year, 1796, that Chemistry first engaged his articles ;' describing their qualities with far attention; and as a Member of the Man- less earnestness than a London linen raper chester Literary and Philosophical Institution, would show in commending the very different of which he afterwards became President, he articles on which lie his shelves... placed before them in successive years a series Dalton's doctrines, therefore, needed other of papers of great value, in connexion with advocacy than his own to bring them fairly this and other branches of Natural Philoso- before the world. Nor was this aid wanting. phy; evincing both the extent of his objects We shall have to mention before we conclude and the energetic and successful labour he the names of those eminent Chemists who bestowed upon them. We have not space to speedily recognised the value of the discovery, enumerate these different Memoirs; but may and sought by their labours to verify and say.generally that the most important of them extend it. His own life proceeded meanwhile relate to the weight, temperature, and mois in the same course of tranquil labour. He ture of the atmosphere, furnishing, with his was now, however, less occupied with new reșearches on rain and evaporation, the basis objects than with the completion of his preof modern meteorology--to the various phe-vious researches, and the removal of objecnomena of heat and cold, as produced by or tions which had been raised to certain parts determining the state of other bodies and to of them. With all his love of truth, in scithe constitution of mixed gases, and especial-ence as in other things, Dalton was strongly ly of those forming the atmosphere. Later tenacious of conclusions once formed ; and observations and experiments, less rude than there were many opinions to which he clung, those which he employed, have tended to in- long after more exact experiments than his validate some of his conclusions. But many own had shown them to be doubtful or remain untouched-all have contributed to inadmissible. We may name as instances, the advancement of science--and all give his obstinate adherence to the atomic weights eminent proof of his sagacity and boldness of be first assigned, though proved to be incorreseaech.

rect—his reluctance to adopt the doctrine of We do not here follow the labours or writ- volumes, received by all other chemists-and ings of Dalton into the great discovery of bis long struggle against the recognition of his life, as we shall speak of this hereafter. chlorine as a chemical element. Before it was sufficiently matured for publica- Though always recluse in his habits, bis tion, he was invited early in 1804 to give a reputation, now established both at home and course of Lectures on Natural Philosophy at abroad, inevitably enlarged his intercourse the Royal Institution in London. With some with the world. Manchester too, at least kind and valuable aid from Davy, he appears those in it who found leisure for anything to have gone through the course satisfactorily, beyoud the labours and profits of the loom, and, from his own account, with a good deal began to feel pride in the fame of their fellowof applause. We cannot but think, however, townsman. But his private life was little that he unconsciously overrated his success; changed in its simplicity-his character not and that what he considered such was in at all. While streets, factories, and steamsome part a courteous regard of his audience | engines were growing up multitudivously to the simplicity and peculiarities of the around, he continued to reside in the same man. A few years later, when his discoveries quiet house and family in which he finally were still only partially known, we heard him closed his career. He seldom went into what deliver a short course on this subject at Edin. is called society. His associates were chiefly burgh to a scanty audience. It would be those who had pursuits akin to his own, and hard to conceive anything more uncouth or a few intimate friends and pupils, with whom ineffective than his manner of dealing with he sometimes unbent himself after the labours the great physical truths that lay before him. of the day. One of these friends describes His experiments

, as made in public, frequent- him as exceedingly cheerful and facetious on ly failed. His voice was harsh, indistinct, and such occasions. We can readily believe in

. unemphatical; and he was singularly wanting his cheerfulness, but find it difficult to imagine in the language and power of illustration, in Dalton anything approaching to wit. needful to a lecturer on these high matters Even in the fashion of his amusemeuts there of philosophy, and by which Davy and Fara- was the same order and method as in other day have given such lustre to their great dis- things. Every Thursday afternoon he incoveries. Among other instances of his odd dulged in his favourite diversion of bowling; appropriation of epithets, we recollect that in watching with a sort of scientific eagerness treating of oxygen, hydrogen, nitrogen, &c. the motions of the bowls, and noting down --those great elements which pervade all minutely in a book all the losses or gains of

13 nature-he generally spoke of them as, 'these the few pence for which the game was played.

a

a

In every other habit of his life, as to hours, selves in the human intellect. Io the higher labour, and food, there was the same sim- acceptation of the term, Dalton could bardly plicity, order, and temperance.

