FRIENDS OF BOULTON AND WATT--THE LUNAR SOCIETY.
As men are known by the friends they make and the books they read, as well
as by the recreations and pursuits of their leisure hours, it will help
us to an appreciation of the characters of Boulton and Watt if we glance
briefly at the social life of Soho during the period we have thus rapidly
passed under review.
Boulton was of a thoroughly social disposition, and made friends wherever
he went. He was a favourite alike with children and philosophers, with
princely visitors at Soho, and with quiet Quakers in Cornwall. When at
home, he took pleasure in gathering about him persons of kindred tastes
and pursuits, in order at the same time to enjoy their friendship, and to
cultivate his nature by intercourse with minds of the highest culture.
Hence the friendships which he early formed for Benjamin Franklin, Dr.
Small, Dr. Darwin, Josiah Wedgwood, Thomas Day, Lovell Edgeworth, and
others equally eminent; out of which eventually grew the famous Lunar
Society.
Towards the close of last century, there were many little clubs or
coteries of scientific and literary men established in the provinces,
the like of which do not now exist,--probably because the communication
with the metropolis is so much easier, and because London more than ever
absorbs the active intelligence of England, especially in the higher
departments of science, art, and literature. The provincial coteries of
which we speak, were usually centres of the best and most intelligent
society of their neighbourhoods, and were for the most part distinguished
by an active and liberal spirit of inquiry. Leading minds attracted
others of like tastes and pursuits, and social circles were formed which
proved in many instances the source of great intellectual activity as
well as enjoyment. At Liverpool, Roscoe and Currie were the centres of
one such group; at Warrington, Aikin, Enfield, and Priestley, of another;
at Bristol, Dr. Beddoes and Humphry Davy of a third; and at Norwich, the
Taylors and Martineaus of a fourth. But perhaps the most distinguished of
these provincial societies was that at Birmingham, of which Boulton and
Watt were among the most prominent members.
From an early period, the idea of a society, meeting by turns at each
other’s houses, seems to have been entertained by Boulton. It was probably
suggested in the first place by his friend Dr. Small. The object of the
proposed Society was to be at the same time friendly and scientific.
The members were to exchange views with each other on topics relating to
literature, art, and science; each contributing his quota of entertainment
and instruction. The meetings were appointed to be held monthly at the
full of the moon, to enable distant members to drive home by moonlight;
and this was the more necessary as some of them--such as Darwin and
Wedgwood--lived at a considerable distance from Birmingham.
When Watt visited Soho in 1768, on his way home from London to Glasgow,
some of the members of the Society--Dr. Small, Dr. Darwin, and Mr.
Keir--were invited to meet him at _l’hôtel de l’amitié sur Handsworth
Heath_, as Boulton styled his hospitable mansion. The Society must,
however, have been in a somewhat undefined state at even a considerably
later period, as we find Boulton writing to Watt in 1776, after the
latter had settled in Birmingham, “Pray remember that the celebration of
the third full moon will be on Saturday, March 3rd. Darwin and Keir will
both be at Soho. I then propose to submit many motions to the members
respecting new laws and regulations, such as will tend to prevent the
decline of a Society which I hope will be lasting.” The principal members,
besides those above named, were Thomas Day, R. Lovell Edgeworth, Samuel
Galton, Dr. Withering, Baskerville the printer, Dr. Priestley, and James
Watt. Each member was at liberty to bring a friend with him, and thus
many visitors of distinction were present at the meetings of the Society,
amongst whom may be named Mr. Smeaton, Dr. Parr, Sir Joseph Banks,
Sir William Herschel, Dr. Solander, De Luc, Dr. Camper, and occasional
scientific foreigners.
Dr. Darwin was regarded as the patriarch of the Society. His fame as a
doctor, philosopher, and poet, was great throughout the Midland Counties.
He was extremely speculative in all directions, even in such matters as
driving wheel-carriages by steam,--also a favourite subject of speculation
with Mr. Edgeworth.[292] Dr. Darwin’s time, however, was so much engrossed
by his practice at Lichfield, that he was not very regular in his
attendance at the meetings, but would excuse himself for his absence by
such a letter as the following:--
“DEAR BOULTON,--I am sorry the infernal divinities who visit
mankind with diseases, and are therefore at perpetual war with
Doctors, should have prevented my seeing all your great men at
Soho to-day. Lord! what inventions, what wit, what rhetoric,
metaphysical, mechanical, and pyrotechnical, will be on the wing,
bandied like a shuttlecock from one to another of your troop
of philosophers! while poor I, I by myself I, imprison’d in a
postchaise, am joggled, and jostled, and bump’d, and bruised
along the King’s high-road, to make war upon a stomach-ache or a
fever!”[293]
[292] As early as August, 1768, we find Dr. Small in one of
his letters describing Edgeworth to Watt as “a gentleman of
fortune, young, mechanical, and indefatigable, who has taken a
resolution to move land and water carriages by steam, and has
made considerable progress in the short space of time that he
has devoted to the study.”
