the investigator in this field :
"It is surely", said the Unknown, "a pure delight ... to
produce as it were a microcosm in the laboratory of art,
1 Concerning the identity of Philalethes and the "Unknown",
cf. ib. I, London 1839, 433 438.
2 Ib. IX 345. 3 Ib> IX 347-
12 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
and to measure and weigh those invisible atoms, which, by
their motions and changes according to laws impressed upon
them by the Divine Intelligence, constitute the universe of
things. The true chemical philosopher sees good in all the
diversified forms of the external world. Whilst he investi-
gates the operations of infinite power, guided by infinite
wisdom, all low prejudices, all mean superstitions disappear
from his mind." * "I do not mean that he should affix
written prayers and inscriptions or recommendations of his
processes to Providence, as was the custom of Peter Wolfe,
who was alive in my early days ; but his mind should always
be awake to devotional feelings, and in contemplating the
variety and the beauty of the external world, and developing
its scientific wonders he will always refer to that infinite
wonder, through whose beneficence he is permitted to enjoy
knowledge; and, in becoming wiser, he will become better;
he will rise at once in the scale of intellectual and moral
existence, his increased sagacity will be subservient to a
more exalted faith, and in proportion as the veil becomes
thinner, through which he sees the causes of things, he will
admire more the brightness of the divine lights, by which
they are rendered visible." 2
These passages were written by Davy for publication.
But in his diaries and letters we find the same ideas.
We cite a few examples:
"April 6. 1827. Did not shoot, but returned thanks to
the Great Cause of all being for all His mercies to me, an
undeserving and often ungrateful creature, but now most
grateful. May I become better and more grateful and more
humble-minded every day.
September 2. I took my exercise well with less fatigue,
and certainly feel better. Offered up my thanksgiving to
the O. O. 0. 3 with tears of gratitude and feelings of intense
1 Collected Works LX 361. * Ib. IX 367.
3 Instead of the name of God, Davy writes, here as elsewhere,
O. O. O., instead of "Thanks be to God", he writes frequently only
G. O. O. O., i. e. gratias Omnipotent! or Omniscienti.
H. DAVY. 13
September 27. St. Goar. ... As I have so often alluded
to the possibility of my dying suddenly, I think it right
to mention that I am too intense a believer in the Supreme
Intelligence, and have too strong a faith in the optimism
of the system of the universe, ever to accelerate my dis-
solution. The laurel-water, laudanum, and opium that are in
my dressing-case are medicines. I have been and am taking
a care of my health which I fear it is not worth, but which,
hoping it may please Providence to preserve me for wise
purposes, I think my duty G. O. O. O. *
June 3. 1828. Aussee in Steiermark. I indulge in the
idea that you are well and happy and enjoying a life which
I can say I only support supposing that it please Omni-
science to preserve me for some ends which I cannot
understand, but which I trust belong to the great plan of
goodness and mercy belonging to the Divine mind." 2
For the Protestant religious ethos Davy showed little
liking, at least in the latter part of his life. But it
is worthy of note that he regarded the Catholic Church
and the Catholic spirit with the greatest friendliness.
The influence of the Catholic religion on the mass of
the people, the hearty festive joy of their Sunday in
contrast to the Puritanical restraint of the English Sab-
bath impressed him vividly. In this connection his
brother writes 3 :
"The obedience which the Church requires, the submis-
sion of reason, the unlimited faith, he considered favourable
to religious feeling, and the securest harbour for the unfor-
tunate and afflicted, the strongest hold against popular schism,
scepticism, and fanaticism; and in accordance with the fa-
culties and wants of the human mind, especially as regard-
ing its affections. On the latter point he expresses him-
1 Memoirs of the Life of Sir Humphry Davy , by his brother
John Davy, in Collected Works I 345 376 381.
2 Letter to his brother John, ib. I 388.
3 Collected Works I 431.
14 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
self strongly in his diary on the 14* of June, 1827, at
Aussee, on occasion of that beautiful ceremony, the Fete-
Dieu. His words are : 'Struck with the affecting nature
and superiority of the Catholic religion, which gives joy and
comfort to the human heart, by making a festivity and not
a hard duty of worship,.- it is the Fete-Dieu.' His views
of the weakness and fallacy of reason on the subject of
religion might have promoted a bias in his mind in favour
of this church ; and having travelled much in Roman Catholic
countries, and witnessed the powerful influence which reli-
gion there has over the people, as regards habits of life and
daily feelings, the bias might have been confirmed from
seeing the positive civil and social advantages which it gives
in comparison with the Protestant; its levelling, unaristo-
cratic nature ; its being no distinguisher of persons, its bring-
ing all classes of people together, without distinction, in
mixed worship, under the same roof, its throwing open the
most splendid churches to the populace and allowing them
to be made an asylum to the pauper."
