QforttBU ItttWEtfiitg ffitbtara 3t^aca, Stem f arh Q 171.H98Sr"*""'^'-"'"^ IIIMWimiii'' ^'''"=3tion, essays. 3 1924 01? ?53 799 Cornell University Library The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924012253799 Unter national Science Xibrar^ SCIENCE AND EDUCATION ESSAYS BY THOMAS H. HUXLEY Hbe 'flClerner Company JSoof! imanutactuvers aftron, ©bio S)^ PREFACE The apology offered in the Preface to the first volume of this series for the occurrence of repeti- tions, is even more needful here I am afraid. But it could hardly be otherwise with speeches and essays, on the same topic, addressed at intervals, during more than thirty years, to widely distant and different hearers and readers. The oldest piece, that " On the Educational Value of the Natural History Sciences," contains some crudities, which I repudiated when the lecture was first reprinted, more than twenty years ago; but it will be seen that much of what I have had to say, later on in life, is merely a development of the propositions enunciated in this early and sadly- imperfect piece of work. In view of the recent attempts to disturb the compromise about the teaching of dogmatic the- vi PEBFAdE ology, solemnly agreed tb by the first School Boird for London, the fifteenth Essay; and, more par- ticularly, the note on p. 388, may be found inter- esting. T. H. H. HOSESLEA, EmTBOUBNB, i September ith, 1893. CONTENTS 1 JOSEPH PWBSTLET [1874] _ . . . . 1 (An Address delirered on the occasion of the presentation of a statue of Priestley to the town of Birmingham) II Oir THE EDUCATIONAL TALUE OF THE NATURAL HISTOBT SCIENCES [1854] 38 (An Address delivered in S. Martin's Hall) III EMANCIPATION— BLACK AND WHITE [1865], M IV A ttlBEKAL EDUCATION ; AND WHEKE TO FIND IT [1868] . 78 (An Address to the South London Work- ing Men's College) Tii viii CONTENTS V PAGE SCIENTIFIC EDUCATIOK : NOTBS OF AN AFTEE-DINNER SPEECH [1869] . . . : Ill (Liverpool Philomathic Society) VI SCIENCE AND CULTURE [1880] 134 (An Address delivered at the opening of Sir Josiah Mason's Science College, Bir- mingham) VII ON SCIENCE AND ART IN RELATION TO EDUCATION [1882] 160 (An Address to the members o£ the Liver- pool Institution) VIII UNIVERSITIES : ACTUAL AND IDEAL [1874] 189 (Rectorial Address, Aberdeen) IX ADDRESS ON UNIVERSITY EDUCATION [1876] 235 (Delivered at the opening of the Johns Hopkins University, Baltimore) ON THE STUDY OF BIOLOGY [1876] 268 (A Lecture in connection with the Loan Collection of Scientific Apparatus, South Kensington Museum) CONTENTS ix XI PAGE ON ELEMENTARY INSTRUCTION IN PHYSIOLOGY [1877] . . 294 XII ON MEDICAL EDUCATION [1870] 303 (An Address to the students of the Faculty of Medicine in University College, London) XIII THE STATE AND THE MEDICAL PROFESSION [1884] . . . 323 XIV THE CONNECTION OF THE BIOLOGICAL SCIENCES -WITH MEDICINE [1881] 347 (An Address to the International Medical Congress) XV THE SCHOOL BOARDS : WHAT THEY CAN DO, AND WHAT THEY MAY DO [1870] 374 XVI TECHNICAL EDUCATION [1877] 404 XVII ADDRESS ON BEHALF OF THE NATIONAL ASSOCIATION FOR THE PROMOTION OF TECHNICAL EDUCATION [1887] . 427 JOSEPH PEIESTLBY [1874] It the man to perpetuate whose memory we have this day raised a statue had been asked on what part of his busy life's work he set the highest value, he would undoubtedly have pointed to his voluminous contributions to theology. In season and out of season, he was the steadfast champion of that hypothesis respecting the Divine nature which is termed Unitarianism by its friends and Socinianism by its foes. Eegardless of odds, he was ready to do battle with all comers in that cause; and if no adversaries entered the lists, he would sally forth to seek them. To this, his highest ideal of duty, Joseph Priestley sacrificed the vulgar prizes of life, which, assuredly, were within easy reach of a man of his singular energy and varied abilities. For this object he put aside, as of secondary importance, those scientific investigations which he loved so 1 JOSEPH PEIESTLEY [1874] It the man to perpetuate whose Uieindry we have this day raised a statue had been asked on what part of his busy life's work he set the highest value, he would undoubtedly have pointed to his voluminous contributions to theology. In season and out of season, he was the steadfast champion of that hypothesis respecting the Divine nature which is termed Unitarianism by its friends and Socinianism by its foes. Eegardless of odds, he was ready to do battle with all comers in that cause; and if no adversaries entered the lists, he would sally forth to seek them. To this, his highest ideal of duty, Joseph Priestley sacrificed the vulgar prizes of life, which, assuredly, were within easy reach of a man of his singular energy and varied abilities. For this object he put aside, as of secondary importance, those scientific investigations which he loved so 1 2 JOSEPH PRIESTLEY i well, and in which he showed himself bo com- petent to enlarge the boundaries of natural knowl- edge and to win fame. In this cause he not only cheerfully suffered obloquy from the bigoted and the unthinking, and came within sight