Chapter X (1)

Mr. Faraday's introduction to Sir H. Davy.--A renewed
correspondence on the subject of the Gunpowder
Manufactory.--Davy obtains permission from Napoleon
to visit the Continent.--He embarks in a Cartel from
Plymouth.--Is arrested at Morlaix.--Arrives at Paris.--Visits
the Louvre.--His extraordinary conduct upon that
occasion.--Inspects the Colossal Elephant, and is introduced
to M. Alavair, its architect.--The discovery of the dungeons
of the Bastile.--Davy's interesting letter to M. Alavair.--He
attends a meeting of the Institute.--Is visited by all the
principal _savans_ of Paris.--The adventure which befell
Lady Davy in the Thuilleries' Garden.--Anniversary dinner
of the Philomatic Society.--The junior Chemists of France
invite Davy to a splendid entertainment.--How far Davy is
entitled to be considered the discoverer of the true nature
of Iodine.--Napoleon's unlucky experiment with the Voltaic
battery.--Davy is presented to the Empress Josephine.--An
account of the Court ceremony at Malmaison.--Remarks on
the conduct of Davy during his visit to Paris.--He quits
the capital of France, and proceeds, by way of Lyons, to
Montpellier.--Is assisted in experiments on sea-weed by M.
Berard.--Crosses the Alps.--Arrives at Genoa.--Institutes
experiments on the Torpedo.--Visits Florence, and accomplishes
the combustion of the diamond, by the great lens in the cabinet
of Natural History.--Experiments on Iodine.--He examines the
colours used by the Ancients.--Visits all the celebrated
Philosophers of Italy and Switzerland, with whom he works in
their laboratories.--Returns to England.

It is said of Bergman, that he considered the greatest of his discoveries to have been the discovery of Scheele.[1] Amongst the numerous services conferred upon Science by Sir Humphry Davy, we must not pass unnoticed that kind and generous patronage which first raised Mr. Faraday from obscurity, and gave to the chemical world a philosopher capable of pursuing that brilliant path of enquiry which the genius of his master had so successfully explored.

[1] See Note at page 42, vol. i.

The circumstances which first led Mr. Faraday to the study of chemistry, and by which he became connected with the Royal Institution, were communicated to me, by himself, in the following letter.

TO J. A. PARIS, M.D.

MY DEAR SIR, Royal Institution, Dec. 23, 1829.

You asked me to give you an account of my first introduction
to Sir H. Davy, which I am very happy to do, as I think the
circumstances will bear testimony to his goodness of heart.

When I was a bookseller's apprentice, I was very fond of
experiment, and very averse to trade. It happened that a
gentleman, a member of the Royal Institution, took me to hear
some of Sir H. Davy's last lectures in Albemarle Street. I took
notes, and afterwards wrote them out more fairly in a quarto
volume.

My desire to escape from trade, which I thought vicious and
selfish, and to enter into the service of Science, which I
imagined made its pursuers amiable and liberal, induced me at
last to take the bold and simple step of writing to Sir H.
Davy, expressing my wishes, and a hope that, if an opportunity
came in his way, he would favour my views; at the same time I
sent the notes I had taken at his lectures.

The answer, which makes all the point of my communication, I
send you in the original, requesting you to take great care of
it, and to let me have it back, for you may imagine how much I
value it.

You will observe that this took place at the end of the year
1812, and early in 1813 he requested to see me, and told me
of the situation of assistant in the Laboratory of the Royal
Institution, then just vacant.

At the same time that he thus gratified my desires as to
scientific employment, he still advised me not to give up
the prospects I had before me, telling me that Science was
a harsh mistress; and, in a pecuniary point of view, but
poorly rewarding those who devoted themselves to her service.
He smiled at my notion of the superior moral feelings of
philosophic men, and said he would leave me to the experience
of a few years to set me right on that matter.

Finally, through his good efforts I went to the Royal
Institution early in March of 1813, as assistant in the
Laboratory; and in October of the same year, went with him
abroad as his assistant in experiments and in writing. I
returned with him in April 1815, resumed my station in the
Royal Institution, and have, as you know, ever since remained
there.

I am, dear Sir, very truly yours,

M. FARADAY.

The following is a note of Sir H. Davy, alluded to in Mr. Faraday's letter:

TO MR. FARADAY.

SIR, December 24, 1812.

I am far from displeased with the proof you have given me
of your confidence, and which displays great zeal, power of
memory, and attention. I am obliged to go out of town, and
shall not be settled in town till the end of January: I will
then see you at any time you wish.

It would gratify me to be of any service to you. I wish it may
be in my power.

I am, Sir, your obedient humble servant,

H. DAVY.

I must now recall the reader's attention to the affair of the gunpowder manufactory, to which some allusion has been already made. It is far from my wish to intrude upon the public any account of a private transaction; but the circumstances to which I must refer are already well known, and I believe, moreover, that they have been the subject of misrepresentation.

The letters I shall introduce appear to me highly interesting; and by the warmth of feeling with which they repel the bare suspicion of his prostituting science to the acquisition of wealth, to develope a feature in his character too important to be omitted in a memoir of his life.

From the following letter, it would appear that Davy's alarms, with respect to his responsibilities, were first awakened by a sight of the labels, in which his name was introduced.[2]

[2] I am here bound to state, from a careful examination of all
the original documents, that his name was introduced in the very
words which he suggested, and which I have at this moment before
me in his own handwriting:--so differently, however, does the
same sentence strike the eye in print and in manuscript, that an
author frequently does not recognise his own composition.

