,,the ,,history ,,of ,,chemistry4 ,,by ,,thomas ,,thomson1 ,m4 ,d4 ,f4,r4,s4 ,l4 ,e42 ,f4,l4,s42 ,f4,g4,s41 c4 ,,regius ,,professor ,,of ,,chemistry ,,in ,,the ,,university ,,of ,,glasgow4 ,,in ,,two ,,volumes4 ,,vol4 ,,ii4 ,,london3 ,,henry ,,colburn ,,and ,,richard ,,bentley1 ,,new ,,burlington ,,street4 #ahca4 ,c4 ,,whiting1 ,,beaufort ,,house1 ,,strand4 ,,contents ,,of ,,the ,,second ,,volume4 ,,chapter ,i4 ,page ,of the foundation and progress of scientific chemistry in ,great ,britain #a ,,chapter ,,ii4 ,of the progress of philosophical chemistry in ,sweden #bf ,,chapter ,,iii4 ,progress of scientific chemistry in ,france #ge ,,chapter ,,iv4 ,progress of analytical chemistry #aij ,,chapter ,v4 ,of electro-chemistry #bea ,,chapter ,,vi4 ,of the atomic theory #bgg ,,chapter ,,vii4 ,of the present state of chemistry #cji ,,history ,,of ,,chemistry4 ,,chapter ,i4 ,,of ,,the ,,foundation ,,and ,,progress ,,of ,,scientific ,,chemistry ,,in ,,great ,,britain4 ,while ,mr4 ,cavendish was extending the bounds of pneumatic chemistry1 with the caution and precision of a ,newton1 ,dr4 ,priestley1 who had entered on the same career1 was proceeding with a degree of rapidity quite unexampled2 while from his happy talents and inventive faculties1 he contributed no less essentially to the progress of the science1 and certainly more than any other ,british chemist to its popularity4 ,joseph ,priestley was born in #agcc1 at ,fieldhead1 about six miles from ,leeds in ,yorkshire4 ,his father1 ,jonas ,priestley1 was a maker and dresser of woollen cloth1 and his mother1 the only child of ,joseph ,swift a farmer in the neighbourhood4 ,dr4 ,priestley was the eldest child2 and1 his mother having children very fast1 he was soon committed to the care of his maternal grandfather4 ,he lost his mother when he was only six years of age1 and was soon after taken home by his father and sent to school in the neighbourhood4 ,his father being but poor1 and encumbered with a large family1 his sister1 ,mrs4 ,keighley1 a woman in good circumstances1 and without children1 relieved him of all care of his eldest son1 by taking him and bringing him up as her own4 ,she was a dissenter1 and her house was the resort of all the dissenting clergy in the country4 ,young ,joseph was sent to a public school in the neighbourhood1 and1 at sixteen1 had made considerable progress in ,latin1 ,greek1 and ,hebrew4 ,having shown a passion for books and for learning at a very early age1 his aunt conceived hopes that he would one day become a dissenting clergyman1 which she considered as the first of all professions2 and he entered eagerly into her views3 but his health declining about this period1 and something like phthisical symptoms having come on1 he was advised to turn his thoughts to trade1 and to settle as a merchant in ,lisbon4 ,this induced him to apply to the modern languages2 and he learned ,french1 ,italian1 and ,german1 without a master4 ,recovering his health1 he abandoned his new scheme and resumed his former plan of becoming a clergyman4 ,in #ageb he was sent to the academy of ,daventry1 to study under ,dr4 ,ashworth1 the successor of ,dr4 ,doddridge4 ,he had already made some progress in mechanical philosophy and metaphysics1 and dipped into ,chaldee1 ,syriac1 and ,arabic4 ,at ,daventry he spent three years1 engaged keenly in studies connected with divinity1 and wrote some of his earliest theological tracts4 ,freedom of discussion was admitted to its full extent in this academy4 ,the two masters espoused different sides upon most controversial subjects1 and the scholars were divided into two parties1 nearly equally balanced4 ,the discussions1 however1 were conducted with perfect good humour on both sides2 and ,dr4 ,priestley1 as he tells us himself1 usually supported the heterodox opinion2 but he never at any time1 as he assures us1 advanced arguments which he did not believe to be good1 or supported an opinion which he did not consider as true4 ,when he left the academy1 he settled at ,needham in ,suffolk1 as an assistant in a small1 obscure dissenting meeting-house1 where his income never exceeded #cjl4 a-year4 ,his hearers fell off1 in consequence of their dislike of his theological opinions2 and his income underwent a corresponding diminution4 ,he attempted a school2 but his scheme failed of success1 owing to the bad opinion which his neighbours entertained of his orthodoxy4 ,his situation would have been desperate1 had he not been occasionally relieved by sums out of charitable funds1 procured by means of ,dr4 ,benson1 and ,dr4 ,kippis4 ,several vacancies occurred in his vicinity2 but he was treated with contempt1 and thought unworthy to fill any of them4 ,even the dissenting clergy in the neighbourhood thought it a degradation to associate with him1 and durst not ask him to preach3 not from any dislike to his theological opinions2 for several of them thought as freely as he did2 but because the genteeler part of their audience always absented themselves when he appeared in the pulpit4 ,a good many years afterwards1 as he informs us himself1 when his reputation was very high1 he preached in the same place1 and multitudes flocked to hear the very same sermons1 which they had formerly listened to with contempt and dislike4 ,his friends being aware of the disagreeable nature of his situation at ,needham1 were upon the alert to procure him a better4 ,in #ageh1 in consequence of the interest of ,mr4 ,gill1 he was invited to appear as a candidate for a meeting-house in ,sheffield1 vacant by the resignation of ,mr4 ,wadsworth4 ,he appeared accordingly and preached1 but was not approved of4 ,mr4 ,haynes1 the other minister1 offered to procure him a meeting-house at ,nantwich in ,cheshire4 ,this situation he accepted1 and1 to save expenses1 he went from ,needham to ,london by sea4 ,at ,nantwich he continued three years1 and spent his time much more agreeably than he had done at ,needham4 ,his opinions were not obnoxious to his hearers1 and controversial discussions were never introduced4 ,here he established a school1 and found the business of teaching1 contrary to his expectation1 an agreeable and even interesting employment4 ,he taught from seven in the morning1 till four in the afternoon2 and after the school was dismissed1 he went to the house of ,mr4 ,tomlinson1 an eminent attorney in the neighbourhood1 where he taught privately till seven in the evening4 ,being thus engaged twelve hours every day in teaching1 he had little time for private study4 ,it is1 indeed1 scarcely conceivable how1 under such circumstances1 he could prepare himself for ,sunday4 ,here1 however1 his circumstances began to mend4 ,at ,needham it required the utmost economy to keep out of debt2 but at ,nantwich1 he was able to purchase a few books and some philosophical instruments1 as a small air-pump1 an electrical machine1 c4 ,these he taught his eldest scholars to keep in order and manage3 and by entertaining their parents and friends with experiments1 in which the scholars were generally the operators1 and sometimes the lecturers too1 he considerably extended the reputation of his school4 ,it was at ,nantwich that he wrote his grammar for the use of his school1 a book of considerable merit1 though its circulation was never extensive4 ,this latter circumstance was probably owing to the superior reputation of ,dr4 ,lowth1 who published his well-known grammar about two years afterwards4 ,being boarded in the house of ,mr4 ,eddowes1 a very sociable and sensible man1 and a lover of music1 ,dr4 ,priestley was induced to play a little on the ,english flute2 and though he never was a proficient1 he informs us that it contributed more or less to his amusement for many years4 ,he recommends the knowledge and practice of music to all studious persons1 and thinks it rather an advantage for them if they have no fine ear or exquisite taste1 as they will1 in consequence1 be more easily pleased1 and less apt to be offended when the performances they hear are but indifferent4 ,the academy at ,warrington was instituted while ,dr4 ,priestley was at ,needham1 and he was recommended by ,mr4 ,clark1 ,dr4 ,benson1 and ,dr4 ,taylor1 as tutor in the languages2 but ,dr4 ,aiken1 whose qualifications were considered as superior1 was preferred before him4 ,however1 on the death of ,dr4 ,taylor1 and the advancement of ,dr4 ,aiken to be tutor in divinity1 he was invited to succeed him3 this offer he accepted1 though his school at ,nantwich was likely to be more gainful2 for the employment at ,warrington was more liberal and less painful4 ,in this situation he continued six years1 actively employed in teaching and in literary pursuits4 ,here he wrote a variety of works1 particularly his ,history of ,electricity1 which first brought him into notice as an experimental philosopher1 and procured him celebrity4 ,after the publication of this work1 ,dr4 ,percival of ,manchester1 then a student at ,edinburgh1 procured him the title of doctor in laws1 from that university4 ,here he married a daughter of ,mr4 ,isaac ,wilkinson1 an ironmonger in ,wales2 a woman whose qualities he has highly extolled1 and who died after he went to ,america4 ,in the academy he spent his time very happily1 but it did not flourish4 ,a quarrel had broken out between ,dr4 ,taylor and the trustees1 in consequence of which all the friends of that gentleman were hostile to the institution4 ,this1 together with the smallness of his income1 #ajjl4 a-year1 and #ael4 for each boarder1 which precluded him from making any provision for his family1 induced him to accept an invitation to take charge of ,millhill chapel1 at ,leeds1 where he had a considerable acquaintance1 and to which he removed in #agfg4 ,here he engaged keenly in the study of theology1 and produced a great number of works1 many of them controversial4 ,here1 too1 he commenced his great chemical career1 and published his first tract on air4 ,he was led accidentally to think of pneumatic chemistry1 by living in the immediate vicinity of a brewery4 ,here1 too1 he published his history of the ,discoveries relative to ,light and ,colours1 as the first part of a general history of experimental philosophy2 but the expense of this book was so great1 and its sale so limited1 that he did not venture to prosecute the undertaking4 ,here1 likewise1 he commenced and published three volumes of a periodical work1 entitled ,the ,theological ,repository1 which he continued after he settled in ,birmingham4 ,after he had been six years at ,leeds1 the ,earl of ,shelburne 7afterwards ,marquis of ,lansdowne71 engaged him1 on the recommendation of ,dr4 ,price1 to live with him as a kind of librarian and literary companion1 at a salary of #bejl4 a-year1 with a house4 ,with his lordship he travelled through ,holland1 ,france1 and a part of ,germany1 and spent some time in ,paris4 ,he was delighted with this excursion1 and expressed himself thoroughly convinced of the great advantages to be derived from foreign travel4 ,the men of science and politicians in ,paris were unbelievers1 and even professed atheists1 and as ,dr4 ,priestley chose to appear before them as a ,christian1 they told him that he was the first person they had met with1 of whose understanding they had any opinion1 who was a believer of ,christianity2 but1 upon interrogating them closely1 he found that none of them had any knowledge either of the nature or principles of the ,christian religion4--,while with ,lord ,shelburne1 he published the first three volumes of his ,experiments on ,air1 and had collected materials for a fourth1 which he published soon after settling in ,birmingham4 ,at this time also he published his attack upon ,drs4 ,reid1 ,beattie1 and ,oswald2 a book which1 he tells us1 he finished in a fortnight3 but of which he afterwards1 in some measure1 disapproved4 ,indeed1 it was impossible for any person of candour to approve of the style of that work1 and the way in which he treated ,dr4 ,reid1 a philosopher certainly much more deeply skilled than himself in metaphysics4 ,after some years ,lord ,shelburne began to be weary of his associate1 and1 on his expressing a wish to settle him in ,ireland1 ,dr4 ,priestley of his own accord proposed a separation1 to which his lordship consented1 after settling on him an annuity of #aejl41 according to a previous stipulation4 ,this annuity he continued regularly to pay during the remainder of the life of ,dr4 ,priestley4 ,his income being much diminished by his separation from ,lord ,shelburne1 and his family increasing1 he found it now difficult to support himself4 ,at this time ,mrs4 ,rayner made him very considerable presents1 particularly at one period a sum of #djjl42 and she continued her contributions to him almost annually4 ,dr4 ,fothergill had proposed a subscription1 in order that he might prosecute his experiments to their utmost extent1 and be enabled to live without sacrificing his time to his pupils4 ,this he accepted4 ,it amounted at first to #djl4 per annum1 and was afterwards much increased4 ,dr4 ,watson1 ,mr4 ,wedgewood1 ,mr4 ,galton1 and four or five more1 were the gentlemen who joined with ,dr4 ,fothergill in this generous subscription4 ,soon after1 he settled in a meeting-house in ,birmingham1 and continued for several years engaged in theological and chemical investigations4 ,his apparatus1 by the liberality of his friends1 had become excellent1 and his income was so good that he could prosecute his researches to their full extent4 ,here he published the three last volumes of his ,experiments on ,air1 and various papers on the same subject in the ,philosophical ,transactions4 ,here1 too1 he continued his ,theological ,repository1 and published a variety of tracts on his peculiar opinions in religion1 and upon the history of the primitive church4 ,he now unluckily engaged in controversy with the established clergy of the place2 and expressed his opinions on political subjects with a degree of freedom1 which1 though it would have been of no consequence at any former period1 was ill suited to the peculiar circumstances that were introduced into this country by the ,french revolution1 and to the political maxims of ,mr4 ,pitt and his administration4 ,his answer to ,mr4 ,burke's book on the ,french revolution excited the violent indignation of that extraordinary man1 who inveighed against his character repeatedly1 and with peculiar virulence1 in the house of commons4 ,the clergy of the church of ,england1 too1 who began about this time to be alarmed for their establishment1 of which ,dr4 ,priestley was the open enemy1 were particularly active2 the press teemed with their productions against him1 and the minds of their hearers seem to have been artificially excited2 indeed some of the anecdotes told of the conduct of the clergy of ,birmingham1 were highly unbecoming their character4 ,unfortunately1 ,dr4 ,priestley did not seem to be aware of the state of the nation1 and of the plan of conduct laid down by ,mr4 ,pitt and his political friends2 and he was too fond of controversial discussions to yield tamely to the attacks of his antagonists4 ,these circumstances seem in some measure to explain the disgraceful riots which took place in ,birmingham in #agia1 on the day of the anniversary of the ,french revolution4 ,dr4 ,priestley's meeting-house and his dwelling-house were burnt2 his library and apparatus destroyed1 and many manuscripts1 the fruits of several years of industry1 were consumed in the conflagration4 ,the houses of several of his friends shared the same fate1 and his son narrowly escaped death1 by the care of a friend who forcibly concealed him for several days4 ,dr4 ,priestley was obliged to make his escape to ,london1 and a seat was taken for him in the mail-coach under a borrowed name4 ,such was the ferment against him that it was believed he would not have been safe any where else2 and his friends would not allow him1 for several weeks1 to walk through the streets4 ,he was invited to ,hackney1 to succeed ,dr4 ,price in the meeting-house of that place4 ,he accepted the office1 but such was the dread of his unpopularity1 that nobody would let him a house1 from an apprehension that it would be burnt by the populace as soon as it was known that he inhabited it4 ,he was obliged to get a friend to take a lease of a house in another name2 and it was with the utmost difficulty that he could prevail with the landlord to allow the lease to be transferred to him4 ,the members of the ,royal ,society1 of which he was a fellow1 declined admitting him into their company2 and he was obliged to withdraw his name from the society4 ,when we look back upon this treatment of a man of ,dr4 ,priestley's character1 after an interval of forty years1 it cannot fail to strike us with astonishment2 and it must be owned1 ,i think1 that it reflects an indelible stain upon that period of the history of ,great ,britain4 ,to suppose that he was in the least degree formidable to so powerful a body as the church of ,england1 backed as it was by the aristocracy1 by the ministry1 and by the opinions of the people1 is perfectly ridiculous4 ,his theological sentiments1 indeed1 were very different from those of the established church2 but so were those of ,milton1 ,locke1 and ,newton4 ,nay1 some of the members of the church itself entertained opinions1 not indeed so decided or so openly expressed as those of ,dr4 ,priestley1 but certainly having the same tendency4 ,to be satisfied of this it is only necessary to recollect the book which ,dr4 ,clarke published on the ,trinity4 ,nay1 some of the bishops1 unless they are very much belied1 entertained opinions similar to those of ,dr4 ,clarke4 ,the same observation applies to ,dr4 ,lardner1 ,dr4 ,price1 and many others of the dissenters4 ,yet1 the church of ,england never attempted to persecute these respectable and meritorious men1 nor did they consider their opinions as at all likely to endanger the stability of the church4 ,besides1 ,dr4 ,horsley had taken up the pen against ,dr4 ,priestley's theological opinions1 and had refuted them so completely in the opinion of the members of the church1 that it was thought right to reward his meritorious services by a bishopric4 ,it could hardly1 therefore1 be the dread of ,dr4 ,priestley's theological opinions that induced the clergy of the church of ,england to bestir themselves against him with such alacrity4 ,erroneous opinions advanced and refuted1 so far from being injurious1 have a powerful tendency to support and strengthen the cause which they were meant to overturn4 ,or1 if there existed any latent suspicion that the refutation of ,horsley was not so complete as had been alleged1 surely persecution was not the best means of supporting weak arguments2 and indeed it was rather calculated to draw the attention of mankind to the theological opinions of ,priestley2 as has in fact been the consequence4 ,neither can the persecutions which ,dr4 ,priestley was subjected to be accounted for by his political opinions1 even supposing it not to be true1 that in a free country like ,great ,britain1 any man is at liberty to maintain whatever theoretic opinions of government he thinks proper1 provided he be a peaceable subject and obey rigorously all the laws of his country4 ,dr4 ,priestley was an advocate for the perfectibility of the human species1 or at least its continually increasing tendency to improvement--a doctrine extremely pleasing in itself1 and warmly supported by ,franklin and ,price2 but which the wild principles of ,condorcet1 ,godwin1 and ,beddoes at last brought into discredit4 ,this doctrine was taught by ,priestley in the outset of his ,treatise on ,civil ,government1 first published in #agfh4 ,it is a speculation of so very agreeable a nature1 so congenial to our warmest wishes1 and so flattering to the prejudices of humanity1 that one feels much pain at being obliged to give it up4 ,perhaps it may be true1 and ,i am willing to hope so1 that improvements once made are never entirely lost1 unless they are superseded by something much more advantageous1 and that therefore the knowledge of the human race1 upon the whole1 is progressive4 ,but political establishments1 at least if we are to judge from the past history of mankind1 have their uniform periods of progress and decay4 ,nations seem incapable of profiting by experience4 ,every nation seems destined to run the same career1 and the history may be comprehended under the following heads3 ,poverty1 liberty1 industry1 wealth1 power1 dissipation1 anarchy1 destruction4 ,we have no example in history of a nation running through this career and again recovering its energy and importance4 ,greece ran through it more than two thousand years ago3 she has been in a state of slavery ever since4 ,an opportunity is now at last given her of recovering her importance3 posterity will ascertain whether she will embrace it4 ,dr4 ,priestley's short ,essay on the ,first ,principles of ,civil ,government was published in #agfh4 ,in it he lays down as the foundation of his reasoning1 that it must be understood1 whether it be expressed or not1 that all people live in society for their mutual advantage2 so that the good and happiness of the members1 that is the majority of the members of any state1 is the great standard by which every thing relating to that state must be finally determined2 and though it may be supposed that a body of people may be bound by a voluntary resignation of all their rights to a single person or to a few1 it can never be supposed that the resignation is obligatory on their posterity1 because it is manifestly contrary to the good of the whole that it should be so4 ,from this first principle he deduces all his political maxims4 ,kings1 senators1 and nobles1 are merely the servants of the public2 and when they abuse their power1 in the people lies the right of deposing and consequently of punishing them4 ,he examines the expediency of hereditary sovereignty1 of hereditary rank and privileges1 of the duration of parliament1 and of the right of voting1 with an evident tendency to democratical principles1 though he does not express himself very clearly on the subject4 ,such were his political principles in #agfh1 when his book was published4 ,they excited no alarm and drew but little attention2 these principles he maintained ever after1 or indeed he may be said to have become more moderate instead of violent4 ,though he approved of a republic in the abstract2 yet1 considering the prejudices and habits of the people of ,great ,britain1 he laid it down as a principle that their present form of government was best suited to them4 ,he thought1 however1 that there should be a reform in parliament2 and that parliaments should be triennial instead of septennial4 ,he was an enemy to all violent reforms1 and thought that the change ought to be brought about gradually and peaceably4 ,when the ,french revolution broke out he took the side of the patriots1 as he had done during the ,american war2 and he wrote a refutation of ,mr4 ,burke's extraordinary performance4 ,being a dissenter1 it is needless to say that he was an advocate for complete religious freedom4 ,he was ever hostile to all religious establishments1 and an open enemy to the church of ,england4 ,how far these opinions were just and right this is not the place to inquire2 but that they were perfectly harmless1 and that many other persons in this country during the last century1 and even at present1 have adopted similar opinions without incurring any odium whatever1 and without exciting the jealousy or even the attention of government1 is well known to every person4 ,it comes then to be a question of some curiosity at least1 to what we are to ascribe the violent persecutions raised against ,dr4 ,priestley4 ,it seems to have been owing chiefly to the alarm caught by the clergy of the established church that their establishment was in danger2--and1 considering the ferment excited soon after the breaking out of the ,french revolution1 and the rage for reform1 which pervaded all ranks1 the almost general alarm of the aristocracy1 at least1 was not entirely without foundation4 ,i cannot1 however1 admit that there was occasion for the violent alarm caught by ,mr4 ,pitt and his political friends1 and for the very despotic measures which they adopted in consequence4 ,the disease would probably have subsided of itself1 or it would have been cured by a much gentler treatment4 ,as ,dr4 ,priestley was an open enemy to the establishment1 its clergy naturally conceived a prejudice against him1 and this prejudice was violently inflamed by the danger to which they thought themselves exposed2 their influence with the ministry was very great1 and ,mr4 ,pitt and his friends naturally caught their prejudices and opinions4 ,mr4 ,burke1 too1 who had changed his political principles1 and who was inflamed with the burning zeal which distinguishes all converts1 was provoked at ,dr4 ,priestley's answer to his book on the ,french revolution1 and took every opportunity to inveigh against him in the house of commons4 ,the conduct of the ,french1 likewise1 who made ,dr4 ,priestley a citizen of ,france1 and chose him a member of their assembly1 though intended as a compliment1 was injurious to him in ,great ,britain4 ,it was laid hold of by his antagonists to convince the people that he was an enemy to his country2 that he had abjured his rights as an ,englishman2 and that he had adopted the principles of the hereditary enemies of ,great ,britain4 ,these causes1 and not his political opinions1 appear to me to account for the persecution which was raised against him4 ,his sons1 disgusted with this persecution of their father1 had renounced their native country and gone over to ,france2 and1 on the breaking out of the war between this country and the ,french republic1 they emigrated to ,america4 ,it was this circumstance1 joined to the state of insulation in which he lived1 that induced ,dr4 ,priestley1 after much consideration1 to form the resolution of following his sons and emigrating to ,america4 ,he published his reasons in the preface to a ,fast-day ,sermon1 printed in #agid1 one of the gravest and most forcible pieces of composition ,i have ever read4 ,he left ,england in ,april1 #agie1 and reached ,new ,york in ,june4 ,in ,america he was received with much respect by persons of all ranks2 and was immediately offered the situation of professor of chemistry in the ,college of ,philadelphia2 which1 however1 he declined1 as his circumstances1 by the liberality of his friends in ,england1 continued independent4 ,he settled1 finally1 in ,northumberland1 about #acj miles from ,philadelphia1 where he built a house1 and re-established his library and laboratory1 as well as circumstances permitted4 ,here he published a considerable number of chemical papers1 some of them under the form of pamphlets1 and the rest in the ,american ,transactions1 the ,new ,york ,medical ,repository1 and ,nicholson's ,journal of ,natural ,philosophy and ,chemistry4 ,here1 also1 he continued keenly engaged in theological pursuits2 and published1 or republished1 a great variety of books on theological subjects4 ,here he lost his wife and his youngest and favourite son1 who1 he had flattered himself1 was to succeed him in his literary career3--and here he died1 in #ahjd1 after having been confined only two days to bed1 and but a few hours after having arranged his literary concerns1 inspected some proof-sheets of his last theological work1 and given instructions to his son how it should be printed4 ,during the latter end of the presidency of ,mr4 ,adams1 the same kind of odium which had banished ,dr4 ,priestley from ,england began to prevail in ,america4 ,he was threatened with being sent out of the country as an alien4 ,notwithstanding this1 he declined being naturalized2 resolving1 as he said1 to die as he had lived1 an ,englishman4 ,when his friend ,mr4 ,jefferson1 whose political opinions coincided with his own1 became president1 the odium against him wore off1 and he became as much respected as ever4 ,as to the character of ,dr4 ,priestley1 it is so well marked by his life and writings1 that it is difficult to conceive how it could have been mistaken by many eminent men in this kingdom4 ,industry was his great characteristic2 and this quality1 together with a facility of composition1 acquired1 as he tells us1 by a constant habit while young of drawing out an abstract of the sermons which he had preached1 and writing a good deal in verse1 enabled him to do so much3 yet1 he informs us that he never was an intense student1 and that his evenings were usually passed in amusement or company4 ,he was an early riser1 and always lighted his own fire before any one else was stirring3 it was then that he composed all his works4 ,it is obvious1 from merely glancing into his books1 that he was precipitate2 and indeed1 from the way he went on thinking as he wrote1 and writing only one copy1 it was impossible he could be otherwise3 but1 as he was perfectly sincere and anxious to obtain the truth1 he freely acknowledged his mistakes as soon as he became sensible of them4 ,this candour is very visible in his philosophical speculations2 but in his theological writings it was not so much to be expected4 ,he was generally engaged in controversy in theology2 and his antagonists were often insolent1 and almost always angry4 ,we all know the effect of such opposition2 and need not be surprised that it operated upon ,dr4 ,priestley1 as it would do upon any other man4 ,by all accounts his powers of conversation were very great1 and his manners in every respect very agreeable4 ,that this must have been the case is obvious from the great number of his friends1 and the zeal and ardour with which they continued to serve him1 notwithstanding the obloquy under which he lay1 and even the danger that might be incurred by appearing to befriend him4 ,as for his moral character1 even his worst enemies have been obliged to allow that it was unexceptionable4 ,many of my readers will perhaps smile1 when ,i say that he was not only a sincere1 but a zealous ,christian1 and would willingly have died a martyr to the cause4 ,yet ,i think the fact is of easy proof2 and his conduct through life1 and especially at his death1 affords irrefragable proofs of it4 ,his tenets1 indeed1 did not coincide with those of the majority of his countrymen2 but though he rejected many of the doctrines1 he admitted the whole of the sublime morality and the divine origin of the ,christian religion2 which may charitably be deemed sufficient to constitute a true ,christian4 ,of vanity he seems to have possessed rather more than a usual share2 but perhaps he was deficient in pride4 ,his writings were exceedingly numerous1 and treated of science1 theology1 metaphysics1 and politics4 ,of his theological1 metaphysical1 and political writings it is not our business in this work to take any notice4 ,his scientific works treat of electricity1 optics1 and chemistry4 ,as an electrician he was respectable2 as an optician1 a compiler2 as a chemist1 a discoverer4 ,he wrote also a book on perspective which ,i have never had an opportunity of perusing4 ,it is to his chemical labours that he is chiefly indebted for the great reputation which he acquired4 ,no man ever entered upon any undertaking with less apparent means of success than ,dr4 ,priestley did on the chemical investigation of airs4 ,he was unacquainted with chemistry1 excepting that he had1 some years before1 attended an elementary course delivered by ,mr4 ,turner1 of ,liverpool4 ,he was not in possession of any apparatus1 nor acquainted with the method of making chemical experiments2 and his circumstances were such1 that he could neither lay out a great deal of money on experiments1 nor could he hope1 without a great deal of expense1 to make any material progress in his investigations4 ,these circumstances1 which1 at first sight1 seem so adverse1 were1 ,i believe1 of considerable service to him1 and contributed very much to his ultimate success4 ,the branch of chemistry which he selected was new3 an apparatus was to be invented before any thing of importance could be effected2 and1 as simplicity is essential in every apparatus1 he was most likely to contrive the best1 whose circumstances obliged him to attend to economical considerations4 ,pneumatic chemistry had been begun by ,mr4 ,cavendish in his valuable paper on carbonic acid and hydrogen gases1 published in the ,philosophical ,transactions for #agff4 ,the apparatus which he employed was similar to that used about a century before by ,dr4 ,mayow of ,oxford4 ,dr4 ,priestley contrived the apparatus still used by chemists in pneumatic investigations2 it is greatly superior to that of ,mr4 ,cavendish1 and1 indeed1 as convenient as can be desired4 ,were we indebted to him for nothing else than this apparatus1 it would deservedly give him high consideration as a pneumatic chemist4 ,his discoveries in pneumatic chemistry are so numerous1 that ,i must satisfy myself with a bare outline2 to enumerate every thing1 would be to transcribe his three volumes1 into which he digested his discoveries4 ,his first paper was published in #aggb1 and was on the method of impregnating water with carbonic acid gas2 the experiments contained in it were the consequence of his residing near a brewery in ,leeds4 ,this pamphlet was immediately translated into ,french2 and1 at a meeting of the ,college of ,physicians in ,london1 they addressed the ,lords of the ,treasury1 pointing out the advantage that might result from water impregnated with carbonic acid gas in cases of scurvy at sea4 ,his next essay was published in the ,philosophical ,transactions1 and procured him the ,copleyan medal4 ,his different volumes on air were published in succession1 while he lived with ,lord ,shelburne1 and while he was settled at ,birmingham4 ,they drew the attention of all ,europe1 and raised the reputation of this country to a great height4 ,the first of his discoveries was nitrous gas1 now called deutoxide of azote1 which had1 indeed1 been formed by ,dr4 ,hales2 but that philosopher had not attempted to investigate its properties4 ,dr4 ,priestley ascertained its properties with much sagacity1 and almost immediately applied it to the analysis of air4 ,it contributed very much to all subsequent investigations in pneumatic chemistry1 and may be said to have led to our present knowledge of the constitution of the atmosphere4 ,the next great discovery was oxygen gas1 which was made by him on the #ast of ,august1 #aggd1 by heating the red oxide of mercury1 and collecting the gaseous matter given out by it4 ,he almost immediately detected the remarkable property which this gas has of supporting combustion better1 and animal life longer1 than the same volume of common air2 and likewise the property which it has of condensing into red fumes when mixed with nitrous gas4 ,lavoisier1 likewise1 laid claim to the discovery of oxygen gas2 but his claim is entitled to no attention whatever2 as ,dr4 ,priestley informs us that he prepared this gas in ,m4 ,lavoisier's house1 in ,paris1 and showed him the method of procuring it in the year #aggd1 which is a considerable time before the date assigned by ,lavoisier for his pretended discovery4 ,scheele1 however1 actually obtained this gas without any previous knowledge of what ,priestley had done2 but the book containing this discovery was not published till three years after ,priestley's process had become known to the public4 ,dr4 ,priestley first made known sulphurous acid1 fluosilicic acid1 muriatic acid1 and ammonia in the gaseous form2 and pointed out easy methods of procuring them3 he describes with exactness the most remarkable properties of each4 ,he likewise pointed out the existence of carburetted hydrogen gas2 though he made but few experiments to determine its nature4 ,his discovery of protoxide of azote affords a beautiful example of the advantages resulting from his method of investigation1 and the sagacity which enabled him to follow out any remarkable appearances which occurred4 ,carbonic oxide gas was discovered by him while in ,america1 and it was brought forward by him as an incontrovertible refutation of the antiphlogistic theory4 ,though he was not strictly the discoverer of hydrogen gas1 yet his experiments on it were highly interesting1 and contributed essentially to the revolution which chemistry soon after underwent4 ,nothing1 for example1 could be more striking1 than the reduction of oxide of iron1 and the disappearance of the hydrogen when the oxide is heated sufficiently in contact with hydrogen gas4 ,azotic gas was known before he began his career2 but we are indebted to him for most of the properties of it yet known4 ,to him1 also1 we owe the knowledge of the fact1 that an acid is formed when electric sparks are made to pass for some time through a given bulk of common air2 a fact which led afterwards to ,mr4 ,cavendish's great discovery of the composition of nitric acid4 ,he first discovered the great increase of bulk which takes place when electric sparks are made to pass through ammoniacal gas--a fact which led ,berthollet to the analysis of this gas4 ,he merely repeated ,priestley's experiment1 determined the augmentation of bulk1 and the nature of the gases evolved by the action of the electricity4 ,his experiments on the amelioration of atmospherical air by the vegetation of plants1 on the oxygen gas given out by their leaves1 and on the respiration of animals1 are not less curious and interesting4 ,such is a short view of the most material facts for which chemistry is indebted to ,dr4 ,priestley4 ,as a discoverer of new substances1 his name must always stand very high in the science2 but as a reasoner or theorist his position will not be so favourable4 ,it will be observed that almost all his researches and discoveries related to gaseous bodies4 ,he determined the different processes1 by means of which the different gases can be procured1 the substances which yield them1 and the effects which they are capable of producing on other bodies4 ,of the other departments of chemistry he could hardly be said to know any thing4 ,as a pneumatic chemist he stands high2 as an analytical chemist he can scarcely claim any rank whatever4 ,in his famous experiments on the formation of water by detonating mixtures of oxygen and hydrogen in a copper globe1 the copper was found acted upon1 and a blue liquid was obtained1 the nature of which he was unable to ascertain2 but ,mr4 ,keir1 whose assistance he solicited1 determined it to be a solution of nitrate of copper in water4 ,this formation of nitric acid induced him to deny that water was a compound of oxygen and hydrogen4 ,the same acid was formed in the experiments of ,mr4 ,cavendish2 but he investigated the circumstances of the formation1 and showed that it depended upon the presence of azotic gas in the gaseous mixture4 ,whenever azotic gas is present1 nitric acid is formed1 and the quantity of this acid depends upon the relative proportion of the azotic and hydrogen gases in the mixture4 ,when no hydrogen gas is present1 nothing is formed but nitric acid3 when no azotic gas is present1 nothing is formed but water4 ,these facts1 determined by ,cavendish1 invalidate the reasoning of ,priestley altogether2 and had he possessed the skill1 like ,cavendish1 to determine with sufficient accuracy the proportions of the different gases in his mixtures1 and the relative quantities of nitric acid formed1 he would have seen the inaccuracy of his own conclusions4 ,he was a firm believer in the existence of phlogiston2 but he seems1 at least ultimately1 to have adopted the view of ,scheele1 and many other eminent contemporary chemists--indeed1 the view of ,cavendish himself--that hydrogen gas is phlogiston in a separate and pure state4 ,common air he considered as a compound of oxygen and phlogiston4 ,oxygen1 in his opinion1 was air quite free from phlogiston1 or air in a simple and pure state2 while azotic gas 7the other constituent of common air7 was air saturated with phlogiston4 ,hence he called oxygen dephlogisticated1 and azote phlogisticated air4 ,the facts that when common air is converted into azotic gas its bulk is diminished about one-fifth part1 and that azotic gas is lighter than common air or oxygen gas1 though not quite unknown to him1 do not seem to have drawn much of his attention4 ,he was not accustomed to use a balance in his experiments1 nor to attend much to the alterations which took place in the weight of bodies4 ,had he done so1 most of his theoretical opinions would have fallen to the ground4 ,when a body is allowed to burn in a given quantity of common air1 it is known that the quality of the common air is deteriorated2 it becomes1 in his language1 more phlogisticated4 ,this1 in his opinion1 was owing to an affinity which existed between phlogiston and air4 ,the presence of air is necessary to combustion1 in consequence of the affinity which it has for phlogiston4 ,it draws phlogiston out of the burning body1 in order to combine with it4 ,when a given bulk of air is saturated with phlogiston1 it is converted into azotic gas1 or phlogisticated air1 as he called it2 and this air1 having no longer any affinity for phlogiston1 can no longer attract that principle1 and consequently combustion cannot go on in such air4 ,all combustible bodies1 in his opinion1 contain hydrogen4 ,of course the metals contain it as a constituent4 ,the calces of metals are those bodies deprived of phlogiston4 ,to prove the truth of this opinion1 he showed that when the oxide of iron is heated in hydrogen gas1 that gas is absorbed1 while the calx is reduced to the metallic state4 ,finery cinder1 which he employed in these experiments1 is1 in his opinion1 iron not quite free from phlogiston4 ,hence it still retains a quantity of hydrogen4 ,to prove this1 he mixed together finery cinder and carbonates of lime1 barytes and strontian1 and exposed the mixture to a strong heat2 and by this process obtained inflammable gas in abundance4 ,in his opinion every inflammable gas contains hydrogen in abundance4 ,hence this experiment was adduced by him as a demonstration that hydrogen is a constituent of finery cinder4 ,all these processes of reasoning1 which appear so plausible as ,dr4 ,priestley states them1 vanish into nothing1 when his experiments are made1 and the weights of every thing determined by means of a balance3 it is then established that a burning body becomes heavier during its combustion1 and that the surrounding air loses just as much weight as the burning body gains4 ,scheele and ,lavoisier showed clearly that the loss of weight sustained by the air is owing to a quantity of oxygen absorbed from it1 and condensed in the burning body4 ,cruikshank first elucidated the nature of the inflammable gas1 produced by the heating a mixture of finery cinder and carbonate of lime1 or other earthy carbonate4 ,he found that iron filings would answer better than finery cinder4 ,the gas was found to contain no hydrogen1 and to be in fact a compound of oxygen and carbon4 ,it was shown to be derived from the carbonic acid of the earthy carbonate1 which was deprived of half its oxygen by the iron filings or finery cinder4 ,thus altered1 it no longer preserved its affinity for the lime1 but made its escape in the gaseous form1 constituting the gas now known by the name of carbonic oxide4 ,though the consequence of the ,birmingham riots1 which obliged ,dr4 ,priestley to leave ,england and repair to ,america1 is deeply to be lamented1 as fixing an indelible disgrace upon the country2 perhaps it was not in reality so injurious to ,dr4 ,priestley as may at first sight appear4 ,he had carried his peculiar researches nearly as far as they could go4 ,to arrange and methodize1 and deduce from them the legitimate consequences1 required the application of a different branch of chemical science1 which he had not cultivated1 and which his characteristic rapidity1 and the time of life to which he had arrived1 would have rendered it almost impossible for him to acquire4 ,in all probability1 therefore1 had he been allowed to prosecute his researches unmolested1 his reputation1 instead of an increase1 might have suffered a diminution1 and he might have lost that eminent situation as a man of science which he had so long occupied4 ,with ,dr4 ,priestley closes this period of the ,history of ,british ,chemistry--for ,mr4 ,cavendish1 though he had not lost his activity1 had abandoned that branch of science1 and turned his attention to other pursuits4 ,,chapter ,,ii4 ,,of ,,the ,,progress ,,of ,,philosophical ,,chemistry ,,in ,,sweden4 ,though ,sweden1 partly in consequence of her scanty population1 and the consequent limited sale of books in that country1 and partly from the propensity of her writers to imitate the ,french1 which has prevented that originality in her poets and historians that is requisite for acquiring much eminence--though ,sweden1 for these reasons1 has never reached a very high rank in literature2 yet the case has been very different in science4 ,she has produced men of the very first eminence1 and has contributed more than her full share in almost every department of science1 and in none has she shone with greater lustre than in the department of ,chemistry4 ,even in the latter part of the seventeenth century1 before chemistry had1 properly speaking1 assumed the rank of a science1 we find ,hierne in ,sweden1 whose name deserves to be mentioned with respect4 ,moreover1 in the earlier part of the eighteenth century1 ,brandt1 ,scheffer1 and ,wallerius1 had distinguished themselves by their writings4 ,cronstedt1 about the middle of the eighteenth century1 may be said to have laid the foundation of systematic mineralogy upon chemical principles1 by the publication of his ,system of ,mineralogy4 ,but ,bergman is entitled to the merit of being the first person who prosecuted chemistry in ,sweden on truly philosophical principles1 and raised it to that high estimation to which its importance justly entitles it4 ,torbern ,bergman was born at ,catherinberg1 in ,west ,gothland1 on the #bjth of ,march1 #agce4 ,his father1 ,barthold ,bergman1 was receiver of the revenues of that district1 and his mother1 ,sara ,hgg1 the daughter of a ,gotheborg merchant4 ,a receiver of the revenues was at that time1 in ,sweden1 a post both disagreeable and hazardous4 ,the creatures of a party which had had the ascendancy in one diet1 they were exposed to the persecution of the diet next following1 in which an opposite party usually had the predominance4 ,this circumstance induced ,bergman to advise his son to turn his attention to the professions of law or divinity1 which were at that time the most lucrative in ,sweden4 ,after having spent the usual time at school1 and acquired those branches of learning commonly taught in ,sweden1 in the public schools and academies to which ,bergman was sent1 he went to the ,university of ,upsala1 in the autumn of #ageb1 where he was placed under the guidance of a relation1 whose province it was to superintend his studies1 and direct them to those pursuits that were likely to lead young ,bergman to wealth and distinction4 ,our young student showed at once a decided predilection for mathematics1 and those branches of physics which were connected with mathematics1 or depended upon them4 ,but these were precisely the branches of study which his relation was anxious to prevent his indulging in4 ,bergman attempted at once to indulge his own inclination1 and to gratify the wishes of his relation4 ,this obliged him to study with a degree of ardour and perseverance which has few examples4 ,his mathematical and physical studies claimed the first share of his attention2 and1 after having made such progress in them as would alone have been sufficient to occupy the whole time of an ordinary student--to satisfy his relation1 ,jonas ,victorin1 who was at that time a magister docens in ,upsala1 he thought it requisite to study some law books besides1 that he might be able to show that he had not neglected his advice1 nor abandoned the views which he had held out4 ,he was in the habit of rising to his studies every morning at four o'clock1 and he never went to bed till eleven at night4 ,the first year of his residence at ,upsala1 he had made himself master of ,wolf's ,logic1 of ,wallerius's ,system of ,chemistry1 and of twelve books of ,euclid's ,elements3 for he had already studied the first book of that work in the ,gymnasium before he went to college4 ,he likewise perused ,keil's ,lectures on ,astronomy1 which at that time were considered as the best introduction to physics and astronomy4 ,his relative disapproved of his mathematical and physical studies altogether2 but1 not being able to put a stop to them1 he interdicted the books1 and left his young charge merely the choice between law and divinity4 ,bergman got a small box made1 with a drawer1 into which he put his mathematical and physical books1 and over this box he piled the law books which his relative had urged him to study4 ,at the time of the daily visits of his relative1 the mathematical and physical books were carefully locked up in the drawer1 and the law books spread upon the table2 but no sooner was his presence removed1 than the drawer was opened1 and the mathematical studies resumed4 ,this incessant study2 this necessity under which he found himself to consult his own inclinations and those of his relative2 this double portion of labour1 without time for relaxation1 exercise1 or amusement1 proved at last injurious to young ,bergman's health4 ,he fell ill1 and was obliged to leave the university and return home to his father's house in a state of bad health4 ,there constant and moderate exercise was prescribed him1 as the only means of restoring his health4 ,that his time here might not be altogether lost to him1 he formed the plan of making his walks subservient to the study of botany and entomology4 ,at this time ,linnus1 after having surmounted obstacles which would have crushed a man of ordinary energy1 was in the height of his glory2 and was professor of botany and natural history in the ,university of ,upsala4 ,his lectures were attended by crowds of students from every country in ,europe3 he was enthusiastically admired and adored by his students4 ,this influence on the minds of his pupils was almost unbounded2 and at ,upsala1 every student was a natural historian4 ,bergman had studied botany before he went to college1 and he had acquired a taste for entomology from the lectures of ,linnus himself4 ,both of these pursuits he continued to follow after his return home to ,west ,gothland2 and he made a collection of plants and of insects4 ,grasses and mosses were the plants to which he turned the most of his attention1 and of which he collected the greatest number4 ,but he felt a predilection for the study of insects1 which was a field much less explored than the study of plants4 ,among the insects which he collected were several not to be found in the ,fauna ,suecica4 ,of these he sent specimens to ,linnus at ,upsala1 who was delighted with the present4 ,all of them were till then unknown as ,swedish insects1 and several of them were quite new4 ,the following were the insects at this time collected by ,bergman1 and sent to ,upsala1 as they were named by ,linnus3 ,phalna4 ,bombyx monacha1 camelina4 ,noctua ,parthenias1 conspicillaris4 ,perspicillaris1 flavicornis1 ,plebeia4 ,geometra pennaria4 ,tortrix ,bergmanniana1 ,lediana4 ,tinea ,harrisella1 ,pedella1 ,punctella4 ,tenthredo4 ,vitellina1 ustulata4 ,ichneumon4 ,jaculator niger4 ,tipula4 ,tremula4 ,when ,bergman's health was re-established1 he returned to ,upsala with full liberty to prosecute his studies according to his own wishes1 and to devote the whole of his time to mathematics1 physics1 and natural history4 ,his relations1 finding it in vain to combat his predilections for these studies1 thought it better to allow him to indulge them4 ,he had made himself known to ,linnus by the collection of insects which he had sent him from ,catherinberg2 and1 drawn along by the glory with which ,linnus was surrounded1 and the zeal with which his fellow-students prosecuted such studies1 he devoted a great deal of his attention to natural history4 ,the first paper which he wrote upon the subject contained a discovery4 ,there was a substance observed in some ponds not far from ,upsala1 to which the name of coccus aquaticus was given1 but its nature was unknown4 ,linnus had conjectured that it might be the ovarium of some insect2 but he left the point to be determined by future observations4 ,bergman ascertained that it was the ovum of a species of leech1 and that it contained from ten to twelve young animals4 ,when he stated what he had ascertained to ,linnus1 that great naturalist refused to believe it2 but ,bergman satisfied him of the truth of his discovery by actual observation4 ,linnus1 thus satisfied1 wrote under the paper of ,bergman1 ,vidi et obstupui1 and sent it to the academy of ,stockholm with this flattering panegyric4 ,it was printed in the ,memoirs of that learned body for #agef 7p4 #aii71 and was the first paper of ,bergman's that was committed to the press4 ,he continued to prosecute the study of natural history as an amusement2 though mathematics and natural philosophy occupied by far the greatest part of his time4 ,various useful papers of his1 connected with entomology1 appeared from time to time in the ,memoirs of the ,stockholm ,academy2 in particular1 a paper on the history of insects which attack fruit-trees1 and on the methods of guarding against their ravages3 on the method of classing these insects from the forms of their larv1 a time when it would be most useful for the agriculturist to know1 in order to destroy those that are hurtful3 a great number of observations on this class of animals1 so various in their shape and their organization1 and so important for man to know--some of which he has been able to overcome1 while others1 defended by their small size1 and powerful by their vast numbers1 still continue their ravages2 and which offer so interesting a sight to the philosopher by their labours1 their manners1 and their foresight4--,bergman was fond of these pursuits1 and looked back upon them in afterlife with pleasure4 ,long after1 he used to mention with much satisfaction1 that by the use of the method pointed out by him1 no fewer than seven millions of destructive insects were destroyed in a single garden1 and during the course of a single summer4 ,about the year #ageg he was appointed tutor to the only son of ,count ,adolf ,frederick ,stackelberg1 a situation which he filled greatly to the satisfaction both of the father and son1 as long as the young count stood in need of an instructor4 ,he took his master's degree in #ageh1 choosing for the subject of his thesis on astronomical interpolation4 ,soon after1 he was appointed magister docens in natural philosophy1 a situation peculiar to the ,university of ,upsala1 and constituting a kind of assistant to the professor4 ,for his promotion to this situation he was obliged to ,m4 ,ferner1 who saw how well qualified he was for it1 and how beneficial his labours would be to the ,university of ,upsala4 ,in #agfa he was appointed adjunct in mathematics and physics1 which1 ,i presume1 means that he was raised to the rank of an associate with the professor of these branches of science4 ,in this situation it was his business to teach these sciences to the students of ,upsala1 a task for which he was exceedingly well fitted4 ,during this period he published various tracts on different branches of physical science1 particularly on the rainbow1 the crepuscula1 the aurora-borealis1 the electrical phenomena of ,iceland spar1 and of the tourmalin4 ,we find his name among the astronomers who observed the first transit of ,venus over the sun1 in #agfa1 whose results deserve the greatest confidence4#a ,his observations on the electricity of the tourmalin are important4 ,it was he that first established the true laws that regulate these curious phenomena4 #a ,see ,phil4 ,trans41 vol4 lii4 p4 #bbg1 and vol4 lvi4 p4 #he4 ,during the whole of this period he had been silently studying chemistry and mineralogy1 though nobody suspected that he was engaged in any such pursuits4 ,but in #agfg ,john ,gottschalk ,wallerius1 who had long filled the chair of chemistry in the ,university of ,upsala1 with high reputation1 resigned his chair4 ,bergman immediately offered himself as a candidate for the vacant professorship3 and1 to show that he was qualified for the office1 published two dissertations on the ,manufacture of ,alum1 which probably he had previously drawn up1 and had lying by him4 ,wallerius intended to resign his chair in favour of a pupil or relation of his own1 whom he had destined to succeed him4 ,he immediately formed a party to oppose the pretensions of ,bergman2 and his party was so powerful and so malignant1 that few doubted of their success3 for it was joined by all those who1 despairing of equalling the industry and reputation of ,bergman1 set themselves to oppose and obstruct his success4 ,such men unhappily exist in all colleges1 and the more eminent a professor is1 the more is he exposed to their malignant activity4 ,many of those who cannot themselves rise to any eminence1 derive pleasure from the attempt to pull down the eminent to their own level4 ,in these attempts1 however1 they seldom succeed1 unless from some want of prudence and steadiness in the individual whom they assail4 ,bergman's ,dissertations on ,alum were severely handled by ,wallerius and his party3 and such was the influence of the ex-professor1 that every body thought ,bergman would be crushed by him4 ,fortunately1 ,gustavus ,,iii4 of ,sweden1 at that time crown prince1 was chancellor of the university4 ,he took up the cause of ,bergman1 influenced1 it is said1 by the recommendation of ,von ,swab1 who pledged himself for his qualifications1 and was so keen on the subject that he pleaded his cause in person before the senate4 ,wallerius and his party were of course baffled1 and ,bergman got the chair4 ,for this situation his previous studies had fitted him in a peculiar manner4 ,his mathematical1 physical1 and natural-historical knowledge1 so far from being useless1 contributed to free him from prejudices1 and to emancipate him from that spirit of routine under which chemistry had hitherto suffered4 ,they gave to his ideas a greater degree of precision1 and made his views more correct4 ,he saw that mathematics and chemistry divided between them the whole extent of natural science1 and that its bounds required to be enlarged1 to enable it to embrace all the different branches of science with which it was naturally connected1 or which depended upon it4 ,he saw the necessity of banishing from chemistry all vague hypotheses and explanations1 and of establishing the science on the firm basis of experiment4 ,he was equally convinced of the necessity of reforming the nomenclature of chemistry1 and of bringing it to the same degree of precision that characterized the language of the other branches of natural philosophy4 ,his first care1 after getting the chair1 was to make as complete a collection as he could of mineral substances1 and to arrange them in order according to the nature of their constituents1 as far as they had been determined by experiment4 ,to another cabinet he assigned the ,swedish minerals1 ranged in a geographical manner according to the different provinces which furnished them4 ,when ,i was at ,upsala1 in #ahab1 the first of these collections still remained1 greatly augmented by his nephew and successor1 ,afzelius4 ,but no remains existed of the geographical collection4 ,however1 there was a very considerable collection of this kind in the apartments of the ,swedish school of mines at ,stockholm1 under the care of ,mr4 ,hjelm1 which ,i had an opportunity of inspecting4 ,it is not improbable that ,bergman's collection might have formed the nucleus of this4 ,a geographical collection of minerals1 to be of much utility1 should exhibit all the different formations which exist in the kingdom3 and in a country so uniform in its nature as ,sweden1 the minerals of one county are very nearly similar to those of the other counties2 with the exception of certain peculiarities derived from the mines1 or from some formations which may belong exclusively to certain parts of the country1 as1 for example1 the coal formations in the south corner of ,sweden1 near ,helsinburg1 and the porphyry rocks1 in ,elfsdale4 ,bergman attempted also to make a collection of models of the apparatus employed in the different chemical manufactories1 to be enabled to explain these manufactures with greater clearness to his students4 ,i was informed by ,m4 ,ekeberg1 who1 in #ahab1 was magister docens in chemistry at ,upsala1 that these models were never numerous4 ,nor is it likely that they should be1 as ,sweden cannot boast of any great number of chemical manufactories1 and as1 in ,bergman's time1 the processes followed in most of the chemical manufactories of ,europe were kept as secret as possible4 ,thus it was ,bergman's object to exhibit to his pupils specimens of all the different substances which the earth furnishes1 with the order in which these productions are arranged on the globe--to show them the uses made of all these different productions--how practice had preceded theory and had succeeded in solving many chemical problems of the most complicated nature4 ,his lectures are said to have been particularly valuable4 ,he drew around him a considerable number of pupils1 who afterwards figured as chemical discoverers themselves4 ,of all these ,assessor ,gahn1 of ,fahlun1 was undoubtedly the most remarkable2 but ,hjelm1 ,gadolin1 the ,elhuyarts1 and various other individuals1 likewise distinguished themselves as chemists4 ,after his appointment to the chemical chair at ,upsala1 the remainder of his life passed with very little variety2 his whole time was occupied with his favourite studies1 and not a year passed that he did not publish some dissertation or other upon some more or less important branch of chemistry4 ,his reputation gradually extended itself over ,europe1 and he was enrolled among the number of the members of most scientific academies4 ,among other honourable testimonies of the esteem in which he was held1 he was elected rector of the ,university of ,upsala4 ,this university is not merely a literary body1 but owns extensive estates1 over which it possesses great authority1 and1 having considerable control over its students1 and enjoying considerable immunities and privileges 7conferred in former times as an encouragement to learning1 though1 in reality1 they serve only to cramp its energies1 and throw barriers in the way of its progress71 constitutes1 therefore1 a kind of republic in the midst of ,sweden3 the professors being its chiefs4 ,but while1 in literary establishments1 all the institutions ought to have for an object to maintain peace1 and free their members from every occupation unconnected with letters1 the constitution of that university obliges its professors to attend to things very inconsistent with their usual functions2 while it gives men of influence and ambition a desire to possess the power and patronage1 though they may not be qualified to perform the duties1 of a professor4 ,such temptations are very injurious to the true cause of science2 and it were to be wished1 that no literary body1 in any part of the world1 were possessed of such powers and privileges4 ,when ,bergman was rector1 the university was divided into two great parties1 the one consisting of the theological and law faculties1 and the other of the scientific professors4 ,bergman's object was to preserve peace and agreement between these two parties1 and to convince them that it was the interest of all to unite for the good of the university and the promotion of letters4 ,the period of his magistracy is remarkable in the annals of the university for the small number of deliberations1 and the little business recorded in the registers2 and for the good sense and good behaviour of the students4 ,the students in ,upsala are numerous1 and most of them are young men4 ,they had been accustomed frequently to brave or elude the severity of the regulations2 but during ,bergman's rectorship they were restrained effectually by their respect for his genius1 and their admiration of his character and conduct4 ,when the reputation of ,bergman was at its height1 in the year #aggf1 ,frederick the ,great of ,prussia formed the wish to attach him to the ,academy of ,sciences of ,berlin1 and made him offers of such a nature that our professor hesitated for a short time as to whether he ought not to accept them4 ,his health had been injured by the assiduity with which he had devoted himself to the double duty of teaching and experimenting4 ,he might look for an alleviation of his ailments1 if not a complete recovery1 in the milder climate of ,prussia1 and he would be able to devote himself entirely to his academical duties2 but other considerations prevented him from acceding to this proposal1 tempting as it was4 ,the ,king of ,sweden had been his benefactor1 and it was intimated to him that his leaving the kingdom would afflict that monarch4 ,this information induced him1 without further hesitation1 to refuse the proposals of the ,king of ,prussia4 ,he requested of the king1 his master1 not to make him lose the merit of his sacrifice by augmenting his income2 but to this demand the ,king of ,sweden very properly refused to accede4 ,in the year #agga1 ,professor ,bergman married a widow lady1 ,margaretha ,catharina ,trast1 daughter of a clergyman in the neighbourhood of ,upsala4 ,by her he had two sons2 but both of them died when infants4 ,this lady survived her husband4 ,the ,king of ,sweden settled on her an annuity of #bjj rix dollars1 on condition that she gave up the library and apparatus of her late husband to the ,royal ,society of ,upsala4 ,bergman's health had been always delicate2 indeed he seems never to have completely recovered the effects of his first year's too intense study at ,upsala4 ,he struggled on1 however1 with his ailments2 and1 by way of relaxation1 was accustomed sometimes1 in summer1 to repair to the waters of ,medevi--a celebrated mineral spring in ,sweden1 situated near the banks of the great inland lake1 ,wetter4 ,one of these visits seems to have restored him to health for the time4 ,but his malady returned in #aghd with redoubled violence4 ,he was afflicted with hemorrhoids1 and his daily loss of blood amounted to about six ounces4 ,this constant drain soon exhausted him1 and on the #hth of ,july1 #aghd1 he died at the baths of ,medevi1 to which he had repaired in hopes of again benefiting by these waters4 ,the different tracts which he published1 as they have been enumerated by ,hjelm1 who gave an interesting account of ,bergman to the ,stockholm ,academy in the year #aghe1 amount to #ajf4 ,they have been all collected into six octavo volumes entitled ,opuscula ,torberni ,bergman ,physica et ,chemica--with the exception of his notes on ,scheffer1 his ,sciagraphia1 and his chapter on ,physical ,geography1 which was translated into ,french1 and published in the ,journal des ,mines 7vol4 iii4 ,no4 #ae1 p4 #ee74 ,his ,sciagraphia1 which is an attempt to arrange minerals according to their composition1 was translated into ,english by ,dr4 ,withering4 ,his notes on ,scheffer were interspersed in an edition of the ,chemiske ,frelsningar of that chemist1 published in #aggd1 which he seems to have employed as a text-book in his lectures3 or1 at all events1 the work was published for the use of the students of chemistry at ,upsala4 ,there was a new edition of it published1 after ,bergman's death1 in the year #agif1 to which are appended ,bergman's ,tables of ,affinities4 ,the most important of ,bergman's chemical papers were collected by himself1 and constitute the three first volumes of his ,opuscula4 ,the three last volumes of that work were published after his death4 ,the fourth volume was published at ,leipsic1 in #aghg1 by ,hebenstreit1 and contains the rest of his chemical papers4 ,the fifth volume was given to the world in #aghh1 by the same editor4 ,it contains three chemical papers1 and the rest of it is made up with papers on natural history1 electricity1 and other branches of physics1 which ,bergman had published in the earlier part of his life4 ,the same indefatigable editor published the sixth volume in #agij4 ,it contains three astronomical papers1 two chemical1 and a long paper on the means of preventing any injurious effects from lightning4 ,this was an oration1 delivered before the ,royal ,academy of ,sciences of ,stockholm1 in #agfd1 probably at the time of his admission into the academy4 ,it would serve little purpose in the present state of chemical knowledge1 to give a minute analysis of ,bergman's papers4 ,to judge of their value1 it would be necessary to compare them1 not with our present chemical knowledge1 but with the state of the science when his papers were published4 ,a very short general view of his labours will be sufficient to convey an idea of the benefits which the science derived from them4 #a4 ,his first paper1 entitled ,on the ,aerial ,acid1 that is1 carbonic acid1 was published in #aggd4 ,in it he gives the properties of this substance in considerable detail1 shows that it possesses acid qualities1 and that it is capable of combining with the bases1 and forming salts4 ,what is very extraordinary1 in giving an account of carbonate of lime and carbonate of magnesia1 he never mentions the name of ,dr4 ,black2 though it is very unlikely that a controversy1 which had for years occupied the attention of chemists1 should have been unknown to him4 ,mr4 ,cavendish's name never once appears in the whole paper2 though that philosopher had preceded him by seven or eight years4 ,he informs us1 that he had made known his opinions respecting the nature of this substance1 to various foreign correspondents1 among others to ,dr4 ,priestley1 as early as the year #aggj1 and that ,dr4 ,priestley had mentioned his views on the subject1 in a paper inserted in the ,philosophical ,transactions for #aggb4 ,bergman found the specific gravity of carbonic acid gas rather higher than #ae1 that of air being #a4 ,his result is not far from the truth4 ,he obtained his gas1 by mixing calcareous spar with dilute sulphuric acid4 ,he shows that this gas has a sour taste1 that it reddens the infusion of litmus1 and that it combines with bases4 ,he gives figures of the apparatus which he used4 ,this apparatus demands attention4 ,though far inferior to the contrivances of ,priestley1 it answered pretty well1 enabling him to collect the gas1 and examine its properties4 ,it is unnecessary to enter into any further details respecting this paper4 ,whoever will take the trouble to compare it with ,cavendish's paper on the same subject1 will find that he had been anticipated by that philosopher in a great many of his most important facts4 ,under these circumstances1 ,i consider as singular his not taking any notice of ,cavendish's previous labours4 #b4 ,his next paper1 ,on the ,analyses of ,mineral ,waters1 was first published in #aggh1 being the subject of a thesis1 supported by ,j4 ,p4 ,scharenberg4 ,this dissertation1 which is of great length1 is entitled to much praise4 ,he lays therein the foundation of the mode of analyzing waters1 such as is followed at present4 ,he points out the use of different reagents1 for detecting the presence of the various constituents in mineral water1 and then shows how the quantity of each is to be determined4 ,it would be doing great injustice to ,bergman1 to compare his analyses with those of any modern experimenter4 ,at that time1 the science was not in possession of any accurate analyses of the neutral salts1 which exist in mineral waters4 ,bergman undertook these necessary analyses1 without which1 the determination of the saline constituents of mineral waters was out of the question4 ,his determinations were not indeed accurate1 but they were so much better than those that preceded them1 and ,bergman's character as an experimenter stood so high1 that they were long referred to as a standard by chemists4 ,the first attempt to correct them was by ,kirwan4 ,but ,bergman's superior reputation as a chemist enabled his results still to keep their ground1 till his character for accuracy was finally destroyed by the very accurate experiments which the discovery of the atomic theory rendered it necessary to make4 ,these1 when once they became generally known1 were of course preferred1 and ,bergman's analyses were laid aside4 ,it is a curious and humiliating fact1 as it shows how much chemical reputation depends upon situation1 or accidental circumstances1 that ,wenzel had1 in #agff1 in his book on affinity1 published much more accurate analyses of all these salts1 than ,bergman's--analyses indeed which were almost perfectly correct1 and which have scarcely been surpassed1 by the most careful ones of the present day4 ,yet these admirable experiments scarcely drew the attention of chemists2 while the very inferior ones of ,bergman were held up as models of perfection4 #c4 ,bergman1 not satisfied with pointing out the mode of analyzing mineral waters1 attempted to imitate them artificially by chemical processes1 and published two essays on the subject2 in the first he showed the processes by which cold mineral waters might be imitated1 and in the other1 the mode of imitating hot mineral waters4 ,the attempt was valuable1 and served to extend greatly the chemical knowledge of mineral waters1 and of the salts which they contain2 but it was made at too early a period of the analytical art1 to approach perfection4 ,a similar remark applies to his analysis of sea-water4 ,the water examined was brought by ,sparmann from a depth of eighty fathoms1 near the latitude of the ,canaries3 ,bergman found in it only common salt1 muriate of magnesia1 and sulphate of lime4 ,his not having discovered the presence of sulphate of magnesia is a sufficient proof of the imperfection of his analytical methods2 the other constituents exist in such small quantity in sea-water that they might easily have been overlooked1 but the quantity of sulphate of magnesia in sea-water is considerable4 #d4 ,i shall pass over the paper on oxalic acid1 which constituted the subject of a thesis1 supported in #aggf1 by ,john ,afzelius ,arfvedson4 ,it is now known that oxalic acid was discovered by ,scheele1 not by ,bergman4 ,it is impossible to say how many of the numerous facts stated in this thesis were ascertained by ,scheele1 and how many by ,afzelius4 ,for1 as ,afzelius was already a magister docens in chemistry1 there can be little doubt that he would himself ascertain the facts which were to constitute the foundation of his thesis4 ,it is indeed now known that ,bergman himself intrusted all the details of his experiments to his pupils4 ,he was the contriver1 while his pupils executed his plans4 ,that ,scheele has nowhere laid claim to a discovery of so much importance as that of oxalic acid1 and that he allowed ,bergman peaceably to bear away the whole credit1 constitutes one of the most remarkable facts in the history of chemistry4 ,moreover1 while it reflects so much credit on ,scheele for modesty and forbearance1 it seems to bear a little hard upon the character of ,bergman4 ,when he published the essay in the first volume of his ,opuscula1 in #aggi1 why did he not in a note inform the world that ,scheele was the true discoverer of this acid8 ,why did he allow the discovery to be universally assigned to him1 without ever mentioning the true state of the case8 ,all this appeared so contrary to the character of ,bergman1 that ,i was disposed to doubt the truth of the statement1 that ,scheele was the discoverer of oxalic acid4 ,when ,i was at ,fahlun1 in the year #ahab1 ,i took an opportunity of putting the question to ,assessor ,gahn1 who had been the intimate friend of ,scheele1 and the pupil1 and afterwards the friend of ,bergman4 ,he assured me that ,scheele really was the discoverer of oxalic acid1 and ascribed the omission of ,bergman to inadvertence4 ,assessor ,gahn showed me a volume of ,scheele's letters to him1 which he had bound up3 they contained the history of all his chemical labours4 ,i have little doubt that an account of oxalic acid would be found in these letters4 ,if the son of ,assessor ,gahn1 in whose possession these letters must now be1 would take the trouble to inspect the volume in question1 and to publish any notices respecting this acid which they may contain1 he would confer an important favour on every person interested in the history of chemistry4 #e4 ,the dissertation on the manufacture of alum has been mentioned before4 ,bergman shows himself well acquainted with the processes followed1 at least in ,sweden1 for making alum4 ,he had no notion of the true constitution of alum2 nor was that to be expected1 as the discovery was thereby years later in being made4 ,he thought that the reason why alum leys did not crystallize well was1 that they contained an excess of acid1 and that the addition of potash gave them the property of crystallizing readily1 merely by saturating that excess of acid4 ,alum is a double salt1 composed of three integrant particles of sulphate of alumina1 and one integrant particle of sulphate of potash1 or sulphate of ammonia4 ,in some cases1 the alum ore contains all the requisite ingredients4 ,this is the case with the ore at ,tolfa1 in the neighbourhood of ,rome4 ,it seems1 also1 to be the case with respect to some of the alum ores in ,sweden2 particularly at ,hnster on ,kinnekulle1 in ,west ,gothland1 which ,i visited in #ahab4 ,if any confidence can be put in the statements of the manager of those works1 no alkaline salt whatever is added2 at least1 ,i understood him to say so when ,i put the question4 #f4 ,in his dissertation on tartar-emetic1 he gives an interesting historical account of this salt and its uses4 ,his notions respecting the antimonial preparations best fitted to form it1 are not accurate3 nor1 indeed1 could they be expected to be so1 till the nature and properties of the different oxides of antimony were accurately known4 ,antimony forms three oxides3 now it is the protoxide alone that is useful in medicine1 and that enters into the composition of tartar-emetic2 the other two oxides are inert1 or nearly so4 ,bergman was aware that tartar-emetic is a double salt1 and that its constituents are tartaric acid1 potash1 and oxide of antimony2 but it was not possible1 in #aggc1 when his dissertation was published1 to have determined the true constituents of this salt by analysis4 #g4 ,bergman's paper on magnesia was also a thesis defended in #agge1 by ,charles ,norell1 of ,west ,gothland1 who in all probability made the experiments described in the essay4 ,in the introduction we have a history of the discovery of magnesia1 and he mentions ,dr4 ,black as the person who first accurately made out its peculiar chemical characters1 and demonstrated that it differs from lime4 ,this essay contains a pretty full and accurate account of the salts of magnesia1 considering the state of chemistry at the time when it was published4 ,there is no attempt to analyze any of the magnesian salts2 but1 in his treatise on the analysis of mineral waters1 he had stated the quantity of magnesia contained in one hundred parts of several of them4 #h4 ,his paper on the shapes of crystals1 published in #aggc1 contains the germ of the whole theory of crystallization afterwards developed by ,m4 ,hauy4 ,he shows how1 from a very simple primary form of a mineral1 other shapes may proceed1 which seem to have no connexion with1 or resemblance to the primary form4 ,his view of the subject1 so far as it goes1 is the very same afterwards adopted by ,hauy3 and1 what is very curious1 ,hauy and ,bergman formed their theory from the very same crystalline shape of calcareous spar--from which1 by mechanical divisions1 the same rhombic nucleus was extracted by both4 ,nothing prevented ,bergman from anticipating ,hauy but a sufficient quantity of crystals to apply his theory to4#b #b ,i shall mention afterwards that the real discoverer of this fact was ,assessor ,gahn1 of ,fahlun4 #i4 ,in his paper on silica he gives us a history of the progress of chemical knowledge respecting this substance4 ,its nature was first accurately pointed out by ,pott2 though ,glauber1 and before him ,van ,helmont1 were acquainted with the liquor silicus1 or the combination of silica and potash1 which is soluble in water4 ,bergman gives a detailed account of its properties2 but he does not suspect it to possess acid properties4 ,this great discovery1 which has thrown a new light upon mineral bodies1 and shown them all to be chemical combinations1 was reserved for ,mr4 ,smithson4 #aj4 ,bergman's experiments on the precious stones constitute the first rudiments of the method of analyzing stony bodies4 ,his processes are very imperfect1 and his apparatus but ill adapted to the purpose4 ,we need not be surprised1 therefore1 that the results of his analyses are extremely wide of the truth4 ,yet1 if we study his processes1 we shall find in them the rudiments of the very methods which we follow at present4 ,the superiority of the modern analyses over those of ,bergman must in a great measure be ascribed to the platinum vessels which we now employ1 and to the superior purity of the substances which we use as reagents in our analyses4 ,the methods1 too1 are simplified and perfected4 ,but we must not forget that this paper of ,bergman's1 imperfect as it is1 constitutes the commencement of the art1 and that fully as much genius and invention may be requisite to contrive the first rude processes1 how imperfect soever they may be1 as are required to bring these processes when once invented to a state of comparative perfection4 ,the great step in analyzing minerals is to render them soluble in acids4 ,bergman first thought of the method for accomplishing this which is still followed1 namely1 fusing them or heating them to redness with an alkali or alkaline carbonate4 #aa4 ,the paper on fulminating gold goes a great way to explain the nature of that curious compound4 ,he describes the properties of this substance1 and the effects of alkaline and acid bodies on it4 ,he shows that it cannot be formed without ammonia1 and infers from his experiments that it is a compound of oxide of gold and ammonia4 ,he explains the fulmination by the elastic fluid suddenly generated by the decomposition of the ammonia4 #ab4 ,the papers on platinum1 carbonate of iron1 nickel1 arsenic1 and zinc1 do not require many remarks4 ,they add considerably to the knowledge which chemists at that time possessed of these bodies2 though the modes of analysis are not such as would be approved of by a modern chemist2 nor were the results obtained possessed of much precision4 #ac4 ,the ,essay on the ,analysis of ,metallic ,ores by the wet way1 or by solution1 constitutes the first attempt to establish a regular method of analyzing metallic ores4 ,the processes are all imperfect1 as might be expected from the then existing state of analytical chemistry1 and the imperfect knowledge possessed1 of the different metallic ores4 ,but this essay constituted a first beginning1 for which the author is entitled to great praise4 ,the subject was taken up by ,klaproth1 and speedily brought to a great degree of improvement by the labours of modern chemists4 #ad4 ,the experiments on the way in which minerals behave before the blowpipe1 which ,bergman published1 were made at ,bergman's request by ,assessor ,gahn1 of ,fahlun1 who was then his pupil4 ,they constitute the first results obtained by that very ingenious and amiable man4 ,he afterwards continued the investigation1 and added many improvements1 simplifying the reagents and the manner of using them4 ,but he was too indolent a man to commit the results of his investigations to writing4 ,berzelius1 however1 had the good sense to see the importance of the facts which ,gahn had ascertained4 ,he committed them to writing1 and published them for the use of mineralogists4 ,they constitute the book entitled ,berzelius on the ,blowpipe1 which has been translated into ,english4 #ae4 ,the object of the ,essay on ,metallic ,precipitates is to determine the quantity of phlogiston which each metal contains1 deduced from the quantity of one metal necessary to precipitate a given weight of another4 ,the experiments are obviously made with little accuracy3 indeed they are not susceptible of very great precision4 ,lavoisier afterwards made use of the same method to determine the quantity of oxygen in the different metallic oxides2 but his results were not more successful than those of ,bergman4 #af4 ,bergman's paper on iron is one of the most important in his whole works1 and contributed very materially to advance the knowledge of the cause of the difference between iron and steel4 ,he employed his pupils to collect specimens of iron from the different ,swedish forges1 and gave them directions how to select the proper pieces4 ,all these specimens1 to the number of eighty-nine1 he subjected to a chemical examination1 by dissolving them in dilute sulphuric acid4 ,he measured the volume of hydrogen gas1 which he obtained by dissolving a given weight of each1 and noted the quantity and the nature of the undissolved residue4 ,the general result of the whole investigation was that pure malleable iron yielded most hydrogen gas2 steel less1 and cast-iron least of all4 ,pure malleable iron left the smallest quantity of insoluble matter1 steel a greater quantity1 and cast-iron the greatest of all4 ,from these experiments he drew conclusions with respect to the difference between iron1 steel1 and cast-iron4 ,nothing more was necessary than to apply the antiphlogistic theory to these experiments1 7as was done soon after by the ,french chemists17 in order to draw important conclusions respecting the nature of these bodies4 ,iron is a simple body2 steel is a compound of iron and carbon2 and cast-iron of iron and a still greater proportion of carbon4 ,the defective part of the experiments of ,bergman in this important paper is his method of determining the quantity of manganese in iron4 ,in some specimens he makes the manganese amount to considerably more than a third part of the weight of the whole4 ,now we know that a mixture of two parts iron and one part manganese is brittle and useless4 ,we are sure1 therefore1 that no malleable iron whatever can contain any such proportion of manganese4 ,the fact is1 that ,bergman's mode of separating manganese from iron was defective4 ,what he considered as manganese was chiefly1 and might be in many cases altogether1 oxide of iron4 ,many years elapsed before a good process for separating iron from manganese was discovered4 #ag4 ,bergman's experiments to ascertain the cause of the brittleness of cold-short iron need not occupy much of our attention4 ,he extracted from it a white powder1 by dissolving the cold-short iron in dilute sulphuric acid4 ,this white powder he succeeded in reducing to the state of a white brittle metal1 by fusing it with a flux and charcoal4 ,klaproth soon after ascertained that this metal was a phosphuret of iron1 and that the white powder was a phosphate of iron3 and ,scheele1 with his usual sagacity1 hit on a method of analyzing this phosphate1 and thus demonstrating its nature4 ,thus ,bergman's experiments led to the knowledge of the fact that cold-short iron owes its brittleness to a quantity of phosphorus which it contains4 ,it ought to be mentioned that ,meyer1 of ,stettin1 ascertained the same fact1 and made it known to chemists at about the same time with ,bergman4 #ah4 ,the dissertation on the products of volcanoes1 first published in #aggg1 is one of the most striking examples of the sagacity of ,bergman which we possess4 ,he takes a view of all the substances certainly known to have been thrown out of volcanoes1 attempts to subject them to a chemical analysis1 and compares them with the basalt1 and greenstone or trap-rocks1 the origin of which constituted at that time a keen matter of dispute among geologists4 ,he shows the identity between lavas and basalt and greenstone1 and therefore infers the identity of formation4 ,this is obviously the true mode of proceeding1 and1 had it been adopted at an earlier period1 many of those disputes respecting the nature of trap-rocks1 which occupied geologists for so long a period1 would never have been agitated2 or1 at least1 would have been speedily decided4 ,the whole dissertation is filled with valuable matter1 still well entitled to the attention of geologists4 ,his observations on zeolites1 which he considered as unconnected with volcanic products1 were very natural at the time when he wrote3 though the subsequent experiments of ,sir ,james ,hall1 and ,mr4 ,gregory ,watt1 and1 above all1 an accurate attention to the scori from different smelting-houses1 have thrown a new light on the subject1 and have shown the way in which zeolitic crystals might easily have been formed in melted lava1 provided circumstances were favourable4 ,in fact1 we find abundant cavities in real lava from ,vesuvius1 filled with zeolitic crystals4 #ai4 ,the last of the labours of ,bergman which ,i shall notice here is his ,essay on ,elective ,attractions1 which was originally published in #agge1 but was much augmented and improved in the third volume of his ,opuscula1 published in #aghc4 ,an ,english translation of this last edition of the ,essay was made by ,dr4 ,beddoes1 and was long familiar to the ,british chemical world4 ,the object of this essay was to elucidate and explain the nature of chemical affinity1 and to account for all the apparent anomalies that had been observed4 ,he laid it down as a first principle1 that all bodies capable of combining chemically with each other1 have an attraction for each other1 and that this attraction is a definite and fixed force which may be represented by a number4 ,now the bodies which have the property of uniting together are chiefly the acids and the alkalies1 or bases4 ,every acid has an attraction for each of the alkalies or bases2 but the force of this attraction differs in each4 ,some bases have a strong attraction for acids1 and others a weak2 but the attractive force of each may be expressed by numbers4 ,now1 suppose that an acid a is united with a base m with a certain force1 if we mix the compound a m with a certain quantity of the base n1 which has a stronger attraction for a than m has1 the consequence will be1 that a will leave m and unite with n2--n having a stronger attraction for a than m has1 will disengage it and take its place4 ,in consequence of this property1 which ,bergman considered as the foundation of the whole of the science1 the strength of affinity of one body for another is determined by these decompositions and combinations4 ,if n has a stronger affinity for a than m has1 then if we mix together a1 m1 and n in the requisite proportions1 a and n will unite together1 leaving m uncombined3 or if we mix n with the compound a m1 m will be disengaged4 ,tables1 therefore1 may be drawn up1 exhibiting the strength of these affinities4 ,at the top of a column is put the name of an acid or a base1 and below it are put the names of all the bases or acids in the order of their affinity4 ,the following little table will exhibit a specimen of these columns3 ,sulphuric ,acid4 ,barytes ,strontian ,potash ,soda ,lime ,magnesia4 ,here sulphuric acid is the substance placed at the head of the column1 and under it are the names of the bases capable of uniting with it in the order of their affinity4 ,barytes1 which is highest up1 has the strongest affinity1 and magnesia1 which is lowest down1 has the weakest affinity4 ,if sulphuric acid and magnesia were combined together1 all the bases whose names occur in the table above magnesia would be able to separate the sulphuric acid from it4 ,potash would be disengaged from sulphuric acid by barytes and strontian1 but not by soda1 lime1 and magnesia4 ,such tables then exhibited to the eye the strength of affinity of all the different bodies that are capable of uniting with one and the same substance1 and the order in which decompositions are effected4 ,bergman drew up tables of affinity according to these views in fifty-nine columns4 ,each column contained the name of a particular substance1 and under it was arranged all the bodies capable of uniting with it1 each in the order of its affinity4 ,now bodies may be made to unite1 either by mixing them together1 and then exposing them to heat1 or by dissolving them in water and mixing the respective solutions together4 ,the first of these ways is usually called the dry way1 the second the moist way4 ,the order of decompositions often varies with the mode employed4 ,on this account1 ,bergman divided each of his fifty-nine columns into two4 ,in the first1 he exhibited the order of decompositions in the moist way1 in the second in the dry4 ,he explained also the cases of double decomposition1 by means of these unvarying forces acting together or opposing each other--and gave sixty-four cases of such double decompositions4 ,these views of ,bergman's were immediately acceded to by the chemical world1 and continued to regulate their processes till ,berthollet published his ,chemical ,statics in #ahjb4 ,he there called in question the whole doctrine of ,bergman1 and endeavoured to establish one of the very opposite kind4 ,i shall have occasion to return to the subject when ,i come to give an account of the services which ,berthollet conferred upon chemistry4 ,i have already observed1 that we are under obligations to ,bergman1 not merely for the improvements which he himself introduced into chemistry1 but for the pupils whom he educated as chemists1 and the discoveries which were made by those persons1 whose exertions he stimulated and encouraged4 ,among those individuals1 whose chemical discoveries were chiefly made known to the world by his means1 was ,scheele1 certainly one of the most extraordinary men1 and most sagacious and industrious chemists that ever existed4 ,charles ,william ,scheele was born on the #aith of ,december1 #agdb1 at ,stralsund1 the capital of ,swedish ,pomerania1 where his father was a tradesman4 ,he received the first part of his education at a private academy in ,stralsund1 and was afterwards removed to a public school4 ,at a very early period he expressed a strong desire to study pharmacy1 and obtained his father's consent to make choice of this profession4 ,he was accordingly bound an apprentice for six years to ,mr4 ,bouch1 an apothecary in ,gotheborg1 and after his time was out1 he remained with him still1 two years longer4 ,it was here that he laid the groundwork of all his future celebrity1 as we are informed by ,mr4 ,grunberg1 who was his fellow-apprentice1 and afterwards settled as an apothecary in ,stralsund4 ,he was at that time very reserved and serious1 but uncommonly diligent4 ,he attended minutely to all the processes1 reflected upon them while alone1 and studied the writings of ,neumann1 ,lemery1 ,kunkel1 and ,stahl1 with indefatigable industry4 ,he likewise exercised himself a good deal in drawing and painting1 and acquired some proficiency in these accomplishments without a master4 ,kunkel's ,laboratorium was his favourite book1 and he was in the habit of repeating experiments out of it secretly during the night-time4 ,on one occasion1 as he was employed in making pyrophorus1 his fellow-apprentice was malicious enough to put a quantity of fulminating powder into the mixture4 ,the consequence was a violent explosion1 which1 as it took place in the night1 threw the whole family into confusion1 and brought a very severe rebuke upon our young chemist4 ,but this did not put a stop to his industry1 which he pursued so constantly and judiciously1 that1 by the time his apprenticeship was ended1 there were very few chemists indeed who excelled him in knowledge and practical skill4 ,his fellow-apprentice1 ,mr4 ,grunberg1 wrote to him in #aggd1 requesting to know by what means he had become such a proficient in chemistry1 and received the following answer3 ,i look upon you1 my dear friend1 as my first instructor1 and as the author of all ,i know on the subject1 in consequence of your advising me to read ,neumann's ,chemistry4 ,the perusal of this book first gave me a taste for experimenting1 myself2 and ,i very well remember1 that upon mixing some oil of cloves and smoking spirit of nitre together1 they took fire4 ,however1 ,i kept this matter secret4 ,i have also before my eyes the unfortunate experiment which ,i made with pyrophorus4 ,such accidents only served to increase my passion for making experiments4 ,in #agfe ,scheele went to ,malmo1 to the house of an apothecary1 called ,mr4 ,kalstrom4 ,after spending two years in that place1 he went to ,stockholm1 to superintend the apothecary's shop of ,mr4 ,scharenberg4 ,in #aggc he exchanged this situation for another at ,upsala1 in the house of ,mr4 ,loock4 ,it was here that he accidentally formed an acquaintance with ,assessor ,gahn1 of ,fahlun1 who was at that time a student at ,upsala1 and a zealous chemist4 ,mr4 ,gahn happening to be one day in the shop of ,mr4 ,loock1 that gentleman mentioned to him a circumstance which had lately occurred to him1 and of which he was anxious to obtain an explanation4 ,if a quantity of saltpetre be put into a crucible and raised to such a temperature as shall not merely melt it1 but occasion an agitation in it like boiling1 and if1 after a certain time1 the crucible be taken out of the fire and allowed to cool1 the saltpetre still continues neutral2 but its properties are altered3 for1 if distilled vinegar be poured upon it1 red fumes are given out1 while vinegar produces no effect upon the saltpetre before it has been thus heated4 ,mr4 ,loock wished from ,gahn an explanation of the cause of this phenomenon3 ,gahn was unable to explain it2 but promised to put the question to ,professor ,bergman4 ,he did so accordingly1 but ,bergman was as unable to find an explanation as himself4 ,on returning a few days after to ,mr4 ,loock's shop1 ,gahn was informed that there was a young man in the shop who had given an explanation of the phenomenon4 ,this young man was ,scheele1 who had informed ,mr4 ,loock that there were two species of acids confounded under the name of spirit of nitre2 what we at present call nitric and hyponitrous acids4 ,nitric acid has a stronger affinity for potash than vinegar has2 but hyponitrous acid has a weaker4 ,the heat of the fire changes the nitric acid of the saltpetre to hyponitrous3 hence the phenomenon4 ,gahn was delighted with the information1 and immediately formed an acquaintance with ,scheele1 which soon ripened into friendship4 ,when he informed ,bergman of ,scheele's explanation1 the professor was equally delighted1 and expressed an eager desire to be made acquainted with ,scheele2 but when ,gahn mentioned the circumstance to ,scheele1 and offered to introduce him to ,bergman1 our young chemist rejected the proposal with strong feelings of dislike4 ,it seems1 that while ,scheele was in ,stockholm1 he had made experiments on cream of tartar1 and had succeeded in separating from it tartaric acid1 in a state of purity4 ,he had also determined a number of the properties of tartaric acid1 and examined several of the tartrates4 ,he drew up an account of these results1 and sent it to ,bergman4 ,bergman1 seeing a paper subscribed by the name of a person who was unknown to him1 laid it aside without looking at it1 and forgot it altogether4 ,scheele was very much provoked at this contemptuous and unmerited treatment4 ,he drew up another account of his experiments and gave it to ,retzius1 who sent it to the ,stockholm ,academy of ,sciences 7with some additions of his own71 in whose ,memoirs it was published in the year #aggj4c ,it cost ,assessor ,gahn considerable trouble to satisfy ,scheele that ,bergman's conduct was merely the result of inadvertence1 and that he had no intention whatever of treating him either with contempt or neglect4 ,after much entreaty1 he prevailed upon ,scheele to allow him to introduce him to the professor of chemistry4 ,the introduction took place accordingly1 and ever after ,bergman and ,scheele continued steady friends--,bergman facilitating the researches of ,scheele by every means in his power4 #c ,konig4 ,vetensk4 ,acad4 ,handl4 #aggj1 p4 #bjg4 ,so high did the character of ,scheele speedily rise in ,upsala1 that when the ,duke of ,sudermania visited the university soon after1 in company with ,prince ,henry of ,prussia1 ,scheele was appointed by the university to exhibit some chemical processes before him4 ,he fulfilled his charge1 and performed in different furnaces several curious and striking experiments4 ,prince ,henry asked him various questions1 and expressed satisfaction at the answers given4 ,he was particularly pleased when informed that he was a native of ,stralsund4 ,these two princes afterwards stated to the professors that they would take it as a favour if ,scheele could have free access to the laboratory of the university whenever he wished to make experiments4 ,in the year #agge1 on the death of ,mr4 ,popler1 apothecary at ,kping 7a small place on the north side of the lake ,mler71 he was appointed by the ,medical ,college provisor of the apothecary's shop4 ,in ,sweden all the apothecaries are under the control of the ,medical ,college1 and no one can open a shop without undergoing an examination and receiving licence from that learned body4 ,in the course of the examinations which he was obliged to undergo1 ,scheele gave great proofs of his abilities1 and obtained the appointment4 ,in #aggg the widow sold him the shop and business1 according to a written agreement made between them2 but they still continued housekeeping at their joint expense4 ,he had already distinguished himself by his discovery of fluoric acid1 and by his admirable paper on manganese4 ,it is said1 too1 that it was he who made the experiments on carbonic acid gas1 which constitute the substance of ,bergman's paper on the subject1 and which confirmed and established ,bergman's idea that it was an acid4 ,at ,kping he continued his researches with unremitting perseverance1 and made more discoveries than all the chemists of his time united together4 ,it was here that he made the experiments on air and fire1 which constitute the materials of his celebrated work on these subjects4 ,the theory which he formed was indeed erroneous2 but the numerous discoveries which the book contains must always excite the admiration of every chemist4 ,his discovery of oxygen gas had been anticipated by ,priestley2 but his analysis of atmospheric air was new and satisfactory--was peculiarly his own4 ,the processes by means of which he procured oxygen gas were also new1 simple1 and easy1 and are still followed by chemists in general4 ,during his residence at ,kping he published a great number of chemical papers1 and every one of them contained a discovery4 ,the whole of his time was devoted to chemical investigations4 ,every action of his life had a tendency to forward the advancement of his favourite science2 all his thoughts were turned to the same object2 all his letters were devoted to chemical observations and chemical discussions4 ,crell's ,annals was at that time the chief periodical work on chemistry in ,germany4 ,he got the numbers regularly as they were published1 and was one of ,crell's most constant and most valuable correspondents4 ,every one of his letters published in that work either contains some new chemical fact1 or exposes the errors and mistakes of some one or other of ,crell's numerous correspondents4 ,scheele's outward appearance was by no means prepossessing4 ,he seldom joined in the usual conversations and amusements of society1 having neither leisure nor inclination for them4 ,what little time he had to spare from the hurry of his profession was always employed in making experiments4 ,it was only when he received visits from his friends1 with whom he could converse on his favourite science1 that he indulged himself in a little relaxation4 ,for such intimate friends he had a sincere affection4 ,this regard was extended to all the zealous cultivators of chemistry in every part of the world1 whether personally known to him or not4 ,he kept up a correspondence with several2 though this correspondence was much limited by his ignorance of all languages except ,german2 for at least he could not write fluently in any other language4 ,his chemical papers were always written in ,german1 and translated into ,swedish1 before they were inserted in the ,memoirs of the ,stockholm ,academy1 where most of them appeared4 ,he was kind and affable to all4 ,before he adopted an opinion in science1 he reflected maturely on it2 but1 after he had once embraced it1 his opinions were not easily shaken4 ,however1 he did not hesitate to give up an opinion as soon as it had been proved to be erroneous4 ,thus1 he entirely renounced the notion which he once entertained that silica is a compound of water and fluoric acid2 because it was demonstrated1 by ,meyer and others1 that this silica was derived from the glass vessels in which the fluoric acid was prepared2 that these glass vessels were speedily corroded into holes2 and that1 if fluoric acid was prepared in metallic vessels1 and not allowed to come in contact with glass or any substance containing silica1 it might be mixed with water without any deposition of silica whatever4 ,it appears also by a letter of his1 published in ,crell's ,annals1 that he was satisfied of the accuracy of ,mr4 ,cavendish's experiments1 showing that water was a compound of oxygen and hydrogen gases1 and of ,lavoisier's repetition of them4 ,he attempted to reconcile this fact with his own notion1 that heat is a compound of oxygen and hydrogen4 ,but his arguments on that subject1 though ingenious1 are not satisfactory2 and there is little doubt that if he had lived somewhat longer1 and had been able to repeat his own experiments1 and compare them with those of ,cavendish and ,lavoisier1 he would have given up his own theory and adopted that of ,lavoisier1 or1 at any rate1 the explanation of ,cavendish1 which1 being more conformable to his own preconceived notions1 might have been embraced by him in preference4 ,it is said by ,dr4 ,crell that ,scheele was invited over to ,england1 with an offer of an easy and advantageous situation2 but that his love of quiet and retirement1 and his partiality for ,sweden1 where he had spent the greatest part of his life1 threw difficulties in the way of these overtures1 and that a change in the ,english ministry put a stop to them for the time4 ,the invitation1 ,crell says1 was renewed in #aghf1 with the offer of a salary of #cjjl4 a-year2 but ,scheele's death put a final stop to it4 ,i have very great doubts about the truth of this statement2 and1 many years ago1 during the lifetime of ,sir ,joseph ,banks1 ,mr4 ,cavendish1 and ,mr4 ,kirwan1 ,i made inquiry about the circumstance2 but none of the chemists in ,great ,britain1 who were at that time numerous and highly respectable1 had ever heard of any such negotiation4 ,i am utterly at a loss to conceive what one individual in any of the ministries of ,george ,,iii4 was either acquainted with the science of chemistry1 or at all interested in its progress4 ,they were all so intent upon accomplishing their own objects1 or those of their sovereign1 that they had neither time nor inclination to think of science1 and certainly no money to devote to any of its votaries4 ,what minister in ,great ,britain ever attempted to cherish the sciences1 or to reward those who cultivate them with success8 ,if we except ,mr4 ,montague1 who procured the place of master of the ,mint for ,sir ,isaac ,newton1 ,i know of no one4 ,while in every other nation in ,europe science is directly promoted1 and considerable sums are appropriated for its cultivation1 and for the support of a certain number of individuals who have shown themselves capable of extending its boundaries1 not a single farthing has been devoted to any such purpose in ,great ,britain4 ,science has been left entirely to itself2 and whatever has been done by way of promoting it has been performed by the unaided exertions of private individuals4 ,george ,,iii4 himself was a patron of literature and an encourager of botany4 ,he might have been disposed to reward the unrivalled eminence which ,scheele had attained2 but this he could only have done by bestowing on him a pension out of his privy purse4 ,no situation which ,scheele could fill was at his disposal4 ,the universities and the church were both shut against a ,lutheran2 and no pharmaceutical places exist in this country to which ,scheele could have been appointed4 ,if any such project ever existed1 it must have been an idea which struck some man of science that such a proposal to a man of ,scheele's eminence would redound to the credit of the country4 ,but that such a project should have been broached by a ,british ministry1 or by any man of great political influence1 is an opinion that no person would adopt who has paid any attention to the history of ,great ,britain since the ,revolution to the present time4 ,scheele fell at last a sacrifice to his ardent love for his science4 ,he was unable to abstain from experimenting1 and many of his experiments were unavoidably made in his shop1 where he was exposed during winter1 in the ungenial climate of ,sweden1 to cold draughts of air4 ,he caught rheumatism in consequence1 and the disease was aggravated by his ardour and perseverance in his pursuits4 ,when he purchased the apothecary's shop in which his business was carried on1 he had formed the resolution of marrying the widow of his predecessor1 and he had only delayed it from the honourable principle of acquiring1 in the first place1 sufficient property to render such an alliance desirable on her part4 ,at length1 in the month of ,march1 #aghf1 he declared his intention of marrying her2 but his disease at this time increased very fast1 and his hopes of recovery daily diminished4 ,he was sensible of this2 but nevertheless he performed his promise1 and married her on the #aith of ,may1 at a time when he lay on his deathbed4 ,on the #bast1 he left her by his will the disposal of the whole of his property2 and1 the same day on which he so tenderly provided for her1 he died4 ,i shall now endeavour to give the reader an idea of the principal chemical discoveries for which we are indebted to ,scheele3 his papers1 with the exception of his book on air and fire1 which was published separately by ,bergman1 are all to be found either in the ,memoirs of the ,stockholm ,academy of ,science1 or in ,crell's ,journal2 they were collected1 and a ,latin translation of them1 made by ,godfrey ,henry ,schaefer1 published at ,leipsic1 in #aghh1 by ,henstreit1 the editor of the three last volumes of ,bergman's ,opuscula4 ,a ,french translation of them was made in consequence of the exertions of ,m4 ,morveau2 and an ,english translation of them1 in #aghf1 by means of ,dr4 ,beddoes1 when he was a student in ,edinburgh4 ,there are also several ,german translations1 but ,i have never had an opportunity of seeing them4 #a4 ,scheele's first paper was published by ,retzius1 in #aggj2 it gives a method of obtaining pure tartaric acid3 the process was to decompose cream of tartar by means of chalk4 ,one half of the tartaric acid unites to the lime1 and falls down in the state of a white insoluble powder1 being tartrate of lime4 ,the cream of tartar1 thus deprived of half its acid1 is converted into the neutral salt formerly distinguished by the name of soluble tartar1 from its great solubility in water3 it dissolves1 and may be obtained in crystals1 by the usual method of crystallizing salts4 ,the tartrate of lime is washed with water1 and then mixed with a quantity of dilute sulphuric acid1 just capable of saturating the lime contained in the tartrate of lime2 the mixture is digested for some time2 the sulphuric acid displaces the tartaric acid1 and combines with the lime2 and1 as the sulphate of lime is but very little soluble in water1 the greatest part of it precipitates1 and the clear liquor is drawn off3 it consists of tartaric acid1 held in solution by water1 but not quite free from sulphate of lime4 ,by repeated concentrations1 all the sulphate of lime falls down1 and at last the tartaric acid itself is obtained in large crystals4 ,this process is still followed by the manufacturers of this country2 for tartaric acid is used to a very considerable extent by the calico-printers1 in various processes2 for example1 it is applied1 thickened with gum1 to different parts of cloth dyed ,turkey red2 the cloth is then passed through water containing the requisite quantity of chloride of lime3 the tartaric acid1 uniting with the lime1 sets the chlorine at liberty1 which immediately destroys the red colour wherever the tartaric acid has been applied1 but leaves all the other parts of the cloth unchanged4 #b4 ,the paper on fluoric acid appeared in the ,memoirs of the ,stockholm ,academy1 for #agga1 when ,scheele was in ,scharenberg's apothecary's shop in ,stockholm1 where1 doubtless1 the experiments were made4 ,three years before1 ,margraaf had attempted an analysis of fluor spar1 but had discovered nothing4 ,scheele demonstrated that it is a compound of lime and a peculiar acid1 to which he gave the name of fluoric acid4 ,this acid he obtained in solution in water2 it was separated from the fluor spar by sulphuric1 muriatic1 nitric1 and phosphoric acids4 ,when the fluoric acid came in contact with water1 a white crust was formed1 which proved1 on examination1 to be silica4 ,scheele at first thought that this silica was a compound of fluoric acid and water2 but it was afterwards proved by ,weigleb and by ,meyer1 that this notion is inaccurate1 and that the silica was corroded from the retort into which the fluor spar and sulphuric acid were put4 ,bergman1 who had adopted ,scheele's theory of the nature of silica1 was so satisfied by these experiments1 that he gave it up1 as ,scheele himself did soon after4 ,scheele did not obtain fluoric acid in a state of purity1 put only fluosilicic acid2 nor were chemists acquainted with the properties of fluoric acid till ,gay-,lussac and ,thenard published their ,recherches ,physico-chimiques1 in #ahaa4 #c4 ,scheele's experiments on manganese were undertaken at the request of ,bergman1 and occupied him three years2 they were published in the ,memoirs of the ,stockholm ,academy1 for #aggd1 and constitute the most memorable and important of all his essays1 since they contain the discovery of two new bodies1 which have since acted so conspicuous a part1 both in promoting the progress of the science1 and in improving the manufactures of ,europe4 ,these two substances are chlorine and barytes1 the first account of both of which occur in this paper4 ,the ore of manganese employed in these experiments was the black oxide1 or deutoxide1 of manganese1 as it is now called4 ,scheele's method of proceeding was to try the effect of all the different reagents on it4 ,it dissolved in sulphurous and nitrous acids1 and the solution was colourless4 ,dilute sulphuric acid did not act upon it1 nor nitric acid2 but concentrated sulphuric acid dissolved it by the assistance of heat4 ,the solution of sulphate of manganese in water was colourless and crystallized in very oblique rhomboidal prisms1 having a bitter taste4 ,muriatic acid effervesced with it1 when assisted by heat1 and the elastic fluid that passed off had a yellowish colour1 and the smell of aqua regia4 ,he collected quantities of this elastic fluid 7chlorine7 in bladders1 and determined some of its most remarkable properties3 it destroyed colours1 and tinged the bladder yellow1 as nitric acid does4 ,this elastic fluid1 in ,scheele's opinion1 was muriatic acid deprived of phlogiston4 ,by phlogiston ,scheele meant1 in this place1 hydrogen gas4 ,he considered muriatic acid as a compound of chlorine and hydrogen4 ,now this is the very theory that was established by ,davy in consequence of his own experiments and those of ,gay-,lussac and ,thenard4 ,scheele's mode of collecting chlorine gas in a bladder1 did not enable him to determine its characters with so much precision as was afterwards done4 ,but his accuracy was so great1 that every thing which he stated respecting it was correct so far as it went4 ,most of the specimens of manganese ore which ,scheele examined1 contained more or less barytes1 as has since been determined1 in combination with the oxide4 ,he separated this barytes1 and determined its peculiar properties4 ,it dissolved in nitric and muriatic acids1 and formed salts capable of crystallizing1 and permanent in the air4 ,neither potash1 soda1 nor lime1 nor any base whatever1 was capable of precipitating it from these acids4 ,but the alkaline carbonates threw it down in the state of a white powder1 which dissolved with effervescence in acids4 ,sulphuric acid and all the sulphates threw it down in the state of a white powder1 which was insoluble in water and in acids4 ,this sulphate cannot be decomposed by any acid or base whatever4 ,the only practicable mode of proceeding is to convert the sulphuric acid into sulphur1 by heating the salt with charcoal powder1 along with a sufficient quantity of potash1 to bring the whole into fusion4 ,the fused mass1 edulcorated1 is soluble in nitric or muriatic acid1 and thus may be freed from charcoal1 and the barytes obtained in a state of purity4 ,scheele detected barytes1 also1 in the potash made from trees or other smaller vegetables2 but at that time he was unacquainted with sulphate of barytes1 which is so common in various parts of the earth1 especially in lead-mines4 ,to point out all the new facts contained in this admirable essay1 it would be necessary to transcribe the whole of it4 ,he shows the remarkable analogy between manganese and metallic oxides4 ,bergman1 in an appendix affixed to ,scheele's paper1 states his reasons for being satisfied that it is really a metallic oxide4 ,some years afterwards1 ,assessor ,gahn succeeded in reducing it to the metallic state1 and thus dissipating all remaining doubts on the subject4 #d4 ,in #agge he gave a new method of obtaining benzoic acid from benzoin4 ,his method was1 to digest the benzoin with pounded chalk and water1 till the whole of the acid had combined with lime1 and dissolved in the water4 ,it is requisite to take care to prevent the benzoin from running into clots4 ,the liquid thus containing benzoate of lime in solution is filtered1 and muriatic acid added in sufficient quantity to saturate the lime4 ,the benzoic acid is separated in white flocks1 which may be easily collected and washed4 ,this method1 though sufficiently easy1 is not followed by practical chemists1 at least in this country4 ,the acid when procured by precipitation is not so beautiful as what is procured by sublimation2 nor is the process so cheap or so rapid4 ,for these reasons1 ,scheele's process has not come into general use4 #e4 ,during the same year1 #agge1 his essay on arsenic and its acid was also published in the ,memoirs of the ,stockholm ,academy4 ,in this essay he shows various processes1 by means of which white arsenic may be converted into an acid1 having a very sour taste1 and very soluble in water4 ,this is the acid to which the name of arsenic acid has been since given4 ,scheele describes the properties of this acid1 and the salts which it forms1 with the different bases4 ,he examines1 also1 the action of white arsenic upon different bodies1 and throws light upon the arsenical salt of ,macquer4 #f4 ,the object of the little paper on silica1 clay1 and alum1 published in the ,memoirs of the ,stockholm ,academy1 for #aggf1 is to prove that alumina and silica are two perfectly distinct bodies1 possessed of different properties4 ,this he does with his usual felicity of experiment4 ,he shows1 also1 that alumina and lime are capable of combining together4 #g4 ,the same year1 and in the same volume of the ,stockholm ,memoirs1 he published his experiments on a urinary calculus4 ,the calculus upon which his experiments were made1 happened to be composed of uric acid4 ,he determined the properties of this new acid1 particularly the characteristic one of dissolving in nitric acid1 and leaving a beautiful pink sediment when the solution is gently evaporated to dryness4 #h4 ,in #aggh appeared his experiments on molybdena4 ,what is now called molybdena is a soft foliated mineral1 having the metallic lustre1 and composed of two atoms sulphur united to one atom of metallic molybdenum4 ,it was known before1 from the experiments of ,quest1 that this substance contains sulphur4 ,scheele extracted from it a white powder1 which he showed to possess acid properties1 though it was insoluble in water4 ,he examined the characters of this acid1 called molybdic acid1 and the nature of the salts which it is capable of forming by uniting with bases4 #i4 ,in the year #aggg was published the ,experiments of ,scheele on ,air and ,fire1 with an introduction1 by way of preface1 from ,bergman1 who seems to have superintended the publication4 ,this work is undoubtedly the most extraordinary production that ,scheele has left us2 and is really wonderful1 if we consider the circumstances under which it was produced4 ,scheele ascertained that common air is a mixture of two distinct elastic fluids1 one of which alone is capable of supporting combustion1 and which1 therefore1 he calls empyreal air2 the other1 being neither capable of maintaining combustion1 nor of being breathed1 he called foul air4 ,these are the oxygen and azote of modern chemists4 ,oxygen he showed to be heavier than common air2 bodies burnt in it with much greater splendour than in common air4 ,azote he found lighter than common air2 bodies would not burn in it at all4 ,he showed that metallic calces1 or metallic oxides1 as they are now called1 contain oxygen as a constituent1 and that when they are reduced to the metallic state1 oxygen gas is disengaged4 ,in his experiments on fulminating gold he shows1 that during the fulmination a quantity of azotic gas is disengaged2 and he deduces from a great many curious facts1 which are stated at length1 that ammonia is a compound of azote and hydrogen4 ,his apparatus was not nice enough to enable him to determine the proportions of the various ingredients of the bodies which he analyzed3 accordingly that is seldom attempted2 and when it is1 as was the case with common air1 the results are very unsatisfactory4 ,he deduces from his experiments1 that the volume of oxygen gas1 in common air1 is between a third and a fourth3 we now know that it is exactly a fifth4 ,in this book1 also1 we have the first account of sulphuretted hydrogen gas1 and of its properties4 ,he gives it the name of stinking sulphureous air4 ,the observations and new views respecting heat and light in this work are so numerous1 that ,i am obliged to omit them3 nor do ,i think it necessary to advert to his theory1 which1 when his book was published1 was exceedingly plausible1 and undoubtedly constituted a great step towards the improvements which soon after followed4 ,his own experiments1 had he attended a little more closely to the weights1 and the alterations of them1 would have been sufficient to have overturned the whole doctrine of phlogiston4 ,upon the whole it may be said1 with confidence1 that there is no chemical book in existence which contains a greater number of new and important facts than this work of ,scheele1 at the time it was published4 ,yet most of his discoveries were made1 also1 by others4 ,priestley and ,lavoisier1 from the superiority of their situations1 and their greater means of making their labours speedily known to the public1 deprived him of much of that reputation to which1 in common circumstances1 he would have been entitled4 ,priestley has been blamed for the rapidity of his publications1 and the crude manner in which he ushered his discoveries to the world4 ,but had he kept them by him till he had brought them to a sufficient degree of maturity1 it is obvious that he would have been anticipated in the most important of them by ,scheele4 #aj4 ,in the ,memoirs of the ,stockholm ,academy1 for #aggi1 there is a short but curious paper of ,scheele1 giving an account of some results which he had obtained4 ,if a plate of iron be moistened by a solution of common salt1 or of sulphate of soda1 and left for some weeks in a moist cellar1 an efflorescence of carbonate of soda covers the surface of the plate4 ,the same decomposition of common salt and evolution of soda takes place when unslacked quicklime is moistened with a solution of common salt1 and left in a similar situation4 ,these experiments led afterwards to various methods of decomposing common salt1 and obtaining from it carbonate of soda4 ,the phenomena themselves are still wrapped up in considerable obscurity4 ,berthollet attempted an explanation afterwards in his ,chemical ,statics2 but founded on principles not easily admissible4 #aa4 ,during the same year1 his experiments on plumbago were published4 ,this substance had been long employed for making black-lead pencils2 but nothing was known concerning its nature4 ,scheele1 with his usual perseverance1 tried the effect of all the different reagents1 and showed that it consisted chiefly of carbon1 but was mixed with a certain quantity of iron4 ,it was concluded from these experiments1 that plumbago is a carburet of iron4 ,but the quantity of iron differs so enormously in different specimens1 that this opinion cannot be admitted4 ,sometimes the iron amounts only to one-half per cent41 and sometimes to thirty per cent4 ,plumbago1 then1 is carbon mixed with a variable proportion of iron1 or carburet of iron4 #ab4 ,in #aghj ,scheele published his experiments on milk1 and showed that sour milk contains a peculiar acid1 to which the name of lactic acid has been given4 ,he found that when sugar of milk is dissolved in nitric acid1 and the solution allowed to cool1 small crystalline grains were deposited4 ,these grains have an acid taste1 and combine with bases3 they have peculiar properties1 and therefore constitute a particular acid1 to which the name of saclactic was given4 ,it is formed1 also1 when gum is dissolved in nitric acid2 on this account it has been called1 mucic acid4 #ac4 ,in #agha his experiments on a heavy mineral called by the ,swedes tungsten1 were published4 ,this substance had been much noticed on account of its great weight2 but nothing was known respecting its nature4 ,scheele1 with his usual skill and perseverance1 succeeded in proving that it was a compound of lime and a peculiar acid1 to which the name of tungstic acid was given4 ,tungsten was1 therefore1 a tungstate of lime4 ,bergman1 from its great weight1 suspected that tungstic acid was in reality the oxide of a metal1 and this conjecture was afterwards confirmed by the ,elhuyarts1 who extracted the same acid from wolfram1 and succeeded in reducing it to the metallic state4 #ad4 ,in #aghb and #aghc appeared his experiments on ,prussian blue1 in order to discover the nature of the colouring matter4 ,these experiments were exceedingly numerous1 and display uncommon ingenuity and sagacity4 ,he succeeded in demonstrating that prussic acid1 the name at that time given to the colouring principle1 was a compound of carbon and azote4 ,he pointed out a process for obtaining prussic acid in a separate state1 and determined its properties4 ,this paper threw at once a ray of light on one of the obscurest parts of chemistry4 ,if he did not succeed in elucidating this difficult department completely1 the fault must not be ascribed to him1 but to the state of chemistry when his experiments were made2 in fact1 it would have been impossible to have gone further1 till the nature of the different elastic fluids at that time under investigation had been thoroughly established4 ,perhaps in #aghc there was scarcely any other individual who could have carried this very difficult investigation so far as it was carried by ,scheele4 #ae4 ,in #aghc appeared his observations on the sweet principle of oils4 ,he observed1 that when olive oil and litharge are combined together1 a sweet substance separates from the oil and floats on the surface4 ,this substance1 when treated with nitric acid1 yields oxalic acid4 ,it was therefore closely connected with sugar in its nature4 ,he obtained the same sweet matter from linseed oil1 oil of almonds1 of rape-seed1 from hogs' lard1 and from butter4 ,he therefore concluded that it was a principle contained in all the expressed or fixed oils4 #af4 ,in #aghd he pointed out a method by which citric acid may be obtained in a state of purity from lemon-juice4 ,he likewise determined its characters1 and showed that it was entitled to rank as a peculiar acid4 ,it was during the same year that he observed a white earthy matter1 which may be obtained by washing rhubarb1 in fine powder1 with a sufficient quantity of water4 ,this earthy matter he decomposed1 and ascertained that it was a neutral salt1 composed of oxalic acid1 combined with lime4 ,in a subsequent paper he showed1 that the same oxalate of lime exists in a great number of roots of various plants4 #ag4 ,in #aghf he showed that apples contain a peculiar acid1 the properties of which he determined1 and to which the name of malic acid has been given4 ,in the same paper he examined all the common acid fruits of this country--gooseberries1 currants1 cherries1 bilberries1 c41 and determined the peculiar acids which they contain4 ,some owe their acidity to malic acid1 some to citric acid1 and some to tartaric acid2 and not a few hold two1 or even three1 of these acids at the same time4 ,the same year he showed that the syderum of ,bergman was phosphuret of iron1 and the acidum perlatum of ,proust biphosphate of soda4 ,the only other publication of ,scheele1 during #aghe1 was a short notice respecting a new mode of preparing magnesia alba4 ,if sulphate of magnesia and common salt1 both in solution1 be mixed in the requisite proportions1 a double decomposition takes place1 and there will be formed sulphate of soda and muriate of magnesia4 ,the greatest part of the former salt may be obtained out of the mixed ley by crystallization1 and then the magnesia alba may be thrown down1 from the muriate of magnesia1 by means of an alkaline carbonate4 ,the advantage of this new process is1 the procuring of a considerable quantity of sulphate of soda in exchange for common salt1 which is a much cheaper substance4 #ah4 ,the last paper which ,scheele published appeared in the ,memoirs of the ,stockholm ,academy1 for #aghf3 in it he gave an account of the characters of gallic acid1 and the method of obtaining that acid from nutgalls4 ,such is an imperfect sketch of the principal discoveries of ,scheele4 ,i have left out of view his controversial papers1 which have now lost their interest2 and a few others of minor importance1 that this notice might not be extended beyond its due length4 ,it will be seen that ,scheele extended greatly the number of acids2 indeed1 he more than doubled the number of these bodies known when he began his chemical labours4 ,the following acids were discovered by him2 or1 at least1 it was he that first accurately pointed out their characters3 ,fluoric acid ,molybdic acid ,tungstic acid ,arsenic acid ,lactic acid ,gallic acid ,tartaric acid ,oxalic acid ,citric acid ,malic acid ,saclactic ,chlorine4 ,to him1 also1 we owe the first knowledge of barytes1 and of the characters of manganese4 ,he determined the nature of the constituents of ammonia and prussic acid3 he first determined the compound nature of common air1 and the properties of the two elastic fluids of which it is composed4 ,what other chemist1 either a contemporary or predecessor of ,scheele1 can be brought in competition with him as a discoverer8 ,and all was performed under the most unpropitious circumstances1 and during the continuance of a very short life1 for he died in the #ddth year of his age4 ,,chapter ,,iii4 ,,progress ,,of ,,scientific ,,chemistry ,,in ,,france4 ,i have already given an account of the state of chemistry in ,france1 during the earlier part of the eighteenth century1 as it was cultivated by the ,stahlian school4 ,but the new aspect which chemistry put on in ,britain in consequence of the discoveries of ,black1 ,cavendish1 and ,priestley1 and the conspicuous part which the gases newly made known was likely to take in the future progress of the science1 drew to the study of chemistry1 sometime after the middle of the eighteenth century1 a man who was destined to produce a complete revolution1 and to introduce the same precision1 and the same accuracy of deductive reasoning which distinguishes the other branches of natural science4 ,this man was ,lavoisier4 ,antoine ,laurent ,lavoisier was born in ,paris on the #bfth of ,august1 #agdc4 ,his father being a man of opulence spared no expense on his education4 ,his taste for the physical sciences was early displayed1 and the progress which he made in them was uncommonly rapid4 ,in the year #agfd a prize was offered by the ,french government for the best and most economical method of lighting the streets of an extensive city4 ,young ,lavoisier1 though at that time only twenty-one years of age1 drew up a memoir on the subject which obtained the gold medal4 ,this essay was inserted in the ,memoirs of the ,french ,academy of ,sciences1 for #agfh4 ,it was during that year1 when he was only twenty-five years of age that he became a member of that scientific body4 ,by this time he was become fully conscious of his own strength2 but he hesitated for some time to which of the sciences he should devote his attention4 ,he tried pretty early to determine1 experimentally1 some chemical questions which at that time drew the attention of practical chemists4 ,for example3 an elaborate paper of his appeared in the ,memoirs of the ,french ,academy1 for #agfh1 on the composition of gypsum--a point at that time not settled2 but which ,lavoisier proved1 as ,margraaf had done before him1 to be a compound of sulphuric acid and lime4 ,in the ,memoirs of the ,academy1 for #aggj1 two papers of his appeared1 the object of which was to determine whether water could1 as ,margraaf had pretended1 be converted into silica by long-continued digestion in glass vessels4 ,lavoisier found1 as ,margraaf stated1 that when water is digested for a long time in a glass retort1 a little silica makes its appearance2 but he showed that this silica was wholly derived from the retort4 ,glass1 it is well known1 is a compound of silica and a fixed alkali4 ,when water is long digested on it the glass is slightly corroded1 a little alkali is dissolved in the water and a little silica separated in the form of a powder4 ,he turned a good deal of his attention also to geology1 and made repeated journeys with ,guettard into almost every part of ,france4 ,the object in view was an accurate description of the mineralogical structure of ,france--an object accomplished to a considerable extent by the indefatigable exertions of ,guettard1 who published different papers on the subject in the ,memoirs of the ,french ,academy1 accompanied with geological maps2 which were at that time rare4 ,the mathematical sciences also engrossed a considerable share of his attention4 ,in short he displayed no great predilection for one study more than another1 but seemed to grasp at every branch of science with equal avidity4 ,while in this state of suspension he became acquainted with the new and unexpected discoveries of ,black1 ,cavendish1 and ,priestley1 respecting the gases4 ,this opened a new creation to his view1 and finally determined him to devote himself to scientific chemistry4 ,in the year #aggd he published a volume under the title of ,essays ,physical and ,chemical4 ,it was divided into two parts4 ,the first part contained an historical detail of every thing that had been done on the subject of airs1 from the time of ,paracelsus down to the year #aggd4 ,we have the opinions and experiments of ,van ,helmont1 ,boyle1 ,hales1 ,boerhaave1 ,stahl1 ,venel1 ,saluces1 ,black1 ,macbride1 ,cavendish1 and ,priestley4 ,we have the history of ,meyer's acidum pingue1 and the controversy carried on in ,germany1 between ,jacquin on the one hand1 and ,crans and ,smeth on the ether4 ,in the second part ,lavoisier relates his own experiments upon gaseous substances4 ,in the first four chapters he shows the truth of ,dr4 ,black's theory of fixed air4 ,in the #dth and #eth chapters he proves that when metallic calces are reduced1 by heating them with charcoal1 an elastic fluid is evolved1 precisely of the same nature with carbonic acid gas4 ,in the #fth chapter he shows that when metals are calcined their weight increases1 and that a portion of air equal to their increase in weight is absorbed from the surrounding atmosphere4 ,he observed that in a given bulk of air calcination goes on to a certain point and then stops altogether1 and that air in which metals have been calcined does not support combustion so well as it did before any such process was performed in it4 ,he also burned phosphorus in a given volume of air1 observed the diminution of volume of the air and the increase of the weight of the phosphorus4 ,nothing in these essays indicates the smallest suspicion that air was a mixture of two distinct fluids1 and that only one of them was concerned in combustion and calcination2 although this had been already deduced by ,scheele from his own experiments1 and though ,priestley had already discovered the existence and peculiar properties of oxygen gas4 ,it is obvious1 however1 that ,lavoisier was on the way to make these discoveries1 and had neither ,scheele nor ,priestley been fortunate enough to hit upon oxygen gas1 it is exceedingly likely that he would himself have been able to have made that discovery4 ,dr4 ,priestley1 however1 happened to be in ,paris towards the end of #aggd1 and exhibited to ,lavoisier1 in his own laboratory in ,paris1 the method of procuring oxygen gas from red oxide of mercury4 ,this discovery altered all his views1 and speedily suggested not only the nature of atmospheric air1 but also what happens during the calcination of metals and the combustion of burning bodies in general4 ,these opinions when once formed he prosecuted with unwearied industry for more than twelve years1 and after a vast number of experiments1 conducted with a degree of precision hitherto unattempted in chemical investigations1 he boldly undertook to disprove the existence of phlogiston altogether1 and to explain all the phenomena hitherto supposed to depend upon that principle by the simple combination or separation of oxygen from bodies4 ,in these opinions he had for some years no coadjutors or followers1 till1 in #aghe1 ,berthollet at a meeting of the ,academy of ,sciences1 declared himself a convert4 ,he was followed by ,m4 ,fourcroy1 and soon after ,guyton de ,morveau1 who was at that time the editor of the chemical department of the ,encyclopdie ,mthodique1 was invited to ,paris by ,lavoisier and prevailed upon to join the same party4 ,this was followed by a pretty vigorous controversy1 in which ,lavoisier and his associates gained a signal victory4 ,lavoisier1 after ,buffon and ,tillet1 was treasurer to the academy1 into the accounts of which he introduced both economy and order4 ,he was consulted by the ,national ,convention on the most eligible means of improving the manufacture of assignats1 and of augmenting the difficulty of forging them4 ,he turned his attention also to political economy1 and between #aggh and #aghe he allotted #bdj arpents in the ,vendomois to experimental agriculture1 and increased the ordinary produce by one-half4 ,in #agia the ,constituent ,assembly invited him to draw up a plan for rendering more simple the collection of the taxes1 which produced an excellent report1 printed under the title of ,territorial ,riches of ,france4 ,in #aggf he was employed by ,turgot to inspect the manufactory of gunpowder2 which he made to carry #abj toises1 instead of #ij4 ,it is pretty generally known1 that during the war of the ,american revolution1 the ,french gunpowder was much superior to the ,british2 but it is perhaps not so generally understood1 that for this superiority the ,french government were indebted to the abilities of ,lavoisier4 ,during the war of the ,french revolution1 the quality of the powder of the two nations was reversed2 the ,english being considerably superior to that of the ,french1 and capable of carrying further4 ,this was put to the test in a very remarkable way at ,cadiz4 ,during the horrors of the dictatorship of ,robespierre1 ,lavoisier began to suspect that he would be stripped of his property1 and informed ,lalande that he was extremely willing to work for his subsistence4 ,it was supposed that he meant to pursue the profession of an apothecary1 as most congenial to his studies3 but he was accused1 along with the other farmers-general1 of defrauding the revenue1 and thrown into prison4 ,during that sanguinary period imprisonment and condemnation were synonymous terms4 ,accordingly1 