of martyr- dom; but bore with that which is much harder to be borne than all these, the unfeigned astonish- ment and hardly disguised contempt of a brilliant society, composed of men whose sympathy and esteem must have been most dear to him, and tq whom it was simply incomprehensible that a phi- losopher should seriously occupy himself with. any form of Christianity. It appears to me that the man who, setting before himself such an ideal of life, acted up to it consistently, is worthy of the deepest respect, whatever opinion may be entertained as to the real value of the tenets which he so zealously pro- pagated and defended.. But I am sure that I speak not only for myself, but for all this assemblage, when I say that our purpose to-day is to do honour, not to Priestley, the Unitarian divine, but to Priestley, the fearless defender of rational freedom in thought and in action: to Priestley, the philosophic thinker; to that Priestley who held a foremost place among "the swift runners who hand over the lamp of life," * and transmit from one generation to an- * " Quasi cursores, Titai lampada tradunt."— Lucr. De Berum Nat. ii. 78. I JOSEPH PRIESTLEY 3 other the fire kindled, in the childhood of the -world, at the Promethean altar of Science. The main incidents of Priestley's life are so well known that I need dwell upon them at no great length. Born in 1733, at Fieldhead, near Leeds, and brought up among Calvinists of the straitest or- thodoxy, the boy's striking natural ability led to his being devoted to the profession of a minister of religion; and, in 1752, he was sent to the Dissenting Academy at Daventry — an institution which authority left undisturbed, though its ex- istence contraTened the law. The teachers under whose instruction and influence, the young man came at Daventry, carried out to the letter the injunction to "try all things: hold fast that which is good," and encouraged the discussion of every imaginable proposition with comjdete freedom, the leading professors taking opposite sides; a discipline which, admirable as it may be from a purely scientific point of view, would seem to be calculated to make acute, rather than sound, divines. Priestley tells us, in his " Autobiog- raphy," that he generally found himself on the un- orthodox side: and, as he grew older, and his fac- ulties attained their maturity, this native tendency towards heterodoxy grew with his growth and strengthened with his strengtli. He passed from Calvinism to Arianism; and finally, in middle life, 4 JOSEPH PKIESTLBY i landed in that very broad form of Ilnitarianism by which his craving after a credible and consist- ent theory of things was satisfied. On leaving Daventry Priestley became minister of a congregation, first at Needham Market, and secondly at Nantwich; but whether on account of his heterodox opinions, or of the stuttering which impeded his expression of them in the pulpit, little success attended his efforts in this capacity. In 1761, a career much more suited to his abilities became open to him. He was appointed "tutor in the languages" in the Dissenting Academy at Warrington, in which capacity, besides giving three co\irses of lectures, he taught Latin, Greek, French, and Italian, and re'ad lectures on the the- ory of language and universal grammar, on ora- tory,* philosophical criticism, and civil law. And it is interesting to observe that, as a teacher, he encouraged and cherished in those whom he in- structed freedom which he had enjoyed, in his ! own student days, at Daventry. One of his pupils telli us that, " At the conclusion of his lecture, he always enoouwf ed his students to express their sentiments relative to the sub- ject of it, and to urge any objections to what he had deliv- ered, without reserve. It pleased him when any one com- menced such a conversation. In order to excite the freest discussion, he occasionally invited the students to drink tea with him, in order to canvass the subjects of his lectures. I do not recollect that he ever showed the least displeasure at the strongest objections that were made to what he de- I JOSEPH PRIESTLEY 5 livered, but I distinctly remember the smile of approbation with which he usually received them : nor did he fail to point out, in a yery encouraging manner, the ingenuity or force of any remarks that were made, when they merited these characters. His object, as well as Dr. Aikin's, was to engage the students to examine and decide for themselves, uninfluenced by the sentiments of any other persons." • It would be difficult to give a better description of a model teacher than that conveyed in these words. From his earliest days, Priestley had shown a strong bent towards the study of nature; and his brother Timothy tells us that the boy put spiders intg bottles, to see how long they would live in the same air — a curious anticipation of the investi- gations of his later years. At Nantwich, where he set up a school, Priestley informs us that he bought an air pump, an electrical machine, and other instruments, in the use of which he in- structed his scholars. But he does not seem to have