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UNIVERSITY OF CALIFORNIA.

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LETTERS OF FARADAY AND SCHCENBEIN

THE

LETTERS

FARADAY AND SCHCENBE1N

•

1836—1862

WITH NOTES, COMMENTS

AND

REFERENCES TO CONTEMPORARY LETTERS

EDITED BY

GEORG W. A. KAHLBAUM

AND

FRANCISV. DARBISHIRE

"C'est un cheri et grand plaisir que cette
correspondence avec un homme com me vous."

, , , , , Oct. 20. 1838.

i j1 "AUGUSTS

DE LA KIVE TO SCHOENBEIN.

BALE LONDON

BENNO SCHVVABE WILLIAMS & NORGATE

PRINTED BY M. WERNER -RIEHM. BALE.

DEDICATED

SVANTE ARRHENIUS

AND

WALTHER NERNST

224191

PREFACE

THE publication of historical documents, and letters are such
documents, should be controlled by two principles. In the first
place they should be set forth in exact agreement with the original,
and in the next place provided with as many suitable comments
as possible, to explain their meaning.

In preparing these letters for publication we have laid down
these two rules as a guide for our conduct, remaining innocent
of the smallest change, printing them with all their many imper-
fections, faults and errors. Only when we were satisfied that, to
prevent a mistaken interpretation, alterations could not well be
neglected, we yielded. We have however enclosed such ad-
ditions in brackets.

But why all this ? Because any change of that kind is a
willfull misrepresentation of the original text; though for the
most part, perhaps invariably, done from quite disinterested
motives, it is nevertheless an inaccuracy. How are we to deter-
mine whether the writer did not make a point of constantly
employing some Torm of speech, which now sounds strange,
nay incorrect ? It would not even be the first time that misprints

Vlll

were deliberately included in printed copies; how much more
should we keep unchanged the pardonable slips in confidential
messages. Who is to decide whether sixty years ago a different
sense was not attached to what at the present time strikes us
as irregular? Moreover what is to be the limit for legitimate
changes? In short we have avoided all alterations.

As regards punctuation however, we have made bold to
introduce some emendations. Faraday was not given to intro-
ducing these signs: dashes and commas are sometimes, but
rarely, met with, full stops never. In order to save the readers
of this book the annoyance which it caused the readers of the
originals, we have transferred Schoenbein's more or less super-
fluous punctuation to Faraday's letters, and we venture to believe
that we have lessened the difficulties of understanding their
meaning.

With regard to the second point one should surely aim,
as far as possible, at placing one's self in the position of the
writer or the receiver of the letter. Faraday writes, for example :
"Since my unfortunate letter to my late friend M. Hachette
hurried Nobili into such mistakes." Now this information is of
no value, so long as you are unacquainted with the particulars
concerning this incident, and I hold it to be the duty of an
editor to enlighten one on all such points.

To perform this duty was an arduous task, and these expla-
nations, notes, and marginal comments involve more labour than
the reader fancies. However we never shrunk from the under-
taking, and so we made brief notes on anything that impressed
us as deserving notice, our intention being to bring the reader,
as it were, into close fellowship with the two writers. To what

extent we have accomplished what we attempted the reader must
decide. I am however most happy to acknowledge the services
rendered by Mr. Francis V. Darbishire, who joined me when a
considerable amount of the work had been carried out, and who,
following up the subject with the greatest skill, also added
many a valuable comment to the part already finished.

The story of the origin and progress of this publication is
as follows. These letters were among the first material I received
for the life of Schoenbein which I am now in the act of compiling.
Miss Jane Barnard, Faraday's niece, very kindly sent me that
portion of the correspondence which was in her possession, and
to this Schoenbein's family added the share written by Faraday.
This took place in the autumn of the year 1897. On glancing
over these letters and finding out what a really important part
they played in the development of the history of science in
the middle of our century, I immediately decided on publishing
them in full. To this end copies of the letters had to be taken,
and it was Dr. Friedrich Tschopp-Miiller, professor of Mathe-
matics and Physics at the Academy here, and for many
years my fellow-worker, who took upon himself this tedious
work, and carried it through with so much care and indefati-
gable attention that I must express to him my heartiest grati-
tude. Without such assistance, owing to my numerous professional
duties, the edition could not have been completed at the appointed
time. To ascertain the correctness of the reading, I read the
original and Dr. Tschopp followed his copy, comparing word for
word. It required much perseverence on the part of us two
Germans in order to decipher Faraday's all but illegible scrawls.
What an Englishman can make out without much effort, is very

perplexing to a foreigner, who has only acquired the native
idiom artificially. The comparative facility with which Schoen-
bein's letters were read is quite worthy of notice ; it is due to
the fact that, though written in English, they were thought in
German, from which they are in fact a translation.

In this manner the whole correspondence was read and
explored, notes being added whenever they were considered
to be essential. These additions were in German, for I had
at first thought of bringing out a German as well as an English
edition. It was at the beginning of the year 1899, when
about one half had been provided with explanations, that I
resolved to invite one of my English acquaintances to take
charge of the English edition, in as much as my own know-
ledge of English is not fully sufficient for the requirements of
such a case; preface and introduction were, for the same reason,
written by me in German and translated by Mr. Darbishire.
However, before settling the preliminaries of this undertaking
in the manner intended, Mr. Darbishire, during the Christmas
holidays, applied to me for the right of translating my edition
of the letters of Berzelius and Schoenbein. I readily gave my
consent and thus our friendly relations began.

Unhappily Mr. Darbishire was otherwise occupied at that
time, so that, during the summer term, we had to continue our
work without his aid. When the first sheets were in the press
he came to Bale and took up his work with great eagerness,
and in so doing he rendered the greatest service in bringing
these letters before the public, and has earned for himself my
sincerest gratitude. After consulting with my publisher the idea
of a separate German edition was abandoned.

Miss Jane Barnard in addition to placing these letters at
my disposal has, at my request, most generously made a gift
of them to the Library of the University of Bale, under the
condition that access may be had to them at any future time.
In consequence of this genuine act of kindness the complete
series of these valuable and important documents are now to
be preserved at Schcenbein's scene of activity, for Schoenbein's
daughters have also renounced their claim in favour of the
University Library.

The artistic supplement added to the book, is the work
of the young and promising artist F. Kraus of Bale, who drew
it from the photograph, kindly lent me by Miss Barnard, taken
in 1857 by Maull and Polybank. It is the one serving as fron-
tispiece to Dr. Bence Jones' Life of Faraday and we must
not omit to express our obligation to Messrs. Longmanns,
Green & Co. for kindly offering to consent to its reproduction
here. The portrait of Schcenbein is drawn after a statuette
from the year 1855 by the late Mr. Breikle of Munich, and some
contemporary photographs.

The number of misprints is unfortunately very large, but
it must be borne in mind that the printers were dealing with
a foreign language.

Together with these letters I am, jointly with Dr. E. Thon,
bringing out the correspondence of Schcenbein with Liebig; it
will be published in Leipsic and is to form the fifth part of
the Monographs from the History of Chemistry.

GEORG W. A. KAHLBAUM.

Bale, September iSth, 1899.

INTRODUCTION

THESE letters reveal to the reader's mind the likeness of two
persons, who became acquainted with each other under the
influence of science, and who all their lifetime continued in
undiminished friendship and mutual esteem. Though as dissi-
milar from each other in thought and conduct as one could
well conceive, they harmonized in their implicit obedience to
science, which held possession of their entire lives, in their
pure love of truth and in their steadfast and unshaken con-
fidence in each other.

One of these, Schoenbein, in a paper, which however he
did not publish till he was in his thirty-sixth year, describes
a most remarkable observation he was led to make, when
studying the relation of iron to nitric acid. Even at the present
day we have not succeeded in gaining clear insight into the
cause from which this phenomenon proceeds. Such a want
of knowledge in relation to this point worried him; and so
he hastened to impart his observations to the foremost leaders
in the domain of science.

xiv

He wrote a precise and critical letter to Berzelius, the
venerable patriarch of Stockholm , he wrote to Poggendorff at
Berlin, the editor of the most widely circulating- continental
journal, and he wrote to Faraday. Nearly ten years previously,
during a brief sojourn in the English metropolis, he had had
the extreme satisfaction of being present at one of his world-
famed Friday Evening Lectures; but he did not take advantage
of his opportunity to converse with him. Schoenbein was
constrained to take this somewhat unusual step of making a
communication to an entire stranger, by a keen desire on his
part, to reason with his fellow-workers in the same branch of
science, upon what at that moment occupied his time and
thoughts. He worked heart and soul at whatsoever he took
in hand, and was inspired by the significance of his research
to such an extent, that he would take for granted a corres-
ponding active interest on the part of other scientific men.

As to Faraday this turned out to be true. He printed
the first letter in the Philosophical Magazine , and upon a
second communication, also published in the Philosophical Maga-
zine, he made remarks and criticisms, in a letter to one of the
editors of the said journal, to illustrate, as it were, the opinion
he had formed on the value of Schoenbein's results. With this
the intercourse between the Englishman and the Swabian
was established — Schoenbein continued a staunch and loyal
Swabian.

He was born at Metzingen in Swabia in 1799, and was
accordingly eight years junior to Faraday, and a similarity
•existed between the two, in as much as Schoenbein also was
of humble parentage. He was the son of a dyer.

In 1813 he entered a chemical factory at Boblingen, as
an apprentice to Bonz and Son, at that time Metzger and
Kaiser. After serving his term of seven years apprenticeship,
he was articled to the chemical factory of Dr. Dingier at Augs-
burg, the editor of the well known Polytechnical Journal. In 1821
he entered at the University of Erlangen, where the great
thinker Schelling exerted a powerful influence upon him; but he
removed to Tubingen University in the same year, returning
once more to Erlangen (during the winter term of 1822 to 1823),
to finish his studies, after which he received an appointment at
Friederich Frobel's renowned school. In 1825 he became a
teacher at Dr. Mayo's institute at Epsom, on the recommen-
dation of his friend C. F. Wurm. For two years he remained
in England, where the conditions of living and the character
of the people were very much to his mind, particularly when
contrasted to France, where he went later. He had just
returned to England, in the autumn of the year 1828, when
he was invited to take, temporarily, the place of Peter
Merian at Bale, who had fallen ill; and then in 1835 he
was appointed full professor of Chemistry and Physics at the
latter University.

In January 1836 his correspondence with Faraday com-
menced. The reading of these letters is in truth a great
delight. For, apart from their historical value, they bring be-
fore our minds these two eminent men, with all their feelings,
sympathies, and individual dispositions, and involuntarily pro-
duce in us a sense of kindly feeling towards them. To
effect this is one of the duties, and not the least, of the
biographer. Appreciating the importance of letters for the

xvi

just valuation of a person's merit and worth, Dr. Bence Jones
gave to his well known book the title of: "Life and Letters
of Faraday."

We offer letters only, and nothing more, but with this
complete collection, which continued in existence for a life
time, we share the secrets and inclinations of two men, who
are reckoned among the noblest of their race.

GEORG W. A. KAHLBAUM.

Bale, September, I5th, 1899.

Sekcenbein to Faraday^
SIR,

As our continental and particularly German perio-
dicals are rather slow in publishing scientific papers, and as I
am anxious to make you as soon as possible acquainted with
some new electro-chemical phaenomena lately observed by me,
I take the liberty to state them to you by writing. Being
tempted to do so only by scientific motives, I entertain the
flattering hope, that the contents of my letter will be received
by you with kindness. The facts, I am about laying before
you seem to me not only to be new, but at the same time
deserving the attention of chemical philosophers. Les void?

If one of the ends of an iron wire be made red hot, and
after cooling be immersed in nitric acid, spec. gr. 1.35, neither
the end in question nor any other part of the wire will be
affected, whilst the acid of the said strength is well known to
act rather violently upon common iron. To see how far the
influence of the oxidized end of the wire goes, I took an iron
wire of 50' in length and o'".5 in thickness, heated one of its
ends about 3" in length, immersed it in the acid of the strength
above mentioned, and afterwards put the other end into the
same fluid. No action of the acid upon the iron took place.

1 This letter is published in the Phil. Mag. S. 3. vol. 9. 1836. p. 53
tinder the following title: "On a peculiar voltaic condition of Iron, by Professor
Schoenbein, of Bale." It is, although the original is not in our possession, reprinted
here for the sake of completeness.

2 Schoanbein also describes these results in his first letter to Berzelius, dated
April 22, 1836. Kahlbaum Briefwechsel Berzelius-Schcenbein. Basel. 1898. p. 13.

.*. :: •:**! •*•**! t : /. * "• — 2 —

From a similar experiment made upon a cylindrical iron bar
of 1 6' in length and 4'" diameter the same result was obtained.
The limits of this protecting influence of oxide of iron with
regard to quantities I have not yet ascertained ; but as to the
influence of heat, I found that above the temperature of about
75° the acid acts in the common way upon iron, and in the
same manner also, at common temperatures, when the said
acid contains water beyond a certain quantity, for instance,
i, 10, 100, and even 1000 times its volume. By immersing an
iron wire in nitric acid of sp. gr. 1.5 it becomes likewise in-
different to the same acid of 1.35.

But by far the most curious fact observed by me is, that
any number of iron wires may be made indifferent to nitric
acid by the following means. An iron wire with one of its
ends oxidized is made to touch another common iron wire;
both are then introduced into nitric acid of sp. gr. 1.35, so as
to immerse the oxidized end of the one wire first into the one
fluid, and to have part of both wires above the level of the
acid. Under these circumstances no chemical action upon the
wires will take place, for the second wire is, of course, but a
continuation of that provided with an oxidized end. But no
action occurs, even after the wires have been separated from
each other. If the second wire, having become indifferent, be
now taken out of the acid and made to touch at any of its
parts not having been immersed, a third wire, and both again
introduced into the acid so as to make that part of the second
wire which had previously been in the fluid enter first, neither
of the wires will be acted upon either during their contact or
after their separation. In this manner the third wire can make
indifferent or passive a fourth one, and so on.

Another fact, which has as yet, as far as I know, not been
observed, is the following one. A wire made indifferent by
any of the means before mentioned is immersed in nitric acid
of sp. gr. 1.35, so as to have a considerable part of it remaining

out of the fluid; another common wire is put into the same
acid, likewise having one of its ends rising above the level of
the fluid. The part immersed of this wire will, of course, be
acted upon in a lively manner. If the ends of the wires which
are out of the acid be now made to touch one another, the
indifferent wire will instantly be turned into an active one, what-
ever may be the lengths of the parts of the wires not immersed.
(If there is any instance of chemical affinity being transmitted
in the form of a current by means of conducting bodies, I think
the fact just stated may be considered as such.) It is a matter of
course that direct contact between the two wires in question is not
an indispensably necessary condition for communicating chemical
activity from the active wire to the passive one; for any metal
connecting the two ends of the wires renders the same service.

Before passing to another subject, I must mention a fact,
which seems to be one of some importance. An iron wire
curved into a fork is made to touch at its bend a wire provided
with an oxidized end; in this state of contact both are intro-
duced into nitric acid of sp. gr. 1.35 and 30°, so as first to
immerse in the acid the oxidized end ; the fork will, of course,
not be affected. If now a common iron wire be put into the
acid, and one of the ends of the fork touched by it, this end
will immediately be acted upon, whilst the other end remains
passive; but as soon as the iron wire with the oxidized end is
put out of contact with the bend of the fork, its second end is
also turned active. If the parts of the fork rising above the
level of the acid be touched by an iron wire, part of which
is immersed and active in the acid, no communication of chemi-
cal activity will take place, and both ends of the fork remain
passive; but by the removal of the iron wire (with the oxidized end)
'from the bend of the fork this will be thrown into chemical action.

As all the phaenomena spoken of in the preceding lines
are, no doubt, in some way or other dependent upon a peculiar
electrical state of the wires, I was very curious to see in what

4 —

manner iron would be acted upon by nitric acid when used as
an electrode. For this purpose I made use of that form of the
pile called the couronne des tasses, consisting of fifteen pairs
of zinc and copper. A platina wire was connected with (what
we call) the negative pole of the pile, an iron wire with the
positive one. The free end of the platina wire was first plunged
into nitric acid sp. gr. 1.35, and by the free end of the iron
wire the circuit was closed. Under these circumstances the iron
was not in the least affected by the acid; and it remained in-
different to the fluid not only as long as the current was passing
through it, but even after it had ceased to perform the function
of the positive electrode. The iron wire proved, in fact, to be
possessed of all the properties of what we have called a passive
one. If such a wire is made to touch the negative electrode,
it instantaneously becomes an active one and a nitrate of iron
is formed ; whether it be separate from the positive pole or still
connected with it, and the acid be strong or weak.

But another phaenomenon is dependent upon the passive
state of iron, which phaenomenon is in direct contradiction with
all the assertions hitherto made by philosophical experimenters.
The oxygen at the anode arising from the decomposition of
water contained in the acid, does not combine with the iron
serving as the electrode, but is evolved at it, just in the same
manner as if it were platina, and to such a volume as to bear
the ratio of I : 2 to the quantity of hydrogen evolved at the
cathode. To obtain this result I made use of an acid containing
20 times its volume of water; I found, however, that an acid
containing 400 times its volume of water still shows the phae-
nomenon in a very obvious manner. But I must repeat it, the
indispensable condition for causing the evolution of the oxygen
at the iron wire is to close the circuit exactly in the same
manner as above mentioned. For if, exempli gratia, the circuit
be closed with the negative platina wire, not one single bubble
of oxygen gas makes its appearance at the positive iron ; neither

is oxygen given out at it, when the circuit is closed, by plunging
first one end of the iron wire into the nitric acid, and by after-
wards putting its other end in connexion with the positive pole
of the pile. In both cases a nitrate of iron is formed, even in
an acid containing 400 times its volume of water; which salt
may be easily observed descending from the iron wire in the
shape of brownish-yellow-coloured streaks.

I have still to state the remarkable fact, that if the evolution
of oxygen at the anode be ever so rapidly going on, and the
iron wire made to touch the negative electrode within the acid,
the disengagement of oxygen is discontinued, not only during
the time of contact of the wires, but after the electrodes
have been separated from each other. A few moments holding
the iron wire out of the acid is, however, sufficient to recom-
municate to it the property of letting oxygen gas evolve at its
surface. By the same method the wire acquires its evoluting
power again, whatever may have been the cause of its loss.
The evolution of oxygen also takes place in dilute sulphuric and
phosphoric acids, provided, however the circuit be closed in the
manner above described. It is worthy of remark, that the dis-
engagement of oxygen at the iron in the last-named acids is
much easier stopt, and much more difficult to be caused again,
than is the case in nitric acid. In an aqueous solution of caustic
potash, oxygen is evolved at the positive iron, in whatever manner
the circuit may be closed, but no such disengagement takes place
in aqueous solutions of hydracids, chlorides, bromides, iodides,
fluorides. The oxygen, resulting in these cases from the decom-
position of water, and the anion (chlorine, bromine etc.) of the other
electrolyte decomposed combine at the same time with the iron.

To generalize these facts, it may be said, that indepen-
dently of the manner of closing the circuit, oxygen is always
disengaged at the positive iron, provided the aqueous fluids in
which it is immersed do not (in a sensible manner) chemically
act upon it; and that no evolution of oxygen at the anode in

contact with iron under any circumstances takes place, if besides
oxygen another anion is set free possessed of a strong affinity
for iron. This metal having once had oxygen evolved at itself,
proves always to be indifferent to nitric acid of a certain strength,
whatever may be the chemical nature of the fluid in which the
phaenomenon has taken place.

I have made a series of experiments upon silver, copper,
tin, lead, cadmium, bismuth, zinc, mercury, but none showed
any resemblance to iron, for all of them were oxidized when
serving as positive electrodes. Having at this present moment
neither cobalt nor nickel at my command, I could not try these
magnetic metals, which I strongly suspect to act in the same
manner as iron does.

It appears from what I have just stated that the anomalous
bearing of the iron has nothing to do with its degree of affinity
for oxygen, but must be founded upon something else. Your
sagacity, which has already penetrated into so many mysteries
of nature, will easily put away the veil which as yet covers
the phaenomenon stated in my letter, in case you should think
it worth while to make it the object of your researches.

Before I finish I must beg of you the favour of overlooking
with indulgence the many faults I have, no doubt, committed
in my letter. Formerly I was tolerably well acquainted with
your native tongue, but now, having been out of practice in
writing or speaking it, it is rather hard work to me to express
myself in English.

It is hardly necessary to say that you may privately or
publicly make any use of the contents of this letter.

I am, Sir, your most obedient servant

C. T.(?) SCHOENBEIN,
Prof, of Chem. in the University of Bale.

Bale, May 17, 1836.

Schcenbein to Faraday.
SIR

I feel much obliged to you for the kind manner in
which you mentioned my late researches on iron in the philoso-
phical Magazine.1 It is this kindness which encourages me to
address to you a second letter on the same subject First allow me
to make some observations regarding the explanation, you give
about the cause of the peculiar voltaic condition of iron. If I
have not misunderstood it, you account for the inactivity of
this metall by two suppositions; one of which is, that a film
of oxide is formed round the iron similar to that produced by
heating the metall; the second, that this oxide has the property
of not being dissolved by nitric acid of a certain strength.
Now the formation of such an oxide takes place perhaps, when
iron is in voltaic association for instance with platina; in this
case water may be decomposed and the oxigen resulting from
the decomposition combine with iron to form the supposed
oxide. But, how is it, when iron is made inactive by plunging
it into strong nitric acid? I should not think, that in this case
either nitric acid or water is decomposed; that is to say, that
an oxide is formed. There is another fact of a similar kind,
which likewise makes me doubt of the existence of the film in
question. This fact is, that iron wire turns inactive even in
common nitric acid by repeated immersions, that is to say, after
this metall has been acted upon in the usual way, after deut-
oxide of iron and a nitrate has been formed. Now I think, we
may ask why, in this instance, the common chemical action is,
at once, s[t]opt and how it happens, that, on a sudden an oxide
is formed of a description quite different from what the first

1 Phil. Mag. 8.3. vol. 9. 1836. p. 57, a letter communicated to Mr. Phillips,
a joint editor of the Phil. Mag. In it Mr. Faraday points out that these experiments
afford an additional proof that "voltaic electricity is due to chemical action, and
not to contact." cf. Phil. Mag. vol. 6. p. 36.

one (deutoxide) was. I confess, I have not the slightest idea
about the cause of such a change of action. There is another
fact, which clearly shows, that under some circumstances at
least, the inactive state of iron has nothing to do with a peculiar
strength of nitric acid. In my last letter I had the honour to
state to you, that iron serving as the positive electrode of a
pile proves to be inactive in nitric acid, whatever its degree
of aqueous dilution may be, whilst a wire made inactive either
by immersion in strong nitric acid or by association with oxide
of iron (produced by heating) is acted upon in the common
way by nitric acid containing water beyond a certain quantity.
Now if one of the circumstances determining the peculiar con-
dition of iron were a peculiar strength of nitric acid, there should
be common chemical action in one case as well as there is in
the other, but the contrary being the fact, we are entitled to
draw the conclusion, that the inactivity of iron is not always
dependent upon a peculiar strength of the acid. As we must
evidently give up one part of the explanation in one case, I
am afraid, there is sufficient reason to make us doubtful of its
holding good in other ones. As to the film of oxide, which
you think to be formed round the iron in all cases, where this
metall shows its peculiar condition, I have also observed, that
a coating of a blackish substance is produced round an iron
wire, when, being connected with the anode of the pile, it was
plunged into common nitric acid, closing at the same time the
circuit; but I could never remark the least change in the metallic
state of the surface of the wire, in case it was immersed in
dilute acid (containing about 10 times its volume of water)
under the circumstances mentioned. In the very moment, when
I brought the iron wire into the fluid, the evolution of oxigen
began at the metall. The same experiment made in solution
of potash, showed the same phenomenon. If for instance in
the latter case a film were produced, I should think the wire
provided with it and put into common nitric acid was to prove

as inactive, as a wire, whose end had previously been oxidized
by heating; such, however, is not the case. According to your
experiments, there always dissolves some iron in nitric acid,
even whilst this metall renders the function of the positive
electrode. I found the same, but only when I made use of
common nitric acid, never when it was considerably dilute.
I, therefore, strongly suspect, that the nitrate to be met with
in the first case, is not produced within the acid. I ascribe its
formation to the vapours rising out of the acid, which corrode
the iron laid bare to them. The salt thus produced and first
deposited on the superior part of the iron wire is afterwards
carried down into the fluid by capillary action. As it appeared
to me a point of importance to know, whether iron, under the
circumstances mentioned, is or is not dissolved in nitric acid,
I took particular care of ascertaining the fact. For this purpose
I made in one instance use of an acid containing 10 times its
volume of water, left in it the wire (being connected with the
pile) for fully six hours and afterwards saturated the acid with
ammonia. Not the smallest quantity of oxide was precipitated,
though the volume of oxigen evolved at the iron during the
time had comparatively been considerable. From a second
experiment I obtained the same result. I put a solution of potash
into a tumbler, and dilute nitric acid upon it in such a manner, as
to prevent the fluids from mixing with one another. An iron wire
serving as the positive electrode and reaching down to the bottom
of the tumbler, was left in it for three hours. Not the slightest bit
of oxide made its appearance; as soon however, as the circuit
was broken, greenish flakes of oxide of iron were precipitated;
and the same substance was seen forming, in case the circuit had
not been closed in the manner required for causing the evolution
'of oxigen. From these facts I think it may safely be inferred, that
nitric acid does not dissolve iron, whilst this metall is placed under
the influence of a current moving through it in a certain direction.
As the existence of such a relation of a current to chemical

— IO —

action would be of the greatest importance to science, I lively
hope, you will pay a particular attention of this subject and
enter into a close investigation of it. I pass now to another
subject. During my researches on iron, I often made the obser-
vation, that nitric acid, remaining the same with regard to its
strength and temperature acts with a different degree of inten-
sity upon the metall mentioned. If for instance iron wire, being
in the same state, as it is sold, be plunged into nitric acid
spec. grav. 1.35 and 12° the metall is violently acted upon and
continues to be so, as long as there is any particle of iron left.
But if the wire be taken out of the acid after a few moments'
action, held for a second or two in the air, and replunged into
the acid, the degree of intensity of action will already be a
little diminished; and having four, at most, five times repeated
the same operation, the metall will cease altogether to be
affected by the acid, in fact it will then be in its well-known
peculiar voltaic condition. Between the greatest violence of
action and complete inactivity, there are certainly an infinite
number of intermediate degrees of intensity of action. But we
may distinguish two principal ones; one which is superior and
another which is inferior to the degree of that influence of
platina, which tends to stop chemical action. Indeed, if a platina
wire is made to touch an uncleaned iron wire after having for
the first time been immersed in nitric acid of the strength
above mentioned, it cannot interrupt chemical action, but it will
stop it, after the second or third immersion of the iron. An-
other fact worthy of remark is, that the degree of stability of
the inactive state of iron called forth by immersing this metall
several times in nitric acid spec. grav. 1.35, is much greater
than that produced by voltaic association or by immersion in
strong nitric acid. For if an iron wire made inactive by one
of the latter means is turned again into the active state, it will
be much more violently affected by the acid, than a wire brought
into its peculiar condition by the way of immersions in common

, — II —

nitric acid. That the latter wire is more strongly inactive than
one brought into this peculiar state by any other method is
still more obviously indicated by the fact, that in most cases
it turns by touching within the acid another wire, (which has
been made slowly active in this acid) into an inactive one;
whilst a common wire made inactive by immersion in strong
nitric acid, or by transference or by a direct voltaic association
is always thrown into a violent action by being touched by a
slowly active wire. I must not omit to mention, that an iron
wire having once been made inactive by repeated immersions,
will under no circumstances whatever be so lively acted upon
by nitric acid, as a common one, and the action commenced
at it can always be stopt by platina, provided the acid be not
too dilute or too hot. The peculiar lustre, the white colour
and the soft touch of the surface of a wire turned inactive by
immersions in common nitric acid likewise deserve to my opinion
to engage attention of scientific men. Such a wire is, indeed,
as to its appearance so like platina, that it can hardly be dis-
tinguished from this metall. Even after the file had several
times passed over its surface, I thought the colour of the metall
to be still whiter, than that of a common wire's surface (like-
wise produced by filing). Several persons to whom I showed
such wires, were of the same opinion. If my observations should
happen to be correct, it would prove, that the action of the
acid upon the iron spoken of occasions a very remarkable
change of aggregation of its particles; and it is, perhaps by
such a change, that we may account for some of the anomalous
bearings of iron. Before I conclude I must mention a fact I
find already alluded to in a paper l of Herschel's,2 a paper which
by the bye I saw but a little while ago in looking over in
periodicals, the articles treating on nitric acid. This fact consists

1 Annales de Chimie et de Physique, 1833. T. 54- p. 87.

2 Sir John Herschel was born in 1792 at Slough near Windsor and died
in 1871 in London.

in a sort of action of nitric acid upon iron, which for its extra-
ordinary character highly merits farther scientific inquiry. The
best way of calling forth the phenomenon is the following one.
A common iron wire having been made inactive by simple
immersions in nitric acid sp. gr. 1.35 is touched within this fluid
by a piece of copper ; the wire will by this means be thrown
into action which action, however, is not continuous, but takes
place, as it were, by pulsations1, in other words the wire will
alternately be active and inactive. Sometimes it happens that
the wire relapsed into its inactive state after the first touch of
the copper ; in such a case, it must repeatedly be retouched
by this metall in order to obtain the effect desired. Temperature
and the degree of dilution of the acid, within which the action
occurs, remaining the same, the number of pulsations performed
in equal spaces of time remain likewise the same. By augmenting
the temperature and the quantity of water of the acid the inter-
vals of action and inaction are made shorter and at last these
two states follow each other in such quick succession as to pass
into a continuous action. Different wires separate from one
another, being in the same acid and exhibiting the phenomenon
in question, do not pulsate together; but as soon as they are
put in contact with each other either within or without the acid,
the whole set of wires pulsate at the same time, a fact, which
is worthy of remark. Herschel's assertion according to which
only an acid, having already been made use of for inducing in
iron wires the inactive state, is capable of exhibiting the pheno-
menon spoken of, does not agree with what I have observed;
for I found, that quite pure nitric acid renders the service, when
an iron wire made inactive by immersions is plunged into it
and turned active again by the way described. This fact, I
think, proves, that the cause of the pulsation-like action lies
rather in the state of the wire than in that of the acid.

As the "Bibliotheque universelle" will before long publish
some papers of mine, written on the same subjects, with which

I have taken the liberty to entertain you in the preceding lines,
you will, perhaps, think it worth your while to have a look at
them, and excuse me, when I do at present not enter into
further details.

Recommending my humble individual to your kind indul-
gence I am, Sir, your most obedient Servant

Prof. SCHOENBEIN.

Bale Septb. I2th 1836.

Scticenbein to Faraday.
SIR

The Philosophical Society of Bale in one of their last
meetings 1 elected you their honorary member and I am charged
by our President to forward the diploma and ask you the
favour to accept of the latter as a weak expression of the high
esteem, which our Society entertain for you, on account of the
eminent services, you have rendered to natural Science.

I take at the same time the liberty of sending you the
paper enclosed and to beg you to lay it before the Royal
Society, in case you should think it worthy of being submitted
to this distinguished body. If not, there is, perhaps, something
or other in it, which deserves to be published in the Philo-
sophical Magazine.

You have, no doubt, taken notice of the hypothesis published
in the number of Septbr. of the Bibliotheque universelle,2 by
which Mr. Mousson3 tries to account for the peculiar condition
of iron and all the phenomena connected with this subject.
Though it may be ingenious in some respects it is overthrown

1 Held on Nov. 23, 1836.

2 A. Mousson Bibl. Univ. T. 5. 1836. p. 165.

s Joseph R. A. Mousson Ph. D. was born in 1805 at Solothurn and died
in 1890 at Ziirich. Ho was professor of Physics at the Grammar School and
later at the Technical High School at Zurich.

M —

by the single fact, that by a current the inactive state of iron
may be called forth in fluids which do not contain nitric acid
and which consequently do not allow of the formation of nitrous
acid, the protecting substance of Mr. Mousson. But there are
many other reasons besides, which put the fallacy of the theory
in question beyond doubt. I have circumstantially stated them
in a paper, sent the other day to the Editors of the "Bibliotheque"
for being published. I cannot but take a second time the liberty
to draw your attention upon the transference of the inactive
state of iron from wire to wire, a fact which, to my opinion,
is yet very far from being satisfactorily accounted for. Supposing
the peculiar condition of iron being due to a film of oxide
covering the metal, your hypothesis accounts, indeed, very
well for an inactive wire's being thrown into action by another
metal, which, itself active, touches the former. In this case,
there is a current produced, by which hydrogen is set free at
the inactive wire, which hydrogen reduces the film to the metallic
state, renders consequently the wire active. Now if an inactive
wire is associated with an ordinary one, and one end of the
former immersed in common nitric acid previous to the one
end of the latter, this wire will also become inactive. The
galvanometer shows, that in the moment, where the end of the
second wire is plunged into the nitric acid, a current is produced,
passing, as in the first case, from the wire last immersed through
the acid into the inactive one. Now in one case the current
throws the inactive wire into action, and in the other it renders
an ordinary wire inactive; that is to say, the same cause pro-
duces two effects exactly opposite to one another. It is obvious,
that the current in the latter case should decompose water,
evolve hydrogen at the inactive wire and render the latter
active in the same way, as in the first case. Now I ask, why
does hydrogen in one case decompose the film of oxide covering
the inactive wire and not in the other ? The two cases present
no difference, except in the manner, in which the circuit is

closed. It might, perhaps, be said, that in the second case, the
current is so soon stopt, that it cannot separate hydrogen enough,
as to reduce entirely the film to the metallic state. But this
will not do, because the same current, which is supposed to be
too weak, to set free that quantity of hydrogen necessary for
the complete decomposition of the film of oxide round the
inactive wire, is considered to be sufficiently strong to separate
so much of oxigen, as is required for forming a protecting
film round the ordinary wire. Now from the fact that the
quantity of oxigen evolved at the positive electrode is exactly
the chemical equivalent to the quantity of hydrogen set free
at the negative electrode, we are obliged to draw the con-
clusion, that the quantity of hydrogen developed during the
act of transfering the inactive state from the inactive wire to
the ordinary one, is sufficient to decompose the film of the first
wire. Insufficiency of the current can, therefore, not be the
reason, why the inactive wire remains in its peculiar state under
the circumstances mentioned.

I think the preceding observations are such, as to justify
my former assertion, that we are still very far from knowing
any thing about the way, in which the inactive state of iron is
transfered from one wire to another. Before leaving this subject
I cannot help recalling to you a circumstance, which bears
strongly upon the point in question; it is the fact, that an iron
wire performing the function of the positive electrode is rendered
inactive in nitric acid, when by its being plunged into this fluid
the circuit is closed; whilst the same wire is acted upon by the
acid when the circuit is closed by the negative electrode. Now
we remark the same difference of effect with a single voltaic
pair consisting of ordinary iron and platina or any other negative
-metal, for when we close the circuit by its positive element
ordinary iron, the peculiar condition will be called forth in this
metal, when closed by the negative element, the same iron will be
active, though, as already stated, there is in both cases a current

produced, moving in the same direction. Now why do the
different effects depend upon the manner of closing the circuit?
This question once satisfactorily answered, we shall be much
wiser, than we are now about the subject; but I suspect, it will
be a difficult task to get up such an answer. It is not beyond
possibility, that our phenomenon is independent of an electric
current, though one is always accompanied by the other; and
it is, perhaps this very circumstance that renders the tracing
of its cause so very difficult. If it should be found to be im-
possible to explain the excitation of the peculiar state of iron
and the destruction of it by the action of a current, then I am
afraid, we shall be obliged to look out for another hypothesis,
which may, perhaps, postulate a new agency different from
Electricity for explaining the facts in question. But may heaven
preserve us from more agencies, we have still enough of them.
Up to this present moment, I have not yet received the
papers, which you were so kind to dispatch for me some time
ago. Shall I, perhaps, apply to the british ambassador at Bern,
to whom they have most likely been sent?

Before closing this letter, I take the liberty to ask you a
favo[u]r. Our Establishment wants to get a good magnetic-
electrical Machine, by means of which the principal experiments
on Magneto- electricity may easily be made in classes. Now
if it be not too much asked, the Committee of our Museum
should feel themselves laid under great obligations to you,
would you be so kind as to order such an apparatus to be sent
to us by a Londoner instrument-maker.

Excuse my long letter and accept kindly the assurance of

my being

Yours

very truly
Bale Nov. 26th 1836. C. F. SCHOENBEIN.

— i; —

Schcenbein to Faraday^
DEAR SIR

Some weeks ago I had an opportunity to send you
a paper "On a peculiar action of Iron upon some salts",2 which, I
hope, will by this time have reached you. Having since observed
some new facts, regarding the transference of the active and
inactive state of Iron from wire to wire, facts which I think to
be of some importance to electro-chemical science, I take the
liberty to communicate them to you by writing.

FIRST FACT.

A and B represent vessels containing nitric acid sp. gr. 1.35
and CPD a platina wire connecting them. If the oxidized end E
of an iron wire EF be put into A, and F afterwards into B,
F turns active, though a current passes from F through the acid
into D. (Usual condition for calling forth the peculiar state.)

SECOND FACT.

If CPD be a wire of a metal, which is acted upon by the
acid in A and B, for instance silver, copper, iron, brass etc.; the
end F of the iron wire will turn inactive on its being plunged
into B, after the immersion of the oxidized end E in A. (The
same takes place, if the middle part of the connecting wire P
consists of Platina; and the ends C and D of Silver, Copper etc.)

1 This letter was inserted in the Phil. Mag. S. 3. vol. 10. 1836. p. 133
under the following heading: "Further experiments on a peculiar voltaic con-
dition of iron.

2 Phil. Mag. 8.3. vol. ic. 1836. p. 267.

THIRD FACT.

If C P D be an iron wire, its end D inactive, C active, and
the end E (not oxidized) first plunged into A and F afterwards
into B, F turns inactive, that is to say assumes the state of D.
(The inactive iron end D may be replaced by platina and the
active one C by any metal, which is acted upon by the acid
in A, without causing a change of result by so doing.)

FOURTH FACT.

If every thing be precisely so, as in the forgoing case, but
E oxidized and first put into A, F turns likewise inactive on
its being afterwards immersed into B.

FIFTH FACT.

If CPD be again an iron wire the end D inactive (made
so not by heating but by immersing it into strong nitric acid)
and the end F put into B and E afterwards into A, not only
E but also D turns active, whatever the number of wires may
be similar to CPD, all their inactive ends in B turn active
under the circumstances mentioned; though these wires do not
touch each other at any point.

SIXTH FACT.

If the four electrodes of two piles (each consisting of about
half a dozen of pairs of Zinc and Copper) be introduced into
two vessels containing common nitric acid in such a manner,
that the positive electrode of one pile and the negative one
of the other dip into the same vessel and the oxidized end of
an iron wire be plunged into any of the vessels and its ordinary
end afterwards into the other one, the latter turns inactive, just
in the same way, as if the two vessels were connected by a
copper-wire. But to obtain this result it is required to bend
up the second, that is to say the ordinary end, thus U> pre-
vious to immersion.

Now why does F in the first case not become inactive by
the current produced by its being plunged into B? It seems
to be an indispensable condition for calling forth the inactive
state in iron, that in the moment of its being immersed into
the acid a current of a certain energy is passing through it.
The current produced by the part of the metal immersed is of
sufficient strength, when both ends of the iron wire plunge into
the acid contained in only one (small) vessel ; but when this
same current has to pass through the acid of two vessels and
besides to enter and issue into and from the connecting platina
wire, its strength is diminished below the degree necessary for
producing the effect in question. But if this way of accounting for
the fact be correct, it is to [be] asked, how it comes, that with
a connecting wire, whose ends are attacked by the acid of the
vessels different results are obtained. It is obvious, that in the
second case, two currents moving in opposite directions and
originating in C and D are established, as soon as the iron
wire EF has connected the vessels A and B. Besides these
currents a third one is produced by the immersion of F in B.
But this current having to make the same way, which 'the current
in the first case must pass, why is its effect different from
what that of the latter is? Now it seems to me, that if two
currents of opposite direction circulate through our circuit of the
second case, they remove in some way or other the obstacles,
which the third current (in itself of weak power) would have to
overcome, if it was moving alone through the circuit; or in
other terms if two opposite currents cross the nitric acid, its
conducting power for a third current is increased. In the third
case, there are likewise two opposite currents established, as
soon as F dips in B; one produced by C the other by E; and
there is again a current excited by F, which must be considered
as the cause of the peculiar state of this end. It is only to be
wondered at, why D when having been made inactive by
immersion in strong nitric acid or by the help of platina, is

not rendered active by the current produced by F; for from

the same reasons, why F turns inactive, D should be thrown

into action. But from many facts it appears, that a much stronger

current is required to change the inactive state into the active

one, than that current is, by which an ordinary wire can be

rendered inactive. The fourth fact will be accountable, if we

consider, that in this case, there comes a current from C to F,

which added to that produced by F itself, becomes strong

enough, as to call forth the inactive state in F, though it is

still too weak, to render D active and probably only so on

account of the absence of two other opposite currents. As to

the fifth case, E turns active, because in the moment of its

immersing there are no two opposite currents put into circulation;

the current produced by E is therefore too weak, to excite in E

the peculiar state and there are besides the two currents of

C and F, which would more than neutralize the current of E.

Now the current originated by F being continuous and besides

powerful compared to that excited by an iron wire's turning

inactive, would for itself throw D into action, but its energy

is still increased by the two opposite currents produced at C

and E. About the sixth fact, I say nothing, as its connexion

with the foregoing ones is sufficiently clear. I allow the inference,

I have drawn from the facts stated, is rather hazardous and in

apparent contradiction to the generally established principle, that

two equal but opposite currents annihilate each other and that the

circuit, through which such currents move is exactly in the same

state, as if no currents were passing through it. But I think that

without adopting my view of the subject the facts spoken of remain

quite unaccountable. Whatever cause however, they depend upon,

to my opinion they deserve to be closely searched into, as their

minute investigation will no doubt, lead to some-interesting result.

The last number of the "Bibliotheque universelle" .* contained

a paper of mine "on the bearing of iron to oxigen11, which happens

1 Bibl. Univ. T. 5. 1836. p. 397.

to be full of most unhappy misprints. They will, no doubt, be
corrected in the forthcoming number. I am very anxious to
know your opinion about the contents of the said paper.

Begging your pardon for having repeatedly intruded upon
you a badly written letter, I take the liberty of calling myself

Yours

very truly
Bale Dec. 26th 1836. DR SCHQENBEIN.

Faraday to Schcenbein.

Royal Institution 28 Jan. 1837
MY DEAR SIR

About a fortnight ago I received your letter of the
26 December last by Post and was so much interested by the
facts that I took it to the Editor of the Philosophical Magazine
for insertion in his periodical : it is now printed and on Monday,
the day after tomorrow will be published. I have not added
a word to it for I think with you that at present we do not
understand the subject. The Editor showed me a translation
of your paper from Poggendorff1 on my explication or imaginary
explication, which I was glad to see he was going to print, and
to that I added a note in my own name namely saying that
I was not at an}' time satisfied with my own idea and that
neither you nor Mousson hat expressed it in the same manner
that I had ventured to put it forth.2 Whether this will be in
the next N° of the Philosophical Magazine or not I do not
know. But you will see them in due time.

Only yesterday I received the packet which you referred
to in your last letter though your letter in the packet is dated
26 November so it has been a long time on the Road.

1 Poggend. Annal. Bd. 39. 1836. p. 137.
1 Phil. Mag. S. 3. vol. 10. 1836. p. 172.

Will you do me the favour to express my sincere and humble
thanks to the Society of Basle for the great honor it has done
me. I only hope I may prove worthy of it but will trust on
the kindness of the members to think I will try to deserve it.

With regard to your paper for the Royal Society. I do
not want to read it, being anxious to acknowledge your letters
by to nights post and the time is almost gone

I am My dear Sir

Your obliged and faithful Servant

M. FARADAY.

Aft

Faraday to Sch&nbein.

London Royal Institution 6. Feby 1837
MY DEAR SIR

I now write to you upon the result of my inquiries.
In the first place with regard to your Paper. I did not wish to
present it unless I thought it would in all probability be printed
in the Transactions of the Royal Society; and I found that that
might not be the case because the Council seldom if ever print
papers in the Transactions upon subjects which have recently
been dealt upon and are matter of communication to other
societies or Transactions or Journals; unless the paper sent to
them has not some decisive news or some new discovery on the
subject. But that I might be quite right, I showed your paper to
some who would have been consulted and finding them to be of
opinion that it would not come within the rules which regulate
the Council I have kept it back.

If you approve therefore I will alter the wording of those
parts which require it (or perhaps you will send me the alterations)
and then I will send it to the Philosophical Magazine. If printed
there and you wish it I could have 100 copies or less of the

— 23

paper itself printed off separately by paying the expense of
the paper or work but I do not know how I should send them
to you. The copies of the papers I sent to you went from
the Royal Society through the Ambassadors hands and very
probably are lying at Bern. But I cannot tell.

With respect to the Magneto electric machine I inquired
at Newmans the price of them : I found those of full size were
12 Guineas by themselves and 14 Guineas with the different
apparatus required to heat a wire, shock the system, decompose
water etc. If you approve the price I will order one; but send
me word how it shall be addressed.

I am (in haste) my dear Sir

Very truly Yours obliged

M. FARADAY.

Schcenbein to Faraday.^-
DEAR SIR

I take once more the liberty to address to you by
writing a short account of the results of my latest researches on
the peculiar condition of iron. To my opinion, these results,
though they do not yet solve the riddle of the subject, are such
as to excite scientific curiosity, at least, as much, as the facts did,
a description of which I had the hono[u]r to communicate to you
last year.2 The space allotted to a letter being so small, I am
obliged to be as concise as possible in discribing the phenomena,
recently observed by me; but if you should be interested with
the details of the subject, I take the liberty of referring you to
a paper of mine, which in some time will be published in

1 Faraday inserted this letter in Phil. Mag. S. 3. vol. to. 1837. p. 425 under
the following title : "Experiments on the peculiar voltaic condition of iron as
excited by peroxide of lead.

• Phil. Mag. 8.3. vol. 9. 1836. p. 53; vol. 10. 1836. p. 133 and 267.

24 —

"Poggendorffs Annalen".1 In the first place I must tell you,
that the most powerful voltaic association, into which iron can
be brought, in order to excite its peculiar condition, is that
with peroxide of lead.2 A common iron wire, one of the ends
of which is covered with this substance proves to be inactvie
not only towards nitric acid of a given strength, but towards
nitric acid containing any quantity of water ; whilst as you know,
my oxidized iron wire, or one associated with platina etc. is
acted upon by this acid if much diluted just in the same manner
as unprotected iron. But the superiority of the association
mentioned to any other at present known is exhibited in a still
more striking manner by putting the two ends of an iron wire,
(one of which is covered by peroxide of lead) into an aqueous
solution of the common sulphate of copper in the same way,
as the two ends of the oxidized wire etc. are plunged into
common nitric acid. Under these circumstances not the smallest
particle of copper will be precipitated on any part of the wire
immersing into the said solution; this peculiar state of the wire,
however, lasts only so long, as both ends of it are plunging in
the solution ; for no sooner the protected one is removed from
the liquid, than the other one left immersing turns active, that
is to say throws down copper. In this respect, therefore, there
is a great difference between the action of the wire in question
upon the solution of blue vitriol, and that of the oxidized one
upon common nitric acid. This difference of action implies an-
other, namely the impossibility of transferring within the copper
solution the peculiar state from wire to wire, which to do is
so easy within nitric acid. I must not omit here to state the
remarkable fact, that by mixing the solution of the sulphate

1 Poggend. Annal. Bd. 43. 1837. p. 89.

2 In a letter addressed to Mr. Taylor (vide Phil. Mag S. 3. vol. 10. 1837.
p. 175) Faraday, after reading Nobili's paper on his new chromatic scale, directs
Schoenbeins attention to the condition of the iron plates in Nobili's experiment;
his impression is that the colours of the thin plates are due to peroxide of lead
formed at the positive electrode in the solution of acetate of lead used.

with a comparatively small quantity of chloride of sodium
(common salt) the calling forth of the peculiar condition is
prevented, not only in the foregoing case, but in all that will
be mentioned afterwards. This fact is by no means an insulated
one and depends upon the same cause, which prevents the
disengagement of oxigen at the iron (whilst constituting the
positive electrode of the pile) out of a solution of haloid salts etc.
Presuming, that by rendering iron inactive towards sulphate of
copper in the way discribed, a current would be excited as to
its direction equal to that, produced by calling forth the peculiar
state of this metal within nitric acid, and having had recourse
to the galvanometer, I was very much struck on finding that
the needle was not in the least affected. The instrument I made
use of in my experiments, though indicating rather weak currents,
does certainly not possess the highest degree of sensibility
possible; (it contains about 100 coils) but as in a scientific point
of view it is of very great importance to know, whether the
peculiar condition of iron can in any way be called forth with-
out exciting at the same time a current, I beg you to decide
this question by means of your most delicate galvanometer.
If your experiments should happen to place beyond doubt the
absence of any current under the before mentioned circum-
stance, why such a result would allow of drawing very curious
inferences from it, and prove, in the first place, that the in-
activity of iron has as to its origin nothing to do with what
we call a current. A series of phenomena, regarding the action
of iron wire (associated with peroxide of lead) upon a solution
of sulphate of copper may be called forth, which exhibits a
beautiful analogy to that set of facts, communicated to you in
my letter, you had the kindness to have inserted in the Phil.
'Magazine No. 59. J To obtain with iron in the said solution
results similar to those mentioned in my letter, with regard to
the action of this metal upon nitric acid, the following conditions

1 Phil. Mag. 8.3. vol. 10. 1837. p. 133.

26 —

must be fulfilled.1 In the first and second case the oxidized
iron wire EF is to be replaced by a wire, whose end E is
covered with peroxide of lead, every other thing remains the
same as stated in my letter. As to the third fact, CPD is to
be an iron wire having its end D associated with peroxide of
lead; EF is to be a common iron wire. With respect to the
fourth case, E instead of being oxidized must be covered with
peroxide of lead. To obtain a result analogous to the fifth fact,
the iron wire CPD its end D being associated with the men-
tioned substance, must first be put into the vessels. Supposing
D to be within B, the end E of an iron wire EF is to be
plunged into A and F afterwards into B. As the third case
shows it, F will turn under these circumstances inactive. Things
being in this state, put the one end of a third common iron
wire into B and afterwards its other end into A, and F will
cease to be in its peculiar condition. Now, whatever the number
of wires similar to that of EF may be, all their inactive ends
being within B turn active under the circumstances mentioned,
though they do not touch each other anywhere. Concerning
the sixth case, it is obtained exactly in the same manner as
stated in my letter, provided the oxidized end be replaced by
one covered with peroxide of lead. Bending up the common
end of the experimental wire, is, hower, not required. The best
way of associating an iron wire with peroxide of lead is, to
make it the positive electrode of a crown of cups (containing
about a dozen of pairs of copper and zi[nk]) and to put the free
end of this wire into a solution of the common acetate of lead
(Saccharum Saturni) for about 8 — 10 minutes. By the action
of the pile the peroxide is deposited on the positive iron wire.
En passant I must tell you, that many reasons lead me to be-
lieve, that iron associated with this substance will form the
most powerful voltaic element known, and I am just about to
construct out of such couples a pile. As to the chemical nature
1 vide fig. in letter to Mr. Faraday. 26th of Dec. 1836. p. 17.

— 27 —

of the matter producing the colours of Nobili's1 chromatic scale2
a notice of mine will shortly be published in Poggendorffs
Annals,3 from which you will see, that your idea about the subject
is entirely correct4 and consequently the view of the italian
Philosopher wrong. Some of the facts regarding the peculiar
condition of iron and observed by Mr. Noad 5 are, as you will
easily perceive, quite the same which were already stated in
my letter above mentioned. In publishing them as new ones,6
the gentleman was most likely not aware of my observations.
I cannot close these lines without expressing you my sincere
thanks for the service, which you so kindly rendered me by
forwarding my last paper to the editors of the Phil. Magazine.7

I am, my dear Sir very truly your's
Bale April 2/th 37 C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 2nd May. 1837.
MY DEAR SIR

At last I have pressed on Mr. Newman our in-
strument maker to the point of having a Magneto-electric Machine

1 Leopoldo Nobili formerly captain of artillery was professor of Physics at
the Grand-ducal Museum at Florence. He was born in 1784 at Trassilico in Modena
and died in August 1835 at Florence.

2 Taylor, Scientific memoirs prt. I, 1837. p. 108. "A memoir on colours
in general, and particularly on a new chromatic scale deduced from metallochromy
for scientific and practical purposes," from Bibl. Univ. T. 44. 1830. p. 337.

3 Poggend. Annal. Bd. 40. 1837. P- 621.
* Phil. Mag. 8.3. vol. 10. 1837. p. 175.

5 Henry Minchin Noad Ph. D. (Giessen) was born in 1815 at Stawford in
Somerset as the son of a cloth manufacturer upon whose death in 1845 he devoted
himself wholly to scientific research, working under A. W. Hofmann in London.
He was Professor of Chemistry at St. Georges Hospital, consulting chemist to
several iron works and an F. R. S. He died in 1877 in London.

6 Phil. Mag. S. 3. vol. 10. 1837. p. 276.

7 Phil. Mag. S. 3. vol. 10. 1837. p. 133.

— 28 —

ready for you; until that was effected I delayed writing to you.
He tells me that before the week is out the apparatus will be
shipped and I shall go to his shop to-morrow to see it all
complete before packing. He will write to you sending a bill
of lading etc. so as to inform you of the conveyance and the
time etc. etc.

In the packet there will be also the copies of your last
paper in the Philosophical Magazine l about which you wrote to
me. They are only just now printed. I was very much interested
in the reading of the experiments but am as much puzzled as
ever as to the direct cause of the condition into which the iron
comes. I have no doubt however that your perseverance will
in time meet with its due reward; and when we do learn what
it is that so balances things, we may well expect that a great
many other things will at the same time come into view, and
new light be thrown on many matters now dark and obscure.

I have been doing nothing lately i. e. I have been labouring
in the ordinary things of my vocation. Much business and little
health have left me no time for research: but I hope in the
autumn to follow your active example and then perhaps add
a few things more to the magnificent accumulation of facts
which has been brought together of late years by the conjoined
efforts of the labourers in Electrical Science.

Wishing you all health and strength and happiness.

I am

My dear Sir

Your very faithful servant

M. FARADAY.

1 Experimental researches on a peculiar action of iron upon solutions of
some metallic salts. Phil. Mag. S. 3. vol. 10. 1837. p. 267.

Faraday to Schcenbein.

R. Institution 4 May 1837.
MY DEAR SIR

I have just received your letter of the 2/th of
April l and rejoice at your continued progress. I have made
one or two of the experiments but they want more care and
attention than I can give them at present for I am exceedingly
occupied. I shall send it to the Phil Mag for the Editor to

print if he pleases.2

Ever. Truly Yours

M. FARADAY.

Schcenbein to Faraday.
MY DEAR SIR

I have just now published a little work in german
containing a detailed account of my researches on the peculiar
condition of Iron, which I was so presumptuous as to dedicate
to You.3 As my motive for doing so was no other than the
desire of publicly expressing my feelings of respect and regards
towards you, I entertain the flattering hopes, you will be indulgent
enough, as to grant me a pardon for the great liberty, I have
taken and accept in kindness of the feeble tribute offered by
my humble individual to a Man, whose name stands so high
in the scientific world. Should the British Association for the
advancement of Science happen to receive scientific works as

1 vide 23.

2 Experiments on the peculiar voltaic condition of iron as excited by peroxide
of lead. Phil. Mag. S. 3. vol. 10. 1837. p. 425.

* Das Verhalten des Eisens zurn Sauerstoff. Ein Beitrag zur Ervveiterung
electro-chemischer Kenntnisse. Von Dr. L. (sic.) F. Schcenbein, Professor der
Chemie in Basel. Basel 1837.

— 30 —

presents, you would oblige me very much by sending one of
the copies laid by to the president of that society for being
produced at their next meeting in Liverpool. Though it has
been a favo[u]rite plan of mine, these last five or six years, once
to attend the meetings of this learned body and to visit Old
England once more, a country which I love as much as I do
my own native land, up to this time I have not yet been able
to satisfy my wishes in this respect. I hope, however, to see
them one day fulfilled.

The other day I got a letter from Mr. Berzelius,1 the contents
of which relate to my observations on the peculiar state of
Iron. This distinguished Chemist, though he does not yet give
a decided opinion upon the subject, is inclined to think, that
in one notice of yours, published some time ago in the Phil.
Mag.,2 which alludes to the observations of Ritter3 and de la Rive4
regarding the secondary piles and the electrical state of polar
Platina-wires, the true cause of the inactivity of Iron is hinted
at. According to the view of Berzelius, Iron performing the
function of the positive Electrode undergoes a change, with
regard to its primitive electrical condition in such a manner,
as to be turned from a positive electrical body into a negative
one. As my views with respect to electro-chemical subjects
essentially differ from those of Berzelius', I cannot, on this
account, think the idea of that Philosopher correct; but it appears
to me that it is not in accordance even with one of the principles
of the electro-chemical system, such as laid down by Mr. B.
himself. For the suggested Idea implies the assertion, that Iron
whilst performing the function of the anode, or to speak the
old language, whilst acting the part of the positive pole, is

1 May 4th 1837. vide Kahlbaum Briefwechsel Berzelius- Schoenbein.
Basel 1898. p. 20.

2 Thil. Mag. S. 3. vol. 9. 1836. p. 57 and 122.

3 Journ. de Phys. T. 57. 1803. p. 401.

4 Bibl. Univ. T. 3. 1836. p. 375.

— 3 1 —

capable of being, at the same time, in a negative electrical
state; in other terms, that Iron, under the circumstances men-
tioned, exhibits two opposite electrical states and consequently
attracts and repels Oxigen at the same time. But such a kind
of action is, to my opinion, a thing quite impossible and must
be held as such even by those, who agree with the views of B.
I have reason to believe, that Mr. B. will treat this question
more circumstancially in his next annual Report, and then we
shall see, whether the obscure subject will be more cleared up,
than it is now. Some of our continental papers, particularly
german ones, have still much to do with Mr. Crosse's l insects,
said to be manufactured out of siliceous matter by the agency
of a current. As these Journals frequently make use of your
Name to prove the truth of the pretended discovery and enter
in this respect into particulars, such for instance, as to assert,
those insects had been exhibited by you at the meetings of
the Royal Institution I should be very much obliged to you,
if you would have the kindness to tell me, what to think of
such reports. You may easily imagine, that our scientific men
strongly doubt of the correctness of these extraordinary tales
or rather do no believe in them at all.

The magneto-electrical Machine, which you were so kind
to procure for our institution, arrived here some weeks ago.
During its passage through "la belle France" it was so roughly
handled, most likely by the custom house-people and waggoners
there that some parts of it were broken. Now it is arranged
again and works exceedingly well.

I was very sorry indeed, to learn from one of your former
letters, that you did not enjoy of full health. On account of
Yourself and the scientific world at large I confidently hope
and ardently desire it will and may, by this time, be entirely
reestablished. A trip to the Continent and into our beautiful
Alp[e]s would, perhaps do a great deal of good to you. Should

1 cf. the following letter.

— 32 —

you ever cross the channel and happen to touch Bale, I would
feel myself highly honoured, if you had the kindness to visit me.
Accept, my dear Sir, the assurance of my being.

Yours very truly
Bale July 9. 1837. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 21. September 1837
MY DEAR SIR

Your very pleasant and acceptable letter of the
9th of July with the accompanying books I received only last
week, whilst at Liverpool, at the very meeting you refer to
and I heartily wish that you had been there yourself. It is
now five years since I have been able to attend any of these
meetings but I was very much pleased with the one to which
I now refer. - - As to your book 1 and its dedication I thank
you for both. With respect to the latter all the value it has
in my eyes is due to the kindly and hearty feeling which it
proves you have towards me for in that I feel honour far beyond
the public expression of it: and in that respect your letter is
equally valuable with the dedication and even more so. As
the Association forms no collection of books or apparatus I gave
the said copy of your work to Professor Henry2 of Philadelphia
in the United States with a view of extending what you have
done as far and as fast as possible and wherever the English
language is found. He was exceedingly obliged to me for it
and I only wish that you and he had met at Liverpool.

1 Das Verhalten des Eisens zum Sauerstoff. Ein Beitrag zur Erweiterung
electro-chemischer Kenntnisse. Bale. 1837.

2 Prof. Joseph Henry was born in 1797 at Albany, N. Y. and died in 1878
at Washington, where he was professor of Physics.

33 —

Respecting Berzelius' opinion of the state of the Iron etc.
etc. it enters into the general mass of uncertainty regarding this
very strange yet beautiful subject and must wait until we see
the true light before it can have its right place assigned it.
My mind is I think as yours is; waiting until something appears
before it with conviction and then let us hope that not merely
the opinions but the facts themselves will all start into a perfect
order not again to be disturbed.

With regard to Mr. Crosse's * insects 2 etc. I do not think any-
body believes in them here except perhaps himself and the
mass of wonder-lovers. - - I was said in the English papers
to have proved the truth of his statement, but I immediately
contradicted the matter publicly and should have thought that
nobody who could judge in the matter would have suspected
me of giving evidence to the thing for a moment. Contradict
it in my name as fully as you please. It is but just of me to
say that in conversation with Mr. Crosse I was very much pleased
with him and with the readiness with which he received my
critical remarks. As regards the cristallization supposed as real
he was lugged into view and must not be charged with having
pressed himself forward. He is in fact a very modest man but
has been dragged into an unkind situation.

I am glad to find the Magneto-electric machine pleases you
now that it has been restored to a proper condition. What a nui-
sance it is that we cannot have philosophical things conveyed to
and fro from one country to another without the risk of great
injury or even destruction to them.

And now my dear Sir good-bye for the present. You
cannot think how much each letter of yours tantalizes me

1 Andrew Crosse who was born at Broomfield near Taunton in Somerset
died in July 1855 at Bridgewater.

2 A description of some experiments made with the voltaic battery for the
purpose of producing crystals in the process of which experiments certain insects
constantly appeared. Trans. Elect. Soc. of London 1837. p. 10. Vide also Sillim.
Journ. vol. 35. p. 125.

— 34

for they all make me wish I had known you a little sooner. It
is now just about two years since I and my wife were at Bale
for a day or two on our return home from Switzerland to
England. Whether I shall ever see the continent again or not

I cannot say

I am My dear Sir

Yours most sincerely

M. FARADAY.

Schcenbein to Faraday.

Bale 5 Novemb. 1837.
MY DEAR SIR

I am exceedingly obliged to you for your very
kind letter of last month. It made me deeply regret not to
have been present at the late meeting of the British Association,
but as I told you before, my absence from Liverpool was rather
a forced than a voluntary one. If possible I shall cross the
channel next year to remain in dear Old England as long as
circumstances will allow it; for I will not conceal it from you,
that I am strongly attached to your native country, so much
so that I should consider one of the most ardent wishes I am
entertaining as fulfilled, if I could for ever live in that happy
and interesting Island. Your langage, history, literature and
science have been favo[u]rite objects of my study and leisure-
occupation these last fifteen years and at this present moment
everything regarding Great Britain has a peculiar interest
with me.

I do not know, whether I mentioned it to you in one of
my former letters, that about a dozen of years ago, when I
was in London a gentleman from there introduced me into
the Royal Institution at the same day you delivered a lecture

-- 35 —

on the then new discovery of Arago,1 respecting the action of
rotating metallic plates on suspended magnets etc. I still
recollect the great pleasure with which I witnessed your
-experiments on that subject, but being then rather a shy and
bashful young man I did not venture to enter into a conversation
with you in spite of my inclination to do so and though I
had, after the lecture was over, a favo[u]rable opportunity to
speak to you. I mention these trifling occurrences to show
you that my acquaintance with you has already been of rather
a long standing. You can easily imagine, how sorry I must
be for having lost the favo[u]rable opportunity of seeing you at
Bale during your stay there; it is only the hope of meeting
you soon on your side of the water, that mitigates a little my
vexation. Mr. de la Rive2 on his return from England to Geneva
passed through Bale about a fortnight ago and paying me a
visit, I learned from him some particulars regarding the state
of your health, after which I was very anxious to enquire, having
been told by yourself, you were rather suffering. I wish from
all my heart and as ardently as any of your friends can do,
the speedy and complete reestablishment of your health. Mr.
-de la Rive seemed to be quite satisfied with the meeting at
Liverpool.

The short notice contained in the last number of the
Biblioth. univers.3 respecting Dr. Andrew's4 researches on the
action of nitric acid upon Bismuth, has induced me to make
some experiments on the same subject and I now take the

1 Dominique Frangois Jean Arago astronomer at Paris was born in 1786
and died at Paris in 1853.

2 Auguste Arthur de la Rive, born in 1801 was originally a law student
until he met Ampere and Faraday. He was appointed professor at the Academy
-of Geneva in 1823 as successor to Prevost and in 1825 as successor to Pictet.
He was an F. R. S. and died at Marseilles in 1837.

* Kibl. Univ. 1837.

4 Thomas Andrews M. D., professor of Chemistry in the Royal Belfast
Institution was born in 1813 at Belfast and died in 1885.

- 36 -

liberty to give you a short account of the results obtained from
them. It certainly cannot be denied, that there exists some
analogy between the peculiar condition of Iron and that of
Bismuth but my impression at present is, that there is only a
similarity and not an identity of cases. This opinion is founded
upon the following facts. The chemical action of Iron upon
nitric acid can, as it is now well known, be entirely stopped
by a variety of ways, whilst according to my experiments it
is impossible to obtain such a result with Bismuth. I voltaically
associated this metal with all the substances known to be capable
of rendering Iron completely inactive but by so doing I could
never succeed so far as to prevent Bismuth from being chemically
acted upon by nitric acid. It is true, by putting in contact the
metallic body in question with Platinum the chemical action of
nitric acid spec. gr. 1.4 may be reduced to such a low degree of
intensity, that no visible disengagement of binoxide of nitrogen
takes place and the piece of Bismuth (immersed in nitric acid)
assumes a bright appearance. But the oxidable metal being in this
state is nevertheless uninterruptedly attacked by the acid fluid, as
it can be easily shown by having recourse to the galvanometer.
There are besides some other facts, which put the continuance
of chemical action in the circumstances mentioned beyond any
doubts. I think I have first ascertained the remarkable fact, that
Iron can be rendered thoroughly inactive not only towards the
oxigen of nitric acid (of any degree of dilution) but also to the
oxigen disengaged (by the action of a voltaic current) out of
aqueous solutions of any oxidized body or any oxyelectrolyte.
You know, that such a state of Iron is called forth by making
this metal act the part of the positive electrode of a pile and
closing the circuit in a certain manner. Now if Bismuth be
placed in these very same circumstances, it does not seem to
undergo any change whatever, for it is violently acted upon by
nitric acid (of spec. gr. 1.4) and unites with the oxigen resulting
from the electro-chemical decomposition of water or any other

,- ~ 37 —

oxyelectrolyte. It is particularly the last mentioned difference
of bearing between the two metals, which makes me suspect,
that the peculiar condition of Iron is not produced by the same
cause which occasions the inactivity of Bismuth, that is to say
that the latter effect is not brought about by a current passing
in a certain direction through Bismuth. There is another fact
which seems to speak in favo[u]r of this opinion. According to
my experiments peroxide of Lead proves to be the most power-
ful of all substances, which are capable of turning common Iron
into its peculiar state. Peroxide of Lead, in whatever manner
I tried to combine it with Bismuth did not appear to have any
action upon the metal, for this substance was dissolved by nitric
acid just in the same way, as it was, when put into the said
fluid without any voltaic association. Now it is to be asked in
what manner does Platinum weaken the chemical action of nitric
acid upon Bismuth ? Are we to believe that in the case in
question the former acts in a quite peculiar way, that it puts
into play on agency of a nature as yet unknown and entirely
different from current electricity? I am certainly not much
inclined to draw any such inference from the fact alluded to
but at the same time I must confess, that for the present at
least, I am not able at all of accounting for the anomaly spoken
of. Before passing from the subject of the peculiar condition
of Bismuth to another one, allow me to mention to you some
more phenomena, which bear upon the same matter and which
have, perhaps, not yet been observed by Mr. Andrews. After
(by the agency of Platinum) the violent action of nitric acid
(spec. gr. 1.4) upon Bismuth has been changed into a slow one
and both metals brought out of contact, Bismuth loses its
metallic lustre and assumes a blackish appearance; after a short
time, however, the metal turns bright again by itself and remains
so, until it is touched a second time by platinum. As long as
the contact between both metals is maintained, there is certainly
no change of the surface of Bismuth to be observed, but no

- 38 -

sooner have they ceased to touch each other, than the Bis-
muth begins to blacken again, it reassumes however after some
lapse of time its former lustre. This change of surface can be
effected as often, as you like. I have ascertained, that Bis-
muth covered with the said blackish coating is more energeti-
cally acted upon by nitric acid, than it is, when its surface
appears to be bright. Now as Platinum by means of its contact
with Bismuth causes a very considerable diminution of the
energy of chemical action of the acid upon the latter metal
and makes always and intantaneously disappear the black film
from it, the reproduction of this coating under the circumstances
before-mentioned is a fact very strange, indeed, and altogether
anomalous. Another fact also worthy of being stated is that
the black film can be produced either by moving the bright
Bismuth about within the acid or by causing the acid to be
moved about the metal. I do not yet know what the black
substance consists of, but whatever it may be its production
in the last-mentioned way is no doubt due to the removal of
some stratum surrounding the bright metal and protecting the
Bismuth against the violent action of nitric acid. This supposed
stratum consists perhaps of a solution of nitrate of Bismuth
mixt with some nitrous acid.

If Bismuth being in its peculiar state or covered with the
blackish film be sightly touched with a platinum wire within
nitric acid of spec. gr. 1.4 a gazeous substance will be dis-
engaged at the wire all the while contact is maintained between
the metals. Having not yet made the experiment on a scale
large enough as to allow the collection of the gas, I do not
know its nature. I have stated however the fact to you, because
the development of a gazeous body under the circumstances
alluded to must appear very odd, if we consider, that no gas
whatsoever is disengaged at the negative electrode when nitric
acid of some strength for instance one of spec. gr. 1.4, will be
subject to the action of the current of a pile. Now in the case

— 39

spoken of the platinum wire does certainly act the part of the
negative electrode. As every circumstance connected with the
peculiar condition of readily oxidable metals appears to me to
be of some importance I will not omit to mention the fact, that
inactive Iron cannot be brought into contact with inactive Bis-
muth, without being thrown into chemical action. Iron, however,
voltaically associated with Platinum is proof to the exciting in-
fluence of the passive Bismuth and capable of destroying the
often mentioned black substance just in the same manner, as
Platinum. Some few words more on the peculiar state of Bis-
muth and I have done with this subject of which I am afraid
I have already entertained you too long. By immersing that
metal for a few seconds into nitrous acid it is turned inactive,
so that it can be put into nitric acid of spec. gr. 1.4 without
being sensibly attacked by the latter.

The Biblioth. univers.1 also alludes to a paper read at Liver-
pool by Mr. Hartley on the preservation of Iron against the
action of Sea water.2 The fact stated by that gentleman is on
account of its anomaly highly interesting and seems to enter
into that class of electro-chemical phenomena, which have been
the subject of my researches these last two years. If you
recollect a statement of mine made in a paper "on a peculiar
action of Iron"3 etc. you will be aware that the result obtained
from Mr. Hartley's experiments4 does not quite agree with what
I have found and to be a general fact.5 The statement alluded

1 Bibl. Univ. 1837.

2 At the meeting of the British Association held at Liverpool in 1837.
vide Brit. Ass. Rep. 1837 (pt. 2), p. 56. : On preventing the corrosion of cast
and wrought iron immersed in sea-water.

3 Experimental researches on a peculiar action of iron upon solutions of
some metallic salts. Phil. Mag. S. 3. vol. 10. 1836. p. 267. cf. also Uber das

"Verhalten des Eisens zum Sauerstoff. Poggend. Annal. Bd. 38. 1836. p. 493.

4 Phil. Mag. S. 3. vol. 10. 1837. p. 554.

b A discussion of Hartleys work by Schoenbein is to be found in Poggend.
Annal. Bd. 43. 1838. p. 13: Einige Bemerkungen fiber die Erfahrung Hartleys in
Betreff des Eisens.

— 40 —

to runs as follows: Insolations, containing, besides oxyelectro-
lytes, others of a different nature, for instance hydracids, haloid
salts etc., no evolution of oxigen takes place (at the Iron, being
the positive electrode of the pile) in whatever manner the circuit
may be closed. Now if in Mr. Hartley's voltaic arrangement
Brass is to Iron (in an electrical point, of view) what Platinum
is to the latter or any other readily oxidable metal according
to my experiments we should suppose that Iron, being voltaic-
ally associated with Brass, would be chemically acted upon by
Seawater, that is to say be oxidized and chloridized. You may
easily ascertain the correctness of m}^ statement by plunging
an Iron wire which is connected with the positive pole of a pile
into an aqueous solution of chloride of sodium closing thereby
the circuit. You will observe that Iron is not turned inactive,
but corroded and effects are produced quite consonant to the
well known electro-chemical laws. I made a couple of days
ago some experiments with seawater itself and I found that Iron
was attacked when a current passed from the metal into the
fluid. As you can easily imagine the disagreement of Mr.
Hartley's observations with mine makes me exceedingly desirous
of getting as soon as possible acquainted with the particulars
of that gentleman's researches. I hope the next number of the
Philosophical Magazine will satisfy my curiosity on this point.
Last Summer during a short stay at Stuttgart I made in
the laboratory of Professor Degen 1 there and in company with
this able Chemist some experiments upon Cobalt and Nickel to
ascertain, whether these metallic bodies are capable of being
rendered inactive.2 Having but a very small quantity of those
metals at our disposal, we were obliged to limit the number

1 August F. E. Degen, Professor of Physics and Chemistry at the Technical
High School at Stuttgart, was born in 1802 at Ludwigsburg and died in 1850
at Stuttgart.

2 Berzelius in a letter to Schoenbein dated May 4th 1837 had suggested
repeating similar experiments to those which iron had been subjected to, on nickel
and cobalt. Kahlbaum. Briefwechsel Berzelius-Schoenbein. Basel. 1898. p. 22.

4 1

of our experiments to very few ones and to execute them on
a very small scale. The results obtained from them were, how-
ever, such as to convince us, that the peculiar condition cannot
be excited either in Cobalt or in Nickel, at least not in the
same way as it is done in Iron. This fact seems to indicate,
that the peculiar voltaic state of the latter metal has nothing
to do with its magnetic properties.

The french papers have been talking for some time about
a discovery (said to have been made by a certain Mr. Sorel l
a Frenchman) which if it should turn out to be something more
than a mere news-papers1 invention, would be indeed a most
wonderful thing. By dint of god knows what sort of substance,
the news-papers call it voltaic- powder, Mr. Sorel is said to be
able of changing Iron and any other readily oxidable metal such,
as to give them (with regard to their chemical bearings to
oxigen) the properties of the precious ones. Such a discovery,
of course, cannot be made in our days without being turned
to practical advantage and so, indeed, the papers tell us, that
Mr. Sorel is going to enter into partnership with the well known
Mr. Cockerill in order to make use of his discovery in the large
establishments of the latter gentleman. By the manner in which
some German papers took notice of the results of my late
researches2 on the peculiar condition of Iron, I too have already

1 In his pamphlet: Verhalten des Eisens zum Sauerstoff. Basel 1837, which
he dedicated to Faraday and which is dated June 4th 1837, Schcenbein on
p. 90 says that by means of passivity iron should be convertible into precious
metals. Since we failed to come across Sorels paper — it is not even mentioned
in the Catalogue of the Royal Society — or to discover anything about his
history, we are unable fully to appreciate Schrenbeins reasons for taking such a
lively interest in Sorels results.