The discovery of Davy and Rumford did not take
its place among the accepted truths of science until
about the middle of the 19* Century, when the genius
of Julius Robert Mayer pressed it conclusively to the
front. With him, therefore, we must occupy ourselves
more closely *.
Born at Heilbronn on November 25 th 1814, the son
of an apothecary, Robert devoted himself to the study
1 Die Mechanik der Warme. Gesammelte Schriften von Robert
Mayer. Dritte, erganzte und mit historisch-literarischen Mitteilungen
versehene Auflage , herausgeg. von Dr. Jakob J. Weyrauch,
Stuttgart 1893. Kleinere Schriften und Briefe von Robert Mayer.
Nebst Mitteilungen aus seinem Leben. Herausgeg. von Dr. Jakob
J. Weyrauch, Stuttgart 1893. Ru mel i n, Erinnerungen an R. Mayer,
in Allgemeine Zeitung, Stuttgart u. Augsburg 1878, Beil. Nr. 120 122,
p. 1761 1778 1795. Also printed in "Leopoldina" XV, Halle 1879,
34 50. Cf. ib. XIV, Halle 1878, 82.
J. R. MAYER. 15
of medicine, and on the completion of his course in
1840 made a voyage as ship's doctor to Batavia. While
engaged bleeding the seamen, he found that the blood
in the veins of the arms was not, as in our latitudes,
dark, but, on the contrary, rather bright. The attempt
to explain this simple fact gave Mayer the first impulse
to his discovery. The blood changes colour according
as it combines in the lungs with the oxygen of the
atmosphere, and this combination is a kind of com-
bustion, which has for outcome the natural warmth of
the body. Thus by the consequent thinking-out of his
observation, Mayer was led on to the question of the
origin of bodily heat and of heat in general. What
is meant, he asked himself, by saying that heat arises?
Is this origination a starting out of nothing, is the
cessation of heat a veritable annihilation , or are both
merely a transformation of a something already in
existence? These questions troubled him incessantly.
"I threw myself", he writes, "so eagerly into the investi-
gation, that I (and many a one will laugh at me for it)
busied very little to collect information about the remote
region in which I was, but preferred to stay on board, where
I could pursue my work without interruption. Often I felt
as it were inspired: such a feeling as I do not remember
to have ever experienced before or after. Certain ideas
which flashed into my mind in the roadstead of Surabaja
were followed up and led to further questions. Those days
are gone: but the systematic establishment of what then
suggested itself to me, taught me that truth is that which
is not only subjectively felt but can also be objectively
demonstrated. . . . The time will certainly come when these
truths will belong to the common stock of science, but who
will establish them, or when, who can say?" *
Wey ranch, Kleinere Schriften 212 213.
1 6 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
The day of recognition came at last, but not till after
a long and weary struggle. No review would accept
his first essay, a fact for which Mayer's style was to
blame, for although his scheme of thought was clear
and sequent enough he omits, in reducing it to writing,
so many connecting links as to produce the impression
of incoherence. His early essays on the Theory of Heat
attracted hardly any notice. This and his cruel treatment
at the hands of the reviewers threw him into a sort of
nervous tumult so violent that he had at times to be
confined in a lunatic asylum. But his ideas gradually
made their way.
"No greater genius", declared Tyndall in 1891, "than
Robert Mayer has appeared in our century. Some
men who now overshadow him will undoubtedly be
placed beneath him in the future history of science."
And to the discoverer himself he writes in 1866:
"I am a plain blunt man who speaks his mind, and
therefore you must accept my words without a trace
of flattery, when I say that I never turn to your scien-
tific writings without wonder. That you , in a small
provincial town, and occupied with the duties of your
profession, should have shot so far in advance of all
other men, is to me astonishing. I know no similar
case in the history of science." 1
Clausius expressed himself in similar terms. As soon
as his attention had been drawn to Mayer's writings he
corroborated Tyndall's opinion of them. He was "amazed
at the multitude of just and beautiful ideas contained
in them" 2 .
1 Weyrauch, Kleinere Schriften 212 213.
2 Clausius, Die mechanische Warmetheorie I 3 , Braunschweig
1887, 396; II 2 , ib. 1879, 326.
