it acts in diffusing light.
* The effects of expansion, melting, evaporation, the permanent elansticity of gases and vapors, and many other phenomena, formerly referred
to the action of a peculiar agent called heat, are now supposed to be the
result of the motion which the ether-waves communicate to the material
particles of the bodies on which they strike or through which they are
transmitted. To understand this, we must remember that the molecules,
even of the densest solids, are supposed to be separated from each other
by comparatively large spaces filled with ether, through which the
waves of heat and lig,ht may move more or less freely, just as the waves
of air pass between the branches in a forest. Moreover, as the waves
of air impart motion to the branches of the trees, and afterwards are
kept in motion by the waving boughs, so also the material particles of a
body may set in motion the waves of ether, or receive motion from them
in return.
49 
RELIGION AND CHEMISTRY.
Indeed, this effect is one of the thousand conhe atmos- ditions on which the existence of organic
phere diffuses life depends. Were it not for the influence
the sun's heat.
of the atmosphere, the greatest extremes
of temperature would be produced by the alternation of day and night, and even were the density
of the atmosphere reduced only one half, the variation would be so great as to render the existence
of the higher forms of organic life impossible, except,
perhaps, in the more favored regions of the earth.
But not only does the atmosphere diffuse the
heat of the sun's rays, it also acts, and even more
The atmo- effectually, in retaining on the surface
The atmosphereretains the heat which the earth is constantly
the sun's beat.
th   bt. receiving from that great central luminary.
The atmosphere has been compared to a mantle,
and the comparison is just; for, like a huge cloak,
it envelops the earth in its folds, and protects it
from the chill of the celestial spaces through which
we are rushing with such frightful velocity. In
order to understand how a thin and transparent
medium like air can thus act to keep the earth
warm, we must recur to some of the facts established above.
As the ether-waves, breaking on the eye more
or less rapidly, produce the different sensations of
ieatoflowand color, so when breaking on the skin they
high intensity. occasion analogous differences in the sensation of heat, which, although not so accurately
distinguished, because the sense is less delicate,
nevertheless are as real as the difference between
50
[LECT. U. 
0
LECT. H.]"    TESTIMONY OF THE ATMOSPHERE.
a low and sweet musical note, and one.that is high
and shrill. There are waves of heat which break
upon our nerves of feeling like the shrill cry of
the cricket on the ear, and seem to penetrate to
the very brain, while there are others which fall
like the low tones of an organ, diffusing throughout the system a genial glow. Such, for example, is the difference between  the heat from a
hard-coal fire and that from a steam radiator.
The waves of the first sort, from their small size
and rapid motion, can readily pass through glass
and other transparent media, when the large
waves with their slow motion are in a great
measure stopped.
Now it is found that the sunbeam is chiefly
niade up of waves of the first class, which are
therefore able readily to penetrate the atmosphere
and warm the surface of the earth. The earth
thus warmed becomes itself a hot body, surrounded
by an intensely cold space, and, like any other hot
body, tends to lose its heat by radiation. But
the waves of heat which the earth * sets in motion are of the second class, long and slow undulations, and these are in great measure arrested by
the atmosphere; indeed, as experiments have
proved, they are chiefly absorbed by the lower
strata, t in which we live and move.
* The pitch, if we may so speak, and penetrating power of the heatwaves depend on the temperature of the body by which they are set in
motion, and in proportion as the temperature rises the Fitch is higher,
and the penetrating power greater.
f Professor Tyndall has shown that this effect is due almost entirely
51 
RELIGION AND CHEMISTRY.
Thus it is that the atmosphere keeps us warm;
and if you desire further proof of the correctness
of these experimental deductions, ascend any high
mountain, and, as the thickness of the aerial covering above you is diminished by the elevation,
you will find that the chill increases, vegetation slowly disappears, and before long you will
reach a region of eternal snow and ice. It is true
that there are other causes acting to lower the
temperature at high elevations, but the one just
noticed is by far the most important, as well as
the primary cause. The effect of the atmosphere
is precisely similar to that of the glass sashes of
a hothouse. The glass, like the atmosphere, allows the rapidly undulating waves of the sun to
pass,* but almost entirely arrests the large and
slowly undulating billows, which radiate from the
vegetation within. They are each, in fact, a trap
to catch the sunbeam.
The atmosphere not only thus acts in diffusing
the sun's rays, and retaining the heat which they
The atmos- bring to us, but it also subserves an
phere distrib- equally important end in distributing
utes the sun's
heat.    their genial  warmth  over  the  whole
surface of the earth, thus moderating the climate
to the aqueous vapor in the atmosphere, which is present in greatest
quantity in the strata nearest to the earth.
* In the sunbeam, as it passes through space, there are undoubtedly
waves of low pitch in abundance, but these are almost entirely arrested
by the atmosphere before reaching the surface of the earth. It has
been estimated that of the heat the earth receives from the sun about
one third is thus absorbed.
52
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
of the temperate zone,. and mitigating the intense
heat of the tropics. Air, like all gases, is expanded by heat, and thus rendered specifically
lighter, and on this simple principle all our methods of warming and ventilating are based. When
now it is remembered that the atmosphere under
the tropics must become more intensely heated
by the vertical rays of the sun than it is in-the
temperate zones, the result will be obvious. The
heated air rises, and the cold air rushes in from the
north and south to take its place. Thus, two general currents are excited in the aerial ocean of each
hemisphere, one on the surface of the earth tending towards the equator, and another, higher in
the atmosphere, tending towards the poles. These
currents, however, do not blow due north or south;
for many causes combine to turn them from their
primitive directions.
In the first place, the rotation of the globe on
its axis imparts to objects on the surface a motion
from west to east, varying in velocity, Trade wi.ds
from nothing, at the poles, to the speed
of a cannon-ball, at the equator. In consequence
of this, a mass of air moving towards the equator
is constantly arriving at a point on the surface
of the earth, which is moving towards the east
more rapidly than the point it has just left; and
as, in virtue of the law of inertia, the moving mass
cannot accommodate itself instantaneously to the
increased velocity, it is left a little behind, - that
is, a little to the west, at every step. Hence, the
53 
RELIGION AND CHEMISTRY.
lower or polar currents bend more and more
towards the west as they approach the equator,
acquiring in the northern hemisphere a south westerly, and in the southern hemisphere a northwesterly direction; and the currents of the two
hemispheres, meeting at the equator, combine to
produce the great trade-wind, which, in the Pacific Ocean, blows constantly from the east to
the west, and would blow regularly in this direction all round the globe if the continents did not
intervene to disturb its course at various points.
The effect of the earth's rotation on the current
of warm air which flows from the equator in the
upper atmosphere, must evidently be the reverse
of that just described, bending it constantly to the
east, and giving to it in the northern hemisphere
a northwesterly, and in the southern hemisphere a
southeasterly direction. But the upper and lower
currents do not long retain this relative position;
for, as the first comes northward, it gradually sinks,
and, long before reaching this latitude, touches the
surface of the earth. Then, of course, it comes in
collision with the current from the north, and here
a strife for the mastery ensues. Sometimes the one
and sometimes the other prevails, and this alternating ascendency is one of the chief causes which render the winds of temperate climates so irregular.
Again, the unequal heating effect of the sun's
rays on the earth, as compared with the sea, comCauses of ir- bined with the irregular distribution of
regulsity.  land and water over the surface of the
54
[LECT. IL 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
globe, tends to complicate still further the motion
of the aerial currents.   For reasons which will
hereafter appear, the land is more heated by the
sun's rays than the sea, when under the same conditions, and, on the other hand, as soon as the sun
is withdrawn,.it cools more rapidly. Hence, on an
island in a warm climate we generally have, during
the day-timne, a current of heated air rising from
the surface of the earth, and a current of cooler
air flowing in on all sides from the ocean to take
its place, while after sunset the land soon cools
below the temperature of the surrounding ocean,
and the current is reversed. Thus is produced
the daily alternation of land and sea breezes,
which is so familiar to every one who has visited
the tropics, where these phenomena are most
strongly marked.
Quite a similar reciprocal action between the
continents and the great ocean is caused by the
alternation of seasons, and of this the
Monsoons.
monsoons of the Indian Ocean are a remarkable illustration. This mediterranean ocean,
shut off from the influence of the general tradewinds by the great continental masses which surround it, has a system of aerial currents peculiar
to itself, blowing six months of the year in one
direction and six months in the other. These are
set in motion by the unequal heating of the continents of Asia and Africa during the extreme
seasons. In the months of December, January,
and February, the part of Africa south of the
55 
RELIGION AND CHEMISTRY.
equator is exposed to the vertical rays of a summer's sun, while the countries of Southern Asia
are feeling the comparative cold of their winter. The natural consequence is, that a stream of
cold air rushes across the Indian Ocean to feed
the intensely heated current which is rising over
the burning plains of Africa, producing a strong
northeasterly breeze, which is the winter monsoon
of India. When, however, the sun comes north of
the equator, all these conditions are reversed. The
ocean air now rushes to the more heated plains
of India, and the summer monsoon sets in, which
blows from the southwest, the change from one to
the other being always attended by variable winds
and furious storms.
Lastly, the position of mountain chains and the
configuration of the continents, which break and
turn the winds, or open to them a freer channel,
have an important influence in determining the
direction of the aerial currents on the earth. But
we have not time for further details; they are given
in all works on physical geography,* and the student of natural theology will find that subject rich
in illustrations of God's wisdom and power. We
have already become sufficiently acquainted with
the general plan to understand how the atmosphere
acts in equalizing the climate of the globe. The
aerial' currents which come to us from the south
bring with them the heat of the tropics, and distribute it over the temperate zone. As they blow
* See "Earth and Man," by Professor Arnold Guyot.
56
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
from the southwest, they naturally exert the
greatest heating power on the western coasts of
the continents, and this is one great cause of the
well-known fact that the climate of Western Europe is so much milder than our own, and the climate of California and Oregon so much warmer
than that of the corresponding latitudes on the
eastern coast of Asia. Moreover, the sea-breezes
on islands and along sea-coasts, the monsoons of
the Indian Ocean, and other local currents, all combine, as our theory shows, to produce the same
general result, cooling such regions of the earth
as from any cause have become overheated, and
transferring the warmth to places where it is
more needed. Just as the heat of burning fuel is
diffused over a whole building from the furnace by
the currents of air it sets in motion, so the sun's
heat is diffused over the earth from the tropics by
the great terrestrial currents we have so briefly described. Indeed, as already stated, in all our methods of heating, we merely apply, on a small scale,
the same general principles which are at work
around us in the atmosphere.
But, although the heat of the sun might set in
motion these aerial currents, they would have but
little effect in warming our northern cli- Capacity ofthe
mate, were it not that the air has been air for heat.
endowed with a certain capacity of holding heat.
All substances possess this capacity to a greater or
less degree, but the differences between them are
very large. Thus the amount of heat required tc
57 
RELIGION AND CHEMISTRY.
warm a pound of water is ten times greater than
would be required to raise the temperature of a
pound of iron, and thirty times greater than would
be required to raise the temperature of a pound
of mercury to an equal extent.   Hence, under
the same conditions, a pound of water may be
said to contain ten times as much heat as a pound
of iron, and thirty times as much as a pound of
mercury; or, again, in other words, the capacity
of water for heat is ten times greater than that of
iron, and thirty times greater than that of mercury.  The capacity of air for heat is, weight for
weight, about twice as great as that of iron, and
although only one fifth as great as the capacity
of water, it is yet greater than that of most
other- substances. The point, however, to which
I wish to direct your attention, is the fact that
this capacity is exactly adjusted to the office
which the air has been appointed to fill. Were
the capacity of the air less, the hot air from
the tropics would bring to us proportionally less
heat; were it greater, the reverse would be the
case; and in either event, the distribution of temperature on the earth would be changed. To what
extent such a change would affect the general
welfare of man, it is impossible to determine; but
when we consider how far the history of man has
been influenced by climate, it will appear that the
present distribution of the human race - the existence, for example, of a large and influential city in
'this place,- may be said to depend on the adjust
58
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
ment of the capacity of the atmosphere for heat;
and yet it depends no less on ten thousand other
conditions, many of them far more important than
this. How truly, then, it may be said,.that even
here on earth we live in "a city which hath foundations, whose builder and maker is God "!
Such are a few of the more obvious marks of
design, which may be discovered by studying the
relations of the atmosphere to light and
Relations of the
heat.  I might here close one division of atmosphere to
electricity.
my subject; but I should fail to give you electricity
an adequate idea of the wonderful play of physical
forces in the atmosphere, were I to leave out of
view that mighty agent which charges the artillery
of heaven and feeds the flaming torches in the
northern sky. It is true that the atmospheric relations of electricity are very imperfectly understood, and the important ends which it undoubtedly
subserves in the economy of nature almost entirely
unknown. We cannot, therefore, expect that they
will furnish us with many additional illustrations of
the Divine attributes; but since electrical phenomena play so conspicuous a part in the atmosphere,
and must have been included in its plan, they should
not certainly be overlooked if we would gain a general idea, however imperfect, of the whole design.
Of all the assumed agents of nature there is hardly
one which is so.little understood, and yet has been
so carefully studied, as electricity. To the Nature of eleuneducated it affords the convenient expla- triity.
59 
RELIGION AND CHIEMISTRY.
nation of most obscure phenomena, while with men
of science it is the object of much laborious investigation and careful theorizing. The study of its phenomena has been fruitful in the discovery of facts;
but it has as yet led to but few general principles,
and has furnished only a meagre explanation of
those grand displays of nature in which it seems to
be such an important agent.
In regard to the nature of electrieity, we are entirely ignorant. The phenomena of light and heat *
admit, to say the least, of an intelligible explanation, and can be referred to a dynamical origin; but
in the case of electricity we are obliged to be content with collecting facts, and must await the further progress of science to reveal the now hidden
cause. I am well aware that electricity has been
regarded as a very rare and subtile fuid, and that this
theory has not only afforded a plausible explanation
of most of the phenomena of statical electricity, but
also that the numerical results based upon it have
been most remarkably verified by experiment. Yet
nevertheless, although the theory may still be used
as a convenient frame in which to exhibit the facts,
there are but few investigators of the present day
who would claim for it more than a very partial
foundation in truth, and most would reject it altogether as utterly untenable.
The fundamental facts of electricity were known
to the ancients, and are familiar to every one. If
a stick of sealing-wax or a glass tube is rubbed
*See a recent work by Tyndall on Heat as a Form of Motion.
60
[LECT. H. 
LEcT. II.]    TESTIMONY OF THE ATMOSPHERE.
with a warm silk handkerchief, it becomes, as we
say, electrified, and in this condition has Fundamental
the power of attracting pieces of paper facts.
or any light particles of matter. When the scientific men of the last century came to examine these
phenomena more carefully, they found that the
handkerchief was also electrified and thrown into
a state differing from that of the glass in the
one case and that of the resin in the other, very
much as the north pole of a magnet differs from its
south pole.  They found also that the resin was
electrified oppositely to the glass, and they hence
concluded that there were two kinds of electricity,
which they distinguished by the names resinous and
vitreous, or positive and negative. They also discovered that this agent could readily be drawn off
from electrified bodies by the metals, but only with
difficulty, if at all, by such materials as India-rubber,
glass, resin, or silk, and they were hence led to divide substances into conductors and non-conductors
of electricity. A good conductor, when insulated by
non-conductors, was found to retain for a short time
the electricity it had received from the electrified
glass or resin, although the charge was soon dissipated by the surrounding air, especially when moist.
By bringing in the aid of machinery, and thus increasing the surfaces of friction, it was found possible
to enhance very greatly the effects obtained with a
glass tube; and this was the origin of the electrical
machine. This familiar instrument is merely a mechanical contrivance for rubbing together glass and
61 
RELIGION AND CHEMISTRY.
silk, with two insulated metallic conductors for receiving the two kinds of electricity thus generated.
If the hand or a metallic knob was brought near the
prime conductor of the machine when highly electrified, it was found that a luminous discharge followed, which was termined an electrical spark; and it
was found possible by means of a glass jar, coated
inside and outside with some metallic leaf, called a
Leyden jar, to accumulate the two electricities in
such large quantities that, when allowed to flow together, the discharge was capable of producing violent mechanical action, similar to that of lightning,
although on a vastly reduced scale. It was also
discovered that electricity passes readily through
the greatly rarefied atmosphere in the receiver of
an air-pump, causing a luminous effect similar to the
aurora borealis. Lastly, it was observed that electricity readily escapes into the atmosphere from a
pointed conductor, and, conversely, that a heavy
charge can be silently and harmlessly drawn from
an electrified body by holding near it the point
of a needle.  By attaching a pointed conductor to
a boy's kite, Franklin succeeded in drawing an electric spark from a thunder-cloud, and having thus
established the identity between atmospheric and
friction electricity, he erected the pointed rod, which
protects our dwellings against the lightning's stroke.
More recently it has been discovered that friction is by no means the only source of electricity,
and it seems probable that no change, either chemical or physical, takes place in Nature without some
62
[LECT. IL 
LEICT. II.]    TESTIMONY OF THE ATMOSPHERE.
manifestation of this agent. It was at first supposed that there were several kinds of electricity,
which were named thermoelectricity, magnetoelectricity, voltaic electricity, and animal electricity,
according to the nature of the process in which
the electrical action was developed; but it is
now universally conceded that all are only different manifestations of the same agent, and most
investigators believe that electricity will in time be
shown to be a form of molecular motion analogous
to that which produces the phenomena of light
and heat, although it has not as yet been found possible to frame a comprehensive and intelligible theory based upon this hypothesis. Again, it has been
found that friction is a far more general source of
electricity than was at first believed. In fact, electrical phenomena appear to be a constant result of
friction, whatever may be the nature of the substances rubbed. Thus it is developed by blowing
air over glass, and the hydroelectric machine, one
of the most effective means of generating electricity
we possess, owes its surprising energy to the friction
of globules of water against the sides of the ventcock of a steam-boiler.*
When, now, we consider that the air is always
subbing over the surface of the earth, at times with
* This machine consists simply of a small steam-boiler insulated on
glass pillars, having a peculiarly-constructed vent-cock and provided
with suitable metallic conductors for receiving the electricity. The
steam, as it escapes under high pressure, becomes filled with globules of
water which rub against the sides of the vent-tube, and this is so shaped
as to facilitate their formation.
5
63 
RELIGION AND CHEMIISTRY.
great rapidity, we shall not be surprised to learn
Atmospheric that both bodies are constantly in an
electricity. electrified condition, the earth being generally charged negatively, and the atmosphere positively. Even in fair weather it is always possible
to detect the presence of free electricity in the
atmosphere; and during a storm, when clouds filled
with vesicular drops of water are hurried over the
surface, grinding against the hills and the trees, or
against each other, the atmosphere becomes a vast
hydroelectric machine, whose sparks are the lightning, and the noise of its discharges the thunder.
Again, the various chemical and physical changes
which are going on around us, -such as the vital
processes of animals and plants, the combustion of
fuel, volcanic action, the evaporation of water, -all
undoubtedly add to the electrical excitement of the
atmosphere, and more or less modify the result. It
is not important for us, however, to study the
action of each one of these causes; for we have,
probably, in the friction of moist air driven by the
winds, the chief source of atmospheric electricity;
and when we consider the amount of friction which
must attend the rapid motion of storm-clouds, or of
a tornado through the atmosphere, the wonder is,
not that an occasional thunderbolt should kindle a
conflagration, or even cause a death, but that every
storm does not lay waste the earth along its fiery
track. Moreover, when we appreciate the vastness of
the scale on which the electrical machine of nature
is constructed, the thunder-storm ceases to surprise
64
[LECT. II. 
LECT. II.] TESTIMONY OF THE ATMOSPHERE.
us, and only calls our attention to those beneficent
provisions by which we and our race are saved by
a constant miracle from the fate of the cities of
the plain.   That the atmospheric electricity was
designed to subserve many important and beneficent ends, the whole analogy of nature compels us
to believe; but while our present ignorance conceals them from our sight, we may still discover
evidence of God's goodness and wisdom in those
simple provisions by which the atmosphere is preserved from violent or frequent electrical excitement, and its charge drawn down harmlessly to the
earth.
Since the atmosphere is at best a very poor conductor, the electricity developed by the processes
just considered tends to accumulate, and
Protection
under peculiar conditions the clouds may against light
become so highly charged, that at length  ing.
the pentup power acquires sufficient force to break
through all barriers, and the lightning dashes to
the earth, crashing, rending, and burning on its
way. To guard his roof from its destructive action,
man erects the lightning-rod, whose bristling points
quietly drain the clouds, or, failing to do this, receive the charge, and bear it harmlessly to the
earth. But ages before Franklin pointed the first
rod to the storms, the merciful Parent of mankind
had surrounded the dwellings of his children with
a protection far more effectual than this; for, since
the creation of organic life, every pointed leaf,
every twig, and every blade of grass have been
65 
RELIGION AND CHEMISTRY.
silently disarming the clouds of their destructive
weapon. It is difficult to improve upon nature,
and man constantly finds that in his best inventions
he has been anticipated from eternity by a greater
Inventor than he. So not long after Franklin had
discovered the efficacy of metallic points in dissipating a charge of electricity, and had applied
the principle in constructing the lightning-rod, it
was found that a common blade of grass pointed
with nature's exquisite workmanship was three
times as effectual as the finest cambric needle, and
a single twig far more efficient than the metallic
points of the best-constructed rod. When, now,
you reflect how many thousand of these vegetable
points every large tree directs to the sky, and consider what must be the agency of a single forest
with its innumerable twigs, or of a single meadow
with its countless blades of grass, and then when
you remember that these are only subsidiary to
those vast lightning-conductors, the mountainchains, whose craggy summits pierce the clouds
themselves, and still further, when you learn that
the raindrops and snow-flakes have been made
good conductors, so that during the storms a bridge
for the lightning is thrown across from the clouds
to the earth, you will see how abundant the
protection is, and with what care Providence has
guarded  us from  the  destructive agent.   It is
only under unusual circumstances, when electricity is developed more rapidly than it can be dissipated through these numberless channels, that
66
[LECT. II. 
LECT. II.]    TESTBIONY OF THE ATMOSPHERE.
a violent discharge takes place, and if then it tears,
burns, or kills, it also reveals the Merciful Hand
which constantly spares. Moreover, through this
servant of his pleasure, God is constantly educating
and elevating his creatures. In the wild corsuscations of the lightning, and in the reverberating
roll of the thunder, Nature exhibits one of her
grandest aspects, before which man is awed and
terrified, while he admires and adores; and also
when, through the cold, dry air of the arctic region
the electric charges shoot down to the earth in
tremulous flashes, then Nature lights up her grand
displays of northern fires, which enliven the long
night of the arctic winter, or in this more favored
climate excite the curiosity and call forth the admiration of all.* y
I must here conclude this very imperfect sketch
of the physical adaptations of the atmosphere to
the ends it subserves on the earth. We Distinctive
studied in the first place its aeriform con- marks of the
design of
dition, and found that its density not only nature.
forms an essential part of the scheme of organic nature, but also is closely related to the dimensions of
the solar system. In this Lecture we have studied
the relations of the atmosphere to light, heat, and
electricity; and although we have been able only to
glance at some of the more prominent features in
* I am indebted for many of the above illustrations to an admirable
paper on atmospheric electricity in the American Almanac for 1854, by
my friend and colleague, Prof. Joseph Lovering.
67 
RELIGION AND CHEMISTRY.
these wonderful displays of creative energy, we have
found, wherever we turned, abundant illustrations
of the wisdom, power, and goodness of our God. I
trust that you have been impressed by the vastness,
the complexity, and yet the simplicity and harmony
of the whole design, for these are the chief points
which I have endeavored to set forth. But O how
imperfect any conception which I can give you
must be! This atmosphere is sustained in the
proper working of all its parts only by the exact
balancing of a thousand conditions. Attempt to
make yourself acquainted with these conditions,
and, disregarding those which you recognize at
once as surpassing human intelligence, study only
such as are thoroughly understood and universally
admitted to have been primary conditions in the
plan of nature before the atmosphere could exist
as it is. This is not an impossible task. It would
require years of study, and it would lead you into
every department of physical science, but the result
would well repay your labor. You would find it
easy to follow out any one line of the conditions,
until it became lost in the obscurity of the unknown;
but to form a conception of the simultaneous working of all in their varied relations, or even of two or
three, you would soon discover to be a hopeless task.
The complication of this wonderful machinery so far
transcends man's mental power, that to understand
its combined action is simply impossible. But although you would thus be made most keenly sensible of the limits of your human powers, you would
68
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
also be filled with gratitude for the great privilege
you enjoyed of studying this divine mechanism,
even if you could understand its workings only
obscurely and in part.
Paley has compared the mechanism of nature to
a watch, and, so far as the argument for design is
concerned, the analogy is perfect. We must never
forget, however, that there is an essential difference
between the scheme of nature and the most complicated human mechanism. I have seen a carpetloom weaving a pattern composed of twelve different colors, and, as I watched the shuttles of various
colored yarns which were selected by the hands of
the machine with unerring certainty, and thrown
through the warp, it seemed as if the very iron were
endowed with intelligence, and the impression was
one of wonder and bewilderment. To comprehend
such complexity appeared impossible; but the more
I studied the details of the machine, the more thoroughly I understood the mode of its action, until at
last the wonder vanished; and although not ceasing to admire the skill of the inventor, I felt I had
comprehended the whole, and could even conceive
of the mental process by which such a wonderful
combination of means had been made and adjusted
to produce the desired end. The artist was ingenious, but the machine was still human.
How different it is with the mechanism of nature! Here, also, it is true, the more we study, the
more we understand the workmanship; but then
we never reach the limit. The more our powers of
69 
RELIGION AND CHEMISTRY.
thought and observation are developed, and the
more our experience is enlarged, the more the field
of possible knowledge expands before us. The lar ger our attainments, the less we seem to know.
We still recognize the unmistakable marks of
intelligence in the design, but it is no longer an
intelligence we can fathom; we feel that it is infi nitely above us: in a word, we feel that it is God
Would that my feeble language might convey to
you the full power of this impression; for until you
are conscious of the infinite beauty and skill with
which the numberless parts of nature have been
fashioned and adjusted, you cannot appreciate the
force of the conviction which the impression gives.
You may make yourselves familiar with the dimensions of Mont Blanc; you may read the most
glowing descriptions of this monarch of mountains,
heightened by all the arts of eloquence or of poetry;
you may cross the ocean and travel to the beautiful valley of Chamouni at its base; you may even
climb its side, study its glaciers, and cross its fields
of snow: but you will form no adequate conception
of its grandeur, until, ascending one of the lofty
mountain-peaks which surround it, you see its
summit still towering above your head, apparently
higher than before. So it is in the study of nature.
No description can give you an adequate conception
of the impression which it leaves upon the mind.
It is not until, after long study, the student has
become thoroughly acquainted with some one portion, however limited, of its wonderful economy,
70
[LECT. II. 
LECT. II.]    TESTIMONY OF THE ATMOSPHERE.
that he begins to appreciate the perfection of its
parts, the infinite skill with which all have been
adjusted, and the true grandeur of the whole.
By most men these heights of knowledge are
unattainable. Why, then, should we hesitate to
receive the evidence of a philosopher like Newton,
who, after spending a long life in the investigation
of nature, and with a success unparalleled in the
history of science, uttered this memorable senti ment shortly before his death: "I do not know
what I may appear to the world; but to myself I
seem to have been only like a boy playing on the
sea-shore, and devoting myself now and then to
finding a smoother pebble or a prettier shell than
ordinary, while the great ocean of truth lay all un explored before me." I know this sentiment has
been so often repeated as to seem trite, but, coming
from whom it does, it cannot be too often quoted.
It is the testimony of the greatest master of science
to its greatest and sublimest truth.
We can all recognize the marks of design in
nature, and when we add to this evidence of our
senses the testimony of a man like Newton, who
assures us that the more our powers are enlarged,
and the wider our knowledge becomes, the grander
and vaster the design will appear, until it surpasses
all our powers of thought or imagination, we begin
to feel the full depth of the truth I have been en deavoring to enforce.  If our minds are incapable
!Qf comprehending the plan, who could have been
l equal to the design?  "Whence, then, cometh wis
71 
RELIGION AND CHEMISTRY.
"dom, and where is the place of understanding,
"seeing it is hid from the eyes of all living, and
"kept close from the fowls of the air?  God under"standeth the way thereof, and he knoweth the
"place thereof. For he looketh to the ends of the
"earth, and seeth under the whole heaven, to make
"the weight for the winds and a way for the light"ning of the thunder. Then did he see it and de"clare it; he prepared it, yea, and searched it out.
"And unto man he said, Behold the fear of the Lord,
"that is wisdom, and to depart from evil is under"standing."
72
[LECT. II. 
LECTURE III.
TESTIMONY OF OXYGEN.
WERE we to limit our regards to those physical
qualities of the atmosphere which we studied in
the first two Lectures, we should overlook the
most wonderful adaptations in its divine economy.
These properties belong to the atmosphere, in
great measure at least, in virtue of its aeriform
condition, and, so far as we know, an atmosphere
composed of other gases, and still having the same
density, would soften the intensity of the light, and
diffuse the genial influences of the sun's heat, as
well as air. Not so, however, with the chemical
qualities of the atmosphere, which we are next to
consider. These belong to the atmosphere solely
as air, and could not have been obtained with any
other known materials.
When a chemist,wishes to investigate the nature
of a new substance, his first step is to analyze it.
Let us, therefore, as a preliminary to our Composition
present inquiry, ascertain what is the com- of air.
position of this aeriform matter we call air. The
air has been analyzed hundreds of times in every
latitude and in every climate; and the result has
been uniformly that which is given in the following table: 
RELIGION AND CHEMISTRY.
Composition of the Atmosphere.*
Oxygen
Nitrogen
Carbonic Acid
Aqueous Vapor       (average)
Nitric Acid
Ammonia                  traces.
Carburetted Hydrogen
100.00
Composition in Tons.
1,233,010 billions of tons.
3,994,593      "     "
5,287     "      "
54,460    "    "
Besides oxygen and nitrogen gases, which, as you
will notice, are the chief constituents, there are always present in the atmosphere the vapor of water,
carbonic acid, and ammonia gas; and if we add to
these uniform constituents the various exhalations
constantly arising from the earth, we shall have as
accurate an idea of the composition of the air as
chemistry can give. While, however, the proportions of oxygen and nitrogen are almost absolutely
constant, those of the other ingredients are very
fluctuating, and the total quantity exceedingly
small, never amounting in all, exclusive of aqueous
vapor, to more than one part in a thousand, unless
in some confined locality, and under very unusual
circumstances. Do not, however, measure the im
* Miller's Elements of Chemistry.
74
[LEWcr. Il.
20.61
77.95
.04
1.40
Oxygen
Nitrogen
Carbonic Acid
Aqueous Vapor 
TESTIMONY OF OXYGEN.
portance of these variable and in a degree accidental constituents by their amount, for, although
present in such small quantities, they are not less
essential in the atmosphere than the two gases
which make up almost its entire mass.
Moreover, we must carefully avoid the error of
considering air as a distinct substance, like water
or coal. On the contrary, it is merely a mechanical mixture of its constituent gases, and is in no
sense a definite chemical compound. Indeed, we
may regard the globe as surrounded by at least
three separate atmospheres, - one of oxygen, one
of nitrogen, and one of aqueous vapor, -all existing simultaneously in the same space, yet each entirely distinct from the. other two, and only very
slightly influenced by their presence. To each of
these atmospheres the Author of nature has assigned separate and different functions. They are
like so many servants in a household, each with
its distinct set of duties, which they discharge with
a fidelity and diligence unknown to any earthly
service. Let us consider what those duties are,
and see how skilfully each is adapted to the offices
which it is designed to fill.
Were all the other constituents of the air removed, the earth would still be surrounded by an
atmosphere of oxygen, having about one fifth of
the density, and exerting at the surface of the
globe about one fifth of the pressure, of the present atmosphere. In studying the chemical relations of air, let us begin with some of the more
75
LECT. II.] 
RELIGION AND CHEMISTRY.
important functions of this remarkable substance,
and these will fully occupy our time during this' 
and the next succeeding Lecture.
It is easy to prepare oxygen in a pure state.  It
is then a perfectly colorless and transparent gas,
Propertiesof  and so persistently does it retain its aerioxygen. form condition, that man has not been
able, by the greatest pressure he can exert, or by
the greatest degree of cold he can artificially produce, to reduce it to the liquid or solid state. A
German chemist, Natterer, submitted this gas to the
combined action of intense cold and a pressure of
over forty-five thousand pounds, or twenty tons,
on a square inch, but he did not succeed in changing its condition. This is quite an exceptional fact
in nature. Almost all aeriform substances, when
submitted to the action of great cold, are condensed to liquids, and many of these liquids have
been frozen; but oxygen and nitrogen are an exception to the rule, and persistently retain their
aeriform condition under the widest variations of
temperature which exist on the earth. The importance of this fact will be seen at once on com  Permae  paring the condition of the oxygen and
PermanenceI 
of itsaeriform nitrogen in the atmosphere with that of
condition.   the aqueous vapor.  A  fall of temperature of only a few degrees will generally condense a portion of the vapor, and, small as is its
relative amount, the resulting rain is at times
poured down upon the earth in deluging floods;
76
[LEc-r. HI. 
TESTIMONY OF OXYGEN.
and if you consider what must have been the destructive results had the whole mass of the atmosphere been liable to a similar fluctuation, even under
extreme conditions, you will discover in the permanency of oxygen a most obvious adaptation of its
properties to the thermal condition of our globe.
The permanently aeriform state of oxygen will
appear still more remarkable when we consider
how largely it enters into the composition of the
solid crust of the earth. Oxygen belongs to that
class of substances which the chemists call elements,
because they have never succeeded in resolving
them into simpler parts, and of all the elements
it is by far the most widely diffused. As we have
already seen, one fifth of the volume of the atmosphere consists of this gas; but this is a small amount
compared with that which enters into the composition of most substances. You may be surprised at
the statement, but it is nevertheless true, that between one half and one third of the crust of this
globe and of the bodies of its inhabitants consists
of oxygen. No less than eight ninths of all water is
formed of the same gas. It makes up three fourths
of our own bodies, not less than four fifths of every
plant, and at least one half of the solid rocks. Remembering now that twenty tons of pressure on a
square inch are not sufficient to reduce oxygen to a
liquid condition, consider what must be the strength
of that force which holds it thus imprisoned. Why,
in this tumbler of water there are no less than six
cubic feet of oxygen gas, condensed to a liquid con
77
LECT. III.] 
RELIGION AND CHEMISTRY.
dition, and held there by the continuous action of
a force which can be measured only by hundreds of
tons of pressure.  We call the force chemical affin
ity; but who shall measure its power? Who but
He who could make with such a subtile material the
rocks, with which he "laid the foundations of the
earth," and the waters which roll over its surface?
Oxygen gas, like all other forms of aeriformn matter, tends to expand, and can be prevented from
Density. obeying this natural tendency only by en         closing it in an air-tight receiver. As it
exists in our glass jars, under the ordinary conditions of temperature and pressure, one cubic foot of
oxygen weighs 590.8 grains, although in its more
expanded state, as it exists in the atmosphere at
the surface of the globe, it has but one fifth of this
density.   One cubic foot of nitrogen gas weighs,
under the same circumstances, 517.5 grains; but
although there is such a decided difference between
the specific gravities of the two gases, yet so perfectly are they mixed together throughout the
whole extent of the atmosphere, that analysis has
been unable to detect the slightest difference in
composition between the air brought from the summits of the Alps and that from the deepest mine in
Cornwall. Why, you may ask, do not these gases
obey the well-known laws of hydrostatics, the heavier oxygen sinking to the surface of the earth, and
the lighter nitrogen floating above it? Simply be         cause gases, unlike the other forms of matDiffusive force.
ter, have the property of diffusing through
78
[LECT. IH. 
TESTIMONY OF OXYGEN.
each other, and existing together in the same space.
The presence of one gas does not prevent the entrance of another into the space which it occupies,
and if two open jars, containing different gases,
are placed together, mouth to mouth, each gas will
expand until it fills the whole volume. Moreover,
the greater the difference between the densities of
the gases, and the greater the consequent tendency
to separate, the stronger is the force by which they
are compelled to mix together. This force is called
the force of diffusion, and it has been adjusted with
great nicety in the plan of creation. Were this
force in the atmosphere much less than it is, the
two gases composing air would have separated partially, and the atmosphere have become unfitted for
many of its important functions. Take, for example,
the function of transmitting sound.
As the air is now constituted, there is a constancy
of pitch, however far sound travels. Any tone once
generated remains the same tone until it dies away.
Its degree of loudness alters in proportion to the
distance of the listener, but the pitch is constant.
Were it not, however, for this law of diffusion,were the atmosphere not perfectly homogeneous,
and the gases of which it consists even partially
separated, - there would have been a very different
result. The constancy of pitch could no longer have
been depended upon. The sound as it travelled
would vary its pitch with the ever-varying medium
through which it passed, and would arrive at the
ear with a tone entirely different from that with
6
79
LECT. III.] 
RELIGION AND CHEMISTRY.
which it started. Nor would it require any great
difference in the medium to produce a sensible result, and to confuse all those delicate differences of
pitch on which the whole art of music depends.
Whenever, therefore, you may be next enjoying
the grand Pastoral Symphony of Beethoven or the
Requiem of Mozart, recall the careful adjustment of
forces by which alone these magnificent creations
of genius were rendered possible, and you cannot
fail to recognize in this simple law of nature the
same hand which first strung the lyre and made the
soul of man responsive to its seven notes.
Returning again to the qualities of oxygen, let
us notice, in the next place, that it is entirely desti         tute either of odor or of taste. This fact
Passive and
active condi- is a matter of common experience; for as
ons.  oxygen exists in a free state in the atmosphere, it would there manifest these properties did
they exist: and reflect how essential these negative
qualities are to our comfort and well-being. Moreover, in its ordinary condition, oxygen seems entirely devoid of any active properties. It does not
affect the most delicate and evanescent vegetable
dyes, which the weakest chemical agents will either
alter or destroy. And consider the oxygen as it
exists in the air. How bland and seemingly inactive it is there! Reflect that it bathes the
most delicate animal organism, that it pervades
the minutest air-passages of the lungs, - remember
that it is in contact with all matter,- and every
substance will seem to bear evidence to the fact
80
[LECT. III. 
TESTIMONY OF OXYGEN.
that oxygen in the state of gas possesses no active
properties, and  is incapable of manifesting  any
strong chemical force. And yet, if you infer thai
oxygen always appears in this passive condition
and is under all circumstances incapable of violent
action, you will be entirely deceived; for so fai
from being one of the weakest, it is the strongest of
the chemical elements, and beneath this apparent
mildness there is concealed an energy so violent,
that, when once thoroughly aroused, nothing can
withstand it. A single spark of fire will change
the whole character of this element, and what was
before inert and passive becomes in an instant violent and irrepressible. The gentle breeze which
was waving the corn and fanning the browsing
herds, becomes the next moment a consuming
fire, before which the works of man melt away
into air.
And here I must correct an erroneous, although
very common impression, that there is something
substantial in fire. This is one of those
Nature of fire.
ideas, originating in an illusion of the
senses, which we have inherited from a more ignorant age, and which our modern science cannot
wholly dispel from the popular mind. Fire was
formerly regarded as one of the elementary forms
of matter, and all burning was supposed to consist
in the escape of this principle of fire, previously
pent up in the combustible substance. In support
of this doctrine the old philosophers confidently
pointed at flame as the visible manifestation of
LECT. II.]
81 
RELIGION AND CHEMISTRY.
the escaping fire-element. And, childish as it may
seem, this was the prevalent belief of the world
for at least two thousand years.
The last phase which the doctrine assumed was
the phlogiston theory of the last century. In the
hands of Bergmann and Stahl, the vague ideas of
the time received a more material form, and were
embodied in a philosophical system. They termed
the principle of fire phlogiston, and burning, or the
escape of fire, dephlogistication, and their ingenious
systemn did not a little to retard the progress of
truth. It never seems to have occurred to the
philosophers of that age to weigh the results of
burning, or if they did by accident, they most
blindly ignored the result, and it was not until
1783, when the true theory of combustion was discovered, that modern chemistry began. The fortunate discoverer was Lavoisier. He proved, by
simply weighing the products of combustion, that
burning, instead of being a loss of phlogiston, is a
union of the burning substance with the oxygen
of the air, and this theory is now one of the best
established principles of science.
Burning is merely chemical change, and all combustion with which we are familiar in common life
is a chemical combination of the burning substance, whether it be coal, wood, oil, or gas, with the
oxygen of the air. Combustion is simply a process
of chemical combination, and the light and heat
which are evolved in the process are only the concomitants of the chemical change. Why those
82
[LECT. III. 
TESTIMONY OF OXYGEN.
mysterious influences of light and heat are radiated from the coal which is combining with oxygen
in our grates, we may understand better hereafter;
but this much we already know, - that the sensations of light and heat are caused by waves of an
ethereal medium breaking upon the extremities of
the delicate nerves of our human organism; and
that such waves are set in motion during the
chemical change which we call combustion. What
the chemist chiefly studies, however, is the change
itself, and to this we will for the present confine
our attention.
The products of ordinary combustion, that is, the
compounds of oxygen with the elements of coal,
wood, and gas, are only two in number, carbonicacid gas, and aqueous vapor. These, as is well
known, are perfectly colorless and transparent aeriform substances, wholly without odor or taste, and
entirely devoid of every active quality. For this
reason they escape without observation from the
burning wood, ascend our chimneys, and by the
force of diffusion are spread throughout the atmosphere; but if, as may readily be done by chemical
means, we collect the neglected smoke and weigh
it, we shall find that it weighs much more than the
burnt wood, and, as more careful experiments will
show, its weight is exactly equal to that of the
wood added to that of the oxygen of the air con sumed during the burning.
And, my friends, this smoke, though so long
unnoticed by man, was not overlooked by the
83
LECT. IA.] 
RELIGION AND CHEMISTRY.
Author of nature. It is a part of his grand and
beneficent design in the scheme of organic na ture. No sooner do the products of that wood
burning on your hearth escape into the free ex
panse of the outer air, than a new cycle of changes
begins. The carbonic acid and the aqueous vapor,
after roving at liberty for a time, are absorbed
by the leaves of some wide-spreading tree, smiling in the sunshine, and in the tiny laboratory
of their green cells are worked up by those wonderful agents, the sun-rays, into new wood, absorbing from the sun a fresh supply of power,
which is destined, perhaps, to shed warmth and
light around the fireside of a future generation.
But let us not anticipate our subject. In a future Lecture I hope to discuss this wonderful cycle
of changes at same length. At present I wish to
direct your attention to the remarkable contrast
of qualities presented by the element oxygen
in its active and passive conditions. How is this
complete inversion of properties to be explained?
There is a cloud of mystery hanging over the subject, which the progress of knowledge has not as
yet entirely dispelled; but so far as the cause is
known, I will endeavor to make it intelligible. The
difference in the action of oxygen in these two conditions depends on temperature. At the ordinary
temperature of the air its chemical affinities are
dormant, and, although endowed with forces which
are irresistible when in action, it awaits the necessary conditions to call them forth. One of the
84
[LECT. IIl. 
TESTIMONY OF OXYGEN.
grandest works of ancient art which have come
down to us is the colossal statue of the Farnese
Hercules. The hero of ancient mythology is represented in an erect form, leaning on his club, and
ready for action; but at the moment every one of
the well-developed muscles of his ponderous frame
is fully relaxed, and the figure is a perfect ideal
of repose, yet a wonderful embodiment of power.
Here in this antique we have most perfectly typified the passive condition of oxygen, the hero of
the chemical elements. Raise now the temperature
to a red heat, and in a moment all is changed.
The dormant energies of its mighty powers are
aroused, and it rushes into combination with all
combustible matter, surrounded by those glorious
manifestations of light and heat which every conflagration presents.
In order to evoke the latent forces in the oxy gen of the atmosphere, it is not necessary, how ever, to raise the temperature of any con- Fire, how
siderable portion either of the gas or of sustained.
the combustible. There is a provision in nature
by which chemical combination, once started at
any portion of the combustible mass, is sustained
until the whole is consumed. All chemical com bination is attended by the evolution of heat, and
in the combination of oxygen with most combusti ble substances the amount of heat thus generated
is so great, that by the burning of one portion suf ficient heat is evolved to raise the temperature of a
second portion to the point of ignition, and thus
85
LECT. IHI.] 
RELIGION AND CHEMISTRY.
the process is continued.  Consider, for example,
what takes place in the burning of a jet of gas.
We start the combustion by bringing the flame of a
lighted match over the orifice. By this the temper ature of the gas and that of the air surrounding it
are raised to a red-heat, and chemical combination
at once ensues. But the chemical union, as just
stated, is attended with the evolution of great heat,
which, before it is dissipated-by the air, raises to
the point of ignition the temperature of the next
portion of gas issuing from the burner. This, com bining in its turn with the oxygen of the air, gener ates a fresh quantity of heat, and thus keeps up the
combustion so long as the gas is supplied. What
I have shown to be true of these gas-burners is
equally true of all ordinary combustion, and so a
single spark may be sufficient to light up a conflagration which will reduce to ashes a whole village
or involve a city in ruin.
Thus it appears that burning is chemical combination with oxygen, that this union is attended
with the evolution of heat, and that a high temperature is the condition under which oxygen manifests its latent power. But you may say, these
facts do not explain the difference between the two
states of oxygen, they merely give the conditions
under which these states are manifested; and this
is true. Why it is that at one temperature oxygen is so completely passive, and at another temperature, a few hundred degrees higher, so highly
active, we not only cannot explain, but we cannot
86
[LECT. III. 
TESTIMONY OF OXYGEN.
even conjecture. The facts are undisputed; the
causes lie hid among the counsels of the All-Wise.