TO JOHN GEORGE CHILDREN, ESQ.

MY DEAR CHILDREN, Rokeby, July -- 1813.

I am very sorry you did not come to Cobham, as the party was
very pleasant.

Your apparatus was magnificent, worthy an Imperial Institute:
there were some swine however for the pearls; at least, there
was one,--you cannot suppose I mean any other than----.

I have been much disturbed and vexed by enquiries respecting
the price of _my_ gunpowder, which from the labels I find is
supposed to be _sold_ by me. These labels must be altered, so
as to put in a clear point my relations to the manufacture;
and it must be understood by the public that I have given my
gratuitous assistance and advice only.

I have written to Mr. Burton by post, giving two forms. I shall
do you more good if these are adopted than I can now; and I
wish them to be adopted speedily, as it may otherwise get
abroad that I have nothing to do with the powder, and that my
name is used in a manner which does not meet my approbation.

In the labels in the windows, it should not be _under my
directions_, for this implies that I am a superintendent
in the manufactory; but it should be--"RAMHURST GUNPOWDER,
manufactured by Messrs. B. C. and Co. In the composition of
this powder, the proprietors have been assisted by the advice
and assistance of Sir H. Davy."

A fair statement will do the manufacture good. Misapprehension
will do it much harm.

I am now at Rokeby; we shall be in a few days at Braham Castle,
Lord Mackenzie's, near Dingwall, where we shall stay for a
week. After that we shall go to the Marquis of Stafford's,
Dunrobin, near Goldspie.

I am, my dear Children,

Very truly and affectionately yours,

H. DAVY.

TO THE SAME.

MY DEAR CHILDREN, Edinburgh, July 22.

I wrote to you from Rokeby. I expressed my feelings respecting
the gunpowder. I have been in extreme harass and anxiety from
the idea of the use of my name, without the proper explanation,
and I certainly expected that no use would have been made
of it without my sanction. I never saw the label for the
canister till it came to me upon one of them, and I immediately
expressed that I was not satisfied with it.

I told Mr. Burton expressly, that in all cases in which my name
was used it must be in my own way. He is now at the head of
your firm; but it is to _you_, and not to _him_, that I have
given, and shall give my assistance.

Every feeling of friendship and affection prompts my wishes to
be useful to you; I have not the same relations to Mr. Burton.

I am very sorry to give you any trouble on this business, but I
am sure you cannot wish me to remain in a state of anxiety; and
all the friends with whom I have consulted think it absolutely
necessary for my reputation, that, when my name is used, a
clear statement should be given of the true nature of the
connexion.

I think it will be more useful to you, and increase your
influence and power in the partnership, if my assistance is
stated as given to you, and to you only--in this way: "RAMHURST
GUNPOWDER, manufactured by Messrs. Burton, Children, and
Co. after an improved process, founded upon experiments and
investigations made by Sir H. Davy, and communicated by him to
Mr. J. G. Children, under whose immediate superintendence the
gunpowder is made."

I have fully made up my mind on this matter: and if you approve
of the above form, I will state it to be the only one to which
I will consent.

If the gunpowder is called Sir H. Davy's powder, it must be
stated in all cases where my name is used, that it is so called
in honour of my discoveries in chemistry, and because I have
given my gratuitous assistance in making the experiments and
investigations on which the process is founded.

I have resolved to make no profit of any thing connected with
science. I devote my life to the public in future, and I must
have it clearly understood, that I have no views of profit in
any thing I do. I am, my dear Children,

Very affectionately yours,

H. DAVY.

In subsequent letters, which it is not necessary to publish, Davy dwells upon the necessity of his engagements as a partner being legally cancelled, as he cannot endure the idea of his philosophical repose and usefulness being disturbed by the cares of business, or the trouble of litigation.

It is scarcely necessary to add, that all the parties concerned in this transaction most readily and cheerfully met Davy's wishes, all erroneous impressions were effaced, and the affair was adjusted amicably and satisfactorily; and he prepared to quit England with a mind relieved from all the fears and anxieties which had so unfortunately oppressed it.

* * * * *

After the Emperor of the French had sternly refused his passport to several of the most illustrious noblemen of England, it was scarcely to be expected that Sir H. Davy would have been allowed to travel through France, in order to visit the extinct volcanoes in Auvergne, and afterwards to examine that which was in a state of activity at Naples.

No sooner, however, had the discovery of the decomposition of the alkalies and earths, and its probable bearings upon the philosophy of volcanic action, been represented by the Imperial Institute to Napoleon, than, with a liberality worthy of the liberator of Dolomieu, and consistent with his well-known patronage of science, he immediately and unconditionally extended the required indulgence.

In consequence of this permission, Sir Humphry and Lady Davy, the former accompanied by Mr. Faraday as secretary and chemical assistant, and the latter by her own waiting-maid, quitted London on the 13th of October 1813, and proceeded to Plymouth; at which port they immediately embarked in a cartel for Morlaix in Brittany.

On landing in France, they were instantly arrested by the local authorities of the town, who very reasonably questioned the authenticity of their passports, believing it impossible that a party of English should, under any circumstances, have obtained permission to travel over the Continent, at a time when the only English in France were detained as prisoners. They were accordingly compelled to remain during a period of six or seven days at the town of Morlaix, until the necessary instructions could be received from Paris. As soon, however, as a satisfactory answer was returned, they were set at liberty; and they reached the French capital on the evening of the 27th of the same month.