[293] Dr. Darwin to Boulton, April 5, 1778. When the Doctor
removed to Derby in 1782, he wrote,--“I am here cut off from
the milk of science, which flows in such redundant streams
from your learned Lunatics, and which, I can assure you, is a
very great regret to me.” In another letter he said,--“I hope
philosophy and fire-engines continue to go on well. You heard
we sent your Society an air-balloon, which was calculated to
have fallen in your garden at Soho; but the wicked wind carried
it to Sir Edward Littleton’s. Pray give my compliments to
your learned Society.” In another letter he wrote,--“I hope
Behemoth has strength in his loins. Belial and Ashtaroth are
two other devils of consequence, and good names for engines of
Fire.” When he heard of the Albion Mill being burnt down, the
Doctor wrote,--“The conflagration of the Albion Mill grieved me
sincerely, both as it was a grand and successful effort of human
art, and also because I fear you were a considerable sufferer
by it. I well remember poor old Mr. Seward comparing the
Immortality of the Soul (in a devout sermon) to a fire-engine.
He might now have made it a type of the mortality of this world,
and the conflagration of all things.”
While Dr. Darwin and Mr. Edgeworth were amongst the oldest members of the
Society, Dr. Priestley, the discoverer of oxygen and other gases, was one
of the most recent. We find Boulton corresponding with him in 1775,[294]
principally on chemical subjects, and supplying him with parcels of
fluor spar for purposes of experiment. Five years later, in 1780, he was
appointed minister of the Presbyterian Congregation assembling in the New
Meeting-house, Birmingham; and from that time forward he was one of the
most active members of the Lunar Society, by whom he was regarded as a
great acquisition.
[294] In a letter from Priestley to Boulton, dated London, 6th
November, 1775, he wrote,--“I shall not quarrel with you on
account of our different sentiments in politics. When I tell you
what is fact, that the Americans have constructed a cannon on
a new principle, by which they can hit a mark at a distance of
a mile, you will say their ingenuity has come in aid of their
cowardice! I would tell you the principle of it, but that I am
afraid it would set your superior ingenuity to improve upon it
for the use of their enemies.” From Boulton’s memoranda-books
we find that the subject of improved artillery had occupied his
attention some ten years before.
Dr. Priestley was a man of extraordinary gifts and accomplishments. He
had mastered many languages before he was twenty years old. He was well
versed in mechanical philosophy and metaphysics, a skilled dialectician,
and the most expert chemist of his time. Possessed by an irrepressible
activity and untiring perseverance, he became an enthusiast on whatever
subject he undertook, whether it was an inquiry into history, theology,
or science. He himself likened experimental philosophy to hunting, and
in his case it was the _pursuit_ of facts that mainly concerned him.
He was cheerful, hopeful, and buoyant; possessed of a most juvenile
temperament; happiest when fullest of work; ranging from subject to
subject with extraordinary versatility; laying aside metaphysics to
pursue experiments in electricity, next taking up history and politics,
and resting from these to experiment on gases,--all the while carrying
on some public controversy on a disputed point in religion or politics.
For it is a curious fact; that gentle, affectionate, and amiable though
Priestley was,--devout in temperament, and single-minded in the pursuit of
truth,[295]--he was almost constantly involved in paper wars. He described
himself, and truly, as “one of the happiest of men;” yet wherever he
went, in England or America, he stirred up controversy and exasperated
opponents, seeming to be the very Ishmael of polemics.
[Illustration: DR. PRIESTLEY.]
At the time when he settled at Birmingham, Priestley was actively engaged
in prosecuting inquiries into the constitution of bodies. He had been
occupied for several years before in making investigations as to the
gases. The discovery of carbonic acid gas by Dr. Black of Edinburgh, had
attracted his attention; and, living conveniently near to a brewery at
Leeds, where he then was, he proceeded to make experiments on the fixed
air or carbonic acid gas evolved during fermentation. From these he went
on to other experiments, making use of the rudest apparatus,--phials,
tobacco-pipes, kitchen utensils, a few glass tubes, and an old gun-barrel.