The temperature at which oxygen assumes its
active condition is called the point of ignition. Although fixed for each substance, it differs Point of ignivery greatly with the different kinds of tion.
combustible matter, being determined, apparently,
by their relative affinities for the great fire element.
Thus phosphorus ignites at a temperature less than
that of boiling water, sulphur at 5000, wood only
at a full red heat, anthracite coal at a white heat,
while iron requires the highest heat of a blacksmith's forge. Beginning with a phosphorus match,
which can be ignited by friction, and using the more
combustible materials as kindlings, we can readily
attain in our furnaces the highest temperature required, and thus the energies of this powerful agent
are fully at the command of man. But notice at
the same time that the point of ignition of wood,
coal, and common combustibles, has been placed
sufficiently above the ordinary temperature of the
air to insure the general safety of our combustible
dwellings; and when we consider how liable they
are, even now, to accidents from fire, we shall appreciate the care which has been taken by our
Heavenly Father to guard us against this terrible
danger.
But even this precaution would have been insufficient to secure safety, were it not that the active energies of oxygen, even when aroused, have
been most carefully tempered by extreme dilution.
87
LECT. III.J 
RELIGION AND CHEMISTRY.
It would be easy to show by experiment that the
slowness of combustion depends on the fact that
in the atmosphere oxygen is mixed with a great
mass of an inert gas, and the proportions have been
so adjusted in the scheme of creation as generally
to restrain the awakened energies of the fire-element within the narrow limits which man appoints;
but when, through his misfortune or carelessness, it
overrides these limits, and, from administering to
man's wants, becomes the agent of his destruction,
we are reminded in the awful conflagration by what
a delicate tenure we hold our earthly possessions,
and how small a change would be sufficient to involve all organized matter in a general conflagration. Remember now that fire is one of the most
valuable servants of mankind; that it is the source
of all artificial heat and light; that in the steamengine it is the apparent origin of that power which
animates the commerce and the industry of the civilized world; that under its influence iron becomes
plastic, and the ores give up their metallic treasures;
that it is, in fine, the agent of all the arts, - and
you cannot wonder that in a ruder age the Romans should have enthroned its presiding deity on
Olympus, or the Persians worshipped its supposed
essence as divinity itself. Looking at it again, in
the light of modern science, as merely the manifestation of the latent power of this bland and diffusive atmosphere, the truth seems almost incredible. To think that this, the strongest of the chemical elements, which, although a permanent gas,
88
[LECT. III. 
TESTIMONY OF OXYGEN.
forms more than one half of the solid earth, and
is endowed with such mighty affinities that it is retained securely in this solid state, could have been
so shorn of its energies as not to singe the down of
the gossamer, and yet so tempered that its powers
may be evoked at the will of man and made subservient to his wants! To me the double condition
of oxygen is one of the most remarkable phenomena of nature. I ponder over it again and again,
with increasing wonder and admiration at the skill
of the infinite Designer, who has been able to unite
in the same element perfect mildness and immeasurable power. It seems as if the millennium of the
Hebrew prophet were prefigured in the atmosphere.
"The wolf also shall dwell with the lamb, and the
"leopard shall lie down with the kid, and the calf
"and the young lion and the fatling together, and
"a little child shall lead them."
If I have succeeded in making clear the relations
of this twofold character of oxygen to man and his
works, I think that you cannot fail to have been
impressed with the evidence of design which the
subject affords. This evidence is seen in the facts,
first, that the same element is at different temperatures endowed with such opposite and apparently
incompatible qualities; secondly, that in each of its
conditions the properties are so skilfully adapted to
the functions which it is appointed to perform;
thirdly, that the temperature at which it assumes
its active state has been so accurately adjusted
to the thermal conditions of the globe; and lastly,
89
LECT. III.] 
RELIGION AND CHEMISTRY.
that its active energies have been so carefully
guarded, and placed to so great a degree under
the control of man. But we have not as yet half
exhausted the subject. Here, as everywhere else
in nature, the argument is cumulative; the more
we study, and the more our knowledge is enlarged,
the more it grows upon us; and wherever we may
leave the field, we always are conscious that there
is a still richer harvest to be reaped beyond.
If the crust of the globe is a fair sample of the
whole mass, oxygen was the chief material emOxygen the
Oxygen the ployed by the Great Architect in conchief worl-  structing our earth.   Moreover, world    builder. building was a process of burning like
those we have been studying, and the foundations
of the earth were undoubtedly laid in flames.
When we attempt to break up the various materials around us into simpler parts, we soon reach
a class of substances which cannot be further decomposed. Simple inspection will show that granite rock, for example, is a mixture of three minerals, called feldspar, mica, and quartz. We know,
also, that feldspar consists of alumina, potash, and
silica, that mica contains the same materials in
different proportions, and that quartz is silica alone.
Lastly, the chemists have discovered that alumina
is composed of alunzinum and oxygen, potash of potassium and oxygen, and silica of silicon and oxygen.
But here we must stop; for when you ask us of
what these last-named materials are made, we find
90
[LECT. III. 
TESTIMONY OF OXYGEN.
ourselves in the condition of the old philosopher,
who got on very well with his fiat earth, supporting it on an elephant, and the elephant on four
tortoises, until he came to seek a resting-place for
the tortoises; but then his'theory failed. So is it
with our science. These undeoomposed materials
are the blocks on which the whole is built; and we
are totally ignorant of what lies below.
We call all substances which have never yet
been decomposed, whatever may be their nature,
chemical elements, and of such about sixty.-five are
now known. Setting apart oxygen as the supporter of combustion, the great mass of the remaining elements are combustible; that is, under
certain conditions they combine rapidly with oxygen, evolving light and heat. Indeed, many of the
combustible substances with which we are most
familiar are elements. Charcoal is an element,
phosphorus is an element, sulphur is an element,
iron and all other metals are elements, and out of
such combustible materials, together with oxygen,
the world is made, and chiefly out of oxygen.
When we burn charcoal in air, or pure oxygen
gas, the burning is a process of world-making. The
charcoal combines with oxygen, and the result is
a transparent, colorless gas, called carbonic-acid.
Many may not have heard of such a substance before, but it is always present in the atmosphere, at
least in small quantities, and if we continue our
process of world-making a little further, we shall
find that it enters into the composition of some of
the most familiar rocks and minerals.
91
LECT. III.] 
RELIGION AND CHEMISTRY.
I have at the bottom of this closed glass tube a
small piece of a yellowish-white metal, looking very
much like a flattened shot; and so it is, but the
metal is not lead, although it resembles lead very
closely. Like lead it is quite soft, and can be
easily beaten into leaves thinner than writingpaper; but it is very much lighter than lead, and
tarnishes so rapidly in the air that we are obliged
to keep it thus protected. We call the metal
calcium, and although you may never have seen
the substance before, it is one of the most abundant metals in nature; yet a great rarity, because
of the extreme difficulty with which it is extracted
from its ores.  When  heated to redness, calcium
burns with a brilliant white light and a scintillating flame. In burning, it combines of course
with oxygen, and the result is lime, common
quicklime, such as is used for making mortar.
This is a process which in the original worldmaking must have played a very important part,
for lime rocks form a large portion of the earth's
crust. None of these rocks, however, will slake like
quicklime, and we must go a step further in our
world-building, and bring in the agency of water,
before we can reach the actual condition of things.
We have now before us two products of burning,
one a solid, called lime, made by uniting calcium
with oxygen, the other a gas, called carbonic-acid,
made by uniting charcoal with oxygen. Both
are soluble to a certain extent in water, and
these clear solutions, called lime-water and soda
92
[LECT. mI. 
TESTIMONY OF OXYGEN.
water respectively, are even more familiar to you
than the substances themselves. Mix now the
solutions together. The water becomes at once
very turbid, and there soon settles from it a white
powder. The lime and carbonic acid have united,
and this is the result. If we collect and examine
the white powder we shall find that it is chalk,
and from the same material, spread in thick layers
over the ocean-bed, and subsequently hardened by
the mutual action of heat and water, have been
formed limestone, marble, and the different varieties of lime rock, which are all ores of calcium.
But we may study with profit a second example of world-building. I have here a small
quantity of another very abundant element, called
silicon, but, like calcium, a comparative rarity, because it is with difficulty obtained pure.   It resembles in many respects carbon, and has been
observed in three different states, corresponding
to charcoal, graphite, and diamond. Like carbon,
it also is combustible, combining with the oxygen of the air when heated to a high temperature, and forming a very hard white solid, called
by chemists silica, which is the same thing as
quartz, rock-crystal, agate, jasper, calcedony, opal,
&c. All these familiar minerals are merely different conditions of this one material, and contain
over one half their weight of oxygen gas. When
ground to a coarse powder by the action of running
streams, they become sand, and the grains of sand,
compacted together, form sandstone and similar
LECT. III.]
93 
RELIGION AND CHEMISTRY.
rocks; and you will begin to appreciate the enormous amount of silicon which must have been
burnt up in the process of world-making, when you
learn that at least one half of the solid crust of
the earth consists of silica in its different varieties.
Setting aside the silica for a moment, let us turn
to another very widely distributed element, called
aluminum. This brilliant white metal, comparing
favorably even with silver in lustre, was until very
recently as great a rarity as calcium or silicon; but
within a few years a process has been invented by
which it can be extracted from its ore at a cost
sufficiently low to render the metal available in
the arts, and it has now come into quite general
use for making mathematical instruments, for jewelry, and for similar purposes. It forms also, with
copper, a valuable alloy, which does not readily
tarnish, and resembles gold so closely that the
two cannot be distinguished by their external appearance.
Aluminum, like most of the metals, is combustible, although it does not burn readily in the air,
unless the temperature is very high and the metal
finely subdivided; but it then burns very brilliantly, emitting a vivid light, and forming a compound called by chemists alumina, which is melted
by the intense heat to a yellowish transparent
glass, and is the same substance from which nature makes the sapphire and the ruby. Emery
also, which, on account of its great hardness, is
used so largely for polishing, is only a rougher
94
[L.ECT. HI. 
TESTIMONY OF OXYGEN.
form of the same material. Unite now the alumina
to silica, and we get clay. Burn the clay, and we
have, according to the fineness of the materials,
porcelain, pottery-ware, or bricks.
Taking next the element magnesium, which is
also a brilliant white metal, allied to zinc, you notice
that it takes fire even in the flame of a candle, and
burns with dazzling brilliancy. The result is magnesia, so much used as a medicine. Unite magnesia
to silica, and we have, according to the proportions,
hornblende or augite, two minerals which abound
in many varieties of rock. Add water to the composition, and we get also serpentine or soapstone,
with several other allied mineral species.
I might multiply these illustrations indefinitely,
but I will limit myself to only one other example.
Here is a metallic element called potassium, so light
and combustible that it swims and burns on water.
Burning in water may seem, at first sight, very paradoxical; but in studying chemistry, we must be
ready to give up old prejudices. Water is almost
pure oxygen, containing in the same volume more
than one hundred times as much of the fire-element
as air, and all combustibles would burn in water
were it not that the oxygen is imprisoned in the
liquid by an immensely strong force. Potassium,
however, has such intense chemical affinities that
it will break through all bars and bolts in order to
unite with oxygen, and it therefore burns thus brilliantly even in the midst of water. The result is
a white solid called potash, which in the experi
7
95
LECT. HII.1 
RELIGION AND CHEMISTRY.
ment dissolves in the liquid. Melt together now
potash, lime, and silicious sand, and we have glass.
Unite silica, alumina, and potash, and we get feldspar; combine them in little different proportions,
and we have mica; varying again the proportions,
we obtain garnet. Lastly, mix quartz and feldspar
together with mica or hornblende, in an indiscriminate jumble, and we have the several varieties of
granitic rocks.
Such then are some of the steps in the process
of world-building. I do not mean to imply that
we can reproduce all these substances in our laboratories, although even this is true in almost every
case. My object is only to show what must have
been in general the process of nature, and to make
evident the fact that oxygen has been the chief
world-builder. But why call oxygen the worldbuilder more than the other elements? This diagram will answer, and it illustrates one of the most
Silicon.
Oxygen.
Aluminum.
Magnesium.
Calcium.
K. Na Fe C.
S H C1 N. 1 52 others.
remarkable facts to which the study of this function of oxygen has led. Of the 65 known ele
96
[LECT. III. 
TESTIMONY OF OXYGEN.
ments, thirteen alone make up at least -A-%  of the
whole known mass of the earth. Of this, oxygen
forms about I silicon about 4; then we have aluminum, magnesium, calcium, potassium (K), sodium
(Na), iron (Fe), carbon (C), sulphur (S), hydrogen
(H), chlorine (C1), and nitrogen (N) filling up nearly
the other fourth, while the 52 remaining elements
-including all the useful metals except iron -do
not constitute altogether more than x 00.  The diagram, however, only represents the relative proportions very rudely, as the subdivisions are necessarily
based on very rough estimates and imperfect data.
Evidently, then, so far as our knowledge extends, oxygen, silicon, and carbon, together with a
few metals, have been the chief building-materials
employed by the Great Architect, and oxygen has
been, as it were, the universal cement by which the
other elements have been joined together to form
that grand and diversified whole we call our earth.
One more remark in regard to this subject, and
I will close my Lecture. It is probable that there
was a time, long before even geological history,
when the elements were in a free state; when the
oxygen now solidified was a gas forming an atmosphere, and when at the fiat of the Almighty the
union of the elements began. Then our earth became a bright, burning star, radiating its heat and
light into space. Indeed, if we accept the nebular
hypothesis of Laplace, the earth was formerly a part
of the sun, was thrown off by the centrifugal force
from his burning mass, and like a spark from a forge
97
LECT. III.] 
RELIGION AND CHEMISTRY.
soon burnt out, although after this lapse of time
the great central fire is burning still. But whether
Laplace is right or not, this much is certain. The
crust of the earth, so far as we can examine it, is
like a burnt cinder, and the atmosphere of oxygen which surrounds it is merely the residuum left
after the general conflagration,- left because there
was nothing more to burn. Unmeasured ages have
passed away since then; the earth's crust has cooled
and solidified; the waters have been condensed and
gathered into the great ocean-basins; the dry land
has been covered with verdure and peopled with
all kinds of four-footed beasts, winged fowls, and
creeping things; the waters have been tenanted
with countless forms of swimming creatures; and,
last of all, man has come to live in this fair creation, and study the wonders of his dwelling-place.
He finds on the earth's burnt crust an abundant
supply of combustible material for all his wants.
But if the world was once burnt up and the elements glowed with fervent heat, how is it that
these combustibles have been left unconsumed?
Modern science has been able to answer this question. It has discovered that during the long geological ages a silent power has been slowly recovering a small amount of combustible material from
the wreck of the first conflagration. The sunbeam
has partly undone the work of the fire, and whatever now exists on the earth unburnt, wood, coal,
or metal, we owe to that wonderful agent, the
solar light. How the result has been accomplished,
I propose to consider in a future Lecture.
98
[LFEc-r. 1II. 
~
3j'
LECTURE IV.
TESTIMONY OF OXYGEN. - Concluded.
BESIDES the two extreme conditions of oxygen,
there exists still a third, in a measure intermediate
between them, but still differing essen- Thirdcondition
tially from either,- a condition in which ofoxygen.
the element discharges functions, less brilliant it is
true, but not less interesting and instructive, than
those which we studied in the last Lecture. The
phenomena in which this condition of oxygen is
chiefly active require, as a general rule, months,
or even years, for their full Inanifestation. Moreover, they are so silent and unobtrusive, as frequently to be passed unnoticed; but nevertheless, when we have become acquainted with their
magnitude and importance, I am sure you will
agree with me that they far surpass in true
grandeur those dazzling displays of power which
the fire-element manifests when fully aroused.
This third phase of the element can be best
studied in its effects, and to two of these I will
now ask your attention.
Every one knows that, when wood or any other
organized structure is exposed to the moist atmosphere, it gradually decays.  It first be-  Decay.
comes rotten, and then slowly disappears.
*.   - 
RELIGION AND CHEMISTRY.
All may not know, however, that decay consists in
a slow union of the organized structure with oxygen, and that the log of wood which is left to rot
in the forest undergoes precisely the same change
as one which is burnt on the hearth. The sole
difference is, that, while the last is burned up in a
few hours, the first entirely disappears only after
the lapse of many years. Wood, like all organized
vegetable structures, consists mainly of three elements, charcoal, hydrogen, and oxygen. When
heated on the hearth, in contact with the air, it
takes fire and burns; that is, its combustible elements combine with oxygen, the carbon to form
carbonic acid, and the hydrogen to form aqueous
vapor, both of which escape by the chimney. But
of these two ingredients of the wood, hydrogen is
by far the most combustible; that is, it has the
greatest tendency to combine with oxygen, and
therefore burns first, leaving the less combustible
charcoal in the form of glowing coals. If at this
point we take up one of these coals and quench it
in water, it will be found to be common black charcoal; but if left on the hearth, the coal also burns,
gradually smouldering away, and passing up the
chimney as carbonic-acid gas.
Quite a similar succession of phenomena is presented in the forest during the process of decay.
In decay, as in burning, the oxygen of the air
unites with the hydrogen of the wood more rapidly than with the charcoal, and in consequence the
rotten wood becomes darker and darker, from the
100
[LEF,T. IV.
I I
*- -: eee eee:
!..-....... 
TESTIMONY OF OXYGEN.
excess of black charcoal, as the change advances.
Moreover, if the supply of air is insufficient, as
when the wood is buried in swamps, it is finally
reduced to coal, which corresponds to half-burnt
wood. In the open air, however, the charcoal as
well as the hydrogen is burnt, and the log of wood
is resolved, as in ordinary combustion, into carbonic
acid and water, leaving only a few handfuls of
earth to mark the spot where it lay. This change
requires years before it is fully consummated, and
it is not therefore wonderful that its nature should
not have been understood until a comparatively
recent period. Thanks to modern chemistry, the
subject is now less obscure. We may not be able
to trace all the steps of the process, but this much
we know Decay and burning are essentially the
same chemical change. The substances involved
are the same, the results are the same, and we have
even been able to prove that the amount of heat
generated is the same, the only difference being,
that, in burning, the whole amount of heat is set
free in a few hours, producing phenomena of intense ignition; while in the process of decay the
same quantity, slowly evolved during perhaps a
century, escapes notice.
It has been observed, that, if wood be left in
contact with dry oxygen, it may be kept indefinitely without undergoing  change,-a fact sufficiently proved by the mummy cases of Egypt,
which in that dry climate have been preserved for
over three thousand years;-also, that if wood is
101
LECT. IV.] 
RELIGION AND CHEMISTRY.
impregnated with many salts, as in the process of
Kyanizing or Burnetizing, decay may be arrested
even in a damp situation for a long time. In both
cases the prevention depends on destroying certain very unstable compounds which are present
in all green wood, and which start the decay.
These are termed by chemists albuminous substances, the chief of which, vegetable albumen, is
almost identical with the white of an egg. The
great bulk of all vegetable structures, as was stated
above, consists of only three elements, charcoal,
hydrogen, and oxygen; but these albuminous substances - which, as a rule, are present only in very
small quantities - contain in addition to the three
just mentioned a fourth element, nitrogen. Partly
because they contain nitrogen, and partly, unquestionably, in consequence of the complex manner in
which the four elements are combined, the albuminous substances are vastly more unstable than the
great mass of vegetable matter, and in the presence of moisture they soon undergo an internal
change, called putrefaction, or fermentation, by
which they are broken up into simpler compounds.
The precise nature of the process is not understood,
but nothing appears to be added to the substance
unless it be water, and the change seems to consist
in the falling to pieces of a complex organic structure. At all events, oxygen gas is not essential
to the process, but the oxygen of the air which
happens to be in contact with the fermenting
substances in some mysterious way undergoes a
102
[LEC'r. IV. 
TESTIMONY OF OXYGEN.
remarkable change. It becomes endowed with active properties even at the ordinary temperature,
and, with its affinities thus exalted, slowly consumes the wood, together with all other organic
compounds present. Moreover, the process, once
started, sustains itself. As, in burning, the union
of the combustible matter with oxygen engenders
sufficient heat to maintain the surrounding gas in
its highly active modification, so in like manner
the process of decay seems to modify continually
the neighboring oxygen, arousing its energies, and
thus continuing the change when once begun.
While the plant is in great measure made up
of non-nitrogenized substances, the animal, on the
other hand, consists almost entirely of albuminous
compounds. The flesh, the nerves, and the bones
of our bodies all contain nitrogen, and, like the
vegetable albumen, are prone to decay; and this
change is constantly going on in our living members.  In a most profound sense, "in the midst of
life we are in death." The materials of our bodies
are being constantly renewed, and the great mass
of their structure changes in less than a year.*
At every motion of your arm, and at every breath
you draw, a portion of the muscles concerned is
actually burnt up in the effort. During life, in
* The rapidity of the change has not been accurately determined.
Some authors state that the great mass of the body changes every
month, and when we consider the large quantities of water, carbonic
acid, and ammonia daily secreted, the statement appears credible; but
in the absence of direct proof we have set the limit unnecessarily high
in order to avoid the slightest exaggeration.
103
LxcT. IV.] 
RELIGION AND CHEMISTRY.
some utterly mysterious manner, beyond the range
of all human science, the various gases and vapors
of the atmosphere, together with a small amount
of a few earthy salts, are elaborated into vari ous organized structures.  They first pass into the
organism of the plant, and thence are transferred
to the body of the animal; but no sooner are
they firmly built into the animal tissues, than a
destructive change begins, by which before long
they are restored to the air or the soil, only to
renew the same cycle of ceaseless change. Life,
during its whole existence, is an untiring builder,
the oxygen of the atmosphere a fell destroyer;
and when at last the builders cease, then the spirit
takes its heavenward flight, and leaves the frail
tenement to its appointed end. Dust returns to
the dust, and these mortal mists and vapors to
the air.
I know that there are some who entertain a
vague fear that these well-established facts of
Doctrine ofthe chemistry conflict with one of the most
resurrection. cherished doctrines of the Christian faith;
but so far from this, I find that they elucidate and
confirm it. I admit that they do disprove that
interpretation frequently given to the doctrine of
the resurrection, which assumes that these same
material atoms will form parts of our celestial
bodies; but then I find that this interpretation is
as much opposed to Scripture as to science. The
Saviour himself, in his reply to the incredulous
Sadducees, severely rebuked such a material con
104
[LECT. IV. 
TESTIMONY OF OXYGEN.
ception of his spiritual revelation, and the great
Apostle to the Gentiles, in his vision of the glorified body, distinctly declares that this body is not
the body that shall be; but that, as the grain
sown in the furrow rises into the glory of the fulleared corn, "so when this corruptible shall have
put on incorruption, and this mortal shall have
put on immortality," our natural body, sown in
dishonor and weakness, will be raised a spiritual
body, clothed in glory and in power.  "And as
"we have borne the image of the earthy, we shall
"also bear the image of the heavenly."
The glorious doctrine of the resurrection here
presented, modern scientific discoveries most fully
confirm. They have shown that our only abiding
substance is merely the passing shadow of our outward form, that these bones and muscles are dying
within us every day, that our whole life is an unceasing metempsychosis, and that the final death is
but one phase of the perpetual change. Thus the
idea of a spiritual body becomes not only a possible
conception, but, more than this, it harmonizes with
the whole order of nature; and now that we can
better trace the processes of growth in the organic
world, and understand more of their hidden secrets, the inspired words of Paul have acquired
fresh power, and convey to us a deeper meaning
than they ever gave to the early Fathers of the
Church. It is no wonder that, when men were less
enlightened, the doctrine should have been misinterpreted; but now, when the truth has been illu              5*
105
LECT. IV.] 
RELIGION AND CHEMISTRY.
minated by the study of nature, why longer harass
the understanding and vex the spirit with these
material clogs?  Hear again  the words of the
Apostle: "This I say, brethren, that flesh and blood
cannot inherit the kingdom of God; neither doth
corruption inherit incorruption."  "For this corruptible must put on incorruption, and this mortal
must put on immortality." And now, turning to
the glorious truth as Christ revealed it and Paul
preached it, how greatly is our faith strengthened by these lights of nature! All philosophy
assures us that the finite and limited can be manifested only under form.
"That each, who seems a separate whole,
Should move his rounds, and, fusing all
The skirts of self again, should ral
Remerging in the general Soul,
"Is faith as vague as all unsweet:
Eternal form shall still divide
The eternal soul from all beside;
And I shall know him when we meet."
Chemistry has shown us that it is the form alone
of our mortal bodies which is permanent, and that
we retain our personality under constant change;
and lastly, in organic nature, the sprouting of the
seed, the breaking of the bird from the egg, the
bursting of the butterfly from the chrysalis, and
ten thousand other transmutations not less wonderful, which we are daily witnessing around us,
all unite their analogy to elucidate and confirm
the glorious and comforting doctrine of a material
resurrection in form.
106
[LEcT. IV. 
TESTIMONY OF OXYGEN.
Moreover, when we remember that our organs
of vision and hearing are capable of receiving impressions either of light or sound only when the
rapidity of the undulations which cause them is
comprised within certain very narrow limits, and
when we recall the facts stated in a previous
Lecture, that there are waves of light and sound
of which our dull senses take no cognizance, that
there is a great difference even in human perceptivity, and that some men, more gifted than
others, can see colors or hear sounds which are
invisible or inaudible to the great bulk of mankind,
you will appreciate how possible it is that there
may be a world of spiritual existence around us -
inhabiting this same globe, enjoying this same nature- of which we have no perception; that in
fact the wonders of the New Jerusalem may be in
our midst, and the songs of the angelic hosts filling
the air with their celestial harmony, although unheard and unseen by us. Let me not be understood as implying that science has in any sense
revealed to us a spiritual world, or that it gives
the slightest shadow of support to those products
of imposture, credulity, and superstition, which,
under the name of witchcraft, mesmerism, or spiritualism, have in every age of the world deceived
so many. The only revelation man has received
of a spiritual existence is contained in the Bible;
but modern science has rendered the conception
of such an existence possible, and in this way has
removed a source of doubt. The materialist can no
107
LEcr. IV.] 
RELIGION AND CHEMISTRY.
longer say that the spiritual world is inconceivable;
for these discoveries show that it may be included
in the very scheme of nature in which we live,
and thus, although science may not remove the
veil, it at least answers this cavil of materialism.
Returning now to the main subject, consider for
a moment the importance of this ghostly office of
oxygen in the scheme of organic nature. Reflect
how soon this fair world would become a great
charnel-house were it not for these provisions, by
which its youth is constantly renewed. Remember
also that this process of decay furnishes the materials from which young life builds her fresh and
blooming forms; that, although in the midst of life
we are in death, it is equally true that death is
only a phase of life. Then these changes of outward nature will assume a new aspect. It will
be seen that they are the beneficent provisions of
infinite wisdom, in themselves full of interest and
beauty, and only sad and melancholy as they are associated with bereaved affections and disappointed
hopes, or with that only real death, the moral death
of the soul.  "0 death, where is thy sting?  0
"grave, where is thy victory?  The sting of death
"is sin; and the strength of sin is the law. But
"thanks be to God, which giveth us the victory
"through our Lord Jesus Christ."
I might profitably occupy several hours in describing the various processes of slow combustion,
for they are all rich in illustrations of skilful design; but I must content myself with only one
108
[LEcT. IV. 
TESTIMONY OF OXYGEN.
other example, and from the many which crowd
upon me I have chosen respiration, because it is so well understood and because it is so intimately associated with our own
physical existence. Respiration is a true example
of combustion. The seat of the combustion is
the lungs.  The substance burnt is sugar.  The
products are carbonic-acid gas and water.
The materials of animal food may be divided into three classes: non-nitrogenized substances, such
as starch and sugar; nitrogenized substances, like
lean meat and eggs; and, lastly, fatty substances,
like butter. To these must be added a small proportion of earthy salts, which, however, as they
enter into the composition of almost all varieties
of food, do not properly form a distinct class. All
of the three classes of food are absolutely necessary to support the life of the higher animals,
and especially of man, and they are all contained
in those articles of diet which will of themselves
alone sustain life. Milk may be regarded as the
type of animal food.
position of Milk.*
Natural state.
87
4~
3
4S
Evaporated
to dryness.
(nearly)                 }             41
100             100
* Johnston's Chemistry of Common Life.
109
LECT. IV.]
Wat
Curl
Butt
Sug~
Ash
343
231
37 
RELIGION AND CHEMISTRY.
It contains, in the first place, a non-nitrogenized
substance, sugar; in the second place, a nitrogenized substance, casein, which separated from milk
forms cheese; and, lastly, a fatty substance, which
when separated by churning forms butter.
Wheaten Bread.      Lean Beef.
45              78
6              19
Water (and blood),
Fibrin or gluten,
Fat,
Starch, &c.,
48
100
Bread, again, consists of starch, a non-nitrogenized
substance, of gluten, a nitrogenized substance, and
it also contains about two per cent of a peculiar
oil. No article of food which does not contain
all three of these classes of substances can alone
support life for  any  length of time.   A  man
would starve to death on starch alone, on meat
alone, or on butter alone. The relative proportion, however, in which these three classes of
substances are required by man, depends on his
outward circumstances, such as the climate, his
physical activity, his occupation, or his peculiar
temperament, and to the right balance of his food
he is guided by experience.
The different classes of food serve different functions in the body. The nitrogenized and a portion
of the fatty substances are used to supply the constant waste of the tissues which result from all the
animal processes. They are in some unknown way
110
[LE:CT. IV.
1
3
100 
TESTIMONY OF OXYGEN.
vitalized in the system, and converted into new
muscles, tendons, and nerves, which take the place
of those that have been used up. On the other
hand, the non-nitrogenized substances, such as
starch, are supposed to take no part in the formation of new tissues, and to be merely the fuel
by which the animal heat is maintained. Let us
very briefly follow these substances through the
body, and see when and how they are burnt.
By far the greater part of our daily food consists
of varieties of starch or sugar. These two substances are almost identical in composition, and
starch may be converted into sugar with the greatest ease. Leaving out of view the large amount
of water which all our food contains, we find that of
wheaten bread no less than 39 per cent consists
of starch or sugar; of potatoes fully 92 per cent
is made up of the same materials, and in general
they form over four fifths of the solid part of all
our food. These substances when taken into the
stomach are almnost instantaneously converted by
the saliva and the gastric juice into the variety
of sugar known as grape-sugar, so called because
it is the sweet principle of ripe grapes. The sweet
principle of honey and molasses, and the incrustation which is so frequently seen on figs and raisins,
are also essentially the same substance.   Grapesugar, being very soluble, dissolves in the water
present, and the solution is absorbed by the veins
which ramify on the surface of the intestinal canal, into which the digested food passes from the
8
111
LECT. IV.] 
RELIGION AND CHEMISTRY.
stomach.  The blood, now containing sugar in solution, returns through the liver to the right side
of the heart, and by this organ, which consists essentially of two ingeniously contrived force-pumps,
arranged side by side, it is forced through the
lungs, where the sugar is brought in contact with
the air. Let us next examine for a moment this
remarkable structure.
The lungs, as is well known, consist of two large
organs, on either side of the chest, called the left
and the right lung. The right lung is divided into
three smaller lungs, called lobes, the left into but
two. On examining any one of these lobes it will
be found to be made up of an immense number
of small membranous bags, all closely packed together. These small bags, called cells, connect by
means of the bronchial tubes and windpipe with
the air, through the nose and mouth. They vary
in size, but on  an average are about  fI  of an
inch in diameter, and the total number of the
cells in the lungs has been estimated at six hundred millions. Their walls are exceedingly thin,
and the cells may therefore be easily compressed.
The whole mass of the lungs is also exceedingly
elastic, and by the action of a system of muscles
their volume is alternately increased and diminished in the process of respiration. The amount
of air which is thus drawn into the cells, and
again expelled at each inspiration, differs in different individuals. The average quantity in the
ordinary tranquil respiration of an adult is about
112
[LECT. IV. 
TESTIMONY OF OXYGEN.
a pint; but in a full respiration it may be as
much as two and a half pints, and by an effort
the lungs may be made to inhale from five to
seven pints. As the average in health is about
eighteen inspirations a minute, which corresponds
to about eighteen pints of air inhaled and exhaled, it follows that three thousand gallons of
air pass through the lungs of an adult man
every day.   Some  estimate it as high  as four
thousand gallons a day for an average man in
average circumstances, and as high as five thousand seven hundred gallons a day for an athletic
man undergoing severe exertion. In order that
you may form an idea of this quantity, I will
add that four thousand gallons of air would fill
a room measuring about eight and a half feet in
each dimension.
Let us now turn to the blood, and examine the
apparatus by which it is exposed to the air in
the lungs. As we have already seen, the blood
charged withsugar is received into the heart, from
whence it is pumped through a long tube, called
the pulmonary artery, into the lungs. This artery
divides again and again until it is reduced to very
small capillary tubes, which ramify on the surfaces
of the air-cells. The walls of these capillaries are
formed of the thinnest conceivable membrane, so
as to bring-the blood into as close contact as possible with the air. HIere oxygen gas is absorbed
in large quantities, and carbonic-acid gas evolved.
The blood now holds in solution at the same time
113
Lp.c-r. IV.] 
RELIGION AND CHEMISTRY.
oxygen gas and sugar, and, thus charged, it returns
by a series of veins to the left side of the heart,
when by the second of the two force-pumps it is
again forced through the general circulation of the
body. In the mean time the oxygen absorbed by
the blood while in the lungs burns up the sugar.
Sugar, like wood, consists of carbon, hydrogen, and
oxygen. The last two are present in the proportions to form water, so that sugar may be said to
be composed of charcoal and water. Of these two
substances the charcoal only is combustible. This,
during the circulation of the blood, is slowly burnt
up by the dissolved oxygen, and converted into
carbonic acid, which remains in solution until it is
discharged, when the blood returns again to the
lungs, or else escapes through the skin.
Thus it appears that respiration is a process of
combustion, in which the fuel is sugar, and the
smoke carbonic acid and aqueous vapor. I need
not dwell on a fact so universally known as the
presence of carbonic acid in the breath. All, however, may not know how large is the volume of
this gas which they daily exhale. It varies with
age, sex, food, health, and a variety of other circumstances. In a full-grown man the weight of
carbonic acid evolved from the lungs varies from
one to three pounds in twenty-four hours, which
is equivalent to from nine to twenty-seven cubic
feet.  During the present Lecture the amount of
carbonic acid which has been exhaled into this
room by my audience is equal to at least seven
114
[LECT. IV. 
TESTIMONY OF OXYGEN.
hundred and fifty cubic feet,* and would fill a
room measuring about nine feet in each direction.
From the quantity of carbonic-acid gas exhaled
we can very readily calculate the amount of charcoal burnt, which in a full-grown man will vary
from five to fifteen ounces in twenty-four hours.
Hence, the amount of charcoal which in the form
of sugar has been burnt up in the lungs of my
audience during the last hour, is equal to at least
twenty-six pounds,* which I have had weighed
out and placed on the Lecture table, in order to
give you an idea of the quantity. Moreover, it
has been proved that the quantity of heat evolved
by a given amount of charcoal in burning is absolutely the same, whether the combustion be rapid
or slow, so that the same amount of heat has been
generated in our bodies during the last hour by
the slow process of respiration as would have been
set free by burning this basketful of charcoal. It
is no wonder, then, that the temperature of the
body is always so much above that of the air, and
that even in the coldest climate the heat of the
blood is maintained as high as ninety-six degrees.
In regulating the temperature of his body, man
follows instinctively the same rules of common
sense which he applies in warming his dwellings.
In proportion as the climate is cold, he supplies the
loss of heat by burning more fuel in his lungs, and
hence tlhe statements of arctic voyagers, who have
told us that twelve pounds of tallow-candles make
* Calculated for one thousand persons.
115
LECT. IV.] 
RELIGION AND CHFISTRY.
only an average meal for an Esquimaux, are not
inconsistent with the deductions of science.
Respiration, then, like decay, is a process of slow
combustion, in which the oxygen of the air attacks
and consumes, even at the ordinary temperature,
the sugar in the blood. Let us now compare with
it the rapid combustion of the same substance.
During this Lecture every robust man present has
on an average burnt up the equivalent of about two
ounces of sugar. This combustion has taken place
so quietly, and has set free the requisite amount of
heat so gradually, that we have not been conscious
of it. In the blood, where it has been going on,
sugar and oxygen, as we have seen, are in close
contact. In this crucible I have mixed together
just two ounces of sugar and two ounces and a
quarter of solidified oxygen, solidified by the force
of chemical affinity and bound up in a white salt
called chlorate of potash. The oxygen and sugar
are therefore here lying side by side, as in the
blood, but the conditions of slow combustion which
exist in the body not being present in the crucible, they will remain in contact indefinitely, until
some external agency is applied. The oxygen is
now in its passive condition, but a single drop of
sulphuric acid will arouse its dormant energies,
and you have instantly one of the most dazzling
displays of combustive energy which can be produced by art. The only difference between this
brilliant deflagration and the combustion which,
during the last hour, has taken place in each of
116
[LECT. IV. 
TESTIMONY OF OXYGEN.
our bodies, is simply this; the heat which in the
blood has been imperceptibly evolved during an
hour, was here concentrated into a few moments,
and therefore produced phenomena of intense ignition. All the other conditions, the material burnt,
the quantity of material employed, the products
generated, and the amount of heat evolved, are in
both cases essentially the same.
On comparing these two phenomena together,
reflect for a moment on the false estimate which
we are apt to make of the phenomena of nature.
The splendid displays of combustion arrest our
attention by their very brilliancy, while we overlook the silent yet ceaseless processes of respiration and decay, before which, in importance and
magnitude, the grandest conflagrations sink into insignificance. These are but the spasmodic efforts
of nature; those, the appointed means by which
the harmony and order of creation are preserved.
Those of us who have merely studied the brilliant
phenomena of nature appreciate but imperfectly
the grandeur of its forces, and "those of us who
limit our appreciation of the powers of oxygen to
the energies displayed by this element in its fully
active state, form but a very inadequate idea of
the aggregate results accomplished by it in the
economy of the world." Contemplate the amount
of oxygen employed in the function of respiration
alone. Faraday has roughly estimated that the
amount of oxygen required daily to supply the
lungs of the human race is at least one thousand
117
LEc-r. IV.] 
RELIGION AND CHEMISTRY.
millions of pounds; that required for the respiration of the lower animals is at least twice as much
as this, while the always active processes of decay
require certainly no less than four thousand millions of pounds more, making a total aggregate of
seven thousand millions of pounds required to
carry on these processes of nature alone. Compared with this, the one thousand millions of
pounds which, as Faraday estimates, are sufficient
to sustain all the artificial fires lighted by man,
from the camp-fire of the savage to the roaring
blaze of the blast-furnace or the raging flames of
a grand conflagration, seem small indeed.
Amount of Oxygen required Daily.*
Whole population,              1,000,000,000
Animals,                       2,000,000,000
Combustion and Fermentation,  1,000,000,000
Decay and other processes,     4,000,000,000
Oxygen required daily,    -   8,000,000,000 lbs.
Tons.
3,571,428 in a day.
1,304,642,357 in a year.
Whole quantity, 1,178,158,000,000,000.
How utterly inconceivable are these numbers,
which measure the magnitude of nature's processes,
-eight thousand millions of pounds of oxygen
consumed in a single day! When reduced to tons,
* Taken from Faraday's Lectures on the Non-Metallic Elements, but
correcting an obvious error in reducing the pounds to tons.
118
[L:c'r. IV. 
TESTIMONY OF OXYGEN.
the numbers are equally beyond our grasp, for
it corresponds to no less than 3,571,428 tons. If
such be the daily requisition of this gas, will not
the oxygen of the atmosphere be in time exhausted? It is not difficult to calculate approximately the whole amount of oxygen in the atmosphere. It is equal to about 1,178,158 thousand
millions of tons; a supply which, at the present
rate of consumption, would last about nine hundred thousand years. We need not, therefore, fear
that the amount of oxygen in the atmosphere will
be sensibly diminished in our day or generation;
but then this period, immense as it is, is not to be
compared with the ages of geological time. The
time which has elapsed since thle coal we are now
burning was deposited in its beds is to be counted
by many millions of years, so that since the coal
epoch the oxygen of the atmosphere must have
been all consumed again and again.  Why, then,
has it not all been removed from the atmosphere?
Simply because, in the beautiful balance of creation,
there is always some recuperative process for every
such loss. In the case before us, it is, as we have
seen, the vegetation. As fast as our breath, our
fires, and the process of decay around us are removing the life-giving oxygen, just so fast it is
restored by every green leaf which waves in the
sunshine, and by every blade of grass which sprouts
under our feet. What the animal removes, the
plant restores.
I have before stated that, in the process of de
119
LECT. IV.] 
RELIGION AND CHEMISTRY.
cay, the oxygen of the atmosphere, which is ac tive in producing the change, is undoubtedly in
a peculiarly modified condition, a con Ozone.
dition in which its affinities are high ly exalted even at the ordinary temperature of
the air; and I also stated that this active condi tion of the element is apparently maintained by
the process of decay itself. This subject has been
greatly elucidated by recent discoveries. Of all
the known processes of slow combustion, the simplest and the most active is the slow combustion
of phosphorus. This familiar substance, used to tip
the ends of lucifer matches, if exposed to the moist
air, slowly combines with oxygen, shining at the
same time in the dark with a peculiar phosphorescent light, whence the name of the substance,
from two Greek words, signifying light-bearer.
The process is therefore entirely analogous to
decay and respiration; but since phosphorus is a
chemical element, the change is far simpler, and
can be more readily studied, and for this reason
it may serve to elucidate those more complex
processes of nature.
A few years since, Professor Scho6nbein, a distinguished Swiss chemist, discovered that, while a
stick of phosphorus was slowly burning in a jar
of moist air, a portion of the oxygen present
underwent a most remarkable change. Without
entering into the details of these experiments, I
will simply state that, when thus modified, ordinary oxygen seems entirely transformed. The
120
[LECT. IV. 
TESTIMONY OF OXYGEN.
great mass of the oxygen of the air, as you will
remember, is wholly devoid of odor, and without
action on the most delicate organic structures or
the most fleeting vegetable colors; but when thus
treated it acquires a very strong and pungent
odor, rapidly rusts polished metals, excites decay
in organized tissues, and at once bleaches the
most permanent dyes. Could there be a more
complete inversion of properties?   One  of the
most striking characteristics of this new modification of oxygen is its peculiar odor, and hence
Schonbein calls it ozone, from a Greek verb signifying to smell. Unfortunately, up to this time
we have not been able to prepare ozone except
in a very dilute condition, for the most active
process with which we are acquainted does not
modify more than 3-0 of the whole volume of
oxygen employed; but judging from its action
in this diluted state, pure ozone is the most corrosive element known.
It frequently happens that a great discovery
supplies the wanting links between a number of
obscure facts, and thus adds quite as much to our
knowledge by its indirect bearings as by the positive additions it makes to the general stock. So it
has been with the discovery of ozone. Every one
who has used an electrical machine must have noticed the peculiar smell which follows the electrical
discharge. This was formerly supposed to be the
odor of the electrical fluid itself; but as soon as
ozone was discovered, the odor was recognized at
121
LECT. IV.] 
RELIGION AND CHEMISTRY.
once as belonging to this new agent, and it was
soon ascertained that electricity is one of the most
efficient means of modifying the oxygen of the air.
Moreover, the recent investigations of Scho6nbein
appear to prove that ozone is merely electrified oxygen. He has shown that there are two varieties of
ozone, corresponding to the positive and negative
electricities, which seem to have the power of entering into chemical union, for when brought together they neutralize each other, and ordinary
passive oxygen is the result.
Returning now to the fact that the slow coinbustion of phosphorus throws a portion of the
surrounding oxygen into a peculiar condition, in
which it is highly active in producing decay and
other processes of oxidation,- it certainly seems
probable that decay and respiration, which are
also examples of slow combustion, may  act on
the air in the same way. Moreover, the inference that ozone is the active agent in these processes is also supported by the fact that it is
always present, to a greater or less extent, in
the atmosphere, although, at most, in exceedingly
minute quantities. Observations on the subject
have now been made for several years, and from
these it appears that the quantity of ozone in
the atmosphere varies with the season and with
the state of the weather. The amount has been
found to be greater at night than during the day,
and greatest just before sunrise. It is greater in
winter than in summer, and at all seasons it is
122
[LECT. IV. 
TESTIMONY OF OXYGEN.
very greatly increased during stormy weather,
especially during a snow-storm. The amount is
unusually large during one of our easterly storms,
and during a thunder-shower the whole surrounding atmosphere frequently becomes pervaded with
its peculiar odor, especially in the neighborhood
of the place where lightning has struck.
Ozone, being so highly corrosive, cannot be present in the atmosphere in such perceptible quantities without producing important effects, 9td some
persons have thought not only to refer to it the
various processes of slow combustion, but also to
trace a connection between the prevalence of various contagious diseases and the excess or deficiency of ozone in the air of the infected district; but these speculations are not as yet based
on sufficient evidence, and are not worthy of serious attention.
Without, however, introducing any theories not
yet fully established into the line of our argument,
this much is clear. Oxygen gas appears in nature
in three conditions, or under three manifestations;
-first, entirely passive, as in the great mass of the
air; secondly, partially active, in the processes of
decay and respiration; thirdly, highly active, in
the phenomena of combustion. In each of these
conditions its properties have been adjusted with
infinite skill and delicacy, on the one hand to the
thermal and electrical conditions of the globe, and
on the other, to the constitution of man and of
all organic nature.
123
LECT. IV.] 
RELIGION AND CHEMISTRY.