Shortly after his arrival, Davy called upon his old friend and associate Mr. Underwood, who, although one of the _détenus_, had during the whole war enjoyed the indulgence of residing in the capital.

The expected arrival of Davy had been a subject of conversation with the French _savans_ for more than a month. Amongst those who were loudest in his praises, was M. Ampère, who had for several years frequently expressed his opinion that Davy was the greatest chemist that had ever appeared. Whether this flattering circumstance had been communicated to the English philosopher I have no means of ascertaining; but Mr. Underwood informs me that the very first wish that Davy expressed was to be introduced to this gentleman, whom he considered as the only chemist in Paris who had duly appreciated the value of his discoveries; an opinion which he afterwards took no care to conceal, and which occasioned amongst the _savans_ much surprise, and some dissatisfaction. M. Ampère, at the time of Davy's arrival, was spending the summer at a place a few miles from Paris, in consequence of which the introduction so much desired was necessarily delayed.

On the 30th he was conducted by Mr. Underwood to the Louvre. The English philosopher walked with a rapid step along the gallery, and, to the great astonishment and mortification of his friend and _cicerone_, did not direct his attention to a single painting; the only exclamation of surprise that escaped him was--"What an extraordinary collection of fine frames!"--On arriving opposite to Raphael's picture of the Transfiguration, Mr. Underwood could no longer suppress his surprise, and in a tone of enthusiasm he directed the attention of the philosopher to that most sublime production of art, and the chef d'oeuvre of the collection. Davy's reply was as laconic as it was chilling--"Indeed, I am glad I have seen it;" and then hurried forward, as if he were desirous of escaping from any critical remarks upon its excellencies.

They afterwards descended to view the statues in the lower apartments: here he displayed the same frigid indifference towards the higher works of art. A spectator of the scene might have well imagined that some mighty spell was in operation, by which the order of nature had been reversed:--while the marble glowed with more than human passion, the living man was colder than stone! The apathy, the total want of feeling he betrayed on having his attention directed to the Apollo Belvidere, the Laocoon, and the Venus de Medicis, was as inexplicable as it was provoking; but an exclamation of the most vivid surprise escaped him at the sight of an Antinous, treated in the Egyptian style, and sculptured in _Alabaster_.[3]--"Gracious powers," said he, "what a beautiful stalactite!"

[3] The celebrated Italian antiquary Visconti has so denominated
it.

What a strange--what a discordant anomaly in the construction of the human mind do these anecdotes unfold! We have here presented to us a philosopher, who, with the glowing fancy of a poet, is insensible to the divine beauties of the sister arts! Let the metaphysician, if he can, unravel the mystery,--the biographer has only to observe that the Muses could never have danced in chorus at his birth.

On the following morning, Mr. Underwood accompanied him to the Jardin des Plantes, and presented him to the venerable Vauquelin, who was the first scientific man he had seen in Paris. On their return they inspected the colossal Elephant which was intended to form a part of the fountain then erecting on the site of the Bastile. Davy appeared to be more delighted with this stupendous work than with any object he saw in Paris: to its architect, M. Alavair, he formed an immediate attachment. It has been observed that, during his residence in this city, his likes and dislikes to particular persons were violent, and that they were, apparently, not directed by any principle, but were the effect of sudden impulse.

In the course of removing the foundations, and in digging the canal, the subterranean dungeons of the Bastile were discovered; they were eight in number, and were called _Les Oubliettes_. As they were under the level of the ditch of the fortress, any attempt to escape from them by piercing the wall, must have inevitably drowned the unhappy prisoner together with all those who inhabited the contiguous cells; one of which was discovered with the entrance walled up. Upon demolishing this wall there appeared the skeleton of the last wretched person who had been thus entombed. In all these discoveries Davy took the warmest interest.

Upon the construction of the Elephant, he wrote a letter to M. Alavair, to which I am desirous of directing the attention of my scientific readers. It derives its peculiar interest from the opinion which he at that period entertained upon the subject of the excitement of Voltaic action by the contact of different metals.

TO M. ANTOINE ALAVAIR.

SIR, November 1813.

It will give me much pleasure if I can repay your civility to
me by offering any hints that may be useful in the execution of
the magnificent work constructing under your directions.

Ten parts of copper to one of tin is an excellent composition
for a work upon a great scale, nor do I believe any proportions
can be better.

There is no fear of any decay in the armatures, if they can be
preserved from the contact of moisture; but if exposed to air
and moisture, the presence of the bronze will materially assist
their decay. Wherever the iron is exposed to air, it should, if
possible, be covered with a thin layer of bronze. When the iron
touches the foundation of _lead_, it should in like manner be
covered either by lead or bronze. A contact between metals has
no effect of corrosion, unless a Voltaic circle is formed with
moisture, and then the most oxidable metal corrodes; and iron
corrodes rapidly both with lead and bronze.

The cement which will probably be found the most durable will
be lime, fine sand, and scoria of iron. The materials should be
very fine and intimately mixed. The ancients always made their
cements for great works some months before they were used. I
have the honour to be, Sir, with much consideration,

Your obedient humble servant,

H. DAVY.

Davy took up his abode at the Hotel des Princes, Rue Richelieu; whither the principal _savans_ of Paris hastened to pay their respects; which they did with an alacrity and cheerfulness equalled only by the courtesy of manner with which they expressed their congratulations.