2 In a letter to Poggendorff Schoanbein however complains that on the
continent so little attention is paid to his work on the passivity of iron. Poggendorff
in his answer (Jan. igth 1838) puts it down to the fact that such a subject is of
too chemical a nature for philosophers, whereas chemists despise anything that
requires more thought than is necessary to prepare and decompose chemical
compounds.

gained the reputation of being a little bit of an Alchymist. Nay
offers of money even have been made to me, in order to get
the secret of changing Iron into Platinum or some such thing
out of me.

You will oblige me very- much by forwarding in a way
most convenient to you the inclosed parcel to its place of
destination.

Believe me ever to be

Yours very truly

C. F. SCHOENBEIN.

Schcenbein to Faraday.1
MY DEAR SIR

From a series of experiments lately made by me
with the view of ascertaining the voltaic relations of some per-
oxides, platina and inactive iron to one another I have obtained
some results, which, to my opinion, are such as to throw some
additional light upon the cause of voltaic electricity and modify,
to a certain degree at least, the notions we have, hitherto, enter-
tained about that interesting subject. You will recollect that
the voltaic relation of peroxide of lead to Iron engaged my
attention some time ago and you are, perhaps also aware of
the fact stated by me in "PoggendorfFs Annalen"2 that the
peroxide in question if voltaically associated with iron disappears
by degrees when plunged into nitric acid of any strength. Now,
as we know, that no chemical action whatever takes place in
the circumstances mentioned, iron being in its peculiar condition
and having, in a voltaic point of view, all the properties of

1 This letter is printed in Phil. Mag. S. 3. vol. IO. 1837. p. 225. the
heading under which it was inserted reading as follows: "On the peculiar voltaic
relations of certain peroxides, platina and inactive iron.

2 Poggend. Annal. Bd. 41. 1837. p. 55.

— 43

platina, I could not but be very much surprised at the dis-
appearance of the peroxide of lead. Although I was not able
of tracing at the time any voltaic current and of accounting
for any disturbance of the electric equilibrium of the arrangement
alluded to, I nevertheless suspected, that the dissolution of the
mentioned substance was effected under the influence of current
electricity. Having now at my disposal a galvanometer, which
is provided with 2000 coils and made in other respects very
delicate, I have taken up that subject again and attempted first
to ascertain, whether there is any voltaic relation of platina to
inactive iron. In contradiction to the results which You and I
obtained some time ago, I have found out by means of my
galvanometer, that iron being in its peculiar condition and
associated with platina gives rise to a sensible current if put
into nitric acid, be the latter ever so strong or somewhat diluted
with water. Making use of an acid ofsp.gr. 1.4 the deviation
of the needle (on putting the iron and platina wires in connection
with the galvanometer), amounted to about 90°. I must not
omit to state, that the current excited in the circumstances
mentioned is not a momentary but a continuous one and at
the same time quite independent of any oxidation of the iron.
The direction of the current in question is such as it would be,
if the latter metal was attacked by the acid, that is to say,
inactive iron is positive to platina. Another fact as curious and
interesting as that just stated is the following one. Two platina
wires being connected by one set of their ends with the galvano-
meter and by the other set with nitric acid or an aquous solution
of sulfate of copper, excite a current, provided one of the ends
(immersing in the fluid) of one of the platina \vires be covered
with a film of peroxide of lead. The current passes from the
platina through the fluid to the peroxide. When the said film
is so thin as to produce, what is called "Nobili's colours",1 it
disappears within a very few seconds after having been immersed

1 Bibl. Univ. T. 44. 1830. p. 331.

into nitric acid and the whole arrangement connected with the
wire of the galvanometer. From the facts stated, it appears that
platina is positive with regard to peroxide of lead, and that the
disappearance of that compound is caused by a current, which
eliminates hydrogen at the negative peroxide, by which means the
latter is reduced to protoxide of lead and rendered soluble in nitric
acid. In a similar manner I have ascertained that the voltaic
relation of inactive iron to peroxide of lead is exactly the same,
as that of platina to the said peroxide. In using peroxide of silver
instead of that of lead voltaic effects are produced quite the same
as those which were just spoken of; that is to say, a continuous
current is excited to which the peroxide acts the part of the
cathode and either of the metals in question that of the anode. As
to the voltaic relation, which one of the mentioned peroxides bears
to the other my experiments have shown, that peroxide of silver
is always negative with regard to the peroxide of lead, be the
fluid made use of nitric acid or a solution of blue vitriol. Now
from all the facts above stated, I think, we are allowed to draw
two important inferences: I. that peroxide of silver, peroxide
of lead, platina and inactive iron represent a series of substances,
in which the preceding one is always negative with regard to
that which follows in the list 2. that any two of the four sub-
stances mentioned being voltaically associated with one another
and put either into nitric acid or a solution of sulfate of copper
excite a continuous current, which is not due to oxidation or
any chemical change. It is hardly necessary to add that the
currents produced in the said circumstances are extremely feeble,
being only indicated by most delicate galvanometers. You will
agree with me, that the facts spoken of are highly important
in a scientific point of view, as they do produce evidence in
favo[u]r of that theory, which asserts, that by the mere contact
of heterogeneous substances their electrical equilibrium can be
disturbed, quite independent of any chemical action taking place
between them. All chemists certainly maintain, that pure nitric

acid for instance, does not chemically affect at all either platina
or peroxide of lead; and inactive iron too, as we now well
know, is not the least attacked by the said acid. Now I ask,
whence does the current originate, which is produced, when we
combine the substances in question in such a manner, as to
form with them a voltaic arrangement. I have attempted to
answer that puzzling question in a paper, which, before long,
will be published in Poggendorff's Annales1 as well as in the
Biblioth. univ.2 and in which you will besides find a detailed
account of all the experiments made by me upon the subject
spoken of. If my time was not so much taken up with a variety
of business I would have drawn up a memoir in English and
sent it to the Editors of your excellent philosophical Magazine
for insertion; but those gentlemen will, perhaps, give a trans-
lation of the paper. Before closing my letter allow me to com-
municate to you in a general manner the view, which I have
taken of the subject in question. In the first place, I must tell
you, that I am by no means inclined to consider mere contact
in any case as the cause of excitement ot even the most feeble
current. I maintain, on the contrary, in accordance with the
principles of the chemical theory, that any current produced
in a hydroelectric voltaic circle is always due to some chemical
action. But as to the idea, which I attach to the term "chemical
action" I go farther, than You and Mr. de la Rive seem to go;
for I maintain, that any tendency of two different substances to
unite chemically with one another must be considered as a
chemical action, be that tendency followed up by the actual
combination of those substances or be it not and that such a
tendency is capable of putting electricity into circulation. I will
try to render this idea of mine somewhat clearer by applying
it to some particular cases. Supposing a voltaic circle be com-
posed of platina, peroxide of lead and nitric acid, I say, that

1 Poggend. Annal. Bd. 43. 1838. p. 229.

2 Bibl. Univ. T. 14. 1838. p. 395.

the current excited in such an arrangement is due first to the
tendency of the acid to unite with the protoxide of lead or,
what is the same, to the tendency of one proportion of the
oxigen to separate from the peroxide ; secondly to the tendency
of water to combine with the same protoxide to form a hydrate
and thirdly to the tendency of water to withdraw a proportion
of oxigen from the peroxide to produce peroxide of hydrogen,
wh(ich) tendency, from very well known chemical reasons, is
yet increased by the presence of the acid. It is true, none of
the said tendencies do lead to any chemical results; for no
nitrate of lead, no hydrate, no peroxide of hydrogen is actually
produced; but are we allowed to infer from the want of a
practical result, that no chemical action whatever takes place,
when nitric acid and peroxide of lead are put in contact with
one another ? I ask, are we to suppose, that the chemical affinities
alluded to are entirely dormant and incapable of any exertion?
The results from my late experiments induce me to answer the
question in the negative. Being quite of your opinion, that
chemical affinity and current electricity are but different forms
of the same thing, I cannot help thinking that any sort of
chemical action or tendency must be capable of being trans-
formed into the shape of a current. For that current, which
is produced by inactive iron (being voltaicaliy associated with
platina) I likewise account by a chemical tendency on the part
of the former metal. Though inactive iron be not in the least
attacked by nitric acid, its affinity for the oxigen of the latter
is, on that account, by no means, entirely destroyed; the metal,
whilst surrounded by the acid is continually tending to oxidize
itself and the current excited in such a case is nothing else but
as it were the electrical translation of a chemical exertion.

All the cases above stated, where currents are observed,
independent of any chemical change, can easily be explained
by applying to them the same principle, by means of which
we have accounted for the current produced by nitric acid and

peroxide of lead etc. Having already passed the usual limits
of a letter, I add only one more observation to my former,
and I have done. According to my experiments peroxide of
silver proves to be the most powerful means for exciting in
iron its peculiar voltaic condition. It surpassed in this respect
even the peroxide of lead. An iron wire, for instance, one
end of which is covered with only a small particle of the first-
mentioned substance will not be attacked either by nitric acid
of any degree of dilution or by a solution of blue vitriol. The
voltaic association of one substance with the other is easily
effected by connecting one end of an iron wire with the positive
electrode of a pile and by plunging for a few minutes the other
end of the wire into a solution of nitrate of silver. I am just
about to write a paper on that interesting subject.

I am my dear Sir

Your's very truly
Bale Dec 31. 1837. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 22 Jany 1838
MY DEAR SIR

I have received two kind letters from you since
I wrote last and must reply although I shall be able to write
only a very short letter for now my severe duties for the Season
have commenced and I get little rest and not the time I require
for experiments and papers. The greater part of the former
and the whole of the last of yours I have sent to the Philo-
sophical Magazine.1 Your results are of the highest interest and
must encourage you to work on in the mind which is your
possession. The consequences which you produce with the

1 Phil. Mag. 8.3. vol. 12. 1837. p. 225: On the mutual voltaic relations of
certain peroxides, platina, and inactive iron.

peroxide of lead are in perfect accordance with my views of
voltaic action and I go with you to the extent of labour in
actions which are of a chemical nature in their origin though
not producing i. e. not proceeding to the extent of causing
combination or decomposition. See paragraphs 623. 624. etc.
of the sixth series of my experimental researches.1 I am not
yet prepared to go the length of admitting that such an attraction
can cause a continuous current of electricity i. e. that an action
or force can produce an effect and not itself be lowered or
equivalently affected at the same time. But I have not your
letter at present and perhaps that is not what you mean.

In the peroxide of lead action I suppose you have a body
which originates the current by its attraction for hydrogen, acts
at the opposite side of the arrangement to what the zinc or
other oxygen attracting body does. But the cause of the anions
and cations with respect to the current produced is the same
as in all other cases. Is it not so ? I am half afraid of writing
this chit chat not having your letter by me.

I have been working very hard lately on Induction. I have
sent two papers to the Royal Society and am experimenting
and writing for the third and fourth. You shall have them
printed soon and I must not stop to tell you my views for to
tell them piecemeal would give you no information. Since my
unlucky letter to my late friend M. Hachette2 hurried Nobili5

1 Experimental researches in Electricity. Phil. Trans. 1834. p. 55.

- Jean N. P. Hachette was born in 1769 at Mezieres. He was professor
at the Academy of Science at Paris up to his death which took place in 1834.

3 Bence Jones in his Life of Faraday describes the circumstances here
alluded to as follows (vol. 2. p. 17). The contents of a short and hasty letter
written to M. Hachette by Faraday three weeks after his first paper was read
at the Royal Society (Nov. 24. 1831) were printed in "Le Temps" Dec. 18. 1831.
M. Nobili immediately considered the subject given to the philosophical world
for general pursuit and wrote two memoirs both of which accuse Faraday of
errors of experiments and theory, and, beyond that, of good faith. In the Phil.
Mag. for June 1832 Faraday published a translation of Nobili's paper with notes
and later in the year wrote a long letter to M. Gay-Lussac for the purpose of
rectifying the misinterpretation given to his words.

— 49 —

into such mistakes I have been rather averse to giving short
or premature accounts of my views.

Again I must have yours. For the present in haste
I am My dear Sir

Your obliged and faithful friend
M. FARADAY.

Schcenbein to Faraday.
MY DEAR SIR

Dr. Brabant whose agreeable and interesting ac-
quaintance I made at Bale is the kind bearer of these lines.
Enclosed you will find a paper containing some hypothetical
views on the peculiar condition of iron, which was first intended
for the Phil. Magazine, but which I think, after having read it
over again altogether unfit for publication on account of its
being too much conjectural.1 Nevertheless I take the liberty
of sending the paper to you, hoping you will peruse it with
kind indulgence.

You are, no doubt, now aware of the attacks2 recently made
by Mr. Fechner3 upon your theory of the pile. I have abready
tried to answer some of his objections in Poggendorffs Annalen4
and have also written a paper for the Phil. Magazine5 which is

1 Conjectures on the cause of the peculiar condition of iron. Phil. Mag.
8.3. vol. 13. 1838. p. 256.

2 Poggend. Annal. Bd. 42. 1837. p. 481; for a translation of this paper see
Phil. Mag. 8.3. vol. 13. 1838. p. 205 : Justification of the contact theory of gal-
vanism, by G. T. Fechner.

3 Gustav Theodor Fechner was professor of Physics at Leipzig from
1834 — 1839, subsequently also of Anthropology. He was born in 1801 at Gross-
8archen (Lusatta) and died in 1887 at Leipzig.

4 Poggend. Annal. Bd. 44. 1838 p. 59: Einige Bemerkungen tiber Fechners
Rechtfertigung der Kontakttheorie des Galvanismus.

5 Phil. Mag. 8.3. vol. 13. 1838. p. 161: Discussion of Mr. Fechners views
of the theory of galvanism, with reference, particularly, to a circuit including
two electrolytes and the relations of inactive iron.

— 50 —

in the parcel addressed to Mr. Taylor.1 I am confident, however,
that you yourself will, before long, appreciate the facts which
have been brought forward by Mr. F. and declared by him to
be irreconcilable to the very first principles of the chemical
theory of galvanism 2 and I must not conceal from you, that the
scientific public in Switzerland and Germany are rather impatiently
Avaiting for a refutation of Fechner's assertions on your part.

Believe me to be

Yours

very truly
Bale, June I4th 1838. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 30. July 1838.
MY DEAR SIR

You know how I value your letters and may conclude
that the last was very pleasant to me ; though there is always
a feeling of deep regret that the treasures which accompany
your communications being in the German language are sealed
up to me. I was out of town when your letter arrived and
have not had the fortune to see Dr. Brabant but I hope he
enjoyed himself in England.

1 Richard Taylor, owner of a large printing firm, from which he retired
in 1803, was born in 1781 at Norwich and died in 1858 in London. He was,
nominally, one of the editors of the Phil. Mag.

2 Through Fechners arguments Poggendorff actually deserted from the
chemical theorists. This change of opinion he relates in three letters to Schoenbein
dated respectively Jan. 19, April 14 and May 31. 1838. According to the first,
after weighing the arguments brought forward by either party, he is almost an
the point of being convinced; in the second he confesses himself to have be-
come a follower of Volta's theory and in the last he points out that Schoenbeins
arguments in favour of the chemical theory are unavailing. "Ich bin durch sie
nicht bekehrt" he writes "und glaube schwerlich dass Fechner es wird".

Your paper on the possible condition of Iron in its peculiar
state I have taken to Mr. Taylor (as well as the parcel). Your
theory is just now in that state as respects the facts of the
case that one may very well be allowed the be not too sure
either for or against it but you can hardly think I should
consider any opinion of yours as unworthy of publication. I have
far too much respect for the judgment you have shown in these
very delicate and difficult enquiries.

You mention Fechner's objections to my theory and I am
exceedingly anxious to see and consider them but do not know
whether they are all acceptable to me or not. Would you
mind referring me in your next to Poggendorff or other Journals
in which they are ; mentioning the pages in ^vhich the path of
the objection or the positive experiments are and then I will
have them translated. I am rather in hopes that the paper
you say you have sent to Mr. Taylor will in fact refer to and
perhaps state them. I am very anxious to know of all important
objections but I do not mind about slight ones. Many have
been made to me which been left to themselves have disappeared
in a few months from the minds of the objecters themselves; but
good and valid objections are of great importance and often I
think prove the key to new discoveries.

Dr. Poggendorff1 who was here lately told me of Fechners
objections but when he learnt from me that I by no means
go the length of De la Rive and that I admit many other modes
#f electrical excitement besides chemical action, I thought he
seemed to think that Fechners objections were rather against
De la Rive than me. Perhaps what I am saying has not reference
to Fechners objections but what I believe is that the Electricity
which characterises the Voltaic pile (binding [?] the phenomenon

1 Johann Christian Poggendorff Ph. D. M. D. formerly an apothecary, was
born in 1796 at Hamburg He was professor at the University and member of
the Academy of Science at Berlin where he died in 1877. He edited 160 volumes
of the Annalen which bear his name.

— 52 —

to that instrument] is of chemical origin; is another form of
chemical affinity and I think the notes to paragraphs 856. 921.
928 indicate that to be my meaning, besides the general tenor
of the papers and descriptions contained in it.

I have been writing on Induction and have three new
papers (series n. 12. und I3),1 and shall soon have a fourth
for you. I am rather uncertain whether you receive those I
send you by our Royal Society. If you do not let me know:
and if you know any channel which [is] fitter for the purpose
and will tell me I will send them to you by it at once. -

I am very heavy in experiment just now and have some
results with crystals which I think you will approve of. - - I
must now conclude in haste but not the less

Sincerely Yours

M. FARADAY.

Schcenbein to Faraday.

Bale 12. Aug. 1838.
MY DEAR SIR

Your kind letter of the 3Oth ult lays me under
the agreeable obligation to renew my correspondence with you
and to thank you for the indulgence with which you received
my communications.

As to the objections brought forward by Mr. Fechner
against the chemical theory of galvanism, you will find the
principal ones in Poggendorffs Annalen number 12. p. 508 — 510.
1837 and number 3. p. 433 — 440. 1838. I think Dr. Poggen-
dorff was mistaken in believing- Mr. Fechner's arguments not
to be referable to your theory for as much as I understand
the assertions of that philosopher they go so far as broadly
to deny chemical action to be an electromotive force and to

1 Phil. Trans. 1838. p. I and 79. p. 83 and p. 125.

/"• — 53 —

make the current produced by a hydro-electric pile entirely
independent of any chemical change taking place within the
said voltaic arrangement. Now I should suppose such a doctrine
disagrees not only with de la Rives' views, but also with yours.
Mr. Fechner being esteemed as one of the ablest electricians
in Germany, I think it is worth your while to appreciate the
facts on which he has founded his opposition to the chemical
theory. As for me I am not yet prepared to yield the point to
Fechner and to osider his experiments as conclusive evidence
against your views.

Last year a little work was published by Mr. Pfaff l in
Kiel bearing the title: Revision der Lehre vom Galvanismus
(Review of the doctrines regarding Galvanism). You are no
doubt aware of Pfaff s having been these last forty years one
of the staunchest supporters of Volta's theory in Germany.
The work alluded to was written with the view of putting the
correctness of his favo[u]rite hypothesis beyond doubt and to
prove the entire fallacy of the chemical theory of the pile and
contains at the same time an account of many voltaic experi-
ments made by Pfaff for the purpose of supporting his views.
A large portion of the book has reference to your researches.2

I think the publication of a short review of the work
mentioned by the means of the Phil. Magazine would prove
acceptable to the british scientific public.

The different branches of natural science being rather much
cultivated at this present moment in the North of Europe and

1 Christian Heinrich Pfaff M. D. Ph. D. professor of Medicine, Physics and
Chemistry at Kiel was born in 1773 at Stuttgart and died in 1852 at Kiel.

2 A passage from a letter from de la Rive to Schcenbein should not be
omitted here, as it expresses very characteristically his view on the value of
Pfaff's book. He writes on Oct. 20. 1838: "Vous pouvez compter que je ne
parlerai de lui que pour dire que je n'en parlerai pas, car son ouvrage est aussi
mauvais dans le fond que detestable dans la forme." These words illustrate the
way in which at that time followers of either side would assail their adversaries;
it does not however give a true estimate of Pfaffs importance as a philosopher
or of the value of his contributions to the history of voltaic theories.

— 54

most papers of the philosophers there published in the german
language the editors and reviewers of the british scientific
journals will do well in paying some attention to german
publications. The french are woefully neglectful in that respect.
As you take so lively an interest in everything that relates to
electrical science I must not omit to draw your attention upon
the recent researches of Mr. Munk af Rosenschold ] on the voltaic
pile. It seems to me that the Swedish (!) philosopher has obtained
some results which are novel and rather of importance. Pogg.
Ann. number 2 & 3 1838 contain the papers on the subject.2

Having just now returned from a trip into the Alps tafken]
during our holidays I am rather busy in experiments. They
refer to transitory chemical changes (which certain compounds
undergo by being heated) as connected both with a modification
of colo[u]r and voltaic currents.3 I think I shall be able to
demonstrate or to render probable at least, that chemical
decompositions and recompositions take place under circum-
stances, where such changes have not been suspected as yet.

You will lay me under many obligations by sending me
your late papers on induction. Having got once a communi-
cation of yours by the means of the Royal Society I think
this channel will be sure enough.

Believe me to be

sincerely Yours

C. F. SCHOENBEIN.

My right hand having been a little injured lately by some
accidental cause, you will be kind enough to excuse my bad
writing.

1 Peter Samuel Munk af Rosenschold lecture assistant in Chemistry at the
University of Lund, was born at Lund in 1804 and died in 1860.

2 Untersuchungen iiber Electrizitat. Poggend. Annal. Bd. 43. 1838. p. 193
und 440.

3 These results he sums up in a paper in Poggend. Annal. Bd. 45. 1838.
p. 263 : Uber die Ursache der Farbenveranderung welche manche Korper unter
der Warme erleiden.

Y " 55 —

Schosnbein to Faraday.
MY DEAR SIR

As an acquaintance of mine is on the point of
leaving Bale to go to London, I make use of the favo[u]rable
opportunity to tell you in a few words, that some weeks ago
I observed some voltaic phenomena which I think to be entirely
novel and rather of great importance to our favo[u]rite science.
Being just now occupied with drawing up for you a paper in
English which is to contain a detailed account of my results,1
I will not enter at present into particulars and confine myself
to stating the general fact, that fluid compound bodies being at
the same time electrolytes are capable of assuming a peculiar
state, which I term their electrical polarisation; because such
a fluid being in that condition possesses the power to produce
a voltaic current quite by itself i. e. without the assistance of
any chemical action going on between the fluid and a metallic
body. The inferences which a fact of such an extraordinary
nature allows to draw with respect to Chemistry in particular
are very, as you will easily conceive, very interesting.
I have only yet time to call myself

Yours

very truly
Bale 15. Septbr. 1838. C. F. SCHOENBEIN.

Schosnbein to Faraday.

Bale, Oct. 20. 1838.
MY DEAR SIR

I take the liberty to make you acquainted with
some results which I have lately obtained from my researches
and which I think are such, as to merit some attention on the
part of philosophers.

1 Phil. Mag. 8.3. vol. 14.. 1838. p. 43.

- 56 -

Plausible and ingenious as the views of Mr. Becquerel on
the cause of the currents of Ritter's l secondary piles and of
the electro-motive power acquired by polar wires are, some
facts led me the other day to doubt of the correctness of
the theory of the celebrated french philosopher and induced
me to investigate once more the circumstances under which
what they call secondary currents are excited. I found that
platina-wires acting as electrodes within aqueous solutions of
chemically pure acids or alcalies acquire the property of exciting
secondary currents just as well as they do within solutions of
salts. As in those circumstances the decomposition and recom-
position of a salt is quite out of the question, I think we must
infer from such a fact, that the hypothesis of Mr. B. is erroneous.
But is it not possible, that some portions of the constituent
parts of the body electrolysed stick to the polar wires and
produce by their reunion the secundary current? By the result
of the following experiment, we are, to my opinion entitled to
answer that question in the negative. Platina-wires plunging
into chemically pure muriatic acid and being connected with
the poles of a pile the current of which was so feeble as not
to be capable of decomposing even jodide of potassium, I
say wires, thus circumstanced, acquired in a few seconds an
electro-motive power, which produced a deviation of the needle
of my delicate galvanometer of 160°. As under these circum-
stances, neither muriatic acid nor water could have been electro-
lysed, the secondary current obtained is consequently not due
to the reunion of Chlorine and Hydrogen, or Oxigen and
Hydrogen.

But there is another fact, to which I take the liberty of
drawing your attention, a fact which on account of its novelty and
peculiarity cannot fail exciting a good deal of scientific curiosity.

1 Johann Wilhelm Ritter was born in 1776 in Samitz in Silesia and died 1810
in Munich. At first he was an apothecary's assistant, later he practiced as a
physician in Gotha and Weimar and was a Member of the Academy in Munich

( ~ 57 ~~

When the branches of a tube bent in the shape of a U
are rilled with chemically pure muriatic acid and by the means
of two platina-wires connected with the poles of a pile, whose
current is not able of causing the electrolysation of the fluid
mentioned, the two columns of acid (contained in the branches),
after the current having for a few seconds passed through
them, appear to be voltaically polarized.1 For if the electrodes
•are removed from the branches and replaced by another pair
of platina-wires a delicate galvanometer (of about 2000 coils)
on being placed between the latter, indicates a current passing
from the acid column, which had been connected with the
negative polar wire to that column, which had been in commu-
nication with the positive wire ; that is to say one column of
acid is to the other like zinc to platina.

Having drawn up a paper, in which all my observations
regarding the voltaic polarisation of fluid and solid bodies are
stated and which, I hope will soon be published by the Bib-
liotheque universelle 2 as well as by Poggendorffs Annalen,3
I do no enter now into any more details on that subject; but
I cannot help communicating to you my views on the cause
of the strange phenomenon in question.

You have shown, that weak currents can pass through elec-
trolytes, without decomposing them; but are we to infer from
such a fact, that a current incapable of electrolysing acts in
no way whatever upon the electrolytic body ? Is it not probable,
that the current in question has so much power as to turn all
the hydrogen-sides of the molecules of muriatic acid towards
the negative electrode and the Chlorine sides towards the positive
one, and is it not allowed to suppose, that the current weakens
at the same time the affinity of the constituent parts of the

1 cf. Schcenbeins letter to Berzelius Oct. I4th 1838. Kahlbaum. Brief-
wechsel p. 25.

2 Bibl. Univ. T. 18. 1838. p. 166.

3 Poggend. Annal. Bd. 46. 1838. p. 109.

electrolyte for each other? Now if we admit such a state of
things and if it be further supposed that the effect does not
immediately cease with its cause, we can, I think, rather easily
conceive the way in which the secondary current is produced
by the polarized muriatic acid. The particles of Chlorine and
Hydrogen composing a molecule of acid will as soon as the
current of the pile ceases circulating through the fluid, begin
to act upon each other, i. e. enter again into their primitive
state of intimate combination. Now such an action being of
a chemical nature, a current must be produced by it, as to its
direction precisely of the kind, as observed. Though I must
allow, that my hypothesis is rather bold, yet I cannot conceive
another and I am inclined to think that neither the chemical
theory of Galvanism nor that of Volta can easily account for
the enigmatical phenomenon. Will you be so kind and let
me have your views about the strange fact? Before passing
to another subject I must not omit to tell you, that it is not
only muriatic acid, which is capable of being voltaically polarized,
other electrolytic fluids for instance the hydrate of sulphuric
acid have the some property. - The controversy about the
source of current electricity produced by the common voltaic
arrangement is still continued in Germany and there is in that
country an obvious leaning towards the views of Volta. The
arguments, however, brought forward in favo[u]r of that Theory
are, to my opinion at least, by no means such as to be called
decisive ones. Mr. Pfaff, for instance thinks the fact, that a
current is excited by muriatic acid acting upon chloride of
sodium or by a pile charged with an aqueous solution of sulphate
of zinc chemically pure, as quite irreconcilable with the prin-
ciples of the chemical theory.1 I must confess, that it is beyond
my power to conceive, how objections of such a kind can be
raised in earnest by such a distinguished philosopher, as Mr.
Pfaff is. Will you not come forward and take part in the contest ?
1 Poggend. Annal. Bd. 41. 1840. p. 10.

— 59 —

We must indeed, stick closely together, if we are not to be over-
powered, and considered as beaten by our antagonists. At the
meeting of the german association at Fribourg I had an oppor-
tunity of reconnoitering the field.

I am my very dear Sir

Yours most truly

C. F. SCHOENBEIN.

Schcenbein to Faraday.
MY DEAR SIR

As Mr. Iselin an acquaintance of mine is going
to London I cannot let pass this favo[u]rable opportunity
without presenting to you my best compliments.

Since I had the hono[u]r to write you my last letter I
have been working rather hard in making voltaic researches
and I think I may be allowed to say that my endeavours have
not proved altogether fruitless. Amongst other facts hitherto
not yet well understood I have been trying to clear up by
experiment those which refer to the voltaic polarisation of
polar wires, the polarisation of electrolytic fluids, the apparent
change of the electro-motive power of metals and the secon-
dary piles of Ritter. As far as I am able to judge the results
of my researches are such as to throw a strong light upon
the cause of the phenomena alluded to and to prove that the
latter are only due to ordinary chemical action and that there
is no such thing as any change of the electro-chemical nature
of any metal or a true voltaic polarisation. The forthcoming
-number of the Bibliotheque universelle l will publish a memoir
in which I have given an account of some of my investigations.
In the same paper I have pointed out to the attention of

1 Bibl. Univ. T. 23. 1839. p. 189.

philosophers the very remarkable and close analogy that exists
between the voltaic action of Chlorine and Bromine and that
of the peroxides of Manganese, Lead and Silver. I am almost
sure that the way in which I explain the voltaic effects produced
by the named substances will very nearly coincide with your
views upon the subject. As to the peculiar condition of iron
I think I have at last discovered its true cause. Having still
some experiments to perform in order to put my theory beyond
doubt I will not entertain you with the details of it, I can,
however not omit to say that I have reason to consider the
peroxide of hydrogen as the immediate cause of the anomalous
bearings of inactive iron.

I hope to be able of publishing before long a satisfactory
account of all the voltaic phenomena which that metal gives
rise to ; at the same time I shall communicate a series of new facts
regarding the voltaic action of peroxide of hydrogen which by
the bye is a most interesting substance in a galvanic point of view.

I am just writing a little work, in which (what the French
call) the "galvanisation" of metals1 is treated of according to
the present state of electrical Science and proved by matter-
of-fact arguments that the tensile electrical state of bodies does
not in the least interfere with the chemical bearings natural
to them. You know much better than I do that in a scientific
point of view the principle laid down by Sir H. Davy with
regard to the subject in question is erroneous and that never-
theless a great many scientific and practical men continue to
consider it as true. You will therefore agree with me that it
is rather a seasonable undertaking to remove false notions by
establishing a true theory of galvanisation.

Do you think it likely that an english bookseller would
be inclined to publish a little work (of about 4 sheets) of that

1 Nouvelle theorie de la galvanisation des metaux. Communicated to the
British Association at their meeting held at Birmingham in 1839. Bibl. Univ.
T. 23. 1839. p. 189.

description and pay something for its copyright ? You will
oblige me very much by letting me know your opinion about
this matter and give your kind council upon it.

I take the liberty to send you some papers of mine which
I published in German last year;1 that on voltaic polarisation
will perhaps be known to you by the Bibl. univ. If you should
happen to see Mr. Daniell 2 and Dr. Buckland 3 pray be so kind
to deliver to them the parcels inclosed.

These last four or five months I have not seen any
number of the Philosophical Magazine (the only scientific journal
published in English I have access to at Bale). I know conse-
quently not the least of what is going on in the philosophical
world on the other side of the water.

As to your recent researches on electric induction I am
also almost completely unacquainted with their results.

Before closing my letter I take the liberty to recommend
to you its bearer Mr. Iselin, he is an excellent young man
and belonging to a highly respectable family of Bale.

I am my dear Sir

Yours most truly
Bale Febr. 18 1839. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 8. April 1839.
MY DEAR FRIEND

I should think that I might be teasing you with
a letter unnecessarily by the post were it not that your last
contains an enquiry that I think you would wish me to answer.

1 Poggend. Annal. vol. 43. 1838. p. 229 and ibid. vol. 46. 1838. p 109.

2 John Frederic Daniell F. R. S. professor of Chemistry at Kings College in
London from its foundation in 1831, was born in 1790 and died in London in 1845.

3 William Buckland F. R. S. , canon of Christ Church and professor of
Mineralogy and Geology at Oxford. He was a Trustee of the British Museum,
was born in 1784 at Axminster and died in 1856 at Clapham.

— 62 —

I had not the pleasure to meet your friend Mr. Iselin and now
I am writing from the country to which I have gone for the
sake of general health. At the time however that it does me
good in that respect it cuts me off from access to the Journals
so that I hope when I return to see something of what you
have been doing.

The points you write about in your letters are of the
greatest consequence or at least they appear so to me and
the general tenor of my thoughts and conclusions is such as to
make me expect that you are in the right. I shall beg to
know particularly the conclusions which you establish and the
phenomena caused by the peroxide of hydrogen and especially
too the full turn and particular history of the Iron actions. That
has been a very provoking and stimulating subject; but I was
quite sure your perseverance would have at last its full reward
and I can say most honestly that I have been as it were
merely waiting until you should tell us what it was.

About the proposed work I do not know what to say or
advise as to its publication here. What I could wish is one
thing and what I ought to urge you to is another. I think you
are aware that books are very expensive here, I mean in the
getting up and that therefore few if any booksellers will speculate
except upon such as may be sure to have a sale. Now science has
no such security in England and more is the shame for the country.
Do you remember the pamphlet by Moll l on the Alleged
decline of science in England?* That MS. he sent to me and I
tried to get it published. At last I printed it, hoping the sale
would defray a part at least of the printers bill which I settled.
But strange to say I never received one shilling back towards

1 Gerrit Moll, professor of Mathematics and Physics at Utrecht was born
at Amsterdam in 1838 and died in 1875.

2 Faraday in a letter to R.Phillips dated Sept. 23. 1831 writes: "I under-
stand the new taken by Moll is not at all agreeable to some." S. P. Thompson
in his Life of Faraday believes Faraday even had a large share in the production
ot Moll's paper.

the expences. I tell you this merely to account for my small
hopes in your case for I confess I was much damped by the
results of my confidence and experience. I have however
made some enquiries but have not got farther than this that some
booksellers would print and publish the work for you at your
risk but I intend to go a little farther before I close this letter.

I have been working on electrical induction for some time
past and hope by this that you will have received Nrs. XL XII.
XIII & XIV 1 of the experimental researches and that the
argument will obtain your consideration and approval. You
may think that I am anxious for the judgment which able
man may pronounce on my view of the action of the particles
of matter in this important electrical function - I am also
reprinting the whole series of researches in one volume so as
to place them within the reach of some who have inquired after
them. That indeed has been the sole object for I expect no return.

These things nearly done I am now thinking of looking
at the contact question again in reference to the paper with
which Marianini2 has honoured the VIII3 series of my researches.4
I feel in no hurry to do this for I think the point is already
determined and that the progress of this part of Electrical
knowledge will soon come in as tests and decide the true
origin of the electricity in the pile. Nevertheless I mean to
experiment and if any thing good arises publish. Adieu for

the present mv dear Sir

Yours faithfully

M. FARADAY.

1 Phil. Mag. S. 3. vol. 12. 1838. p. 206. viz nth series p. 206; 1 2th p. 426;
1 3th p.43°-

2 Stefano Giovanni Marianini L. L. D. professor of Physics at Pavia, Venice
and Modena, was born in 1790 at Zeme, Piemont and died in 1866 at Modena.

3 Phil. Trans. 8.3. 1834. p. 425.

4 Examination of a fourth experiment adduced by Prof. Faraday in support
of M. de la Rive's Theory, and regarded by Dr. Fusinieri to be demonstrative.
Mem. di Fis. sperimenti. Modena vol. 2. 1838. p. I. cf. also Phil. Mag. S 3.
vol. 18. 1841. p. 193.

29th. April. - - Ever since the former date of this letter
have I been waiting for answers from booksellers and have
only now received one which is of the nature I expected
unfavourable. I will delay this letter no longer

Yours most truly

M. FARADAY.

Schcenbein to Faraday.
MY DEAR SIR

Presuming an account of the proceedings of the
swiss association for the advancement of Science of last year
will not prove disagreeable to you I take the liberty of sending
you two copies of it one of which you will perhaps be so kind
as to present to the Royal Society. The Gentleman who will
deliver them to you is a former pupil of mine M. Burckhardt
M. D. of Bale. He is going to make a stay in London with
the intention of getting acquainted with the principal hospitals and
scientific establishments of your great metropolis. By furthering
in any way you think fit the views of Dr. Burckhardt you will
lay me under many obligations and I can assure you that by
so doing your kindness will be bestowed upon a young man
whose character is excellent and whose family connexions at
Bale are highly respectable.

My leisure time is continually devoted to making voltaic
researches and in the course of these two last months I have
been lucky enough as to ascertain a series of facts which, to
my opinion, will sooner or later become of some importance
to organic Chemistry. If possible I shall before long send a
paper to the Editors of the Phil. Mag. which will contain a
detailed account of my results.

Another subject intimately connected with the chemical
theory of Galvanism has taken up much of my time lately. I
have made out many cases, where currents are excited appa-

- 65 -

rently quite independent of chemical action. According to the
chemical theory of the pile no current ought to be produced
by an arrangement consisting for instance of spungy platina,
compact platina or gold and strong acetic acid, there coming no
chemical action into play in the case. But the fact is that under
the circumstances mentioned a current makes its appearance and
what is still more strange, that the current during circuits being
closed changes its direction in such a manner, that s[p]ungy
platina is in the beginning negative and afterwards positive.

Another circumstance also ill agreeing with the theoretical
views of the present day is the fact, that Silver and even Copper
being placed within acetic acid bear to spungy platina the same
voltaic relations as Gold or compact Platina does. All the
currents spoken of disappear after having lasted for some time
but by introducing bubbles of air into the acid fluid near the
metals immersed new currents can be excited. Being convinced
of the correctness of the chemical theory of Galvanism I cannot
but suspect that the currents in question are due to some (as
yet hidden) chemical action proceeding from spungy platina.
I shall not spare either pains or time to trace out the true
cause of the strange phenomena alluded to.

Flattering myself with the hopes of being soon fav[o]ured
with a letter from you I am my dear Sir

Yours most truly
Bale April 21. 1839. C. F. SCHOENBEIN.

Schcenbein to Faraday.

Bale July 3. 1839.
MY DEAR SIR

I am very much obliged to you for your very
kind letter of the 28th1 of April and I offer you my most sincere

1 cf. postscript to Faradays letter of the 8th of April p. 8 1.
E

66 —

thanks for your friendly endeavours to get for my manuscript
a publisher. What you had the kindness to communicate to
me regarding that affair induced me to abandon the idea of
having my little work1 published in English, I should like how-
ever very much to lay its principal contents before the asso-
ciation in Birmingham2 and to submit the results of my late
researches to the consideration of the british philosophers and
most particularly to yours.

As I think to be able to prove by facts that the electrical
state of bodies has no influence whatsoever upon their chemical
bearings i. e. that the very first principle of the electro-chemical
theory of Berzelius is erroneous ; as I am also prepared to show
that the protection of metals for instance of copper or iron against
the chemical action of seawater being apparently effected by
voltaic means has directly nothing to do with the play of elec-
trical forces and as I am pretty sure to have found out the true
theory of what is called the galvanization of metals and so have
accurately determined the circumstances under which an (appa-
rent) change of the chemical relations of the metallic bodies is
effected I should suppose that communications of such a kind
would prove rather acceptable to the association and be received
with some interest by them. Desirous, however, as I am of
attending the meeting at Birmingham I am afraid I shall not
be able of crossing the water on account of the great expense
which such a journey would occasion to me. Certainly if there
were a chance of the association's granting some money for the
purpose of continuing the researches on the subjects alluded to
I should not hesitate to undertake the journey. Now if it would
not be too importunate on my part I should venture to ask
you the favo[u]r of letting me know your opinion upon that point.

1 Nouvelle theorie de la galvanisation des metaux. Bibl. Univ. T. 23.
1839. p. 189.

2 Communicated to the British Association at their meeting held at Birming-
ham in 1839.

By the same mail I send you this letter a paper of mine
is forwarded to the Editors of the Phil. Mag. which treats of a
peculiar voltaic arrangement1 being in some respects the very
reverse from what our ordinary hydro-electric circles are. The
memoir contains at the same time the statement of some curious
facts which seem to refute the principle laid down by de la Rive2
and Becquerel3 according to which any sort of chemical action
is capable of producing a current. These gentlemen laboured
to my humble opinion under a great mistake in making such
an assertion and I am inclined to think that the views the philo-
sopher of Geneva takes of Galvanism at large and of the pile
in particular are very far from being correct and founded upon
facts.

Within a short time I shall publish the details of the results
•of my researches regarding that interesting question and I imagine
that it will be no very difficult task to me, to demonstrate that
the oxidation of any metal caused by nitric acid etc. does not
throw the least quantity of electricity into circulation and that
it is only to the chemical action of electrolytic bodies that we
must ascribe the power of exciting currents.

Your important discoveries regarding the intimate connexion
which exists between electrolysation and current-electricity have,
as far as I understand the subject, not yet been duly appreciated
by the philosophers of the the Continent and least so by de la
Rive and Becquerel.

I hope your stay in the country will have entirely reestab-
lished your health and enabled you to resume your wonted
scientific occupations. I am now left alone in Bale, my family
hav ing gone into the mountains of the Jura to spend the summer

1 Notice on some peculiar voltaic arrangements. Phil. Mag. S. 3. vol. 15.
1839. S. 136.

2 Phil. Mag. S. 3 vol. n. 1837. p. 274. vide also Annal. de Chem. et Phys.
vol. 37. 1828. p. 225 and vol. 39. p. 297.

3 Annal. de Chimie T. 23. 1323. p. 135.

— 68 —

there ; as soon, however, as the vacations will have begun, I
shall join them. A six week's living on the heights of the Jura
and breathing the pure air of the hills would, perhaps, do you
a great deal of good ; can you not manage it to come over to-
us? I should be exceedingly happy, if I could ramble about
with you in our valleys und wander in your company from one
crag to another.

Entertaining the pleasing hopes of seeing you sooner or

later I am my dear Sir

Your's most sincerely

C. F. SCHOENBEIN.

Faraday to Schosnbein.

Royal institution 17. August 1839.
MY DEAR SIR

I ought to have written to you sooner but I have
hitherto been unable to say whether I could go to the Meeting
at Birmingham or not. I find now that / cannot. As regards
any opinion that I can form respecting their appropriation of
funds; not having been at any of the Commitees I do not
know on what principles they proceed but I am told they have
not as yet granted money except for expts. in England or
by Englishmen but I cannot suppose that is a rule. At the
same time I should be afraid to give you any impression which
might lead to error.

I shall be most anxious for your researches especially
those bearing upon the necessity of electrolytes in the current and
the inutility of bodies not acting as electrolytes yet poss[ess]ing
oxidizing powers etc. I suppose that your explications will include
Becquerels pile of acid and alkali about which much is now
said and I presume properly also. But folks are so apt to neglect
the amount of action that I cannot trust all I hear of it ; I hear
it is very energetic and very effective etc. but I do : not hear

- 69 -

how much current force is produced for a certain amount of
acid and alcaline force used.

I hope you are now in excellent health and all your family.
I never think of the time when I was in Bale a few years ago
without regret since being there I did not see you.

I am My dear Sir
Your faithful Snt.

M. FARADAY.

Faraday to Schcenbein.

Royal Institution 24. Septbr. 1839.
MY DEAR SCHOENBEIN

I leave town this afternoon for a week or ten
days to join my wife at Hastings and least I should not see
you again write this note as a remembrance. I have been
pulled about a good deal or I should have looked after you
but I expect you have been out of town until to day.

You left a number of the Bibliotheque Universelle here
which I join with this note least any mistake should arise re-
specting it. I have read your paper carefully and the effects
are certainly very remarkable.

If I do not see you again I wish you a most happy return to
your family and the delight of finding them all in excellent health.

I shall send this note etc. to Blackfriars road where I hope
it will find you.

Remember me to Cooper.1

I am, dear Sir, Yours faithfully Snt.

M. FARADAY.

1 He was staying with John Thomas Cooper, teacher of Chemistry at the
Russel Institute and subsequently at the Aldersgate School of Medicine in London.
He was born in 1790 at Greenwich and died in 1854 in London.

Schcenbein to Faraday.
MY DEAR SIR

I was very sorry indeed, I could not have the
pleasure of bidding personally farewell to you before my leaving"
England and of expressing viva voce my thanks for the many
proofs of kindness and friendship which I received from you
during my late stay at London. Several times I called at the
Royal Institution with the view of seeing you but to my infinite
regret I invariably received the disappointing answer: Mr,
Faraday is not at home, he is still in the country. I will not
conceal it from you that I intended to take up much more of
your precious time than I actually did and that my principal
view in visiting England was to enjoy as often as possible the
society of that philosopher to whom I feel myself attached by
a sort of intellectual affinity and by feelings of congeniality
more than to any other man. I ardently wish and confidently
hope it will fall to my lot to see you once more in this world
and to have an opportunity of making good again what acci-
dental circumstances made me lose. I am just now reading
the accounts of your late researches on electrical induction *
and I cannot help telling you that some of your results appear
to me to be of the utmost importance and such as to throw a
strong light upon a series of highly interesting phenomena and
particularly upon that of electrolysation. The fact that electrical
induction is an action of contiguous particles seems to me to
vie in interest with any other discovery ever made in electrical
science and what I am only surprized at is the circumstance,
that amongst our continental philosophers that fact has not
yet met with that attention which it so eminently deserves. I am
however confident that before long the subject will be taken
up and excite general interest.

1 Experimental researches in Electricity II, 12 and 13 series. On induction,
Phil. Trans. 1838 p. I. p. 83. p. 125. Poggend. Annal. Bd. 44. 1839. S. I u. 537;
Bd. 47. 1839. S. 33, 271 u. 529; Bd. 48. 1839. S. 269, 424 u. 513.

A most extraordinary circumstance at first sight is, that
magneto-electrical and voltaic induction do apparently not depend
upon such a molecular action. What are we to conclude from
that difference? Though I am not fond of making conjectures
on dark subjects, still I cannot help starting some hypothetical
ideas regarding the point in question. It appears to me that
what we call static electricity is only a state of tendency of
something to move in certain direction and that current-elec-
tricity is the actual motion of that something. That motion
must not be considered as one of weighty particles but as a
motion of something that is not affected by gravity ; as a peculiar
motion of ether if you like. According to these hypothetical
views we can easily conceive, how a vibratory motion might
be propagated through a space or medium empt}^ of weighty
particles but filled up with some imponderable matter which is
capable of being brought into a moving state. The only thing
difficult to conceive is the relation of that imponderable agency
to the weighty particles in their natural and excited condition
that is to say the way in which both are acting upon each other.
It is possible that a state of tendency to motion may be brought
about in ether only by a peculiar action of ponderable particles
upon that fluid and that consequently such a state cannot exist
in it without the presence or agency of matter, whilst moving
ether of itself has the power to impart motion to ether being
at rest. The fact that currents of perceptible energy can make
their appearance only in matter is perhaps dependent upon a
considerable condensation of the ethereal fluid round the pon-
derable particles and it may be that the degree of the con-
ducting and inducteous power of a substance is proportionate
to the density of ether contained in it, as for instance the degree
-of density of the air is proportionate to its conducting power
of sound. Vague and venturous as all these views may appear
they are perhaps at the present state of electrical science the
only ones which we are able to conceive.

In the last number of Poggendorffs Annalen there is a
very interesting paper of Jacobi l to which I take the liberty
to direct your attention. The german philosopher proves in
it by a matter of fact argument that the amount of magnetic
power produced by any voltaic arrangement is always pro-
portionate to the chemical effects of the latter or that what is
called the intensity of a current is not independent of its
quantity. 2

Bearer of these lines Mr. Bachofen3 Juris Doctor of Bale
a friend of mine and an excellent young man is making a stay
in England with the view of getting acquainted with your laws
and administration of justice, he is therefore very much desirous
of being introduced to some eminent english lawyers and judges.
As you have perhaps some means to procure to my friend such
a sort of acquaintance I should be very much obliged to you if
you would be kind enough to render to Mr. Bachofen that favour.

Pray remember me most friendly to Mrs. Faraday and be-
lieve me to be

Yours

most sincerely
Bale Dec. i;th 1839. C. F. SCHOENBEIN.

Schoenbein to Faraday.^
MY DEAR FARADAY

Having of late been much taken up with researches
of a peculiar sort and obtained results from them which I am
vain enough to think not entirely unworthy of your notice I

1 Moritz Hermann von Jacobi, originally an architect in Prussia, was a
Member of the Academy of Science at St. Petersburg. Born in 1801, died in 1874.

2 Poggend. Annal. Bd. 48. 1839. p. 26.

8 Johann Jacob Bachofen was born in 1815 at Bale. In 1842 he became
professor of Roman Law at Bale, but resigned in 1848.

4 This letter was read at the meeting of the Royal Society held on May 7. 1840
and a short abstract appeared Phil. Mag. S. 3. vol. 17. 1840. p. 293 under the

r — 73 —

take the liberty to give you a short account of my doings.
The phosphorous smell which is developped when electricity
(to speak the profane language) is passing from the points of a
conductor into air or when lightn'ng happens to fall upon some
terrestrial object, or when water is electrolysed, has been
engaging my attention the last couple of years and induced
me to make many attempts at clearing up that mysterious
phenomenon. Though baffled for a long time, at last I think
I have have succeeded so far as to have got the clue which
will lead to the discovery of the true cause of the smell in
question. The facts which refer to that subject are as follows:

1. The phosphorous smell given off during the electro-
lysation of water is only disengaged at the positive electrode
and no trace of it at the negative one.

2. The odoriferous principle can be preserved in well
closed glass bottles for any length of time.

3. The disengagement of that smell depends

a) upon the nature of the metal constituting the positive
electrode

b) upon the chemical constitution of the (electrolytic) fluid
being placed between the electrodes

c) upon the temperature of that fluid. With reference to

a) I have to state that of all metals examined by me
it is only gold and platina which do yield the smell.
The more readily oxidable metals as well as char-
coal will not allow the disengagement of that prin-
ciple, not even iron though this substance when acting
the part of the positive electrode resembles so very
much the precious metals. As to

following heading: "On the odour accompanying electricity and on the proba-
bility of its dependence on the presence of a new substance." Copious correc-
tions (presumably in the handwriting of the Secretary, Mr. S. H. Christie) have
been omitted ; the letter is here given just as Schoenbein wrote it.

74 —

fj) I have found out that the smell is disengaged out
of dilute (chemically pure) sulphuric, phosphoric v
nitric acid, of aqueous solutions of many salts, and
that it is never obtained from common or strong
nitric acid, from solutions of protosulphate of iron
or any substance having a great affinity for oxigen,
from aqueous solutions of chlorides, bromides, jodides,
muriatic acid, hydrobromic acid etc. If only a small
quantity of nitrous acid, protosulphate of iron, proto-
chloride of iron or of tin be added to dilute sul-
phuric, phosphoric, nitric acid, the disengagement
of the odoriferous principle will not take place.
With reference to an. aqueous solution of potash I
have made the curious observation that sometimes
it yields the smell and sometimes it does not; even
dilute sulphuric acid exhibits that anomaly but very
rarely. I have not yet been able to ascertain the
cause of that phenomenon. With reference to

8) I have made out that any electrolytic fluid which
is capable of disengaging the phosphorous smell
at a moderate temperature will not yield it when
heated near its boiling point.

4. If a comparatively small quantity of powdered charcoal,
iron, zinc, tin, lead, antimony, bismuth, arsenic or some drops
of mercury are thrown into a bottle containing the odorous
principle (received at the positive electrode) the smell will
be very quickly, almost instantaneously destroyed. Charcoal
powder and iron filings act the most rapidly. The same effect
is produced by pouring a small portion of nitrous or common
fuming nitric acid or solutions of protosulphate of iron, proto-
chloride of iron or of tin into such a bottle. If platina or gold
be brought in a red-hot state into the vessel, the smell will
also be annihilated.

— 75 —
/

5. If platina or gold plate be plunged only for a few seconds
into an atmosphere of oxigen gas having been disengaged at
the positive electrode and exhibiting the peculiar smell the
metals mentioned will be powerfully polarized in the negative
way, just in the same manner as if they had been plunged
into the vapours of bromine or chlorine. But to obtain that
effect it is necessary that the metals be not covered with
moisture. The thinnest film of water surrounding their surface
will prevent them from assuming the electro-negative condition.
To a very slight degree copper acts like gold or platina. I
was not able to polarize zinc, brass, iron.

6. Gold and platina being heated are incapable of assuming
the polar state.

7. If a piece of platina be polarized in the way before
mentioned and afterwards brought for a few moments into an
atmosphere of hydrogen the electro-motive power of the metal
will be destroyed (if not too long kept in the latter gas). The
some effect is obtained by heating the polarized plate.

8. A polarized stripe of gold or platina plate preserves
its voltaic condition for some time in the open air.

9. The current produced by polarized gold or platina is
of a short duration.

10. Oxigen having been deprived of its odoriferous prin-
ciple by the means indicated at 4 for instance by charcoal
has altogether lost its polarizing power and you may keep
platina as long you like within such oxigen, the metal will
never acquire any perceptible degree of voltaic polarity.

11. If a stripe of clean platina or gold plate be held
opposite to a blunt point of a metallic rod (which is attached
to the first conductor of a well working common electrical
machine) at a distance of about an inch or so, few turns of
the glass-plate will be sufficient to polarize to a sensible degree
the metallic stripe. The voltaic state excited in the metal

- 76 -

under these circumstance is the electro-negative one. I made
my experiments with a platina plate I '/2 inch long and l/3 of
an inch wide; after having alternately exposed the two sides
of my plate to the action of the electrical brush (produced
at blunt point of the rod) for about 25 seconds I obtained
a deviation of 1700. The fluid into which I plunged the plate
was water containing y9 of sulphuric acid and my galvano-
meter made use of is provided with 2OOO and some hundreds
coils. Gold acts in the same way as platina does, copper is
very slightly polarized under these circumstances but not so
zinc, iron and brass; at least I could not succeed to excite in
the latter metals that voltaic condition.

12. Gold or platina is negatively polarized whether being
held in the hand or insulated.

13. The same metals do not assume the polar state if they
are attached to the first conductor i. e. if the electricity is
made to pass from those metals into the surrounding air.

14. Gold and platina are negatively polarized be the first
conductor charged with positive or negative electricity.

15. If those metals are covered with the thinnest film of
moisture they are incapable of being polarized by the electrical
brush, neither is the peculiar voltaic condition called forth in
them when they are exposed to the action in a heated state.

1 6. When the point from which the brush issues is heated
or wetted cold or dry gold and platina will also not be
polarized by the latter (brush).

17. That point being heated or moistened* does not
disengage the phosphorous smell.

1 8. The brush having been deprived by any means of its
peculiar smell has entirely lost its polarizing power.

* The best way to destroy the electrical smell or rather to piece its
appearance is to envelop the blunt point with a peace of linen impregnated
with distilled water.

(' ~ 77 ~~

19". Platina being negatively polarized by common electri-
city loses its electro-motive power when plunged into an
atmosphere of hydrogen for a few seconds and the same effect
is obtained by heating the metal.

20. In common air the polarized gold or platina preserves
its peculiar voltaic state for some hours.

21. The current produced by these (polarized) metals are of
so short a duration, that they may be considered as instantaneous

It seems to me that the above mentioned facts allow some
important conclusions to be drawn from and a series of conjec-
tures to be founded upon. Allow me to mention some of them.

a) The peculiar smell produced by lightning, common elec-
tricity and the voltaic current is due to some particular
gazeous body

b) The voltaic and chemical bearings of that body are very
similar to those of chlorine and bromine.

c) Water, atmospheric air and perhaps all sorts of matter
do contain an electrolyte whose anion is the odoriferous
principle in question and whose cation is most likely
hydrogen.

d) That electrolyte is decomposed by lightning, common
electricity and the voltaic current and its odoriferous
anion liberated.

e) The polarizing or electromotive power of that anion is
resulting from its great tendency to unite with the hydrogen
of water etc. It acts in that respect like chlorine or
bromine.

f) The chemical affinity of the odoriferous substance for
other bodies is such as to surpass with respect to inten-
sity that of most, perhaps of all what they call electro-
negative elements.

g) The electrolyte spoken of being present in water and
atmospheric air it is probable that that compound acts

- 78 -

an important part in the house-hold of nature and it is
not unlikely that its workings are closely connected with
the more general electrical phenomena of our globe.

My first Idea was that the smell in question might be due
to a compound being produced at the positive elektrode by
some secondary action, but the whole body of facts above-
mentioned are to my opinion not favorable to such a view.
To raise my conclusions and conjectures to undoubtful certainty,
the supposed elementary substance must be obtained pure and
in an insulated state. The beautiful voltaic arrangement of
our friend Mr. Grove can alone make us arrive at that end
and I shall write to him in order to engage his attention to
that subject. What I have communicated to you, is as you
will easily perceive a very rough and imperfect sketch of the
results of my late researches. The subject is far from being
exhausted and requires a good deal more of experimental
investigation. I hardly want to tell you that I am working night
and day to get deeper into the mine and nearer to its hidden
treasures. In the report I have to lay before the british
association next autumn a detailed account of my investigations
will be given and I hope it will be such as to be considered
as not being quite void of scientific interest.

If you should think the contents of my letter important
enough as to merit the attention of the royal Society or the
royal institution you are entirely at liberty to communicate
them to those learned bodies. I have not yet made them
known in any continental journal or to any society except to
our philosophical society at Bale.

The other day I saw in Galignani's Sunday Observer a
very imperfect account of your last paper read before the
Royal Society on the source of current-electricity.1 Some of

1 Read in part on March igth and concluded at the meeting of March 26th 1840.
The paper was entitled: Researches in Electricity, ijth series. On the source of
power in the Voltaic Pile.

your proofs for the truth of the chemical theory of Galvanism
were mentioned and to my opinion they are such as to leave
no doubt about the subject. But I am afraid the philosophers
of the north will hear no reason, and find out some new piece
of sophistry in order to keep up their favorite hypothesis.

Our friend Grove wrote me the other day l communicating
to me some very interesting results of his late researches with
which you are no doubt acquainted. What do you think
about the fact that the transfer or oxidation of particles in
the voltaic arc is definite for a definite current?2 Important
as such a fact is I cannot yet understand it, that is to say, I
cannot conceive that by the simple oxidation of the positive
electrode the current can be conducted in the same way
as by electrolysis, both actions being so very different from
each other.

From Mr. Grove's letter I also learned to my infinite
regret that you are not yet enjoying perfect health.3

My dear Faraday allow me to repeat my former request
and permit me to readvise you not to overwork yourself and
to manage a little your mental and physical forces, for your
health and life are most precious to your friends in particular
and to the scientific world at large. We cannot yet spare
you and you must continue to be our leader for many years

1 March 7. 1840.

2 With a battery of 36 zinc and platina pairs he found that the spark
taken between platina points in pure oxygen diminishes the volume of the gas;
consequently platina is slightly oxidable by the voltaic heat. In pure Hydrogen
not the slightest difference is observable between the two electrodes, wheter the
zinc be positive and platina negative or vice versa. "I endeavoured" he con-
tinues "and not without some success to prove that the transfer or detachment
of particles in the voltaic arc is definite for a definite current " By taking the
•discharges in a graduated vessel of atmospheric air to which a little oxygen had
been added, between a positive point of zinc and a negative point of platina*
he found that the quantity of oxygen absorbed by the deflagration bore to the
oxygen evolved a ratio of i-oo to 1-17.

3 "I saw Dr. Faraday yesterday" he writes "he is far from well I regret
to say."

8o —

to come. But to have our wishes accomplished and our hopes
realized you ought to listen a little to the entreaties of your
friends and to grant to your mind and body some rest. I am
sure Mrs Faraday will be of my opinion and confident she
will not cease reminding you of it.

Pray remember me most friendly to your Lady and let
me have before long good tidings from you.

Believe me, my dear Faraday

yours faithfully

Bale April 4th 1840. C. F. SCHOENBEIN.

Faraday to Schcenbein. l

Brighton 24 April 1840.
MY DEAR SCHOENBEIN

Here I am in 'the country again, to which I often
run for a short period each time for the good of my health.
It refreshes me and makes me able to get on with the duties
of the season. Your last letter I received just before I left
town and though I have it not here and cannot pretend to
remember it yet shall give you a sort of an acknowledgment.
It is certainly very important and you seem to me to have got
a good hold of the subject so that I feel sure you will pull it
entirely out of its hole and before you have done will let us
know all about it. The many facts you bring to bear on the
matter and the way in which you make their relations evident
is most striking. I am waiting most anxiously for the full deve-
lopment of the partially known anion. If you do succeed in
establishing its independent existence and obtaining it in sensible

1 The deciphering of this letter of Faraday's was attended with anusual
difficulties.

— Si —

quantities (by weight) it will be really a wonderful thing. But
what cannot electricity do and what deeper and more refined
searcher-out is there in experimental philosophy than it.

The smell at the positive pole or electrode I had often
observed and I will tell you what happened to me respecting
it as I was working on the Voltameter.1 In trying the definite
inductions of that instrument I had made the same platina
plate positive many times in succession and observed in con-
sequence that the peculiar smell of the evolved gas diminished
(the fluid was dilute Sulphuric acid). Knowing at that time
that the Pos. pole gave the smell, the observation led me to
go in rendering the same plate positive, and at last I obtained
mixed gases from the instrument which had not the smell in
question and when afterwards I obtained more gas, making the
contacts in the same way, still there was no smell. There was
a darkish deposit upon the platina plate which had been so often
rendered positive, which gradually appeared, as the uniform
application of the voltaic battery to the plates went on, but
having attained this state of the instrument, I now made that
plate negative, which had been so long positive and that Pos.
which had been Neg. and now the gas evolved had its full
smell as before. I made contact in that direction till smell was
exhausted and then reversing contact it again appeared. Other
things then took me off from this scent.

As to your letter and its matter I did not know what to
do with it, for as you said the expts. would be printed in your
Report for the association, so they could not according to their
rules print them in the Phil. Transactions, if they had agreed
as to the matter; I then thought of sending it to the Philoso-
phical Magazine but at last gave it to the Secretary of the Royal
Society, Mr. Christie, to read2 and if Council thought fit to notice
in the proceedings and in the mean time thought I would tell

1 Sept. 1832.

* Phil. Mag. 8.3. vol. 17. 1840. p. 293.
F

— 82 —

you. After the reading I can withdraw it and then send it
to the Phil. Magazine at once. It ought to be published some-
where and directly. You probably know the Royal Society
will read a paper but however good its character they do not
print it in the Transactions if it is intended to go anywhere
else first.

Your doubts of Groves1 announcement of a definite transfer
of matter accross air etc. coincide with my own. I cannot deny
it but it is a thing so peculiar that it requires the most convincing
proofs. Many thanks for your encouragement about induction.
Hare2 has written me a letter in Silliman's Journal3 which I have
just been answering here.4 His criticismus have not yet driven
me from my ground. As to dynamic induction I wont attack
that again. I perceive you have had since notice of my papers
on the origin of electricity in the voltaic pile. As soon as
printed you shall have the papers. I experimented very carefully
for my own conviction and have come to De la Rive's view
exactly as regards the origin. I say nothing of his theory of
the pile as an instrument consisting of many voltaic elements.
There I do not go with him.

I am most grateful for your very kind expressions. They
encourage and cheer me when I feel low. Understand me, I
mean your kind expressions as a friend and after my health
which in the whole is pretty well. But the memory goes. Your
friend Mr. Bachofen has been here and I hope enjoyed himself
you know that I should not make company for him, for my
retiring habits are likely to increase rather than diminish and

1 Phil. Mag. S. 3 vol. 16. 1840. p. 338.

- Robert Hare M. D. Professor of Chemistry at Philadelphia, was born
in 1781 and died in 1858 at Philadelphia.

3 A letter to Prof. Faraday, on certain theoretical opinions. Silliman. Journ.
¥01.38. 1840. N° I. vide also Phil. Mag. S. 3. vol. 17. 1840. p 44.

4 An answer to Dr. Hare's letter on certain theoretical opinions. Phil.
Mag. S. 3 vol. 17. 1840. p. 54.

- 83 -

it is for those I already know, amongst which you are a principal
one, that I wish to keep my thoughts. I am ever

My dear Schoenbein

Your obliged and faithful friend

M. FARADAY.

Schoenbein to Faraday.
MY DEAR FARADAY

Only to show you that I am still alive and have
not entirely forgotten my dear friend in the Royal Institution
I am taking up my pen to write a few lines. — Having these
last six months been obliged to lecture a good deal I could
not find much leisuretime for carrying on my investigations on
"ozone" and for that reason I am unable to communicate to
you any scientific news from me. After Christmas I shall
however set to work again and renew my attempts at insulating
the principle which produces the electrical smell.

Berzelius 1 wrote me the other day and invited me to con-
tinue my researches on the subject alluded to in so flattering
and encouraging a manner that I cannot help complying with
the wishes expressed by such an authority. The Swedish philo-
sopher is much inclined to adopt the views I have taken of
the subject and thinks it highly probable that there exists an
electrolytic body being composed of ozone and hydrogen and
invariably associated with water just in the same way as, accor-
ding to the most recent results of Mr. B., chloride of sodium
-is always found to be accompanied by small traces of bromide
and Jodide of Sodium. Berzelius says in his letter that if I
should happen to succeed in insulating ozone such a result

1 Nov. 3. 184.0. Kahlbaum. Briefvvechsel. p. 40.

would constitute one of the most brilliant discoveries ever made
in chemical science. My object now is to get at my disposal
a pile of great electrolysing power, a pile, of course, being-
constructed after Grove's principle. My pecuniary means being
of rather a limited nature I do not know yet how to arrive at
my end, a pile, being such as I think it ought to be in order
to enable me of working out my subject, would perhaps cost
£ 80 — 100. Do you think it likely that some institution or
some private individual in London or England would be inclined
to lend me for some time an apparatus of the description
desired?

I have not yet seen abstracts from your late paper on the
source of voltaic electricity in the german scientific periodicals.
Is it perhaps not yet published ? The germans and Poggen-
dorff at the head of them are getting daily deeper involved into
the meshes of the contact-theory. I am rather anxious to see
your recent results made known in my country as soon as
possible. If you could send me a copy of it I would myself
translate the memoir and make some proper comments upon
its contents.

Pray pay my best respects to Mrs. Faraday and believe me

Yours

most sincerely

Bale Dec. 2Oth 1840. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 27. March 1841
MY DEAR SCHOENBEIN

I write, not because I have any thing to say, but
because I should be glad to attach a link to memory's chain
that you may not forget me, as well also as to rejoice with

you in your activity, though it reminds me that I have very
little at present of my own.

My medical friends have required me to lie bye for a
twelvemonth and give me hopes that memory (without it is
very hard work to go on) may perhaps come on. They want to
persuade me that I am mentally fatigued and I have no objection
to think so. My own notion is, I am permanently worse: we
shall see. Now for the principle the ozone, have you proceeded
further with it yet? As to the battery, I have mentioned the
matter of your last letter to some persons but have not much
to say to you in consequence. Grove has had a powerful
battery of his own construction but you know him as well as
I do would I conclude if you thought fit apply to him.

You letter though dated 2Oth Dec. 1841, speaks as if you
had not received my last papers, those on the chemical action
of the voltaic element etc. I trust you have had them long
since ; for me I have been laid bye so long as almost to have
forgotten them.

Neither have I read much lately so that I seem quite out
of the knowledge of things. But nothing can make me forget

your kind feelings and it is to them * and to preserve them

I now write, for there value seems to grow upon me whilst
that of mere philosophy seems to decrease.

But I must conclude. My wife desires to be friendly remem-
bered to you and hopes that all yours are well. We both desire

your happiness.

Ever my dear Schoenbein

Yours faithfull
M. FARADAY.

1 The verb between to and them is missing in the original.

86 —

Schcenbein to Faraday.
MY DEAR FARADAY

It was indeed with heartfelt joy and no small
degree of pleasure that I received the other day your kind
letter, though its contents are not quite such as I had wished
them to be. I am however confident that the predictions of
your medical friends will be fully realized and a temporary
relaxation and abstinence from mental exertions go a great way
in restoring the primitive elasticity of your mind and all the
powers of your memory. To a certain degree I can speak from
my own experience for after having worked rather too hard
and overstrained a little too much my intellectual faculties I felt
more than once a sort of mental drowsiness coming upon me
and an ebbing of spirits which made me almost entirely unfit
for any thing requiring a certain degree of moral force but the
healing powers of time and quietness gave me always quickly
back the freshness of my mind and why should this not be the
case with you?

A temporary change of air and social relations would
according to my humble opinion do a great deal of good to
you for I cannot help thinking that the thick and heavy atmo-
sphere of London in connexion with its neverceasing noise and
bustle must be very far from proving congenial and beneficial
to your constitution. On the other hand I am almost sure that
inhaling for a couple of months the light and ethereal air of
our mountainous regions would produce wonderful effects upon
your frame and be the true panacea for your complaint. You
have, my dear Faraday, no idea of the delicious sensations which
alpine nature never fails exciting and you cannot imagine how
refreshing, bracing and invigorating a montain life of some weeks
duration only proves to be. I have often seen men mentally
and bodily fatigued going to the heights of the Rigi or other

- 87 -
/

spots of a similar kind and returning replete with health and
good spirits, after having spent no more than a month there.

Can you not make up your mind for carrying such a plan
into execution and coming over to Switzerland in the course
of next summer, say July or August, the best season for making
a stay in the higher parts of our country ? I know a certain
place in the Canton of Vaud being not very far from the lake
of Geneva and delightfully situated near the entrance of the
valley of Valais which I am almost sure you would like very
much. They call it Bex and it is the residence of my friend
Mr. Charpentier l director of the salt-works there, an eminent
geologist and what is still more valuable the most amiable and
good-natured man you can possibly meet with, who would do
any thing in his power to make your temporary stay at Bex
as agreeable as possible. There you could live quite to your
taste, move about entirely at your ease and remain thoroughly
unmolested from unwished-for visitors and other inconveniences
of town life. And if you had no objections to it, 1 should feel
most happy to act as your cicerone for a week or two. Pray
think seriously of my proposals and do not reject them at
once for they have proceeded not from any selfish views, that
is to say from the wish of enjoying your personal presence
in my country, though I openly confess that your visit would
make me a most happy man no ! they have originated in the
purest and most disinterested motives of friendship. I hope
Mrs. Faraday will be a warm supporter of my idea and readily
enter into my views.

In case you should feel inclined to spend part of the summer
in Switzerland, pray let me know your mind as soon as you
can in order to enable me of taking the preliminary steps with
Mr. Charpentier.

1 Johann G. F. Charpentier, manager of saltworks at Bex was born in 1786
(or 1787) at Freiberg in Saxony. He was Honorary Professor of Geology at
the Academy of Lausanne and died at Bex in 1855.

— 88 —

How I would glory if my counsels should be followed up
and lead to those results which I am now anticipating from them.

Though I have not been altogether idle this winter I have
done very little in the way of scientific research, lectures and
other sorts of unphilosophical occupations] having taken up all
my leisure time. With the beginning of May I trust I shall be
able to commence working again and that the ozone will be
the very first subject I shall take into my hands is hardly
necessary to say. But my small battery, from which I can get
only 15 cubic inches of mixt gases per minute will, I am afraid,
not furnish a sufficient quantity of the subtle principle; I shall
however try to make the best of it.

I am very sorry to tell you, that your last papers have
not yet reached Bale which makes me fear that they are lost.
Pray remember me kindly to Mrs. Faraday and believe me

Your's

most faithfully

Bale April 8th 1841. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 4 June 1841
MY DEAR SCHOENBEIN

I must write you but a short note for I feel the
need of doing all to procure rest, but I could not longer let
your most kind letter pass unnoticed. Such feeling is too
valuable to allow me to run any risk of letting you suppose
I do not estimate it and more, feel greatly cheered by it. I think
we shall be in Switzerland this year but the advice to me is
to avoid all towns, all friendjs and all scientific thought or
occupation. We shall be lead in part by the progress of
things and though I may not see you do not think it will be

- 89 -

whithout some sorrow if I found that must be the case. If we
are at or near Basel you will see me. Whether we shall see
Bex or not is doubtful but I shall take your letter with me
and if there, shall go to M. Charpentier with it.

As to science I know nothing of its progress at present;
hereafter perhaps. In the mean time I feel the good affect of
rest and am, when resting, well in health and happy in thought.

Ever My dear Schoenbein

Yours affectionately

M. FARADAY.

I am ashamed to make you pay any postage for this but
cannot help it. M. F.

Faraday to Schoenbein.

Zug 7. Septr. 1841

MY DEAR SCHOENBETN

I write from this place to say that we expect to
be at Bale in our very rapid passage homewards on Monday
or Tuesday next, but are not sure. If you will have your papers
ready I will call on you as soon as we arrive. I hope we shall
find you, Madame Schoenbein and the family quite well and hope
you will make our best respects. We have been pretty well
on or Journey, but just now some of us are suffering from bad
colds. I think however they are leaving us. We have been
round to Bienne, Berne, Thun, Brientz, Interlaken, Qrindelwald,
Hospenthal, Lucerne etc. including the Wengernalps, the Gemmi,
the Grimsel etc. and now must go home. Trusting to find

you happy, active and well I am

My dear friend

Yours Ever
M. FARADAY.

— 90 —

Sch&nbein to Faraday.
MY DEAR FRIEND.

Mr. Forbes passing on his journey to Scotland
through London I send through him a few lines to you with
the view of letting you know that your kind letters arrived
here when I was absent from Bale. I could therefore not
answer them nor charge you with the papers, I intended
to forward through your kindness to England. Nevertheless
I thank you very much for your goodness. I was very glad
indeed to learn that you were doing pretty well when you
left Switzerland and must ardently hope, that you will feel for
a long time the beneficial effects of your stay at Zug. You
will lay me under great obligations by favouring me with a
few lines and letting know your friend, how you are now and
how you performed your way home. May the answer be such
as true friendship and heartfelt sympathy must wish it to be.-
My wife and children are quite well and the former was indeed
very sorry for not having seen you once more before your
departure; for you must know that she is a great admirer of
you and that you are standing very high in her graces since
your visit. Pray remember me kindly to Mrs. Faraday and

accept the assurance of my being

Yours most truly

Bale Sept. 2/th 1841. C. F. SCHOENBEIN.

I was in the greatest hurry when I wrote these lines and
you will therefore be kind enough to excuse my bad writing.

Faraday to Schcenbein.

Royal Institution 14. Octr. 1841.
MY DEAR SCHOENBEIN

I write a very hasty note in reply to your kind
letter by Mr. Forbes to say we are here safe and well and happy

to be at home again. I feel myself exceedingly well in health.
Memory is where it was, but if I do not make too many or
too early calls upon it perhaps it may improve. I regretted
much that I could not see you or Madame Schcenbein again,
but was obliged to give up the thought. Give my most
respectful and earnest remembrances to her. I rejoice that you
have that greatest source of earthly happiness, the source of
happiness at home.