The pursuit was a source of constant pleasure to him. He had entered
upon an almost unexplored field of science. Then was the childhood of
chemistry, and he gazed with large-eyed wonder at the marvels which his
investigations brought to light. He had no teacher to guide him--nothing
but experiment; and he experimented constantly, carefully noting the
results. Observation of facts was his great object; the interpretation
of the facts he left to others. Such was Priestley, and such were his
pursuits, when he settled at Birmingham in 1780.
[295] Mrs. Schimmelpenninck, who had no sympathy for Dr.
Priestley’s religious views, nevertheless bears eloquent
testimony to the beauty of his character. She speaks of him as
“a man of admirable simplicity, gentleness, and kindness of
heart, united with great acuteness of intellect. I can never
forget,” she says, “the impression produced on me by the serene
expression of his countenance. He, indeed, seemed ever present
with God by recollection, and with man by cheerfulness....
A sharp and acute intellectual perception, often a pointed,
perhaps a playful expression, was combined in him with a most
loving heart.... Dr. Priestley always spent part of every
day in devotional exercises and contemplation; and unless the
railroad has spoilt it, there yet remains at Dawlish a deep and
beautiful cavern, since known by the name of “Dr. Priestley’s
cavern,” where he was wont to pass an hour every day in solitary
retirement.”--‘Life of Mary Ann Schimmelpenninck.’
There can be little doubt that his enthusiasm as an experimenter in
chemistry exercised a powerful influence on the minds of both Boulton and
Watt, who, though both full of work, anxiety, and financial troubles, were
nevertheless found taking an active interest from this time forward in
the progress of chemical science. Chemistry became the chief subject of
discussion at the meetings of the Lunar Society, and chemical experiments
the principal recreation of their leisure hours.
“I dined yesterday at the Lunar Society (Keir’s house),” wrote
Boulton to Watt; “there was Blair, Priestley, Withering, Galton,
and an American ‘rebel,’ Mr. Collins. Nothing new except that
some of my white Spathos Iron ore was found to contain more air
than any ore Priestley had ever tried, and, what is singular,
it contains no common air, but is part fixable and part
inflammable.”[296]
To Henderson, in Cornwall, Boulton wrote, two months later,--
“Chemistry has for some time been my hobby-horse, but I am
prevented from riding it by cursed business, except now and then
of a Sunday. However, I have made great progress since I saw
you, and am almost an adept in metallurgical moist chemistry. I
have got all _that_ part of Bergmann’s last volume translated,
and have learnt from it many new facts. I have annihilated Wm.
Murdock’s bedchamber, having taken away the floor, and made the
chicken kitchen into one high room covered over with shelves,
and these I have filled with chemical apparatus. I have likewise
set up a Priestleyan water-tub, and likewise a mercurial tub for
experiments on gases, vapours, &c., and next year I shall annex
to these a laboratory with furnaces of all sorts, and all other
utensils for dry chemistry.”[297]
[296] Boulton to Watt, 3rd July, 1781. Dr. Black denominated
carbonic acid gas “fixed air” because of his having first
discovered it in chalk, marble, &c., wherein it was _fixed_
until the furnace or other means extracted it from its fixture.
[297] Boulton to Henderson, 6th September, 1781.
The “Priestleyan water-tub” and “mercurial tub,” here alluded to, were
invented by Priestley in the course of his investigations, for the purpose
of collecting and handling gases; and the pneumatic trough, with glass
retorts and receivers, shortly became part of the furniture of every
chemical laboratory.
Josiah Wedgwood was another member of the Lunar Society who was infected
by Dr. Priestley’s enthusiasm for chemistry; and, knowing that the
Doctor’s income from his congregation was small, he and Boulton took
private counsel together as to the best means of providing him with funds
so as to place him in a position of comparative ease, and enable him
freely to pursue his investigations. The correspondence which took place
on the subject is creditable to all parties concerned; and the more so to
Boulton, as he was embarrassed at the time by financial difficulties of
the most distressing kind, as has been already explained in a preceding
chapter. Wedgwood had undertaken to sound Dr. Priestley, and he thus
communicated the result to Boulton:--
“The Doctor says he never did intend or think of making any
pecuniary advantage from any of his experiments, but gave them to
the public with their results, just as they happened, and so he
should continue to do, without ever attempting to make any private
emolument from them to himself.
“I mentioned this business to our good friend, Dr. Darwin, who
agrees with us in sentiment, that it would be a pity that Dr.
