In the 51st lecture on “General Policy” we read:—
“The gain of the merchants, it is said, is not always the gain of the country in general. If, for instance, a merchant imports foreign goods by which the consumption of national manufactures is hurt, though the merchant should be gainer by those goods, the State is a loser. As, on the other hand, a merchant may export the manufactures of his own country to his own loss and the nation’s gain. But if the merchants be gainers, the consumers, that is those for whose use manufactures are established, having a power of purchasing or not at pleasure, must be so too. And if, after sufficient trial, it be found that merchants importing foreign goods can sell these cheaper than the manufactures can be bought at home, it is an indication that it is not for the interest of the nation at large to encourage such manufactures.
“Though exportation makes a nation rich, we are not to judge of the quantity of riches which a nation gains by trade from exportation only, but the importation must also be considered. If these exactly balance one another nothing can be said to be gained or lost, just as a person is not the richer for selling a quantity of goods if he buy to the same amount. Nay, though the exportation be lessened, if the importation be lessened more than in proportion, it proves an increase of gainful trade, notwithstanding the decrease of exportation. This, however, is estimating the value of commerce by the mere increase of money. But a nation may flourish by internal commerce only, and what is external commerce between two nations not united in government would be internal if they should come under the same government. In every fair bargain the buyer and the seller are equally gainers, whether money be accumulated by either of the parties or not.
“It is a great mistake to confound the king’s revenue with the gain a nation makes by its trade. No man would presume to say it is more for the public benefit that the nation should expend a million or more every year with foreigners, in order to raise a hundred thousand pounds to the revenue by the customs, than to save that million or more within ourselves and to raise only the hundred thousand pounds the other way. But Ministers of State are apt to estimate the value of everything to the country by the gain it brings, and that immediately to themselves....
“The legislature of any country has seldom interfered in the affairs of commerce, but commerce has suffered in consequence to it, owing to the ignorance of statesmen, and even of merchants themselves, concerning the nature of trade. And indeed the principles of commerce are very complicated and require long experience and deep reflection before they can be well understood....
“Most politicians have injured commerce by restricting, confining or burthening it too much; the consequence of which has been that by aiming at great immediate advantage they have cut off the very springs of all future advantage. The inconveniences which have arisen to a nation from leaving trade quite open are few, and very problematical in comparison of the manifest injury it receives from being cramped in almost any form whatsoever....
“Mr Colbert, a man of great probity, knowledge and industry ... would have done better to have listened to the advice of an old merchant, who being consulted by him about what he should do in favour of trade, said, ‘Laissez nous faire.’”
In another place he says:—
“The happiness of all nations, therefore, as one great community, will be best promoted by laying aside all national jealousy of trade, and by each country cultivating those productions or manufactures which they can do to the most advantage; and experience, in a state of perfect liberty, will soon teach them what those are. In this state of things the only advantage will be on the side of industry and ingenuity, and no man or nation ought to wish it to be anywhere else.”
With regard to questions of political and civil liberty, the theory of the progress of law, the influence of religion on civil society, the connection of modes of religion with forms of government, the teaching is precisely what we should expect in such a hot-bed of liberal dissent as the Warrington Academy. With regard to the connection between civil government and religion he says:—
“The principal sufferer by this alliance between the Church and the State is religion itself, that is, the members of society as professors of religion and deriving advantages from it. For when it is thus guarded by the State, if it be faulty or wants reformation, it must long continue so. The professors of it, being interested in its support, will do everything in their power to prevent any alteration, though it should be ever so much wanted....
“It is alleged, in favour of these establishments, that religion has an influence on the conduct of men in this life. No doubt it has, as it connects the hopes of a future life with good behaviour in this. But this is done in all sects of Christians, and as much in those which are reprobated by the State as those which are encouraged by it. Besides, if this was the true cause of attachment to Christian establishments, the friends of them would be much more jealous of unbelievers than they are of sectaries, which does not appear to be the case.... One would think that Christian Governments might content themselves with establishing the Christian religion in general without confining themselves to any particular mode of it. But so far is this from being the case, that by the present laws of this country a man who denies the doctrine of the Trinity, which has no more imaginable connection with the good of the State than the doctrine of Transubstantiation, is deemed a blasphemer and sentenced to suffer confiscation of goods and imprisonment....