devoted himself seriously to physical science until 1766, when he had the great good fortune to meet Benjamin Franklin, whose friendship he ever afterwards enjoyed. Encouraged by Franklin, he wrote a " History of Electricity," which was pub- lished in 1767, and appears tp have met with con- siderable success. In the same year, Priestley left Warrington to become the minister of a congregation at Leeds; * lAft and Correspondence of Dr. Prieitley, by J. T. Eutt. VoLI. p. 50. i 6 JOSEPH PBIBSTLBF i and, here, happening to live next door to a public brewery, as he says, " I, at first, amused myself with making experiments on the fixed air which I found ready-made in the process of fermentation. When I removed from that house I was under the necessity of making fixed air for myself; and Mie experiment leading to another, as I have distinctly and faithfully noted in my various publications on the sub- ject, I by degrees contrived a convenient apparatus for the purpose, but of the cheapest kind. " When I began these experiments I knew very little of chemistry, and had, in a manner, no idea on the subject be- fore I attended a course of chemical lectures, delivered in the Academy at Warrington, by Dr. Turner of Liverpool. But I have often thought that, upon the whole, this circum- stance was no disadvantage to me ; as, in this situation, I was led to devise an apparatus and processes of my own, adapted to my peculiar vjews; whereas, if I had been pre- viously accustomed to the usual chemical processes, I should not have so easily thought of any other, and without new modes of operation, I should hardly have discovered anything materially new." * The first outcome of Priestley's chemical work, published in 1773, was of a very practical charac- ter. He discovered the way of impregnating water with an excess of " fixed air," or carbonic acid, and thereby producing what we now know as "soda water" — a service to naturally, and still more to artificially, thirsty souls, which those whose parched throats and hot heads are cooled by morning draiights of that beverage, cannot too gratefully acknowledge. In the same year, • Autoliography, %% 100, 101. I JOSEPH PRIESTLEY 7 Priestley communicated the extensive series of observations which his industry and ingenuity had accumulated, in the course of four years, to the Eoyal Society, under the title of " Observations on Different Kinds of Air " — a memoir which was justly regarded of so much merit and importance, tjiat the Society at once conferred upon the author the highest distinction in their power, by awarding him the Copley Medal. In 1771 a proposal was made to Priestley to accompany Captain Cook in his second voyage to the South Seas. He accepted it, and his congre- gation agreed to pay an assistant to supply his place during his absence. But the appointment lay in the hands of the Board of Longitude, of which certain clergymen were members; and whether 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; but, at any rate, they objected to Priestley " on account of his religious principles," and appointed the two Forsters, whose " religious principles," if they had been known to these well- meaning but not far-sighted persons, would probably have surprised them. 61 8 JOSEPH PEIESTLEY i In 1773 another proposal was made to Priest- ley. Lord Shelburne, desiring a "literary com- panion," had been brought into communication with Priestley by the good offices of a friend of both, Dr. Price; and offered him the nominal post of librarian, with a good house and appoint- ments, and an annuity in case of the termination of the engagement. Priestley accepted the offer, and remained with Lord Shelburne for seven years, sometimes residing at Calne, sometimes travelling abroad with the Earl. Why the connection terminated has never been exactly known; but it is certain that Lord Shelburne behaved with the utmost consideration and kindness towards Priestley; that he fulfilled his engagements to the letter; and that, at a later period, he expressed a desire that Priestley should return to his old footing in his house. Probably enough, the politician, aspiring to the highest offices in the State, may have found the posi- tion of the protector of a man who was being denounced all over the country as an infidel and an atheist somewhat embarrassing. In fact, a pas- sage in Priestley's " Autobiography " on the occa- sion of the publication of his " Disquisitions relat- ing to Matter and Spirit," which took place in 1777, indicates pretty clearly the state of the case: — " (126) It being probable that this publication would be unpopular, and might be the means of bringing odium on my patron, several attempts were made by his friends, I JOSEPH PRIESTLEY 9 though none by himself, to dissuade me from persisting in it. But being, as I thought, engaged in the cause of im- portant truth, I proceeded without regard to any conse- quences, assuring them that this publication should not be injurious to his lordship." It is not unreasonable to suppose that his lordship, as a keen, practical man of the world, did not derive much satisfaction