be called a man of genius. He had not those Occasionally he visited London, or made wings with which some men soar over the excursions into the Lake scenery of his native ocean of undiscovered truth, discovering county. A notable incident in a life thus regions to be submitted hereafter to luman tranquil was a visit to Paris in 1822, which intelligence and power. But he brought to we know to have afforded him singular plea- his researches, as we have seen, the habits of sure. Six years before, he had been elected a a sagacious and intrepid thinker, swayed by Corresponding Member of the Academy of no authority but that of facts, and sedulous Sciences—a proof of the reputation he had in seeking for these by his own labours and already earned abroad. Mr. Dockray, his methods. We believe this description to incompanion on this journey, graphically de- clude all that is most peculiar in his character scribes a dinner given to Dalton by Laplace as a philosopher. at his country-seat at Arcueil, the beautiful Dalton's connexion with the French Acagrounds of which derive no less fame from demy was not limited to his first honour in having been the residence of this philosopher, it. In 1830, on the death of Sir H. Davy, than from the earlier destiny of the spot as he was elected to fill his place as one of the the abode of the Emperor Julian, when Go- eight Foreign Associates of the Academy; a vernor of Gaul. Ai this dinner Berthollet, distinction, from its rarity, fitly regarded as Arago, Cuvier, Biot, and Fourier were among among the highest which science can bestow. the guests_names all illustrious in the annals It is remarkable that until 1822 he was not of science. Mr. Dockray pictures to us Dal- elected a Fellow of the Royal Society. The ton walking in the evening through the ruins absence of all ambition or effort on his part which yet remain of Julian's residence, be- must be received as the cause of this delay. tween Laplace and Berthollet-a remarkable In 1826 his high merits as a discoverer were group, and almost as much so in the diversity fully recognised by the Society in the award of the men as in the community of their fame. to him of the first of the royal prizes given From our recollection of Laplace we feel how after their institution. great must have been the contrast between Honours indeed now began to fall more him and Dalton—the latter what we have thickly upon bim. The establishment of the already described him--the former equally British Association in 1831, the annual meetplacid in demeanour, but with the air, habits, ings of which Dalton repeatedly attended, and courtesies of an old French nobleman. was in some part concerned in this effect. In estimating their relative genius we must Though his discoveries were at this time fully needs rank Laplace far above the level of established and familiar to the scientific world, Dalton. Both of them mathematicians, they the seclusion of his life had permitted fow to yet trod in mathematical paths so remote know him personallly; and the Quaker phifrom each other, as almost to efface every losopher, now well advanced in years, stood vestige of this connexion. The very diversity among his brethren in science at these meethere is the exponent of the scientific character tings, a new object of attention and interest. of the two men.

Dalton may be said to have The simplicity of his demeanour, from which worked in straight lines, both in mathematics age had taken off its earlier uncouthness, won and general physics ; with definite objects upon the feelings of all; and even at later placed clearly before his conceptions, which meetings of the Association, when the novelty he pursued steadily by the simplest, or even had worn off, Dalton was ever regarded with rudest, methods to the attainment of the affectionate veneration. results desired. The genius of Laplace took In 1832, at the meeting of the Association for its sphere of action the wide domain of at Oxford, the honorary degree of D.C.L. was the universe: and while by the mighty power conferred upon him, in conjunction with of his mathematical analysis he was removing Faraday, Brewster, and Robert Brown. The anomalies, and reconciling even the secular same honour he received at Edinburgh two perturbations of the planets to the one great years later. In 1833, under Lord Grey's law of gravitation, he applied the same power government, a pension of 1501. a-year was and the same methods of evidence to almost settled upon him, providing a happy release every part of human knowledge. He worked from the burden of elementary teaching. not in straight lines, but sweeping over a vast About the same time the people of Manchester circle, and bringing each part into relation subscribed 20001. for tho statue of a man with the whole.

who thus honoured their town ; and its exeIt is difficult to give any single definition cution was fitly committed to Chantrey, whose of genius, having due regard to the endless genius rendered it a wonderful work. While varieties and anomalies which present them-Dalton was in London, sitting to this great