Here I must conclude my brief sketch of this
wonderful element. If I have succeeded in im pressing on your minds some of its more char acteristic qualities, if, above all, you have become
aware how exactly and delicately these qualities
have  been adjusted to the scheme of creation,
and if you have seen how the smallest perma nent change would disturb the result, - this is all
that I could hope. It might be expected that the
element with which creative power built up the
greater part of our globe, leaving only a small
excess to constitute its atmosphere, would furnish
abundant evidence of design, and how fully is this
expectation realized! Would that I might present
to you the evidence more forcibly! But it is possible in a popular lecture only to touch at some of
the more striking points, and I have felt all the
time like a school-boy at play, in spring, in some
garden rich in flowers, snatching here and there a
few of the more gaudy tulips, which had fully
bloomed, but leaving the beautiful and delicate
buds all unnoticed. But then these buds of knowledge shall blossom, and when the summer comies,
the rose and the myrtle will fill the air with fragrance, and bear a still sweeter testimony of goodness and of love.
124
[LECT. IV. 
LECTURE V.
TESTIMONY OF WATER.
THE atmosphere, as you will remember, consists
mainly of two permanent and elementary gases;
and having in our last Lecture discussed the functions of its active element, oxygen, it would seem
natural to consider next the offices of nitrogen,
that most singularly inert gas, which constitutes no
less than four fifths of its whole mass; but we shall
understand more clearly the complicated relations
of this truly wonderful substance, associated as it
is with all the higher forms of corporeal vitality,
after we are acquainted with two of the remarkable
cycles in nature, in which the water and carbonic
acid of the atmosphere play a conspicuous part. It
is true that these two substances are very variable
constituents, and make up at best only an exceedingly small fraction of the whole mass of the air;
but nevertheless, they discharge functions no less
important than those of oxygen and nitrogen, and
we shall find that they are equally rich in illustrations of the wisdom and power of God.
I have already alluded to the fact, that the most
striking illustrations of creative wisdom have been
discovered in those substances which are the most
abundantly distributed through nature, and which 
RELIGION AND CHEMISTRY.
are the most intimately associated with man, and
this not only because they have been more careful ly studied, but also because they have the most inm portant fiunctions to fulfil, and have been especially
adapted to their appointed ends. Of no substance
is this principle more remarkably true than it is of
water. As you well know, water is the liquid of the
globe, and, if we except certain transient products
of volcanic action, it is the only liquid which exists
naturally on its surface. Moreover, it is in constant
circulation, and, like the blood in our bodies, is the
medium through which nourishment is conveyed
to all parts of organized nature, and its life sustained.
We should naturally expect that a substance filling
so important a place in the scheme of creation
would furnish undoubted evidences of design, and
it will be my object in the present Lecture to illustrate a few of the more striking examples of adaptation which its qualities present, beginning with
the aeriform condition of water as it exists inll the
atmosphere.
The condition of the atmosphere of aqueous vapor, which surrounds the globe, differs essentially
The aqueous from that of the permanent gases which
circulation. are simultaneously present. Oxygen and
nitrogen cannot be reduced to liquids even by the
intense cold at the poles. It is very different with
aqueous vapor. The slightest reduction of temperature, when the air is saturated with moisture, is
sufficient to condense a portion of the vapor to
water, and to shower it on the earth in drops of
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[LECT. V. 
TESTIMONY OF WATER.
rain. On the other hand, when the temperature
rises, the heat converts more water into vapor, and
the aqueous atmosphere is replenished. Thus it is
that the atmosphere of aqueous vapor on the earth
is liable to very great fluctuations, from which the
Creator has protected the great mass of the air by
endowing oxygen and nitrogen with the power of
retaining the aeriform condition under all circumstances; and we shall find that the fluctuation in
the one case is as important as the stability in
the other.
I stated in the last Lecture that our atmosphere
may be regarded as made up of three partial atmospheres, simultaneously surrounding the globe,
and as was the case with the atmosphere of oxygen,
we shall best understand the fluctuations of the
aqueous atmosphere if we begin by eliminating for
a moment from our thoughts the other two. In
order to make the subject clear, it will be necessary for me to dwell very briefly on a few well established facts in meteorology, which, although not
very interesting in themselves, will unfold to us
some of the beautiful provisions of nature by which
the aqueous circulation on the globe is maintained.
If there were no free oxygen or nitrogen gas, the
earth would still be surrounded with an atmosphere
of aqueous vapor, and we are able to foresee, in
some small measure, what the conditions of such an
atmosphere would be. Its density at the sea level
would depend chiefly on the temperature, and
would therefore vary very rapidly with the latitude,
9
127
LECT. V.] 
RELIGION AND CHEMISTRY.
and would be constantly changing at the same locality with the alternations of the climate. We are
able to determine approximately what the density
would be at any given temperature, and a few of
the results are included in the following table.
Weight at the Sea Level of one Cubic Foot of Vapor.
Temperature.    Weight.      Temperature.    Weight.    Temperature.    Weight.
Fahrenheit.     Grains.      Fahrenheit.    Grains.      Fahrenheit.     Grains.
0~          0.78           40~           3.09           70~           8.00
10~           1.11           50~          4.28            80~         10.81
20~           1.58           60~          5.87           90~          14.50
30~          2.21
It is evident from these numbers, that a very
small change of temperature would cause immense
fluctuation in such an atmosphere. At 0~ one cubic foot of the aqueous atmosphere could contain
only about three fourths of a grain of vapor, while
at 80~ it could contain fifteen times as much, and
hence, although under the tropics the density of our
assumed atmosphere would be comparatively large,
there would be almost a complete vacuum at the
poles. Into this vacuum the vapor would flow from
the equator, and thus in either hemisphere there
would result a perfect torrent of vapor rushing towards the north or south. But it is also evident
that, as this current became chilled in passing
through the cooler climate of the temnperate zone
the vapor would gradually condense to water, which,
falling on the land or on the ocean, would return
in time to the equator, ready to begin again the
same succession of ceaseless changes.
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[LECT. V. 
TESTIMONY OF WATER.
Although the presence of the air materially modifies, it does not essentially change, the aqueous circulation. The air retards the formation of vapor,
but does not prevent it, and at any given temperature the same amount of water will evaporate into
a given space, whether it be a perfect vacuum or
filled with air. Thus, for example, when air at 80~
is saturated with moisture, it contains, as before,
exactly 10.81 grains of vapor, and the table just
given applies equally well to the actual condition
of the globe, covered with its dense atmosphere of
oxygen and nitrogen, as to the case just assumed.
There is, however, a most important difference between the two conditions, -a difference on which
the adaptation of the system of aqueous circulation
in the order of nature entirely rests.
Were there no air on the globe, the quantity
of vapor would adjust itself almost instantaneously
to any variation of temperature, and the maximum amount possible would always be present at
any given place. An elevation of temperature
would be attended by rapid evaporation, and the
amount of water required to fill the space would
suddenly flash into vapor; while, on the other
hand, a corresponding depression of temperature
would be accompanied with an equally sudden precipitation of the excess of water which the air
could no longer contain, not in genial showers or
diffusive rain, but in terrific torrents, of which the
deluging showers of the tropics can give us only a
feeble conception; for the drops, falling without
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resistance, would be as destructive in their effects
as volleys of leaden shot.
In the actual condition of the atmosphere, the
presence of a dense medium very greatly retards
these changes, and although it does not
The rain.
alter their essential nature, it moderates
their action and mitigates the violence of their effects. An elevation of temperature is followed by
an evaporation of water into the air; but the process is comparatively slow, and it is a long time before the air is fully saturated. So also when the air
is saturated, a depression of temperature is followed
by the condensation of a portion of the vapor into
rain; but here again the mass of the atmosphere
tempers the abruptness of the transition, and allays its violence. The vapor condenses first into
vesicles, which are minute hollow bubbles of water,
so light that they float in the atmosphere, and
when these bubbles break, and the drops of rain
fall, they again are wafted down so slowly through
the resisting medium, and alight so softly, that the
"soft falling snow and  the diffusive rain" have
become fit emblems of the beneficence of God, as
they give the strongest evidences of his wisdom
and skill. Moreover, the glorious clouds, which
add so much to the beauty of the landscape, and
typify in their virgin whiteness the purity of
heaven, are only collections of these vesicles of
water floating in the upper atmosphere, and mark
the stage of transition between vapor and rain; and,
further still, it is probable, as I stated in a previous
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[LF.CT. V. 
TESTIMONY OF WATER.
Lecture, that it is these same minute vesicles which
tint the morning and evening sky with their gorgeous hues and cover our earthly dwelling-place
with its canopy of blue.
Again, the presence of the air very greatly retards the aqueous circulation above described, without altering its essential character. There is now
the same great difference between the density of
the atmosphere of vapor at different latitudes, as
if it were the only atmosphere on the globe, and
the dense vapor of the tropics tends constantly to
flow towards either pole; but as it cannot move
without carrying with it the whole mass of the
atmosphere, this tendency merely increases the
velocity of those great aerial currents already described in a previous Lecture. Still the general
fact remains the same. From the whole surface
of the globe water is constantly evaporating into
the aqueous atmosphere which surrounds it. The
heated air from the tropics, heavily charged with
moisture, is continually moving towards the colder
regions, both of the north and of the south; and
as the current thus becomes chilled, the vapor is
slowly condensed, and the water showered down in
fertilizing rains on the land. Thus it is that those
beautiful provisions which we see in the rain all
depend on the presence of the air, and result from
a careful adjustment of the properties of aqueous
vapor to the exact density of our atmosphere.
" Hath the rain a Father?"  Science, by discovering these evidences of skilful adaptation, has most
131
LECT. V.] 
RELIGION AND CHEMISTRY.
conclusively answered this question, and the answer
is the same now as in the days of Job.  "Behold,
"God is great...... He maketh small the drops
"of water: they pour down rain according to the
"vapor thereof."
But what becomes of the rain? Would that I
could answer this question satisfactorily. We all
understand the general theory of the aqueous circulation, but the deepest philosophy and the keenest science are not able to fathom its details, or to
comprehend in their fulness the world of wonderful adaptations which the question unfolds. We
all know that the drops of rain percolate through
the soil, and collect in natural reservoirs formed
between the layers of rock, and that these reservoirs supply the springs. The rills from numerous
adjacent springs unite to form a brook, which increases as it flows, until it finally becomes the majestic river, rolling silently on its course. Every
drop of that water has been an incessant wanderer
since the dawn of creation, and it will soon be
merged again in the vast ocean, only to begin
anew its familiar journey. If you would gain an
idea of the magnitude and extent of this wonderful circulation, you must bring together in imagination all the rivers of the world, the Amazon
and the Orinoco, the Nile and the Ganges, the Mississippi and the St. Lawrence, and, adding to these
the ten thousands of lesser streams, endeavor to
form a conception of the incalculable amount of
water which during twenty-four hours they pour
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TESTIMONY OF WATER.
into the vast basin of the world, and then remember that during the same period at least four times
as much water must have been raised in vapor,
and scattered in rain over the surface of the land.
Would you form an idea of the importance of this
circulation, you must not limit your appreciation
to its economical value, as a great source of power,
working the mills and the forges of civilized man,
and building up vast marts of manufacturing industry, nor must you regard alone its commercial value, bearing as it does on its bosom to the
ocean the freights of empires. These applications
of power, however important in themselves, are
insignificant in extent compared with those mighty
agencies which the aqueous circulation is constantly exerting in nature. It has been the great agent
of geological changes: here washing away continents, and there building them up; here gullying
out valleys, and there smoothing away inequalities
of surface; here dissolving out the particles of
metals from the solid rocks, and there collecting
them together in beds of useful ores. It has cov
ered the earth with verdure and animal life, by conveying nourishment to the plant and food to the
animal. It sustains our own bodies, for it is a portion of this very circulation which ebbs and flows
in our veins, and whose pulsations beat out the
moments of our lives; and could I bring together
in one picture the infinite number of beneficent
ends which it has been made by Providence to subserve, I am sure that you would agree with me
133
LECT. V.] 
RELIGION AND CHEMISTRY.
that there is not in nature stronger evidence of
design than in the adaptations of this simple and
familiar liquid.
In order that we may appreciate in some humble
measure the force of this evidence, let us consider
some of the qualities of water; but at the same
time let us not forget that the strength of our
argument lies not so much in the fact that each
property has been skilfully adjusted to some specific end, as it does in the harmonious working of
all the separate details. Hiad man creative power,
the first would fall within the range of his intelligence; but to adapt the same substance to a thousand different ends, and to adjust each of its properties to a thousand different conditions, covering
with their complex network all the known  uni
verse, implies a power nothing less than infinite,
and an intelligence nothing lower than divine. It
is evident, however, that we can gain a knowledge
of the general plan only by studying the details,
and unfortunately it is to these details that our accurate knowledge is almost entirely confined. We
can see, for example, that each property of water
has been designed for some specific purpose. We
can also recognize the evident fact, that all the
properties work harmoniously together in the general scheme of nature; but, in the present state of
knowledge, to trace the intimate relations of these
properties is frequently as impossible as it is to
form a clear conception of the coexistence and har
monious action of all. Yet in these very facts lies
134
[LECT. V. 
TESTIMONY OF WATER.
the whole force of the argument from design, and
it is only the limitations of our knowledge and
faculties which weaken the impression on our
minds. But were these limitations removed, all
argument would become unnecessary, for then reasoning would be exchanged for vision, and in the
refulgence of the Divine Presence we should know
even as we are known.
It is a familiar fact, that moisture is an essential
condition of organic life; but few persons, I suspect, are aware that this familiar liquid Water a conconstitutes the greater part of all organ- stituentoforized beings.  The physical man has been ganized beings.
described by one writer as consisting of merely a
few pounds of solid matter distributed through six
pailfuls of water, and it is a fact that no less than
four fifths of these bodies of ours are made up of
water. Yet this is a small proportion compared
with the amount which enters into the structure
of most of the lower animals. Some of these, such
as the medusm, - stnfshes, - are little else than
organized water. Professor Agassiz obtained from
one of the large. sunfishes found on our coast,
weighing thirty pounds, only two hundred and
forty grains of solid matter; and we may safely say
that at least nine hundred and ninety-nine parts in
a thousand of these singular animals consist of
water. Water constitutes to almost as great an
extent most of the vegetable products which are
articles of food, as will be seen by the accompanying table.
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LECT. V.] 
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cent of water.
Potatoes  "    75   "      " cc"c
Apples        "   80    "
Carrots      "   83    "
Turnips      "   90    "
Watermelons  "   94    "
Cucumbers    "   97    "
It is evident from these facts, that water is the
chief material of which all organized structures
are formed, and in studying the aqueous circula tion we have already become acquainted with the
beautiful provisions of nature by which this life giving liquid is distributed over the earth, and
showered down upon the meadow and forest alike.
Without water organic life cannot exist, and where
from any local causes the supply fails, there we find
a barren wilderness; while, on the other hand, the
genial influences of the rain will soon make even
"the desert blossom as the rose."  It is a remarkable
fact of physical geography, that the distribution
of water by the aqueous circulation is rendered
more effective by the peculiar structure of the
continents, and the position of the great mountain-chains.
"The mountain-chains," writes Professor Guyot,
in his excellent work on "Earth and Man," "are
great condensers placed here and there along the
continents to rob the winds of their treasures, and
to serve as reservoirs for the rain-waters, and to
distribute them afterwards as they are needed over
136
[LiccT. V.
C6
t;
cc
cc
cc
cc
cc 6c 
TESTIMONY OF WATER.
the surrounding plains. Their wet and cloudy
summits are untiringly occupied with this important work, and from their sides flow numberless
torrents and rivers, carrying in all directions wealth
and life."
Thus the mountains, whose majestic forms affect
so powerfully the human soul, and which have exerted such an influence on the history of the race,
are also among the most beneficent means in the
Divine Providence by which the earth has been
fertilized and rendered a fit abode for man. Moreover, these mountain-chains have been evidently
so distributed as to give the greatest efficiency to
the aqueous circulation, and to irrigate the continents most effectively with their fertilizing floods.
We cannot therefore suppose that even these
ridges on the earth's surface, which are the lasting
records of ancient geological changes, were fixed
by chance, for they also bear traces of His intelligence who'seethl the end from the beginning, fand
every part of whose works is adapted to every
other.  "Lord, thou hast been our dwelling-place
"in all generations. Before the mountains were
"brought forth, or ever thou hadst formed the earth
"and the world, even from everlasting to everlasting,
"thou art God."
But it is not the mountains alone which condense
the vapor of the atmosphere; for under certain
conditions the level plains act in a similar 
way, and distil down the precious drops of
dew upon field and meadow, distributing it among
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LECT. V.] 
RELIGION AND CHEMISTRY.
the plants with discriminating care for the necessi  ties of each. The dew is simply another phase of
the great aqueous circulation, and like the rain it is
a persuasive witness of the wisdomn of the Divine
Disposer, who has adjusted its amount to the wants
of the vegetable world. Every one has noticed
the deposition of moisture on a pitcher of ice-cold
water during a summer's day, and in this familiar
fact we hlave at once an example and an illustra tion of the simple provision by which, during even
the long droughts of summer, the plants receive
a partial supply of water, sufficient at least to sus tain their life until the later rains bring the autumn
fruits to maturity, and stimulate a more vigorous
growth.
The explanation of the dew upon the pitcher is
very simple. The layer of air in contact with its
cold mass is rapidly cooled, and when it can no
longer hold all the moisture it contains, the excess
is deposited in drops on the surface. Exchange
now the pitcher for the earth, and you have at once
an explanation of the proximate cause of the dew.
After sunset the earth, like the pitcher, cools down
the layer of atmosphere immediately in contact with
it to such a degree that the whole of the vapor can
no longer retain its aeriform condition. As a necessary result, a portion is condensed and deposited upon the surface, and this is what we call dew. But it
will be asked, What cools the earth so suddenly after
-the setting of the sun? for this is not so evident as
the cause of the coldness of the pitcher. Certainly
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[LECT. V. 
TESTIMONY OF WATER.
not, and the question will lead us to a study of those
relations in which the adaptations to be discovered
in this natural phenomenon are chiefly to be found.
The earth, as I stated in the second Lecture, is
moving with immense rapidity through a space,
whose temperature is at least 270 degrees below the
zero of Fahrenheit's thermometer, and, like a heated
cannon-ball hung in the middle of a cold room, it is
continually losing heat by radiation. The dense
atmosphere with which it is enveloped, acting, as we
have seen, like a blanket, protects the earth from
the intense cold of space to a certain extent; but
still the constant loss of heat is so great, that, were
the sun's rays withheld for a few days, the temperature of the surface-land, even in the tropics,
would fall as low as it is now at the poles during
the long night of the arctic winter. In the daytime the earth receives from the sun more heat
than it loses; but when this great thermal source
is temporarily withdrawn, the loss of heat continuing as rapidly as before, the surface becomes quickly
cooled, and the deposition of dew follows, as just
explained; or, if the temperature falls below the
freezing point, the dew is changed to frost.
You must all have noticed that the most copious
deposition both of dew and frost takes place on clear
nights, and that during cloudy weather this supply
of moisture is entirely withheld. The reason is
obvious. The earth loses heat by radiation, and
the clouds, intericepting the rays, reflect them back
to the earth. A shed or any other protection
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LECT. V.] 
RELIGION AND CHEMISTRY.
spread over the ground acts in the same way, and
it is well known that a covering, however slight, is
sufficient to protect tender plants from the blight
of the early frosts. Can it then be an accident, a
mere result of chance, that the dew is deposited
most abundantly where it is needed most, and that
this supply of moisture fails only when the clouds
promise a more copious draught of liquid nourishment from the rain?
There is still another fact presented by the dew,.
which is equally suggestive. The heavens do not
distil down their.liquid treasures upon all objects
alike, but the dew is deposited much more abundantly on the herbage, the shrubs, and the trees,
which need the refreshing moisture, than on fallow
land, the sandy plain, or the beaten road; and here
again the cause has been discovered. It is evident
from the general theory of the subject, that the largest amount of dew will fall on the coldest surface,
and it is equally obvious that, other things being
equal, those objects will cool most rapidly which
have the smallest supply of heat to lose, and which
radiate it with the greatest freedom. Now it has
been ascertained by experiment, that the facility of
radiating heat depends entirely on the nature of
the surface, and the surfaces of leaves have such a
remarkable power in this respect, that it would seem
as if they were specially designed for the purpose.
If next you consider how small a quantity of matter the leaves contain compared with their large radiating surfaces, you will see that there are all the
140
[LECT. V. 
TESTIMONY OF WATER.
conditions present of rapid cooling. When, therefore, under a clear evening sky, the rays of heat
are escaping from all objects into the celestial space,
the green foliage soon becomes colder than the barren rocks or the inanimate clod, and receives in consequence a greater supply of dew.
It will be remembered, as I stated in the second
Lecture of this course, that the points of leaves have
the power of silently discharging the thunderbolts
of heaven, and that in consequence every tree acts
far more efficiently to avert the stroke of this
destructive agent than the best constructed lightning-rod. Is not now the force of this evidence
of adaptation very greatly enhanced, when we find
that the surfaces of these same leaves have been
endowed with an equally remarkable power of radiating heat, by which they are insured a daily
supply of moisture when they need it most?
Could the adaptation of the structure of the leaf to
these two entirely distinct physical conditions of
the atmosphere be the result of anything but intelligence? Admitting that we can possibly conceive, - as Mr. Darwin and the modern advocates
of the development theory would have us believe,
- that under.the pressure of circumstances a plant
may have the power of changing its structure so as
to adapt it to the external conditions, still I think
no one will be so bold as to maintain that there
can be any brute agency in vegetation endowed
with such foresight as to have adapted the material
and structure of each leaf from the very first to
141
LECT. V.]
t 
RELIGION AND CHEMISTRY.
the physical conditions of the globe, and this, moreover, for the purpose of effecting ends so remotely
connected with its own organization as the discharge of electricity or the radiation of heat. If
this can result from chance, under its modern name
of natural selection, then chance is but a counterfeit name of God. Gideon believed that God would
save Israel, because the dew fell on the fleece but
not on the ground, and afterwards on the ground
but not on the fleece, and shall we doubt the reality
of the Divine Providence, before whom a similar
miracle is repeated every evening, with such beneficent results? If it be the mark of intelligence to
be able to fathom and comprehend this wonder of
Nature, can it be anything below Infinite Intelligence "who hath begotten the drops of dew"?
I might with advantage enter more into detail in
regard to the laws of the distribution both of the
rain and of the dew, but time and space forbid. I
have been able only to open the subject; yet if I
have succeeded in impressing you with the extent
of the field which these beautiful phenomena present to your inquiry, it is all that I could expect.
We have seen that it is through these familiar channels that liquid nourishment is conveyed to the organic world, and the reservoirs supplied which feed
the great river-system of the globe. But we should
form a very imperfect idea of the resources of nature were we to limit our regards of the aqueous
circulation to this important use. The life-blood of
our bodies, which conveys to each muscle the nour
142
[LECT. V. 
TESTIMONY OF WATER.
ishment it requires, when it returns again through
the veins, this errand well done, is no less usefully
employed in carrying away the portions Water the
of the tissues which have been worn out in great purifier.
the processes of life; and where from any cause this
last function is not faithfully discharged, and the
wasted muscles are allowed to remain in the system, disease and death are the inevitable results.
So also is it with the life-liquid of nature, which in
the rain and the dew carries food to the whole organic world. When this office has been fulfilled, it
returns again to the ocean, washing away those
waste products of organic life, which, if they remained, would cause pestilence and general decay.
It is true that we cannot trace all the details of
this cleansing process; but you need not the aid of
science to assure you of the general facts. Let the
free flowing of the rain-water be interrupted, and
you well know that stagnant pools, breeding pestilence, or deadly swamps, exhaling malaria, are the
immediate results. I cannot overstate the importance of this function of the aqueous circulation, or
too strongly insist on the evidence of wisdom which
the adaptation of the properties of water to this
beneficent end implies. It is the great cleansing
agent of the world. Wherever it flows, there it purifies, and its limpid streams, clear as crystal, are fit
emblems of the purity of heaven. Hence the significance of this liquid in all religious systems. The
ancient Egyptians worshipped the water of the Nile,
and the Hindoo idolaters of the present day rever              10
143
LECT. V.]
I 
RELIGION AND CHEMISTRY.
ence with equal devotion the water of the Ganges.
Passing to Judaism, we find the washing with water
enjoined as a sacred duty by the Hebrew law; and
lastly, in the Christian dispensation the pure liquid
has become the medium of its most sacred rite, and
the outward washing of baptism typifies that inward "washing of regeneration," by which alone
man is saved.
Glancing now for a single moment at the msthetic aspects of the subject, consider what sources of
pleasure the varied phases of the aqueous circu]ation furnish, and what an influence on the soul of
man they are calculated to exert. The bubbling
spring, the purling rill, the murmuring brook, the
sparkling cascade, the roaring torrent, the majestically flowing river, are familiar images of poetry,
and the occasions of mental emotions which all have
experienced and none can fully describe, while the
mighty cataract and the ocean-storm are among
the sublimest aspects of nature, and inspire the beholder with reverence and awe. When, now, you
reflect that the chords of the human soul have been
so strung as to vibrate in sympathy with these emotions of the material creation, and that thus the
aqueous circulation has been made a means of instructing and elevating the human race, can you refuse to accept the evidence of wisdom and goodness
which a system so far-seeing in its design, and so
beneficent in its results, affords?
The mechanism of nature differs, as we have
seen, from the creations of human ingenuity, in the
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[LECT. V. 
TESTIMONY OF WATER.
fertility of its resources. Man combines numerous
means in order to produce a single end; but in
nature the most varied and apparently incompatible results flow from a single design. In God's
works the means are employed, not as we use them
in the poverty of our resources, but from the exuberance of riches. To use the language of another,
"All the means are ends, and all the ends are
means"; ald the grand result is an harmonious system, in which every part is a whole, and where the
whole that is known is felt to be only a very insignificant part. Such is the character of the aqueous
circulation, which we are now studying, and assuredly the numerous results we have already seen
flowing from this simple mechanism are sufficient
to mark the system as Divine; but we have not as
yet exhausted its resources. Indeed, we have been
all the time looking at only one side of the design,
and there is a whole set of adaptations yet unnoticed, which are no less important in the scheme'of
organic nature than those we have so briefly considered; and when we have become acquainted with
these, we shall find still other phases of this boundless plan presented to our view, and not until man
ceases to learn by study, or the waters cease to roll,
will the subject be exhausted.
We have thus far only considered the agency of
the aqueous circulation in distributing over the
earth the chief constituent of all organic Agency of
matter, together with some of the second- water in
ary enwhich the rver-system ofthdistributing
ary ends which the river-system of the heat.
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LECT. V.] 
RELIGION AND CHEMISTRY.
globe subserves. But there is another condition of
organic life no less essential than moisture. The
animal kingdom is absolutely dependent on the vegetable, and plants cannot grow except within a limited range of temperature. Therefore, unless during at least a portion of the year the amount of heat
supplied is sufficient to maintain the temperature
of the climate within the required limits, organic
life cannot exist in that region. Now t4his familiar
substance, water, has been endowed with most remarkable and unusual properties, by which the
aqueous circulation has been made a great means
of distributing heat, and thus of sustaining organic
life in vast tracts of country where otherwise it
could not exist; and it is to this class of its adaptations that I wish next to call your attention.
One of the prominent inventions of modern times
is the method of heating large buildings by steam.
Latentheat You must all have seen the apparatus.
of steam. There is first the boiler, where the steam
is generated by the combustion of fuel; then pipes,
by which it is distributed to the different rooms;
next the iron radiators, in which the steam is condensed to water, and during this change gives out
heat, which is radiated from the corrugated surface
of the iron; and, lastly, the return pipes, through
which the condensed water flows back to the boiler,
ready to start again on the same journey. Every
one is familiar with these external aspects of the
apparatus; but all may not know that the efficiency
of the method depends entirely upon a remarkable
146
[LECT. V. 
TESTIMONY OF WATER.
quality of water, a quality which is not possessed to
the same degree by any other known liquid. Were
you to test with a thermometer the temperature of
the water in the boiler and that of the steam rising
from it, you would be surprised to find,-if you were
not forewarned of the fact,-that they were both at
precisely the same point; and yet in order to change
one pound of boiling water into one pound of steam
it is necessary to burn up sufficient coal to raise the
temperature of ten pounds of ice-cold water to the
boiling point. The coal which is burning under the
boiler does not raise the temperature of the water.
Press the fire ever so hard, you cannot increase the
temperature either of the water or of the steam by a
single degree. The effect of increasing the fire will
be only to generate steam more rapidly, for the
whole of the immense amount of heat set free by
the burning fuel is absorbed by the boiling water in
changing into steam.  But this heat is not lost.  It
remains latent in the steam, is carried by it into the
different rooms, and there, when the steam changes
back again into water, it is all given up, without
the slightest diminution, diffusing its genial warmth
through the house. The steam, therefore, is merely
the vehicle by which heat is carried over the building. The heat comes from the burning fuel in the
cellar, and originally it came from the sun; for the
coals burning under the boiler are merely fagots,
as it were, of condensed sunbeams, gathered by the
plants of some ancient geological epoch, subsequently fossilized and preserved in the earth for our use
147
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RELIGION AND CHEMISTRY.
The steam merely acts the part of a common carrier; but what I wish you to notice is the fact that
steam is peculiarly fitted for the work, because it
has been made capable of holding so large a quantity of heat.
Your attention perhaps has been called to the efficiency and economy of this method of heating,
you have admired its neatness and absolute safety
from fire, and have been delighted with the softness
of the temperature which it diffuses through the
rooms. Or, if you have examined more closely the
details of the apparatus, you must have been struck
with the ingenuity of the adjustments by which it
is self-regulated. Yet this is no new invention. A
similar apparatus, on a vastly grander scale, working
with far greater economy and efficiency, and provided with adjustments of wonderful delicacy, which
perfectly regulate its action, and which never fail
and never wear out, has been at work ever since
the dawn of the creation, and is at this moment softening the inclemency of our Northern winter.
The general aqueous circulation is a great steamheating apparatus, with its boiler in the tropics and
its condensers all over the globe. The sun's rays
make the steam, and wherever dew, rain, or snow
falls, there the heat, which came originally from the
sun, and which has been brought from the tropics
concealed in the folds of the vapor, is set free to
warm the less favored regions of the earth. This
apparatus of nature, although so much simpler, and
working without pipes, iron boiler, or radiators, is
148
[LECT. V.
0 
TESTIMONY OF WATER.
exactly the same in principle as the steam-heater,
which may be seen at work in almost every large
factory. It is true that the atmospheric vapor is a
much better vehicle of heat than ordinary steam, and
it is also true that this thermal application is but
one of the hundred uses of the aqueous circulation;
but still the general method is the same, and both
systems owe their efficiency to the unique property with which water has been endowed. It is true
that other liquids in changing into vapor absorb
heat, but the heat stored up in these vapors is vastly less than that in steam, and it must be noticed
that, of all created forms of matter, this familiar
liquid, which fills the ocean, which distils upon us
in the rain, and which flows in the rivers, is the only
substance which has been thus especially endowed.
Is this an accidental concurrence of circumstances?
or is it, on the contrary, the work of Infinite Wisdom? We regard, and with reason, the beautiful
invention of man, by which our dwellings are
warmed, as an evidence of intelligence; and can we
refuse to recognize the existence of that higher Intelligence, which not only adjusted the more perfect
system of nature, but also created the properties
of water, on which the efficiency of both depends?
Having considered that peculiar quality of va por through which the aqueous circulation becomes
an important means of distributing the sun's heat
over the surface of the globe, we might next discuss
more at length the extent of its influence, and ex amine in detail the ingenious system of checks and
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RELIGION AND CHEMISTRY.
balances by which the action of this great heating
apparatus is regulated, and its constant working se cured; but here, as before, having glanced at the
main points, I must leave it to your study to fill the
unavoidable blanks, and pass on to consider another
special property of water by which a similar result
is secured.
The amount of heat required to raise the tem perature of a pound of water, or of any other
Capacity of substance, one degree, is capable of exact
water for heat. measurement, and the quantity has been
determined experimentally for almost every known
substance. These experiments have led to a remarkable result, to which I alluded in a former
Lecture. It appears that, when water is heated
through a given number of degrees, it absorbs
more than twice as much heat as any other substance except hydrogen gas,-  which is one of its
constituent elements,- and more than ten times
as much as iron and most of the metals.  It is not
probable that many of my audience have verified
this striking result, but you all know how long it
takes to boil a tea-kettle, even over a brisk fire, and
have, therefore, some conception of the amount
of heat which cold water is capable of absorbing.
This familiar experience shows that water has a
very great capacity of holding heat, and accurate
experiment has proved, as just stated, that at the
same temperature water contains more than twice
as much heat as any other solid or liquid known.
The importance of this simple provision will ap
150
[LECT. V. 
TESTIMONY OF WATER.
pear, if you reflect that it makes the ponds, the
lakes, and the oceans great reservoirs of heat. It
not only requires a vast amount of heat to warm
one of these large bodies of water, but when once
warmed they cool very slowly. Hence the marked
difference between the oceanic and the continental
climate in the same latitude. During the summer
the ocean eagerly absorbs the heat of the sun's rays,
which are showered upon it in such profusion; but
water has so great a capacity for heat, that the
ocean, nevertheless, does not grow very warm,
and, moreover, a large amount of the heat it receives is carried away by the vapor which is constantly rising from its surface. In winter, on the
other hand, the water gives up its heat to warm
the colder air; but it contains such an inexhaustible supply, that the loss does. not materially lower
its temperature. There results in consequence a
great uniformity of temperature, in which the air,
by its perpetual contact with the surface of the
water, necessarily shares, and this uniformity extends, in a greater or less degree, to the climate
of all islands and sea-board districts. It is quite
different with the surface of continents.   There
the soil becomes rapidly heated under the vertical
rays of a summer's sun, and, as its particles are
immovable, the surface-layer soon rises to a high
temperature, while, on the other hand, in winter it
is cooled by radiation with equal rapidity; and this
is the cause of those extremes of heat and cold
which characterize all countries of the temperate
LECT. V.]
151 
RELIGION AND CHEMISTRY.
zone removed from the influence of the ocean.
The oceanic climate is moderate, while the conti nental climate is excessive. During the day, under
the same circumstances, the land is warmer than
the sea, and colder during the night, or, taking the
different seasons, the land is warmer than the sea in
summer and colder in winter. These general principles have been verified by the extensive series of
meteorological observations which, during the last
twenty-five years, have been made all over the civilized world. You will find an excellent abstract
of the results in Professor Guyot's work on "Earth
and Man," before referred to. I have time only to
cite a few familiar facts in illustration of my subject, which I will give nearly in his words.
"On the coast of Cornwall shrubs as delicate as
the laurel or the camellia are green through the
whole year, while under the same latitude in the
interior of the continents, the most hardy trees can
alone brave the rigor of the winter. But on the
other hand, the mild climate of England cannot
ripen the grape, although almost under the same
parallel grow the delicious wines of the Rhine. At
Astrachan, on the northern shore of the Caspian, as
Humboldt tells us, the grapes and fruits of every
kind are as beautiful and luscious as in the Canaries and in Italy; the wines have all the fire of
those of the South of Europe, although in the same
latitude, at the mouth of the Loire, on the Atlantic
sea-coast, the vines hardly flourish at all. But while
in the South of France the winter is a perpetual
152
[LECT. V. 
TESTIMONY OF WATER.
spring, the summers of the Caspian are succeeded
by a winter of almost polar severity."
I might multiply illustrations, but these are sufficient to show how the remarkable property of
water which we are considering tends to equalize
the climate of the globe.
This influence of water is very greatly increased
by the oceanic currents, which, like the winds, are
set in motion by the heat of the sun, and Oceanic
are constantly carrying the warm waters  currents.
of the tropics toward the poles. One of the most
remarkable of these currents is the Gulf-Stream,
which flows near our coast, and which diffuses the
warm waters of the Caribbean Sea and the Gulf
of Mexico over the Northern Atlantic, deposit,
ing on the shores of Scotland and Norway the
plants and seeds of the tropics. It is solely the
heat which these waters bring with them from the
equator that has made the island of Great Britain
so great a centre of commerce and civilization; for
it must be remembered that the latitude of England is the same as that of Labrador, and, were it
not for the influence of this ocean current, her soil
would be equally desolate and barren. If the configuration of our Western Continent were only so
slightly changed as to give a passage to the great
equatorial current through the present Isthmus of
Panama, a change insignificant in comparison with
those which have heretofore taken place, " the
mountains of Wales and Scotland would become
again the abode of glaciers, and civilization would
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RELIGION AND CHEMISTRY.
disappear before the invasion of arctic cold." * So
also it is to the enormous mass of heated water
which the Gulf-Stream pours into the seas surrounding Northern Europe that Sweden and Norway owe their temperate climate, while at the corresponding latitudes on our own continent the land
is shrouded in eternal ice and snow.
But, my friends, all these provisions for distributing heat over the earth's surface would have
Pointofmaxi- been insufficient to maintain organic life
mum density. in our Northern climate, were it not for
still another remarkable property with which water
has been endowed, -a property even more entirely
unique than either of those we have studied, and
one which seems to be an exception to the general
laws of nature. The familiar cycles of organic life,
both in animals and plants, are intimately associated with the succession of the seasons, and this in
its turn depends on the inclination of the earth's
axis to the plane of the ecliptic, and on the great
primary laws by which this axis is constantly maintained in a position parallel to itself during the
revolution of the planet around the sun. To these
fundamental conditions in the formation of the solar
system the whole constitution of organic life on the
earth has been adjusted; and Professor Whewell,
in his excellent Bridgewater Treatise, has discussed
at length the evidences of design which this circumstance affords. It would be foreign, however,
* W. Hopkins's Address before the Geological Society of Great
Britain.
154
[LECT. V. 
TESTIMONY OF WATER.
to my plan, to consider these evidences here; but,
assuming the succession of the seasons as a part of
the order of creation, and as a means of adapting a
larger portion of the earth's surface for the habitation of organized beings, it is evident that the
higher forms of organic life could be sustained in
these Northern regions only by furnishing to the
plants and animals an adequate protection against
the intense cold of winter, and thus preserving
the growth of one summer until the returning
sun awakens new life in the succeeding spring.
The required protection has been provided by
making a most marked exception to the general
laws of expansion in the case of water. It is the
general law of nature, that all substances are expanded by heat and contracted by cold, and water
forms no exception to the general rule, except
within certain very narrow limits of temperature,
shortly to be noticed.  Indeed, were it not for
the expansion, we could not readily either heat or
cool a large mass of liquid matter. All liquids are
very poor conductors of heat, and can be heated
only by bringing their particles successively in contact with the source of heat. When you set a
tea-kettle over a fire, the first effect of the heat
is to expand the particles of water resting on the
bottom of the kettle, which, being thus rendered
specifically lighter, rise, and are succeeded by colder
particles, which are heated and rise in their turn;
and thus a circulation is established by which all
the particles are successively brought in contact
155
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RELIGION AND' CHEMISTRY.
with the heated bottom of the kettle, and in the
course of time the temperature of the whole mass
is raised to the boiling point. The case is similar
when you add ice to a pitcher of water in order to
cool it.  Thie water at the top of the pitcher, in
contact with the ice, is of course cooled, and, being
thus rendered specifically heavier than the water
below, sinks and gives place to the warmer water,
which is cooled and sinks in its turn, and thus as
before a circulation is established, which continues
until the temperature of the whole water is reduced to 40~. But at this point the circulation is
entirely arrested; for, in consequence of its singular constitution, water at 39~ is lighter than water
at 40~, and consequently remains at the' top. And
so it is as the temperature sinks toward the freezing point. The colder the water, the lighter it
becomes, and the more persistently it remains at
the surface. Hence, although the upper layers of
water may be readily cooled to the freezing point,
yet, in consequence of its poor conducting power,
the great body of the liquid below will remain at
the temperature of 40~.
The cold atmosphere of winter acts upon the
ponds and lakes exactly as the ice on the water in
the pitcher. They also are cooled from the surface, and a circulation is established by the constant sinking of the chilled water until the temperature falls to 400. But at this point, still eight
degrees above the freezing point, the circulation
stops. The surface-water, as it cools below this
156
[LECT. V. 
TESTIMONY OF WATER.
temperature, remains at the top, and in the end
freezes; but then comes into play still another provision in the properties of water. Most substances
are heavier in their solid than in their liquid state,
but ice, on the contrary, is lighter than Icelighter
water, and therefore floats on its surface. than water.
Moreover, as ice is a very poor conductor of heat,
it serves as a protection to the lake, so that at the
depth of a few feet, at most, the temperature of the
water during winter is never under 400, although
the atmosphere may continue for weeks below zero.
If water resembled other liquids, and continued
to contract with cold to its freezing point, - if this
exception had not been made, the whole order of
nature would have been reversed. The circulation
just described would continue until the whole mass
of water in the lake had fallen to the freezing point.
The ice would then first form at the bottom, and
the congelation would continue until the whole
lake had been changed into one mass of solid ice.
Upon such a mass the hottest summer would produce but little effect; for the poor conducting
power would then prevent its melting, and instead
of ponds and lakes we should have large masses of
ice, which during the summer would melt on the
surface to the depth of only a few feet. It is unnecessary to state that this condition of things
would be utterly inconsistent with the existence of
aquatic plants or animals, and it would be almost
as fatal to organic life everywhere; for not only
are all parts of the creation so indissolubly bound
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LECT. V.] 
RELIGION AND CHEMISTRY.
together that, if one member suffers, all the other
members suffer with it, but moreover the soil itself
would, to a certain extent, share in the fate of the
ponds. The soil is always more or less saturated
with water, and, under existing conditions in our
temperate zone, the frost does not penetrate to
a sufficient depth to kill the roots and seeds of
plants which are buried under it. But were water
constituted like other liquids, the soil would remain
frozen to the depth of many feet, and the only effect of the summer's heat would be to melt a few
inches at the surface. It would be, perhaps, possible to cultivate some hardy annuals in such a climate, but this would be all. Trees and shrubs
could not brave the severity of the winter. Thus,
then, it appears that the very existence of life in
these temperate regions of the earth depends on an
apparent exception to a general law of nature, so
slight and limited in its extent that it can only
be detected by the most refined scientific observation.
Moreover, this exceptional property is united in
water with another quality, which greatly aids in
Snow a poor preserving vegetable life during the winconductor   ter months.  We shudder at the thought
of heat.
of heat of snow, but nevertheless it affords a most
effectual protection to the soil, forming as warm a
covering as would the softest wool. Water in all
its conditions has been made a very bad conductor of heat, and snow is ranked with wool among
the poorest of conductors. Heat, therefore, cannot
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[LECT. V. 
TESTIMONY OF WATER.
readily escape from a snow-covered soil, and thus
its temperature is prevented from falling materially
below the freezing point, however great the severity
of the season. Notice now how, when winter sets
in and the cold increases to such a degree as to endanger the tender plants, Nature promptly spreads
her great frost-blanket over forest, prairie, meadow,
and garden alike, so that all may slumber on in
safety until the sun returns and melts away the
downy covering, when the buds break forth again
and the trees put on a new mantle of living green.
This leads me to speak of still another remarkable property of the wonderful liquid we are studying; for nature has provided in the consti                                          Heat of fusion.
tution of water a most effectual means of
tempering the transition of the seasons, and protecting vegetation against the early frosts of autumn
or the first deceptive glow of returning spring. In
order to freeze a liquid it is necessary to remove
from it a certain quantity of heat called the heat of
fusion, and the more of this heat a liquid contains,
with the more difficulty of course it freezes, and
when once frozen the less readily the solid melts.
Now water contains a larger amount of heat of fusion than any other liquid yet examined, and in
this respect, therefore, it is also peculiarly constituted. And mark how this property tends to pros
duce the result just noticed. As the weather becomes cooler in autumn, our ponds and lakes gradually give up the stores of heat which they contain,
until the temperature of the whole mass of water is
11
159
LECT. V.] 
RELIGION AND CHEMISTRY.
reduced to 40~; then the surface-water cools still
further to the freezing point; but before it can become any colder than this the water must freeze,
and in freezing it will set free four times as much
heat as it has already given out in cooling from the
temperature of summer (63~) to the freezing point.
It is evident, therefore, that freezing must be a slow
process.  Moreover, it is also a warming process,
and although the temperature of surrounding objects can never be thus raised above, the freezing
point, nevertheless, the immense amount of heat
evolved greatly tends to retard the approach of severe cold, and prepares the way for the inclemency
of winter. So also, when Spring comes, vegetation
is not awakened by her first blushes to be exposed
to the blights of the early frosts, and before the
snow covering can be melted off the danger is
mostly passed. Again, when we consider what devastating floods would sweep the earth were the icy
bonds of winter suddenly dissolved, we shall discover still further evidence of the wisdom of that
Being who has so adjusted the properties of water
that both frost and freshet are the exception, not
the rule.
I have said that water presents the only wellestablished exception to the laws of expansion by
heat, and some writers on natural theology have
dwelt on this point as one of great importance to
their argument.   But I cannot think they are
wise; for, to say the least, they rest their argument
on our ignorance and not on our knowledge. It is
160
[LECT. V. 
TESTIMONY OF WATER.
true that in the present state of science the anomalous expansion of water near the freezing point
seems to be an exception to the general laws of
nature; but hereafter this very anomaly may appear to be the natural result of a more general
law not yet discovered, or, like the perturbations
in the orbits of the planets, may prove to be
the strongest confirmation of the very law it now
seems to invalidate. Moreover, I do not share in
that indefinite dread of natural laws which troubles
so many religious minds. To me the laws of nature
afford the strongest evidences of the existence of a
God, and in their uniformity I see merely the constant action of an omnipresent Creator, who acts
with perfect regularity because he acts consistently
and with infinite wisdom. I believe that all parts
of nature are correlated by laws, and that the wider
our knowledge becomes, the more universal these
laws will appear.  I do not, therefore, regard the
constitution of water as something apart from law,
and as the evidence of a power coming down as it
were upon law to make an exception to it. This is
making altogether too much of law. God is not
bound by law. He acts wisely, beneficently, and
with a definite plan, and the most we can claim for
natural laws is, that they are our imperfect human
expressions of this Divine plan. Moreover, that is
a far nobler view of God's wisdom which supposes
him to be able to harmonize special adaptations
with general laws. What I find so'remarkable in
the constitution of water is, not that it is an excep
161
LFer. V.]
