JOSEPH PRIESTLEY (1733-1804), was born on 13th March 1733 at Fieldhead near Birstal, in the West Riding of Yorkshire. His father, Jonas Priestley, was a woollen-cloth dresser and apparently of very moderate means. His mother was the only child of Joseph Swift, a farmer at Shafton near Wakefield. The paternal grandfather, also named Joseph, was a churchman whose high moral character became a sacred tradition in his family. The young Joseph’s parents were Nonconformists. They had six children in eight years, and on the birth of the last, in the hard winter of 1739, the mother died. During those years Joseph lived a good deal with his maternal grandfather at Shafton. But he relates that his mother "was careful to teach him the Assembly’s Catechism," and that, with a view of impressing on his mind "a clear idea of the distinction of property," she on one occasion made him carry back a pin which he had picked up at the house of an uncle. Three years after the loss of his mother, his father’s sister. Mrs Keighley, a lady is good circumstances, having no children of her own, took the boy to live with her.

At the age of twelve he was sent to neighbouring endowed school, where, under the tuition of a clergyman, Mr Hague, he made rapid progress in classics, while on holidays, by way of recreation, he learned Hebrew from Mr. Kirkley, a Dissenting minister. On the removal of the clergyman Mr Kirkley opened a school of his own, and Priestley became entirely his pupil. From the age of sixteen to nearly twenty his health was unsatisfactory, and he attended neither school nor college, but still continued his studies in private with occasional assistance. It was thought that his constitution would be better adapted to an active than to a sedentary life, and with a view to commerce he learned French, Italian, and German without assistance. But the aunt, Mrs Keighley, had set her heart on making a minister of him, and young Priestley’s own aspirations took the same form. When, therefore, his health improved, the offer of a mercantile situation in Lisbon was surrendered, and Priestley in his twentieth year (1752) was sent to Daventry, where there existed a Nonconformist academy, originally founded by Dr Doddridge at Northampton, and removed after his incapacitation by illness or on his death in 1751.

There is no mention of any hesitation on the part of Priestley or his friends as to whether he should enter he established church or not. But there was certainly nothing in his theological creed at this period to have prevented his taking orders. The hindrance, therefore, must have been his adherence to the Nonconformist tradition on questions of ecclesiastical polity and ritual. There were, however, in his early associations some elements which not only help to explain his after career but throw a curious light on the fluid condition of Nonconformist denominations in those days as compared with their sectarian fixedness now. He was brought up in the principles of Calvinism. But he tells us his aunt’s house "was the resort of all the Dissenting ministers in the neighbourhood without distinction; and those who were most obnoxious on account of their heresy were most as welcome to her, if she thought them honest and good men -- which she was not unwilling to do -- as any others." Notwithstanding the comparative freedom of the conversations to which he listened, young Priestley as seventeen was strictly orthodox, and anxiously endeavored to realize the experiences he supposed to be necessary to conversion. His chief trouble was what he could not repent of Adam’s transgression, a difficulty the never surmounted. The pressure of this impossibility forced his candid mind to the conclusion that there must be a mistake somewhere, and he began to doubt whether he was really so much entangled in Adam’s guilt has had been taught. Accordingly he was refused admission into the communion of the Independent Church which his aunt attended. His adhesion to Calvinism was now considerably relaxed. But this did not interfere with his entrance at Daventry. Dr Doddridge had not combined his educational aims to students for the ministry, and he not only refused to impose theological tests but he incurred reproach by resolutely refusing to press his own orthodox creed on the heterodox pupils occasionally received. Priestley’s intellectual preparation previous to his entrance is noteworthy. Besides being a fair classic, he had improved his Hebrew by giving lessons in that language. He had acquired three modern languages. He had "learned Chaldee and Syriac, and just begun to read Arabic"; nor was he disproportionately backward in mathematics. He had also mastered 's Gravesande’s Elements of Natural Philosophy, and various text-books of the time in logic and metaphysic. It cannot surprise us that he "was excused all the studies of the first year and a great part of those of the second.’ At Daventry he stayed three years, taking a prominent part in the singularly free discussions that seem to have formed a considerable part of the academical exercises. "In this situation," he says, "I saw reason to embrace what is generally called the heterodox side of almost every question." His chief tutors were Dr. Ashworth of conservative and the Rev. Samuel Clark of decidedly liberal tendencies. Priestley’s speculations at this time were philosophical rather than scientific. Under the influence of Hartley’s Observations of Man and Collins’s Philosophical Enquiry he exchanged his early Calvinism for a system of "necessarianism," -- that is, he learned to hold that the invariable connexion of cause and effect is an inviolable in the moral as in the material world. During these early years he began his enormous industry as a writer, and in particular laid down the lines of his Institutes of Natural and Revealed Religion.