from this assur- ance. The " evident marks of dissatisfaction " which Priestley says he first perceived in his patron in 1778, may well have arisen from the peer's not unnatural uneasiness as to what his domesticated, but not tamed, philosopher might write next, and what storm might thereby be brought down on his own head; and it speaks very highly for Lord Shelburne's delicacy that, in the midst of such perplexities, he made not the least attempt to interfere with Priestley's freedom of action. In 1780, however, he intimated to Dr. Price that he should be glad to establish Priestley on his Irish estates: the sugegstion was interpreted, as Lord Shelburne probably intended it should be, and Priestley left him, the annuity of £150 a year, which had been promised in view of such a con- tingency, being punctually paid. After leaving Calne, Priestley spent some little time in London, and then, having settled in Bir- mingham at the desire of his brother-in-law, he was soon invited to become the minister of a large congregation. This settlement Priestley consid- 10 JOSEPH PRIESTLEY i ered, at the time, to be " the happiest event of his life." And well he might think so; for it gave him competence and leisure; placed him within reach of the best makers of apparatus of the day; made him a member of that remarkable "Lunar Society," at whose meetings he could exchange thoughts with such men as Watt, Wedgwood, Darwin, and Boulton; and threw open to him the pleasant house of the Galtons of Barr, where these men, and others of less note, formed a society of exceptional charm and intelli- gence.* But these halcyon days were ended by a bitter storm. The French Revolution broke out. An electric shock ran through the nations; whatever there was of corrupt and retrograde, and, at the same time, a great deal of what there was of best * See The Life of Mary Anne Schimmelpenninch. Mrs. Schimmelpenninck (nee Galton) remembered Priestley very well, and her description of him is worth quotation : — " A man of admirable simplicity, gentleness and kindness of heart, united with great acuteness of intellect. I can never forget the impression produced on me by the serene ex- pression of his countenance. He, indeed, seemed present with God by recollection, and with man by cheerfulness. I remember that, in the assembly of these distinguished men, amongst whom Mr. Boulton, by his noble manner, his fine countenance (which much resembled that of Louis XIV.), and princely munificence, stood pre-eminently as the great Mecsenas ; even as a child, I used to feel, when Dr. Priestley entered after him, that the glory of the one was terrestrial, that of the other celestial ; and utterly far as I am removed from a belief in the sufficiency of Dr. Priestley's theological creed, I cannot but here record this evidence of the eternal power of any portion of the truth held in its vitality." I JOSEPH PRIESTLEY H and noblest, in European society shuddered at the outburst of long-pent-up social tires. Men's feelings M-ere excited in a way that we, in this generation, can hardly comprehend. Party wrath and virulence were expressed in a manner un- paralleled, and it is to be hoped impossible, in our times; and Priestley and his friends were held up to public scorn, even in Parliament, as fomenters of sedition. A *• Church-and-King " cry was raised against the Liberal Dissenters; and, in Birmingham, it was intensified and specially directed towards Priestley by a local controversy, in which he had engaged with his usual vigour. In 1791, the celebration of the second anniversary of the taking of the Bastile by a public dinner, with which Priestley had nothing whatever to do, gave the signal to the loyal and pious mob, who, unchecked, and indeed to some extent encouraged, by those who were responsible for order, had the town at their mercy for three days. The chapels and houses of the leading Dissenters were wrecked, and Priestley and his family had to fly for their lives, leaving library, apparatus, papers, and all their possessions, a prey to the flames. Priestley never returned to Birmingham. He bore the outrages and losses inflicted upon him with extreme patience and sweetness,* and betook * Even Mrs. Priestley, who might be forgiven for re- garding the destroyers of her household gods with some asperity, contents herself, in writing to Mrs. Barbauld, with the sarcasm that the Birmingham people " will scarcely find 1^ ' JOSEPH PRIESTLEY i ■himself to London. But even his scientific col- leagues gave him a cold shoulder; and though he was elected minister of a congregation at Hackney, he felt his position to be insecure, and finally de- termined on emigrating to the United States. He landed in America in 1794; lived quietly with his sons at Northumberland, in Pennsylvania, where his posterity still flourish; and, clear-headed and busy to the last, died on the 6th of February, 1804. Such were the conditions under which Joseph Priestley did the work which lay before him, and then, as the ISTorse Sagas' say, went out of the story. The work itself was of the most varied kind. No human interest