“In all other countries the established religion is that of the majority of the people, and the writers in defence of it vindicate it on this principle, viz., that it is the religion of the majority, whatever that be. But in Ireland we have a most remarkable exception to this rule. There the established religion is not that of the majority but of a small minority of the people, perhaps not more than that of one in ten of the inhabitants. That so flagrant an abuse of power should exist, and under a Government pretending to justice, and even to liberality, is barely credible.”
Here again much water has flowed under the bridges since these words were penned, but the bread which Priestley cast upon the stream, as well as that upon which he nurtured the young gentlemen of the Warrington Academy, has, we recognise, not been wholly wasted. In regard to what he considered other anomalies, the State still takes upon itself a “great, dangerous and unnecessary burthen” by undertaking the care of religion. From the remains of superstition the clergy are still considered as a distinct order of men in this country, and they are in a manner represented in Parliament by the bishops having seats in the House of Lords. “From which,” he says, “if they had a just sense of the nature of their office, and consulted their true dignity, they would retire of their own accord. At present their seat in the House only flatters their pride and gives the minister so many votes.”
In regard to other items of political and social development, it is noteworthy that Priestley was a consistent opponent of national education as we understand it to-day, on the ground that in his judgment it was inimical to liberty and the natural rights of parents. His position, in fact, was very similar to that taken up by a considerable and influential section of Liberal Dissenters prior to 1870.
Whilst at Warrington he also gave lectures on the “Theory of Language,” on the “Laws and Constitutions of England,” and on “Oratory and Criticism”—all of which were subsequently published, and which may still be read with profit, despite Lord Brougham’s sneering allusion to the adventurous tutor afflicted with an incurable stutter who, having never heard any speaking save in the pulpits of meeting-houses, promulgated rules of eloquence and of jurisprudence to the senators and lawyers of his country. The adventurous tutor with the incurable stutter even taught Elocution, also Logic and Hebrew for a time, and one year he gave a course of lectures on Anatomy.
Whilst at Warrington he published a Chart of Biography, exhibiting by lines and spaces the succession of the eminent men in every age and of every profession, with the relative length of their lives, and in such manner that at any given epoch it could be seen not only who flourished in it, but how all their ages stood with respect to one another, who were a man’s contemporaries, how far any of them was before him, or how far after him, in the order of their births or deaths.
The Chart of Biography procured for its compiler the degree of Doctor of Laws of the University of Edinburgh.
It has been said of Priestley that he was not a man who made friends. If it is meant by this that he was essentially a self-centred recluse, who sought his relaxation in change of occupation, or only within his own family circle, the statement gives a wholly imperfect idea of the man and is very wide of the truth.
In reality he was one of the most gregarious and most easily approachable of individuals, a man of strong, active human sympathies and of much social charm. There is abundant evidence of this in the testimony of his contemporaries; it is illustrated by numberless anecdotes, and is reflected in almost every letter of his correspondence.
It was, doubtless, under the impulse of the social instincts of his nature that, whilst at Warrington, he was led to begin the practice of spending one month in every year in London. This, remarks his son, was of great use to him. He saw and heard a great deal. A new turn was frequently given to his ideas. New and useful acquaintances were formed, and old ones confirmed. London then, as now, was the centre of the intellectual life of the kingdom and the Royal Society the seat of its scientific activity. To a man of Priestley’s versatility and eagerness, whose curiosity ranged practically over every department of human knowledge, these annual visits were a sort of intellectual tonic and gave a powerful stimulus to his activity.
On the first of them he made the acquaintance of men who, in their several capacities, proved to be true and valuable friends, notably, Dr Richard Price, Mr Canton, and Dr Benjamin Franklin.
Dr Price, a philosopher, and an eminent nonconformist divine, and one of the leading Arians of his time, is best known by his work on morals, and by his writings on financial and political questions. Among these, his papers in the Philosophical Transactions on “Life Insurance” and on the “Proper Method of Calculating the Values of Contingent Reversions,” are specially noteworthy. His pamphlet on the National Debt is said to have influenced Pitt in establishing the Sinking Fund for its extinction, and that on the “Policy of the War with America” to have contributed to the declaration of independence by the Americans. His liberal opinions gained him the friendship and patronage of Lord Shelburne. The acquaintance with Priestley soon ripened into a lasting friendship, which was in nowise disturbed by the controversy on materialism and necessity in which they subsequently engaged. Price and Priestley held similar views as to the French Revolution, and both were denounced with equal fierceness by Burke. Price died in the spring of 1791, and his funeral sermon was preached by Priestley, who succeeded him in the care of the Gravel Pit Meeting at Hackney. He was a man for whom Priestley ever entertained the warmest feelings of friendship on the ground of his amiable simplicity, his truly Christian spirit, disinterested patriotism and true candour.