Priestley should have any cares or cramps to interrupt him in the
fine vein of experiments he is in the midst of, and is willing
to devote his time to the pursuit of, for the public good. The
Doctor will subscribe, and has thought of some friends who, he is
persuaded, will gladly do the same....
“You will see by the enclosed list that one cannot decently exceed
ten guineas unless it be under the cover of a friend’s name, which
method I shall take if I think it necessary to write more than
ten; but that is the subscription I shall begin with, and for
three years certain.
“Dr. Darwin will be very cautious who he mentions this affair
to, for reasons of delicacy which will have equal weight with us
all. I mentioned _your_ generous intention to Dr. P., and that we
thought of 20_l._ each; but that, you will perceive, cannot be,
and the Doctor says much less will suffice, as he can go on very
well with 100_l._ per annum.”[298]
[298] Wedgwood to Boulton, Etruria, 10th March, 1781.
Boulton wrote Wedgwood in reply, requesting that the money subscribed
should be collected and paid to Dr. Priestley in such a way as not to
wound his sensitive feelings. He suggested that in order to avoid this, it
might be better if, instead of an annual subscription, a dozen gentlemen
were found willing to give a hundred pounds each for the purpose of buying
an annuity, or investing the amount in stock for the Doctor’s benefit.
“I have never yet spoken to him on the subject,” he added; “I
wish to avoid it, and so doth my neighbour Galton. Therefore
I beg you will manage the affair so that we may contribute our
mites to so laudable a plan, without the Doctor knowing anything
of the matter, and favour us with a line on the subject at your
leisure.”[299]
[299] Boulton to Wedgwood, 30th March, 1781.
In a subsequent part of the same letter he indicated the subject of
Priestley’s experiments at the time:--
“We have long talked,” said he, “of Phlogiston without knowing
what we talked about; but now that Dr. Priestley hath brought the
matter to light, we can pour that element out of one vessel into
another, can take it out of one metal and put it into another,
can tell how much of it, by accurate measurement, is necessary
to reduce a calx to a metal, which is easily done, and without
putting that calx into contact with any visible thing. In short,
this goddess of levity can be measured and weighed like other
matter. For the rest, I refer you to the Doctor himself.”
The discussions at the Lunar Society were not, however, exclusively
chemical, but were varied according to the visitors who from time to time
honoured the members with their presence. Thus, in the autumn of 1782,
the venerable Smeaton, having occasion to be in Birmingham upon canal
business, was invited to attend a meeting of the Society held in Watt’s
house at Harper’s Hill. Watt thus described the evening’s proceedings in
a letter to Boulton, then in London:--
“He [Smeaton] grows old, and is rather more talkative than he was,
but retains in perfection his perspicuity of expression and good
sense. He came to the Philosophers’ Meeting at my house on Monday,
and we were receiving an account of his experiments on rotatives
and some new ones he has made, when unluckily his facts did not
agree with Dr. Moyes the blind philosopher’s theories, which made
Moyes contradict Smeaton, and brought on a dispute which lost us
the information we hoped for, and took away all the pleasure of
the meeting, as it lasted two hours without coming half an inch
nearer to the point.”[300]
A few days later, we find De Luc paying his first visit to Watt at
Birmingham, accompanied by Baron Reden, who desired to inspect the
Soho works. “M. De Luc,” wrote Watt, “is a modest ingenious man. On
Wednesday, Wilkinson, Reden, and he sent for me to ‘The Castle’ after
dinner, and kept me to supper. On the following day De Luc came to
breakfast, and spent the whole forenoon, insensing[301] himself with
steam and steam-engines. He is making a book, and will mention us in it.
Dr. Priestley came also to dinner, and we were all good company till six
o’clock, when Wilkinson set off for Broseley, and they for London.”
[300] Watt to Boulton, 26th October, 1782.
[301] A common word in the north,--meaning literally _putting
sense into_ one.
Meanwhile Priestley continued to pursue his investigations with
indefatigable zeal, discovering one gas after another,[302] and
immediately proclaiming the facts which he brought to light, so that other
minds might be employed on them besides his own. He kept nothing secret.
Perhaps, indeed, he was too hasty in publishing the results of experiments
still unfinished, as it occasionally led him into contradictions which
a more cautious method of procedure would have enabled him to avoid.
But he was thoroughly honest, ingenuous, and single-minded in all his
proceedings, entertaining the conviction that in the end truth would
vindicate itself, and that all that was necessary was to inquire ardently,
to experiment incessantly, and to publish freely.