was without its attrac- tion for Priestley, and few men have ever had so many ' irons in the fire at once; but, though he may have burned his fingers a little, very few who have tried that operation have burned their fingers so little. He made admirable discoveries in science; his philosophical treatises are still well worth reading; his political works are full of insight and replete with the spirit of freedom; and while all these sparks flew off from his anvil, the controversial hammer rained a hail of blows on orthodox priest and bishop. While thus engaged, the kindly, cheerful doctor felt no more wrath or so many respectable characters, a second time, to make a bonfire of." I JOSEPH PEIBSTLEY 13 uncharitableness towards his opponents than a smith does towards his iron. But if the iron could only speak! — and the priests and bishops took the point of view of the iron. No doubt what Priestley's friends repeatedly urged upon him — ^that he would have escaped the heavier trials of his life and one more for the advancement of knowledge, if he had confined himself to his scientific pursuits and let his fellow- men go their way — was true. But it seems to have been Priestley's feeling that he was a man and a citizen before he was a philosopher, and thaf the duties of the two former positions are at least as imperative as those of the latter. More- over, there are men (and I think Priestley was one of them) to whom the satisfaction of throwing down a triumphant fallacy is as great as that which attends the discovery of a new truth; who feel better satisfied with the government of the world, when they have been helping Providence by knocking an imposture on the head; and who care even more for freedom of thought than for mere advance of knowledge. These men are the Carnots who organise victory for truth, and they are, at least, as important as the generals who visibly fight her battles in the field. Priestley's reputation as a man of science rests upon his numerous and important contributions to the chemistry of gaseous bodies; and to form a 14 JOSEPH PEIBSTLBT i just estimate of the value of his work — of the extent to which it advanced the knowledge of fact and the development of sound theoretical views — we must reflect what chemistry was in the first half of the eighteenth century. The vast science which now passes under that name had no existence. Air, water, and fire were still counted among the elemental bodies; and though Van Helmont, a century before, had dis- tingiiished different kinds of air as gas ventosum and gas sylvestre, and Boyle and Hales had ex- perimentally defined the physical properties of air, and discriminated some of the various kinds of aeriform bodies, no one suspected the existence of the numerous totally distinct gaseous elements which are now known, or dreamed that the air we breathe and the water we drink are compounds of gaseous elements. But, in 1754, a young Scotch physician, Dr. Black, made the first clearing in this tangled backwood of knowledge. And it gives one a wonderful impression of the juvenility of scientific chemistry to think that Lord Brougham, whom so many of us recollect, attended Black's lectures when he was a student in Edinburgh. Black's researches gave the world the novel and startling conception of a gas that was a permanently elastic fluid like air, but that differed from common air in being much heavier, very poisonous, and in having the properties of an acid, capable of neutral- I JOSEPH PRIESTLEY 15 ising the strongest alkalies; and it took the world some time to become accustomed to the notion. A dozen years later, one of the most sagacious and accurate investigators who has adorned this, or any other, country, Henry Cavendish, published a memoir in the " Philosophical Transactions," in which he deals not only with the "fixed air" (now called carbonic acid or carbonic anhydride) of Black, but with " inflammable air," or what we now term hydrogen. By the rigorous application of weight and measure to all his processes. Cavendish implied the belief subsequently formulated by Lavoisier, that, in chemical processes, matter is neither created nor destroyed, and indicated the path along which all future explorers must travel. Nor did he him- self halt until this path led him, in 1784, to the brilliant and fundamental discovery that water is composed of two gases united in fixed and con- stant proportions. It is a trying ordeal for any man to be com- pared with Black and Cavendish, and Priestley cannot be said to stand on their level. Neverthe- less his achievements are not only great in them- selves, but truly wonderful, if we consider the dis- advantages under which he laboured. Without the careful scientific training of Black, without the leisure and appliances secured by the wealth of Cavendish, he scaled the walls of science as so many Englishmen have done before and since his 16 JOSEPH PEIESTLBY i day; and trusting to mother wit to supply the place of training, and to ingenuity to create apparatus out of washing tubs, he discovered more new gases than all his predecessors put together had