John Canton, a notable schoolmaster in his day, is best known for his electrical inquiries and for his work on the compressibility of water, and his name is associated with the phosphorescent substance first obtained by him by calcining oyster shells with flowers of sulphur.
Among the Canton papers in the possession of the Royal Society is a letter from Seddon to Canton introducing Priestley, in which the latter is described as the author of A Chart of Biography and of an Essay on Education, and in which the writer says of the bearer:—
“You will find him a benevolent, sensible man, with a considerable share of learning. Besides the studies which belong to his profession, he has a taste for Natural Philosophy which will not render him less agreeable to you.”
That Priestley greatly enjoyed and profited by his Christmas in London is evident from the terms in which he refers to it in a letter to Canton under date February 14, 1766.
“The time I had the happiness to spend in your company appears upon revision like a pleasing dream. I frequently enjoy it once again in recollection, and ardently wish for a repetition of it. I wish, but in vain, that it may ever be in my power to return in kind your generous communication of philosophical intelligence and discoveries.”
He concludes the letter by expressing a desire to become a Fellow of the Royal Society.
Benjamin Franklin, journeyman printer and journalist, statesman and diplomatist, was about sixty years old when Priestley, then a man of little more than half his age, first made his personal acquaintance. The Royal Society, which had formerly ridiculed the discoveries which have given Franklin his undisputed position as one of the most eminent natural philosophers of his time, had paid him, although still a British subject, the distinguished compliment of making him an honorary fellow. At the time of Priestley’s coming to town he was occupied with the great struggle on behalf of the American Colony which ended in the defeat of the Stamp Act, and his famous examination before a Committee of Parliament had made him an object of great popular interest. During the eight or nine succeeding years in which Franklin remained in England his acquaintance with Priestley grew into the closest friendship, and there can be no question that the friendship reacted powerfully on Priestley’s work as a political thinker and as a natural philosopher. Indeed, it may be truthfully said that Franklin made Priestley into a man of science.
As the result of this intercourse with Canton and Franklin, Priestley offered to compile what he called “a distinct and methodical account” of the history of discoveries in electricity, provided he could be supplied with the necessary books. Franklin warmly seconded the proposal, and undertook, with the assistance of friends, to furnish all existing literature on the subject. As a matter of fact almost the whole of the historical account in Priestley’s book is taken from the Philosophical Transactions of the Royal Society, which was then the chief source of information concerning electrical science, inasmuch as the English electricians of that period, in addition to their own original papers, which were both numerous and important, introduced into the Transactions detailed accounts of all the principal books on electricity published abroad. In putting together his work, Priestley, having, as he says, a pretty good machine, was led to endeavour to ascertain several facts which were in dispute, and was thus led by degrees into a large field of experimental inquiry, in which he spared no expense that he could possibly afford. One of the most important of his discoveries is that charcoal is a good conductor. He describes coloured circles produced by receiving discharges from 21 square feet of glass on metal plates. When an electrical battery is discharged light bodies placed near the electric circuit are moved. Priestley ascribes this motion to what he calls the force of the lateral explosion, and he conceives it to depend upon the sudden elasticity given to the air. He found that a long circuit conducts much worse than a short circuit, even when the conductors are the same; also, that when the circuit contains an imperfect conductor a spark passes to bodies near, no electricity being communicated.
The work necessitated much correspondence with Franklin and others of his philosophical friends in London, and much of his leisure was devoted to his own experimental observations. Nevertheless, the book was completed in less than a year. Hasty and imperfect as it was, “The History and Present State of Electricity. With Original Experiments, illustrated with Copperplates,” was well received and ran through five editions in its author’s lifetime. Its publication at once stamped Priestley as a man of science; it secured him recognition as such in scientific circles at home and abroad, and was the immediate cause of his election, on June 12, 1766, into the Royal Society. The growing interest in the subject induced him to put together a Familiar Introduction to the Study of Electricity, which had also a considerable measure of success and was the means of popularising a knowledge of the main facts then known concerning Frictional Electricity. Priestley was instrumental in reviving the use of large electrical machines and batteries. The first of the large machines for which Nairne became famous was constructed in consequence of a request made to Priestley by the Grand Duke of Tuscany to procure for him the best machine that could be made in England. One of his machines, which figured in his History, and also in his Familiar Introduction, is in the possession of the Royal Society.