From Daventry he went in 1755, at twenty-two years of age, to take charge of a small congregation at Needham Market in Suffolk. This church was halting between Presbyterianism and Independency, being subsidized by both. Priestley insisted on dropping the Independent connexion. As a consequence he had to content himself with a salary of £30, and succeeded in living on less. His studies had not in the least chilled his devotion to the sacred work, which indeed to the end of his life he counted his highest honour. He was diligent in preaching and teaching, but his intellectual freedom, together with a physical difficulty in speech, prevented in attaining popularity. To cure the defect in speech he paid twenty guineas, given by his aunt, to a London specialist or quack. But this difficulty turned out to be as irremediable as his intellectual unconformability; and the only permanent advantage from his visit to the metropolis was an introduction to various scholars of the day, such as Dr Price, also Dr Benson and Dr Kippis, friends of Lardner. Later on he made the acquaintance of the last also through some manuscript notes on the doctrine of atonement, which attracted the great scholar’s attention.





In 1758 Priestley removed to Nantwich, obtaining a more congenial congregation; and there he established a school, which increased his income but lessened his literary activity. Always bringing his best intelligence to bear on everything he undertook, he varied his elementary lessons with instruction in natural philosophy, illustrated by experiments, for which he could now afford the needful instruments. "These," he says, "I taught my scholars in the highest class to keep in order, and to make use of; and by entertaining their parents and friends with experiments, in which the scholars were generally the operators, and sometimes the lectures too, I considerably extended the reputation of my school." Up to this time his studies had been entirely literary and theological-philosophical. It is noteworthy that his efforts to liberalize education turned his attention to science. He was probably one of the very first teachers to appreciate the importance of physical science to early culture.

In 1761 he was appointed classical tutor in a Nonconformist academy, then recently established at Warrington on the same liberal principles as the institution at Daventry. In this position he passed six of his happiest years, pursuing his scientific studies, especially in chemistry and electricity, enjoying congenial intercourse with Dr Turner of Liverpool, also with Wedgwood’s partner Mr Bentley, Dr Enfield, and various Manchester men whose sons or grandsons helped to form the "Manchester school." In 1762 he married the daughter or Mr Isaac Wilkinson, an ironmaster of Wrexham. At Warrington Priestley received the complimentary degree of LL.D. from Edinburgh, apparently in recognition of his Chart of History. On a visit to London he made the acquaintance of Dr Franklin, and his researches in electricity procured his election to the Royal Society in 1766.

In the following year (1767) Dr Priestley removed to Leeds to take charge of Mill Hill chapel; and in the same year published his History of Electricity, a work suggested by Dr Franklin, and contributing greatly to the author’s fame. Now, however, he turned once more to speculative theology, and surrendered the Arianism he had hitherto loosely held, adopting instead definite Socinian views. In addition to preaching and teaching diligently in his congregation he carried on his chemical researches with results considered at the time startling. Chemistry was hardly in its infancy; it was unborn. "The vast science," says Mr Huxley, "which now passes under that name had no existence." Living next door to a brewery Dr Priestley amused himself with experiments on the "fixed air" (carbonic acid) produced there, and succeeded in forcing it into water. Thus commenced his researches on "different kinds of air," remarkable rather to the impulse they gave to controversy and experiment than for any mature scientific results. He had a keen instinct for surmise, but no adequate method of research and verification. On this point Roscoe and Schorlemmer observe in their treatise on Chemistry (vol. i. p. 18) that "Priestley’s notion of original research, which seems quite foreign to our present ideas, may be excused, perhaps justified by the state of science in his day. He believed that all discoveries are made by chance, and he compares the investigation of nature to a hound, wildly running after, and here and there chancing on game (or, as James Watt called it, ‘his random haphazarding’), whilst we would rather be disposed to compare the man of science to the sportsman, who having, after persistent effort, laid out a distinct plan of operations, makes reasonably sure of his quarry." At this time also he wrote various political tracts and papers, always in favour of popular rights, and in particular hostile to the attitude of the Government towards the American colonies.