done. He laid the foundations of gas analysis; he dis- covered the complementary actions of animal and vegetable life upon the constituents of the atmos- phere; and, finally, he crowned his work, this day one hundred years ago, by the discovery of that " pure dephlogisticated air " to which the French chemists subsequently gave the name of oxygen. Its importance, as the constituent of the atmos- phere which disappears in the processes of respira- tion and combustion, and is restored by green plants growing in sunshine, was proved somewhat later. For these brilliant discoveries, the Eoyal Society elected Priestley a fellow and gave him their medal, while the Academies of Paris and St. Petersburg conferred their membership upon him. Edinburgh had made him an honorary doctor of laws at an early period of his career;_but, I need hardly add, that a man of Priestley's opinions re- ceived no recognition from the universities of his own country. That Priestley's contributions to the knowledge of chemical fact were of the greatest importance, and that they richly deserve all the praise that has been awarded to them, is unquestionable; but it must, at the same time, be admitted that he had no comprehension of the deeper significance of his I JOSEPH PKIESTLBY 17 work; and, so far from contributing anything to the theory of the facts which he discoyered, or assisting in their rational explanation, his influence to the end of his life was warmly exerted in favour of error. From first to last, he was a stiff adherent of the phlogiston doctrine which was prevalent when his studies commenced; and, by a curious irony of fate, the man who by the discovery of what he called " dephlogisticated air" furnished the essential datum for the true theory of com- bustion, of respiration, and of the composition of water, to the end of his days fought against the inevitable corollaries from his own labours. His last scientific work, published in 1800, bears the title, " The Doctrine of Phlogiston established, and that of the Composition of Water refuted." When Priestley commenced his studies, the cur- rent belief was, that atmospheric air, freed from accidental impurities, is a simple elementary sub- stance, indestructible and unalterable, as water was supposed to be. When a combustible burned, or when an animal breathed in air, it was supposed that a substance, " phlogiston," the matter of heat and light, passed from the burning or breathing body into it, and destroyed its powers of supporting life and combustion. Thus, air contained in a vessel in which a lighted candle had gone out, or a living animal had breathed until it could breathe no longer, was called " phlogisticated." The same result was supposed to be brought about by the IS JOSEPH PRIESTLEY i addition of what Priestley called " nitrous gas " to common air. In the course of his researches, Priestley found that the quantity of common air which can thus become " phlogisticated," amounts to about one- fifth the volume of the whole quantity submitted to experiment. Hence it appeared that common air consists, to the extent of four-fifths of its vol- ume, of air which is already " phlogisticated"; while the other fifth is free from phlogiston, or " dephlogistieated." On the other hand, Priestley found that air " phlogisticated " by combustion or respiration could be " dephlogistieated," or have the properties of pure common air restored to it, by the action of green plants in sunshine. The ques- tion, therefore, would naturally arise — as common air can be wholly phlogisticated by combustion, and converted into a substance which will no longer support combustion, is it possible to get air that shall be less phlogisticated than common air, and consequently support combustion better than common air does? Now, Priestley says that, in 1774, the possi- bility of obtaining air less phlogisticated than common air had not occurred to him.* But in pursuing his experiments on the evolution of air from various bodies by means of heat, it happened that on the 1st of August, 1774, he threw the heat * Experiments and Observations on Different Kinds of Air, vol. ii. p. 31. I JOSEPH PRIESTLEY 19 of the sun, by means of a large burning glass which he had recently obtained, upon a substance which was then called mercurius calcinatus per se, and which is commonly known as red precipitate. " I presently found that, by means of this lens, air was expelled from it very readily. Having got about three or four times as much as the bulk of my materials, I admitted ■water to it, and found that it was not imbibed by it. But what surprised me more than I can well express, was that a candle burned in this air with a remarkably vigorous flame, very much like that enlarged flame with which a candle burns in nitrous air, exposed to iron or lime of sulphur ; but as I had got nothing like this remarkable appearance from any kind of air besides this particular modification of nitrous air, and I knew no nitrous acid was used in the preparation of mercurius calcinatus, I was utterly at a loss how to account for it. " In this case also, though I did