CHAPTER V
Goes to Leeds as minister of the Mill Hill Chapel—Resumes his studies in Speculative Theology—The Theological Repository—Becomes a Unitarian—Priestley as a controversialist—His Theory and Practice of Perspective—His literary characteristics—Begins his inquiries on Pneumatic Chemistry—His invention of soda-water—Receives the Copley Medal of the Royal Society.
Although Priestley lived in philosophic contentment with his lot at Warrington, happy in his occupations and in the society of congenial colleagues, the circumstances of the Academy were not fortunate. The institution never wholly recovered from the unhappy differences between the trustees and the first head of the Educational Staff, and in time many of the subscribers grew lukewarm in their support. Priestley had a remarkable power of adapting himself to his environment; he was one of the most even-tempered of men and had a capacity for being cheerful that would have extorted admiration even from Socrates. “But,” says Miss Aiken, “the Alma Mater of Warrington was ever a niggardly recompense of the distinguished abilities and virtues which were enlisted in her service.” One hundred pounds a year, with a house and a few boarders—hungry lads at £15 a year, exclusive of washing and candles—meant little towards the res angusta domi. Moreover, little Sarah Priestley had made her appearance, and the uncertain prospects which were before that young lady, coupled with the condition of her mother’s health, which was not wholly satisfactory at Warrington, led him to contemplate the expediency of giving up school-mastering and of resuming his profession of the ministry. Accordingly he was induced to accept an invitation to take charge of the congregation of Mill Hill Chapel, at Leeds, where he was already pretty well known, and thither he removed in 1767.[12]
Although it was no part of his duty to preach when at Warrington, he had from choice continued the practice, and wishing to maintain the character of a Dissenting minister, he had, as we have already seen, been ordained whilst there. His tendency to stammer was still a difficulty. Indeed, whilst at Nantwich it was so marked that he had almost resolved to abandon the calling. By reading aloud and very slowly every day, and by taking pains, he in some measure got the better of his defect, but he never wholly overcame it.
At Leeds he found a liberal, friendly and harmonious congregation, to whom his services, of which he was not sparing, were very acceptable. There, he says, he had no unreasonable prejudices to contend with, so that he had full scope for every kind of exertion. His activity and zeal in the special duties of his office led him to prepare and print catechisms for the young and to form various classes of catechumens and to instruct them in the principles of religion. He also published discourses on “Family Prayer,” on the “Lord’s Supper” and on “Church Discipline,” some of which were not altogether to the liking of members of the Established Church. Indeed, the first of his controversial pieces was written in answer to some angry remarks on one of these discourses written by a clergyman in the neighbourhood.
His return to the active duties of the ministry naturally induced him to resume the studies in Speculative Theology which had occupied him at Needham but which had been in large measure interrupted by the business of teaching at Nantwich and Warrington. He now published his Institutes of Natural and Revealed Religion, and began the publication of The Theological Repository, a collection of papers on theological questions, contributed by himself and a number of neighbouring ministers and others. The work eventually extended to six volumes, three of which were printed whilst he was at Leeds.
“The Theological Repository,” says the Rev. Charles Wicksteed,[13] “was one of those publications which will always appear from time to time in every body in which there is much activity and much freedom of thought. It had, however, a very slender circulation, and was very little read by any but theologians of the Liberal school. Indeed, it discussed questions which were viewed with terror by many even of the Liberal school itself, because it, in fact, purposely deserted the beaten track of opinion and opened out those questions on which difficulties began to be felt, or on which fresh light was wanted. It aimed at collecting the contributions of free, independent and thoughtful minds—towards correct ultimate decisions, without pretending itself to furnish those decisions. This is ever a position which the bigoted violently resent, which the unlearned cannot understand, on which even the candid and liberal often look with a dissatisfaction not unmingled with fear, but which is, notwithstanding, the essential preliminary of correct settled opinion in every age of thought. It is a position often assumed by the most contemplative and the most thoroughly honest men of the generation, but one which is never understood until the generation which produced and neglected it is passed. If there were not this neutral ground on which inquiring spirits can meet, beyond the hackneyed and settled points in which alone the many are interested, there would be an end to thought, which in a short time would prove an end to active, healthy, influential and tested truth.”
Shortly after his removal to Leeds, Priestley avowed himself an adherent to that school of theological opinion which its enemies associate with the name of Fausto Sozzini; that is, he became what has been called a humanitarian, or a believer in the doctrine that Jesus Christ was in nature solely and truly a man, however highly exalted by God.