A# 
RELIGION AND CHEiMISTRY.
tion to the general laws of nature, but that, while
filling its place in the general plan, it has been endowed with such extreme properties, and that in
each case the peculiar property has special adaptations at once so complex and so important. Not
only has water this exceptional property of expanding when other liquids contract, but moreover, of
all known substances, it has the greatest capacity
for heat; so also, when changing into vapor, it absorbs more heat than any other liquid; again, it
is far lighter in the solid than in the liquid state;
and lastly, it contains the largest amount of heat
of fusion as yet observed in any substance. All
this may be in harmony with general laws. I have
no doubt that it is; but the existence of the law
does not in the least impair the significance of
the fact, that in each of these respects water has
been peculiarly constituted. This one liquid of
the globe, which covers more than three fourths
of its surface, which circulates through all its channels, which percolates through all its pores, which
constitutes three fourths of all organized beings,
has been endowed with these four pre-eminent
qualities, on each of which the whole order of
terrestrial nature may be said to depend. I cannot conceive of stronger evidence of design than
this; and if these facts do not prove the existence
of an intelligent Creator, then all nature is a deception and our own faculties a lie. Yet, my
friends, this is only a small part of the evidence
of design which science has discovered in this fa
162
[LECT. V. 
TESTIMONY OF WATER.
miliar liquid. I might occupy several Lectures
with this subject alone, but I have time only to
glance at two more striking facts.
Water is the most universal solvent known, and
there are but few substances which are not to a
greater or less degree dissolved by it. Solvent power
Those which we call insoluble generally of water.
differ from the rest only in degree. Thus, all lime
rocks dissolve to a limited extent in spring water,
and the same is also true of almost all mineral substances. The magnificent crystals which we frequently find in the rocks are formed in almost every case by a deposition of the mineral substance
from a state of solution in water. The feeble solvent power of the water for these substances is
made up by the large volume of the solution, and
the length of time occupied in the process of crystallization. Many of the large crystals which may be
seen in cabinets of minerals have been unquestionably thousands of years in formation. And not only
does the solvent power of water stud the cavities
of the rocks with gems, but it is also constantly
producing most important changes in the rocky
structures of the globe itself, here cementing together the loose sands, and there converting the
soft clays into firm and solid rock.
Again, the solvent power of water extends to
aeriform as well as to solid substances, so that the
gases composing the air pervade the lakes and the
oceans as well as the atmosphere. Indeed, it is on
the gases dissolved in the water that all the aquatic
163
LECT. V.] 
RELIGION AND CHEMISTRY.
plants and animals live, and the members of the
various finny tribes breathe the free oxygen dissolved in the water, as we breathe the oxygen of
the air. Again, the process of respiration is essentially the same with these lower animals that it
is with us, and the structure of their organs has
been adjusted to the amount of this life-sustaining
element, which water is capable of dissolving.
Moreover, the power which water possesses of dissolving oxygen is much greater than its power of
dissolving nitrogen, and hence the air dissolved in
the ocean is proportionally much richer in oxygen
than our atmosphere. This is undoubtedly another quality with which water has been endowed in
order to render the oceans, the lakes, and the
rivers a fit habitation for that world of organic
life which modern zoology has revealed. That we
are unable to trace all its relations, is evidently
owing to the imperfectilon of our knowledge. But
here a new field of study opens before us, which,
when fully explored, will undoubtedly prove as rich
in the evidence of design as the atmosphere itself.
It is not, however, merely as a solvent, that
water is an important agent in the great laboraWater asa tory of the world. I have already stated
chemical agent. to what an extent all animal and vegetable substances are composed of water, and that
some, such as the jelly-fishes among animals, and
the gourd family among plants, may be said to be
living forms of water. But we should entertain a
very erroneous conception of the condition of the
164
[LECT. V.
I 
TESTIMONY OF WATER.
water in these animal and vegetable structures,
were we to regard it as so much dead material,
building up the form like the bricks in an edifice.
This water is in constant circulation, conveying
nourishment to all the parts, and at the same
time removing from the system those tissues which
have fulfilled their functions and become effete.
It is being constantly decomposed, and as rapidly again reformed, assuming the most protean
conditions, and administering to the functions of
the animal economy in a thousand ways.
As a constituent of inorganic matter, water is no
less important than it is in organized being. A substance so bland as water, and apparently so entirely
inactive, which fills the most delicate vegetable
cells, and penetrates the finest capillaries of the
body, -whose minuteness and delicacy no art can
approach, nor imagination scarcely conceive,-yet
without affecting either in the slightest degree, we
should suppose would be endowed with no affinities, and capable of exerting no chemical force.
Yet what is the fact? In attempting to classify
chemical compounds, I have studied with care the
chemical history of water, and its relations to other
substances, and it is still to me a perfect enigma in
nature. For, so far from being that inert material
which its bland exterior would seem to indicate, it
is among the most important of chemical agents,
forming some of the most stable compounds, and
surprising the chemist by the strength of its affinities. Not only is water a common constituent of
165
LECT. V.] 
RELIGION AND CHEMISTRY.
most crystalline salts, and an essential ingredient
of many of the powerful acids which are used both
in the arts and in the chemnist's laboratory, but it
makes also a not unimportant part of the rocky
crust of the globe. Besides forming the immense
deposits of ice which perpetually surround either
pole, and the glaciers which creep down the high
mountain slopes, we find that water enters as an
essential ingredient into the composition of talcose
and chlorite slate, gypsum, serpentine, soapstone,
and other rocks. Moreover, water is the medium
in which Inost chemical processes take place, and
throughout all geological history it has been producing the most fundamental changes in the composition of the earth's crust, the extent of which
geologists are only of late beginning to appreciate. It is now supposed that granite and similar rocks, which were formerly regarded as products of igneous fusion, have been really formed
from loose beds of mud and clay, through the
transforming power of this wonderful and powerful agent.
When, lastly, we consider the composition of
water, our wonder is still further increased  for
Composition it consists of two permanent gases, conof water. densed by the force of chemical affinity
to the liquid condition. With one of these, oxygen, you are already familiar.  The other is a
light, combustible gas, called hydrogen, fourteen
and a half times lighter than air, and by far the
lightest form of matter known. One cubic foot of
166
[LECT. V. 
TESTIMONY OF WATER.
water yields more than eighteen hundred cubic feet
of a mixture of these two gases, and so persistently
do they retain their aerifornm condition, that not
even a pressure of twenty tons on the square inch
is sufficient to reduce them to liquids. Yet, immense as this pressure seems, requiring all the
mechanical skill of man to apply it, that force must
be still greater which is constantly acting in every
drop of water to hold these highly elastic gases
in the liquid state. It is difficult to estimate the
magnitude of such power, as our only standard of
measurement is the quantity of some other force,
equally immeasurable, which is required to balance
the first. Water is easily decomposed by electricity, and the amount of this agent required to force
apart its constituents may perhaps give you some
imperfect conception of the magnitude of that
power by which they are so securely imprisoned.
The statement may seem incredible, but yet it
has been proved by Professor Faraday, that it
requires more electricity to decompose a drop of
water than to charge a thunder-cloud.
What a revelation of power we have here! In
every drop of water there is a constant striving of
the elements to escape; they are exerting a force
to break the bonds that unite them, which can
be measured only by the power of concentrated
thunderbolts, and yet this immense force is kept in
check by a force of equal power, and so exactly
balanced that not the slightest disturbance can occur. When, now, I reflect that this chemical force
167
LECT. V.] 
RELIGION AND CHEMISTRY.
has produced a result which all human strength,
aided by the appliances of modern art, has been
unable to effect, - that in every particle of water
the force is still acting, so that every rain-drop
which falls, animates the river, or swells the ocean,
is a silent monitor of human weakness, I am overwhelmed by that mystery in nature, which here as
elsewhere ever points upward to the Infinite, and
thus silently teaches that the mighty influence
which binds the atoms of the rain-drop is merely
the manifestation of His ceaseless power who holdeth "the waters in the hollow of His hand."
It is a very common mistake to suppose that the
grand in nature is to be seen only in its great
water-falls and its lofty mountains, and that, in order to appreciate the omnipotence of the Creator,
we must cross oceans and explore continents; for,
to the intellectual eye, there is more evidence of
omnipotence, more real grandeur, in a single raindrop, than in the roar of Niagara or in the magnitude of Mont Blanc. The more I study the evidence of design in this simple liquid, the more I
find there is to learn, and I feel the utter inadequacy of any language to convey the full and complete idea.  Review for a moment  the examples
of adaptation which have been so briefly noticed.
Remember that water is the liquid of our globe,
and the only liquid which exists in any abundance
on its surface. The total amount of all other
liquids is in comparison but as "a drop of a
bucket."  Consider, next, that its specific gravity
168
[LECT. V. 
TESTIMONY OF WATER.
has been so adjusted that our ships float, and the
oceans are made great highways for the nations;
that it is easily converted into vapor, and as easily
condensed to fertilizing rain and refreshing dew,
which nourish the growing plants, fill the springs,
and keep the rivers, the great arteries of the
globe, in circulation; that at a comparatively low
temperature it is changed into highly elastic steam,
which, imprisoned by man in his iron boilers, has
become the great civilizer of the world; that it
has been so exceptionally constituted that the great
mass cannot be cooled below forty degrees, and
again has been made such a poor conductor of
heat that, when the surface is frozen, the very
ice becomes a protection against the cold; that to
this same liquid there has been given a very great
capacity for heat, and that thus it has been made
the means of tempering materially the climates of
the globe. Add to this, that water has been made
an almost universal solvent; that from the substances it holds in solution the crustacea form their
shells and the coral polypi build their reefs; that
it fills the cavities of the rocks with gems, and their
fissures with useful ores. Besides this host of wonderful mechanical adaptations, remember that water
has been made a chemical agent of great energy
and power; that there have been united in it the
apparently incompatible qualities of blandness and
great chemical force; that, although in the laboratory of nature it corrodes the most resisting rocks,
it also circulates through the leaflets of the rose
169
LECT. V.] 
RELIGION AND CHEMISTRY.
and the still more delicate human lungs; that it
forms the greater part of all organized beings, from
the lichen to the oak, and from the polyp to man.
Reflect, now, that these are only a few of the
grosser qualities and functions of this remarkable
compound, gleaned here and there from many
others no less wonderful, and you will form still
but a very imperfect conception of the amount of
design which has been crowded into it. Attempt
to find a liquid, which, if in sufficient quantity,
might supply its place, and you will be still further
impressed by this evidence of intelligence and of
thought. Of all the materials of our globe, water
bears most conspicuously the stamp of the Great
Designer, and as in the Book of Nature it teaches
the most impressive lesson of His wisdom  and
power, so in the Book of Grace it has been made
a token of God's eternal covenant with man, and
still reflects His never-fading promise from the
painted bow.
170
[LECT. V. 
LECTURE VI.
TESTIMONY OF CARBONIC ACID.
WHEN standing by some quiet mill-stream, have
you ever speculated on the origin of the power
which is animating the machinery of that great factory on its banks, spinning and weaving the crude
cotton into miles of cloth every week? And if,
perchance, you have visited Niagara, did the thought
strike you, when gazing up at those floods of
water, which came tumbling over the rocky cliffs,
and plunging into the seething sea at your feet,
that similar floods had been pouring over that
ancient river-bed for countless ages, yet without
diminishing the inexhaustible supply? Or, if it
has been at once your privilege and your terror to
witness that grandest sight of nature, a violent
storm at sea, have you been impressed by the
untiring might of that mysterious agent which
impels the raging winds and upheaves the roaring
billows?  Whence can come all the power? and
what keeps in motion that wonderful aqueous circulation, which we studied in the last Lecture?
Although the origin of this never-ceasing motion
may be still concealed, we have at least traced back
the power to a proximate source in the great central
luminary of our system.  It is the gentle influences 
RELIGION AND CHEMISTRY.
of the sunbeam which raise the water in vapor, and
it is the same solar rays which keep in motion the
great aerial currents, spreading the clouds over the
earth, and distilling down their liquid treasures "to
satisfy the desolate and waste ground, and to cause
the bud of the tender herb to spring forth." Incredible as it may appear, it is actually the sun
which weaves the cloth, which feeds the fountains
of Niagara, and it is his delicate rays which rule in
the tempest and direct the storm. But there are
other influences of the sunbeam still more subtile
than these, and there are other cycles of changes, as
grand as the aqueous circulation, of which the sun
is also the ever-active cause,
Referring to the table before given, representing
the composition of the atmosphere, you will noCirculation  tice that the great aerial ocean contains
ofcarbon. more than five million billions of tons of
an aeriform substance called carbonic acid. This
amount, although absolutely very great, is nevertheless only a small fraction of the whole atmosphere, making up less than a thousandth of its
total mass. A cubic foot of air does not contain
more than a quarter of a grain of carbonic acid;
yet there is not one of the atmospheric constituents which is more intimately associated with organic life, or which discharges more important
functions.  Although itself a colorless gas, carbonic
acid consists of ordinary black charcoal combined
with oxygen, and these elements are united by one
of the strongest affinities known in nature. Yet,
172
[LECT. VI. 
LFCTr. VI.]  TESTIMONY OF CARBONIC ACID.
intense as this force is, the power of the sun is
greater, and his rays, acting on the green leaves of
the plants, are constantly decomposing the gas and
liberating the charcoal, to be incorporated into the
various forms of vegetable life. Here, however, it
remains only for a brief period; for when the plants
have finished their allotted term of life, the charcoal
again unites with oxygen, and in the form of carbonic acid is restored to the atmosphere by the
process of combustion or decay. But frequently,
before these destructive changes complete the cycle,
the charcoal undergoes a further transformation, and
through the process of digestion becomes a part of
the body of the animal. Yet this transmutation, as
a general rule, only hastens the final result; since
thie processes of animal life are very rapid, and
sooner or later the charcoal is burnt up in the
body and breathed out into the atmosphere, ready
to renew the same series of changes. I wish to ask
your attention this evening to the evidences of design which may be discovered by studying this
wonderful circulation of carbon; and we shall find
that the properties both of carbon and of carbonic
acid have been most carefully adjusted to the part
which they play in the great scheme of nature.
We might begin our study at any link of this endless chain of phenomena; but in order to bring the
subject into an orderly succession to our previous
trains of thought, let us return to the phenomena
of combustion, which we considered in the third
Lecture, and study the details of this familiar process a little more closely.
173 
RELIGION AND CHEMISTRY.
All fuel, without exception, contains charcoal, or,
as the chemists call it, carbon. Wood, soft coal,
Composition  oil, wax, and similar combustibles, which
of fuel.  burn with flame, contain besides carbon
a variable quantity of hydrogen and oxygen; but
hard coal, coke, and common wood charcoal are
almost pure carbon. The adaptations of each of
these classes of combustibles demand special notice,
and let us begin by studying the evidences of design which are to be found in an ordinary hardcoal fire; and while, in imagination, we are preparing the fire to be lighted on the grate, we may
study with profit some of the external properties
of the coal, for even they betray the master hand
of the Great Architect.
Examining closely this lump of charcoal, you will
notice that it retains all the delicate structure of
Infasibilityof the wood from which it was prepared.
carbon.  Here is the fibrous bark next the sapwood, and then the annual rings, all as on a stick
of beech-wood; and if you will take the pains to
make a thin section of the charcoal, you will find,
on examining it with a microscope, that the minutest cells have been preserved. You know how
charcoal is made. The wood is exposed to a high
temperature in the charcoal mounds or furnace, by
which the gases which it contains are driven off,
while the charcoal, not being volatile, remains behind. Here, then, is a remarkable fact,- that, although the wood has been exposed to a red heat
in the process of carbonization, yet the minutest
174
[LEFcr. VI. 
LECT. VI.]  TESTIMONY OF CARBONIC ACID.
cells have not been destroyed; and it illustrates an
equally remarkable quality of charcoal, on which,
as we shall see, its usefulness as fuel very greatly
depends. Carbon, in all its forms, is absolutely infusible. It does not even soften at the highest
temperatures which can be attained by art, and it is
for this reason that the charcoal retains so perfectly
the structure of the wood. Were carbon fusible at
a red heat, the charcoal would run together to a
shapeless mass in the mounds or furnaces in which
it is prepared, and did it even soften at this temperature, the forms of these delicate cells could
never have been preserved. Viewed in connection
with the volatile qualities of the other elements of
organized beings, the extreme fixity of carbon in
its uncombined condition is worthy of your special
attention. The only other essential elements of
organic matter are oxygen, hydrogen, and nitrogen; and these three substances are not only gases,
but gases which even by the greatest cold or by
thousands of atmospheres of pressure cannot be
condensed to the liquid condition; yet so strong is
the tendency of carbon to remain solid, that it condenses these gases around itself in every organized
substance that exists. Carbon is thus the solid
substratum of organized matter, the skeleton, as it
were, of every organic form. Hlow evidently, then,
has the attribute of infusibility been adapted to
this important function which carbon has been appointed to subserve!
Examining again this lump of charcoal which
12
175 
RELIGION AND CHEMISTRY.
we are using to kindle the fire, mark that it has
Black color a black color and is perfectly opaque.
andopacity. These qualities are so evident to the
most superficial observation that they are apt to
be passed unnoticed, and yet it is these qualities of
charcoal which make it so valuable as the basis of
printing ink.  All my audience may not know that
printing ink is a mixture of lamp-black and oil, and
that the letters on a printed page are formed by
thin layers of black charcoal spread over the white
paper; and charcoal is peculiarly well adapted for
this use, since, however finely subdivided, it never
loses its dead black color and perfect opacity.
But this property of charcoal would be useless
to the scholar for diffusing knowledge, were it
not combined with qualities still more remarkable,
and almost unique. Carbon is not acted upon by
atmospheric agents, and, moreover, is absolutely
insoluble in any liquid, with perhaps the exception
of melted iron. The letters of the first Bible ever
printed are as black as they were the day they left
the types. They have been exposed to the action
of atmospheric air for four hundred years, and, were
carbon in the slightest degree acted upon by the
atmosphere, they would long since have disappeared. As it is, they will endure as long as the
paper on which they are printed lasts.
The almost unparalleled insolubility of charcoal is
a quality equally important in this relation, for were
charcoal even to a slight extent soluble in water,
the books of our fathers would have been rendered
176
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
illegible by the dampness to which all libraries are
more or less exposed; and were carbon soluble even
in such liquids as alcohol, ether, or the volatile oils,
the printed page would not have been, as now, safe
from alteration, and all kinds of fraud would have
been easy. We justly honor the names of Gutenberg and Faust, whose art has done so much to enlighten and civilize the globe, and we bestow due
admiration on those improvements in the art of
printing, nowhere more developed than in our own
land, which have made the press the great agent
of power, and elevated the moral and intellectual
above the physical man. But while we pay just
tribute to the genius of these benefactors of mankind, let us not forget that greater Benefactor, who
was before them all; for in the most familiar qualities of this piece of charcoal, on which the art of
printing so greatly depends, there has been displayed since the foundation of the globe an evidence of wisdom and skill before which all human
ingenuity sinks into insignificance.
But, my friends, the most remarkable attribute of
carbon does not appear in this piece of charcoal;
for of all the chemical elements carbon Modifications
is by far the most protean in its aspects, of carbon.
and charcoal is but one of its many manifestations.
In the first place, there are the numerous varieties
of coal, including charcoal, coke, lamp-black, and
bone-black, all having the same general properties,
and most of them partaking more or less of the
structure of the organic tissues from which they
177 
RELIGION AND CHEMISTRY.
were made. But besides these varieties, which, although differing so much in their outward aspect,
have all essentially the same properties, there are
two entirely different states of carbon, differing as
much from each other and from common charcoal
as any two solids possibly could.
Are you aware that the brilliant gem you prize
so highly is the same chemical element as these
black coals? The diamond is merely crysDiamond.
tallized charcoal, and although we cannot
crystallize charcoal artificially in our laboratories,
and do not even know how the diamonds are
made in the great laboratory of nature, yet there
is no fact of chemistry better established than this.
To those who are not familiar with the results
of modern chemistry, it seems almost incredible,
and even the chemist can hardly believe the truth
while he affirms it. It is at utter variance with
the whole doctrine of his science; it cannot be
reconciled with any of his previous conceptions,
and constantly reminds him of the limitations of
his knowledge and the uncertainty of his philosophy. And, turning to the more familiar aspects
of the subject, how singular the fact, and how
typical of the universality of Christian brotherhood, that He who "hath made of one blood all
nations of men," should have also made of the
same material the priceless brilliant which adorns
the diadem of the prince, and the soot which begrimes the cabin of the humblest peasant! How
different the estimation in which these two forms
178
[LECT. VI. 
LEcr. VI.]    TESTIMONY OF CARBONIC ACID.
of carbon are held! and yet, if the marks of Divine
wisdom can give nobility to a substance, the one is
as excellent as the other.
But carbon exists in still a third modification, differing as much from the diamond as that differs
from charcoal.  Every one who has used
Graphite.
a common lead pencil is familiar with
graphite, and it is a fact as remarkable as the
one just noticed, that the same carbon which
forms the letters of a printed page fills also the
lines of the pencil sketch. Graphite is simply a
modification of charcoal, and if this fact is not so
well known as the humble relationship of the diamond, it probably arises from the circumstance
that graphite has been generally called plumbago,
or black-lead, a misnomer which has given a very
erroneous conception of its nature. Graphite is
frequently mixed with impurities, but it never contains lead, and in its finest condition it is nearly
pure carbon. Compare now graphite with the diamond. Could there be two substances more unlike? the one the softest of minerals, the other the
very hardest; the one dull and opaque, the other
brilliant and transparent. But besides these external differences they have also a different crystalline
form, a different specific gravity, a different capacity for heat, and, in fine, excepting that they are
both infusible and combustible, there is not one
point of resemblance between them. How then,
you will ask, do we know that they are both the
same substance as charcoal? Simply because, when
179 
RELIGION AND CHEMISTRY.
combined with oxygen, they all yield the self-same
compound.
All three of the modifications of carbon are
combustible, although they take fire at very different temperatures. Charcoal will burn at a red
heat, the diamond at a white heat, while graphite requires the highest temperature which can
be attained by art. But however different may
be the temperatures required, the process is the
same in all cases and the result is the same. The
burning is simply combination with the oxygen of
the air, and the result of that combination is carbonic-acid gas. Moreover, it has been proved by
the most careful experiments that a given weight
of either substance yields precisely the same weight
of carbonic acid. Chemically considered, then, the
diamond, graphite, and charcoal are the same substance, although, physically regarded, no substances
could be more unlike. Chemical identity, therefore, does not consist in identity of properties, and
we must admit that the same chemical element
may manifest itself under utterly different physical
aspects.
This remarkable phenomenon, which has been
fully recognized only of late years, has been called
by chemists allotropism,* and the diamond,
Allotropism.
plumbago, and charcoal are different allotropic modifications of the element carbon. Such
differences of manifestation, moreover, are not confined to carbon, nor are they exceptional occur
* Derived from two Greek words signifying difference of condition.
180
[LECr. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
rences among the elements. We have already
seen that oxygen may exist in an active and in a
passive modification, which stand in as striking an
antithesis to each other as the diamond and charcoal, and the same is true of the different conditions
of sulphur, phosphorus, and silicon. Again, these
phenomena are not limited to the elementary substances, for they have been observed in many compounds as well, and every year enriches our knowledge with fresh examples. In what, then, are such
developments to end? If substances so utterly unlike as the diamond, graphite, and charcoal are
merely modifications of the same element, why may
not all substances be merely different allotropic
states of a few universal principles, or possibly of
only one single essence? Such, and many similar
questions, arise in the mind of the chemist while
contemplating these obscure phenomena.   They
cannot be answered in the present state of chemistry, and they throw a degree of uncertainty and
doubt on its whole philosophy. I shall have occasion to dwell upon this subject more at length
in another Lecture, and have adduced the facts at
this time chiefly as further illustrations of that fertility of resources which so strikingly marks all the
results of creative skill. To me this characteristic of
the works of nature is one of the most convincing
evidences of divinity.  While studying the simple
adaptation of means to ends which we find everywhere around us, we recognize in the plan something analogous to the creations of human skill. and
181 
RELIGION AND CHEMISTRY.
we almost feel a conscious relationship with its Au  thor. But when we consider this incomprehensi ble power, by which the same substance has been
endowed with entirely different and incompatible
properties, and not only this, but has been adapted
in each condition with equal skill to produce the
most opposite and seemingly irreconcilable results.
we are also made to feel most keenly, that, al though man was created in the image of his Maker,
he resembles the Divine Original only as the finite
can resemble the Infinite.  "For my thoughts are
"not your thoughts, neither are your ways my
"ways, saith the Lord. For as the heavens are
"higher than the earth, so are my ways higher
"than your ways, and my thoughts than your
"thoughts."
Of all the properties of coal, the one with which
we are most familiar is its combustibility; and
Burningof  while we have been discussing its exterhard coal. nal properties, the hard-coal fire has been
built in the grate, and it is ready to be lighted.
The combustion of coal in one or the other of its
varieties is the great source of all the artificial heat
used by man. Although so entirely passive towards
atmospheric agents at the ordinary temperature,
yet when heated to a red heat it takes fire and
combines with the oxygen of the air with great
rapidity. The burning of coal is so familiar to
every one that it would seem hardly necessary to
dwell upon the subject here. But although the
experiment is repeated every day in every grate
182
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
of this city, and although it has been familiar to
you all from infancy, there are, nevertheless, phenomena connected with it which few have observed
and still fewer fully appreciated. It is a great mistake, but a mistake too frequently made even by
scientific men, to suppose that new knowledge can
be gathered only from the unexplored fields of science, when by the most familiar walks of life there
are countless riches of truth which the reapers in
the hurry of the harvest have passed unnoticed, and
which will abundantly reward the careful gleaners.
In the coal fire on which you daily gaze, there is
enough to be discovered to engross the attention
of the most diligent student of nature. Let us see,
therefore, if we too cannot learn something new at
least to us from the burning coals.
The first fact to which I would call your attention, is the difficulty experienced in lighting coal.
In order to kindle the fire we have placed Pointofignion the bottom of the grate, first, some tion.shavinilgs, then some charcoal, and last of all the
hard anthracite coal. We can readily set fire to
the shavings with a match, and they in their turn
will ignite the charcoal; but it requires the intense
heat of the burning charcoal to ignite the anthracite.
Charcoal will not burn unless at a full red-heat,
and hard coal requires a still higher temperature.
But notice now another fact: when once inflamed,
the heat evolved by the combination of the carbon
with oxygen is sufficient to sustain the tempera,
ture at the point of ignition. Here, again, we see
183 
RELIGION AND CHEMISTRY.
most admirably illustrated the adaptation of the
properties of the chemical elements to.entirely different ends. In order that carbon might serve as
the solid substratum of all organized beings, it was
necessary that it should be made unalterable by
the air within the limits of terrestrial temperature,
but at the same time the economy of nature required that it should be made combustible, that
is, endowed with strong affinities for oxygen; yet
these affinities have been so carefully regulated,
that they are called into play only at a high temperature, and are thus placed entirely under the
control of man.
Now that the coal is in violent combustion, combining rapidly with oxygen, notice that it burns
Bright light entirely without flame. We have here
but no flame. rapid chemical combination, with all the
phenomena of active burning, and yet no flame,
simply because flame is always burning gas, and in
a hard-coal fire it is not a gas, but a highly fixed
solid, that is burning. Charcoal and anthracite are
almost the only combustibles which burn in this
way. Most others, even when naturally solids, are
converted into gases at a high temperature, and
therefore burn with flame; but carbon in all its
forms, when uncombined, persistently retains its
solid condition, even in the hottest fire.
Remark, also, that this combustion is attended
with a very bright white light, and compare it
with the more  violent combustion of hydrogen,
with which most of my audience must be familiar.
184
[LECT. VI. 
LECT. VI.]    TESTLIMONY OF CARBONIC ACID.
Hydrogen burns with a flame, because it is a gas;
but this flame is almost invisible, because gases,
however intensely heated, do not emit a bright light.
The charcoal burns without flame because it is a
permanent solid, but for this very reason it emits a
great amount of pure white light.  So far, at least,
as ordinary experience extends, white light is emitted only from ignited solid matter. * Therefore
neither white light nor flame is a necessary concomitant even of the most rapid combustion, the
first depending solely on the solid, and the last on
the aeriform, condition of the burning substance.
If, as in the burning of a candle, both flame and
white light attend the process, it is because both
solid and aeriform matter are there burning; and
when we come to examine this phenomenon more
closely, we shall find that the result is produced by
a most beautiful adaptation of properties.
Let me next call your attention to the importance of the infusibility of charcoal in connection
with its use as fuel.  However high the
Use as fuel
temperature at which it burns, however dependsonits
intense the furnace heat, charcoal never infusibility.
intense the furnace heat, charcoal never
* I use the phrase white light because an ignited gas or vapor may
emit a colored light, and it has been found that the color is in each case
determined by the chemical composition of the ignited mass; but the
light emitted from the gases or vapors of which the flames of ordinary
combustibles consist, is at best very feeble. The light of such flames, as
will soon appear, comes almost entirely from solid particles of charcoal,
and when these from any cause are not present, the flame only yields a
very faint blue light. The appearance of the whole flame is then the
same as that which may always be seen near the orifice of a bat-wing
gas-burner.
185 
RELIGION AND CHEMISTRY.
loses its solid condition, and on this wholly depends
its application for generating heat. Were coal fusible, even at a very high temperature, it would melt
and run out from our grates and furnaces, and the
genial fire could not as now have been localized on
the hearth. The enjoyment of the social fireside
is thus closely connected with a familiar property
of this wonderful element.
But our fire is slowly burning away, and already
more than one half of the coal has been consumed.
The products What has become of it? Do you point
The products
of combustion to the ashes? These are only the earthy
aeriform. impurities, which are more or less mixed
with the pure carbon, and constitute but a small
fraction of the whole mass of the coal. The carbon
itself has combined with the oxygen of the air and
formed a colorless and invisible gas, which has escaped by the chimney. I have already stated in
my Lecture on Oxygen, that this gas has acid qualities, and we have named it carbonic acid. Reflect
now on the importance of the circumstance, that
this compound of oxygen and carbon is aeriform,
and consider what a marked evidence of design
and adaptation is to be found in the very fact that
the products of ordinary combustion are invisible
gases, which ascend our chimneys and are wafted
away by the currents of the atmosphere. As the
common experience is confined to the burning of
coal, wood, oil, and similar combustibles, consisting
mainly of carbon and hydrogen, men naturally associate with smoke the idea of a gas, and are apt
186
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
to think that the aeriformn condition is a necessary
result of the nature of things. But it is not so.
This peculiar provision in the case of carbon and
hydrogen is an exception to the general rule. Tihe
two combustible elements which are most closely
allied to carbon in all their properties, boron and
silicon, not only form solids by burning, but two of
the most fixed solids known in nature, one of
which, silica, constitutes, as we have seen, at least
one half of the rocky crust of our globe; and the
same is true of almost all the other combustible
elements. A very interesting experimnent in illustration of this fact may be made by burning a piece
of phosphorus under a dry glass receiver. The
smoke of phosphorus is solid, and it will fall in
thick white flakes, producing within the glass the
appearance of a miniature snow-storm. Picture to
yourself the desolation which would be produced
were the order of nature so far changed as to make
the products of burning coal like those of burning
phosphorus. Every furnace would become a volcano, and we should soon be buried beneath the
smoke of our own fires.  When, now, we consider
that a special provision has been made in the case
of that substance whose combustion administers to
our wants by evolving light and heat, what evidence does it open to us of the all-wise forethought
of the Great Original!
But this is not all. Let me.now call your attention to an additional fact in regard to the carbonic
acid which is escaping from our coal fire. The gas is
187 
RELIGION AND CHEMISTRY.
entirely devoid both of odor and of taste, and, more   The products over, when in a sufficiently diluted condi T~he products
of combustion tion it can be breathed with impunity.
harmless. Consider what an amount of this product
is daily formed, and you will then be able to appre ciate the importance of this circumstance. The
amount of carbonic acid which escapes from an av erage-sized iron blast-furnace in the course of a
single hour is equal to at least two tons, and the
amount which is generated even by our coal fire is
surprisingly large. Moreover, no less than two
thousand tons * of this gas are breathed into the air
by the population of this city in a single day. If
carbonic acid had been a pungent or corrosive gas,
coal could not have been used as fuel; for its combustion, like that of sulphur, would soon have rendered the air irrespirable. But so entirely destitute
is it of any perceptible odor or taste, that, although
it has been evolved in these immense quantities
from every fire lighted by man since he appeared
on the globe, it so entirely escaped notice that its
existence was not even suspected until it was discovered by Dr. Black about a century ago.
There is still another remarkable phenomenon
attending a coal fire, which, although it cannot be
The smoke has made evident to the senses, has been subthe same vol- stantiated again and again by the most
ume as the
oxygen con-  accurate experiments.   The  volume of
sured....a 
sumed.  carbonic-acid gas formed by the combustion is exactly equal to the volume of oxygen con
* Calculated for 400,000 inhabitants.
188
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
sumed. It is a consequence of this fact, that the
volumne of the air is not in the slightest degree increased by the vast quantity of carbonic-acid gas
which is daily poured into it. The gas occupies
precisely the same space as the oxygen removed
during the combustion, and thus the equilibrium of
the atmosphere is not disturbed. It is true that we
probably cannot see all the bearings of this simple
provision; but we know enough to recognize in it
a most marked evidence of design.
The last fact in connection with the coal fire to
which I would direct your attention is the large
amount of heat which the combustion of Heat of
coal liberates, and on which its use as fuel combustion.
very largely depends. One pound of charcoal, in
burning completely, generates sufficient heat to
raise the temperature of 80.8 pounds of water from
the freezing to the boiling point. Every pound of
charcoal may, therefore, be regarded as containing
sufficient heat to boil eighty pounds of ice-cold
water. What a vast amount of heat then lies
buried in those inexhaustible beds of mineral coal,
in which our country is so rich! And have we not
another remarkable evidence of Divine wisdom in
the fact that carbon, a substance which, on account
of its infusibility and other qualities, is so well
adapted for fuel, has been made a great reservoir of heat, from which man can draw an unlimited supply?  When we remember that this heat,
through the expansion of steam, may be converted
into mechanical force, and that hence these beds of
189 
RELIGION AND CHEMISTRY.
coal are not only magazines of heat, but stores
of force, which have been accumulating from the
foundation of the globe for the use of civilized man,
and when we reflect that it is this force which is animating our commerce, weaving our cloth, forging
our iron, and impelling the printing-press, how can
we express our praises of the foresight of that Providence which endowed coal with such wonderful
qualities, made it a vast repository of heat and
of force, and then spread it bountifully over the
globe?
We have discovered, my friends, all these wonderful indications of design and adaptation in this
simple experiment, so familiar as to be almost trite,
so frequently repeated as to pass unnoticed, and
they are constantly speaking to us of the great
Author of nature from the fireside of every home,
and from the furnace of every work-shop in the
land. The followers of Zoroaster still worship, in
India, fire as divinity, and regard these burning
coals as sacred. Behind this superstition and idolatry there is concealed true wisdom, by which we
may well profit. Fire is neither divinity, nor yet
its emblem. It has no other reality than as a phenomenon attending a chemical change; but in the
qualities with which charcoal has been endowed in
order to produce this phenomenon, in the delicate
adjustment of forces  by which the destructive
change is confined within due limits, there are indications of divinity which may well make us
thoughtful, and consecrate with additional sanctity
190
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
the family hearth; and if I have succeeded, how ever imperfectly, in making audible to your intellectual ear this mute eloquence of burning coal,
our time has not been spent in vain.
I have thus far drawn all my illustrations from
the burning of charcoal and hard coal, simply because these familiar forms of fuel are near- Burning of
ly pure carbon, and the phenomena at- softcoai.
tending their combustion are comparatively simple.
They burn, as we have seen, without flame, and for
the reason that carbon does not volatilize, even at
the highest temperatures. It is different, however,
with soft coal, wood, oil, wax, and all other combustible materials which are used for generating light.
They do not consist wholly of carbon; but this element is always combined with hydrogen, and most
of these combustibles contain also in addition a limited amount of oxygen. When heated, they all
evolve common illuminating-gas, and for this reason
burn with a flame. In fact, the gas we are burning here to-night was made from just such materials. If you will visit the gas-works of this
city, you will see long rows of iron retorts, firmly
built into large brick furnaces.  In tl!ese retorts
the gas is made, and they are connected by
means of a complicated system of tubes with all
the numberless gas-burners of this large Manufacture
city.  Every few hours the retorts are of illminat
charged with soft coal, which soon be-  g-gas.
comes heated to a low red heat. At this temperature it slowly gives off gas, and it is the gas thus
13
191 
RELIGION AND CHEMISTRY.
formed which is now illuminating this hall. After
three or four hours the gas has been all driven off,
but there is still left in the retorts the greater
part of the carbon of the coal, in a condition which
is called coke. This is then removed and used for
feeding thle furnaces, and a new charge of soft coal
is introduced in its place. Coke is an excellent
fuel, but, like charcoal, it burns without flame.
The processes which, in the manufacture and
use of illuminating-gas, are spread over a whole
city, are united in every soft-coal fire. The gas
which is burning at this jet was generated in
the retorts of the gas-works, and brought here in
iron tubes to be burnt. In the grate the gas is
made and burnt in successive moments, but the
process is identical in both cases, When you throw
a fresh supply of soft coal on the grate, the first
effect of the heat is to generate illuminating-gas,
which at once takes fire and burns with a brilliant
blaze. But after some time the flame ceases, because all the volatile elements of the coal have
been expelled, and the coke, which is left, merely
smoulders, like charcoal or anthracite. What is
true of soft coal is also true of wood and of all
this class of combustibles.
Flame, as I have before stated, is in all cases
burning gas. As we are generally familiar with it,
Nature of   flame is a cloud of illuminating-gas comflame.   bining on its exterior surface with the
oxygen of the air. In a gas lamp the gas is sup plied ready made at the jet. In an oil lamp or a
192
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
candle, the gas is manufactured as fast as it burns.
The use which we make of the flame in all these
cases, is to generate light, and the qualities of carbon have been most admirably adjusted to produce
that result. This is the point which I wish next to
illustrate, and we shall understand this beautiful
example of adaptation more readily by analyzing
the burning of some one of the light-generating materials. I will therefore select a common wax candle as my example, because it is familiar to every
one, and illustrates all the points I have in view.
Nothing could be simpler than the candle itself
It is a long cylinder of wax formed around a string
made of loose cotton threads, which we call the
wick. The wax, that familiar secretion of the
honey-bee, is composed chemically of carbon, hydrogen, and a little oxygen; the wick, as the microscope would show us, is merely a collection of
fine vegetable tubes. Let us now light the candle.
For that purpose we apply the flame of a friction
match to the end of the wick, and mark the result.
The heat of the match melts the wax around the
base of the wick, and now the peculiar virtue of
these vegetable tubes comes into play. All fine
tubes have the power of sucking up liquid, and the
finer the tube, the greater the height to which the
liquid is thus elevated. The tubes of the wick
are vastly finer than any that man can make, and
the melted wax is at once drawn up to the flame
of the match. There it is volatilized by the high
temperature, and a cloud of red-hot combustible
193
i 
RELIGION AND CHEMISTRY.
gas forms around the summit of thd wick. Like
the rain-drop, or any other fluid body in a free
state, it assumes a spherical form, but being much
lighter than  the air, this
sphere of gas  no  sooner
forms than it begins to as                        cend, and, being very com                        bustible, is burnt up by
the oxygen of the air with
great rapidity, so that be                        fore it has risen an inch
from the wick it is reduced
to  a  point.  Meanwhile,
however, the first sphere is followed by others, which
in rapid succession meet with the same fate, and at
any moment we have a large number of these little
spheres, one above the other, rapidly diminishing in
size from the lowest to the highest, which has then
become a mere point. Hence results the familiar
conical form of the flame. But our match is long
since burnt out, and what, you will ask, now volatilizes the wax? Solely the heat evolved by the
burning gas. This heat converts the wax into
vapor as fast as it creeps up the wick, and thus the
flame being constantly supplied with combustible
gas, the candle continues to burn until it is all consuined. The candle-flame is then merely a cone
of volatilized wax, rapidly combining on its exterior surface with the oxygen of the air, and as rapidly replenished from below by the constant conversion of fresh wax into vapor. In this process
194
[LEe,r. VI. 
Lcrr. VI.]   TESTIMONY OF CARBONIC ACID.
light and heat are evolved; but these are generated solely on the exterior surface of the flame,
where the burning takes place. Within it is perfectly dark, as can be easily shown by pressing
down upon it a piece of window-glass, through
which the interior may be seen. Let us now study
this chemical process more carefully, as it is on a
very delicate play of affinities that the whole illuminating power of the flame depends.
The combustible gas formed from wax is composed
essentially of charcoal and hydrogen. The light and
combustible hydrogen has so great a tendency to
retain its aeriform condition, that, when combined
with carbon, it renders even this, the most fixed of
all the elements, aeriform; but the moment the
bonds of chemical affinity are loosened, the carbon
resumes its solid condition. Such a change takes
place in the flame, and it is the particles of solid
charcoal thus liberated which render it luminous.
Of the two elements of the gas, hydrogen has the
greatest affinity for oxygen, and therefore burns
first, momentarily setting free the carbon, which is
sprinkled in a fine powder through the burning gas.
This is at once intensely heated, and each glowing
particle becomes a centre of radiation, throwing out
its luminous pulsations in every direction. The
sparks last, however, but an instant; for the next
moment the charcoal is itself consumed by the
fierce oxygen, now aroused to full activity, and
nothing but a transparent gas rises from the flame.
But the same process continues; other particles
195 
RELIGION AND CHEMISTRY.
succeed, which become ignited in their turn, and
hence, although the sparks are evanescent, the
light is continuous.
Thus it appears that all our artificial light, the
light which we are enjoying this evening, depends
upon this provision, by which the particles of char coal linger for a moment in the flame before they
are burnt. Let me again repeat, white light is
emitted only by ignited solid matter. The flame
of pure hydrogen gives very little light, because
there are in it no solid particles, and were the
affinity of oxygen for carbon slightly greater than
at present, the flame of the candle would be as
little luminous: then the carbon would burn simultaneously with the hydrogen, and there would be
no pulverized charcoal in the flame to radiate light.
On the other hand, were the affinity of oxygen
for carbon a little less than at present, the carbon
particles would not burn in the flame, but would
escape from it in clouds of dense soot. Our Heavenly Father has so carefully adjusted the relative
affinity of oxygen for the two elements of these
lightgiving gases, that the hydrogen should burn
a smnall fractional part of a second before the carbon. During this brief interval of time, imperceptible to our unaided senses, the solid particles
of charcoal are set free, become ignited, and give
motion perhaps to a single wave of light; but the
instant after, they too rush into combination with
the great fire-element, and not a particle is left to
dim the transparency of the air. The smallest
196
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
variation in either force would destroy the adjustment by which this result is produced, and our
lamps and candles would cease to give their light.
How delicate the adjustment!  How beneficent the
result! How evident the design!
To me the marks of God's designing hand are
more conspicuous in that familiar candle-flame than
in the grand cycles of astronomy, or in the wonderful mechanismi of the human body. I return to it
again and again with renewed confidence, and always find fresh satisfaction and increasing faith.
There are many who believe with Laplace that this
glorious system of suns and planets, with all its
complex movements and adjustments, might be
evolved out of a nebulous chaos by the sole action
of the primary laws of motion; and now, after the
great French mathematician has furnished a world
to begin with, a modern naturalist asks us to believe that this hand of mine, with all its wonderful
combination of nerves, bones, and muscles, was developed out of the claw of an animalcule, or some
such thing, by what he calls the law of natural seletion; and although these and similar theories may
be held consistently with a belief in a Divine Disposer of the spiritual affairs of men, yet it is too
true that to many of their advocates the order
of nature signifies nothing higher than self-existing
matter, directed by inexorable necessity. But no
cosmogonist has been able to go behind the chemical elements, and until human philosophy can show
how these forms of matter, with all the marvellous
197 
RELIGION AND CHEMISTRY.
adjustments among their properties, have been
evolved out of the "star dust" of the original
chaos, or out of nothing, and can adjust by natural
causes the delicate play of forces in that most familiar of all phenomena, a candle-flame, it will not
be able to overthrow the evidence of design afforded by this genial winter-evening light; and
the fact that these would-be world-makers explain
most satisfactorily what men know least about, is,
to say the least, not in favor of their theories.
Yes, my friends, it is these most familiar evidences
of design which are the most impregnable against
the attacks of materialism. It is these household
altars that we find always burning to enlighten our
dull understanding, to disperse our gloomy doubts,
and to reveal to us the presence of our God.