I know nothing of scientific matters and have not looked
at a Journal yet. I have nothing to write you and am ashamed
to send you this letter and would not do it, making you pay
double postage, but that you have desired it

Ever My dear friend

Truly yours

M. FARADAY.
ftfh

Schosnbein to Faraday.
MY DEAR FARADAY

You can hardly imagine how gratified I felt at
the contents of your last letter short as it was. You are well
again and by that I understand that you have become
the Faraday of former days, that your health is entirely
reestablished, that your spirits have regained their wonted
elasticity and that you are allowed to resume your favo[u]rite
studies. I did certainly not learn quite so much from
your own note; an article however which I saw in some
english paper contained statements going that length. I
congratulate you upon that happy state of things from all
my heart and do confidently hope that you will enjoy for
many years to come that degree of health without which life
is hardly a desirable gift. "Modus est in rebus" do the classics
say, and pray, my dear friend, mind that maxim, i. e. do not

— 92 —

any more overwork yourself and manage both your mental
and physical powers. You have already done enough for
Science and if there is any man being entitled to the enjoy-
ment of "otium cum dignitate" it is you, my dear Faraday.

I wonder whether you will guess at the author of the
work1 of which I am charged to forward you a copy. I should
think you know him well enough.

These last three months I have been rather busy in my
laboratory. My investigations turned upon the electrolysing
power of simple voltaic circles and to the peculiar condition
of iron.

As to both the subjects I was fortunate enough to ascertain
a series of novel facts which, I trust, will render some little
service to the chemical theory of voltaic electricity. I intend
to publish my results in one of the next numbers of de la
Rive's "Archives".2

Mrs. Schoenbein is quite well and charges me with her
best compliments to you and Mrs. Faraday

Believe me
Yours

most sincerely

Bale, April 9 1842. C. F. SCHOENBEIN.

Pray be so kind to forward the parcels inclosed to their
respective destinations, by such an act of kindness you will

very much oblige

Your

friend S.

1 Mitteilungen aus dem Reisetagebuche eines deutschen Naturforschers.
Basel 1842. An anonymous pamphlet by Schcenbein, extracts of which appeared
in the AthenEeum. See letter to Schrenbein Sept. 6. 1843.

2 Arch, de 1'Electr. T. 2. 1842. p. 241 and ibid p. 267.

— 93 —

Schcenbein to Faraday.
MY DEAR FARADAY

As an acquaintance of mine is going to London
I cannot let pass such an excellent opportunity without writing
a few lines to you.

Some weeks ago I was myself on the point to cross the
water with the view of attending the meeting of the british
Association at Manchester, when some unlooked for circum-
stances occurred which prevented me from putting that plan
into execution. I was very sorry for this failure and am the
more so now that I know you were there, but we must patiently
submit to what we cannot alter. About a week previous to
the opening of the meetings of the said association I sent a
paper to one of its secretaries and asked him the favo[u]r to
put it into the hands of the president of chemical Section.
I trust the memoir has reached Manchester and been read;
in that case its contents will be known to you and as they
bear upon some important points regarding the theory of
Galvanism I am rather anxious to know what you will think
about the views I have taken of the case. I am inclined to
believe that some of the facts stated in my paper do offer
additional evidence in favo[u]r of that theory according to
which hydro-electric currents are due to chemical action. The
phenomena being exhibited by iron when acting the part of
the cathode within an aqueous oxy-acid appear to me to be
rather of an interesting nature though very difficult to be
accounted for. The longer I am examining the peculiar con-
dition of iron the more does that state become enigmatical
to me so that at this present moment I cannot conceive the
least idea about the cause of that extraordinary phenomenon.

Having of late worked a good deal again on that subject
I have ascertained some novel facts which are very curious
indeed and of which I take the liberty to mention one. Under

— 94 —

certain circumstances iron is capable of maintaining its peculiar
condition within common nitric acid though acting as the
negative electrode of a voltaic arrangement. Supposing that
condition to be due to a superficial oxidation of iron or a
film of oxigen covering that metal, should the hydrogen, being
eliminated at the iron electrode, not unite with that oxygen
and throw the metal into chemical action ? Before long I shall
publish a memoir on the subject in de la Rive's "Archives".1
In the next number of that periodical you will see a notice
of mine regarding a voltaic pile I have constructed out of
mere cast iron.2 The power which that arrangement exhibits
is really wonderful and beats that of any other if we take
into consideration the cheapness of the materials being employed
for its construction.

Some time ago I took the liberty to send you by an
acquaintance of mine five copies of a work on England3 asking
you at the same time the favo[u]r to forward them to their
respective places of destination. I entertain the flattering hopes
that the remarks which the author of the said book has ven-
tured to make on your account will not have proved in any
way unpleasant to your feelings. You will easily recognize in
the publication alluded to the pen of a friend of yours and
of a friend who feels most warmly for you. Mrs. Schoenbein
unites with me in her best regards to you and Mrs. Faraday
and begs me to remember her friendly to her friends in Al-

bemarl[el-Street

For ever

Yours

most faithfully

Bale July 8th 1842. C. F. SCHOENBEIN.

1 Arch, de 1'Elect. T. 2. 1842. p. 267.

2 Arch, de 1'Elect. T. 2. 1842. p. 286.

3 vide p. 92, note I.

If you should happen to have anything to be sent to me,
Mr. Worringer, bearer of these lines, who will communicate
you his address, will be kind enough to take charge of it.

Faraday to Schosnbein.

Tynemouth 10 August 1842.
MY DEAR SCHOENBEIN

I have received both your letters i. e. those of the
dates of April Qth and July 8th; the last just now at Tynemouth
so that if your friend went to the Institution, I lost the pleasure
of seeing him and in any little attention to him the pleasure
of doing anything as thanks to you for your continual and
unvarying kindness which is to me a great value, for though
I now feel pretty nearly excluded as a workman in science it
would grieve me much to think that I was forgotten by the
few friends which similarity of pursuit has accidentally, as it
were, made for me. I rather hope and am persuaded of it in
your case that whilst they vigorously run their successful career
they will let me look on and rejoice in their progress.

We have been here (Northumberland) for 5 or 6 weeks
and must soon return home again. Although I am ashamed to
write about myself yet I am sure you will wish to know that
I am well in bodily health and in good spirits; as long as I
do not exert my memory it remains just as it was.

You appear to have heard that I was at Manchester and
so I was, in a manner, but if you had been there I should not
have seen you and did not have the pleasure of hearing your
papers which however I think were read, but I have no access
to any report here and cannot from memory tell you whether
I did or did not read a report of it in the papers sent me.
The facts are these: I did not mean to go, but the Society of

96 -

Sciences at Modena wrote to Herschel l and myself saying they
had appointed us to represent them at the Association and as
he at first said he could not go and wrote to me on the matter
I went to Manchester and made my appearance at the Committee
meeting on the day previous to the opening of the General
Meeting and reported the credentials of the society which
I represented; having done that I left Manchester early in
the morning in which the great body met und so escaped
London.

The volumes you sent2 and of which I think I know the
author I immediately conveyed to their destination. You know
I do not read German but just before I came here I was looking
at some of the words which caught my attention and guessing
at the meaning suspect the book was written by a very partial
friend of mine. The volume is now in the hands of a friend
who when I go back is to tell me something of what it says.

I shall look for your paper in the "archives" with some
impatience I see that in No. 4 De la Rive says he was obliged
to postpone it to the next number3 where I suppose I shall
find the account of the Iron battery also.4 That Iron is a very
various matter and evidently must be of great importance to
the theory of Electrical action because it is a case of one sub-
stance assuming such different conditions of electrical action.
I hope you will ultimately find the key to all the phenomena
which no doubt are simple and [I] am fully persuaded great
discoveries (now unexpected) [will] be the reward.

Pray give my kindest remembrances to Mrs. Schoenbein
and try to raise up a recollection of me in the minds of the
children. I wonder whether they would know me if they saw

1 Sir John Herschel, was born in 1792 at Slough near Windsor and died
in 1871 in London. He was very wealthy and spent many years in South
Africa for the purpose of making astronomical observations.

* vide note I, p. 92.

3 Arch, de 1'^lect. 1842. p. 267.

4 ibid, p 286.

— 97 —

me again. My wife unites in best wishes and thought to your-
self and your wife. May you both enjoy together all the
health and happiness that a contented mind can desire.

Ever Most Truly Yours

M. FARADAY.

Schcenbein to Faraday.

MY DEAR FARADAY

An opportunity offering itself to me for sending
letters to England, I cannot help making use of it and expressing
you my thanks for the kind lines you had the goodness to
address to me from Tynemouth the other day. I am very
happy indeed to learn from your letter, that you are enjoying
health and what is still more valuable that you are in good
spirits. I am strongly inclined to consider such a state of body
and mind as a sure indication that your memory will also be
entirely restored to its primitive power and that you will soon
be enabled to reenter into your scientific career. Should how-
ever our expectations not be quite fulfilled and should you
be obliged to be a little careful with yourself, as to undertaking
philosophical researches, you must bear in mind that you are
entitled to the "otium cum dignitate"; for you have contributed
your full share to the general stock of science and already
done more in that line, than it falls to the lot of the great
majority of philosophers to be able of doing during their whole
life. You know as well as I do that we are not to measure
the length of our earthly existence by the number of years to
which it extends ; the true magnitude of life is determined
only by the intrinsic value of our doings and in that respect,
it may be said that some men do and live in one single year
more and longer than many others do in fifty.
G

- 98 -

My papers on the electrolysing power of simple voltaic
circles1 and the peculiar condition of Iron2 will he published
in the forthcoming number of the "Archives" and I am really
very curious to know what you will say about the subject. As
to the cause of the inactive state which that metal assumes
under certain circumstances I am still in the dark and must
say that the longer I am investigating the subject the more
inexplicable and enigmatical it becomes to me. I have now
succeeded to make Iron the negative electrode within common
nitric acid, without destroying, by so doing, its peculiar con-
dition, into which state that metal is brought previous to its
performing the function mentioned. Such a fact seems to ex-
clude altogether the Idea of a film of oxygen being the cause
of the inactivity of Iron. In spite of the difficulties I have
hitherto met in my endeavours to solve the problem in question
I shall not give up the hope to succeed at last. My letter and
paper sent to the British Association to Manchester have not
yet been acknowledged, an ommission of formality which I
rather wonder at. Or is it perhaps the custom not to acknow-
ledge such communications? I dare say you have heard of
Moser's3 discoveries.4 If true, they are really wonderful, and
to my opinion the most important ones made in our days.
What interesting conclusions may be drawn from the simple
fact that in utter darkness the image of a medal is impressed
upon a common plate of silver etc. this effect being produced
at a sensible distance. In the last number of Poggendorffs

1 Arch, de l'61ectr. T. 2. 1842. p. 241.

2 ibid. p. 267.

3 Ludwig Ferdinand Moser was born in 1805 at Berlin. From 1839 he
was professor of Physics at Konigsberg where he died in 1880.

4 Schcenbein is alluding to the so called breath-images which he adopted
as a support of his theory of contact action. It is well known however that
Mosers explication no longer holds good, but has been replaced by a more
rational one by Waidele, whereby the importance of his discovery was greatly
minimized.

— 99 —

Annals1 you will find all the particulars about the subject alluded
to. Though the little work,2 I took the liberty of sending you
some months ago, is hardly worth your notice still I should not
be sorry if you were made acquainted with the contents of some
of its chapters. They contain in some respects the articles of
faith of the author and would give you some insight into the
views he takes of nature, mankind etc. Though some of those
views will most likely not quite agree with your way of think-
ing, I trust and am confident that such a difference of opinion
will on your part not loosen the bonds of friendship by which
the author feels himself so intimately attached to you. The
germans are a very queer set of beings and you are well
aware, that the author of the said publication belongs to that
nation and has not altogether divested himself of the peculia-
rities of his country men. These are said to be born meta-
physicians, very fond of the subtilities of philosophy and prone
to mysteries. Though I believe to have taken my stand on
rather a solid ground and being very averse to obscure and
misty speculations, still there is a german bias left in my mind
which looks in the midst of the material world for something
immaterial, and which is strongly inclined to see even in the
most common phenomenon, exhibited to our senses, the immediate
and direct manifestation of something spiritual, of that power
in and by which every thing lives and exists and which is the
foundation and the source of the most minute being, as well
as of the infinity of the universe. The way in which the ma-
jority of philosophers consider Nature is to me, I openly confess
it to you, too crude, too material, too narrow, too onesided.
It is true, they declare nature to be an admirable machinery
constructed with consummate skill, arranged with infinite wis-
dom; but for all that it is to them a machinery only, and that
is too little for me. I must look upon the visible and material

1 Poggend. Annal. Bd. 56. 1842. p. 177 u. 569 Bd. 57, 1842. p i.

2 vide note I. p. 92.

— IOO - —

world with very different eyes in order to satisfy the demands
of my mind. But enough of a subject which is too delicate
and extensive to be spoken of in a letter.

A few days ago I returned from a trip which I took into-
the south of Germany during our Midsummer -holidays and
which carried me through some parts of the Black Forest. Most
of the valleys of that chain of mountains are really delightful,,
and such as I am sure you would like ; fresh air, picturesque
hills, dark woods, limpid streams etc. are to be found there in
abundance. Could you not manage it, to spend next summer
some weeks with Mrs. Faraday in some retired corner there?
Mrs. Schoenbein and myself would be exceedingly happy to-
join you.

My wife and Children are quite well with the exception
of my eldest daughter who fell ill of nervous fever two or
three weeks ago. We have however reason to hope that she
will recover. The good Child recollects you perfectly well,
even in her illness, and Mrs. Schoenbein continues to think you
the most amiable of all philosophers she ever met with in her
life, which opinion I do, of course, not combat at all. I flatter
myself that Mrs. Faraday has not forgotten Mrs. Schoenbein
and does still reckon her amongst the number of her friends.
Pray remember me most friendly to her and be so kind to
tell her that Mrs. Schoenbein is very anxious to make her personal
acquaintance. We must therefore go with our wives to the
Black Forest.

In concluding my letter, I beg you to believe me

Yours

most faithfully

Bale Aug. 22. 1842. C. F. SCHOENBEIN.

— IOI —

Faraday to Schcenbein.

Royal Institution 18 Feby 1843
MY DEAR FRIEND

I was about to write to you the other day and
was stopped by a reason, which you will perhaps think very
odd and insufficient unless indeed you bring a little German
subtlety of thought to bear upon it. I had put the book, which
to me is a sealed book, into the hands of Grove and just as I
was about writing he sent me two pages of writing, a trans-
lation of part which his wife has made: — it was the authors
opinion of myself1 and was a character so beautiful and of which
I felt myself so utterly unworthy, even if it had come from my
loving wifes thought, that I was quelled under it and constrained
to be pen-dumb. I do not doubt your sincerity in the least, but
knowing a little of my own heart I cannot help thinking of the
hypocrisy, which must have contributed to such an impression.
You see I have my fancies as well as you; you will perhaps
count amongst them this, that I think but poorly of human nature,
but certainly in my own heart I find nothing to raise my esti-
mate of it; at the same time, I must allow that I find a great
deal which does do so amongst my friends. The upshot is, that
though I cannot appropriate your good opinion, I thank you
most earnestly for it and will try to become in some degree what
you describe. I wish your book was translated here. I heard
very highly of it from Kohl the Russian traveller who spoke of
its character also in Germany.2

1 The passage here referred to by Faraday is in Schcenbeins Reisetagebuch
(Bale, 1842) p. 277. "It is my conviction" he says "that, so far as scientific
merit is concerned, Faradays discoveries surpass those of Davy, his teacher; though
we may call the work of the latter more brillant, more striking. However, even
if we merely owed to Faraday the discovery of magneto-electricity, that alone
would suffice to entitle him to immortal fame."

2 Johann Georg Kohl was born in 1808 at Bremen, lived for many years
in Russia, and died in 1878 at Bremen.

' IO2

I have now your paper in the "Archives" and purpose
taking it on Monday to Brighton to read, but I must not delay
my letter for that, for I do not know what else may come over
me to stop my writing --a small thing is to me a great ob-
stacle at times and I fear to trust the future. I think I saw
in some paper of Herschels l lately a notion that the peculiar
Iron was Iron in another state and yet iron z — like the existence
of two states of carbon or sulphur or other bodies that show
at times and under certain circumstances these or such differences.

I am surprised at what you say of the British Association
not acknowledging your paper. If I can remember I will take
the first opportunity of asking the reason.

Moser's papers3 I am now reading in the translation in
Taylors Scientific Memoirs.4 So many persons were putting
forth accounts of effects, that I ventured in a short note in the
Literary Gazette to suggest, that all such experiments and state-
ments should now be accompanied by some fundamental experi-
ments made in Vacuo and others made with rock salt. Many
of the effects I have heard described, I have no doubt are due
to mere vapours. Such effects may be separated from those
of radiation in a certain degree by making them in vacuo -

1 Phil. Mag. S. 3. vol. 14. 1839. p. 32. which deals with meteoric iron from
South Africa. In dissolving a specimen of it in nitric acid for the purpose of
analysis, Herschel found that towards the end of the solution the iron assumed
the peculiar state of resistance to the action of the acid, observed by Schcenbein.

- A similar suggestion was made by Berzelius in Stockholm Akad. Handl.
1843. p. I. Schoenbeins reply to this is contained in a letter to Berzelius dated
Feb. 23. 1844 in which he says: "The only remarkable thing about it is, that
the allotropy should be confined to the surface, and not extend in any degree
to the interior of the iron; for the current which determines the passivity of the
iron goes through every part of the iron, which serves as positive electrode."
Kahlbaum, Briefwechsel. p. 42.

8 vide note 4. p. 98.

4 Scientific Memoirs (Taylor") Prt. 3. 1843. p. 422. The treatises giving an
account of his discoveries are: On the action of light on bodies; On invisible
light; and On the power which light possesses of becoming latent.

— 103 —

and also again by interposing rock salt - - for there seems no
reason to doubt that Moser's experiments of true radiation
would succeed, though a thin plate of rock salt were interposed.1

During the last 8 or 9 months I have worked a little on
the Electricity of high pressure steam and sent a paper to the
Royal Society2; perhaps they may print it and then I shall again
have the pleasure of sending you a paper of mine. The elec-
tricity is not due to evaporation — nor to the steam itself —
but solely (I believe) to the friction of the particles of water
which the steam carries with it and I can make it Positive or
Negative on either side at pleasure. Water standing above

3 and all other bodies yet tried on, become Positive when

rubbed against other bodies.

Peltier's4 expts and views of the relation of the earth and
space rather startle me. What do you think? I do not think
I shall be able to assent to the properties which he gives to
space.

You really hold out very tempting pictures of the Black
forest etc. etc. etc. but none more tempting than the hearty
pleasure of seeing you and Mrs. Schcenbein and the children -
to all remember us very kindly. But this year will not see
us out of Britain, and Scotland will be the farthest place we
shall go to. There, family friends have looked for years for us

1 Robert Hunt F.R. S. (of the Mining School, at Chelsea) comes to the
conclusion that the effect in question is dependent on a chemico-mechanical
action, or what Berzelius has called catalytic action. Prater on the other hand,
replying to Hunt in the Athenaeum (1843, P- 59**) reminds him, that Mosers
images cannot be taken at any distance from the plate when polishing, boiling
or screens are used. The effect in question seems therefore, according to Prater,
to be mere chemical action, produced by direct contact.

* An abstract of it is to be found. Phil. Mag. S. 3 vol. 22. 1843. p. 570.
vide also i8th ser. Researches on Electricity. Phil. Trans. 1843. P- T7-

3 The word after above is, in the original, illegible.

4 Jean Charles Athanase Peltier was born at Ham in 1785. He was a
watchmaker and dealer in clocks till 1815, after which he lived on his own
means in Paris, where he died in 1845.

- IO4 —

and I doubt whether even they will see us this year after all.
Again with heartiest feelings of remembrances to you and Mrs.

Schoenbein from us both.

I am My dear friend

Gratefully Yours .
M. FARADAY.

Schoenbein to Faraday.
MY DEAR FARADAY

Having for a great length of time neither seen
nor learned anything from you I felt, as you may easily
imagine, no small degree of satisfaction and pleasure at the
receipt of the letter you had the kindness to write to me some
months ago. The mere sight of lines written by your hand,
independent of their contents, does call forth in my mind
feelings very similar to those which we experience in looking
at the portrait of a beloved absent friend.

As to that part of the "German Philosopher's Work"
which refers to the amiable philosophical inhabitant of the
Royal Institution, I must beg to be allowed to differ widely
from you and am bold enough, as to say that to my opinion
the german writer knows, in some respects at least, the
british philosopher much better, nay infinitely better, than you
do. Having to write about some other things I cannot give
you the reasons which make me hold such an opinion ; one of
them I shall however mention. As you are a Philosopher
yourself, you must be well aware that objects being placed
too near to the eye cannot be distincly seen by that organ.
It is your case, my dear friend, you have seen the man of
whom I am speaking at a distance which is too small, as to
allow you to see him well, and so distinctly, as our german
did, who was more favo[u]rably placed than you are. If you

— 105 —

think that the book in question would be relished by british
readers we could perhaps manage here a translation of it, as
some english persons capable of doing such a work are living
at Bale.

Knowing a little of the language myself, and the author
too, I could perhaps also render some service to make the
translation as correct as possible. Pray be so kind and let
me know your opinion about that subject in your next letter.

I have read with much interest the notice in which you
gave an account of some experiments made on electrical induc-
tion.1 As far as I am able to judge, I think that the results
you have obtained are conclusive in favour of the views you
developed some years ago in your papers "on the phenomena
of induction." I only wonder that our continental philosophers
have as yet not paid that degree of attention to the subject,
which it so fully deserves and which will ultimately not fail
being excited. It is perhaps a certain laziness, inherent to
human nature, that makes even men of science unwilling to
shift out of old-beaten tracks and .enter into paths newly
opened, though these should happen to be ever so well laid out.

The fact that the electricity developed in steam of high
pressure2 is due to friction appears to me rather a surprizing
one.3 Is it not possible that the dispersion or disaggregation
of the fluid water, caused by the expansion of steam, has
something to do with the phenomenon alluded to ? If I am
not mistaken it has been observed that the atmosphere near
a cataract, i. e. the small particles of water flying about at
such a place, are in an excited state. I am indeed very curious
to see the paper in which your results are discribed.

1 Speculation touching electric induction. Phil. Mag. S. 3. vol. 24: 1844. p. 136

2 Phil. Trans. S. 3. vol. 22. 1843. p. 570.

3 Davy says on p. 138 of his Chemical Philosophy: "All cases of vaporization
produce negatve electricity in the bodies in contact with the vapour". In 1843
Peltier contributed the following paper to the Acad. Sci. Bull, at Brussels T. 10.
p. 318: Sur le developpement de 1'electricite par un jet de vapeur.

io6 —

In a small way I am continually occupied with voltaic
researches and think I shall be able to send you some memoirs
within a short time. One of these papers will treat on the
frequency of chemical effects produced by mere contact1 and
another on the phenomena of electrolysis.2 I am afraid you
will think some of my conjectures rather too bold. - - What
do you say about Grove's gaseous Battery ? 3 You will perceive
that I published a paper on that subject in the last number
of de la Rive's Archives.4 It seems our friend thinks the
combination of isolated oxigen with isolated hydrogen to be
a source of voltaic electricity. I cannot yet make up my
mind to believe such a thing; my experiments at least do
not lead to such an inference. De la Rive read the other
day in the french Academy a memoir on the chemical action
of a simple pile which as far as I know its contents, offers a
good deal of scientific interest. The philosopher of Geneva
has made use of a voltaic combination pointed out by me
some years ago and arranged it so, that it yields a considerable
power. Peroxide of lead is the electronegative and zinc the
electropositive element of de la Rive's arrangement. Peltier's
statements are to me as yet no more than mere assertions
and highly improbable conjectures. Although I dislike the
very shadow of a controversy I could not help addressing
a few words5 to Mr. Martens6 who has been writing very

1 Uber die Haufigkeit der Beriihrungswirkungen auf dem Gebiete der
Chemie. Basel 1843.

2 Uber die Ursache der Erhohung des Leitungsvermogens des Wassers
durch Sauren, Alkalien und Salze.

3 Phil. Mag. 8.3. vol. 21. 1842. p.417- Ibid. vol. 22. 1843. p. 376. See also
ibid. vol. 23. p. 165: On the theory of the gaseous voltaic battery, by Schoenbein.

4 Arch, de 1'Electr. T. 3. 1842. p. 69.

5 Einige Bemerkungen in Betreff der Arbeit des Herrn Martens iiber die
Passivitat des Eisens. Poggend. Annal. Bd. 59. 1843. p. 149.

6 Martin Martens was born in 1797 at Mastricht. Originally physician, he
became professor of Chemistry and Botany first in Mastricht, then in Loevven,
where he died in 1863.

strange memoirs on voltaic subjects these last two or three
years.1

I regret very much indeed that your last letter cuts off my
hopes, of seeing you on the continent in the course of this
summer. If you won't come to me, you are running the risk of
having your privacy broken in upon by my humble Individual,
but do not be afraid that such a thing will happen in the year 1843.

Mrs. Schoenbein and my children are doing well, the latter
were during the whole winter suffering a good deal by a
violent hooping-cough.

I confidently hope that the state of your health will be
daily improving and the whole strength both of your body and
mind entirely reestablished. Mrs. Schoenbein unites with me
in her kindest regards to Mrs. Faraday and to yourself.

Ever Your's most truly
Bale April 26. 1843. C. F. SCHOENBEIN.

Schoenbein to Faraday.
MY DEAR FARADAY

As a friend of mine is going to England, I take
the liberty to send you through him some papers in the con-
tents of which you will perhaps take some interest. I am rather
sorry that one of the memoirs is written in german, I trust
however that before long a french version of it will be pub-
lished in the "Bibliotheque universelle" and in that case I ask
you the favo[u]r to let me know, what you are thinking about
the views I have taken of the chemical effects which are pro-
duced by contact.2

1 Martens published the results of his investigations, which he commenced
in 1841 in the Acad. Sci. Bull, at Brussels. Sur la theorie de la pile voltaique,
ibid. T. 9. 1842. p. 192.

2 vide note l. p. 106.

— io8 —

A circumstance that appears to me to offer a good deal of
scientific interest and to which I have paid a particular attention in
my paper, is the fact, that the chemical affinity of some elementary
bodies, for certain substances, is, in many instances, very much
enhanced by bringing those bodies into such a state, as ought,
according to our present notions, to make them less inclined
to enter into a chemical combination, than they are when not
so conditioned. Chlorine for instance does not chemically unite
with isolated hydrogen at the common temperature and in
darkness, whilst chlorine being placed under the same circum-
stances readily combines with hydrogen, if the latter body
happens to be chemically associated with Sulphur, Selenium,
Phosphorus, Nitrogen, Arsenic, Antimony, Tellurium etc. Oxigen
does not unite with hydrogen without being heated or put in
contact with Platinum, if both elements happen to exist in an
isolated state; but oxigen being associated with sulphur, and
hydrogen being combined with the same substance, do readily
form water even at very low degrees of temperature. Chemistry
teems as it were, with facts of a similar description. As far as
I know very little or no attention has as yet been paid to the
influence exerted by one ingredient part of a binary compound
upon the chemical bearings of the other constituent part. This
influence, however, is to my opinion well worthy of being
closely studied and very far from being explained by the prin-
ciples of what they call the electro-chemical theory. As to the
latter, do you not think it high time to subject it to a most
severe and scrutinizing review ? To my humble opinion it rests
upon a very doubtful and unsatisfactory matter of fact foundation.

If Mr. Ryhiner1 the bearer of these lines should happen to
deliver them in person to you, pray receive him kindly and let

1 A very well known name at Bale. Perhaps he was a son of Prof.
J. H. Ryhiner of Bale. A Madame Ryhiner is mentioned in letters to Schcenbein
from Grove (Nov. I4th 1843), who speaks of Mr. Ryhiner as her son, and from
de la Rive (Jan. nth 1847).

him see the Royal Institution. He was once a pupil of mine
and is in every respect a most excellent and amiable young-
man.

In offering to you and Mrs. Faraday my most hearty salu-
tations

I am my dear Faraday

Yours

most truly
Bale May 11. 1843. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 16 May 1843
MY DEAR FRIEND

I must begin to write you a letter, though feeling,
as I do, in the midst of one of my low, nervous attacks, with
memory so treacherous, that I cannot remember the beginning-
of a sentence to the end - - hand disobedient to the will, that
I cannot form the letters, bent with a certain crampness, so
I hardly know whether I shall bring it to a close with con-
sistency or not. But that most valued thing, your kindness,
moves me to write, when to another I would not reveal my
weakness by a halting letter. As to your opinion and power of
judgment etc. of a certain person 1 I have no doubt the ad-
vantages you possess which, I admit, have shown you blemishes
as well as beauties; but I will not put your candour to the tets
by asking for them. The glass of a kind heart through which
you look has something to do with the matter.

Now as to the book in English I am afraid to say any
thing on the matter, not because of my opinion of it, for how

1 p. 277 of his ' Mitteilungen aus dem Reisetagebuch eines deutscheti
Naturforschers."

— no —

can that be anything but favourable; but because of the woeful
mistakes which I have made in judgments of this kind before.
I will tell you a case. A dear friend, a foreigner, now dead, sent
me a M. S. on English scientific matters, which I thought good,
and booksellers of character told me they thought good and
attractive. In one way or another it led to the printing and
publishing of the work. I paid for the printing and did not
receive one farthing back from the sale. I could not tell
my friend this ; he never asked for or had an account, and the
thought often comes back to my mind that up to the day of
his death, he might perhaps imagine I had made a profit by his
work and never rendered him an account. — So much for my
judgment in these matters. In fact I find the Booksellers prospects
are nothing but words, words, words. — I wish Murray would
take your work in his own hands, for then I know he would
use a sound discretion, but I do not know how to get him
to do so.

As to the steam paper,1 it is now printing and when you
have it I hope you will think the reasoning satisfactory. The
point that the water must be pure is a very strong one as
a ground for conclusions - - As to Grove I do not recollect
that he says isolated oxygen and hydrogen can by combining
produce a current of electricity2 - - but I have no confidence
in my memory in such matters. - - I have been reading with
great pleasure some of your papers lately, but am so confused
I cannot just now remember which; but I have not yet touched
No. 7 of the "Archives" where I see your name - - it now
lies before me, but fear to read because of the giddiness.

1 On the electricity evolved by the friction of water and steam against
other bodies. Phil. Trans, vol.6. 1843 p. 17.

2 Phil. Mag. S. 3. vol. 14. 1839 p 130. Grove says at the conclusion of an
account of an experiment in which a galvanometer was deflected when connected
with two strips of platina covered by tubes containing oxygen and hydrogen:
"I hope, by repeating this experiment in series, to effect decomposition of water
by means of its composition'1.

— Ill —

De la Rive is here and I have seen his experiment on the
increase of the decomposing power of a single pair of plates
by adding in the inductive power brought into play at the moment
of interrupting the current.1 Grove brought the account over
from Paris and tells me that he found all there, that he spoke
to, apparently aware of the effect. I imagine this was only be-
cause they recognized in it an action due to the principle I
had examined in Exp. Researcs series IX.2, especially as illus-
trated at 1084. For myself I thank De la Rive for a very beau-
tiful form of the application, though it is the same principle, and
I do not see why a thermo- current should not be exalted in
the same manner until it could effect chemical action and now
indeed I have a faint recollection that Watkins or somebody
has done that also.

I grieve to hear of Mrs. Schoenbein's illness and cares with
the children, I wish there were nothing but happy pleasure in
her way. But all these cares have their reward in a mothers
bosom, and though we dislike them at the moment, it is better
they should be than not. Nevertheless I am very glad to find that
all are improving. The kindest thoughts from us both to you both.

Ever My dear Schoenbein

Your faithful friend

M. FARADAY.

Faraday to Schoenbein.

London Royal Institution 8 Aug 1843
MY DEAR FRIEND

I have the opportunity, though in haste, of sending
you a copy of my last paper, probably the last. I know you

1 Grove relates in a letter to Schoenbein (Nov. 14. 1843) that ^e has been
-working on what he calls voltaic reaction, a method of increasing the force of
a voltaic combination by adding to it a reaction occasioned by itself, vide Phil.
Mag. 8.3. vol. 13. 1843. p. 443-

2 Phil. Trans. 8.3. vol. 18. 1835. p. 41.

112 —

will accept it kindly. — I have had and still feel part of a strong-
attack of giddiness, so must not write much. If Dr. Yates1 sees
you do me the favour to receive him as my friend; if he should
not be able to see you, still he has promised to send on this
letter and the paper. — You remember a little word that paseds
about a translation of a certain book.2 Now a young man of
my acquaintance who is a corrector of the press and acquainted
with many languages, more or less, has had some thoughts of
translating it if he could find a bookseller to publish it — but
he has not found that yet. - - I told him you were connected
with the author of the book and that from what / knew he
ought to write to you first. — I believe he has done so. — I
saw him the other day and found that he had no knowledge
of any publisher as yet; indeed that he had not inquired among
his connections in the trade or intended to do so till he heard
from you. — I wish the book more published in our language
— and I wish the translation were made at Bale. - - But it is
the undertaking publisher we want and I am afraid that in that
respect both plans will fall through. — However I do not know
Mr. Vincents resources or connexions; - - all that I know is he
is in a printing house and can manage that part of the affair
and its expences in a very different way to what I could.

I received your letter by a friend not long ago and con-
clude you had one from me by post about the same time.

With kindest remembrances to Mrs Schoenbein and the

family I am as ever

Your faithful friend

M. FARADAY.

My wife is not with me just now or she would desire to
join me in every good wish to you M. F.

1 James Yates F.R. S. at first a clergymen, retired into private life in 1848;
he was born in 1789 at Toxteth Park and died in 1871 at Highgate.

2 vide note I. p. 92.

— H3 —

Faraday to Schcenbein.

R. Institution 6 Septr. 184^
MY DEAR FRIEND

I wrote to you 5 or 6 weeks ago by Dr. Yates,
but do not feel sure you will have seen him yet. Now I find
your friend Mr. Ryhiner is on the point of returning to Basle
and so spoil half a sheet of paper for a word with you. - - I
hope all are well and happy. My kindest remembrances to
Mrs. Schoenbein — — interrupted — — now I return. I called at
the Royal Society to day and found my paper on steam for
you was gone. — I have not another copy or I would send it-
Mr. Armstrong J has constructed a magnificent steam electric
apparatus,2 which I should think produces about 8 or 10 times
as much electricity as our large machine in a given time. — I
have seen nothing of your book yet except some extracts in
the Athenaeum. — Several are longing for it.

I must conclude, for both head and hand are very unsteady.

Ever Dear Schonbein

Your faithful friend

M. FARADAY.
ft*

Schoenbein to Faraday.

Bale Febr 17. 1844.
MY DEAR FARADAY

An acquaintance of mine going to London I avail,
myself of the opportunity for sending you a little work3 in

1 Sir W. G. Armstrong L, L. D. born 1810 at Newcastle-on-Tyne. was brought
up to the bar and practiced as a barrister at Newcastle. . He then founded the well
known engine-factory, became military-engineer, but in 1863 again took charge
of his factory.

2 Phil. Mag. S. 3. vol. 23. 1843. p. 194. see also ibid. vol. 22. 1843. p. i.
Grove writes to Schrenbein (Aug. 20. 1842): "When I left London Faraday was
at work upon the electricity of steam. I lent him an apparatus by means of
which I had obtained the spark at the London Institution."

3 This little book is doubtless Schoenbeins pamphlet on contributions to
physical chemistry, dated Dec. 1844, which he devides into three sections: i. Uber

which I have tried to develop some theoretical views regarding
the source of voltaic electricity and some electrolytical pheno-
mena. There is also a paper in the book treating of chemical
effects produced by contact, on which I should like very much
to have your opinion. Having these many years entertained
strong doubts about the correctness of the atomic theory and
been inclined to consider what is called a "molecule" of a body
as a centre of physical forces, I have tried to make that view
bear upon the chemical actions being produced by contact
(See page 22 — 25). Mr. Grove writes me in his last letter,1
that the other day you had broken a lance against the atomic
theory in the Royal Institution.2 As our mutual friend does not
tell me any particulars about the view you have taken of the
subject, I am indeed very curious to see the next number of
the Phil. Magazine3 which I understand will give the substance
of your lecture. Having had no less than 19 hours to lecture
a week in the course of this winter, you may easily imagine
that I had no time for making researches: I grow indeed im-
patient of that everlasting schoolmastering and am longing for
being placed under circumstances more favorable to scientific
pursuits.

It is possible that I shall have the pleasure of seeing you
in England about the mid-summer holidays, the execution of
this bold plan of mine does however depend upon circumstances
over which I have got very little control. Once being sure
of the possibility of the journey I shall take the liberty to
acquaint you with the probable date of my arrival at London.

die Haufigkeit der Beriihrungswirkungen in der Chemie. 2. Uber die Ursache
der Erhohung des Leitungsvermogens des Wassers durch Sauren, Alkalien und
Salze. 3. Uber die Ursache der hydroelektrischen Strome.

1 Jan. 30. 1844.

1 "I saw Faraday a few days ago" he writes ''he has been giving a lecture
at the Royal Inst. on some speculations on the nature of matter in which he
has run a tilt against the Atomic Theorists".

8 A speculation touching electric conduction and the nature of matter; Phil.
Mag. 8.3. vol.24. 1844. p. 136.

Mrs. Schoenbein and the Children are doing quite well; the
two eldest girls are now going to school and promise to be-
come very blue; I shall however take good care that that
coloring does not grow too intense, for that sort of blue is
not much to my liking.

My wife desires to be most particularly remembered to
you and Mrs Farada}7 and reckons upon the great pleasure of
seeing you both once more at Bale.

Pray present my humble respects to your lady and be-
lieve me

Your's

most faithfully

C. F. SCHOENBEIN.

NB. The Philosophical Faculty of our University has con-
ferred its degree upon our Friend Grove.1

Be kind enough as to forward the inclosed parcels to their
respective places of destination. S.

Schcenjbein to Faraday.

Bale, March 30.
MY DEAR FARADAY

Some weeks ago I took the liberty to send you,
through an acquaintance of mine a little work containing some
memoirs on voltaic and other philosophical subjects. I should
like very much indeed that you were made acquainted with
the substance of those papers, as they relate to some interesting
questions of voltaic and chemical Science.

1 "Will you convey my most grateful thanks to the Philosophical Faculty
of your University and say that I feel most highly honoured by the degree conferred
upon me and that I shall study to deserve the good opinion which has induced
them to grant it." (Letter from Grove to Schcenbein, Jan. 30. 1844.)

2 The date has been added later and is in Faradays hand.

In case I should happen to succeed in isolating the principle
of ozone, as I hope I shall before long, I have a good mind to go
to York with the view of performing my philosophical miracle
before the British association. What do you think of that plan?"
Its execution would perhaps give some zest to the proceedings
of the chemical section there. From having lately worked a
little too much I am rather knocked up and want some relax-
ation. A trip to England would no doubt do me a great deal
of good, but Mrs. Sch. will hear of no such thing and declares
such a locomotion as downright wantonness.1 But after all she
would not throw any great obstacle in my way, if I insisted
upon the visit. She charges me to present to you and Mrs
Faraday her humble respects, in which I of course join

Your's

Schcenbein to Faraday?
MY DEAR FARADAY

Having of late made a series of experiments
with the view of producing by chemical means that odoriferous
principle which I have called "Ozone" and which is, as you
are well aware, disengaged at the positive electrode during
the electrolysis of water, as well as near the points, out of
which common Electricity is passing into the atmospheric air, and
believing that I have succeeded in the attempt, I think you will

1 Schcenbein's frequent journeys, in fact, never seem to have been much
to Mrs. Schoenbeins liking. Thus he wrote to his wife from London, Sept. i. 1839:
''Du siehst also, meine Hebe Frau, dass man den Mann doch in manchen Dingen
machen lassen muss".

2 Faraday on receipt of this letter sent it to Mr. Christie, by whom it was
received on April Qth, to read at the Royal Society. With the exception of some
slight alterations, it was read unchanged under the following title : "On the
production of Ozone by chemical means. By Professor Schcenbein." The Phil.
Mag. (vol. 24. 1844. p. 466) and the Proceedings of the Royal Society (vol. 5-
1844. p. 507) both contain short abstracts of it.

read with some interest a summary account of my proceedings
and results. (The details regarding these researches will be
described in a paper which is to be published in one of the
forthcoming numbers of the "Archives" and "Poggendorff's
Annals".)1

If at the common temperature, a piece of phosphorus be
put into a bottle filled with ordinary air, an atmosphere is very
rapidly formed in it, which possesses the property of polarizing
positively a plate of Gold or Platinum which is2 plunged into
the said atmosphere for a few moments. In one instance, the
needle of my galvanometer was deflected 90° by a gold plate,
which had remained for twenty seconds within a bottle, whose
air had previously been in contact with phosphorus for only*
one minute.

The positively polarizing power of that atmosphere arrives
at its maximum of intensity, sometimes, within the space of a
few minutes, sometimes z#4 that of as many days, according to
circumstances, into the description of which I cannot enter at
this present moment.

That maximum being once reached the intensity of the
polarizing power decreases, and within more or less time sinks
down to zero, but not to remain in that state. The atmos-
phere, after having assumed a neutral, or inactive voltaic con-
dition, passes into an opposite state i. e. acquires the power of
polarizing negatively a plate of Gold or Platinum which is 5
put into it (the atmosphere) for a few seconds. This newly
acquired power is, according to circumstances, either slowly
or rapidly gaining in intensity until it reaches also its maximum.
Having arrived at that point the atmosphere does not undergo
any other change of state, if left to itself. I am able* to bring

1 The italics are our own and signify that the passages in question were
omitted at the reading of the paper, or otherwise amended ; whereas the notes
will in each case give the original reading of Schoenbeins letter.

2 being. 3 but one. 4 within. 5 being. 6 I have got it under my control.

— iiS —

about the described variations of the voltaic condition of our
atmosphere, either in a slow or sudden manner, and with respect
to that point of my experiments I will only say that the rapidity
of the changes alluded to, essentially depends upon the degree
of temperature at which phosphorus is acting upon the atmo-
spheric air. Supposing our atmosphere to have l assumed its
neutral condition, remove the phosphorus from the bottle and
put into the latter any readily oxidable metal, being in the/~<?rra2
of filings or powder, e. g. iron, tin, zinc etc. or any other sub-
stance being eager to unite with oxigen, for instance the
protochloride of tin or of iron, or the common iron vitriol,
shake the atmosphere with one of the bodies named and it
(the atmosphere) will almost instantaneously be brought again
to a positive condition of consi[de]rable intensity, which state
does not seem to be liable to change any more. If on the
other hand our atmosphere, after having acquired its highest
degree of negatively polarizing power, be treated in the manner
described, for instance with iron filings, this power is not only
entirely and suddenly destroyed, but the atmosphere changes
altogether its voltaic nature and assumes a highly electro-
positive condition. It is a matter of course that by the
quantity of oxidable matter put into the negative atmosphere,
we may regulate at pleasure its voltaic condition. (The inten-
sity of its negatively polarizing power may be only diminished,
or the atmosphere may be rendered neutral, or more or less
Positive from the slightest degree of that state to its maximum.)
Before farther proceeding in the account of my researches, I
must not omit to mention the fact that by putting a solution
of chloride of Gold into an atmosphere, whose positive con-
dition has been restored by means of readily oxidable substances,
that condition is suddenly and irrecoverably destroyed.

From the facts stated, it appears that by the slow action
of phosphorus upon atmospheric air two gazeous princibles

1 having. 2 shape.

are simultaneously produced, which are opposite to each other
with regard to their voltaic properties; one of them is an
eminently electropositive body, the other a still more power-
fully electro-negative one. Under ordinary circumstances the
generation of the first principle prevails at the beginning of the
said action over that of the second one, but in the more
advanced stages of that chemical process the contrary takes
place. The production of the electro-negative principle be-
comes more copious than that of the positive one and hence
it comes, that our atmosphere, whilst remaining in contact
with phosphorus passes through different stages of voltaic con-
dition until it arrives at the maximum of its negatively
polarizing power.1 But what is the nature of the two prin-
ciples ? As to the electropositive one, I am inclined to think
it to be vaporous phosphorus mixt up with particles of
what is called "phosphatic acid". (Et void mes raisons for
making such a supposition. If you pass very slightly a piece
of phosphorus over a plate of gold or platinum, the latter
deflects very perceptibly the needle, if it be voltaically com-
bined with a similar metallic stripe being in its ordinary
state. The said deflection is such as to indicate a current
passing from the phosphorated plate to the common one. I
have also ascertained the fact that a plate of platinum or
gold being surrounded with a solution of phosphorous acidy
as well as of phosphatic acid, is positive to a similar plate
being plunged either into acidulated (by muriatic acid for
instance) or chemically pure water. That phosphorus is capable
of assuming the vaporous state at the common temperature,
no Chemist I think doubts of and that by the slow action of
phosphorus upon atmospheric air phosphatic acid is produced

1 Grove writes in a letter to Schoenbein (Jan. 5. 1845): "Some of your results
are very curious ; particularly that of the two different sorts of polarisation by
phosphorus. I have been making some expts. with Phosphorus but had not
observed or indeed sought for such an effect."

— I2O —

belongs to the class of well-known facts) It is however possible,
and I think it even likely, that besides the two positive sub-
stances mentioned a third one of the same voltaic kind is
generated in my experiment, but I do not think it reasonable
yet to state the reasons for my holding such an opinion. I
must however not omit to mention that the electropositive
principle or principles, if shaken with a solution of chloride of
gold throw down a perceptible quantity of that metal a fact
that merits to be taken into consideration.

But what is the chemical nature of the electro-negative
substance generated during the slow action of phosphorus upon
the atmospheric air? Do not be startled at my telling you
at once that it is my "Ozone", for I have got my good
reasons for making such a bold assertion. The princible ones
are as follows:

1. As long as our atmosphere exhibits a notably strong
polarizing power of the positive kind, its smell is similar to
that of garlick i. e. to l the smell which we ascribe to phos-
phorus; as soon however as that atmosphere is approaching
to its neutral voltaic state, an easily perceptible change in its
odor takes place also. It now begins to resemble that of
Ozone. That smell grows stronger and stronger, the more
exalted becomes the electro-negative condition of our atmos-
phere, and before having arrived at the maximum of its negative
intensity, it is utterly impossible to the most delicate nose to
perceive the slightest difference as to smell, between the odori-
ferous principle disengaged at the positive electrode during
the electrolysis of water, and that being generated by the slow
action of phosphorus upon the atmospheric air.

2. All the substances being possessed of the power to
annihilate almost instantaneously the odor of ozone are without
any exception capable also of destroying suddenly the same
smell of our atmosphere.

— 121

3- All the substances having the property of destroying
the negatively polarizing power of the odoriferous oxigen
being eliminated at the positive electrode during the electrolysis
of water, do also destroy the same power possessed by our
ozone-like smelling atmosphere. To the facts mentioned I
might yet add some others which you could hardly help con-
sidering as sufficient to prove, I think, beyond any shade of
doubt the identity of the two principles in question.

The alleged matter-of-fact reasons are however, to my
opinion at least, such as will fully bear out the correctness
of my assertion, according to which "Ozone" is formed during
the slow action of phosphorus upon the atmospheric air. The
question "what is ozone itself?" I am not yet prepared to
answer, I hope however to be able to send1 you very soon
some scientific news upon"* that subject, being at this present
moment very busy with isolating that curious principle. But
whatever ozone may be, it appeares to me to be a most
remarkable fact, a phenomenon highly worthy of all the attention
of philosophers, that the odoriferous principle spoken of is
generated under circumstances, being, apparently at least, so
essentially different from each other. For I ask what similarity
exists* between the passing of common electricity from a
charged conductor into the atmosphere, the electrolysis of
acidulated water and the slow action of phosphorus upon atmos-
pheric air? Different as these circumstances appear to be, it
will and must ultimately turn out that, with regard to the possi-
bility of the generation of "Ozone" offered by them, they are
alike. At any rate, you will agree with me in the opinion that
a great number of accurate experiments must yet be made
before we shall be enabled to clear up the mystery which still
hangs about the subject.

I think however that the path is now opened which will
lead us to the solution of our problem and it is not necessary

1 of sending. 2 about. 3 does exist.

— 1 22 —

to assure you that I shall endeavour to the utmost of my powers
to arrive at that end.

Should you think the contents of this letter interesting
enough to be communicated to the Royal Society I have no
objection to your doing so or to your making any use of them
you think fit.

I remain

My dear Faraday

Your's

most faithfully

Bale March 30 1 844 C. F. SCHOENBEIN.

P. S. To obtain the results such as they are described
in the preceding lines it is indispensably necessary to depolarize
the electrodes after each experiment made with them and the
galvanometer. Heating them red hot is the easiest method to
effect that depolarization.

Faraday to Schcenbein.

Royal Institution 12. April 1844
MY DEAR FRIEND

I received your letter three or four days ago
and was very greatly interested by it I have given it to Mr
Christie1 to read at the Royal Society. -- I do most earnestly
hope that you will make out and establish this Ozone; it is a
very fine thing to do and as you say, though the means of
proving it seem to be anomalous and strange when composed
together, yet most great discoveries in science have appeared
equally strange and confused to us in the first instance. — I have
not yet repeated the experiments for certain private troubles

1 Samuel Hunter Christie, F. R. S. Professor of Mathematics at Woolwich,
was born in 1784 in London and died 1865 at Twickenham.

— 123 —

have brought me low in health and spirits and my dear wife
and I are now at Brighton (tho' I date by habit us above, from
the Royal Institution). But I hope we shall soon be better and
this what you say leads me to think, we may have the pleasure
of seeing you here i. e. in London and also at York, for I believe
I must go there myself this year if I possibly can. — I do not
know that we have any scientific news here, but I am a very
bad indicator, for my bad memory both loses recent things and
sometimes suggests old things as new, making all appear misty
and doubtful to me. — Our communications through the Royal
Society are quite closed or else I should have sent you a short
paper, being a speculation about matter 1 - - perhaps you may
have seen it in one shape or another, at all events when you
come, you will put the few pages into your portmanteau.

One hundert remembrances to Mrs. Schoenbein and all the
little (? big) ones. It would be pleasant to see your fauns (?)
in Switzerland amongst (?) the rock and hills etc. but that is a
fancy only. I doubt whether I shall ever leave England again. —
I hope that the next news of you will be news of still further
advance in the ozone discovery but any will be pleasant to my

thoughts.

Ever Very Affectionately Yours

M. FARADAY.

Sckcenbein to Faraday?
MY DEAR FARADAY

Since I wrote you last I have continued my resear-
ches on "ozone" and obtained from them results which seem

1 vide sopra Schcenbeins letter of Febr. iyth 1844. p. 113. and Phil. Mag.
S. 3. vol. 24. 1844, p. 136.

'2 This letter also Faraday sent to the Royal Society. The Phil. Mag. printed
an abstract of it in vol. 24. 8.3. 1844. p. 467 under the following heading: "On
the production of Ozone by chemical means". An abstract is also to be found
in the Proceedings of the Royal Society vol. 5. 1844. p. 508.

— 124 —

to be important enough, as to justify my addressing to you
another letter on the subject. I have succeeded in putting it*
beyond even a shade of doubt that the odoriferous principles
which arez disengaged during electrical discharges in the
common air, the electrolysis of water and the slow action of
phosphorus upon the atmosphere are absolutely indentical to
one another, as to their chemical nature and that my ozone,
as I originally suspected it be, is really a halogenous body
very closely resembling to Chlorine.3 The named principle has
the power i) of destroying vegetable colors, 2) of decomposing
a variety of compounds which are decomposed by Chlorine,
for instance sulphuretted hydrogen, Ammonia, Jodide of po-
tassium. Water also is decomposed by Ozone in similar cir-
cumstances under which Chlorine produces that effect, ex. gr.
when sulphurous acid or a number of readily oxidable matters
are simultaneously acting upon water. 3) of changing the yellow
ferro-cyanide of potassium into the red one. I could add
many other facts more, showing the chlorine-like nature of ozone,
but the stated ones are sufficient to prove the correctness of
my assertion. Ozone, if inhaled, proves very deleterious to the
constitution and produces effects similar to those called forth
by Chlorine. A mouse has* already fallen victim to my dis-
covery and I myself have strongly felt the powerful action
of ozone upon the system. Having drawn up a paper in
which I have given a detailed account of the results obtained
from my researches and which I hope will soon be published,
I take the liberty to refer you for the sake of particular in-
formation to that memoir.5 I cannot however help adding, that

1 to put it. 2 being.

3 Grove in 1840 in a letter to Schoenbein dated Oct. 13, suggested a new
name for ozone, for the purpose of giving expression to this close resemblance:
"By the bye, why not call it ozine," he writes, "as you consider it an analogue
of chlorine, iodine etc., and not of boron."

4 is.

5 Uber die Er/.eugung des Ozons auf chemischem Wege. Basel 1844.

- 125 -

the whole body of facts which I have been lucky enough to
ascertain, render it highly probable, if not certain, that ozone is
derived from azote, that is to say that the latter body is a
compound consisting of ozone and hydrogen. Starting from
that conclusion or if you like supposition the disengagement of
Ozone taking place under circumstances apparently so widely
differing from each other, is very easily accounted for. i) The
disengagement of Ozone in atmospheric air by means of common
electricity. If an electrical discharge takes place in the common
air, the oxigen of the latter unites with the hydrogen of azote
and sets Ozone at liberty. Should hydrochloric acid happen
to be a constituent part of our atmosphere instead of Azote,
a series of phenomena would take place at the points of emission
of an electrical machine closely resembling those which we ob-
serve now at those points. A smell of Chlorine would make
its appearance there, a stripe of gold held into the electrical
brush would become negatively polarized, starch mixt up with
jodide of potassium would turn blue, the yellow ferro-cyanide
be changed into the red one, organic coloring matter be bleached,
etc and the whole series of the phenomena mentioned, rendered
impossible to take place, if the points of emission were surrounded
by an atmosp[h]ere holding some sulphuretted hydrogen, sul-
phurous acid, vaporous phosphorus, etc dissolved. Indeed the
disengagement of ozone at those points is entirely stopt by
mixing up the atmosphere with very small quantities of the
gazeous substances last mentioned, as you will learn from my
memoir.

2) The disengagement of ozone by the slow action of
Phosphorus upon the atmospheric air. Phosphorus being simul-
taneously in contact with Azote and Oxigen causes the latter
to unite with the hydrogen of azote, whilst another portion of
oxigen combines with phosphorus to form phosphorus acid.
Ozone is set at liberty, part of which reacts however upon
phosphorus, forming ozonide of phosphorus, whilst another part

126

Is thrown into the air, being placed above the phosphorus. That
compound being in contact with water is changed into phos-
phoric acid and ozonide of hydrogen i. e. Azote. The trans-
formation of phosphorus into phosphatic acid, whilst that ele-
mentary bod}7 is acted upon by atmospheric air essentially
depends upon the action mentioned. I must not omit to mention
that all vaporous or gazeous substances which, when mixt up
with atmospheric air prevent phosphorus from emitting light
(for instance vapo[u]r of ether, alcohol, carburetted hydrogen etc.)
do also stop the disengagement of ozone, as well as the oxi-
dation of phosphorus.

3) The disengagement of Ozone by voltaic electricity.
Azote being an electrolyte, like hydrochloric acid, is decom-
posed into its constituent parts by a current, if dissolved in
water i. e. rendered liquid by that agency. According to the
results of my recent researches water, being deprived of atmo-
spheric air, i. e. Azote, does not yield the smallest quantity of
Ozone at the positive electrode and acquires that property
again by shaking that sort of water with atmospheric air. I
may as well mention here, that water containing only very
small quantities of sulphurous acid, sulphuretted hydrogen, in
short those substances which have the power to prevent the
disengagement of Ozone near electrical points, does not yield
the slightest trace of ozone. From the preceding remarks you
will perceive that the disengagement of Ozone brought about
by electrical, voltaic and chemical means is easily and simply
accounted for by supposing azote to be ozonide of hydrogen.
Conclusive however as my results appear to me to be as to the
compound nature of azote, I readily allow that many more ex-
periments must be made and in particular that of isolating
Ozone, before my conclusion or supposition can or will be
considered as decisive. On treating my ozone with a solution
of potash I obtain nitrate of potash, which fact goes rather far
to prove the identity of nitric and ozonic acid. You have made

the same experiment in causing the electrical brush to act upon
a piece of paper being impregnated with a solution of potash.
You got salpeter by the electrical ozone, I by ozone being
produced in the chemical way. In your experiment, as well
as in mine, the formation of nitric acid, is due to a secundary
chemical action and not to the immediate or direct union of
Azote and Oxygen. I think it likely that during the action of
Ozone upon the alkaline solution, not only ozonate of potash
is formed, but also ozonide of potassium, just in the same manner
as out of Chlorine and potash, chlorate of potash and Chloride
of potassium are produced. It is however a chemical possibility
also that ozone and potash generate nothing but Ozonate of
potash. If you wish to repeat my principal experiments I strongly
recommend to you the use of paper being impregnated with
starch and jodide of potassium. It is a test for ozone being
far superior even to the most delicate galvanometer. By that
means you will easily ascertain the disengagement of ozone
near a piece of phosphorus if that body is put into the open
air after, having been a little rubbed and dried by filtering paper.
Provided the slow oxidation of phosphorus be rather rapid,
your test-paper will not fail being turned blue in a few instants.
At a low temperature no such result will be obtained. To
give you a matter-of-fact proof of the bleaching power of
ozone I lay by three stripes of litmus paper J of which No. i
was bleached by the electrical brush (produced by a four hours
working of the machine), Nr. 2 by voltaic ozone and Nr. 3 by
chemical ozone. As the latter one is in a more condensed
state it bleaches more rapidly than the two other sorts of
ozone do.

1 These strips are however missing. Attached to a letter to Berzelius,
•dated April I4th 1844 are three strips shewing clearly the similarity of the
bleaching actions of voltaic, chemical and electrical ozone. In fact one of them
is the identical strip with which he for the first time proved the bleaching power of
the electrical smell. Kahlbaum, Briefwechsel Berzelius-Schoenbein Basel 1898. p. 48.

— 128

To produce a fair quantity of ozone, put a piece of phos-
phorus into a bottle being filled with common air and expose the
whole to a temperature of 15 — 25 ° C. Within a few minutes you
will find your air charged with ozone already sufficient to turn
your test paper into blue, and after an hours action the bleaching
power of our atmosphere is such as to render (within a short time)
a piece of litmus paper, not strongly colo[u]red, entirely white.

As the matter which I have now got into my hands pro-
mises to become rather a rich mine for scientific research, I
flatter myself that you will not think me intrusive if I take
the liberty to acquaint you from time to time with my results.
I trust however, that before the year will be much older, I
shall have the pleasure of paying you a visit and work with
you in the Royal Institution; for I have a strong mind to cross
the water in the month of July. Pray let me soon hear
from you and excuse my hastily and badly written letter. As
you may easily imagine I am now in rather a feverish state,
working from morning to night in my laboratory and sleeping
very little at night. (Mrs, Schcenbein is quite surprized at my
taciturnity and prolonged absences from home. She unites
with me in kind regards to you and Mrs. Faraday and begs to

be kindly remembered by you)

Your's very faithfully

Bale April igth 1844. C. F. SCHOENBEIN.

(Do you think a paper on Ozone would prove acceptable
to the Royal Society'?) S.

Faraday to Schcenbein.

Royal Institution April 29. 1844.
MY DEAR FRIEND

Though I wrote you only a few days ago yet
having received two other letters from you I think it will be

— 129 —

better to trouble you with a line, though I hope with no post-
age. — Your Swiss postage always embarrassed me, for I was
told I could pay and yet found, there was always something
of a double postage in one direction.

But to reply. I have received a few days ago your letter
of Feby 17. with the books and the diploma for Grove1 — I
thank you heartily for the share for me and only regret that
I cannot read it — and have sent the other things to their desti-
nation. Your friend I did not see, I believe I \vas at Brighton
at the time. —

Your last letter I have also had and it really is one to
surprize and delight your friends, among whom I count myself
one, and not the least warm in his feelings. I have read it but
once and it is now out of my possession for I sent it at once
to the Royal Society. — You will have seen by my answer
to your first letter that, as you told me to use them as I thought
fit, I had sent it there, wishing it at all events to be read there
and communicated to the Fellows, and therefore on receipt of
your second I sent it also to Mr Christie, the Secretary, with-
out loss of time. As my health will not allow me to go to
the meetings I do not know as yet whether they have been
read. One of your letters says something about the question
whether a paper for the R. S. would be acceptable. -- - Now
here I must explain or else you will perhaps think I have not
done rightly with your letters. I have the impression that the
Royal Society prints no papers that are not original and do
not appear first in their own Transactions, but that they would
be glad to hear such valuable letters as yours and print_them

1 Grove had received an honorary degree of the University of BSle. Tn a
letter to Schoenbein dated June I. 1844 Grove acknowledges the safe arrival
of the diploma. The degree was conferred on Feb. 12. 1844, when Schoenbein
was Vice-chancellor, or Rector as he is termed at .Bale. Grove is described
'as a "vir doctissimus, acer et diligens rerum, quae ad physicam pertinent,
investigator, .... columnarum voltaicarum conditor nee non pneumaticse
columnse, cuius in rerum naturae cognitione maxima vis est, inventor etc.
I

— 130 —

in their proceedings which, as they are reported and indeed
given at full length in the Philosophical Magazine, would pro-
duce an early publication and show that the letters and the
matter had been at the Royal Society. All your letters gave
me to understand that your papers would appear immediately
in the "Archives" and also probably in some other form, so I
could not promise Mr Christie an original memoir from you.
You must correct me if I have been in error.

From your letters I conclude we shalll have the pleasure
of seeing you this summer either at York or here or both.
Speaking of York reminds me that a communication from you
on your subject of ozone and your last discoveries would be
of great value to the Association and sure to be warmly re-
ceived. With the best wishes and remembrances from my
wife and myself to Madam Schoenbein and family I am ever

Yours

M. FARADAY.
titf

Schoenbein to Faraday.
MY DEAR FARADAY

I have at last succeeded in isolating my Ozone
and think you will be rather curious to know how that result
has been obtained. I made use of twelve bottles, each holding
about 30 litres, put in each of them a piece of phosphorus of
about an inch long and suffered that body to act upon the
atmospheric air, being contained in the bottles, at a temperature
of 12 — 16° R. for 24 hours. After that time the atmosphere
of the vessels was rather richly charged with ozone. I then
carefully removed the phosphatic acid, having been formed
during the process, by rinsing the bottles with distilled water
and treated their remaining gazeous contents with a solution
of jodide of potassium. In shaking the bottles with that liquid

Ozone is instantly taken up and Jodine eliminated. 1 had of
course to repeat the same operation many a time before the
solution of jodide of potassium was completely decomposed and
changed to what I consider to be ozonide of potassium.1

As far as I have examined the latter compound it appears
to be a white substance, not very soluble in water, feeble
taste, is decomposed by a variety of acids, notably by sulphuric
and muriatic acid, yielding at the same time ozone in its free
state. Ozonide of potassium when newly prepared is completely
neutral i. e. does not change in the least either blue or reddened
litmus paper, but during evaporation it becomes alcaline and
bleaches by degrees a piece of litmus paper, if the latter be
alternately plunged into the solution of ozonide of potassium
and taken out to let it dry in the atmosphere.

That solution being mixt up with some jodide of potassium
throws down jodine, if acidulated by a variety of acids. And
hence it follows that the presence of ozonide of pot. may easily
be detected by starch containing some jodide of pot and acidu-
lating the substance to be examined with muriatic or sulphuric
acid. The presence of the smallest traces of the ozonide is
indicated by the blue colo[u]ring of the mixture. If the purest
potash is heated and kept in fusion at the open air for some
time, the remaining part, if dissolved in distilled water and
acidulated with dilute sulphuric acid turns deeply blue starch
mixt up with some jodide of pot. That fused potash acts exactly,
as an artificially made mixture of ozonide of potassium and pure
potash would do. I am inclined to think that under the circum-
stances mentioned part of the potash is really changed into
ozonide of potassium. By heating strongly nitrate of potash,
or any other nitrate containing an alkaline base, a substance is
produced which being dissolved in water and acidulated exhibits
the same properties as potash acquires by being strongly heated.

1 vide p. 134, where he writes to Faraday, May 3ith, informing him that
this salt is not pure, but contains appreciable quantities of an iodate.

— 132 —

It is hardly possible that peroxide of potassium is the cause
of the elimination of jodine, that substance being instantly
decomposed when brought in contact with water or acids.
If moist starch containing jodide of potassium be exposed to
the open air, by degrees it turns blue; if a piece of linen be
drenched with an aqueous solution of jodide of potassium and
suspended in the open air for a couple of days, it yields a
feeble yellow solution if treated with distiHed water. That
yellow liquid colors pure moist starch into blue which indicates
the presence of free jodine. And if the said yellow solution
be heated to drive off the free jodine the remaining part being
acidulated causes a blue coloring in liquid starch. You obtain
the same results, only to a slighter degree, in making use of
asbestum fibres instead of linen or paper. Heat jodide of
potassium in the open air and hold a piece of paper being
drenched either with pure starch or with starch containing jodide
of potassium and you will find that for a great length of time
the test paper is perceptibly colored. If you dissolve the re-
maining part of the fused jodide in water and put some muriatic
acid to it, the solution assumes a yellowish tint and turns pure
starch bluish. It seems therefore that under the circumstances
indicated ozonide of potassium is formed, for I cannot account
for the reactions observed in another manner. By burning
potassium on a foil of platinum you obtain a substance which,
if dissolved in dilute muriatic acid colours deeply blue starch
containing jodide of potassium and that reaction takes place
even after having heated for a short time the said acid solution.
It seems to be a fact also connected with the ozone business.
If dilute and chemically pure sulphuric acid, holding however
some air dissolved, be heated to the boiling point with pure
peroxide of manganese or peroxide of lead, a gazeous substance
makes its appearance which has the property of turning my
test-paper blue. Having entertained the boiling of the said
mixture for some minutes the reaction ceases to take place.

Let the open vessel cool down again and be exposed for some
time to the air, the starch paper will be colored afresh, if you
heat the mixture again to its boiling point. As often as you
repeat the same operation you will invariably obtain the same
result. It seems to me that there cannot be the question of
Chlorine as being the cause of the elimination of jodide, it must
be something else. Now if azote happens to consist of Ozone
and Hydrogen and if nascent Oxigen be capable of taking up
the Hydrogen of azote in the same way, as it unites with that
element being contained in hydroch[l]oric acid, all the reactions
stated may easily be accounted for, if we take at the same time
into consideration the slight degree of solubility of azote in
water. Indeed, if we suppose the azote of the atmospheric air
to be replaced by hydro-chloric acid and if we farther suppose
the latter compound to be as slightly soluble in water as azote
is, the very same phenomena would take place. I have ascer-
tained many other facts not yet mentione[d] to you, all of them
are such as to speak in favour of my notion, that azote is an
electrolytic compound and consists of Ozone and Hydrogen.
I finished yesterday a little work l which contains a detailed
account of all my researches on ozone; it consists of about 10
printed sheets and de la Rive cau[sed] a french translation2 to
be made in Geneva. As the subject is rather original and im-
portant, don't you think that an english version of the book
would be favo[u]rably received in England. I wrote Grove
about it, but have not yet got any answer from him.3

1 He refers to his pamphlet: :'Uber die Erzeugung des Ozons auf chemischen
Wege". Basel 1844.

2 De la production de 1'ozone par voie chimique. Extrait des Archives de
1'Electricite No. 15, Geneve 1844.

3 Grove writes to him on Jan. 5th 1845 "I do not think many would pur-
chase it in England ; the few Electricians and Chemists who read French have
already seen it at the Institutions in the Archives ; but if you have several
volumes to spare, there can be no harm in your sending them to Watkins to
sell on commission."

In confidently hoping that you will enjoy perfect health

I am .

my dear mend

Your's

most faithfully

Bale Mai 29. 1844. C. F. SCHOENBEIN.

Dont forget to present Mrs. S. and my humble respects to
Mrs. Faraday and excuse my bad writing.

Schcenbein to Faraday.

MY DEAR FRIEND

I write you a few lines to tell you that after
having more closely examined the salt of which I spoke in
my last letter as of pure ozonide of potassium, I found it to
contain appreciable quantities of a jodate. I must therefore
ask", y'oii the favo[u]r not to communicate my letter to the
Royal Soci'ety at least not that part of it which regards the
isolation of Ozone. It seems that in treating my ozoniferous
atmosphere with jodide of potassium a good portion of ozone
is taken up and does occasion the formation of the jodate
mentioned. But even this action appears to be an additional
proof of the analogy which exists between Chlorine and Ozone.
Berzelius, to whom I communicated my results about six weeks
ago,1 takes a very lively interest in the ozone affair and
encourages me to sift the matter to the bottom.2

Your's

very faithfully
Bale 31. Mai 1844. C. F. SCHOENBEIN.

1 April 1 4th 1844.

2 In a letter dated May i6th 1844 which he concludes as follows: "You
must devote all your time to this so important investigation, you must follow it

— 135 —
/

Faraday to Schoenbein.

R. Instution 19 June 1844.
MY DEAR SCHOENBE1N

I have received yours and written again so closely
lately as to have little to say upon the present occasion other
than that I wait to hear in due time more of Ozone - - and
to introduce my good friend Dr. Holland * to you. I only
wish I could have brought him to your house myself and so
astonish you and Madam Schoenbein and my playmates. Any
kindness you can show him will be very acceptable to your

sincere friend
M. FARADAY.

Schoenbein to Faraday.
MY DEAR FARADAY

Having made a journey into Germany with Mrs.
Schoenbein and the children during our mid-summer holidays
I could not have the pleasure of seeing your friend Dr. Holland
who had favo[u]red Bale with a visit whilst we were absent.
I was indeed very sorry for it.

My first series of researches "on ozon" 2 was finished about
eight weeks ago and I take the liberty to send you a copy
of the little work in which You will find my results fully des-
cribed. Had the french translation been out I should have
offered you a copy of it, instead of the german original, I

up with the true perseverance of a Bunsen, and if possible not abandon it until
we are perfectly clear about it". Kahlbaum Briefwechsel Berzelius-Schcenbein
Basel 1898. p. 60.

1 Most likely Sir Henry Holland M.D.F.R.S. physician-in- ordinary to Prince
Albert who was born in 1788 at Knutsford and died in 1873 in London.

2 He is evidently again alluding to his pamphlet: "Uber die Erzeugung
des Ozons auf chemischem Wege".

- 136 -

hope, however to find before long an opportunity for sending
you the french book.

The subject in question is far from being exhausted and
I think I shall be obliged to work hard next winter to get
at the bottom of the matter. I am afraid I shall not be able
to carry my plan into execution and attend the meeting at
York; but you know perhaps some person who will undertake
making some abstracts from my work with the view of com-
municating them to the association.

In that case you will perhaps have the kindness to read
them there, provided you think them interesting enough for
such a purpose.

If the committee of the british association, of which you
are no doubt a member, should consider the subject of ozon
as worthy of its attention and wish me to make a report on
the farther researches I am about to institute on that matter,
I shall undertake the task with the greatest pleasure and attend
in person their next meeting for that purpose.

I am quite sure that a good deal of interesting facts will
yet be brought to light with regard to the subject of ozon.

Should I be able to cross the water, next autumn, I shall
not fail sending you word in time and try to arrive at London
about a week previous to the opening of the meeting.

Mrs. Schoenbein and the Children are quite well and I am
charged to remember them to their constant friend in Albemarle
Street. Pray present my best compliments to your Lady and

believe me

Your's

most truly
Bale Aug. 27. 1844. C. F. SCHOENBEIN.

P. S. Suppose the french translation of my work on ozon
to be finished early enough as to arrive in England at the

/ — 137 —

time of the . meetings of the Association, do you think it
advisable to send a certain number of copies there for sale ?
The work will cost about two shillings.1

Faraday to Schcenbein.

Dover 14. Septr. 1844
MY DEAR SCHOENBE1N

I received your letter etc here where I had come
with my wife for a week or ten days, for a little revival of
general health and where we are kept at present by a sad
accident which happened to my only brother, who was also
here with is wife. In bathing from a machine the sea shook the
machine, he lost his footing, fell and broke two ribs. After
that he dressed and walked to his lodgings and whether in so
doing or at the time of the accident we cannot say, but the broken
ends of the ribs had injured the lungs in some degree, so that
air escaped. This happened last monday and though he is going
on favourably at present, yet it makes us very anxious. — I had
engaged and intended to go to the meeting at York and may still
go, if he goes on well next week; but it is, as you will see,
very possible that I may not be there. However we hope for
the best in his case.

As to Ozone you know now that my bad memory and weak
head cuts me off from many things and amongst others from
that as to working, for I am not able to preserve anything

1 Schcenbein not only wished the results of his researches to. become known>
he also hoped to gain some pecuniary advantage by them, such was his inex-
perience in such matters. Thus de la Rive, in whose "Archives" the French
translation of his memoir appeared writes to him (June 30. 1844): "Mais, mon
cher et illustre professeur, vous etes bien innocent de croire qu'on en vendra . . .
Croyez moi, n'esperez jamais tirer un parti quelconque financier de memoires
scientifiques."

- 138 -

constantly, as I used to do, and only by great management con-
trive to follow up piecemeal some views and pursuits of my own
- my inability to bring them to a quick and distinct conclusion
is to me evidence, I cannot work as I have done. But I read
your letters with great interest and though the subject is very
difficult, still am satisfied you will not leave it till you have
settled it. — I sent them to the Royal Society with the restriction
you made and also shewed them to Grove, Daniell and others. Now
we have your accounts also in the Archives. — When I return
home, which will be for one day if- not more next week, I will
send Your German book to Grove who reads german, I believe,
and ask him about it and extracts from it for York.

It is so many years since I was at any of the meetings
of the Association (except a few hours only at Birmingham or
Manchester I forget which) that L really know nothing of their
nature and whether a book like yours, if ready, would sell there
or not. Judging by my own feelings I should think it would.
Richd Taylor of the Phil Mag whose brother is the treasurer
would be very like to know, but the time is so near that it
does not allow me to enquire and communicate his opionion, so
as to enable any arrangements - - and I am tied up here.

I will take care that either by myself or by your letter
your kind offer to report at the next meeting on the state of
the Ozone subject shall be laid before the proper body.

My wife is with me and desires her kind remembrances; she
had not forgotten your intention of being here this year. Remem-
ber us both to Mrs. Schoenbein and to the growing up flock.
I suppose I should see a difference now to what I saw when

at Basle

Ever My dear Schoenbein

Yours

M. FARADAY.

— 139 —

Faraday to Schcenbein.

Royal Institution 25. Octr. 1844.
MY DEAR SCHOENBEIN

I write a brief note now that the York meeting-
is over (and I have returned from Durham, whither I was sent
immediately after by our Government to be present at an
inquest on the death of 95 men who were killed by explosion in
a coal mine) to say that I stated at the meeting your propo-
sitions or willingness to report to them next year on Ozone
and I found that there was already a resolution on the books
in which they had agreed to ask you to do so. I conclude there-
fore that you will hear to that purport in due course and
I earnestly hope that you will then have a specimen to show
us. If it be possible, I have no doubt you will, for I know
your energy and I never yet knew such energy to fail, unless
nature were against it. - - The next years meeting is to be at
Cambridge - - and the time is settled, which I intended to have
told you but I cannot remember it and cannot remember
where to look for it — my old infirmity — but you very likely
have seen the date and know far more about it than I do. -

I am working but I cannot get on. -- Work is now closed
with me and one thing or another is continually occurring to
prevent progress - - I think I must at last entirely shut out
this world for now my progress is slow and like that of the
tortoise - - a trifle to others stops me altogether.