on the #hth of ,may1 #agid1 he suffered on the scaffold1 with twenty-eight farmers-general1 at the early age of fifty-one4 ,it has been1 alleged that ,fourcroy1 who at that time possessed considerable influence1 might have saved him had he been disposed to have exerted himself4 ,but this accusation has never been supported by any evidence4 ,lavoisier was a man of too much eminence to be overlooked1 and no accused person at that time could be saved unless he was forgotten4 ,a paper was presented to the tribunal1 drawn up by ,m4 ,hall1 giving a catalogue of the works1 and a recapitulation of the merits of ,lavoisier2 but it was thrown aside without even being read1 and ,m4 ,hall had reason to congratulate himself that his useless attempts to save ,lavoisier did not terminate in his own destruction4 ,lavoisier was tall1 and possessed a countenance full of benignity1 through which his genius shone forth conspicuous4 ,he was mild1 humane1 sociable1 obliging1 and he displayed an incredible degree of activity4 ,his influence was great1 on account of his fortune1 his reputation1 and the place which he held in the treasury2 but all the use which he made of it was to do good4 ,his wife1 whom he married in #agga1 was ,marie-,anna-,pierette-,paulze1 daughter of a farmer-general1 who was put to death at the same time with her husband2 she herself was imprisoned1 but saved by the fortunate destruction of the dictator himself1 together with his abettors4 ,it would appear that she was able to save a considerable part of her husband's fortune3 she afterwards married ,count ,rumford1 whom she survived4 ,besides his volume of ,physical and ,chemical ,essays1 and his ,elements of ,chemistry1 published in #aghi1 ,lavoisier was the author of no fewer than sixty memoirs1 which were published in the volumes of the ,academy of ,sciences1 from #aggb1 to #aghh1 or in other periodical works of the time4 ,i shall take a short review of the most important of these memoirs1 dividing them into two parts3 ,i4 ,those that are not connected with his peculiar chemical theory2 ,,ii4 ,those which were intended to disprove the existence of phlogiston1 and establish the antiphlogistic theory4 ,i4 ,i have already mentioned his paper on gypsum1 published in the ,memoirs of the ,academy1 for #agfh4 ,he proves1 by very decisive experiments1 that this salt is a compound of sulphuric acid1 lime1 and water4 ,but this had been already done by ,margraaf1 in a paper inserted into the ,memoirs of the ,berlin ,academy1 for #agej1 entitled ,an ,examination of the constituent parts of the ,stones that become luminous4 ,the most remarkable circumstance attending this paper is1 that an interval of eighteen years should elapse without ,lavoisier's having any knowledge of this important paper of ,margraaf2 yet he quotes ,pott and ,cronstedt1 who had written on the same subject later than ,margraaf1 at least ,cronstedt4 ,what makes this still more singular and unaccountable is1 that a ,french translation of ,margraaf's ,opuscula had been published in ,paris1 in the year #agfb4 ,that a man in ,lavoisier's circumstances1 who1 as appears from his paper1 had paid considerable attention to chemistry1 should not have perused the writings of one of the most eminent chemists that had ever existed1 when they were completely within his power1 constitutes1 ,i think1 one of the most extraordinary phenomena in the history of science4 #b4 ,if a want of historical knowledge appears conspicuous in ,lavoisier's first chemical paper1 the same remark cannot be applied to his second paper1 ,on the ,nature of ,water1 and the ,experiments by which it has been attempted to prove the possibility of changing it into ,earth1 which was inserted in the ,memoirs of the ,french ,academy1 for #aggj4 ,this memoir is divided into two parts4 ,in the first he gives a history of the progress of opinions on the subject1 beginning with ,van ,helmont's celebrated experiment on the willow2 then relating those of ,boyle1 ,triewald1 ,miller1 ,eller1 ,gleditch1 ,bonnet1 ,kraft1 ,alston1 ,wallerius1 ,hales1 ,duhamel1 ,stahl1 ,boerhaave1 ,geoffroy1 ,margraaf1 and ,le ,roy4 ,this first part is interesting1 in an historical point of view1 and gives a very complete account of the progress of opinions upon the subject from the very first dawn of scientific chemistry down to his own time4 ,there is1 it is true1 a remarkable difference between the opinions of his predecessors respecting the conversion of water into earth1 and the experiments of ,margraaf on the composition of selenite4 ,the former were inaccurate1 and were recorded by him that they might be refuted2 but the experiments of ,margraaf were accurate1 and of the same nature with his own4 ,the second part of this memoir contains his own experiments1 made with much precision1 which went to show that the earth was derived from the retort in which the experiments of ,margraaf were made1 and that we have no proof whatever that water may be converted into earth4 ,but these experiments of ,lavoisier1 though they completely disproved the inferences that ,margraaf drew from his observations1 by no means demonstrated that water might not be converted into different animal and vegetable substances by the processes of digestion4 ,indeed there can be no doubt that this is the case1 and that the oxygen and hydrogen of which it is composed1 enter into the composition of by far the greater number of animal and vegetable bodies produced by the action of the functions of living animals and vegetables4 ,we have no evidence that the carbon1 another great constituent of vegetable bodies1 and the carbon and azote which constitute so great a proportion of animal substances1 have their origin from water4 ,they are probably derived from the food of plants and animals1 and from the atmosphere which surrounds them1 and which contains both of these principles in abundance4 ,whether the silica1 lime1 alumina1 magnesia1 and iron1 that exist in small quantity in plants1 be derived from water and the atmosphere1 is a question which we are still unable to answer4 ,but the experiments of ,schrader1 which gained the prize offered by the ,berlin ,academy1 in the year #ahjj1 for the best essay on the following subject3 ,to determine the earthy constituents of the different kinds of corn1 and to ascertain whether these earthy parts are formed by the processes of vegetation1 show at least that we cannot account for their production in any other way4 ,schrader analyzed the seeds of wheat1 rye1 barley1 and oats1 and ascertained the quantity of earthy matter which each contained4 ,he then planted these different seeds in flowers of sulphur1 and in oxides of antimony and zinc1 watering them regularly with distilled water4 ,they vegetated very well4 ,he then dried the plants1 and analyzed what had been the produce of a given weight of seed1 and he found that the earthy matter in each was greater than it had been in the seeds from which they sprung4 ,now as the sulphur and oxides of zinc and antimony could furnish no earthy matter1 no other source remains but the water with which the plants were fed1 and the atmosphere with which they were surrounded4 ,it may be said1 indeed1 that earthy matter is always floating about in the atmosphere1 and that in this way they may have obtained all the addition of these principles which they contained4 ,this is an objection not easily obviated1 and yet it would require to be obviated before the question can be considered as answered4 #c4 ,lavoisier's next paper1 inserted in the ,memoirs of the ,academy1 for #agga1 was entitled ,calculations and ,observations on the ,project of the establishment of a ,steam-engine to supply ,paris with ,water4 ,this memoir1 though long and valuable1 not being strictly speaking chemical1 ,i shall pass over4 ,mr4 ,watt's improvements seem to have been unknown to ,lavoisier1 indeed as his patent was only taken out in #agfi1 and as several years elapsed before the merits of his new steam-engine became generally known1 ,lavoisier's acquaintance with it in #agga could hardly be expected4 #d4 ,in #aggb we find a paper1 by ,lavoisier1 in the ,memoirs of the ,academy1 ,on the ,use of ,spirit of ,wine in the analysis of ,mineral ,waters4 ,he shows how the earthy muriates may be separated from the sulphates by digesting the mixed mass in alcohol4 ,this process no doubt facilitates the separation of the salts from each other3 but it is doubtful whether the method does not occasion new inaccuracies that more than compensate the facility of such separations4 ,when different salts are dissolved in water in small quantities1 it may very well happen that they do not decompose each other1 being at too great a distance from each other to come within the sphere of mutual action4 ,thus it is possible that sulphate of soda and muriate of lime may exist together in the same water4 ,but if we concentrate this water very much1 and still more1 if we evaporate to dryness1 the two salts will gradually come into the sphere of mutual action1 a double decomposition will take place1 and there will be formed sulphate of lime and common salt4 ,if upon the dry residue we pour as much distilled water as was driven off by the evaporation1 we shall not be able to dissolve the saline matter deposited2 a portion of sulphate of lime will remain in the state of a powder4 ,yet before the evaporation1 all the saline contents of the water were in solution1 and they continued in solution till the water was very much concentrated4 ,this is sufficient to show that the nature of the salts was altered by the evaporation4 ,if we digest the dry residue in spirit of wine1 we may dissolve a portion of muriate of lime1 if the quantity of that salt in the original water was greater than the sulphate of soda was capable of decomposing3 but if the quantity was just what the sulphate of soda could decompose1 the alcohol will dissolve nothing1 if it be strong enough1 or nothing but a little common salt1 if its specific gravity was above #jhbj4 ,we cannot1 therefore1 depend upon the salts which we obtain after evaporating a mineral water to dryness1 being the same as those which existed in the mineral water itself4 ,the nature of the salts must always be determined some other way4 #e4 ,in the ,memoirs of the ,academy1 for #aggb 7published in #aggf71 are inserted two elaborate papers of ,lavoisier1 on the combustion of the diamond4 ,the combustibility of the diamond was suspected by ,newton1 from its great refractive power4 ,his suspicion was confirmed in #afid1 by ,cosmo ,,iii41 ,grand ,duke of ,tuscany1 who employed ,averani and ,targioni to try the effect of powerful burning-glasses upon diamonds4 ,they were completely dissipated by the heat4 ,many years after1 the ,emperor ,francis ,i4 caused various diamonds to be exposed to the heat of furnaces4 ,they also were dissipated1 without leaving any trace behind them4 ,m4 ,darcet1 professor of chemistry at the ,royal ,college of ,paris1 being employed with ,count ,lauragais in a set of experiments on the manufacture of porcelain1 took the opportunity of trying what effect the intense heat of the porcelain furnaces produced upon various bodies4 ,diamonds were not forgotten4 ,he found that they were completely dissipated by the heat of the furnace1 without leaving any traces behind them4 ,darcet found that a violent heat was not necessary to volatilize diamonds4 ,the heat of an ordinary furnace was quite sufficient4 ,in #agga a diamond1 belonging to ,m4 ,godefroi ,villetaneuse1 was exposed to a strong heat by ,macquer4 ,it was placed upon a cupel1 and raised to a temperature high enough to melt copper4 ,it was observed to be surrounded with a low red flame1 and to be more intensely red than the cupel4 ,in short1 it exhibited unequivocal marks of undergoing real combustion4 ,these experiments were soon after repeated by ,lavoisier before a large company of men of rank and science4 ,the real combustion of the diamond was established beyond doubt2 and it was ascertained also1 that if it be completely excluded from the air1 it may be exposed to any temperature that can be raised in a furnace without undergoing any alteration4 ,hence it is clear that the diamond is not a volatile substance1 and that it is dissipated by heat1 not by being volatilized1 but by being burnt4 ,the object of ,lavoisier in his experiments was to determine the nature of the substance into which the diamond was converted by burning4 ,in the first part he gives as usual a history of every thing which had been done previous to his own experiments on the combustion of the diamond4 ,in the second part we have the result of his own experiments upon the same subject4 ,he placed diamonds on porcelain supports in glass jars standing inverted over water and over mercury2 and filled with common air and with oxygen gas4#d #d ,the reader will bear in mind that though the memoir was inserted in the ,mem4 de l',acad41 for #aggb1 it was in fact published in #aggf1 and the experiments were made in #agge and #aggf4 ,the diamonds were consumed by means of burning-glasses4 ,no water or smoke or soot made their appearance1 and no alteration took place on the bulk of the air when the experiments were made over mercury4 ,when they were made over water1 the bulk of the air was somewhat diminished4 ,it was obvious from this that diamond when burnt in air or oxygen gas1 is converted into a gaseous substance1 which is absorbed by water4 ,on exposing air in which diamond had been burnt1 to lime-water1 a portion of it was absorbed1 and the lime-water was rendered milky4 ,from this it became evident1 that when diamond is burnt1 carbonic acid is formed1 and this was the only product of the combustion that could be discovered4 ,lavoisier made similar experiments with charcoal1 burning it in air and oxygen gas1 by means of a burning-glass4 ,the results were the same3 carbonic acid gas was formed in abundance1 and nothing else4 ,these experiments might have been employed to support and confirm ,lavoisier's peculiar theory1 and they were employed by him for that purpose afterwards4 ,but when they were originally published1 no such intention appeared evident2 though doubtless he entertained it4 #f4 ,in the second volume of the ,journal de ,physique1 for #aggb1 there is a short paper by ,lavoisier on the conversion of water into ice4 ,m4 ,desmarets had given the academy an account of ,dr4 ,black's experiments1 to determine the latent heat of water4 ,this induced ,lavoisier to relate his experiments on the same subject4 ,he does not inform us whether they were made in consequence of his having become acquainted with ,dr4 ,black's theory1 though there can be no doubt that this must have been the case4 ,the experiments related in this short paper are not of much consequence4 ,but ,i have thought it worth while to notice it because it authenticates a date at which ,lavoisier was acquainted with ,dr4 ,black's theory of latent heat4 #g4 ,in the third volume of the ,journal de ,physique1 there is an account of a set of experiments made by ,bourdelin1 ,malouin1 ,macquer1 ,cadet1 ,lavoisier1 and ,baum on the white-lead ore of ,pullowen4 ,the report is drawn up by ,baum4 ,the nature of the ore is not made out by these experiments4 ,they were mostly made in the dry way1 and were chiefly intended to show that the ore was not a chloride of lead4 ,it was most likely a phosphate of lead4 #h4 ,in the ,memoirs of the ,academy1 for #aggd1 we have the experiments of ,trudaine1 de ,montigny1 ,macquer1 ,cadet1 ,lavoisier1 and ,brisson1 with the great burning-glass of ,m4 ,trudaine4 ,the results obtained cannot be easily abridged1 and are not of sufficient importance to be given in detail4 #i4 ,analysis of some waters brought from ,italy by ,m4 ,cassini1 junior4 ,this short paper appeared in the ,memoirs of the ,academy1 for #aggg4 ,the waters in question were brought from alum-pits1 and were found to contain alum and sulphate of iron4 #aj4 ,in the same volume of the ,memoirs of the ,academy1 appeared his paper ,on the ,ash employed by the ,saltpetre-makers of ,paris1 and on its use in the ,manufacture of ,saltpetre4 ,this is a curious and valuable paper2 but not sufficiently important to induce me to give an abstract of it here4 #aa4 ,in the ,memoirs of the ,academy1 for #aggg1 appeared an elaborate paper1 by ,lavoisier1 ,on the ,combination of the matter of ,fire1 with ,evaporable ,fluids1 and the ,formation of ,elastic aeriform ,fluids4 ,in this paper he adopts precisely the same theory as ,dr4 ,black had long before established4 ,it is remarkable that the name of ,dr4 ,black never occurs in the whole paper1 though we have seen that ,lavoisier had become acquainted with the doctrine of latent heat1 at least as early as the year #aggb1 as he mentioned the circumstance in a short paper inserted that year in the ,journal de ,physique1 and previously read to the academy4 #ab4 ,in the same volume of the ,memoirs of the ,academy1 we have a paper entitled ,experiments made by ,order of the ,academy1 on the ,cold of the year #agge1 by ,messrs4 ,bezout1 ,lavoisier1 and ,vandermond4 ,it is sufficiently known that the beginning of the year #aggf was distinguished in most parts of ,europe by the weather4 ,the object of this paper1 however1 is rather to determine the accuracy of the different thermometers at that time used in ,france1 than to record the lowest temperature which had been observed4 ,it has some resemblance to a paper drawn up about the same time by ,mr4 ,cavendish1 and published in the ,philosophical ,transactions4 #ac4 ,in the ,memoirs of the ,academy1 for #aggh1 appeared a paper entitled ,analysis of the ,waters of the ,lake ,asphaltes1 by ,messrs4 ,macquer1 ,lavoisier1 and ,sage4 ,this water is known to be saturated with salt4 ,it is needless to state the result of the analysis contained in this paper1 because it is quite inaccurate4 ,chemical analysis had not at that time made sufficient progress to enable chemists to analyze mineral waters with precision4 ,the observation of ,lavoisier and ,guettard1 which appeared at the same time1 on a species of steatite1 which is converted by the fire into a fine biscuit of porcelain1 and on two coal-mines1 the one in ,franche-,comt1 the other in ,alsace1 do not require to be particularly noticed4 #ad4 ,in the ,mem4 de l',acadmie1 for #aghj 7published in #aghd71 we have a paper1 by ,lavoisier1 ,on certain ,fluids which may be obtained in an aeriform ,state1 at a degree of ,heat not much higher than the mean ,temperature of the ,earth4 ,these fluids are sulphuric ether1 alcohol1 and water4 ,he points out the boiling temperature of these liquids1 and shows that at that temperature the vapour of these bodies possesses the elasticity of common air1 and is permanent as long as the high temperature continues4 ,he burnt a mixture of vapour of ether and oxygen gas1 and showed that during the combustion carbonic acid gas is formed4 ,lavoisier's notions respecting these vapours1 and what hindered the liquids at the boiling temperature from being all converted into vapour were not quite correct4 ,our opinions respecting steam and vapours in general were first rectified by ,mr4 ,dalton4 #ae4 ,in the ,mem4 de l',acadmie1 for #aghj1 appeared also the celebrated paper on heat1 by ,lavoisier and ,laplace4 ,the object of this paper was to determine the specific heat of various bodies1 and to investigate the proposals that had been made by ,dr4 ,irvine for determining the point at which a thermometer would stand1 if plunged into a body destitute of heat4 ,this point is usually called the real zero4 ,they begin by describing an instrument which they had contrived to measure the quantity of heat which leaves a body while it is cooling a certain number of degrees4 ,to this instrument they gave the name of calorimeter4 ,it consisted of a kind of hollow1 surrounded on every side by ice4 ,the hot body was put into the centre4 ,the heat which it gave out while cooling was all expended in melting the ice1 which was of the temperature of #cb1 and the quantity of heat was proportional to the quantity of ice melted4 ,hence the quantity of ice melted1 while equal weights of hot bodies were cooling a certain number of degrees1 gave the direct ratios of the specific heats of each4 ,in this way they obtained the following specific heats3 ,specific heat4 ,water #a ,sheet-iron #jajiihe ,glass without lead 7crystal7 #jaibi ,mercury #jjbi ,quicklime #jbafhi ,mixture of #i water with #af lime #jdciaaf ,sulphuric acid of #ahgjeh #jccdeig #d sulphuric acid1 #c water #jfjcafb #d sulphuric acid1 #e water #jffcajb ,nitric acid of #abihie #jffacia #i nitric acid1 #a lime #jfahie #a saltpetre1 #h water #jhafg ,their experiments were inconsistent with the conclusions drawn by ,dr4 ,irvine1 respecting the real zero1 from the diminution of the specific heat1 and the heat evolved when sulphuric acid was mixed with various proportions of water1 c4 ,if the experiments of ,lavoisier and ,laplace approached nearly to accuracy1 or1 indeed1 unless they were quite inaccurate1 it is obvious that the conclusions of ,irvine must be quite erroneous4 ,it is remarkable that though the experiments of ,crawford1 and likewise those of ,wilcke1 and of several others1 on specific heat had been published before this paper made its appearance1 no allusion whatever is made to these publications4 ,were we to trust to the information communicated in the paper1 the doctrine of specific heat originated with ,lavoisier and ,laplace4 ,it is true that in the fourth part of the paper1 which treats of combustion and respiration1 ,dr4 ,crawford's1 theory of animal heat is mentioned1 showing clearly that our authors were acquainted with his book on the subject4 ,and1 as this theory is founded on the different specific heats of bodies1 there could be no doubt that he was acquainted with that doctrine4 #af4 ,in the ,mem4 de l',acadmie1 for #aghj1 occur the two following memoirs3 ,report made to the ,royal ,academy of ,sciences on the ,prisons4 ,by ,messrs4 ,duhamel1 ,de ,montigny1 ,le ,roy1 ,tenon1 ,tillet1 and ,lavoisier4 ,report on the ,process for separating ,gold and ,silver4 ,by ,messrs4 ,macquer1 ,cadet1 ,lavoisier1 ,baum1 ,cornette1 and ,berthollet4 #ag4 ,in the ,mem4 de l',acadmie1 for #agha1 we find a memoir by ,lavoisier and ,laplace1 on the electricity evolved when bodies are evaporated or sublimed4 ,the result of these experiments was1 that when water was evaporated electricity was always evolved4 ,they concluded from these observations1 that whenever a body changes its state electricity is always evolved4 ,but when ,saussure attempted to repeat these observations1 he could not succeed4 ,and1 from the recent experiments of ,pouillet1 it seems to follow that electricity is evolved only when bodies undergo chemical decomposition or combination4 ,such experiments depend so much upon very minute circumstances1 which are apt to escape the attention of the observer1 that implicit confidence cannot be put in them till they have been often repeated1 and varied in every possible manner4 #ah4 ,in the ,memoires de l',acadmie1 for #agha1 there is a paper by ,lavoisier on the comparative value of the different substances employed as articles of fuel4 ,the substances compared to each other are pit-coal1 coke1 charcoal1 and wood4 ,it would serve no purpose to state the comparison here1 as it would not apply to this country2 nor1 indeed1 would it at present apply even to ,france4 ,we have1 in the same volume1 his paper on the mode of illuminating theatres4 #ai4 ,in the ,memoires de l',acadmie1 for #aghb 7printed in #aghe71 we have a paper by ,lavoisier on a method of augmenting considerably the action of fire and of heat4 ,the method which he proposes is a jet of oxygen gas1 striking against red-hot charcoal4 ,he gives the result of some trials made in this way4 ,platinum readily melted4 ,pieces of ruby or sapphire were softened sufficiently to run together into one stone4 ,hyacinth lost its colour1 and was also softened4 ,topaz lost its colour1 and melted into an opaque enamel4 ,emeralds and garnets lost their colour1 and melted into opaque coloured glasses4 ,gold and silver were volatilized2 all the other metals1 and even the metallic oxides1 were found to burn4 ,barytes also burns when exposed to this violent heat4 ,this led ,lavoisier to conclude1 as ,bergman had done before him1 that ,barytes is a metallic oxide4 ,this opinion has been fully verified by modern chemists4 ,both silica and alumina were melted4 ,but he could not fuse lime nor magnesia4 ,we are now in possession of a still more powerful source of heat in the oxygen and hydrogen blowpipe1 which is capable of fusing both lime and magnesia1 and1 indeed1 every substance which can be raised to the requisite heat without burning or being volatilized4 ,this subject was prosecuted still further by ,lavoisier in another paper inserted in a subsequent volume of the ,memoires de l',acadmie4 ,he describes the effect on rock-crystal1 quartz1 sandstone1 sand1 phosphorescent quartz1 milk quartz1 agate1 chalcedony1 cornelian1 flint1 prase1 nephrite1 jasper1 felspar1 c4 #bj4 ,in the same volume is inserted a memoir ,on the ,nature of the aeriform elastic ,fluids which are disengaged from certain animal ,substances in a state of ,fermentation4 ,he found that a quantity of recent human fces1 amounting to about five cubic inches1 when kept at a temperature approaching to #fj emitted1 every day for a month1 about half a cubic inch of gas4 ,this gas was a mixture of eleven parts carbonic acid gas1 and one part of an inflammable gas1 which burnt with a blue flame1 and was therefore probably carbonic oxide4 ,five cubic inches of old human fces from a necessary kept in the same temperature1 during the first fifteen days emitted about a third of a cubic inch of gas each day2 and during each of the second fifteen days1 about one fourth of a cubic inch4 ,this gas was a mixture of thirty-eight volumes of carbonic acid gas1 and sixty-two volumes of a combustible gas1 burning with a blue flame1 and probably carbonic oxide4 ,fresh fces do not effervesce with dilute sulphuric acid1 but old moist fces do1 and emit about eight times their volume of carbonic acid gas4 ,quicklime1 or caustic potash1 mixed with fces1 puts a stop to the evolution of gas1 doubtless by preventing all fermentation4 ,during effervescence of fcal matter the air surrounding it is deprived of a little of its oxygen1 probably in consequence of its combining with the nascent inflammable gas which is slowly disengaged4 ,,ii4 ,we come now to the new theory of combustion of which ,lavoisier was the author1 and upon which his reputation with posterity will ultimately depend4 ,upon this subject1 or at least upon matters more or less intimately connected with it1 no fewer than twenty-seven memoirs of his1 many of them of a very elaborate nature1 and detailing expensive and difficult experiments1 appeared in the different volumes of the academy between #aggd and #aghh4 ,the analogy between the combustion of bodies and the calcination of metals had been already observed by chemists1 and all admitted that both processes were owing to the same cause2 namely1 the emission of phlogiston by the burning or calcining body4 ,the opinion adopted by ,lavoisier was1 that during burning and calcination nothing whatever left the bodies1 but that they simply united with a portion of the air of the atmosphere4 ,when he first conceived this opinion he was ignorant of the nature of atmospheric air1 and of the existence of oxygen gas4 ,but after that principle had been discovered1 and shown to be a constituent of atmospherical air1 he soon recognised that it was the union of oxygen with the burning and calcining body that occasioned the phenomena4 ,such is the outline of the ,lavoisierian theory stated in the simplest and fewest words4 ,it will be requisite to make a few observations on the much-agitated question whether this theory originated with him4 ,it is now well known that ,john ,rey1 a physician at ,bugue1 in ,perigord1 published a book in #afcj1 in order to explain the cause of the increase of weight which lead and tin experience during their calcination4 ,after refuting in succession all the different explanations of this increase of weight which had been advanced1 he adds1 ,to this question1 then1 supported on the grounds already mentioned1 ,i answer1 and maintain with confidence1 that the increase of weight arises from the air1 which is condensed1 rendered heavy and adhesive by the violent and long-continued heat of the furnace4 ,this air mixes itself with the calx 7frequent agitation conducing71 and attaches itself to the minutest molecules1 in the same manner as water renders heavy sand which is agitated with it1 and moistens and adheres to the smallest grains4 ,there cannot be the least doubt from this passage that ,rey's opinion was precisely the same as the original one of ,lavoisier1 and had ,lavoisier done nothing more than merely state in general terms that during calcination air unites with the calcining bodies1 it might have been suspected that he had borrowed his notions from those of ,rey4 ,but the discovery of oxygen1 and the numerous and decisive proofs which he brought forward that during burning and calcination oxygen unites with the burning and calcining body1 and that this oxygen may be again separated and exhibited in its original elastic state oblige us to alter our opinion4 ,and whether we admit that he borrowed his original notion from ,rey1 or that it suggested itself to his own mind1 the case will not be materially altered4 ,for it is not the man who forms the first vague notion of a thing that really adds to the stock of our knowledge1 but he who demonstrates its truth and accurately determines its nature4 ,rey's book and his opinions were little known4 ,he had not brought over a single convert to his doctrine1 a sufficient proof that he had not established it by satisfactory evidence4 ,we may therefore believe ,lavoisier's statement1 when he assures us that when he first formed his theory he was ignorant of ,rey1 and never had heard that any such book had been published4 ,the theory of combustion advanced by ,dr4 ,hook1 in #affe1 in his ,micrographia1 approaches still nearer to that of ,lavoisier than the theory of ,rey1 and indeed1 so far as he has explained it1 the coincidence is exact4 ,according to ,hook there exists in common air a certain substance which is like1 if not the very same with that which is fixed in saltpetre4 ,this substance has the property of dissolving all combustibles2 but only when their temperature is sufficiently raised4 ,the solution takes place with such rapidity that it occasions fire1 which in his opinion is mere motion4 ,the dissolved substance may be in the state of air1 or coagulated in a liquid or solid form4 ,the quantity of this solvent in a given bulk of air is incomparably less than in the same bulk of saltpetre4 ,hence the reason why a combustible continues burning but a short time in a given bulk of air3 the solvent is soon saturated1 and then of course the combustion is at an end4 ,this explains why combustion requires a constant supply of fresh air1 and why it is promoted by forcing in air with bellows4 ,hook promised to develop this theory at greater length in a subsequent work2 but he never fulfilled his promise2 though in his ,lampas1 published about twelve years afterwards1 he gives a beautiful chemical explanation of flame1 founded on the very same theory4 ,from the very general terms in which ,hook expresses himself1 we cannot judge correctly of the extent of his knowledge4 ,this theory1 so far as it goes1 coincides exactly with our present notions on the subject4 ,his solvent is oxygen gas1 which constitutes one-fifth part of the volume of the air1 but exists in much greater quantity in saltpetre4 ,it combines with the burning body1 and the compound formed may either be a gas1 a liquid1 or a solid1 according to the nature of the body subjected to combustion4 ,lavoisier nowhere alludes to this theory of ,hook nor gives the least hint that he had ever heard of it4 ,this is the more surprising1 because ,hook was a man of great celebrity2 and his ,micrographia1 as containing the original figures and descriptions of many natural objects1 is well known1 not merely in ,great ,britain1 but on the continent4 ,at the same time it must be recollected that ,hook's theory is supported by no evidence2 that it is a mere assertion1 and that nobody adopted it4 ,even then1 if we were to admit that ,lavoisier was acquainted with this theory1 it would derogate very little from his merit1 which consisted in investigating the phenomena of combustion and calcination1 and in showing that oxygen became a constituent of the burnt and calcined bodies4 ,about ten years after the publication of the ,micrographia1 ,dr4 ,mayow1 of ,oxford1 published his ,essays4 ,in the first of which1 ,de ,sal-nitro et ,spiritu ,nitro-areo1 he obviously adopts ,dr4 ,hook's theory of combustion1 and he applies it with great ingenuity to explain the nature of respiration4 ,dr4 ,mayow's book had been forgotten when the attention of men of science was attracted to it by ,dr4 ,beddoes4 ,dr4 ,yeats1 of ,bedford1 published a very interesting work on the merits of ,mayow1 in #agih4 ,it will be admitted at once by every person who takes the trouble of perusing ,mayow's tract1 that he was not satisfied with mere theory2 but proved by actual experiment that air was absorbed during combustion1 and altered during respiration4 ,he has given figures of his apparatus1 and they are very much of the same nature with those afterwards made use of by ,lavoisier4 ,it would be wrong1 therefore1 to deprive ,mayow of the reputation to which he is entitled for his ingeniously-contrived and well-executed experiments4 ,it must be admitted that he proved both the absorption of air during combustion and respiration2 but even this does not take much from the fair fame of ,lavoisier4 ,the analysis of air and the discovery of oxygen gas really diminish the analogy between the theories of ,mayow and ,lavoisier1 or at any rate the full investigation of the subject and the generalization of it belong exclusively to ,lavoisier4 ,attempts were made by the other ,french chemists1 about the beginning of the revolution1 to associate themselves with ,lavoisier1 as equally entitled with himself to the merit of the antiphlogistic theory2 but ,lavoisier himself has disclaimed the partnership4 ,some years before his death1 he had formed the plan of collecting together all his papers relating to the antiphlogistic theory and publishing them in one work2 but his death interrupted the project4 ,however1 his widow afterwards published the first two volumes of the book1 which were complete at the time of his death4 ,in one of these volumes ,lavoisier claims for himself the exclusive discovery of the cause of the augmentation of weight which bodies undergo during combustion and calcination4 ,he informs us that a set of experiments1 which he made in #aggb1 upon the different kinds of air which are disengaged in effervescence1 and a great number of other chemical operations discovered to him demonstratively the cause of the augmentation of weight which metals experience when exposed to heat4 ,i was young1 says he1 ,i had newly entered the lists of science1 ,i was desirous of fame1 and ,i thought it necessary to take some steps to secure to myself the property of my discovery4 ,at that time there existed an habitual correspondence between the men of science of ,france and those of ,england4 ,there was a kind of rivality between the two nations1 which gave importance to new experiments1 and which sometimes was the cause that the writers of the one or the other of the nations disputed the discovery with the real author4 ,consequently1 ,i thought it proper to deposit on the #ast of ,november1 #aggb1 the following note in the hands of the secretary of the academy4 ,this note was opened on the #ast of ,may following1 and mention of these circumstances marked at the top of the note4 ,it was in the following terms3 ,about eight days ago ,i discovered that sulphur in burning1 far from losing1 augments in weight2 that is to say1 that from one pound of sulphur much more than one pound of vitriolic acid is obtained1 without reckoning the humidity of the air4 ,phosphorus presents the same phenomenon4 ,this augmentation of weight arises from a great quantity of air1 which becomes fixed during the combustion1 and which combines with the vapours4 ,this discovery1 which ,i confirmed by experiments which ,i regard as decisive1 led me to think that what is observed in the combustion of sulphur and phosphorus1 might likewise take place with respect to all the bodies which augment in weight by combustion and calcination2 and ,i was persuaded that the augmentation of weight in the calces of metals proceeded from the same cause4 ,the experiment fully confirmed my conjectures4 ,i operated the reduction of litharge in close vessels with ,hales's apparatus1 and ,i observed1 that at the moment of the passage of the calx into the metallic state1 there was a disengagement of air in considerable quantity1 and that this air formed a volume at least one thousand times greater than that of the litharge employed4 ,as this discovery appears to me one of the most interesting which has been made since ,stahl1 ,i thought it expedient to secure to myself the property1 by depositing the present note in the hands of the secretary of the academy1 to remain secret till the period when ,i shall publish my experiments4 ,,lavoisier4 ,paris1 ,november #aa1 #aggb4 ,this note leaves no doubt that ,lavoisier had conceived his theory1 and confirmed it by experiment1 at least as early as ,november1 #aggb4 ,but at that time the nature of air and the existence of oxygen were unknown4 ,the theory1 therefore1 as he understood it at that time1 was precisely the same as that of ,john ,rey4 ,it was not till the end of #aggd that his views became more precise1 and that he was aware that oxygen is the portion of the air which unites with bodies during combustion1 and calcination4 ,nothing can be more evident from the whole history of the academy1 and of the ,french chemists during this eventful period1 for the progress of the science1 that none of them participated in the views of ,lavoisier1 or had the least intention of giving up the phlogistic theory4 ,it was not till #aghe1 after his experiments had been almost all published1 and after all the difficulties had been removed by the two great discoveries of ,mr4 ,cavendish1 that ,berthollet declared himself a convert to the ,lavoisierian opinions4 ,this was soon followed by others1 and within a very few years almost all the chemists and men of science in ,france enlisted themselves on the same side4 ,lavoisier's objection1 then1 to the phrase ,la ,chimie ,franaise1 is not without reason1 the term ,lavoisierian ,chemistry should undoubtedly be substituted for it4 ,this term1 ,la ,chimie ,franaise was introduced by ,fourcroy4 ,was ,fourcroy anxious to clothe himself with the reputation of ,lavoisier1 and had this any connexion with the violent death of that illustrious man8 ,the first set of experiments which ,lavoisier published on his peculiar views1 was entitled1 ,a ,memoir on the ,calcination of ,tin in close ,vessels2 and on the ,cause of the increase of ,weight which the ,metal acquires during this ,process4 ,it appeared in the ,memoirs of the ,academy1 for #aggd4 ,in this paper he gives an account of several experiments which he had made on the calcination of tin in glass retorts1 hermetically sealed4 ,he put a quantity of tin 7about half a pound7 into a glass retort1 sometimes of a larger and sometimes of a smaller size1 and then drew out the beak into a capillary tube4 ,the retort was now placed upon the sand-bath1 and heated till the tin just melted4 ,the extremity of the capillary beak of the retort was now fused so as to seal it hermetically4 ,the object of this heating was to prevent the retort from bursting by the expansion of the air during the process4 ,the retort1 with its contents1 was now carefully weighed1 and the weight noted4 ,it was put again on the sand-bath1 and kept melted till the process of calcination refused to advance any further4 ,he observed1 that if the retort was small1 the calcination always stopped sooner than it did if the retort was large4 ,or1 in other words1 the quantity of tin calcined was always proportional to the size of the retort4 ,after the process was finished1 the retort 7still hermetically sealed7 was again weighed1 and was always found to have the same weight exactly as at first4 ,the beak of the retort was now broken off1 and a quantity of air entered with a hissing noise4 ,the increase of weight was now noted3 it was obviously owing to the air that had rushed in4 ,the weight of air that had been at first driven out by the fusion of the tin had been noted1 and it was now found that a considerably greater quantity had entered than had been driven out at first4 ,in some experiments1 as much as #ajjf grains1 in others #ihg grains1 and in some less than this1 when the size of the retort was small4 ,the tin in the retort was mostly unaltered1 but a portion of it had been converted into a black powder1 weighing in some cases above two ounces4 ,now it was found in all cases1 that the weight of the tin had increased1 and the increase of weight was always exactly equal to the diminution of weight which the air in the retort had undergone1 measured by the quantity of new air which rushed in when the beak of the retort was broken1 minus the air that had been driven out when the tin was originally melted before the retort was hermetically sealed4 ,thus ,lavoisier proved by these first experiments1 that when tin is calcined in close vessels a portion of the air of the vessel disappears1 and that the tin increases in weight just as much as is equivalent to the loss of weight which the air has sustained4 ,he therefore inferred1 that this portion of air had united with the tin1 and that calx of tin is a compound of tin and air4 ,in this first paper there is nothing said about oxygen1 nor any allusion to lead to the suspicion that air is a compound of different elastic fluids4 ,these1 therefore1 were probably the experiments to which ,lavoisier alludes in the note which he lodged with the secretary of the academy in ,november1 #aggb4 ,he mentions towards the end of the ,memoir that he had made similar experiments with lead2 but he does not communicate any of the numerical results3 probably because the results were not so striking as those with tin4 ,the heat necessary to melt lead is so high that satisfactory experiments on its calcination could not easily be made in a glass retort4 ,lavoisier's next ,memoir appeared in the ,memoirs of the ,academy1 for #agge1 which were published in #aggh4 ,it is entitled1 ,on the ,nature of the ,principle which combines with the ,metals during their ,calcination1 and which augments their ,weight4 ,he observes that when the metallic calces are reduced to the metallic state it is found necessary to heat them along with charcoal4 ,in such cases a quantity of carbonic acid gas is driven off1 which he assures us is the charcoal united to the elastic fluid contained in the calx4 ,he tried to reduce the calx of iron by means of burning-glasses1 while placed under large glass receivers standing over mercury2 but as the gas thus evolved was mixed with a great deal of common air which was necessarily left in the receiver1 he was unable to determine its nature4 ,this induced him to have recourse to red oxide of mercury4 ,he showed in the first place that this substance 7mercurius prcipitatus per se7 was a true calx1 by mixing it with charcoal powder in a retort and heating it4 ,the mercury was reduced and abundance of carbonic acid gas was collected in an inverted glass jar standing in a water-cistern into which the beak of the retort was plunged4 ,on heating the red oxide of mercury by itself it was reduced to the metallic state1 though not so easily1 and at the same time a gas was evolved which possessed the following properties3 #a4 ,it did not combine with water by agitation4 #b4 ,it did not precipitate lime-water4 #c4 ,it did not unite with fixed or volatile alkalies4 #d4 ,it did not at all diminish their caustic quality4 #e4 ,it would serve again for the calcination of metals4 #f4 ,it was diminished like common air by addition of one-third of nitrous gas4 #g4 ,it had none of the properties of carbonic acid gas4 ,far from being fatal1 like that gas1 to animals1 it seemed on the contrary more proper for the purposes of respiration4 ,candles and burning bodies were not only not extinguished by it1 but burned with an enlarged flame in a very remarkable manner4 ,the light they gave was much greater and clearer than in common air4 ,he expresses his opinion that the same kind of air would be obtained by heating nitre without addition1 and this opinion is founded on the fact that when nitre is detonated with charcoal it gives out abundance of carbonic acid gas4 ,thus ,lavoisier shows in this paper that the kind of air which unites with metals during their calcination is purer and fitter for combustion than common air4 ,in short it is the gas which ,dr4 ,priestley had discovered in #aggd1 and which is now known by the name of oxygen gas4 ,this ,memoir deserves a few animadversions4 ,dr4 ,priestley discovered oxygen gas in ,august1 #aggd2 and he informs us in his life1 that in the autumn of that year he went to ,paris and exhibited to ,lavoisier1 in his own laboratory the mode of obtaining oxygen gas by heating red oxide of mercury in a gun-barrel1 and the properties by which this gas is distinguished--indeed the very properties which ,lavoisier himself enumerates in his paper4 ,there can1 therefore1 be no doubt that ,lavoisier was acquainted with oxygen gas in #aggd1 and that he owed his knowledge of it to ,dr4 ,priestley4 ,there is some uncertainty about the date of ,lavoisier's paper4 ,in the ,history of the ,academy1 for #agge1 it is merely said about it1 ,read at the resumption 7rentre7 of the ,academy1 on the #bfth of ,april1 by ,m4 ,lavoisier1 without naming the year4 ,but it could not have been before #agge1 because that is the year upon the volume of the ,memoirs2 and besides1 we know from the ,journal de ,physique 7v4 #dbi71 that #agge was the year on which the paper of ,lavoisier was read4 ,yet in the whole of this paper the name of ,dr4 ,priestley never occurs1 nor is the least hint given that he had already obtained oxygen gas by heating red oxide of mercury4 ,so far from it1 that it is obviously the intention of the author of the paper to induce his readers to infer that he himself was the discoverer of oxygen gas4 ,for after describing the process by which oxygen gas was obtained by him1 he says nothing further remained but to determine its nature1 and ,i discovered with much surprise that it was not capable of combination with water by agitation1 c4 ,now why the expression of surprise in describing phenomena which had been already shown8 ,and why the omission of all mention of ,dr4 ,priestley's name8 ,i confess that this seems to me capable of no other explanation than a wish to claim for himself the discovery of oxygen gas1 though he knew well that that discovery had been previously made by another4 ,the next set of experiments made by ,lavoisier to confirm or extend his theory1 was ,on the ,combustion of ,phosphorus1 and the ,nature of the ,acid which results from that ,combustion4 ,it appeared in the ,memoirs of the ,academy1 for #aggg4 ,the result of these experiments was very striking4 ,when phosphorus is burnt in a given bulk of air in sufficient quantity1 about four-fifths of the volume of the air disappears and unites itself with the phosphorus4 ,the residual portion of the air is incapable of supporting combustion or maintaining animal life4 ,lavoisier gave it the name of mouffette atmospherique1 and he describes several of its properties4 ,the phosphorus by combining with the portion of air which has disappeared1 is converted into phosphoric acid1 which is deposited on the inside of the receiver in which the combustion is performed1 in the state of fine white flakes4 ,one grain by this process is converted into two and a half grains of phosphoric acid4 ,these observations led to the conclusion that atmospheric air is a mixture or compound of two distinct gases1 the one 7oxygen7 absorbed by burning phosphorus1 the other 7azote7 not acted on by that principle1 and not capable of uniting with or calcining metals4 ,these conclusions had already been drawn by ,scheele from similar experiments1 but ,lavoisier was ignorant of them4 ,in the second part of this paper1 ,lavoisier describes the properties of phosphoric acid1 and gives an account of the salts which it forms with the different bases4 ,the account of these salts is exceedingly imperfect1 and it is remarkable that ,lavoisier makes no distinction between phosphate of potash and phosphate of soda2 though the different properties of these two salts are not a little striking4 ,but these were not the investigations in which ,lavoisier excelled4 ,the next paper in which the doctrines of the antiphlogistic theory were still further developed1 was inserted in the ,memoirs of the ,academy1 for #aggg4 ,it is entitled1 ,on the ,combustion of ,candles in atmospherical ,air1 and in ,air eminently ,respirable4 ,this paper is remarkable1 because in it he first notices ,dr4 ,priestley's discovery of oxygen gas2 but without any reference to the preceding paper1 or any apology for not having alluded in it to the information which he had received from ,dr4 ,priestley4 ,he begins by saying that it is necessary to distinguish four different kinds of air4 #a4 ,atmospherical air in which we live1 and which we breath4 #b4 ,pure air 7oxygen71 alone fit for breathing1 constituting about the fourth of the volume of atmospherical air1 and called by ,dr4 ,priestley dephlogisticated air4 #c4 ,azotic gas1 which constitutes about three-fourths of the volume of atmospherical air1 and whose properties are still unknown4 #d4 ,fixed air1 which he proposed to call 7as ,bucquet had done7 acide crayeux1 acid of chalk4 ,in this paper ,lavoisier gives an account of a great many trials that he made by burning candles in given volumes of atmospherical air and oxygen gas enclosed in glass receivers1 standing over mercury4 ,the general conclusion which he deduces from these experiments are--that the azotic gas of the air contributes nothing to the burning of the candle2 but the whole depends upon the oxygen gas of the air1 constituting in his opinion one-fourth of its volume2 that during the combustion of a candle in a given volume of air only two-fifths of the oxygen are converted into carbonic acid gas1 while the remaining three-fifths remain unaltered2 but when the combustion goes on in oxygen gas a much greater proportion 7almost the whole7 of this gas is converted into carbonic acid gas4 ,finally1 that phosphorus1 when burnt in air acts much more powerfully on the oxygen of the air than a lighted candle1 absorbing four-fifths of the oxygen and converting it into phosphoric acid4 ,it is evident that at the time this paper was written1 ,lavoisier's theory was nearly complete4 ,he considered air as a mixture of three volumes of azotic gas1 and one volume of oxygen gas4 ,the last alone was concerned in combustion and calcination4 ,during these processes a portion of the oxygen united with the burning body1 and the compound formed constituted the acid or the calx4 ,thus he was able to account for combustion and calcination without having recourse to phlogiston4 ,it is true that several difficulties still lay in his way1 which he was not yet able to obviate1 and which prevented any other person from adopting his opinions4 ,one of the greatest of these was the fact that hydrogen gas was evolved during the solution of several metals in dilute sulphuric or muriatic acid2 that by this solution these metals were converted into calces1 and that calces1 when heated in hydrogen gas1 were reduced to the metallic state while the hydrogen disappeared4 ,the simplest explanation of these phenomena was the one adopted by chemists at the time4 ,hydrogen was considered as phlogiston4 ,by dissolving metals in acids1 the phlogiston was driven off and the calx remained3 by heating the calx in hydrogen1 the phlogiston was again absorbed and the calx reduced to the metallic state4 ,this explanation was so simple and appeared so satisfactory1 that it was universally adopted by chemists with the exception of ,lavoisier himself4 ,there was a circumstance1 however1 which satisfied him that this explanation1 however plausible1 was not correct4 ,the calx was heavier than the metal from which it had been produced4 ,and hydrogen1 though a light body1 was still possessed of weight4 ,it was obviously impossible1 then1 that the metal could be a combination of the calx and hydrogen4 ,besides1 he had ascertained by direct experiment1 that the calces of mercury1 tin1 and lead are compounds of the respective metals and oxygen4 ,and it was known that when the other calces were heated with charcoal1 they were reduced to the metallic state1 and at the same time carbonic acid gas is evolved4 ,the very same evolution takes place when calces of mercury1 tin1 and lead1 are heated with charcoal powder4 ,hence the inference was obvious that carbonic acid is a compound of charcoal and oxygen1 and therefore that all calces are compounds of their respective metals and oxygen4 ,thus1 although ,lavoisier was unable to account for the phenomena connected with the evolution and absorption of hydrogen gas1 he had conclusive evidence that the orthodox explanation was not the true one4 ,he wisely1 therefore1 left it to time to throw light upon those parts of the theory that were still obscure4 ,his next paper1 which was likewise inserted in the ,memoirs of the ,academy1 for #aggg1 had some tendency to throw light on this subject1 or at least it elucidated the constitution of sulphuric acid1 which bore directly upon the antiphlogistic theory4 ,it was entitled1 ,on the ,solution of ,mercury in vitriolic ,acid1 and on the ,resolution of that ,acid into aeriform sulphurous ,acid1 and into ,air eminently ,respirable4 ,he had already proved that sulphuric acid is a compound of sulphur and oxygen2 and had even shown how the oxygen which the acid contained might be again separated from it1 and exhibited in a separate state4 ,dr4 ,priestley had by this time made known the method of procuring sulphurous acid gas1 by heating a mixture of mercury and sulphuric acid in a phial4 ,this was the process which ,lavoisier analyzed in the present paper4 ,he put into a retort a mixture of four ounces mercury and six ounces concentrated sulphuric acid4 ,the beak of the retort was plunged into a mercurial cistern1 to collect the sulphurous acid gas as it was evolved2 and heat being applied to the belly of the retort1 sulphurous acid gas passed over in abundance1 and sulphate of mercury was formed4 ,the process was continued till the whole liquid contents of the retort had disappeared3 then a strong heat was applied to the salt4 ,in the first place1 a quantity of sulphurous acid gas passed over1 and lastly a portion of oxygen gas4 ,the quicksilver was reduced to the metallic state4 ,thus he resolved sulphuric acid into sulphurous acid and oxygen4 ,hence it followed as a consequence1 that sulphurous acid differs from sulphuric merely by containing a smaller quantity of oxygen4 ,the object of his next paper1 published at the same time1 was to throw light upon the pyrophorus of ,homberg1 which was made by kneading alum into a cake1 with flour1 or some substance containing abundance of carbon1 and then exposing the mixture to a strong heat in close vessels1 till it ceased to give out smoke4 ,it was known that a pyrophorus thus formed takes fire of its own accord1 and burns when it comes in contact with common air4 ,it will not be necessary to enter into a minute analysis of this paper1 because1 though the experiments were very carefully made1 yet it was impossible1 at the time when the paper was drawn1 to elucidate the phenomena of this pyrophorus in a satisfactory manner4 ,there can be little doubt that the pyrophorus owes its property of catching fire1 when in contact with air or oxygen1 to a little potassium1 which has been reduced to the metallic state by the action of the charcoal and sulphur on the potash in the alum4 ,this substance taking fire1 heat enough is produced to set fire to the carbon and sulphur which the pyrophorus contains4 ,lavoisier ascertained that during its combustion a good deal of carbonic acid was generated4 ,there appeared likewise another paper by ,lavoisier1 in the same volume of the academy1 which may be mentioned1 as it served still further to demonstrate the truth of the antiphlogistic theory4 ,it is entitled1 ,on the ,vitriolization of ,martial ,pyrites4 ,iron pyrites is known to be a compound of iron and sulphur4 ,sometimes this mineral may be left exposed to the air without undergoing any alteration1 while at other times it speedily splits1 effloresces1 swells1 and is converted into sulphate of iron4 ,there are two species of pyrites2 the one composed of two atoms of sulphur and one atom of iron1 the other of one atom of sulphur and one atom of iron4 ,the first of these is called bisulphuret of iron2 the second protosulphuret1 or simply sulphuret of iron4 ,the variety of pyrites which undergoes spontaneous decomposition in the air1 is known to be a compound1 or rather mixture of the two species of pyrites4 ,lavoisier put a quantity of the decomposing pyrites under a glass jar1 and found that the process went on just as well as in the open air4 ,he found that the air was deprived of the whole of its oxygen by the process1 and that nothing was left but azotic gas4 ,hence the nature of the change became evident4 ,the sulphur1 by uniting with oxygen1 was converted into sulphuric acid1 while the iron became oxide of iron1 and both uniting1 formed sulphate of iron4 ,there are still some difficulties connected with this change that require to be elucidated4 ,we have still another paper by ,lavoisier1 bearing on the antiphlogistic theory1 published in the same volume of the ,memoirs of the ,academy1 for #aggh1 entitled1 ,on ,combustion in general4 ,he establishes that the only air capable of supporting combustion is oxygen gas3 that during the burning of bodies in common air1 a portion of the oxygen of the atmosphere disappears1 and unites with the burning body1 and that the new compound formed is either an acid or a metallic calx4 ,when sulphur is burnt1 sulphuric acid is formed2 when phosphorus1 phosphoric acid2 and when charcoal1 carbonic acid4 ,the calcination of metals is a process analogous to combustion1 differing chiefly by the slowness of the process3 indeed when it takes place rapidly1 actual combustion is produced4 ,after establishing these general principles1 which are deduced from his preceding papers1 he proceeds to examine the ,stahlian theory of phlogiston1 and shows that no evidence of the existence of any such principle can be adduced1 and that the phenomena can all be explained without having recourse to it4 ,powerful as these arguments were1 they produced no immediate effects4 ,nobody chose to give up the phlogistic theory to which he had been so long accustomed4 ,the next two papers of ,lavoisier require merely to be mentioned1 as they do not bear immediately upon the antiphlogistic theory4 ,they appeared in the ,memoirs of the ,academy1 for #aghj4 ,these memoirs were1 #a4 ,second ,memoir on the different ,combinations of ,phosphoric ,acid4 #b4 ,on a particular ,process1 by means of which ,phosphorus may be converted into phosphoric ,acid1 without ,combustion4 ,the process here described consisted in throwing phosphorus1 by a few grains at a time1 into warm nitric acid of the specific gravity #abihie4 ,it falls to the bottom like melted wax1 and dissolves pretty rapidly with effervescence3 then another portion is thrown in1 and the process is continued till as much phosphorus has been employed as is wanted2 then the phosphoric acid may be obtained pure by distilling off the remaining nitric acid with which it is still mixed4 ,hitherto ,lavoisier had been unable to explain the anomalies respecting hydrogen gas1 or to answer the objections urged against his theory in consequence of these anomalies4 ,he had made several attempts to discover what peculiar substance was formed during the combustion of hydrogen1 but always without success3 at last1 in #aghc1 he resolved to make the experiment upon so large a scale1 that whatever the product might be1 it should not escape him2 but ,sir ,charles ,blagden1 who had just gone to ,paris1 informed him that the experiment for which he was preparing had already been made by ,mr4 ,cavendish1 who had ascertained that the product of the combustion of hydrogen was water4 ,lavoisier saw at a glance the vast importance of this discovery for the establishment of the antiphlogistic theory1 and with what ease it would enable him to answer all the plausible objections which had been brought forward against his opinions in consequence of the evolution of hydrogen1 when metals were calcined by solution in acids1 and the absorption of it when metals were reduced in an atmosphere of this gas4 ,he therefore resolved to repeat the experiment of ,cavendish with every possible care1 and upon a scale sufficiently large to prevent ambiguity4 ,the experiment was made on the #bdth of ,june1 #aghc1 by ,lavoisier and ,laplace1 in the presence of ,m4 ,le ,roi1 ,m4 ,vandermonde1 and ,sir ,charles ,blagden1 who was at that time secretary of the ,royal ,society4 ,the quantity of water formed was considerable1 and they found that water was a compound of #a volume oxygen #aia volume hydrogen4 ,not satisfied with this1 he soon after made another experiment along with ,m4 ,meusnier to decompose water4 ,for this purpose a porcelain tube1 filled with iron wire1 was heated red-hot by being passed through a furnace1 and then the steam of water was made to traverse the red-hot wire4 ,to the further extremity of the porcelain tube a glass tube was luted1 which terminated in a water-trough under an inverted glass receiver placed to collect the gas4 ,the steam was decomposed by the red-hot iron wire1 its oxygen united to the wire1 while the hydrogen passed on and was collected in the water-cistern4 ,both of these experiments1 though not made till #aghc1 and though the latter of them was not read to the academy till #aghd1 were published in the volume of the ,memoirs for #agha4 ,it is easy to see how this important discovery enabled ,lavoisier to obviate all the objections to his theory from hydrogen4 ,he showed that it was evolved when zinc or iron was dissolved in dilute sulphuric acid1 because the water underwent decomposition1 its oxygen uniting to the zinc or iron1 and converting it into an oxide1 while its hydrogen made its escape in the state of gas4 ,oxide of iron was reduced when heated in contact with hydrogen gas1 because the hydrogen united to the oxygen of the acid and formed water1 and of course the iron was reduced to the state of a metal4 ,i consider it unnecessary to enter into a minute detail of these experiments1 because1 in fact1 they added very little to what had been already established by ,cavendish4 ,but it was this discovery that contributed more than any thing else to establish the antiphlogistic theory4 ,accordingly1 the great object of ,dr4 ,priestley1 and other advocates of the phlogistic theory1 was to disprove the fact that water is a compound of oxygen and hydrogen4 ,scheele admitted the fact that water is a compound of oxygen and hydrogen2 and doubtless1 had he lived1 would have become a convert to the antiphlogistic theory1 as ,dr4 ,black actually did4 ,in short1 it was the discovery of the compound nature of water that gave the ,lavoisierian theory the superiority over that of ,stahl4 ,till the time of this discovery every body opposed the doctrine of ,lavoisier2 but within a very few years after it1 hardly any supporters of phlogiston remained4 ,nothing could be more fortunate for ,lavoisier than this discovery1 or afford him greater reason for self-congratulation4 ,we see the effect of this discovery upon his next paper1 ,on the ,formation of ,carbonic ,acid1 which appeared in the ,memoirs of the ,academy1 for #agha4 ,there1 for the first time1 he introduces new terms1 showing1 by that1 that he considered his opinions as fully established4 ,to the dephlogisticated air of ,priestley1 or his own pure air1 he now gives the name of oxygen4 ,the fixed air of ,black he designates carbonic acid1 because he considered it as a compound of carbon 7the pure part of charcoal7 and oxygen4 ,the object of this paper is to determine the proportion of the constituents4 ,he details a great many experiments1 and deduces from them all1 that carbonic acid gas is a compound of ,carbon #jge ,oxygen #aic ,now this is a tolerably near approximation to the truth4 ,the true constituents1 as determined by modern chemists1 being ,carbon #jge ,oxygen #bjj ,the next paper of ,m4 ,lavoisier1 which appeared in the ,memoirs of the ,academy1 for #aghb 7published in #aghe71 shows how well he appreciated the importance of the discovery of the composition of water4 ,it is entitled1 ,general ,considerations on the ,solution of the ,metals in ,acids4 ,he shows that when metals are dissolved in acids1 they are converted into oxides1 and that the acid does not combine with the metal1 but only with its oxide4 ,when nitric acid is the solvent the oxidizement takes place at the expense of the acid1 which is resolved into nitrous gas and oxygen4 ,the nitrous gas makes its escape1 and may be collected2 but the oxygen unites with the metal and renders it an oxide4 ,he shows this with respect to the solution of mercury in nitric acid4 ,he collected the nitrous gas given out during the solution of the metal in the acid3 then evaporated the solution to dryness1 and urged the fire till the mercury was converted into red oxide4 ,the fire being still further urged1 the red oxide was reduced1 and the oxygen gas given off was collected and measured4 ,he showed that the nitrous gas and the oxygen gas thus obtained1 added together1 formed just the quantity of nitric acid which had disappeared during the process4 ,a similar experiment was made by dissolving iron in nitric acid1 and then urging the fire till the iron was freed from every foreign body1 and obtained in the state of black oxide4 ,it is well known that many metals held in solution by acids may be precipitated in the metallic state1 by inserting into the solution a plate of some other metal4 ,a portion of that new metal dissolves1 and takes the place of the metal originally in solution4 ,suppose1 for example1 that we have a neutral solution of copper in sulphuric acid1 if we put into the solution a plate of iron1 the copper is thrown down in the metallic state1 while a certain portion of the iron enters into the solution1 combining with the acid instead of the copper4 ,but the copper1 while in solution1 was in the state of an oxide1 and it is precipitated in the metallic state4 ,the iron was in the metallic state2 but it enters into the solution in the state of an oxide4 ,it is clear from this that the oxygen1 during these precipitations1 shifts its place1 leaving the copper1 and entering into combination with the iron4 ,if1 therefore1 in such a case we determine the exact quantity of copper thrown down1 and the exact quantity of iron dissolved at the same time1 it is clear that we shall have the relative weight of each combined with the same weight of oxygen4 ,if1 for example1 #d of copper be thrown down by the solution of #ce of iron2 then it is clear that #ce of iron requires just as much oxygen as #d of copper1 to turn both into the oxide that exists in the solution1 which is the black oxide of each4 ,bergman had made a set of experiments to determine the proportional quantities of phlogiston contained in the different metals1 by the relative quantity of each necessary to precipitate a given weight of another from its acid solution4 ,it was the opinion at that time1 that metals were compounds of their respective calces and phlogiston4 ,when a metal dissolved in an acid1 it was known to be in the state of calx1 and therefore had parted with its phlogiston3 when another metal was put into this solution it became a calx1 and the dissolved metal was precipitated in the metallic state4 ,it had therefore united with the phlogiston of the precipitating metal4 ,it is obvious1 that by determining the quantities of the two metals precipitated and dissolved1 the relative proportion of phlogiston in each could be determined4 ,lavoisier saw that these experiments of ,bergman would serve equally to determine the relative quantity of oxygen in the different oxides4 ,accordingly1 in a paper inserted in the ,memoirs of the ,academy1 for #aghb1 he enters into an elaborate examination of ,bergman's experiments1 with a view to determine this point4 ,but it is unnecessary to state the deductions which he drew1 because ,bergman's experiments were not sufficiently accurate for the object in view4 ,indeed1 as the mutual precipitation of the metals is a galvanic phenomenon1 and as the precipitated metal is seldom quite pure1 but an alloy of the precipitating and precipitated metal2 and as it is very difficult to dry the more oxidizable metals1 as copper and tin1 without their absorbing oxygen when they are in a state of very minute division2 this mode of experimenting is not precise enough for the object which ,lavoisier had in view4 ,accordingly the table of the composition of the metallic oxides which ,lavoisier has drawn up is so very defective1 that it is not worth while to transcribe it4 ,the same remark applies to the table of the affinities of oxygen which ,lavoisier drew up and inserted in the ,memoirs of the ,academy1 for the same year4 ,his data were too imperfect1 and his knowledge too limited1 to put it in his power to draw up any such table with any approach to accuracy4 ,i shall have occasion to resume the subject in a subsequent chapter4 ,in the same volume of the ,memoirs of the ,academy1 this indefatigable man inserted a paper in order to determine the quantity of oxygen which combines with iron4 ,his method of proceeding was1 to burn a given weight of iron in oxygen gas4 ,it is well known that iron wire1 under such circumstances1 burns with considerable splendour1 and that the oxide1 by the heat1 is fused into a black brittle matter1 having somewhat of the metallic lustre4 ,he burnt #adef grains of iron in this way1 and found that1 after combustion1 the weight became #aib grains1 and #ig ,french cubic inches of oxygen gas had been absorbed4 ,from this experiment it follows1 that the oxide of iron formed by burning iron in oxygen gas is a compound of ,iron #ce ,oxygen #aaa ,this forms a tolerable approximation to the truth4 ,it is now known1 that the quantity of oxygen in the oxide of iron formed by the combustion of iron in oxygen gas is not quite uniform in its composition2 sometimes it is a compound of ,iron #c ,oxygen #a ,while at other times it consists very nearly of ,iron #ce ,oxygen #a and probably it may exist in all the intermediate proportions between these two extremes4 ,the last of these compounds constitutes what is now known by the name of protoxide1 or black oxide of iron4 ,the first is the composition of the ore of iron so abundant1 which is distinguished by the name of magnetic iron ore4 ,lavoisier was aware that iron combines with more oxygen than exists in the protoxide2 indeed1 his analysis of peroxide of iron forms a tolerable approximation to the truth2 but there is no reason for believing that he was aware that iron is capable of forming only two oxides1 and that all intermediate degrees of oxidation are impossible4 ,this was first demonstrated by ,proust4 ,i think it unnecessary to enter into any details respecting two papers of ,lavoisier1 that made their appearance in the ,memoirs of the ,academy1 for #aghc1 as they add very little to what he had already done4 ,the first of these describes the experiments which he made to determine the quantity of oxygen which unites with sulphur and phosphorus when they are burnt3 it contains no fact which he had not stated in his former papers1 unless we are to consider his remark1 that the heat given out during the burning of these bodies has no sensible weight1 as new4 ,the other paper is ,on ,phlogiston2 it is very elaborate1 but contains nothing which had not been already advanced in his preceding memoirs4 ,chemists were so wedded to the phlogistic theory1 their prejudices were so strong1 and their understandings so fortified against every thing that was likely to change their opinions1 that ,lavoisier found it necessary to lay the same facts before them again and again1 and to place them in every point of view4 ,in this paper he gives a statement of his own theory of combustion1 which he had previously done in several preceding papers4 ,he examines the phlogistic theory of ,stahl at great length1 and refutes it4 ,in the ,memoirs of the ,academy1 for #aghd1 ,lavoisier published a very elaborate set of experiments on the combustion of alcohol1 oil1 and different combustible bodies1 which gave a beginning to the analysis of vegetable substances1 and served as a foundation upon which this most difficult part of chemistry might be reared4 ,he showed that during the combustion of alcohol the oxygen of the air united to the vapour of the alcohol1 which underwent decomposition1 and was converted into water and carbonic acid4 ,from these experiments he deduced as a consequence1 that the constituents of alcohol are carbon1 hydrogen1 and oxygen1 and nothing else2 and he endeavoured from his experiments to determine the relative proportions of these different constituents4 ,from these experiments he concluded1 that the alcohol which he used in his experiments was a compound of ,carbon #bfbie part4 ,hydrogen #gbee ,water #ehfa ,it would serve no purpose to attempt to draw any consequences from these experiments2 as ,lavoisier does not mention the specific gravity of the alcohol1 of course we cannot say how much of the water found was merely united with the alcohol1 and how much entered into its composition4 ,the proportion between the carbon and hydrogen1 constitutes an approximation to the truth1 though not a very near one4 ,olive oil he showed to be a compound of hydrogen and carbon1 and bees' wax to be a compound of the same constituents1 though in a different proportion4 ,this subject was continued1 and his views further extended1 in a paper inserted in the ,memoirs of the ,academy1 for #aghf1 entitled1 ,reflections on the ,decomposition of ,water by ,vegetable and ,animal ,substances4 ,he begins by stating that when charcoal is exposed to a strong heat1 it gives out a little carbonic acid gas and a little inflammable air1 and after this nothing more can be driven off1 however high the temperature be to which it is exposed2 but if the charcoal be left for some time in contact with the atmosphere it will again give out a little carbonic acid gas and inflammable gas when heated1 and this process may be repeated till the whole charcoal disappears4 ,this is owing to the presence of a little moisture which the charcoal imbibes from the air4 ,the water is decomposed when the charcoal is heated and converted into carbonic acid and inflammable gas4 ,when vegetable substances are heated in a retort1 the water which they contain undergoes a similar decomposition1 the carbon which forms one of their constituents combines with the oxygen and produces carbonic acid1 while the hydrogen1 the other constituent of the water1 flies off in the state of gas combined with a certain quantity of carbon4 ,hence the substances obtained when vegetable or animal substances are distilled did not exist ready formed in the body operated on2 but proceeded from the double decompositions which took place by the mutual action of the constituents of the water1 sugar1 mucus1 c41 which the vegetable body contains4 ,the oil1 the acid1 c41 extracted by distilling vegetable bodies did not exist in them1 but are formed during the mutual action of the constituents upon each other1 promoted as their action is by the heat4 ,these views were quite new and perfectly just1 and threw a new light on the nature of vegetable substances and on the products obtained by distilling them4 ,it showed the futility of all the pretended analyses of vegetable substances1 which chemists had performed by simply subjecting them to distillation1 and the error of drawing any conclusions respecting the constituents of vegetable substances from the results of their distillation1 except indeed with respect to their elementary constituents4 ,thus when by distilling a vegetable substance we obtain water1 oil1 acetic acid1 carbonic acid1 and carburetted hydrogen1 we must not conclude that these principles existed in the substance1 but merely that it contained carbon1 hydrogen1 and oxygen1 in such proportions as to yield all these principles by decompositions4 ,as nitric acid acts upon metals in a very different way from sulphuric and muriatic acids1 and as it is a much better solvent of metals in general than any other1 it was an object of great importance towards completing the antiphlogistic theory to obtain an accurate knowledge of its constituents4 ,though ,lavoisier did not succeed in this1 yet he made at least a certain progress1 which enabled him to explain the phenomena1 at that time known1 with considerable clearness1 and to answer all the objections to the antiphlogistic theory from the action of nitric acid on metals4 ,his first paper on the subject was published in the ,memoirs of the ,academy1 for #aggf4 ,he put a quantity of nitric acid and mercury into a retort with a long beak1 which he plunged into the water-trough4 ,an effervescence took place and gas passed over in abundance1 and was collected in a glass jar2 the mercury being dissolved the retort was still further heated1 till every thing liquid passed over into the receiver1 and a dry yellow salt remained4 ,the beak of the retort was now again plunged into the water-trough1 and the salt heated till all the nitric acid which it contained was decomposed1 and nothing remained in the retort but red oxide of mercury4 ,during this last process much more gas was collected4 ,all the gas obtained during the solution of the mercury and the decomposition of the salt was nitrous gas4 ,the red oxide of mercury was now heated to redness1 oxygen gas was emitted in abundance1 and the mercury was reduced to the metallic state3 its weight was found the very same as at first4 ,it is clear1 therefore1 that the nitrous gas and the oxygen gas were derived1 not from the mercury but from the nitric acid1 and that the nitric acid had been decomposed into nitrous gas and oxygen3 the nitrous gas had made its escape in the form of gas1 and the oxygen had remained united to the metal4 ,from these experiments it follows clearly1 that nitric acid is a compound of nitrous gas and oxygen4 ,the nature of nitrous gas itself ,lavoisier did not succeed in ascertaining4 ,it passed with him for a simple substance2 but what he did ascertain enabled him to explain the action of nitric acid on metals4 ,when nitric acid is poured upon a metal which it is capable of dissolving1 copper for example1 or mercury1 the oxygen of the acid unites to the metal1 and converts into an oxide1 while the nitrous gas1 the other constituent of the acid1 makes its escape in the gaseous form4 ,the oxide combines with and is dissolved by another portion of the acid which escapes decomposition4 ,it was discovered by ,dr4 ,priestley1 that when nitrous gas and oxygen gas are mixed together in certain proportions1 they instantly unite1 and are converted into nitrous acid4 ,if this mixture be made over water1 the volume of the gases is instantly diminished1 because the nitrous acid formed loses its elasticity1 and is absorbed by the water4 ,when nitrous gas is mixed with air containing oxygen gas1 the diminution of volume after mixture is greater the more oxygen gas is present in the air4 ,this induced ,dr4 ,priestley to employ nitrous gas as a test of the purity of common air4 ,he mixed together equal volumes of the nitrous gas and air to be examined1 and he judged of the purity of the air by the degree of condensation3 the greater the diminution of bulk1 the greater did he consider the proportion of oxygen in the air under examination to be4 ,this method of proceeding was immediately adopted by chemists and physicians2 but there was a want of uniformity in the mode of proceeding1 and a considerable diversity in the results4 ,m4 ,lavoisier endeavoured to improve the process1 in a paper inserted in the ,memoirs of the ,academy1 for #aghb2 but his method did not answer the purpose intended3 it was ,mr4 ,cavendish that first pointed out an accurate mode of testing air by means of nitrous gas1 and who showed that the proportions of oxygen and azotic gas in common air are invariable4 ,lavoisier1 in the course of his investigations1 had proved that carbonic acid is a compound of carbon and oxygen2 sulphuric acid1 of sulphur and oxygen2 phosphoric acid1 of phosphorus and oxygen2 and nitric acid1 of nitrous gas and oxygen4 ,neither the carbon1 the sulphur1 the phosphorus1 nor the nitrous gas1 possessed any acid properties when uncombined2 but they acquired these properties when they were united to oxygen4 ,he observed further1 that all the acids known in his time which had been decomposed were found to contain oxygen1 and when they were deprived of oxygen1 they lost their acid properties4 ,these facts led him to conclude1 that oxygen is an essential constituent in all acids1 and that it is the principle which bestows acidity or the true acidifying principle4 ,this was the reason why he distinguished it by the name of oxygen4#e ,these views were fully developed by ,lavoisier1 in a paper inserted in the ,memoirs of the ,academy1 for #aggh1 entitled1 ,general ,considerations on the ,nature of ,acids1 and on the ,principles of which they are composed4 ,when this paper was published1 ,lavoisier's views were exceedingly plausible4 ,they were gradually adopted by chemists in general1 and for a number of years may be considered to have constituted a part of the generally-received doctrines4 ,but the discovery of the nature of chlorine1 and the subsequent facts brought to light respecting iodine1 bromine1 and cyanogen1 have demonstrated that it is inaccurate2 that many powerful acids exist which contain no oxygen1 and that there is no one substance to which the name of acidifying principle can with justice be given4 ,to this subject we shall again revert1 when we come to treat of the more modern discoveries4 #e ,from 1 sour1 and 1 which he defined the producer of acids1 the acidifying principle4 ,long as the account is which we have given of the labours of ,lavoisier1 the subject is not yet exhausted4 ,two other papers of his remain to be noticed1 which throw considerable light on some important functions of the living body3 we allude to his experiments on respiration and perspiration4 ,it was known1 that if an animal was confined beyond a certain limited time in a given volume of atmospherical air1 it died of suffocation1 in consequence of the air becoming unfit for breathing2 and that if another animal was put into this air1 thus rendered noxious by breathing1 its life was destroyed almost in an instant4 ,dr4 ,priestley had thrown some light upon this subject by showing that air1 in which an animal had breathed for some time1 possessed the property of rendering lime-water turbid1 and therefore contained carbonic acid gas4 ,he considered the process of breathing as exactly analogous to the calcination of metals1 or the combustion of burning bodies4 ,both1 in his opinion acted by giving out phlogiston2 which1 uniting with the air of the atmosphere1 converted it into phlogisticated air4 ,priestley found1 that if plants were made to vegetate for some time in air that had been rendered unfit for supporting animal life by respiration1 it lost the property of extinguishing a candle1 and animals could breathe it again without injury4 ,he concluded from this that animals1 by breathing1 phlogisticated air1 but that plants1 by vegetating1 dephlogisticated air3 the former communicated phlogiston to it1 the latter took phlogiston from it4 ,after ,lavoisier had satisfied himself that air is a mixture of oxygen and azote1 and that oxygen alone is concerned in the processes of calcination and combustion1 being absorbed and combined with the substances undergoing calcination and combustion1 it was impossible for him to avoid drawing similar conclusions with respect to the breathing of animals4 ,accordingly1 he made experiments on the subject1 and the result was published in the ,memoirs of the ,academy1 for #aggg4 ,from these experiments he drew the following conclusions3 #a4 ,the only portion of atmospherical air which is useful in breathing is the oxygen4 ,the azote is drawn into the lungs along with the oxygen1 but it is thrown out again unaltered4 #b4 ,the oxygen gas1 on the contrary1 is gradually1 by breathing1 converted into carbonic acid2 and air becomes unfit for respiration when a certain portion of its oxygen is converted into carbonic acid gas4 #c4 ,respiration is therefore exactly analogous to calcination4 ,when air is rendered unfit for supporting life by respiration1 if the carbonic acid gas formed be withdrawn by means of lime-water1 or caustic alkali1 the azote remaining is precisely the same1 in its nature1 as what remains after air is exhausted of its oxygen by being employed for calcining metals4 ,in this first paper ,lavoisier went no further than establishing these general principles2 but he afterwards made experiments to determine the exact amount of the changes which were produced in air by breathing1 and endeavoured to establish an accurate theory of respiration4 ,to this subject we shall have occasion to revert again1 when we give an account of the attempts made to determine the phenomena of respiration by more modern experimenters4 ,lavoisier's experiments on perspiration were made during the frenzy of the ,french revolution1 when ,robespierre had usurped the supreme power1 and when it was the object of those at the head of affairs to destroy all the marks of civilization and science which remained in the country4 ,his experiments were scarcely completed when he was thrown into prison1 and though he requested a prolongation of his life for a short time1 till he could have the means of drawing up a statement of their results1 the request was barbarously refused4 ,he has therefore left no account of them whatever behind him4 ,but ,seguin1 who was associated with him in making these experiments1 was fortunately overlooked1 and escaped the dreadful times of the reign of terror3 he afterwards drew up an account of the results1 which has prevented them from being wholly lost to chemists and physiologists4 ,seguin was usually the person experimented on4 ,a varnished silk bag1 perfectly air-tight1 was procured1 within which he was enclosed1 except a slit over against the mouth1 which was left open for breathing2 and the edges of the bag were accurately cemented round the mouth1 by means of a mixture of turpentine and pitch4 ,thus every thing emitted by the body was retained in the bag1 except what made its escape from the lungs by respiration4 ,by weighing himself in a delicate balance at the commencement of the experiment1 and again after he had continued for some time in the bag1 the quantity of matter carried off by respiration was determined4 ,by weighing himself without this varnished covering1 and repeating the operation after the same interval of time had elapsed1 as in the former experiment1 he determined the loss of weight occasioned by perspiration and respiration together4 ,the loss of weight indicated by the first experiment being subtracted from that given by the second1 the quantity of matter lost by perspiration through the pores of the skin was determined4 ,the following facts were ascertained by these experiments3 #a4 ,the maximum of matter perspired in a minute amounted to #bfbe grains troy2 the minimum to nine grains2 which gives #agfc grains1 at a medium1 in the minute1 or #ebhi ounces in twenty-four hours4 #b4 ,the amount of perspiration is increased by drink1 but not by solid food4 #c4 ,perspiration is at its minimum immediately after a repast2 it reaches its maximum during digestion4 ,such is an epitome of the chemical labours of ,m4 ,lavoisier4 ,when we consider that this prodigious number of experiments and memoirs were all performed and drawn up within the short period of twenty years1 we shall be able to form some idea of the almost incredible activity of this extraordinary man3 the steadiness with which he kept his own peculiar opinions in view1 and the good temper which he knew how to maintain in all his publications1 though his opinions were not only not supported1 but actually opposed by the whole body of chemists in existence1 does him infinite credit1 and was undoubtedly the wisest line of conduct which he could possibly have adopted4 ,the difficulties connected with the evolution and absorption of hydrogen1 constituted the stronghold of the phlogistians4 ,but ,mr4 ,cavendish's discovery1 that water is a compound of oxygen and hydrogen1 was a death-blow to the doctrine of ,stahl4 ,soon after this discovery was fully established1 or during the year #aghe1 ,m4 ,berthollet1 a member of the academy1 and fast rising to the eminence which he afterwards acquired1 declared himself a convert to the ,lavoisierian theory4 ,his example was immediately followed by ,m4 ,fourcroy1 also a member of the academy1 who had succeeded ,macquer as professor of chemistry in the ,jardin du ,roi4 ,m4 ,fourcroy1 who was perfectly aware of the strong feeling of patriotism which1 at that time1 actuated almost every man of science in ,france1 hit upon a most infallible way of giving currency to the new opinions4 ,to the theory of ,lavoisier he gave the name of ,la ,chimie ,franaise 7,french ,chemistry74 ,this name was not much relished by ,lavoisier1 as1 in his opinion1 it deprived him of the credit which was his due2 but it certainly contributed1 more than any thing else1 to give the new opinions currency1 at least1 in ,france2 they became at once a national concern1 and those who still adhered to the old opinions1 were hooted and stigmatized as enemies to the glory of their country4 ,one of the most eminent of those who still adhered to the phlogistic theory was ,m4 ,guyton de ,morveau1 a nobleman of ,burgundy1 who had been educated as a lawyer1 and who filled a conspicuous situation in the ,parliament of ,dijon3 he had cultivated chemistry with great zeal1 and was at that time the editor of the chemical part of the ,encyclopdie ,mthodique4 ,in the first half-volume of the chemical part of this dictionary1 which had just appeared1 ,morveau had supported the doctrine of phlogiston1 and opposed the opinions of ,lavoisier with much zeal and considerable skill3 on this account1 it became an object of considerable consequence to satisfy ,morveau that his opinions were inaccurate1 and to make him a convert to the antiphlogistic theory2 for the whole matter was managed as if it had been a political intrigue1 rather than a philosophical inquiry4 ,morveau was accordingly invited to ,paris1 and ,lavoisier succeeded without difficulty in bringing him over to his own opinions4 ,we are ignorant of the means which he took2 no doubt friendly discussion and the repetition of the requisite experiments1 would be sufficient to satisfy a man so well acquainted with the subject1 and whose mode of thinking was so liberal as ,morveau4 ,into the middle of the second half-volume of the chemical part of the ,encyclopdie ,mthodique he introduced a long advertisement1 announcing this change in his opinions1 and assigning his reasons for it4 ,the chemical nomenclature at that time in use had originated with the medical chemists1 and contained a multiplicity of unwieldy and unmeaning1 and even absurd terms4 ,it had answered the purposes of chemists tolerably well while the science was in its infancy2 but the number of new substances brought into view had of late years become so great1 that the old names could not be applied to them without the utmost straining3 and the chemical terms in use were so little systematic that it required a considerable stretch of memory to retain them4 ,these evils were generally acknowledged and lamented1 and various attempts had been made to correct them4 ,bergman1 for instance1 had contrived a new nomenclature1 confined chiefly to the salts and adapted to the ,latin language4 ,dr4 ,black had done the same thing3 his nomenclature possessed both elegance and neatness1 and was1 in several respects1 superior to the terms ultimately adopted2 but with his usual indolence and disregard of reputation1 he satisfied himself merely with drawing it up in the form of a table and exhibiting it to his class4 ,morveau contrived a new nomenclature of the salts1 and published it in #aghc2 and it appears to have been seen and approved of by ,bergman4 ,the old chemical phraseology as far as it had any meaning was entirely conformable to the phlogistic theory4 ,this was so much the case that it was with difficulty that ,lavoisier was able to render his opinions intelligible by means of it4 ,indeed it would have been out of his power to have conveyed his meaning to his readers1 had he not invented and employed a certain number of new terms4 ,lavoisier1 aware of the defects of the chemical nomenclature1 and sensible of the advantage which his own doctrine would acquire when dressed up in a language exactly suited to his views1 was easily prevailed upon by ,morveau to join with him in forming a new nomenclature to be henceforth employed exclusively by the antiphlogistians1 as they called themselves4 ,for this purpose they associated with themselves ,berthollet1 and ,fourcroy4 ,we do