On the 2nd of November, Davy attended the First Class of the Institute, and was placed on the right hand of the President, who on taking the chair announced to the meeting that it was honoured by the presence of "Le Chevalier Davy."

While Davy was at the meeting of the Institute, a curious adventure occurred to Lady Davy, the relation of which, by showing the state of surveillance in which the citizens of Paris were held at that period, will enable us to appreciate the extent of the obligation conferred upon Sir Humphry by the Emperor.

Her Ladyship, attended by her maid, had walked into the Thuilleries' Garden. She wore a very small hat, of a simple cockle-shell form, such as was fashionable at that time in London; while the Parisian ladies wore bonnets of most voluminous dimensions. It happened to be a saint's day, on which, the shops being closed, the citizens repaired in crowds to the garden. On seeing the diminutive bonnet of Lady Davy, the Parisians felt little less surprise than did the inhabitants of Brobdignag on beholding the hat of Gulliver; and a crowd of persons soon assembled around the unknown exotic; in consequence of which, one of the inspectors of the garden immediately presented himself, and informed her Ladyship that no cause of '_rassemblement_' could be suffered, and therefore requested her to retire. Some officers of the Imperial Guard, to whom she appealed, replied, that, however much they might regret the circumstance, they were unable to afford her any redress, as the order was peremptory. She then requested that they would conduct her to her carriage; an officer immediately offered his arm, but the crowd had by this time so greatly increased, that it became necessary to send for a corporal's guard; and the party quitted the garden, surrounded by fixed bayonets.

November 3rd, Humboldt and Gay-Lussac paid their first visit of compliment to Davy.

5th.--M. Ampère, who came to Paris expressly for the occasion, was introduced to Davy by Mr. Underwood, and the two philosophers appeared equally delighted with each other. Some years afterwards, however, this feeling of friendly regard, on the part of Davy, was turned into one of bitter aversion, in consequence, as it has been supposed, of certain perfidious insinuations, by which some of the _savans_, instigated by feelings of jealousy, had contrived to prejudice his mind; and which even led him to exert all his efforts to oppose the election of Ampère as a foreign member of the Royal Society.

After Ampère's visit, Mr. Underwood accompanied Sir H. and his lady to the Imperial Library in the Rue Richelieu, and afterwards to the Cathedral of Notre Dame, where they inspected the crown and imperial regalia. The splendour of the coronation mantle of Napoleon may be imagined, when it is stated that its weight exceeded eighty pounds, and that it was lined with the skins of six thousand ermines.

6th.--They visited the Museum of French Monuments, in the Rue des Petits Augustines, which contained the tombs and sculptured ornaments preserved from the churches that were demolished during the Revolution. This interesting collection, shortly after the restoration of the Bourbons, was dispersed. It is a singular fact, that Davy expressed more admiration at this inferior exhibition of art, than he did at that of the Greek and Roman statues in the Museum of the Louvre. Whether his taste had been vitiated by the inspection of less perfect models in his earlier days, is a question which I shall leave more competent judges to decide.

10th.--They dined with Count Rumford at Auteuil, who showed his laboratory to Davy: this was exactly eight months before the poor brokenhearted Count sank into the grave, the victim of domestic torment, and of the persecutions of the French _savans_, instigated by his wife, the widow of the celebrated Lavoisier.

13th.--The anniversary dinner of the Philomatic Society took place on this day, at a restaurateur's in the Rue St. Honoré; M. Dumeril in the chair. Although it was very unusual to invite any stranger upon this occasion, Sir H. Davy and his English friend were requested to favour the company by their presence. Thirty-three members were in attendance, amongst whom were Ampère, Brogniart, Cuvier, Chevreuil, Dulong, Gay-Lussac, Humboldt, Thénard, &c.

At this dinner various complimentary toasts were proposed: and first, the Royal Society of London, for which Davy having returned thanks, gave the Imperial Institute. The Linnæan Society of London, and the Royal Society of Berlin, were given in succession. But the circumstance which evinced the greatest feeling and delicacy towards their English guest, was the company's declining to drink the health of the Emperor. It placed their personal safety even in some jeopardy; and not a little apprehension was afterwards felt as to how far Napoleon might resent such a mark of disrespect, for seven-eighths of the members present were placemen.

November 17th.--Mr. Underwood states that on this day he met Humboldt at dinner at Davy's hotel; and he adds--"I do not know whether you are aware that Sir Humphry had a superstitious dislike at seeing a knife and fork placed crosswise on a plate at dinner, or upon any other occasion; but I can assure you that such was the fact; and when it occurred in the company of his intimate friends, he always requested that they might be displaced; whenever this could not be done, he was evidently very uncomfortable."[4]

[4] I repeat this as I received it: from my own personal
knowledge I can neither confirm nor refute it; although I
am inclined to believe that Davy was tinged with a degree
of superstitious feeling, or a certain undefined species
of credulity, which shelters itself under the acknowledged
inadequacy of human reason to connect causes with effects.

At about this period, but I am unable to ascertain the particular day, the junior Chemists, with Thénard as their leader, gave Davy a sumptuous dinner at one of the most celebrated restaurateurs in Paris. The following persons formed a committee for that purpose: Gay-Lussac, Thénard, Dulong, Chevreul, Laugier, Robiquet, and Clement. As it was by the chemists only that this dinner was given, neither Arago nor Ampère was included; but Berthollet, Chaptal, and Vauquelin were invited.