not give suflicient atten- tion to the circumstance at that time, the flame of the can- dle, besides being larger, burned with more splendour and heat than in that species of nitrous air ; and a piece of red- hot wood sparkled in it, exactly like paper dipped in a solu- tion of nitre, and it consumed very fast — an experiment which I had never thought of trying with nitrous air." • Priestley obtained the same sort of air from red lead, but, as he says himself, he remained in ignorance of the properties of this new kind of air for seven months, or until March 1775, when he found that the new air behaved with "nitrous gas " in the same way as the dephlogisticated part of common air does; f but that, instead of being * Experiments and Observations on Different Kinds of Air, vol. ii. pp. 34, 35. t i^^^- ^1- i- P- ^- 20 JOSEPH PRIESTLEY i diminished to four-fifths, it almost completely vanished, and, therefore, showed itself to be " be- tween five and six times as good as the best common air I have ever met with." * As this new air thus appeared to be completely free from phlogiston, Priestley called it " dephlogisticated air." What was the nature of this air? Priestley found that the same kind of air was to be obtained by moistening with the spirit of nitre (which he terms nitrous acid) any kind of earth that is free from phlogiston, and applying heat; and con- sequently he says: " There remained no doubt on my mind but that the atmospherical air, or the thing that we breathe, consists of the nitrous acid and earth, with so much phlogiston as is necessary to its elasticity, and likewise so much more as is required to bring it from its state of perfect purity to the mean condition in which we find it." t Priestley's view, in fact, is that atmospheric air is a kind of saltpetre, in which the potash is re- placed by some unknown earth. And in speculat- ing on the manner in which saltpetre is formed, he enunciates the hypothesis, " that nitre is formed by a real decomposition of the air itself, the bases that are presented to it having, m such circum- * Experiments and Observations on Different Kinds of Air, vol. ii. p, 48. t -?*»<*• P- 85> I JOSEPH PBIBSTLEY 21 stances, a nearer affinity with the spirit of nitre than that kind of earth with which it is united in the atmosphere."* It wonld have been hard for the most ingenious person to have wandered farther from the truth than Priestley does in this hypothesis; and, though Lavoisier undoubtedly treated Priestley very ill, and pretended to have discovered dephlogisticated air, or oxygen, as he called it, independently, we can almost forgive him when we reflect how different were the ideas which the great French chemist attached to the body which Priestley dis- covered. They are like two navigators of whom the first sees a new country, but takes clouds for moun- tains and mirage for lowlands; while the second determines its length and breadth, and lays down on a chart its exact place, so that, thenceforth, it serves as a guide to his successors, and becomes a secure outpost whence new explorations may be pushed. Nevertheless, as Priestley himself somewhere remarks, the first object of physical science is to ascertain facts, and the service which he rendered to chemistry by the definite establishment of a large number of new and fundamentally important facts, is such as to entitle him to a very high place among the fathers of chemical science. * Ibid. p. 60. The italics are Priestley's own. 22 JOSEPH PRIESTLEY i It is diflacult to say whether Priestley's philo- sophical, political, or theological views were most responsible for the bitter hatred which was borne to him hy a large body of his country- men,* and which found its expression in the malignant insinuations in which Burke, to his everlasting shame, indulged in the House of Commons. Without centaining much that will be new to the readers of Hobbs, Spinoza, Collins, Hume, and Hartley, and, indeed, while making no pretensions to originality, Priestley's "Disquisitions relating to Matter and Spirit," and his " Doctrine of Philo- sophical Necessity Illustrated," are among the most powerful, clear, and unflinching expositions of materialism and necessarianism which exist in the English language, and are still well worth reading. Priestley denied the freedom of the will in the sense of its self-determination; he denied the ex- • " In all the newspapers and most of the periodical publications I was represented as an unbeliever in Revela- tion, and no better than an athiest." — Autobiography, Rutt, vol. i. p. 124. " On the walls of houses, etc., and especially where I usually went, were to be seen, in large characters, ' Madan fob ever ; Damn Priestley ; no Pkesbtteman- isM ; Damn the Presbttbeians,' etc., etc. ; and, at one time, I was followed by a number of boys, who left their play, repeating what they had seen on the walls, and shout- ing out, ' Damn Priestley ; damn him, damn Mm, for ever, for ever,' etc., etc. This was no doubt a lesson which thev had been taught by their parents, and what thev, I fear, had learned from their superiors." — Appeal