not know what part each took in this important undertaking2 but1 if we are to judge from appearances1 the new nomenclature was almost exclusively the work of ,lavoisier and ,morveau4 ,lavoisier undoubtedly contrived the general phrases1 and the names applied to the simple substances1 so far as they were new1 because he had employed the greater number of them in his writings before the new nomenclature was concocted4 ,that the mode of naming the salts originated with ,morveau is obvious2 for it differs but little from the nomenclature of the salts published by him four years before4 ,the new nomenclature was published by ,lavoisier and his associates in #aghg1 and it was ever after employed by them in all their writings4 ,aware of the importance of having a periodical work in which they could register and make known their opinions1 they established the ,annales de ,chimie1 as a sort of counterpoise to the ,journal de ,physique1 the editor of which1 ,m4 ,delametherie1 continued a zealous votary of phlogiston to the end of his life4 ,this new nomenclature very soon made its way into every part of ,europe1 and became the common language of chemists1 in spite of the prejudices entertained against it1 and the opposition which it every where met with4 ,in the year #agif1 or nine years after the appearance of the new nomenclature1 when ,i attended the chemistry-class in the ,college of ,edinburgh1 it was not only in common use among the students1 but was employed by ,dr4 ,black1 the professor of chemistry1 himself2 and ,i have no doubt that he had introduced it into his lectures several years before4 ,this extraordinary rapidity with which the new chemical language came into use1 was doubtless owing to two circumstances4 ,first1 the very defective1 vague1 and barbarous state of the old chemical nomenclature3 for although1 in consequence of the prodigious progress which the science of chemistry has made since the time of ,lavoisier1 his nomenclature is now nearly as inadequate to express our ideas as that of ,stahl was to express his2 yet1 at the time of its appearance1 its superiority over the old nomenclature was so great1 that it was immediately felt and acknowledged by all those who were acquiring the science1 who are the most likely to be free from prejudices1 and who1 in the course of a few years1 must constitute the great body of those who are interested in the science4 #b4 ,the second circumstance1 to which the rapid triumph of the new nomenclature was owing1 is the superiority of ,lavoisier's theory over that of ,stahl4 ,the subsequent progress of the science has betrayed many weak points in ,lavoisier's opinions2 yet its superiority over that of ,stahl was so obvious1 and the mode of interrogating nature introduced by him was so good1 and so well calculated to advance the science1 that no unprejudiced person1 who was at sufficient pains to examine both1 could hesitate about preferring that of ,lavoisier4 ,it was therefore generally embraced by all the young chemists in every country2 and they became1 at the same time1 partial to the new nomenclature1 by which only that theory could be explained in an intelligible manner4 ,when the new nomenclature was published1 there were only three nations in ,europe who could be considered as holding a distinguished place as cultivators of chemistry3 ,france1 ,germany1 and ,great ,britain4 ,for ,sweden had just lost her two great chemists1 ,bergman and ,scheele1 and had been obliged1 in consequence1 to descend from the high chemical rank which she had formerly occupied4 ,in ,france the fashion1 and of course almost the whole nation1 were on the side of the new chemistry4 ,macquer1 who had been a stanch phlogistian to the last1 was just dead4 ,monnet was closing his laborious career4 ,baum continued to adhere to the old opinions2 but he was old1 and his chemical skill1 which had never been accurate1 was totally eclipsed by the more elaborate researches of ,lavoisier and his friends4 ,delametherie was a keen phlogistian1 a man of some abilities1 of remarkable honesty and integrity1 and editor of the ,journal de ,physique1 at that time a popular and widely-circulating scientific journal4 ,but his habits1 disposition1 and conduct1 were by no means suited to the taste of his countrymen1 or conformable to the practice of his contemporaries4 ,the consequence was1 that he was shut out of all the scientific coteries of ,paris2 and that his opinions1 however strongly1 or rather violently expressed1 failed to produce the intended effect4 ,indeed1 as his views were generally inaccurate1 and expressed without any regard to the rules of good manners1 they in all probability rather served to promote than to injure the cause of his opponents4 ,lavoisier and his friends appear to have considered the subject in this light3 they never answered any of his attacks1 or indeed took any notice of them4 ,france1 then1 from the date of the publication of the new nomenclature1 might be considered as enlisted on the side of the antiphlogistic theory4 ,the case was very different in ,germany4 ,the national prejudices of the ,germans were naturally enlisted on the side of ,stahl1 who was their countryman1 and whose reputation would be materially injured by the refutation of his theory4 ,the cause of phlogiston1 accordingly1 was taken up by several ,german chemists1 and supported with a good deal of vigour2 and a controversy was carried on for some years in ,germany between the old chemists who adhered to the doctrine of ,stahl1 and the young chemists who had embraced the theory of ,lavoisier4 ,gren1 who was at that time the editor of a chemical journal1 deservedly held in high estimation1 and whose reputation as a chemist stood rather high in ,germany1 finding it impossible to defend the ,stahlian theory as it had been originally laid down1 introduced a new modification of phlogiston1 and attempted to maintain it against the antiphlogistians4 ,the death of ,gren and of ,wiegleb1 who were the great champions of phlogiston1 left the field open to the antiphlogistians1 who soon took possession of all the universities and scientific journals in ,germany4 ,the most eminent chemist in ,germany1 or perhaps in ,europe at that time1 was ,martin ,henry ,klaproth1 professor of chemistry at ,berlin1 to whom analytical chemistry lies under the greatest obligations4 ,in the year #agib he proposed to the ,academy of ,sciences of ,berlin1 of which he was a member1 to repeat all the requisite experiments before them1 that the members of the academy might be able to determine for themselves which of the two theories deserved the preference4 ,this proposal was acceded to4 ,all the fundamental experiments were repeated by ,klaproth with the most scrupulous attention to accuracy3 the result was a full conviction1 on the part of ,klaproth and the academy1 that the ,lavoisierian theory was the true one4 ,thus the ,berlin ,academy became antiphlogistians in #agib3 and as ,berlin has always been the focus of chemistry in ,germany1 the determination of such a learned body must have had a powerful effect in accelerating the propagation of the new theory through that vast country4 ,in ,great ,britain the investigation of gaseous bodies1 to which the new doctrines were owing1 had originated4 ,dr4 ,black had begun the inquiry--,mr4 ,cavendish had prosecuted it with unparalleled accuracy--and ,dr4 ,priestley had made known a great number of new gaseous bodies1 which had hitherto escaped the attention of chemists4 ,as the ,british chemists had contributed more than those of any other nation to the production of the new facts on which ,lavoisier's theory was founded1 it was natural to expect that they would have embraced that theory more readily than the chemists of any other nation3 but the matter of fact was somewhat different4 ,dr4 ,black1 indeed1 with his characteristic candour1 speedily embraced the opinions1 and even adopted the new nomenclature3 but ,mr4 ,cavendish new modelled the phlogistic theory1 and published a defence of phlogiston1 which it was impossible at that time to refute4 ,the ,french chemists had the good sense not to attempt to overturn it4 ,mr4 ,cavendish after this laid aside the cultivation of chemistry altogether1 and never acknowledged himself a convert to the new doctrines4 ,dr4 ,priestley continued a zealous advocate for phlogiston till the very last1 and published what he called a refutation of the antiphlogistic theory about the beginning of the present century3 but ,dr4 ,priestley1 notwithstanding his merit as a discoverer and a man of genius1 was never1 strictly speaking1 entitled to the name of chemist2 as he was never able to make a chemical analysis4 ,in his famous experiments1 for example1 on the composition of water1 he was obliged to procure the assistance of ,mr4 ,keir to determine the nature of the blue-coloured liquid which he had obtained1 and which ,mr4 ,keir showed to be nitrate of copper4 ,besides1 ,dr4 ,priestley1 though perfectly honest and candid1 was so hasty in his decisions1 and so apt to form his opinions without duly considering the subject1 that his chemical theories are almost all erroneous and sometimes quite absurd4 ,mr4 ,kirwan1 who had acquired a high reputation1 partly by his mineralogy1 and partly by his experiments on the composition of the salts1 undertook the task of refuting the antiphlogistic theory1 and with that view published a work to which he gave the name of ,an ,essay on ,phlogiston and the ,composition of ,acids4 ,in that book he maintained an opinion which seems to have been pretty generally adopted by the most eminent chemists of the time2 namely1 that phlogiston is the same thing with what is at present called hydrogen1 and which1 when ,kirwan wrote1 was called light inflammable air4 ,of course ,mr4 ,kirwan undertook to prove that every combustible substance and every metal contains hydrogen as a constituent1 and that hydrogen escapes in every case of combustion and calcination4 ,on the other hand1 when calces are reduced to the metallic state hydrogen is absorbed4 ,the book was divided into thirteen sections4 ,in the first the specific gravity of the gases was stated according to the best data then existing4 ,the second section treats of the composition of acids1 and the composition and decomposition of water4 ,the third section treats of sulphuric acid2 the fourth1 of nitric acid2 the fifth1 of muriatic acid2 the sixth1 of aqua regia2 the seventh1 of phosphoric acid2 the eighth1 of oxalic acid2 the ninth1 of the calcination and reduction of metals and the formation of fixed air2 the tenth1 of the dissolution of metals2 the eleventh1 of the precipitation of metals by each other2 the twelfth1 of the properties of iron and steel2 while the thirteenth sums up the whole argument by way of conclusion4 ,in this work ,mr4 ,kirwan admitted the truth of ,m4 ,lavoisier's theory1 that during combustion and calcination1 oxygen united with the burning and calcining body4 ,he admitted also that water is a compound of oxygen and hydrogen4 ,now these admissions1 which1 however1 it was scarcely possible for a man of candour to refuse1 rendered the whole of his arguments in favour of the identity of hydrogen and phlogiston1 and of the existence of hydrogen in all combustible bodies1 exceedingly inconclusive4 ,kirwan's book was laid hold of by the ,french chemists1 as affording them an excellent opportunity of showing the superiority of the new opinions over the old4 ,kirwan's view of the subject was that which had been taken by ,bergman and ,scheele1 and indeed by every chemist of eminence who still adhered to the phlogistic system4 ,a satisfactory refutation of it1 therefore1 would be a death-blow to phlogiston and would place the antiphlogistic theory upon a basis so secure that it would be henceforth impossible to shake it4 ,kirwan's work on phlogiston was accordingly translated into ,french1 and published in ,paris4 ,at the end of each section was placed an examination and refutation of the argument contained in it by some one of the ,french chemists1 who had now associated themselves in order to support the antiphlogistic theory4 ,the introduction1 together with the second1 third1 and eleventh sections were examined and refuted by ,m4 ,lavoisier2 the fourth1 the fifth1 and sixth sections fell to the share of ,m4 ,berthollet2 the seventh and thirteenth sections were undertaken by ,m4 de ,morveau2 the eighth1 ninth1 and tenth1 by ,m4 ,de ,fourcroy2 while the twelfth section1 on iron and steel was animadverted on by ,m4 ,monge4 ,these refutations were conducted with so much urbanity of manner1 and were at the same time so complete1 that they produced all the effects expected from them4 ,mr4 ,kirwan1 with a degree of candour and liberality of which1 unfortunately1 very few examples can be produced1 renounced his old opinions1 abandoned phlogiston1 and adopted the antiphlogistic doctrines of his opponents4 ,but his advanced age1 and a different mode of experimenting from what he had been accustomed to1 induced him to withdraw himself entirely from experimental science and to devote the evening of his life to metaphysical and logical and moral investigations4 ,thus1 soon after the year #agij1 a kind of interregnum took place in ,british chemistry4 ,almost all the old ,british chemists had relinquished the science1 or been driven out of the field by the superior prowess of their antagonists4 ,dr4 ,austin and ,dr4 ,pearson will1 perhaps1 be pointed out as exceptions4 ,they undoubtedly contributed somewhat to the progress of the science4 ,but they were arranged on the side of the antiphlogistians4 ,dr4 ,crawford1 who had done so much for the theory of heat1 was about this time ruined in his circumstances by the bankruptcy of a house to which he had intrusted his property4 ,this circumstance preyed upon a mind which had a natural tendency to morbid sensibility1 and induced this amiable and excellent man to put an end to his existence4 ,dr4 ,higgins had acquired some celebrity as an experimenter and teacher2 but his disputes with ,dr4 ,priestley1 and his laying claim to discoveries which certainly did not belong to him1 had injured his reputation1 and led him to desert the field of science4 ,dr4 ,black was an invalid1 ,mr4 ,cavendish had renounced the cultivation of chemistry1 and ,dr4 ,priestley had been obliged to escape from the iron hand of theological and political bigotry1 by leaving the country4 ,he did little as an experimenter after he went to ,america2 and1 perhaps1 had he remained in ,england1 his reputation would rather have diminished than increased4 ,he was an admirable pioneer1 and as such1 contributed more than any one to the revolution which chemistry underwent2 though he was himself utterly unable to rear a permanent structure capable1 like the ,newtonian theory1 of withstanding all manner of attacks1 and becoming only the firmer and stronger the more it is examined4 ,mr4 ,keir1 of ,birmingham1 was a man of great eloquence1 and possessed of all the chemical knowledge which characterized the votaries of phlogiston4 ,in the year #aghi he attempted to stem the current of the new opinions by publishing a dictionary of chemistry1 in which all the controversial points were to be fully discussed1 and the antiphlogistic theory examined and refuted4 ,of this dictionary only one part appeared1 constituting a very thin volume of two hundred and eight quarto pages1 and treating almost entirely of acids4 ,finding that the sale of this work did not answer his expectations1 and probably feeling1 as he proceeded1 that the task of refuting the antiphlogistic opinions was much more difficult1 and much more hopeless than he expected1 he renounced the undertaking1 and abandoned altogether the pursuit of chemistry4 ,it will be proper in this place to introduce some account of the most eminent of those ,french chemists who embraced the theory of ,lavoisier1 and assisted him in establishing his opinions4 ,claude-,louis ,berthollet was born at ,talloire1 near ,annecy1 in ,savoy1 on the #ith of ,december1 #agdh4 ,he finished his school education at ,chambry1 and afterwards studied at the ,college of ,turin1 a celebrated establishment1 where many men of great scientific celebrity have been educated4 ,here he attached himself to medicine1 and after obtaining a degree he repaired to ,paris1 which was destined to be the future theatre of his speculations and pursuits4 ,in ,paris he had not a single acquaintance1 nor did he bring with him a single introductory letter2 but understanding that ,m4 ,tronchin1 at that time a distinguished medical practitioner in ,paris1 was a native of ,geneva1 he thought he might consider him as in some measure a countryman4 ,on this slender ground he waited on ,m4 ,tronchin1 and what is rather surprising1 and reflects great credit on both1 this acquaintance1 begun in so uncommon a way1 soon ripened into friendship4 ,tronchin interested himself for his young protge1 and soon got him into the situation of physician in ordinary to the ,duke of ,orleans1 father of him who cut so conspicuous a figure in the ,french revolution1 under the name of ,m4 ,egalit4 ,in this situation he devoted himself to the study of chemistry1 and soon made himself known by his publications on the subject4 ,in #agha he was elected a member of the ,academy of ,sciences of ,paris3 one of his competitors was ,m4 ,fourcroy4 ,no doubt ,berthollet owed his election to the influence of the ,duke of ,orleans4 ,in the year #aghd he was again a competitor with ,m4 de ,fourcroy for the chemical chair at the ,jardin du ,roi1 left vacant by the death of ,macquer4 ,the chair was in the gift of ,m4 ,buffon1 whose vanity is said to have been piqued because the ,duke of ,orleans1 who supported ,berthollet's interest1 did not pay him sufficient court4 ,this induced him to give the chair to ,fourcroy2 and the choice was a fortunate one1 as his uncommon vivacity and rapid elocution particularly fitted him for addressing a ,parisian audience4 ,the chemistry-class at the ,jardin du ,roi immediately became celebrated1 and attracted immense crowds of admiring auditors4 ,but the influence of the ,duke of ,orleans was sufficient to procure for ,berthollet another situation which ,macquer had held4 ,this was government commissary and superintendent of the dyeing processes4 ,it was this situation which naturally turned his attention to the phenomena of dyeing1 and occasioned afterwards his book on dyeing2 which at the time of its publication was excellent1 and exhibited a much better theory of dyeing1 and a better account of the practical part of the art than any work which had previously appeared4 ,the arts of dyeing and calico-printing have been very much improved since the time that ,berthollet's book was written2 yet if we except ,bancroft's work on the permanent colours1 nothing very important has been published on the subject since that period4 ,we are at present almost as much in want of a good work on dyeing as we were when ,berthollet's book appeared4 ,in the year #aghe ,berthollet1 at a meeting of the ,academy of ,sciences1 informed that learned body that he had become a convert to the antiphlogistic doctrines of ,lavoisier4 ,there was one point1 however1 upon which he entertained a different opinion from ,lavoisier1 and this difference of opinion continued to the last4 ,berthollet did not consider oxygen as the acidifying principle4 ,on the contrary1 he was of opinion that acids existed which contained no oxygen whatever4 ,as an example1 he mentioned sulphuretted hydrogen1 which possessed the properties of an acid1 reddening vegetable blues1 and combining with and neutralizing bases1 and yet it was a compound of sulphur and hydrogen1 and contained no oxygen whatever4 ,it is now admitted that ,berthollet was accurate in his opinion1 and that oxygen is not of itself an acidifying principle4 ,berthollet continued in the uninterrupted prosecution of his studies1 and had raised himself a very high reputation when the ,french revolution burst upon the world in all its magnificence4 ,it is not our business here to enter into any historical details1 but merely to remind the reader that all the great powers of ,europe combined to attack ,france1 assisted by a formidable army of ,french emigrants assembled at ,coblentz4 ,the ,austrian and ,prussian armies hemmed her in by land1 while the ,british fleets surrounded her by sea1 and thus shut her out from all communication with other nations4 ,thus ,france was thrown at once upon her own resources4 ,she had been in the habit of importing her saltpetre1 and her iron1 and many other necessary implements of war3 these supplies were suddenly withdrawn2 and it was expected that ,france1 thus deprived of all her resources1 would be obliged to submit to any terms imposed upon her by her adversaries4 ,at this time she summoned her men of science to her assistance1 and the call was speedily answered4 ,berthollet and ,monge were particularly active1 and saved the ,french nation from destruction by their activity1 intelligence1 and zeal4 ,berthollet traversed ,france from one extremity to the other2 pointed out the mode of extracting saltpetre from the soil1 and of purifying it4 ,saltpetre-works were instantly established in every part of ,france1 and gunpowder made of it in prodigious quantity1 and with incredible activity4 ,berthollet even attempted to manufacture a new species of gunpowder still more powerful than the old1 by substituting chlorate of potash for saltpetre3 but it was found too formidable a substance to be made with safety4 ,the demand for cannon1 muskets1 sabres1 c41 was equally urgent and equally difficult to be supplied4 ,a committee of men of science1 of which ,berthollet and ,monge were the leading members1 was established1 and by them the mode of smelting iron1 and of converting it into steel1 was instantly communicated1 and numerous manufactories of these indispensable articles rose like magic in every part of ,france4 ,this was the most important period of the life of ,berthollet4 ,it was in all probability his zeal1 activity1 sagacity1 and honesty1 which saved ,france from being overrun by foreign troops4 ,but perhaps the moral conduct of ,berthollet was not less conspicuous than his other qualities4 ,during the reign of terror1 a short time before the #ith ,thermidor1 when it was the system to raise up pretended plots1 to give pretexts for putting to death those that were obnoxious to ,robespierre and his friends1 a hasty notice was given at a sitting of the ,committee of ,public ,safety1 that a conspiracy had just been discovered to destroy the soldiers1 by poisoning the brandy which was just going to be served out to them previous to an engagement4 ,it was said that the sick in the hospitals who had tasted this brandy1 all perished in consequence of it4 ,immediate orders were issued to arrest those previously marked for execution4 ,a quantity of the brandy was sent to ,berthollet to be examined4 ,he was informed1 at the same time1 that ,robespierre wanted a conspiracy to be established1 and all knew that opposition to his will was certain destruction4 ,having finished his analysis1 ,berthollet drew up his results in a ,report1 which he accompanied with a written explanation of his views2 and he there stated1 in the plainest language1 that nothing poisonous was mixed with the brandy1 but that it had been diluted with water holding small particles of slate in suspension1 an ingredient which filtration would remove4 ,this report deranged the plans of the ,committee of ,public ,safety4 ,they sent for the author1 to convince him of the inaccuracy of his analysis1 and to persuade him to alter its results4 ,finding that he remained unshaken in his opinion1 ,robespierre exclaimed1 ,what1 ,sir6 darest thou affirm that the muddy brandy is free from poison8 ,berthollet immediately filtered a glass of it in his presence1 and drank it off4 ,thou art daring1 ,sir1 to drink that liquor1 exclaimed the ferocious president of the committee4 ,i dared much more1 replied ,berthollet1 when ,i signed my name to that ,report4 ,there can be no doubt that he would have paid the penalty of this undaunted honesty with his life1 but that fortunately the ,committee of ,public ,safety could not at that time dispense with his services4 ,in the year #agib ,berthollet was named one of the commissioners of the ,mint1 into the processes of which he introduced considerable improvements4 ,in #agid he was appointed a member of the ,commission of ,agriculture and the ,arts3 and in the course of the same year he was chosen professor of chemistry at the ,polytechnic ,school and also in the ,normal ,school4 ,but his turn of mind did not fit him for a public teacher4 ,he expected too much information to be possessed by his hearers1 and did not1 therefore1 dwell sufficiently upon the elementary details4 ,his pupils were not able to follow his metaphysical disquisitions on subjects totally new to them2 hence1 instead of inspiring them with a love for chemistry1 he filled them with langour and disgust4 ,in #agie1 at the organization of the ,institute1 which was intended to include all men of talent or celebrity in ,france1 we find ,berthollet taking a most active lead2 and the records of the ,institute afford abundant evidence of the perseverance and assiduity with which he laboured for its interests4 ,of the committees to which all original memoirs are in the first place referred1 we find ,berthollet1 oftener than any other person1 a member1 and his signature to the report of each work stands generally first4 ,in the year #agif1 after the subjugation of ,italy by ,bonaparte1 ,berthollet and ,monge were selected by the ,directory to proceed to that country1 in order to select those works of science and art with which the ,louvre was to be filled and adorned4 ,while engaged in the prosecution of that duty1 they became acquainted with the victorious general4 ,he easily saw the importance of their friendship1 and therefore cultivated it with care2 and was happy afterwards to possess them1 along with nearly a hundred other philosophers1 as his companions in his celebrated expedition to ,egypt1 expecting no doubt an eclat from such a halo of surrounding science1 as might favour the development of his schemes of future greatness4 ,on this expedition1 which promised so favourably for the ,french nation1 and which was intended to inflict a mortal stab upon the commercial greatness of ,great ,britain1 ,bonaparte set out in the year #agih1 accompanied by a crowd of the most eminent men of science that ,france could boast of4 ,that they might co-operate more effectually in the cause of knowledge1 these gentlemen formed themselves into a society1 named ,the ,institute of ,egypt1 which was constituted on the same plan as the ,national ,institute of ,france4 ,their first meeting was on the #fth ,fructidor 7#bdth of ,august71 #agih2 and after that they continued to assemble1 at stated intervals4 ,at these meetings papers were read1 by the respective members1 on the climate1 the inhabitants1 and the natural and artificial productions of the country to which they had gone4 ,these memoirs were published in #ahjj1 in ,paris1 in a single volume entitled1 ,memoirs of the ,institute of ,egypt4 ,the history of the ,institute of ,egypt1 as related by ,cuvier1 is not a little singular1 and deserves to be stated4 ,bonaparte1 during his occasional intercourse with ,berthollet in ,italy1 was delighted with the simplicity of his manners1 joined to a force and depth of thinking which he soon perceived to characterize our chemist4 ,when he returned to ,paris1 where he enjoyed some months of comparative leisure1 he resolved to employ his spare time in studying chemistry under ,berthollet4 ,it was at this period that his illustrious pupil imparted to our philosopher his intended expedition to ,egypt1 of which no whisper was to be spread abroad till the blow was ready to fall2 and he begged of him not merely to accompany the army himself1 but to choose such men of talent and experience as he conceived fitted to find there an employment worthy of the country which they visited1 and of that which sent them forth4 ,to invite men to a hazardous expedition1 the nature and destination of which he was not permitted to disclose1 was rather a delicate task2 yet ,berthollet undertook it4 ,he could simply inform them that he would himself accompany them2 yet such was the universal esteem in which he was held1 such was the confidence universally placed in his honesty and integrity1 that all the men of science agreed at once1 and without hesitation1 to embark on an unknown expedition1 the dangers of which he was to share along with them4 ,had it not been for the link which ,berthollet supplied between the commander-in-chief and the men of science1 it would have been impossible to have united1 as was done on this occasion1 the advancement of knowledge with the progress of the ,french arms4 ,during the whole of this expedition1 ,berthollet and ,monge distinguished themselves by their firm friendship1 and by their mutually braving every danger to which any of the common soldiers could be exposed4 ,indeed1 so intimate was their association that many of the army conceived ,berthollet and ,monge to be one individual2 and it is no small proof of the intimacy of these philosophers with ,bonaparte1 that the soldiers had a dislike at this double personage1 from a persuasion that it had been at his suggestion that they were led into a country which they detested4 ,it happened on one occasion that a boat1 in which ,berthollet and some others were conveyed up the ,nile1 was assailed by a troop of ,mamelukes1 who poured their small shot into it from the banks4 ,in the midst of this perilous voyage1 ,m4 ,berthollet began very coolly to pick up stones and stuff his pockets with them4 ,when his motive for this conduct was asked1 ,i am desirous1 said he1 that in case of my being shot1 my body may sink at once to the bottom of this river1 and may escape the insults of these barbarians4 ,in a conjuncture where a courage of a rarer kind was required1 ,berthollet was not found wanting4 ,the plague broke out in the ,french army1 and this1 added to the many fatigues they had previously endured1 the diseases under which they were already labouring1 would1 it was feared1 lead to insurrection on the one hand1 or totally sink the spirits of the men on the other4 ,acre had been besieged for many weeks in vain4 ,bonaparte and his army had been able to accomplish nothing against it3 he was anxious to conceal from his army this disastrous intelligence4 ,when the opinion of ,berthollet was asked in council1 he spoke at once the plain1 though unwelcome truth4 ,he was instantly assailed by the most violent reproaches4 ,in a week1 said he1 my opinion will be unfortunately but too well vindicated4 ,it was as he foretold3 and when nothing but a hasty retreat could save the wretched remains of the army of ,egypt1 the carriage of ,berthollet was seized for the convenience of some wounded officers4 ,on this1 he travelled on foot1 and without the smallest discomposure1 across twenty leagues of the desert4 ,when ,napoleon abandoned the army of ,egypt1 and traversed half the ,mediterranean in a single vessel1 ,berthollet was his companion4 ,after he had put himself at the head of the ,french government1 and had acquired an extent of power1 which no modern ,european potentate had ever before realized1 he never forgot his associate4 ,he was in the habit of placing all chemical discoveries to his account1 to the frequent annoyance of our chemist2 and when an unsatisfactory answer was given him upon any scientific subject1 he was in the habit of saying1 ,well2 ,i shall ask this of ,berthollet4 ,but he did not limit his affection to these proofs of regard4 ,having been informed that ,berthollet's earnest pursuits of science had led him into expenses which had considerably deranged his fortune1 he sent for him1 and said1 in a tone of affectionate reproach1 ,m4 ,berthollet1 ,i have always one hundred thousand crowns at the service of my friends4 ,and1 in fact1 this sum was immediately presented to him4 ,upon his return from ,egypt1 ,berthollet was nominated a senator by the first consul2 and afterwards received the distinction of grand officer of the ,legion of ,honour2 grand cross of the ,order of ,reunion2 titulary of the ,senatory of ,montpellier2 and1 under the emperor1 he was created a peer of ,france1 receiving the title of ,count4 ,the advancement to these offices produced no change in the manners of ,berthollet4 ,of this he gave a striking proof1 by adopting1 as his armorial bearing 7at the time that others eagerly blazoned some exploit71 the plain unadorned figure of his faithful and affectionate dog4 ,he was no courtier before he received these honours1 and he remained equally simple and unassuming1 and not less devoted to science after they were conferred4 ,as we advance towards the latter period of his life1 we find the same ardent zeal in the cause of science which had glowed in his early youth1 accompanied by the same generous warmth of heart that he ever possessed1 and which displayed itself in his many intimate friendships still subsisting1 though mellowed by the hand of time4 ,at this period ,la ,place lived at ,arcueil1 a small village about three miles from ,paris4 ,between him and ,berthollet there had long subsisted a warm affection1 founded on mutual esteem4 ,to be near this illustrious man ,berthollet purchased a country-seat in the village3 there he established a very complete laboratory1 fit for conducting all kinds of experiments in every branch of natural philosophy4 ,here he collected round him a number of distinguished young men1 who knew that in his house their ardour would at once receive fresh impulse and direction from the example of ,berthollet4 ,these youthful philosophers were organized by him into a society1 to which the name of ,socit d',arcueil was given4 ,m4 ,berthollet was himself the president1 and the other members were ,la ,place1 ,biot1 ,gay-,lussac1 ,thenard1 ,collet-,descotils1 ,decandolle1 ,humboldt1 and ,a4 ,b4 ,berthollet4 ,this society published three volumes of very valuable memoirs4 ,the energy of this society was unfortunately paralyzed by an untoward event1 which imbittered the latter days of this amiable man4 ,his only son1 ,m4 ,a4 ,b4 ,berthollet1 in whom his happiness was wrapped up1 was unfortunately afflicted with a lowness of spirits which rendered his life wholly insupportable to him4 ,retiring to a small room1 he locked the door1 closed up every chink and crevice which might admit the air1 carried writing materials to a table1 on which he placed a second-watch1 and then seated himself before it4 ,he now marked precisely the hour1 and lighted a brasier of charcoal beside him4 ,he continued to note down the series of sensations he then experienced in succession1 detailing the approach and rapid progress of delirium2 until1 as time went on1 the writing became confused and illegible1 and the young victim dropped dead upon the floor4 ,after this event the spirits of the old man never again rose4 ,occasionally some discovery1 extending the limits of his favourite science1 engrossed his interest and attention for a short time3 but such intervals were rare1 and shortlived4 ,the restoration of the ,bourbons1 and the downfall of his friend and patron ,napoleon1 added to his sufferings by diminishing his income1 and reducing him from a state of affluence to comparative embarrassment4 ,but he was now old1 and the end of his life was approaching4 ,in #ahbb he was attacked by a slight fever1 which left behind it a number of boils3 these were soon followed by a gangrenous ulcer of uncommon size4 ,under this he suffered for several months with surprising fortitude4 ,he himself1 as a physician1 knew the extent of his danger1 felt the inevitable progress of the malady1 and calmly regarded the slow approach of death4 ,at length1 after a tedious period of suffering1 in which his equanimity had never once been shaken1 he died on the #fth of ,november1 when he had nearly completed the seventy-fourth year of his age4 ,his papers are exceedingly numerous1 and of a very miscellaneous nature1 amounting to more than eighty4 ,the earlier were chiefly inserted into the various volumes of the ,memoirs of the ,academy4 ,he furnished many papers to the ,annales de ,chimie and the ,journal de ,physique1 and was also a frequent contributor to the ,society of ,arcueil1 in the different volumes of whose transactions several memoirs of his are to be found4 ,he was the author likewise of two separate works1 comprising each two octavo volumes4 ,these were his ,elements of the ,art of ,dyeing1 first published in #agia1 in a single volume3 but the new and enlarged edition of #ahad was in two volumes2 and his ,essay on ,chemical ,statics1 published about the beginning of the present century4 ,i shall notice his most important papers4 ,his earlier memoirs on sulphurous acid1 on volatile alkali1 and on the decomposition of nitre1 were encumbered by the phlogistic theory1 which at that time he defended with great zeal1 though he afterwards retracted these his first opinions upon all these subjects4 ,except his paper on soaps1 in which he shows that they are chemical compounds of an oil 7acting the part of an acid7 and an alkaline base1 and his proof that phosphoric acid exists ready formed in the body 7a fact long before demonstrated by ,gahn and ,scheele71 his papers published before he became an antiphlogistian are of inferior merit4 ,in #aghe he demonstrated the nature and proportion of the constituents of ammonia1 or volatile alkali4 ,this substance had been collected in the gaseous form by the indefatigable ,priestley1 who had shown also that when electric sparks are made to pass for some time through a given volume of this gas1 its bulk is nearly doubled4 ,berthollet merely repeated this experiment of ,priestley1 and analyzed the new gases evolved by the action of electricity4 ,this gas he found a mixture of three volumes hydrogen and one volume azotic gas3 hence it was evident that ammoniacal gas is a compound of three volumes of hydrogen and one volume of azotic gas united together1 and condensed into two volumes4 ,the same discovery was made about the same time by ,dr4 ,austin1 and published in the ,philosophical ,transactions4 ,both sets of experiments were made without any knowledge of what was done by the other3 but it is admitted1 on all hands1 that ,berthollet had the priority in point of time4 ,it was about this time1 likewise1 that he published his first paper on chlorine4 ,he observed1 that when water1 impregnated with chlorine1 is exposed to the light of the sun1 the water loses its colour1 while1 at the same time1 a quantity of oxygen gas is given out4 ,if we now examine the water1 we find that it contains no chlorine1 but merely a little muriatic acid4 ,this fact1 which is undoubted1 led him to conclude that chlorine is decomposed by the action of solar light1 and that its two elements are muriatic acid and oxygen4 ,this led to the notion that the basis of muriatic acid is capable of combining with various doses of oxygen1 and of forming various acids1 one of which is chlorine3 on that account it was called oxygenized muriatic acid by the ,french chemists1 which unwieldy appellation was afterwards shortened by ,kirwan into oxymuriatic acid4 ,berthollet observed that when a current of chlorine gas is passed through a solution of carbonate of potash an effervescence takes place owing to the disengagement of carbonic acid gas4 ,by-and-by crystals are deposited in fine silky scales1 which possess the property of detonating with combustible bodies still more violently than saltpetre4 ,berthollet examined these crystals and showed that they were compounds of potash with an acid containing much more oxygen than oxymuriatic acid4 ,he considered its basis as muriatic acid1 and distinguished it by the name of hyper-oxymuriatic acid4 ,it was not till the year #ahaj1 that the inaccuracy of these opinions was established4 ,gay-,lussac and ,thenard attempted in vain to extract oxygen from chlorine4 ,they showed that not a trace of that principle could be detected4 ,next year ,davy took up the subject and concluded from his experiments that chlorine is a simple substance1 that muriatic acid is a compound of chlorine and hydrogen1 and hyper-oxymuriatic acid of chlorine and oxygen4 ,gay-,lussac obtained this acid in a separate state1 and gave it the name of chloric acid1 by which it is now known4 ,scheele1 in his original experiments on chlorine1 had noticed the property which it has of destroying vegetable colours4 ,berthollet examined this property with care1 and found it so remarkable that he proposed it as a substitute for exposure to the sun in bleaching4 ,this suggestion alone would have immortalized ,berthollet had he done nothing else2 since its effect upon some of the most important of the manufactures of ,great ,britain has been scarcely inferior to that of the steam-engine itself4 ,mr4 ,watt happened to be in ,paris when the idea suggested itself to ,berthollet4 ,he not only communicated it to ,mr4 ,watt1 but showed him the process in all its simplicity4 ,it consisted in nothing else than in steeping the cloth to be bleached in water impregnated with chlorine gas4 ,mr4 ,watt1 on his return to ,great ,britain1 prepared a quantity of this liquor1 and sent it to his father-in-law1 ,mr4 ,macgregor1 who was a bleacher in the neighbourhood of ,glasgow4 ,he employed it successfully1 and thus was the first individual who tried the new process of bleaching in ,great ,britain4 ,for a number of years the bleachers in ,lancashire and the neighbourhood of ,glasgow were occupied in bringing the process to perfection4 ,the disagreeable smell of the chlorine was a great annoyance4 ,this was attempted to be got rid of by dissolving potash in the water to be impregnated with chlorine2 but it was found to injure considerably the bleaching powers of the gas4 ,the next method tried was to mix the water with quicklime1 and then to pass a current of chlorine through it4 ,the quicklime was dissolved1 and the liquor thus constituted was found to answer very well4 ,the last improvement was to combine the chlorine with dry lime4 ,at first two atoms of lime were united to one atom of chlorine2 but of late years it is a compound of one atom of lime1 and one of chlorine4 ,this chloride is simply dissolved in water1 and the cloth to be bleached is steeped in it4 ,for all these improvements1 which have brought the method of bleaching by means of chlorine to great simplicity and perfection1 the bleachers are indebted to ,knox1 ,tennant1 and ,mackintosh1 of ,glasgow2 by whose indefatigable exertions the mode of manufacturing chloride of lime has been brought to a state of perfection4 ,berthollet's experiments on prussic acid and the prussiates deserve also to be mentioned1 as having a tendency to rectify some of the ideas at that time entertained by chemists1 and to advance their knowledge of one of the most difficult departments of chemical investigation4 ,in consequence of his experiments on the nature and constituents of sulphuretted hydrogen1 he had already concluded that it was an acid1 and that it was destitute of oxygen3 this had induced him to refuse his assent to the hypothesis of ,lavoisier1 that oxygen is the acidifying principle4 ,scheele1 in his celebrated experiments on prussic acid1 had succeeded in ascertaining that its constituents were carbon and azote2 but he had not been able to make a rigid analysis of that acid1 and consequently to demonstrate that oxygen did not enter into it as a constituent4 ,berthollet took up the subject1 and though his analysis was also incomplete1 he satisfied himself1 and rendered it exceedingly probable1 that the only constituents of this acid were1 carbon1 azote1 and hydrogen1 and that oxygen did not enter into it as a constituent4 ,this was another reason for rejecting the notion of oxygen as an acidifying principle4 ,here were two acids capable of neutralizing bases1 namely1 sulphuretted hydrogen and prussic acid1 and yet neither of them contained oxygen4 ,he found that when prussic acid was treated with chlorine1 its properties were altered2 it acquired a different smell and taste1 and no longer precipitated iron blue1 but green4 ,from his opinion respecting the nature of chlorine1 that it was a compound of muriatic acid and oxygen1 he naturally concluded that by this process he had formed a new prussic acid by adding oxygen to the old constituents4 ,he therefore called this new substance oxyprussic acid4 ,it has been proved by the more recent experiments of ,gay-,lussac1 that the new acid of ,berthollet is a compound of cyanogen 7the prussic acid deprived of hydrogen7 and chlorine3 it is now called chloro-cyanic acid1 and is known to possess the characters assigned it by ,berthollet3 it constitutes1 therefore1 a new example of an acid destitute of oxygen4 ,berthollet was the first person who obtained prussiate of potash in regular crystals2 the salt was known long before1 but had been always used in a state of solution4 ,berthollet's discovery of fulminating silver1 and his method of obtaining pure hydrated potash and soda1 by means of alcohol1 deserve to be mentioned4 ,this last process was of considerable importance to analytical chemistry4 ,before he published his process1 these substances in a state of purity were not known4 ,i think it unnecessary to enter into any details respecting his experiments on sulphuretted hydrogen1 and the hydrosulphurets and sulphurets4 ,they contributed essentially to elucidate that obscure part of chemistry4 ,but his success was not perfect2 nor did we understand completely the nature of these compounds1 till the nature of the alkaline bases had been explained by the discoveries of ,davy4 ,the only other work of ,berthollet1 which ,i think it necessary to notice here1 is his book entitled ,chemical ,statics1 which he published in #ahjc4 ,he had previously drawn up some interesting papers on the subject1 which were published in the ,memoirs of the ,institute4 ,though chemical affinity constitutes confessedly the basis of the science1 it had been almost completely overlooked by ,lavoisier1 who had done nothing more on the subject than drawn up some tables of affinity1 founded on very imperfect data4 ,morveau had attempted a more profound investigation of the subject in the article ,affinit1 inserted in the chemical part of the ,encyclopdie ,mthodique4 ,his object was1 in imitation of ,buffon1 who had preceded him in the same investigation1 to prove that chemical affinity is merely a case of the attraction of gravitation4 ,but it is beyond our reach1 in the present state of our knowledge1 to determine the amount of attraction which the atoms of bodies exert with respect to each other4 ,this was seen by ,newton1 and also by ,bergman1 who satisfied themselves with considering it as an attraction1 without attempting to determine its amount2 though ,newton1 with his usual sagacity1 was inclined1 from the phenomena of light1 to consider the attraction of affinity as