"

sculptor, it was suggested by his friend, Mr. he fell out of bed, and was found lifeless on Babbage, that he should be presented at the the floor. A post-mortem examination showed king's levee. His own acquiescence being no recent rupture of any, blood vessel, but obtained, the preliminaries of his dress as au great venous congestion, and in one part of Oxford Doctor of Laws settled, and prepara- the brain distinct traces of the extravasation, tory instructions given by enacting the levee which had probably produced the first parain a private room, he was presented to Wil-lytic attack. There was too much of ostenliam IV., who seems to have questioned him tation in all that followed the event. His with the kind familiarity which belonged to coffin, placed in public in the Town Hall, was that sovereign's nature. Mr. Babbage, the dux visited by more than 40,000 spectators, and a

. as well as auctor in this presentation, heard procession of nearly 100 carriages followed it one court officer say to another, Who the to the grave. This was scarcely in accordance dm is that fellow whoin the king keeps talk with the life and character of the man. ing to so long ? This gentleman would have The portrait of Dalton, prefixed to Dr. Henbeen still more surprised bad he seen the ry's volume, and taken from Chantrey's bust, Quaker garb concealed under the scarlet robe faithfully represents his countenance, and of the University of Oxford.

especially what we would venture to term the Dalton's life was continued ten years austere gentleness of his expression. His was beyond this time, to the age of 78, but we a face which told the whole character at once have little more to record. The last few years --its earnestness, simplicity, and truth; and formed a period of gradual but sensible decay even that power of patient, methodical labour, in his faculties both of mind and body, con

which marked and determined every step in sequent upon a paralytic seizure in 1837, fol. his career. lowed in 1838 by a slighter attack of the same We have

very

little clue to Dalton's relinature. He did not die until 1844; but the gious opinions. He was scarcely ever heard antecedents of the change were on him be- to allude to the subject; and though he atfore, and, for some time at least, consciously tended twice every Sunday at the Friends? so to himself.

In 1840 he presented a paper Meeting-House, be never took other than a to the Royal Society on the phosphates and silent part in their devotional exercises. When arseniates ; so obscure throughout, and the such was his reserve upon this point, even to conclusions so erroneous, that the Council those most intimate with him, we have no declined its publication in the Transactions. right to hazard suppositions of our own, which Dalton, much mortified, printed it separately, can never be verified, and which might perwith the indignant comment annexed to it chance be widely removed from the truth.

Cavendish, Davy, Wollaston, and Gilbert are After this short sketch of Dalton's life and no more.'

Even after this, indeed, he pub- personal character, we have still to speak of lished four short chemical essays; but these the discovery which gives the greatest lustre were probably the result of prior labours, to his name, of its connexion with prior syssince the last two contain the elements of a tems or theories, and of the influence it has discovery of so much interest, that he himself | had on the subsequent progress and direction says, 'It is the greatest discovery that I know of physical inquiry. Yet we feel the difficulty, of, next to the atomic theory. We may if not impossibility, of giving a popular view briefly denote the subject, by stating that it of the atomical philosophy. Its relations to was that curious research into the relative con- every branch of natural science have become ditions of the water and solid parts of hy- so numerous, close, and complex, that no drated salts, which has since been so admirably superficial glance could present more than a prosecuted by Playfair and Joule; verifying vague idea of the grandeur of the theme; in the main, while modifying in parts, the re- while, if pursued into details, its illustration markable results obtained by Dalton's saga- becomes equally obscure from their multiplicity. We do not find anything to tell us at city, froin the questions still existing upon what period the latter was engaged in this matters of fact, and from controversies which inquiry; but doubtless some time before that yet hang over some of the conclusions of impairment of bis mental powers to which we theory. have just alluded.