The delicacy with which the affinity of oxygen
for carbon has been adjusted appears still more
Smeltingof wonderful when we consider another of
the metals. the uses of this force in nature. The
useful metals, which may be said to be the tools of
civilized life, are seldom found in nature in a pure
state. They generally occur combined with oxygen, and this compound, which is called the ore of
the metal, is found in beds or veins of the rocks,
where it has been deposited through the agency
of water. After the miner has dug out the ore
from the earth, and washed it free from impurities, it is the business of the smelter to melt out
the pure metal. Now in this ore the metal is combined with oxygen, and unless the smelter could
198
[LECT. VL 
LEcr. VI.]   TESTIMONY OF CARBONIC ACID.
break this bond; the highest temperature of his
furnace would be unavailing. But the merciful
Parent of mankind, when he thus locked up these
his choicest gifts, gave to man a key which would
unlock the treasure-house, but left him to find out
its use; and as in the progress of humanity the
metals were required to advance civilization and
multiply the comforts of life, the secret was discovered, and the treasures one by one were brought
to light. The only key needed was charcoal. The
Creator has endowed carbon with a power so strong,
that it readily overcomes the force by which the
metals are united to oxygen, and by simply heating the ore with charcoal the metal is set free.
Would that I could give you an idea of the
strength of the force which is required to produce this result. The affinity of carbon for oxygen is one of the most powerful forces known in
nature, so great as to be immeasurable by our ordinary human standards, and yet it is this same force
which produces that delicate result, the light of a
candle-flame. With such wonderful skill does God
wield these mighty agents of his power.
Consider, finally, how this power of reducing the
metallic ores has been united in charcoal to those
other qualities which render it so valuable as fuel.
The smelter heats his furnace with the self-same
coals which reduce the ore. These coals remain
unchanged in contact with the ore until they have
done their work, and then are converted into a colorless and harmless gas, which escapes by the chim
199 
RELIGION AND CHEMISTRY.
ney and is wafted away by the air; while, on the
other hand, the melted metal, freed from its long
imprisonment, flows out below in glowing streams,
ready to be cast into thousands of useful forms.
Review, now, for a moment, the qualities of carbon, and notice how manifold and important are
the functions which this element has been appointed to subserve. It has been made hard and
brilliant, for the glazier's diamond and the monarch's crown. It has also been made soft and black,
for the artist's pencil and the printer's ink. It has
been made indestructible by atmospheric agents,
and thus has preserved for us the wisdom of past
ages, and will transmit our bequests of knowledge
to those that are to come. It has been made combustible, and at the same time infusible, in order to
localize our fires and confine them within their appointed bounds. It has been made a great reservoir of heat, in order that it might protect us from
the winter's cold, and shed its enlivening warmth
around  the family hearth.  It has been endowed
with a strong affinity for oxygen, in order that it
might reduce the metallic ores; but at the same
time this affinity has been so carefully adjusted
that the carbon particles linger in the flame for a
moment before passing into invisible gas, and thus
become a source of light as well as of heat. Lastly, the product of its combustion is a gas so transparent that it does not even cloud the atmosphere,
and so bland that it bathes the most delicate organisms without harm. What an array of evidence
200
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
have we here! But this, my friends, is only the
first stage of that grand circulation of carbon in
nature, which we proposed to ourselves as our subject this evening. The product of all these various processes of combustion is carbonic acid, and
let us now follow this gas into the atmosphere, and
examine some of its more familiar qualities.
Carbonic acid is so perfectly transparent and so
devoid of every active quality that its presence cannot be recognized by any of our senses, Properties of
and we must therefore call in the aid of carbonic acid.
experiment to make evident its existence. This is
the reason why it remained so long unknown, the
method we now use for detecting its presence having been first discovered by Dr. Black only a little
more than a century ago. The method is very
simple. Carbonic acid has a great tendency to
combine with lime, and the result of this combination is that familiar white solid called chalk. Now
-lime is to a certain extent soluble in water, while
chalk is insoluble; and hence, if lime-water is exposed to an atmosphere containing carbonic acid,
the formation of particles of chalk, rendering the
transparent solution turbid, will indicate the presence of the gas. Such a result is actually obtained
by exposing lime-water in a saucer for a few days
to the atmosphere, and any one can convince himself by this simple experiment of the existence
of carbonic acid in the medium around us, as well
as in the air which is exhaled from the lungs.
201 
RELIGION AND CHEMISTRY.
Indeed, the breath is so loaded with this product
of combustion that lime-water is rendered milky
by blowing into it for only a few minutes. The
quantity of carbonic acid in the atmosphere, how ever, is relatively very small, not amounting to more
than a few ten-thousandths of its whole weight. It
enters to a far greater extent into the composition
of many rocks. All limestones have the same com position as chalk, and contain nearly one half of
their weight of carbonic acid, rendered solid by the
force of chemical affinity. These rocks, indeed, are
the great reservoirs of this aeriform compound, and
when you consider how widely the limestones are
distributed, underlying whole districts of country,
reaching down to unknown depths, and piled up
into vast mountain-chains, you can form some appreciation of the extent to which carbonic-acid gas
was used in laying the foundations of the globe.
When pure, carbonic-acid gas will instantly extinguish flame, and is perfectly irrespirable, causing
the epiglottis to close spasmodically and producing.
immediate death by asphyxia. When so far diluted
as to admit of being received into the lungs, it acts
like a narcotic poison, causing drowsiness and insensibility, and this even when a candle will burn in
the gas.   Hence the accidents which not unfrequently arise fromn heating a sleeping-chamber with
a portable charcoal-furnace, or when from an imperfection in the flue the smoke of the hot-air furnace
escapes into the house. Carbonic acid is not, however, poisonous in the strict sense of that term. On
202
[LECT. VI. 
LEcT. VI.]  TESTIMONY OF CARBONIC ACID.
the contrary, it is always present in the blood in
large quantities, and with it bathes all the tissues
of the body. The carbonic acid results, as we have
seen, from that slow combustion constantly going
on in the blood, by which the animal heat is maintained, and it is an essential condition of life that
this product should be secreted from the body as
fast as it is formed. If the atmosphere contains
more than a small percentage of the gas, the process of secretion is arrested, and fatal results necessarily ensue.
The density of carbonic acid is much greater
than that of either of the other constituents of the
atmosphere, the same volume weighing one half as
much again as common air. Indeed; it is so heavy
that it can be poured from one vessel to another
like water, and the immense volumes of carbonic
acid which are constantly flowing from our lungs
and furnaces would cover the whole surface of the
earth with their deadly vapor, were it not that the
Creator has provided, by those simple laws of diffusion, which we studied in a former Lecture, that
this noxious gas should be dispersed as fast as generated, and so mixed with the great mass of the
atmosphere as to be rendered harmless by extreme
dilution. The unfortunate accidents which sometimes occur to persons who descend incautiously
into cellars or wells, where the carbonic acid is
generated more rapidly than it can be dissipated,
constantly remind us that the existence of animal
life on the globe depends upon this beneficent
203 
RELIGION AND CHEMISTRY.
provision. The large kilns in which lime is burnt
into quicklime are constantly pouring out streams
of carbonic-acid gas, and many a poor houseless
wanderer, attracted by the heat of the kiln, has
lain down to rest in the stream, and slept to wake
no more. Were the force of diffusion much less
than it is, we should all be constantly exposed to a
similar fate; and when we lie down at night, it is
only this guardian angel which prevents the deadly
fuimes of our own fires from descending on our beds.
Carbonic acid is soluble in water, a given volume
of this liquid being capable of absorbing its own
volume of the gas, irrespective of the temperature
or pressure. We should therefore expect to find
carbonic acid in solution in all water exposed to
the air, and in fact a cubic foot of r ver,r lake, or
ocean water generally contains a very much greater amount of this gas than an equal volume of the
atmosphere. Water, when holding carbonic acid
in solution, has its solvent power very greatly increased. It then dissolves in large quantities all the
varieties of limestone, and even granite rocks cannot
wholly resist its action; but these solutions, when
exposed to the air, gradually lose the carbonic
acid, and with it their solvent power, incrusting
with calcareous matter the moss, the twigs, or the
walls of caverns on which the liquid may chance to
rest. It is the solvent power of such water, acting
slowly through ages of time, that has hollowed out
that immense cavern in the limestone strata of
Kentucky, and it is from the solution thus made
204
[LECT. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
that those stalactitic ornaments have been formed
which add so much to its beauty and interest. It
is also this same agency which in other places has
deposited beds of calcareous tufa over great areas,
and cemented together loose sands into firm rocks;
and finally, it is from the lime dissolved in the
water of the ocean, that the crustacea form their
shells and the coral polypi build their reefs.*
The origin of carbonic acid is the same in water
as in air. In the water we have not, of course, active combustion; but this, as we have seen, is an insignificant source of carbonic acid when compared
with the never-ceasing functions of respiration and
decay, and these are as active in the rivers, the
lakes, and the oceans as in the atmosphere. Moreover, the purpose which the carbonic acid subserves is the same in both cases, and this deserves,
finally, our attentive study.
I have already intimated that carbonic acid is
one of the few articles of which the food of plants
consists. Let us trace, for a moment, the history
of the plant. The seed containing the germ is
placed in the soil. The genial warmth of the sun
calls it into activity, and it shoots forth its small
leaflets into the air. For a short time the small
stock of starch and similar nourishment stored in
the seed by a wise Providence serves for its sup
* The whole peninsula of Florida has been in great measure built
up by these little animals with the lime rock which the waters of the
Mississippi pour into the Galf, and which they have dissolved from the
lime deposits of our Western States.
205 
RELIGION AND CHEMISTRY.
port; but this is soon exhausted, and for the future
the plant must depend for its food upon the soil
and upon the air. The articles which compose its
diet are exceedingly simple. They are water, carbonic acid, and ammonia, substances always present
in the atmosphere and in every fertile soil. As
soon as the young plant has expanded its green
leaves it absorbs these substances, partly through
its rootlets from the soil, and partly through its
leaves from the air. The leaf, a tissue of minute
organic cells, is the laboratory in which, from these
few compounds, are elaborated the different organs
of the plant. The sun's rays, acting on the green
parts of the leaf, give to them the power of absorbing water, carbonic acid, and ammonia, and of
constructing from the materials thus obtained the
woody fibre, starch, sugar, and other compounds of
which the plant consists. We have analyzed the
woody fibre, and we know that it is composed of
charcoal and water. Nineteen ounces of wood contain nine ounces of charcoal and ten ounces of
water. Moreover, the amount of charcoal required
to make nineteen ounces of wood is contained in
thirty-three ounces of carbonic acid. If, then, we
add together thirty-three ounces of carbonic acid
and ten ounces of water, and subtract from this
sum twenty-four ounces of oxygen, we shall have
just the composition of wood. This is what the
sun's light accomplishes in the leaves of the plant.
It decomposes the carbonic acid, and unites its carbon to the elements of water to form the wood.
206
[LEer. VI. 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
What I have stated to be true of wood is equally
true of starch, gum, sugar, and most of the products
of vegetable life. All these, with a few exceptions,
which I shall notice in the next Lecture, are pre pared by the plant from carbonic acid and water,
under the influence of the sun's light. Why it is
that starch is deposited in the cells of the potato,
sugar in those of the sugar-cane, and gum and
woody fibre, more or less, in all plants, we do not
know. These are the mysteries of organic life,
which no science has been able to solve. This
much, however, is certain. The acorn, buried in
the ground, grows into the noble oak. Of that
wide-spreading tree, at least nine tenths consist of
charcoal and water. The water was absorbed, as
such, directly from the atmosphere; the charcoal
was recovered from the carbonic acid decomposed
by the sun's rays. Here is the wonderful fact.
The gentle influences of the sunbeam have the
power of reversing the process of combustion, of
overcoming the intense affinity of the fire element,
tearing it apart from the carbon, and restoring it to
the air. How great this power is, I have already
endeavored to illustrate. I have stated that the
affinity of oxygen for carbon is one of the strongest
affinities known to nature, immeasurable by any
human standard. In order to decompose carbonic
acid in our laboratories, we are obliged to resort to the most powerful chemical agents, and to
conduct the process in vessels composed of the
most resisting materials, under all the violent mani
14
207 
RELIGION AND CHEMISTRY.
Gestations of light and heat, and we then succeed
in liberating the carbon only by shutting up the
oxygen in a still stronger prison; but under the
quiet influences of the sunbeam, and in that most
delicate of all structures, a vegetable cell, the
chains which unite together the two elements fall
off, and while the solid carbon is retained to build
up the organic structure, the oxygen is allowed to
return to its home in the atmosphere. There is
not in the whole range of chemistry a process more
wonderful than this. We return to it again and
again, with ever increasing wonder and admiration,
amazed at the apparent inefficiency of the means,
and the stupendous magnitude of the result. When
standing before a grand conflagration, witnessing
the display of mighty energies there in action, and
seeing the elements rushing into combination with
a force which no human agency can withstand,
does it seem as if any power could undo that work
of destruction, and rebuild those beams and rafters
which are disappearing in the flames? Yet in a
few years they will be rebuilt. This mighty force
will be overcome; not, however, as we might expect, amidst the convulsion of nature, or the dashing of the elements, but silently, in a delicate leaf
waving in the sunshine. And this is not all.
Those luminous waves which beat upon the green
surface of the leaf are there arrested, and their
moving power so completely absorbed, that the reflected rays will not even affect the exquisitely
sensitive plate of the photographer. But the power
208
[LECT. VIL 
LECT. VI.]    TESTIMONY OF CARBONIC ACID.
of the light has not been lost, and when the wood
is burnt and the carbon converted back into carbonic acid, this power reappears undiminished in
the heat which radiates from the burning embers.
The heat, therefore, which the wood contains, and
which it gives forth on burning, comes from the
sun. What a beautiful provision of Providence
have we here!  During the summer, when  the
sun is warming us with his genial rays, he is also
laying up in the growing wood vast stores of heat,
which will warm us at the winter evening fireside,
when his rays have been withdrawn.
But you will tell me, it is not wood, it is coal,
which is burning in the grate, and you will lead
me, perhaps, to the mouth of some black coal-pit,
and ask if those dismal regions below ever saw the
sun. Certainly! and it is one of the most remarkable revelations of modern science, that the stonelike coal was once alive. Coal is the remains of an
ancient vegetation, which flourished on the earth
ages before man first walked in Eden. The process
by which it has been formed and buried in the
earth is well known. You can see it now forming
in many tropical swamps. There you will find a
vast mass of vegetable matter, the result of a rank
vegetation, gradually decaying under water. The
land is gradually sinking, and as this bed of peat
sinks with it, it becomes covered with mud and
sand, which numerous streams are constantly washing into the swamp. This goes on year after year,
century after century, age after age, until the bed
209 
RELIGION AND CHEMISTRY.
is buried hundreds of feet beneath the surface. In
the mean time the vegetable tissues undergo a sort
of internal combustion, similar to that which takes
place in a charcoal mound. Wood consists, you
will remember, of charcoal and the elements of
water. The oxygen which it contains reacts on
the carbon and  hydrogen.   Carbonic  acid and
water are formed, which escape, while the rest of
the hydrogen and carbon unite together to form
the coal. The reaction is a true process of combustion, and the heat thus evolved aids the chemical
change, and gives to the coal its baked appearance.
This change it requires long ages to complete.
Millions and millions of times has the earth repeated its annual revolution around the sun, and
the whole external appearance of the globe has
changed since those mighty forests grew, which
have been petrified in the coal. But though such
long intervals have elapsed, their history has not
been lost. It has been written on the rocks, the
mighty monuments of past ages. The geologists
have read it, and we know with as much certainty
the form of the leaves and the structure of the
stems of those ancient trees, as we do those of the
oak or the chestnut. We know also that every
atom of coal which now lies buried hundreds of
feet beneath the surface was once a part of the atmosphere, and that the heat which it evolves by
burning was received from the sun, when the carbonic acid was decomposed by the light in the
leaves of the ancient trees. Consider for a moment
210
[LECT. VL 
LECT. VI.]   TESTIMONY OF CARBONIC ACID.
of what immense value to man are those beds of
coal. Without them modern civilization would
have been impossible. Remember that since the
dawn of creation the sun has been employed in accumulating these vast stores of force, and thus preparing the globe for civilized man. We may admire the genius of a Papin and a Watt, who have
told us how to use this force, and who have thus
covered the ocean with steamships, and the land
with railroads; but let us not forget that infinitely greater wisdom which saw the end from the
beginning, and before the mountains were brought
forth or ever the continents were formed, laid up
the beds of coal in the early strata, and preserved
them through the long ages of geological time
until the earth was fitted to become the abode of
man.
I have now glanced at some of the distinctive
features of the great circulation of carbon in nature,
and have endeavored to show that the sun's rays
are the prime moving power of the whole. I trust
that you have been impressed with the grandeur
of its cycles, the delicacy of its adjustments, and
the mighty power of that mysterious influence by
which it is sustained; but above all may it be
my privilege to have succeeded in making clear
to your intellectual vision those marks of wisdom
and of power which have been so visibly stamped
upon this Divine economy.
211 
LECTURE VII.
TESTIMONY OF NITROGEN.
IN order to complete my very imperfect sketch of
the wonderful adaptations which the various qualities and functions of our atmosphere present, I wish
in my Lecture this evening to examine with you the
properties of nitrogen, that aeriform element which
is its chief constituent, making up no less than four
fifths of its entire mass. This gas, although so
seemingly inert, discharges functions no less important than those of oxygen to the well-being of man.
Nitrogen not It is not, however, like oxygen, an elewidely diffused. ment widely distributed in nature, and entering as a chief constituent into the composition
of the globe. The atmosphere is the only great
reservoir of nitrogen, and to this and to the bodies
of organized beings its presence is almost exclusively confined. It seems to be the essential element of all the higher forms of corporeal vitality,
and it is frequently called the zooyen, or life-generator. By some mysterious process it is constantly
being withdrawn from the atmosphere, and entering
into the composition of the numberless living forms
which clothe the earth with verdure and crowd it
with animal life; but these forms soon pass away,
and by the inevitable process of decay the nitrogen 
TESTIMONY OF NITROGEN.
is restored to the great reservoir from which it
was originally withdrawn. Science has not as yet
been able to follow all the steps of this remarkable process, but, nevertheless, enough is known to
show that the properties of nitrogen have been
most admirably adapted to the numerous important
ends which it has been appointed to subserve.
Nitrogen is then peculiarly the element of the
atmosphere. It not only constitutes the greater
part of the aerial ocean, but it exists there in a perfectly free and uncombined condition, and -with
the self-limiting exceptions just noticed-is found
nowhere else.  Occupying so important a place
in the scheme of creation, we should nat                                          Negative
urally expect to find in nitrogen a sub- properties of
stance full of the highest interest.  Yet nitrogen.
nothing could be less inviting than its external
properties. A permanent gas, even at the lowest
temperatures, without color or odor, it is entirely
devoid of every active property. It will extinguish
a candle immersed in it, and will not sustain animal life: but these are merely negative qualities;
for animals cannot live in an atmosphere of nitro gen, solely because it does not contain oxygen, and
it will not support combustion because it is not en dowed with active affinities. And in all other out ward aspects nitrogen is equally inert. It exerts
no action whatever upon the most delicate chem ical compounds, and with a few unimportant excep tions will not enter into direct combination with
any of the chemical elements. Consider also the
213
Lper. VII.] 
RELIGION AND CHEMISTRY.
nitrogen as it exists in the atmosphere. Although
in immediate contact with the most violent of the
elements, and exposed to its action when in its
fiercest state, under the varying influences of light,
heat, and electricity, yet no combination between
the two results, except to a very limited extent,
and under peculiarly oblique conditions. Through
an ordinary iron blast-furnace there pass in the
course of a single day many tons of this mixture
of nitrogen and oxygen called air. The oxygen, as
we know, causes the most violent chemical action;
but although the nitrogen is brought into contact
with the same intensely heated coal and iron, no
combination, at least of any importance, ensues.
Shall we then conclude that nitrogen is entirely
unendowed with chemical affections,   that it is capable of forming no chemical compounds, and of
producing no powerful effects,- that it is, in fine, a
mere dead weight in the atmosphere, placed there,
for the want of something better, to fill up
Compounds
of nitrogen  the void and to give the required denformed only by
indirect pro  sity, as a ship is frequently loaded with
cesses.  ballast when there is a lack of freight?
Such is the conclusion to which the appearances
would naturally lead, and such is the conclusion at
which the chemists arrived in the early stages
of their inquiry.   Yet no  conclusion could be
more at variance with actual facts; for so far is
it from true that nitrogen is the uninteresting
substance which these negative qualities would
seem to indicate, that there are but few elements
214
[Ll'CT. VII. 
TESTIMONY OF NITROGEN.
which form a larger number of compounds, or
which are endowed with more varied powers when
the necessary conditions of combination are fulfilled.  Nitrogen can be made to unite with the
other elements only by indirect and circuitous processes. It is one of its most distinctive qualities
to avoid direct comnbination; but when the necessary conditions are present, it surprises us by the
readiness with which it combines, and by the great
variety and remarkable character of the resulting compounds. When we should least expect it,
we find, not single compounds, but whole classes,
springing into existence, which, while they often
defy our investigations by their protean character, excite our admiration by the simplicity of
their constitution and by the beauty of the plan
according to which they have all been fashioned.
The points, then, which especially characterize nitrogen, and in which the evidences of design in its
constitution are to be traced, are, first, its unexampled inertness when in a free condition; secondly,
the variety and remarkable nature of its compounds; thirdly, the peculiarly oblique processes
by which all its compounds are formed; and, lastly,
their very great instability.
Nitrogen may be very appropriately termed the
ballast of the atmosphere, and this is undoubtedly
the most obvious of its functions.  Air,  toge
Nitrogen the
you will remember, is not in any proper ballastofthe
sense of the term a distinct substance. atmosphere.
It is a mixture of several substances, or rather
215
LrCT. VII.] 
RELIGION AND CHEMISTRY.
there coexist around the globe at least three differ ent atmospheres, one of nitrogen, one of oxygen,
one of aqueous vapor, and perhaps we should add,
as a fourth, one of carbonic acid, each with its own
peculiar characteristics, and so entirely distinct that
it would retain all its essential properties were the
rest removed. Again, when studying in our fifth
Lecture the general features of the great aqueous
circulation on the earth, we discovered that the
whole plan turns on the fact that the atmosphere
of aqueous vapor is mixed with a large mass of
other aeriform matter, which moderates all atmospheric changes and mitigates the violence of their
effects. It also appeared in the third Lecture that
the atmosphere of oxygen has been subjected to
a similar restraint, and that the aroused energies
of this terrible destroyer are most carefully tempered by great dilution. As the atmosphere is
constituted, the oxygen cannot reach the burning
combustible without carrying with it the whole
mass of the surrounding air; but if this mass of aeriform matter were not present, the devouring element would rush upon its prey with a fury which
nothing could withstand, and iron * would burn as
readily as straw. Moreover, in several other connections we have shown that it is an essential condition in the scheme of terrestrial nature that the air
should have its actual density. See now how beautifully all the conditions are fulfilled in the atmos
* An iron watch-spring burns with the greatest readiness in a jar of
pure oxygen gas.
216
[LECT. VII. 
TESTIMONY OF NITROGE,N.
phere. The proportion of oxygen has been most
carefully adjusted to the necessities of animal life,
and made so small that the violence of the fire-element may be restrained within due limits.  The
amounts of aqueous vapor and of carbonic acid
have in like manner each been accurately adjusted
to the purposes which it was appointed to subserve, and then, in order to make up the required
density, a large mass of a perfectly inert gas has
been added. Thus in the very inertness of nitrogen we find the most obvious evidence of adaptation. Its negative qualities are precisely those required in a substance which is designed to act as so
much dead material, adding to the density of the
atmosphere without interfering with the functions
of its active agents.
Consider, also, how very greatly this evidence
of design is enhanced by the fact that nitrogen is
found only in the atmosphere and in the
Evidence of
bodies of organized beings, into which it special adapt
has been temporarily withdrawn. It is tion.
not, like oxygen, carbonic acid, or water, a main
constituent of the globe, and cannot therefore be
regarded, as the fatalists would have us believe, as
so much material left over after the solid globe had
been condensed by the molecular forces from a
chaotic nebula.   Nitrogen  is not only  exactly
adapted to the functions it subserves in the at,
mosphere, but moreover these are its only uses,
and I cannot see how it is possible to resist the conclusion that it was especially designed for the place
217
LECT. VII.] 
RELIGION AND CHEMISTRY.
it fills. That you may appreciate the strength of
this evidence, let me illustrate the subject by an
example from common life, which will be more to
our purpose than a philosophical analysis of the
argument itself.
It does not follow that the square granite blocks
which form the greater part of the front of yonder
magnificent warehouse, however well adjusted they
may be, were actually cut with reference to this
building, although the strong presumption is that
they were. Nor does it follow that those highly
ornamented window-caps and that elaborate cornice
were originally designed for this particular edifice,
although the presumption that such was the case is
still stronger than before. Nay, more, it is not even
absolutely certain that those skilfully carved ornaments which adorn the front, and are built into the
walls, were originally intended to be placed where
they are, although to doubt this conclusion would
be the extreme of incredulity. I admit, it is barely
possible that they were originally made for another
building, rejected, perhaps for some defect, and
afterwards put up here. But I will show you
where there is an evidence of design in the buildingmaterial of this warehouse which you will be forced
to accept. It is not conspicuous, and might be
overlooked. Just here at the corner of the building there is a very peculiarly shaped block of stone.
You never saw one like it before. This extraordinary shape was required by the peculiar form of
the building lot and the position of the walls on
218
[LLECT. VII. 
TESTIMONY OF NITROGEN.
the adjoining estate. The sides of the lot are not
perpendicular to the front, and the block has been
cut to the precise angle of the bevel, and at the
same time exactly fits the adjacent walls.   The
conclusion that this block was designed for that
place is irresistible. No sane mind would doubt it
for a moment. I do not say there is not one
chance in many millions, estimated on the doctrine
of probabilities, that a block of this exact size and
shape might have been found among the refuse
stock of the stone-cutter's yards; but I do say, that,
in the absence of absolute proof to the contrary, the certainty that this granite block was wrought with
reference to the place it fills, and that the exact
correspondence of its dimension and angles was the
result of measurement, is as great as it is possible
to attain by any process of reasoning short of a
mathematical demonstration; moreover, it is as
great as can be obtained in physical science, or
in any department of human knowledge one step
removed from the facts of consciousness or of observation.
The evidence that nitrogen was designed for
the place which it fills in the atmosphere is vastly
stronger than this. The force of the argument in
the illustration just cited evidently increases very
rapidly, the more singular the shape of the granite
block, and the more accurately its form has been
adjusted to the place it fills. Now nitrogen is as
unique among the chemical elements, as water is
among the compounds. Its external properties are
*   *  e*,  
ee'
219
LECT. VII.] 
RELIGION AND CHEMISTRY.
so entirely different from those even of the class of
elements to which it belongs, that chemists can
hardly believe that it is a simple substance, and for
the last fifty years have been vainly attempting to
decompose it; but it has resisted all their efforts,
and the more intimately they have become ac quainted with its properties, the more singular and
exceptional it has appeared. At the same time,
while presenting these remarkable anomalies, nitrogen has been fitted to the unique place which it
fills in the scheme of creation, with a nicety and
precision which it is as much beyond our powers of
thought to conceive, as it is beyond my feeble language to describe. It is not only that one or two
of the corners of this block of nature's edifice have
been bevelled to an exact angle, but it has been
adjusted at every point to the ten thousand conditions of that complex structure which I have
been describing, but how imperfectly! during this
course of Lectures, with a skill immeasurably
beyond all human art, and with an intelligence
which "looketh to the ends of the earth and seeth
under the whole heaven." If this is so, - and you
will find that my guarded expressions fall far short
of the truth, - why not use in these matters of
faith the same common sense which we apply with
so much success in common life, and which in our
daily intercourse it would be nothing short of madness to disregard? We do not hesitate to trust the
skill and honesty of a fellow-man, whom we not
only have never seen, but even as to whose char
220
[LECT. VII. 
TESTIMONY OF NITROGEN.
acter our sole evidence is the most indefinite testimony. Why, then, not accept the precious and
comforting truths of religion, and repose equal faith
in the providence of your Heavenly Father, on evidence which, you must admit, is ten thousand fold
stronger, and when you have everything to gain,
and nothing to lose? Is if said, there is still room
for doubt? Of course there is. God be thanked!
there is no relation in life in which there is not
doubt. Were there no doubt, there would be no
faith, no trust, no confidence, no love; the heart
would be absorbed in the intellect, religion would
become an axiom, and morality a formula of mathematics. Use but one half of the observation, one
half of the intelligence, which are never at fault
in the business of life, and these marks of the Creator's wisdom and providence which lie all around
us will become as evident as the sun. Act on
this evidence, and the door of grace will be opened,
new light will stream into the soul, and all nature
will be seen radiant with a Father's love.
All this striking evidence of design and adaptation we have discovered in the most obvious of the
attributes of nitrogen,- in those merely Compounds of
negative qualities in virtue of which it nitrogen.
increases the density of the atmosphere without
interfering with the functions of the active constituents. It would not, however, be in accordance
with that economy of resources which we find
everywhere in nature, that the uses of nitrogen
should be limited to this single object; and after
221
LEcr. VI.] 
RELIGION AND CHEMISTRY.
what we have already seen to be true in the case
of oxygen, we shall not be surprised to find this
singular element suddenly changing its character
and appearing in a new condition. The second
point, as you will remember, which I am to illustrate in regard to nitrogen, is the variety and remarkable nature of its compounds, as well as the
singularly oblique processes by which they are
formed; and, having examined the marks of design
it bears in its first manifestation, let us now study
the no less impressive evidence presented by the
second. It would be entirely out of place in a
course of Lectures like the present, to describe in
detail any of the countless nitrogenized compounds
which are known to chemistry, and it would require a long course of Lectures merely to illustrate
the characteristic features of the great classes into
which they may be subdivided. I shall be able
only to glance at a few general facts which illustrate the point now under discussion, and also the
part which nitrogen plays in organic nature.
Although nitrogen presents such an indifferent
exterior towards the oxygen of the atmosphere, it
can, nevertheless, be made to combine with it by
resorting to certain oblique processes, and there
Nitric acid. may be thus formed no less than five difNitric acid.
ferent compounds.  Every one is familiar
with that highly corrosive liquid called nitric acid,
and this is one of the compounds in question. Under certain conditions it is formed by the union of
the oxygen and nitrogen which are mixed together
222
[LECT. VII. 
TESTIMONY OF NITROGEN.
in the air. The only essential difference between
the bland atmospheric air and this highly active
chemical agent consists in the fact that in air the
elements are only mixed together, while in the
acid they are chemically combined. Were nitrogen to be suddenly endowed with the active affinities which from its position among the chemical
elements we might naturally expect it to possess,
then a large part of the atmosphere would be showered down upon the earth in floods of nitric acid.
It is only the unexampled inertness of nitrogen
which prevents the formation of this deadly compound. But although so corrosive when pure, nitric acid when immensely diluted is one of the few
materials which nourish and sustain vegetable life,
and therefore provision has been made that it
should be formed in the atmosphere, but only under very restricted conditions and to a very limited
extent. When electrical sparks are passed through
a confined quantity of air, in the presence of some
alkaline substance, such as potash, soda, or lime, a
very partial combination takes place between the
two elements, and an infinitesimal quantity of nitric
acid is formed. So also when organic matter decays
in the presence of these same alkalies, a similar combination, although to a very slight extent, results.
Nitric acid is endowed with such violent affinities
that it does not remain in a free state. It at once
enters into combination with the alkalies, forming a
class of salts, of which saltpetre is the best known
example, and from those salts the common nitric
15
223
LECT. VII.] 
RELIGION AND CHEMISTRY.
acid is extracted for the uses of the arts. Nitrogen,
you will notice, acts here very much like a selfwilled child. All the powers of nature cannot compel it to combine directly with oxygen; but if you
offer to it these alkalies as an inducement, and make
your approaches sufficiently indirect, you can coax
it to combine, and nitric acid is then formed. We
do not understand how the peculiar conditions just
mentioned conspire to produce the result; but the
whole phenomenon seems to be mysteriously connected with ozonized oxygen, and is undoubtedly
another phase of that obscure subject, allotropism, to
which we alluded in a previous Lecture. See now
how beautifully this attribute of nitrogen has been
adapted to the conditions of vegetable life, and
made the means by which the plant is furnished
with one of the articles of its food. Every discharge of lightning is accompanied by a partial
combination of the elements of the atmosphere, and
the nitric acid which is thus formed and washed
down by the rain-water serves to fertilize the soil
and bring the growing corn to maturity. So in
like manner, when life is extinct, and the organized
forms are resolved into their original elements, the
very process of decay causes a similar combination,
and thus sweetens the flowers which spring from
the grave.
But not only does nitrogen combine with oxygen. It unites also with hydrogen, that element
which is the very antithesis of oxygen, and forms
a most remarkable compound called ammonia.
224
[LECT. VII. 
TESTIMONY OF NITROGEN.
This substance is the very reverse of nitric acid in
all its chemical relations, but like nitric acid it is a
highly active and caustic agent.  I need
Ammonia.
not dwell upon this fact; for the common
smelling-bottle has made every one familiar with
this pungent substance. Nitrogen manifests the
same indifference towards hydrogen that it does
towards oxygen, and the two elements can be made
to unite only by indirect processes, which are not
well understood. The most important of these is
the process of decay. This destructive change in
all the higher forms of organized beings is attended
with the formation of ammonia, and the same nitrogenized compound is a uniform result of the normal functions of animal life. You will not, therefore, be surprised to learn that traces of ammonia,
as of nitric acid, are found in the atmosphere and
in all rain-water. Indeed, it is generally supposed
that the two are in combination, forming a salt
called nitrate of ammonia, but the amount present
is at best very small.
Ammonia is thought by many to be a more important article of vegetable diet than nitric acid;
but our knowledge of agricultural chemistry is very
imperfect, and chemists are not agreed on many
of the most fundamental points.* Still, as I have
* Since these Lectures were written, it has been stated by several
investigators that the chief nitrogen compound in the atmosphere and
in rain-water is nitrite of ammonia, which differs from the nitrate of ammonia mentioned above only in containing a smaller proportion of oxygen. Whether the last is also normally present does not yet appear, and
to what extent the one or the other may be concerned in the processes of
225
LECT. VII.]
i 
RELIGION AND CHEMISTRY.
before stated, nitrogen is an essential element of
all the higher forms of corporeal vitality, and compounds like those we have been considering are
the appointed channels by which it is introduced
into the organization of the plant. Had these compounds been allowed to form to any extent in the
atmosphere, they would soon have rendered the
globe uninhabitable.   It was  therefore essential
that nitrogen should be endowed with that unexampled inertness which it manifests in its gaseous
state. But had not at the same time a power of
combination, under certain restricted conditions,
been granted, this chemical element would not
only have been an isolated phenomenon in nature,
an exception to its general laws, but its usefulness
would have been restricted to the least remarkable
of its functions. Unlike the results of human skill,
this creation of Divine wisdom has been adapted
vegetable growth, has not been determined. From one point of view,
nitrite of ammonia may be regarded as composed of nitrogen gas and
water, and some chemists believe that it is formed by the direct union
of these two substances, and that this union is favored by the processes
of evaporation, combustion, and decay, which are constantly going on in
the atmosphere. This theory is certainly supported by many facts, and
those who hold it generally believe that nitrite of ammonia is the chief,
if not the sole, source from which the plants derive their supply of nitrogen, while others attach only a secondary importance to the recent experiments. If the theory is correct, the formation of nitrate of ammonia-  the presence of which in surface-water, and in the soil, under
certain conditions, is beyond doubt- would be the natural result of
the subsequent union of nitrite of ammonia (formed as just described)
with the oxygen of the air; but, as intimated above, the whole subject
is still very obscure, and from any experiments yet made we should not
be justified in drawing definite conclusions.
226
[LECT. VIL 
TESTIMONY OF NITROGEN.
to the most varied and apparently incompatible
ends; and while in the atmosphere it is a mere dead
weight, it is also the most plastic of the elements, is
capable of entering into the most complex relations,
and thus serves as the peculiar substratum of all
the higher forms of organized being.
The last point I am to illustrate in regard to
nitrogen is perhaps the most characteristic of its
features, and it is one on which its rela                                          Instability of
tions in the scheme of organized nature nitrogenized
very greatly depend.   All the compounds compounds.
of nitrogen are very unstable, and the slightest
force is generally sufficient to overpower the delicate affinities by which the elements are held together, when the nitrogen at once returns to its
home in the atmosphere. Although this inert element may be coaxed into combination, it never
forms strong compounds. Its affinities, although
so varied, are at best very feeble and delicate. It
is always a weak timber in a chemical structure,
and when this timber breaks, as it certainly will,
sooner or later, the whole falls. You will need no
further illustration of this fact than to be told that
gunpowder, percussion-powder, and gun-cotton are
all nitrogenized compounds, and owe their wellknown properties to the weak affinities of this element. Nitric acid is only a little more stable than
these explosive agents, and ammonia, although one
of the most permanent of nitrogenized compounds,
is still very easily decomposed. Passing next to
organized substances, we find this distinguishing
227
LECT. VII.] 
RELIGION AND CHEMISTRY.
character still more  conspicuous.   As we  have
already seen, it is always the nitrogenized compounds which start the decay in vegetable or animal structures; and thus the great characteristic
feature of all organized matter, its proneness to
change and decay, nay, even death itself, is clearly
foreshadowed in the properties of nitrogen. When
the Creator first endowed this element with its
feeble affinities, He also passed the doom of all living creatures: "Dust thou art, and unto dust shalt
thou return."
Here I must leave this division of my subject.
It would be highly interesting to study the innumerable phases in which nitrogen manifests itself
in the world of living matter; to trace how, under
the guidance of that mysterious principle of life, the
most complex organic compounds are educed from
such simple materials as water, carbonic acid, ammonia, and nitric acid; to follow these nitrogenized
compounds through their varied history, from the
time they are first generated in the plant until they
are incorporated into the brain, the muscles, and the
bones of man; to notice at every stage the same
instability which so strikingly characterizes all the
compounds of this singular element, capable of existing only under the continued influence of the vital
principle, and, when that ceases to act, gradually
degenerating and falling back into the simple products from which they sprang; but all such details
would be incompatible with the plan of these Lectures, and must therefore be reluctantly passed by.
228
[LECT. VII. 
TESTIMONY OF NITROGEN.
If, however, I have been able to place before you in a
clear light the main features of this remarkable element, - its isolated existence in the atmosphere, its
unparalleled inertness in the aeriform condition, its
power of combination under restricted conditions,
the great variety and complexity of its compounds,
and, finally, their singular proneness to decomposition and decay, - it is all that I could expect. We
have seen that in each of these respects nitrogen
has been adapted with exquisite skill to the unique
part which it plays in the scheme of the world; and
this element, although outwardly so unattractive
and dull, has borne the richest testimony to the
wisdom, the goodness, and the power of God.
Having now become acquainted with the characteristic features of nitrogen, let us next consider
the part which this element plays in that Circulation
grand circulation of matter in organic na- of nitrogen.
ture, which has been already in part described. I
have before stated that the plant is a true apparatus
of reduction, in whose leaves carbonic acid is decomposed by the solar light. The plant absorbs carbonic acid partly through its leaves from the air,
and partly through its roots from the soil. The
sun's'rays, acting upon the green surface of the leaf,
decompose in some mysterious way the carbonic
acid, overcoming the intense affinities of its elements, fixing the carbon, and setting free the oxygen, to be restored to the air. From the carbon
thus obtained, and from the water, ammonia, and
229
LECT. VII.] 
RELIGION AND CHEMISTRY.
nitric acid, which are the other articles of its food,
together with a few inorganic salts, the plant constructs its tissues. If in their production carbonic
acid and water alone take part, there result such
The plant   substances as woody fibre, starch, g,m,
of organucic   and sugar, and of these nine tenths of all
materal.   vegetable structures consist.  If the nitrogen compounds are likewise employed in the
process, these are formed, besides, such nitrogenized products as albumen, caseine, and fibrine.
These last names may not be so familiar to you as
the first, but you are equally familiar with the substances, and will recognize them at once when told
that the white of an egg is nearly pure albumen,
that cheese consists almost entirely of caseine, and
meat of fibrine.  Although these substances are
best known to us as animal products, they are likewise found in all those vegetables which are articles
of food. Albumen and caseine can readily be extracted from either peas or potatoes, and gluten,
the substance which gives tenacity to flour-paste,
has the same composition as animal fibrine.
The animal, unlike the plant, has not the power
of forming the substance of its tissues from inor         ganic compounds, but it receives them
The animal
an assimilator ready formed from the vegetable kingand conumer. dom. It transmutes the vegetable products into a thousand shapes in order to adapt them
to its uses, but its peculiar province is to assimilate
and consume, not to produce. The nitrogenized
compounds just referred to are the portion of its
230
[LECT. VH. 
TESTIMONY OF NITROGEN.
food which supplies the constant waste attending all
the vital processes. The non-nitrogenized starch
and sugar, although they form the greater part of
our food, are never actually incorporated into the
tissues of the body, and, as we have already seen, are
merely the fuel by which its temperature is maintained. The animal may either receive its nitrogenized food directly from the plant, as is the case
with all herbivora, or only indirectly, like the carnivora; but in either case the origin is the same, and
by the process of digestion these, originally at least,
vegetable products are assimilated and converted
into bones, muscles, or nerves, as the necessities of
the animal may require. We find that during this
process these substances do not undergo any fundamental change, but merely become parts of more
finely organized tissues. We discover in the blood
albumen and caseine, having precisely the same
composition as that which may be prepared from
potatoes, and the substance of the muscle does not
differ essentially from the gluten of flour-meal.
Do not, however, suppose that the part of the animal is less noble than that of the plant. It is really
much higher.  We must be careful to make
Distinction bea distinction, too frequently overlooked, tweenmatter
between the organized structure and the andorganism.
material of which it consists. There is the same
difference here as between a house and the bricks
of which it is built. It was formerly supposed that
organic matter was formed under peculiar influences,
and subject to special laws. But it is now known
231
LEcr. VII.] 
RELIGION AND CHEMISTRY.
that animal and vegetable substances obey the same
laws of affinity as mineral matter, and the recent
progress of chemistry has given us great reason to
believe that we may be able one day to prepare all
the materials of which plants and animals build
their cells. Here, however, chemistry stops and creation begins. The great Architect of nature alone
can fashion this dead material into living forms.*
The vegetable kingdom is a great laboratory, in
which the sun's rays manufacture from the gases
of the atmosphere, and from a few earthy salts of
the soil, the different materials which the organic
builders employ. There the bricks are made, and
from these the animal builds his bones and muscles.
He does not make the bricks, but he does what is
far more glorious, he builds with them his delicate
frame, and as the work of the builder is higher
than that of the brick-maker, so in the scale of being is the animal higher than the plant, and the
more noble in proportion as its structure is more
intricate and elaborate.
While the plant is a true apparatus of reduction,
the animal is a true apparatus of combustion, in
which the substances it derived from the vegetable
are burnt and restored to the atmosphere in the
form of carbonic acid, water, and ammonia, ready to
* I do not forget the alleged facts of spontaneous generation; but in
all cases where living organisms have been produced without visible
germs, there has been a falling back of organized material from a higher
to a lower condition; and, if we except certain very untrustworthy experiments of the late Mr. Weekes, in no case has even the lowest type
of an organic cell been produced from unorganized matter, unless
through the natural processes of growth.
232
[LECT. VII. 
TESTIMONY OF NITROGEN.
be again absorbed by the plant and to repass through
the phases of organic life. Our bodies are furnaces,
- furnaces continually burning, - whose
Motion in the
fuel is our own flesh, and the smoke of animal therewhose  fires is the food of the plant.  ultofbrning.
Every time I strike a blow a portion of the muscle is consumed, actually burnt up in producing
the force. In every muscular effort I make, in
every word I utter, in every step I take, a portion of the muscles concerned is burnt, and motion
can no more be produced in the animal body without a combustion of its tissues, than it can be generated in a steam-engine without burning fuel under its boiler. As in the steam-engine the burning
fuel is the source of its power, so in the animal
body the burning muscle is the immediate cause
of all its motions. I will to strike a blow, but it is
not I that produce the motion. It is the muscle,
and in the exertion the muscle is consumed. The
muscle, however, does not originate the motion,
any more than the fuel originates the motion of
the steam-engine. The fuel, we have seen, does
not originate heat. It is merely a reservoir of
heat, and in burning it merely gives up the heat
it once received from the sun. So the muscle is
merely a reservoir of force, and in burning it gives
out the force it contains. The force it contains it
also received from the sun, when its substance was
formed by the sun's rays acting upon the leaves of
the plants.
What a wonderful revelation is this! Muscular
233
LECT. VII.] 
RELIGION AND CHEMISTRY
power originates in the sun. We do not create
Muscular   the force; we do not originate it; we
power origi-  mrlt
nates inghe  merely excite it.  The force which origirun.     nally came from the sun lies dorminant in
the muscles until our will calls it into activity.
Our bodies are machines, perfect machines it is
true, but yet machines. Like all other machines,
they merely transmit power, they cannot create it.
They very closely resemble a steam-engine.  As we
must constantly feed the engine with fuel, so we
must supply our bodies with food in order to repair
the muscle which is burnt, and we can no more be
said to originate that force which manifests itself in
our bodies, than the stoker, who shovels the fuel
into the grate, can be said to originate the force of
the steam-engine. We are not our bodies, although
we live in them, and direct their motions. They
move by forces which emanate from a source far
higher than us, and we stand in the same relation
to them in which an engineer does to his machine.
Certainly Lavoisier, the great father of modern
chemistry, had caught a glimpse of the results
which it has been left for more modern science to
establish, when he wrote: " Organization, sensation,
voluntary motion, life, only exist on the surface of
the earth, and in places exposed to the light. It
might be said, indeed, that the fable of Prometheus
was an expression of a philosophical truth, which
had not escaped the penetration of the ancients.
Without light, nature were without life and without soul; a beneficent God, in shedding light over
234
[LECT. VII. 
TESTIMONY OF NITROGEN.
creation, strewed the surface of the earth with organization, with sensation, and with thought."