On the morning of the 23rd of November,[5] M. Ampère called upon Davy, and placed in his hands a small portion of a substance which he had received from M. Clement; and, although it had been in the possession of the French chemists for more than twelve months, so entirely ignorant were they of its true nature and composition, that it was constantly spoken of amongst themselves as X, the _unknown_ body.

[5] The date of this event is important; and Mr. Faraday, in
referring to his Journal, finds it to be correctly stated.

How far the suggestions of Davy led to the discovery of the chemical nature of this interesting substance, which has been since distinguished by the name of _Iodine_, is a question which has given rise to much discussion on the Continent. It has been moreover questioned, how far the love of science, and the fervour of emulation, can justify the interference which Davy is said to have displayed upon the occasion. He is accused of having unfairly taken the subject out of the hands of those who were engaged in its investigation, and to have anticipated their results.

As his biographer, I feel that it is not only due to the character of Davy, but essential to the history of Science, that these questions should be impartially examined; and I have spared no pains in collecting facts for their elucidation. Mr. Underwood, who was in the constant habit of associating with the parties concerned in the enquiry, has furnished me with some important particulars, and his testimony is fortified by published documents.

The substance under dispute was accidentally discovered by M. Courtois, a manufacturer of saltpetre at Paris, but kept secret by him for several years; at length, however, he communicated it to M. Clement, who made several experiments on it, but without any favourable result. On the 23rd of August 1813, Clement exhibited to Mr. Underwood the beautiful experiment of raising it into a violet-coloured vapour, and that gentleman assures me that this was the only peculiar property which had at that time been recognised as distinguishing it. A few days previous to this event, M. Ampère had received a specimen of the substance, which he had carefully folded up in paper, and deposited in his pocket, but on arriving at home, and opening the packet, he was surprised to find that his treasure had vanished. Clement, however, furnished him with another supply, and it was this parcel that Ampère transferred into the hands of Davy; and "for which," says Mr. Underwood, "he told me a few days ago, that Thénard and Gay-Lussac were extremely angry with him."

The first opinion which the French chemists entertained respecting the nature of Iodine, was that it was either a compound of muriatic acid, or of chlorine, since it formed with silver what appeared to be a muriate, or a chloride of that metal; but Davy at once observed that the substance so produced blackened too quickly in the sun to justify that opinion. He, however, determined to submit it to a more rigorous examination; and during the latter part of November he worked upon it at his hotel with his own apparatus, and on the 3rd of December in the laboratory of M. Chevreul, at the Jardin des Plantes, with whom, it may be stated in passing, he perhaps formed a stricter intimacy than with any other chemist during his sojourn in Paris. Chevreul, however, be it known, was a brother of the angle; and I understand that he still preserves, as sacred trophies, some artificial flies with which Davy had supplied him.

Having pointed out the channel through which Iodine first fell into the hands of Davy, let us pursue its history. The first public notice of its existence was read by Clement at the Institute, on the 29th of November 1813. At the meeting of the 6th of December, Gay-Lussac, who had only received some 'X' a few days previous to this date, presented a short note, in which he gave the name of _Iode_ to the body, and threw out a hint as to its great analogy to chlorine, while he stated that two hypotheses might be formed as to its nature, that it might be considered as a simple substance, or as a compound of oxygen. On the 13th of the same month, a letter addressed to M. le Chevalier Cuvier, and dated December 11th, was read from Davy to the Institute, in which he offered a general view of its chemical nature and relations;[6] and on the 20th of January 1814, he communicated to the Royal Society of London, a long and elaborate paper, dated Paris, December 10, 1813, and entitled, "Some Experiments and Observations on a new Substance, which becomes a violet-coloured gas by Heat." In this paper, while the author assigned to Gay-Lussac all the credit to which his communication of the 6th of December may be supposed to entitle him, he evidently felt that some explanation was due to the chemical world for his having pursued the enquiry. "M. Gay-Lussac," he observes, "is still engaged in experiments on this subject, and from his activity and great sagacity, a complete chemical history of it may be anticipated. But as the mode of procuring the substance is now known to the chemical world in general, and as the combinations and agencies of it offer an extensive field for enquiry, and will probably occupy the attention of many persons; and as the investigation of it is not pursued by the discoverer himself, nor particularly by the gentlemen to whom it was first communicated, I shall not hesitate to lay before the Royal Society an account of the investigations I have made upon it; and I do this with the less scruple, as my particular manner of viewing the phenomena has led me to some new results, which probably will not be considered by the Society as without interest in their relation to the general theory of chemistry, and in their possible application to some of the useful arts."

[6] See _Annales de Chimie_, tome 88, p. 322. It appears from Mr.
Faraday's Journal, that he worked upon Iodine with a borrowed
Voltaic pile, at his hotel, on the morning of the 11th; and the
results of his experiments are described at the conclusion of the
above letter.

It was not until August 1814, that Gay-Lussac read his paper on the subject, which was subsequently published in the _Annales de Chimie_.

After the above short, but I trust honest statement, can any reasonable doubt exist, that, if Davy had not visited Paris, Iodine would have remained at the end of the year 1814, as it had been for two preceding years--the unknown X?

In a communication published in the first volume of the Royal Institution Journal, Davy offers the following observations upon this subject: "With regard to Iodine, the first I had of it was from M. Ampère, who, before I had seen the substance, supposed that it might contain a new supporter of combustion.

