Chapter XI (3)

"or of something capable of being converted into phlogisticated
air.... That water enters into the composition of alkaline air seems
necessary to be admitted, because it is decomposed into inflammable
air, which I cannot help thinking necessarily requires water. It
seems, however, clearly to be inferred ... that there is no occasion
to admit the _alkaline principle_ into the number of _elements_; the
_alkalinity_, as I may say, some way or other, arising from
phlogiston, or phlogisticated air, as _acidity_ arises from
dephlogisticated air."

After these theoretical speculations, "in which," he says, "I fear I have not communicated much light, though it is as much as I have been able to get," Priestley proceeds to make some observations relating to _phlogiston_, "the existence of which is at present a great subject of discussion with philosophers; some maintaining that there is no such thing, and others holding the doctrine of Stahl on the subject."

"According to Stahl, phlogiston is a real substance, capable of being
transferred from one body to another; its presence or absence making a
remarkable difference in the properties of bodies, whether it add to
their _weight_ or not. Thus he concluded that oil of vitriol deprived
of water, and united to phlogiston, becomes sulphur; and that the
calces of metals, by the addition of the same substance, become
metals.... What is now contended for is that in the oil of vitriol
changing into sulphur something is lost and nothing gained, and also
that a calx becomes a metal by the loss of air only. And did facts
correspond to this theory it would certainly be preferable to that of
Stahl, as being more simple; there being one principle less to take
into our account in explaining the changes of bodies. But I do not
know of any case in which phlogiston has been supposed to enter into a
body, but there is room to suppose that something does enter into
it....

"What has been insisted upon, as most favourable to the exclusion of
phlogiston, is the revival of mercury without the addition of any
other substance from the precipitate _per se_. In this case it is
evident that mere _heat_ ... is sufficient to revive the metal. And as
what is expelled from this calx is the purest dephlogisticated air, it
has been said that mercury is changed into this calx by imbibing pure
air, and therefore becomes a metal again, merely in consequence of
parting with that air."

The dexterous Mr Kirwan, not long before he himself embraced the French doctrine, furnished Priestley with an argument which satisfied him that this cardinal fact can be accounted for without excluding phlogiston. "Since therefore the supposition is exceedingly convenient, if not absolutely necessary, to the explanation of many other facts in chemistry, it is at least advisable not to abandon it."

"That calces do not become metals merely by parting with the air they
contain, is evident from my experiments on heating them in contact
with inflammable air, in which the inflammable air, or some necessary
part of it, is undoubtedly absorbed; and though a little moisture be
deposited in the process, it may well be supposed to be that which in
conjunction with phlogiston constituted the inflammable air. And what
can the other principle that is absorbed by the calx be but the same
thing which, when united to water, is recovered again from the metal
and found to be inflammable air having all the same properties with
that which was employed in the revival of it. Metals therefore are not
simple substances, but consist of their calces, and something else
which they take from inflammable air. And as the same may also be
taken from any combustible substance, it corresponds exactly to
Stahl's phlogiston, and therefore the doctrine of it is confirmed by
these experiments; that is, we must still say that in all combustible
substances there is a principle capable of being transferred to other
substances, which when united to the calces of metals makes them to be
metals, and which, united to oil of vitriol (deprived of its water)
makes it to be sulphur."

Thus was the ingenious man effectually entangled in his errors, his ingenuity helping him to deceive himself by evading the force of truth. To err is human. If Priestley saw through a glass darkly, and but dimly discerned the truth, he at least strove, so far as in him lay, to reach the light. Posterity forgives, and may well forget, his errors in grateful recognition of the many noble services he rendered to our common humanity, and in humbling recollection of the suffering and sacrifice with which those services were requited.

FOOTNOTES

[1]The Gregorian Calendar was not adopted in Great Britain until 1751.
In 1752 eleven days were left out of the Calendar, September 3rd
being counted the 14th. The change of style probably accounts for
the confusion in the various dates of Priestley's birth given by
different writers. In Chalmers's _General Biographical Dictionary_
the date is given as March 18; in Allen's _American Biographical and
Historical Dictionary_ and in Thomson's _History of the Royal
Society_ as March 24; Corry, in his _Life of Priestley_, gives March
24; Hoefer, in his _Histoire de la Chimie_, gives March 30, probably
following Dumas's _Philosophie de Chimie_; Cuvier, in his _Eloge_,
says that he was born near Bristol in 1728! In a letter to Wedgwood,
dated March 23, 1783, Priestley says in a postscript "This day I
complete my half century."