Although, my friends, it thus appears that our
bodies are mere channels of force, machines whose
motive power emanates from the great Relation of
centre of the solar system, let us, while mind to
we recognize this startling result of sci- matter.
ence, remember the no less certain fact of consciousness, -that we are not our bodies, though we live
in them,- that this conscious personality is something entirely apart from, and infinitely superior to,
these corporeal atoms in which it is temporarily enshrined, surviving as it does all their changes. Let
us also keep clearly in view the still more glorious
truth, that this machine, with all its infinite capabilities of good and evil, is put entirely at our command; that not one conscious motion can take
place unless we will it; and that this will of ours can
set in action a chain of causes which no space can
bound and no time can limit. Let us then well consider how great is the power which has thus been
delegated to us, let us duly weigh the awful responsibility it involves, and so act that, when the Master
claims his own, we may not be ashamed to render
up the account of our stewardship.
Moreover, although it is true that these bodies
themselves are constantly dissolving into air, that
the material atoms which compose them will in a
few short weeks all be gone, and that The ital
there is nothing but the shadow of our principle.
forms which we can call our own, we must also re
235
LECT. VII.] 
RELIGION AND CHEMISTRY.
member that there is a mysterious principle with in, constantly renewing and reparing our wasting
frames,-a cunning architect superintending a thou sand builders who are constantly reconstructing,
with materials prepared by vegetation, the bones,
the muscles, and the nerves, as fast as they are
wasted and consumed; making, in a most mysteri ous way, beyond all human comprehension, here the
fibre of a muscle, there the filament of a nerve, here
building up a bone, there uniting a tendon, fashion ing each with scrupulous nicety, and fitting each to
its place with never-failing skill. But no sooner is
the work of the architect done, than another great
power comes in to destroy it. The oxygen gas
which the blood absorbs in the lungs and carries
to the different parts of the body burns up these
carefully elaborated tissues, converting them into
carbonic acid, water, and ammonia, which pass
into the atmosphere, from which they originally
came.   Life is, in fact, a constant struggle between the builders and the destroying element of
the air; and when its short term is ended, and the
builders cease because they are wearied and few,
then " the dust returns to the earth as it was, and
"the spirit returns unto God who gave it."
But let us not sorrow as those who have no hope;
"for we know that if our earthly house of this tab"ernacle was dissolved, we have a building of God,
"an house not made with hands, eternal in the
"heavens." And cannot He who has clothed us
with our earthly house provide for us a better and
236
[LECT. VI. 
TESTIMONY OF NITROGEN.
more enduring mansion? and are not all these wonderful changes in our present bodies a foreshadowing of the final consummation, when our earnest desire "to be clothed upon" shall be satisfied, and
"mortality shall be swallowed -up of life "?
Such is a very imperfect sketch of that great
cycle of changes, of which all organic nature is
merely a passing phase.  Let us review
for a moment  its main features.  When
the foundations of the globe were laid, there were
collected in the atmosphere all the essential elements of organized beings. From this inexhaustible storehouse the plant absorbs water, carbonic
acid, and ammonia, which were placed there for its
use, and which have been made to serve as its nourishment and food. It is the special office of the
plants to elaborate from these few mineral substances, and a small amount of earthy salts, all the
materials of organized beings. The animal receives
these crude materials already prepared, and builds
with them its various tissues; but no sooner are
the cell-walls finished, and the structure ready to
discharge its vital functions, than it is consumed
by almost the very act which gave it life. The carbonic acid, water, and ammonia are restored to the
atmosphere, and the cycle is complete.
Of this Divine economy the sun's rays are the
great moving cause, and it is their mysterious power
which is constantly reappearing in all the varied
phases of organic life. And not in these alone;
for, as we have seen, this same gentle influence
237
LECT. VII.] 
RELIGION AND CHEMISTRY.
keeps in motion the aerial currents which blow our
ships across the ocean. It raises the water which
turns the wheels of our factories. It drives the locomotive over the iron road, and impels the steamer
through the waves.  It roars at the cannon's mouth,
and charges the grander artillery of the skies.
There is no motion on the globe which cannot be
traced directly or indirectly to the sun, and were
his rays to lose their mysterious power, all nature
would become silent, motionless, and dead.*
But in thus tracing to the sun all these varied
phenomena, let us not forget that we have not yet
found the great First Cause. The problem is not yet
solved; the profoundest truth has yet to be told.
This mysterious force, which the sun pours in ceaseless floods upon the earth,-whence comes it? You
have already answered the question. The answer
is on your lips.  I have but to re-echo it, and how
can I better do this than in the words of that blind
poet to whom misfortune had revealed the true
meaning of light!
"Hail, holy Light! offspring of Heaven first born;
Or of the Eternal co-eternal beam
May I express thee unblamed? since God is light,
And never but in unapproached light
Dwelt from eternity, dwelt then in thee,
Bright effluence of bright essence increate."
* For a most eloquent statement of the same truth I would refer the
reader to the closing chapter of a recent work by Professor Tyndall of
London, on Heat considered as a Mode of Motion. It is but justice to
myself to state that the last half of the present Lecture was first delivered before the Lowell Institute, in Boston, in the winter of 1853 - 54,
essentially as it now stands.
238
[LECT. VI. 
LECTURE VIII.
ARGUMENT FROM SPECIAL ADAPTATIONS.
I HAVE endeavored thus far in this course of Lectures to present a few of the prominent illustrations
of the attributes of God, which have been discovered
in the adaptations of the atmosphere to the conditions of organic life on the earth. We have read together one brief chapter of that evidence of design
with which the book of nature is filled, and
Adaptations
I cannot but trust that we have gained a proofof
from our study nobler conceptions and God's being.
more enlarged views of the wisdom, power, and
goodness of our Heavenly Father. Every one who
accepts the Bible as a divine revelation will rejoice
to find how beautifully and how entirely the facts of
science confirm its great fundamental truths. But
have not these evidences of nature a greater value
even than this? Do they not prove, independently
of all revelation, the existence of a wise and omnipotent First Cause, at least so far as there is any moral
certainty in the world? I am persuaded that they
do, and I believe that they furnish the only logical
ground on which a system of revealed religion can
be based. In my introductory Lecture I stated
that I preferred to discuss the adaptations of nature
as illustrations of the attributes of God, rather than
16 
RELIGION AND CHEMISTRY.
as absolute proofs of Ilis being; but now that we
have surveyed the ground, let us consider whether
they are not really moral proofs, with all the certainty that any proof not strictly a mathematical
demonstration can give.
The argument from adaptation is one which addresses itself to every human being. It is suited to
every intellect, and comes home to every man's exCharacterof perience. It is based on a principle of
le g,,nt.
theargumentthe human mind, -whether the result of
experience or of intuition we need not inquire,which compels it to infer design when it sees adaptation. Who doubts that the flint arrow-heads and
stone implements found in New England, rough and
misshapen as they are, were made by men? To
question the universal belief would be regarded as
little short of insanity. Why then not apply the
same common sense to the interpretation of nature? The unlettered do, and believe, in their simple
faith, that the feathered songster and the delicate
flower were made by their Heavenly Father's hand.
It is only those of us whose minds have been unsettled by the subtilties of logic who doubt, and, if
we could analyze our doubts, I think they would be
found, in most cases, to arise from a vague fear that,
since nature stands on a level so much above man's
experience, the ordinary principles of reasoning may
possibly not apply, and we may be misled by apparent analogies. But why this fear? There is no
essential difference between the adaptations foLmd
in nature and the adaptations made by men. Both
240
[LF-CT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   241
employ means to attain some important result, and
in many cases they secure the end by precisely the
same means. The telescope and microscope are but
reproductions of the eye, and, although very imperfect reproductions at the best, they imitate in all
their essential features this beautiful optical apparatus of nature.*  It is true that the adaptations of nature are vastly superior to the results of human skill,
and it is also true that their origin is beyond our
personal experience. We have seen the process of
making a watch and the process of making a telescope. We know how the principles of both were
discovered, and the whole subject lies within the
range of our experience; but no man ever made or
ever can make an eye, and the entire process of its
growth and development is utterly beyond the
range even of man's conception.  All this is true;
but if you reflect a moment, you will find that this is
just what is to be expected, seeing that God is the
Creator and we are His creatures, and so far from
weakening, this very characteristic greatly strengthens the evidence. Moreover, it must be remem
* The power which the eye possesses of adaptation to near and distant objects, combining the uses of the microscope and the telescope,
and the capacity of self-adjustment, preserving always a perfect achromatism and freedom from spherical aberration, have never been reached
in nearly the same degree by art. Moreover, in the eye this perfection
is attained with a focal length of only half an inch, which vastly increases the difficulty. It is also a fact worthy of notice, that the improvements in optical instruments have preceded rather than followed the
discoveries of physiologists, thus serving to explain the functions of
the eye; and inventions like that of achromatic lenses, to which men
have been led by theoretical study, have been found to be anticipated
in nature. 
RELIGION AND CHEMISTRY.
bered that, if the design is of an infinitely higher
order, the evidence of the design is infinitely more
ample. A rude, misshapen image is a convincing
evidence of human intelligence; but all nature with
its numberless adaptations - from the properties of
the crude elements up to the wonderful structure
of the human frame -is given us as evidence of
the wisdom of God.
The argument from the adaptations of nature is
of the kind we call cumulative.  Its force depends
on the concurrence of many and varied The argument
examples.  It is not based on one isolated cumulative.
case of adaptation, or even on a thousand; but
there is a host of conditions, which no man can
number, each adjusted to each, and all bound together in one harmonious whole. Consider only
the examples we have discovered in the very narrow field to which we have limited our study.
How numberless are the conditions on which the
harmonious working of the varied functions of the
atmosphere depends! In the first place, there is
the expansive tendency of the air, sustained by the
solar heat, and restrained by the force of gravity,
by which alone it is held to the surface of the
globe. Then there is the density, exactly adjusted
to the human organism, and depending on the
measures and weights of the solar system. Next
there are all the delicate relations to light, heat,
and electricity. Passing to the separate constituents of the atmosphere, there is oxygen, with its
three distinct modifications, endowed with fiery
242
[LECT. VIIL
I 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   243
affinities, and yet so carefully guarded as to be a
beneficent servant of man, intrusted with most
varied and seemingly incompatible functions, and
discharging each with equal fidelity and precision;
next, there is water, nourishing all nature with its
dews and rains, tempering the polar climates with
the latent warmth of its genial currents, and protecting with its great frost-blanket the delicate
plants from the winter's cold, - exceptional in all
its qualities, and each adapted to some beneficent
end; then comes carbonic acid, concealing in its
transparent folds the solid frame-work of all organized beings, and the source of those priceless beds
of coal, with their inexhaustible stores of heat and
force; and lastly, but not least in interest or importance, there is nitrogen, so remarkably inert, and
yet endowed with such varied affinities, forming
such numberless compounds, and imparting to all
such singular instability. As we thus hastily review the ground we have surveyed together, you
will recall the numerous adaptations which we discovered while studying the wonderful cycles of
change in which all these substances conspire, wheel
revolving within wheel, and yet all moving with
such delicacy and beauty of adjustment that no jar
is felt through all this complicated mechanism, and
not the slightest derangement occurs in any of its
ten thousand parts.
Now the argument for design unfolded in this
brief chapter of the book of nature comes home to
us with the cumulative weight of all this testimony, 
RELIGION AND CHEMISTRY.
Perhaps plausible objections might be urged against
individual examples of adaptation which have been
advanced; but any one who questions the general
fact must be prepared to disprove all. Were there
but a single instance of adaptation, or only two or
three, the sceptic might urge with a show of reason that this was the result of accident, -arose
from the  fortuitous concourse of atoms "; but the
examples of adaptations which we have discovered
merely in the atmosphere, all interlacing with each
other, and all working together in the general
scheme, are by themselves alone so great a number
that, if we take no higher ground than the mathematical theory of probabilities, the chances against
the supposition that this system, even as we know
it, was the result of accident, are almost infinite,
and can be expressed numerically only when the
sands on the sea-shore are counted. If such, then,
is the weight of the evidence which the atmosphere
gives, what must be the force of the argument in
which all nature joins its united testimony? Truly,
the number of atoms in the universe is not sufficiently large to express the probabilities against
this forlorn hope of atheism!
But, my friends, the sceptic should be heard, and,
having presented our side, let us listen to what he
Summingup of has to say in reply.   The whole arguthe argument. ment from special adaptations may be
summed up in a few words. Within the sphere of
human experience, adaptation proves the existence
of an intelligence adequate to the conception and
244
[LECT. VIII.. 
Licr. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   245
execution of the design. We find in nature adaptations similar to the results of human intelligence,
only of an infinitely higher order, and hence by
analogy we conclude that these must have issued
from an infinitely wise and omnipotent Designer.
The argument assumes the reality of the human intelligence as consciously a power and an originator
within its own sphere, and reasons from this to a
similar conscious intelligence in the Author of nature. The argument assumes, also, the truthfulness
of the human faculties as a source of knowledge,
without which it is of course useless to reason
at all.
Now the adaptations of nature are facts which
every one must admit, the sceptic among the rest.
Moreover, he must also admnit that the
Burden of
conclusion which we  have drawn from proofis with
these premises is the all but universal the sceptic.
conclusion of mankind. Plutarch, writing eighteen
centuries ago, without the light of the Christian
revelation, bears this remarkable testimony to the
universality of the religious idea:  "If you  go
through the world, you may find cities without
walls, without letters, without rulers, without dwellings, without wealth, without money, without theatres and manly sports; but there was never yet
seen nor will be seen by man a single city without
temples and gods, or without prayers, oaths, proph ecies, and sacrifices, used to obtain blessings and
benefits, or to avert curses and calamities. Nay, I
am of opinion that a city might be sooner built 
RELIGION AND CHEMISTRY.
without any ground beneath it, than a commonwealth could be constituted altogether destitute of
belief in the gods, or, being constituted, could be
preserved." * The discoveries of modern travellers
have not more fully confirmed the general truth of
Plutarch's statement, than the experiments of modern socialists have proved the soundness of his
opinion. No savage tribe has yet been found on
which a belief in a higher power has not at least
glimmered, and no community which has attempted
to ignore religion has lasted a generation.   The
sceptic, then, if he rejects our conclusion, is bound
to prove that the natural inference of man is based
in error. If he sets aside the general rule of faith,
and refuses assent to the universal creed,- "Quod
semper, quod ubique, quod ab omnibus creditun
est," t - he must explain, whatever theory lie may
adopt, how it comes to pass that all mankind have
been duped, and all nature has issued in a lie. The
burden of proof is with him, and how does he meet
it? Generally, in one of two ways.
In the first place, he attacks the validity of the
conclusion on purely speculative grounds, saying
Universal   that adaptation is no longer an evidence
cepticism.   of design when applied to subjects beyond
* EVPOLe 8' av  e7rl&v lro6XLa adrTElXrov, aypauLatrovv, a Oa-LXErovs,
aoL'Kovs, adxpltzarovv, volito-uarov pr7 aeotzvas, 7rEipovv Oda'rpov KaL yvzuva1ao)V advipov ~e  7rdXEco  KaL dOEov, laH  XpouE'vrl EfZXaLS, ItLqac oPpKoL.,!qrE
pAavre,lats, tzr, OvaLa&s Eer ayaOov, pr8' a7rorpo7ra7s KaKYv, OUVL  I(rrTLv
oZ8' ErraL 7YFYOVYa OEari7v' adXak 7rod'X  av Po~ oOK& El!aXov X'ov OV X pL,
i1 iroXLreLa 7. 7'Ep'L 0e,v 8drs' v6LatpEOfL'on  7ravrcirao&,'orao'tY XaELi,y
XaloDo'a r7pw1oat.  Plutarch, YIpos KoX~orqv, xxxi.
t Vincentius Lerinensis, written 434 A. D.
246
[LECT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   247
the range of all human experience. He may support this position by questioning, with Hlume, the
competency of the human faculties as a source of
knowledge, or, like Comte, he may deny all final
causes, and maintain that there is no evidence of
anything behind the external phenomena of nature; but whatever form the scepticism may assume, the conclusion is the same, and the argument
for design is ruled out as invalid.
With regard to this position I have only a few
words to say. Design in nature, I admit, cannot
be demonstrated; for the truths of natural
Design not
religion cannot be evolved from a math- capable of
ematical formula.  The argument is based demonstration.
on analogy, and although the analogies are so close
and so broad that to my mind they amount to
moral proofs, and the conclusion appears as certain
as any theorem of geometry, still I admit that, in
the technical language of logic, the evidence is
probable, and not demonstrative. But as a student
of physical science, it is not my business to defend
the credibility of the human faculties, or to discuss
the doctrine of causation. The task belongs to the
metaphysicians, and, as I stated in my first Lectrue, I shall not encroach on their peculiar province.
Nor do I think it important to dwell on the value
of analogical reasoning. Modern writers have not
been able to add much to Bishop Butler's masterly
discussion of the subject, and every man, however
sceptical he may be in his speculative opinions,
must admit, with the author of" The Analogy," that 
RELIGION AND CHEMISTRY.
"probability is the very guide of life."  One consideration, however, may be of value in answering
objections; namely, that, since the difficulties which
are found in natural theology reappear with equal
strength in all departments of knowledge, no objections can be reasonably urged against the methods
of the former, which apply equally well to our most
familiar processes of thought. - It may be fairly presumed that such objections are more apparent than
real, and that they indicate not the inconsequence
of our logic, but only the necessary limitations of
our faculties.
Now analogy is not only the guide of common
life, but it is also the basis on which physical
science chiefly rests; and if this method of reasoning be disallowed, all the results of science beyond
those of mere observation and demonstration must
fall with it. It is frequently said, that scientific
truth can be demonstrated, but religious truth must
be accepted on faith; and in part this is true; but
the statement is one of those loose sayings whose
Provinceof partial truth only renders the latent error
demonstration. more dangerous. No word is more frequently misused than demonstration. Technically,
this term only applies to that form of absolute
proof with which we deal in geometry or pure
logic; but, popularly, a principle is said to be demonstrated when all that can be claimed for it is a
high degree of moral certainty. In this double use
of the term the error of the above statement lies,
for it is made in one sense, and -frequently at
248
[LECT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   249
least - understood in the other. Truth wholly new
is never reached by demonstration; for demonstration cannot yield what is not already implied in
the premises with which it starts. The truths of
geometry and mechanics may be demonstrated; but
then they are virtually contained in the axioms and
definitions on which these sciences rest. All scientific generalization is based on analogy; and moreover, a great mass of the scientific truth which lies
within the range of direct observation we owe to
the same principle; for even here analogy directed
the student to what he subsequently observed.
Indeed, the great inspiring and directing power
in the mind of the successful investigators of nature is the force of analogy.  It is this Anal,ogythe
which constantly leads them to pronounce ~nchief guide
in physical
conclusions unsound, although apparent- science
ly sustained by experiment, and to accept others
which are seemingly at variance with facts. It is
this which leads them through long and laborious
investigations to establish principles which they believe to be true, and sustains them in their efforts
through successive failures to ultimate success. As
indefinite and uncertain as the analogies of nature
frequently seem to be, as unsatisfactory as they
may appear to the great mass of mankind, and as
impossible as it is to make them intelligible except
to those already versed in scientific inquiries, yet
the history of science shows that, when based on an
extended knowledge and a mature experience,
they very seldom lead astray. 
RELIGION AND CHEMISTRY.
The method of scientific discovery is frequently
misunderstood, and the philosophy of Bacon, how         ever important in correcting old abuses,
Method of
scientific   has done not a little towards creating the
discovery.   misapprehension.  Many persons seem to
think that the author of the Novum  Organum
gave to man a rule, by which, with the aid of a sort
of mechanical logic called induction, the laws of nature may be discovered, very much as a last is
turned out by a lathe. Yet nothing could be further from the truth. So far as the observation of
phenomena is concerned, - which must always be
the occupation of the great mass of scientific men,
-the methods are as mechanical as those of
other learned professions, requiring chiefly a quick
eye, a delicate touch, a ready perception, and most
of all a clear head capable of discriminating between
the accidentals and the essentials, which are always
singularly blended in natural phenomena. But
the great generalizations, which form the framework of knowledge, are not reached by rule; nor
as a general thing are they in their inception of
slow growth. On the contrary, they usually come
First the   like intuitions to the mind, with the raconception. pidity of the lightning's flash, and it is frequently possible to mark the day and the hour when
the revelation was made. But such revelations of
scientific truth are vouchsafed only to those highly
favored minds which through long study and pa.
tient investigation have been brought into perfect
sympathy with the harmonies of nature; and if we
250
[LECT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   251
analyze the conditions of the mental process, we
shall find that these great discoveries are really the
result of analogical reasoning.
But although the conception is thus sudden, the
verification of the truth is frequently long and laborious.  Great discoveries are not achieved Afterwards the
in an hour or a day.  Nature has so con- verification.
cealed her truths, and surrounded them by so many
adventitious circumstances, that they can be disclosed to the world only after long and careful study.
First comes the conception, afterwards the toilsome
investigation by which it is proved that the facts of
nature accord with the generalization. The investigation may lead to a great modification of the
original idea, or may show that it must be wholly
abandoned, and meanwhile another may have taken its place, to go through the same scrutiny in its
turn; but still the conception which proves to be
the law of nature is the real discovery. This, as
we have seen, is the result of analogy, and most
clearly vindicates the relationship of the mind of
man to the Intelligence whence issued the Universe.
Every great scientific generalization will illustrate more or less clearly the principles here
stated. It is true that many minds fre- Illustration of
quently concur in developing one grand the method.
idea, and the evolution may occupy so long an interval of time that the new truth appears to be the
growth of an age, rather than the gift of any one
man. Yet it is possible in almost every case to
trace the successive steps of the discovery. This is 
RELIGION AND CHEMISTRY.
especially true of the law of gravitation. Whether
the first idea was suggested to Newton by the fall
of an apple, it is not important to inquire; but the
popular anecdote illustrates the nature of the original thought, which was undoubtedly sudden and
intuitive, although, as Newton has himself expressly stated, it was the result of analogical reasoning.
The conception once formed, the work of verification was long and laborious, and the results were
at first so unsatisfactory, that Newton at one time
abandoned his theory altogether, as unsupported by
observation. It was not, indeed, until a new arc
of the meridian had been measured by Picard in
France -several years after the first conceptionthat the facts were found to agree even approximately with the theory, and astronomers have been
occupied ever since in verifying the grand thought.
The same general facts reappear in the case of the
wave-theory of light, first conceived by Huyghens
and subsequently verified by the successive discoveries of Malus, Fresnel, and Young; and we may
lay it down as an almost universal principle, that
scientific truth is discovered through analogy and
verified by comparison with the facts of nature.
If now you will turn to the great central truth
of natural religion, you will find that it has as good
The fundamen- credentials as the best established laws of
tal truth of science. We have first the conception,natural religion 
restsonthe  not only the conception of a few highly
sanle basis as gt      b *nvr*
the laws of   gifted minds, but the universal conception
science.    of mankind.  We find afterwards this con
252
[LECT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   253
ception verified, - not only in the history of the
race, but also in the experience of each individual
man, and moreover the conception is apparently intuitive in every mind. Even if the sceptic denies
the reality of both special and general providence,
he must admit that, as the almost universal rule,
both history and experience have only served to
confirm and strengthen the religious idea.
We return now to the remark above quoted, better able both to appreciate the truth it contains and
to unmask the fallacy it conceals. It is true that a
large part of the results of science may be demonstrated, but the truths which are capable of this
absolute proof are already contained in the premises on which the demonstration rests; they are in
all cases reached by the human intelligence working
on its own definitions and processes of thought, and
this, too, even when the theoretical truth is afterwards found realized in nature. The highest forms,
however, of scientific truth are not capable of denm onstration, and rest only on probable evidence, al though the probability in their favor is so great as to
beget the highest degree of moral certainty. In like
manner, a great part of the truths of religion must
be accepted on faith; but then the evidence in favor
of the great fundamental truth of natural religion
is as strong as the evidence for the law of gravita tion, and the certainty is as great. More- Province
over, faith is not peculiar to religion. All of faith.
our knowledge not the result of personal observa tion and investigation is held on faith, that is, on 
RELIGION AND CHEIISTRY.
trust in other men, and absolutely all knowledge is
held on trust in the authority of our own powers.
Much of the knowledge which we hold without question, it is utterly beyond the capacity of our own
intellects to verify, and moreover, no one doubts
the existence of truths which now lie beyond the
scope of the most gifted genius, but which hereafter
may be attained by man.   The scientific  truths
which it is not essential for us to know are left in
the dark on purpose to stimulate study, and thus
to educate the human race. Religious truths, on
the other hand, it is essential for us to know, and,
since they in like manner transcend our present
powers, they have been specially revealed. We are
called upon to accept them on sufficient evidence,
and this is all that is meant by faith. Faith, then, is
as truly a ground of belief in science and in commnon life as it is in religion, and it occupies a more
important place in religion only because religious
truth is itself so important, and so greatly transcends, in its essence, our limited human faculties.
Our reply, then, to the first position of the sceptic is this. Your objections apply as well to all
knowledge as they do to religious truth, and, if you
are consistent with yourself, you must reject the
evidences of science as well as the evidences of
religion. As we are not prepared to go this length,
we shall with equal consistency hold to both. It is
but justice to state that Hume, the most philosophical of the sceptics, pushed his speculations to their
necessary consequences, and denied the existence
254
[LECT. VIIL 
LECTr. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   255
of matter and spirit alike. But although from its
very boldness difficult to refute, this form of scepticism is by no means the most dangerous; for in the
present age of the world a system of philosophy is
not likely to gain many adherents which, in the first
article of its creed, utterly shocks all human selfconceit, by declaring that man neither knows nor
can know anything with certainty.
In the second place, the sceptic attacks the argument for design by setting up a theory of his own
to explain the origin of the universe. He Absolute
tacitly admits that the burden of proof is materialism.
with him, and that, if he rejects the popular belief,
he is bound to sho how this cosmos might have
been issued without intelligence and without a God.
This he attempts to do, and the result is nearly as
many theories as there have been strong scientific
intellects in the world united with unbelieving
hearts. To refute each of these theories in detail
would be a labor like that of Hlercules in slaying
the L      ernnan Hydra; for until Almighty Power
shall sear the foul sore from which the whole brood
proceeds, their unholy heads will start up more rapidly than they can be cut down. The most daring
theories of this kind are those of the German materialists of the present day. As much as they may
differ among themselves in regard to details, the
boldest of these speculators agree in maintaining
that absolutely nothing exists, or ever has existed,
except matter and motion; that matter in its essence is uncreated and eternal; that motion is self              17
. o 
RELIGION AND CHEMISTRY.
sustained; that mind is only a mode of motion, and
that all the phenomena both of matter and of mind
are the working out of an inexorable necessity.
Hence they conclude that religion is a fable, and
immortality a dream.
Here is atheism.   This is the natural fruit of
materialism; and we are glad that it has ripened,
that men may see how disgusting and revolting it
is, and how corrupt the tree must be which can
bear such fruit. We are glad that men should
know what must be the result of all their vain
speculation and the seeking after false gods. The
theory is perfectly consistent with itself, and an
absolute necessity if nature be divorced from its
Creator; for all philosophy has proved that either
the theory of the Christian, or this theory of the
materialist, with all its enormity, must be true.
There is no half-way halting-place between. This
course of Lectures has been a continued protest
against the materialist's interpretation of nature,
and I have not another word to add; for if a man
wishes to believe that his purest loves and his holiest affections are only motions of brain-particles,
nothing that can be said would have the slightest
weight. If he has not already the refutation in his
own consciousness of being, human power cannot
aid him; no philosophy can extricate him from
the slough.  "Ephraim is joined to idols: let him
alone."
It is seldom, however, that materialism shows its
revolting features among us. It is too cunning
256
[LECT. VIII. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   257
and too cautious.  It always appears disguised,
and is for this reason far more seductive. It presents the attraction of great learning and
Materialism
of great apparent profiundity, entangling initsmore
1 > ]~~~~~~rfie forms.
many  in  its meshes  before  they are refed forms.
aware of their danger. It does not deny the reality of the human intellect, but, on the contrary,
takes pride in its authority and power. It even
admits the evidence of design, but at the same
time insidiously undermines all religious belief;
not so much, however, by what it declares, as by
what it leaves to be inferred; not so much by the
doctrines it inculcates, as by the spirit it keeps alive
and fosters. In this refined form, materialism is by
far the most prevalent phase of the unbelief of our
time, and it is difficult to meet chiefly on account
of its very vagueness and simulation. It lives almost entirely in the ever-changing theories and
speculations of science, which it utterly misinterprets and misapplies, forgetting that they are merely provisional expedients, which the next wave of
advancing knowledge may wash away. Development is the pet word of its philosophy, and it
constantly aims to show how the whole Development
scheme of nature, with all its adaptations, theories.
might have been evolved through the concurrent
action of various unintelligent causes alone. As
it attacks the argumenit for design on scientific
grounds, it becomes the duty of the student of nature to expose its errors. It is, however, a most
protean antagonist, and no sooner is it defeated in 
RELIGION AND CHEMISTRY.
one form than it reappears in another.  Every new
development theory in any department of science
furnishes it with fresh food. For a long time the
famous nebular hypothesis of Laplace supplied it
with abundant nourishment, and quite recently it
has taken a fresh start, and grown most vigorously,
on Mr. Darwin's very ingenious book entitled "The
Origin of Species." But these are only two examples of a large number of similar works, which, being less able and less original, have had their day
and been forgotten.
The danger of these works lies not so much in
what they actually contain, as in their general
The danger of tendency; not so much in the theories
such theories. of their authors, as in the wrong conclusions which will inevitably be drawn from them,
and to which in many cases they logically lead.
Darwin, for example, professes to show that all the
living forms of plants and animals, man included,
have been during the geological ages slowly developed from a few germs, or possibly from only one, by
the action of a principle which he calls the "law of
natural selection," and he sustains the hypothesi by
a most formidable array of experiments and facts.
Such a theory as this, ingenious if not true, professing to explain one of the greatest mysteries,
and presented in a fascinating style, finds its converts everywhere, and this, too, on grounds entirely
independent of its scientific merit. That very same
noble aspiration which leads men to imperil even
life itself in investigating the secrets of nature,
258
[LECT. VIII. 
LECr. VII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   259
makes them also ready to lend a willing ear to any
theory which professes to explain the mystery of
creation. Hence the reason why works like the
Vestiges of Creation, and those just mentioned,
captivate and injure so many. If they merely
stimulated curiosity, and led to study, no one could
object to their influence, however erroneous he
might think their philosophy. But, unfortunately,
most readers, of whom it is no disparagement to
say that they are not in a condition to weigh the
evidence, accept the theory without examination,
and, if sceptically inclined, their whole belief in an
overruling Providence is shaken to its base.
It is in vain to urge that these theories may be
consistent with a pure faith; for as long as they are
not so regarded by the popular mind, -which invariably appeals to them as proofs of materialism, -
the evil which they cause is not remedied. It may
be said, and said with some justice, that a writer
cannot be blamed for the abuse of his Dutyof
theory; but it must be admitted  that scientific men.
the abuse is a great evil, and an author, if he be a
religious man, is bound to guard against it by every
means in his power. We should be very slow to
charge any man with infidelity, for we know how
often the human mind, in its eccentricities and inconsistencies, has united a true faith to the most
sceptical and subversive speculations. But we do
say, that the least a Christian philosopher can do
for his faith is to give such a tone and spirit to his
work as to render misinterpretation impossible; and 
RELIGION AND CHEMISTRY.
if he neglects to do this, he has no right to complain if his own opinions are misjudged. It is to no
purpose to reply, that religion is out of place in a
work on science; for the class of books to which we
refer are not addressed to scholars, but to the general reading public, and, in some cases at least, they
are appeals from the settled convictions of thinking
men to the unformed opinions of the popular mind.
A scientific man who presents his theories in an attractive form to the public, before they have passed
the ordeal of criticism by his peers, appeals to a
court which has no right to judge, and whose
opinion would be worth nothing if given. Real
and permanent injury may be thus inflicted, and
an author has no right to take advantage of the
ignorance of his readers. If he does this to gain a
transient notoriety, it may be a pardonable error;
but I cannot find language sufficiently strong to
express my condemnation of those popular writers
who insidiously undermine the faith of the community by imposing crude speculations on their ignorance.
I shall not attempt to discuss the intrinsic value
of the various theories of development. They have
all been judged in a competent court, and the almost unanimous verdict of scientific men has been
simply "not proven." This is true even of the
nebular hypothesis of Laplace, which many astronomers are inclined to accept as a convenient theory,
a sort of scaffolding for their science, but as nothing
more durable; and still more is it true of the differ
260
[LECT. VIII. 
LECr. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   261
ent theories which from time to time have been
advanced to explain the origin of species. Man
will not be likely to disown his divine parentage
until some at least of the links which connect him
with the brutes can be pointed out. If any theory
of development be true, there must have been an
indefinite number of links between the noblest chimpanzee and the most degraded Hottentot, and yet
the progressionists, Darwin included, have failed to
discover a single one.
But leaving to those who are competent judges
the task of exposing the unsoundness of these
speculations, let us inquire what bear- Development
ing they have on the evidence of de- theories do not
impair the atsign.  I answer,  absolutely  none.  As- gumentfor
suming that Mr. Darwin could establish design.
his peculiar theory in all its generality, - and I
have no doubt that it has an element of truth,
- it would not impair the evidence of design in
the slightest degree, and the same is true of any
development theory whatsoever short of absolute
materialism. Those persons who imagine that they
overthrow natural religion, fall into a capital error.
It requires manifestly the same infinite intelligence
to create a universe by a process of development
as by a single creative fiat. Your belief that the
beautiful piece of mechanism standing on your
mantel-shelf was made by an intelligent man, would
not be impaired if you were told that the artist was
employed several years in its construction. The
evidence of design in the clock is in its beautifully 
RELIGION AND CHEMISTRY.'
adjusted mechanism. The evidence of design in
nature is in the wonderful adaptation of its parts.
We can easily go back in the geological records to
the time when the present order of nature did not
exist, and the fact that the innumerable forms of
organic life, with the adaptations of currents, soil,
and climate essential to their being, have been developed out of the conditions which existed on the
globe during the coal epoch, is no less an evidence
of design, than the fact that the clock was developed
out of the crude iron and brass used in its construction.
"We lament," says a recent writer, "to see the
question between a sudden and a gradual genesis of
organic types discussed on both sides - not, indeed,
by the principals in the dispute, but by secondary
advocates -too much as if it were a question between God and no God. In not a few of the progressionists the weak illusion is unmistakable, that
with time enough you may get everything out of
next to nothing. Grant us, they seem to say, any
tiniest granule of power, so close upon zero that
it is not worth begrudging; allow it some trifling
tendency to infinitesimal increment; and we will
show you how this little stock became the cosmos
without ever taking a step worth thinking of, much
less constituting a case for design. The argument
is a mere appeal to an incompetency in the human
imagination, in virtue of which magnitudes evading
conception are treated as out of existence, and an
aggregate of inappreciable increments is simulta
262
[LECT. VIH. 
LECT. VIII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   263
neously equated in its cause to nothing, in its effect to the whole of things.  You manifestly want
the same causality whether concentrated on a moment or distributed through incalculable ages, only,
in drawing upon it, a logical theft is more easily
committed piecemeal than wholesale. Surely it is
a mean device for a philosopher thus to crib causation by hair-breadths, to put it out at compound interest through all time, and then disown the debt;
and it is in vain, after all; for dilute the intensity
and change the form as you will of the Power that
has issued the universe, it remains, except to your
subjective illusion, nothing less than infinite, and
nothing lower than divine."
So far as the genesis of nature is concerned, I am
not sure that a development theory is not the more
probable. At all events, it is a question of facts to
be decided by scientific investigation, and by that
alone. Let us insist that all theories of cosmogony
shall be judged on their own merits; but let us
also insist that they shall be kept within their own
sphere, and not allowed to have a voice in questions on which they have absolutely no bearing.
Again I repeat, no development theory can impair
the evidence of design; for that evidence is based on
facts wholly independent of any theory of cosmogony, and to which all theories must conform. If
they do not, they will inevitably fall. Thile difficulty
to my mind in Mr. Darwin's particular theory is not
in its development feature, but in the fact that he
refers the development to what I can understand 
RELIGION AND CHEMISTRY.
only as an unintelligent cause. HIe may be able to
give a different interpretation to his theory, and I
greatly regret that he does not; but unless he can
show that it is consistent with the action of an in telligent First Cause, it will soon be forgotten, like
those that have gone before it. This is the crite rion by which all such theories are finally judged,
after the excitement of the controversy by which
they are heralded has passed, and after the common
sense of mankind has settled down upon its sober
second-thought.  That they have an injurious bearing while they last, is frequently more the fault of
the secondary advocates than of the principals in
the dispute, and we must not expect to cure the evil
by indiscriminate censure or by social excommunication. So long as man thinks, he will speculate;
and I rejoice that neither political nor ecclesiastical tyranny  can touch this prerogative of free
thought. The true remedy consists in exposing
the fallacy of the shallow philosophy which is so
ready to bring forward these crude speculations as
proofs of materialism, and also in diffusing among
educated people more spiritual views of nature
and its laws.
To this subject I shall return in the next Lecture.
But so far as the argument for design is concerned,
all these considerations are unnecessary. The evidence is so ample and broad, that we can afford to
waive all that part of it which has been called in
question by the progressionists; without weakening
in the slightest degree the force of the argument.
264
[LECT. VIII. 
LECT. VII.] ARGUMENT FROM SPECIAL ADAPTATIONS.   265
Before the first organic cell could exist, and before
Mr. Darwin's principle of natural selection could
begin that work of unnumbered ages which was
to end in developing a perfect man, nay, The evidence
even before the solid globe itself could of design in
be condensed from Laplace's nebula, the matter prior
chemical elements must have been creat- ries of devel                                             opment.
ed, and endowed with those properties by
which alone the existence of that cell is rendered
possible.
But although, for the sake of argument, we might
yield to the progressionists all those examples of
adaptation which they claim to explain by their
theories, such a concession is really of no value.
The parts of nature, as we have seen, are so intimately linked together that, if there is design anywhere, there is design everywhere; and as the
structure of the human body is prefigured by the earliest vertebrate forms buried in the geological strata,
so, and as unquestionably, the whole scheme of
organic life is prefigured in the gases composing the
atmosphere. If, therefore, I have proved that there
is evidence of design in the constitution of the atmosphere, I have also proved that the whole scheme
of nature is the result of Divine Intelligence, and
that the great argument of natural theology rests
on a basis which no present theories * of develop
* We of course refer only to such theories and speculations as are
based on observed facts; for no others are worthy of serious consideration. Science has not as yet gone one step behind the chemical elements, and until it has, no speculations in regard to a primordial condition of matter can have any bearing on our subject.
0 
RELIGION AND CHEMISTRY.
ment can touch. To show that there is evidence
of design in these stones of nature's edifice has been
the chief object of this course of Lectures. It has
been my constant aim to set forth in a clear light
the startling fact that the footprints of the Creator
are nowhere more plainly visible than on that very
matter which the materialists so vainly worship,
and if I have thus been able to remove doubts
from the mind of any honest seeker after God, I
shall feel that my labor has not been lost.
But however earnest our purpose or sincere our
convictions, the spectres of our doubts will sometimes return, and hover around these evidences of
our faith. Treat them not lightly either in yourself
or in those you love. Respect all honest doubts;
for it is the noblest natures which feel them and
suffer most.  His must be a dull heart which is not
sometimes appalled by the mystery of our being.
Remember, however, that these doubts are from
within, not from without. They are the offspring of
your fears, and not of your science. The evidence
is ample. It is more faith that you need. Fight
then these spectres of your mind as you would the
enemies of your peace, not with doubtful disputations, but with earnest thought and prayer, and
Power shall be with you
" in the night,
Which makes the darkness and the light,
And dwells not iir the light alone."
266
[LECT. VIII. 
LECTURE IX.
ARGUMENT FROM GENERAL PLAN.
IT has been my object in the previous Lectures
of this course to develop before you the great argument of Natural Theology as it is presented by the
atmosphere. I have endeavored to show that there
is abundant evidence of design, even in the properties of the chemical elements, and hence that the argument rests upon a basis which no present theories
of development can shake. Having dwelt upon the
argument from special adaptations at as great length
as my time will permit, I wish in my Lecture of this
evening to ask your attention to another class of
evidences of the Divine attributes, which, although
less conspicuous, may be even more impressive to
some minds than those we have studied. The indications of an Infinite Intelligence are not only to be
found in the adaptations of nature, but they also appear, and still more visibly, in the grand laws by
which the whole material universe is directed.
I am well aware that the laws of nature, so far
from being regarded as evidences of the existence
of a beneficent God, are felt by many minds to be
actual hinderances to their faith. They are thought
to give to the whole scheme of nature a mechanical
aspect, and to be inconsistent with belief in a su 
RELIGION AND CHEMISTRY.
perintending Providence. I also know that there
are many scientific men who regard the laws of na ture as the manifestation of blind physical forces,
and who recognize a Providence, if at all, only in
the very few recorded instances where the normal
action of these forces has been averted by a special
miraculous interposition. But even admitting this
philosophy, still I think it will appear that these
laws bear so conspicuously the marks of Intelligence, and are so analogous to the results of human
thought, that we cannot resist the conclusion that
they were originally, at least, ordained by an intelligent Creator, or in other words that the laws of
nature are the thoughts of God. For myself, I regard the laws of nature as the most direct evidence
possible of Infinite wisdom, and it will be my object
to show that this opinion is sustained by the strongest analogies.
Regarded from a scientific point of view, physical
laws are merely our human expressions of that
Definition of order which we discover in the material
physical laws. universe. In its highest form, the law is
capable of a precise quantitative statement, and
gives the bases for mathematical calculation and
prediction. Thus the law of gravitation enables
the astronomer to calculate what will be the position of the bodies of the solar system at any future
epoch, and to predict almost to the very second the
exact time when an eclipse will begin, and what
will be the precise path of its shadow over the
earth. The greater part of the laws of nature do
268
[LECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
not, however, admit of precise mathematical statement, and are inerely the expressions of the order
which has been observed in the phenomena of nature, whether in respect to form, in respect to number, or in any other particular. It is convenient to
distinguish these merely phenomenal laws from the
higher class, which are usually called dynamical
laws; but the distinction is an artificial one; for it
is probable, at least, that in all cases the phenomenal laws are merely the phases of some higher dynamical law not yet discovered. Moreover, if we
believe that all phenomena are direct manifestations of the Divine Will, then there is no law apart
from God. His action is not necessitated or prescribed by any conditions, even although imposed
by Himself.  He is constantly acting in nature,
consciously and freely; but He acts uniformly,
consistently, and with a plan, because He is omniscient and omnipotent. Man acts with inconstancy, because he is a finite being, and must be
guided by probabilities; but with God, who seeth
the end from the beginning, there is no "variableness, neither shadow of turning."
The whole material universe may then be re.
garded as the manifestation of one grand comprehensive creative thought, which God is slowly'working out in nature. To study this thought in all its
details is the prerogative of man, and this study
has been the appointed means of cultivating his intellect and elevating his condition. From time to
time the more gifted students have caught glimpses
269 
RELIGION AND CHEMISTRY.
of parts of the grand thought, and these glimpses
we call laws; but even the law of gravitation, the
most perfect of all, is felt to be but a partial truth,
and all eternity will be required to comprehend
the scheme. Let us now, in order to elucidate and
confirm this simple doctrine, compare some of the
laws of nature with the results of human thought,
and, whatever may be our theory of causation, we
cannot but be impressed with the striking analogy
between the two.
The idea of symmetry is inherent in every human mind. It may be more or less cultivated by
The idea of experience, but the germs of the idea are
symmetry. found even in the savage. However rude
his condition, man is pleased with a symmetrical
disposition of objects, and his taste is offended when
the laws of symmetry are grossly violated, although
he may have no name for the idea. Corresponding
with this idea in our minds, we find symmetry everywhere in nature. The parts of an animal are symmetrically arranged round the body, and the leaves
of a plant are symmetrically disposed around the
stem, but nowhere in nature is the idea of symmetry so fuilly developed as in the mineral kingdom.
Almost every solid substance, when slowly deposited from a liquid or aeriform condition, assumes
rystals. a definite symmetrical shape which is peCrystals.
culiar to the substance. Such symmetrical forms are called crystals, and the process by
which they are obtained is called crystallization.
Freedom of motion- such as the particles of mat
270
[LECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
ter have in the fluid condition- is an essential
condition of crystallization. Moreover, as the substance becomes solid, the particles must have sufficient time to arrange themselves in accordance
with the tendency of the molecular forces, and the
longer the time occupied in the process of crystallization, the more perfect we find the crystals. The
perfect crystals represent the natural condition of a
substance, and the peculiar form is the most essential and characteristic of all its properties.
Crystals are always polyhedrons, that is, solids
bounded by plane faces, and these faces are symmetrically disposed about certain straight  ystems of
lines called axes.  Moreover, it has been crystals.
observed that, although we might conceive of an
infinite number of systems of straight lines, there
are only six, or at most seven, such systems in nature, and all crystals, with possibly one exception,
are formed by the symmetrical disposition of planes
around one or the other of the six systems represented in Fig. 2. The first five of these systems
have each three axes, and the last alone has four.
In No. I the three axes are of equal length and at
right angles to each other. This arrangement is
called the monometric system, from two Greek words
signifying one measure. In No. 2 the axes are all
at right angles, as before; but the vertical axis is
either longer or shorter than the other two. This
is called the dimetric system, - two measures. In No.
3 the axes are still at right angles, but of unequal
length. This is called the trimetric system, - three
18
271 
RELIGION AND CHEMISTRY.