Nor does the difficulty end here. In disAt Dalton's age a change of this nature, cussing these questions of the atomio theory, and evidently connected with cerebral disease, we often touch on that debateable ground is insuperable by remedies, and sure to be between mathematics and metaphysics, which augmented by time. Though appointed a D'Alembert has well named "l'abime des invice-president at the meeting of the British certitudes, there being scarcely a step in the Association at Manchester, 1842, it was merely discussion which does not approach in some as a tribute to his name. In May, 1844, an- point or other to this boundary of human inother fit occurred; and on the 27th of July telligence. While modern science is defining.

by strict numerical formula the proportions ment, or mutual substitution of the atoms in which the molecular combinations of bodies composing them. take place-and often with such certainty Following then this suggestion as to order, that the chemist can foretell the results of an the speculative part of the atomic philosophy analysis before the labours of the laboratory first comes before us. In every age and com have begun--the demonstration of facts thus munity there are certain minds prone, from obtained is at every step urging the mind to their very constitution, to an earnest scrutiny wards those unseen properties and profound of the world around them. It is an instinctive laws of the material world, where thought is and almost compulsory use of one of those forced to pause and further demonstration is powers committed to man by his Maker; the lost in darkness. Some men, by a certain variety of which powers in different men felicity of faculties, may penetrate into this seems as much the object of a wise design, as obscurity beyond their fellows; but to all their original bestowal. The mere existence there is a limit, which such men also are best of Matter in its relation to Spirit, and the endable to discover and define. There may be less forms and changes which material bodies rashness indeed in marking it too absolutely, assume, whether subordinate to human will for the science of our own day has often swept or not, irresistibly excite such minds to some over what seemed to be the final limits of form of speculation, however vague in method our knowledge; and the subject before us is or conclusion. We may omit here all notice one where physical evidences still crowd upon of those crude notions of earlier ages and us from so many separate and unexpected ruder races on this subject, which have parsources, that it is hard to curb the efforts of tially come down to us; but we must pause the mind to theorize upon the results already awhile amidst the riper speculations on the obtained.

elementary qualities of matter, which the phiThis very multiplication of proofs is in it-losophers and poets of Greece and Rome have self a hindranco to a concise and popular transmitted to later ages. To the Greeks view of the modern atomic doctrine. The more especially we owe those theories, at once physical evidence is not merely various in its subtle and bold, which, while they seize a sources

, but presents peculiar modifications, portion of truth by a sort of intuitive percepadding much to its complexity. The recent tion, do yet neglect to fortify this by experidiscoveries in Isomorphism, Ísomerism, and ment or exact observation.' It is hard to A Hotrophy (names in themselves formidable explain how a people, not merely subtle and to the ear), indicating some of the various inventive, but capable of high thoughts and modes in which the molecules of matter, philosophy, and keenly inquisitive into the simple or compound, are related to, or act secrets of nature, should never have been upon, one another, -all bear essentially on fairly imbued with the principle and methods the question of the atomical constitution of of experimental research. The exceptional bodies; and require an interpretation accor- cases are rare, and rather augment than lessen dant at least, if not common, to all

. An ele- our wonder at the fact. It is surprising that mentary view of the subject is further embar- the success of particular experiments and inrassed by the anomalous or doubtful points ductions should not have led the way to other which still remain for solution,-such as the like researches, even had the principle of incase of a numerical series, perfect in its other quiry not been suggested by the phenomena parts, being stopped by an anomalous fraction, of the world around. only to be removed by a better analysis which However this may be, the absence of anymay bring the refractory element into the thing like analysis limited the Greek philososcale from which it seemingly departs; or phy to purely speculative doctrines regarding by altering the first terms so as to convert matter, and the various concourse and comthe fraction into a simple number in the se. binations of atoms to which its forms and mes.

qualities are due. Of these theories, the The statement of these difficulties is not volume of Professor Daubeny now before usaltogether without its use. It suggests, first, unpretending in form, but of great merit in the demarcation, as far as such can be drawn, execution-gives a clear and sufficient acbetween the metaplıysical and physical parts count. Dr. Daubeny brings indeed high quaof the atomic philosophy—between that which lifications to his work-a philosophical spirit, is purely or chiefly speculative, and that which classical knowledge, and an intimate acquaindepends on experiment and is expressed by tance with the doctrines and discoveries of formulæ of numbers. And further, in regard modern Chemistry. All are required for the to the latter class of researches, it indicates complete view of a subject of such wide comthe purport and scope of the inquiry, as em- pass and complexity. bracing all those relations of bodies which de- The first great problem belonging to it pend on the numerical proportions, arrange- one which has engaged the attention of