[2]T. Wemyss Reid, _Memoir of John Deskin Heaton_, p. 7 _et seq._

[3]The "Great Frost," as it was called, which, beginning on December 26,
1739, continued with the greatest intensity till February 17, 1740.
Above London Bridge the Thames was completely frozen over, and
numerous booths were erected on it for selling liquor, etc., to the
multitudes who daily flocked there.

[4]_The Inquirer_, January 16, 1904.

[5]Dr Andrew Kippis, an eminent Presbyterian, was the minister of the
Prince's Street Chapel, Westminster, and had at his disposal funds
which he could employ in assisting young ministers in their
education and first settlement. Priestley enjoyed his friendship
through life. Kippis, who was the editor of the _Biographia
Britannia_, was elected into the Royal Society in 1779, and served
on its council.

[6]William Eyres of Warrington, who was one of the most remarkable
printers of his day, produced a number of works noted for their
typographic excellence and beauty. He printed, in addition to the
works above mentioned, the first editions of Mrs Barbauld's poems,
Gilbert Wakefield's _Lucretius_, and other well-known classics.

[7]She was then sixty-two, and lived twenty years longer.

[8]The lines were the well-known stanza:--

"Life! We've been long together
Through pleasant and through cloudy weather;
'Tis hard to part when friends are dear,
Perhaps 'twill cost a sigh, a tear;
Then steal away, give little warning.
Choose thine own time;
Say not good-night, but in some brighter clime
Bid me good-morning."

[9]He lies buried near Castlehead, in Cartmel, Lancashire, where his
monument, a pyramidal mausoleum containing some twenty tons of iron,
is a notable feature in the landscape. On it is the following
epitaph written by himself:--

"Delivered from persecution of malice and envy here rests John
Wilkinson, Iron Master, in certain hopes of a better state and
heavenly mansion, as promulgated by Jesus Christ, in whose Gospel he
was a firm believer. His life was spent in action for the benefit of
man, and he trusts in some degree to the glory of God."

[10]This portrait was formerly in the possession of Mrs Crouch,
Priestley's youngest sister, and, according to Mrs Bilbrough of
Gildersome (_née_ Ellen Priestley), was brought by Mrs Crouch,
"along with the old family clock from her father's, Fieldhead, when
she came to live here in 1787." The picture was once placed in the
window of a carver and gilder's shop at Leeds, when Priestley
stopped to look at it in passing by. A woman happened to be doing
the same, and, on seeing him, exclaimed, "Why, here's the fellow
himself!" A photographic copy of it was presented to the subscribers
to the Stephen Statue in the Oxford Museum.

[11]There is a pencil-drawing of the house, made by the son of Dr
Kenrick of Warrington, among the Yates papers in the possession of
the Royal Society.

[12]The Chapel, or "Meeting House" as it was called in Priestley's time,
adjoined the Alms House Garth and was erected in 1673, after the
passage of the Act of Indulgence. It was pulled down in 1847 and the
present Mill Hill Chapel erected on its site.

[13]"_Lectures on the Memory of the Just._ A Series of Discourses on the
Lives and Times of the Ministers of Mill Hill Chapel, Leeds."

[14]He had in John Lee, a native of Leeds and a man of about his own
age, who became Solicitor-General in 1782, a friend who offered to
further his interests in that matter. Priestley, in his
autobiography, says: "Mr Lee showed himself particularly my friend
at the time I left Lord Shelburne, assisting me in the difficulties
with which I was then pressed, and continuing to befriend me
afterwards by seasonable benefactions."

[15]Richard Brinsley Sheridan at that time represented Stafford in the
House of Commons. Both he and Fox sympathised with Priestley and
sought to secure him compensation for his losses.

[16]Withering's _Botanical Arrangement_, 2nd Ed. 3 vols. 1792.

[17]Mercuric oxide made by heating quicksilver in air.

[18]Nitrous oxide: _see_ p. 182.

[19]Mercuric oxide made by heating mercuric nitrate.

[20]See the author's _Essays in Historical Chemistry_--"Priestley,
Cavendish, Lavoisier and La Révolution Chimique."