Remember us both most kindly to all with you. I should

like to see [ ] Basle again.

Ever Your faithful

M. FARADAY.

— 140 —

Schoenbein to Faraday.

Bale November 25th 1844.
MY DEAR FARADAY.

I think it is full time to acknowledge the last
two letters you have been kind enough to address to me.

The official invitation to prepare a report about my resear-
ches on ozon for the british association I received the other
day and certainly I shall not fail complying with the wishes
expressed to me. If possible I shall read that report myself
at Cambridge and perform the necessary experiments. You
know perhaps that I attended the meeting of the italian asso-
ciation at Milan1 to make there a communication on my recent
investigations; unfortunately however the chemical section was
not such as I could have wished it to be, only a few chymists
being there who really deserved that denomination. Amongst
them was Piria2 who suggested the idea, that all the effects
I ascribe to a peculiar principle, "to my ozon", might be due to
nitrous acid. Though the smell of the two substances be as
different as possible and other properties of ozon stated in my
last memoir be not those of nitrous acid, the italian Chymist
stuck rather tenaciously to his opinion. Immediately after my
return from Milan I took up the subject again and made a
series of experiments with the view of getting the most decisive
matter of fact evidence for proving the peculiarity of my prin-
ciple and I think I have perfectly succeeded in putting even
beyond the shade of a doubt that Ozon and nitrous acid have
nothing to do with one another.

My principal proofs are as follows:3

1 Discussion sur 1'ozone. Compt. rend. d. seances du congres scient. de
Milan. 1844. Sulla produzione dell' ozono per via chimica. Milano. 1845.

2 Rafaello Piria was born in 1815 at Sevilla in Calabria. He was professor
of chemistry at Turin where died in 1865.

3 Vide Poggend. Annal. Bd. 63. 1844. p. 520.

1. Two stripes of platinum after having been plunged equally
long, one into atmospheric air mixt up with vapour of nitrous
acid the other into air containing ozon, produce a current the
direction of which is such as to indicate the ozonized stripe to
be the negative part of the circuit. Ozon is therefore a body
more electro-negative than nitrous acid.

2. A stripe of platinum having been negatively polarized
by Ozon looses its voltaic condition and becomes neutral when
plunged for a short time into an atmosphere containing nitrous
acid.

3. Air being ever so much charged with Ozon looses its
peculiar smell, its electro-motive power, its property of destroy-
ing vegetable colours etc. when mixt up with the proper
quantity of the vapour of nitrous acid. The smell of the latter
acid also disappears under the circumstances mentioned.

4. An ozonized atmosphere may be shaken for a great
length of time with peroxide of lead being suspended in some
water without loosing its characteristic properties, whilst air
charged with vapours of nitrous acid and treated in the same
manner becomes inodorous and looses its properties which are
due to nitrous acid.

5. A solution of sulfate of protoxide of iron turns brownish
when shaken with an atmosphere containing only traces of
nitrous acid, whilst the same solution being treated with air,
which happens to be ever so much charged with Ozon remains,
as to its colour, unchanged and yields a whitish precipitate.

6. Blue and humid litmus-paper placed within a strongly
ozonized atmosphere is completely bleached within about 10 — 15
minutes without assuming the slightest reddish tint, whilst paper
of the same description being suspended in vapours of nitrous
acid first turns red and requires hours or even days to become
entirely bleached. And in that case the paper is very strongly
acid i. e. impregnated with nitric acid, whilst the paper bleached
by Ozon is always quite free from any trace of acid.

142 —

7. Phosphorus being (in darkness) introduced into atmo-
spheric air which is only slightly charged with vapours of nitrous
acid, ceases to give out any light and becomes and continues
to be completely dark, whilst phosphorus put into strongly
ozonized air happens to shine even more lively than it does
in common air.

The facts above mentioned clearly show that Ozon is no
acid principle and not to be confounded with nitrous acid.1

I must not omit to mention that the voltaic bearings of
Chlorine and Bromine to nitrous acid are strikingly similar to
those in which Ozon and the last-named acid are standing to
each other. A stripe of platinum ever so powerfully polarized
either by Chlorine or Bromine looses its negative polarity
Avhen plunged into an atmosphere containing vapours of nitrous
acid.

The electro-motive power enjoyed by a chlorine or Bromine
atmosphere is also destroyed if mixt up with a proper quantity
of the vapour of nitrous acid. Such a close analogy as does
exist between Chlorine, Bromine and Ozone appears to me to
be an important fact and to speak in favour of the view I
have taken of the nature of Ozon. Indeed the more I com-
pare experimentally the properties of Chlorine and Bromine
with those of Ozon the more I get struck with the similarity
of the three [principles]. But whatever Ozon may be, it is
at any rate a very interesting substance and just the thing
made to excite the curiousity both of Chymists and natural
philosophers. As to me, I shall do what I can to clear up
the subject.

You may easily imagine that I feel very anxious to hear
soon about the results of your present philosophical doings and
I am quite sure that they will be highly interesting to science,
for allow me to tell you, you cannot take any subject into

1 See Poggend. Annal. Bd. 63. 1844. p. 520: "Ozone 1st nicht salpetrige
Saure".

— M3 —

your hands without getting something excellent out of it, be
it sooner or later.

Mrs. Schoenbein and the Children are quite well and all
of them charge me with their best salutations both to you and
your lady. Pray remember me also very kindly to Mrs. Faraday

and believe me

Yours

most truly

C. F. SCHOENBEIN.

I ardently wish and earnestly hope that your brother will
by this time have entirelv recovered from his serious accident.

Faraday to Schoenbein.

Royal Institution 20. Feby. 1845.
MY DEAR FRIEND

I cannot call to mind whether I wrote to you last,
or whether yours to me still remains unanswered, in which
things my memory becomes more and more treacherous. My
impression is, that I heard from you not very long ago — but
now I cannot find the letter - - as I write it comes to my
mind that I have sent it to Mr. Christie for the Royal
Society - - but the order of these events or the order of the
matter contained in your letters and papers on Ozone I cannot
remember. I have lately been reading the account you give
in the Archives de TElectricite l and am astonished as I read
at the mass of concurrent evidence : it is so great. Surely you
must some day succeed in getting Ozone in quantity - - it
seems whilst reading, as if you were every moment on the
point of doing so. — Yet when I want to recall and arrange the

1 Archives de 1'Electr. T. 5. 1845. p. n.

144 —

many facts and arguments I become altogether confused; my
memory will not serve me and I really become dull sometimes,
to find how in this way I am left behind in the use and appre-
ciation of what others have done. Unless there be some visible
body before my eyes, or some large fact approaching with
force to the external senses, and easy to be produced, to sustain,
by a sort of material evidence the existence of a thought, the
thought fades away and however much I may have endeavoured
to measure out and fix my judgment at the time of receiving
and considering the thought, afterwards I fear to trust to the
conclusion I have come to, because the thought and the consi-
derations in which it was founded have left me. It is only
in this way, I can account for the hesitation I have in making
up my mind on many points of chemical philosophy which are
now before the scientific world.

I have been at work these last 6 or 8 months on the
condensation of gases - - a very tangible subject, giving very
strong impressions of its nature and effects every now and then
by an explosion, though I have met with very few, only two
indeed, and these rather expected and in some degree prepared
for. - - You will have seen the general result in the Annales
de Chimie 1 but I hope soon to send you the paper from the
Philosophical Transactions,2 that is, if I can find a way to send
it. I have been waiting to write to you, that I might send
you at the instant of doing so an account of the condensation
of oxygen, but as yet he will not yield, though I have given
him a pressure of 60 atmospheres, at a temperature of I4O°F.
below o°;3 and now I must lay by the experiments for a while
- for, first I am not well, having been confined almost entirely,

1 Annales de Chimie, T. 15. 1845. P- 257-

2 On the liquefaction and solidifaction of bodies generally existing as gases,
Phil. Trans. 1845. p. 155.

3 Cailletet of Paris and Pictet of Geneva, it will be remembered, succeeded
in liquifying oxygen, but not till 1877, at a pressure of 320 atm. and a tempera-
ture of • — 140° C.

— M5 -

to my rooms for the last three weeks - - next my head is
becoming giddy with the continuance of the investigation -
and finally I must prepare to lecture after Easter. - - Yet I
could not lay down all these things and amongst them my in-
tention of writing to you, without carrying the latter into effect,
though as you will see in a very imperfect manner. But that
does not stop me. I do not expect to make my letters scien-
tific communications, for from the reasons I have given you,
they must ever be unsteady and doubtful in that respect, my
memory of the things thus to be spoken of being so - - but
I write them and especially to you, my dear friend, as kindly
remembrances of good feeling and grateful expressions for
encouragement and happiness, communicated to me from minds
having feelings akin to my own. — With kindest remembrances
to Mrs. Schcenbein and the growing flock

I am as Ever

Your faithful

M. FARADAY.

Schcenbein to Faraday.

MY DEAR FARADAY

I have made up my mind to read my report on
Ozone myself and illustrate the subject by a series of experi-
ments to be exhibited before the chemical section. Intending
to leave Bale the I2th instant I hope to arrive in town Mon-
day the 1 6th and I need not say you, how delighted I would
be to see you on that or the following day. As I shall pass
.the shop of Mr. Watkins (Charing cross), pray send me a few
lines there to acquaint me whether I can have the pleasure of
meeting you at the Royal Institution.
K

— 146

In entertaining the pleasing hopes of shaking very soon
hands with you and paying my humble respects in person to
your Lady I am, my dear Faraday

Your's

most faithfully

Bale June 4th 1845. C. F. SCHOENBEIN.

Aft

Faraday to Schcenbein.

R Institution 14 June 1845
DEAR SCHOENBEIN

We are in town. I do not know, when you
will be here, but I hope to be at home when you call. I shall
be engaged from 4 o'clock on Monday, but I expect my wife
will be at liberty then, as well as before.

Ever Yours

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

Ever since my return from England I have been
rather busy, and tried to make out the relations which Ozone
bears to nitrogen and its oxycompounds. I think I have succee-
ded in ascertaining some facts, being calculated to throw some
light upon the cause of what is called spontaneous nitrification,
and I am inclined to believe, that I have extended a little the
limits of our knowledge regarding the oxycompounds of azote.
As you will learn from some papers l sent to the chemical

1 vide Chetn. Soc. Mem. vol. 3. 1845 — 1848. p. 2. cf. also Poggend. Annal.
Bd. 67. 1845. p. 127 and Bibl. Univ. T. I. 1845. pag. 31.

M7 —

society, my strong opinion is that there exist only three primitive
-degrees of oxidation of nitrogen, NO, NO 2 and NO 4. As to the
hydrate of nitric acid, it is to me NO 4 + HO 2 and agreeably
to that view, I must consider a normal nitrate as NO 4 -t- RO2.
It appears to me highly probable that nitrous acid = NO 3,
is nothing but a loose compound of NO 4 + NO 2, and a normal
nitrite NO 2 + RO2, instead of NO 3 + RO. The reasons for
admitting the existence of a compound = NO 2 + HO 2 seem
to me very strong and some facts stated in the papers before
mentioned, can, to my opinion, only be accounted for by that
admission.

If you think the notice laid by of sufficient importance,
as to interest the Royal Society, you will oblige me by laying
it before that body. If not, you have full liberty, either to
insert it (perhaps in the shape of a letter addressed to you)
in the philosophical Magazine, or read it before the chemical
Society. At any rate, I should • be very glad indeed if you
would favour me with your opinion about the subjects alluded
to in this letter.

Mrs. Schoenbein and the children are quite well and charge
me to offer both to you and Mrs. Faraday their kindest regards.
In the pleasing. hopes of hearing soon good news from you,

I am my dear Faraday

Yours most truly

Bale Oct. 2Oth 1845. C. F. SCHOENBEIN.

P. S. I had nearly forgotten telling you, that I have made
a good many experiments on the bleaching powers of atmos-
pheric air, ozonized by the means of phosphorus.

The results obtained with linnen are such as to make me
believe it possible to bleach oeconomically into ozon and
establish a process upon that principle, being superior to any
hitherto employed. One of the bits of linnen laid by was
bleached with the only means of ozone within a fortnight, the

— 148

other is a pattern of the raw linen.1 Do you not think that
something might be made out of that affair? I am told that
a german Chymist, who has got some knowledge of my process,
is about to take out a patent upon it in England. He ought
to be prevented from doing so, as he has no right for it.

Faraday to Schcenbein.*

Brighton 13 Nov. 1845
MY DEAR SCHOENBEIN

I received yours of the 2Oth Ultimo and have
sent off the paper to the Royal Society2 with my humble
opinion, that it is good. You know I am not (and have no
time to be) in the Councils. Your bleaching is very remar-
kable and good.

At present I have scarcely a moment to spare for any
thing, but work. I happen to have discovered a direct relation
between magnetism and light, also electricity and light, and the
field it opens is so large and I think rich, that I naturally wish
to look at it first. — I have sent one paper to the Royal3 and
am about another. - - I actually have not time to tell you
what the thing is, - - for I now see no one and do nothing
but just work.

My head became giddy and I have therefore come to this
place, but still I bring my work with me. When I can catch

1 The strips of linen are no longer attached to the letter.

2 Phil. Trans. 1846. p. 137.

3 For fully forty years he searched after the relation of electricity and mag-
netism to light. In 1845 it was that while experimenting with heavy glass
through which he passed lines of magnetic force and, at the same time, a
polarized ray of light he proved that magnetic force and light have relations to
each other. As a result he sent his igth series of researches in electricity to
the Royal Society (Phil. Trans. 1846. p. i): "On the magnetic affection of light
and the illumination of the lines of magnetic force" (see Bence Jones vol. 2. p. 195.)-

— 1 49 —

time I will tell you more. But in the midst of all this philo-
sophy, do not forget to remember both my wife and myself to
Mrs. Schoenbein. The thought of being quietly with you in
the mountains, or on the river forms a strange contrast with
my present most active state.

Ever, Dear Schoenbein

Your grateful friend

M. FARADAY.

You can hardly imagine how I am struggling to exert

my poetical ideas just now for the discovery of analogies and

remote figures respecting the earth, sun, and all sorts of things

- for I think that is the true way (corrected by judgment)

to work out a discovery.

M. F.

Aft

Schoenbein to Faraday.
MY DEAR FARADAY

I am much obliged to you for the very kind
letter you favoured me with some weeks ago and you may
easily imagine that its contents, vague and general as they
were, proved highly interesting to me and set my curiousity
on tiptoe. As far as I can judge, your last discovery will
eclipse all your former ones, brilliant as they are.

The other day I had a letter from de la Rive ', who I see
entertains as yet the opinion, that the action excited by mag-
netism upon polarized light is not directly due to that force
but to a change brought about in the molecular arrangement
of your glass by magnetism.2 It seems, that the same view

1 Oct. i2th 1845.

J "Elle est d'une grande importance," he writes, though he does not agree
with Faradays interpretation of its cause, for he continues "Je crois que 1'aimant
ou les courants electriques exercent leur action non sur la lumiere, mais sur les

of the case is taken by the parisian philosophers. I am as
yet too little acquainted with the particulars of your discovery,
as to be capable of forming a correct notion about it, but the
little I know of it makes me strongly believe, that de la Rive
and the french are wrong and you in the right. It appears
to me that the prime focus of the case is such, as to lead
every impartial philosopher to the conclusion you have drawn
from the fundamental phenomenon ascertained by you. How
the molecular arrangement of a bit of amorphous glass can
be changed by magnetical action in such a way, as to make
that medium act upon a beam of polarized light in the manner
you have observed, is a thing, which, I openly confess it, goes
beyond my conception. I am however confident that you
will not be long in bringing forward such an overwhelming
mass of the strongest matter of fact evidence in favour of the
view you have taken of the subject, that all those little objec-
tions, which I am afraid do not entirely originate in the love
of truth, will be easily reduced to what they really are. I hail
in your discovery, the beginning of a new era in the history
of philosophy, and am at any rate sure that it will ultimately
lead to great things.

As to my little self I have of late turned entirely Chymist,
being almost exclusively occupied with researches on nitric
acid and the other oxy-compounds of nitrogen, subjects which
appear to be closely connected with my Ozone business. As
to nitric acid, I am now almost quite sure that it does not
exist and that what Chymists call the first hydrate of that
imaginary compound is NO 4.+ HO 2 and not NO 5 + HO, much
less NO e + H. The normal nitrates exempl. gr. nitrate of baryte,

molecules du cristal et que c'est un phe'nomene du meme genre que les pheno-
menes mole"culaires de vibration qui resultent sur les corps non magnetiques de
1'action des currants discontinue's."

Grove in a letter dated Nov. 16. 1845 writes to Schrenbein : "Faraday has
made a great dicovery .... I am anxious to know what the point is that has
enabled him to succeed. I tried last year for several weeks and failed."

nitrate of lead, are to me NO 4 + BaCh, NO 4 + PbO2 etc.
Our poor late friend Daniell l would be very sorry to hear
such heretical doctrine.

Before long I hope to be able to reassume some voltaic
researches regarding electrolysis, having a notion, that much
is to be done yet in that branch of science, in spite of your
beautiful doings in that line. - - Whether I shall succeed in
establishing what I think at present to be true, I can of course
not say; I am however confident that my endeavours will not
prove entirely fruitless.

They say that Dr. Neef2 of Francfort has made a discovery
establishing also a connection between light and electricity,3
but I dont know the particulars about it. I confess however
that I doubt as yet of the correctness of the fact.

Pray present my best compliments and Mrs. Schoenbein's
also your Lady and believe me

Yours

most faithfully
Bale Dec. 30. 1845. C. F. SCHOENBEIN.

Schcenbein to Faraday.
MY DEAR FARADAY.

Amid the glories of your really grand and admirable
discovery I venture to trouble you with a comparatively insigni-
ficant and prosaic subject. I have of late also made a little
chemical discovery which enables me to change very suddenly,

1 J. F. Daniell it will be remembered died on March 13. 1845.

2 Christian Ernst Neef Ph. D. physician in Frankfort on the Main where
he was born in 1781 and died in 1849.

3 Schrenbein is alluding to his paper bearing the following title "Uber das
Verhaltnis der elektrischen Polaritat zu Licht und Wa'rme" which is printed in
Poggend. Annal Bd. 64. 1845. p. 414.

152

very easily and very cheaply common paper in such a way, as
to render that substance exceedingly strong and entirely water
proof.1 Inclosed you will find a specimen of paper of the said
description and a sample of common paper, out of which the former
has been prepared. In throwing the prepared paper into water
you will easily convince yourself that it stands the action of that
fluid for any length of time, without loosing in the least its leather-
like toughness. Paper which has been lying in water for many
days is still as tenacious as it was in the beginning.2 The
same sort of paper being written allows to be laid up in water,
strongly acidulated with muriatic acid and freed in that way
from its ink, without receiving the slightest injury, or leaving
the least trace of the letters. The most brittle and thinnest
paper, after having for a few seconds only, been exposed to
the action of my agent, becomes very tough, substancial and
water proof.3 Hence it follows that in employing my process,
out of the same quantity of rags, a much larger number of
sheets of paper can be manufactured than it is possible to do
in following up the present way of making paper,4 without dimi-
nishing the strength of the production. Another essential ad-
vantage connected with my method of preparing paper is, that
the injurious effects produced by chloride of lime are entirely

1 On March 5th 1846 Schoenbein writes to Berzelius acquainting him at
some length with the properties and mode of preparation of his paper, and en-
closes specimens of it to illustrate his communication. Kahlbaum, Briefwechsel
Berzelius-Schcenbein. p. 80. By citing a few parallel passages from his letter
to Berzelius we have endeavoured to illustrate the similarity of the terms in
which he has in each case put his ideas into words.

3 However long it is exposed to the action of water it retains its coherence,
ibid. p. 8 1.

3 Thin and extremely brittle paper acquires by my process a firmness and
toughness equal to that of much thicker ordinary paper of the toughest texture,
ibid. p. 8l.

4 ... and moreover my process has the advantage, that it allows of a much
larger number of sheets being made from the same quantity of rags, than in
the ordinary method of paper making, ibid. p. 8 1.

,~ — 153 —

paralysed by it. My prepared paper can be easily written and
printed upon. Paper enjoying the properties mentioned is, to my
opinion, a valuable substance and in many respects very superior
to common paper, it ought therefore to be manufactured on a
large scale. My process of giving common paper those properties
being of a very easy application and very cheap too, I do not
see any reason why, it should not be made use of at once. I am
of course desirous of turning, if possible, the discovery alluded
to to some account in favour of a certain poor schoolmaster
of Bale, who in the interest of science is rather anxious to get
a little more independent, than he is now. To obtain that end,
I ask you the favour to grant me your kind advice regarding
that affair. You are perhaps connected with some first-rate
british paper manufacturer or it lies in your power to put me
in communication with one or some of them.1

Before long you will hear of some other little chemical
exploits I have of late performed; they consist principally in
remarkable transformations of ,the most common vegetable sub-
stances. These and other things I found out in making researches
on my favorite subject, ozone.

Pray present Mrs. Schoenbein's compliments and my own
to your Lady. Favo[u]r me soon with an answer to this letter

and believe me

Your's

most sincerely
Bale Febr. 27. 1846. C. F. SCHOENBEIN.

1 Concerning his offer to give the Swedish Government instructions con-
cerning this new method of his in the interest of the paper industry of that
country Schcenbein does not seem to have received an answer on the part of
Berzelius.

The only encouragement Grove could give him, after enquiring in several
quarters, was that it might be worked into something, if it could be applied
very cheaply to brown paper, for outer wrappers. Letter to Schoenbein, Aug. 16. 1846.

— 154 —

Faraday to Schcenbein.

R. Institute 5 March 1846.
MY DEAR SCHOENBEIN

Excuse my sending you a very short letter, but
I am just now burdened with business and thought and my
head often aches. - - I received your letter the day before
yesterday and sent it at once with the specimens to Mr. Dicken-
son one of our largest paper makers (whom I slightly know)
and desired him, if the result interested him, to communicate at
once with you. Of course I have not as yet had time to hear
any thing, [even] if he should think of writing to me.

I did not examine your paper1 but sent it off at once.
It reminded me of some that I had seen some years ago, in
which the paper had been passed through a clean infusion of
tannin and so had its gelatine size converted into leather.
That process at one time looked very promising, and I do not
know, why it was not pursued, except it was because, soon after,
gelatine was to a great extent dismissed as the sizing materia^
and resin and oil in the form of soap, decomposed by alum,
substituted for it.

I should be glad to send you a copy of my last papers
but our Royal Society is very slow and I see many descriptions
of results obtained in France, Italy and elsewhere — all of which
are in my papers of last year - - but which have been reob-
tained by those who have worked on the notices.

I am also puzzled about the best way of sending them to
you with certainty.

Our best thanks and remembrances to Mrs. Schoenbein and

her flock

Ever Yours

M. FARADAY.

1 Schcenbein also sent specimens of his paper to Poggendorff who suggests
employing it for making window panes, and writes as follows (May i, 1846) "Das

r I55

Schoenbein to Faraday.
MY DEAR FARADAY

Don't take it ill if I venture to trouble you once
more with my little affair, I flatter myself however that the
interest which seems to be connected with the subject will
excuse my intenseness. To give you an idea of what may be
made out of vegetable fibre, I send you a specimen of a trans-
parent substance which I have prepared out of common paper.
This matter is capable of being shaped out into all sorts of
things and forms and I have made from it a number of beauti-
ful vessels. The first perfect one I obtained is destined to be
sent to the Mistress of the Royal Institution, as soon as a con-
venient opportunity will offer itself for doing so and I shall
ask the Lady mentioned to preserve it as a sort of scientific
keepsake. In taking the liberty to forward to you a little
piece of my transparent paper, I must beg you to keep it
entirely to yourself and consider it as a stric[t]ly confidential
communication, and I ask you this piece of favour because my
secret with regard to my water proof paper is connected with
that substance. I shall however be obliged to you if you will
have the kindness to exhibit it before a Friday Meeting of
the Royal Institution.

There is another point about which I take the liberty to
ask your kind advice. I am enabled to prepare in any quan-
tity a matter which, next gunpowder, must be regarded as the
most combustible substance known. So inflammable is that
matter, that on being brought in contact with the slightest spark,
it will instantly be set on fire, leaving hardly any trace of

glasartige Papier ist in der That sehr schon, und ich mochte wiinschen, dass Sie
ein solches dick darstellen konnten, um es als Fensterscheiben anzuwenden." In
the same letter he advises him to apply to the directors of the Prussian Bank
as his paper might with advantage be employed for the manufacture of bank
notes.

- i56 -

ashes and if the combustion be caused within closed vessels
a violent explosion takes place. That combustible substance
is, as I will confidently tell you, raw cotton, prepared in a
simple manner, which I shall describe you hereafter. I must
not omit to mention that water has not the least action upon
my matter, i. e. that it may be immersed ever so long in that
fluid, without loosing its inflammability, after having been dried
again. A substance of that description seems to be applicable
to many purposes of daily life and I should think that it might
advantageously be used as a powerful means of defense and
attack. Indeed the congrevian rockets l can hardly be more
combustible than my prepared cotton is. What shall I do with
that matter ? Shall I offer it to your government ? I have in-
closed a little bit of that really frightful body and you may
easily convince yourself of the correctness of my statements
regarding its properties.2

As to my prepared paper you will be interested in lear-
ning that it proves to be a highly electrical substance as will
appear from the following facts.3

1. In putting half a dozen of sheets one above another
and passing once or twice the hand over the uppermost one,
all the sheets will stick together so, as if they had been joined
by the means of a glutinous matter.

2. The experiment being made in the dark, a prepared
sheet rubbed becomes luminous, and on separating two excited

1 The Congreve rocket was invented for use in war by Sir William Congreve
(born 1772 in Staffordshire, died 1828 at Toulouse). When used for bombard-
ment it was armed with a combustible material, inclosed in a metallic case, which
is inextinguishable when kindled, and scatters its fire on every side.

8 Berzelius writing on Nov. i8th 1846 congratulates him on his discovery
in the following terms: "Allow me to convey to you my sincerest compliments
on this interesting and significant discovery, the practical nature of which you
promptly understood how to appreciate". Kahlbaum, Briefwechsel Berzelius-
Schcenbein. p. 87.

3 See also: "Uber elektrisches Papier". Poggend. Annal. Bd. 68. 1846. p. 159.

,- — 157 —

sheets from each other a great number of beautiful sparks are
seen breaking out between the paper.

3. An excited sheet held over the head makes the hair
stand on end.

4. The disc of the common electrophor placed upon an
excited sheet, lying upon the naked table, yields sparks of some
inches in length.

5. A couple of sheets being lively rubbed develop a strong
odour of ozone.

6. The electricity developed by my paper is the nega-
tive one.

The facts stated render it almost certain that out of
my paper powerful electrical machines may be constructed,
which will perhaps replace the plate arrangements. I shall
soon have a paper machine. I need hard[l]y say that the
transparent substance is still more electrical than the prepared
paper.

Before I conclude I must offer you my grateful thanks
for the kindness with which you put me in communication
with Mr. Dickenson. Before entering into any negociation
with him, I will wait a little longer for other offers, for it seems
to me that he has not quite fully appreciated the qualities of
my paper.

Don't you think the Bank would like to have their notes
made of that paper? From the specimens of what we call
silkpaper laid by, you will see how much the prepared bit
surpasses in strength and impermeability the common one.
I inclose also a specimen of paper having been very slightly
prepared and being distinguished by its beautiful play of colour.
Perhaps some use may be made of it.

I am overcurious to learn more particulars regarding your
investigations and it is indeed a great pity that the regulations
of the Royal Society cause such a delay in publishing scientific
results communicated to that body.

- I58 -

Mrs. Schoenbein and the girls are doing well and beg me
to present to you and Mr. Faraday the kindest regards.
Believe me my dear Faraday

Your's most faithfully
Bale March 18. 1846. C. F. SCHOENBEIN.

NB. To shelter the transparent matter from injury I have
put it between some bits of prepared paper glued together
by wafers at their four corners. - In drying a little the
prepared stripes Nr. I and II you will easily recognise their
electrical condition by rubbing them with the hand over a
common bit of paper.

Schoenbein to Faraday.
MY DEAR FARADAY

A favo[u]rable opportunity is just now offering
itself for sending you some larger bits of my prepared paper.
They will enable you to try its electrical power and other
qualities. The degree to which it can be excited will perhaps
astonish you and I should think that on this account it will
prove an acceptable substance to electricians.

Ever Your's most truly
Bale March 23. 1846. C. F. SCHOENBEIN.

NB. My prep, paper being in a completely raw state it
-of course cannot look well. The thin one seems to be very
fit for bank notes.

I open the letter to tell you that I have just now made
some preliminary experiments about the explosive power of
my prepared cotton and found that it is rather considerable.
A common soldier's gun charged with the eighth part of an
ounce only, caused a pretty strong explosion.1 S.

1 cf. letter to Berzelius June loth 1846. Kahlbaum, Briefvvechsel Berzelius-
•Schoenbein. p. 85.

— 159 —

It was most likely the first time that a gun had been fired
by the means of cotton. That substance so advantageous to
brother Jonathan might one day prove dangerous to him,
particularly as an easy means to cause wholesale conflagrations.

Schcenbein to Faraday.

MY DEAR FARADAY

Mr. Prevost1 is kind enough to charge himself
with the little box containing a liliputian bell made out of my
transparent paper. It is however, not that mentioned in my
last letter to you and destined for Mrs. Faraday. This little
piece of chemical workmanship must find its way to Albemarle
Street through another channel and at another time.

Your's

very truly

Bale, March 24 1846. C. F. SCHOENBEIN.

Schcenbein to Faraday?

(Aug 22. 1846)

MY DEAR FARADAY

Having learned from Grove3 the great loss you
had to suffer some days ago4 I hardly dare to ask you whether

1 J. L. Prevost, a genevese emigre who settled in London and became partner
-of the firm Maurice Prevost & Co.

* The letter bears no date; the postmark is Aug. 22nd 1846.

3 In a letter dated Aug. 16. 1846. He merely writes: "Faraday's brother
•was killed last week, being thrown from his gig."

4 Faraday writes to Mrs. Faraday: ''It is supposed the horse must have
been frightened, or run against a post, but the cart was overturned, my poor
brother cast out. and so injured on the head as not to recover his consciousness
again." He died Aug. 13. 1846. Bence Jones vol. 2. p. 226.

— i6o

one of these days I could see you, and communicate with you
on some important subject. Pray remind me kindly to Mrs.

Faraday and believe me

Yours

very truly

6 Golden Square C. F. SCHOENBEIN.

Regent Street.

Faraday to Schcenbein.

Tunbridge Wells. 24 Aug 1846.
MY DEAR SCHOENBEIN

I received your letter here and though sad events
make me unable to profit at once by your presence in London,
yet I should like to see you if it can be. Now I shall be in
town next Monday morning (alone) and if you should be in
town and would perhaps like to see an experiment or two
on the Magnetic action of bodies, I would undertake to show
them to you. In that case I would stop in town an hour or
two and devote the morning to you and we would experiment
and talk from any hour you please, beginning at 9 o'clock A. M.
- Besides I want to talk with you about the paper etc.

Write me a note to the Institution saying what you will
do and the hour and send it to the Royal Institution and it will
be forwarded to me wherever I am.

Mrs. Faraday unites in kind wishes to you

Yours affect.

M. FARADAY.
titf

Schcenbein to Faraday.
MY DEAR FARADAY

I have just recived your kind note and am glad
to learn from it that there is a chance of seeing you here. I

— 161 —

shall not fail being at the Royal Institution Monday morning
and most happy to witness some experiments and have some
talk with you. The affair which has brought me over to Eng-
land refers to my explosive cotton, which I have so much im-
proved that it has all the appearance of becoming a dangerous
rival to gunpowder. As to its explosive powers "gun cotton", as
I call it, is very superior to powder ; in given cases one part of
it does the work of four parts of gun-powder and under the
most unfavourable circumstances the force of gun-cotton is as
2 : i to that of gun powder. In the course of the two last months
I have made many experiments with cannons, mortars, rifles etc.
and obtained results which I am allowed to call highly satis-
factory. The same way be said with regard to blasting rocks.1

The residuum left by gun cotton amounts to nothing; it
does not heat perceptibly the fire arms, nor produce any smoke,
if prepared to its maximum. The way of preparing it is simple,
cheap, and without any danger of explosion. I myself and
many friends who have seen the effects of the matter are in-
clined to believe, that gun cotton will be made use of in many
cases, where gun powder is at present employed.

Now the object of my journey to England is to see, whether
something might be done with that explosive matter2 and I

1 On June 20. 1846. He writes to Berzelius: "I have several times used
my gun cotton for blasting in a tunnel which is being made through shell-lime-
stone in our neighbourhood and in the opinion of the workmen it was as effective
as three times the quantity of powder." Kahlbaum, Briefwechsel. p. 85.

2 The results of his application for patents are mentioned (at a later
date) by Grove at different occasions. Thus on Febr. i. 1847 he writes: "I have
drawn up an agreement by which you are to have one fourth part of the profits
of the working of your invention within the States of Mexico. Col. Colquhoun
says he thinks you will make more by your Mexican, than by your English patent.
I hope you may realize a good fortune by both." In a letter of an earlier date
(Nov. 13. 1846) he writes : "1 have a letter from M. Louyet Professor of Chemistry
Brussels : he is anxious to patent your gun cotton there. He says he is informed
that the government will not grant anything and therefore if you are inclined to
patent it, he will get the patent taken out and worked, and arrange with you
for your share of the profits, as you may agree."

1 62

shall take the liberty to take some quantity with me to the
Institution to show you the effects. It is not unlikely that some
experiments will be made at Woolwich to prove the power of
my production. Hershel has already taken some steps to that
effect,1 and you will perhaps be able to give me some hints
respecting the affair.

In hoping to see you monday next, I beg you to present
my humble compliments to Mrs. Faraday and believe me

Your's

very truly

6 Golden Square C. F. SCHOENBEIN.

25. Aug. 1846.

Faraday to Schcenbein.

Royal Institution 18. Deer. 1846.
MY DEAR SCHOENBEIN

I really feel as if I wished to know whether you
are yet in the flesh or whether you have gone off altogether
like a piece of your own cotton.2 I can never hear of your
name now, except from some one who has a commercial value
attached to it, either one way or the other; and nobody suggests
you to my mind as that dear, quiet, lively, philosopher, and
yet somewhat sentimental friend that I so much like to think
of. Your name is now a name of power: - - it always has

1 In October 1846 the British Government voted a grant of £. 1500 for
the purpose of experiments with gun cotton; these took place on Oct. 9 1846,
in the presence of Schoenbein himself and, among others, of Sir James Hogg,
President of the East India Company, and were very successful.
•• = r. * This reminds, one of an expression employed by Grove in a letter to
Schcenbein (Aug. 31. 18481. After giving want to his great disappointment at
Schoenbeins not attending the british Association at Swansea, Groves native place,
he says: "All chemists were there, but no Schoenbein. You ought to be "hoist
with your own petard" i. e. blown up with gun-cotton."

been a name of mental power; - - but now it is powerful in
the gross things of this world: - - and it often makes me smile
when I hear people talking of Schoenbein - - I mean of the
Gun-cotton Schoenbein, to think how little they know of his true ^
spirit and pleasant ways. Each sticks something on to the
name like that he would have himself desired to have it, had
he been the Gun-cotton man. But joking apart I am glad
to think, that, now there is some, and I suppose a great, chance
that a portion of the good things of this life will fall to your
share, who have so well deserved them ; and in causing them,
have done so, not for their own sakes merely but in the true
and correct pursuit and love of science. Long may you and
yours live to enjoy, first a contented and happy mind, and
with it those temporal goods which God may think fit to give you.
I suppose you heard of Mr. Lancaster's accident with some
Gun-cotton prepared by a Mr. Taylor. His gun burst and it is
well he was not more than slightly wounded in the arm.1 It
was the time of his going out next after you and I and he
were together. - - I hear talking all round me and see adver-
tisements, from the parties representing you, continually in the
papers; but as you know I do not meddle with any thing
commercial, so I know little or nothing of what has been done
or is likely to be done. - - I hope we shall some day have
a simple and philosophical account of the substance; - - its
analysis, and above all the philosophical views and reasonings
you connect with it; for I know, by a few words which you
dropped that you have such. -- Mr. Brande2 is going to give

1 Berzelius in a letter to Schcenbein (March 12. 1847) mentions that at a
meeting of the Royal Academy of Stockholm serious disasters were reported to
have occurred at Brunswick, caused by the bursting of rifles through too power-
ful a charge of gun cotton. Kahlbaum, Briefwechsel, p. 91.

* William Thomas Brande, professor of Chemistry at the Royal Institute
was born in 1788 in London. He succeeded Sir Humphry Davy in 1813; from
1854 he held the post simultaneously with Faraday. He died in 1866 at Tun-
bridge Wells.

164

an account of Gun-cotton on the first Friday Evening here,
and thus I expect to get a summary of that which is known.1
I have worked since you were here, but have nothing par-
ticular as yet: - - and now I cannot work, for I am laid on the
shelf for a while. - - My health generally is very good; but
an affection has come on in the knee, like that I had in the
other leg ten years ago (too much fluid in the joint;) and so I
am obliged to bandage it, and incline it, and lay it up in a stool
or couch: -- and in fact nurse it, and consequently the body
and head and hands belonging to it. I am obliged to write
now over a table ; and that to one who has heretofore written
and done all things standing, is troublesome, because it brings
on oppression of the lungs and head. So I think I will even
cut short this rambling letter, which is just intended to come
as a little chat, and to produce, as I hope it will soon, some
account of your whereabouts; that I may know where my
old friend is, and what he is about. Do not forget in the midst
of your other thoughts to speak of me with all kind feelings
to Mrs. Schcenbein and the family. If things run upon velvet I
should not wonder if you brought somebody with you next time.

Ever Dear Schoenbein Yours Truly

M. FARADAY.

Schoenbein to Faraday.
MY DEAR FARADAY

I am very much obliged to you for the really
kind and friendly lines you favoured me with the other day
and I won't be long in acknowledging them. As to the late
doings of your humble friend they have been of very little

1 Grove at the meeting of the British Association at Southampton, Sept. 1846
read a paper on Schoenbeins gun-cotton with experiments some of which were
most effective ; for example when he exploded guncotton while in contact with
powder, without igniting the latter.

- i65 -

consequence ever since my return from England and Mrs.
Schcenbein's having been delivered of a girl six weeks ago
has interfered with my usual occupations and kept me out of
my laboratory. And to tell you the truth my scientific zeal
has been checked by a variety of annoying occurrences con-
nected with the gun cotton affair. True it is, my knowledge
of the World has been vastly increased these last four or five
months, but I am afraid that my esteem for mankind has not
grown in the same ratio. I could tell you a great many things
of an incredible description, but I will not trouble you with
datailing facts which I should like never to have become
acquainted with myself. So much however I must say that by
the occurrences alluded to my temper which is usually not much
liable to be ruffled and the placidity of my mind have been
suffering these many months. I hope however that time, the
powerful physician, will remedy what has been spoiled. As you
take some interest in the substance I had the fortune, or mis-
fortune, to find out and to which I have given the name "gun-
cotton", you will allow me to communicate to you some facts I
ascertained previously to having made the noisy discovery. You
are perhaps aware that my researches on Ozone led me to think
NO 5 a chemical non-entity and consider what they call mono-
hydrate of nitric acid not as NO 5 + HO but NO 4 + HO 2, the
normal nitrates as NO 4 -f ROs, SO 3 4- HO as SO 2 + HO 2 and
Rose's Compound 2 SO 3 -f NO 2 as SO 2 + NO 4. Those views
and some other considerations made me conjecture that on mixing
together 2 (SO 2 + HO 2) with NO 4 + HO 2, 2 SO 2 -*• NO 4 would
be formed and 3 HO 2 either eliminated or brought into a loose
state of combination with Rose's bisulphate of binoxide of
Nitrogen. Supposing such a reaction to take place, I of course
inferred farther that the acid mixture mentioned would act as
a highly oxidizing agent, as a sort of aqua regia in which
HO2 replaces Chlorine; I likewise conjectured that in taking
away by the means of oxidable substances HO 2, supposed to

1 66

exist in the said acid mixture, the latter would exhibit the
properties of Rose's Compounds.1 It may be that those hypo-
thetical views are as wrong as they militate against the notions
Chymists of the present day are entertaining regarding the
nature of nitric acid etc., but in putting myself under their
guidance I succeeded in ascertaining a number of facts which
appear to me to be entirely novel and not void of scientific
interest, facts too which seem to speak rather in favour of my
hypothesis. The statements I am going to make will show
how far I am entitled to say so. If some flores sulphuris are
stirred up with a mixture of nitric acid of 1.5 and common
oil of vitriol or chemically pure sulphuric acid of 1.85, a lively
disengagement of sulphurous acid gas will issue, the tempera-
ture rise, the sulphur disappear and a colourless liquid be left,
out of which binoxide of nitrogen is abundantly disengaged,
when mixed up with water. That fluid exhibits in other terms
all the chemical bearings of a solution of Rose's 2 SOs + NOs
in the monohydrate of sulphuric acid. The action described,
i. e. the formation of sulphurous acid, takes place even at a
temperature of 32° F. (For farther particulars I take the liberty
to refer you to a paper which will soon be published in
Poggendorffs Annalen on the subject.2) I have found out that
if one drop only of nitric acid of 1.5 be mixed up with four
ounces of oil of vitriol, flores sulphuris, being added to that
mixture, will cause a still perceptible formation of sulphurous

1 H. Rose, professor of Chemistry at Berlin, in 1839 contributed to Poggend.
Annal. (Bd. 47. p. 605) a paper entitled: "Uber eine Verbindung der wasserfreien
Schwefelsaure mit dem Stickstoffoxyd," in which he describes a compound which
we to day call nitrosyl sulphuric acid = SOz^^or SO2 OQ\^. On leading a
current of nitric oxide, carefully dried by means of calcium chloride, into an-
hydrous sulphuric acid, the oxide is absorbed and a compound produced in the
form of white crystals, which when thrown into water decompose readily, giving
off dark red fumes. From the results of his analyses Rose gives it a formula
"made up of one atom of sulphuric acid and one atom of nitric acid," i. c. S + N.

2 Uber die Salpeter-Schwefelsaure und deren Verhalten zum Schwefel, Selen,
Phosphor und Jod, Poggend. Annal. Bd. 70. 1847. p. 87.

- i67 -

acid gas, which may be easily shown by holding, some paste
of starch mixed with jodide of potassium and rendered blue
by Chlorine over the vessel, which holds the acid mixture.
The blue colour of the paste will be discharged under the
circumstances mentioned. Phosphorus and Selenium are likewise
readily oxidized in our mixture at very low temperatures chan-
ging the latter such as to render it capable of disengaging
binoxide of nitrogen on being mixed with water. Even Jodine,
exhibiting so little tendency to unite with oxigen, is at low
temperatures readily oxidized in our acid mixture, being partly
transformed into jodic acid, partly into a lower degree of
oxidation (most likely into the jodic oxide of Millon1) which
unites with sulphuric acid and remains dissolved in the acid
mixture. A good deal of jodic acid contaminated with some
sulphuric acid is precipitated. To obtain the reaction described
it is required to shake powdered jodine with the nitro-sulphuric
acid without applying any heat. (For farther particulars see
the paper alluded to.)

After having made many experiments with inorganic sub-
stances and the acid mixture and recollecting the curious
bearings of olefiant gas2 to Ozone I tried a number of organic
matters and began writh common sugar. That substance being
in a powdered state at a temperature of about 36° F was stirred
up with a mixture of one volume of nitric acid of 1.5 and
two volumes of oil of vitriol. The sugar first assumes a semi-
transparent appearance but after a few* minutes stirring gathers
up into a lump of a very tough paste which sticks to the
stirring rod and can easily be removed from the acid mixture.
On kneading that paste with warm water all the adhering acid
particles are taken away and a substance is left, enjoying all

1 Nicolas Auguste Eugene Millon, professor of Chemistry at the Military
Hospital of Val-de-Grace at Paris. He was born in 1812 at Chalons sur Marne
and died at St. Seine-l'Abbaye (Cote d'Or) in 1867. See Memoire sur de nou-
velles combinaisons oxygenees de 1'iode. Annul, de Chimie, T. 12. 1844. p. 353.

2 Basl. Ber. Bd. 7. 1845. p. 7.

1 68

the essential properties of resinous matters. It is nearly
tasteless, yellowish white, insoluble or nearly so in water, solid
and brittle at low temperatures, easily fusible; at the common
temperature it can be malaxated, assuming a most beautiful
but transient silvery hue, easily soluble in essential oils, ether
etc. and going off like gunpowder when heated to a certain
degree. Some more statements regarding that curious matter
will soon be published in PoggendorfFs Annales.1 After having
gone so far, the discovery of those substances of which I took
the liberty to send you specimens last March and of which they
talk now so much in Paris, was a matter of course. Guncotton,
transparent paper, fulminating paper etc. made rapidly their
appearance one after the other and I must not omit to state
that all those results were obtained in the months of December
(1845), January and February (1846). As to gun cotton I send
you an account of an analysis made by Mr. Bottger in Frank-
furt who used acetic ether as a solvent to obtain that fulmi-
nating matter in a chemically pure state from common gun cotton.
Hundred parts ot pure guncotton contain 2

found calculated

Carbon 27.43 28.1

Hydrogen .... 3.54 3.1

Nitrogen 14.26 14.5

Oxigen 54.77 54.3

After Ballot's Analysis Xyloidin contains

found calculated

Carbon 37.29 37.31

Hydrogen .... 4.99 4.84

Nitrogen . . . . 5.17 5.76

Oxigen 52-55 52.09

1 Cber eine eigentumlicheVeranderung des Zuckers, durch Salpeter-Schwefel-
saure bewerkstelligt. Poggend. Annal. Bd. 70. 1847. P- Io°-

2 Dr. Pettenkofer's numbers differ somewhat from these. He finds for
C 26.26 H 2 75 N 4.52 O 66.47, from which he calculates the following formula
for gun-cotton Ci2H7NOj5. (Augsburger Allg. Zeitg. Dec. 12. 1846.)

169 —

Hence it appears that the chemical composition of gun
cotton differs essentially from that of Braconnot's1 xyloidin, which
latter substance besides, as you well know, easily dissolves in
strong acetic acid and muriatic acid and is thrown down by
water from such solutions whilst gun cotton is not acted upon
by those acids. Nitric acid of 1.38 readily takes up Xyloidine
not to be thrown down again by water, whilst the same acid
has no action upon gun cotton.2

It is perhaps not unknown to you that the french philo-
sophers took no notice of gun cotton sooner than after the
meeting at Southampton 3 and were in the beginning rather in-
credulous as to the reality of that substance. But when there
could exist no longer any doubt about the matter it was
declared by more than one Chymist to be Braconnot's Xyloi-
dine and consequently the invention of the poudre-coton claimed
as a french one.4 Silently I smiled at the assertion, knowing
it to be unfounded and so very easy to find out the mistake.
Indeed in the middle of last month the french academy was
informed that as to properties and composition, gun cotton
essentially differs from Braconnet's Xyloidine and the former
is made up of what the have called Pyroxyloidine. Though
the existence of such a substance had even not in the slightest

1 Henri Braconnot was born at Commercy in 1781 and died at Nancy in
1855. cf. Annal. d. Chimie I. 52. 1833. p. 290. De la transformation de plusieurs
substances vegetales en un principe nouveau (Xyloidine).

2 The difference between gun cotton and Xyloidine forms the substance
of a letter to Mr. Louyet (Nov. 17. 1846) an abridgment of which appeared in
Compt. Rend. T. 23. 1846. p. 983.

3 Grove, it will be remembered, read a paper on Schoenbeins gun-cotton
at the British Association meeting at Southampton 1846. vide p. 164. note I.

4 J. Pelonze also, at a meeting of the French Academy in 1846, said he
had 10 years ago found, that in a solution of amidon, wood fibres, paper, rags
etc. in cone, nitric acid, xyloidine is formed when water is added. Comp. Rend.
T. 7. 1838. p. 713: ''Note sur les produits de 1'acide nitrique sur 1'amidon et sur
le ligneux." cf. also: "Observations sur la pyroxyline, considered principalement
comme base des amorces fulminantes." Ibid. T. 23. 1846. p. 1020.

— I/O —

manner been hinted at before the middle of November last,
and though it be well known that I have been experimenting
upon guncotton the whole year round, I am, after an opinion
expressed before the french academy and echoed by many
french papers, entitled only to the hono[u]r of having first
applied to the purposes of gunpowder what had been dis-
covered by another. I openly confess that I cannot conceive
with what right such an assertion could have been made, if it
have been ever made and I must leave it to the judgment of
impartial scientific men to decide who is to be considered as
the first discoverer or inventor of gun cotton. I must beg
you a thousand pardons for having spoken so much of my little
affairs, but as you have yourself expressed a wish to be in-
formed about them you will, I am sure of it, be indulgent.

Up to this present moment I have not yet derived any
pecuniary advantage from my discovery, I hope however to
get something out of it. I was very sorry to learn your being
laid up and fervently wish you will soon be able to make use
of your limb. Mrs. Schoenbein and the Children are' well and
beg to be kindly remembered to you and Mrs. Faraday.

Should you think some of the facts mentioned in this
letter interesting enough to be communicated in one of your
Friday Meetings or elsewhere I don't think I can have any
objection to their being made known. Wishing you and your
Lady a very happy new year I am

My dear Faraday

Your's

most truly
Bale Dec. 26. 1846. C. F. SCHOENBEIN.

— 171 —

Schoenbein to Faraday.1
MY DEAR FARADAY

Having a good opportunity for sending you a
few lines, I will make use of it to tell you something about
my little doings. You are no doubt struck with the peculiarity
of the ink in with this letter is written, and I am afraid you
will think it a very bad production; but in spite of its queer
colour, you will like it when I tell you what it is, and when
I assure you that as long as the art of writing has been prac-
tised, no letter has ever been written with such an ink. Dealing
now again in my ozone business, I found out the other day
that all manganese salts, be they dissolved or solid, are de-
composed by ozone, hydrate of peroxide of manganese being
produced and the acid set at liberty. Now to come round
again to my sulphate of manganese. The writing being dry,
the paper is suspended within a large bottle, the air of which
is strongly ozonized by means of phosphorus. After a few
minutes the writing becomes visible, and the longer you leave
it exposed to the action of ozone the darker it will become.
Sulphurous acid gas uniting readily with the peroxide of man-
ganese to form a colourless sulphate, the writing will come out
again when again exposed to ozonized air. Now all this is
certainly mere playing; but the matter is interesting in a scientific
point of view, in as much as dry strips of white filtering paper
drenched with a weak solution of sulphute of manganese fur-
nish us with rather a delicate and specific test for ozone, by
means of which we may easily prove the identity of chemical,
voltaic and electrical ozone, and establish with facility and cer-
tainty the continual presence of ozone in the open air. I have
turned brown my test-paper within the electrical brush, the

1 This letter is reprinted here from Phil. Mag. 8.3. vol. 21. 1847. p. 176.
to which Faraday communicated it under the following title: "On a new test
for ozone." See also Erdm. Journ. Bd. 42. 1847. p. 383.

ozonized oxigen obtained from electrolysed water and the at-
mospheric air ozonized by phosphorus. The quantity of ozone
produced by the electrical brush being so very small, it requires
of course some time to turn the test-paper brown.

As it is inconvenient to write with an invisible ink, I will
stop here; not however before having asked your kind indul-
gence for the many blunders and faults which my ozone bottle
will no doubt bring to light before long.

Yours very truly
Bale July, i. 1847. C. F. SCHOENBEIN.

Faraday to Schcenbein.1

Royal Institution 23 Octr. 1847.
MY DEAR SCHOENBEIN

With absolutely nothing to say I still feel a linger-
ing desire to write to you and though I have waited days and
weeks in hopes that my thoughts would brighten I will wait
no longer, but just make a return to your very characteristic
letter by one which will be distinguished only by its contrast
with it. You would perhaps see by the Philosophical Magazine2
that I had received yours for the whole was printed there
except three or four lines at the end. The novelty and beauty
of your new test for ozone is very remarkable and not less
its application to the detection of Ozone from such different
sources as Phosphorus, the Electrical brush and Electrolysis-
I shame to say that I have not yet repeated the experiments,
but my head has been so giddy that my Doctors have abso-
lutely forbidden me the privilege and pleasure of working or

1 Bence Jones in his Life of Faraday (vol. 2. p. 23 1) prints this letter,
except a few lines at the end.

2 "On a new test for ozone" Letter to Mr. Faraday I. July 1847. Phil.
Mag. 8.3. vol. 31. 1847. p. 176. vide p. 171.

thinking for a while and so I am constrained to go out of
town be a hermit, and take absolute rest. In thinking of my
own case it makes me rejoice to know of your health and
strength and to look on whilst you labour with a constancy
so unintermitting l and so successful. Long may it be so to
the joy and happiness of yourself, wife and family. My wife
desires to be remembered to you most earnestly and is always
glad when your name turns up either in reading and conver-
sation. Remember me in the same manner to Mrs. Schcenbein
and those of yours that I have seen and believe me to be

Ever My dear Schcenbein

Yours Most Truly

M. FARADAY.

I do not talk about Gun cotton: because I think you will
let me know when anything philosophical or important turns
up respecting it which would give you pleasure to tell me.
But you may suppose that I do not hope the less in respect
of it. M. F.

Schcenbein to Faraday.
MY DEAR FARADAY

I am very sorry indeed to learn from your kind
letter that the state of your health is not such as your friends
so ardently wish it to be. I think turning your back to noisy
smoky London and living in some retired quiet corner blessed
with a pure atmosphere is by far the best you can do. And
the winter past I should in your place quit England for a time
and take up a temporary abode at some spot on the beautiful
lake of Como, or at Meran or somewhere there about. Placing
yourself in the midst of a serene, grand scenery will afford

1 Faraday certainly wrote unintermitting; Bence Jones has changed it into
unremitting.

174 —

your mind a beneficial excitement and inhaling a pure balmy
air will strengthen your frame and recall the elasticity of your
spirits. Beautiful as England is in many respects, nature there
is too tame and uniform, the sky too pale, the air too thick
to suit your present condition. Excuse my acting the part of
a medical adviser but as my council comes from the conviction
that it is the best which can be given to you, I am sure you
will not take it ill.

You know my heterodoxical ' notions regarding the nature
of Chlorine which after the old creed I hold to be an oxy-
compound similar in constitution to the peroxides of hydrogen,
manganese etc. Now those notions are the source of all the
experiments I have made these many years and if I have been
fortunate enough to ascertain some interesting facts, I owe it
entirely to my strange hypothetical views and to reasonings
founded upon them. You are also aware that Ozone bears in
many respects a very close resemblance to Chlorine, Bromine
and Jodine and the strongest atmosphere of ozone being almost
instantaneously destroyed by powder of Charcoal, I was curious
to see how Chlorine Bromine etc are acted upon by powdered
charcoal and my experiments have led to results of which I
shall give you a summary account.2

1 This habit of Schcenbeins to apply to his new ideas the term "hetero-
doxical" is often wet with in letters to and from his friends. Pettenkofer, for
example writes, March 6. 1866: "I am eagerly awaiting news from you and anxious
to know what satanic trick you heretic have again been up to." Henri St. Claire
Deville in a similer strain, in December 1859 addresses him as a consummate
master of chemical sorcery. Vide note I. p. 40. Kahlbaum und Thon, Brief-
wechsel, Liebig-Schrenbein. Leipzig 1899.

2 See also his paper: Das Verhalten der Kohle zu Chlor, Brom, Jod, Chlor-
kalk und Untersalpetersaure. Poggend. Annal. Bd. 73. 1847. p. 326. That this
resemblance is closely associated with the naming of ozone is rendered evident
by a passage from a letter from Schcenbein to Arago, reprinted in the Comptes
Rend, of April 27. 1840. p. 709, where he says, that being all but convinced
that his odoriferous principle must be grouped together with chlorine and
bromine, he proposes giving it the name of ozone. This passage is interesting
from the fact that it is the first time the name "ozone" appeared in print.

, — 175 —

1. The strongest atmosphere of Chlorine on being shaken
with powder of common charcoal is almost instantaneously
destroyed at the common temperature as well as at 212°.

2. A current of Chlorine passing through a tube filled with
powder of charcoal is readily taken up, much heat being dis-
engaged from the latter. The charcoal thus treated does not

o o

exhibit the odour of Chlorine, even if considerably heated, but
emits fumes of muriatic acid and yields the same acid to water.
The freshly prepared chlorified charcoal has however like Chlorine
the power of discharging the colour of an Indigo solution and
decomposing jodide of potassium, but in leaving it for some time
in contact with water or atmospheric air it looses that property.

3. The strongest aqueous solution of Chlorine, if shaken
with a sufficient quantity of charcoal powder quickly looses
its yellow colour, smell, bleaching power etc., muriatic acid being
produced. Powder of charcoal is also capable of completely
destroying the bleaching power of aqueous solutions of hypo-
chlorites, for instance that of the common Chloride of lime.
The same effect is produced by Charcoal upon what Berzelius
considers as deutochloride of manganese and which is obtained
by treating peroxide of manganese with muriatic acid at the
common temperature. Charcoal transforms the solution of that
compound into that of the common protochloride of manganese.

4. The densest atmosphere of Bromine Vapour most rapidly
and completely disappears even at a temperature of 212° when
brought in contact with powder of Charcoal, and liquid Bromine
on being mixt up with the same powder is rendered so latent,
that the mixture may be heated to 212° without yielding a
trace of bromine; at a higher temperature however some Bromine
is given off. The brominiferous charcoal has the power of dis-
charging the colour of Indigo solution and decomposing jodide
of potassium. The strongest aqueous solution of Bromine on
being shaken with powder of charcoal becomes colourless, looses,
its smell, bleaching power etc.

- 1 76 -

5. Charcoal powder causes rapidly the disappearence of
the densest vapour of Jodine even at a temperature of 212° and
an intimate mixture of 9 parts of Charcoal and one part of
jodine exhibits not the slightest smell and does not yield a
trace of vapour of jodine even at the boiling point of water,
at a considerably higher temperature however some Jodine
vapour is disengaged. The colour of an acqueous solution of
Jodine is quickly discharged by powder of charcoal.

6. A colourless mixture of one part of hyponitric acid and
9 parts of water on being mixt up with charcoal powder gives
rise to a most lively and abundant disengagement of deutoxide
of azote, no carbonic acid being produced under these circum-
stances. Monohydrate of nitric acid on being put in contact
with charcoal powder even at a temperature of o ° F is partly
decomposed, hyponitric acid being eliminated but no carbonic
acid produced. You know that I consider that monohydrate
as NO 4 + HO 2 and hold the opinion that on mixing hyponitric
acid and water together two compounds are formed : NO 4 4- HO 2
and NO 2 -f HO 2. Now as to the decomposition of what they
call monohydrate of nitric acid effected by Charcoal, I am in-
clined to ascribe it to the well known power of that substance
of composing the peroxide of hydrogen and agreeably to the
same hypothesis, I account for the disengagement of deutoxide
of azote out of the mixture before mentioned. HO 2 united to
NO 2 is decomposed by Charcoal into water and oxigen, the
latter being thrown upon some NO 2 -I- HO 2, to form NO 4 + HO 2
and the NO 2, being freed from HO 2, set free. -

It seems to me that the facts above mentioned are not due
to the well known power of charcoal of absorbing gazeous
bodies, but to something else, of which we have not yet got
a clear notion and I am inclined to think that the cause which
makes charcoal act upon Chlorine, Bromine, Jodine in the manner
described is the same that gives to charcoal the power of des-
troying Ozone, Thenard's peroxide of hydrogen, permanganic

,- — '77 —

acid, monohydrate of nitric acid, what they call aqueous hypo-
nitric acid, solutions of the hypochlorites etc, without producing
carbonic acid. But what that cause is, I am far from being
prepared to say. At any rate it is a fact worthy of conside-
ration, that all the substances that are so peculiarly acted upon
by charcoal bear the same electromotive character; they are
electro-negative bodies.

Before I conclude, allow me to mention to you another
fact which I ascertained some time ago and will interest you.
If paste of starch being mixt up with so much jodide of lead,
as to give the former a lively yellow colour, be spread over
a band of white paper and exposed to the action of direct
solar rays, it suddenly turns its colour, becoming green in the
first instance and dark blue within a very few seconds. This
change of colour effected by direct solar light is almost as in-
stantaneous as that brought about by a strong atmosphere of
chlorine or ozone and of course due to an elimination of
jodine from the jodide of lead. *

I am not aware of any other substance being so suddenly
and perceptibly affected by solar light as the said paste proves
to be, and on that account I think it might be used as a means
for examining more closely the relative chemical powers of the
different species of rays of which white solar light is made up.

Living at this present moment amidst the clamour of civil
war and writing under the impression of extraordinary events,
I am sure you will be indulgent to me as to the great imper-
fection of this letter. Pray present my best compliments to
Mrs. Faraday and believe me, my dear Faraday,

Your's most truly
Bale November 19. 1847. C. F. SCHOENBEIN.

1 This subject is dealt with in Poggend. Annal. Bd. 73. 1847. p. 136. Uber
'die Einvvirkung des Lichts auf Jodbleistarke. See also Erdmann Journ. Bd. 46.
1847. p. 442.

#*
M

Faraday to Sckcenbein.

Brighton 17 March 1848
MY DEAR SCHOENBEIN

I find my letters begin to take a character which
cannot be wondered at, considering all things, but which recurs
oftener than I could wish; however it shall not prevent me
writing to you. I find a difficulty in answering or even acknow-
ledging properly a scientific letter, for I cannot now hold it
at once in my mind, so as to make the expression of my
thoughts consistent and applicable. The memory of the parts
fail me. Therefore I am not about to reply to your last (Nov.
1847) but just to write a word or two of affectionate remem-
brance and nothing else. Indeed I cannot altogether make up
my mind that, as my scientific occupation passes away, the
many kind remembrances of friends, thoughts and acts, should
pass away with it, so you must just bear with me and whilst
you write me letters full of energy and interest, be content to
receive almost incoherent scraps in return. When I received
yours, if I remember my feelings aright, I think I felt doubt-
ful whether you did or did not wish me to send it to the
Phil. Mag. and I think I did not send it. Will you by a single
word let me know your mind on these occasions. - - I wrote
a paper in the P. M. on the diamagnetism of gases and flame *
and sent you a copy by some channel. If you have seen it
I hope you approve. I feel as if every paper I write must
be my last - - but no one knows. Things may revive again
- and if not, what great cause I have to be thankful for the
health and strength and blessings that have been and are at
this moment granted me. - - With our kindest remembrances
to Madame Schcenbein and the children I am, my dear friend,

Ever most truly yours

M. FARADAY.

1 On the diamagnetic conditions of flame and gases. Phil. Mag. S. 3. vol. 31,
1847. p. 401.

— 179 —

You will be sorry to see the tone of this short note, but
my dearest husband is not quite so well as usual, but I hope
he will improve. May I add my kind remembrances to his
and sign myself Yours very truly

S. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

To give you a sign of life I send you some lines
through a former pupil of mine, Mr. Burckhardt of Bale. In
spite of all the revolutions and commotions wrhich have taken
place around us these last eight months I have not given up my
favorite researches and been rather industrious in my labora-
tory. Amongst other things I have made many experiments
on the action exerted by Ozone upon metals at the common
temperature and obtained pretty results. I have found out
that with a few exceptions all metallic bodies are oxidized by
Ozone to the highest degree they are capable of, Silver and
Lead for instance being transformed at once into the peroxide
of those metals, arsenic and antimony into arsenic and anti-
monic acid, without passing through their intermediate degrees
of oxidation. Though Silver be reputed to be much less
oxidable than Copper, Zinc, Tin etc., it is more rapidly oxidized
by Ozone, than the metals mentioned. Polished plates of Silver
Copper, Tin, Zinc being suspended within a strongly ozonized
atmosphere are very differently acted upon. After half an
hour's suspension the silverplate will have lost its metallic
lustre and be covered with a layer of peroxide of Silver, whilst
the plates of the other metals may remain for 24 hour's within
our atmosphere without losing sensibly of there brilliancy. It
may therefore be said that with regard to Ozone Silver is
one of the most readily oxidable metals, provided silver and
the other metals be exposed to the action of our oxidizing

i8o

agent in the shape of compact and polished plates. Being in
a state of minute mechanical division all the common metals,
silver of course included, appear to take up the oxigen of ozone,
equally rapidly. The specimen laid by is a layer of peroxide
of silver having been produced within 24 hours round a plate
of very pure and highly polished silver. Arsenic and Anti-
mony in the shape of brilliant metallic spots produced upon
glass tubes or porcellain according to Marsh's method exhibit
interesting bearings to Ozone. The arsenious spots are rapidly
acted upon by Ozone and transformed into arsenic acid. 10 — 15
minutes are sufficient to make entirely disappear an arsenious
spot, when placed in air richly charged with ozone, whilst a
similar spot of antimony, put under the same circumstances
requires many days, to loose its metallic lustre and be turned
into the white hydrate of antimonic acid. I must not omit to
state that Ozone produced by common electricity acts exactly
upon the two kinds of spots like voltaic or chemical Ozone.
With my rather poor electrical machine I succeeded in making
entirely disappear a strong arsenious spot within 10 — 12 minutes,
whilst a similar antimonious spot placed aside the former one
and exposed at the same time to the action of the electrical
brush was not yet sensibly affected, and had retained all its
metallic brilliancy. Ozone is therefore one of the means by
which arsenic may be easily distinguished from antimony.1

I think I have also succeeded in tracing out the cause of
phosphorus being not able to produce ozone or (what is
most intimately connected with it) undergo slow combustion
in pure oxigen of the usual density and common temperature.
The slow combustion of phosphorus being caused by Ozone,,
it follows that all the circumstances which prevent or favor
the generation of that oxidizing agent must also prevent or
favor that slow combustion. Now a most essential condition

1 Poggend. Annal. Bd. 75. 1848 p. 361: Das Ozon als Mittel zur Unter-
scheidung der Arsen- von den Antimonflecken.

i8i

! i

of the production of ozone is a certain degree of rapidity of
the evaporation of phosphorus; (only vaporous but not the
solid phosphorus determines the formation of ozone); any physical
circumstance facilitating the said evaporation favors therefore
the generation of ozone, or enlivens the slow combustion of
phosphorus. In oxigen, rarefied to a certain degree, ozone is
produced and phosphorus becoming luminous at the common
temperature, and in common oxigen the same phenomena take
place, provided the temperature of the gas be raised by a
certain number of degrees. Rarefaction or the heating of
oxigen gas favors the evaporation of phosphorus and conse-
quently the formation of ozone etc.

In .Hydrogen and Nitrogen, having the same elasticity and
temperature as oxigen, phosporus evaporates more rapidly than
in the last named gas and hence it comes, that in a mixture of
hydrogen and oxigen, nitrogen and oxigen of the usual elasti-
city and temperature, ozone is produced and phosphorus
becoming luminous, whilst in pure oxigen of the same tem-
perature and elasticity the phenomena mentioned do not take
place. I have circumstancially described my results in Poggen-
dorffs Annals and I hope they will soon be published.1

During the summer I made with my family a stay at a
beautiful spot near the lake of Lucerne on the "Rotzberg" in
the Canton of Untervvalden. We were very happy there and
often said that our hill would be a place for our friend Faraday
and his Lady. We led a truly dolce far niente life and my
girls were jumping about in the hills like chamois. Confidently
hoping you and Mrs. Faraday will enjoy at least tolerable

health, I am, my dear friend,

\ our s most truly

About Oct. 1848 perhaps.2 C. F. SCHOENBEIN.

1 liber die Erzeugung des Ozons durch Phosphor in reinem Sauerstoffgas.
Poggend. Annal. Bd. 75. 1848. p 377.

2 This date was added by Faraday at a much later period. On the same
sheet of paper on which Schoenbein wrote a sketch for an obituary notice on

— 1 82 —

Faraday to Sch&nbein.

Royal Institution 15. Deer. 1848.
MY DEAR SCHOENBEIN

What a delight it is to think that you are quietly
and philosophically at work in the pursuit of science; - - or
else are enjoying yourself with Madame Schcenbein and the
children amongst the pure and harmonious beauties of nature
- rather than fighting amongst the crowd of black passions
and motives that seem now a days to urge men every where
into action. What incredible scenes every where, what unworthy
motives ruled for the moment, under high sounding phrases,
and at the last what disgusting revolutions. Happy are we
here who have thus far been kept from these things and hope
to be so preserved in the future.

You last letter was quite a treat. I cannot tell when it
came for my memory is worse than ever and it happens to
have no date. The condition of Silver is indeed very curious -
indeed the longer you work at this subject the more unexpected
your results are and I cannot doubt that you will some day
soon have them all opening out and taking their respective places
in one consistent, bright and beautiful whole.

I have been working also a little and have sent two papers
to the Royal Society on the Crystalline Polarity of bismuth
and other bodies and its relation to the Magnetic force.1 — A
cristal of bismuth is subject to the action of the Magnet, for
there is one direction through it which always tends to place
itself in the Magnetic axis. This direction I have called the

Berzelius (see Kahlbaum, Briefwechsel p. 96) we have discovered a draft of this
letter. Now Berzelius died on Aug. 7. 1848; the letter must therefore have been
begun about the middle of August at Rotzberg. Therefore, although some time
must have elapsed before he completed it — for it was posted at Bale — it
seems very probable that it was written as early as September and not October.
1 On the crystalline polarity of bismuth and other bodies and on its relation
to the magnetic form of force. Phil. Trans. 1849. p. i.

Magnecrystallic axis of the crystal. It makes the crystal point
as a magnetic needle would point, yet is the result not an effect
of attraction or repulsion or polarity, for the bismuth is repelled,
as a diamagnetic body, as much and no more than if it had not
this set. If it be fused and then resolidified, all this power
is lost, because it belonged to a regular crystallization and
that has now become irregular.

Antimony and Arsenic are also magnecrystallic, like bis-
muth — and crystalline plates of these metals taken from broken
up masses point well, provided the whole of the fragment be
uniformly crystallized.

Not only are diamagnetic bodies, like those mentioned, but
also Magnetic bodies, Magnecrystallic. Thus a crystal of
protosulphate of iron is so, having the Magnecrystallic axis
perpendicular to two of the faces of the rhombic prism, in which
that salt crystallizes.

I can by arrangement oppose the Magnecrystallic force
either to the magnetic or the diamagnetic condition of bodies
- so that I can make a crystal of Sulphate of iron recced
from a magnetic pole, or a crystal of bismuth approach towards
it, against what we should otherwise consider their natural
tendency.

As I said just now this effect is not one of attraction or
of repulsion but of position only, and is as far as I can see a
new' effect or an exertion of force new to us.

At first I thought the cause of these phenomena different
to that which produced Pluckers1 results described in his paper2
on the "repulsion of the Optic axes of crystals by the Magnetic
poles", but now I think it is the same, though my forces are

1 Julius Plucker Ph. D. was born at Elberfeld in 1801. He was professor
of Mathematics at Halle, and professor of Mathematics and Physics at Bonn
where he died in 1868. He was recipient of the Copley medal.

2 Uber die Abstossung der optischen Axen der Krystalle durch die Pole
der Magneten. Poggend. Annal. Bd. 72. 1847. p. 315.

1 84

axial and he refers his results to equatorial forces or to re-
pulsion. I will however tease you no more with these matters,
but send you the printed papers as soon as I can.

With our kindest remembrances to Madam Schoenbein

I am, My dear friend,

Most truly Yours

M. FARADAY.

Sclicenbein to Faraday.
MY DEAR FARADAY

Our Chief Magistrate Burgomaster Sarasin, friend
to your friend and a liberal patron to science, taking a trip to
England will be kind enough to deliver these lines and the
papers laid by into your hands and I am sure you will be glad
to make the acquaintance of the highly worthy gentleman.

The paper in octavo ! deals with the voltaic pile and that
in quarto2 contains an account of my recent researches on
ozone3 of which I talked in my last letter to you.4 To give
you a substantial proof of the correctness of my statement I
send you a little bit of peroxide of silver and nitrate of potash

1 Uber die chemische Theorie der Volta'schen Siiule. Poggend. Annal.
Bd. 78. 1849. S. 289.

2 Uber das Ozon, Denkschrift zur Einweihung des neuen Museums in
Basel, 1849.

3 Schcenbeins spelling of ozone is anything but consistent. Sometimes he
writes ozon, at other times ozone; in this letter he has even added a circumflex
accent. Professor Vischer of Bale, at Schcenbeins request, offered to devise a
name for his new body and derived it from o£mv, the present participle of ogiti',
smelling. We would therefore emphasize the fact that, for this reason, the correct
pronunciation is 6/zon, and not ozon/.

4 Whether Schcenbein, in referring to his last letter, alludes to the one
written in September 1848 is not quite evident; there seems in fact to be a
gap here; we are however unable to determine by how many letters it was
filled up.

- i85 -

both the substances having been prepared by the means of
ozone.

Little being known of ozone in England, don't you think
the subject fit for being once treated before one of the Friday
meetings of the Royal Institution? It allows of a great number
of striking experiments to be made. - - Should you like the
Idea I would give you a list of those I think to be the most
interesting and instructive ones.1

As you know no doubt Mr. Henry, the Chymist who is
Headbrewer in some great brewery of the City, pray let him
have the enclosed.

My best compliments to Mrs. Faraday and my kindest

regards to \Tourself

Yours

most truly
Bale, March 27. 1850. C. F. SCHOENBElN.

Faraday to Schcsnbein.

Royal Institution II May 1850
MY DEAR SCHOENBElN

I have seen Burgomaster Sarasin who has very
kindly brought me your papers and letter. I wish I could show
him any useful attention, but you know what an out-of-the-world
man I am. Your German papers are very tantalizing, I know
the good there must be within and yet I cannot get at it. But
now my thoughts are on Ozone. I like your idea of an Evening
here, but it cannot be this season for the arrangements are full.
Yet that in some degree suits me better, for though I should
like to give it, I am a slow man (want of memory) and
therefore require preparation. Now I shall lock up your

1 Faraday delivered this lecture in June 1851.

1 86 —

letters and reread them and also the papers; but let me pray
you to send me a list of the experiments which you know
to suit a large audience, also, if you can, the references to the
best French (or English) papers giving an account of its develop-
ment and progress. Also your present view, - - also the best
and quickest methods of making ozonized air and such other
information as I shall need. Probably other matter will arise
before 1851 and I will get possession of it as we go along.
If you come over here you shall give the subject yourself i. e.
if you can arrange and keep to time etc. if not, I must do my
best. But every year I need more cramming, even for my own
particular subjects. - - Now do not delay to send me the list
of experiments, because you suppose there is plenty of time
etc etc, but let me have them that I may think over them
during the vacation. I should like to do the matter to my own
satisfaction: there are however very few things in which I
satisfy myself now. I hoped to have had a paper to send you
ere this, but Taylor is slow in the printing. Give our kindest
remembrances to Madame Schoenbein

Ever, My dear friend,

Yours truly

M. FARADAY.

Faraday to Sc/icenbein.1

Royal Institution 19. Novr. 1850
MY DEAR SCHOENBEIN

I wish I could talk with you instead of being
obliged to use pen and paper. I have fifty matters to speak
about, but either they are too trifling for writing, or too im-

1 A portion of this letter is reprinted in Silvanus P. Thompson's Life and
Work of Faraday, p. 206, a most excellent and fascinating book. Bence Jones.
vol. 2. p 258 gives the whole of it.