Sozzini’s doctrine brought down upon its teacher the ill-will of a Cracow mob; his house was wrecked, his books and manuscripts destroyed, his life threatened, and he was driven from the city. Two hundred years later the Socinian Priestley went through precisely the same experience. Wrecking the homes, pillaging the property and injuring the persons of heresiarchs might seem an extraordinary way of identifying oneself with the doctrine of the gentle author of the Sermon on the Mount if history had not made us pretty familiar with such spectacles. At Leeds, as already stated, Priestley published the first of the series of controversial pieces on religion and politics which ceased only with his death. By some strange irony of fate this man, who was by nature one of the most peaceable and peace-loving of men, singularly calm and dispassionate, not prone to disputation or given to wrangling, acquired the reputation of being perhaps the most cantankerous man of his time, who delighted in tilting against established usage, and whose hand, Ishmael-like, was against every man’s. By sheer force of circumstances he became an indefatigable pamphleteer, apparently ever ready to vindicate the cause of civil and religious liberty, to champion the principles and conduct of Dissenters, and to attack what he considered the inveterate prejudices of the prevailing religion of his countrymen.
As a controversialist his methods were beyond reproach, and the arts of casuistry were wholly foreign to his character. He was so obviously sincere and fair-minded that he frequently overcame prejudice and disarmed criticism by his unconscious unwritten appeal to the finer instincts of his adversaries. He made many enemies but he won far more friends: the enemies were for the most part men whom history willingly lets die; the friends were of every sect, and some of them were among the chief glories of the eighteenth century.
The following characteristic letter to his friend, Miss Aiken, is interesting as illustrating the action of the active, eager mind which, as its owner says, found scope for every kind of exertion at this period of his life:—
“Leeds, 13th June 1769.
“Dear Miss Aikin,—You will be surprised when I tell you I write this on the behalf of Pascal Paoli and the brave Corsicans, but it is strictly true. Mr Turner of Wakefield, who says he reads your poems, not with admiration, but astonishment, insists upon my writing to you to request that a copy of your poem, called Corsica, may be sent to Mr Boswell, with permission to publish it for the benefit of those noble islanders. He is confident that it cannot fail greatly to promote their interest, now that a subscription is open for them, by raising a generous ardour in the cause of liberty and admiration of their glorious struggle in its defence. Its being written by a lady, he thinks, will be a circumstance very much in their favour and that of the poem, but there is no occasion for Mr Boswell to be acquainted with your name unless it be your own choice some time hence. I own I entirely agree with Mr Turner in these sentiments, and therefore hope Miss Aikin will not refuse so reasonable a request, which will, at the same time, lay a great obligation on her friends in England and contribute to the relief of her own heroes in Corsica. Consider that you are as much a general as Tyrtæus was, and your poems (which, I am confident, are much better than his ever were) may have as great an effect as his. They may be the coup de grace to the French troops in that island, and Paoli, who reads English, will cause it to be printed in every history of that renowned island.
“Without any joke, I wish you would comply with this request. In this case you have only to send a corrected copy to me at Leeds, to Mr Johnson in London, and I will take care to introduce it to the notice of Mr Boswell by means of Mr Vaughan or Mrs Macauley, or some other of the friends of liberty and Corsica in London. The sooner this is done the better. Mr Turner regrets very much that it was not done some time ago. I shall not tell you what I think of your poems for more than twenty reasons, one of which is that I am not able to express it. We are now all expectation at the opening of every packet from Warrington.
“My piece on Perspective is nearly ready for the press. Come and see us before it is quite printed, and I will engage to teach you the whole art and mystery of it in a few hours. If you come a month after I may know no more about the matter than anybody else. I am about to make a bolder push than ever for the pillory, the King’s Bench Prison, or something worse. Tell Mr Aikin he may hug himself that I have no connection with the Academy. On Monday next Mr Turner and I set out on a visit to the Archdeacon at Richmond.
“With all our compliments to all your worthy family, I am, with the greatest cordiality, your friend and admirer,
“J. Priestley.”
Pasquale de Paoli, the Corsican patriot, whose struggles to secure the independence of his native island had excited warm sympathy in England and had enlisted the pen of Boswell, was at that time a refugee in this country, having been defeated, after a stubborn resistance, by the French under Count Vaux. The poem on “Corsica,” one of the earliest and most beautiful of Miss Aikin’s productions, was written in 1768, at about the period of the appearance of Boswell’s Account of Corsica, but it was first published in 1773 in a collection of her poems, of which four editions, the first in 4to, the three others in 8vo were printed in that year.