INDEX

A
Aikin, Anna Lætitia, 33, 43;
her poem _Corsica_, 70, 75.
Aikin, John, 32, 33, 36, 121.
Aikin, Lucy, 38.
_Air, Experiments and Observations on Different Kinds of_, Priestley's
treatise on, 77, 103, 167 _et seq._
Air, Fixed, 175, 176;
Priestley's view of its nature, 220.
Air, Inflammable, 179, 220.
Alkaline Air (Ammonia), Priestley's isolation of, 185;
its properties, 186;
decomposition of by electricity, 210;
nature of, 221.
Ammonia Gas, Priestley's discovery of, 185;
its properties, 186.
Ammonium Sesquicarbonate, Synthesis of, by Priestley, 186.

B
Barbauld, Mrs (Anna Lætitia Aikin), 33, 160.
Belloc, Madame, account of the Priestleys, 2;
of the times of Priestley, 5;
her account of Mrs Priestley, 49.
Bewley, Richard, his mephitic julep, 79.
Birmingham Riots of 1791, 120 _et seq._
Bolton, H. Carrington, his account of the Lunar Society, 96.
Boulton, Matthew, founds the Lunar Society of Birmingham, 94.
Boyle, Robert, his recognition that different elastic fluids exist,
174.
Bright, Henry A., his account of the Warrington Academy, 34.
Burke, Edmund, his denunciation of Priestley, 147.

C
Canton, John, his school, 9, 62.
"Conversion of Water into Air, Seeming," Priestley's work on, 216.
_Corruptions of Christianity_, Priestley's, 106.

D
Darwin, Erasmus, his connection with the Birmingham Lunar Society, 94,
95.
Daventry Academy, 18.
Dephlogisticated Air (Oxygen), Priestley's discovery of, 184, 192 _et
seq._
_Doctrine of Phlogiston Established_, Priestley's last scientific
work, 162.

E
Edgeworth, Richard Lovell, his account of the Lunar Society, 96.
Electricity, History of, Priestley's, 63.
Enfield, William, 33, 43.
Eudiometry, 182, 207, 208.
Eyres, William, of Warrington, 38.

F
Faujar St Fond, his visits to Priestley, 103.
Fieldhead, 3.
Fluor Acid Air, 198.
Forster, John Reinhold, 33, 81.
Franklin Benjamin, 63, 91, 92;
his opinion of Priestley, 93.

G
Galton, Samuel, 94, 96.
Gases, diffusion of, 202.
"General History of the Christian Church to the Fall of the Western
Empire," 109, 163.
Gordon, Rev. Alexander, his account of Priestley as a theologian, 109.

H
Harrison, Frederic, on Priestley, 1.
Horner, Leonard, his account of the Lunar Society, 102.
Hutton, Miss, her account of Priestley as a preacher, 105.

I
India-rubber, its use for erasing lead-pencil marks, 72.

J
"Jesus and Socrates compared," Priestley's Essay, 163.

K
Keighley, Mrs Sarah, 3, 8, 12.
Keir, Captain, 94, 127.
Kippis, Dr Andrew, 24, 26.
Kirwan, Richard, 215, 223.

L
Lavoisier, his relations to the discovery of oxygen, 195, 196, 198,
201, 215.
"Letters to a Philosophical Unbeliever," Priestley's, 85.
Lindsey, Theophilus, his friendship for Priestley, 73, 106.
Lunar Society of Birmingham, 94 _et seq._

M
Magellan, or Magalhæns, 84, 205.
Marine Acid Air (Hydrogen Chloride), Priestley's discovery of, 184.
"Melioration of Air, by the Growth of Plants," Priestley's paper on,
208.

N
Nitrosulphuric Acid, discovery of, 204.
Nitrous Air (Nitric Oxide), Priestley's work on, 181;
his application of it to Eudiometry, 182;
nature of, 221.
Nitrous Acid, discovery of, 182;
nature of, 221.