"Who had most share in developing the chemical history of that body, must be determined by a review of the papers that have been published upon it, and by an examination of their respective dates. When M. Clement showed Iodine to me, he believed that the hydriodic acid was muriatic acid; and M. Gay-Lussac, after his early experiments, made originally with M. Clement, formed the same opinion, and _maintained_ it, when I _first_ stated to him my belief that it was a new and peculiar acid, and that Iodine was a substance analogous in its chemical relations to Chlorine."

I was very desirous of ascertaining the feeling which at present prevails amongst the French chemists upon this subject; and I therefore requested Mr. Underwood to make such enquiries as might elicit the required information. In a letter from that gentleman, dated "Paris, August 22, 1830," he says, "Though Thénard and Gay-Lussac retain great bitterness of feeling towards Davy, on account of the affair of Iodine, Chevreul and Ampère are still, as they ever were, of opinion, that such a feeling has its origin in a misconception; that what Davy did, was from the honest desire of promoting science, and not from any wish to detract from the merit of the French chemists."

During his visit to Paris, Davy was not introduced to the Emperor. Lady Davy observed to me, that, although Sir Humphry felt justly grateful for the indulgence granted to him as a Philosopher, he never, for a moment, forgot the duty he owed his country as a Patriot; and that he objected to attend the levee of her bitterest enemy. On the other hand, it is said that Napoleon never expressed any wish to receive the English chemist; and those who seek in the depths for that which floats upon the surface, have racked their imaginations in order to discover the source of this mysterious indifference; but I apprehend that we have only to revert to the political state of Europe in the year 1813, and the problem will be solved.

Amongst the reasons for supposing that the Emperor must have felt ill disposed towards the English philosopher, the following story has been told; which, as an anecdote, is sufficiently amusing; and I can state upon the highest authority, that it is moreover perfectly true.

It is well known that Bonaparte, during his whole career, was in the habit of personal intercourse with the _savans_ of Paris, and that he not unfrequently attended the sittings of the Institute. Upon being informed of the decomposition of the alkalies, he asked, with some impetuosity, how it happened that the discovery had not been made in France?--"We have never constructed a Voltaic battery of sufficient power," was the answer. "Then," exclaimed Bonaparte, "let one be instantly formed, without any regard to cost or labour."

The command of the Emperor was of course obeyed; and, on being informed that it was in full action, he repaired to the laboratory to witness its powers; on his alluding to the taste produced by the contact of two metals, with that rapidity which characterised all his motions, and before the attendants could interpose any precaution, he thrust the extreme wires of the battery under his tongue, and received a shock which nearly deprived him of sensation. After recovering from its effects, he quitted the laboratory without making any remark, and was never afterwards heard to refer to the subject.

It is only an act of justice to state that Davy, during his residence in the French capital, so far from truckling to French politics, never lost an opportunity of vindicating with temper the cause of his own country. At the Théâtre de la Porte Saint Martin, a melodrame was got up, with the avowed intention of exposing the English character to the execration of the audience. Lord Cornwallis was represented as the merciless assassin of the children of Tippoo Saib. Davy was highly incensed at the injustice of the representation, and abruptly quitted the theatre in a state of great indignation.

Whatever objections might have existed in his mind, as to his attending a levee of the Emperor, they did not operate in preventing his being presented to the Empress at Malmaison; but he could not be prevailed upon to appear upon that occasion, in any other than a morning dress; and it was not until after repeated entreaty, and the assurance that he would not be admitted into the _Salle de reception_, that he consented to exchange a pair of half-boots that laced in front, and came over the lower part of his pantaloons, for black silk stockings and shoes. His constant answer to the remonstrances of his friends was, "I shall go in the same dress to Malmaison as that in which I called upon the Prince Regent at Carlton House."

The introduction of Sir Humphry and Lady Davy to the Empress Josephine, took place at Malmaison on the 30th of November. The only English present were, the Earl of Beverley, a _détenue_; General Sir Edward Paget, a prisoner of war, taken in Spain, and Mr. Underwood; and it was the first levee at which any of our countrymen had been introduced, with the exception of Mr. Underwood, who had been frequently in the habit of paying his court to the Empress, and to whom, indeed, he was indebted for those indulgences which have been already mentioned.

The persons present having arranged themselves in a semicircle, the Empress entered the _Salle de reception_, and in her usual gracious manner addressed each individual. After this court ceremony, her Majesty retired, having previously signified to a select few, her desire that they should follow her into the private apartment.

In the Boudoir, the conversation became general, and turned upon certain works of art; and upon Lady Davy expressing, in very florid terms, her admiration of some beautifully embellished cups of Porcelain, which were stationed on the mantelpiece, her Majesty, with that good-nature which ever distinguished her, immediately presented her with a specimen.

The Empress then proposed that Lady Davy should on this occasion visit her conservatories, upon which it is well known she had lavished large sums, and was ambitious to be thought to possess all that was rare and curious. Lady Davy having expressed some apprehensions as to the coldness of the day, and appearing to be but thinly clad, one of the Dames du Palais was commanded to provide cloaks; and in a short time, Mr. Underwood says, a _mountain_ of the most costly and magnificent furs, that probably ever appeared even in a Regal Palace, were displayed before her; the splendid trophies, we may conclude, of the Royal conciliation at Tilsit.

It was on the 13th of December 1813, that Davy was elected a corresponding member of the First Class of the Imperial Institute; there were forty-eight members present, and he had forty-seven votes: Guyton de Morveau being the only person who opposed his election.