, - 1 87 ^

portant; for what can one discuss or say in a letter? Where is
the question and answer, and explication that brings out clear
notions in a few minutes? whilst letters only make them more
obscure, because one cannot speak freely one's notions, and yet
guard them merely as notions. But I am fast loosing my time
and yours too. I received your complimentary kindness, and
like it the better because I know it to be as real as com-
plimentary. Thanks to you, my dear friend, for all your feelings
of good will towards me. The bleachings by light and air are
very excellent. I see a report of part of your paper in the
account of the Swiss Association, but not of the latter part.1
However, a friend has your paper in hand and I hope to have
the part about atmospheric electricity soon sent to me. I should
be very glad indeed to have from any one, and above all from
you, a satisfactory suggestion on that point. I know of none as yet.
By the bye 1 have been working with the oxygen of the
air also. You remember that three years ago I distinguished
it as a Magnetic gas in my paper on the diamagnetism of
flame and gases founded on Bancalari's2 experiment. Now I
find in it the cause of all the annual and diurnal, and many of
the irregular, variations of the terrestrial magnetism. The ob-
servations made at Hobarton, Toronto, Greenwich, St. Peters-
burg, Washington, St. Helena, the Cape of Good Hope and
Singapore all appear to me to accord with and support my
hypothesis. I will not pretend to give you an account of it
here, for it would require some detail and I really am weary
of the subject. I have sent in three long papers to the Royal
Society and you shall have copies of them in due time and
reports probably much sooner in Taylors Magazine.

1 Schweiz. Naturf. Gesellsch. Verh. 1850. p. 44. The meeting was held at
Aarau. Aug. 5 — 7. 1850.

2 Michele Alberto Bancalari, professor of Physics at Genua was born in 1805
at Chiavari. He was the discoverer of diamagnetism of the flame. Sull magne-
tismo dei gasi (Giornale di Roma. Vide also Poggend. Annal. Bd. 73. 1848.
p. 257 and 286).

— 1 88 —

I forwarded your packets immediately upon the receipt
of them.

But now about ozone. I was in hopes you would let me
have a list ot points with reference to where I should find the
accounts in either English or French Journals, and also a list
of about 20 experiments fit for an audience of 500 or 600
persons, - - telling me what sized bottles to make ozone by
phosphorus in — the time, and necessary caution etc. etc. etc. -
My bad memory would make it a terrible and almost impossible
task, to search from the beginning and read up; whereas you,
who keep all you read, or discover with the utmost facility,
could easily jot me down the real points. - - If you refer to
any such notes in your last letter when you ask me whether
I have received a memoir on Ozone and some other things
then I have not received any such notes and I cannot, indeed
I cannot, remember about the memoir.

I was expecting some such notes and I still think you
mean to send me them and though I may perhaps not give
Ozone as an Evening before Easter, still do not delay to let
me have them, because I am slow, - - and losing much that I
read of, have to imbibe a matter two or three times over; and
if I do Ozone I should like to do it well.

My dear wife wishes to be remembered to you and I
wish most earnestly to be brought to Madame Schoenbein's
mind. Though vaguely I cling to the remembrance of an hour
or two out of Bale at your house, and though I cannot recall
the circumstances clearly to riVy mind, I still endeavour again
and again to realise the idea.

Ever My dear Schoenbein

Yours most trul}r

M. FARADAY.

1 89

i
Schcenbein to Faraday.

MY DEAR FARADAY

Will you be kind enough to forward the parcels
inclosed to their places of destination. There is no hurry in
it, you may deliver them quite beseemly. If you should happen
to get the parcel with my sulphuret-papers, it is very possible
that those of lead have turned brown again. I see that by
degrees sulphate of lead is acted upon by paper in the dark,
so as to become brown i. e. sulphuret of lead.

I at least cannot account in another way for the fact that
sulpuret of lead paper often, having been completely bleached
by ozonized or insolated oxigen, turns gradually brown again
in the dark.

The silhouettes laid by, which, except the figures, were
once quite white, will show you that action.

Yours

very truly

Bale 25. Nov. 1850. C. F. SCHOENBEIN.

Faraday to Sckcenbein.^

Brighton 9 December 1850
MY DEAR SCHOENBEIN

I have just read your letter dated July 9. i85O2
exactly six months after it was written. I received the parcel
containing it just as I was leaving London and I do not doubt
it was in consequence of your moving upon the receipt of
my last to you a few weeks ago. Thanks, thanks, my dear
friend, for all your kindness. I have the Ozonometer and the

1 Reprinted in part in Bence Jones vol.2, p. 261.

2 This letter to Faraday of July 9. 1850 is missing.

— i go

summary and all the illustrative packages safe, and though I have
read only the letter as yet, and that I may acknowledge your
kindness, write before I have gone through the others; yet I
see there is a great store of matter and pleasure for me. As
to your theory of atmospheric electricity, I am very glad to
see you put it forward; of course such a proposition has to
dwell in one's mind, that the idea may be compared with other
ideas and the judgment become gradually matured ; for it is
not like the idea of a new compound which the balance and
qualitative experiments may rapidly establish; still as I study
and think over your account of Ozone and insulated oxygen, so
I shall gradually be able to comprehend and imbibe the idea.
Even as it is I think it is as good as any and much better
than the far greater number of hypotheses which have been
sent forth, as to the physical cause of atmospheric electricity
- and some very good men have in turns had a trial at the
matter. - - In fact the point is a very high and a very glorious
one: - - we ought to understand it and I shall rejoice if it is
you that have hold of the end of the subject. You will soon
pull it clearly into sight.1

The German account2 you sent me of insolated oxygen
and your theory of atmospheric electricity is in the hands of
a young friend who is translating it. - - Whilst it is going on
and also in reading your letter a question arises in my mind
about the insolated oxygen which perhaps I shall find answered
Avhen I come to read the paper. It is whether the oxygen

1 Schcenbein derives electricity of clouds from a chemical process, or rather
from a voltaic source, the essential conditions being the presence of atmospheric
water, atmospheric oxygen and sun light. Ordinary oxygen, under the influence
of solar rays, becomes more active, its behaviour being then somewhat like that
of ozon. In this state it polarizes water, of which the clouds are made up, by
means of its chemical affinity to hydrogen, and thus atmospheric electricity is
produced.

" Uber den Einfluss des Sonnenlichtes auf die chemische Thatigkeit des
Sauerstoflfs und den Ursprung der Wolkenelektrizitat und des Gewitters. Basel 1850.

— igi —

having been insolated is then for a time a different body out
of the presence of light as well as in it. I think an American '
(I forget who) says that Chlorine after being exposed to the
sun is of brighter colour and acts far more readily than such
as has been kept in the dark for a time. Suppose a little box
blackened inside, with two little glass windows, that a ray of
sun light could be passed through it, and the box filled with
oxygen, and a proper test paper put up in the dark part of
the box: would it show change or must the test paper be in
the ray to be acted upon ? Of course Ozone would act upon
it in the dark place. Is insolated oxygen like ozone in that
respect? - - I do not doubt that I shall find the answer amongst
the data that I am in possession of and so do not trouble your-
self for a reply just now. As I told you in my last I must
talk about atmospheric Magnetism in my Friday evenings
before Easter and I am glad that Ozone will fall in the summer
months, because I should like to produce some of the effects
here. I think I told you in my last how that oxygen in the
atmosphere, which I pointed out three years ago in my paper
on flame and gases as so very magnetic compared to other
gases,2 is now to me the source of all the periodical variations
of terrestrial magnetism; and so I rejoice to think and talk at
the same time of your results which deal also with that same
atmospheric oxygen. What a wonderful body it is.

Ever my dear Schoenbein

Yours faithfully

M. FARADAY.

1 John William Draper, professor of Chemistry at New-York, made this
observation. His chief paper on the subject, however, was not published till 1857.
See Phil. Mag. 8.4. vol. 14. 1857. p. 3: "The influence of light upon chlorine etc."

2 Phil. Mag. 8.3. vol. 31. 1847. p. 410. This paper was also published
at full length in Poggend. Annal. Bd. 73. 1848. p. 256.

Faraday to Sckcenbein.^

Brighton 13 Dec. 1850
MY DEAR SCHOENBEIN

It will be very strange if I do not make your subject
interesting. I have gone twice through the M S. and the illus-
trations. Both are beautiful. — As soon as I reach home I shall
begin to prepare for ozone, making and repeating your experi-
ments. This morning I hung out at my window one of the
Ozonometer slips. That was about two hours ago. — Now when
I moisten it, a tint of blue comes out between Nos 4 and 5
of the scale. Though I face the sea and have 'the wind on
shore, still I am not aware that the spray can do this or any
thing that comes from the sea water; but before I send off this
letter I shall go down and try the sea itself.

Well! I have been to the sea side and the sea water
does nothing of the kind - - nor the spray - - but as I walk
on the shore holding a piece of the test paper in my hand for
a quarter of an hour, at the end of that time it, by moistening,
shows a pale blue effect.

That which is up at my window has been out in the air
four hours and it, when wetted, comes out a strong bluejtint
about as Nr. 6 of the scale. The day is dry but with no sun,
the lower region pretty clear, but clouds above.

After reading your notes and examining the illustrations,
I could not resist writing to you, though, as you see, I have

nothing to say.

Ever truly yours

M. FARADAY.

1 This letter is printed in full in Bence Jones, vol. 2. p. 262.

f - '» -

Faraday to Schcenbein.1

Royal Institution 5. March 1851.
MY DEAR FRIEND.

I had your hearty Christmas letter in due time 2 -
and was waiting for the papers referred to in it when lo! they
arrived about four days ago and your friend Professor Bolley3
called and left them, and his address. I was ill and, I believe,
in bed and could not see him. I have not been out of the
house for a week or more, because of inflamed throat and in-
fluenza, being unable to speak and obliged to give up lecturing,
but I am now improving and trust I shall see the Professor
soon. The papers and the specimens of oil of turpentine are
all quite safe and most valued treasures. I have read the papers
through and I think you must now begin to rejoice in ozone,
for though it has cost you a great deal of trouble and work,
still it has surely made wonderful way and, what is more, is
progressing and will progress. Though you may sometimes
get tired of it, still I think you never take it up afresh without
being rewarded. I have been consulting with a medical friend
about the medical paper4 and he (Dr. Bence Jones5) recommends
that it be sent to the Medico chirurgical society - where it
will be introduced at once into the minds of the Medical Pro-
fession and appear in the transactions. Tomorrow we shall

1 Bence Jones gives this letter vol. 2. p. 281, but more or less abridged.

• This letter alluded to is, we regret to say, not among those in our
possession.

3 Alexander Pompeius Bolley Ph. D., Director of the Technical High School
at Zurich from 1859 to 1865. He was born at Heidelberg in 1812 and died in 1878
at Zurich. Together with Eisenlohr, Bolley was one of Schoenbeins most in-
timate friends.

* "Uber einige mittelbare physiologische Wirkungen der atmospharischen
Elektrizitat." Med. Chir. Soc. Trans. Vol.34. 1851. p. 205.

5 Henry Bence Jones M. D. a pupil of Liebigs was born in 1813 at
Thorington Hall in Suffolk and died in 1873 in London. He was physician to
St. Georges Hospital, London and wrote the well known History of Faradays Life.
N

194 —

meet again when he will have read the paper and we shall decide.
The chemical paper I have sent off at once to the Chemical
Society, it will appear there in time for me to have access to,
and use of it, on my or rather your evening, which I expect will
be 1 3th June or the middle of our Great Exhibition. When I
drew out a sort of preliminary sketch of the subject, I was
astonished at the quantity of matter - - real matter - - and
its various ramifications; and it seems still to grow upon me.
What you will make it before I begin to talk, I do not know.

I do not as yet see any relation between the magnetic
condition of oxigen and the ozone condition, but who can say
what may turn up? I think you make an inquiry or two as
to the amount of magnetic force which oxigen carries into its
compounds. This is indeed a wronderful part of the story, for
magnetic as gaseous oxygen is, the substance seems to lose all
such force in compounds. Thus water which is 8/9ths oxygen
contains no sensible trace of it: and peroxide of iron which
itself consists of two most magnetic constituents — is scarcely
sensibly magnetic; so little have either of these bodies carried
their forces into the resulting compound. Sometimes I think
we may understand a little better such changes by thinking
that magnetism is a physical rather than a chemical force, but
after all, such a difference is a mere play upon words, and
shows ignorance rather than understanding. But you know
there are really a great many things we are as yet ignorant
of — and amongst the rest the infinitesimal proportion of our
knowledge to that which really is to be known. I have a copy
of my last papers ready for you and if Professor Bolley can
take charge of it, shall give it into his hands.

I read your theory of the pile * in the Geneva journal
with great pleasure and go with you, I think, to the full extent.
My mind was quite prepared for the view years ago. I do

1 "Uber die chemische Theorie der Volta'schen Saule." Poggend. Annal.
Bd. 78. 1849. p. 289. cf. also Archives de Geneve. T. 13. 1849. p. 192.

— 195 —

•not suppose you ever see the back numbers of an old work,
which s'ill drags its slow length along, or else you would see
that at Paragraph 949. 950. and again 1164 and 1345, 1347,
and elsewhere, that I was ready to agree with you 10 or 15
years back.

I have no doubt I answer your letters very badly — but,
my dear friend, do you remember that I forget, and that I can
no more help it than a sieve can help the water running out
of it. Still you know me to be your old and obliged and
affectionate friend, and all I can say is, the longer I know you
the more I desire to cling to you

Ever My dear Schoenbein

Yours affectionately

M. FARADAY.

Faraday to Schcenbein}-

Hastings 19 April 1851.
MY DEAR SCHOENBEIN

Here we are at the seaside ; and my mind so vacant
(not willingly) that I cannot get an idea into it. You will
wonder, therefore, why I write to you, since I have nothing to
say, but the fact is I feel as if I owed you a letter and yet
cannot remember clearly how that is. Still I would rather appear
stupid to you than oblivious of your kindness, and yet very
forgetful I am. In six or seven weeks I shall be talking of
Ozone. I hope I shall not discredit you or fail in using well
all the matter you have given me, abundant and beautiful
as it is. But I feel that my memory does not hold things
together in hand as it used to do. Formerly I did not care

1 With the exception of a few lines towards the end Bence Jones' Life
contains this letter in full, vol. 2. p. 282.

196 —

about the muliplicity of items, they all took their place and
I picked out what I wanted at pleasure. Now I am conscious
of but few at once and it often happens that a feeble point
which has present possession of the mind obscures from re-
collection a stronger and better one, which is ready and wai-
ting. But we must just do the best we can, - - and you may
be sure I will do as well for }^ou as I could for myself.

I set about explaining the other evening my views of
atmospheric magnetism l and found when I had done that I
had left out the two or three chief points. I only hope that
the printed papers contain them and that they will be found
good by the men who are able to judge -- The copy for you
is either with your or on the way for the gentleman whom
you introduced to me whose name I forget (from Aarau?)2
kindly took charge of it.

And now, my dear Schcenbein, with kindest remembrances
to Madame Schcenbein (and my wife joins all she can to you

and yours)

I am as ever

Most truly yours

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

I think an excellent likeness of our illustrious
countryman Euler? will prove acceptable to you. It was made
at the expense of Basle and I am charged by the Council of

1 See "Experimental researches in Electricity" 26. and 27. Series. Phil. Trans.
1851. p. 29 and 85. R. Inst. Proc. Vol. i. p. 56.

2 Professor Bolley.

3 Leonhard Euler, professor of Physics at St. Petersburg, and for a time
professor of Mathematics at Berlin. He was born in 1707 at Riehen near Bale
and died 1783 at St. Petersburg.

our Museum to send you a copy of it, as an humble homage they
desire to render you. There are some other copies joined and
intended for the Royal Society etc. and I beg you to be kind
enough to forward them quite leisurely to their respective
places of destination. From Mr. Burckhardt I learned that you
are doing well, he was highly pleased with the Lion of the
Royal Institution. I am continually riding my hobby horse
and now and then pick up something new. I am very sorry
I did not sooner ascertain some facts; they would have made
a good figure in Ozone. You shall before long have details
about them. By this time I think your lecture on that subject
wrill be over; let me know something of the matter. In the
beginning of August I intend to go to Glarus, where the meeting
of our association will take place. Have you no mind to come
over and ramble about a little with me ?

Pray present my best compliments to Mrs. Faraday and
believe me

Quite in a hurry. Your's

very truly
Bale Aug. 25. I85I.1 C. F. SCHOENBEIN.

P. S. Mr. Sarasin a young friend of mine has the kindness
to take charge of the parcel; should he happen to deliver it in
person pray receive kindly. S.

1 This date is misleading and evidently incorrect. Faraday's answer to
this note bears the date Aug. i and can be verified by the postmark. Moreover
Schonbein himself speaks of his going to Glarus at the beginning of August.
Hence we are justified in dating this letter July 25, in the place of August 25.

198

Faraday to Schoenbein*

Tynemouth I August 1851
MY DEAR SCHOENBEIN

On running away from the bustle and weariness
of London I brought your letter here intending to answer it long
before now and lo! I have been attacked by inflammation of the
throat, have had a quinsy and been held in much pain and debility
until now. I will not longer delay, believing that a few words
are better than none. I have not yet received the portrait of
Euler but doubt not it is at home. Will you do me the favour
to return my most sincere thanks to the Council of the Museum
for the great [honour] they have done me in favouring me
with a copy, which I shall ever look upon with great pleasure.
The others I will deliver according to their addresses.

The Ozone Evening went off wonderfully well; our room
overflowed and many went away unable to hear (my account
at least) of this most interesting body. Through your kindness
the matter was most abundant and instructive, and the experi-
ments very successful. The subject has been sent into the
world so much piecemeal, that many were astonished to see
how great it became when it was presented as one whole,
and yet my whole must have been a most imperfect sketch,
for I found myself obliged to abridge my thoughts in every
direction. - - Many accounts were printed by different parties
and some very inaccurately, since they had to catch up what
they could. A notice of four pages appeared in the proceedings
of the Royal Institution2 and though I think that has appeared
in the Athenaeum or the Philosophical Magazine, yet I shall
send you copies of it when I can. The subject excited great

1 This letter also Bence Jones prints (vol. z. p. 283); the beginning anrl
end are omitted.

- On Schonbein's ozone, R. Inst. Proc. Vol. I. 1851. p. 94.

— 199 —

interest and from what the folks said ! had no reason to be
ashamed either for the subject or myself.

And now my dear Schoenbein I am very weary. Per-
haps to day you are at Glarus - - I was two days at Ipswich
at our meeting, no more for want of strength. Queens balls
- Paris fetes — etc etc etc, I am obliged (and very willing)
to leave all to others.

With kindest remembrances to Mad. Schcenbein and yourself
in which my wife has full part.

I am ever yours

M. FARADAY.

Faraday to Schcenbein.

Royal Institution 16 Deer. 1851
MY DEAR SCHOENBEIN

If I do not write at once (and even though I
may seem to have but little to write about, yet if I delay) all
that I have to say passes from my remembrance and I involun-
tarily become remiss in my duty. Dr. Bence Jones has just
called on me to say that the Society, having printed the paper
you sent to me, in their Transactions, have sent 25 copies of
it to (him), however for you. It occupies 16 pages. Can you
help me in telling me how I shall send these to you ? I will
do whatever you may instruct me in. I have, besides, a formal
letter of thanks to you from the British Museum for the Por-
trait of Euler which I will send at the same time.

I keep working away at Magnetism, whether well or not
I will not say. It is at all events to my own satisfaction.
Experiments are beautiful things and I quite revel in the
making of them. Besides they give one such confidence and,
as I suspect that a good many think me somewhat heretical

— 2OO —

in magnetics or perhaps rather fantastical, I am very glad to
have them to fall back upon.

Remember me very kindly to Madam Schoenbein and

believe me to be

Ever most trul}r yours

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

What may be the cause of the very long silence
kept by your friend on the Rhine ? This question has perhaps
more than once been asked in the Royal Institution these last
six months. First of all, let me assure you that that somewhat
strange taciturnity has nothing to do with any thing being in
the remotest degree akin to forgetfulness.

Why, I don't know, but the fact is, that Mr. Schcenbein
has of late conceived an almost invincible dislike to pen and
ink, so that nothing but the most cogent reasons can force
him to make use of them. He therefore has become a most
lazy correspondent to all his friends. Whether that antipathy
be a symptom of advanced age or only one of those unaccoun-
table fits and whims, which even the strongest minds are now
and then liable to, I cannot say, but this I know, that he trusts
your inexhaustible kindness will grant full pardon and indul-
gence to this piece of human frailty of his. Though strongly
disinclined to handle the pen, he has not yet lost his relish
for scientific pursuits and, as far as I know, was rather active
last winter. It cannot be unknown to you that our mutual
friend entertains very curious and even highly strange notions
regarding oxigen, which he considers as the first-rate Deity,
not only of the chemical but of the whole terrestrial world
He is indeed a most enthusiastic devotee to that Deity, talking

2OI —

and thinking of nothing but of her, praising and exalting her
glory, wherever he can. He pretends that our philosophers,
much as they think to know of oxigen, are as yet blinded
and ignorant of the omnipotence of that mighty ruler of the
elementary world. Upon many agents, considered as equal to
oxigen, he looks down as upon upstarts and usurpers, assuming
powers and privileges to which they have no right and declares
that an infinite number of glorious deeds ascribed to the agency
of inferior deities, are in fact the work of what he calls the
"Jove of the philosophical Olympos."

As a matter of course, our friend entertains feelings of
peculiar love and esteem towards those, whom he considers
as high-priests to his Jupiter and who tend to increase the
authority and glory of the king of elements. He asserts that
you are the leader of those chosen adepts; that you more
than any other have unravelled the mysteries of the wonderful
workings of oxigen in nature and that you are the man who
first has brought to light, that the influence of our friends favorite
deity reaches far beyond the limits of the chemical world. He
goes even so far as to maintain that upon your discovery of
the magnetical powers of oxigen a new philosophical era will
be founded.

Having said so much about our queer and enthusiastic
friend you will not be surprized when I tell you that he is
continually worshipping his goddess in a little smoky room,
which he calls "Jove's temple" and if I be not misinformed,
there, upon a sort of "tripod", he asks all sorts of questions
with the view of getting as deep as possible into the mysteries
of his deity. The other day he hinted at very strange an-
swers having received from his oracle. Oxigen, he says, is the
lord and master even of the most subtle and all pervading
beings in existence, destroying and creating light, making and
unmaking colors at pleasure etc. Indeed, he showed me some
very strange tangible substances exhibiting in a most extra-

— 2O2

ordinary manner the nature of a chameleon, for within a few
minutes I saw the very same thing assuming white, green, yellow,
orange, light-red, dark-red and even black colors. Heaven knows
how such a wonderful change was brought about; our friend
says that his oxigen and nothing but his oxigen had been the
Charmer; but being afraid that he is a little cracked, I am

•

rather sceptical about his assertions. He also talks now and
then of oxigen being closely allied to the great powers of Elec-
tricity and Magnetism and gives to understand that their apparent
might and force are only borrowed from his sovereigns.

I wonder whether he will divulge his queer Ideas to the
world; but I should like to see them kept back from the
philosophers of our days, for these people are too sober and
rational, as to relish the extravagant notions of our hot-headed
friend.

Mrs. Schcenbein and the Children are well and have not
forgotten their English friend to whom they beg to be kindly
remembered. Mrs. Faraday, I hope, recollects still the writer
of these lines and will be indulgent enough as to accept
friendly his compliments.

Pray let me soon hear of your doings and believe me

Yours most truly
Bale, Mai 7. 1852. C. F. S.

Faraday to Schcenbein.

Royal Institution 2 June 1852
MY DEAR FRIEND

Though very stupid and weary yet I write, chiefly

for the purpose of thanking you for your last very kind letter

- it was quite a refresher and it did me good. - - I wish

— 203 —

more had such power, then I should think I might be of some
little use amongst my friends by cheering them up.

Your paper in the Chirurgical Transactions ' - - I think
I asked you what I should do with some copies that were
printed off. However I forget whether you told me any thing
about them - - and I find by enquiring that Dr. Bence Jones
has sent them to you by a friend that hoped to see Basle,
perhaps you have them already.

Presently you will have three papers2 of mine all at once.
Two from the Phil. Trans, and one from the Phil. Mag. — They
all relate to one subject i. e. the lines of magnetic force.

Every now and then I stir up my audience by talking
about your ozone — and then there are many enquiries. I wish
we had a good general English account of it, both as to its
preparation, actions, and history. An acquaintance of mine, the
Revd Mr. Sidney, is busy putting slips from your ozonometer,
which I have supplied him with, through the cleft stems of
vegetable and says he procures many effects just like those
of ozone. - - In such cases however there is a great deal to
eliminate, as clue to other actions of the ozonometrical strip, and
the juices, before he will have his subject clear. Still experimen-
tation is always useful.

What are your mysterious results - - or what the results
of your mysterious friend? -- Have you made gold or even
rather . . . .,3 for it is a more useful metal, or have you con-
densed oxygen? — I wish you could tell me what liquid or solid

1 vide sopra p. 193.

2 "On the physical lines of magnetic force" Phil. Mag. Vol. 3. 1852. p. 401,
"On lines of magnetic force; their definite character, and their distribution with
a magnet and through space." Phil. Trans. 1852. p. 25 and ''On the employment
of the induced magneto-electric current as a test and measure of magnetic
forces." Ibid. p. 137.

3 This passage is unintelligible unless we assume that after "rather"
Faraday forgot to name the metal he was thinking of. What it was, we are of
course unable to say, but would suggest inserting, for example, "iron".

— 204 —

oxygen is like. I have often tried to coerce it and long to know.
With kindest remembrances to Mrs Schoenbein

I am My dear Schoenbein

Your lazy friend

M. FARADAY.

Schosnbein to Faraday.

MY DEAR FARADAY

To give you a sign of life I write these lines quite
in a hurry. They will be delivered to you by the kindness
of our mutual friend Dr. Whewell.1 Your last letter shall be
answered at a more convenient time and so, as it merits, for
your friend is in this present moment not in his writing-mood.
He has continued to ride his hobby-horse and found out
different little things. If you have got a friend knowing german,
he will perhaps give you the substance of papers, I have pub-
lished in Erdmanns' Journal for pratical Chemistry.2

Tuas litteras expectabo, quum ut, quid agas, turn, ubi sis
sciam, cura, ut omnia sciam, sed maxime ut valeas. Tuae uxori
carissima salutem

Bale Aug. 29. 1852. C. F. S.

1 William Whewell D. D. Master of Trinity College Cambridge was born
in 1794 at Lancaster. He was professor of Mineralogy till 1832, and from 1838
to 1855 professor of Moral Philosophy at Cambridge, where he died in 1866.

2 Erdmanns Journal for 1852 contains eleven papers by Schcenbein, dealing
among other subjects with ozone (Bd. 51. p. 343 and 349), the relation of oxygen
to electricity, magnetism and light (p. 135) and the active oxygen in nitrous
acid (p. 129).

ftft

2O5

Sckcenbein to Faraday.
MY DEAR FARADAY

I trust you received in due time the letter I sent
you through Dr. Whewell some months ago. Now I avail
myself of a friend going to London , to forward to you a
paper of mine, which I hope will not remain a sealed book
to you. If you should feel curious to decipher that whimsical
letter I once wrote you about oxigen, get the memoir trans-
lated by some friend of your's and you will perhaps be inter-
ested in the matter, as it regards some of your most impor-
tant discoveries.

Entertaining the notion that in many, if not in all cases,
the color exhibited by oxycompounds is due to the oxigen
contained in them, or to express myself more distinctly, to a
peculiar chemical condition of that body, I have continued my
researches on the subject and obtained a number of results which
I do not hesitate to call highly curious and striking. Far be
it from me to think, on that account, my hypothesis correct
and proved; but the fact is that I owe the discovery of a
number of remarkable phenomena solely and exclusively to
the conjecture mentioned. I am nearly sure that you will be
pleased to repeat the experiments, for either by mere physical
means or by chemical ones you may make and unmake or
change the color of a certain substance without altering the
chemical constitution of those matters. To my opinion, that
wonder is performed by changing the chemical condition of the
oxigen of the oxycompound.

I cannot help thinking that the colors of substances, which
up to this present moment have been very slightly treated (in
a chemical point of view) will one day become highly important
to chemical science and be rendered the means to discover
the most delicate and interesting changes taking place in the
chemical condition of bodies. In more than one respect the

2O6

color of bodies may be considered the most obvious "signatura
rerum", as the revealer of the most wonderful actions going on
in the innermost recesses of substances, as the indicator of the
most elementary functions of what we call ponderable matter.
But alas! Whilst we are pleased with and wonder at that
rich field of chromatic phenomena, which continually strike
our eye, we know as yet little or nothing of the connexion
which certainly exists between the chemical nature of bodies and
the influence it exerts upon light. We must try to dissipate
that thick darkness which still hangs about and obscures the
most luminous phenomena. Clearing up but the smallest part
of that vastly important subject would be of more scientific
value, I think, than discovering thousand and thousand new
organic compounds, things which I cannot help considering in
the same light as I do the infinite number of figures which
may be produced by the caleidoscope.1

What would the world say of a man, who should take the
trouble to shake for whole years that plaything and de[s]cribe
minutely all the shapes (pretty as they might be) he had ob-
tained from his operation!

You know, I am no great admirer of the present state
of Chemistry, and of the Ideas leading the researches, made
upon that field. Atoms, weight, ratio of quantities, endless

1 This metaphor, we are informed, is one to which Schcenbein was very
partial, in writing as well as in conversation. Passages from two letters to
Liebig will suffice to bear this out. On September 5. 1853 he writes, after
agreeing with Liebig that many fundamental facts are still required, if the scope
of chemistry as an exact science is to enjoy a material expansion of its limits,
as follow; "Now a days" he says "the results achieved are only the growth of
facts of inferior importance, and the value we attach to the information thus
acquired is hardly greater than what we would attribute to the production of
novel combinations in the kaleidoscope."

Then again, on September 22. 1867 he says: "The aim of modern chemistry
appears hardly apt to increase our knowledge of such phenomena. An infinite
number of kaleidoscopic images, which the perseverence of chemists brings to
light, after all, contributes but little to a better comprehension of chemical affinity,
and adds but feeble information to the leading questions of the day."

2O/ —

production, and formula of compounds, i. e. the "caput mortuum"
of nature, are the principal if not only subjects with which the
majority of our Chymists know to deal. Force, power, action,
life in fact, are, as it were, phantoms to them, disliked if not
hated. The world being a system of Ideas, its very essence,
power and intellect, how can we expect great things from men
who so much mistake the nature of nature ? In perusing what
is written above I find it is not worth of being sent over the
water, but having no more time to write another letter, you
must take it as it is and excuse my random talking. Mrs.
Schoenbein and the Children are well and beg to be kindly
remembered to you. My best compliments to Mrs. Faraday
.and to you the assurance that I shall for ever remain

Yours

most truly

Bale Oct. 17. 1852. C. F. SCHOENBEIN.

Faraday to Schcenbein.^

Brighton 9 Deer. 1852
MY DEAR FRIEND

If I do not write to you now I do not know
when I shall — and if I write to you now I do not know what
I shall say — for I am here sleeping, eating and lying fallow,
that I may have sufficient energy to give half a dozen juvenile
Christmas lectures. The fact is I have been working very hard
— for a long time — to no satisfactory end; all the answers I
have obtained from nature have been in the negative, and
though they shew the truth of nature as much as affirmative
answers, yet they are not so encouraging and so for the present
I am quite worn out. I wish I possessed some of your points

1 Bence Jones reproduces portions of this letter, in vol. 2. p. 292.

— 208

of character. — I will not say which, for I do not know where
the list might end, and you might think me simply absurd and,
besides that, ungrateful to Providence.

I had your letter by Dr. Whewell and I have received
also your last of the i/th October and the paper and I hope
when I return home to get the latter done into English. It
is a very great shame to us that such papers do not appear
at once in English but somehow we cannot manage it. Taylor
appears to be much embarrassed in respect of the Scientific
memoirs. I hope now that they have changed their shape and
are to appear in two series, physical and chemical, that they
will be more servicable to such as I am.

Your letter quite excites me and I trust you will establish
undeniably your point. It would be a great thing to trace
the state of combined oxigen by the colour of its compound,
not only because it would show that the oxigen had a special
state, which could in the compound produce a special result
- but also because it would, as you say, make the optical
effect come within the category of scientific appliances and
serve the purpose of a philosophic induction and means of
research, whereas it is now simply a thing to be looked at.
Believing that there is nothing superfluous, or deficient, or
accidental, or indifferent, in nature I agree with you in believing
that colour is essentially connected with the physical condition
and nature of the body possessing it, and you will be doing a
very great service to philosophy if you give us a hint, however
small it may seem at first, in the development, or as I may
even say in the perception of this connexion.1

As I read your letter I wondered whether there was any
connexion between your phenomena and those recently inves-

1 That idea which continually governed Schcenbeins theoretical views was
that the same matter, independently of its chemical character, is capable of
acquiring diverse properties , under varying curcumstances. Proof of this is
furnished by the change of colour at different temperatures; hence it is that he
time and again reverted to questions of this nature.

2O9

tigated by Stokes.1 I do not mean any immediate likeness,
but distant connexion. He has been rendering the invisible,
chemically acting rays, visible2 - - that is to say he has been
converting them into visible rays. - - You, by giving a given
condition to a substance, make it, when in compounds, send one
ray to the eye - - and then by giving it another condition
cause it to send other rays to the eye, the body being chemi-
cally the same. Both these are phenomena of radiation, and
both are connected with chemical agencies or forces. If they
could be connected, what a heap of harvests would spring up
between the two. - - I do not know enough yet of Stokes'
phenomona to form any thing but a crude idea and I know
nothing of yours yet, so that you will think me very absurd
to write such stuff; but then it is only to a friend.

You are very amusing with your criticisms on Organic
chemistry.3 I hope that in due time the chemists will justify

1 George Gabriel Stokes, professor of Mathematics at Cambridge was born
in 1819 at Skreen, Co. Sligo, Ireland.

2 "On the change of refrangibility of light," Roy. Soc. Proc. 1850 — -1854.
p. 195 and 333. "On the change of refrangibility of light and the exhibition
thereby of the chemical rays," Roy. Soc. Proc 1850 — 1854. p. 259.

3 He seems to have expressed similar criticisms to Grove, for in a letter
dated Jan. 5. 1845 the latter writes: "I quite agree with the remarks at the close.
I think chemistry is being frittered away by the hairsplitting of the organic chemists;
we have new compounds discovered, which scarcely differ from the known ones
and when discovered are valueless — very illustrations perhaps of their refinements
in analysis, but very little aiding the progress oi true science." On the other
hand he writes, after commenting on Becquerels process for extracting metals
by voltaic means: "Who would not have been laughed at if he had said in 1800
that metals could be extracted from their ores by electricity or that portraits could
be drawn by chemistry." (Aug. 20. 1847.)

We might also quote Graham's views, which are contained in a letter to
Schcenbein, dated Jan. 9. 1862: "Your very kind letter acknowledging receipt
of my paper has afforded me much gratification; the more so, that the stand-
point from which you have always surveyed chemistry, is high and philoso-
phical .... The various modifications of oxygen (an element) which you have
established, with the compounds into which they carry their properties are dis-
coveries of a fundamental character, leading into new regions of science, quite
aside from the routine chemistry of the day."
O

- 2IO -

their proceedings by some large generalisations deduced from
the infinity of results which they have collected. For me I
am left hopelessly behind and I will acknowledge to you that
through my bad memory organic chemistry is to me a sealed
book. Some of those here, Hoffman ' for instance, consider
all this however as scaffolding, which will disappear when the
structure is built. I hope the structure will be worthy of the
labour. I should expect a better and a quicker result from
the study of the powers of matter, but then I have a predi-
lection that way and am probably prejudiced in judgment.
My wife's kindest remembrances to you and yours. My earnest
wishes for the happiness of you all

Ever my dear Schoenbein
Your Affectionate friend

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

I had already given up the hope of my paper
having reached you, when I was most agreeably undeceived
by your kind letter from Brighton. I am really curious to
know what you will think about my notions on the relations
of the different conditions of oxigen to the voltaic, magnetic
and optical properties of that body. The conviction of their
being correct has by no means been shaken by my recent
experimental results, of which you shall hear before long. But
however they may turn out, I trust, they will at any rate draw
the attention of philosophers to a most important set of
phenomena.

1 August Wilhelm Hofmann Ph.D. was born at Giessen in 1818. In 1848
he was professor at the Royal College of Chemistry in London; in 1865 professor
at Berlin, where he died in 1892.

I am not acquainted with the experiments of Stokes, but
from what you say about them, I am inclined to believe that
they are closely connected with my subject. I am just now
working upon the optical action of nitrous gas (NO2)1 upon the
solutions of the protosalts of iron, which, as you are well
aware, is so very striking. As I entertain the notion that the
deep coloring2 of those solutions produced by NO2 is due to
a change of the condition of the oxigen, being contained in
the base of the ironsalt, i. e. to the transformation of the in-
active state of that oxigen into the active one, I suspect that
the paramagnetic force of the black liquid is smaller than the
sum of the paramagnetic forces of its constituent parts. You
know that by uniting 1000 equiv. of inactive i. e. paramagnetic
•oxigen to one equiv. of paramagnetic deutoxide of Nitrogen,
a diamagnetic compound is produced and you are likewise
aware, that the two eq. of oxigen united to NO2 exist in
hyponitric acid in the ozonic or excited condition. Again by
associating 2 equiv. of the highly paramagnetic protoxide of
iron to one equiv. of paramagnetic oxigen a compound is
obtained being, according to your own experiments, magne-
tically indifferent. I have shown in my paper that Fe2O3

is = 2 Fe O + O, that is to say that the third equiv. of the
peroxide of Iron exists in the exalted condition. From these
facts I infer, that in the first case the diamagnetism of 2 equiv.
of ozonic Oxigen is stronger than the paramagnetism of the
two equiv. of inactive oxigen contained in NO2; and that in
the latter case the diamagnetism of one equiv. of ozonic Oxigen
neutralizes the paramagnetism of 2 equiv. of. protoxide of
Iron. Now I conjecture that by uniting the two paramagnetic
•compounds: a protoiron salt to NO2, either a diamagnetic or

1 Schcenbein has in this letter placed the indices above, whereas, it will
be remembered, he usually writes them below.

2 vide his papers on changes of colour. Sitz.-Ber. der Wiener Akad. Hd. II.
p. 464. .^ii^

212 —

a less paramagnetic fluid will be obtained. I should it consider
as a great favor, if you would settle that point by experiment.

I trust the bracing air of Brighton will refresh your body
and mind so much as to enable you not only to resume your
Lectures, but what is more important, your scientific labors.
We cannot spare you, our present age being so woefully
deficient of original thinkers and experimental Philosophers.
There are indeed but a very few to whom I might say: You
are the salt of the Earth, but if the salt have lost his savour,
wherewith shall it be salted ? Permit me to tell you that I
count you amongst those few.

Mrs. Schoenbein and the Children are well. My eldest
daughter is now rather a big Child i. e. a grown up Lady.
They charge me with their best compliments to you and Mrs.
Faraday, to whom you will remember me in particular and in
the most friendly manner. Excuse my badly written letter,
which I was obliged to scribble down in a great hurry and
believe me, my dear Faraday

Yours

most truly

Bale Dec. i8th 1852. C. F. SCHOENBEIN.

Schoenbein to Faraday.
MY DEAR FARADAY

Many months ago I sent you a letter and some
papers of mine without having received from you any answer
since. Being afraid of my parcel having been miscarried I
forward to you another by the kindness of Mr. Drew 1 of
Southampton and hope you will get it in time.

1 John Drew, a school teacher at Southampton, was born in 1809 at
Bower Chalk, Wiltshire and died in 1857 at Surbiton in Surry.

— 213 —

The single paper treats of a subject of a general nature,
and if you should feel curious to get acquainted with certain
views of your friend Schoenbein, you will perhaps find some-
body translating it for you.

The question of the nature of Ozone seems to have been
settled in the laboratory of Mr. Bunsen1 at Heidelberg and it
appears that both views hitherto entertained about that subtle
agent are correct2; there is one sort of Ozone containing
nothing but Oxigen and another that contains some hydrogen.
Common oxigen, being absolutely anhydrous, is transformed
into the first one by electrical discharges, as de la Rive3 and
Berzelius4 maintained some years ago. The odoriferous prin-
ciple disengaged at the positive Electrode on electrolysing
water is a compound consisting of two Eq. of pure Ozone or
allotropic oxigen and one Eq. of water = HO 3.

How such a wonderful change of properties can be effected
in oxigen without adding to or taking away any ponderable
substance from that body is indeed very difficult to say; I at
least know nothing about it, but suspect that something very
fundamental is at the bottom of that fact. It is a riddle to
be solved by you only.

Just preparing for a journey to Vienna and Munich, I am
in a great hurry and you will therefore excuse the emptiness
of this letter. I promise you to write a better one after my return,
which will not be prolonged beyond four weeks. I intend to
go down the Danube, the scenery of which is as yet entirely
new to me.

1 Robert Wilhelm Bunsen, professor of Chemistry at Marburg, Breslau (1851)
and Heidelberg (1852). He was born in 1811 at Gottingen and died at Heidel-
berg on the i6th of August 1899.

2 cf. Baumert: "Uber eine neue Oxydationsstufe des Wasserstoffes und
deren Verhaltnis zum Ozon." Poggend. Annal. Bd. 89. 1853. p. 38.

3 cf. Arch, de 1'Elect. T. 5. 1845. p. n.

4 Berzelius, Jahresbericht. Bd. 26. 1847. p. 64.

— 214

Pray transmit leisurely the volume laid by to Mr. Grove,
who I think now and then sees you in the Royal Institution.

In asking you the favor to present my best compliments
to Mrs. Faraday I am

My dear Faraday

Your's

most truly

Bale July 11. 1853. , C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 25 July 1853
MY DEAR SCHOENBEIN

I believe it is a good while since I had your
last letter i. e. the one previous to that I received by the
hands of Mr. Drew. — But consider my age and weariness
and the rapid manner in which I am becoming more and more
inert - - and forgive me. Even when 1 set about writing I am
restrained by the consciousness that I have nothing worth
communication. To be sure many letters are written having
the same character; but then there is something in the manner
which makes up the value : and which when I receive a letter
from a kind friend, such as you, often raises it in my estimation
far above what a mere reader would estimate it at. So you
are going down the Danube, one point on which I once saw,
and are about enjoying a holiday in the presence of pure
nature. May it be a happy and a health giving one and may
you return to your home loving it the better for the absence
and finding there all the happiness which a man, sound both
in mind and body, has a right to expect on this earth.

I have not been at work except in turning the tables upon
table turners — nor should I have done that but that so many

— 215 —

enquiries poured in upon me that I thought it better to stop
the inpouring flood by letting all know at once what my views
and thoughts were.1 What a weak, credulous, incredulous, un-
believing, superstitious, bold, frightened, what a ridiculous world
ours is, as far as concerns the mind of man. How full of in-
consistencies, contradictions and absurdities it is. I declare
that taking the average of many minds that have recently come
before me (and apart from that spirit which God has placed
in each) and accepting for a moment that average as a stan-
dard, I should far prefer the obedience, affections and instinct
of a dog before it. Do not whisper this however to others.
There is One above who worketh in all things and who governs
even in the midst of that misrule to which the tendencies and
powers of man are so easily perverted.2

The Ozone question appears indeed to have been consi-
derably illuminated by the researches in Bunsen's laboratory.

- But why do you think it wonderful that Oxygen should
assume an allotropic condition ? We are only beginning to
enter upon the understanding of the philosophy of molecules
and I think, by what you say in former letters, that you are
feeling it to be so. Oxygen is of all bodies to me the most
wonderful, as it is to you. And truly, the views and expec-
tations of the philosopher in relation to it would be as wild
as those of any table turner etc. etc. etc. were it not that the
philosopher has respect to the la^vs under which the wonderful
things that he acknowledges come to pass, and to the never
failing recurrence of the effect when the cause of it is present.

- At the close of our Friday Evenings I gave a little account

' Faraday after opening the question, which had taken so strong a hold
of the public mind, in a letter to the "Times", in June, so Bence Jones tells
us, wrote a long letter to the Athenaeum for Juli 2 1853, °f which he was a
little ashamed for "I think it ought not to have been required". He does not
hope to convince all who refer this purely physical subject to electricity, or to
some unrecognised physical force, or even to some supernatural agency.

2 This passage is given in Thompsons Life and Work of Faraday, p. 252.

— 216 —

to our members of Fremy and Becquerels1 expts. in producing
Ozone by Electricity — and I confess myself glad that, whilst,
at Heidelberg, they have shewn an HO3, they have also proved

the existence of a trace of O.

My dear Schoenbein, I really do not know what I have
been writing above and I doubt whether I shall reread this
scrawl, least I should be tempted to destroy it altogether. So
it shall go as a letter carrying with it our kindest remem-
brances to Madam Schoenbein and the sincerest affection and
esteem of

Yours Ever Truly

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY

Some weeks ago I returned from the journey I
have undertaken to Bavaria, Austria etc. during our mid-summer-
holidays; and I can assure you that it was a very plesant one.
The first stay I made at Munich, where I remained no less
than ten days, finding that town highly pleasing and interesting
both for the men and the things, I chanced to meet and see
there. I think you would relish it as much as I did and if
you should have any mind to cross the water once more, I
strongly recommend you taking a trip to the Capital of Bavaria.
The number of exquisite objects of painting, sculpture, archi-
tecture etc. accumulated there, is very great indeed and placed
so closely together that you may see and enjoy them with
perfect ease and comfort. Of course I met Liebig 2 at Munich,

1 Fremy et Becquerel, Recherches electrochimiques sur les proprie"tes des
corps electrises. Paris Comptes rendus. T. 34. 1852. p. 399.

* Justus von Liebig Ph. D. M. D. started life as an apothecary's assistant.
Later he became professor of chemistry at Giessen and at Munich (from 1852).
He was born at Darmstadt in 1803 and died at Munich in 1873.

whom I knew before little more than by sight, but within the
first five minutes we had found out the footing upon which
both of us could move comfortably enough.1 You will laugh
when I tell you that Liebig asked me to deliver a lecture be-
fore a very large audience in his stead and Mr. Schoenbein,
though reluctantly, yielded to that strange demand. The subject
treated was that queer thing called "Ozone" which ten or
twelve years ago as you are perhaps aware, was declared by
a countryman of your's and pupil of Liebig's to be a "nonens".
Nothing was easier to me than proving its corporeal existence
and our friend Liebig, in spite of the unfriendly feelings he
formerly entertained towards my poor child, has now taken
it into his favor and seems even to have fallen deeply in
love with the creature. He has therefore repeatedly entreated
me to write a sort of biography of my progeny and give an
account of its education and the accomplishments it has acquired
under my tuition during the last decennium. I do not know

1 Schcenbein relates this meeting with Liebig in his "Menschen und Dinge"
(published in 1855) which in fact is a record of his esperiences and adventures
during this trip. We must however confine ourselves to quoting a few passages
descriptive of this meeting with Liebig :

"It was about the year 1820, that two youths were wont to attend daily
the lectures delivered by the professor of chemistry at Erlangen, sitting together
on the same bench, knowing of each other their names only and nothing else.
The one was slender and slim, his gait erect, boldly he faced the world; the other
short and stout, and stooping somewhat; a physiognomist might have taken him
for a theosophist or a fanciful philosopher.

Even as they lived at Erlangen, so they parted, neither having any know-
ledge of the aims the other had determined upon. Not many years elapsed
before the fame of one spread over the world; whereas to the other fell a
more humble lot.

Without avoiding, or seaking each other, a friend (Professor Pettenkofer
of Munich) brought them together. Veni, vidi, victus sum, the one exclaimed
and gladly was he vanquished. What two terms at college, what a period of thirty
years were incapable of achieving, was now brought to pass by a few moments.

Notwithstanding the great dissimilarity of their characters, they were
alike in one respect: "in their devotion to science and in their zealous aspirations
and endeavours to reveal to mankind the operations and the functions of nature".

218 —

yet whether I shall comply with his wishes being not very fond
of copying myself over and over again.

My trip on the Danube down from Ratisbonne to Vienna
proved highly delightful to me, though I experienced the mis-
hap of losing my pocket-book and along with it may passport,
no joke to a travaller who was about to enter the austrian
Empiry. No unpleasant results however issued from that ad-
venture. The scenery down the river merits to be called beau-
tiful; now and then the Danube is forced to make its way
through very deep and narrow ravines, the top of the hills
being covered with ruined castles, churches, convents, country
seats etc. and their declivities richly woo ded ; another time you
enjoy a beautiful and extensive view on the Alps of the Tyrol,
Salzburg, Styria etc. —

Vienna itself is a fine and a noble town, full of interesting
objects of science and arts and its inhabitants have become
proverbial for their good nature. There is therefore no wonder
that I enjoyed there very agreeable days. - In going home I
passed through Prag, Dresden, Leipzic, Frankfort etc seeing
little more of those cities than their steeples and towers, for
having stayed out so long, I was obliged to return to Bale as
quickly as possible. Mrs. Schoenbein and the girls have during
my absence been living in the hills, according to our usual
style of passing the midsummer holidays. My eldest daughter
has been absent from home these last 5 months and lives very
happy on the beautiful lake of Geneva, at a little place called
Rolle. She hast almost grown up into womanhood, is very
like her mother, only a little taller and upon the whole a good-
natured and dutiful child. I think you would like her. Our
friend de la Rive was kind enough to invite her to pass the
approaching season of the vintage at his country seat, near
Geneva.

Now having talked so much about myself and my family,
it is time to ask you how you and your amiable Lady are

doing. I hope well, in spite of the oriental and other affairs
of the world. I should feel over happy if it fell to my lot
to see you once more and to accomplish my wishes I see no
other means than your coming over to us.

Mrs. Schoenbein joins me in her kindest regards to Mrs.
Faraday and I beg you to believe me for ever

Your's

most truly

Bale Septbr. 24. 1853. C. F. SCHOENBEIN.

Faraday to Schmnbein.

Royal Institution 27 January 1854
MY DEAR FRIEND

Your letter of Octr. last was well timed, for it
found me somewhat tired and out of health and by its happy,
affectionate feeling was quite a cheerer. I do not find that as
my philosophical past wears out, I at all diminish in my desire
for the kindly, sympathizing and brotherly feelings which have
grown up with it. Your holiday trip must have been a delight-
ful one, but such things are for quasi young men. I have be-
come a mere looker on. Still I and my wife do get a few
short trips, for instance to Wales, or Norfolk, or Brighton, but
as to crossing the Channel again I doubt it. — I enjoy greatly
the account of your meeting with Liebig, and the Ozone affair:
- it was very excellent and came off well for you. I like
such an end to a controversy, and I think you must feel that
you have had a very refined revenge upon your too hasty
and too positive opponents. Furthermore I think the chrono-
logy of Ozone, as you speak of it, would be a very desirable
thing.

22O

Your family account is very pleasant and I try to imagine
Miss Schoenbein upon the model of what I remember of Madame
Schoenbein when we were in Basle: — but I have no doubt
my idea is a great mistake. - - No matter, it is very pleasant,
and you must give our kindest remembrances to Madame
Schoenbein. I do not suppose there is any body else at home
who remembers me. It would be a delightful thing to accept
your invitation and pop in: - - but unless I can go by the
telegraph line I am afraid that will not happen.

By the bye I have lately been examining some very curious
facts obtained with telegraph lines of which you will see a
report in our proceedings l in due time for I gave an account
of them last Friday to our Members. They cover copper wire
with Gutta Percha here (for insulation in submarine and other
cases) so perfectly, that it remains beautifully insulated. I worked
with 100 miles in coils immersed in the water of a canal; yet
with 360 pairs of plates the conduction through the gutta percha
was able to deflect a delicate galvanometer only 5 °. The copper
wire is Vie of an inch in thickness and the thickness of the Gutta
percha on it is about l/io of an inch - - so that TOO miles
gives a Leyden jar, of which the inner coating (the copper
wire) has a surface of 8272 square feet, and the outer coating
(the water at the G. P.) four times that amount or 33000 square
feet. - This wire took a charge from a Voltaic battery and
could give back the electricity in a discharge having all the
characters of a Voltaic current.

Furthermore such a wire when under ground or under
water is so affected by the transition of dynamic into static
electricity, as to require a hundredfold the amount of tension
for the transmission of an electric pulse, as the same wire
suspended in the air: an effect of this kind is the interpretation
of the extraordinary diversity in the expression of electric

1 "On subterraneous electrotelegraph wires." Phil. Mag. Vol. 7. 1854. p. 396
and "On electric conduction." Roy. Inst. Proc. Vol.2. 1854 — 1858. p. 123.

- 221 —

velocity given by different experimenters. — But you will hear
of all this in the report, when it comes out, which will be soon.
Our librarian Mr. Vincent tells me that the Berichte der
Verhandlungen der Naturforschenden Gesellschaft Basel, Band
T to 8 are not in our Library and he cannot get them here. He
thinks your University distributes them to different bodies. If
so is it possible for us to have that privilege? I ask you in
all ignorance. — But do not by any means let me be ignorantly

intrusive.

Ever My dear Schoenbein

Yours

M. FARADAY.

Schoenbein to Faraday.

Bale Febr. loth 1854.
MY DEAR FARADAY

At last I have seen again some lines from the
Master of the Royal Institution and I can assure you that the
mere sight of his handwriting gave me infinite pleasure, as it
yielded me a visible proof of his being still amongst the living,
and able to handle the pen, for I will not conceal it from
you, that the long silence he kept this time, had already begun
to cause feelings of uneasiness about the well-being of the
dearest of my friends.

What you tell me of your late electrical experiments
makes me very curious to learn the details of them, which I
hope will soon be the case. It seems to me that we are as
yet very far from having arrived at a standstill in electrical
researches.

As to my little scientific doings I have continued to study
the influence exerted by temperature upon the colors of sub-
stances and obtained some pretty results. You are perhaps

222

aware that some time ago I tried to prove that a great number
of oxycompounds being more or less colored at the common
temperature, would turn colorless on being sufficiently cooled
down, each of such substances having its peculiar temperature
at which its color entirely disappears. I think I have satis-
factorily proved that even common Ink is in that case, and
you may easily convince yourself of the correctness of the
statement. Color a weak solution of gallic acid, by some drops
of a dilute solution of perchloride of iron, darkblue, even to.
opaqueness; put the colored liquid into a frigorific mixture of
muriatic acid and snow until frozen, and you will of course
obtain a darkcolored ice; cool it then down to about 40° below
zero, or somewhat less, and you will have a colorless ice, which
on increasing its temperature again will reassume its color,
before having arrived at its melting point. From some reasons,
I was led to conjecture that there must exist a series of bodies
that exhibit the reverse behaving i. e. grow colored on their
temperature being sufficiently lowered, and my conjectures
proved to be correct. The coloring matters of a great number of
red and blue flowers such as Dahlias, Roses etc. being associated
to sulphurous acid, are at the common temperature nearly or
entirely colorless; now aqueous solutions of those matters, having
been uncolored by aqueous sulphurous acid, become beautifully
and intensely recolored on being sufficiently cooled down, to
lose their color again on raising the temperature of the ice,
and I must not omit to mention that the colorless state is
reassumed before the melting of the ice.

I have particularly worked upon the coloring matter of a
certain sort of darkbrown Dahlia, very common with us, which
exhibits the change of color indicated in a most beautiful manner.
On account of the easy mutability of that matter in its dis-
colored state, I preserve it by the means of filtering paper,
which I rub with the leaves of the flower and suffer it to dry;
.such paper, of which I send you a little specimen, yields very

•easily the coloring matter to water, coloring beautifully the
latter. A fresh solution of that kind should always be employed
on making the experiment and you will be successful, when
you employ my paper for preparing the solution.

It is a fact worthy of remark that such a solution rendered
colorless by SO2 turns colored also by heating it to its
boiling point.

In want of something better, you might perhaps give the
substance of my late researches on colors and the connexion
with the chemical constitution of the matters exhibiting them
in a Friday Evening, for the effects are very striking. Part
of the results are described in the X volume of the proceedings
of the Phil. Society of Bale, part in a memoir published in the
proceedings of the Academy of Vienna which most likely will
be republished in Liebigs Annals and some, notably those
above mentioned, are not yet made known at all.

You are most likely aware that Dr. Baumert1 has of late
confirmed the results previously obtained by de la Rive,
Marignac, Berzelius and myself as to the capability of the
purest i. e. absolutely anhydrous Oxigen of being thrown into
its ozonic state by the means of the electrical discharge and
I am therefore inclined to think that we can no longer doubt
of the important fact that oxigen may exist in two different
states, in an active and inactive one, in the ozonic condition
and in the ordinary state.

Now such a fact cannot fail bearing upon a great number
of chemical phenomena and I am just now drawing up a sort
of memoir in which I try to embody the Ideas and Views on
Electrolysis, Thermolysis and Photolysis (sit venia verbis).
I have been carrying about in my head, these many years,

1 Friedrich Moritz Baumert was born in 1818 at Hirschberg in Silesia and
died in 1865. He for many years practiced as a physician at Breslau and in 1855
was nominated Professor of Chemistry at Bonn. It is very probable that his
paper on ozon was worked out at Breslau, when Bunsen was professor there
in 1851 and 1852.

— 224

ideas so very strange and queer, that they will meet with but
very little favo[u]r.

To give you some notion about their singularity and
heterodoxical character allow me to state some of them, but
in doing so I must ask you the favor to consider them as
mere Ideas and Views.

1. There are no other electrolytes (taken that term in the
limited sense, you attach to it) than oxycompounds.

2. There are no compound Ions such as acids, and it is
only the basic oxide of salts upon which the electrolysing
power of the current is exerted.

3. The theory of Davy on the nature of Chlorine, Bromine,
Jodine, the acids and salts is unfounded.

4. Electrolysation depends, in the first place, upon the
capability of common oxigen to assume the ozonic state, when
put under the influence of electrical discharge, and in the
second place, upon the power of the current to carry, under
given circumstances, matters from the positive to the negative
electrode i. e. in the direction of the current itself.

5. The transfer of the electrolytic fluid from the positive
to the negative electrode, as observed by Wiedemann, and
others, is closely connected with the travelling of the kation
in the same direction.

6. The travelling of the anion, i. e. Oxigen, is only ap-
parent or relative, being caused by the real travelling of the
kation.

7. Chemical decomposition caused by electricity, heat, and
light depends upon allotropic modifications of one or the other
constituent part of the compounds decomposed.

8. Chemical synthesis caused by electricity, heat and light
is closely connected with allotropic modifications of one or
the other matter conserned in that chemical process.

9. The notions of chemical affinity such as they are enter-
tained at present cannot be maintained any longer.

You see such assertions are bold enough, so bold indeed,
that I am afraid even You, the boldest philosopher of our age,
will shake your head; but I think there is no harm in going
a little too far, truth will make its way in spite of it and if
the feelings of our cook-like Chymists, who are brewing on
and on their liquors and puddings, without paying much attention
to the conditions of the primary matters they are continually
mixing together, should be roused even to wrath, I would not
only care very little about it, but even take some pleasure in it,
for I cannot deny that now and then I grow very angry about
the narrow, or little-mindedness of the generality of the tribe.1
Being now in a confessing mood of mind, I will openly tell you
that Davy's theoretical views are most particularly unpalatable
to my scientific taste, and I cannot help thinking that they have
retarded rather than accelerated the progress of sound chemical
science. — As to some of his scientific doings they are certainly
of a superior kind and nobody can value them more than I do.
The heterodoxical memoir alluded to will not henceforth go
forth to the world, for I shall try to work it out as well as I can.

In April next I think to fetch my eldest daughter back
again from the "Welschland" 2 to put the second there. Your

1 This harsh verdict was one frequently returned by the old school of
chemistry — we have on several occasions given illustrations thereof — and per-
chance they were not far wrong. Notwithstanding its great practical value and
importance, its extraordinary development, of so extreme consequence to political
economy, organic chemistry remains — this should not be forgotten — the chemistry
of one element only, of carbon. We have therefore no reason to be surprized,
if such a system caused displeasure to those, who were as yet unacquainted with
so one-sided a training.

Even Wohler expresses himself dissatisfied with the position of organic
chemistry, for he writes to Schoenbein, May 21. 1862, from Gottingen : "I am
afraid I shall have to give up my trade ; I am far too inert to keep up with
organic chemistry, it is becoming too much for me, though I may boast of
having contributed something to its development. The modern system of for-
mulae is to me quite repulsive."

• By "Welschland" is meant French Switzerland, whese children were sent
to learn French.
P

226

imagination gives you a correct idea of Miss Schoenbein, for
she is really in many respects a second edition of her Mother.
Our phil. society will take great pleasure in sending you the
whole series of their proceedings and in receiving, what your
Institution is publishing. As the crossing of the channel and
coming over to Switzerland is a matter of a couple of days,
I will not give up the pleasing hopes of seeing you and Mrs.
Faraday once more with us in Bale, where you have more
friends and admirers than you are aware of.

Pray present my most humble compliments to your Lady

and believe me

Your most affectionate friend

C. F. SCHOENBEIN.

NB. Mrs. Schoenbein and the Children charge me to remem-
ber them kindly to you.

As I have something to send to Southampton you will
receive my letter from that town.

P. S. In reading over the preceding lines I feel I have
written a very bad english letter, but I will not write another
for fear of making it still worse. Being entirely out of the
habit of speaking, writing and I may say even reading in your
native tongue, I must necessarily lose the knowledge of it.
And that you must take for my excuse. S.

Schoenbein to Faraday,

MY DEAR FARADAY

These lines will be delivered to you by Mr. Merian
of Bale a former pupil, and the son of a most intimate friend

22;

of mine, the well know swiss Geologist Peter Merian.1 My
young friend being an Engineer and going to England with the
particular view of seeing your railways and establishments for
manufactoring locomotives etc. you would render him a great
-service by getting him introduced to some superintending rail-
way engineers and manufacturers of locomotives. Mr. Merian
is a very excellent man, distinguished mathematician, well
versed in engineering, and in every respect highly respectable.
You may therefore strongly and confidently recommend him
to any of your friends and I need not say that by doing so
you will lay me under very great obligations.

You have no doubt received my last letter as well as a
memoir of mine, which I sent you through Mr. Gould, the
Ornithologist, and I have gratefully to acknowledge the receipt
•of your last paper on Electricity.

Its contents proved highly interesting to me and most
particularly to that part of it which refers to the variations of
the velocity of the current.2

Having repeatedly been called upon by Mr. Liebig to
draw up for his annals a paper embodying all the leading facts
relative to Ozone I have a last complied with the wishes of
my new friend, and send you a copy of it.3 From a note of
Liebig's joined to my paper you will perceive that the cele-
brated Chymist of Munich has taken a lively interest in the
matter4 and in a letter, he wrote me a couple of days ago, he

1 Peter Merian was from 1820 — 1828 professor of Chemistry at Bale, where
Tie was born in 1795 anc' where he died in 1883. From 1835 he was honorary
professor of Geology.

2 Benjamin Apthorp Gould, Director of the Albany Observatory N. Y.
{born in 1824 at Boston) also contributed a paper on the velocity of galvanic
currents, vide Sillim. Journ. (N. S.) vol. II and 17. 1851.

3 It is a compilation of everything concerning Ozone and appeared in Liebigs.
Annal. Bd. 89. 1854. p. 257 under the following heading: "Uber verschiedene
'Zustande des Sauerstoffs "

4 He writes to Schcenbein, Sept. 19. 1853: "Your visit to Munich was a
momentous one for me, for through it 1 have become acquainted with the

— 228 —

expresses his conviction, that the discovery of the ozonic Con-
dition ot Oxigen, and the facts connected with that subject, will
exert a great influence upon the future development of Chemical
Science.1 I have been of a similar opinion these many years.

My paper on the chemical effects produced by Electricity>
Heat and Light, of which I talked to you in my last letter is
going to be printed2 and as soon as finished, you shall have
it, but I am sorry for you to say that it is written in my native
tongue; being however not very voluminous you may easily
get it translated for you. I should like very much indeed that
you would take notice of its contents.

Mrs. Schcenbein and the girls are doing well and charge
me with their best compliments to their friend at the Royal
Institution. I join my kindest regards to Mrs. Faraday and.

am for ever

Your's

most truly
Bale April 9. 1854. C. F. SCHOENBEIN.

Schcenbein to Faraday.
MY DEAR FARADAY

Mr. Stehlin, Juris utriusque Doctor, of Bale will
perhaps take the liberty to call upon you, to enquire after the

interesting results of your investigations; I look upon them as of the greatest
consequence to the development of natural philosophy." Vide Kahlbaum and
Thon, Briefwechsel Liebig-Schoenbein, p. 18. Leipzig 1899.

1 Liebig says: "Professor Schrenbein , at my request, has compiled his
investigations on this subject. To me these phenomena and observations, which
this renowned investigator describes, are of the highest importance and conse-
quence to science, for the disclosure of new properties of matter has ever been
the origin of new laws and the source of insight into phenomena hitherto not
accounted for."

- Basl. Verh. Bd. i. 1854. p. 18.

229

address of Mr. Grove and in that case I beg you to be friendly
to my young friend, who is an excellent and uncommonly well
informed man. Going to England with the intention of making
himself acquainted with the law and courts of the country, you
may perhaps be able to favor the views of Dr. Stehlin by
giving him an introductory line to some of your friends, who
happen to be a lawyer or otherwise connected with a court
or a lawyer's inn.

I am back again from the journey I made the other day
to the lake of Geneva, and thank God brought home my eldest
daughter in perfect health. She has turned out a good girl,
being highly affectionate to her parents and sisters. I think
you would like her.

Pray let me soon hear from you and believe me

Your's

most truly

Bale Mai 4th 1854. C. F. SCHOENBEIN.

Mrs. and Miss Schoenbein join me in their kindest regards
to Mrs. Faraday and yourself.

Faraday to Schcenbein.

Royal Institution 15 May 1854.
MY DEAR SCHOENBEIN

Your letters stimulate me, by their energy and
kindness, to write, but they also make me aware of my inabi-
lity, for I never read yours, even for that purpose, without
feeling barren of matter, and possessed of nothing, enabling
me to answer you in kind: — and then on the other hand, I cannot

— 230 —

take yours and think it over, and so generate a fund of philo-
sophy, as you do, for I am now far too slow a man for that-
What is obtained tardily by a mind, not so apt as it may have
been, is soon dropped again by a failing power of retention,,
and so you must just accept the manifestation of old affection
and feeling in any shape that it may take, however imperfect.
— I received your paper: and though a sealed book to me at
present, I have put it into thehands of Mr. Stokes whose resear-
ches on light I think I mentioned to you.1

I made the experiments on the Dahlia colours, which you
sent me, and they are very beautiful. Since then I have also
made the experiment with ink, and Carbonic acid (liquid), and
succeeded there also to the extent you described. I had no
reason to expect, from what you said, that dry ink would
lose its colour, but I tried the experiment and could not find,
that the carbonic acid bath had power to do that Many years
ago, I was engaged on the wonderful power, that water had,
when it becomes ice, of excluding other matters. I could even
break up compounds by cold; thus, if you prepare a thin glass
test tube, about the size of the thumb, and a feather so much
larger, that when in the tube, and twirled about, it shall rapidly
brush the sides: if you prepare some dilute sulphuric acid, so
weak that it will easily freeze at o° Fhrt. - - and putting that
into the tube, with the feather, you put all into a good freezing
mixture of salt and snow: — if finally, whilst the freezing goes
on, you rotate the feather continually and quickly, so as to
continually brush the interior surface of the ice formed, clearing
off all bubbles and washing that surface with the central liquid;
you may go on until a half, or two thirds, or more, of the
liquid is frozen and then, pouring out the central liquid, you
will find it a concentrated solution of the acid. After that, if
you wash out the interior of the frozen mass, with two or three
distilled waters, so as to remove all adhering acid, and then

1 vide sopra p. 209.

warm the tube by hand, so as to bring out the piece of ice,
it, upon melting, will give you pure water,

not a trace of sulphuric acid remaining in it. The same was
the case with common salt solution, Sul. Soda, Alcohol, etc
etc, and if I remember rightly, even with some solid compounds
of water. I think I recollect the breaking up of crystals of Sulphate
of Soda by cold, and I should like very much now to try the
effect of a carbonic acid bath on crystals of Sulphate of copper.
So it strikes me that in the effect of the cold on the colourless
dahlia solution, the reappearance of the colour may depend upon
the separation of the Sulphurous acid from the solidifying water.

Your nine conclusions in the letter you last sent me are
very strong and will startle a good many, but if the truth is
with them, I should not mind the amazement they will pro-
duce nor need you mind it either; but the chemist, of which
body I do not count myself one now a days, will want strong
proof and be slow to convince. — As to the electrical matters
I referred to, I expect you have received by post a printed
account of what I there referred to.

I think some of my letters must have missed; you scold
me so hard. As I cannot remember what I have sent or said,
I am obliged to enter in a remembrance the letters written or
received and looking to it find the account thus:1 1852 Decr 8.
S. to F.2 - - Dec. 9. F. to S.3 - - Dec. 29. S. to F.4 - 1853

1 Faraday, in enumerating these letters apparently gives the dates on which
he received them from Schosnbein, so that the dates at first sight do not seem
to correspond with Schoenbeins.

'* Missing: unless we assume that he received the October 17. letter as
late as December. In his letter to Schcenbein of December 9 he at all events
speaks of it as Schcenbeins last letter. 3 vide -p. 207. 4 vide p. 210.

— 232 —

July 24. S. to F.1 - - July 25. F. to S.2 -- Octr S. to F.3 -
1854. Jan* 27. F. to S.4 - - Feb? 17. S. to F.5 -- May 15. F.
to S6. and considering that I have little or nothing to say and
you are a young man, in full vigour, that is not so very bad
an account, so be gentle with your failing friend.

You say that in April you are to fetch a daughter from
the "Welchland" etc. I had the foolish thought (perhaps), that
you were coming to England and have been hoping to see
you, but I suppose mine was all a mistake, for here is May.
As for us, we do not expect to move far from home now; the
imagination rambles and the desire also, but the body is too
heavy and earthly. Our kindest remembrance to Madame
Schoenbein and to all, who remember us. Young folks cannot
be expected to retain much idea of old ones, after so long

a while

Ever My dear friend

Affectionately Yours

M. FARADAY.
Ait

Schoenbein to Faraday.

MY DEAR FARADAY

Now a days people talk so much about the won-
derful improvements of the ways of communication, and inter-
course being established between the different parts of the
civilized world and to us it is a most difficult matter to send
a little parcel from Bale to London. Without that deplorable
deficiency, you had certainly received many weeks ago the

1 probably Schcenbeins letter of July nth. 2 vide p. 214. * perhaps
Schcenbeins letter of September 24, p. 216. 4 vide p. 219. 5 vide p. 221
letter of February loth. 6 vide p. 229. Between No. 5 and 6 are the two
letters brought over by Mr. Merian and Dr. Stehlin respectively, which Faraday
has forgotten to mention.

— 233 —

paper enjoined, but I was forced to wait until chance yielded
me an opportunity to forward it to you. I should like very
much, you would read the memoir for it contains my views on
the proximate cause, not only of Electrolysis but also of what
I have ventured to term Thermolysis, Photolysis, Electrosyn-
thesis, Thermosynthesis and Photosynthesis, i. e. of chemical
decompositions and compositions being effected by the agencies
of electricity, light and heat. My leading idea is this, that
the phenomena mentioned are due to allotropic modifications,
which the elementary bodies, being concerned in those analytical
and synthetical processes, undergo, when placed under the in-
fluence of the agencies named.

HO is decomposed, because its O, on being put under

the influence of the current happens to be transformed into O l
(by which I mean ozonized Oxigen) which as such cannot

form water with H. Oxide of Silver, which I hold to be AgO
is decomposed by heat, because this agency transforms O
into O, which cannot combine with Ag etc. etc. etc. Perhaps
a friend of your's will take the trouble to translate the paper,
for without reading the whole chain of my reasoning and
arguments, I am afraid, you will not well understand the neolo-
gical views of your friend. As to the electrosynthesis of oxigen
and oxidable matters, I think I have been entirely successful
in proving that it is due to the ozonisation of oxigen being
effected by electrical discharge.

1 The history of the origin of these signs is to be found in a paper read
by Schcenbein before the Scientific Club of Bale, on April 21. 1847, an abstract
of which appeared in the "Verhandl. der Naturf. Gesellsch. in Basel." Bd. 8.
1846 — 1848, p. 6. In it he proposes calling oxygen, capable of combining with
other bodies at ordinary temperatures, "oxylised oxygen" , and giving expression
to this difference, in their respective formulae, by the addition of the letter o,
for oxylised oxygen. Thus the peroxides of hydrogen and of manganese he
writes, respectively, HO + O and MnO + O. Since, according to his views,
chlorine, bromine, and iodine are normal peroxides, their formulae must be
MuO + 6, BrO + 6 and IO + d.

234 —

At this present moment I am busily engaged in researches
on the desozonising influence, being exerted by ponderable

matters upon O, and the results already obtained leave, I think,
no doubt, that a number of substances enjoy, conjointly with

heat, the power of transforming both free and latent O into O,
a fact which is interesting enough, but by no means surprizing
to me. Ozonized oxigen by whatever means, electrical or
chemical, it may have been generated, on being put in contact
with the peroxides of lead, manganese, silver, the oxides of
mercury, the oxide of copper or silver and gold, the peroxide
of iron etc., is immediately brought back to its inactive state
and the simplest way of showing this desozonizing action is
as follows: Charge bottles with air being strongly ozonized by
phosphorus, introduce some finely powdered peroxide of Silver,
Lead, Manganese, Iron etc. and shake the whole for half a
minute, or less, and you will find that your Ozone is gone,
no smell and action upon the test-paper being perceived any
more. The substances just named, being saturated with oxigen
cannot, as oxidable matters do, take up Ozone and hence it
seems to follow that in one case the disappearance of ozonized
oxigen is due to its having been transformed into O, in the
same way as this change of state is effected by heat.

Thenard's i peroxide of Hydrogen2 is to me HO + O and
you know well enough that the oxides, which, according to
my late experiments, destroy the ozonized condition of oxigen,

have also the power of decomposing HO + O into HO and O.
Chlorate of potash is to my notion ozonized oxigen, asso-

ciated to muriate of potash, now this O may speedily be trans-
formed into O by the aforesaid oxides and peroxides and I
find that peroxide of iron enjoys that power to a very remark-

1 Louis Jacques Th6nard, professor of Chemistry at the College de France
was born in 1777 at Louptiere and died in 1857 at Paris.

2 Paris M6m. Acad. Sci. T. 3. 1818. p. 385. cf. a Gilb. Annal. Bd. 64.
1820. p. i.

— 235 —

able degree, for l/iooo part of it only, being mixt with the
melted salt, will cause a lively disengagement of oxigen, even
at a temperature, at which the pure chlorate does not yet
yield a trace of that gas. '/loo part of the peroxide named
gives rise to such a violent elimination of oxigen as nearly to
approach an explosion and produce an incandescence of the salt.
A small portion only of a large and intimate mixture of
one part of peroxide of iron and 50 parts of chlorate of potash
being just heated to the point of fusion of the salt occasions
such a rapid and complete decomposition of the latter, that
the whole mass quickly and spontaneously becomes incandes-
cent without having time to fuse. The higher the degree of
mechanical division given to the oxide employed, the greater
the desozonising or decomposing power of that matter. I
entertain very little doubt that the same cause which acts in
the peroxide of iron etc, and determines the transformation

of free O into O, also produces the same effect upon ozonized
Oxigen, being contained in the peroxide of Hydrogen, Chlorate
of potash etc ; in other terms that the desozonisation of the oxigen
of the oxy-compounds named and their decomposition are pheno-
mena depending upon each other. It appears to me, to be a very
singular fact, and therefore worthy of remark, that the oxigen
of all the oxides or peroxides, which enjoy the power of des-
ozonising free O etc, exists either wholly or partly in the
ozonized state itself. I hardly need add that what they call
catalytic actions are to my opinion referable to allotropic
phenomena. But of that more another time. From the prece-
ding communications you will easily perceive, that I cannot
get out of the charmed circle, drawn round me by that arch-
conjurer called oxigen, and I am afraid, so long as I can walk,
I shall move on that narrow ground.