In 1771 he was nearly appointed to accompany Captain Cook to the South Seas. But the Government of the day was shocked at the idea of giving official position to a Socinian minister, and Priestley was disappointed. Shortly afterwards he accepted the somewhat anomalous situation of "literary companion" and librarian to Lord Shelburne. With this nobleman he traveled in Holland and Germany, returning by Paris, where he spent a month in 1774. the position gave him ample leisure for his scientific and literary pursuits. But on the completion of his most noteworthy philosophical treatise, Disquisitions on Matter and Spirit, the connexion was dissolved. It has been surmised that the patron feared to share the unpopularity of his client’s views. Those views Priestley himself considered to be "materialistic." It is a question of words. Seeing that he denied impenetrability to matter, it is difficult to say why the substance he left might not as well be called spirit as anything else.





In 1780 he removed to Birmingham, where he enjoyed the friendship of James Watt and his partner Boulton, also of Dr Darwin, grandfather of the illustrious man in whom the honours of the name culminated. Here Dr Priestley again took charge of a congregation, and resumed his theological efforts in a controversy with the bishop of Waterford, and in a laborious History of the Corruptions of Christianity. But bad times were at hand. The French Revolution excited passionate controversy, and Priestley was naturally on the side of the revolutionists. In 1791 the anniversary of the capture of the Bastille was observed in Birmingham by a dinner at which he was not present, and with which he had nothing to do. But the mob wished to testify by some signal deed their abhorrence of the un-English notions propounded at the dinner, and therefore burned down Priestley’s chapel and house. Before the deed was done they waded knee deep in torn manuscripts, and amused themselves with futile efforts to make an electric machine avenge its owner’s impiety by firing the papers with a spark. The blow was a terrible one. Priestley and his family had escaped violence by timely flight, but every material possession he valued was destroyed and the labours of years annihilated. But neither despair nor bitterness possessed him. He left Birmingham, and for three years preached in Hackney, then a suburban village, and in 1794 he went out to the young States whose cause he had advocated, to spend the last ten years of his life in the land of the future. He resided at Northumberland in Pennsylvania, eager as ever for controversy and research. His materialism, so-called, never dimmed his hope of immortality. His religion to the end was characterized by a childlike simplicity of spirit. On his death-bed he would have his grandchildren to kneel by his side for their daily prayers, and listened with pleasure to the hymns they lisped. On the 6th of February 1804 he clearly and audibly dictated a few alterations he wished to make in some of his publications. "That is right," he said, "I have now done"; and within an hour he quietly expired.

The interest of Dr Priestley’s life lies not so much in any splendid achievements, either literary or scientific, but rather in the character of the man. His career also affords a typical illustration of the mutual relation and interaction of several great factor of human progress at a very critical period. As a Nonconformist minister, born into a Calvinistic circle, educated in an Independent academy, developing into a Socinian divine, yet maintaining always the most friendly relations with clergymen, priests, and orthodox ministers, he gives us a curious insight into the condition of English religion just before its sectarian divisions had hardened into modern form. As a pioneer in the investigation of gases and the discoverer of oxygen he helped -- but, it must be admitted, as often by his mistakes as by his success -- to erect chemistry into a science. As a professed materialist whose doctrines seemed at the same time to merge matter in force he, amongst others, prepared the way of the modern agnosticism, which declines to look behind phenomena. As a politician he anticipated nineteenth-century radicalism. In general, as an exceptionally single-eyed and fearless searcher after truth he bore the brunt of persecution by vulgar ignorance, and in his disappointments illustrated how little can be practically accomplished by isolated enlightenment apart from popular education.