[302] He discovered, in the course of his inquiries at different
periods, no fewer than nine new gases,--oxygen, nitrogen (a
discovery also claimed by Cavendish and Rutherford), nitric
oxide, nitrous oxide, sulphurous acid, muriatic acid (chlorine),
volatile ammonia, fluo-silicic acid, and carbonic oxide,--“a
tribute to science,” as is truly observed by Dr. Henry, “greatly
exceeding in richness and extent that of any contemporary.”
One of the most interesting speculations to which Priestley’s experiments
gave rise was the composition of water. The merit of discovering the
true theory has been variously attributed to Watt, to Cavendish, and
to Lavoisier; and perhaps no scientific question has been the subject
of more protracted controversy. It had been known for some years that
a certain mixture of inflammable and dephlogisticated air (hydrogen and
oxygen), or common air and hydrogen, could be fired by the electric spark.
The experiment had been made by Volta and Macquer in 1776–7; and in the
spring of 1781 Priestley made what he called a “random experiment” of
the same kind, to entertain some philosophical friends. He exploded a
mixture of common air and hydrogen in a glass globe by sending an electric
spark through it, and when the explosion had taken place it was observed
that the sides of the glass were bedewed with moisture. Mr. Warltire,
a lecturer on Natural Philosophy at Birmingham,[303] was present at the
experiment, and afterwards repeated it in a copper flask for the purpose
of trying “whether heat is heavy or not.” In the mean time, Mr. Cavendish,
who had for some years been occupied in the special study of pneumatic
chemistry, and satisfactorily solved the question of the true composition
of atmospheric air, having had his attention directed to Mr. Warltire’s
experiment, repeated it in London, in the summer of 1781, employing a
glass vessel instead of a copper one; and again the deposit of dew was
observed on the sides of the glass. This phenomenon, which Priestley
had disregarded, appeared to him to be of considerable importance, and
“likely to throw great light” upon the subject of the disappearance of
oxygen during combustion, which he had been pursuing experimentally by
means of his well-known eudiometer. “The liquid which resulted from the
detonations was very carefully analysed, and proved in all the experiments
with hydrogen and air, and in some of those with hydrogen and oxygen,
to be pure water; but in certain of the latter it contained a sensible
quantity of nitric acid. Till the source of this was ascertained, it would
have been premature to conclude that hydrogen and oxygen could be turned
into pure water.”[304] These experiments, however, were not published,
being still regarded as inconclusive. But with the communicativeness
which distinguishes the true man of science, Cavendish made them known to
Priestley, and, through his friend Dr. Blagden, to Lavoisier. It was not
until January, 1784, that he communicated the results of his long series
of experiments on the subject to the Royal Society.
[303] We find among the Boulton MSS., a letter from Priestley,
dated Calne, 28th September, 1776, introducing Warltire to
Boulton as follows:--“As I know you will take pleasure in
everything in which the advancement of science is concerned, I
take the liberty to recommend to you Mr. Warltire, who has been
some time in this part of the country, and who is going to read
lectures on the subject of Air at Birmingham. I think him an
excellent philosopher, as well as a modest and agreeable man.
He is perfectly acquainted with his subject, and has prepared a
set of experiments which have given the greatest satisfaction
wherever he has been. He has been so obliging as to spend
some time with me, and has given me much assistance in my late
experiments, of which he can give you some account.”
[304] Wilson’s ‘Life of Cavendish,’ p. 60. In this work, the
claims of Cavendish are strongly advocated. The case in favour
of Watt is alike strongly and ably stated by Mr. Muirhead in
his ‘Correspondence of the late James Watt on his Discovery of
the Theory of the Composition of Water.’
In the mean time Watt’s attention had been directed to the same subject
by the experiments of Priestley, and he was led to the same conclusions
as Cavendish, though altogether independent of him, and by means of a
different class of experiments. We find him writing to Boulton, then at
Cosgarne, as follows, in 1782:--
“You may remember that I have often said that if water could be
heated red hot, or something more, it would probably be converted
into some kind of air, because steam would in that case have
lost all its latent heat, and that it would have been turned
wholly into sensible heat, and probably a total change of the
nature of the fluid would ensue. Dr. Priestley has proved this by
experiment. He took lime and chased out all the fixed air, and
made it exceedingly caustic by long-continued and violent heat.
He then added to it two ounces of water, and as expeditiously as
possible subjected it again to a strong heat, and he obtained
two ounces’ _weight_ of air; and, what is most surprising, a
balloon which he interposed between the retort and receiver was
not sensibly moistened, nor at all heated that could be observed.