to the Public on the Subject of the Riots at Birmingham. I JOSEPH PRIESTLEY 23 istence of a soul distinct from the body; and as a natural consequence, he denied the natural im- mortality of man. In relation to these matters English opinion, a century ago, was very much what it is now. A man may be a necessarian without incurring graver reproach than that implied in being called a gloomy fanatic, necessarianism, though very shocking, having a note of Calvinistie orthodoxy; but, if a man is a materialist; or, if good authori- ties say he is and must be so, in spite of his assertion to the contrary; or, if he acknowledge himself unable to see good reasons for believing in the natural immortality of man, respectable folks look upon him as an unsafe neighbour of a easli- box, as an actual or potential sensualist, the more virtuous in outward seeming, the more certainly loaded with secret " grave personal sins." ^Nevertheless, it is as certain as anything can be, . that Joseph Priestley was no gloomy fanatic, but as cheerful and kindly a soul as ever breathed, the idol of children; a man who was hated only by those who did not know him, and who charmed away the bitterest prejudices in personal inter- course; a man who never lost a friend, and the best testimony to whose worth is the generous and tender warmth with which his many friends vied with one another in rendering him substantial help, in all the crises of his career. The unspotted purity of Priestley's life, the 62 24 JOSEPH PEIBSTLEY i strictness of his performance of every duty, his transparent sincerity, the unostentatious and deep- seated piety which breathes through all his corre- spondence, are in themselves a sufficient refutation of the hypothesis, invented by bigots to cover uneharitableness, that such opinions as his must arise from moral defects. And his statue will do as good service as the brazen image that was set upon a pole before the Israelites, if those who have been bitten by the fiery serpents of sectarian hatred, which still haunt this wilderness of a world, are made whole by looking upon the image of a heretic who was yet a saint. Though Priestley did not believe in the natural immortality of man, he held with an almost naive realism that man would be raised from the dead by a direct exertion of the power of God, and thenceforward be immortal. And it may be as well for those who may be shocked by this doc- trine to know that views, substantially identical with Priestley's, have been advocated, since his time, by two prelates of the Anglican Church: by Dr. Whately, Archbishop of Dublin, in his well- known " Essays "; * and by Dr. Courtenay, Bishop of Kingston in Jamaica, the first edition of whose remarkable book " On the Future States," dedi- cated to Archbishop Whately, was published * First Series. On Some of the Peculiarities of the Christian Religion. Essay I. " Revelation of a Future State." I JOSEPH PRIESTLEY 25 in 1843 and the second in 1857. According to Bishop Courtenay, " The death of the body will cause a cessation of all the activity of the mind by way of natural consequence ; to continue for ever unless the Creator should interfere.'' And again: — " The natural end of human existence is the ' first death,' the dreamless slumber of the grave, wherein man lies spell- bound, soul and body, under the dominion of sin and death — that whatever modes of conscious existence, whatever fu- ture state of ' life 'or of ' torment ' beyond Hades are re- served for man, are results of our blessed Lord's victory over sin and death ; that the resurrection of the dead must be preliminary to their entrance into either of the future states, and that the nature and even existence of these states, and even the mere fact that there is a futurity of consciousness, can be known only through God's revela- tion of Himself in the Person and the Gospel of His Son." —P. 389. And now hear Priestley: — " Man, according to this system (of materialism), is no more than we now see of him. His being commences at the time of his conception, or perhaps at an earlier period. The corporeal and mental faculties, in being in the same substance, grow, ripen, and decay together ; and whenever the system is dissolved, it continues in a state of dissolu- tion till it shall please that Almighty Being who called it into existence to restore it to life again." — "Matter and Spirit," p. 49. And again: — " The doctrine of the Scripture is, that God made man of the dust of the ground, and by simply animating this 26 JOSEPH PRIESTLEY ^ organized matter, made man that living percipient and. in- telligent being that he is. According to Revelation, death is a state of rest and insensibility, and our only though sure hope of a future life is founded on the doctrine of the resur- rection of the whole man at some distant period ; this as- surance being sufficiently confirmed to us both by the evi- dent tokens of a Divine commission attending the persons who delivered the doctrine, and especially by the actual resurrection of Jesus Christ, which is more authentically attested than any other fact in history."— /ii