The copy seen by Priestley was in manuscript. Whether it was shown to Boswell or to Paoli is not recorded.
The piece on Perspective was published in 1770, under the title of “A Familiar Introduction to the Theory and Practice of Perspective. With copperplates.” He gave as his reason for writing it that, having occasion to make drawings of philosophical instruments and apparatus he had felt the need of a work treating of perspective. It will be seen in the various editions of his works that the words “Priestley del” are engraved at the left-hand corner of the copperplates of the illustrations. The book had a considerable sale and was frequently recommended by drawing-masters. A second edition appeared in 1782 and it continued to be used well into the nineteenth century.
It is interesting to note that the first printed account of the use of india-rubber for the purpose of erasing lead pencil marks occurs in the preface to this work. It ran thus:—
“Since this work was printed off I have seen a substance excellently adapted to the purpose of wiping off from paper the marks of black lead pencil. It must therefore be of singular use to those who practise drawing. It is sold by Mr Nairne, mathematical instrument maker, opposite the Royal Exchange. He sells a cubical piece of about half an inch for three shillings, and he says it will last several years.”
The “bolder push than ever for the pillory, the King’s Bench Prison, or something worse,” probably refers to the anonymous pieces which he published in support of “Wilkes and Liberty” in the course of the memorable struggle between the freeholders of Middlesex and the House of Commons concerning the rights of free representation by parliamentary constituencies which at that time agitated the country. Wilkes had shortly before the date of this letter been fined by the King’s Bench £1000 and sentenced to twenty-two months’ imprisonment for publishing an impious libel, and had been expelled from the House of Commons—to which, however, he was repeatedly returned by the electors of Middlesex.
The Richmond visit to Archdeacon Blackburne, whose son had been at the Warrington Academy, is memorable from the circumstance that on its occasion Priestley first met Theophilus Lindsey, with whom he contracted an intimate and lasting friendship, which greatly influenced the lives and fortunes of both, and of which Priestley subsequently wrote that it had been a source of more real satisfaction to him than any other circumstance in his whole life.
The busy pamphleteer found time, however, to put together more ambitious works than Wilkes and Liberty. The success of his History of Electricity induced him to attempt the compilation of the history of all the branches of experimental philosophy, and he made proposals to publish a History of Discoveries Relating to Vision Light and Colours. The subscription to this work was not, however, sufficient to induce him to proceed, and after a considerable outlay in the purchase of books and other material the project was abandoned.
Priestley was, perhaps, the most industrious bookmaker of his age. Boswell indeed dubbed him a “literary Jack-of-all-Trades,” and he was busy with proof-sheets even to the day of his death. In fact, the closing act of his life, before he put his hand to his face to hide the last flicker of the vital spark, was to make a correction in a proof-sheet. He usually composed in shorthand, and much of this work was done in the family circle, sitting by the parlour fire. Conversation never disturbed him. Although his style is somewhat prolix, his language is simple and direct and his meaning invariably clear. Charges that his writings were hasty performances in nowise disturbed him. Indeed, he was wont to say that some of those that were most hurriedly done were among those that were best received. Whatever might have been the time he spent on their composition he was confident that more would not have contributed to their perfection in any essential particular, and about anything farther he was never very solicitous. His object, he said, was not to acquire the character of a fine writer but of a useful one. Pecuniary gain was never the chief object of his work; several of his books, indeed, were written with the prospect of certain loss. Many writers before and since the great lexicographer have left us what they have imagined to have been the secret of their success as literary craftsmen, and have told us of the means by which they gained their proficiency of composition and mastery of style. Priestley has no pretensions to be considered a master of style; nevertheless, it is of interest to learn how he acquired facility in writing the simple, unaffected English which characterises his literary work. It came, he said, from a practice of committing to writing as much as he could of the sermons he heard, and of composing much in verse. With regard to the sermons, he says:—
“This practice I began very early, and continued it until I was able from the heads of a discourse to supply the rest myself. For, not troubling myself to commit to memory much of the amplification, and writing at home almost as much as I had heard, I insensibly acquired a habit of composing with great readiness, and from this practice I believe I have derived great advantage through life, composition seldom employing so much time as would be necessary to write in long hand anything I have published.”