The works of Dr Priestley, as collected and edited by John Towill Rutt, fill twenty-five octavo volumes, one of which, however, consists of memoirs and correspondence. The date of this collected edition is 1832. it contains upwards of 130 separate works, varying in size from brief pamphlets to treatises in four volumes, and his labours range over almost all possible subjects of human knowledge or speculation. Mathematics, chemistry, physiology, grammar, logic, mental and moral philosophical, history, theology, interpretation or prophecy, politics, and sociology, all alike furnished theme for Priestley’s untiring pen, and if he did not write on any of them with striking originality he treated all with freedom and intelligence. In 1761 he issued his first published works, a treatise on the Scripture Doctrine of Remission and The Rudiments of English Grammar. From that date till 1767 he was content with publishing something every alternate year. But from 1767 to 1804 he allowed only two years to go by unmarked by one or more publications, many of them remarkable as monuments of conscientious and laborious industry. His first scientific work, The History and Present State of Electricity, with Original Experiments, was published in 1767. the rapid advance of science has left to this similar works of his little more than an antiquarian interest. But the treatise illustrates his prophetic spirit, inasmuch as it shows how far he was in advance of his contemporaries in appreciation of the prospects of physical research. In 1774 he issued his first volume of Experiments and Observations on Different Branches of Air, &c. In this volume he announced his discovery of "dephlogisticated air," now known as oxygen. The then prevalent theory of phlogiston, or the combustible principle in matter, betrayed him into great confusion, evident enough in the very name he gave to his new "branch of air." Nevertheless it is said of him in Roscoe and Schorlemmer’s Chemistry (vol. i. p. 16) that "no one obtained more important results or threw more light upon the chemical existence of a number or different gases than Joseph Priestley." These Experiments and Observations were continued through five volumes, of which the last appeared in 1780. Perhaps the limit of Priestley’s power of growth is illustrated by the persistency with which he clung to phlogiston notwithstanding the discoveries of Black, Lavoisier, and Cavenish. In 1800 he issued a treatise called The Doctrine of Philogiston established, and that of the Composition of Water refuted. In a letter of that year to the Rev. T. Lindsay he says, "I have well considered all that my opponents have advanced, and feel perfectly confident of the ground I stand upon. In this definite treatise all that is contained in my former publications on the subject, with many new experiments. Though nearly alone, I am under no apprehension of defeat." Dr Priestley clearly failed to appreciate the progress of the science he had done so much to promote. But the attempt made by Lavoisier to claim for himself a concurrent discovery of oxygen at the same time as Priestley’s was certainly unjustifiable. This achievement, together with the first preparation of nitric oxide, nitrous oxide, hydrochloric acid, and other important gases, constitutes the true ground of his fame as a scientific pioneer (see Roscoe and Schorlemmer, l.c.).

Priestley’s chief theological works were the Institutes of Natural and Revealed Religion, A History of the Corruptions of Christianity, and A General History of the Christian Church to the Fall of the Western Empire. Bishop Horsley’s criticisms on the second of these works produced letters in reply, "with additional evidence that the primitive church was Unitarian." His principal metaphysical writings were Disquisitions relating to Matter and Spirit and various essays and letters on necessarianism. A complete list of his works will be found in vol. i. part ii. of Rutt’s collected edition. (J. A. P., jr.)


Related Pages: Joseph Priestley in the History of Chemistry



The above article was written by: James Allanson Picton, M.A., M.P.; Independent Minister of Hackney, 1868-76; Member of School Board for London, 1869-78; author of New Theories and the Old Faith, The Mystery of Matter, Oliver Cromwell: the Man and his Mission, and Life of Sir James A. Picton.