I cannot conclude without expressing you my most grateful
thanks for the kind letter, with which you favored me some
weeks ago and I must tell it you over and over again, that

- 236 -

the mere sight of your hand writing gives me infinite pleasure
and always conjures up the image of its author, whom I revere
and love more intensely than any other of my friends.

I read your remarks on the chemical effects produced by
cold with the greatest interest; it is indeed a subject of research
worth while to pay the greatest attention to and I very little
doubt, that your conjecture on the proximate cause of the
recoloring of the Dahlia pigmentum is correct.

I must not omit to tell you that we have kept in readiness
the numbers of the proceedings of the Phil. Society of Bale
for the library of the Royal Institution, these many months;
but up to this present moment we have not yet found a con-
venient opportunity for sending them off and beg therefore
not to be charged with carelessness.

Next month I shall take a trip to the eastern Cantons of
Switzerland, to attend a meeting of our Swiss Association and
go perhaps for a week or so to Munich and Nuremberg. Mrs.
Schoenbein intends to pass some time with her parents at
Stuttgart, and the girls, who are at home, will be placed on
the heights of the Jura to inhale its bracing air, jump about
like chamois on rocks and in dales, in woods and on meadows.
They charge me to offer to yourself and Mrs. Faraday their
kindest regards, to which I join my own. Believe me my

dear Faraday for ever

\ our s

Bale July 4. 1854. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 15 Septr. 1854
MY DEAR SCHOENBEIN

Just a few scattered words of kindness, not philo-
sophy, for I have just been trying to think a little philosophy
(magnetical) for a week or two, and it has made my head

— 237 —

ache, turned me sleepy in the day-time as well as at nights,
and, instead of being a pleasure has for the present nauseated
me. Now you know that is not natural to me, for I believe
nobody has found greater enjoyment in physical science than
myself; but it is just weariness, which soon comes on, but I
hope will soon go off, by a little rest. However, rest is not
to be had yet, for as I have not been to the British Association
for some years, I have promised to go next week to Liverpool,
and I know from experience, that is not rest. I do not intend
to stop more then three days. Though I date from the In-
stitution, I may say that we are 12 or 14 miles out of town,
getting some fresh air. We are often obliged to go out of
town and that is the reason why I have not seen your friend
Mr. Stehlin whose letter I had, I think, some time after that
of the 4th July though dated before it.

The July letter was a great delight; both your kindness
and your philosophy most acceptable and refreshing. I hope
to get your paper translated, but there is a great deal of vis
inertia in our way, and I cannot overcome it, as I would
wish to do. It is the more difficult for me to criticize it,
because I feel a good deal of it myself, and am known to
withdraw from the labour and responsibilities of Scientific work,
and this makes me very glad that you have got hold of Liebig,
for I hope he will aid1 in developing your Ozone views.

Much of your letter of the 4th of July I should like to
have sent to the Philosophical Magazine; it was such a fine,
free, brief comment on Ozone, in many of its positions, and
I think might have helped to call the attention of chemists,
where an elaborate memoir might fail ; but I did not take the
liberty. In fact I should not like to send all you write, for if
I were to put in some of your former remarks about the errors
of the theories and the nonsense of organic chemistry etc, we
should both be extinguished, or at least sent to Coventry.

1 Bence Jones, who gives this letter, reads "act in developing," vol. 2. p. 341.

I said we were in the country and I met lately here the
Dr. Drew (that I believe is the name) who undertook to obtain
Ozone observations for you in England. He spoke, as if his
correspondents were discouraged by the uncertainty of their
results, and indeed Airy ' also wrote to me, to ask me if I
was aware, that test papers which would give, after exposure,
a certain degree of indication of ozone, lost much of the power
in 2 or 3 hours after, and then gave a less degree. Dr. Drew
talked about these points, but I said little and rather referred
him to you, to whom he said he was about to send some
communications.

You give a happy account of your family. You are a
happy man to have such a family, and you are happ^v in the
temperament which fits you for the enjoyment of it. May God
bless every member of it and yourself with a cheerful and
relying spirit and love to each other. Remember us to them all

Ever my dear friend,

affectionately yours

M. FARADAY.
Aft

Schoenbein to Faraday.
MY DEAR FARADAY

From the very long silence I have kept, you will
draw all sorts of conclusions, but I am quite sure, that none
of them proves to be correct, for the simple reason that even
Mr. Schoenbein himself cannot account for his taciturnity. I
have been neither unwell, nor low-spirited, nor overbusy, nor
any thing else that could have prevented me from breaking

1 George Biddel Airy, professor of Astronomy and Physics at Cambridge,
and, from 1836 Director of the Greenwich Observatory. Hewas born in 1801
at Alnwick in Northumberland.

— 239 —

it sooner, and least of all, I have forgotten my dear and
amiable friend at the Royal Institution.

But if I have not written to, I have written, at least, about
you and in telling you so much, I have revealed to you an
author's secret, which I beg you however to keep as yet to
yourself. The matter stands thus: I have been composing a
book these last six months, certainly not a scientific one, for
doing such a thing suits, as you well know, neither the taste
nor the powers of your friend; it is a sort of "quodlibet" or
as the musical term runs a "potpourri" i. e. a most variegated
motley of things. You recollect perhaps the trip I made to
Munich and Vienna some time ago, and its having turned out
so very pleasant, induced me to try my graphic powers with
the view of making Mrs. Schoenbein and the girls, as it were,
partners of my journey.

Wives and Children are very partial judges of the litterary
productions of their husbands and fathers and you will there-
fore not be surprized, when I tell you that my excellent help-
mate and young ladies made no exception so the rule. They
found, indeed, every thing I had written and read to them so
very excellent that they started one day the idea of having
my scribbling published. However great my dislike to book-
making is and how little I care for gaining laurels in the line
of authorship, I at last yielded to the entreaties of my darlings,
that is to say, promised to try what I could do in the matter.
And, indeed, I have finished the work and a copy, legibly and
nicely written out, lies in my desk, but when it will go to the
printer and be published, that is a thing, which I cannot tell.

You will laugh, when I inform you that in spite of the
embryonic state of my spiritual child, I have already baptized
and given it the name "Glosses on Men and Things by an
elderly Man".1 This title has, as you see, elasticity enough,

1 "Menschen undDinge. Mitteilungen aus dem Reisetagebuch eines deutschen
Naturforschers." Published anonymously in 1855.

240 —

and I will not conceal it from you that I have made full use
of its vagueness, having thronged all sorts of reflections and
queer ideas into the opusculum.

On account of its motley character I should like you
could read that strange composition, but it being written in
german, I am afraid its contents will never come to your
knowledge.

It is, however, time to return to yourself and tell you in
what manner I have written about you. In the above mentioned
book there is a little chapter bearing the title "Fachmanner"
gallice "Specialites" and anglice perhaps - - but I am unable
to translate the word into your language — I mean to denote
by that term Men devoting their whole life and mind to one
object. By no means admiring what they call universal geniuses,
and being convinced that it is the "specialites" to whom we
owe every real progress in science, arts etc., I have, with a
view of proving the correctness of my opinion, drawn up four
slight sketches of such "Fachmanner", of Berzelius, von Buch,
Cuvier and of — of — but be it spoken out, of Faraday. I hope
you will not tax me with indiscretion for having taken that
liberty and believe that in doing so your friend has been
actuated by the best motives.

As to science I have of late done nothing at all and do
not recollect to have passed a winter so inactively and lazily
as the last. When spring calls forth again the dormant powers
of the earth, I hope I shall then feel too its congenial influence,
and be stirred into action, for there is matter enough to work
upon and of laborers there are not too many.

My collegue Professor Wiedeman l an excellent philosopher
has (partly on my instigations) taken up Electrolysis again,

1 Gustav Heinrich Wiedemann was born in 1829 at Berlin. He was
professor of Physics at Bale, at Braunschweig, Karlsruhe and from 1871 to his
death, which took place in April 1899, at Leipzig. From 1877 he was the
editor of the Annalen der Physik und Chemie, as successor to Poggendorft.

— 241

that fundamental phenomenon, I used to call the true copula
of Chymistry and natural philosophy and obtained some results
that seem to speak very much in favor of my heretic opinion,
according to which in all the oxysalts the electrolysing power
of the current is solely and exclusively exerted upon their
basic oxides and that there is no such thing as an oxy-com-
pound Jon.

I proposed Mr. Wiedemann to electrolize salts containing
the same base and acid in different proportions and see whether,
by the same current, different or equal quantities of metal be
eliminated from such salts. If my notion should happen to
be correct, it is manifest that under the circumstances mentioned,
equal quantities ought to be eliminated. The salts as yet
carefully electrolyzed are the mono -and tribasic acetates of
lead and Mr. Wiedemann has ascertained, that on electro-
lysing them by the same current they yielded equal quantities
of lead. I may add that in those experiments my collegue
uses as a sort of voltameter a solution of nitrate of silver i. e.
the weight of metal being eliminated from that salt as the ....
measure of the amount of the electrolysing power of the
current employed. Now upon one equivalent of silver Mr. W.
obtained one equiv. of lead, both from the neutral and tribasic
acetate. Hence it seems to follow, that the current has nothing
to do with the acid ; in other terms that the latter is no Anion.
In my late paper "on the chemical effects of Electricity, Heat
and Light11 I have circumstancially developed my notions on
the Electrolysis of the Oxy-salts and you have perhaps taken
notice of them.

I entertain no doubt you have spent the winter in high
scientific spirits and performed some exploits in spite of the
warlike mood of the public mind, which by the bye, I do not
relish at all and am inclined to consider as madness. I hardly
need tell you how happy I should feel if you would favor
me soon with your good news and not requite silence by
Q

— 242

silence. All my family are doing well and charge me with
their best compliments to you and Mrs. Faraday, to which I
join my own. Believe me my dear Faraday for ever

Your's

most truly

Bale Febr. 27. 1855. C. F. SCHOENBEIN.

Aft

Faraday to Schcsnbein.1

Hastings 6 April 1855
MY DEAR FRIEND

I have brought your letter here, that I might
answer its great kindness at some time when I could remem-
ber quietly all the pleasure I have had since the time I first
knew you. — I say remember it «//, but that I cannot do ; for
as a fresh incident creeps dimly into view, I lose sight of the
old ones, and I cannot tell how many are forgotten altogether.
But think kindly of your old friend; you know it is not
willingly, but of natural necessity, that his impressions fade
away. I cannot tell what sort of a portrait you have made
of me; all I can say is, that whatever it may be I doubt whether
I should be able to remember it, indeed I may say, I know
I should not, for I have just been under the sculptor's hands,
and I look at the clay and I look at the marble, and I look
in the glass, and the more I look the less I know about
the matter and the more uncertain I become. But it is of no
great consequence; label the marble, and it will do just as
well as if it were like. The imperishable marble of your book
will surely flatter.2

1 This letter is given in Bence Jones vol. 2. p. 355.

2 We here give a translation of some of the passages devoted to Faraday:
"The disciple came to the master, one worthy of the other; keen perception

— 243

You describe your state as a very happy one — healthy,
idle, and comfortable. Is it indeed so? or are you laying up
thoughts which are to spring out into a rich harvest of in-
tellectual produce ? I cannot imagine you a do-nothing, as I
-am; your very idleness must be activity. As for your book,
it makes me mad to think I shall lose it. There was the
other (which the "Athenaeum" ' or some other periodical
reviewed) in German, but we never saw it in English.2 I often
lent it to others, and heard expressions of their enjoyment, and
.sometimes had snatches out of it, but to me it was a shut book.
How often have I desired to learn German, but headache and
giddiness have stopped it.

I feel as if I had pretty well worked out my stock of
original matter, and have power to do little more than recon-
-sider the old thoughts. I sent you by post a notice of a Friday
Evening here, and would have sent you a paper from the
Philosophical Magazine; -- but I am afraid of our post, i. e.,

.and individual deeds soon developed under the teaching he here received. The
•wings of the young eagle quickly stretched out and qualified him to the highest
flights; the scholar outdoing his teacher: and so he came to he the profoundest
^and most productive among disco\erers. His refined spirit forced its way into
the most hidden workings of the forces of -nature and revealed them to the
•unenlightened mind; his prophetic eye enabled him to penetrate to undiscovered
fields, which he made accessible to others .... Following the impulse of his mind
he, in maturer years, limited his researches to a definite sphere. To comprehend
the primary function of matter as manifested in its relation to the phenomena
•of electricity, magnetism, chemical affinity and gravity : that is the goal which
the genius of Faraday is striving after, and which, as the highest reward for
-his astonishing energy, he will surely reach."

1 vide Faradays letter to Schcenbein Sept. 6. 1843. P- IT3

2 Had it not been for the difficulty of finding a publisher, an English
translation of his "Mittheilungen (vide p. 112) would most likely have appeared.
Tor Mr. Benjamin Vincent writing to Schoenbein from London, Juli 3. 1843,
after reading through Schoenbeins book, tells him that he found so much to
interest and amuse him, that he felt very much inclined to present it to the
British public. In fact he began a translation of it and to his letter subjoins
-specimens of his work, which show that he had quite entered into the spirit
.and individuality of Schoenbeins style.

— 244

I am afraid that unawares, I may put my friends to much
expense. I receive almost daily newspapers and journals,
which, coming by post, are charged to me two, three, and
four shillings, until I absolutely cannot afford it; and fearing
that with equal innocency I may be causing my friends incon-
venience, I have abstained. However, I hope that a friend of
mine, Mr. Twining, will, in the course of a month or two, put
the paper I speak of in your way. You will therein perceive
that I am as strong as ever in the matter of lines of magnetic
force and a magnetic medium; and, what is more, I think that
men are beginning to look more closely to the matter than
they have done heretofore, and find it a more serious affair
than they expected. My own convictions and expectations
increase continually; that, you will say, is because I become
more and more familiar with the idea. It may be so and in
some measure1 must be so; but I always tried to be very
critical on myself before I gave anybody else the opportunity,
and even now I think I could say much stronger things against
my notions than any body else has. Still the old views are
so utterly untenable as a whole, that I am clear they must
be wrong, whatever is right.

I had forgotten that Wiedemann was in Basle; give my
kindest remembrances to him. I think I received a paper on
electrolysis from him, but out here cannot remember, and
cannot refer. Our sincerest remembrances also to Mrs. Schcen-
bein and the favourable family critics. I can just imagine them,
hearing you read your MS., and flattering you up, and then
giving you a sly, mischievous, mental poke in the ribs etc.
They cannot think better of you than I do. Ever my dear
Schcenbein Your attached friend,

M. FARADAY.

1 Bence Jones, who has made several alterations, reads "manner," and
further on "kindest" for "sincerest".

— 245

Schcenbein to Faraday.

MY DEAR FARADAY

How could I employ the leisure hour of a fine
May morning better, and more agreeably, than by devoting
it to an epistolary conversation with my dear Friend Faraday,
whom I besides owe an answer to his last amiable letter; and
to-day let me talk a little of Science.

As you cannot avert your mind from the contemplation
of that mysterious agency, called Magnetism, I am unable to
let Oxigen out of sight and of late I have been actively wor-
king again on that curious subject, not, I think, without some
little succes. You know that these many years I have enter-
tained the notion, according to which not only free, but also
Oxigen being chemically associated to some matter or other,
is capable of existing in two different conditions: in the common,
or inactive, and the exalted, or ozonic state, and to distinguish
by signs those different conditions from one another I have

given to ozonised oxigen the symbol O denoting the inactive
O by its usual sign = O. Considering the peroxides of
hydrogen, nitrogen (hyponitric acid), Barium, Manganese, Lead
etc as compounds containing both sorts of oxigen, I have given
them the formula HO + 6, NO2 +26, BaO + 6, MnO + 6,
Pb O + O etc and, as you are well aware, made these last six
years, many experiments with the view of separating from the
oxycompounds mentioned, and other similar ones, their ozonised
oxigen, without obtaining however satisfactory results.

Some time ago Mr. Houzeau l communicated to the french
academy a paper, in which he suggested ideas on the different
states of the oxigen,2 being contained in compounds, being

1 Auguste Houzeau was born in 1829 at Elbreuf, Seine-inferieure and is
professor of Chemistry at the Ecole Superieure at Rouen.

8 Recherches sur 1'oxygene a 1'etat naissant. Comptes rendus T. 40.
1855. p. 947-

246

exactly the same which I for the first time ventured to express:
in Poggendorff s Annals seven or eight years ago and have
since more fully developed in the publications of the PhiL
Society of Bale, notably so in the last number of the procee-
dings of that learned body. The views recently put up by
Mr. Houzeau are therefore rather old acquaintances of mine,
but that Chymist has ascertained a novel fact, and as I con-
sider it, a very interesting one. On adding peroxide of Barium
to the monohydrate of sulphuric acid, he obtained oxigen, en-
joying all the properties of Ozone. I have arrived at the same
end, but in a somewhat different manner. You know, Silver,
being exposed to the action of ozonised oxigen at the common
temperature is transformed into the peroxide of that metal,
and you will recollect that I sent you a small quantity of that
compound, some years ago.1 Now it is from this peroxide of

Silver, which I consider to be AgO 2, that I succeeded to
eliminate some Ozonised Oxigen.

On throwing the said peroxide into the monohydrate of
sulphuric acid a most lively disengagement of a gaseous sub-
stance takes place, conjointly with the formation of sulphate of
Silver. The gas obtained in the manner indicated, enjoys the
following properties: its smell strongly resembles that of Ozone,
but minute quantities being inhaled produce a sort of asthma,
as Ozone does; its electromotive power is strong, and like
that of Ozone or Chlorine, plates of Platinum or Gold becoming
negatively polarised in the gas; it eliminates Jodine from the
jodide of potassium and therefore turns instantaneously my
test-paper dark blue; it rapidly transforms the yellow ferro-
cyanuret of potassium, even in its solid state, into the red one;
it suddenly oxidises sulphurous acid into sulphuric acid, and
sulphuret of lead into sulphate; it energetically and chlorinelike
discharges the colors of organic matters, such as Indigo, Litmus
etc; it colors blue the alcoholic solution of guajacum etc.

1 vide p. 1 80 and p. 184.

247 —

Now all these reactions being exactly those produced by
Oxigen as modified by Electricity or phosphorus, i. e. Ozone,
I think, we may be allowed to conclude, that the gas being
disengaged out of the peroxide of Silver is, or contains at
least, the same principle, i. e. Ozone.

Having but very minute quantities of that peroxide at my
disposal, I, to my great regret, was forced to perform my ex-
periments on a very small scale, but I had enough of the
matter, as to ascertain, that the gas obtained was a mixture
of O and O, in which the latter very much prevailed. Although
there is no doubt to me, that all the oxigen eliminated from
the peroxide does, in the moment of its being set free, exist
in the ozonic state, there are some obvious causes, that account
for the mixt nature of the gas i. e. for the transformation of

0 into O. One of them is the heat being disengaged at the
points of contact between SO3 and AgO2 and the other the
peroxide itself. As to the latter, you know perhaps that last year

1 ascertained the curious fact that a number of substances exert
the same influence upon the ozonised oxigen, as heat does, i. e.
destroy at the common temperature the ozonic condition of that
oxigen without taking up a particle of it. The metallic peroxides
enjoy that strange property in a very high degree, and notably
so that of Silver, compounds, as you see, which to my opinion
contain ozonized oxigen themselves. Now if a particle of peroxide
of Silver, not yet decomposed, happens to come in contact with
a particle of ozonised Oxigen, being disengaged from another
portion of the peroxide, that particle must become desozonised.
There are perhaps some other causes, unknown as yet, that
tend to change O into O in the case before us. I hope you
still possess some of the peroxide of Silver, I sent you some
years ago, and if so, you may even with that small quantity
ascertain the correctness of my statements above made. In
case you repeat my experiments, I advise you to put a little
peroxide into comparatively much oil of vitriol, and do the

248

thing at a low temperature, from reasons that are obvious enough.
To give you some visible proofs of the great chemical power
of the oxigen, having been eliminated from the peroxide of
Silver, by the means above indicated, I join three strips of
paper, one of them being impregnated with sulphuret of lead,
another with indigo solution, a third one with the coloring-
matter of litmus and you will perceive part of each of them
to be bleached.1

This was effected within a few instants by immersing a
moistened end of the strip into the said oxigen.

From more than one reason I cannot help attaching some
importance to the result of my experiments, and believing that, if
properly worked out and philosophically interpreted, it will
lead to others of still greater consequences. And pray, let me
reason and conjecture a little about it.

If it be allowed, that the oxigen being contained in the
peroxide of Silver, exists in the ozonic condition, and it being

a fact, that free O is by heat transformed into O, does it not
appear very likely that the same agency has the power of
changing the O of the peroxide into O, and that this very change
of condition is the proximate cause of the decomposition, which
the peroxide undergoes when sufficiently heated ? And if this
conjecture should happen to be founded, are we not permitted to
account in the same manner, for the decomposition of all the
other oxycompounds being effected by heat and yielding free
inactive Oxigen? I am inclined to think that we are, and in
a paper of mine printed last year I have given detailed reasons
for entertaining such an idea.2 Now supposing my hypothesis
to be true, I am afraid many of our present notions, on the

1 The strips of paper referred to have been mislaid and are no longer
attached to the letter.

2 For further details on this subject a paper in the Gelehrte Anzeigen
(Munich) should be consulted Bd.4i. 1855. p. 108: "Uber die Darstellung des
ozonisierten Sauerstoffes aus Silberoxyd."

— 249 —

phenomena regarding chemical analysis, synthesis, affinities, etc,
cannot be maintained, and must sooner or later be essentially
modified. Stating that peroxide of Silver, for instance, consists
of one Eq. of Silver and two Eq. of Oxigen, and carbonic
acid of one Eq. of Carbon and two Eq. of Oxigen, is telling,
if I may say so, but half the truth, as regards the chemical
constitution of the compounds named, for it implies the asser-
tion, that the oxigen being contained in those compounds is
the same thing, an admission which according to my opinion
cannot be allowed to be true, for O is not O, though the one
may be transformed into the other.

But if the oxigen, being chemically associated to other
matters, be capable of existing in different states and the bear-
ings of the oxycompounds be so much influenced by the
peculiar condition, in which their Oxigen exists in them, are
we not permitted to suspect, that other elementary matters may
also enjoy a similar capacity of assuming different conditions
and be able to exist within compounds in those various states ?
May it not be presumed, that the chemical behaviour of such
compounds essentially depends upon the peculiar condition of
their constituent parts? Is it to be believed that carbon exists
in the oil of turpentine exactly in the same state as it does in char-
coal, and is it not possible that the decomposition of all the
organic substances is effected by heat, because this agency has
the power of transforming carbon from one state into another?
To condense these questions, and others, that easily suggest
themselves, into one, I ask, is it not very likely that, what
they call "allotropism" acts a much more important and general
part in Chymistry than it is thought of as yet ? I for my part
think it to be so.

Now no more of Science, theories and such like ! We
descend to daily life and my family. Being all of us highly
in love with nature, we are very fond of rambling in fields,
and woods, on hills and dales, to admire the unfathomable riches

— 250 —

of beauties being displayed there. May is called in German
"Wonnemonat", which means month of joy, and well meriting
that poetical denomination, it is of course a favorite of ours,
and we indulge during its reign as often as we can in our
rambling propensities by taking trips in the neighbouring country.
The Jura mountains are a particular point of attraction to us,
with their rich woodland, limpid rivulets, green valleys, bold
rocks and fine views. I preface thus to tell you, that some
days ago, on a fine morning, a motley army consisting of big
and small Children, male and female, and old folks too, were
seen marching out of the old gates of Bale tending their steps
towards the "Gempenstollen", the highest and most prominent
point of the Jura in our neighbourhood. Mr. Schoenbein, well
acquainted with all the recesses, and by-ways, round about
us, and his family making up good part of the army, was un-
animously elected commander-in-chief, which important charge
he accepted and filled it up to the best of his powers. The
day turned out a glorious one, nature exhibiting all her charms
By a great and gradually rising round about way, leading
through meadows covered with flowers, green fields, flowering
orchards, beautiful beechwoods crowded with singing birds,
we reached, after a four hours walk the summit of our favorite
hill. A little fatigued, the army desired to camp here, and it
was allowed to do so. The delicately green foliage of fine
beeches, and the crowns of stately firtrees, formed a splendid
canopy, and the mossy ground yielded soft resting places.
Carrying our victuals with us, the dinner was soon ready and
I can assure you that we enjoyed our cold morsels infini-
tely better, than we should have done, had we sat down at
a sumptuous royal table. Our camp being placed upon the
top of a gigantic projecting rock, it commanded a most extensive
and glorious view : to the south at some distance, we saw the
snowy heaventowering Alps of the Berner Oberland, nearer
and to the west a great part of the Vosges and Alsatia, to the

north the Black Forest and Baden, nearest us, the many valleys
and summits of the Jura mountains. Being enchanted by that
glorious sight, we could not but most reluctantly break up our
camp, but Mr. Schoenbein gave orders at last to march home
again, on a road however, different from that we had come,
beautiful also beyond description. Having reached the foot
of the hill the gypsy host was allowed to halt again, for taking
refreshments, and by eight o'clock we approached the walls
of the good town of Bale, where the commander-in-chief dis-
charged his troops, not without having received before, the
thanks from high and low, old and young. I am sure you
yourself and Mrs. Faraday, would have highly relished the
gypsy party; but come over to us and we shall repeat it. Next
midsummer we go to Langenbruck, a village in some pass
of the Jura, intending to stay there for a month. It would be
a high treat to me and us all, if we could spend that time
with you and Mrs. Faraday.

The gentleman who will deliver this letter to you is
Mr. Schweitzer of Bale, an old pupil of mine and whom I
take the liberty to recommend most friendly to your kindness.

Mr. Wiedemann charges me with his best compliments to
you, he is very actively occupied with electrolytical researches
and has received some interesting results.

Should a parcel be directed to you under my address,
pray take and keep it until you find an occasional conveyance
for Bale. There is no hurry for it.

Excuse my immoderately long letter, let me soon have the
favor of a letter and believe me

Your's

most truly

Bale Mai 26th 1855. C. F. SCHOENBEIN.

Don't forget to remember me friendly to Mrs. Faraday.

— 252 —

Faraday to Schcenbein.

Royal Institution 6 Novr. 1855.
MY DEAR SCHOENBEIN

It is quite time I should write you a letter, even
though I may have nothing to say, and yet I surely have
something to write, though it may not be philosophy, for I
trust affection will last out philosophy, and indeed were it not
so, I should fear that I was indeed becoming a worn out
worthless thing. But your last letter abounded in all matter,
both the philosophical and also the domestic and kind, and I
thank you heartily for it. That one day in the country —
how I wish I had been with you, - - but I could not now
walk in Switzerland as I have done in former years. - - All
things suffer a change. May your changes be long deferred,
for you must be very happy as you are. - - And so am I ;
but my happiness is of a quieter kind, than it used to be and
probably more becomes a man 64 years of age; and as we,
i. e. my wife and I, go on our way together, our happiness
arises from the same things and we enjoy it together, with,
I hope, thankfulness to the Giver of every good and perfect gift.
I tried an experiment or two with the oxide of silver and
obtained some results, but not equal to those you sent it, nor
was it to be expected that I should reach the results of a
Master in this subject. Your accounts and observations are
most interesting and exciting, but I dare not try to pursue the
subject, for even the matter I have in Magnetism is often too
much for me and I am obliged to lay it by for a while, so
that I am forbidden by nature to take up any new series of
thought. But that ozone, that oxygen, which makes up more
than half the weight of the world, what a wonderful thing it
is, and yet I think we are only at the beginning of the know-
ledge of its wonders.

— 253 —

By the bye your letters often contain much that I should
like others here to see and I want to ask you whether there
is any objection to my shewing them to Tyndall and letting
him, as one of the Editors of the Phil. Mag, print any of the
philosophical parts, that he may select, in the Magazine. There
are full three pages of your last which, if I were an Editor,
I should have selected: — at the same time you must not in
any way alter the pleasant tone and current of your epistles,
— or else I shall be a great loser.

I cannot now remember how I received your letter and
whether I saw M. Schweitzer, — I rather think not; but whether
I was out of town, or whether he sent me the letter by some
one, I am unable to call to mind. - - I have received no par-
cels for you as yet, - - but will take care of any that come.
I sent you Vol. Ill of Experimental Researches by Mr.
Twining and have no doubt it has reached you — but I have
not seen Mr. Twining since his return from your country.

The General board of health here published a report on
the Cholera epidemic of 1854 and since that, a thick 8VO volume
of Appendix. In the latter I am glad to see they refer to
Ozone in several places p. p. 71. 89. 103 and of course to
you, but whether the observations (by Dr. Moffat) are well
made, and considered, I do not know; - - in any case it in-
dicates that ozone is gaining a growing attention amongst
medical men.

My kindest remembrances to Madame Schoenbein and to
those, whom, by a stretch of imagination, I strive to see
around here, i. e. to the party of the day's excursions, and
my very kind remembrances to M. Wiedemann also. It is
delightful to see thinking workers rise up in Science. Believe

me to be, my dear Schoenbein

Your faithful friend

M. FARADAY.

254

Schcenbein to Faraday.
MY DEAR FARADAY.

Having these many months heard any thing neither
from, nor of you, I had already begun growing anxious about
the state of your health, when to my great satisfaction I was
released from my anxiety by your kind letter of the 6th in-
stant, which has made upon my mind the impression that you
are a perfectly well doing man. May it please kind providence
to preserve you, both to your friends, and Science for many
years to come ! This is one of my most ardent wishes, which
I cannot help expressing you, over and over again; for I see
that you have as yet much work to do, many a problem to
solve, and more than one mystery to divulge to the philo-
sophical world. Indeed, we cannot yet do without the seer
and prophet of nature. -

Since I wrote you last, we, for the first time had here
the most unwelcome visit of the Cholera, but thank God, its
stay was short, and my family, as well as my friends, were
left untouched by it. During the summer Mrs. Schoenbein and
the girls spent a couple of months in the Jura mountains, where
I joined them now and then to their great satisfaction, the father's
disposition for rambling on green and wooded hills being
their's too, and certainly we did not fail gratifying it to a great
extent, walking very often for six or eight consecutive hours
together. You will perhaps smile, when I tell you, that Miss Schoen-
bein has of late become a very zealous english scholar, reading,
writing and speaking away your native tongue in rather a fluent
and elegant style. But pray, do not imagine the father to have
any part in the proficiency of the daughter, for you must be
aware that a parent always proves a very bad master to his
children. Certainly, on being sometimes called upon to look
over the tasks of the young scholar's, I have an occasion to
make some use of the little bit of English I am as yet master

— 255 —
/ ~

of. Number 2 and 3, having caught that liking from her eldest
sister, have become pupils of her's and are going on well
enough in their studies. As to me, I can, of course, have no
objection to that taste for an outlandish tongue and litterature,
being myself somewhat suspected of "Anglomanie", Once
speaking of my daughter's accomplishments, I may as well add
that she is a partly good musician too, playing the piano, not
only with facility, but I think also with some taste. Being
myself a great admirer of the heavenly art of music, and after
my morning's schoolmastering sometimes feeling inclined to
take a little rest on the sopha, I, in a half dozing state of
mind, listen to Beethoven's, Mozart's, Weber's etc. delightful
compositions being performed by Miss Schoenbein. Having for
half on hour or so enjoyed that dreaming pleasure, and taken
a cup of coffee, served up to me by my second daughter, I rise
again quite refreshed, light my segar and go to my laboratory
or to some other business. If you should once mark two
o'clock, after noon, you will hardly miss the truth, if you ima-
gine your friend lying on his couch, and listening to music,
an attitude not very picturesque indeed, but nevertheless, pro-
ving to be an agreeable one to him, that assumes it. Now to
finish with my talking of Miss Schoenbein, I will tell you, that
she is very desirous of visiting England, and seeing the wonders
of your country, but I am afraid, that her wishes will never be
fulfilled, i. e. that she will never prevail upon her father to
carry her there. Now before speaking of philosophy, for I cannot
help talking to you of my bride, allow me to make a proposal to
you, but pray, do not be angry about it. I cannot bear the
Idea of seeing you no more in this world, and it being very
unlikely, that I shall be able to cross once more the water,
and you, in comparison to your friend, being an independent
i. e. moveable man, could you not make up your mind to come
over to us with Mrs. Faraday next year, and spend a month
or two, I won't say, in Bale itself, but in our fine hilly neigh-

— 256

bourhood? where I should try to find out for you a quiet
snug corner, in which you might carry on a sort of life quite
congenial to your taste, and Mrs. Faraday's too. You were,
as I hear, in Glasgow some months ago; now a journey to
Switzerland is not a bit more, than a trip to Scotland, and in
two days, sleeping included, you may be here with ease, by
the way of France. Pray, take that proposal into serious con-
sideration, and believe me that nothing in the world could
prove to me and my family more gratifying, than a visit of
your's and Mrs. Faraday's would do. -

The book, of which I once talked to you,1 has been
out these last three months and as soon as a proper oppor-
tunity will offer itself, you shall have it. Being written in
german, you will declare it to be a sealed book to you, but you
may easily find out a friend of your's being capable of opening
it to you and, indeed, I should like you would acquaint yourself
at least with some part of its tenor, as they contain a sort of
profession of faith of a friend of your's. - The third volume
of your Researches has as yet not reached me, and putting a
high value upon its possession, I beg you to be kind enough,
as to inquire a little after the fate of that volume.

Now let me talk a little of philosophy, and what should,
or could I begin with, but with my favorite subject oxigen,
the mere name of which is hated by Mrs. Schoenbein, having
become jealous as well as afraid of that seducing and mighty
body. Being not quite sure, whether I have written you since
I got some very remarkable results, even on the risk of telling
you the same story twice, I give you a short account of them.
You know that I hold oxigen, both in its free and bound state,
to be capable of existing in two allotropic modifications: in the
ozonic or active and the ordinary or inactive condition. All
the oxy-compounds, yielding common oxigen at a raised tempe-
rature, I consider to contain ozonized oxigen, and I am further

1 "Menschen und Dinge" vide p. 239.

— 257 —

inclined to believe, that the disengagement of common oxigen
from those compounds depends upon the transformation of their
ozonized oxigen into inactive one, or as I use to denote that

allotropic change of O into O. Now a general fact is, that

the oxigen, thus set free, always contains traces of O, more
or less, according to the degree of temperature at which the
oxigen happens to be disengaged from those compounds. The
lower that degree, the larger the quantity of O mixt with O,
though I must not omit to state, that in all cases that quantity
happens to be exceedingly small in comparison to that of O,
obtained at the same time. The best means of ascertaining
the presence of O is the alkoholic solution of guajacum, recently
prepared. You know that O does not in the least change the
color of that resiniferous liquid , whilst free O or PbO + O
etc. have the power of coloring it deep-blue. The blue matter

is, as I think I have proved it, nothing but guajacum + O.
Now if you heat the purest oxide of gold, platinum, silver,
mercury, the peroxides of manganese, lead etc., in fact any
substance yielding oxigen, within a small glass tube, into which
you had previously introduced a bit of filtering paper, being
impregnated with the said guajacum solution, you will see that
bit of paper turning blue, so soon as the disengagement of
oxigen begins to take place. And all the circumstances being
the same, you will farther perceive that the paper is colored
most deeply and rapidly by the oxigen being eliminated from
that oxycompound, which requires the lowest temperature for
yielding part or the whole of its oxigen. Thus the oxigen,
being disengaged from the oxides of gold, platinum and silver,
acts more energetically upon the guajacum solution, than the
oxigen does, being eliminated from the oxide of mercury, the
peroxide of manganese etc. I trust these results will be ob-
tained in the Royal Institution just as well as I get them in
the laboratory of Bale, or else my discovery shall be a very
poor thing. As there cannot, I should think, be any doubt,
R

— 258 —

that all the oxigen being contained for instance in the oxide
of silver, previously to that compound being decomposed by
heat, exists but in one state, be that state what it may, how
then does it happen, we may ask, that at the same time two
different sorts of oxigen, O and O, are disengaged from the
compound named? The answer to this question seems to me
to be, that one of the two kinds of oxigen eliminated, must
be engendered at the expence of the other, or to speak more
correctly, that during the act of the elimination of oxigen from
the oxide of silver, part of that oxigen surfers a change of
condition. Now the oxides of gold, silver etc., enjoying the
power of coloring blue the guajacum solution, just so as free

0 does, I draw from that fact the conclusion, that the condition
of the oxigen being contained in the oxides of gold, silver etc.,
is the ozonic one, and farther infer, that by far the greatest
portion of that O, under the influence of heat, is transformed
into O. Why not the whole of the oxigen, being disengaged
from those oxides, happens to be O, I certainly cannot tell, but

1 think that the very fact of the mixt nature of the oxigen in
question, is, in a theoretical point of view, highly important
and speaks in favor of my notions rather than against them.
Although I have already heavily taxed your patience, I am
afraid, I cannot yet release you from farther listening to my
philosophical talkings, for I have still to speak of a subject
that has of late deeply excited my scientific curiosity and
taken up all my leisure-time. But to give you an Idea of what
I have been doing these last two months, I must be allowed
prefacing a little. You know that I entertain a sort of innate
dislike to touch any thing being in the slightest way connected
with organic Chemistry,1 knowing too well the difficulty of the

1 In one of the chapters of his "Menschen und Dinge" (vide sopra p. 239)
he gives the following description of himself: "The other" - - he had been
comparing himself with Liebig — "the other entered the lists of scientific research
somewhat timidly; if anything, he avoided all intricate subjects, rather than

— 259 —

subject, and the weakness of my powers to grapple with it,
but in spite of this wellgrounded disinclination, I have of late
and as it were by mere chance been carried in the midst of
that field upon the intricacies and depths of which I have been
used all my life to look with feelings of unbounded respect
and even awe. The picking up of a mushroom has led to
that strange aberration of mine, and you will ask how such a
trifling occurrence could do that. The matter stands thus : What
the botanists tell me to be called "Boletus luridus", with some
other sorts of mushroom, has the remarkable property of tur-
ning rapidly blue, when their hat and stem happen to be broken
and exposed to the action of the atm. air. On one of my
ramblings, I found a specimen of the said Boletus, perceived
the change of color alluded to, and being struck with the
curious phenomenon, took the bold resolution to ascertain, if
possible, its proximate cause. I carried home the part, set to
work, and found more than I looked after, a thing which luckily
•enough happens now and then. By the short space being allow-
ed, even to the longest letter, being prevented from entering
into the details of the subject, I confine myself to stating the prin-
cipal results, obtained from my mushroom researches. — Boletus
luridus contains a colorless principle being easily soluble in alkohol,
and as to its relations to Oxigen, bearing the closest resemblance
to Guajacum, as it appears from the fact, that all the oxidizing
agents having the power of blueing the alkoholic solution of
.guajacum, also enjoy the property of coloring blue the alkoholic
solution of our mushroom principle and all the desoxidizing
.substances, by which the blue solution of guajacum is uncolored,
also discharge the. color of the blued solution of the Boletus
matter. From this fact, and others, I infer that this mushroom
principle, like guajacum, is capable of being associated to O and

that he searched for them; on principle and to his own liking he as much as
possible examined plain phenomena only, and stood in almost unconquerable
.awe of everything bordering on organic life."

— 260

is not affected by O. Now the occurrence of a matter, being a
true brother to guajacum, in a mushroom, is a fact pretty
enough of itself, but as to scientific importance far inferior to
what I am going to tell you. The fact that the resinous
Boletus principle, after having been removed from the mush-
room (by the means of Alkohol) is not able to color itself
spontaneously in the atmospheric air, whilst it seems to have
that power, so long as it happens to be deposited in the paren-
chyma of the Boletus, led me to suspect that there exists in the
Boletus luridus, besides the guajacumlike substance, another
matter, being endowed with the property of exalting the
chemical powers of common oxigen, and causing that element

in its O condition to associate itself to the resinous principle
of the mushroom. And Mr. Schoenbein conjectured correctly,,
for I found, that in the juice, being by pressure obtained from
a number of mushrooms belonging to the genera of Boletus
and Agaricus and notably from Agaricus sanguineus (upon
which I principally worked), an organic matter is contained>
enjoying the remarkable power of transforming O into O, and
forming with the latter a compound, from which O may easily
be transferred to a number of oxidable matters, both of an
inorganic and organic nature and I must not omit to state that
the peculiar Agaricus matter, after having been deprived of its

O, may be charged with it again, by carrying through its solution
a current of air. The easiest way of ascertaining the presence
of O in the said Agaricus juice, is to mix that liquid with an
alkoholic solution of guajacum, or the resinous matter of the
Boletus luridus. If the juice happens to be deprived of O,
the resiniferous solutions will not be colored blue, but if it
contains O, the solutions will assume blue color, just so as if
they were treated with peroxide of lead, permanganic acid,,
hyponitric acid etc. From the facts stated, it appears that the
organic matter in question is a true carrier of active oxigen,.
and therefore, when charged with it, an oxidizing agent. Indeed,

26l —

that matter may in many respects be compared to NO 2, which
as it is well known, enjoys to an extraordinary extent the power

of instantaneously transformig O in O and forming a compound
(NO2 -f 2 O) with that O, from which the latter may easily
be thrown upon a multitude of oxidable matters. Now in a
physiological point of view, the existence of such an organic
substance is certainly an important fact, and seems to confirm
an old opinion of mine, according to which the oxidizing effects
of the atmospheric Oxigen (of itself inactive) produced upon
organic bodies, such as blood etc., are brought about by the
means of substances, having the power both of exciting and
carrying oxigen. Before dropping this subject I must not omit
to mention a fact or two more. The peculiar matter being
contained in the juice of Agaricus sanguineus etc., and charged
with O, gives up that oxigen to Guajacum and the latter to the
resinous matter of the Boletus luridus, so that different organic
matters, capable of being associated to O as such, exhibit different
affinities for that oxigen, a fact not without physiological im-
portance. Another fact worthy of remark is the facility, with
which the nature of our agaricus matter may be changed.
On heating its aqueous solution, that has the power of deeply
blueing the guajacum solution, to the boiling point, it not only
looses that property, but also the capacity of becoming an
oxidizing agent, i. e. carrier of oxigen again, however long it
may be put in contact with atmospheric air. I am very sorry
to be prevented from entering more fully into the details of
the subject, but from the little I have said about it, you may
easily understand, why that mushroom affair has of late so
much engaged my attention. As to the little bit of philo-
sophical matter, which now and then my letters to you may
happen to contain, you have, of course, full liberty to do with
it what you think fit.1

1 Printed under the following title: "On ozone and ozonic action in
mushrooms" in Phil. Mag. Vol. II. 1855. p. 137.

262

Before I conclude I must not omit to tell you, that the
Swiss Association, which as you know, has become the mother
of all rambling societies of Europe,1 will meet at Bale next
mid-summer, under the presidency of Peter Merian a most in-
timate friend of mine. Now, if you should comply with my
wishes above expressed, it would be very easy to leave your
retreat in our neighbourhood and join us for a day or so. I
have no doubt, you would like our meeting, which being a
more familiar and much smaller one than that of the british
or german association, is for that very reason more comfortable
and agreeable. On coming here, you will see many of our Swiss
philosophers, amongst others our friend de la Rive. I promise
you a day in Bale, which shall please you and remain, I trust,
in your memory all your lifetime. If it fall to my lot to see
such a day, I shall be the happiest man in the world.

And now I have done, my dear Faraday and ask your
kind indulgence for the unusual length of my letter. Pray do
not keep so long your silence, as you did the last time and

believe me

Your's

most faithfully
Bale Nov. 30. 1855. C. F. SCHOENBEIN.

All the members of my family beg to be kindly remem-
bered to you, and in doing so, I ask you the favor to present
my best compliments to Mrs. Faraday. S.

Mr. Wiedemann also charges me with his compliments
to you.

1 The Swiss Association was founded in 1815 and held their first meeting
at Geneva. Then followed the corresponding German Society founded in 1822
at Leipsic and finally the British Association for the Advancement of Science,,
which met for the first time at York in 1831.

— 263 —

Faraday to Sckcendein.1

Royal Institution 21 March 1856
MY DEAR SCHOENBEIN

The heartiest and the kindest wishes to you and
the best thanks for your last letter. I have it not here (Nor-
wood, for I am resting a head like a sieve) but I know it was
very pleasant, and I think contained some family details, which
made me long to be with you, - - but the fact is, that when
I am with a friend, 1 soon need to get away again, because
of the labour of conversation and its strain upon recollection.
That which induces me to write just now is the fact, that a
letter has been sent to me addressed : Dr. Schcenbein, Royal
Institution, Albemarle Street and then in a corner, care of Dr.
Faraday. I have waited a little while to see if any instructions
would arrive, but have heard no more. Now what would you
wish me to do with it? It is a heavy letter, and if sent by
Post would cost about ten shillings, and yet I cannot help
suspecting that it is only a pamphlet. So I thought it best
to write and ask you what you would wish me to do and
whether you know of and are expecting it.

I do not recollect any news, and shall be glad to lay my
head down again, so with kindest remembrances to Madame
Schoenbein and your damsels

remain as ever

Your Affectionate friend

M. FARADAY.

1 Bence Jones gives this letter (vol. 2. p. 369) but with several omissions.

264

Schoenbein to Faraday.

MY DEAR FARADAY

I hasten to tell you that there is not the slightest
occasion for your being in a hurry regarding the parcel you
talk of in your last letter. I do not know what it contains,
nor who sent it to you. Any opportunity therefore, an early
or a late one, will do for sending the thing over to Basle.

I think I told you some months ago that the friend whom
you charged with delivering the third volume of your resear-
ches to me last year, has not performed his task, and not
liking at all the idea of losing your valuable gift, I repeatedly
ask you the favor of looking a little after the miscarried book.

This time I shall keep my peace on scientific matters from
the simple reason that I could not tell you much, even if I
had the inclination to do so. It is true, I was not quite lazy,
nor did I work quite for nothing last winter, but the exploits
I performed are, as we Germans use to say, but half-laid eggs
and of such embryonic things it is not safe to talk.

I have however a mind to entertain you of another matter
more interesting, at least less dry, than that never ending
subject of Oxigen.

Yesterday it was Easter-Monday and you must know that
in our teutonic lands it is a great day to the whole juvenile
world. I consider it as one of our specific national qualities,
that we are very fond of children and have marked out a
number of days and times of the year round, for the enjoy-
ments of our little ones. Now such a time is Easter-time, and
such a day caster-Monday. Man}^, many weeks before it comes,
the little prattlers talk of nothing, but of the Easter-hare (Oster-
haase in german) and the gifts he may chance to bring, and
what that Easter-hare means you will easily infer from what

- 265 -

passed in the garden of Mrs. Wiedemann l yesterday after-
noon. A host of children were invited by that Lady (having
herself a little boy2 of four years of ago) to make their
appearence at her house at three o'clock punctually. Mothers
and elder sisters conducted the little guests to the appointed
place, at the fixed time, and being assembled in a room they
anxiously and impatiently expected there the announcement
of "The hare has laid his eggs." No sooner had these words
been finished than the rogues were seen running down the
stair case into the garden, dispersing themselves in all directions
and eagerly seeking for the eggs, being put in hidden places:
within hedges, behind bushes etc. The discovery of each egg
was hailed with joyful exclamations and never failed proving
both to the happy finders and the unsuccessful seekers a fresh
stimulus, to continue their searches. But you must not imagine
those "hare eggs11 to have been ordinary ones; they were
beautifully colored : blue, red, yellow, lilac, brown, even varie-
gated, and bearing all sorts of inscriptions: the names of the
Children invited, the drafts of hares, foxes and other animals.

The eggs found by the boys and girls were put in a
basket placed in the centre of the garden, as property of the
little common-wealth, to be equally divided at the end of the
festival and carried home by the Children as the trophies of
the day.

Such like fetes there were hundreds in our town yesterday,
and I dare say millions all over the german lands. Great a
philosopher as you are, sure am I, that such a sight would
give you more pleasure than all the scientific institutions and

1 Gustav Wiedemann who was professor of Physics at Bale from 1854 — 1863
resided in a house in the Hebelstrasse, with a large garden attached to it.

2 Now Prof. Eilhard Wiedemann, of Erlangen, wo was born in 1852 at
Berlin. Me was professor of Physics at Leipzig and Giessen before he was
appointed to Erlangen in the same capacity.

— 266 —

all the curiosities of the whole civilized world together. Now
I am at the end of my letter and have nothing more to say

than that I shall ever remain

Your's

most faithfully
Easter-Tuesday I856.1 C. F. SCHOENBEIN.2

Faraday to Schcenbein?

Royal Institution n April 1856
MY DEAR SCHOENBEIN

My dear wife purposes answering your kind letter
herself; so I leave her pp. I and 2 and shall only say most
hearty thanks for your very pleasant, interesting picture of
juvenile life. I could have enjoyed it very much indeed. I
suppose you were about the biggest child there.

The Volume I sent, was by Mr. Twining, and I dare say
it will make its appearance some day ; for he was not going
to Bale but perhaps near it. Now, however, I have committed
another copy, and also the letter I wrote you about, to Mr.
Roscoe,4 a student under Professor Bunsen at Heidelberg. He
was to leave London, this week for Heidelberg, and I trust
you will soon have the volume ; - - which receive favourably

for my sake

Ever Yours

M. FARADAY.

1 According to the postmark the letter left Bale on March 29. 1856.

2 At the end of the letter Faraday has added these words : Sent by
Mr. Roscoe about April 6th.

s Passages from this letter are given in Bence Jones vol.2, p. 371.

4 Sir Henry Enfield- Roscoe F. R S.; emeritus Professor of Chemistry at
Owens College Manchester, was born in 1833 in London. He also studied at
Heidelberg under Bunsen, with whom in 1857 to 1863 he published his Photo-
chemical Researches.

Aft

- 26; -

f
Mrs. Faraday to Schoenbein.

Royal Institution April I ith 1856
MY DEAR Dr. SCHOENBEIN

The receipt of your letter was an unexpected
pleasure and honour and I hasten to thank you for it, and all
the kind expressions it contains.

It would indeed be a great treat to me to visit Switzer-
land with my husband and to spend a little time quietly, as
you propose, in the midst of your magnificient scenery, if I
had the power of walking any distance, but that I have not,
and I fear I should only be an incumbrance to my companions,
if I attempted it.

I am disabled by a Rheumatic affection (I believe it is),
but happily with little pain, so that our home continues to be
a cheerful and a happy one, as, if you come to London we
should be glad to show you; Mr. Faraday too, I am thankful
to say, is in better health than he was years ago, when I
think he suffered from too much study.

Pray present my best remembrances to Mrs. Schoenbein
and your daughters and believe me, dear Dr. Schoenbein,

Yours very sincerely

S. FARADAY.

Schoenbein to Faraday.

MY DEAR FARADAY

I have to acknowledge the receipt both of your
letter and that of Mrs. Faraday's and grateful as they have
proved to me, I could not help being very sorry for their
contents, which have at once annihilated my hopes of seing
you here this summer.

— 268 —

I ardently wish and confidently hope that your excellent
wife will before long be restored to her full health.

The third volume of your researches reached Basle a few
days ago, and I am very much obliged for that repeated piece
of kindness of Your's. I trust I shall live to see a fourth
volume coming out, containing detailed proofs of the Identity
of Magnetism and Gravity. How I would rejoice if such a
Glory should fall to your lot ! You have however performed
scientific exploits enough, and if there has been any philosopher
who legitimately merited to enjoy the "Otium cum dignitate",
you are that privileged man.

This letter will be delivered to you by Professor Merian 1
of Basle, a most intimate friend of mine and with whom I
am quite sure, you will down-right fall in love at the very
first sight. To his eminent intellectual powers (he is a profound
mathematician) he joins a heart full of the "milk of human
kindness", such as I know no better one. If possible, make his
personal acquaintance and that of his wife too, who happens
to be a pretty good english scholar and a member of the
celebrated family "Bernoulli".2

1 Rudolf Merian, a brother of Peter Merian, was professor of Mathematics
at Bale. He was born at Bale in 1797 and died there in 1871.

2 The renowned mathematicians of this name came from the Netherlands.
Jakob Bernoulli, who died in 1583 had to quit Antwerp and settled down at
Frankfort. A grandson of his, also called Jacob and born about the year 1598,
settled down at Bale and died there in 1634. His eldest son Nicolaus, a
merchant, was born in 1623, died in 1708 and left eleven children, of whom
the fifth, Jacob, and the tenth, Johann, became the eminent authorities on
mathematics. In addition to these no less than nine Bernoullis were more or
less famous mathematicians. "New days of glory in the history of the services,
rendered by the Swiss people to the advancement of science, commenced with
the arrival of the first of the Bernoullis" writes Mr. Merian (in the Verhandl.
der Schweiz. Naturf. Gesellsch. 1838. p. 16). "The transmission of a specific
disposition of mind from generation to generation and the conferring of honour
upon several members of the same house in the same sphere of human know-
ledge, is by no means rare. Scarcely however could one cite an instance which
we might liken to that of the Bernoullis. For a full century the members of
this family were the foremost among the mathematicians of Europe."

269

I send you some papers of mine treating of mushrooms
and ozoniferous organic substances,1 subjects of which I wrote
you some time ago. If you cannot read them give the trifles
to some of your young chemical friends, who may happen to
learn a little bit of German by them, if nothing else.

I returned last night from a beautiful walking trip made
into the Jura mountains and the valley of the Aar. Nothing
could be finer than the landscape I saw, spring being out in
its fullest bloom.

From the fact that I walked 24 — 30 miles a day you may
draw some inferences regarding the constitution of the legs
of your old friend.

Pray, present my best compliments to Mrs. Faraday, thank
her in my name for her kind letter and believe me, my dear

Faraday,

Your's

most faithfully
Bale April 26th 1856. C. F. SCHOENBEIN.

ASt

Sckcenbein to Faraday.
MY DEAR FARADAY

Are you still alive or have you entirely forgotten
your friend on the Rhine? It is indeed an age since I have
seen a line from you and I think it is time to break your long
silence. To induce you to do so I send you this letter con-
jointly with a paper of mine, which I desire very much that

1 "Ueber die nachste Ursache der spontanen Blauung der Pilze". Miinchen.
Abhandl. Bd. 7. 1855. p. 723.

Some papers in other journals treat of the same subject: Erdmann Journ.
Bd. 67. 1855. p. 496. Annal.de Chim. et Fhys. T. 48. 1855. p. 193.

— 270 —

you should acquaint yourself with its contents. It treats of a
matter being, as I believe, full of interest i. e. of the connexion
that, to my opinion, exists between allotropic and catalytic
phenomena.1

During our midsummer vacations I took a trip into the
north of Germany, to me a "Terra incognita", rambled about
in Holstein, visited Hamburg and Berlin, saw many scientific
and other friends, made new ones, paid my respects to the
Senior of the European philosophers at Potsdam in the Royal
Castle, had a very interesting and long conversation with that
eminent old man, touched a little the Thuringian Forest, mounted
the Wartburg, where the great Reformer Luther fought against
the Devil, passed a couple of agreeable days at Frankfurt,
returned home highly satisfied with what I call my "North-pole
expedition", and met my family in good health. Before I set
out to my journey, I had worked a good deal and have done
so ever since my return, not quite for nothing I trust, for I
have succeeded in finding out a number of novel "phenomena
of contact"2 which I hope will add, if not much, at least some-
thing to our stock of knowledge regarding the Chemistry of
Oxigen.

I have already drawn up a voluminous memoir, in which
the results of my experiments are described and knowing that
you take some interest in this kind of researches, I am very
sorry to be prevented (by the smallness of the space allowed
to a letter) from entering into details about my late doings.
But to give you at least a slight Idea of the nature of those
researches let me tell you that they refer to what they call
catalytic actions so far as these concern oxidation. One of the

1 "Ueber den Zusammenhang der katalitischen Erscheinungen mit der
Allotropie." Basel 1856. See also Poggend. Annal. Bd. 100. 1857. S. I and
Phil. Mag. Vol. 12. 1856. p. 457.

2 "Ueber einige neue Reihen chemischer Beruhrungswirkungen" Miinchen.
Abhandl. Bd. 8. 1857. p. 37.

2/1 —

principal results obtained is the fact that in a number of cases
two substances, "toto coelo" differing from each other as to
their chemical nature: Platinum and the red globules of the
blood 1 — produce the same effects i. e. determine oxidizing
actions, which either would not take place at all or but very
slowly without the presence of the substances named, and
some others. I need not point out to you the probable im-
portance of such a remarkable fact to physiology.2

Another fact not quite void of scientific interest is this,
that in some instances I can show, as it were, steps which
the oxidation of certain matters passes: first ozonisation of
inactive oxigen, then a sort of loose combination of that
ozonised oxigen with the oxidable substance, and finally actual
oxidation of the latter. I have reason to believe that on
looking a little closer into that matter, we shall discover a
great number of similar cases and it is not impossible that
any oxidation is a sort of chemical drama, consisting of different
acts, the last of which is real oxidation. Shakespeare says, that
there are many things, between heaven and earth, which the
philosophers do even not dream of, and Schoenbein maintaining
that between the moment on which two isolated elementary
bodies meet, and that of, their chemical associating being
finished, there lies a whole world of phenomena and is very
much of which the Chemists of the present day have as yet
not the slightest notion. There is even within inorganic Chemistry
something which I might call Physiology, and the most in-
teresting and truly scientific object of chemical research lies,
to my opinion, within the short interval of time alluded to, and
hence the great difficulty of such an investigation.

1 In 1857 a paper was published in the Basl. Verh. Bd. 2. p. 3 entitled:
"Uber die Gleichheit des Einflusses, welchen in gewissen Fallen die Blutkorperchen

und Eisenoxydulsalze auf die chemische Thatigkeit des gebundenen Sauerstoffs
ausiiben."

2 Vide Vierordt. Arch, fur physiol. Heilkunde. 1856. p. I : "Uber Sauerstoff-
-erreger und Sauerstofftrager in der organischen Welt."

2/2

Less interesting but pretty enough is a third fact which
I must mention to you, namely that out of free ozonized
oxigen and olefiant gas, formic acid is readily and directly
formed, a result easily accountable by the chemical equation
CiH4 + 8O = 2 CzHt O4. But now enough of Chemistry and
Oxigen.

If you should happen to have a friend in the country
being blessed with girls and desirous to receive for a time in
his family a grown up girl, pretty well versed in the german,
french and english litterature, being a tolerably good musician,
carefully educated and of an excellent moral character, I know
one, whom I should venture to recommend. I must however
not omit to tell you that the girl in question is very far
from wishing to become a paid governess, she desires to be
considered as a friend and member of the family, and make
herself at the same time as useful as possible in the education
of the children. That girl is my own eldest daughter, who is
very anxious to pass six or twelve months in an English family.
I do not much relish those wishes of her's, for I love her
too tenderly, as readily to allow her going to a foreign country,
but if it be possible to place her in a good family I shall
not prevent her from crossing the Channel. Pray let me know,
what you think about the plan of my adventurous, silly >
sweet girl.

Mr. Wiedemann charges me to present to you his best
compliments, he is at this present moment actively engaged
in magnetic researches, which seem to lead to interesting
results.

My friend Mr. Merian and his wife were highly gratified
with the friendly reception they met with at the Royal In-
stitution, and send the kindest remembrances to its amiable
Master and Mistress.

In closing my letter I ask you the favor te remember me
most friendly to Mrs. Faraday and tell her that Mr. Schcenbein

— 2/3 —

had not yet entirely given up his hopes of seeing once more
her Ladyship and her Lord on this side of the water.
Believe me my dear Faraday

Yours

most truly

Bale Septbr. 20. 1856. C. F. SCHOENBEIN.

Pray be kind enough as to send the inclosed paper to
Dr. Whewell as soon as you can.

Faraday to Sckceiibein.

Royal Institution 14 October 1856.
MY DEAR FRIEND

Hearty and healthy, and occupied, and happy,
as you are, let me congratulate you, for every letter of yours
brings me evidence of the existence of a healthy mind in a
sound body. How you have been running about! and you
go home as if you were refreshed, rather than tired by it.
I do not feel so any longer; even if I go away for a little
general health, I am glad to return home again for rest in the
company flf my dear wife and niece. But as the wise man
hath said, there is a time for all things, and my time is to be
quiet and look on, which I am able to do with great content
and satisfaction. - - I expect one of my nieces here very soon,
who will let me into the knowledge of your last paper; in the
mean time I have sent the other copy and your letter to
Dr. Whewell. What you tell me of your paper makes me
long to hear the whole of it; though the very pleasure of getting
knowledge is now mingled with some thoughts of regret at the
consciousness that I very quickly lose it again; - - well - - a
time for all things.
- s

— 2/4 —

I have been occupying myself with gold1 this summer;
I did not feel head-strong enough for stronger things. - - The
work has been of the mountain and mouse fashion; and if I
ever publish it and it comes to your sight, I dare say you will
think so:2 - - the transparency of gold - - its division - - its
action on light, etc etc etc.

Now with regard to Miss Schcenbein's desires. - - I am
sorry that my unsocial habits have left me unacquainted with
any such family as that which I think would suit your view.
Not one name occurs to me; but Grove and to Mrs. Grove I
shall show your letter as soon as they come to town. — It so
happened that two or three years ago Tyndall shewed us a
letter very much to the same purport, regarding a daughter of
one of his German friends; that letter we shewed to a lady
(Miss Hornblower) and it led to Tyndalls friend coming to
London and being with Miss Hornblower for, I think, two years
and it is not very long ago since she went back, very happy
in the thoughts of her residence here. I have shown your letter
to Miss Hornblower in hopes she might know of some family:
and her note to me in reply, is such, that I send it on to you.
Miss Hornblower is a very dear friend of ours, and in her
character and all that is about her, all we could wish; - - but
then she keeps a school. It is an excellent establishment, with
many masters, and the pupils who have been with 'her all love
and respect her. If what she says induces you to write to

1 "Experimental relations of gold (and other metals) to Light (Bakerian
Lecture)." Phil. Trans. 1857. p. 145.

2 In 1816 Faraday, then in his 24th year, gave six lectures at the City
Philosophical Society; of these the fourth was upon radiant matter, the subject
being the transparency of gold and the colour of the light transmitted through
it. "Forty years after this lecture was given", says Bence Jones in a foot note
(p. 195, vol. I), "Faraday published his last paper, full of experiments, in the
Philosophical Transactions, upon this subject." This statement is not quite
accurate. His last paper was printed in 1859, being a note on regelation. Roy.
Soc. Proc. vol. 10. 1859 — 1860. p. 440.

her, do so directly and without hesitation. For your private
thought, I may say she is about 50 years of age, very active,
though not very strong, and has sustained her establishment
of 15 or 20 pupils at Stamford Hill for full 30 years1.

Pray remember me to Wiedemann; — and us most kindly
to Madam and Miss Schoenbein and also to the Merians and

above all to Yourself.

Ever My dear Schoenbein

Yours Most truly

M. FARADAY.

Schoenbein to Faraday.

Bale November 10. 1856.
MY DEAR FARADAY

Many, many thanks both for your own letter and
that of your Friend's. When you happen to see her again,
pray tell her that from many reasons my daughter desires to
stay here during the winter. When spring comes and we live
then, we shall see, whether a move over the water may be
effected. In the mean while your friend will perhaps be kind
enough to let you know her views on the subject in question.
All I can say is this: Miss Schoenbein knows well and speaks
fluently french and german and is considered to be a pretty
good musician, in which accomplishments she is very willing
to make herself useful in the establishment of your friend. As
to the moral character of my daughter, I am too partial to
judge about, but I do not hesitate to qualify her as a modest,
good natured and rather high-minded girl, and the purest
Swabian blood running in her veins she partakes a little of
the poetical spirit said to belong to the native land of her
forefathers.

1 Miss Schoenbein in fact did in the end come to Miss Hornblower's house.

— 276 —

Since I last wrote to you l I have actively continued my
researches on the phenomena of contact, and obtained some
results which are curious enough. You know perhaps, that
according to my former experiments ozonised oxigen, at the
common temperature, oxidizes both the elements of Ammonia,
forming with that compound nitrate of Ammonia; whilst, as
you are well aware, common oxygen under the same circum-
stances does not at all affect either gazeous or aqueous Am-
monia. The same oxigen however , on being put in contact
with certain matters, acquires the power of engendering with
Ammonia nitrous acid i. e. nitrite of Ammonia. Platinum and
copper are such matters. Moisten the former metal (being-
in that state called platinum black} 2 with a strong solution
of Ammonia, leave for a short time those substances exposed
to the action either of common oxigen or atmospheric air,
treat then the metallic powder with some distilled water and
you will easily detect in that liquid the presence of nitrite of
Ammonia. The simplest way of doing so is to add* to that
water some dilute sulphuric acid and paste of starch containing
a little of pure jodide of potassium (free even from the slightest
trace of jodate). Nitrite being present the mixture will become
dark blue.

Assisted a little by heat, even compact platinum is capable
of causing common oxigen to engender a nitrite with Ammonia.
Put some drops of a strong solution of Ammonia into a bottle f
containing air^, introduce into the vessel the heated coil of

1 Beginning from "I have actively continued" this letter is reprinted in
Phil. Mag. vol. 12. 1856. p. 457, under the following title: "On the Oxidation
of the Constituents of Ammonia by porous Media with some Remarks on Nitri-
fication. By Professor Schoenbein of Basle."

'2 Respecting these italics, which are ours, we are following th esame rule
indicated on p. 117, note i.

Schoenbein had written "Ethiops", an expression at that time current on
the continent, but long obsolete in England; it was formerly applied to various
preparations of a black or very dark colour.

3 put. 4 into an airholding bottle.

— 277 -

a thick platinum wire , hold over that coil a strip of filtering
paper, to which sticks paste of starch containing some jodide
of potassium and being acidulated by dilute sulphuric acid, and
you will perceive that paste instantaneously turning dark blue.
Whilst the hot platinum coil rests within the bottle, whitish
vapours make l their appearance, which, on being taken up by
some distilled water, give to that fluid all the properties of
a nitrite solution. On acidulation witkz dilute sulphuric acid
it deeply and instantaneously blues the starch paste containing
the iodide*, and such a strong reaction will be obtained, though
the heated coil may have remained in the bottle but for a few
seconds. The platinum coil does not require being heated
to redness^ to produce that effect, but those of iron wire etc.
must have that temperature to enable oxigen to engender a
nitrite with Ammonia. I above mentioned copper as another
substance ivhich ^vas capable'* of causing ordinary oxigen to
oxidize both the elements of Ammonia at the common tempe-
rature, and I may add that its action even surpassed that of
platinum. To convince yourself of the truth of my statement,
put about 50 grammes of minutely divided copper (such as is
obtained by reducing* oxide of copper by the means of hy-
drogen) into a bottle containing oxigen or air? moisten that
metallic powder with a solution of Ammonia, close or cover
the bottle and you will soon see the vessel fill* with whitish
fumes, which are nitrite of Ammonia; for if you introduce into
the bottle a strip of paper being covered with acidulated paste
of starch that contains some jodide of potassium, it will rapidly
be colored blue. Or if you suspend for a short time strips of
filtering paper being impregnated with distilled water, they will
contain perceptible quantities of nitrite of Ammonia, as you
may easily satisfy yourself by applying the test above men-

1 are making. 2 Being acidulated by. z the iodide holding paste of
starch. 4 red heat. 5 being capable. 6 from heated. 1 an oxigen

or air-containing bottle. 8 see filling the vessel with.

tioned. Even a moistened glassplate or watchglass, used to1
cover the vessel of reaction, will do, to receive within a very
few minutes so much of the nitrite formed as to enable you
to ascertain its presence by the most striking reactions.

To complete my statements I must not omit to mention
that the copper powder soon after having been moistened with
liquid Ammonia, exhibits a rise of temperature, no doubt re-
sulting from the formation of the nitrate of Ammonia. The
blue liquid obtained on shaking copper powder with aqueous
Ammonia and oxigen or atmospheric air, besides oxide of copper,
also contains nitrite of Ammonia, for if you put some soda to
it and boil it up, to drive off the Ammonia and throw down
the black oxide of copper, a solution is obtained which after
being evaporated to dryness, leaves behind a yellowish salt
which consists* principally of nitrite of Soda. This substance
being mixt up with powdered charcoal and heated, burns that
combustible matter, yields with sulphuric acid strong fumes
of nitrous acid, and rapidly discharges the colour of indigo
solution being strongly acidulated by oil of vitriol, colors
brownish a solution of protosulfate* of iron containing free
sulphuric acid etc. Common pure, or atmospheric oxigen on
being put in contact with copper powder and aqueous Am-
monia is so rapidly absorbed,^ that I succeeded in depriving
completely a whole cubic foot of atmospheric air of its oxigen
within a few minutes. Copper and Ammonia may therefore
be used as eudiometric means and for preparing nitrogen from 5
the common air. The facts above stated appear to me to bear
closely upon the important question of nitrifications, and proving
beyond any doubt that under the influence of the contact of
some ponderable matters, inactive oxigen is empowered even
at the common temperature to oxidize both the constituents*
of Ammonia. Before long I hope to be able to give you some

1 by which you. 2 being. 3 vitriol. * taken up. 5 out of.

6 constituent parts.

— 279 —

more details on nitrification , a chemical phenomenon which
at this present moment deeply enjoys my attention.1

(Pray present my best compliments to Mrs Faraday and]

believe me

my dear Faraday

Your's most faithfully

C. F. SCHOENBEIN.

(Mrs. Schcenbein and the young ladies charge me to offer
to you and Mrs. Faraday their kindest regards.)

Faraday to Schcenbein.

Royal Institution 23 January 1857
MY DEAR SCHOENBEIN

I wished to write to you, and therefore wrote to
my friend Miss Hornblower whose former letter you have.
After a few days she wrote me enclosing a letter to Miss
Schoenbein which I now send --it will explain itself and say
more than I can. Your last but one letter I also laid before
Mrs. Grove and some others, but nothing has come of it so
far. Mrs. Grove was anxious to aid the course but could find
no opportunity. You will see that the philosophic part of
your last has appeared in the Phil. Mag. and I trust will aid
by degrees in doing the work of science, but the work is
slow. Look at Ozone, how beautiful it is and yet how its
progress has been resisted and how little it was thought of at
first. — I do not know that I am doing any thing — I forget
— I have been subduing gold and other metals, but probably

1 By this list the alterations are however not completely exhausted; "oxigen",
for example has invariably been changed to "oxygen", words have frequently
been transposed and so forth.

280 —

told you about that — I cannot say, and I must not say more
just now, than to wish all happiness to Miss Schoenbein and
the rest with you and the kindest thoughts to yourself from

Your friend
M. FARADAY.

Sckosnbein to Faraday.
MY DEAR FARADAY

Not knowing exactly the direction of your friend
at Stamford Hill, I take the liberty to inclose a letter, addressed
to her, by my eldest daughter and beg you to forward it to
its place of destination. If the plan of Miss Schoenbein should
happen to be realized, I am very glad to know her placed
with an intimate friend of your's and in your neighbourhood,
being sure that in Stamford Hill she will find a second home,
and in you and Mrs. Faraday a father and mother.

As to the girl herself, being good-natured, cheerful, healthy,
active, and I may add well-informed and well-bred too, I trust
she will please and suit your friend.

During our late crisis and warlike preparations I was very
busy too, but in a very quiet and harmless way. I worked
very hard upon oxigen (for what else should or could I do)
and think to have succeeded in ascertaining a series of novel
facts such as to my opinion at least, leave no shade of doubt
about the correctness of an old notion of mine, according to
which common oxigen must be considered as a chemically
inert body and any oxydizing action apparently being brought
about by O is invariably, and as a conditio sine qua non,
preceded by an allotropic modification (change of chemical
condition) of that elementary substance.

The facts alluded to appeared to me so simple and striking,
when I saw them first, that looked for as they were, I felt

28l —

an infantine joy, to which I could not help giving utterance,
although I was quite alone in my laboratory. You shall know
the details in my next letter, for at this present moment I
have no leisure-time to write an epistolary memoir.

Amongst other little things I have found out that under
given circumstances even strong acids may be chemically asso-
ciated to metallic peroxides, such as PbO-2 and MnOs, yielding,
as you may easily imagine, highly energetic oxydizing solutions,
such indeed, as act like free ozonized oxigen.

So you see, every day a little step is made onward in
my favorite study and I hope progressing still farther for some
time to come, for in the Ozone business much work is yet
left to be done. We have hardly begun the "magisterium".

I don't know, whether you have been told that a great
and wholly unexpected honor was bestowed upon Mr. Schoen-
bein some months ago. A gold medal1 conjointly with a prize
of about 3500 francs has been awarded to him (by the king
of Bavaria) for his investigations on ozonised oxigen. Liebig
being quite intimate with his Majesty, I suspect that our friend
has not been quite strange to the matter. Be that however
as it may, I cannot deny that I was highly gratified by that
Royal munificence, less on account of the monay than of the
meaning of the gift. The existence of the little baby, christened
"Ozone", has been at last acknowledged even by a monarch;
now the schoolmasters must follow the Royal example.

I intend to spend the caster holidays at Munic a place
which from several reasons I am exceedingly fond of and visit
more than any other town. In the first place I have got there
many friends of a very motley description, artists, poets, philo-
sophers etc. and there is even a Nimrod found amongst them.
Varietas delectat. And then the Bavarian capital teems with
master pieces of the fine arts, which, unartistical as I am, I

1 The then king of Bavaria in November 1856 presented Schoenbein with
the Maximilian Medal.

nevertheless relish very much. It is indeed a great treat to
me now and then to shake off from my shoulders the dust of
the laboratory and store up my mind with the Images of
exquisitely beautiful objects, creations certainly belonging to
an order of things infinitely superior to that under which we
range physical phenomena and philosophical truths. And I
will not conceal it from you, that on returning to the earth
from the lofty regions, where Imagination reigns and rules, I
feel myself a better philosopher and matter of fact dealer, for
even on the prosaic ground of palpable matter, we cannot do
without that enchantress who conjures up Ideal worlds.

New being at the end of my stories and sheet I beg you
to pardon the loquacity of

Your

old and affectionate friend

Bale Febr. 9. 1857. C. F. SCHOENBEIN.

P. S. Pray present my best compliments to Mrs. Faraday.

Schcenbein to Faraday.