Fig. 2.
measures.  In No. 4 all the axes are of unequal
length, as in the last, and the two horizontal axes
are at right angles. The vertical axis is also at
right angles to one of the horizontal axes but it is
_f       ~inclined to the other.  Hence the sys               tem is called the rnonoclinie stsWm,
one inclination.  In No. 5 the three
axes are all unequal in length, and all
at oblique angles with one another.
Fig,. 3.
Fig.    Hence the system is cailed the t(riclinic
system,- three inclinations.  Lastly, in No. 6, there
are four axes; of these, three are horizontal, and
form the diagonals of a regular hexagon, as shown
by Fig. 3, and one is vertical, and at right angles
272
[Lier. IX. 
ARGUMENT FROM GENERAL PLAN.
to the plane of the first three.  This is called the
hexayonal system. In all these figures the ends of
the axes have been connected by lines, in order to
render the character of the systems more evident.
It is now easy to see how far the idea of symmetry in man corresponds with the idea in nature;
for, assuming these systems of axes as they Forms ofthe
are found, we may arrange planes around firtsystem.
them in accordance with our ideas of symmetry,
and then compare the results with nature. Let us
now take the simplest of the systems, and fol.
low out this idea. It will be
evident on a moment's reflection, that the number of axes
or lines of symmetry in a crys- 
tal must be at least three in
number, and it will also be evi- 
dent that the simplest arrangement of three straight lines is        Fig. 4.
that represented in No. 1 of.
Fig. 2. This is called the monometric system of
axes, and the lines, as stated above, are all equal,
and all at right angles to each other. More6ver,
by passing a plane through every two of these
axes, as in Fig. 4, we may divide the space around
them into eight similar parts, called octants. Let us
proceed now to dispose planes symmetrically around
these three axes, according to our own ideas of symmetry and entirely independent of any observation
of nature.
We  may,evidently,begin by placing a plane at
LECT. IX.]
273 
RELIGION AND CHEMISTRY.
the end of one of the axes, and perpendicular to it,
as is represented in Fig. 5. But
perfect symmetry will now re                    quire us to place a plane in a
similar position at the other
end of the same axis, and also
at the two ends of each of the
other axes. The result of such
Fig. 5.       a disposition  will be a solid
bounded by six planes, called
a cube. No. 2 in Fig. 12.
Next we may place a plane so as to touch the
ends of two axes and to be par                    allel to the third, as in Fig,. 6.
But symmetry will now require
us to place a plane in every
other similar position, and the
result of such a disposition will
be a solid bounded by twelve
Fig. 6.       planes, called a dodecahedron.
No. 3 in Fig. 12.
Again, we may place a plane so as to touch the
ends of all three axes, as in
Fig. 7. Symmetry will now
require us to place a plane in
every similar position, and the
result will be a solid bounded
by eight planes, called an octa                   hedron.  No. I in Fig. 12.
Fig. 7.          Then we may place a plane
touching the end of one axis,
274
[LECT. IX. 
LECTr. IX.]   ARGUMENT FROM GENERAL PLAN.
but so inclined as to intersect the prolongation
of the other two axes at still greater, but equal,
Fig. &                                Fig. 9.
distances from the centre, like the plane 1: 2: 2
in Fig. 8.* Symmetry will now require that we
should place three such planes in each octant, making twenty-four planes in all, and the intersections
of these planes will give the form represented by
No. 4 in Fig. 12.
Further, we may place a plane touching the ends
of two axes, and intersecting the prolongation of
the third at any given distance from the centre, as
1: 1: 2 in Fig. 9.* Symmetry will now require
that we should place three similar planes in each
octant, twenty-four in all, and the intersection of
* These figures represent only one octant, see Fig. 4. The portion
of the plane 1: 2: 2 in Fig. 8, and of 1: 1: 2 in Fig. 9, which appears
on the resulting form, has been shaded, as have also the portions of the
two planes which start from the corresponding points on the other axes
of the same octant. The end of the axis is assumed to be in each case
at the points marked 1.
275
~ig. ~. 
RELIGION AND CHIEMISTRY.
these planes will give the form represented by No.
5 in Fig. 12.-  -
Also;,.we may place a plane touching the end of
one axis, parallel to the second axis, and intersecting the prolongation of the third at some given
distance from the centre, as either of the planes
1: 2 in Fig. 10.  Symmetry will require us to place
a plane in every siinilar position, and we shall thus
obtain the figure bounded by twenty-four faces
represented by No. 6 in Fig. 12.
Lastly, we may place a plane touching the end
of one axis, and intersecting the prolongations of
the other two at unequal distances from the centre,
like either of the two planes 1: 3:   in Fig. 11.
Symmetry will require us to place six such planes
in every octant,- two at the end of each axis,
making forty-eight in all, and we shall thus obtain
the form represented by No. 7 in Fig. 12.
276
[LECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN..
Of these seven forms, the first three which make
the vertices of the triangular group, are absolutely
invariable.  We may have cubes of different siz(es,
but the relative inclination of the planes is absolutely the same in all, and this is also true of the
octahedron, No. 1, and of the dodecahedron, No. 3.
It is different, however, with the other four forms.
Here also the general disposition of the planes, and
the general appearance of the form, are always the
same; but the relative inclination of the planes may
vary to a limited extent.
Consider, for example, the form No. 5 in Fig. 12.
This form is composed of planes touching  the ends
of two axes and intersecting the prolongation of
Fig. 12L
2,7 
RELIGION AND CHEMISTRY.
the third at any given distance from the centre, as
shown in Fig. 9. Now it is evident that we may
have an infinite number of planes fulfilling these
conditions. The plane must touch the ends of two
axes, and so far it is fixed; but it may intersect the
prolongation of the third at any given distance from
the centre,- at a distance of twice the length of
the semi-axis, or of two and a half times the length,
or of three times the length, or at any other distance. In this way its position may be varied infinitely; but whatever position is given to the first
plane, all the rest must be perfectly symmetrical
with it.
Consider, now, what change such a variation in
the position of the planes will cause in the form.
You will notice, by examining No. 5 in Fig. 12, that
the form may be regarded as an octahedron, No. 1,
bearing a triangular pyramid on each face. When
every plane touches the ends of all three axes,
the form becomes an octahedron.  If the planes,
still touching the ends of two axes, intersect the
prolongation of the third at twice the length of
the semi-axis from the centre, the form is that represented in No. 5. If they intersect at three times
this length, we shall have a similar form, only the
pyramid will be more elevated. If they intersect
at four times this length, the pyramid will be still
higher; and so on, until the planes intersect the
third axis only at an infinite distance, in other
words are parallel to it. Then the faces a and b
on No. 5 will fall into the same plane, and we
278
[LE,CT. IX. 
LCTr. IX.]   ARGUMENT FROM GENERAL PLAN.
shall have the dodecahedron No. 3.  Thus you see
that Fig. 5 is an intermediate form between the
octahedron No. 1 and the dodecahedron No. 3,
shading into them on either side.
In like manner No. 4 is a variable form, intermediate between the octahedron and the cube. So
also No. 6 is a variable form, intermediate between
the dodecahedron and the cube; and finally, No. 7,
the central form, is intermediate between all the
rest, as indicated by the lines of the figure.
Such are the seven forms which we have been
able to obtain by arranging planes around the regular system of axes, according to our idea of perfect
symmetry. Moreover, since these seven forms, with
the variations above described, are the only forms
which we can obtain unless we violate this idea of
perfect symmetry, they may therefore be regarded
as the perfect embodiments of this idea as it exists
in the human mind.
But it is well known that partial symmetry is frequently as pleasing as perfect symmetry. For example, in disposing ornaments in a square room,
perfect symmetry requires the architect to place the
same ornament on each of the four walls. Yet a
certain symmetry is preserved, and at the same
time variety obtained, if only the ornaments on the
opposite walls are made alike; and such a disposition is less stiff than the other.
Now if we apply this principle in arranging our
planes around the axes, we shall obtain in addition'
to the first group of seven forms two other and sim
279
I 
RELIGION AND CHEMISTRY.
Fig. 13.
ilar groups, which may also be regarded as the embodiment of the idea of symmetry, although not of
perfect symmetry. These groups are represented
in Figs. 13 and 18, and the forms numbered alike
correspond in all three. The manner in which
the forms  of the second group are derived from
those of the first is illustrated in Figs.  14,  15,
16, and 17.
Thus in Fig. 14 we have first the shaded form of
the octahedron No. 1 of the first group.  Next we
have, circumscribing the first, the outlines of the
tetrahedron, as it is called, which is No. 1 of the sec ond  roup, and it will be noticed that the planes of
the tetrahedron correspond precisely in position to
280
[LEcT. IX. 
LECr. IX.]   ARGUMENT FROM GENERAL PLAN.
the alternate planes of the octahedron; but they
are proportionally much larger,
and  there are only half as
many.  To carry out a previous illustration, it is as if; instead of hanging a picture on          _
every wall of a square room,
we should hang one on only
every other wall.                      Fig.4.
If now you will: turn back
to, No.4 of the first froup, it will be  seen that, corresponding to each plane of the
octahedron, there is in this form
a set of three planes;- just as
if, instead of hanging a single 
picture on each wall of a square
room, we should hang in each
place a group of three pictures.
Returning again to No. 4 of the         Fig. 15.
second group, it will be evident
fromn inspection, that in this form  a set of three
planes occupies the position of
each plane of the tetrahedron,
that is to say, the groups of
three pictures have been hung
on only every other wall; and
if next you examine Fig. 15
where the form of the second
group is circumscribed around          Fig. 16.
the corresponding form of the
first group -you will readily perceive that the 
RELIGION AND  CHEiMISTRY.
sets of three planes on the outer form occupy the
same position as the alternate sets of three planes
on the inner form.
In like manner, Fig. 16 shows the relation between the two forms numbered 5 in each group, and
Fig. 17, that between the two forms numbered 7.
In No. 5 of the frst group, as in No. 4, there are
three  planes in  he  place of every plane of the
octahedron;-that is, three pictures have been
hung on each wall, but they have been differently
arranged among themselves.  In No. 5 of the sec                    ond group the relative arrange                    ment of the three planes is the
_same as before, but the sets are
(-~ A D S   placed only in every other posi                    tion,-that is, the pictures are
grouped in the new way, but
hung only on every other wall.
;Fig. -7.     So also in No. 7 of the first yroup
we have a set of six planes in
the place of every plane of the octahedron-  six
pictures peculiarly grouped and hung on every wall.
In No. 7 of the second group we have the same set
of six planes placed only in every other position,six pictures grouped as before and hung on every
other wall.
The idea of symmetry which is carried out in all
these forms is evidently that of the octahedron,
which corresponds to the square room in our illustration.
Now if in developing this same idea, we attempt
282
[LIECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
tO derive a hemihedral* from  either of the forms
No. 2, 3, or 6 of the first group, we shall be surprised
to find that no new form results.  The reason is
this.  If you divide up the planes of either of these
forms into sets which shall correspond in position
to the faces of the octahedron, it will. be found that
the same plane always belongs to two or more sets.,
It makes, therefore, no difference whether we place
the sets in every position, or only in every other
position.  The same form results in both cases.  It
is as if the ornaments in our  square room were
brackets, which we could not put in their required
places in the corners against one wall  without haVig them touch the adjoining wall also.
Thus it is that these three forms, regarded from
one point of view are-holohedralt and belong to the
yrst group, while, regarded from another, they are
hemihedral,* and belong to the second. Such anoma-l
lies as these are not uncommon in science.  It is
frequently the case that, to our finite minds at least,
the same substance, or the same form, is an embodiment of two different ideas, so that, while, regarded
from one point of view, it falls into one group of our
classification, regarded from another, it belongs to
quite a different one.
Passing lastly to the third yrgoup, Fig. 18, we find
another set of hemihedral forms, but they are based
on quite a different idea of symmetry; not the idea
embodied in the octahedron, but that which is real
* Having half the number of possible planes.
t Having the fill number of possible planes.
283 
RELIGION AND CHEMISTRY.
Fig. 18.
ized in the form No. 6 of Fig. 12, called the tetrakis-hexahedron (froin Greek words meaning four
times six planes). This form is bounded by twentyfour planes placed in the positions already indicated
in Fig. 10.  If now we place planes only in every
other one of these twenty-four positions - as shown
in Fig. 1-  we shall obtain the form No. 6 of Fig.
18, bounded by twelve pentagons
Comparing next No. 7 of Fig. 12 with No. 6 of
the same group, we shall find that a pair of planes in
the first corresponds to each single plane in the last.
When, therefore, we place a pair of planes in every
one of the twenty-four positions occupied by the
planes of No. 6, we get the form No. 7, bounded by its
284 ~
[LECT. IX. 
LET. IX.]   ARGUMENT FROM GENERAL PLAN.
forty-eight planes; but if we place a pair of planes
only in every other position, as shown by Fig. 20,
we shall develop the form represented by No. 7
of Fig. 18, which is bounded by only twenty-four
planes.  Applying now the same idea to the other
five forms of the,first group, we
find that no new forms are produced;so that of the forms of
the third group only two differ
from those of the frst, and the
reason here is the same as that
already given to explain the similar cases in the secondgroup. The      Fig 19
like forrms may be regarded as
embodying at the same time two different ideas of
symmetry.
I could easily show that the hemihedral forms in
each of the last two groups are related among themselves precisely in the same way as are the holohedral
forms of the first group, but I
am afraid I have already been
too abstruse, and I will not further trespass on your patience. 
Suffice it then to say, that the
three groups of forms we have
figured  are  the  only forms          Fig. 20.
which we  can obtain by arranging planes around the monometric system of
axes, according to the idea of symmetry as it exists
in our minds, and they may therefore be regarded
as the complete embodiment of that idea.
285 
RELIGION AND CHEMISTRY.
Let us now turn to Nature, and compare her
handiwork with these products of our own thought.
Mineralogists have found that the crystals of gold,
silver, copper, the diamond, the ruby, common salt,
alum, fluor-spar, galena, iron pyrites, and a very
large number of other substances, are all formed
around the monometric system of axes, and these
crystals have invariably* one or the other of the
forms we have described. Moreover, the forms of
the crystals of each substance are limited to those of
one group.t Thus we find crystals of fluor-spar in all
the forms of the first group, but never in those which
are peculiar to the other two. In like manner, the
crystals of a complex ore of copper, called tetrahedrite, have exclusively the forms of the second
group, while those of iron pyrites occur only in the
forms of the third. Each substance follows a certain idea of symmetry, which seems to be inherent
and a part of its very nature; so much so, that
when from any cause the character of the symmetry
changes, the substance loses its identity, and even if
its chemical composition does not change, it becomes
to all intents and purposes a different substance.
What has been shown to be true of the regular
system of axes is equally true of the five other systems which have been observed in nature. By arranging planes symmetrically around these axes we
* In some cases a substance crystallizes in the forms of two different
systems, but then the properties differ in the two states as widely as the
form.  The diamond and plumbago are examples of this.
t There may be exceptions to this rule, but if so they have not been
distinctly stated.
286
[LECT. IX. 
LEcT. IX.]   ARGUMENT FROM GENERAL PLAN.
can develop an immense number of forms by a
pure process of thought, and it is these forms alone
which we find among natural crystals. The products of Nature's laboratory correspond, then, exactly to the results of our own thoughts; and how
can we resist the conclusion that they are the manifestations of the thoughts of an intelligent Creator?
In the language of science, the crystal is said to
obey the law of symmetry; but obviously this law
is merely the reflection of the same simple idea
which exists in our own minds, and which must
have previously existed in the mind of God. The
whole science of crystallography is a development
of this idea of symmetry. Like geometry, it is a
product of pure thought, and its truths are entirely
independent of their material forms. Indeed, the
mineral kingdom, so far as it is known, does not
perfectly represent the idea of symmetry, even as
it exists in the human mine There are possible
forms which have never been obtained in nature,
and the science, even as we know it, could never
have been developed by observation alone.
- By following out the simple idea of symmetry,
which is common to all men, we have found that the
results of our own thought perfectly agree Idea of
with the facts of nature.  Let us now take number.
another of the primary ideas which exist in the
human mind, and see how fully that is realized in
the material creation. The idea of number is as inherent in the mind as that of symmetry. I shall
not attempt to discuss its origin or trace its devel             19
287 
RELIGION AND CHEMISTRY.
opment; but assuming, as all will admit, that the
results of human skill constantly exhibit simple numerical relations, let us inquire whether the same
characteristic may not be discovered in nature.
I have already defined a chemical element as a
substance which has never as yet been decomposed,
Chemical   and all the matter with which man is acequivalents. quainted is composed of one or more of
sixty-two elementary substances. When two of
these elements unite together to form a compound
body, the proportions in which they combine are
not decided by chance. You cannot unite these
elementary substances in any proportion you please.
The proportion in each case is determined by an
unvarying law, and the amounts required of either
substance are weighed out by Nature in her delicate
scales with a nicety which no art can attain. Thus,
for example, 23 ounces of sodium will exactly unite
with 35.5 ounces of chlorine; and if you use precisely
these proportions of the two elements, the whole of
each will disappear and become merged in the compound, which is our common table salt. But if, in
attempting to make salt, we bring together clumsily
23.5 ounces of sodium and 35.5 ounces of chlorine,
Nature will simply put the extra half-ounce of sodium on one side, and the rest will unite.
The numbers in the table on page'290 give the
proportions by weight in which the elements unite.
For example, eight pounds of oxygen combine with
six pounds of carbon, with fourteen pounds of nitrogen, and so with the numbers given for the other
288
[LECT. IX 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
substances. We call these numbers combining proportions, and sometimes chemical equivalents, because in many cases they represent equivalent
quantities of the respective elements. Thus, if we
remove sulphur from a chemical compound, and fill
its place with oxygen, it is found that for every sixteen ounces of sulphur removed we must supply
eight ounces of oxygen. Hence, in a chemical
sense, eight ounces of oxygen are the equivalent of
sixteen ounces of sulphur; but the same is not
necessarily true of all the elements.
The standard of these weights is of course arbitrary, but if one number stands for pounds, all the
rest stand for pounds, or if one stands for ounces, all
the rest stand for ounces. It is usual, however, to
leave the standard indefinite, and speak of so many
parts. Again, the weights have only relative values; but if we give to any one a definite value, all
the rest assume definite values. Our unit must necessarily be more or less arbitrary. Most chemists
take hydrogen for the unit of weight, and the numbers given in the table express the equivalent
weights of the other elements calculated on this assumption. But we might take any one of the elements as our starting-point, and many of the European chemists use a system of equivalents calculated
on the assumption that the equivalent of oxygen is
100. This assumption gives an entirely different
system of numbers; but the difference is of no im portance so long as the relative values remain un changed.
289
Ir  
TABLE OF ELEMENTARY SUBSTANCES, WITH THEIR EQUIVAL
AND SYMBOLS.
Sym-  Equiva-             Element.              Symbol. lent.                                       bol.
Hydrogen...
Iodine......
Iridium.....
Iron (Ferrum).
Lanthanum..
Lead (Plumbum).
Lithium.....
Magnesium....
Manganese...
Mercury (Hydrargyrum)
Molybdenum.. 
Nickel.
Niobium (Columbium)
Nitrogen.....
Osmium.....
Oxygen.....
Palladium...
Phosphorus...
Platinum.
Potassium (Kalium) 
Rhodium.....
Gold (Aurum)...  An  196.66 Rhodium............Ro   52
I
Eq
1t
H:
12
9~
2~'
41
10:
2'
10(
4E
2C
4E
14
99
53
31
98
39
52
Element.
13.75
122.0
75.0
68.5
210.0
10.9
80.0
56.0
20.0
6.0
46.0
35.5
26.27
29.5
133.0
31.75
48.0
19.0
4.66
196.66
Aluminum
Antimony (Stibium)
Arsenic
Barium
Bismuth
Boron.....
Bromine....
Cadmium....
Calcium....
Carbon....
Cerium....
Chlorine...
Chromium...
Cobalt.....
Coesium
Copper (Cuprum).
Didymium...
Erbium....
Fluorine
Glucintur.
Gold (Aurum).
A1
Sb
As
Ba
Bi
B
Br
Cd
Cat
C
Ce
C1
Cr
Co
Cs
Cu
D
E
F
G
Au
H
I
Ir
Fe
La
Pb
L
Mg
Mn
mg
Mo
Ni
Nb
N
Os
O
Pd
p
Pt
K
Ro 
NINE  SERIES.
Elements.         Equivalents.      Usual  Specific         P        p. Gr. Color                                    Affinity for
as Gas. of Gas. — Hydrogn
Ozn - 8 n 9.    Gao.Ose.n
8 + a 9ts.   Theo. Observ.   a  Condition. Gravity. Boiling P      s Gas     of Gnity for Oxygen.                   Hydfor
Ozone               8    8      0    Gas                               1.11   Colorless                               Intense
Fluorine           17   19       l    Gas                                                  No compound known   Less intense
Cyanogen           26   26       2    Gas                              1.81   Colorless   Very feeble                 Very strong
Chlorine           35   35.5    3    Gas         1.33   58~ nearly   2.47   Yellow          Very feeble               Very strong
Bromine            80   80       8    Liquid   3           1450         5.54   Red          Feeble                    Less strong
Iodine           125  127    13        Solid      5         347~        8.72   Violet       Decided                    Feeble
EIGHT  SERIES.
Elements.         Equivalents.
Usual Condition. Specific  General Appearance.  Melting Point.    Boing Point.        Sp. Gr
8 + n 8.     Theo. Observ.   n                      Gravity.                                                                g.
Oxygen             8      8     0  Permanent Gas                Colorless                                                    1.11
Sulphur          16     16      1   Solid                2      Yellow                   230o            824~                2.23
Selenium         40      39.7   4   Solid                4.3   Reddish Brown            392~         Red heat                5.68
Tellurium         64    64.5    7   Solid                6.1   Metallic                 661~         White heat               9.00
Six SERIES.
Elements.         Equivalents.
Usual,Condition. Specific
Elementsuivalents.        Usual Condition.  Specrific.  General Appearance.  Melting Point.  Boiling Point.     as Gas
8 + n 6.     Theo. Observ.   n
Nitrogen          14    14       1        Gas                  Colorless                                                      0.97
Phosphorus        32    31       4        Solid          1.77 Transparent Solid          1110               5540             4.42
Arsenic           74    75    11          Solid          5.67 Sub-metallic          Low red heat Red heat                   10.20
Antimony         122   122.3  19          Solid          6.72 Metallic                   840~      Volatile at white heat
Bismuth          212   210      34        Solid          9.82 Metallic                   513~      Barely volatile
v
9
0o
0
tt
Ft
AL 
RELIGION AND CHEMISTRY.
Dr. Prout was the first to notice that many of
the chemical equivalents were simple multiples
of the equivalent of hydrogen, and he
Many of the
equivalents are thought that, if this equivalent were taken
whole numbers.
whole numbers. as unity, the other equivalents could all
be expressed by whole numbers. The progress of
chemistry has not tended to confirm this view, but
on examining the table it will be noticed that a
large number, at least, of the chemical equivalents
on the hydrogen scale are whole numbers, and this
is especially true of those elements which have already been mentioned as forming almost the whole
of the earth's crust. Thus we find in these elementary forms of matter -the blocks with which the
universe has been built - the same simple numerical relations which everywhere appear in the constructions of man.
Still simpler numnerical relations will be discovered
if we consider the different compounds formed by
Law of multiple the same elements. The proportions of
proportions. the elements which enter into such compounds always bear a very simple numerical relation
to each other. Thus there are five compounds of
oxygen and nitrogen which contain these elements
in the proportions indicated in the following table.
C ds of Oxygen and IoNit
Nitrogen.
14 parts.
14 "
14 "
14 "
14 "
Oxygen.
8 parts.
8X2 —16 "
8 X 3 —  24  "
8X4- 32  "
8 X 5-40  s"
Protoxide of Nitrogen
Deutoxide of Nitrogen
Nitrous Acid
Hyponitric Acid
Nitric Acid
292
[LF.Cr. IX.
0 
LE,c. IX.]   ARGUMENT FROM GENERAL PLAN.
It will be noticed that the proportions of oxygen
in these compounds are in all cases simple multiples
of eight, the proportion in the first. In like manner, the compounds of manganese with oxygen
show similar relations.
f Oygen and Mar
Manganese.
27.5 parts.
27.5 "
27.5  "
27.5 "
27.5 "
Oxygen.
8 parts.
8X 1~-=12  "
8X2 -16  "
8X3  -24   "
8 X 3=-28   "
Protoxide of Manganese
Sesquioxide of Manganese
Hyperoxide of Manganese
Manganic Acid
Permanganic Acid
The relation is not quite so simple as in the other
-case, but still the same general truth is evident, and
these two examples are fair illustrations of what
has been observed throughout the whole range of
chemical compounds.
A large number of the chemical elements are
either found naturally in the aeriform condition, or
else can be converted into gases by a
Combining
moderately high temperature, and some proportions by
remarkably simple numerical relations will volume.
appear if we consider the proportions in which
these gases combine by volume. We gave above
a table of combining proportions by weight, and
we give on the next page a table of combining pro portions by volume.
What could be simpler than the numerical
relations presented by this table? These gases
combine either in the proportion of one volume
293 
RELIGION AND CHEMISTRY.
Combining Proportions by Volume.
Sp. Gr.
Calculated.*
10.365
5.526
2.450
1.797
1.301
0.069
8.768
6.976
0.968
1.106
4.334
4.406
2.211
Name of Gas.
Arsenic
Brominic
Chlorine
Cyanog,en
Fluorine
Hydrogen
Iodine
Mercury
Nitrogen
Oxygen
Phosphorus
Selenium
Sulphur
(that is, one quart, one pint, one cubic foot, or
whatsoever unit of volume we employ) of one gas,
to one of the other, or else one volume of one to
two of the other. It is true, however, that combination may take place in any simple multiples of
these proportions, as in the case of the equivalents
by weight. For example, the five compounds of
oxygen and nitrogen contain respectively,
Oxygen.
2 volumes.
2     "
2     "4
2     "c
2     "6
Protoxide of Nitrogen
Deutoxide of Nitrogen
Nitrous Acid
Hyponitric Acid
Nitric Acid
* These specific gravities are calculated on the assumption that the
combining proportions by volume are exact. It will be noticed that
they very closely agree with the observed specific gravities given in the
last column.
294
[LECT. IX.
Sp. Gr.
Observed.
10.65
5.54
2.47
1.81
Volume.
1
2
2
2
2
2
2
2
2
1
1
1
1
0.069
8.716
6.976
0.971
1.106
4.42
5.68
2.23
Nitrogen.
1 volume.
2 ct
3 cc
4 cc
5       6i 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
But there are numerical relations between the
chemical elements even more remarkable than those
we have studied. These substances, which Classification
we call elements solely because they have of elements.
never been decomposed, vary very greatly in their
properties.   At the ordinary temperature of the
air, some are gases, some are liquids, and some are
solids. Some are highly corrosive, like chlorine,
and others perfectly inert, like nitrogen.   Some
have a bright metallic lustre, like gold or silver,
and others are dull, like charcoal or sulphur. Indeed, we find among these substances almost every
possible variety of qualities.
These elements are not to be regarded, however,
as so many distinct creations, each endowed with
the peculiar properties which fit it for the uses it
subserves in the universe, but each entirely independent of all the rest. On the contrary, the whole
world of matter is but one creative thought, expressed with various modifications in the different
elements, but yet one thought comprehending all.
It is true that we have not obtained more than
the most distant glimpses of this Divine plan, but
still we have seen enough to convince us that
there is such a plan underlying the whole material
creation.
Of the sixty-four substances which have never
been decomposed, and which are therefore regarded
as elements, a large number are so exceedingly rare
and so difficult to obtain that their properties have
not been fully studied, and their relations to one
295 
R RELIGION AND CHEMISTRY.
another are not yet known.   Disregarding those
italicized in the table on page 290, the remaining
elements may be classified in six families or series,
three-f which are given on the opposite page of the
same table. We shall best be able to understand
the principles of the classification by examining in
detail one of the families of elements. We might
take either of the six, and I have selected the Nine
Series only because the members of this family of
elements are probably more familiar to you than
any others. The elements which compose the nine
series are all highly active and corrosive chemical
agents. They all form analogous compounds. They
all have, so far as is known, the same crystalline
form, and may replace one another in a chemical
compound without changing the form of the substance. Moreover, they resemble one another in
many other properties which we have not time to
discuss in this connection.
If the resemblances are great, however, the differences are great also; but then these differences folLaw of   low a simple and well-established law of
progression. progression. The properties of this family of elements vary, as we descend the series, by
regular steps.  Let me illustrate.  Consider first
the physical condition of these substances. Ozone
is the active modification of oxygen, and so persistently does it retain its aeriform condition that no
amount of mechanical pressure and cold which we
can command is sufficient to reduce it to a liquid.
The next element, fluorine, is also a gas, but it is so
296
[LECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
highly corrosive that we have not yet been able to
experiment upon it. Cyanogen is a very remarkable substance. It is really a compound, but its
properties resemble so closely those of the other
elements of the series that I have classified it with
them. It is a gas which can by great pressure and
cold be changed to a liquid.   Chlorine, although
generally known as a gas, can be liquefied still more
readily. Bromine is a very volatile liquid, which,
at the temperature of 145~ Fahrenheit, becomes a
gas. Iodine, finally, is a solid, but a solid which is
very fusible, and becomes a gas at a temperature of
347~. At the temperature of a common bread-oven,
all these substances would be gases, and, as is shown
in the eighth column of the table, the densities of
these gases gradually increase as you descend in the
series. Pass now to the color of these elements
when in the state of gas, and you will find that there
is a beautiful chromatic gradation between them
Ozone is colorless; chlorine is yellow, inclining to
green; bromine, orange-red; and iodine, violet.
Consider next the equivalents of these elements, and
you will discover that they stand in a very simple
relation to each other. The equivalent of ozone is
8; that of fluorine is approximately 8 +  9    17;
that of cyanogen, 17 -+  9-  26; that of chlorine,
26 +  9   = 35.  It is probable that, if the series
were complete, the equivalent of the next element
to chlorine would be 35 +  9    44, and those of
the three succeeding elements, 53, 62, and 71 respectively; but no such elements are known. The
297 
RELIGION AND CHIEMISTRY.
next step, however, gives us eighty, which is the
equivalent of bromine. Then again there are four
steps not represented, but at the fifth step we come
to iodine, whose equivalent is 125. You notice that
the common difference of these numbers is in every
case nine, and for this reason I have named this
family of elements the Nine Series.
A relationship like that I have just described,
exists among the members of the other five families into which I have classified the chemical elements. The properties of the elementary substances in each family vary according to a similar
law of progression; but the number which expresses the common difference of the equivalents
is different for each series, and characterizes the
family. The numbers besides 9 are 8, 6, 5, 4, and
3, respectively, and in each case I have given to
the series the name of the numeral which distinguishes it.
How evidently, then, the properties of the elements conform to the idea of number! It is true
that our classification is at fault in many particulars, and I do not suppose that the order of progression here given is more than a very distant
approximation to the actual law of nature; but the
fact that some such law exists, and that it is based
on simple numerical relations, I believe is beyond a
doubt. The same principle of classification applies
to compound bodies as well as to elements, and I
confidently look forward to the time when it will
be possible to classify all substances in one comnpre
298
[LECT. IX. 
LECT. IX.]    ARGUMENT FROM GENERAL PLAN.
hensive scheme, and to represent the relations of
their prdperties by simple arithmetical formula.
Similar numerical relations are found throughout
the whole universe of matter. In the solar system,
for example, with the exception of Nep- Intervals
tune, the intervals between the orbit of betee. the
orbits of the
Mercury and the orbits of the other plan- planets.
ets go on doubling, or nearly so, as we recede from
the Sun. Thus the interval between the Earth and
Mercury is nearly twice as great as that between
Venus and Mercury, the} interval between Mars
and Mercury nearly twice as great as that between
the Earth and Mercury, and so on. Again, if we
compare the periods of revolution around the Sun,
expressed in days, we shall find another simple
numerical relation, as shown by the following table.
Law of Periodic Times.
Observed.       Theoretical.
60,129           62,000
30,687           31,000
10,759           10,333
4,333            4,133
1,200 to 2,000    1,550
687              596
365              366
225              227
88               87
It will be noticed that the period of Uranus is 1
that of Neptune, the period of Saturn 1 that of
Uranus, the period of Jupiter about 2 that of
299
Fractions.
Neptune
Uranus
Saturn
Jupiter
Asteroids
Mars
Earth
Venus
Mercury
}
2,T
8
r-o
i 3
f
1 3 
RELIGION AND CHEMISTRY.
Saturn, the period of the Asteroids about X that
of Jupiter, the period of Mars'about 13
Ratios between
the periods of that of the Asteroids, the period of Venus
the planets.  about -8 that of Mars, and the period of
2 1
Mercury about 31 that of Venus.  The successive
fractions are very simply related to each other, as
will at once appear on writing them in a series,
1 1 2 3  5   8  13 &C.
Notice that, after the first two, each succeeding fraction is obtained by adding together the numerators
of the two preceding fractions for a new numerator, and the denominators for a new denominator.
From this series, however, the Earth is excluded.
Its time of revolution is almost exactly 13 of that
of Mars, and that of Venus nearly'- of that of the
21
Earth; but although these fractions do not fall into
the above series, they are members of a complementary series beginning
1  2 3 5  8  13 &c.
This simple relation was discovered by Professor
Peirce, and he has proposed an explanation for the
anomaly presented by the Earth. But it is not
important to dwell on this point. Our only object
was to show that simple numerical relations appear
in the planetary system, and this, as I trust, has
been fully illustrated.
Passing now to the vegetable kingdom, we find
again the same numerical laws. The leaves of
Arrangement a plant are always arranged in spirals
of leaves.   around the stem.  If we start from any
300
[LECT. IX. 
LECT. IX.]   ARGUMENT FROM GENERAL PLAN.
one leaf, and count the number of leaves around
the stalk and the number of turns of the spiral until
we come to a second leaf immediately over the
first, we find that for any given plant, as an appletree for example (see Figs. 21 and 22 *), the number
3
1
Fig. 21.               Fig. 22.
of leaves and the number of turns of the spiral are
always absolutely the same. The simplest arrangement is where the coincidence occurs at the second
leaf, after a single turn of the spiral; and this may
be expressed by the fraction 21, whose numerator denotes the number of turns of the spiral, and whose
denominator the number of leaves. The next simplest arrangement is when the coincidence occurs at
the third leaf, after a single turn of the spiral, and
may be expressed by the fraction 1.  These two
fractions express respectively the greatest and the
smallest divergence between two successive leaves
which has been observed. The angle between two
* These figures are from Gray's Botanical Text-Book.
301 
RELIGION AND CHEMISTRY.
successive leaves, therefore, is never greater than
180~, or half the circumference of the stem, and
never less than 1200, or one third of the circumference. The arrangement next in simplicity is where
the coincidence occurs at the fifth leaf, after two
turns of the spiral, as is represented in the preceding figures. Other examples are given in the table
LAW OF PHYLLOTAXIS (Leaf-Arrangement).
Number   Number             Angle of Divergence.
Name of Plant.      of Turns  of Leaves.* Fraction.    between two
of Spirsa.*     *successive Leaves.
Grasses,                   1         2                 180~
Sedges,                    1         3                 120~
Apple, )
Cherry,                   2          5                 144~
Poplar, )
Holly,      )
Callistemon,               3         8                1350
Aconite, )
Rosettes of the 
Houseleek,              5        13          f      1380 28'
Cones of the' 1
White Pine, J
Cones of the Euro-  8              21                 137  9'
pean Larch,                                           3
Certain Pine Cones,       13       34           -      137~ 39'
Certain Pine Cones,       21       55         ii      137~ 27'
Typical arrangement which would expose to the      1370 30' 28"
Sun's rays the greatest leaf-surface, 
which follows, and it will be seen that we have precisely the same series of fractions in the arrangement of leaves around the stem of a plant which
appears in the periods of the planets. The fractions
of this series are all gradual approximations to a
* Before a leaf occurs vertically over the first.
302
[LECT. IX. 
LECT. IX.]    ARGUMENT FROM GENERAL PLAN.
mean fraction between 2 and 31, which would give
the most nearly uniform distribution possible to the
leaves, and expose the greatest surface to the sun.
But this law does not stop with the plants. The
same series of fractions expresses also the spiral arrangement of the tentacles of the Polyp and of the
spines of the Echinus. Thus through the whole
realm of nature, from the structure of the crystals
to the dimensions of the human form, a similar numerical simplicity is preserved.
Have you never recognized the composition of
your friend in some anonymous literary article, by
a peculiar phraseology, a turn of style, or a method
of thought which no artifice can conceal? Have
you never felt a glow of pleasure when you unexpectedly discovered on the walls of a picture-gallery the work of a well-known artist, marked by
some peculiarity of grouping or coloring? Has
your attention never been quickened when an orchestra has suddenly struck into a new theme of a
favorite composer, never heard before, but unquestionably his?  If you have experienced these or
similar emotions, you know something of the force
with which such numerical laws impress the mind
of the student of nature, and you also know how
difficult it is to make the power of such impressions
understood. I wish I could give you a full concep tion of this power; for you cannot otherwise feel the
full force of the evidence which these facts afford.
They point directly to an intelligence in nature like
our own, and they are a seal to the declaration of
20
0
303 
RELIGION AND CHEMISTRY.
the Bible, that man was created in the image of his
God.
The broken porticos of the Parthenon still stand
on the Acropolis at Athens to excite the imitation
and win the admiration of the architect.  That
beauty of outline and those faultless proportions,
which modern art has copied, but never excelled,
all depend on an exact conformity of all the parts
to the laws of symmetry and to simple numerical
ratios. We justly regard that ruined temple as the
evidence of the highest intelligence; and when we
find the same symmetry, the same numerical ratios,
appearing everywhere in nature, how can we refuse
to admit that they also are the evidence of intelligence and thought? Moreover, since the laws of
symmetry and number pervade the whole universe,
from the structure of the solar system down to the
organization of a worm, they prove, if they prove
anything, that the whole is the manifestation of
the thoughts of the one great Jehovah, who in
the beginning created all things by the word of
His power.
304
[LECT. IX. 
LECTURE X.
ARGUMENT FROM GENERAL PLAN (CoNCLUDED).-NECESSARY ULIM    ITATIONS OF SCIENTIFIC AND RELIGIOUS THOUGHT.
IN my last Lecture I endeavored to show that
the laws of nature, so far from proving that the
world is governed by an inexorable neces- The error of
sity, furnish the strongest evidence of an pantheism.
overruling mind.  We  must be careful, however,
not to misinterpret this evidence; for analogies
like those we have studied led Schelling and the
philosophers of his school to regard outward nature
not merely as the result of the Divine Thought, but
as identical with that thought, and inseparable from
it. Indeed, there are many among us who regard
the material universe as the manifestation of God,
in the same intimate sense in which our bodies are
the manifestation of our own personality; who
therefore believe that the world is and always has
been a part of His Eternal Being, and who look
upon the laws of nature not merely as the manifestation of an Infinite Intelligence, but as a part
of that Intelligence itself.
This philosophy may be made to appear very
attractive, and even very reverential; but when
followed out to its logical consequences, it reduces
God to the level of nature, and merges His being
in the matter He created. We must be as careful 
RELIGION AND CHEMISTRY.
to avoid the snares of pantheism, as the slough of
materialism. Both are equally destructive of true
religion, and, although they lie on opposite sides of
the Christian's path, they lead to the same result;
and if once enticed from the narrow way, the Christian will be fortunate if Faith rescues him from the
peril before he plunges utterly into the gulf of
atheism. We must not confound the Creator with
the creature. There is a personal God above all
and over all, and although nature manifests His
intelligence, its material forms are only the reflection, not the substance, of Hils Being. The error
of the pantheist arises from a too superficial study
of nature, and if we examine more closely the analogies between the laws of nature and the results
of human thought, I am confident we shall find
that the created forms may be readily distinguished from the Intelligence which gave them
being.
In every human work, we may always distinguish two things, the conception and the execuDistinction be- tion, and the last never exactly conforms
tween the con- to the first. For example, in one of the
ception and the
execution ofa grand Gothic cathedrals of our mother
work.    country we see united in the plan, first,
the idea of the cross, the emblem of our Christian
faith; then the spire, typifying the aspiration of
the soul; and lastly, the long aisles, whose pointed
arches and delicate tracery have been copied from
the interlacing branches of God's first temple. The
combination of these ideas may be said to be the
306
[LECT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
conception of the cathedral; but how differently
has this conception been embodied in the numerous cathedral churches of England! Besides the
peculiar caprices of the architect or builder, we can
trace in each church an evident adaptation of the
parts to special purposes. Here a "lady Illustrated by
chapel" has been included in the design, architecture.
and here the mausoleum of a king or a prelate;
here a portion has been adapted to the reading of
the service, and here to the session of the ecclesiastical court; but however varied the execution, the
same conception is evident in all. So it is in all
architecture. Our modern dwellings are built after
a few general types, and the conception is very
nearly the same in all houses of any one class.
But how differently a skilful architect will arrange
the details, and adjust them to the circumstances
of the location, to the wants of the family, or the
taste of the owner! and no one knows better than
he that the conception of the building is one thing,
and the execution of that conception a very different thing.
In the higher forms of art, the same truth appears even more strikingly. The Transfiguration
of Raphael, that masterpiece of painting, nlustrated
does not hold you breathless before it so in art.
much by what it actually represents, as by what it
embodies and helps you to realize. He who sees
merely what is painted on the canvas will turn
away disappointed, but in the soul of the true student of art, who enters into the spirit of the great
307 
RELIGION AND CHEMISTRY.
painter, the conception grows as he gazes, until he
becomes transported and gains a vision of the splen dor of the Mount. In like manner, it is not that
lovely female face which has endeared the Sistine
Madonna to so many hearts, and made Dresden one
of the shrines of the world. In mere point of exe cution this picture may be surpassed by many
works of living artists; but the conception of a pure
mother's love has been nowhere embodied as there,
and that is the charm.   You stand before  the
Laocoon until the blood grows cold and the muscles
writhe in sympathy, and then you look at the
motionless statue and wonder whence comes the
power.  It is not in the skilfully chiselled marble,
but it is in the conception of the unknown artist,
which the petrified forms suggest. So it is everywhere with the works of man; the conception can
always be distinguished from the embodied fact.
But what need of illustration?   Who  does not
know the difference between the two, and who
has not sadly experienced how far his best efforts
fall short of his ideal? The thought, the conception, how noble! the execution, the reality, how
humble!
Turning now to Nature we find the same distinction there between the conception and the facts.
Nature does not, of course, like man, fall
The same
distinction   below her ideal for want of power, but
nature.   she departs from it in order to adapt her
works to specific ends. Everywhere the conception,
or, as we generally call it, the law, is modified in the
,o 0
I
I           ~'
308
[LECT. X.
. 
LECT. X.]    AROUMENT FROM GENERAL PLAN.
execution to insure special adaptation.  We may
not always be able to discover the adaptation, but
in every case we find that the phenomena do not
exactly conform to the law.  Review for a moment,
with this idea, the few examples of natural laws
which I have so briefly sketched, beginning with
the law of symmetry.
We seldom, if ever, find in nature crystals having
that regularity of form or that perfection of outline
represented in our figures. Natural crys- Ilustrated
tals are invariably more or less distorted by crystaI.
or imperfect.  You would hardly believe the crystal represented by Fig. 23 to be an octahedron,
and yet it is merely this familiar
form somewhat distorted. I admit that the distortion in this
case is unusually great; - still a
perfect crystal is at best a very
rare exception.  It is true that 
in all cases of distortion the rel-    Fig. 23.
ative inclination of the planes
is very nearly constant; but even this is liable to
some variation.  Moreover, there are several forms
of crystals represented in these diagrams,* which
are never found in their perfection in nature  They
are merely shadowed forth, as it were, on other
forms, and so partially that the unpractised eye
would never detect them. So true is this, that, as
I have before stated, the present science of crys tallography could never have been developed by
* See the three groups of crystals given in the last Lecture.
309 
RELIGION AND CHEMISTRY.
observation alone. How evident, then, the distinction between the actual crystals and the thought
which they embody!
Passing next to chemistry, we notice the same
truth in the law of progression by series. We do
Illustrated   not find that the properties of the eleinchemistry. ments in any of the series given in the table on page 291 are exactly those required by the
law; but in each case they approximate more or
less closely to the ideal type. Thus, if the law were
exactly observed, the chemical equivalents would
be those given in the column headed Theoretical;
and it will be seen that these numbers by no means
exactly coincide with the observed equivalents,
which for comparison are placed at the side. The
same is true of the other properties of these elements.
This simple law of relationship, first observed by
myself over ten years since, has been questioned, on
the ground that it does not exactly represent the
fact; and Dumas, of Paris, while adopting essentially
the same system of classification, has modified the
details, in order to obtain a more exact conformity,
carefully redetermining many of the chemical equivalents, with the evident idea that they must exactly
coincide with the law. But surely, if we may reason by analogy, no such precision was to be expected, and, in seeking to realize this illusion, Dumas
overlooked the simple conception and substituted a
most mechanical and improbable system in its place.
It was never supposed that the facts of nature would
310
[LECT. X. 
LECT. X.]   ARGUMENT FROM GENERAL PLAN.
exactly correspond to the law; for it was known
that an exact correspondence between the law and
the phenomena is found absolutely nowhere. All
I claimed was, that with the various elements there
was a general conformity in their properties to this
simple conception of series. I supposed that the
properties of matter had been distributed according
to this general plan; but at the same time, knowing that each element had been specially adapted
to a certain specific end, I did not expect to find
the conception perfectly realized.
When now we study the elements from this point
of view, we at once notice that the departure from
the general law is most marked in those substances
which are most widely distributed in nature, and
where the special adaptations are the most evident.