thinking men in all ages--is the origin and conception than this are the phenomena of nature of Matter, as distinguished from Mind possible fulfilment. It was farther seen (and or Spirit, and also from that notion of the almost by the same necessity) that these void in space which has ever entered into the minute parts, molecules, or atoms, must have inquiry. The genius of the Greek philosophy definite relations, whether of attraction or redealt with this question in its most abstruse pulsion, to one another. All nature, animate forms; but not before such speculations bad or inanimate, teems with evidence to this effect, already found place in the philosophical, reli- and no experiment was needed to attest it. gious, or popular dogmas of yet earlier and The conception of definite proportions in their more remote Oriental races, to whose mental molecular relations-now ripened into a great temperament they seem to have been espe- physical law-can hardly be said to occur in cially congenial. Stripping off the various the ancient philosophy, though some few pasdress and disguises of language, they are in sages may vaguely express the idea. But anfact the self-same questions which have de- other question, yet current in our own time, scended to our own time; and which we are and which in some sort lies at the bottom of destined to transmit—still unresolved, though every atomic theory, engaged more distinctly better defined—to our own philosophical pos- the notice of these schools of antiquity-a terity. Unaided human reason, indeed, under question which neither reason nor experiment whatever form of words or logic it may shelter can ever do more than settle presumptively--its weakness, must ever be baffled by such viz., whether there are truly ultimate molequestions as,—whether matter has any exist cules or atoms of matter insusceptible of ence apart from the perceptions of the intel- further division ? or whether we must here, as lectual being ?--whether it is eternal in itself, elsewhere in nature, veil our reason before and moulded only by the acts of creation, or that metaphysical infinite which bafles alike actually brought into existence by the power definition and conception, and consider matter which has thus moulded it ?-whether, if as divisible without limit or end? eternal, its nature be not such as to limit and The most rational of the Greek philosophers constrain this power, which has framed from settled this abstruse question in the same way it the order of things we see around us ? * in which it has been présumptively determined Wonderful we may well deem it, that man by the sounder methods of modern science. should be gifted with a spirit able to pro- The phrases employed (adiaspeta Meyson pound those and other like subtleties to itself. | αδιαιρέτα σωματα-αμερη τα ελαχιστα, &c.) But true philosophy consists in setting a interpret to us their belief that there are porboundary between these vague impracticabi- tions of matter, inconceivably minute, which lities, which belong not to our reason, and are absolute units in themselves, and admit of that great field of exact observation and ex- no division beyond. This doctrine is wholly periment which the Creator has privileged distinct from the ancient theory of the four man to work in, by giving him faculties fitted len its (the four champions fierce' of Milfor this wiser and better labour.

ton), which served as a coarse formula for All that can rightly be called atomic philo- reason to work upon, before it bad been shown sophy—the investigation of matter in its by experiment how completely these elements molecular parts, and under the different com are mutually convertible throughout every binations and mutual actions of these-comes part of the inaterial world. distinctly within this field of legitimate in- Another point in the ancient atomic philoqniry. Yet here, too, rash speculation had a sophy, anticipating modern inquiry though long period of supremacy. We have already ruduing beyond it, is the question as to the alluded to those hypotheses of the Greek phi- form of configuration of those indivisible losophers, through which, unaided by experi- atoms, which inay be regarded as the true ment, they sought to explain the multiform units of the material world. Here, again, all shapes, combinations, and changes which was mere speculation; and the mathematical matter assumes or undergoes. They saw, as forms assigned to different conditions of matter it was easy to see, that for such an explanation were generally based on the feeblest and most it must be supposed divisible into parts of frivolous analogies. Whether modern science, exquisite minuteness: since under no other with its more severe and scrupulous inquiry,

can ever attain to more perfect proof, is yet * Other speculators again, more purely Oriental in character, assign to matter an actual inherent hidden in the future. Certain paths, which malignity of nature, opposing itself to what is good we shall hereafter notice, seem opening in this in creation, and thence bringing evil into the direction, and have been zealously pursued. world. In the words of Theophrastes

, matter is We live in an age of new methods, as well as πολυ το ουκ υπακούον, ουδε δεχομενον το Ευ. The doctrines of the Chaldeans, of Zoroaster, and of the

new facts in science; and where the object is Indian mythologies, are all based, more or less, on

not in its nature insuperable by human reason, this conception.

we may venture to aspire, if not to certain