J. R. MAYER. 17
What Robert Mayer thought of Materialism and
Christianity, we shall learn from himself. "The anti-
materialistic standpoint which I have assumed, and
which I will never renounce (Mt. x. 32) 1 , is naturally
maintained here also", he writes on June 15 th 1871, in
forwarding to a friend his "Discourses on Natural Science".
Nor did Mayer keep his Christianity locked up in his
heart. At the Scientific Conference held at Innsbruck
in 1869 he was invited to pronounce a discourse, and
he spoke of the conclusions which could be deduced
from his theory in the various departments of know-
ledge 2 . He claimed that the new conception of the
Conservation of Energy necessarily implied the existence
of a spiritual soul in man.
"The French physicist Adolphe Him, who like Joule,
Holtzmann and Helmholtz discovered independently the
mechanical equivalent of heat, classifies all existences, in my
opinion, justly and beautifully, under the three categories:
i. Matter, 2. Force, and 3. the Soul or spiritual principle.
When once we have come to understand that there exist
not only material bodies but also forces, forces in the stricter
sense known to modern science, just as indestructible as
the elements of the chemist, there needs but one more
logical step to the recognition and acceptance of spiritual
realities. In the non-living world we speak of atoms, in the
living world of individuals. But the living body is made
up, as we now know, not solely of material particles but
1 "Everyone, therefore, that shall confess Me before men, I will
also confess him before My Father Who is in heaven. But he that
shall deny Me before men, I will also deny him before My Father
Who is in heaven."
2 Copy of a discourse in the Journal of 43 rd Assembly of German
Naturalists and Doctors in Innsbruck from i8 th to the 24 th Sept. 1869,
Innsbruck 1869, 40 44. Also printed in "Ausland" 1869, 1061
Kneller, Christianity. 2
l8 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
also, in its essence, of forces. Now neither matter nor force
is capable of thought, feeling, or volition. But Man thinks."
He maintains "that in the living brain, physical changes
designated by the name of molecular activity are continually
taking place, and that the spiritual functions of the indi-
vidual are connected in the most intimate manner with
these cerebral processes. But it is a gross blunder to identi-
fy these concurrent activities. An example will demonstrate
this unequivocally. Telegraphic communication cannot, as
every one knows, be established without a simultaneous
chemical process. But the message delivered by the wire,
the contents of the telegram, can by no means be regarded
as a function of this electro-chemical process. This holds
with still greater force of the relation of thought to the
brain. The brain is not the soul, but only the instrument
of the soul. And the soul, not coming within the reach
of sense-perception, is not an object of investigation for
Physics or Anatomy. Thought subjectively accurate is also
objectively true. Were it not for this inalterable har-
mony, pre-established by God, between subject and ob-
ject, all our thinking would necessarily be without fruit.
Logic is the Statics, Grammar the Mechanics, and Language
the Dynamics of thought".
"Let me here conclude. With heartfelt conviction I say
it: A sound philosophy must and can be nothing else than
a propaedeutic to Christianity."
The conviction expressed in these words was with
Mayer a life-long one, and we find it also proclaimed
during his East Indian voyage, when the germinal idea
of his theory first flashed into his mind.
He writes to his parents on Feb. 25 th 1840 shortly before
the sailing of his ship: "I will send up under all skies in-
cessant prayers to the Almighty that He may keep my beloved
parents safe and well." 1 And two days later: "Now for a
time good-bye, my dearest father and mother; my child-
like gratitude for your unwearied kindness to me, my most
Weyrauch, Kleinere Schriften 85.
J. R. MAYER. 19
earnest appeal for forgiveness for my many faults and
failings, my most ardent prayers for your constant welfare.
Weeping I cast myself on your breasts." l
How he occupied himself during the voyage appears
from certain entries. "On the ninth (of March) I succeeded
in extricating my box of books from between-decks. . . .