much stronger than that of gravitation1 or at least as increasing much more rapidly1 as the distances between the attracting particles diminished4 ,bergman1 who had paid great attention to the subject1 considered affinity as a certain determinate attraction1 which the atoms of different bodies exerted towards each other4 ,this attraction varies in intensity between every two bodies1 though it is constant between each pair4 ,the consequence is1 that these intensities may be denoted by numbers4 ,thus1 suppose a body m1 and the atoms of six other bodies1 a1 b1 c1 d1 e1 f1 to have an affinity for m1 the forces by which they are attracted towards each other may be represented by the numbers x1 x#a1 x#b1 x#c1 x#d1 x#e4 ,and the attractions may be represented thus3 ,attraction between m a x m b x#a m c x#b m d x#c m e x#d m f x#e ,suppose we have the compound m a1 if we present b1 it will unite with m and displace a1 because the attraction between m and a is only x1 while that between m b is x#a3 c will displace b2 d will displace c1 and so on1 for the same reason4 ,on this account ,bergman considered affinity as an elective attraction1 and in his opinion the intensity may always be estimated by decomposition4 ,that substance which displaces another from a third1 has a greater affinity than the body which is displaced4 ,if b displace a from the compound a m1 then b has a greater affinity for m than a has4 ,the object of ,berthollet in his ,chemical ,statics1 was to combat this opinion of ,bergman1 which had been embraced without examination by chemists in general4 ,if affinity be an attraction1 ,berthollet considered it as evident that it never could occasion decomposition4 ,suppose a to have an affinity for m1 and b to have an affinity for the same substances4 ,let the affinity between b and m be greater than that between a m4 ,let b be mixed with a solution of the compound a m1 then in that case b would unite with a m1 and form the triple compound a m b4 ,both a and b would at once unite with m4 ,no reason can be assigned why a should separate from m1 and b take its place4 ,berthollet admitted that in fact such decompositions often happened2 but he accounted for them from other causes1 and not from the superior affinity of one body over another4 ,suppose we have a solution of sulphate of soda in water4 ,this salt is a compound of sulphuric acid and soda2 two substances between which a strong affinity subsists1 and which therefore always unites whenever they come in contact4 ,suppose we have dissolved in another portion of water1 a quantity of barytes1 just sufficient to saturate the sulphuric acid in the sulphate of soda4 ,if we mix these two solutions together4 ,the barytes will combine with the sulphuric acid and the compound 7sulphate of barytes7 will fall to the bottom1 leaving a pure solution of soda in the water4 ,in this case the barytes has seized all the sulphuric acid1 and displaced the soda4 ,the reason of this1 according to ,berthollet1 is not that barytes has a stronger affinity for sulphuric acid than soda has2 but because sulphate of barytes is insoluble in water4 ,it therefore falls down1 and of course the sulphuric acid is withdrawn from the soda4 ,but if we add to a solution of sulphate of soda as much potash as will saturate all the sulphuric acid1 no such decomposition will take place2 at least1 we have no evidence that it does4 ,both the alkalies1 in this case1 will unite to the acid and form a triple compound1 consisting of potash1 sulphuric acid1 and soda4 ,let us now concentrate the solution by evaporation1 and crystals of sulphate of potash will fall down4 ,the reason is1 that sulphate of potash is not nearly so soluble in water as sulphate of soda4 ,hence it separates2 not because sulphuric acid has a greater affinity for potash than for soda1 but because sulphate of potash is a much less soluble salt than sulphate of soda4 ,this mode of reasoning of ,berthollet is plausible1 but not convincing3 it is merely an argumentum ad ignorantiam4 ,we can only prove the decomposition by separating the salts from each other1 and this can only be done by their difference of solubility4 ,but cases occur in which we can judge that decomposition has taken place from some other phenomena than precipitation4 ,for example1 nitrate of copper is a blue salt1 while muriate of copper is green4 ,if into a solution of nitrate of copper we pour muriatic acid1 no precipitation appears1 but the colour changes from blue to green4 ,is not this an evidence that the muriatic acid has displaced the nitric1 and that the salt held in solution is not nitrate of copper1 as it was at first1 but muriate of copper8 ,berthollet accounts for all decompositions which take place when a third body is added1 either by insolubility or by elasticity3 as1 for example1 when sulphuric acid is poured into a solution of carbonate of ammonia1 the carbonic acid all flies off1 in consequence of its elasticity1 and the sulphuric acid combines with the ammonia in its place4 ,i confess that this explanation1 of the reason why the carbonic acid flies off1 appears to me very defective4 ,the ammonia and carbonic acid are united by a force quite sufficient to overcome the elasticity of the carbonic acid4 ,accordingly1 it exhibits no tendency to escape4 ,now1 why should the elasticity of the acid cause it to escape when sulphuric acid is added8 ,it certainly could not do so1 unless it has weakened the affinity by which it is kept united to the ammonia4 ,now this is the very point for which ,bergman contends4 ,the subject will claim our attention afterwards1 when we come to the electro-chemical discoveries1 which distinguished the first ten years of the present century4 ,another opinion supported by ,berthollet in his ,chemical ,statics is1 that quantity may be made to overcome force2 or1 in other words1 that it we mix a great quantity of a substance which has a weaker affinity with a small quantity of a substance which has a stronger affinity1 the body having the weaker affinity will be able to overcome the other1 and combine with a third body in place of it4 ,he gave a number of instances of this2 particularly1 he showed that a large quantity of potash1 when mixed with a small quantity of sulphate of barytes1 is able to deprive the barytes of a portion of its sulphuric acid4 ,in this way he accounted for the decomposition of the common salt1 by carbonate of lime in the soda lakes in ,egypt2 and the decomposition of the same salt by iron1 as noticed by ,scheele4 ,i must acknowledge myself not quite satisfied with ,berthollet's reasoning on this subject4 ,no doubt if two atoms of a body having a weaker affinity1 and one atom of a body having a stronger affinity1 were placed at equal distances from an atom of a third body1 the force of the two atoms might overcome that of the one atom4 ,and it is possible that such cases may occasionally occur3 but such a balance of distances must be rare and accidental4 ,i cannot but think that all the cases adduced by ,berthollet are of a complicated nature1 and admit of an explanation independent of the efficacy of mass4 ,and at any rate1 abundance of instances might be stated1 in which mass appears to have no preponderating effect whatever4 ,chemical decomposition is a phenomenon of so complicated a nature1 that it is more than doubtful whether we are yet in possession of data sufficient to enable us to analyze the process with accuracy4 ,another opinion brought forward by ,berthollet in his work was of a startling nature1 and occasioned a controversy between him and ,proust which was carried on for some years with great spirit1 but with perfect decorum and good manners on both sides4 ,berthollet affirmed that bodies were capable of uniting with each other in all possible proportions1 and that there is no such thing as a definite compound1 unless it has been produced by some accidental circumstances1 as insolubility1 volatility1 c4 ,thus every metal is capable of uniting with all possible doses of oxygen4 ,so that instead of one or two oxides of every metal1 an infinite number of oxides of each metal exist4 ,proust affirmed that all compounds are definite4 ,iron1 says he1 unites with oxygen only in two proportions2 we have either a compound of #ce iron and #a oxygen1 or of #ce iron and #ae oxygen4 ,the first constitutes the black1 and the second the red oxide of iron2 and beside these there is no other4 ,every one is now satisfied that ,proust's view of the subject was correct1 and ,berthollet's erroneous4 ,but a better opportunity will occur hereafter to explain this subject1 or at least to give the information respecting it which we at present possess4 ,berthollet in this book points out the quantity of each base necessary to neutralize a given weight of acid1 and he considers the strength of affinity as inversely that quantity4 ,now of all the bases known when ,berthollet wrote1 ammonia is capable of saturating the greatest quantity of acid4 ,hence he considered its affinity for acids as stronger than that of any other base4 ,barytes1 on the contrary1 saturates the smallest quantity of acid2 therefore its affinity for acids is smallest4 ,now ammonia is separated from acids by all the other bases2 while there is not one capable of separating barytes4 ,it is surprising that the notoriety of this fact did not induce him to hesitate1 before he came to so problematical a conclusion4 ,mr4 ,kirwan had already considered the force of affinity as directly proportional to the quantity of base necessary to saturate a given weight of acid4 ,when we consider the subject metaphysically1 ,berthollet's opinion is most plausible2 for it is surely natural to consider that body as the strongest which produces the greatest effect4 ,now when we deprive an acid of its properties1 or neutralize it by adding a base1 one would be disposed to consider that base as acting with most energy1 which with the smallest quantity of matter is capable of producing a given effect4 ,this was the way that ,berthollet reasoned4 ,but if we attend to the power which one base has of displacing another1 we shall find it very nearly proportional to the weight of it necessary to saturate a given weight of acid2 or1 at least those bases act most powerfully in displacing others of which the greatest quantity is necessary to saturate a given weight of acid4 ,kirwan's opinion1 therefore1 was more conformable to the order of decomposition4 ,these two opposite views of the subject show clearly that neither ,kirwan nor ,berthollet had the smallest conception of the atomic theory2 and1 consequently1 that the allegation of ,mr4 ,higgens1 that he had explained the atomic theory in his book on phlogiston1 published in the year #aghi1 was not well founded4 ,whether ,berthollet had read that book ,i do not know1 but there can be no doubt that it was perused by ,kirwan2 who1 however1 did not receive from it the smallest notions respecting the atomic theory4 ,had he imbibed any such notions1 he never would have considered chemical affinity as capable of being measured by the weight of base capable of neutralizing a given weight of acid4 ,berthollet was not only a man of great energy of character1 but of the most liberal feelings and benevolence4 ,the only exception to this is his treatment of ,m4 ,clement4 ,this gentleman1 in company with ,m4 ,desormes1 had examined the carbonic oxide of ,priestley1 and had shown as ,cruikshanks had done before them1 that it is a compound of carbon and oxygen1 and that it contains no hydrogen whatever4 ,berthollet examined the same gas1 and he published a paper to prove that it was a triple compound of oxygen1 carbon1 and hydrogen4 ,this occasioned a controversy1 which chemists have finally determined in favour of the opinion of ,clement and ,desormes4 ,berthollet1 during this discussion1 did not on every occasion treat his opponents with his accustomed temper and liberality2 and ever after he opposed all attempts on the part of ,clement to be admitted a member of the ,institute4 ,whether there was any other reason for this conduct on the part of ,berthollet1 besides difference of opinion respecting the composition of carbonic oxide1 ,i do not know3 nor would it be right to condemn him without a more exact knowledge of all the circumstances than ,i can pretend to4 ,antoine ,franois de ,fourcroy1 was born at ,paris on the #aeth of ,june1 #agee4 ,his family had long resided in the capital1 and several of his ancestors had distinguished themselves at the bar4 ,but the branch from which he sprung had gradually sunk into poverty4 ,his father exercised in ,paris the trade of an apothecary1 in consequence of a charge which he held in the house of the ,duke of ,orleans4 ,the corporation of apothecaries having obtained the general suppression of all such charges1 ,m4 de ,fourcroy1 the father1 was obliged to renounce his mode of livelihood2 and his son grew up in the midst of the poverty produced by the monopoly of the privileged bodies in ,paris4 ,he felt this situation the more keenly1 because he possessed from nature an extreme sensibility of temper4 ,when he lost his mother1 at the age of seven years1 he attempted to throw himself into her grave4 ,the care of an elder sister preserved him with difficulty till he reached the age at which it was usual to be sent to college4 ,there he was unlucky enough to meet with a brutal master1 who conceived an aversion for him and treated him with cruelty3 the consequence1 was1 a dislike to study2 and he quitted the college at the age of fourteen1 somewhat less informed than when he went to it4 ,his poverty now was such that he was obliged to endeavour to support himself by becoming writing-master4 ,he had even some thoughts of going on the stage2 but was prevented by the hisses bestowed on a friend of his who had unadvisedly entered upon that perilous career1 and was treated in consequence without mercy by the audience4 ,while uncertain what plan to follow1 the advice of ,viq4 d',azyr induced him to commence the study of medicine4 ,this great anatomist was an acquaintance of ,m4 de ,fourcroy1 the father4 ,struck with the appearance of his son1 and the courage with which he struggled with his bad fortune1 he conceived an affection for him1 and promised to direct his studies1 and even to assist him during their progress4 ,the study of medicine to a man in his situation was by no means an easy task4 ,he was obliged to lodge in a garret1 so low in the roof that he could only stand upright in the middle of the room4 ,beside him lodged a water-carrier with twelve children4 ,fourcroy acted as physician to this numerous family1 and in recompence was always supplied with abundance of water4 ,he contrived to support himself by giving lessons to other students1 by facilitating the researches of richer writers1 and by some translations which he sold to a bookseller4 ,for these he was only half paid2 but the conscientious bookseller offered thirty years afterwards to make up the deficiency1 when his creditor was become director-general of public instruction4 ,fourcroy studied with so much zeal and ardour that he soon became well acquainted with the subject of medicine4 ,but this was not sufficient4 ,it was necessary to get a doctor's degree1 and all the expenses at that time amounted to #bejl4 ,an old physician1 ,dr4 ,diest1 had left funds to the faculty to give a gratuitous degree and licence1 once every two years1 to the poor student who should best deserve them4 ,fourcroy was the most conspicuous student at that time in ,paris4 ,he would therefore have reaped the benefit of this benevolent institution had it not been for the unlucky situation in which he was placed4 ,there happened to exist a quarrel between the faculty charged with the education of medical men and the granting of degrees1 and a society recently formed by government for the improvement of the medical art4 ,this dispute had been carried to a great length1 and had attracted the attention of all the frivolous and idle inhabitants of ,paris4 ,viq4 d',azyr was secretary to the society1 and of course one of its most active champions2 and was1 in consequence1 particularly obnoxious to the faculty of medicine at ,paris4 ,fourcroy was unluckily the acknowledged protge of this eminent anatomist4 ,this was sufficient to induce the faculty of medicine to refuse him a gratuitous degree4 ,he would have been excluded in consequence of this from entering on the career of a practitioner1 had not the society1 enraged at this treatment1 and influenced by a violent party spirit1 formed a subscription1 and contributed the necessary expenses4 ,it was no longer possible to refuse ,m4 de ,fourcroy the degree of doctor1 when he was thus enabled to pay for it4 ,but above the simple degree of doctor there was another1 entitled docteur regent1 which depended entirely on the votes of the faculty4 ,it was unanimously refused to ,m4 de ,fourcroy4 ,this refusal put it out of his power afterwards to commence teacher in the medical school1 and gave the medical faculty the melancholy satisfaction of not being able to enroll among their number the most celebrated professor in ,paris4 ,this violent and unjust conduct of the faculty of medicine made a deep impression on the mind of ,fourcroy1 and contributed not a little to the subsequent downfall of that powerful body4 ,fourcroy being thus entitled to practise in ,paris1 his success depended entirely on the reputation which he could contrive to establish4 ,for this purpose he devoted himself to the sciences connected with medicine1 as the shortest and most certain road by which he could reach his object4 ,his first writings showed no predilection for any particular branch of science4 ,he wrote upon chemistry1 anatomy1 and natural history4 ,he published an ,abridgment of the ,history of ,insects1 and a ,description of the ,burs ,mucos of the ,tendons4 ,this last piece seems to have given him the greatest celebrity2 for in #aghe he was admitted1 in consequence of it1 into the academy as an anatomist4 ,but the reputation of ,bucquet1 at that time very high1 gradually drew his particular attention to chemistry1 and he retained this predilection during the rest of his life4 ,bucquet was at that time professor of chemistry in the ,medical ,school of ,paris1 and was greatly celebrated and followed on account of his eloquence1 and the elegance of his language4 ,fourcroy became in the first place his pupil1 and afterwards his particular friend4 ,one day1 when a sudden attack of disease prevented him from lecturing as usual1 he entreated ,fourcroy to supply his place4 ,our young chemist at first declined1 and alleged his ignorance of the method of addressing a public audience4 ,but1 overcome by the persuasions of ,bucquet1 he at last consented3 and in this1 his first essay1 he spoke two hours without disorder or hesitation1 and acquitted himself to the satisfaction of his whole audience4 ,bucquet soon after substituted him in his place1 and it was in his laboratory and in his class-room that he first made himself acquainted with chemistry4 ,he was enabled at the death of ,bucquet1 in consequence of an advantageous marriage that he had made1 to purchase the apparatus and cabinet of his master2 and although the faculty of medicine would not allow him to succeed to the chair of ,bucquet1 they could not prevent him from succeeding to his reputation4 ,there was a kind of college which had been established in the ,jardin du ,roi1 which at that time was under the superintendence of ,buffon1 and ,macquer was the professor of chemistry in this institution4 ,on the death of this chemist1 in #aghd1 both ,berthollet and ,fourcroy offered themselves as candidates for the vacant chair4 ,the voice of the public was so loud in favour of ,fourcroy1 that he was appointed to the situation in spite of the high character of his antagonist and the political influence which was exerted in his favour4 ,he filled this chair for twenty-five years1 with a reputation for eloquence continually on the increase4 ,such were the crowds1 both of men and women1 who flocked to hear him1 that it was twice necessary to enlarge the size of the lecture room4 ,after the revolution had made some progress1 he was named a member of the ,national ,convention in the autumn of the memorable year #agic4 ,it was during the reign of terror1 when the ,convention itself1 and with it all ,france1 was under the absolute dominion of one of the most sanguinary monsters that ever existed3 it was almost equally dangerous for the members of the ,convention to remain silent1 or to take an active part in the business of that assembly4 ,fourcroy never opened his mouth in the ,convention till after the death of ,robespierre2 at this period he had influence enough to save the lives of some men of merit3 among others1 of ,darcet1 who did not know the obligation under which he lay to him till long after2 at last his own life was threatened1 and his influence1 of course1 completely annihilated4 ,it was during this unfortunate and disgraceful period1 that many eminent men lost their lives2 among others1 ,lavoisier2 and ,fourcroy is accused of having contributed to the death of this illustrious chemist3 but ,cuvier entirely acquits him of this atrocious charge1 and assures us that it was urged against him merely out of envy at his subsequent elevation4 ,if in the rigorous researches which we have made1 says ,cuvier in his ,eloge of ,fourcroy1 we had found the smallest proof of an atrocity so horrible1 no human power could have induced us to sully our mouths with his ,eloge1 or to have pronounced it within the walls of this temple1 which ought to be no less sacred to honour than to genius4 ,fourcroy began to acquire influence only after the #ith ,thermidor1 when the nation was wearied with destruction1 and when efforts were making to restore those monuments of science1 and those public institutions for education1 which during the wantonness and folly of the revolution had been overturned and destroyed4 ,fourcroy was particularly active in this renovation1 and it was to him1 chiefly1 that the schools established in ,france for the education of youth are to be ascribed4 ,the ,convention had destroyed all the colleges1 universities1 and academies throughout ,france4 ,the effects of this absurd abolition soon became visible2 the army stood in need of surgeons and physicians1 and there were none educated to supply the vacant places3 three new schools were founded for educating medical men2 they were nobly endowed4 ,the term schools of medicine was proscribed as too aristocratical2 they were distinguished by the ridiculous appellation of schools of health4 ,the ,polytechnic ,school was next instituted1 as a kind of preparation for the exercise of the military profession1 where young men could be instructed in mathematics and natural philosophy1 to make them fit for entering the schools of the artillery1 of engineers1 and of the marine4 ,the ,central ,schools was another institution for which ,france was indebted to the efforts of ,fourcroy4 ,the idea was good1 though it was very imperfectly executed4 ,it was to establish a kind of university in every department1 for which the young men were to be prepared by a sufficient number of inferior schools scattered through the department4 ,but unfortunately these inferior schools were never properly established or endowed2 and even the central schools themselves were never supplied with proper masters4 ,indeed1 it was found impossible to furnish such a number of masters at once4 ,on that account1 an institution was established in ,paris1 called the ,normal ,school1 for the express purpose of educating a sufficient number of masters to supply the different central schools4 ,fourcroy1 either as a member of the ,convention or of the ,council of the ,ancients1 took an active part in all these institutions1 as far as regarded the plan and the establishment4 ,he was equally concerned in the establishment of the ,institute and of the ,muse d',histoire ,naturelle4 ,this last was endowed with the utmost liberality1 and ,fourcroy was one of the first professors2 as he was also in the ,school of ,medicine and the ,polytechnic ,school4 ,he was equally concerned in the restoration of the university1 which constituted one of the most useful parts of ,bonaparte's reign4 ,the violent exertions which he made in the numerous situations which he filled1 and the prodigious activity which he displayed1 gradually undermined his constitution4 ,he himself was sensible of his approaching death1 and announced it to his friends as an event which would speedily take place4 ,on the #afth of ,december1 #ahji1 after signing some despatches1 he suddenly cried out1 ,je suis mort 7,i am dead71 and dropped lifeless on the ground4 ,he was twice married3 first to ,mademoiselle ,bettinger1 by whom he had two children1 a son and a daughter1 who survived him4 ,he was married for the second time to ,madame ,belleville1 the widow of ,vailly1 by whom he had no family4 ,he left but little fortune behind him2 and two maiden sisters1 who lived with him1 depended afterwards for their support on his friend ,m4 ,vauquelin4 ,notwithstanding the vast quantity of papers which he published1 it will be admitted1 without dispute1 that the prodigious reputation which he enjoyed during his lifetime was more owing to his eloquence than to his eminence as a chemist--though even as a chemist he was far above mediocrity4 ,he must have possessed an uncommon facility of writing4 ,five successive editions of his ,system of ,chemistry appeared1 each of them gradually increasing in size and value3 the first being in two volumes and the last in ten4 ,this last edition he wrote in sixteen months3 it contains much valuable information1 and doubtless contributed considerably to the general diffusion of chemical knowledge4 ,its style is perhaps too diffuse1 and the spirit of generalizing from particular1 and often ill-authenticated facts1 is carried to a vicious length4 ,perhaps the best of all his productions is his ,philosophy of ,chemistry4 ,it is remarkable for its conciseness1 its perspicuity1 and the neatness of its arrangement4 ,besides these works1 and the periodical publication entitled ,le ,mdecin clair1 of which he was the editor1 there are above one hundred and sixty papers on chemical subjects1 with his name attached to them1 which appeared in the ,memoirs of the ,academy and of the ,institute2 in the ,annales de ,chimie1 or the ,annales de ,muse d',histoire ,naturelle2 of which last work he was the original projector4 ,many of these papers contained analyses both animal1 vegetable1 and mineral1 of very considerable value4 ,in most of them1 the name of ,vauquelin is associated with his own as the author2 and the general opinion is1 that the experiments were all made by ,vauquelin2 but that the papers themselves were drawn up by ,fourcroy4 ,it would serve little purpose to go over this long list of papers2 because1 though they contributed essentially to the progress of chemistry1 yet they exhibit but few of those striking discoveries1 which at once alter the face of the science1 by throwing a flood of light on every thing around them4 ,i shall merely notice a few of what ,i consider as his best papers4 #a4 ,he ascertained that the most common biliary calculi are composed of a substance similar to spermaceti4 ,this substance1 in consequence of a subsequent discovery which he made during the removal of the dead bodies from the burial-ground of the ,innocents at ,paris2 namely1 that these bodies are converted into a fatty matter1 he called adipocire4 ,it has since been distinguished by the name of cholestine2 and has been shown to possess properties different from those of adipocire and spermaceti4 #b4 ,it is to him that we are indebted for the first knowledge of the fact1 that the salts of magnesia and ammonia have the property of uniting together1 and forming double salts4 #c4 ,his dissertation on the sulphate of mercury contains some good observations4 ,the same remark applies to his paper on the action of ammonia on the sulphate1 nitrate1 and muriate of mercury4 ,he first described the double salts which are formed4 #d4 ,the analysis of urine would have been valuable had not almost all the facts contained in it been anticipated by a paper of ,dr4 ,wollaston1 published in the ,philosophical ,transactions4 ,it is to him that we are indebted for almost all the additions to our knowledge of calculi since the publication of ,scheele's original paper on the subject4 #e4 ,i may mention the process of ,fourcroy and ,vauquelin for obtaining pure barytes1 by exposing nitrate of barytes to a red heat1 as a good one4 ,they discovered the existence of phosphate of magnesia in bones1 of phosphorus in the brain and in the milts of fishes1 and of a considerable quantity of saccharine matter in the bulb of the common onion2 which1 by undergoing a kind of spontaneous fermentation was converted into manna4 ,in these1 and many other similar discoveries1 which ,i think it unnecessary to notice1 we do not know what fell to the share of ,fourcroy and what to ,vauquelin2 but there is one merit at least to which ,fourcroy is certainly entitled1 and it is no small one3 he formed and brought forward ,vauquelin1 and proved to him1 ever after1 a most steady and indefatigable friend4 ,this is bestowing no small panegyric on his character2 for it would have been impossible to have retained such a friend through all the horrors of the ,french revolution1 if his own qualities had not been such as to merit so steady an attachment4 ,louis ,bernard ,guyton de ,morveau was born at ,dijon on the #dth of ,january1 #agcg4 ,his father1 ,anthony ,guyton1 was professor of civil law in the ,university of ,dijon1 and descended from an ancient and respectable family4 ,at the age of seven he showed an uncommon mechanical turn3 being with his father at a small village near ,dijon1 he there happened to meet a public officer returning from a sale1 whence he had brought back a clock that had remained unsold on account of its very bad condition4 ,morveau supplicated his father to buy it4 ,the purchase was made for six francs4 ,young ,morveau took it to pieces and cleaned it1 supplied some parts that were wanting1 and put it up again without any assistance4 ,in #agii this very clock was resold at a higher price1 together with the estate and house in which it had been originally placed2 having during the whole of that time continued to go in the most satisfactory manner4 ,when only eight years of age1 he took his mother's watch to pieces1 cleaned it1 and put it up again to the satisfaction of all parties4 ,after finishing his preliminary studies in his father's house1 he went to college1 and terminated his attendance on it at the age of sixteen4 ,about this time he was instructed in botany by ,m4 ,michault1 a friend of his father1 and a naturalist of some eminence4 ,he now commenced law student in the ,university of ,dijon2 and1 after three years of intense application1 he went to ,paris to acquire a knowledge of the practice of the law4 ,while in ,paris1 he not only attended to law1 but cultivated at the same time several branches of polite literature4 ,in #agef he paid a visit to ,voltaire1 at ,ferney4 ,this seems to have inspired him with a love of poetry1 particularly of the descriptive and satiric kind4 ,about a year afterwards1 when only twenty1 he published a poem called ,le ,rat ,iconoclaste1 ou le ,jesuite croque4 ,it was intended to throw ridicule on a well-known anecdote of the day1 and to assist in blowing the fire that already threatened destruction to the obnoxious order of ,jesuits4 ,the adventure alluded to was this3 ,some nuns1 who felt a strong predilection for a ,jesuit1 their spiritual director1 were engaged in their accustomed ,christmas occupation of modelling a representation of a religious mystery1 decorated with several small statues representing the holy personages connected with the subject1 and among them that of the ghostly father2 but1 to mark their favourite1 his statue was made of loaf sugar4 ,the following day was destined for the triumph of the ,jesuit3 but1 meanwhile1 a rat had devoured the valuable puppet4 ,the poem is written after the agreeable manner of the celebrated poem1 ,ververt4 ,at the age of twenty-four he had already pleaded several important causes at the bar1 when the office of advocate-general1 at the parliament of ,dijon1 was advertised for sale4 ,at that time all public situations1 however important1 were sold to the best bidder4 ,his father having ascertained that this place would be acceptable to his son1 purchased it for forty thousand francs4 ,the reputation of the young advocate1 and his engaging manners1 facilitated the bargain4 ,in #agfd he was admitted an honorary member of the ,academy of ,sciences1 ,arts1 and ,belles ,lettres1 of ,dijon4 ,two months after1 he presented to the assembled chamber of the parliament of ,burgundy1 a memoir on public instruction1 with a plan for a college1 on the principles detailed in his work4 ,the encomiums which every public journal of the time passed on this production1 and the flattering letters which he received1 were unequivocal proofs of its value4 ,in this memoir he endeavoured to prove that man is bad or good1 according to the education which he has received4 ,this doctrine was contrary to the creed of ,diderot1 who affirmed1 in his ,essay on the ,life of ,seneca1 that nature makes wicked persons1 and that the best institutions cannot render them good4 ,but this mischievous opinion was successfully refuted by ,morveau1 in a letter to an anonymous friend4 ,the exact sciences were so ill taught1 and lamely cultivated at ,dijon1 during the time of his university education1 that after his admission into the academy his notions on mechanics and natural philosophy were scanty and inaccurate4 ,dr4 ,chardenon was in the habit of reading memoirs on chemical subjects2 and on one occasion ,morveau thought it necessary to hazard some remarks which were ill received by the doctor1 who sneeringly told him that having obtained such success in literature1 he had better rest satisfied with the reputation so justly acquired1 and leave chemistry to those who knew more of the matter4 ,provoked at this violent remark1 he resolved upon taking an honourable revenge4 ,he therefore applied himself to the study of ,macquer's ,theoretical and ,practical ,chemistry1 and of the ,manual of ,chemistry which ,beaum had just published4 ,to the last chemist he also sent an extensive order for chemical preparations and utensils1 with a view of forming a small laboratory near his office4 ,he began by repeating many of ,beaum's experiments1 and then trying his inexperienced hand at original researches4 ,he soon found himself strong enough to attack the doctor4 ,the latter had just been reading a memoir on the analysis of different kinds of oil2 and ,morveau combated some of his opinions with so much skill and sagacity1 as astonished every one present4 ,after the meeting1 ,dr4 ,chardenon addressed him thus3 ,you are born to be an honour to chemistry4 ,so much knowledge could only have been gained by genius united with perseverance4 ,follow your new pursuit1 and confer with me in your difficulties4 ,but this new pursuit did not prevent ,morveau from continuing to cultivate literature with success4 ,he wrote an ,eloge of ,charles ,v4 of ,france1 surnamed the ,wise1 which had been given out as the subject of a prize1 by the academy4 ,a few months afterwards1 at the opening of the session of parliament1 he delivered a discourse on the actual state of jurisprudence2 on which subject1 three years after1 he composed a more extensive and complete work4 ,no code of laws demanded reform more urgently than those of ,france1 and none saw more clearly the necessity of such a reformation4 ,about this time a young gentleman of ,dijon had taken into his house an adept1 who offered1 upon being furnished with the requisite materials1 to produce gold in abundance2 but1 after six months of expensive and tedious operations 7during which period the roguish pretender had secretly distilled many oils1 c41 which he disposed of for his own profit71 the gentleman beginning to doubt the sincerity of his instructer1 dismissed him from his service and sold the whole of his apparatus and materials to ,morveau for a trifling sum4 ,soon after he repaired to ,paris1 to visit the scientific establishments of that metropolis1 and to purchase preparations and apparatus which he still wanted to enable him to pursue with effect his favourite study4 ,for this purpose he applied to ,beaum1 then one of the most conspicuous of the ,french chemists4 ,pleased with his ardour1 ,beaum inquired what courses of chemistry he had attended4 ,none1 was the answer4--,how then could you have learned to make experiments1 and above all1 how could you have acquired the requisite dexterity8--,practice1 replied the young chemist1 has been my master2 melted crucibles and broken retorts my tutors4--,in that case1 said ,beaum1 you have not learned1 you have invented4 ,about this time ,dr4 ,chardenon read a paper before the ,dijon ,academy on the causes of the augmentation of weight which metals experience when calcined4 ,he combated the different explanations which had been already advanced1 and then proceeded to show that it might be accounted for in a satisfactory manner by the abstraction of phlogiston4 ,this drew the attention of ,morveau to the subject3 he made a set of experiments a few months afterwards1 and read a paper on the phenomena of the air during combustion4 ,it was soon after that he made a set of experiments on the time taken by different substances to absorb or emit a given quantity of heat4 ,these experiments1 if properly followed out1 would have led to the discovery of specific heat2 but in his hands they seem to have been unproductive4 ,in the year #aggb he published a collection of scientific essays under the title of ,digressions ,acadmiques4 ,the memoirs on phlogiston1 crystallization1 and solution1 found in this book deserve particular attention1 and show the superiority of ,morveau over most of the chemists of the time4 ,about this time an event happened which deserves to be stated4 ,it had been customary in one of the churches of ,dijon to bury considerable numbers of dead bodies4 ,from these an infectious exhalation had proceeded1 which had brought on a malignant disorder1 and threatened the inhabitants of ,dijon with something like the plague4 ,all attempts to put an end to this infectious matter had failed1 when ,morveau tried the following method with complete success3 ,a mixture of common salt and sulphuric acid in a wide-mouthed vessel was put upon chafing-dishes in various parts of the church4 ,the doors and windows were closed and left in this state for twenty-four hours4 ,they were then thrown open1 and the chafing-dishes with the mixtures removed4 ,every remains of the bad smell was gone1 and the church was rendered quite clean and free from infection4 ,the same process was tried soon after in the prisons of ,dijon1 and with the same success4 ,afterwards chlorine gas was substituted for muriatic acid gas1 and found still more efficacious4 ,the present practice is to employ chloride of lime1 or chloride of soda1 for the purpose of fumigating infected apartments1 and the process is found still more effectual than the muriatic acid gas1 as originally employed by ,morveau4 ,the nitric acid fumes1 proposed by ,dr4 ,carmichael ,smith1 are also efficacious1 but the application of them is much more troublesome and more expensive than of chloride of lime1 which costs very little4 ,in the year #aggd it occurred to ,morveau1 that a course of lectures on chemistry1 delivered in his native city1 might be useful4 ,application being made to the proper authorities1 the permission was obtained1 and the necessary funds for supplying a laboratory granted4 ,these lectures were begun on the #bith of ,april1 #aggf1 and seem to have been of the very best kind4 ,every thing was stated with great clearness1 and illustrated by a sufficient number of experiments4 ,his fame now began to extend1 and his name to be known to men of science in every part of ,europe2 and1 in consequence1 he began to experience the fate of almost all eminent men--to be exposed to the attacks of the malignant and the envious4 ,the experiments which he exhibited to determine the properties of carbonic acid gas drew upon him the animadversions of several medical men1 who affirmed that this gas was nothing else than a peculiar state of sulphuric acid4 ,morveau answered these animadversions in two pamphlets1 and completely refuted them4 ,about this time he got metallic conductors erected on the house of the ,academy at ,dijon4 ,on this account he was attacked violently for his presumption in disarming the hand of the ,supreme ,being4 ,a multitude of fanatics assembled to pull down the conductors1 and they would probably have done much mischief1 had it not been for the address of ,m4 ,maret1 the secretary1 who assured them that the astonishing virtue of the apparatus resided in the gilded point1 which had purposely been sent from ,rome by the holy father6 ,will it excite any surprise1 that within less than twenty years after this the mass of the ,french people not only renounced the ,christian religion1 and the spiritual dominion of the pope1 but declared themselves atheists6 ,in #aggg ,morveau published the first volume of a course of chemistry1 which was afterwards followed by three other volumes1 and is known by the name of ,elmens de ,chimie de l',acadmie de ,dijon4 ,this book was received with universal approbation1 and must have contributed very much to increase the value of his lectures4 ,indeed1 a text-book is essential towards a successful course of lectures3 it puts it in the power of the students to understand the lecture if they be at the requisite pains2 and gives them a means of clearing up their difficulties1 when any such occur4 ,i do not hesitate to say1 that a course of chemical lectures is twice as valuable when the students are furnished with a good text-book1 as when they are left to interpret the lectures by their own unassisted exertions4 ,soon after he undertook the establishment of a manufacture of saltpetre upon a large scale4 ,for this he received the thanks of ,m4 ,necker1 who was at that time minister of finance1 in the name of the ,king of ,france4 ,this manufactory he afterwards gave up to ,m4 ,courtois1 whose son still carries it on1 and is advantageously known to the public as the discoverer of iodine4 ,his next object was to make a collection of minerals1 and to make himself acquainted with the science of mineralogy4 ,all this was soon accomplished4 ,in #aggg he was charged to examine the slate-quarries and the coal-mines of ,burgundy1 for which purpose he performed a mineralogical tour through the province4 ,in #aggi he discovered a lead-mine in that country1 and a few years afterwards1 when the attention of chemists had been drawn to sulphate of barytes and its base1 by the ,swedish chemists1 he sought for it in ,burgundy1 and found it in considerable quantity at ,thte4 ,this enabled him to draw up a description of the mineral1 and to determine the characters of the base1 to which he gave the name of barote2 afterwards altered to that of barytes4 ,this paper was published in the third volume of the ,memoirs of the ,dijon ,academy4 ,in this paper he describes his method of decomposing sulphate of barytes1 by heating it with charcoal--a method now very frequently followed4 ,in the year #aggi he was applied to by ,pankouke1 who meditated the great project of the ,encyclopdie ,mthodique1 to undertake the chemical articles in that immense dictionary1 and the demand was supported by a letter from ,buffon1 whose request he did not think that he could with propriety refuse4 ,the engagement was signed between them in ,september1 #aghj4 ,the first half-volume of the chemical part of this ,encyclopdie did not appear till #aghf1 and ,morveau must have been employed during the interval in the necessary study and researches4 ,indeed1 it is obvious1 from many of the articles1 that he had spent a good deal of time in experiments of research4 ,the state of the chemical nomenclature was at that period peculiarly barbarous and defective4 ,he found himself stopped at every corner for want of words to express his meaning4 ,this state of things he resolved to correct1 and accordingly in #aghb published his first essay on a new chemical nomenclature4 ,no sooner did this essay appear than it was attacked by almost all the chemists of ,paris1 and by none more zealously than by the chemical members of the academy4 ,undismayed by the violence of his antagonists1 and satisfied with the rectitude of his views1 and the necessity of the reform1 he went directly to ,paris to answer the objections in person4 ,he not only succeeded in convincing his antagonists of the necessity of reform2 but a few years afterwards prevailed upon the most eminent chemical members of the academy1 ,lavoisier1 ,berthollet1 and ,fourcroy1 to unite with him in rendering the reform still more complete and successful4 ,he drew up a memoir1 exhibiting a plan of a methodical chemical nomenclature1 which was read at a meeting of the ,academy of ,sciences1 in #aghg4 ,morveau1 then1 was in reality the author of the new chemical nomenclature1 if we except a few terms1 which had been already employed by ,lavoisier4 ,had he done nothing more for the science than this1 it would deservedly have immortalized his name4 ,for every one must be sensible how much the new nomenclature contributed to the subsequent rapid extension of chemical science4 ,it was during the repeated conferences held with ,lavoisier and the other two associates that ,morveau became satisfied of the truth of ,lavoisier's new doctrine1 and that he was induced to abandon the phlogistic theory4 ,we do not know the methods employed to convert him4 ,doubtless both reasoning and experiment were made use of for the purpose4 ,it was during this period that ,morveau published a ,french translation of the ,opuscula of ,bergman4 ,a society of friends1 under his encouragement1 translated the chemical memoirs of ,scheele and many other foreign books of importance1 which by their means were made known to the men of science in ,france4 ,in #aghc1 in consequence of a favourable report by ,macquer1 ,morveau obtained permission to establish a manufactory of carbonate of soda1 the first of the kind ever attempted in ,france4 ,it was during the same year that he published his collection of pleadings at the bar1 among which we find his ,discours sur la ,bonhomie1 delivered at the opening of the sessions at ,dijon1 with which he took leave of his fellow-magistrates1 surrendering the insignia of office1 as he had determined to quit the profession of the law4 ,on the #beth of ,april1 #aghd1 ,morveau1 accompanied by ,president ,virly1 ascended from ,dijon in a balloon1 which he had himself constructed1 and repeated the ascent on the #abth of ,june following1 with a view of ascertaining the possibility of directing these aerostatic machines1 by an