O
Oxygen, Priestley's discovery of, 184, 192 _et seq._

P
Paoli, Pascal, 70 _et seq._
Parr, Dr Samuel, 113, 144.
Phlogisticated Air (Nitrogen), Priestley's theory of its constitution,
220.
Phlogiston, 98, 100, 162, 214, 222.
Pneumatic Trough, the, 176.
Price, Dr Richard, 61.
Pringle, Sir John, address on award of Copley Medal to Priestley, 80.
Priestley, Jonas, father of Joseph Priestley, 2.
Priestley, Joseph, his birth, 1;
ancestry, 2;
education, 8;
becomes an Arminian, 14;
goes to Daventry, 17;
his studies there, 18;
begins his _Institutes of Natural and Revealed Religion_, 20, 68;
his "thorn in the flesh," 21;
goes to Needham, 22;
his privations there, 23;
goes to Nantwich, 30;
starts a school, 31;
removes to Warrington, 32;
marries, 47;
is ordained, 49;
his _English Grammar_, 32, 51;
_Essay on Education_, 53;
_Lectures on History and General Policy_, 55;
his _Chart of Biography_, 60;
is made Doctor of Laws of Edinburgh, 60;
publishes his _History and Present State of Electricity_, 64;
goes to Leeds, 66;
becomes a Unitarian, 69;
_Theory and Practice of Perspective_, 72;
_History of Discoveries Relating to Vision, Light and Colours_,
73;
his literary characteristics, 74;
his invention of soda-water, 77 _et seq._;
is awarded the Copley Medal, 80;
becomes librarian to Lord Shelburne, 82;
visits the continent, 84;
his _Disquisitions relating to Matter and Spirit_, 86;
_Experiments and Observations on Different Kinds of Air_, 77, 103;
leaves Lord Shelburne, 88;
removes to Birmingham, 93;
his merits as a preacher, 105;
his _History of the Corruptions of Christianity_, 106;
his merits as a theologian, 109;
his love of literature, 111;
his physical characteristics, 114;
his habits of life, 114;
his mental characteristics, 117;
destruction of his house at Birmingham, 120 _et seq._;
his address to the inhabitants of Birmingham, 134;
his account of the riots, 143;
succeeds Dr Price as minister at Hackney, 146;
withdraws from the Royal Society, 147;
determines to leave the country, 149;
his arrival in New York, 155;
settles in Northumberland, 155;
death of Mrs Priestley, 158;
his last days, 162;
his _Doctrine of Phlogiston Established_, 162;
his death, 164.
Priestley, Timothy, 2, 7.

R
Respiration, and the use of the Blood, Priestley's paper on, 203.
Robinson, Henry Crabb, his account of Mrs Barbauld, 46.
Russell, Martha, her account of the Birmingham Riots of 1791, 128.
Russell, William, 105, 126, 149.

S
Sal Ammoniac, Synthesis of, by Priestley, 186.
Scheele, an independent discoverer of Oxygen, 206;
discovers Chlorine, 211.
Schimmelpenninck's, Mrs, account of Priestley, 96.
Seddon, John, 34, 42.
Shelburne, Lord (Marquis of Lansdowne), 82.
Silicon Fluoride, Priestley's preparation of, 198;
its decomposition by water, 199.
Soda-water, invention of, 77.
Sound in Air, 211.
Sozzini, Fausto, 69, 108.
Stahl, author of the hypothesis of phlogiston, 222.
Sulphur dioxide (Vitriolic Acid Air), Priestley's discovery of, 190.
Sulphurated inflammable air (sulphuretted hydrogen), Priestley's
isolation of, 218.
Sulphuretted hydrogen, Priestley's isolation of, 218.

T
Taylor, Dr John, of Norwich, 36.
Theological Repository, the, 68, 105.
Turner, Matthew, teacher of chemistry at the Warrington Academy, 51,
76.

V
Vegetation, relation of to Air, Priestley's discovery of, 178, 208.
Vitriolic Acid Air (sulphur dioxide), Priestley's isolation of, 189.

W
Warrington Academy, the, 33 _et seq._
Water Controversy, the, 97.
Watt, James, his connection with the Lunar Society, 94;
discovery of Composition of Water, 97.
Wedgwood, Josiah, his friendship for Priestley, 55, 83, 137.
Wilkes and Liberty, Priestley's pamphlet on, 73, 152.
Wilkinson, John, 48, 138.
Wilkinson, Mary (Mrs Priestley), 49, 158;
Madame Belloc's account of her, 49.
Withering, Dr, 94, 101, 148.
Wordsworth, William, his admiration of Mrs Barbauld's literary work,
46.

_Colston & Coy. Limited, Printers, Edinburgh._

Transcriber's Notes

--Retained publication information from the printed edition: this eBook
is public-domain in the country of publication.

--Created cover and spine images based on elements in the book.

--Silently corrected a few palpable typos.

--In the text versions only, text in italics is delimited by
_underscores_.

End of Project Gutenberg's Joseph Priestley, by Thomas Edward Thorpe