Triumphantly I waved on high my Bible and my hymn book,
for which before all others I had longed, and which every
day procure for me some blessed hours. The heart with-
drawn from the tumult of the world, is drawn to meditation,
and, living before the glorious face of nature, there is nothing
more beautiful than to elevate one's thoughts to the Creator." 2
"Thanks to the All-Good", he writes home on June 8 th
1840 on reaching the Straits of Sunda, "Who has vouchsafed
me these little trials without which life cannot go on, and
has granted me also the grace never to grow weary of
praising his wisdom." 3 And on July 25 th : "To the All-
Wise Providence of God, so evident in the ordering of my
life, I confidently commit the future also; if He grants me
only one prayer I will cheerfully let all else pass by me:
but in this regard alone I cannot yet sincerely pray: Thy
Will be done. I speak of the hope of once again clasping
my dear ones to my breast." 4
Nor did his years of trial alter in any way this atti-
tude of mind :
"My early feeling", he writes on Dec. 3 I st 1851, "that
scientific truths are to the Christian religion much what
brooks and rivers are to the ocean, has become my most
vital conviction. Tempted as I was to drift with the tempest
of passion, I had made shipwreck in these latter years, had
not in my heaviest hours the Mercy of God, through your
instrumentality, kept me always on the right path. How
indifferent to me are many things which had else been
so important I" 5
1 Ib. 88. 2 Ib. 92. 3 Ib. 95
4 Ib. 97. 5 Ib. 339340.
20 I. A FUNDAMENTAL LAW : THE CONSERVATION OF ENERGY.
Mayer, nevertheless, experienced at times certain of
those confusions which are as it were the patrimony
of Protestantism. He says incidentally, that "in the
supernatural sphere" he "never succeeded in coming to
perfect agreement with himself" *. The passage occurs
in a letter of thanks to Moleschott, and must have in
some degree tempered the hostility of the latter towards
the known religious opinions of Mayer. On another oc-
casion he has words of recognition for a brochure of
D. F. Strauss 2 , apparently the latter's "Two Essays in
Conciliation: 'Perishable and Permanent Elements in
Christianity'; 'On Justinus Kerner'". On the death of
his mother he writes to a friend 3 :
"The firm conviction which I have based on scientific
facts and without any reference to Revelation - - of per-
sonal immortality, and of a higher direction of human life,
was my greatest consolation when I clasped the cold hand
of my dying mother."
But our object here is not to criticise Mayer's reli-
gious belief, but merely to show that he always upheld
firmly those truths which form the basis of Christianity.
To this end a passage such as that last cited is almost
more valuable than the pious utterances to be found
in his letters to his parents, or the fact that on his
death-bed he comforted himself with the frequent repe-
tition of that verse of the Bible: "Blessed are the dead
who die in the Lord." 4
In his scientific correspondence we find also incidental
recognitions of personal immortality, or such expres-
1 Weyrauch, Kleinere Schriften 362.
2 Ib. 92, Letter of March 1840.
3 Ib. 20. 4 Ib. 485.
J. R. MAYER. 21
sions as: "The planetary system, the whole stellar
system in general, are ordinances of Divine wisdom." 1
Towards the Catholic Church, Mayer was very ami-
cably disposed: "The idea of authority", says his friend
Rumelin 2 , "was so dominant with him, that for a time
he dreamed of a fusion of Catholic discipline with Pro-
testant dogma. ... At this time (the time of his con-
valescence), he also took great pleasure in the company
of Catholic priests." When Professor Huefner paid him
a visit at the beginning of his seventieth year, Mayer's
nephew begged him not to talk to his uncle about
Darwin or politics. "Darwin's theory he cannot endure,
and in politics he is a vigorous Ultramontane." 3 In a
conversation on politics with Ringseis in 1 869 he declared :
"Nobody but the Pope can help us." For a time he had
thoughts of becoming a Catholic, but contented himself
with the reflection that internal communion was enough 4 .
Very different was his estimate of modern German
philosophy. "He had", writes Rumelin 5 , "till 1841,
never read a volume of philosophy, nor, so far as I
know, did he ever read one after that year. When I
brought him Hegel's Logic and the volume of the
Encyclopaedia which contains the Philosophy of Nature,
he returned both in a few days saying that he had not
1 Weyrauch ante 423, Letter of 3. Aug. 1869. Ib. 139, Letter
dated 17. July 1842.
2 Allgemeine Zeitung 1878, Beilage Nr. 122, p. 1795; "Leopol-
dina" XV (1879) 54
8 Hovestadt in "Natur und Offenbarung" XL (1894) J 5-
4 Erinnerungen des Dr. Job. Nep. v. Ringseis , herausgeg. von
Em. Ringseis IV, Regensburg 1891, 139.
5 Obituary Notice: Allgemeine Zeitung 1878, Beilage Nr. 121,
22 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
understood a single syllable, and would not, even if
he were to keep on reading them for a hundred years."
Many another, indeed, has had a similar experience,
but it is a token of Mayer's sincerity that he was not
ashamed to admit it with the greatest frankness.