This is especially true of the substances composing
the atmosphere. The elements, oxygen, nitrogen,
carbon, and hydrogen, and the compounds, water,
ammonia, nitric acid, and carbonic acid, are all remarkably unique substances, and were we to examine their external qualities alone, we should never
discover their relationship; but on studying carefully their chemical relations, we find that, while they
have been adapted with such wonderful skill to the
important ends which they have been appointed to
subserve, they have also been made to conform, at
least in their main features, to the general plan.
There is still another point connected with the classification of the elements which is deserving of our
notice in this connection. We have already seen
311 
RELIGION AND CHEMISTRY.
that, although sixty-four elements have been discovered, the greater portion of the earth's crust consists
of only ten or twelve. Indeed, if the remaining
fifty elements were suddenly annihilated, the mass
of the globe, so far as we know, would not be sensibly diminished. Indeed, a large number of the elements occur only in some of the rarest minerals, and
there in such minute quantities that they can be
detected only by the most skilful chemical analysis.
That these very rare elements were designed by the
Creator to subserve important ends, we need not
doubt; but it is certain that they play a very subordinate part on the surface of the globe. For bromine and iodine, and a few others, important applications have been discovered in the arts or in medicine; but the rest, comprising at least one third
of all the known elements, have no apparent value
except as parts of a general plan. In the light of
a utilitarian philosophy they must appear useless;
but to the true student of nature they have a significance which transcends everything else. They are
parts of a universal order, of a Divine cosmos, which
would be incomplete without them. They are the
manifestation of Infinite Intelligence: They embody the thoughts of God. Man's material wants
and pleasures are not the sole end of creation. In
the words of Chevalier Bunsen, "Law is the supreme rule of the universe, and this law is intellect,
is reason, whether viewed in the formation of a
planetary system or in the organization of a worm."
But we must remember, in discussing this ques
312
[LECT. X. 
LECT. X.]   ARGUMENT FROM GENERAL PLAN.
tion, that it does not follow, because we cannot discover any important end which these elements subserve on our earth, that they have no practical
utility. For after acknowledging the dignity which
they acquire when regarded as the characters of
that language in which the creative thoughts have
been written, and as the appointed means of educating the human race, still it does not seem consistent with that economy of resources which appears in all parts of the Divine plan, that they
should have no special functions to discharge in the
cosmos. Now I would suggest, but I offer the suggestion in all humility, that these very rare elements
may be adapted by their peculiar properties to the
thermal conditions of some other planet or some
other stellar system. We have seen that those elements which are the most widely distributed over
the earth are such as are adapted by their properties to the conditions of organic life on the third
planet of the solar system, and it is certainly possible that some different scheme of organic life may
be sustained on Mercury or Uranus, in which elements rare to us take the place of oxygen, nitrogen,
hydrogen, and carbon, and perhaps also the elements missing in our classification may be found in
some other world, revolving around Sirius or Arcturus, where oxygen, sulphur, and iron may be
among the rarities of science.
All this is of course the purest hypothesis, and
such speculation can lead to no positive results; but
the very possibility of the speculation illustrates
313 
RELIGION AND CHEMISTRY.
most pointedly the great truth which I am endeavoring to enforce. The thought which is embodied
in the scheme of the chemical elements is something entirely apart from their material forms, and
the moment this thought is apprehended by man, it
opens to his imagination vistas of possible realities
which entirely transcend all human experience.
If next we compare, more carefully than before,
the periods of revolution of the planets around the
Illustrated in Sun, we shall find that the same principle
onomy.  holds true.  The observed periods, you
will notice by the table on page 299, do not exactly correspond to the simple ratios which express
the law, and the same is true of the distribution of
leaves around the stem of a plant, and in fact of all
classes of phenomena in nature. In each we observe only a tendency towards a maximum effect,
which is the perfect expression of the law, but
which is seldom fully reached. The limits of variation are broader in some cases than in others, but
we find no case in which the accordance is absolute.
In none, however, of the purely physical laws
is this character so strongly marked as in the
structure of animals and plants.  It is well
Illustrated in
botany and known that all organized forms, although
zioi~logy.
szoogy    wonderfully diversified, are fashioned
after a few general types. In the animal kingdom
there are only four general plans, represented by
the Radiata, the Mollusca, the Articulata, and the
Vertebrata, and all the animals of any one of these
great divisions are organized alike. For example,
314
[LECT. X. 
LIt. X.]    ARGUMENT FROM GENERAL PLAN.
in all vertebrate animals we find essentially the
same parts, and frequently where there is no use
for a given organ it is still present in a rudimentary condition. Professor Wyman has found rudimentary eyes in the so-called eyeless fish of the
Mammoth Cave, and any anatomist will point out
to you in the skeleton of a fish, of a reptile, of a
bird, or of a quadruped, the bones which correspond
to the various parts in the skeleton of a man. In
the wing of a bat the bones of the human arm may
readily be traced.
Here then is a most obvious distinction between
the conception and the execution, and the general
plan of the skeleton is preserved even where there
is no use for certain parts, and where we might
perhaps conceive of a simpler arrangement without
them. But, more than this, we find that the variations from what we may regard as the typical form
have been obviously made in order to adapt the
organs to certain specific ends. The same plan
which, developed in its full perfection, appears in
the human hand and arm, reappears, more or less
fully carried out, in the fore legs of a horse, in the
wings of an eagle, and in the pectoral fins of a dolphin; and in each case the organ has been obviously
adapted to some special purpose.  Special adaptation has thus been most beautifully harmonized
with general law, and the conception has been varied in the execution in order to secure some wise
and important end. So also it may be that, when
in the laws of inorganic nature we cannot discover
315 
RELIGION AND CHEMISTRY.
the cause of a variation, a similar wise purpose is
concealed.
This subject is capable of almost indefinite illustration, and the vegetable kingdom is as rich in
examples of the principle we have been discussing
as the animal. I have not, however, time for further details. The whole ground has been most
carefully surveyed by McCosh and Dickie in their
excellent work entitled "Typical Forms and Special
Ends in Creation," and to this I would refer those
who may be interested to pursue the study of these
singular facts. Sufficient, I trust, has already been
said to show that the phenomena of nature and the
results of human thought resemble each other in
their very incompleteness.
While, therefore, a more careful study has tended
to confirm the result at which we arrived in the
last Lecture, and has strengthened the
Nature points
to a personal impression that the universe was created
God.      by an intelligence like our own, we have
also found that the analogies of nature point with
equal distinctness to the conclusion that this intelligence is a being entirely apart from and infinitely
superior to the matter he created or the laws he
ordained. If these analogies are worth anything,
they point not to a supreme spirit of the universe,
pervading and energizing matter, but they prove the
existence of a personal God; one who can sustain
to us the relations of Father, Saviour, and Sanctifier;
one whom we can love, worship, and adore.
But it may be urged that I have drawn my illus
316
[LECT. X, 
LECT. X.]   ARGUMENT FROM GENERAL PLAN.
trations wholly from the phenomenal laws of nature, and entirely overlooked the great dynamical
laws, which, like the law of gravitation, are more
precise. Moreover, it will be said that the history
of astronomy gives us every reason to believe that
these very variations to which I have given such
importance are merely necessary consequences of
some higher law not yet discovered, just as the perturbations of the planetary orbits are the legitimate
results of the very law they seem at first to invalidate. I have no doubt that in part, at least, this will
be found to be the case. But even in regard to the
law'of gravitation, there always have been residual
phenomena, unexplained by the law, and so probably there always will be, until, as we go on widening our generalizations, the last generalization of
all brings us into the presence of that First Cause
through whom and by whom all things are sustained.
I trust that the striking analogies between the
phenomena of nature and the results of human
thought, which I have been able so imper- Force ofthe
fectly to illustrate, have impressed you, as argument.
they impress me, with the profound conviction that
the order of nature is the manifestation of an Infinite Intelligence, but of an Intelligence apart from,
and superior to, the order which it once created
and now upholds. If I have failed in my object, it
is because I have been unable to bring home these
analogies to your understanding. The resemblances
are so striking, that I do not believe a mind which
317 
RELIGION AND CHEMISTRY.
is conversant with the facts, and unbiassed by the
prejudices of philosophy or of education, can resist the conclusion that this scheme of nature is
the manifestation of an intelligence like our own,
at least so far as the Infinite can be said to resemble the finite. Men may reasonably entertain
differences of opinion in regard to the mode of
action of that Being who has created the universe.
They may believe that a certain amount of power,
together with the germ of all future existence, was
implanted in the original chaos, and that the Deity
has never interfered with the natural action and
the unfolding of the causes which He has thus ordained; but whatever theories of cosmogony may
be entertained, short of absolute materialism, he
must be indeed blinded by his prejudices who refuses to recognize in these analogies the evidence
of intelligence and thought.
I do not of course regard analogies as proofs, nor
do I believe that this argument from general plan
Itissubsidiary could supply the place of the great arguto the arg- ment from design. The last lies at the
ment from
special adap  basis of Natural Theology, and all the
tation   rest is merely subsidiary to the great central light. Moreover, while the argument from design comes home to every man's understanding,
these analogies appeal with their full force only to
the few who are able to study the processes of nature for themselves; as they alone are familiar with
the phenomena in which the resemblances are seen.
But to the student, whose life has been passed in
318
[LEcr. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
successful investigation, and whose soul has been
brought into sympathy with the harmo                                         Appeals esnies of nature, these tokens are constantly peciallyto
assuring him of the presence of his God. scientific men.
Every discoverer feels- when in the presence of a
great truth, he cannot resist the feeling - that, in
discovering a law, he has been brought nearer, not
to a blind agency, but to Omnipotence itself To
this conclusion he is not led solely by philosophy;
for although he may defend his conviction on reasonable grounds, in its full power it transcends all
human philosophy. Man cannot always tell why
he knows. But when illuminated from the altar
of his faith all nature wears a new aspect, and
his spiritual eye discovers everywhere acting
that same Infinite Intelligence which "spake in
"time past unto the fathers by the prophets,"
and "hath in these last days spoken unto us by
"his Son."
Do I hear it said that such loose reasoning is a
gross violation of the Baconian philosophy, and of
that severe induction by which alone science has
been built up? But do we not know, have we not
seen, that the whole structure of science rests on
no firmer foundation than these very analogies of
nature,- that at the beginning of all knowledge,
where we should most expect infallibility, we find
only uncertainty and doubt?
Science is a grand temple built by man to glorify
his Maker, its unfinished spire pointing to heaven,
but its foundations resting on a cloud. The work
21
319 
RELIGION AND CHEMISTRY.
has been done as well as faithful hearts and active
hands could do it. Examine its walls and its buttresses, and from base-stone to coping you will find
no  defect.   Each  block  has been  so carefully
wrought and so firmly clamped in its place, with
all the strength of iron logic, that you will unhesitatingly conclude that the mighty structure has
been raised, not for time, but for eternity. Yet all
rests on a cloud. Let that cloud be dispersed, and
only God can tell whether that structure shall stand
or fall.
Are we then, you will ask, to mistrust these
boasted results of science? Is this imposing structure all a phantom, a mere day-dream, from which
we shall awake on the morning of eternity to find
all passed?  Certainly not! God has not endowed
his creature with faculties of observation merely
to deceive him, and with an intellect solely to lead
him into error. He has not raised up the long line
of scientific heroes of every age, merely to deceive
themselves and mislead the world. No! the temple
of science will stand fast. That cloud on which it
rests is a firmer foundation than any granite rock;
for it is not of man, but of God. Yet let us not forget that this assurance is based only on the same
faith which is the " substance of things hoped for,
"the evidence of things not seen."
"We have but faith: we cannot know;
For knowledge is of things we see;
And yet we trust it comes from Thee,
A beam in darkness: let it grow."
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[LECT. X. 
LBECT. X.]   ARGUMENT FROM GENERAL PLAN.
I have endeavored in these Lectures to show that
the evidence which all nature affords of a personal
God, is wholly independent of the theories of cosmogony we may assume. But although our doctrine of causation may not impair the evidence of an
original design, it is not so with the other bearings
of the subject. For if nature be a mere machine,
weaving the complex web of destiny with the same
precision and certainty with which a carpet-loom
weaves the pattern of a carpet, then the Christian's
idea of a superintending Providence cannot be true.
If nature has been evolved solely under necessary
conditions and laws, with which the Creator has
never interfered since he wound up the immense
weight which set the whole in motion and still
maintains the preordained beats of the great pendulum of the universe,- if with an archangel's intellect
we could predict every event in nature with the same
certainty with which we now foretell the phases of
an eclipse, -then I say again that the visions of an
overshadowing Providence, which have appeared to
us at those milestones on our life's journey where,
wearied and disheartened, we have sat down to rest,
are nothing but a delusion and a dream. It does not
remove the difficulty here referred to, to say that our
lives are parts of this preordained plan, or even to
admit that God may interfere in the moral world by
influencing the will of man; for every one is conscious that his will has not been thus directly influenced, and knows, moreover, that the circumstances
of his condition have always concealed, at the time,
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RELIGION AND CHEMISTRY.
the kind Providence by which he has been led. And
when your theory leads to this, that man has been
put into a world of probation and trial and there left
to walk over pitfalls with his eyes blinded, every unsophisticated mind will feel - say what you will - that
the character of the God you worship is more truly
symbolized by the Juggernaut car than by the cross.
I think that a great deal of false prejudice against
scientific study (arises from a mistaken impression
that the materialist's interpretation of nature is the
natural and necessary result of all scientific thought.
HIlence not a few religious minds have concluded
that the methods of science must be all wrong, and
its conclusions wholly untrustworthy. It will not,
therefore, be out of place in this connection to consider briefly whether the materialist's idea of causation is the necessary, or even the probable, conclusion to which the observed facts of nature and the
legitimate methods of science lead. We must remember, however, while discussing this subject, that
we have passed the limits of human knowledge, and
cannot therefore expect by our unaided processes
of thought to prove or disprove anything. We cannot determine absolutely whether the materialist's
theory be true or false; for science has not the
knowledge which would enable it to form a decision.
The only question for us is, whether this theory is
the necessary theory, or even the most probable
theory; and if it is not either the one or the other,
then the theory is of no weight. One man's theory
is as good as another's, provided both are equally
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[LF.cT. X. 
LECTr. X.]   ARGUMENT FROM GENERAL PLAN.
consistent with facts. If, then, we can show on scientific grounds alone that the Christian's theory
of causation is as probable as the materialist's, we
shall in regard to this point also fully vindicate the
religious character we have constantly claimed for
scientific studies. Surely science is no more responsible for the excesses of theorists than is religion
for the crimes of bigots, and it should be sufficient
to satisfy any religious mind, that there is a Christian theory which is perfectly consistent with all
known facts.
It is easy to understand the relative position of
the two theories of causation after we have become
acquainted with the facts which both must necessarily explain. Let us review, then, very briefly,
these facts, which are more or less familiar to every
one. An innate principle of the human mind forces
upon us the conclusion that every change must
have an adequate cause, and leads us to refer the
phenomena  of nature  to what we  call
Idea of force.
forces. Thus the falling of an avalanche,
the flowing of the tides, the beating of the waves,
the blowing of the winds, the crashing of the lightning, the burning of the fire, the moving power of
steam, and the impression of light, must all have an
adequate cause, and to this cause we give the name
of force. We use this word so frequently and so
familiarly that we are apt to think that we associate
with it a definite conception; but a moment's reflection will show that, in regard to the nature or origin of force, we have no absolute knowledge. This
323 
RELIGION AND CHEMISTRY.
word is merely our name for the unknown cause of
natural phenomena. The uneducated mind naturally refers the origin of all force to the bodies
from which it appears to emanate, and regards it
either as a quality inherent in matter, as in the
phenomena of gravitation, or as a property superimposed upon matter, as in the phenomena of light,
heat, magnetism, and electricity. In either case,
however, it is regarded as a quality of matter. Moreover, the uneducated mind, impressed most of all
by the great diversity in physical phenomena, naturally infers that a similar diversity exists in the
force which produces them, and thus is led to the
idea that there are different kinds of force. Hence
men have been led to refer the falling of bodies
towards the earth to a distinct force called gravitation, the motion of a steam-engine to another force
called heat, the burning of a candle to a third force
called chemical affnity, and in like manner to each
class of phenomena they have assigned a peculiar
and separate force.
Such ideas as these are natural in the infancy of
knowledge, and we must remember that, with all our
boast of progress, the human race, so far at
Language of
science liable least as physical science is concerned, is
to mislead. yet in its childhood. The law of gravitation was discovered only a century and a half ago,
and almost the whole of the present sciences of
chemistry and physics has been developed within
the lifetime of men now living. The present generation were educated in those very natural, but crude
324
[LECT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
notions, and it is not until a comparatively recent
period that even scientific men have been persuaded
that these primitive ideas must be wholly abandoned, or at least radically modified. We are now
in a transition stage, and hence arises a great difficulty in discussing the subject. The language even
of modern science is based upon the old ideas, and
we cannot describe natural phenomena without using terms which imply what almost all thinkers now
believe to be erroneous notions. Hence, when we
attempt to present spiritual views of the origin and
nature of force, we are obliged to use terms which
imply the opposite, and our very language appears
to condemn us, or at least prejudices our theory.
This is especially true of the word force, and we
must carefully bear in mind that the origin of phenomena is not explained, because, in the language
of science, they have been referred to an assumed
force with a high-sounding name. Names are not
things, and we know nothing more of the cause
which brings the apple to the ground because New ton has called it the force of gravitation, than we
did before. He gave us the law of the motion, and
enabled us to predict how every apple would fall,
and how every planet would move throughout
space, but the cause of the motion is as closely hid den as ever. In regard to the law of gravitation we
know a great deal; but in regard to the force of
gravitation -whatever we may think or believe
about it - we know absolutely nothing, and the
same is true of every other force.
325 
RELIGION AND CHEMISTRY.
The most remarkable feature of modern science
has been the constant tendency of all investigation,
Transfer of during the last fifty years, to show that
energy.    the same energy, if only differently ap plied, may produce the most diversified phenom ena; and now almost all the so-called forces of the
old philosophy appear to be mutually convertible.
Thus - to begin with a lump of coal- as we have
seen, a certain amount of latent energy resides in
that black mass, which has been called the force of
chemical affinity. Burn the coal, - that is, combine it with oxygen, -and the affinity is satisfied,
but the energy reappears as light and heat. If the
coal is burnt under a steam-boiler, the heat expands
the water and converts it into vapor, and then we
find the energy again in the expansive force of
steam. The steam expands against the piston of
the locomotive, and the energy passes into the
moving train. The rapidly moving mass, in forcing
its way through the air and over the iron track, is
constantly losing its moving power in consequence
of the friction it encounters; but the energy is not
lost, and if we could follow it, we should find it reappearing somewhere as heat. Suddenly the engineer opens a valve, and a portion of the energy of
the steam gives motion to the air, and the effect is a
shrill whistle. The brakeman applies the brakes, and
the train after a few moments comes to rest.  Its
moving power is gone, but the energy is not lost.
The motion has been transformed into heat, and the
smoking brake shows where the energy has gone.
326
[LECT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
Return now again to the lump of coal, and, instead of burning it under a steam-boiler, heat it
in a properly constructed furnace in contact with
roasted zinc ore. This ore is a compound of zinc
and oxygen. The coal, in order to satisfy its intense affinity, seizes on the oxygen and sets the
zinc free. But although the chemical affinity of
the coal has been satisfied, no power has been lost;
for the energy which was before latent in the carbon is now latent in the zinc. Dissolve now the
zinc in dilute sulphuric acid, and the chemical affinity of the zinc will be satisfied, and, if certain conditions are fulfilled, the energy will take the form
of a current of electricity. Cause this current to
flow through a platinum wire, and this energy will
appear in the heat and light radiated from the
glowing metal. Cause the same current to flow in
spiral lines around a bar of iron, and we find the
energy again in the attractive force of an electromagnet. Connect with the electromagnet appropriate machinery, and the same energy may be so
applied that it will move a light boat or turn a
small lathe. Lastly, connect with the dissolving
zinc four thousand miles of iron wire, and the energy will be transmitted across a continent with
the velocity of thought, and write in a distant city
the message which it carries.
Start next from another point. What could be
more dissimilar than magnetism and light? Yet
a magnet may be made the means of producing a
most brilliant light. When we apply steam, or any
327 
RELIGION AND CHEMISTRY.
other force, to turn a large magneto-electric ma chine, the moving power is transmuted by the steel
magnets into a powerful electric current. If now
this current is made to pass through the air be tween two charcoal points placed near together,
the particles of coal become most intensely ignited,
and emit a light which is comparable with that of
the sun.* The same current, if passed through a
quantity of water, will slowly decompose the liquid,
and, while forcing the hydrogen apart from the
oxygen, will transfer a portion of its own energy
to the escaping gases, in which the power will
remain latent until the elements again unite.
Illustrations like these might be multiplied indefinitely; but enough, I think, has been said to
show that, to all appearance at least, the same energy may be transferred from one mass of matter to
another, and that thus, while nothing but the mode
of application has been changed, the power may
reappear under entirely different manifestations, and
produce phenomena wholly unlike those in which
it was but a moment before the active cause. The
truth of this principle becomes still more evident
when we apply in our experiments exact measurements; for we find that in all these transfers of
energy from mass to mass the power reappears undiminished. It may remain latent for a time, as in
a mass of coal, but sooner or later it will reappear
without having undergone the slightest loss.
* It has been proposed to use this method of illumination in some of
the lighthouses on the English coast.
[LEcT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
We must here dwell for a moment upon an important distinction, which has already been implied,
between latent and active energy. It is Latent and
a distinction with which every one is prac active energy.
tically familiar, and it may therefore be made clear
by referring to a few examples. A weight falling
to the ground from a given height is an example
of active energy, while an equal weight suspended
at the same height represents an equivalent amount
of latent energy. In winding up a clock, muscular
energy becomes latent in the suspended weight,
but reappears in mechanical motion as the clock
runs down. So also a lump of coal, as already
stated, represents a certain amount of latent energy. When the coal burns, its energy becomes
active, and takes the form of heat. Again, there is
stored up, if we may so speak, in a mass of zinc, a
large amount of latent energy. If in a galvanic
battery that zinc dissolves in sulphuric acid, this
energy becomes active, and reappears in a current
of electricity. Some persons do not like the term
latent energy, and speak of energy which is not in
action as potential or possible. In like manner
they speak of energy in action as dynamical or
actual. But terms are of no importance, if only the
ideas which they express are ftlilly understood.
Keeping this distinction in view, we shall better
understand the bearings of the important principles
just before stated. When energy, in passing from one
body to another, changes its mode of manifestation,
it seldom flows wholly into one channel, and almost
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RELIGION AND CHEMISTRY.
invariably more or less of it becomes latent. Thus
-to go back to the example of the steam-engine -
of the energy which is latent in the coal and becomes
active in the form of heat when the coal burns, not
more than one tenth at the most produces any useful
mechanical effect. The rest becomes again latent in
changing the water into steam, and in heating and
Energynever expanding the iron, the bricks, the water,
and the air in contact with which the fuel
burns. All this heated matter represents a large
amount of latent energy. It is in the condition of
the wound-up weight of a clock, and as it cools, this
energy is distributed to surrounding bodies. Were
it now possible, at a given instant after the burning
of the coal, to sum up all the energy, both active
and latent, which could be traced directly back to
the burning fuel, it would be found that not the
smallest fraction of the energy originally latent in
the mass of coal had been lost.  In this case, of
course, accurate experiments are out of the question; but wherever it has been possible to apply
measurements, it has been found that the principle
here illustrated holds true. I should not be able
to make the methods of such investigations intelligible without occupying a great deal of time.
Let it then be sufficient to state, that all those who
have most carefully studied the subject have arrived at the same results. There is therefore every
reason to believe that the principle we have been
illustrating is universally true. Let us then embody it in a definite statement. All natural vhe
330
[LECT. X. 
LECT. X.]   ARGUMENT FROM GENERAL PLAN.
nomena are the manzfestation of the same omnipresent energy, which is transferred from one portion of matter to
another without any loss of power.
But if the principle as thus stated be accepted, we
cannot rest here; for it involves this further conclusion, which, however marvellous, must be true.
The sum total of all the active and latent eneryies in the
universe is constant and invariable.  In other words,
power is as indestructible as matter.*
This grand truth is generally called the law of
conservation of energy, and, if it cannot as yet be
regarded as absolutely verified, there can Conservation
be no question that it stands on a better of energy.
basis now than did the law of gravitation one hundred years ago.
But how can I give you any conception of the
sublimity of the truth which this formal language
implies, but which no language is adequate to express? Even poetry in the highest flights of fancy
has never seen such a vision as these vistas of actual realities open to the intellect and imagination
of man. Review in the light of this grand generalization the subsidiary truth which from time to
time I have endeavored to illustrate during this
course of Lectures,- namely, that all terrestrial energy comes from the sun. The accumulated power
of the sun's delicate rays produces, as we before
saw, every motion and every change which takes
place on the surface of this planet, from the falling
* Many philosophers believe, with Newton, that matter in its essence is only a manifestation of power.
331 
RELIGION AND CHEMISTRY.
of an avalanche to the crawling of a worm. But
that energy, as we now know, is not exhausted on
the earth. To use the eloquent language of an other: "Our world is a halting-place where  this
energy is conditioned. Here the Proteus works his
spells; the selfsame essence takes a million shapes
and hues, and finally dissolves into its primitive and
almost formless form. The sun comes to us as heat;
he quits us as heat; and between his entrance and
departure the multiform powers of our globe appear.
They are all special forms of solar power, -the
moulds into which his strength is temporarily
poured, in passing from its source through infinitude." *
Attempt now to bring together in imagination
all the energies acting at one moment on the
earth, and unite them in one tremendous aggregate.
Begin with the moving power of the air, the hurricanes, the tornadoes, the storms, and the gentler
winds which are everywhere at work from the Arctic to the Antarctic Pole, omitting in making the
estimate, if you choose, the lightning and the thunder, which, though brilliant and noisy demonstrations of power, would hardly increase by a unit
the vast sum. Add to this the mechanical power
in the mighty flow of waters, the ocean currents,
the rivers, the cataracts, the glacier-streams, and the
avalanches, all over the globe. Bring into the calculation the forces at work in the various phases of
* Professor John Tyndall, in the work already quoted, "Heat considered as a Mode of Motion."
332
[LECT. X. 
LECr. X.]   ARGUMENT FROM GENERAL PLAN.
animal and vegetable life. Remember the conflagrations, the furnaces, the fires, and the other manifestations of the terrible energies of the atmospheric oxygen, whenever it is aroused. Do not even
forget the comparatively insignificant power which
man is wielding with the aid of powder and of steam.
Making now an immense allowance for what you
must have overlooked, sum this all up, - if you can
without bewilderment,- and what part is it of the
whole? Why, it has been calculated that it is equal
to but one 2,300,000,000th of the force which the
sun is every moment pouring into space. And what
is the Sun? A small star in the infinitude of space,
where shine Sirius and Arcturus, Regulus and A1debaran, Procyon and Capella, with unnumbered
others, all shedding forth a far mightier effluence
than our feeble star; yet the grand total of the
powers streaming from all the suns which human
eye has seen, or which still lie undiscovered in the
depths of space, alone represents the active energy
of the universe. My friends, there are two theories
of causation. One regards this energy as an unin telligent power. The other sees in it simply the
will of the Eternal Jehovah. They are both theo ries.  We  cannot substantiate either.  But which
do you think is the more probable?  Let us not
pass hasty judgment, but soberly weigh all the tes timony, and base our decision on the best scientific
evidence we can obtain, and on that alone.
Thus far in our discussion we have been dealing
with facts and principles which every theory of
333 
RELIGION AND CHEMISTRY.
causation must explain. But we now pass into
what is rather the region of speculation, and we must
step more cautiously. I have used thus far the
terms energy and transfer of energy, without expecting
that you would attach to them any more definite
meaning than that which is conveyed by the words
in their most familiar use. Energy is a definite
thing, which is as palpable to our senses as matter,
and which, in most cases at least, we can measure
as accurately. Any one who has been stunned by
a blow or a fall, has been burnt by a fire, has been
dazzled by the sun, or has received a shock of elec    Energy always tricity, knows well enough what energy
appears as  is; and the doctrine of the conservation
motion.
of energy is wholly independent of any
theory which men may entertain in regard to its essence. For this reason, I have aimed to present the
grand doctrine of modern science entirely free from
all speculations whatsoever; but now that we are
seeking to go behind the external phenomena, it
will be well for us to consider very briefly a theory
which, although it does not profess to explain what
energy is in its essence, nevertheless may give to
the mind a more definite conception of its mnode of
action. The theory, it is true, cannot be regarded
as fully established; but it represents the undoubted tendency of science, and the materialists would,
of all others, be the first to accept it. According to
the modern view, all energy appears as motion, and
this too whether it be manifested in mechanical
work, or in the more subtile phenomena of sound,
334
[LECT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
light, heat, chemical affinity, electricity, or magnetism. We must, however, extend our idea of motion,
and not limit it, as is usually done, to the motion
of masses of matter.
Even the smallest material masses perceptible to
our senses must be regarded as aggregates of still
smaller masses, which we call molecules or atoms.
These atoms, moreover, even in the densest bodies,
cannot be in contact, and we must picture them to
our imagination each as a tiny world,  otion of
poised in space. In using the word atom atoms to be
we  do not mean  to imply  that these considered.
particles of matter are mechanically indivisible,
as its derivation would indicate, but we merely
declare that they are so many separate units so
far as our science is concerned. The same relation which the worlds bear to the cosmos, we conceive that these atoms bear to the micro-cosmos
which every mass of matter represents, and it is
believed that the motions of suns and systems have
their miniature in the motions of these atoms. The
ether, also, of which I spoke in the second Lecture
as filling celestial space, is supposed to pervade
equally the atomic spaces, to surround each atom
with a highly elastic atmosphere, and to be the medium by which motion is transmitted throughout a
universe which includes the infinitesimal as well as
the infinite. Moreover, we conceive that the motion of the atom is the exact counterpart of the
motion of a world or of the motion of a ball, and
that all motion obeys the selfsame laws. As when
22
335 
RELIGION AND CHEMISTRY.
an ivory billiard-ball strikes another, it gives up the
whole or a part of its motion to the second ball, so
we believe that one atom may transmit motion to
another. In like manner as an impulse is transmitted through a long line of billiard-balls, and the last
ball only appears to move, so also we conceive that
the electrical impulse is transmitted from atom to
atom through the telegraph wire, and produces perceptible motion only when transformed into magnetism at the end of a thousand miles. Again, motion
may be transmitted from atoms to masses of matter; for although the impulse imparted by a single
atom may be as nothing, the accumulated effect of
millions on millions of these impulses may be immense. In this way, we conceive, the motions of
the ether particles in the sunbeams unite to produce all the grand phenomena of nature. On the
other hand, the motion of great masses may be
suddenly resolved into the motions of the atoms
composing these masses, and thus, when motion
outwardly appears to cease, it may only be transferred from the previously moving body to the
atoms within. When the cannon-balls, with their
immense velocity, strike the Ironsides, and fall harmlessly from her armor-plates, the particles of iron
take up the motion of the ball, and indicate by a
higher temperature that the energy has not been
lost.
Understanding then the term motion in the extended sense just explained, we shall comprehend
more clearly the theory stated above. This theory
336
[LEcT. X. 
LECRT. X.]    ARGUMENT FROM GENERAL PLAN.
supposes that the phenomena of sound, light, heat,
and electricity are produced by the motions of
atoms, in the same way that the grander phenomena
of mechanics and astronomy are caused by the motion of large masses of matter. The transmission of
energy is, then, the direct result of the transmission
of motion, and the conservation of energy is fully
explained by the well-known law of inertia, which
the motions of all matter necessarily obey. I have
not time to enter into any details in regard to the
mode of motion by which light, heat, and all this
class of phenomena are produced, other than those
already given in the previous Lectures of this
course; but I take great pleasure in referring my
audience to the work of Professor Tyndall, already'
frequently quoted, which is by far the best popular
statement of the subject that has ever been made.
Indeed, great differences of opinion in regard to the
mode of the atomic motion are entertained by those
who accept the theory in its general statement, and
in many cases we can form no conception of the peculiar phase which the motion assumes. It is sufficient
for my purpose if I have been able to make clear
the general principle, and I will only add a few numerical results, which will show what a precise form
the theory has taken in the minds of scientific men.
According to the modern theory, when we heat
a body we merely impart to its atoms a greater velocity of motion. Now, according to the experiments of Professor Joule, when we raise the temperature of a pound of water two Fahrenheit de
ag7 
RELIGION AND CHEMISTRY.
grees, we distribute among the atoms of the liquid
an amount of motion equal to that acquired by a
weight of two pounds in falling 772 feet; and a simple calculation will show that this is represented by
Aa Minie ball, weighing one eighteenth of
Amount of
the atomic   a pound, moving with a velocity of 1,338
motion.    feet in a second.*  The amount of motion,
therefore, which is imparted to the particles of water
in an ordinary tea-kettle during the process-of boiling, must be in the aggregate vastly greater than
that ever acquired by any projectile. We shall arrive at a still more remarkable result, if we examine
in the light of our theory the process of chemical
combination by which water is formed. In this
process of burning, one pound of hydrogen gas
combines with eight pounds of oxygen  gas to
form nine pounds of water. Although the distances which separate the atoms of the two gases
before combination are utterly inappreciable by our
senses, yet, in passing over these distances, they acquire a velocity which causes them to clash together
with tremendous energy, and in the collision this
form of atomic motion is transmuted into that other
mode of motion which we call heat. Incredible as
it may appear, the amount of motion which in the
act of combination alone is thus transmuted into
heat corresponds to the fall of a ton weight down a
precipice 22,320 feet high. Such illustrations might
be multiplied indefinitely; but you will see from
* In making the calculation, it must be remembered that the amount
of motion is measured by the square of the velocity.
338
[LECT. X. 
LECT. X.]    ARGUMENT FROM GENERAL PLAN.
these how purely mechanical the idea is which we
associate with the motion of an atom, and you must
have been impressed by the magnitude of the energy which these atomic motions represent. "I
have seen," says Professor Tyndall, "the wild stone
avalanches of the Alps, which smoke and thunder
down the declivities with a vehemence almost sufficient to stun the observer. I have also seen snowflakes descending so softly as not to hurt the fragile
spangles of which they were composed; yet to produce from aqueous vapor a quantity of that tender
material which a child could carry, demands an exertion of energy competent to gather up the shattered blocks of the largest stone avalanche I have
ever seen, and pitch them to twice the height from
which they fell." If such, then, be the measure of
these atomic motions, we can easily conceive how
the motion of the cannon-ball might be transferred
to the particles of the armor-plate without much
apparent result, and even how the energy of a world
might be maintained by the motion of the atoms in
the sunbeam.
Accepting, then, this new theory of science, and
admitting that all energy is manifested in motion,
we reduce at once our discussion of the doctrine of
causation to this simple question,- What is the
primary cause of motion? If we can explain the
simplest case of motion, we have solved the prob lem for the universe. Take, for example, a boy's
ball, moving through the air under the impulse
of a well-directed blow. Do we not know some
339 
RELIGION AND CHEMISTRY.
thing of the cause of that motion? Is it not connected with the muscular contraction of the boy's
arm, produced by his will? Is not his volition, acting mysteriously on matter, at least the occasion of
the motion? It is perfectly true that the will does
not create the motion. The ball is impelled by a
portion of that energy in nature which man can
neither increase nor diminish. But still the boy's
will is the occasion of the motion. It has opened
the channel through which the energy of nature
has flowed to produce the specific result which the
boy desired. So, in a thousand other ways, man is
able to come down, as it were, upon nature, and to introduce a new condition into the chain of causation.
Place the point of contact as far back as you please,
theorize about the subject as you may, the fact still
remains the same. Our will does act on matter,
and does act to produce most efficient results.
Here is energy exerted of whose cause we have
the consciousness within ourselves, and, if the analogy is worth anything, it points to but one conclusion, - namely, that motion is always the' manifestation of will. As the boy's will acted on that atom
of matter, which, though moved perhaps but a
hair's breadth from its position, set in action -as
if by the touching of a spring- the train of natural
causes which gave motion to the ball, so we may
suppose that the Divine will acts in nature. According to this view, the energy which sustains the
universe is the will of God, and the law of conservation is only the manifestation of His immutable
340
[LEc'T. X. 
ILCT. X.]    LIMITS OF SCENCE AND RELIGION.
being,-" the same yesterday, and to-day, and forever."
We do not say that this theory can be proved,
for certainty here is out of the question; but we
do claim that it is based on the only analogy
which nature affords, that it is a legitimate deduction of science, and that it is perfectly consistent
with Christian faith. On a subject where science
can only grope, the wildest theories are possible;
but these should not trouble a well-balanced mind,
so long as there exists an equally probable theory
which can be reconciled with the purest faith. It
has been my aim in this Lecture to show, not only
that such a theory is tenable, but also that the
Christian theory of causation is the most probable
theory of science; and my earnest hope is, that, for
some minds at least, the considerations I have offered will help to reconcile the apparent conflict
between science and religion, which materialism is
ever striving to foment. Allow me to add, in concluding, one or two other suggestions which may be
of value in the same direction.
I cannot but believe that the appearance of
clashing between science and religion would be
wholly avoided, if the teachers both of Necessary
Necessary
God's unwritten and of His written word limitations of
scientific and
would  pay more regard  to the neces- religious
sary limitations. of scientific and religious thought.
thought. On subjects where the methods of acquiring knowledge are so utterly unlike, where the
relations of the knowledge to the human under
341 
RELIGION AND CHEMISTRY.
standing are so different when gained, it is in
vain to expect literal accordance. Science, both
in its methods and its results, addresses the understanding exclusively; Christianity appeals chiefly
to the heart.  Science aims to instruct; Christianity aims to persuade. Science is attained by
study, and is possible only for the few; Christianity is a free gift from God to all men who will
receive His Son. The results of science are fulily
comprehended, and can be expressed in definite
terms; the truths of Christianity stand on a level
above man's intellect, and can only be shadowed
forth in types and symbols. The forms of science
are constantly changing; the types and symbols of
Christianity are permanent. Lastly, while the language of science may be so varied from time to
time as to express accurately the current ideas,
Christianity necessarily retains the forms through
which it was first revealed. Under such conditions
how can it be expected that the language of revelation should agree with the letter of science?
You might as reasonably find fault with nature because its crystals are not perfect, as criticise the
Bible because its language, although embodying
divine truth, is not free from the necessary limitations and imperfections of the human medium of
thought.
I have not time to develop the.ideas here suggested; but the bearing of the facts is obvious, and
Practicalcon- they lead to important practical conclu
clusion sions.  In the first place, they should
342
[LECT. X. 
LECT. X.]    LIMITS 0O  SCIENCE AND RELIGION.
teach men of science to honor and reverence the
forms of religion. They are the types and symbols
of a higher truth than any Science can teach. Let
Science vindicate her own methods, and allow no
interference within her proper sphere; but unless
she learn that there are other sources of knowledge than material nature, and other channels of
truth than the intellect, her own philosophy will be
confounded, and her light will go out in darkness.
On the other hand, it is equally the duty of the
ministers of religion to honor and respect the methods of science. They have been ordained by God,
and through these processes of thought He is constantly revealing eternal truths to the mind of
man. Insist as strongly as you please that Science
should be allowed no voice in matters of faith.
Scrutinize as closely as you can every step of her
logic; but so long as she keeps within her legitimate province, allow her the largest liberty, and
extend to her the most generous encouragement.
Watch sharply her results, and expose her fallacies
wherever you can find them; but, if your judgment condemns, let it be on scientific grounds, and
not by any arbitrary standard of your own. Above
all, even if you think your most cherished opinions
are in danger, do not withdraw your fellowship
hastily, or be betrayed into undiscriminating censure. Science is paramount within her own province. Do everything in your power to consecrate
her aims and sanctify her spirit, but do not attempt
to control her investigations or restrict her free
343 
RELIGION AND CHEMISTRY.
thought. Await God's time. If science is wrong,
she will sooner or later correct her error. If she is
right, God is on her side, and you would find yourself fighting against the great Jehovah.
Again, a proper appreciation of the necessary
limits of scientific and religious thought should lead
all men to reverence the Word of God as it has
been handed down to us through history. In view
of the facts already intimated, I cannot look with
favor on any attempts at Biblical criticism which
aim to square the language of Scripture by the
results of modern science. They leave a most unpleasant impression on my mind. I believe the
Bible inspired, from the grand epic of creation,
with which it opens, to the glorious vision of the
New Jerusalem at its close. I feel that its very
words are sacred, and if you are so ready to accommodate any part of them to the shifting phases of
science, what certainty can I have in regard to the
whole? The Bible is no text-book of science, and
the attempt to impose an equivocal or mysterious
meaning on its simple and obvious statements degrades and dishonors it in the minds of devout men.
The methods by which its truths are expressed may
be at times rough and uncouth; but they are the
methods chosen by God, consecrated by the blood
of martyrs, and hallowed by the tears of saints; and
they have therefore a power which no other language could have. Break not the mould in which
the forms of faith have been cast, before they have
become firm and hard, lest the precious metal
344
[LicT. X. 
LIMITS OF SCIENCE AND RELIGION.
should itself be lost. Finally, leave religion and
science to their respective methods, and encourage
both alike in their noble calling. Let science, by
cultivating man's intellect, elevate him to nobler
and more spiritual views of God's wisdom and
power. Let religion, by purifying man's heart,
open to him clearer visions of God's purity and
love; and, at last, when this material shall have
vanished, and when the waters of controversy shall
have ceased to roll, the heart and the intellect,
made one and washed clean in the blood of the
Lamb, shall unite in the song of the angels around
the throne, saying, "Blessing, and glory, and wis"domin, and thanksgiving, and honor, and power,
"and might, be unto our God for ever and ever."
But while insisting upon the necessary limitations of scientific and religious thought, I must not
forget that all such considerations bear Limits of natuwith peculiar force upon  the questions raltheology.
which it has been my privilege to discuss in this
course of Lectures.   Therefore, although I have
most carefully endeavored to guard my argument
from the slightest exaggeration, I should not feel
justified in concluding without distinctly stating
how far in my.opinion the argument of natural
theology may be safely carried, and to what extent
unaided science may be said really to prove the
fundamental truths of Christianity.
In the first place, then, I believe that the existence of an intelligent author of nature, infinite in
wisdom and absolute in power, may be proved
LECT. X.]
345 
RELIGION AND CHEMISTRY.
from the phenomena of the material world with as
much certainty as can any general truth of science.
In the second place, I am of opinion that the facts
of nature also prove - although the arguments
adduced may be less convincing- that the author
of nature is a personal being, and the one only
and true God revealed to us in the Bible.  Lastly,
I think that the relations of the human mind to
the material world, viewed in the light of modern
science, give us strong reason to believe, on scientific grounds alone, that the universe is still sustained, in all its parts, by the same omnipotent and
omniscient Will which first called it into being. It
may be that God intrusts the execution of His will
to subsidiary intelligences, and such a belief is perfectly consistent with the above conclusions. But
nature throws no light upon the subject, and
therefore I have not discussed this question. If,
however, such agents exist, the facts of nature just
referred to would tend to show that they must
be intelligent causes, and subject to Him who is
all in all.
To the extent I have indicated I regard the argument of natural theology as logically valid. Moreover, I am persuaded that science confirms and
illustrates the priceless truth which Christ came
on earth to reveal; but I do not believe that the
unaided intellect of man could ever have attained
to certainty in regard to even the least of these
truths, independently of revelation. Nevertheless,
as I stated in my introductory Lecture, I feel that
346
[LECT. X. 
LECT. X.]    LIMITS OF SCIENCE AND RELIGION.
the best service which science can render to religion is in the way of confirmation and illustration, rather than in that of absolute proof, and for
this reason I have preferred to discuss my subject
chiefly from that point of view.
The subject, as prescribed by the founder of these
Lectures, is "The power, wisdom, and goodness of
God as manifested in His works," and to this form
of statement, if interpreted in the sense just indicated, I have nothing to object. I do not believe,
however, in any sense, that nature proves the goodness of God. When the heart has been
Nature does
once touched by the love of God, as notproveGod's
manifested  on  Calvary,  the tokens  of beneficence.
God's goodness are seen everywhere: but before
this, nature, to one who has seen its terrors and
felt its power, looks dark indeed; and the pretence that the material universe, unexplained by
revelation, manifests a God of unmixed beneficence,
not only does harm to religion, but places science
in a false light. The most superficial observation
shows that this is not true. Lightning and tempest, plague, pestilence, and famine, with all their
awful accompaniments, are no less facts of nature
than the golden sunset, the summer's breeze, and
the ripening harvest; and who does not "know'
"that the whole creation groaneth and travaileth in
"pain together until now"? It does not change the
terrible fact to say that nature has been disordered
by man's sin; for sin is itself the greatest evil in
the world, and its ghastly forms meet us at every
347 
RELIGION AND CHEMISTRY.
step. So prominent, indeed, is the evil in nature,
and so insidiously and mysteriously does it pervade
the whole system, that an argument to prove the
malignity of God could be made to appear quite as
plausible as the arguments which are frequently
urged to prove His pure beneficence; and wherever
the unaided human intellect has attempted to make
to itself a beneficent God, it has always made a
malignant Deity as well. Nature manifests God's
wrath no less than His love, and it is a false and
sickly philosophy which attempts to keep the awful
fact out of sight. God is our Father; but nature
could not teach it, and "the Word was made flesh"
to declare it.  God is love; but nature could not
prove it, and the Lamb was "slain from the foundation of the world" to attest it.  Nature is but a
part of God's system, and not until the natural and
the supernatural shall be made one will the mystery of evil be solved.
THE END.
Cambridge: Stereotyped and Printed by Welch, Bigelow, & Co
348
[LECT. X.