Nothing ever exceeded the liberality and unaffected kindness and attention with which the _savans_ of France had received and caressed the English philosopher. Their conduct was the triumph of Science over national animosity,--a homage to genius, alike honourable to those who bestowed, and to him who received it; and it would be an act of ingratitude, a violation of historical justice, on the part of the English biographer, did he omit to express the pride and admiration with which every philosopher in his country continues to regard it. It would have been fortunate for the cause of Science, and fortunate for the historian, could he have terminated the subject with these remarks; but the biographer has an act of justice to perform, which he must not suffer his friendship to evade, nor his partialities to compromise.[7]

[7] In offering these observations, the reader may readily
suppose it has not been without much pain that I have made this
sacrifice of personal feeling to principle. I am, however, bound
to observe, that Sir Humphry's sentiments towards France for the
liberal indulgence granted to him were both grateful and kindly;
and so strongly does Lady Davy participate in that feeling, that
I perhaps owe it to her to state that neither her Ladyship's
journals or information have been used upon this occasion.

It would be an act of literary dishonesty to assert that Sir H. Davy returned the kindness of the _savans_ of France, in a manner which the friends of Science could have expected and desired. There was a flippancy in his manner, a superciliousness and hauteur in his deportment, which surprised as much as they offended. Whatever opinions he might have formed as to the talents of the leading chemists, it was weakness to betray, and arrogance to avow them.

He had, by a single blow, fatally mutilated the system which was the pride and glory of their nation: it was ungenerous to remind them of his triumph. It required but little tact to have reconciled the French philosophers to the revolution he had effected; but, unfortunately, that cannot be said of Davy, which was so wittily observed of Voltaire,--that if he trod upon the toes of their prejudices, he touched his hat at the same time: even the affair of Iodine, had it been skilfully managed, would never have left an angry feeling. It was not his success, but the manner in which he spoke of it, that rendered it so offensive. He should have acted according to the judicious advice given to a member of the clerical profession, upon his consulting a friend as to the propriety of continuing his field-sports, should he become a dignitary of the Church--"You may hunt, but you must not holla."

It may be supposed that the unguarded conduct of Davy reached the ear of the Emperor; for in a conversation with one of the leading members of the Institute, Napoleon took occasion to observe, that he understood the young English chemist held them all in low estimation.

Having thus candidly avowed the errors of Davy, I may be justified in claiming from the reader his confidence in the sincerity with which I shall attempt to palliate them. From my personal knowledge of his character, I am inclined to refer much of that unfortunate manner, which has been considered as the expression of a haughty consciousness of superiority, to the desire of concealing a _mauvaise honte_ and _gaucherie_--an ungraceful timidity, which he could never conquer. The bashful man, if he possess strong passions, will frequently force himself into a state of effrontery, by a violence of effort which passes amongst ordinary observers for the sallies of pride, or the ebullitions of temper; whereas if, on the contrary, his temperament be cold and passionless, he will exhibit traits of the most painful reserve. This proposition cannot, perhaps, be more forcibly illustrated than by a comparison of the manners of Davy and Cavendish, whose temperaments were certainly as much opposed to each other as fire is to ice: the latter, however, was shy and bashful, to a degree bordering upon disease; and nothing so much distressed him as an introduction to strangers, or as his being pointed out as a person distinguished in science. On one of the Sunday evening _soirées_ of Sir Joseph Banks, he happened to be conversing with his friend Mr. Hatchett, when Dr. Ingenhouz, who was rather remarkable for pomposity of manner, approached him with an Austrian gentleman in his hand, and introduced him formally to Mr. Cavendish. He recounted the titles and qualifications of his foreign friend at great length, and concluded by saying, that he had been particularly anxious to be introduced to a philosopher so universally celebrated throughout Europe as Mr. Cavendish. As soon as Dr. Ingenhouz had finished, the Austrian gentleman began; he assured Mr. Cavendish that one of his principal inducements in coming to London, was to see and converse with one whom he considered the most distinguished chemist of the age. To all these high-flown addresses, Mr. Cavendish answered not a single word, but stood with his eyes cast down upon the floor, in a state of the most painful confusion. At length, espying an opening in the crowd, he darted through it with all the speed he could command, and never stopped until he reached his carriage, which immediately drove him home.

From the same cause, probably, arose Davy's inattention and carelessness in those little observances of etiquette, which many may treat as empty and unmeaning ceremonials, but which the members of a polished community regard as the delicate expressions of feeling, and the language of sentiment.

It is said, that on conversing in the chamber of the Institute, he received one of its most distinguished and venerable members, who approached him with the air of salutation, without rising from his seat; a circumstance perhaps in itself of very trifling importance, but it was considered as a mark of disrespect, which is not readily forgiven, when a spirit of rivalry may be supposed to sharpen the affront. It will be remembered that Cæsar might date his loss of popularity to the fact of his having received the Senate while sitting in the porch of the temple of Venus, and that it formed one of the chief pretences of those who organised the conspiracy against his person.

There were, besides, other sources of unpopularity, which we are bound in fairness and candour to impute to the excellencies, rather than to the defects, of his character. If we believe with Johnson, that men have sometimes gained reputation from their foibles, we may certainly admit the converse of the proposition, that they have occasionally lost it from their virtues. Davy, as we have seen, possessed from his earliest years a frankness of disposition which endeared him to all his friends, but in after life it unquestionably exposed him to various annoyances, which by a little reserve he would have certainly escaped. It is quite surprising how much a little mystery, judiciously managed, will achieve. Seven veils converted the fragment of a tile, ploughed up in the neighbourhood of Florence, into an object of awful devotion.[8]

[8] Gray's Letters.