The air produced was but very little more than common air, and
contained scarce any fixed air. So here is a plain account of
where the atmospheric air comes from. The Doctor does me justice
as to the theory.”[305]
[305] Watt to Boulton, 10th December, 1782.
The results of this experiment were by no means conclusive. That water
was composed, at least in part, of air or gas of some kind was obvious;
but what the gas was, and whether it existed in combination with other
gases, was still a matter of conjecture. But Priestley, having proceeded
to repeat Cavendish’s experiment[306] of exploding a mixture of oxygen
and hydrogen in a glass vessel, which was followed by the usual deposit
of water, communicated the fact to Watt, and this at once put him on
the track of the true theory. In a letter to Dr. Black, he communicated
the result of Dr. Priestley’s experiments, stating that “when quite dry
pure inflammable air (hydrogen) and quite dry pure dephlogisticated air
(oxygen) are fired by the electric spark in a close vessel, he finds,
after the vessel is cold, a quantity of water adhering to the vessel
equal, or very nearly equal, to the weight of the whole air.... Are we not
then authorised to conclude, that water is composed of dephlogisticated
and inflammable air or phlogiston deprived of part of their latent heat;
and that dephlogisticated or pure air is composed of water deprived
of its phlogiston and united to heat and light; and if light be only
a modification of heat, or a component part of phlogiston, then pure
air consists of water deprived of its phlogiston or latent heat?”[307]
At the same time Watt wrote to Priestley,--who did not himself see
the force of the experiments as establishing the true composition of
water,--demonstrating the conclusions which they warranted, and which were
identical with those already drawn by Cavendish.
[306] De Luc, Watt’s “ami zélé,” as he described himself,
confirms the fact of Cavendish having, in 1782, communicated
to Priestley the nature of his experiments as well as
his theory of the composition of water, in the following
passage:--“Vers la fin de l’année 1782, j’allai à Birmingham,
où le Dr. Priestley s’étoit établi depuis quelques années. Il
me communiqua alors que M. Cavendish, d’après une rémarque de
M. Warltire, qui avoit toujours trouvé de l’eau dans les vases
où il avoit brúlé un mélange de _l’air inflammable_ et _d’air
atmosphérique_, s’étoit appliqué à découvrir la source de cette
eau, et qu’il avoit trouvé qu’un mélange _d’air inflammable_
et _d’air déphlogistique_ en proportion convenable, étant
allumé par l’étincelle électrique, se convertissoit _tout
entier en eau_.--Je fus frappé au plus haut degré de cette
découverte.”--‘Idées sur la Météorologie,’ tome 2, 1787, pp.
206–7.
[307] Watt to Black, 21st April, 1783.
Whether Priestley had communicated to Watt the theory of Cavendish does
not appear; but it is probable that both arrived at the same conclusions
independently of each other; Cavendish from the result of his own
experiments, and Watt from those of Priestley. Each was quite competent
to have made the discovery; nor is it necessary for the fame of either
to strip a leaf of laurel from the brow of the other. Moreover, we are as
unwilling to believe that Cavendish would have knowingly appropriated to
himself the idea of Watt, as that Watt would have knowingly appropriated
the idea of Cavendish. As it was, however, Cavendish and Watt both claimed
priority in the discovery; the advocates of Watt’s claim resting their
case mainly on the fact of his having first stated his views on the
subject in writing, in a letter which he wrote to Dr. Priestley for the
purpose of being read to the Royal Society in April, 1783. Before that
letter was read, Watt asked that it should be withheld until the results
of some new experiments of Dr. Priestley could be ascertained. These
proving delusive, Watt sent a revised edition of the letter to his friend
De Luc, in November, but the reading of it was delayed until the 29th
April, 1784, before which time, on the 15th January, Cavendish’s paper
on the same subject had been communicated to the Society. Watt was much
annoyed at the circumstance, and alleged that Cavendish had been guilty of
“plagiarism.”[308] At a late period of his life, when all bitter feelings
on the subject had subsided, Watt declared himself indifferent to the
subject of controversy: “After all,” said he, “it matters little whether
Cavendish or I discovered the composition of water; the great thing is,
that it _is_ discovered.”
[308] That Watt felt keenly on the subject, is obvious from
his letter to Mr. Fry of Bristol (15th May, 1784), wherein he
says,--“I have had the honour, like other great men, to have
had my ideas pirated. Soon after I wrote my first paper on the
subject, Dr. Blagden explained my theory to M. Lavoisier at
Paris; and soon after that, M. Lavoisier invented it himself,
and read a paper on the subject to the Royal Academy of
Sciences. Since that, Mr. Cavendish has read a paper to the
Royal Society on the same idea, without making the least mention
of me. The one is a French financier; and the other a member of
the illustrious house of Cavendish, worth above 100,000_l._, and
does not spend 1000_l._ a year. Rich men may do mean actions.