Basle April 25th 1857
MY DEAR FARADAY

I write you these lines to ask you the favor of
letting occasionally know your Friend at Stamford-hill, that,
about the time indicated by her, my daughter will keep herself
ready for her projected journey to England and hope that some
proper travelling companions will in the right season make
their appearance at Basle, under whose guidance Miss Schoen-
bein may safely be carried over to London. -- The last holidays

- 283 -

I passed at Mimic and as you may easily imagine in a very
agreeable manner, though in consequence of having sprained
my leg I was kept in bed there for nearly a week. Liebig
and many other scientific and artistic friends were at home,
so that there was no want of rational enjoyments in the
bavarian capital. Amongst the curiosities seen „ there, there
was a specimen of the poisoned Chinese bread sent to Liebig
for chemical analysis. He found considerable quantities of
Arsenic in it. Of late I (have) worked again a good on my
favorite subject and ascertained a number of facts which seem
to me to put beyond doubt the correctness of that old notion
of mine, according to which oxigen, such as it exists in the
atmosphere, is in a chemical point of view an entirely inert
body and any oxidation being apparently brought about by
it, is preceeded by its allotropic change of condition. The
essential oil of bitter Almonds (Benzule) has become to me a
beautiful object of research, which substance, >being assisted
by solar light, enjoys the power of rapidly taking up common
oxigen and transforming it into that state, in which it produces
all the oxidizing effects of ozonised oyigen l decomposition of
jodide of potassium, coloring blue the solution of guajacum
etc. Leaving that oxigen associated to the oil, it rather rapidly
oxidized that matter into hydrated benzoic acid. In presenting
my best compliments to Mrs. Faraday and begging "you to
drop the inclosed into a letter box I am my dear Faraday

Yours

most truly

C. F. SCHOENBEIN.

1 The results of these investigations Schrenbein sums up in a paper
entitled: "Uber das Verhalten des Bittermandeloles zum Sauerstoff." Basl. Verh.
Bd. 2. 1857. P- 3-

284

Faraday to Schoenbein.

Royal Institution 7. May 1857.
MY DEAR SCHOENBEIN

On receipt of your last I spoke to Miss Horn-
blower who said she had written fully either to you or Miss
Schoenbein and had indeed been expecting an answer, as she
was obliged to keep her own arrangements open until she heard
from you; she seemed glad to learn how the decision went,
but you must judge from her letter whether it requires a direct
answer. - - I think she said that in it she had spoken of time
etc. etc., and I think she mentioned the time, but whether it was
September or any other month I cannot now tell - - I forget
every thing and I am obliged to be content to forget, and this
makes me anxious that no point of the arrangements should
depend upon what I may say. But that direct communication
should convey the necessary information. I should almost certainly
introduce some blunder - - I am daily occupied in making and
repairing mistakes even in the very house I live in.

I have every conviction that Miss Schoenbein will like Miss
Hornblower and when she knows her will soon highly esteem
her. She is a woman of business, but she has always left a
strong and kind impression on the minds of those ladies who
have been with her from abroad, and I have no doubt it will
be so with Your daughter. It can be no slight thing for you
to part with her for a while, but you may be sure that at
Miss Hornblower's she will have a safe home. We shall see
what we can of her, though our residence here and the cir-
cumstance of our having no house cuts short our means of
seeing friends as we could wish - - but all that must be left
- Let me say a word of sympathy on our part to Mrs. Schoen-
bein under the coming circumstances: for the mother cannot
but be anxious on the matter. My wife is an invalid at present

- 285 -

and not yet out of her room or I am sure she would join me in
kindest thoughts to you all.

Ever My dear Schcenbein

Yours

M. FARADAY.

Schoenbein to Faraday.^

Basle, Septbr. i/th 1857.
MY DEAR FARADAY

The moment is fast approaching, which will sepa-
rate my eldest daughter from her home, parents and friends,
and as you may easily imagine, all of us, and Mrs. Schoenbein
most particularly, are looking for that painful hour with feelings
appropriate to the case. The girl herself, however, exhibits on
that occasion more courage than I thought she could command
and though being fully conscious of what she is about to under-
take, the wicked woman does not seem to have lost any of
her wonted spirits. If I were not fully convinced that my
daughter should find a second home with your friend, I cer-
tainly would not have given my consent to her emigrating
there ; and, besides, my knowing, that you and Mrs. Faraday
are near her, gives me confident hopes, that she will be well
off in every respect and meet with good counsel as often as
she will happen to stand in need of it. Pray be kind to the
girl, for though my child, I am allowed to assure you, that
she is a good and excellent creature, who, I have no doubt,
will please you, Mrs. Faraday and Miss Hornblower.

Within a month my second daughter Sophia, who by the
bye was intended to be a philosopher, also will leave me to

1 The chemical part of this letter is published in the Phil. Mag. for 1857.
S. 4. vol. 15. p. 24.

— 286 —

go to the far North and stay over the winter with some friends
of mine at Altona. Though she will be placed in very good
hands, still to be deprived of two daughters at once, who have
these many years given so much life to our little domestic
circle, is rather hard to their parents and younger sisters; but
we cannot help and must suffer the girls to go their own way.
To Mrs. Schoenbein those separatings will cost floods of tears
in spite of her stoical maxims.

In the course of this summer I have been travelling and
working. I saw once more my favorite town "Nuremberg",
that splendid and interesting monument of the middle ages, where
every house, court and street puts you back to times and a
state of things long gone by. At the same time I visited old
intimate friends, (and that was the principal end of my journey)
who thirty some years ago were my fellow students at the
University of Erlangen. I need hardly tell you, that I enjoyed
my trip very much and spent most delicious days with those
old cronies of mine, one of whom happens to be one of the
most extraordinary and amiable men, I know, being highly
poetical, therefore full of imagination, rich of original ideas, of
a matchless humor, teeming with wit and what I do not consider
as the least of his many excellent qualities, full of the milk of
human kindness, in short a genuine man every inch. In the
little book1 which will be presented to you by Miss Schoenbein,
the author has tried to depict the man in the chapter entitled
*Der Freund".2 Having once touched that "opusculum", the

1 cf. Schcenbeins letters to Faraday of Feb. 27 and Nov. 30 1855. pp. 238
and 254; and also Faradays letter to Schcenbein of April 6. 1855. p. 242.

• Schoenbein here alludes to his friend A. von Zerzog, who unquestionably
was an unusually erratic person. He was born in 1799 at Coburg, studied at
Erlangen, Wiirzburg and Jena; together with Schoenbein he was a member of
the patriotic students association (Burschenschaft), for which reason he was prose-
cuted, and punished with a year's confinement in a fortress ; in 1848 he sat as
a member for Frankfort in the German parliament and died in 1880 as owner
of a large estate at Prufeningen Castle near Regensburg. Schoenbein very

- 28; -

authorship of which I leave you to guess, I beg you to accept
that trifling as a keepsake. It it sort of "quodlibet" and hardly
worth while to be read. But if you should feel inclined to
know a little what curious notions a friend of your's is enter-
taining on "Men and things", get some chapters of the little
work translated to you. I see that the author has taken the
liberty to talk even of yourself, but have reason to think, that
in doing so he was actuated by the most friendly motives.

I have continued my researches on oxigen, that inexhaus-
tible source of investigation, and ascertained a series of novel
facts which seem to be not altogether void of scientific interest.
One of those facts is queer and paradoxical enough. What do
you say to a desoxidation of an oxycompound being effected
by the means of oxigen itself? You are perhaps aware, that
some years ago I found out a number of substances enjoying
the power to transform free O into O i. e. to act like heat
The oxides of the precious metals and the metallic peroxides
such as that of manganese, lead etc. belong to that category,
and which are oxy-compounds containing either all or part of
their oxygen in the ozonic condition. Now it appears, that
the action taking place for instance between free O and

PbO + O is reciprocal; for not only the former happens to
be converted into O, but the peroxide of lead is at the same

time reduced to PbO, which seems to show that the O of
PbO + O also becomes desozonized and on that account eli-
minated. The same desoxidizing effect is produced upon PbOa
by the ozonized oil of turpentine and the peroxide of hydrogen
(to me = HO + O). To show those remarkable effects in a
simple manner, I employ a test-paper being impregnated, i. e.
colored with minute quantities of peroxide of lead. If moist

properly says of him, if he would only take upon himself to write but a few
sheets, they would teem with Shakespearean humour and be of greater value
than half the books of the Leipsic exchange. (Vide "Menschen und Dinge"
P- I73-)

— 288 —

strips of that paper be suspended in strongly ozonized air, within
a few hours they will be completely bleached, i. e. PbOa
reduced to PbO. The said test-paper on being put in ozonized
oil of turpentine or peroxide of hydrogen undergoes the same
change. The strips joined will show you that effect. Now
those curious facts seem to me to give room to a very strange
conjecture, which, extraordinary and startling as it may sound,
I cannot help communicating to you. I suspect that there are
two kinds of active oxigen, standing to each other in the relation
of algebraic magnitudes of contrary signs, i. e. being such, as will
neutralize each other into inactive oxigen, if brought together
in equal quantities. Now supposing that there are three kinds

00 0

of oxigen ©, 0, O and assuming that HOa is = HO + © and

PbO2 = PbO + 0, those peroxides, on being brought in contact

with one another, must be catalized, because the © of the

one neutralizes the 0 of the other peroxide into O, which as
such can no more rest associated either with PbO or HO.
For the reduction of PbO2 to PbO being effected by free

O, I am inclined to account in the same way i. e. by assuming
opposite states of the two portions of oxigen , which act
upon each other. In the two isomeric and crystallographically
polar acids of Pasteur's,1 which neutralize each other into
what they call racemic acid, we have a case of an analogous
kind.2

I am, of course, far from believing, that the facts above
stated necessarily lead to such a conclusion, but for the present
I cannot conceive any other hypothesis, by which the desoxi-

dizing effect being produced by free O, ozonized oil of tur-
pentine or peroxide of hydrogen upon Pb O2 could be better

1 Louis. Pasteur was born in 1822 at Dole, Dep. Jura. He was consecu-
tively professor at Dijon, Strassburg, Lille and Paris, where from 1867 he was
professor of Chemistry at the Sorbonne. He died on the 28th of September 1895
He was awarded the Rumford and the Copley medal.

- "Recherches sur les proprietes specifiques des deux acides qui composent
1'acide racemique." Compt. rend. T. 29. 1849. p. 297.

— 289

accounted for. Be that however as it may, as we philosophers
cannot do and notably work without having some hypothetical
views in our heads, I shall place myself for some time under
the guidance of the conjecture alluded to, and see what can
be made out of it. If it leads me to the discovery of some in-
teresting facts, I shall not feel ashamed of it, though it may
turn out to be fallacious. We are no gods, but shortsighted
men and must be content with finding out a little bit of truth
in wading through a sea of errors.

You know it is an old notion of mine, that common oxigen
as such cannot enter into any chemical combination and must
undergo a change of condition i. e. become ozonized before
it acquires oxidizing powers. The oxidation of phosphorus,
oil of turpentine etc. being apparently effected by common
oxigen is typical to me, because we know, and I think with
sufficient certainty, that in those cases the ozonisation of common
oxigen always precedes oxidation. In order to increase as
much as possible the body of evidence, speaking in favor of
that assumption of mine, I have of late worked a good deal
on the oil of bitter almonds (Benzule 4- H), which, as to its
bearings to common oxigen, is certainly one of the most remar-
kable bodies I know; for that oxigen being at the common
temperature placed under the joint influence of the oil named

and solar light, effects a number of oxidations, which O only,
but not O is capable of causing. Under the circumstances
mentioned Jodine is eliminated from jodide of potassium, indigo
solution discolored rapidly enough, the solution of guajacum
blued, a great number of metals oxidized, even Silver not
excepted etc. To convince yourself of that action in a simple
way, add to dilute paste of starch, containing some jodide of
potassium, a drop or two of hyduret of Benzule (free from
prussic acid), shake in the dark that mixture together with
ordinary oxigen, and no action will result; make the same
experiment in the sun and the liquids will almost instantaneously
.- T

290 —

be turned deep blue, just so as if free ozonized oxigen had
acted upon the paste. The same color will make its appearance,
if you treat in a similar way a recently prepared solution of
guajucum. To show that even Silver is oxidized, put some
drops of our oil upon a plate of pure silver and having the
essence moved about in direct sunlight for a minute or two,
aqueous sulphuretted hydrogen, being poured upon the spot of
reaction, will cause a rather abundant precipitation of sulphuret of
silver, a proof of the presence of oxide of silver. I need not
expressly state, that the hyduret of Benzule is oxidized along
with the metals, in consequence of which benzoates are formed :
benzoate of lead, cadmium, copper, silver etc. A very pretty
experiment may be made with metallic arsenic. Lay round a
glass tube a ring of that metal (according to Marsh's methode),
drop some oil of bitter almonds upon it, turn the tube, being
held in horizontal position, round its axis, no action in the dark,
whilst in the direct solar light that ring will rapidly disappear
under the circumstances indicated, arsenic acid being formed,
just so as it is the case in ozonized oxigen. Rings of antimony
being not acted upon, or a least but very slightly under these
circumstances, both the metals may be easily distinguished from
each other by the means of hyduret of Benzule. The details
of my researches on the oil of bitter almonds will be published
by the academy of Munic.1

You know, that nitrification has been, these many years,
a matter of interest and research to me and of late I have
increased our knowledge about that subject by some novel facts.
Some years ago, I found out, that ozonized oxigen transforms
Ammonia into the nitrate of that base; last year I ascertained,
that inactive oxigen on being put in contact with platinum or
copper acquires the power of oxidizing even at the common

1 "Uber des Verhalten des Bittermandelols zum Sauerstoff." Mtinchen.
Abhandl. Bd. 8. 1857. S. 159. In the Miinchen Abhandl. 1857. Bd. 8. p. 383 he
has a supplement to the above paper.

— 291 —

temperature the elements of Ammonia into nitrous acid and
water, nitrite of Ammonia being formed under these circum-
stances.

Now I have discovered that HOa, MmO? (permanganic
acid), or the salts of that acid, for instance permanganate of
potash, on being mixt up with aqueous Ammonia produce nitrites.1
A singular fact is, that free ozonized oxigen alone seems to
be capable of oxidizing the nitrogen of Ammonia into nitric
acid, the ozonized oxigen of oxy-componds or the oxigen being
rendered active by the influence of copper or platinum pro-
duces nitrous acid. Are we to infer from those facts, that the
formation of a nitrite is the first stage of a nitrification?

One gambol more on my hobby-horse and I shall descend
from the animal. I have of late succeeded in ozonizing the oil
of turpentine so strongly that one equiv. of that essence is
associated to one equiv. of oxigen, and you may easily imagine
the great oxidizing power of that oil. By shaking it with peroxide
of lead it becomes desozonized, Pb Qz being reduced to Pb O, a
fact, which according to the statements above made, is a matter
of course.

Now you are released, my dear Friend, from listening to
the talkings of a loquacious philosopher to whom, I hope, you
will prove indulgent, as you have already so often done him
that favor.

Now nothing more than the request to remember me
friendly to the most gracious She-Sovereign of the Royal In-
stitution, whom you will beg in my name to take my girl under
her high protection.

In hoping that you and Mrs. Faraday are doing well. I am
my dear Friend

Your's most faithfully

C. F. SCHOENBEIN.

1 "Uber das Verhalten des Wasserstoffsuperoxydes und der UbermangHn-
saure zum Ammoniak." Erdm Journ. prakt. Chem. Bd. 75. 1858. p. 99.

— 292 —

I must add a remark or two on my peroxide-testpaper.
I prepare it by drenching strips of this filtering paper with a
solution of PbOs and that solution is produced by shaking
together (for abount 15 minutes or so) two volumes of strongly
ozonized oil of Turpentine and one volume of Extractum Saturni
(subacetate of lead). On filtering that mixture I get a trans-
parent liquid being colored like portwine which in fact is oil
of turpentine holding some peroxide and oxide of lead dissolved.
Upon the filter remains a yellow substance, being a mixture of
PbOa and PbO. Within 24 hours a similar mixture is deposited
out of the colored essence. It is a remarkable fact that the
test-paper is rapidly bleached in strongly insolated atmosph.
air, as you will see from a strip laid by, which in a good sun
was completely bleached within an hour's time.1 For that
reason my test-paper must be kept in the dark.2

Faraday to Schcenbein.

Royal Institution 25. Septr. 1857
MY DEAR SCHOENBEIN

I cannot leave my desk without telling you that
yesterday I saw your daughter and received your letter. I
went as soon as possible to Stamford Hill and found Miss
Schcenbein very well, though not yet recovered from her
fatigue - - looking cheerful and happy and, as far as I could

1 These strips have been lost.

* Instructions for preparing another form of test papers are given in the-
Verhandl. der Schweiz. Naturf. Gesellsch. for 1850. p. 44, which we give by way
of comparison : Schcenbein dips writing paper in water in which is dissolved
— pt of lead nitrate or sugar of lead, and after drying them, brings them
under a bell jar, containing some hydrogen sulphide. So soon as the paper
has become perceptibly brown in colour, it is removed and kept in the dark.
Two hours' exposure to a July sun proved sufficient to bleach it to a pure
white, indicating that the lead sulphide had been transformed into lead sulphate*

— 293 —

judge, she and Miss Hornblovver mutually pleased with each
other. You need not doubt that she will find a most kind
and careful friend in Miss Hornblower, a woman of method
and discipline, but who by her tenderness and care makes all
about her love her. You know one cannot judge of results
in a hurry, but the first appearances are most favourable. I
dare say Miss Schoenbein will find enough to do, but a good
moral atmosphere to do it in and hearty good will on all sides.
- We shall learn by degrees what opportunities the routine
supplies and we shall hope to see her at our house when that
is proper, after our return home.

I can easily imagine Madame Schoenbein's anxiety, but
except from what may be founded on difference of habits in
our two countries she need have none. - - It so happens that
I have three niece* with Miss Hornblower at this time and I
hope they will make a friend of Miss Schoenbein and that you
will hear a word or two about them now and then. - Two
of them are sisters to Jeannie whom I think you have met here.

As to the philosophy of the letter I must enjoy and talk
about that another time or else I shall lose the post

Ever My dear friend

Your's

M. FARADAY.

Our kindest thoughts on this occasion to Mrs. Schosnbein
and the Sisters M. F.

Faraday to Schoenbein.^

Royal Institution 24 Novr. 1857
MY DEAR SCHOENBEIN

I dare say you have plenty of letters with the
London post mark now from Stamford Hill, and hardly require

1 Portions of his letter are printed in Bence Jones vol. 2. p. 376.

294 —

to have your English associations stirred up by one from me,
so soon after the last; — but we leave town on Friday for
a little renovation, and I want to relieve myself by writing to
you before we go. I expected you would have seen much
of your last in the Philosophical Magazine before now but
Dr. Francis * told me, a day or two back, that he was writing
for some new type © and 0; for that nothing they have at
present will serve the same purpose: -- then I trust it will
appear as it ought to do . . What a wonderful thing oxigen
is, - - and so I suppose would every other element appear if
our knowledge were more perfect.

Sir James Clarke2 applied to me the other day, to know
if you had been able to draw up a set of practical directions
for the observation of Ozone in the atmosphere; obviating
such difficulties as arise at first, connected "with the time of
exposure, the continued exposure, the moisture or dryness
of the test paper, etc. He seemed well aware of the general
state of he subject, but thought that you would know sooner
than the \v^rld at large, of any perfectionment. His object
is to consider the medical effects of Ozone in nature, where
without doubt it must have some, and perhaps, very important
effects. Probably when you feel that there is any improvement
in the mode of observing you will let us know. I think he
said that Ozone seemed to be abundant about our Queens
residence, Balmoral, in the North.

I ventured to send you a paper3 the other day by the
post. I was assured it would go free and shall be very sorry
if, unaware, I have put you and other friends to post expence,
but I find that the information I obtain by enquiry is often

1 William Francis Ph. D. F. C. S. He was born in 1817 in London and
is partner in the printing firm of Taylor & Francis in London.

2 Sir James Clarke Bart, late Physician-in-Ordinary to the Queen, was
born in 1788 at Cullen and died in London in 1870.

5 "Experimental relations of Gold and other metals to light. Phil. Mag.
8.4. vol. 14. 1857. p. 401.

— 295 —

very uncertain in its nature, though positive in its form. The
paper was about Gold, and the relation of it and other metals
to light. Many facts came out during the enquiry which sur-
prized me greatly; especially the effects of pressure and also
those relating to polarized light. Lately I have been working
on1 the relation of time to actions at a distance; - as those
actions which class as magnetic. But the subject is very diffi-
cult, — the requisite apparatus requires to be frequently remade,
each time being more perfected; and whether I shall catch
the -~^- part of a second (if required) seems very doubtful.
In the mean time I am for the present tired and must lay the
research on the shelf.

Since I wrote to you we have had Miss Schcenbein here:
- but since that I have not been able to see her or my old
friend Miss Hornblower either, at Stamford Hill: Probably
when the Christmas Holidays come on, we shall have the
opportunity; but my wifes health is so infirm and our capa-
bilities so limited at the Institution, that I dare not think of what
we should like, before the time comes: I have undertaken to
give half a dozen juvenile lectures after Christmas; — whether
they will come off (as we say) or not, is doubtful. Patience -

I hope that Madame Schoenbein is cheered by her daughters
letters. Miss Schoenbein assured me that there was a great
deal of correspondence going on, and from the manner in
which I heard of it, I should trust that it was cheerful. Re-
member me in the kindest manner to the anxious mother.

I do not think we have much scientific news, at least I
do not hear of much; but then I do not go within reach of
the waves of sound, and so must consent to be ignorant. Indeed
too much would drive me crazy in the attempt to hold it.

Ever My dear Schoenbein

Yours most truly

M. FARADAY.

1 Bence Jones prints "at".

296 —
Faraday to Schcenbein^

MY DEAR SCHOENBEIN

I got as far as Stamford day (which I very

rarely do)^and cam a better reminder of the fitness of

writing to you. Poor as I may be in subject matter yet a
daughter, and your daughter, is surely quite enough. She looked
very well and I was very glad to see her so contented, happy
and cheerful. When she first came to this country I was very
much frightened, least the experiment should fail, for that
would have been no trifle; but now all anxiety of that kind
is over. It was impossible, but that all her views of life, so-
ciety, and manners should have been formed upon her experience
and habits of home, and her own country, and I felt sure that
much of what is good amongst us , must have been hidden
from her for a time by the novelty of the customs, manners,
and occupation she would find here. But she is a girl of sense
and I think was not long in passing through the show and form
of things to the reality beneath. As far as I can see the reality

has not been her and of Englishman feel proud and

as very glad. However I dare say you know her mind in all

these things far better than I can do. What I can see is that
she seems happy in things as they are and growing in the
estimation of those around her. Indeed there are many points
in which I, who am at a distance, can see she is an example
to all around her, such as her judgment, her steadiness of
purpose, her conscience of things, her toleration of the judg-

1 This letter has been partly destroyed by some corrosive acid, with it
the date. The clue by which we were guided in ascertaining the approximate
date, is the fact that he speaks of his intention of proceeding with his investi-
gations on action at a distance. In the letter to Schcenbein dated Nov. 24. 1857
he informs him that he has been working on the relation of time to action at
a distance. Hence these two letters presumably belong to the same period,
and as he speaks of Miss Schoenbein having already been some time in England
we would fix the date at about November, 1857.

— 297

ments of others, her truthfulness, and her propriety and many
others which make the bases of a good mental character. She
appeared to be very well. I wish I could see more of her
amongst us, but the bad and uncertain state of my wife's health,
and her little strength is a great barrier to our desires.

I cannot just now remember what were the last points of
philosophy which you sent me or even those of my own which
are worth speaking of to you. I work very slowly now I
want to proceed with action at a distance and from .....
forgetting .... over I hope ..... exertion ..... we shall see.

Commend me to Mrs. Schoenbein: even the poor talk I have
given you about her daughter will incline her a little towards
me. Say I hope , she will receive her back some day or
another, and find reason to be not less proud of her, than she
ever has been : - - even when she was a baby

Ever My dear Schoenbein

Very affectionately Yours

M. FARADAY.

Schoenbein to Faraday.

MY DEAR FARADAY.

I am afraid you will be dissatisfied with Mr.
Schoenbein and think him to be a very lukewarm friend, if
not even a forgetful one, and I must allow, appearances are
strongly speaking against him; but I can assure you at the
same time, that coldness of feelings has nothing to do with
the silence he has been keeping these many months.

You know perhaps that in our commonwealth I have be-
come a sort of a political and public character i. e. a member
of our little parliament and as such I have got duties to fulfill.
Now, of late, a party having sprung up amongst us, that

298

attempted to change some fundamental principles of our con-
stitution and your friend being a staunch conservative, he con-
jointly with his political friends of course opposed that tendency>
and the consequence was, that in our senate we had some
battles to fight, in which I could not help taking some active
part, both within and out of doors.

You will no doubt smile at Mr. Schcenbein's acting a
political part and you are quite right in doing so, for I will
and cannot deny myself, that he is by no means the proper
man for dealing in politics and may add, that the bias of his
mind does not go that way neither. You must be aware,
however, that the citizens of a small republic, such as our's
is, are not always allowed indulging their private taste; they
are now and then, as it were, forced to handle things, which
they have not the slightest mind to touch, and such is Mr.
Schcenbein's case. Our many-headed sovereign (the people)
proves in general to be more imperious and exacting than
your monarchs even, so that very often very little choice is
left us between following and disobeying his pleasure and
commands.

I tell you all these things, indeed very insignificant in
themselves, to account for and justify my long taciturnity, for
you may easily imagine, that the mind being seriously occupied
with such matters, is little apt for any thing else, even not
for letter-writing.

Now, after having carried a most signal and decisive
victory over our antagonists, we belong again to ourselves, so
that nothing prevents us from re-assuming our wonted peaceful
work and I hasten to make use of the very first moment of
the leisure-time regained to pay old debts to my friends.

First of all permit me to express you my most grateful
thanks for the very numerous proofs of kindness and bene-
volence which you have of late been pleased to bestow upon
my daughter. She was really overhappy in having been

— 299 —

favored so much as to enjoy the enviable privilege of passing
some days at the Royal Institution and getting introduced into
the amiable family of your near relations. And I need not
add, that the juvenile lectures, which you kindly allowed her
to attend, highly pleased and interested the girl. I do not
wonder at all the great pleasure and gratifications she has
derived from such favors, and in reading the girl's lively des-
criptions of what she saw, heard and felt on the occasion, I
could not help envying Miss Schoenbein and being a little
jealous of her. The girl looks on the new world of wonders,
in which she has been placed, with open eyes and all the
freshness of youth, and, even at the risk of being taxed with
partiality , I tell you, that the young maid now and then sur-
prises me by the justness of remarks, which she makes upon
men and things.

According to her often repeated assurances, my daughter
feels quite happy in England and has (to me the most im-
portant point) become so exceedingly fond of her sphere of
activity there , that the Idea of soon returning to Bale is far
from being a flattering one to her. Her truly filial attachment
to Miss Hornblower is daily growing stronger and deeper and
every letter of her's bears ample evidence of the feelings both
of the deepest affection and highest veneration she entertains
towards your excellent friend. You may easily conceive, how
much gratifying such news must prove to myself, as well as
to Mrs. Schcenbein and as it was by your kind interference,
that our beloved Child has been so happily placed, both of
us feel ourselves laid under the deepest obligations to you
and you may rest assured, that this great piece of friendship
will never be forgotten by us. Mrs. Schcenbein charges me
to offer you in her name the most heartfelt thanks for your
kindness.

From the very same reasons, that forced me to be neg-
lectful to my friends as a correspondent, I have for some time

— 300 —

very little worked, though it would not be quite true if I said
to have been entirely idle. Now and then I took up some
little piece of work, but without doing any thing being worth
while of speaking about. I entertain however the hopes, that
the forthcoming spring, in renewing all nature around us, will
also call forth some dormant powers of my mind and stir me
up again to scientific activity. At this present moment there
is some dullness, I had almost said, sleepiness about me and
it is full time to get rid of that drowsy disposition of mind.
I saw the other day my last letter to you in the Philosophical
Magazine; the epistolary production hardly merited the honor
of being printed, be that however as it may, there is at any
rate no harm in publishing such trifles and queer Ideas. I will
not let pass unnoticed a little misprint, which is singular enough.
Whilst from several reasons I have made it a point never to
communicate any thing to the french academy, the printer has
put "Academy of Paris" instead of Munic. Or have I perhaps
made the mistake myself in my letter?1 Errare humanum est;
I do not think it however worth while , that the error should
be corrected. From what you told me in your last letter, it
appears that you are at present engaged in researches of the
highest importance, for the problem to be solved is really of
a transcendent nature. You only could think of undertaking
such a bold enterprize and I wish you from all my heart full
success. How does Mrs. Faraday fare? I confidently hope
and ardently wish, that she is going better. Pray present my
best compliments and kindest regards to her. In begging you
kindly to excuse the emptiness of my letter I am, my dear

Faraday for ever

Yours

most faithfully
Bale Febr. I5th 1858. C. F. SCHOENBEIN.

1 vide p. 290 from which it will be seen that he wrote Munich and not Paris.

Sckcenbein to Faraday.1
MY DEAR FARADAY.

These last six months I have been rather busily
working on oxygen, and flatter myself not to have quite in
vain maltreated my favourite; for I think I can now prove the
correctness of that old idea of mine, according to which there
are two kinds of allotropic modifications of active oxygen, standing
to each other in the relation of + to — , i. e. that there is a
positively-active and a negatively-active oxygen, - - an ozone
and an antozone, which on being brought together neutralize
each other into common or inactive oxygen, according to the

0 0

equation © -f 0 = O.

The space allotted to a letter being so small. I cannot
enter into the details of my late researches, and must confine
myself to some general statements, which I hope, however,
will give you a clear notion of the nature of my recent doings-
Having written a paper on the subject, that will before long be
published in the transactions of the Academy of Munich, I shall
not fail to send it to you as soon as possible.

Ozonised oxygen, as produced from common oxygen by
the electrical spark or phosphorus, is identical with that con-
tained in a number of oxy-compounds, the principal ones of
which are the oxides of the precious metals, the peroxides of
manganese, lead, cobalt, nickel and bismuth, - - permanganic,
chromic and vanadic acids; and even the peroxides of iron and
copper may be numbered amongst them.

The whole of the oxygen of the oxides of the precious
metals exists in the ozonic state, whilst in the rest of the oxy-
compounds named, only part of their oxygen is in that condition.
I call that oxygen negatively-active, or ozone par excellence,

1 This letter is reprinted from Phil. Mag. S. 4. vol. 16. p. 178 in which it
had been inserted under the following heading: "Further observations on the
allotropic modifications of oxygen , and the compound nature of chlorine,
bromine etc."

— 302 —

and give it the sign 0, on account of its electromotive bearing.
Though generally disinclined to coin new terms, I think it
convenient to denominate the whole class of the oxy-com-

pounds containing 0 "ozonides". There is another, less nume-
rous series, of oxy-compounds, in which part of their oxygen

exists in an opposite active state, i. e. © or antozone, where-
fore I have christened them "antozonides". This class is com-
posed of the peroxides of hydrogen, barium, strontium, and the
rest of the alkaline metals; and on this occasion I must not
omit to add, that what I have hitherto called ozonized oil of

turpentine, aether, etc., contain their active oxygen in the ©
state, and belong therefore to the class of the "antozonides".
Now, on bringing together (under proper circumstances) any

ozonide with any antozonide, reciprocal catalysis results, the 0

of the one and the © of the other neutralizing each other
Into O, which as such, cannot be retained by the substances

0 0

with which it had been previously associated in the 0 or ©
condition. The proximate cause of the mutual catalysis of so
many oxycompounds depends therefore upon the opposite
states of the active oxygen contained in these compounds.
I will now give you some details on the subject.

1. Free ozonized oxygen = 0, and peroxide of hydrogen
= HO + ©, or peroxide of barium = BaO + © (the latter
suspended in water), on being shaken together destroy each
other, HO + © or BaO + © being reduced to HO or BaO,

o o

and © and 0 transformed into O.

2. Aqueous permanganic acid = Mn2 O2 -f 5 0, or a solution
of permanganate of potash mixed with some dilute nitric acid,
is almost instantaneously discoloured by peroxide of hydrogen
or peroxide of barium, the nitrate of the protoxide of manganese
being formed in the first case, and in the second, besides this
salt, the nitrate of baryta. It is hardly necessary to state,
that in both cases the 0 of the permanganic acid and the ©
of the peroxide of hydrogen or barium are disengaged as O.

— 303 —

3- An aqueous solution of chromic acid containing some
nitric or sulphuric acid and peroxide of hydrogen, are rapidly
transformed into the nitrate or sulphate of oxide of chromium,
HO, and inactive oxygen, which is of course disengaged. A
solution of chromic acid mixed with some nitric acid and
BaO2 gives a similar result, nitrate of baryta and oxide of
chromium being formed, and O disengaged.

4. If you add to a mixture of any peroxide salt of iron
and the red ferro-sesquicyanuret of potassium (both substances
dissolved in water) some peroxide of hydrogen, prussian blue,
will be thrown down, and inactive oxygen set free. On in-
troducing into a mixture of nitrate of peroxide of iron and the
ferro-sesquicyanuret of potassium the peroxide of barium a
similar reaction takes place, prussian blue, hydrate of baryta, etc.
being formed, and inactive oxygen eliminated. From these facts
it appears that, under certain conditions, even peroxide of iron
and HO2 or BaO2 are capable of catalyzing each other into
FeO and HO, or BaO and O.

5. Under certain circumstances PbO2 or MnO2 are soluble
in strong acetic acid, as you may see in one of my papers
joined to this letter; now if you add to such a solution HO2
orBaO2, the peroxides will be reduced to HO or BaO and
PbO or MnO, inactive oxygen disengaged.

6. It is a well known fact that the oxide of silver = Ag O,

or the peroxide of that metal Ag ©2, and the peroxide of

hydrogen = HO + ©, catalyze each other into metallic silver,

water and inactive oxygen. Other ozonides, such as Pb O + 0

0 0

or MnO + 0, on being brought in contact with HO + ©, are
transformed into PbO or Mn O, HO and O. Now the peroxide

0 0

of barium = BaO + ©, acts like HO + ©. If you pour water
an intimate mixture of AgO, or AgO2 and BaO2, a lively
disengagement of inactive oxygen will ensue, AgO, AgO2 and
BaO2 being reduced to metallic silver and baryta. In concluding
the first part of my letter, I must not omit to state the general

— 304 —

fact, that the oxygen disengaged in all cases of reciprocal cata-
lysis of oxy-compounds, behaves in every respect like inactive
oxygen.

There is another set of chemical phaenomena, in my opinion,
closely connected with the polar states of the active oxygen
contained in the two opposite classes of peroxides. You know
that a certain number of oxy-compounds, for instance the
peroxides of manganese, lead, nickel, cobalt, bismuth, silver
and also permanganic, chromic, and vanadic acids, furnish with
muriatic acid chlorine, whilst another set, such as the peroxides
of barium, strontium, potassium etc., are not capable of elimi-
nating chlorine, either out of the said acid or any other chloride.
This second class of oxy-compounds produces, however, with
muriatic acid, the peroxide of hydrogen; and it is quite
impossible in any way to obtain from the first class of the
peroxides HO2, or from the second chlorine. You are aware
that, from reasons of analogy, I do not believe in the doctrine
of chlorine, bromine, being simple bodies, but consider those
substances as oxy-compounds, for instance the peroxides of
manganese, lead, etc., in other terms, as "ozonides". Chlorine

is therefore to me the peroxide of murium = MuO + 0,
hydrochloric acid — MuO + HO, and, as already mentioned, the

0 O

peroxide of barium = BaO + ©, that of hydrogen = HO -t- ©,

()

and the peroxide of manganese = MnO + 6. Proceeding
from these suppositions, it is very easy to account for the
different way in which the two sets of peroxides are acted
upon by muriatic acid.

From reasons as entirely unknown to us HO can be

chemically associated only with ©, and with no other modifi-
cation of oxygen, to constitute what is called the peroxide of
hydrogen; and in a similar way MnO (the hypothetical anhy-
drous muriatic acid of older times) is capable of being united

only to 0 to form the so-called chlorine, which I denominate
peroxide of murium. If we cause MnO + HO to react upon

— 305 —
BaO -f- ©, MnO unites with BaO, and HO with ®; but if you

bring together MnO + HO with Mn + 0, part of MnO is

associated to MnO, another part to O, water being eliminated,
according to the equation 2 (Mn O, HO) + Mn O + O = Mn O,
MnO + MnO, 0 + 2 HO.

As you will easily perceive, from these views it would
follow that, under proper circumstances, two opposite peroxides,
on being intimately and in the right proportion mixed together
and acted upon by muriatic acid, could yield neither chlorine
nor peroxide of hydrogen, but mere inactive oxygen. If some-
what dilute muriatic acid be poured upon an intimate mixture
of five parts of peroxide of barium and two parts of peroxide
of manganese, the whole will be rapidly transformed into the
muriates of baryta and protoxide of manganese, the active
oxygen of both the peroxides being disengaged in the inactive
condition, and not a trace of free chlorine making its appearance.
The same result is obtained from dilute hydrobromic acid.

Another consequence of my hypothesis is this: that an in-
timate and correctly proportionate mixture of two opposite per-
oxides, such as the peroxide of barium and of lead, on being
acted upon by any oxy-acid, cannot produce the peroxide of
hydrogen; or, to express the same thing in other terms, muriatic
acid must act upon the said mixture exactly in the same way
as the oxy-acids do ; and that indeed is the case. Mixtures
of the peroxides just mentioned and acetic, or nitric acids, are
readily converted into the acetates or nitrates of baryta and
protoxide of manganese, the active oxygen of both the peroxides
being of course disengaged in the inactive condition.

Before I close my long story I must mention one fact
more, which, in my opinion, is certainly a very curious one.
If you mix an aqueous and concentrated solution of bromine
with a sufficient quantity of peroxide of hydrogen, what happens?
A very lively disengagement of inactive oxygen takes place,
the liquid becomes sour, and on adding some aqueous chlorine
u

to it, bromine reappears. From hence we are allowed to con-
clude, that, on bringing bromine in contact with peroxide of
hydrogen, some so-called hydrobromic acid is produced. The
hypothesis at present prevailing cannot account for the formation
of that acid otherwise than by admitting that bromine takes
up the hydrogen of HO2, eliminating the two equivalents of
oxygen united to H. I, of course, take another view of the
case, bromine is to me an ozonide like peroxide of lead, etc.,

0 0

i. e. the peroxide of bromine — BrO + 0. Now HO -t- © and

BrO + 0 catalyze each other into HO, BrO, and inactive oxygen,
BrO + HO forming hydrobromic acid, or what might more pro-
perly be called hydrate of bromiatic acid.

You see that I am growing more and more hardened in
my heretical notions, or to speak more correctly, in my ortho-
dox views; for it was Davy who acted the part of a heretic
in overthrowing the old, venerable, true creed. Indeed the
longer I compare the new and old doctrine on the nature of
chlorine, etc. with the whole material of chemical facts bearing
upon them, the less I am able to conceive how Davy could
so lightly and slightly handle the heavy weight of analogies
which, in my opinion, speak so very strongly and decisively
in favour of Berthollet's views. There is no doubt Sir Humphry
was a man of great genius, and consequently very imaginative;
but I am almost inclined to believe that, by a certain wantonness,
or by dint of that transcendent faculty of his mind, he was
seduced to conjure up a theory intended to be as much out of
the way and "invraisemblable" as possible, and serve never-
theless certain theoretical purposes; and certainly, if he enter-
tained the intention of solving such a problem, he has wonder-
fully succeeded. But what I still more wonder at is both the
sudden and general success which that far-fetched and strained
hypothesis met with, and the tenacity with which the whole
chemical world has been sticking to it ever since its imaginative
author pleased to divulge it: and all this could happen in spite

of the fact that the new doctrine, in removing from the field
of chemistry a couple of hypothetical bodies, was, for analogy's
sake forced to introduce fictitious compounds, not by dozens
only, but by hundreds, - - the oxy-sulphion, oxy-nitrion, and
those "nonentia". But enough of this subject, upon which I
am apt to grow warm and even angry. Although the results
I have obtained from my recent investigations cannot but in-
duce me to begin another, and I am afraid, endless series of
researches. I shall for the present cut short the matter and in-
d ulge for some time in absolute idleness.

I am, my dear Faraday

Yours most truly
Bale, June 25. 1858. C. F. SCHOENBEIN.

Schcenbein to Faraday.
MY DEAR FARADAY

I take the liberty to introduce to you Professor
Vischer l of Basle, an intimate friend and colleague of mine,
who intends to make a stay at London for some time and is
kind enough as to take charge of a parcel containing volu-
minous letters, scientific papers and something else destined
for the Sovereign of the Royal Institution. It will perhaps in-
terest you to learn on this occasion, that my friend, being an
•excellent greek scholar, acted the part of a god-father, when
I christened my Child "Ozone" 19 years ago.

Mr. Vischer does, of course, not meddle in any way
with chemistry, but is in every other respects a true "savant",

1 Wilhelm Vischer was born in 1808 at Bale, where he also died in 1874.
'He was Professor of Greek there. It was he, it will he remembered, who
tiamed ozone, deriving it from the Greek word ogtif, smelling. Vide also p. 174.
and p. 184.

whose personal acquaintance, I trust, will afford you much
pleasure.

I am my dear Faraday

Your's most sincerely

Bale Jun. 28. 1858. C. F. SCHOENBEIN.

Faraday to Schcenbein.

Royal Institution 28 July 1858.
MY DEAR SCHOENBEIN

Though I date as above yet I am residing in
the country and that has caused me to miss your friend
M. Vischer, which I was very sorry for. I called in Golden
square - - and wrote a letter in hopes he might return there
but have heard nothing yet, direct from him.

But I saw Miss Schoenbein last Sabbath day and she gave
me the papers and letters from you and your portrait, all of
which I was very glad to have. I like the portrait very much
and was vastly glad to have it. It is very like my old friend,,
but I perceive he is getting a little, a very little older ; when
you see my photograph, which Miss Schoenbein has, you will
see that is my case, but then I have the advantage of you
by eight or ten years - - and am getting not merely older
but idler and that is a worse thing.

I like your summary, brief as it is, of your views, very
much and was just on the point of sending it off to Messrs
Taylor and Francis for the Phil. Mag. when I doubted a little
about the latter end, and as the date was too late for this
month, thought I would write to you. It is the part about Davy
and the criticism on his view, and those of chemists generally.
I have no objection to them, for I think all hypotheses unwhole-

— 309 —

some, unless accompanied by criticisms — but I was not sure
whether you might object, intending it for me only. As there
is time, tell me so in a short note before I send the MS.
to the Editors for their acceptance or judgment.

Miss Schcenbein seems quite well. — So are we generally
and so must you be considering your intentions. I have no
philosophy for you I am idle

Ever truly your's

My dear friend
M. FARADAY.

*»

Schoenbein to Faraday.

Speicher on the heights of the Canton
of Appenzell Aug. 4th 1858.

MY DEAR FARADAY

I won't let wait you long for an answer to your
very kind letter, with which you favored me some days ago,
and first of all permit me to tell you that I felt much gratified
at learning from it, that you have not altogether condemned
my heretical views. You are aware that I have these many
years entertained them and tried on more than one occasion
to combat Davy's doctrine on the nature of Chlorine etc. I
can therefore see no harm in making known those views to
the scientific public of England, though I am quite sure that
they will be but slightly relished by the majority of the british
Chymists. I am even prepared to see Mr. Schcenbein declared
to be half if not an entire fool, but being very little ambitious
and caring far more for what I consider to be true, than for
earning applause and eulogies from others, I shall take very
cooly any strictures made upon my old-fashioned notions.

If you think my last letter to you worthy of being published
in the Philosophical Magazine I give you full liberty to modify
and curtail it, wher'e and in what manner soever you please
to do so. Getting more and more out of practice to speak
and write your native tongue, I have no doubt, that my
epistolary production will teem with all sorts of grammatical
blunders and if your kindness is not too much taxed by the
demand, I ask you the favor to correct the most palpable
faults of my letter, in order to render it less grating to
english ears.

These last three weeks Mrs. Schoenbein, my two youngest
daughters and myself have been residing upon the heights of
the canton of Appenzell, that spot of Switzerland, I am most
particularly fond of. It is the greenest land I know and I
doubt very much, whether Ireland, emphatically called "the
Emerald Island" can compete with Appenzell, the whole country
about looking like an immense carpet of the softist velvet and
being broken up into numberless hills, chasms, valleys, dales,
which here and there are patched with fir-woods and covered
with neat and snug little houses, the mere sight of which
conveys comfort to the eye. Add to all these beauties a most
extensive view on a great part of Switzerland, Swabia, Bavaria
and the Tyrol, between which the "swabian sea", the stately
lake of Constance is expanding its broad and blue sheet of
water, you will readily allow, that such a seat and sight deser-
vedly merit to be called glorious.

All of us, as you may easily imagine, fully enjoy the
charms of the country, the peculiar nature of which seduces
us to lead a truly gipsy life, to-day making this, to-morrow
another hill our temporary laager. As often as I discover
new beauties, I cannot help saying to myself: how should my
friend Faraday enjoy such a sight! That under such circum-
stances Chymistry and every sort of philosophy are entirely
forgotten, I hardly need assuring you.

In the beginning of next week we shall leave our alpine
abode, Mrs. Schoenbein and the girls returning to Basle and
Mr. Schoenbein going to Jena.

Pray present our best compliments to Mrs. Faraday and

believe me

Your's

most truly

C. F. SCHOENBEIN.

Schcenbein to Faraday.

MY DEAR FARADAY1

As Doctor Bernoulli, a former pupil of mine is
going to London and from there to Guatemala, I make use of
this opportunity to send you through my young friend amongst
other memoirs that paper, in which I have treated the reci-
procal Katalysis of a number of oxycompounds.2 You may
give the "fasciculum" to a scientific friend, who happens to be
master of the german tongue. The little parcel joined, you
will be good enough to forward it to its place of destination.
It is not long since I returned from a journey undertaken
to the south-west of Germany, which has turned out highly
pleasant and interesting to me. First I attended the meeting
of german philosophers held at Carlsruhe in the middle of
September last, which was the most numerous and brilliant one,
I have as yet had the good luck of attending. With a very
few exceptions all the leading scientific men of Germany were

1 This letter bears no date from the context however it follows that it
must have been written in September 1858.

2 Uber die gegenseitige Katalyse einer Reihe von Oxyden, Superoxyden
und Sauerstoffsauren. Basl. Verh. Bd. 2. 1858. p. 139.

present: Liebig, Woehler,1 Bunsen, Magnus,2 Dove3 and a host
of pthers. Under such "auspiciis" the meeting could not but
be excellent. All sorts of honors and attentions were showered
down upon us from the grand duke and his young amiable
duchess (the sister of the husband of your princess), the
government and magistrates , down to the very lowest in-
habitants of the capital. I think indeed, that science has very
seldom been so much honored in its representatives, as it was
the case at Carlsruhe some weeks ago.

Both their Royal Highnesses, all the Ministers, a number
of political notabilities and the chief Magistrate of the Metro-
polis attended all the general meetings, holding out from the
beginning to the end. No less than three times we enjoyed
the hospitality of the reigning duke, supping, dining and taking
tea with the court. Of other festivities there was no want :
the finest plays were acted before the learned audience, splendid
balls given in honor of the philosophers, the town of Baden-
Baden, in the beautiful ruins of the magnificently situated old
castle, treated the association in a sumptuous style, and the
good people of Durlach invited us to enjoy their delicious
grapes in their vine-yards, celebrating, what we call a "Wintzer-
fest11 (vintage-feast) in which beautiful young Ladies of the
town, clad in white, offered in a graceful and highly engaging
manner the choicest fruits of the Land to the philosophers
present, the number of whom wras very great indeed, at least
five or six hundred. In music-loving Germany nothing can be
done without songs and other musical performances, and cer-
tainly we had plenty of them, along with patriotic toasts and

1 Friedrich Wohler M. D. was born in 1800 at Eschersheim near Frank-
fort. He worked under Berzelius for a short time and was professor of Chemistry
at Gottingen where he died in 1882. He received the Copley medal.

2 Heinrich Gustav Magnus Ph. D., professor of Physics at the University
of Berlin, was born in 1802 at Berlin where he also died in 1870.

3 Heinrich Wilhelm Dove Ph. D. was born in 1803 at Liegnitz. He was
professor of Physics at Berlin till his death in 1879.

other manifestations of joy at Carlsruhe, Baden and Durlach.
The people on the other side of the water have hardly a
notion of the teutonic enjoyments and the comfortable ease,
in which those things are done. Am I right or not, if I say,
that pleasure is a sort of business to the majority of the Eng-
lish and the enjoyment of it too much ruled by the codex of
"bienseance", and the statutes of which are too much in favor
of formalities and ceremonies. Bat every nation may have its
own ways and whims, and after all "de gustibus non est dispu-
tandum". After having been fully satiated by intellectual and
bodily pleasures at Carlsruhe, I took a trip with Liebig, Rose l
and some other philosophers to see some interesting establish-
ments in the country, and then, tempted by the glorious weather
of antumn and the seducing neighbourhood of the finest scenery
of the Rhine, I lounged about in the classical regions of the
history of the Rhine, visiting many an old friend and drinking
more than a glass of old Hock. One Excursion was most
particulary beautiful: With a couple of friends I descended
from Mayence to Bingen and arrived there, all of us, devout
reverers of father Rhine, went up to the chapel Saint Rochus,
emptying there in honor of his Majesty a bottle or two of his
most generous and incomparable nectar. Those heights afford
one of the most picturesque views along the Rhine. I won't
tell you any more about my idle ramblings, suffice it to know,
that they proved delicious, and that Mr. Schoenbein was "joli-
ment" scolded by Mrs. Schoenbein on account of his very long
outstayings. By this time I have entered the career of every
day life and shall, before long, live again in the consortium of
my chemical hero, whose interior nature I want to know much
better, than I do now. You have no doubt enjoyed a tranquil
and pastoral country-life at Hamptoncourt and I confidently

1 Heinrich Rose Ph. D. studied Chemistry under Berzelius and was professor
of Chemistry at the University of Berlin. He was born in 1795 at Berlin and
died there in 1864.

3M —

hope, that Mrs. Faraday's health has been much benefited by
it. Miss Schoenbein is, as far as I know, doing well at Stam-
ford Hill and continues to like her stay in England.

Expecting to hear soon of and from you, and asking you
the favor to present my humble respects to Your Lady I am,
my dear Faraday

for ever your's

(Sept. 1858) c. F. SCHOENBEIN.

Pray be kind to the bearer of this letter, written in a hurry.

Faraday to Schcenbein.

Royal Institution 13. Novr. 1858'
MY DEAR SCHOENBEIN

Daily and hourly am I thinking about you and
yours, and yet with as unsatisfactory a result as it is possible
for me to have. I think about Ozone, about Antozone, about
the experiments you showed Dr. Bence Jones, about your
peroxide of barium, your antozonized oil of turpentine, and it
all ends in a giddines and confusion of the points that ought
to be remembered. I want to tell our audience what your
last results are upon this most beautiful investigation, and yet
am terrified at the thoughts of trying to do so, from the diffi-
culty of remembering from the reading of one letter to that
of another, what the facts in the former were. I have never
before felt so seriously the evil of loss of memory and of
clearness in the head; and though I expect to fail some day
at the lecture table, as I get older, I should not like to fail in
ozone, or in any thing about you. I have been making some

1 Printed in Bence Jones vol. 2. p. 403.

— 315 —

of the experiments Dr. B. Jones told me of, and succeed1 in
some but do not succeed in all. Neither do I know the shape
in which you make them, as (I understand) good class ex-
periments and telling proofs of an argument. - - Yet without
experiments I am nothing. If I were at your elbow for an
hour or two, I would get all that instruction (as to precaution)
out of you, which might bring my courage up. I remember
in old times (at the beginning of Ozone), you charged me with
principles and experiments. I wonder whether you could help
me again? Most likely not, and it is a shame that I should
require it; but without such help and precautions on my part,
I am physically unable to hold my place at the table. And
without I justify my appearance on a Friday Evening I had
better withdraw from the duty.

What I should want, would be from ten to fifteen, or at
most twenty, table experiments, with such instructions as to
vessels, quantities, states of solution, materials, and precautions,
as would make the experiments visible to all, and certain and
ready. Also the points of the general subject, in what you
have found to be the best order for the argument and its proof.

I have sought for the old bottle of antozone oil of turpentine,
but believe I have used it all up. I fear it is of no use trying
to make it by the end of January, next year: - - yet about
that time I must give the evening if I give it at all. If you
encourage me to give the argument (and I can only try if
you help me), have you any of the substance you could spare?
and could you find conveyance for it by rail or otherwise?
I fear there is no other substance that will represent it: — i. e.
that approaches so near to isolated antozone, as that body does.

Now do not scold me. I am obliged to speak as I do.
Perhaps you had better tell me that I must give up the sub-
ject, for that I can hardly succeed in telling it properly by the
way I propose. Do not hesitate to say so, for I am well pre-

1 Bence Jones (p. 404) reads "succeeded".

pared by my inner experience in other matters, to suppose
that may be the case. But then tell me so at once, that I
may think over my position here for January.

Now for a more cheery subject. I saw Miss Schoenbein
a few days ago (after a long interval) and was glad to see her
looking well and happy. I am sure you will not think the
worse of us for the effect England has had upon her, when
you see her again. She will make you, her mother, sisters
and all happy. But I know she tells you all about herself and
as to her state of contentment or happiness that will breathe
in her letters. I have more to say, but cannot bring it to
mind. Believe me to be as Ever My dear Schoenbein

Your true and obliged friend

M. FARADAY.

Faraday to Schoenbein.

Royal Institution 25 Novr. 1858 ]

Warmest thanks, my dear friend, for your last kind
letter:2 it has given me courage, and yet when I look into the
journals about ozone and see how many things there are, which
have been said by different men, and how thoroughly I have
forgotten most of them: it makes me very doubtful of myself,
for I cannot hold many points in hand at once, as I used to
do, but I shall trust in your strength and kindness. I have
repeated, as I said, some of your results. The peroxide of
barium, which I have, seems to do pretty well, but it is vesi-

1 A few passages from this letter are included by Bence Jones in his
Life of Faraday (vol. 2. p. 405).

2 This letter also has been lost.

cular and gray and so unlike what Brodie l made with great
care and called the right peroxide,2 that I doubt it, but I shall
know better when I receive your instructions. I have forgotten
the preparation of HO© by the fluor salicic acid - - where is
it described in French, or where is it? - - What strength do
you prepare HO<5), strong or dilute? - - The peroxide of man-
ganese, do you employ the natural or of the artificial? what
is your process of preparation for solution in A. A. and do
you use it wet or dry?

I have had the paper on reciprocal catalysis (23 June 1858)
translated, so have, with the letters etc, obtained possession
of part of your thoughts. But it is the experimental proofs
and the method of making them perfectly, about which I am
anxious and none but the discovering philosopher himself knows
how best to make their value evident. For that reason I desire
to work with your tools, and in your way and if the chemical
[preparations] you refer to are to be bought in Bale, in what
you know to be the right state, send them to me, but if not,
do not waste your time personally. I shall prepare them from
your instructions.

I had your letters etc by Dr. Bernoulli on the i/th instant.
I did not see him for he sent them by post and was to leave
London the next day. He had been ill and detained in Berlin.
But I could not tell when you had written, for your letter had
no date and strange to say neither had his, except the Post-
mark. Yours by him and mine to you must have passed in
the road.

Kindest remembrances to the household from one always

under obligation to you and ever vours

M. FARADAY.

1 Sir Benjamin Collins Brodie professor of Chemistry at Oxford, from 1855
to 1873. He was born in 1817 in London and died in 1880.

2 Notice on further experiments as to the reduction of metallic oxides by
the peroxide of barium. Chem. Soc. Journ. vol. 7. 1855. p. 304.

Faraday to Schoenbein.

MY DEAR SCHOENBEIN

I have received the packet safe from M. Rumpf
and write instantly to acknowledge it, with all thanks. But I
have not any thing for Miss Schoenbein; I think M. Rumpf
means to deliver, what you have sent, himself. Your daughter
was very well and happy last Friday evening, when I had the
honor to be in their company at Stamford Hill

Ever Yours
2 Dec. 1858 M. FARADAY.

Faraday to Schoenbein.

Royal Institution 19 Jan. 1859
MY DEAR FRIEND

I have received your last of the I3th instant.1
You will be weary of my thanks nevertheless I send them.
The peroxide of barium I have, has been very good in all
former experiments. I hope tomorrow it will prove as good
In those, I shall report from your last. I do not at all doubt
it. The evening does not come off until the 25th of next
month, but I have sent the tickets to Hampstead to Mr. Rumpf
— and Miss Schoenbein -- also to Miss Hornblower and others
whom you know more or less. I have had some of the German
papers translated and hope I have get hold of the subject
thoroughly, if I can only keep it; but memory is most trea-
cherous and I am obliged to look at every reading to see
whether ozone is 0 or ©. I stick it before my eyes, but that
is a clumsy way.

1 This letter referred to by Faraday has been mislaid.

— 319 —

You seem to me to be leading a very gay life. Well,
I am happy you have health, strength and spirits to do so: -
that they may long continue with you is the earnest wish of

Ever Yours

M. FARADAY.

Faraday to Schcenbein.

Royal Institution 16 Feby. 1859
MY DEAR FRIEND

I must write, not knowing but that you may
walk in during the act. I have delayed thus long, thinking
that possibly when my letter got to Basle you might be here :
- but whatever may be the case I must write. If you do
not get my letter, Mrs. Schoenbein will and though Miss Horn-
blower wrote off to her on Monday, immediately that she knew
the cause of your dear daughters death and I can say nothing
in the way of information more than she can, still my letter
will not be wrong. Last Thursday, I think, they had sent to
us to learn Dr. Bence Jone's hours, intending to see him on
the Saturday perhaps. On Sunday morning as I was dressing
about V2 P- 7 o'clock, a messenger brought me a note which
telling me of Miss Schoenbeins very serious state, sent me first
to Dr. Bence Jones and then to Stamford Hill: but I was too
late to see the poor girl alive. She died at 1/2 p. 7 o'clock.
Dr. Bence Jones came in very soon after and then we tele-
graphed off to you the first time. In the evening of the same
•day, Sunday, I sent off the second telegraph message - - On
Monday Morning an examination took place, Dr. B. Jones being
present and he tells me it was perforation of the stomach, a
matter which could neither be foretold nor distinguished during
life (for there was no sickness), nor aided if known, and so

— 320 —

her end came and, as I understand with great peace of mind
as to the future, though with much present pain of body.

We de not know what to expect, whether you are coming
or not. Perhaps even now there is news of you at Stamford
Hill, but we are some miles apart and unfortunately I have
been ill and am confined to this house. I expect to hear from
Miss Hornblovver in the course of a few hours. You will either
by letter or in person instruct her what to do, but if nothing
is heard from you the burial must take place on Friday next.
Miss Hornblower told me she had had a telegraphic message
from you, but they are of necessity very brief. I left word
writh Miss Hornblower that if you come, and it suited you,
we should be very glad to make your home here for the time.
There are some friends of Miss Schoenbein at Hampstead, and
I think also in Warwickshire where she spent her holidays.
They have been informed and I believe one of them, a Clergy-
man from Warwickshire, purposes being at the funeral. But
I am very imperfectly informed of these matters, which are
all held doubtful until it is known what you will do.

I write to you, though I think you may not be at Basle
and once I thought of writing to her Mother. This letter in-
deed is as much to Mrs. Schoenbein as to you. Your good
daughter had made unto herself friends, who thought very
much of her and I grieve to think she will not return to you
to be a comfort to you both in future years. But God's will
be done. You may think of her with great, though melan-
choly pleasure. She was full of thought latterly about you
and the Ozone evening. I send you a note of hers to me
only five days before her death.

My dear Wife and Niece, as knowing Miss Schosnbein,
join with me in all sympathy with you both and your children.
My niece's sisters have been indebted to her care for them at
Stamford Hill. Associations in every way have risen about her,
poor girl, and she will be mourned by many and for some time.

— 321 —

My dear friend - - I can write to you about nothing else
and I can do no good in writing - - I simply grieve again
and again for your loss and ours.

Most affectionately Yours

M. FARADAY.

The note from Miss Schoenbein referred to above is still
preserved among Schoenbein's letters to Faraday, so that we
are in the position to reprint it here. The time and date of
her death have been added by Faraday.

Miss Schoenbein to Faraday.

Stamford Hill Feb. 8th 59.
DEAR MR. FARADAY,

Emboldened by your great kindness, I venture to
take advantage of your offer of one more ticket in my father's
name. This subject of Ozone being one that seems particularly
interesting to medical gentlemen, I make this request in behalf
of one of them.

I must add that my father is quite envious for this great
privilege that is in store for me, of hearing your lecture.

Believe me, dear Mr. Faraday
very truly yours

EMILIE SCHOENBEIN.

Died at half past 7 o'clk A. M. on the I3th Feb. 1859 -

M. F.

Aft

Schoenbein to Faraday}-

Bale Febr. (25.) 1859.

MY DEAREST FRIEND,

I enclose a few lines to acknowledge the kind
letter of Mrs. Faraday's and your nieces, which really produced
a soothing effect upon our harrowed minds and bleeding hearts;
and it is particularly Mrs. Schoenbein that feels most thankfully
for that proof of friendly and sympathizing feelings. Mr. Crowdy
of Winchester and Miss Mayo of Hampstead, friends of mine
and Emilia's, have most kindly and spontaneously offered to
me to put a tombstone upon the grave of my deeply lamented
daughter and ask my permission to do so as a favor. We
were deeply touched by the delicate expression of their
friendly feelings and gratefully accept of their kindness offered ;
but nevertheless I should consider it as the most grateful
deed of yours if you would join your dear name to their's.
Mrs. Schcenbein's bodily health is, thank God, nearly reestabli-
shed, but the sadness of her heart as yet very great; there
are however intervals of tranquil resignation to the inscrutable
decree of heaven. I have begun my lectures again, but in
what state of mind I leave you to imagine. The whole world
has become stale and insipid to me, has even assumed a sad
appearance.

Pray offer my most grateful thanks to Mrs. Faraday and

your niece and pity

your deeply mourning

friend.

1 Faraday's letter of February 24th appears to be an answer to the above
note from Schoenbein, which is therefore misdated and probably written about
ten days earlier, for Faraday says in his letter (vide p. 323): "I am glad you
would receive mine" (i. e. the one dated Feb. 16) "about the same time." In
the original the date is undoubtedly Feb. 25th, nevertheless we have for the
above reasons placed it before Faradays letter.

— 323 —

Faraday to Sckcenbein.

Royal Institution 24 Feb. 1859
MY DEAR DEAR FRIEND

I received your touching letter, and I am glad
you would receive mine about the same time. Your cry of
anguish may well pierce our hearts here, for if the effect of
the blow was stunning to us how much more would it be so
to you. And that you should at the same moment be burdened
with the heavy weight of Mrs. Schoenbeins illness! I do indeed
grieve for you, but I hope you are by this time somewhat
relieved in respect of that heavy home anxiety. Do tell her
how we feel for her, and the two poor sisters. I am glad
you did not come here, for your first duty was at home, to
succour and support those dependent on you. You could well
trust Miss Hornblower, for she had learnt to love your daughter.
I have no doubt she has written of all things personal to you
and Mrs. Schoenbein, and will fulfill all your possible wishes.
I expect too that by this time you will have had letters from
Dr. Bence Jones, Grove and others for I have shown your
letters to me and Miss Hornblower unto them.

You mentioned the matter of a tombstone in your letter
to me and affectionately desired to have my name by yours
on it. I suppose this is usual with you, but with us it is very
rare, or even unknown, and would excite much remark. That
would be of no consequence , if the remarks were indifferent
in their nature, but they would here be sure to carry a reli-
gious feeling or meaning with them, and as I am known to be
a dissenter, strongly differing from the Episcopal church here,
would give rise to much remark among those who know me.
I understand too, that a dear friend of your daughter (I think
the name is Crowdy) has written to you direct about the in-
scription on the stone. I believe he performed the funeral
service, but as I know it would be a Church of England ser-

324

vice, in which I could not conscienciously join, I was not there.
However his letter with Miss Hornblower's communications
will bring about the fulfilment of the proper arrangements.

Poor girl - - (happy girl I well may say considering her
strong hope in death) - - we were hoping to have her with
us tomorrow evening, but how vain are all our plans. Instead
of a glad and buoyant heart I shall go to my work, as work
indeed. I was desiring to put it off, but when I began to
look about for the purpose, I found so many engagements had
been made contingent upon the evening, and that even the
Prince Consort was coming, that I could not properly change
the date. I only hope that I shall not break down. I know
I shall not be able to forget for the hour, and an overpowering
thought may break in.

I hope that you are beginning to turn a little to occu-
pation. I know how distasteful it will be, but you must be
drawn away at times from the heavy thought; even though
the exertion may be painful, it will be healing. Do think of
this for the sake of yourself and your family and your friends
and may God give you that grave and gentle consolation by
degrees, which you ask for in your letter to me

Ever My dear Schcenbein

Your Affectionate friend

M. FARADAY.

Faraday to Schcenbein.1

Royal Institution London 25 April 1859
MY DEAR SCHOENBEIN

I have just seen your letter to Miss Hornblower,
and so write knowing you will be at home again. I am glad

1 Portions of this letter are printed in Bence Jones vol.2, p. 422.

— 325 —

you went out, for though all things would be distasteful to
you still they work out the transition back again from sudden
and deep grief to a more collected, healthy, and necessary
state of mind. For the same reason, I am very glad that
Mrs. Schoenbein has left home for a little while, and trust that
it may calm her spirits and do her good. It is impossible for
me to write to you, or do any thing connected with you
without thoughts of your dear daughter entering in. I have
a volume of my collected experimental papers on physical
and chemical matters to send you by the first opportunity.
It was ready when Miss Schoenbein's box was sent to you
from Stamford Hill, but I felt as if I could not intrude the
book into so sacred a deposit as that box was, and so retained
it for some fitter opportunity. I gave a Friday Evening on
Ozone and Antozone for which only a few weeks before I
had given tickets at her request to some friends of hers, but
I could not, and cannot, talk to you about it. I did my best,
though with thoughts often pressing in; still let me thank you
for what you had, before the sad event, done to help me.
Your letter to Miss Hornblower spoke of a cypress tree;
and I went yesterday to see the state of such trees as are on
the ground and how they are likely to grow. - Those that
are up, do not look well ; but if Miss Hornblower will let me,
I shall do what I can to plant such a tree on the spot. At
present I cannot see her on the matter, for you will be sorry
to hear that we are in trouble and anxious on her account.
She fell some four or five years ago and hurt her knee ; it has
never ceased to be painful, and from falls since has become
worse, and at last an operation was decided upon. This was
performed the day before yesterday under the influence of
chloroform, and by a very clever surgeon. He removed part
of the bone which had become injured and unhealthy, and we
hope for good results; but time and patience will be required.
The accounts last night were favourable, but the time since

— 326 —

the operation is as yet too short to allow of any thing beyond
a hasty and imperfect judgment.

I sent your letter to Grove. He has been suffering from
a sharp attack of rheumatic gout, which confined him to the
house, but he is now getting better. — All your friends think
of you and feel for you.

For a little on the other side, I may say that we are
pretty well. My wife joins me in kindest remembrances and
thoughts; and so too does my niece Jeannie for though she
is not much known to you yet she was to Miss Schcenbein. —
Extend these sympathizing thoughts to the children who remain
to comfort you, Ever, My dear Schoenbein

Your's

M. FARADAY.

Schoenbein to Faraday.
MY DEAR FARADAY

The long silence I have kept to you is, I am
afraid, the most palpable proof of your friend's having become
a poor man indeed. Formerly it was a real treat to me to
write you a letter, now I have to make the greatest effort to
take up my pen, and fulfill even the most urgent duties of a
correspondent and it is hardly necessary to tell you the cause
of that change. My mind is no more what it was a short
time ago; its former cheerfulness is gone and melancholy
feelings and sadness have taken possession of it, weighing
the more heavily upon me, that Mrs. Schcenbein is very far
from being comforted and consoled about our grievous loss.
Indeed time has as yet proved to us all a very poor healer of
the deep wound, which was inflicted upon us four months ago.
To distract a little my mind from domestic sorrow, and to

forget the highly deplorable state of the affairs of Europe, I
have these last three months shut up myself in my laboratory
and I may say turned my back upon the rest of the world,
avoiding even to touch a newspaper or to hear a syllable
spoken about politics. Dry and stale as the subject must be
to a mind grievously affected, I mean oxigen, I have taken it
up again and worked upon it harder than I ever did. And I
think not quite for nothing. First I ascertained the hypo-
chlorites, manganates and ferrates (or rather the acids of those
salts) to be "Ozonides", i. e. decomposable by the Antozonides:
HO2, KOs, BaO2 etc. Then I tried to show, that the nascent
state of oxigen as such has nothing to do with the oxidizing
powers of that element, and during the last six weeks I have
almost exclusively occupied myself with what I call "the
chemical polarization of neutral oxygen".1 After having once
ascertained a number of facts (known to you) from which I
drew the inference, that there are two active kinds of oxigen
standing to each other in the relation of 4- to — , I thought
it possible,' even likely, that both kinds of active oxigen are
at the same time produced out of inactive O, as often as one
of them makes its appearance. Proceeding from those notions
I first looked far HO + © as a production of the slow com-
bustion of phosphorus, during which process, at it is well known,
ozonized oxigen — 0 is engendered. My conjecture proved
fully correct, peroxide of hydrogen being produced and con-
tained in the sour fluid called phosphatic acid. And so closely
are the two facts connected with one another, namely the
ozonisation of inactive oxigen and the formation of HOa, that
you will never obtain the one substance without the other.
Being once sure of that important coincidence, I extended my
researches to the productions of the slow combustion of Ether
and found to my no small satisfaction, that in this case too

1 cf. "Uber die chemische Polarisation des Sauerstoffs." Poggend. Annal.
Bd. 108. 1859. p. 471.

- 328 -

notable quantities of peroxide of hydrogen (the type of the
Antozonides) are engendered, conjointly with another compound
containing 0 (or Ozonide). After having ascertained those facts,
my attention was directed to the electrolysis of water and I
think, there can be entertained no doubt, that not only 0 but
also HO2 i. e. © makes its appearance at the positive electrode.
Under proper precautions I have reduced permanganic acid
to MnO, CrOs to Cr2Os etc., in fact desoxidized a number
of bodies at that electrode. Reducing oxy-compounds at the
electrode , where oxygen is disengaged , seems to be para-
doxical enough. As to the small quantities of ozonized oxigen
disengaged, and HO 2 formed during the electrolysis of water
at the positive Electrode, I think, they must be considered as
the surviving witnesses of the chemical polarization of the O
of HO 2, which O is transformed by the current into © and 0.
The inactive Oxigen disengaged during the Electrolysis of
water is most likely a secundary production, proceeding from
the depolarisation or neutralization of © and 0. Before long my
papers on those queer subjects will be published, and you
shall have them as soon as possible, as I flatter myself, that
the matter will interest you. If I have correctly accounted
for the novel facts lately discovered by me, i. e. if neutral
oxigen be capable of being chemically polarized, or thrown
into opposite states of chemical activity at the same time, well,
I should think, I had done something to advance a little our
knowledge of that mysterious and important element.

Our Midsummer-holidays having commenced I intend to
go one of these days to the "Berner Oberland" to fetch my
two eldest girls, who have for some weeks been staying at a
watering-place for the use of a mineral spring there and returned,
we have a notion to visit a retired part of the Black Forest.

I confidently hope you, Mrs. Faraday and your Niece are
doing well and as to Miss Hornblower, I was very sorry indeed
to learn from you, that she had been obliged to undergo a

— 329 —

•

painful operation. I ardently wish that by this time, she will
be entirely cured and enjoy perfect health. Pray remember
me most friendly to all of them, excuse my poor, stale and
insipid letter and write soon to

Your

poor friend

Bale July igth 1859. C. F. SCHOENBEIN.

Faraday to Sckoenbein.

Royal Institution 23. September 1859
MY DEAR SCHOENBEIN

The state to which you consider that grief has
reduced you, must, I think be mine by course of nature and
years; for I am just as you describe, weary, unwilling to write,
and have nothing to say, really nothing to say; or else, surely
I should have written sooner to you. Yesterday was my birth-
day and I then completed my 68th year. Well! many men
are at that time of life far stronger than I am, either in body,
memory, or mind ; but surely I ought to remember how many
pass away before that age, -- and how plentiful and wonderful
have been the mercies and goodness I have enjoyed during
this long series of years. Indeed, I think it is only when I
have to fulfill some expectation, as in giving a discourse, or
writing to a friend like you, that I wish my powers were more
than they are: and yet the very wish is ungrateful and brings
to my mind a reproach. -

I was very glad to hear of you, and I hope the journey
you were about to undertake to fetch your daughters home,
with the intended little episode in the Black forest, will have
done you all good. I have just had a little piece of enjoyment
amongst fine scenery, for I have been in Scotland for a fort-

— 330 —

night, and passed a few days among the lochs and mountains in
the Avestern parts. I have also been two days at the British
Association at Aberdeen; but was glad to leave it quickly, and
before the visits to Balmoral came on: for pleasant and happy
as the occasions are, they are by their excitement a weariness
to me: yet I was for the 48 hours with very kind friends.
The whole matter would have suited you better than me.

Our friend Miss Hornblower continues in great pain; and
I think we may consider the operation as a failure. Certainly
it has failed to give the relief that was hoped for. She cannot
move without crutches, nor without great pain. My wife and
niece are pretty well: — the former desires her kindest remem-
brance to you, the latter is still in Scotland.

Very many thanks for Your scientific news. I see you
will carry oxygen much farther yet, and expect, with every
letter, some new point. As for me I am barren; the best I
have are some negative results about electricity, heat and

gravity.

Good bye My dear Schcenbein

Ever faithfully Yours

M. FARADAY.

Schcenbein to Faraday.

MY DEAR FARADAY

My having spent the autumnal vacations partly
at Neuchatel, partly at Presinge, the seat of our friend de la
Rive, on the frontiers of Savoy, and returned to Basle but a
few days ago, must excuse this late answer of mine to your
last kind letter. Hard working had made such a temporary
relaxation quite necessary to my mind. First of all, allow me
to offer my most heartfelt congratulation to you on account of

the celebration of your 68th birthday, and let us hope, that it
may please Him, who is the sovereign Lord of our life, to
grant the return of many more. Generally speaking a long
age is rather an equivocal gift and in the most favorable case
accompanied with many evils, which human flesh is heir to,
amongst which not the slightest one is the feeling and con-
sciousness that we have lost the buoyancy of youth. But
there are some privileged men, whose mind, in spite of carrying
a heavy load of years upon their back, remain elastic and
green, continuing to take the liveliest interest with every thing,
regarding the higher and nobler aims of mankind. Either I
am entirely mistaken, or you are such a man. May your body
be a little broken down, your hairs have turned grey or white,
your countenance be furrowed by wrinkles, perhaps even your
walk and step somewhat tottering, what is that to you, who
are still soaring in the highest regions of philosophy, whilst
youngsters, replete with bodily powers are crawling upon the
lowest ground. A little more or less of memory, precious as
this gift is, does not matter much, and after all, according to
what you have accomplished during your career of life, you
are more than any other man entitled to enjoy the "otium cum
dignitate". There is a german saying "Fiinfzig Jahre Stille-
stand, sechzig Jahr fangt's Alter an" and according to it, your
friend must now also be called an old man, having the eighteenth
of this month accomplished his sixtieth year. It is certainly
with some reluctance, that I acknowledge myself to be a
"senex", but my grey hairs give but two obvious an evidence
in favor of the truth, and I must submit to what I cannot
change. Although far advanced in the career of life, I never-
theless feel still rather youthly and have not yet lost to a
perceptible degree my ancient love for science and philosophical
research, and that I consider as an invaluable boon, received
from Him, who is the Giver of all good things, and as calcu-
lated to cheer up the evening of my life. Like you, I have

— 332 —

every reason to be most grateful to kind Providence for what
fell to my lot , modest as it has been and not always made
up of smiles and sunshine. But now enough of birthday
reflections. During the summer gone by I have been rather
active in my laboratory and trust my doings will not have
been quite useless. Pray, listen now a little to my random
talkings about philosophical matters. First of all know, that
I continued to work upon what I have called "the chemical
polarization of neutral Oxigen1'1 of which subject I communi-
cated you something in my last letter and from it you will
recollect , that during the slow combustion of phosphorus and
aether, as well as the Electrolysis of water, both kinds of active
Oxigen (© and 0) make their appearance, the former in the
shape of HO + ©.