His criticism of Darwin may also find a place here:
"What from my standpoint I have to urge against Darwin's
Theory is above all this: We see with our own eyes innu-
merable new individuals coming continually into existence
in the vegetable and animal worlds by propagation and
fertilisation. But how this comes about is for Physiology
a completely insoluble riddle, a secret beyond our discovery.
It is a case in which the well-known couplet of Haller finds
the fullest application:
'Ins Inn're der Natur dringt kein erschaffner Geist ;
Zu glucklich, wem sie noch die auss're Schale weist.' l
"But although in these matters which lie so immediately
beside us we are compelled to confess complete ignorance,
the good Darwin, like another Lord God, offers us a com-
plete explanation of a far more fundamental problem, the
most fundamental of all, namely, the origin of organic life
on our planet ! This to my mind goes so ludicrously beyond
the limits of human capacity, that I think of certain words
of St. Paul. Beyond doubt the Darwinians are good propa-
gandists, and the theory has won so many adherents in
Germany on this sole account, that capital could be made
out of.it for Materialism." 2
In England not Mayer but Joule (f 1889) is regarded
as having established the modern Theory of Heat 3 . James
"No created mind can penetrate the secrets of nature;
Too happy is it if it can know the outer shell."
2 Weyrauch, Kleinere Schriften 460, Mayer to Schmid,
22. Dec. 1874.
3 Osborne Reynolds, Memoir of James Prescott Joule : Me-
moirs and Proceedings of the Manchester Literary and Philosophical
PRESCOTT JOULE. 23
Prescott Joule was born on Dec. 24 th 1818, at Salford,
near Manchester. His father was a wealthy brewer,
and Joule was never under the necessity of earning his
bread, nor did he interest himself at any period of his
life in the business of the brewery. After preparatory
studies with a private tutor he attended lectures in
Chemistry given by Dalton, and then devoted himself
to experiment and research. The most noteworthy fruits
of his great patience and perseverance are sufficiently
well-known, namely, the formulation of the mechanical
equivalent of heat and the important law, known as
The first preliminary account of his experiments on
the Theory of Heat was submitted by Joule to the
Meeting of the British Association held at Cork on
July 23* 1843. In an addendum to this paper dated
August 1843 we read:
"I shall lose no time in repeating and extending these ex-
periments, being satisfied that the grand agents of nature
are, by the Creator's Fiat, indestructible, and that whatever
mechanical force is expended, an exact equivalent of heat
is always obtained." *
On other occasions also Joule gladly invokes the
name of the Creator, whether to base on His Will the
indestructibility of Energy or to exalt the Divine Omni-
potence and Wisdom manifested in the constitution of
Society. Vol. VI. Fourth Series. Manchester 1892. Cf. Scientific
papers of J. P. Joule, 2 vols, London 1884 1887 (vol. I contains
Joule's treatises, vol. II his correspondence on scientific matters). Das
mechanische Warme - Aquivalent. Gesammelte Abhandlungen von
J. P. Joule. Ins Deutsche iibersetzt von J. W. S p e n g e 1. Braun-
schweig 1872. Nature XXVI (26. Oct. 1882), Nr. 678.
1 Reynolds, Memoirs VI 71.
24 I. A FUNDAMENTAL LAW: THE CONSERVATION OF ENERGY.
the world. Thus we find at the end of his essay "On
the Alteration of Temperature consequent on the Rare-
faction or Condensation of the Atmosphere", read be-
fore the Royal Scientific Society on June 2O th 1844:
"Believing that the power of destroying things belongs to
the Creator alone, I entirely co-incide with Roget and
Faraday in the opinion that any theory which, when carried
out, demands the annihilation of force, is necessarily erro-
In a lecture on "Matter, Vital Force, and Heat", deli-
vered in 1857, Joule states that he regards the argument
against the destructibility of matter drawn from the fact
that matter is the outcome of creation as of itself all
"We might reason a priori, that such absolute destruction
of living force cannot possibly take place, because it is
manifestly absurd to suppose that the powers with which
God has endowed matter, can be destroyed any more than
that they can be created by man's agency ; but we are not
left with this argument alone, decisive as it must be to
every unprejudiced mind." 5
A whole sub-division of the discourses in question
is devoted to an exposition of the "wonderful arran-
gements of creation" which depend on the interchange
of vital force and heat.
"He turns first to stellar space . . . (phenomena) which speak
in language which cannot be misunderstood of the wisdom
and beneficence of the Great Architect of Nature."
"Thus it is that order is maintained in the universe nothing