May you and I always persevere in our integrity, and despise
such doings.”
Pneumatic chemistry continued to form the principal subject of discussion
at the Lunar Society, as we find from numerous references in Boulton
and Watt’s letters. “The Lunar Society,” wrote Watt to his partner,
“was held yesterday at Mr. Galton’s at Barr. It was rather dull, there
having been no philosophical news lately except Mr. Kirwan’s discovery
of an air from phosphorus, which takes fire of itself on being mixed
with common or dephlogisticated air.”[309] Among Watt’s numerous
scientific correspondents was M. Berthollet, the eminent French chemist,
who communicated to him the process he had discovered of bleaching by
chlorine. Watt proceeded to test the value of the discovery by experiment,
after which he recommended his father-in-law, Mr. Macgregor, of Glasgow,
to make trial of it on a larger scale. This, however, was postponed until
Watt himself could find time to superintend it in person. At the end
of 1787, we find him on a visit to Glasgow for the purpose, and writing
Boulton that he is making ready for the trial. “I mean,” he writes, “to
try it to-morrow, though I am somewhat afraid to attack so fierce and
strong a beast. There is almost no bearing the fumes of it. After all,
it does not appear that it will prove a _cheap_ way of bleaching, and it
weakens the goods more than could be wished, whatever good it may do in
the way of expedition.”[310] The experiment succeeded, and we find Mr.
Macgregor, in the following February, “engaged in whitening 1500 yards
of linen by the process.” The discovery, not being protected by a patent,
was immediately made use of by other firms; but the offensive odour of the
chlorine was found exceedingly objectionable, until it was discovered that
chlorine could be absorbed by slaked lime, the solution of which possessed
great bleaching power, and this process in course of time superseded all
the old methods of bleaching by chlorine.
[309] Watt to Boulton, 20th September, 1785.
[310] Watt to Boulton, 30th December, 1787. Boulton MSS.
It has been recently surmised that the action of light upon nitrate of
silver formed the subject of discussion at the Lunar Society, and of
experiments by Boulton and Watt; but we find no indications of this
in their correspondence. They were so unreserved with each other on
all matters of business as well as science that, had any phenomena
of so remarkable a character as those which have issued in the art of
photography become known to either Boulton or Watt, we feel confident that
they must have formed the subject of much personal discussion, and of many
written communications. But both correspondents are alike entirely silent
on the subject; and we infer that no such experiments were made by them,
or, if made, that they led to no results![311]
[311] Mr. W. P. Smith, of the Patent Museum, raised this question
at a meeting of the Photographic Society held on the 3rd
November, 1863. Certain photographic pictures on metal plates
were found in Mr. Boulton’s library at Soho, which, it was
supposed, had not been opened for about fifty years: and it was
accordingly inferred that these photographs had been the work
of Mr. Boulton, or some member of the Lunar Society, about the
year 1791. One of them was supposed to be a view of Soho House
“before the alterations, which were made previous to 1791.”
But the evidence is very defective, as has been clearly shown
by M. P. W. Boulton, Esq., the grandson of Mr. Boulton, in his
‘Remarks concerning certain Photographs supposed to be of early
Date’ (Bradbury and Evans, 1864). Instead of having been closed
for fifty years, the room in which the pictures were found,
was in constant use, and the books were freely accessible. It
is also very doubtful whether the house represented in one of
the pictures is old Soho House; the strong probability being
that it is not, but a house still standing at Winson Green.
The explanation given by Mr. M. P. W. Boulton seems to be the
true one--that the room in question having been used by a Miss
Wilkinson, an experimenter in photography after its invention
by Niepce, these photographs were merely the results of her
first amateur experiments in the art. The late Mr. Murdock,
son of William Murdock of Soho, who lived in the immediate
neighbourhood, was also a very good photographist, and was
accustomed to meet Miss Wilkinson to make experiments in the
new art.
There can be no doubt that the Wedgwoods of Etruria, more
particularly Josiah’s son Thomas, as well as Humphry Davy,
were early engaged in experimenting on the action of light
upon nitrate of silver, but they wholly failed in fixing the
pictures. A letter, dated “January, 1799,” is quoted in the
‘Photographic Journal’ for Jan. 15, 1864, as from James Watt
to Josiah Wedgwood (which must be an error, as Josiah died in
1795), in which the following words occur:--“I thank you for
your instructions respecting the silver pictures, about which,
when at home, I will make some experiments.” If such experiments
were really made, we have been unable to find any record of
them.