As regards the verses, he says:—
“I was myself far from having any pretension to the character of a poet, but in the early part of my life I was a great versifier, and this, I believe, as well as my custom of writing after preachers, mentioned before, contributed to the ease with which I always wrote prose.”
If Priestley was not himself a poet, he was at least the cause of poetry in another. Miss Aikin once told him that it was the perusal of some verses of his that first induced her fledgling muse to soar—so that, he adds, “this country is in some measure indebted to me for one of the best poets it can boast of.” No example of Priestley’s abilities as a “versifier” has come down to us, but in that dainty little sketch of the Warrington society, by Miss Lucy Aikin, from which we have already quoted, allusion is made to his accomplishment.
“Both bouts rimés and vers de société were in fashion with the set. Once it was their custom to slip anonymous pieces into Mrs Priestley’s work-bag. One ‘copy of verses,’ a very eloquent one, puzzled all guessers a long time; at length it was traced to Dr Priestley’s self.”
To the man of science the special interest of Priestley’s connection with Leeds arises from the fact that he began there that fruitful series of inquiries, relating to what he called “the doctrine of air,” which eventually raised him to the position of one of the greatest chemical discoverers of his time. The house in which he first lived whilst at Leeds was in Meadow Lane and adjoined the public brew house of Jakes and Nell. He was thereby led, in the outset, to amuse himself by making experiments on the “fixed air,” or carbonic acid, which is largely produced in the process of fermentation. When he removed to his second house in Basinghall Street, on the site where the schools now stand, he was under the necessity of making the fixed air for himself; and, as he distinctly and faithfully notes in his various publications on the subject, he was led to make one experiment after another until he became, what he does not state, the greatest master of pneumatic chemistry of his age.
When he began these experiments he tells us he knew very little of chemistry. Indeed, he says he had in a manner no idea on the subject before his attention was drawn to it in a course of lectures delivered in the Warrington Academy by Dr Turner of Liverpool. But, as he says, on the whole, this circumstance was no disadvantage to him, as in the situation in which he found himself he was led to devise an apparatus and processes of his own adapted to his peculiar views. If he had been previously accustomed to the usual chemical processes he might not have so easily thought of any other; and without new modes of operation he thinks he should hardly have discovered anything materially new. His means did not permit him to purchase expensive apparatus. Indeed, this very circumstance materially contributed to his success by making his apparatus so simple that his experiments could be readily repeated and their accuracy thereby ensured.
His first contribution to Pneumatic Chemistry was published in 1772. It was a small pamphlet on a method of impregnating water with fixed air, which, being immediately translated into French, excited a great degree of attention to the subject, and this was much increased by the publication of his first experimental paper in the Philosophical Transactions of the Royal Society.
Priestley’s earliest method of impregnating water with carbonic acid consisted in exposing it to the gas above the surface of fermenting wort. This process was no doubt accompanied with many disadvantages and the resulting solution could not have been very palatable. Later on he adopted the method originally employed by Lane in 1709, although apparently in ignorance of Lane’s paper in the Philosophical Transactions, of making the gas from chalk and sulphuric acid and leading it directly into the water by means of a flexible tube provided with an intercepting bladder to retain any solid or acid substance projected from the effervescent materials in the generating flask. At about this period increased attention was being paid to the question of the supply of drinking water in the Navy, owing to the publication of Irving’s plan of making fresh water from sea-water by distillation, and Priestley conceived the idea that if some ready means could be devised of impregnating water with carbonic acid on shipboard the solution might be useful as a preventive of sea scurvy.
Priestley brought his idea to the knowledge of the Duke of Northumberland, and showed a sample of the impregnated water to Sir George Savile, who introduced him to Lord Sandwich, at that time First Lord of the Admiralty in Lord North’s Administration. The Board of Admiralty thought the matter was of sufficient importance to ask for a report from the College of Physicians, and Priestley was requested to appear before that body in order to explain and illustrate his process. The report from the College was favourable, and in consequence two war-ships were fitted with the apparatus.