Having these many years considered the said slow com-
bustion of phosphorus as the type of all the slow oxidations,
which inorganic and organic bodies undergo in the moist
atmospheric air, or pure common oxigen, I suspected, that the
peroxide of hydrogen might be produced , if not in all (from
secondary reasons) , at least a great number of cases , and
directed therefore my attention first to the slow oxidation of
the more readily oxidable metallic bodies. My conjecture
proved correct, having already found out that half a dozen of
metals, during their slow oxidation, give rise to the formation
of very appreciable quantities oi HO a, as you will perceive
from the statements to follow. To ascertain with full certainty
small quantities of that compound, I first wanted proper i. e.
most delicate tests for HO 2 and I fully succeeded in finding
out more than one of that description, in corroboration of
which I may tell you, that by the means of them I am able

1 Beginning at this point the remainder of the letter, so far as it does not
concern private matters, was printed in the Phil. Mag. under the following title:
"On the polarisation of oxygen." Vide Phil. Mag. Vol. 18. 1859. p. 510. The
alterations being but trifling we did not deem it essential to take them into
account.

— 333 —

to detect the millionth part of the said peroxide contained in
water and even less than that. These tests depend upon the
oxidizing and reducing effects produced by HO 2 upon certain
substances. Dilute paste of starch containing some jodide of
potassium, if it be mixt up with water containing but half a
millionth of HOa is within a very short time colored darkblue on
adding some drops of a weak dissolution of any protoxide salt
of iron to the mixture. The dilute dissolution of HO 2 slightly
acidulated by SO 3 discharges the red color of an acidulated
dissolution of the permanganate of potash (by reducing the
acid of that salt to the protoxide of manganese). HO 2, even
in a most dilute state, throws down prussian blue out of a
mixture of most dilute dissolutions of the red cyanide of po-
tassium, and any peroxide-salt of iron (by reducing FeaOa
to FeO). Most dilute HO 2, colored blue by some Indigo-
solution, is rapidly discolored, on adding some drops of a
dilute solution of iron vitriol to the mixture. A dilute solution
of chromic acid is certainly a less delicate test for HO 2 than
the mentioned ones are, but its property of being colored
azureblue by water, containing but — *-Q- of HO 2 makes it in
many cases a valuable and practical test, which I always use
when I have to deal with water somewhat rich in HO 2. Now
by the means of those tests I have of late ascertained, that
during the slow oxidation of Zinc, Cadmium, Lead, Tin, Bis-
muthum and Copper (effected by moist common oxigen or
atmospheric air), perceptable quantities of HO 2 are always
formed conjointly with the oxides of those metals. To pro-
duce HO 2, some of the metals being in a state of mechanical
division as Zinc, Cadmium and Lead, have but to be put in
contact with pure water and atmospheric air for a very short
time, but I find it more convenient to amalgamate first the
metals with mercury. Take for instance 100 grammes of Zinc
filings, and the same quantity of Mercury, put them into a
tumbler filled with dilute sulphuric acid, stir up the metals

— 334

by a glass rod and you will soon have a grossly powdered
Amalgama. Now, after having that metallic mixture washed
with water, put it loosely into a funnel, set upon a bottle,
let a very thin vein of distilled water run over the amalgama,
and by the means of dilute paste of starch containing Jodide
of potassium, you will already detect peroxide of hydrogen
in the water having passed (in the manner indicated) only
once over the amalgama, if you add to a mixture of both some
drops of a solution of ironvitriol etc. - - If you shake for a
few seconds the said amalgama together with air and 100 grammes
of distilled water, the latter will have the property of striking
blue the paste of starch, on adding to it a couple of drops of
a dilute solution of any protoxide salt of iron. Water con-
taining i °/o of SO 3, all circumstances being the same, pro-
duces more HO 2 than pure water does. You may satisfy
yourself with one instance. Take 100 grammes of a still liquid
amalgama of Lead, shake it with 100 grammes of the mentioned
acidulated water and atmospheric air for five to six minutes,
separate, by filtering, the sulfate formed from the water, add
to the latter some drops of a dilute solution of Chromic acid
and your liquid will be transiently turned azureblue , a proof
of the presence of HO 2. If you shake one volume of the said
acidulated water, two volumes of pure Ether and some drops
of a dilute solution of CrOs together, the ether assumes a
still deeper blue color. The same acidulated water of course
discharges the color of the permanganate solution etc. In
saying so much about this matter, I must not omit to add that
the quantity of HOa formed under the circumstances reaches
soon its maximum, which does not go beyond ^^ of the quan-
tity of acidulated water employed. The reason of this fact is
obvious. I shall not enter into any more details about the
subject, hoping to find soon an opportunity for sending you
a paper containining all the particulars about this highly in-
teresting formation of HO 2. From the facts above stated and

— 335 —

others not mentioned I am led to conjecture, that all the slow
oxidations taking place in the moist atmospheric air depend
upon what I call "the chemical polarisation of neutral oxigen"
i. e. that this act always precedes that of real oxidation. The
oxidable matter being eager to combine with 0 and water
with © to produce HO -f ©, determine that mysterious po-
larisation of O in a similar manner, as HO 2 is sometimes de-
composed, if placed between two substances, one of which
attracts the oxigen, the other the hydrogen of the compound.
But be that as it may, perfectly sure is now the fact, that
in a number of cases of slow oxidation the counterpart or
antipode of 0 makes its appearance in the shape of HO + ©
and that the latter compound also acts an important part in
those slow oxidations. I am inclined to suspect, that the
chemical polarisation of O is deeply concerned in animal re-
spiration and many other chemical actions going on in nature,
but I will not yet talk about these matters. It seems that the
late results of my researches tend to increase a little our insight
in the workings of our chemical Hero, and you may therefore
easily imagine, that I pursue my investigations on that really
wonderful body with a zeal bordering upon mental excitement.

Mrs. Schoenbein and my children are, as to body, tolerably
well , but the severe loss of our dearest Emilia still presses
very heavily upon us all and most particulary upon the mind
of my poor wife. That great physician Time has not yet
healed much.

With the deepest regret I learn from you, that poor Miss
Hornblower is far from having obtained. the desired result from
the painful operation she was obliged to undergo some months
ago. Pray, remember me most kindly to her and express to
the suffering Lady my fullest sympathy. It requires certainly
an uncommon degree of moral strength and before all a most
absolute submission to the will of God, to maintain herself in
a tolerable condition of mind and spirits. Before closing my

- 336 -

long letter, I ask you the favor to present my kindest regards
to Mrs. Faraday, your Niece and relations, who were so very
kind to my beloved daughter, who is now no more.

Pray, don't be too long in writing me and be assured,
that every word coming from you is of the highest value to

Your

most attached friend

Bale Oct. 26. 1859. C. F. SCHOENBEIN.

Faraday to Schcenbein.1

Royal Institution 27 March 1860.
MY DEAR SCHOENBEIN

It seems to me a long while since we haven spoken
together, and I know that the blame is mine, but I cannot help
it, only regret it, though I can certainly try to bring the fault
to an end. When I want to write to you it seems as if only
nonsense would come to mind, and yet it is not nonsense to
think of past friendship and dear communions. When I try
to write of science, it comes back to me in confusion. I do
not remember the order of things, or even the facts themselves.
I do not remember what you last told me, though I think I
sent it to the Phil. Mag., and had it printed; and if I try to
remember up, it becomes too much, the head gets giddy and
the mental view only the more confused. I know you do not
want me to labour in vain, but I do not like to seem forgetful
of what you tell me and the only relief I have at such times
is to correct myself and believe that you will know the forget-

1 This letter Bence Jones prints in his Life of Faraday vol. 2. p. 433
leaving out however some parts of it.

o *J >-r

56/

fulness is involuntary. After all, though your science is much
to me, we are not friends for science sake only, but for some-
thing better in a man, something more important in his nature,
affection, kindness, good feeling, moral worth ; und so in remem-
brance of these I now write to place myself in your presence,
and in thought shake hands, tongues, and hearts together.

We are all pretty well here. We get on well enough, in a
manner, and are very happy and I cannot wish you better things ;
though I have no intention, when I say that, to imagine you
without your memory or your science. Long may you be privi-
leged to use them for the good of human nature.

Our friend Miss Hornblower suffers very much from an
affection of the knee of which I spoke before to you. Lately
she has seen Sir Benjamin Brodie, who does not make himself
responsible for advising an amputation; he says it is a case so
serious that the profession ought not to be made responsible
for the results of an operation. Whilst going there, I have
several times gone into a place of rest in that neighbourhood,
to look at a stone you know of, and think of you all. Such
places draw my thoughts much now, and have for years had
great interest for me. They are not to me mere places of
the dead, but full of the greatest hope that is set before man,
even in the very zenith of his physical power and mental force.
But perhaps I disturb you in calling your loss to mind; for-
give me. Yet remember me very kindly to the mother and

sisters.

Ever, My dear Schoenbein,

Yours Affectionately

M. FARADAY.

- 338 -

Schcenbein to Faraday.

MY DEAR FARADAY

I have been expecting letters from you these
many months, but up to this moment quite in vain. I trust,
that nothing is wrong with you i. e. that not ill health, or any
other of the evils "which human flesh is heir to" has been
the cause of your long silence. Now Professor Wiedemann
and Dr. Hagenbach1, intimate friends of mine going to London,
I send you some lines through them, to give a sign, that, at
least your friend is still alive. Mr. Wiedemann will tell you,
that I have strictly followed up your very wise advice and
worked rather hard all the year round. The remedy has not
been without its salutary effects, though I cannot say, that the
deep wound inflicted upon us last year is healed. As to Mrs.
Schcenbein, she certainly at intervals seems to be composed
and resigned, but the feelings of deep mourning and distress
darken her mind again.

To give you a notion of my late scientific doings, I send
you some papers on what I call "the chemical polarisation of
the neutral oxigen",2 of which highly interesting subject Mr.
Wiedemann, who has seen the experiments, will give all the
details you may desire to know. I am inclined to believe,
that it is now a matter of fact, that any oxidation, apparently
effected by common or inactive oxigen, is always preceded by
the polarisation of that element. I know now three or four
dozens of cases of slow oxidations, in which that mysterious
act takes place; for instance in that of Phosphorus, Zinc, Iron,
Lead, Copper etc., Ether, and a number of other organic matters:
pyrogallic acid, desoxidized indigo etc.

1 Jakob Eduard Hagenbach, professor of Physics at Bale, where he was
born in 1833.

2 cf. note I. p. 332.

— 339 —

In presence of such a numerous body of. matter-of-fact
evidence, I think, very little doubt can be entertained about
the correctness of the new doctrine, that Oxigen is capable of
being chemically polarized.

How is poor Miss Hornblower? Pray write in your next
letter, how she is doing and remember me most friendly to
your friend.

In entertaining the confident hope, that all is well with
you and yours, I beg you to offer my kindest regards to Mrs.
Faraday, your Niece and Brother.

For ever

Your's

most faithfully
Bale March 29. 1860. C. F. SCHOENBEIN.

Schoznbein to Faraday.
MY DEAR FARADAY

If I am not mistaken, the last letter, I wrote to
you was that, by which I introduced to you Mr. Wiedemann,
about six months ago and having ever since not heard any
news from you, and being very anxious to know, how you
are doing, I take up once more my pen to ask you the favor
of a letter, so much the more, that I am at this present
moment laid up by the gout, a condition of body entirely
new to me and on that very account by no means agreeable.
Indeed, up to the last Wednesday a fortnight, I had known
that of the ills "which human flesh is heir to" only by name
and from english novels; you may therefore easily imagine,
how much I was surprized at finding at once my legs, hitherto
-so loyal and obedient, in a state of open rebellion. No other
choice was left to the poor sovereign, than to let his subjects

340 —

rage and go their own way. To tell you the truth, I am
afraid, that I have not been entirely blameless and it is perhaps,
partly at least, my own fault, that such a catastrophe has
occurred. I have carried on a savage war of conquest these
last four or five months, and to arrive at my end, I was rather
reckless, drawing very largely on the forces of my subjects
and caring very little about their welfare. I certainly carried
the point, but as it seems at the expence of the loyalty of
the inferior classes of my realm ; I entertain however the
flattering hopes, that better times are approaching and a full
restoration of my royal authority will take place before long.
But why waging such a war ? Oxigen, as you well know, is
my hero as well as my foe, and being not only strong but
inexhaustible in strategies and full of tricks, I was obliged to
call up all my forces to lay hold of him, and make the subtle
Being my prisoner. Now to drop the metaphor, I will tell
you, that I have been working very hard these many months
to get the "Antozone" or © in its insulated state and I flatter
myself to have succeeded in that undertaking, at least to a
certain extent.1 You are aware, that from a number of facts,
notably from the reciprocal desoxidizing influence exerted by
many oxy-compounds upon each other, I drew the inference,
that there exist two series of oxides, one of which contain &
the other ©: "the Ozonides and Antozonides." The mutual
desoxidation of those compounds I made dependent upon the
depolarisation or neutralisation of © and 0 into O. Now ©
and 0, being able to be transformed into O, I thought it
possible, even likely, that the contrary might be effected, i. e.
the chemical polarisation of O into © and 0, and you know
that in the course of the last and present year, I have ascer-
tained a great number of facts, that speak, as far as I can see,.

1 Faraday sent this letter to the Phil. Mag. where the philosophical part
of it was inserted under the following heading: "On the insolation of antozone"..
See Phil. Mag. vol. 21. 1861. p. 88.

highly in favor of that Idea. As the typical or fundamental
fact of this chemical polarisation of O, I consider the simul-
taneous production of 0 and HO + © taking place during the
slow combustion of phosphorus. This simultaneity is such, that
ozone never makes its appearance without its equivalent
HO + ©. All the metals slowly oxidizing themselves, HO being
present, such as Zinc, lead, iron etc, give rise to the formation
of HO + © and the same do a great number of organic sub-
stances, such as ether, the tannic, gallic and pyro-gallic acids,
hiematoxiline etc. and even reduced Indigo, being associated
to potash etc., makes no exception to the rule. The same
simultaneity takes place during the electrolysis of water: never
Ozone without peroxide of hydrogen. I admit therefore, that O,
on being put in contact with an oxidable substance and water,
undergoes that change of condition, which I call "chemical
polarisation" i. e. is turned into O and ©, of which the latter
combines with HO to form HO + ©, whilst 0 is associated to
the oxidable matter, such as phosphorus, Zinc etc. In the
preceding statements you have only a very rough outline of
my late researches on the chemical polarisation of neutral
Oxigen; the details on that subject are contained in a number
of papers lately published,1 and of which your english perio-
dicals have as yet not taken any notice. Having gone so far,
I could not but be very curious to try, whether it was not
possible to obtain © in its insulated or free state. I directed
of course my attention to that set of peroxides, which I call
"Antozonides" and tried in different ways to eliminate from
them that part of their oxigen, which I consider to be ©. Already
years ago I remarked, in accordance with an observation made
by Mr. Houzeau2 that the oxigen disengaged from the peroxide

1 He wrote an extensive series of papers on these researches ; they were
chiefly printed in "Gelehrte Anzeigen" and "Sitzungsberichten" of the Munich
Academy of Science, also frequently in "Erdmanns Journal fur praktische Chemie".

2 See Schoenbeins letter dated May 26. 1855. p. 245.

— 342 —

of Barium by the means of the monohydrate of SOs, exhibits
an ozonelike smell and the power of turning my ozone test-
paper blue. Having at that time not yet a notion of two
opposite active conditions of Oxigen, I was inclined to ascribe
those properties to the presence of minute quantities of Ozone
in the said gas, but on examining it more closely, I found it
to be neutral oxigen mixt up with a very small portion of
Antozone or ©. A most important and distinctive property
of Antozone is the readiness, with which it unites with water
to form peroxide of hydrogen, whilst Ozone (alike neutral
oxigen) is entirely incapable of doing so. Hence it comes,
that the oxigen disengaged from BaO + © under certain pre-
cautions, becomes inodorous on being shaken with water, and
that this fluid contains HO 2. The simple cause of the minute
quantities of 0 obtained from BaO + © is the heat disengaged
during the action of SO 3 upon the peroxide by which most
of the © eliminated is transformed into 0.

Now, what do you say to the extraordinary fact, that
the antipode of ozone has these many thousand years been
ready formed and incarcerated, only waiting for somebody to
recognize and let it loose out of its prison. A darkblue species
of Fluorspar has for years been known by the german Minera-
logists, being distinguished by its property of producing a
peculiarly disagreeable smell on being triturated. Many con-
jectures were put up as to the chemical nature of the odorous
matter emitted from the spar: Chlorine, Jodine and even Ozone
were spoken of, but it turned out to be a different thing.
Mr. Schafhaeutl 1 of Munic sent me a month ago some hundred
gramms of the said Fluor-spar (occurring within the veins of
a granitic rock at Woelsendorf a bavarian village near Amberg),
asking me to try my luck in ascertaining the nature of the
smelling matter, and I think I have fully succeeded in making

1 Karl Emil Schafhseutl Ph. D. M. D. professor of Geology and Palae-
ontology at Munich, where he died in 1890. He was born in 1803 at Ingolstadt.

— 343 —

out what it is. Surprizing as it may sound to you and unique
as the fact certainly is, that matter happens to be nothing but
my insolated Antozone. But how do you prove that ? will
you ask me. In the first place it exactly smells like ©, disen-
gaged from BaOa; but smells are fallacious tests. They are;
you shall have another proof, that will irresistibly carry con-
viction with it: on triturating the Fluorspar with water, peroxide
of hydrogen is formed, not in homoeopathic but very percep-
tible quantities. When I found out first this extraordinary fact,
I think it was on the i/th of Nov. last, I could not help
laughing aloud, though I happened to be quite alone in my
laboratory. I laughed, because I strongly suspected my foe
to be hidden in the spar and broke his mask under water
with the view of catching it by that fluid. Indeed, it was to
me, as if I had caught a very cunning fox, long sought after,
in a trap put up for him. To show you, that in saying this
I have neither been joking nor dreaming, I shall send you as
soon as I can, a sample of that wonderful spar, with which
you may easily satisfy your curiousity and convince yourself
of the correctness of my statements.1 I must not omit to tell
you, that, according to some previous experiments of mine,
the Fluor-spar of Woelsendorf contains Vsoooth part of Antozone,
a quantity, as you see not at all homoeopathic. How that
subtle matter got into the spar, I cannot tell. Being once
more upon my legs, I shall, as you may easily imagine, make
a new attack upon my foe, with the view and hope of con-
quering him entirely. The price to be gained by such a fight
is not too dearly paid, even by another fit of gout. Having
already been too prolix about that matter, I must now drop
it; before long you shall read a paper containing the details

i Wcehler writing to Liebig, September 25. 1861 says: "I have repeated
some experiments with the fluorspar from Wcelsendorf, but have failed to satisfy
myself of the accuracy of Schcenbein's results. The odour may turn out to be
free fluorine; it certainly differs greatly from the smell of electrical ozone."

— 344

about insulated ©. Having also worked a good deal on nitri-
fication and obtained a number of novel facts relative to that
interesting chemical process, I could fill up another letter with
a summary statement of them, but there being no space left,
I am forced to give you an account of those researches another
time and confine myself to the simple remark, that in a number
of cases the formation of a nitrate passes through that of a
Nitrite and ozonised oxigen only is capable of oxidizing a
nitrite into a nitrate.

Mrs. Schcenbein and the girls are, thank God, pretty well
and charge me with their kindest regards to you. The deep
wound, caused by the severe loss of our beloved daughter is,
of course not yet healed and we cannot think of it but with
painful feelings, but upon the whole our minds are more com-
posed and resigned. The sad mishap of Miss Hornblower's
caused us much sorrow and we fully sympathize with the
suffering, excellent Lady, confidently hoping, that her present
state is at the least tolerable. Pray, express her our kindest
regards.

Now my dear Faraday excuse kindly the immensurate
length of a badly written letter and don't be long to acknow-
ledge it.

For ever

Your's

most faithfully
Bale Dec. 11. 1860. C. F. SCHOENBEIN.

Don't forget my best compliments to Mrs. Faraday and
your Niece.

— 345

Faraday to Schcenbein.

Royal Institution II January 1861
MY DEAR FRIEND

Whether this letter be long or short, I will write
to you, for I see by my book of dates (I date and enter all
the letters I receive from abroad) that I have neglected you
too long. But all things slip out of my mind, I have nothing
else to say. Do not estimate my esteem and affection for you
by any such measure, as you might draw from my letters, but
value it by the length and quality of your own. As for your
last, I received it so near the end of the month that I sent it
off at once to Dr. Francis, in hopes of seeing it within three
days in the Philosophical Magazine. It did not however appear,
but I have seen a proof since and it will be given to our men
next month.

You really startled me with your independent antozone.
What a wonderful thing oxigen is and to think of the © being
included in a solid body. I suppose you do not despair of
separating it from the fluor spar in its own proper from, what-
ever that may be; for I hope it can exist by itself. Does
heat reduce it to O as it does 0 ? Surely you must hold it
in your hand like a little struggler for if I understand you
rightly it must be a far more abundant body than the Caesium
of Hunsen1 and Knoblauch.2 - - For the hold you have already
obtained over it, I congratulate you, as I would do if you had
obtained a crown, and more than for a new metal.

1 Robert Bunsen late professor of Chemistry at Heidelberg where he died
in 1899. He was born in 1811 at Gottingen.

2 Karl Hermann Knoblauch was professor of Physics at Halle. He was
born in 1820 at Berlin and died in 1895 at Baden-Baden.

In associating Knoblauch's name to Bunsen's Faraday is labouring under a
misapprehension. It is Bunsen and Kirchhof to whom we owe the discovery of
cresium in 1860.

346

But, surely, these wonderful conditions of existence cannot
be confined to oxygen alone. I am waiting to hear that you
have discovered like parallel states with iodine, or bromine, or
hydrogen, and nitrogen. What of nitrogen? is not its apparent
quiet simplicity of action a sham ? not a show, indeed ; but still
not the only state in which it can exist. If the compounds
which a body can form show something of the state and
powers it may have when isolated (as in your 0 O ©), then
what should nitrogen be in its separate state?1

You see I do not work - - I cannot - - but I fancy, and
stuff my letter with such fancies (not a fit return) to you -
Well, any thing to get a letter back from you.

Now I come to a dead stop; for this cold weather has
laid hold of me, and I have either an attack of sciatica, or
perhaps something more serious; we shall see in due time.

My dear Wife also feels the infirmity of years and of
winter; but we cheer each other up. Miss Hornblower is pretty
well, just now. My kindest regards to M. Wiedemann (to whom
I wrote the best I could) and our sincere remembrances to

Madame Schoenbein

Ever My dear friend

Yours

M. FARADAY.

Faraday to Schoenbein.

19 April 1 86 1
MY DEAR SCHOENBEIN

I had a note from Dr. Shuttleworth, and in due
time called on him and received your very precious packet
and letter very safe. I write solely to thank you for it. At

1 For this passage, beginning at "But, surely, these wonderful conditions"
see also Bence Jones vol. 2. p. 441.

347 .

the same time I may say, that I have verified your results,
having repeated the experiments you described in the first part
of your letter. I used as little as possible of the fluor spar,
but I hope more will be found, or that you will discover how
to prepare such a combination, for I am sure that having pro-
ceeded so far, and obtained Antozone in the free state with
that concentration, which it must have, as it leaves the bruised
spar, you cannot stop until you obtain it in the concentrate
and separate state. But take care you do not poison yourself.

Your nitrification results are most interesting, and impor-
tant, and I trust that you will lead them on to a full deve-
lopment and application. You deserve some reward for your
labour; and though you have that which consists in the respect,
praise, and honour, which philosophers award to you, yet there
would be no objection to some of the money power, which
ordinary men value and which is so often obtained by them
in applying the thoughts of the thinkers.

I am still dull, stupid, and forgetful. I wish a discovery
would turn up with me, that I might answer you in a decent,
respectable way. But it will not.

Ever My dear Schoenbein
Yours

M. FARADAY.

Schcenbein to Faraday.

MY DEAR FARADAY

Mr. P. Merian, the well know Geologist and one
of the most intimate friends of mine at Bale, going to England,
I send you through him some bits of the antozoniferous Fluorspar
of Wcelsendorf, which I hope will prove acceptable to you.

Last easier I went to Munic in search for that interesting
material, and was lucky enough to find some there. It is true,
the spar I got is not so richly charged with antozone as that
was, of which I sent you a small specimen some time ago, but
contains enough of it as to enable you to repeat all the experiments,
I described in one of my former letters.

Part of the last midsummer holidays I, with my two youngest
daughters, spent at Seelisberg near the lake of Lucerne, part
of them at Combe Varin a quiet green spot on the heights of
the Jura mountains, and returned to Bale, but last Wednesday,
refreshed in body and mind, both of which were rather tired
and lame by hard working. Later I shall give you a summary
account of my recent doings and the results obtained, which
are rather curious and out of the way facts, not deficient, as I
should think, of scientific interest. They refer to the so called
simple halogenous bodies, principally to Jodine, which substances,
as you well known, I consider to be oxy-compounds, i. c.
Ozonides. The novel facts ascertained are by no means con-
tradictory to that heretical notion ; on the contrary, I think them
to be highly in favor of it. At any rate, by that hypothesis
I was led to the discovery of the facts alluded to.

Mrs. Schcenbein and my daughters are, thank God, doing
pretty well and charge me with their best complements to you
and in begging you to remember me most friendly to Mrs.
Faraday

I am

my dear Faraday

Your's

most faithfully

Bale August i;th 1861. C. F. SCHOENBEIN.

— 349 —

Faraday to Schcenbein.

Royal Institution 19 Septr. 1861
MY DEAR SCHOENBEIN

I lost the sight of Mr. Merian, for when he came
to town I was at Newcastle; — when I came to town he was at
Manchester (where I was not); -- and when he returned 1 was
away: - - I am sent out of town a good deal now; — sometimes
a little Trinity business,1 more generally for rest and health.
But I have the Fluorspar and thank you very sincerely for it
- and I have tried a few of your experiments with it.

When you send me such things, I long for the power I
once had, of taking possession by reading, of all new facts and
making them my own; always in honourable trust for the dis-
coverer. Now that is changed, and when I tried to compare
former experiments with the more recent, I became confused:
and so either in reading such papers as yours, or in trying to
lay their matter before others I become confused, — forgetting
the facts. So you must bear with me, yet not forgetting me ;
for I long to know all you do. No wonder that my remem-
brance fails me, for I shall complete my 70 years next Sunday
(the 22); -- and during these 70 years I have had a happy
life; which still remains happy because of hope and content.

I look forward (?) to your new results with great interest;
but I am becoming more and more timid when I strive to
collate hypotheses relating to the chemical constitution of
matter: I cannot help thinking sometimes whether there is not
some state or condition of which our present notions give us
very little idea, and which yet would reveal to us a flood, a
world of real knowledge , - - a world of facts available both
by practical applications and their illustrations of first principles:

1 In 1861, Bence Jones tells us, Faraday gave ten reports to the Trinity
House and was much occupied with the adjustment of the illuminating apparatus
to the lamp flames in the lighthouses (vol. 2. p. 437).

— 350 —

and yet I cannot shape the idea into a definite form or reach
it by any trial facts that I can devise; and that being the case,
I drop the attempt, and imagine that all the preceding thought
has just been a dreaminess and no more; and so there is an
end of it.1

Good bye My dear friend — Our kindest thoughts to Mrs.
Schoenbein and the girls. I pass now and then the place where
one of them reposes and go in and look at the place.

Miss Hornblower is deeply subjected to physical pain -
We scarcely expect her to survive from week to week.

Ever My dear Schcenbein
Your's

M. FARADAY.

Schcenbein to Faraday?
MY DEAR FARADAY

I have been busily occupied with my favorite
study, and have found out several new facts regarding the
allotropic states of oxigen, their changeability one into another,
and nitrification, and I am inclined to believe that the results
obtained are not quite void of scientific interest.

After many fruitless attempts at isolating ozone from an
"ozonide", I have atlast succeeded in performing that exploit;
and have also found out simple tests for distinguishing with
the greatest ease ozone from its antipode, "antozone". As
to the production of ozone by purely chemical means, the
whole secret consists in dissolving pure manganate of potash

1 Among the letters written by Faraday during the period of his decline
this passage is quoted by Bence Jones (vol. 2. p. 442*.

2 This letter is reprinted from Phil. Mag. 8.4. vol.23. 1862. p. 466 to
which Faraday sent it under the following title: "On the allotropic states of
oxygen and on nitrification." It is not dated, but as Faraday received it "a week
or two ago", it was written in April 1862.

in pure oil of vitriol and introducing into the green solution
pure peroxide of barium, when ozone mixed with common
oxygen will make its appearance, as you may easily perceive
by your nose and other tests. By means of the ozone so
prepared, I have rapidly oxidized silver at the temperature
of - - 20° C, and by inhaling it produced a capital "catarrh".
Regarding nitrification, the most important fact I have dis-
covered is the generation of nitrite of ammonia out of water
and nitrogen, i. e. atmospheric air, which is certainly a most
wonderful and wholly unexpected thing. To state the fact in
the most general manner, it may be said that the salt mentioned
is always produced if water be evaporated in contact with
atmospheric air. This may be shown in a variety of ways. Let,
for instance, a piece of clean linen drenched with distilled
water dry in the open air, moisten it then with pure water,
and you will find that the liquid wrung out of the linen and
acidulated with dilute sulphuric acid (chemically pure) will
strike a blue colour with starch-paste containing iodide of
potassium, by the by, the most delicate test for the nitrites.
It is therefore a matter of course that shirts, handkerchiefs,
table-cloths, in fact all linen, etc., must contain appreciable
quantities of nitrite of ammonia; and if the chemistry of Eng-
land be not entirely different from that of Switzerland, you
will find the same thing at the Royal Institution. The purest
water, suffered to evaporate spontaneously in the open air,
will after some time have taken up enough nitrite of ammonia
(continually being formed at the evaporating surface) to produce
the nitrite reaction. If you make use of water holding a little
potash, or any other alkali, in solution, the same results will
be obtained, i. e. the nitrite of that base will be formed (of
•course in small quantity). The most convenient way of per-
forming the experiment is to moisten a bit of filtering-paper
with a dilute solution of chemically pure potash etc., and to
suspend it for twenty-four hours in the open air. On examining

— 352 —

the paper it will be found to contain a perceptible quantity
of a nitrite, which by a longer exposure of course increases.
But you may still more rapidly convince yourself of the correct-
ness of my statements, if you heat pure water to a temperature
of 50° or 60° C in a porcelain basin, and suspend over the
evaporating surface bands of filtering-paper soaked with a weak
solution of potash, soda, or the carbonates of these bases.
Within a very short time (in ten minutes or 20) there will
enough of the nitrite accumulate in the paper to produce the
reactions of the salt. I enclose a bit of paper treated in
that way for a couple of hours, and by laying it upon a
watchglass and pouring over it acidulated starch-paste con-
taining iodide of potassium, you will perceive the effect pro-
duced. The fact which I have ascertained, that the purest
water mixed with a little chemically pure sulphuric acid or
potash and kept for some time evaporating in the open air
at a temperature of 50° or 60° C (the loss of the liquid being
now and then restored) contains, in the first case a perceptible
quantity of ammonia, and, in the second case, of nitrous acid,
may now he easily accounted for. You know that about
eighteen months ago I found that, during the slow combustion
of phosphorus in moist atmospheric air, very perceptible quan-
tities of nitrite of ammonia are formed, and drew from that
fact the inference that the salt is engendered by 3 equivalents
of water combining directly with 2 equivalents of nitrogen.
Now there is to me hardly any doubt that the production of
that nitrite is due to the evaporation of water taking place
about the phosphorus, whose temperature, in consequence of
its burning state, proves to be higher than that of the surroun-
ding medium, and the fact alluded to must therefore be con-
sidered only as a particular case of a general rule. The same
remark applies to the formation of nitrite of ammonia which
takes place during the rapid combustion of charcoal, etc. in
atmospheric air; combustion, as such, has, I believe, nothing

— 353 —

to do with that formation. I must not omit to tell you that
by means of a large copper still, properly heated, and taking
care not to introduce too much water into the vessel at once,
I can prepare in a very short time several pints of water with
which the reaction of nitrite of ammonia may be produced in
the most striking manner. I hope before long to have an
opportunity of sending you some of this water.

I cannot finish my letter without saying a word or two
about nitrification in general, a fact hitherto so much enveloped
in obscurity. I think the matter is now clear enough. The
evaporation of water is continually going on in the atmosphere,
and along with it the generation of nitrite of ammonia. Now,
this salt being put in contact with the alkaline bases or their
carbonates, nitrites of potash and the other alkalies are formed,
which afterwards gradual!} become oxidized into nitrates. In
our rainy countries these salts are washed away almost as
soon als formed, and carried into the springs, rivers, etc.;
and there is therefore no accumulation of them as in the East
Indies, etc.

That the formation of our nitrite out of water and nitrogen
is a fact highly important for vegetation need hardly be stated.
Indeed each plant, by continually evaporating water into the
atmosphere, becomes a generator of nitrite of ammonia, preparing,
if not all, at least part of its nitrogenous food, and the same
thing takes place in the ground on which it stands. I am
therefore inclined to think that our friend Liebig is right in
asserting that no plant wants any artificial supply of ammonia,
or of matters producing that compound, there being enough
of it offered by natural means. Having communicated the
results of any researches on the subjects mentioned above to
the Academy of Munich, I hope they will soon be published.

I am, my dear Faraday,

Your's most truly

(April 1862) C. F. SCHOENBEIN.

354

To this paper Faraday added the following- note:

(In relation to the peculiar circumstances under which
oxygen and nitrogen combine, it may be worth while here to
refer to the results obtained by Dr. Bence Jones (Phil. Trans. 1851,
p. 407, etc.), where the direct union of these gases in all cases
of combustion in air is described.1 Schoenbein's results depend
upon evaporation. — M. F.)

ft*

Faraday to Schcenbein.

The Green Hampton Court 22 April 1862
MY DEAR FRIEND

I received yours a week or two ago and was so
much struck with the philosophic matter in it, that I sent it off
at once to the Phil. Mag., so that I have not your letter with
me, nor have I the power of ascertaining (being here) when
I wrote to you last. I did not think it had been long ago,
but I know that after a month or five weeks, I lose all count
of the interval of time. I am glad you do not forget me and
I thank you heartily for reproving me, but alas that does not
mend the matter, i. e. the memory, and you must just bear
with me whilst I go on failing.

I have not made Nitrite from the atmosphere yet, by your
method, but the paper you sent me astonishes me by its power,
when tested. I think that discovery very great. You are

indeed a wonderful man and a great encouragement to all

1 Dr. Bence Jones in 1851 published his researches on nitrification which
we can summarize as follows: I. That the action of oxygen takes place in the
body, not only on hydrogen, carbon, sulphur, phosphorus, but also on nitrogen.
2. That in all cases of combustion, if ammonia be present, it will be converted
partly into nitric acid. 3. That the nitrogen of the air is not indifferent in
ordinary cases of combustion, but it gives rise to minute quantities of nitric
acid (see also Phil. Mag. 1851. p. 726).

— 355 —

philosophers, young and old, to persevere. In continuing to
think you remind me of Newton and his results and reward.
For myself I am well and happy, but unproductive. Whilst
I struggled against nature, I often made myself ill and weary,
but since I resign myself I am far better and quite contented.
It would be strange, if I were not - - for though I fall out of
the routes of the philosophers, I do not lose my friends. Ever

My dear Schoenbein

Your friend

M. FARADAY.

Schcenbein to Faraday.
MY DEAR FARADAY.

Professor Eisenlohr l of Carlsruhe a most intimate
friend of mine is going to London and wishing to get intro-
duced to you, I write these few lines to recommend him to
your kindness. You will, I am quite sure, be highly pleased
with the personal acquaintance of that most excellent and
amiable man , who by the bye , is a great admirer of you.
Within a few days I shall leave Bale for Goettingen, where I
intend to spend part of our Midsummer holidays with my
friends there: Woehler, Weber,2 Wagner3 etc. Having worked
rather hard these last eight or ten months, I feel myself a
little tired and my mind now wants some rest and relaxation.
I trust, you have put yourself out of the way during the

1 Wilhelm Eisenlohr, professor of Physics at the Polytechnic Institute at
Carlsruhe. He was born in 1799 at Pforzheim and died in 1872 at Carlsruhe.

2 \Vilhelm Eduard Weber, was professor of Physics at Gottingen, Leipzig
and again at Gottingen (1849) He was born in 1804 at Wittenberg and died
in 1891 at Gottingen.

3 Johann Rudolph Wagner, professor of Physics at the Polytechnic Institute
at Niirnberg, later at the University at Wiirzburg. He was born in 1823 at
Leipzig and died in 1880 at Wiirzburg.

— 356 -

monster exhibition, not to be trodden down by the crowds of
the foreign visitators invading the Royal Institution.

Before long you shall have another letter from me telling
you something about my late scientific doings, which will per-
haps be interesting to you.

In begging you to give my kindest regards to Mrs. Faraday,

I am my dear friend

Your's

most faithfully
Bale July i8th 1862 C. F. SCHOENBEIN.

Faraday to Schcenbein.
DEAR SCHOENBEIN l

Again and again I tear up my letters, for I write
nonsense. I cannot spell or write a line continuously. Whether
I shall recover - - this confusion - - do not know.
I will not write any more. My love to you

ever affectionately yours

M. FARADAY.

When collecting letters and material for the purpose of
writing a life of Faraday Dr. Bence Jones was anxious to have
the original copies of Faradays letters to Schoenbein. He
therefore, at Mrs. Faradays suggestion, expressed a wish to
that effect in a note to Schoenbein dated June 19. 1868. Schcen-
bein very readily complied with this request, and in so doing
wrote a reply which characterizes him so well, and once again
embodies the ties of attachment by which he was bound to
Faraday, in such touching terms, that we cannot refrain from
reproducing it here.

1 This is Faraday's last letter to Schcenbein and is included in the second
volume of Hence Jone's Life p. 45°.

— 357 —

Schcenbein to Dr. Bence Jones.
MY DEAR SIR

Agreeably to the wishes expressed in the lines
with which you favored me the other day, I send you 34 letters
written to me by our deeply lamented friend, during the course
of many years. Certainly the collection is not complete; some
of the letters may be lost, and a number of them mixt up'
with letters from other friends, which I cannot find out at this
present moment.

The last letter I received from Faraday consists of only
a few lines, hardly written, and written with a trembling hand;
it is dated Septbr. iSth 1862 and laid by. From its contents
you may easily imagine that, from delicacy of feelings, I did
not dare answering that letter; for what could I say or write
to our poor friend? and so our correspondence, kept up for
a quarter of a century, dropt, not to be taken up again. Being
so deeply attached to him, I need not tell you, that the inter-
ruption of our epistolary intercourse grieved me to the inner-
most of my heart

It is a matter of course, that you may keep the letters
as long as you like, and I should be very happy, if Wheat-
stone happened to be Your "tabellarius".

Pray present my kindest regards to Mrs. Faraday and

believe me

Your's

most faithfully
Bale June 27. 1868. C. F. SCHOENBEIN.

CONTENTS

1. Schoenbein to Faraday. Bale. May 17. 1836.

Inactivity of iron and other metals and their relation to nitric

acid. Schoenbein apologizes for his poor English ... I

2. Schoenbein to Faraday. Bale. Sept. 12 1836.

Insufficiency of Faraday's attempt to explain passivity of iron by
a film of oxide. Schrenbein's and Herschel's theories of
molecular change 7

3. Schoenbein to Faraday. Bale. Nov. 26. 1836.

Inactivity of iron: Mousson's theory of a film of nitrous acid is
wrong. Schoenbein unwilling to assume new force. Faraday
an honorary member of Phil. Soc. of Bale. Enquiries about
an electrical machine 13

4. Schoenbein to Faraday. Bale. Dec. 26. 1836.

Transference of active and inactive state of iron from wire to wire 17

5. Faraday to Schoenbein. London. Jan. 28. 1837.

Schcenbein's paper sent to Phil. Mag. Faraday not yet satisfied

with his own explication. Expresses thanks for his election 21

6. Faraday to Schoenbein. London. Feb. 6. 1837.

On publication of papers by Roy. Soc. Price of electrical machine 22

7. Schoenbein to Faraday. Bale. April 27. 1837.

Voltaic condition of iron produced by peroxide of lead. Noad's

observations and Nobili's colours 23

8. Faraday to Schoenbein. London. May 2. 1837.

Electrical machine and Phil. Mag. paper sent off .... 27

360

PAGE
9. Faraday to Schocnbein. London. May 4. 1837.

Schcenbein's letter sent to Phil. Mag. 29

10. Schoenbein to Faraday. Bale. July 9. 1837.

Schoenbein dedicates: "Das Verhalten des Eisens zum Sauerstoff"
to Faraday. Berzelius has written to Schoenbein. Crosse's
insects. 29

11. Faraday to Schoenbein. London. Sept. 21. 1837.

Thanks for dedication of book. Crosse's insects . . . . 32

12. Schoenbein to Faraday. Bale. Nov. 5. 1837.

First meeting with Faraday. Close examination of inactivity of
bismuth: Andrews' work. On inactivity of nickel and cobalt,
with Degen. Preservation of iron against sea water by Hartley 34

13. Schoenbein to Faraday. Bale. Dec. 31. 1837.

Voltaic relation of peroxides, platina and inactive iron. De-
finition of chemical action. Peroxide of silver and iron . 42

14. Faraday to Schoenbein. London. Jan. 22. 1838.

Letter sent to Phil. Mag. Faraday's views. Unfortunate letter to

Hachette 47

15. Schoenbein to Faraday. Bale. June 14. 1838.

Fechner's attacks on contact theory 49

16. Faraday to Schoenbein. London. July 30. 1838.

Anything from Schoenbein is worth printing. Poggendorff in

England. Fechner 50

17. Schocnbein to Faraday. Bale. Aug. 12. 1838.

Fechner and Pfaff are voltaists. Rosenschold on voltaic piles.

Change of colour and voltaic currents 52

18. Schocnbein to Faraday. Bale. Sept. 15. 1838.

Polarisation of fluid compound bodies 55

19. Schoenbein to Faraday. Bale. Oct. 20. 1838.

Becquerel's theory of secundary currents is erroneous. Voltaic
polarisation of fluid and solid bodies. Controversy on source
of current electricity on the continent 55

20. Schoenbein to Faraday. Bale. Feb 18. 1839.

Polarisation. Chlorine is like a peroxide. Hydrogen peroxide and

passivity of iron 59

21. Faraday to Schoenbein. London. April 8. 1839.

Approval of Schcenbein's conclusions. Moll's "Decline of Science

in England". Induction. Marianini 61

22. Schoenbein to Faraday. Bale. April 21. 1839.

Voltaic researches and their bearing on organic chemistry.

Chemical theory of galvanism 64

23. Schoenbein to Faraday. Bale. July 3. 1839.

Electrical state does not influence chemical behaviour. Berzelius'
fundamental idea is wrong. De la Rive's and Becquerel's
views on galvanism also. Schoenbein's French pamphlet at the
Brit. Ass. Grant of money 65

24. Faraday to Schoenbein. London. Aug. 17. 1839.

Brit. Ass. and granting of money. Becquerel's pile of acid and alkali 68

25. Faraday to Schoenbein. London. Sept. 24. 1839.

Schoenbein returning to Switzerland 69

26. Schoenbein to Faraday. Bale. Dec. 17. 1839.

Schoenbein on importance of Faraday's papers on induction.
Views on difference between magneto-electrical and voltaic
induction. Definition of static electricity. Jacobi shows that
intensity of a current is independent of its quantity . . 70

27. Schoenbein to Faraday. Bale. April. 4. 1840.

Phosphorous smell developed by electricity and its relations to

chlorine. Faraday's and Grove's latest researches 72

28. Faraday to Schoenbein. London. April 24. 1840.

Faraday's observations on electrical smell, and on Grove's transfer
of matter. Hare's criticism of his induction. Origin of electri-
city in voltaic pile 80

29. Schoenbein to Faraday. Bale. Dec. 20. 1840.

Flattering letter from Berzelius. Schoenbein asks about battery,

to continue his researches on ozone 83

30. Faraday to Schoenbein. London. March 27. 1841.

Faraday feels permanently worse. Schcenbein should apply to

Grove for battery 84

31. Schoenbein to Faraday. Bale. April 8. 1841.

~\\ Lectures have kept him from working on ozone. His battery

yields 15 cub. inches of gas per minute 86

— 362 —

PAGE

. 32. Far a Jay to Schoenbein. London. June 4. 1841.

Faraday is to spend some time in Switzerland , avoiding all

scientific thought 88

33. Faraday to Schoenbein. Zug. Sept. 7. 1841.

Faraday hopes to see Schoenbein at Bale. The stay has done

him good 89

34. Schoenbein to Faraday. Bale. Sept. 27. 1841.

Schoenbein did not see Faraday at Bale 90

.1 35- Faraday to Schoenbein. London. Oct. 14. 1841.

Faraday exceedingly well in health, lias not yet looked at a

scientific journal 90

36. Schoenbein to Faraday. Bale. April 9. 1842.

Schcenbein cautions Faraday not to overwork himself. His
"Reisetagebuch". Is working on electrolysis and peculiar
condition of iron 91

37. Schoenbein to Faraday . Bale July 8. 1842.

Schoenbein prevented from attending the Brit. Ass. at Manchester.
Hydroelectric currents are due to chemical action. Is working
on peculiar state of iron. Voltaic pile out of mere cast iron 93

38. Faraday to Schoenbein. Tynemouth. Aug. 10. 1842.

Faraday pretty nearly excluded as a workman of science. Author

of "Mittheilungen" 95

39. Schoenbein to Faraday. Bale. Aug. 22. 1842.

Inactive iron more and more inexplicable. Moser's breath-images.

"Reisetagebuch" and the Germans . . , . . . 97

40. Faraday to Schoenbein. London. Feb. 18. 1843.

Faraday feels himself unworthy of picture drawn by Schoenbein
in "Reisetagebuch". Herschel on inactive iron. Moser's
images. Faraday working on electricitiy of high pressure
steam. Peltier on space 101

41. Schoenbein to Faraday. Bale. April 26. 1843.

Translation of "Reisetagebuch". On Faraday's induction and
steampaper. Grove's gaseous battery. De la Rive's and
Martens' researches 104

42. Schoenbein to Fa-aday. Bale. May n. 1843.

Influence of one ingredient part of a binary compound upon the other 107

363 —

PAGE

43. Faraday to Schoenbein. London. May 1 6. 1843.

Translation of "Reisetagebuch". De la Rive in England . . 109

44. Faraday to Schoenbein. London. Aug. 8. 1843.

Mr. Vincent willing to translate "Reisetagebuch" . . . .ill

45. Faraday to Schoenbein. London. Sept. 6. 1843.

Armstrong's steam electric apparatus. "Reisetagebuch" in

Athenaeum 113

46. Schoenbein to Faraday. Bale. Feb. 17. 1844.

Schoenbein and Faraday on atomic theory. Grove receives degree

of Bale University 113

47. Schoenbein to Faraday. Bale. March 30. 1844.

Should ozone be isolated Schcenbein will go to York . . 115

48. Schoenbein to Faraday. Bale. March 30. 1844.

Production of Ozone by chemical means 116

49. Faraday to Schoenbein. Brighton. April 12. 1844.

Schoenbein's letter on ozone sent to Roy. Soc. Faraday's memory

a bad indicator of scientific news 122

50. Schoenbein to Faraday. Bale. April 19. 1844.

Identity of three odoriferous principles. Ozone an halogenous

body resembling chlorine. Azote is ozonide of hydrogen . 123

51. Faraday to Schoenbein. London. April 29. 1844.

Production of ozone by chemical means is one to surprize and
delight his friends 128

52. Schoenbein to Faraday. Bale. May 29. 1844.

Ozone isolated. Nature of azote. Book on ozone . . .130

53. Schoenbein to Faraday. Bale May 31. 1844.

Schoenbein's ozonide of potassium was not pure .... 134

54. Faraday to Schoenbein. London. June 19. 1844.

Introduction for Dr. Holland 135

55. Schoenbein to Faraday. Bale. Aug. 27. 1844.

Book on ozone. Schcenbein cannot be at York. Does the Brit.

Ass. give grants of money? 135

364

PAGE

56. Faraday to Schocnbein. Dover. Sept. 14. 1844.

Accident to Faraday's brother. Faraday is reviving his health
at Dover. Grove is to report on Schcenbein's book on ozone
at York ... 137

57. Faraday to Schoenbein. London. Oct. 25. 1844.

Faraday at inquest at Durham. Brit. Ass. and paper on ozone.

Faraday says: "I am working but cannot get on" . . .139

58. Schoenbein to Faraday, Hale. Nov. 25. 1844.

Meeting at Milan: Piria says ozone is nitrous acid. Ozone is

not nitrous acid 140

59. Faraday to Schoenbein. London. Feb. 20. 1845.

Faraday's memory becoming more and more treacherous. Conden-
sation of gases: oxygen 143

60. Schoenbein to Faraday. Bale. June 4. 1845.

Schoenbein will read his paper on ozone at Cambridge himself 145

6 1. Faraday to Schoenbein. London. June 14. 1845.

Faraday hopes to see Schoenbein in town 146

62. Schoenbein to Faraday. Bale. Oct. 20. 1845.

Relation of ozone to nitrogen. Nitrification. Bleaching by

means of ozone 146

63. Faraday to Schoenbein. Brighton. Nov. 13. 1845.

Faraday working very hard : direct relation between magnetism

and light, also electricity and light 148

64. Schoenbein to Faraday. Bale. Dec. 30. 1845.

Schoenbein on Faraday's discovery. Schoenbein on the oxides of

nitrogen. Dr. Neefs discovery of relation of light to electricity 149

65. Schoenbein to Faraday. Bale. Feb. 27. 1846.

Schcenbein's water proof paper 151

66. Faraday to Schoenbein. London. March 5. 1846.

Schoenbein's paper sent to Mr. Dickenson 154

67. Schoenbein to Faraday. Bale. March 1 8. 1846.

Transparent substance from common paper. Explosive cotton.

Electrical properties of his prepared paper . . . 155

68. Schoenbein to Faraday, Bale. March 23. 1846.

Preliminary experiments with his explosive cotton . . . .158

- 365 -

PAGE

69. Schoenbein to Faraday. Bale March 24. 1846.

Bell made from Schcenbein's transparent paper . . . .159

70. Schoenbein to Faraday. London. Aug. 22. 1846.

Schoenbein in England. Death of Faraday's brother . . 159

71. Faraday to Schoenbein. London. Aug. 24. 1846.

Faraday suggests experimenting with Schoenbein at the Royal

Institute ............. 160

72. Faraday to Schoenbein. Tunbriclge Wells. Aug. 25. 1846.

Guncotton. Experiments at Woolwich ...... 160

73. Faraday to Schoenbein. London. Dec. 18. 1846.

Faraday on guncotton-Schcenbein. Accident to Mr. Lancaster.
Brande to lecture on guncotton. Faraday prevented from
working through an affection of the knee ..... 162

74. Schoenbein to Faraday. Bale. Dec. 26. 1846.

Schcenbein's nitrate formulae. History of guncotton and
French claims. Analyses. Resinous matter from sugar . 164

75. Schofnbein to Faraday. Bale. July i. 1847.

Written in sympathetic ink. Test for ozone . . . . .171

76. Faraday to Schoenbein. London. Oct. 23. 1847.

Faraday overworked. On Schcenbein's test for ozone . . .172

77. Schoenbein to Faraday. Bale. Nov. 19. 1847.

Action of charcoal on chlorine etc., which he still regards as
oxycompounds. Change of colour of starch-paste by means
of solar rays ............ 173

78. Faraday to Schoenbein. Brighton. March 17. 1848.

Faraday can no longer remember anything of the past. Note by -•>]
Mrs. Faraday ............ 178

79. Schoenbein to Faraday. Bale. Sept. 1848.

All metals oxidized by ozone. Test for arsenic and antimony.

Oxidation of phosphorus in ozone ...... 179

80. Faraday to Schoenbein. London. Dec. 15. 1848.

Faraday's memory worse than ever. Has worked on crystalline N
polarity of bismuth. Pliickers work ...... 182

— 366 —

PAGE

81. Schoenbein to Faraday. Bale. March 27. 1850.

Schoenbein wishes paper to be read on ozone at the Royal

Institute 184

82. Faraday to Schoenbein. London. Mayli. 1850.

Faraday will give lecture on ozone himself. Would like a list

of suitable experiments 185

83. Faraday to Schoenbein. London. Nov. 19. 1850.

Bleaching by means of ozone. Faraday says oxygen is cause of

the variations of terrestrial magnetism 186

84. Schoenbein to Faraday. Bale. Nov. 25. 1850.

Schoenbein's sulphuret paper, even in the dark, becomes brown

again 189

85. Faraday to Schoenbein. Brighton. Dec. 9. 1850.

Faraday has received ozonometer etc. Approval of Schoenbein's
theory of atmospheric electricity. Speculation on nature of
insulated oxygen 189

86. Faraday to Schoenbein. Brighton. Dec. 13. 1850.

Testing of Schcenbein's ozonometer at Brighton .... 192

87. Faraday to Schoenbein. London. March. 5. 1851.

Schrenbein's papers sent to the Chem. Soc. and the Medico-
Chirurgical Society. Gaseous oxygen, says Faraday, looses
its magnetic properties in compounds 193

88. Faraday to Schoenbein. Hastings. April 19. 1851.

Faraday poor in health. Lecture on ozone in six weeks. Atmos-
pheric magnetism 195

89. Schoenbein to Faraday. Bale. July 25. 1851.

Portrait of Euler brought by Mr. Sarasin '196

90. Faraday to Schoenbein. Tynemouth. Aug. I. 1851.

Faraday's ozone evening went of wonderfully well, and excited

great interest 198

91. Faraday to Schoenbein. London. Dec. 16. 1851.

Faraday working away at magnetism. On experiments . .199

92. Schoenbein to Faraday. Bale. May 7. 1852.

Schoenbein's views on oxygen: "Jove of the philosophical

Olympos" 200

36;

PAGE

93. Faraday to Schoenbein. London. June 2. 1852.

Faraday sends three papers on lines of magnetic force. Rev.

Mr. Sidney on ozone in vegetables 203

94. Schoenbein to Faraday. Bale. Aug. 29. 1852

A brief note delivered by Dr. Whewell 204

95. Schoenbein to Faraday. Bale. Oct. 17. 1852.

Schcenbein's memoir on oxygen. Working on colour of oxy-

compounds. On modern chemists 205

96. Faraday to Schoenbein. Brighton. Dec. 9. 18^2.

Faraday quite worn out with work. Schcenbein's colour theories
quite excite him. Their relation to Stokes' researches. Organic
chemistry is a sealed book to Faraday 207

97. Schoenbein to Faraday. Bale. Dec. 18. 1852.

Connections between Stokes' researches and ScTioenbein's. On
the optical action of nitrous gas upon solutions of protosalts
of iron 210

98. Schoenbein to Faraday. Bale. July 1 1. 1853.

Nature of ozone settled in Bunsen's laboratory by Baumert.

Schoenbein sceptical 212

99. Faraday to Schoenbein. London. July 25. 1853.

Faraday on table turning. Has lectured on ozone . . .214

loo. Schoenbein to Faraday. Bale. Sept. 24. 1853.

Schoenbein at Munich. Met Liebig, who asked him to read a

paper on ozone 216

101 Faraday to Schoenbein. London. Jan. 27. 1854.

Faraday working on telegraph wires. On Schoenbein's meeting

with Liebig 219

102. Schoenbein to Faraday. Bale. Feb. lo. 1854.

Schoenbein's views on chemical action of light, heat, and

electricity. Disapproves strongly of Davy's views . . .221

103. Schoenbein to Faraday. Bale. April 9. 1854.

Schoenbein, at Liebig's request, has compiled a book on ozone 226

104. Schoenbein to Faiaday. Bale. May 4. 1854.

Letter of introduction for Dr. Stehlin . 228

PAGE

105. Faraday to Schoenbein. London. May 15. 1854.

Repetition of Schcenbein's experiments with Dahlia colours.

List of letters written and received ...... 229

106. Schoenbein to Faraday, Bale. July 4. 1854.

Catalytic action and other changes referable to allotropic modi-
fication 232

107. Faraday to Schoenbein. London. Sept. 15. 1854.

Faraday hesitates publishing Schoenbein 's views on chemists.

Dr. Drew and Airy on ozone observations in England . . 236

108. Schoenbein to Faraday. Bale. Feb. 27. 1855.

Passage on Faraday in Schoenbein's "Menschen und Dinge".

Wiedemann on electrolysis 238

109. Faraday to Schoenbein. Hastings. April 6. 1855.

Faraday says: "The imperishable marble of your book will

surely flatter.1' Working on lines of magnetic force . . 242

110. Schoenbein to Faraday. Bale. May 26. 1855.

Attempts to separate the two forms of oxygen from peroxides.
Houzeau's work. Separation of some ozonized oxygen from
peroxide of silver. Wiedemann on electrolysis. Picnic to
the Gempenstollen 245

in. Faraday to Schoenbein. London. Nov. 6. 1855.

Repetition of Schoenbein's experiments. Different effects.

Faraday's high opinion of Wiedemann 252

112. Schoenbein to Faraday. Bale. Nov. 30. 1855.

Schoenbein at home. Cholera at Bale. Allotropic forms of

oxygen. Transformation of oxygen into ozone in mushrooms 254

113. Faraday to Schoenbein. London. March 21. 1856.

Faraday cannot recollect any news 263

114. Schoenbein to Faraday. Bdle. March 29. 1856.

Easter-Day at Mrs. Wiedemann's house 264

115. Faraday to Schoenbein. London. April u. 1856.

Faraday sends a volume of his researches by Mr. Roscoe Note

by Mrs. Faraday 266

369 —

PAGE

116. Schoenbein to Faraday. Bale. April 26. 1856.

Schoenbein hopes to live to see Faraday's proof of the identity

of magnetism and gravity 267

117. Schoenbein to Faraday. Bale. Sept. 20. 1856.

Schoenbein's trip to North Germany. Working on catalysis, and
formation of formic acid. Miss Schoenbein is anxious to spend
a year in England. Wiedemann's investigations. Mr. Merian
in England 269

118. Faraday to Schoenbein. London. Oct. 14. 1856.

Faraday not headstrong enough for much work. Paper on relation

of gold to light. Miss Schcenbein and Miss Hornblovver . 273

119. Schoenbein to Faraday. Bale. Nov. 10. 1856.

Miss Schoenbein's plans. On nitrification 275

1 20. Faraday to Schoenbein. London. Jan. 23. 1857.

Miss Schoenbein. Faraday working on gold 279

121. Schoenbein to Faraday. Bale. Feb. 9. 1857.

Miss Schoenbein. Schcenbein on oxidizing effects. Awarded

the Maximilian medal 280

122. Schoenbein to Faraday. Bale. April 25. 1857.

Miss Schoenbein's visit to England. Schoenbein in Munich:
poisoned bread from China. Transformation of oxygen into
oxone by oil of bitter almonds 282

123. Faraday to Schoenbein. London. May 7. 1857.

Miss Schcenbein's visit to England 284

124. Schoenbein to Faraday. Bale. Sept. 17. 1857.

Miss Schoenbein's visit to England. Schoenbein on his researches
on oil of bitter almonds, nitrification and his peroxide test
paper 285

125. Faraday to Schoenbein. London. Sept. 25. 1857.

Miss Schoenbein at Stamford Hill 292

126. Faraday to Schoenbein. London. Nov. 24. 1857.

Clarke on ozone in atmospheric air. Faraday working on relation

of time to actions at a distance 293

— 370

PAGE

127. Faraday to Schoenbein. London. No date.

Fragment of letter partly destroyed by acid. Faraday on action
at a distance. Miss Schcenbein. From context date about
November 1857 296

128. Schoenbein to Faraday. Bale. Feb. 15. 1858.

Schoenbein as a politician 297

129. Schoenbein to Faraday. Bale. June 25. 1858.

Further observations on the allotropic modifications of oxygen,

and on the compound nature of chlorine, bromine etc. . .301

130. Schoenbein to Faraday. Bale. June 28. 1858.

Letter of introduction for Prof. Vischer, the "god father" of ozone 307

131. Faraday to Schoenbein. London. July 28. 1858.

Faraday doubtful about sending Schoanbein's letter to the Phil.

Mag. owing to his criticisms of Davy's views .... 308

132. Schoenbein to Faraday. Speicher. Au^. 4. 1858.

Schcenbein sees no harm in giving his views on Davy to the

British public. Staying at Appenzell 309

133. Schoenbein to Faraday. Sept. 1858.

Meeting of German Association at Carlsruhe 311

134. Faraday to Schoenbein. London. Nov. 13. 1858.

Faraday practically unable to lecture on ozone without Schcenbein's

help. P'eels loss of memory seriously. Miss Schoenbein . 314

135 Faraday to Schoenbein. London. Nov. 25. 1858.

Information wanted for preparation of hydrogen peroxide . . 316

136. Faraday to Schoenbein. London. Dec. 2. 1858.

Receipt of some packets acknowledged 318

'37- Faraday to Schoenbein. London. Jan. 19. 1859.

Peroxide of barium and lecture on ozone on 25th of Feb. Note
by Miss Schcenbein applying for some tickets for Faraday's
lecture on ozone. Miss Schcenbein died on the 13th of
February 3 ' 8

138. Faraday to Schoenbein. London. Feb. 16. 1859.

Particulars of Miss Schcenbein's death 319

139. Sckoenbein to Faraday. Bale. (Feb. 25.) 1859.

Schoenbein touched by expressions of sympathy at Miss Schoen-

bein's death. Has begun lecturing again 322

140. Faraday to Schoenbein. London. Feb. 24. 1859.

Faraday anxious to put off his lecture on ozone, owing to Miss

Schoenbein's death. Unable to do so . . . . . 323

141. Faraday to Schoenbein. London. April 25. 1859.

Faraday's lecture on ozone 324

142. Schoenbein to Faraday. Rale. July 19. 1859.

Schcenbein again working in his laboratory: slow combustion of

ether, and the reduction of oxy-compounds .... 326

143. Faraday to Schoenbein. London. Sept. 23. 1859.

Faraday's 68th birthday. Negative results in electricity, heat, and

gravity 329

144. Schoenbein to Faraday. Bale. Oct. 26. 1859.

Chemical polarisation of neutral oxygen. Tests for hydrogen

peroxide 330

145. Faraday to Schoenbtin. London March 27. 1 860.

Faraday rather poorly and unable to remember things . . 336

146. Schoenbein to Faraday. Bale. March 29. 1860.

Wiedemann going to England 338

147. Schoenbein to Faraday. Bale. Dec. n. 1860.

Minute description of isolation of antozone from Bavarian fluorspar 339

148. Faraday to Schoenbein. London. Jan. II. 1861.

"You really startle me by your independent antozone," writes

Faraday, who himself is unable to work 345

149. Faraday to Schoenbein. London. April 19. 1861.

By repeating Schoenbein's experiments with the fluorspar, Faraday

gets his antozone 346

150. Schoenbein to Faraday Bale. Aug. 17. 1861.

More antozoniferous fluorspar sent from Wolsendorf . . . 347

151. Faraday to Schoenbein. London. Sept. 19. 1861.

Further experiments with fluorspar 349

— 372 —

PAGE

152. Schoenbein to Faraday. Bale, April 1862.

Allotropic states of oxygen. Isolation of ozone from an ozonide.

General remarks on nitrification. Dr. Bence Jones . . 350

153. Faraday to Schoenbein. London. April 22. 1862.

Schcenbein's nitrite paper sent to the Phil. Mag. Schcenbein and

Newton 354

154. Schoenbein to Faraday. Bale. July 18. 1862.

Letter of introduction for Prof. Eisenlohr, a great admirer of

Faraday 355

155. Faraday to Schoenbein. London. Sept. 1 8. 1862.

Faraday's last letter to Schoenbein. Reference to it in a letter

to Dr. Bence Jones 356

INDEX

Airy, 238.
Andrews, 35.
Arago, 35.
Armstrong, 113.

Bachofen, 72.
Bancalari, 187.
Barnard, Miss, 293.
Baumert, 223, 311, 317.
Becquerel, 67, 71, 86, 87, 216.

— onRitter's secondary piles,56.

— on galvanism, 66.

Bence Jones, 193, 199, 203, 314,

319- 323, 354-

— on nitrification, 355-

— Life of Faraday, 48, 148, 173,

215, 274.

Bernoulli, 268, 311, 317.
Berthollet, 306.
Berzelius, 33, 223.

— on iron, 30, 102.

— electrochemical theory of, 66.

— on ozone, 82, 127, 134

— on water proof paper, 152.
on guncotton, 158.

— in' MenschenundDinge",24O.

— to Schoenbein, 30, 40, 83,

134, 153, IS8, l63-
Bolley, 193, 196.
Bottger, 164.
Brabant. 49, 50.
Bracconnot, 169.
Brande, 163, 164.
Brodie, 317, 337-
Buch, 240.
Buckland, 61.
Bunsen, 266, 312.

— on ozone, 2131 21S-

— on caesium, 345.
Burckhardt, 64, 179, 197.

Cailletet, 144.

Charpentier, 87.

Christie, 73, 81, 116, 122, 129, 143.

Clarke, 294.

Cockerill, 41.

Congreve, 156

Cooper, 69.

Crosse, 31, 33.

Crowdy, 322, 323.

Cuvier, 240.

Daniell, 61, 138, 151.
Davy, 105.

— Schoenbein on, 60, 224, 225,

306, 308. 309.
Degen, 40.
de la Rive, 30, 35, 82, 218, 223.

on chemical action, 45, 51,

106.
on Pfaff, 53.

— on galvanism, 66, 67.
in England, 35, in.

_ book on ozone, 133

— Schrenbein's papers, 137.

— Faraday's discovery, 149.

— to Schrenbein, 53, I37>

149-

Deville, 174.
Dickenson, 154
Dove, 312.
Draper, 191.
Drew, 212, 214, 238.

Eisenlohr, 265.
Euler 196, 198, 199.

374 —

Faraday, member of Phil. Soc. of Bale,

13, 22.
memoir on iron dedicated to,

29, 32
in Schoenbein'sbook, 101, 104,

109, 204, 242.
Crosse's insects 31, 33.
passivity of iron, 7, 21, 28, 62.

— chemical and voltaic action,

45, 48, 51, 82.
action at a distance, 295, 296.
magnetism, 194, 199.
magnetism and light, 148,

149, 15°-

— lines of magnetic force, 203.
polarity of bismuth, 182.
induction, 48, 52, 63, 70, 105.
electricity of steam, 103, 105,

1 10.

condensation of gises, 144,

203
diamagnetism of gases, 178,

187.

oxygen, 187, 190, 191, 194.
ozone, 81, 185, 188, 191, 192,

'94, 195, 197, 198, 315,
317, 318, 320.
magnecrystallic forces, 183.
gold, 274, 279, 294
ice, 230.
crystals, 52
telegraph wires, 221.
table turning, 214.
experiments, 199.
Schcenbein's letters, 33, 50.

papers, 51, 185.
Faraday, Mrs. letter to Schoenbein, 1 79,

267.

Faraday's brother, 137, 143, 159.
Fechner, 49, 51, 52.
Forbes, 90.

Francis, 294, 308, 345.
Fremy 216.

Gould, 227.
Gould, Benjamin, 227.
Graham to Schoenbein, 209.
Grove, 18, 78, 81, 84, 85, no, in,
119 138, 229, 274, 323, 326.

— gaseous battery, 106.
degree at Bale, 115, 129.

— name for ozone, 124

Grove, gun cotton, 161, 164, 169.
— to Schcenbein, 79, in, 113,
114, 115. n9, 133, 150, 153.
159, 161, 162, 209.

Hachette, 48, 59.

Hagenbach, 338.

Hare, 82.

Hartley, 39, 40.

Henry, Prof., 32.

Henry, 185.

Herschel, 11, 12, 96, 162.

Hofmann, 210.

Hogg, 162.

Holland, 135.

Hornblower, Miss, 274 ft.

Hunt, 103.

Houzeau, 245, 341.

Iselin, 59, 61, 62.

Jacobi, 72.

Kirchhof, 345.
Knoblauch, 345.
Kohl, 101.

Lancaster, 163.

Liebig, 206, 216, 258, 283, 312, 343,

353
meeting with Schoenbein, 216,

217.

— on ozone, 227, 228, 237.

— to Schoenbein, 227.
Louyet, 161, 169.

Marianini, 63.
Marignac 223.
Martens, 106, 107.
Magnus, 312.
Mayo, Miss, 322.
Merian, Peter, 227, 347, 348.

his son, 226.

Rudolf, 268, 272.
Moffat, 252.

375

Moll, 62.
Moser, 98, 102.
Mousson, 13, 14, 21.
Munk af Rosenschold, 54.
Murray, 1 10.

Neef, 151.
Newman, 27.
Newton, 355.
Noad, 27.
Nobili, 24, 27, 43, 48.

Pasteur, 288.
Pelonze, 169.
Peltier, 103, 105, 106.
Pettenkofer, 168.

to Schoenbein, 174.

Pfoff, 53, 58.

Phillips, letters from Faraday, 7, 62.

Pictet, 144.

Plucker, 183.

Poggendorff, 41, 51, 52, 84, 154.

becomes voltaist, 50.

to Schoenbein, 41, 154.
Prater, 103.
PreVost, 159.

R.
Ritter, 30.

secundary piles, 56, 59.
Roscoe, 266.
Rose, 165, 166, 313.
Rumpf, 318.
Ryhiner, 108, 112.

Schoenbein, an alchemist, 42.

description by Faraday.
England etc 6, 30, 34, 66,

69, 70, 114. 116, 145,

159; 1 60.

nature and mankind, 99.
Mittheilungen 92, 94, 96,

99, 101, 105, 109, 113,

243-
Menschen und Dinge, 217,

239, 241, 256, 258
Maximilian medal, 281.
Atomic theory, 114.
Chemistry 64, 187, 188,

190, 206, 225, 258.

Schoenbein, passive iron i, 7, 10, 23, 30,

36, 60, 94, 98.
book on, 29, 32, 41.
gun cotton, 155, 156, 158,
161, 165, 169,

173-

discovery, 162.

analysis, 168.

ozone, 121, 124, 134, 142,

146, 167,174,213,

238, 259, 269, 294.

— first mentioned, 83,

124,174,184,307.

— formation, 116, 125.

128, 134, 180,242,

305-

tests, 127, 171, 180,
290.

— book on, 133, 135,

137, 138, 140.

— and nitrous acid, 140.

— and antozone, 301,

3»5.325'34I,345i
347. 35°-
galvanisation of metals, 60,

62, 64, 66.

nitrification, 127, 146, 150,
276, 290, 344, 347. 35 !,

353-
electrolysis 98, 106, 114,

151, 223, 233, 341.
book on Physical Chemistry,

ii3< "5-

changes of colour, 54, 2O5>

208, 222, 230, 236.
polarisation, 55, 327, 332,

338, 341.
on Faraday's work, 101,

142, 149.

meets Liebig, 217.
to Berzelius, I, 57, 102,
127, 152. 156, 158, 161.
to Liebig, 206.
Schoenbein, Miss, 212 ff.
Schweitzer, 251, 253.
Shuttleworth, 346.
Sidney, 203.
Sorel, 41.
Stehlin, 228, 237.
Stokes, 209, 2ii.

T.
Taylor, 163.

— Richard, 50, 51, 138, 186.

376

Taylor, Scientific memoirs, 27, 102,

187, 208.

— and Francis, 208.
Thenard, 234.
Thompson, 62, 186, 215.
Twining, 244, 253, 266.

Vincent, translation of Mittheilungen,

112, 243.

— librarian, 221.
Vischer, 174, 184, 307, 308.

Wagner, 355.

Watkins, ni, 145.

Weber, 355.

Whewell, 204, 205, 208, 273.

Wiedemann, 240, 244, 251, 262, 272,

275i 346.

in England, 338, 339.
electrolysis, 240, 251.
magnetic researches, 272.
Faraday on, 253.
Eilhard, 265
Mrs., 265.
Wohler, 312, 355.

antozone, 343.
— to Schcenbein, 225.

to Liebig, 343.
Worringer, 95.

Yafes, 112.
Zerzog, 286.

CORRIGENDA

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BY THE SAME AUTHOR

Siedetemperatur und Druck in ihren Wechselbeziehungen. Preliminary
studies. Leipsic, J. A. Bart/i, 1885.

Uber normale und abnorme Dampf-Temperatur. Two treatises. Bale
J. G. Baur, 1887.

Aus der Vorgeschichte der Spektralanalyse. A lecture. Bale, Benno
Schwabe, 1888.

Studien iiber Dampfspannkraftsmessungen. Vol. i. Bale, Benno Schwabe
1893-

Die Siedekurven der normalen Fettsauren von der Ameisensaure bis
zur Caprinsaure. Adapted for lecture purposes. Leipsic , Breitkopf
und Hart el, 1894.

Theophrastus Paracelsus. A lecture delivered in honour of Theophrastus
of Hohenheim. Bale, Benno Schwabe, 1894.

Eine Spitzbergenfahrt. Sketches. Leipsic, y. A. Barth, 1896.

Studien iiber Dampfspannkraftsmessungen. Section 2, part i. Bale
Benno Schwabe, 1897.

Mythos und Naturwissenschaften unter besonderer Beriicksichtigung
der Kalewala. A lecture. Leipsic, J. A. Barth, 1898.

Die Entstehung der Dalton'sehen Atomtheorie in neuer Beleuchtung.
Translated from the English of HENRY E. ROSCOE and ARTHUR HARDEN.
No. 2 of the Monographs from the History of Chemistry. Leipsic,
J. A. Barth, 1898.

Zwanzig Briefe , gewechselt zwischen Jons Jakob Berzelius und
Christian Priedrich Schoenbein in den Jahren 1836 — 1847. Bale,
Benno Schwabe, 1898.

Wilhelm Eisenlohr. A lecture delivered to celebrate the centenary of his
birth. Karlsruhe, G. Braun'sche Hofbuchdruckcrei, 1899.

Christian Friedrich Schoenbein, 1799 — 1868. Ein Blatt zur Geschichte des
Neunzehnten Jahrhunderts. Part. I. No. 4 of the Monographs from the
History of Chemistry. Leipsic, J. A. Barth, 1899.

By GEORG W. A. KAHLBAUM and AUG. HOFFMANN:

Tiber die Einfuhrung der Lavoisier'schen Theorie in Deutsehland.
No. I of the Monographs from the History of Chemistry Leipsic, y. A. Barth,
1897.

By GEORG W. A. KAHLBAUM and E. THON:

Justus von Liebig und Christian Friedrich Schoenbein. Briefwechsel
1853 — 1868. No. 5 of the Monographs from the History of Chemistry.
Leipsic, J. A. Barth,

IN THE PRESS:

By GEORG W. A. KAHLBAUM and E. SCHAER :

Christian Friedrich Schoenbein. Ein Blatt zur Geschichte des Neunzehnten
Jahrhunderts. No. 6 of the Monographs from the History of Chemistry.
Leipsic, J. A, Barth.

Messrs. WILLIAMS & NORGATE, London, will shortly publish:

The letters of Berzelius and Schoenbein. By GEORG W. A. KAHLBAUM,
translated by FRANCIS V. DARBISHIRE and NEVILLE V. SIDGWICK.

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