Among the many foreigners who were attracted by this distinguished circle
of scientific men, we find M. Faujas-Saint-Fond, who visited Birmingham
in the course of his tour in England in 1785, while the circle was as yet
unbroken, and Watt, Boulton, Priestley, and the rest, were in the full
tide of business, invention, and inquiry. Saint-Fond had the pleasure of
dining one day with Watt when Dr. Priestley was present, and describes in
glowing terms the interest of their conversation. “Watt,” he says, “joins
to the frankness of a Scotchman the amiability and kindness of a man of
the world. Surrounded by charming children, well educated and full of
talent, he enjoys in their midst the happiness of regarding them as his
friends, while he is almost worshipped by them as the best of fathers.”
A subsequent visit which he paid to Dr. Priestley in company with Dr.
Withering, leads him to describe the philosopher’s house at Fairhill, then
about a mile and a half from Birmingham. “It is,” he says, “a charming
residence, with a fine meadow on one side, and a beautiful garden on the
other. There was an air of perfect neatness about the place within and
without.” He describes the Doctor’s laboratory, in which he conducted his
experiments, as “situated at the extremity of a court, and detached from
the house to avoid the danger of fire.”
“It consists of several apartments on the ground floor. On
entering it, I was struck with the sight of a simple and ingenious
apparatus for making experiments on inflammable gas extracted
from iron and water reduced to vapour. It consisted of a tube,
tolerably long and thick, made out of one piece of copper to avoid
soldering. The part exposed to the fire was thicker than the
rest. He introduced into the tube cuttings or filings of iron,
and instead of letting the water fall into it drop by drop, he
preferred introducing it as vapour. The furnace was fired by coke
instead of coal, this being the best of combustibles for intensity
and equality of heat.... Dr. Priestley kindly allowed me to make
a drawing of his apparatus for the purpose of communicating it to
the French chemists who are engaged in the same investigations as
himself.... The Doctor has embellished his rural retreat with a
philosophical cabinet, containing all the instruments necessary
for his scientific labours; as well as a library, containing a
store of the most valuable books. He employs his time in a variety
of studies. History, moral philosophy, and religion, occupy his
attention by turns. An active, intelligent mind, and a natural
avidity for knowledge, draw him towards the physical sciences;
but a soft and impressible heart again leads him to religious and
philanthropic inquiries.... I had indeed the greatest pleasure
in seeing this amiable savant in the midst of his books, his
furnaces, and his philosophical instruments; at his side an
educated wife, a lovely daughter, and in a charming residence,
where everything bespoke industry, peace, and happiness.”[312]
[312] ‘Voyage en Angleterre, en Ecosse, et aux Iles Hébrides.’
Par B. Faujas-Saint-Fond. 2 vols. Paris, 1797.
Only a few years after the date of this visit, while Priestley was still
busied with his chemical investigations, his house at Fairhill, thus
described by Saint-Fond, was invaded by a brutal mob, who ruthlessly
destroyed his library, his apparatus, and his furniture, and forced him
to fly from Birmingham, glad to escape with his life.
The Lunar Society continued to exist for some years longer. But one by
one the members dropped off. Dr. Priestley emigrated to America; Dr.
Withering, Josiah Wedgwood, and Dr. Darwin, died before the close of the
century; and, without them, a meeting of the Lunar Society was no longer
what it used to be. Instead of an assembly of active, inquiring men, it
was more like a meeting of spectres with a Death’s head in the chair.
The associations connected with the meeting--reminding the few lingering
survivors of the losses of friends--became of too painful a character to
be kept alive; and the Lunar Society, like the members of which it was
composed, gradually expired. Its spirit, however, did not die. The Society
had stimulated inquiry, and quickened the zeal for knowledge of all who
had come within the reach of its influence; and this spirit diffused
and propagated itself in all directions. Leonard Horner, who visited
Soho in 1809, thus referred to the continued moral influence of the
association:--“The remnant of the Lunar Society,” he says, “and the fresh
remembrance in others of the remarkable men who composed it, are very
interesting. The impression which they made is not yet worn out, but shows
itself, to the second and third generation, in a spirit of scientific
curiosity and free inquiry, which even yet makes some stand against the
combined forces of Methodism, Toryism, and the love of gain.”[313]
[313] Horner’s ‘Memoirs and Correspondence,’ ii. 2.