Although it must be admitted that our philosopher lost some popularity during his visit to the French metropolis, the _savans_ did not the less respect his talents, or admire his discoveries. They appear to have been impressed with the same sentiment as that which animated Voltaire, when he asked whether the discovery of Racine's weakness made the part of Phædra less admirable.

M. Dumas, who is certainly by no means distinguished for the readiness with which he is disposed to pay homage to British talent, has declared that Davy was the greatest chemical genius that ever appeared.

In fact, the more the researches of this great experimentalist are studied, the more they must be admired: every attempt to depreciate their intrinsic importance will only serve to display their exalted merits; every attempt to falsify their results will only tend to demonstrate their accuracy. It is by an elaborate examination only, that the full evidence of their truth can be displayed; there are points which the keen eye of genius will discern, that are invisible to a grosser sense: the coldness of criticism then will only make them glow the brighter; like his own potassium, the contact even of ice, so far from extinguishing, will light them up in splendour.

Sir Humphry left Paris on the morning of the 29th of December, and proceeded by the way of Lyons to Montpellier, where he remained for a month, and became acquainted with M. BERARD, who afterwards filled the chemical chair in that university, and in whose laboratory he worked upon the subject of Iodine, and examined many of the marine productions of the Mediterranean, with the view of determining whether they contained that body. M. Berard directed a considerable quantity of the species of _Ulva_, which abounds on the coast of Languedoc, to be burnt for him; and although the ashes consisted for the most part of common salt, he obtained traces of Iodine in the lixivium. From the general results of his experiments, however, he concludes, that the ashes of the _fuci_ and _ulvæ_ of the Mediterranean afford it in much smaller quantities than the sea-weed, from which soda is procured; and it was only in a very few instances that he could derive any evidence of its existence. In the ashes of the corallines and sponges, he could not obtain the slightest indication of its presence. During this period he also extended his enquiries respecting the chemical agencies of Iodine, and the properties of several of its compounds, especially of those in which he believed it to exist in triple combination with alkalies and oxygen, and for which he proposed the name of _Oxy-iodes_.[9]

[9] These are the _Iodates_ of the present day; but Davy, it
would seem, resisted the conviction of Iodic acid being an
_oxy-acid_, upon the same grounds that he opposed the views of M.
Gay-Lussac with regard to the nature of Chloric acid.

While at Montpellier, Davy witnessed the procession of the Pope on his return to Rome. His Holiness appeared in a state of great humiliation, and, on being supplicated by a poor woman to cure her child, he replied, that she must propitiate Heaven by her prayers, for that he was himself a mere mortal, without power to heal or to save.

He quitted Montpellier on the 7th of February, and, accompanied by M. Berard, visited the fountain of Vaucluse; he afterwards continued his route to Nice, crossed the Col de Tende, to Turin, and arrived at Genoa on the 25th of February; from which place the following letter is dated.

TO MR. UNDERWOOD.

MY DEAR UNDERWOOD, Genoa, March 4.

I have not received the letter you announced to me in the
street, concerning Ampère's note, nor any others since I left
Paris. The note came to me through the Prefect of Nice, with an
indorsement by M. Degerand.

I crossed the Alps by the Col de Tende, stayed at Turin three
days, and came here through snow and ice, over the Bochetta,
where I have been waiting for a fair wind for Tuscany. We have
had no impediments except from the snow and the east winds.

If you can hear any thing of the destination of the letters
I have twice missed, I shall thank you to let me know by
addressing me at Rome at the _Posta_. I shall be most happy
to hear some news of you here, and shall always feel a lively
interest in your plans, and in your welfare.

I have been making some experiments here on the Torpedo, but
without any decisive results; the coldness of the weather
renders the powers of the animal feeble; I hope, however, to
resume them at Naples.

Tell M. Ampère, I hope he will not give up the subject of the
laws of the combination of gaseous bodies, which is so worthy
of being illustrated by his talents, and which offers such
ample scope for his mathematical powers, united as they are
with chemical knowledge:--tell him also that I hope he will
sometimes write to me, and that I shall always remember with
pleasure the hours I have passed in his society.

Pray tell me that you are well; and remember me to all that are
interested in me. My wife desires her kind remembrances. I am,
my dear Underwood,

Your very sincere friend,

H. DAVY.

Besides researches on the Torpedo, Davy made farther experiments on the ashes of Sea-weed, which were collected for him by Professor VIVIANI, of Genoa.

He left Genoa by water on the 13th, and arrived at Florence on the 16th of March. Here he worked in the laboratory of the Academia del Cimento, on Iodine; but more particularly on the combustion of the Diamond. The experiments on this latter body were performed by means of the great lens in the cabinet of Natural History; the same instrument as that employed in the first trials on the action of the solar heat on the diamond, instituted by Cosmo III. Grand Duke of Tuscany: upon this occasion, he was assisted by COUNT BARDI, the Director, and SIGNIOR GAZZARI, the Professor of Chemistry at the Florentine Museum.

I have been informed that the hasty, and apparently careless manner in which he conducted his experiments, and which has been already noticed[10] as being characteristic of his style of manipulation, greatly astonished the philosophers of Florence, and even excited their alarm for the safety of the lens, which on all occasions had been used by them with such fastidious caution and delicacy.

[10] Vol. i. p. 144.