The idea that scurvy, in common with other so-called putrid diseases, was due to an insufficient supply of “fixed air” in the animal economy, and that it might be cured by the administration of that gas, originated with Dr Macbride about the middle of the eighteenth century, shortly after Black had established the individuality of the gas, and it was current doctrine with the faculty at the time of Priestley’s experiments. The reasons which Macbride gave in support of his hypothesis are contained in his Essays on Medical and Philosophical Subjects, and are sufficiently ingenious to be worth stating as characteristic of much of the therapeutics of the time. Macbride assumed that substances held together, and acquired the quality of firmness, by virtue of containing a “cementing principle,” which ensured the perfect cohesion of their constituent particles, and that as putrefaction resulted in the decomposition and disintegration of substances, putridity was connected with the loss or disappearance of this cementing or cohering principle. He found that “fixed air” was invariably produced when animal and vegetable substances putrefy, that a greater amount of fixed air is produced from vegetable substances than from animal substances, and that animal and vegetable matters putrefy more rapidly when mixed than when separate, and yield more fixed air in conjunction than apart.
On the basis of these observations Macbride proceeded to explain the well-established fact that a diet mainly composed of animal food is apt to produce sea scurvy, the remedy for which is a sufficient supply of fresh vegetables, by assuming that the virtue of the vegetables was due to the evolution of a greater amount of carbonic acid in the process of digestion, the fixed air so liberated in the body counteracting, by its antiseptic powers, putridity in the circulating fluids.
We are not here concerned with the subsequent history of so-called ærated or soda-water, as it came to be called, but it is worth noting that Priestley’s account of his process contains one remark which is not without significance in view of latter-day developments. He says:—
“I do not doubt but that, by the help of a condensing engine, water might be much more highly impregnated with the virtues of the Pyrmont spring, and it would not be difficult to contrive a method of doing it.”
The manufacture of these waters was subsequently taken up by Priestley’s friend and satellite, as he called himself, Richard Bewley, of Great Massingham, an apothecary, and the inventor of the well-known “mephitic julep.” Bewley appears to have discovered that the addition of a small quantity of carbonate of soda to the water enabled it to absorb and retain an increased quantity of carbonic acid, and to him, therefore, is due the credit of first making what was long called “acidulous soda-water.” The receipt for its manufacture and use, given by Henry of Manchester, is sufficiently quaint to be worth reproduction:—
“To prepare Mr Bewley’s julep dissolve three drachms of fossil alkali in each quart of water, and throw in streams of fixed air till the alkaline taste be destroyed. This julep should not be prepared in too large quantities, and should be kept in bottles very closely corked and sealed. Four ounces of it may be taken at a time, drinking a draught of lemonade or water acidulated with vinegar or weak spirit of vitriol, by which means the fixed air will be extricated in the stomach.”
It is hardly to be supposed that the Royal Society Club in 1773 adopted all the social manners and customs of the period. Nevertheless, its members, who were among the most influential fellows of the Society, were evidently greatly impressed with the merits of Priestley’s soda-water, since the Council of the Society were moved to reward its discoverer with the Copley Medal.
In making the award on St Andrew’s Day 1773, Sir John Pringle, then President of the Royal Society, said:—
“For having learned from Dr Black that this fixed or mephitic air could in great abundance be procured from chalk by means of diluted spirits of vitriol; from Dr Macbride that this fluid was of a considerable antiseptic nature; from Dr Cavendish that it could in a large quantity be absorbed by water; and from Dr Brownrigg that it was this very air which gave the briskness and chief virtues to the Spa and Pyrmont waters; Dr Priestley, I say, so well instructed, conceived that common water impregnated with this fluid alone might be useful in medicine, particularly for sailors on long voyages, for curing or preventing the sea scurvy.”
To-day the Copley Medal is regarded as the highest award which it is in the power of the Society to bestow, and certainly no man starts his scientific career by acquiring it—not even for so signal an invention as that of soda-water.
Whilst Priestley was at Leeds a proposal was made to him that he should accompany Captain Cook in his second voyage to the South Seas. It probably arose from his connection with the Admiralty in the matter of his invention. He tells us that as the terms were very advantageous he consented to it, the heads of his congregation agreeing to keep an assistant to supply his place during his absence. But Mr Banks informed him that he was objected to by some clergymen in the Board of Longitude, who had the direction of this business, on account of his religious principles. “Whether,” said Huxley, in commenting on this circumstance in the course of his speech at the unveiling of the Priestley statue in Birmingham in 1874, “these worthy ecclesiastics feared that Priestley’s presence among the ship’s company might expose his Majesty’s sloop Resolution to the fate which aforetime befell a certain ship that went from Joppa to Tarshish, or whether they were alarmed lest a Socinian should undermine that piety which in the days of Commodore Trunnion so strikingly characterised sailors, does not appear.” The appointment was given to Reinhold Forster, a man, as Priestley fully admitted, far better qualified for the position.