apparatus of his own contrivance4 ,the capacity of the balloon was #aj1dih1jgd ,french cubic feet4 ,the effect produced by this bold undertaking by two of the most distinguished characters in the town was beyond description4 ,such ascents were then quite new1 and looked upon with a kind of reverential awe4 ,though ,morveau failed in his attempts to direct these aerial vessels1 yet his method was ingenious and exceedingly plausible4 ,in #aghf ,dr4 ,maret1 secretary to the ,dijon ,academy1 having fallen a victim to an epidemic disease1 which he had in vain attempted to arrest1 ,morveau was appointed perpetual secretary and chancellor of the institution4 ,soon after this the first half-volume of the chemical part of the ,encyclopdie ,mthodique made its appearance1 and drew the attention of every person interested in the science of chemistry4 ,no chemical treatise had hitherto appeared worthy of being compared to it4 ,the article ,acid1 which occupies a considerable part1 is truely admirable2 and whether we consider the historical details1 the completeness of the accounts1 the accuracy of the description of the experiments1 or the elegance of the style1 constitutes a complete model of what such a work should be4 ,i may1 perhaps1 be partial1 as it was from this book that ,i imbibed my own first notions in chemistry1 but ,i never perused any book with more delight1 and when ,i compared it with the best chemical books of the time1 whether ,german1 ,french1 or ,english1 its superiority became still more striking4 ,in the article ,acier1 ,morveau had come to the very same conclusions1 with respect to the nature of steel1 as had been come to by ,berthollet1 ,monge1 and ,vandermonde1 in their celebrated paper on the subject1 just published in the ,memoirs of the ,academy4 ,his own article had been printed1 though not published1 before the appearance of the ,memoir of the ,academicians4 ,this induced him to send an explanation to ,berthollet1 which was speedily published in the ,journal de ,physique4 ,in ,september1 #aghg1 he received a visit from ,lavoisier1 ,berthollet1 ,fourcroy1 ,monge1 and ,vandermonde4 ,dr4 ,beddoes1 who was travelling through ,france at the time1 and happened to be in ,dijon1 joined the party4 ,the object of the meeting was to discuss several experiments explanatory of the new doctrine4 ,in #aghi an attempt was made to get him admitted as a member of the ,academy of ,sciences2 but it failed1 notwithstanding the strenuous exertions of ,berthollet and his other chemical friends4 ,the ,french revolution had now broken out1 occasioned by the wants of the state on the one hand1 and the resolute determination of the clergy and the nobility on the other1 not to submit to bear any share in the public burdens4 ,during the early part of this revolution ,morveau took no part whatever in politics4 ,in #agij1 when ,france was divided into departments1 he was named one of a commission by the ,national ,assembly for the formation of the department of the ,cte d',or4 ,on the #beth of ,august1 #agia1 he received from the ,academy of ,sciences the annual prize of #bjjj francs1 for the most useful work published in the course of the year4 ,this was decreed him for his ,dictionary of ,chemistry1 in the ,encyclopdie ,mthodique4 ,aware of the pressing necessities of the state1 ,morveau seized the opportunity of showing his desire of contributing towards its relief1 by making a patriotic offering of the whole amount of his prize4 ,when the election of the second ,constitutional ,assembly took place1 he was nominated a member by the electoral college of his department4 ,a few months before1 his name had appeared among the list of members proposed by the assembly1 for the election of a governor to the heir-apparent4 ,all this1 together with the dignity of solicitor-general of the department to which he had recently been raised1 not permitting him to continue his chemical lectures at ,dijon1 of which he had already delivered fifteen gratuitous courses1 he resigned his chair in favour of ,dr4 ,chaussier1 afterwards a distinguished professor at the ,faculty of ,medicine of ,paris2 and1 bidding adieu to his native city1 proceeded to ,paris4 ,on the ever memorable #afth of ,january1 #agic1 he voted with the majority of deputies4 ,he was therefore1 in consequence of this vote1 a regicide4 ,during the same year he resigned1 in favour of the republic1 his pension of two thousand francs1 together with the arrears of that pension4 ,in #agid he received from government different commissions to act with the ,french armies in the ,low ,countries4 ,charged with the direction of a great aerostatic machine for warlike purposes1 he superintended that one in which the chief of the staff of ,general ,jourdan and himself ascended during the battle of ,fleurus1 and which so materially contributed to the success of the ,french arms on that day4 ,on his return from his various missions1 he received from the three committees of the executive government an invitation to co-operate with several learned men in the instruction of the central schools1 and was named professor of chemistry at the ,ecole ,centrale des ,travaux publiques1 since better known under the name of the ,polytechnic ,school4 ,in #agie he was re-elected member of the ,council of ,five ,hundred1 by the electoral assemblies of ,sarthe and ,ile et ,vilaine4 ,the executive government1 at this time1 decreed the formation of the ,national ,institute1 and named him one of the forty-eight members chosen by government to form the nucleus of that scientific body4 ,in #agig he resigned all his public situations1 and once more attached himself exclusively to science and to the establishments for public instruction4 ,in #agih he was appointed a provisional director of the ,polytechnic ,school1 to supply the place of ,monge1 who was then in ,egypt4 ,he continued to exercise its duties during eighteen months1 to the complete satisfaction of every person connected with that establishment4 ,with much delicacy and disinterestedness1 he declined accepting the salary of #bjjj francs attached to this situation1 which he thought belonged to the proper director1 though absent from his duties4 ,in #agii ,bonaparte appointed him one of the administrators-general of the ,mint2 and the year following he was made director of the ,polytechnic ,school4 ,in #ahjc he received the cross of the ,legion of ,honour1 then recently instituted2 and in #ahje was made an officer of the same order4 ,these honours were intended as a reward for the advantage which had accrued from the mineral acid fumigations which he had first suggested4 ,in #ahaa he was created a baron of the ,french empire4 ,after having taught in the ,ecole ,polytechnique for sixteen years1 he obtained leave1 on applying to the proper authorities1 to withdraw into the retired station of private life1 crowned with years and reputation1 and followed with the blessings of the numerous pupils whom he had brought up in the career of science4 ,in this situation he continued about three years1 during which he witnessed the downfall of ,bonaparte1 and the restoration of the ,bourbons4 ,on the #bast of ,december1 #ahae1 he was seized with a total exhaustion of strength2 and1 after an illness of three days only1 expired in the arms of his disconsolate wife1 and a few trusty friends1 having nearly completed the eightieth year of his age4 ,on the #c;d of ,january1 #ahaf1 his remains were followed to the grave by the members of the ,institute1 and many other distinguished men3 and ,berthollet1 one of his colleagues1 pronounced a short but impressive funeral oration on his departed friend4 ,morveau had married ,madame ,picardet1 the widow of a ,dijon academician1 who had distinguished himself by numerous scientific translations from the ,swedish1 ,german1 and ,english languages4 ,the marriage took place after they were both advanced in life1 and he left no children behind him4 ,his publications on chemical subjects were exceedingly numerous1 and he contributed as much as any of his contemporaries to the extension of the science2 but as he was not the author of any striking chemical discoveries1 it would be tedious to give a catalogue of his numerous productions which were scattered through the ,dijon ,memoirs1 the ,journal de ,physique1 and the ,annales de ,chimie4 ,,chapter ,,iv4 ,,progress ,,of ,,analytical ,,chemistry4 ,analysis1 or the art of determining the constituents of which every compound is composed1 constitutes the essence of chemistry3 it was therefore attempted as soon as the science put on any thing like a systematic form4 ,at first1 with very little success2 but as knowledge became more and more general1 chemists became more expert1 and something like regular analysis began to appear4 ,thus1 ,brandt showed that white vitriol is a compound of sulphuric acid and oxide of zinc2 and ,margraaf1 that selenite or gypsum is a compound of sulphuric acid and lime4 ,dr4 ,black made analyses of several of the salts of magnesia1 so far at least as to determine the nature of the constituents4 ,for hardly any attempt was made in that early period of the art to determine the weight of the respective constituents4 ,the first person who attempted to lay down rules for the regular analysis of minerals1 and to reduce these rules to practice1 was ,bergman4 ,this he did in his papers ,de ,docimasia ,minerarum ,humida1 ,de ,terra ,gemmarum1 and ,de ,terra ,tourmalini1 published between the years #aggg and #aghj4 ,to analyze a mineral1 or to separate it into its constituent parts1 it is necessary in the first place1 to be able to dissolve it in an acid4 ,bergman showed that most minerals become soluble in muriatic acid if they be reduced to a very fine powder1 and then heated to redness1 or fused with an alkaline carbonate4 ,after obtaining a solution in this way he pointed out methods by which the different constituents may be separated one after another1 and their relative quantities determined4 ,the fusion with an alkaline carbonate required a strong red heat4 ,an earthenware crucible could not be employed1 because at a fusing temperature it would be corroded by the alkaline carbonate1 and thus the mineral under analysis would be contaminated by the addition of a quantity of foreign matter4 ,bergman employed an iron crucible4 ,this effectually prevented the addition of any earthy matter4 ,but at a red heat the iron crucible itself is apt to be corroded by the action of the alkali1 and thus the mineral under analysis becomes contaminated with a quantity of that metal4 ,this iron might easily be separated again by known methods1 and would therefore be of comparatively small consequence1 provided we were sure that the mineral under examination contained no iron2 but when that happens 7and it is a very frequent occurrence71 an error is occasioned which we cannot obviate4 ,klaproth made a vast improvement in the art of analysis1 by substituting crucibles of fine silver for the iron crucibles of ,bergman4 ,the only difficulty attending their use was1 that they were apt to melt unless great caution was used in heating them4 ,dr4 ,wollaston introduced crucibles of platinum about the beginning of the present century4 ,it is from that period that we may date the commencement of accurate analyzing4 ,bergman's processes1 as might have been expected1 were rude and imperfect4 ,it was ,klaproth who first systematized chemical analysis and brought the art to such a state1 that the processes followed could be imitated by others with nearly the same results1 thus offering a guarantee for the accuracy of the process4 ,martin ,henry ,klaproth1 to whom chemistry lies under so many and such deep obligations1 was born at ,wernigerode1 on the #ast of ,december1 #agdc4 ,his father had the misfortune to lose his whole goods by a great fire1 on the #cjth of ,june1 #agea1 so that he was able to do little or nothing for the education of his children4 ,martin was the second of three brothers1 the eldest of whom became a clergyman1 and the youngest private secretary at war1 and keeper of the archives of the cabinet of ,berlin4 ,martin survived both his brothers4 ,he procured such meagre instruction in the ,latin language as the school of ,wernigerode afforded1 and he was obliged to procure his small school-fees by singing as one of the church choir4 ,it was at first his intention to study theology2 but the unmerited hard treatment which he met with at school so disinclined him to study1 that he determined1 in his sixteenth year1 to learn the trade of an apothecary4 ,five years which he was forced to spend as an apprentice1 and two as an assistant in the public laboratory in ,quedlinburg1 furnished him with but little scientific information1 and gave him little else than a certain mechanical adroitness in the most common pharmaceutical preparations4 ,he always regarded as the epoch of his scientific instruction1 the two years which he spent in the public laboratory at ,hanover1 from ,easter #agff1 till the same time in #agfh4 ,it was there that he first met with some chemical books of merit1 especially those of ,spielman1 and ,cartheuser1 in which a higher scientific spirit already breathed4 ,he was now anxious to go to ,berlin1 of which he had formed a high idea from the works of ,pott1 ,henkel1 ,rose1 and ,margraaf4 ,an opportunity presenting itself about ,easter1 #agfh1 he was placed as assistant in the laboratory of ,wendland1 at the sign of the ,golden ,angel1 in the ,street of the ,moors4 ,here he employed all the time which a conscientious discharge of the duties of his station left him1 in completing his own scientific education4 ,and as he considered a profounder acquaintance with the ancient languages1 than he had been able to pick up at the school of ,wernigerode1 indispensable for a complete scientific education1 he applied himself with great zeal to the study of the ,greek and ,latin languages1 and was assisted in his studies by ,mr4 ,poppelbourn1 at that time a preacher4 ,about ,michaelmas1 #aggj1 he went to ,dantzig1 as assistant in the public laboratory3 but in ,march of the following year he returned to ,berlin1 as assistant in the office of the elder ,valentine ,rose1 who was one of the most distinguished chemists of his day4 ,but this connexion did not continue long2 for ,rose died in #agga4 ,on his deathbed he requested ,klaproth to undertake the superintendence of his office4 ,klaproth not only superintended this office for nine years with the most exemplary fidelity and conscientiousness1 but undertook the education of the two sons of ,rose1 as if he had been their father4 ,the younger died before reaching the age of manhood3 the elder became his intimate friend1 and the associate of all his scientific researches4 ,for several years before the death of ,rose 7which happened in #ahjh7 they wrought together1 and ,klaproth was seldom satisfied with the results of his experiments till they had been repeated by ,rose4 ,in the year #aghj ,klaproth went through his trials for the office of apothecary with distinguished applause4 ,his thesis1 ,on ,phosphorus and distilled ,waters1 was printed in the ,berlin ,miscellanies for #aghb4 ,soon after this1 ,klaproth bought what had formerly been the ,flemming laboratory in ,spandau-street3 and he married ,sophia ,christiana ,lekman1 with whom he lived till #ahjc 7when she died7 in a happy state4 ,they had three daughters and a son1 who survived their parents4 ,he continued in possession of this laboratory1 in which he had arranged a small work-room of his own1 till the year #ahjj1 when he purchased the room of the ,academical ,chemists1 in which he was enabled1 at the expense of the academy1 to furnish a better and more spacious apartment for his labours1 for his mineralogical and chemical collection1 and for his lectures4 ,as soon as he had brought the first arrangements of his office to perfection--an office which1 under his inspection and management1 became the model of a laboratory1 conducted upon the most excellent principles1 and governed with the most conscientious integrity1 he published in the various periodical works of ,germany1 such as ,crell's ,chemical ,annals1 the ,writings of the ,society for the promotion of ,natural ,knowledge1 ,selle's ,contributions to the ,science of ,nature and of ,medicine1 ,khler's ,journal1 c42 a multitude of papers which soon drew the attention of chemists2 for example1 his ,essay on ,copal--on the ,elastic ,stone--on ,proust's ,sel perle--on the ,green ,lead ,spar of ,tschoppau--on the best ,method of preparing ,ammonia--on the ,carbonate of ,barytes--on the ,wolfram of ,cornwall--on ,wood ,tin--on the ,violet ,schorl--on the celebrated ,aerial ,gold--on ,apatite1 c4 ,all these papers1 which secured him a high reputation as a chemist1 appeared before #aghh1 when he was chosen an ordinary member of the physical class of the ,royal ,berlin ,academy of ,sciences4 ,the ,royal ,academy of ,arts had elected him a member a year earlier4 ,from this time1 every volume of the ,memoirs of the ,academy1 and many other periodical works besides1 contained numerous papers by this accomplished chemist2 and there is not one of them which does not furnish us with a more exact knowledge of some one of the productions of nature or art4 ,he has either corrected false representations1 or extended views that were before partially known1 or has revealed the composition and mixture of the parts of bodies1 and has made us acquainted with a variety of new elementary substances4 ,amidst all these labours1 it is difficult to say whether we should most admire the fortunate genius1 which1 in all cases1 readily and easily divined the point where any thing of importance lay concealed2 or the acuteness which enabled him to find the best means of accomplishing his object2 or the unceasing labour and incomparable exactness with which he developed it2 or the pure scientific feeling under which he acted1 and which was removed at the utmost possible distance from every selfish1 every avaricious1 and every contentious purpose4 ,in the year #agie he began to collect his chemical works which lay scattered among so many periodical publications1 and gave them to the world under the title of ,beitrage zur ,chemischen ,kenntniss der ,mineralkrper 7,contributions to the ,chemical ,knowledge of ,mineral ,bodies74 ,of this work1 which consists of six volumes1 the last was published in #ahae1 about a year before the author's death4 ,it contains no fewer than two hundred and seven treatises1 the most valuable part of all that ,klaproth had done for chemistry and mineralogy4 ,it is a pity that the sale of this work did not permit the publication of a seventh volume1 which would have included the rest of his papers1 which he had not collected1 and given us a good index to the whole work1 which would have been of great importance to the practical chemist4 ,there is1 indeed1 an index to the first five volumes2 but it is meagre and defective1 containing little else than the names of the substances on which his experiments were made4 ,besides his own works1 the interest which he took in the labours of others deserves to be noticed4 ,he superintended a new edition of ,gren's ,manual of ,chemistry1 remarkable not so much for what he added as for what he took away and corrected4 ,the part which he took in ,wolff's ,chemical ,dictionary was of great importance4 ,the composition of every particular treatise was by ,professor ,wolff2 but ,klaproth read over every important article before it was printed1 and assisted the editor on all occasions with the treasures of his experience and knowledge4 ,nor was he less useful to ,fischer in his translation of ,berthollet on ,affinity and on ,chemical ,statics4 ,these meritorious services1 and the lustre which his character and discoveries conferred on his country were duly appreciated by his sovereign4 ,in #aghb he had been made assessor in the ,supreme ,college of ,medicine and of ,health1 which then existed4 ,at a more recent period he enjoyed the same rank in the ,supreme ,council of ,medicine and of ,health2 and when this college was subverted1 in #ahaj1 he became a member of the medical deputation attached to the ministry of the interior4 ,he was also a member of the perpetual court commission for medicines4 ,his lectures1 too1 procured for him several municipal situations4 ,as soon as the public became acquainted with his great chemical acquirements he was permitted to give yearly two private courses of lectures on chemistry2 one for the officers of the royal artillery corps1 the other for officers not connected with the army1 who wished to accomplish themselves for some practical employment4 ,both of these lectures assumed afterwards a municipal character4 ,the former led to his appointment as professor of the ,artillery ,academy instituted at ,tempelhoff2 and1 after its dissolution1 to his situation as professor in the ,royal ,war ,school4 ,the other lecture procured for him the professorship of chemistry in the ,royal ,mining ,institute4 ,on the establishment of the university1 ,klaproth's lectures became those of the university1 and he himself was appointed ordinary professor of chemistry1 and member of the academical senate4 ,from #agig to #ahaj he was an active member of a small scientific society1 which met yearly during a few weeks for the purpose of discussing the more recondite mysteries of the science4 ,in the year #ahaa1 the ,king of ,prussia added to all his other honours the order of the ,red ,eagle of the third class4 ,klaproth spent the whole of a long life in the most active and conscientious discharge of all the duties of his station1 and in an uninterrupted course of experimental investigations4 ,he died at ,berlin on the #ast of ,january1 #ahag1 in the #gjth year of his age4 ,among the remarkable traits in his character was his incorruptible regard for every thing that he believed to be true1 honourable1 and good2 his pure love of science1 with no reference whatever to any selfish1 ambitious1 and avaricious feeling2 his rare modesty1 undebased by the slightest vainglory or boasting4 ,he was benevolently disposed towards all men1 and never did a slighting or contemptuous word respecting any person fall from him4 ,when forced to blame1 he did it briefly1 and without bitterness1 for his blame always applied to actions1 not to persons4 ,his friendship was never the result of selfish calculation1 but was founded on his opinion of the personal worth of the individual4 ,amidst all the unpleasant accidents of his life1 which were far from few1 he evinced the greatest firmness of mind4 ,in his common behaviour he was pleasant and composed1 and was indeed rather inclined to a joke4 ,to all this may be added a true religious feeling1 so uncommon among men of science of his day4 ,his religion consisted not in words and forms1 not in positive doctrines1 nor in ecclesiastical observances1 which1 however1 he believed to be necessary and honourable2 but in a zealous and conscientious discharge of all his duties1 not only of those which are imposed by the laws of men1 but of those holy duties of love and charity1 which no human law1 but only that of ,god can command1 and without which the most enlightened of men is but as sounding brass1 or a tinkling cymbal4 ,he early showed this religious feeling by the honourable care which he bestowed on the education of the children of ,valentine ,rose4 ,nor did he show less care at an after-period towards his assistants and apprentices1 to whom he refused no instruction1 and in whose success he took the most active concern4 ,he took a pleasure in every thing that was good and excellent1 and felt a lively interest in every undertaking which he believed to be of general utility4 ,he was equally removed from the superstition and infidelity of his age1 and carried the principles of religion1 not on his lips1 but in the inmost feelings of his heart1 from whence they emanated in actions which pervaded and ennobled his whole being and conduct4 ,when we take a view of the benefits which ,klaproth conferred upon chemistry1 we must not look so much at the new elementary substances which he discovered1 though they must not be forgotten1 as at the new analytical methods which he introduced1 the precision1 and neatness1 and order1 and regularity with which his analyses were conducted1 and the scrupulous fidelity with which every thing was faithfully stated as he found it4 #a4 ,when a mineral is subjected to analysis1 whatever care we take to collect all the constituents1 and to weigh them without losing any portion whatever1 it is generally found that the sum of the constituents obtained fall a little short of the weight of the mineral employed in the analysis4 ,thus1 if we take #ajj grains of any mineral1 and analyze it1 the weights of all the constituents obtained added together will rarely make up #ajj grains1 but generally somewhat less2 perhaps only #ii1 or even #ih grains4 ,but some cases occur1 when the analysis of #ajj grains of a mineral gives us constituents that weigh1 when added together1 more than #ajj grains2 perhaps #aje1 or1 in some rare cases1 as much as #aaj4 ,it was the custom with ,bergman1 and other analysts of his time1 to consider this deficiency or surplus as owing to errors in the analysis1 and therefore to slur it over in the statement of the analysis1 by bringing the weight of the constituents1 by calculation1 to amount exactly to #ajj grains4 ,klaproth introduced the method of stating the results exactly as he got them4 ,he gives the weight of mineral employed in all his analyses1 and the weight of each constituent extracted4 ,these weights1 added together1 generally show a loss1 varying from two per cent4 to a half per cent4 ,this improvement may appear at first sight trifling2 yet ,i am persuaded that to it we are indebted for most of the subsequent improvements introduced into analytical chemistry4 ,if the loss sustained was too great1 it was obvious either that the analysis had been badly performed1 or that the mineral contains some constituent which had been overlooked1 and not obtained4 ,this laid him under the necessity of repeating the analysis2 and if the loss continued1 he naturally looked out for some constituent which his analysis had not enabled him to obtain4 ,it was in this way that he discovered the presence of potash in minerals2 and ,dr4 ,kennedy afterwards1 by following out his processes1 discovered soda as a constituent4 ,it was in this way that water1 phosphoric acid1 arsenic acid1 fluoric acid1 boracic acid1 c41 were also found to exist as constituents in various mineral bodies1 which1 but for the accurate mode of notation introduced by ,klaproth1 would have been overlooked and neglected4 #b4 ,when ,klaproth first began to analyze mineral bodies1 he found it extremely difficult to bring them into a state capable of being dissolved in acids1 without which an accurate analysis was impossible4 ,accordingly corundum1 adamantine spar1 and the zircon1 or hyacinth1 baffled his attempts for a considerable time1 and induced him to consider the earth of corundum as of a peculiar nature4 ,he obviated this difficulty by reducing the mineral to an extremely fine powder1 and1 after digesting it in caustic potash ley till all the water was dissipated1 raising the temperature1 and bringing the whole into a state of fusion4 ,this fusion must be performed in a silver crucible4 ,corundum1 and every other mineral which had remained insoluble after fusion with an alkaline carbonate1 was found to yield to this new process4 ,this was an improvement of considerable importance4 ,all those stony minerals which contain a notable proportion of silica1 in general become soluble after having been kept for some time in a state of ignition with twice their weight of carbonate of soda4 ,at that temperature the silica of the mineral unites with the soda1 and the carbonic acid is expelled4 ,but when the quantity of silica is small1 or when it is totally absent1 heating with carbonate of soda does not answer so well4 ,with such minerals1 caustic potash or soda may be substituted with advantage2 and there are some of them that cannot be analyzed without having recourse to that agent4 ,i have succeeded in analyzing corundum and chrysoberyl1 neither of which1 when pure1 contain any silica1 by simply heating them in carbonate of soda2 but the process does not succeed unless the minerals be reduced to an exceedingly minute powder4 #c4 ,when ,klaproth discovered potash in the idocrase1 and in some other minerals1 it became obvious that the old mode of rendering minerals soluble in acids by heating them with caustic potash1 or an alkaline carbonate1 could answer only for determining the quantity of silica1 and of earths or oxides1 which the mineral contained2 but that it could not be used when the object was to determine its potash4 ,this led him to substitute carbonate of barytes instead of potash or soda1 or their carbonates4 ,after having ascertained the quantity of silica1 and of earths1 and metallic oxides1 which the mineral contained1 his last process to determine the potash in it was conducted in this way3 ,a portion of the mineral reduced to a fine powder was mixed with four or five times its weight of carbonate of barytes1 and kept for some time 7in a platinum crucible7 in a red heat4 ,by this process1 the whole becomes soluble in muriatic acid4 ,the muriatic acid solution is freed from silica1 and afterwards from barytes1 and all the earths and oxides which it contains1 by means of carbonate of ammonia4 ,the liquid1 thus freed from every thing but the alkali1 which is held in solution by the muriatic acid1 and the ammonia1 used as a precipitant1 is evaporated to dryness1 and the dry mass1 cautiously heated in a platinum crucible till the ammoniacal salts are driven off4 ,nothing now remains but the potash1 or soda1 in combination with muriatic acid4 ,the addition of muriate of platinum enables us to determine whether the alkali be potash or soda3 if it be potash1 it occasions a yellow precipitate2 but nothing falls if the alkali be soda4 ,this method of analyzing minerals containing potash or soda is commonly ascribed to ,rose4 ,fescher1 in his ,eloge of ,klaproth1 informs us that ,klaproth said to him1 more than once1 that he was not quite sure whether he himself1 or ,rose1 had the greatest share in bringing this method to a state of perfection4 ,from this1 ,i think it not unlikely that the original suggestion might have been owing to ,rose1 but that it was ,klaproth who first put it to the test of experiment4 ,the objection to this mode of analyzing is the high price of the carbonate of barytes4 ,this is partly obviated by recovering the barytes in the state of carbonate2 and this1 in general1 may be done1 without much loss4 ,berthier has proposed to substitute oxide of lead for carbonate of barytes4 ,it answers very well1 is sufficiently cheap1 and does not injure the crucible1 provided the oxide of lead be mixed previously with a little nitrate of lead1 to oxidize any fragments of metallic lead which it may happen to contain4 ,berthier's mode1 therefore1 in point of cheapness1 is preferable to that of ,klaproth4 ,it is equally efficacious and equally accurate4 ,there are some other processes which ,i myself prefer to either of these1 because ,i find them equally easy1 and still less expensive than either carbonate of barytes or oxide of lead4 ,davy's method with boracic acid is exceptionable1 on account of the difficulty of separating the boracic acid completely again4 #d4 ,the mode of separating iron and manganese from each other employed by ,bergman was so defective1 that no confidence whatever can be placed in his results4 ,even the methods suggested by ,vauquelin1 though better1 are still defective4 ,but the process followed by ,klaproth is susceptible of very great precision4 ,he has 7we shall suppose7 the mixture of iron and manganese to be separated from each other1 in solution1 in muriatic acid4 ,the first step of the process is to convert the protoxide of iron 7should it be in that state7 into peroxide4 ,for this purpose1 a little nitric acid is added to the solution1 and the whole heated for some time4 ,the liquid is now to be rendered as neutral as possible2 first1 by driving off as much of the excess of acid as possible1 by concentrating the liquid2 and then by completing the neutralization1 by adding very dilute ammonia1 till no more can be added without occasioning a permanent precipitation4 ,into the liquid thus neutralized1 succinate or benzoate of ammonia is dropped1 as long as any precipitate appears4 ,by this means1 the whole peroxide of iron is thrown down in combination with succinic1 or benzoic acid1 while the whole manganese remains in solution4 ,the liquid being filtered1 to separate the benzoate of iron1 the manganese may now 7if nothing else be in the liquid7 be thrown down by an alkaline carbonate2 or1 if the liquid contain magnesia1 or any other earthy matter1 by hydrosulphuret of ammonia1 or chloride of lime4 ,this process was the contrivance of ,gehlen2 but it was made known to the public by ,klaproth1 who ever after employed it in his analyses4 ,gehlen employed succinate of ammonia2 but ,hisinger afterwards showed that benzoate of ammonia might be substituted without any diminution of the accuracy of the separation4 ,this last salt1 being much cheaper than succinate of ammonia1 answers better in this country4 ,in ,germany1 the succinic acid is the cheaper of the two1 and therefore the best4 #e4 ,but it was not by new processes alone that ,klaproth improved the mode of analysis1 though they were numerous and important2 the improvements in the apparatus contributed not less essentially to the success of his experiments4 ,when he had to do with very hard minerals1 he employed a mortar of flint1 or rather of agate4 ,this mortar he1 in the first place1 analyzed1 to determine exactly the nature of the constituents4 ,he then weighed it4 ,when a very hard body is pounded in such a mortar1 a portion of the mortar is rubbed off1 and mixed with the pounded mineral4 ,what the quantity thus abraded was1 he determined by weighing the mortar at the end of the process4 ,the loss of weight gave the portion of the mortar abraded2 and this portion must be mixed with the pounded mineral4 ,when a hard stone is pounded in an agate mortar it is scarcely possible to avoid losing a little of it4 ,the best method of proceeding is to mix the matter to be pounded 7previously reduced to a coarse powder in a diamond mortar7 with a little water4 ,this both facilitates the trituration1 and prevents any of the dust from flying away2 and not more than a couple of grains of the mineral should be pounded at once4 ,still1 owing to very obvious causes1 a little of the mineral is sure to be lost during the pounding4 ,when the process is finished1 the whole powder is to be exposed to a red heat in a platinum crucible1 and weighed4 ,supposing no loss1 the weight should be equal to the quantity of the mineral pounded together with the portion abraded from the mortar4 ,but almost always the weight will be found less than this4 ,suppose the original weight of the mineral before pounding was a1 and the quantity abraded from the mortar #a2 then1 if nothing were lost1 the weight should be a #a2 but we actually find it only b1 a quantity less than a #a4 ,to determine the weight of matter abraded from the mortar contained in this powder1 we say a #a3 b33 #a3 x1 the quantity from the mortar in our powder1 and x b_/a #a4 ,in performing the analysis1 ,klaproth attended to this quantity1 which was silica1 and subtracted it4 ,such minute attention may appear1 at first sight superfluous2 but it is not so4 ,in analyzing sapphire1 chrysoberyl1 and some other very hard minerals1 the quantity of silica abraded from the mortar sometimes amounts to five per cent4 of the weight of the mineral2 and if we were not to attend to the way in which this silica has been introduced into the powder1 we should give an erroneous view of the constitution of the mineral under analysis4 ,all the analyses of chrysoberyl hitherto published1 give a considerable quantity of silica as a constituent of it4 ,this silica1 if really found by the analysts1 must have been introduced from the mortar1 for pure chrysoberyl contains no silica whatever1 but is a definite compound of glucina1 alumina1 and oxide of iron4 ,when ,klaproth operated with fire1 he always selected his vessels1 whether of earthenware1 glass1 plumbago1 iron1 silver1 or platinum1 upon fixed principles2 and showed more distinctly than chemists had previously been aware of1 what an effect the vessel frequently has upon the result4 ,he also prepared his reagents with great care1 to ensure their purity2 for obtaining several of which in their most perfect state1 he invented several efficient methods4 ,it is to the extreme care with which he selected his minerals for analysis1 and to the purity of his reagents1 and the fitness of his vessels for the objects in view1 that the great accuracy of his analyses is to be1 in a great measure1 ascribed4 ,he must also have possessed considerable dexterity in operating1 for when he had in view to determine any particular point with accuracy1 his results came1 in general1 exceedingly near the truth4 ,i may notice1 as an example of this1 his analysis of sulphate of barytes1 which was within about one-and-a-half per cent4 of absolute correctness4 ,when we consider the looseness of the data which chemists were then obliged to use1 we cannot but be surprised at the smallness of the error4 ,berzelius1 in possession of better data1 and possessed of much dexterity1 and a good apparatus1 when he analyzed this salt many years afterwards1 committed an error of a half per cent4 ,klaproth1 during a very laborious life1 wholly devoted to analytical chemistry1 entirely altered the face of mineralogy4 ,when he began his labours1 chemists were not acquainted with the true composition of a single mineral4 ,he analyzed above #bjj species1 and the greater number of them with so much accuracy1 that his successors have1 in most cases1 confirmed the results which he obtained4 ,the analyses least to be depended on1 are of those minerals which contain both lime and magnesia2 for his process for separating lime and magnesia from each other was not a good one2 nor am ,i sure that he always succeeded completely in separating silica and magnesia from each other4 ,this branch of analysis was first properly elucidated by ,mr4 ,chenevix4 #f4 ,analytical chemistry was1 in fact1 systematized by ,klaproth2 and it is by studying his numerous and varied analyses1 that modern chemists have learned this very essential1 but somewhat difficult art2 and have been able1 by means of still more accurate data than he possessed1 to bring it to a still greater degree of perfection4 ,but it must not be forgotten1 that ,klaproth was in reality the creator of this art1 and that on that account the greatest part of the credit due to the progress that has been made in it belongs to him4 ,it would be invidious to point out the particular analyses which are least exact2 perhaps they ought rather to be ascribed to an unfortunate selection of specimens1 than to any want of care or skill in the operator4 ,but1 during his analytical processes1 he discovered a variety of new elementary substances which it may be proper to enumerate4 ,in #aghi he examined a mineral called pechblende1 and found in it the oxide of a new metal1 to which he gave the name of uranium4 ,he determined its characters1 reduced it to the metallic state1 and described its properties4 ,it was afterwards examined by ,richter1 ,bucholz1 ,arfvedson1 and ,berzelius4 ,it was in the same year1 #aghi1 that he published his analysis of the zircon2 he showed it to be a compound of silica and a new earth1 to which he gave the name of zirconia4 ,he determined the properties of this new earth1 and showed how it might be separated from other bodies and obtained in a state of purity4 ,it has been since ascertained1 that it is a metallic oxide1 and the metallic basis of it is now distinguished by the name of zirconium4 ,in #agie he showed that the hyacinth is composed of the same ingredients as the zircon2 and that both1 in fact1 constitute only one species4 ,this last analysis was repeated by ,morveau1 and has been often confirmed by modern analytical chemists4 ,it was in #agie that he analyzed what was at that time called red schorl1 and now titanite4 ,he showed that it was the oxide of a new metallic body1 to which he gave the name of titanium4 ,he described the properties of this new body1 and pointed out its distinctive characters4 ,it must not be omitted1 however1 that he did not succeed in obtaining oxide of titanium1 or titanic acid1 as it is now called1 in a state of purity4 ,he was not able to separate a quantity of oxide of iron1 with which it was united1 and which gave it a reddish colour4 ,it was first obtained pure by ,h4 ,rose1 the son of his friend and pupil1 who took so considerable a part in his scientific investigations4 ,titanium1 in the metallic state1 was some years ago discovered by ,dr4 ,wollaston1 in the slag at the bottom of the iron furnace1 at ,merthyr ,tydvil1 in ,wales4 ,it is a yellow-coloured1 brittle1 but very hard metal1 possessed of considerable beauty2 but not yet applied to any useful purpose4 ,in #agig he examined the menachanite1 a black sand from ,cornwall1 which had been subjected to a chemical analysis by ,gregor1 in #agia1 who had extracted from it a new metallic substance1 which ,kirwan distinguished by the name of menachine4 ,klaproth ascertained that the new metal of ,gregor was the very same as his own titanium1 and that menachanite is a compound of titanic acid and oxide of iron4 ,thus ,mr4 ,gregor had anticipated him in the discovery of titanium1 though he was not aware of the circumstance till two years after his own experiments had been published4 ,in the year #agic he published a comparative set of experiments on the nature of carbonates of barytes and strontian2 showing that their bases are two different earths1 and not the same1 as had been hitherto supposed in ,germany4 ,this was the first publication on strontian which appeared on the continent2 and ,klaproth seems to have been ignorant of what had been already done on it in ,great ,britain2 at least1 he takes no notice of it in his paper1 and it was not his character to slur over the labours of other chemists1 when they were known to him4 ,strontian was first mentioned as a peculiar earth by ,dr4 ,crawford1 in his paper on the medicinal properties of the muriate of barytes1 published in #agij4 ,the experiments on which he founded his opinions were made1 he informs us1 by ,mr4 ,cruikshanks4 ,a paper on the same subject1 by ,dr4 ,hope1 was read to the ,royal ,society of ,edinburgh1 in #agic2 but they had been begun in #agia4 ,in this paper ,dr4 ,hope establishes the peculiar characters of strontian1 and describes its salts with much precision4 ,klaproth had been again anticipated in his experiments on strontian2 but he could not have become aware of this till afterwards4 ,for his own experiments were given to the public before those of ,dr4 ,hope4 ,on the #beth of ,january1 #agih1 his paper on the gold ores of ,transylvania was read at a meeting of the ,academy of ,sciences at ,berlin4 ,during his analysis of these ores1 he detected a new white metal1 to which he gave the name of tellurium4 ,of this metal he describes the properties1 and points out its distinguishing characters4 ,these ores had been examined by ,muller1 of ,reichenstein1 in the year #aghb2 and he had extracted from them a metal which he considered as differing from every other4 ,not putting full confidence in his own skill1 he sent a specimen of his new metal to ,bergman1 requesting him to examine it and give his opinion respecting its nature4 ,all that ,bergman did was to show that the metallic body which he had got was not antimony1 to which alone1 of all known metals1 it bore any resemblance4 ,it might be inferred from this1 that ,muller's metal was new4 ,but the subject was lost sight of1 till the publication of ,klaproth's experiments1 in #ahjb1 recalled it to the recollection of chemists4 ,indeed1 ,klaproth relates all that ,muller had done1 with the most perfect fairness4 ,in the year #ahjd he published the analysis of a red-coloured mineral1 from ,bastns in ,sweden1 which had been at one time confounded with tungsten2 but which the ,elhuyarts had shown to contain none of that metal4 ,klaproth showed that it contained a new substance1 as one of its constituents1 which he considered as a new earth1 and which he called ochroita1 because it forms coloured salts with acids4 ,two years after1 another analysis of the same mineral was published by ,berzelius and ,hisinger4 ,they considered the new substance which the mineral contained as a metallic oxide1 and to the unknown metallic base they gave the name of cerium1 which has been adopted by chemists in preference to ,klaproth's name4 ,the characters of oxide of cerium given by ,berzelius and ,hisinger1 agree with those given by ,klaproth to ochroita1 in all the essential circumstances4 ,of course ,klaproth must be considered as the discoverer of this new body4 ,the distinction between earth and metallic oxide is now known to be an imaginary one4 ,all the substances formerly called earths are1 in fact1 metallic oxides4 ,besides these new substances1 which he detected by his own labours1 he repeated the analyses of others1 and confirmed and extended the discoveries they had made4 ,thus1 when ,vauquelin discovered the new earth glucina1 in the emerald and beryl1 he repeated the analysis of these minerals1 confirmed the discovery of ,vauquelin1 and gave a detailed account of the characters and properties of glucina4 ,gadolin had discovered another new earth in the mineral called gadolinite4 ,this discovery was confirmed by the analysis of ,ekeberg1 who distinguished the new earth by the name of yttria4 ,klaproth immediately repeated the analysis of the gadolinite1 confirmed the results of ,ekeberg's analysis1 and examined and described the properties of yttria4 ,when ,dr4 ,kennedy discovered soda in basalt1 ,klaproth repeated the analysis of this mineral1 and confirmed the results obtained by the ,edinburgh analyst4 ,but it would occupy too much room1 if ,i were to enumerate every example of such conduct4 ,whoever will take the trouble to examine the different volumes of the ,beitrage1 will find several others not less striking or less useful4 ,the service which ,klaproth performed for mineralogy1 in ,germany1 was performed equally in ,france by the important labours of ,m4 ,vauquelin4 ,it was in ,france1 in consequence of the exertions of ,rom de ,lisle1 and the mathematical investigations of the ,abb ,hauy1 respecting the structure of crystals1 which were gradually extended over the whole mineral kingdom1 that the reform in mineralogy1 which has now become in some measure general1 originated4 ,hauy laid it down as a first principle1 that every mineral species is composed of the same constituents united in the same proportion4 ,he therefore considered it as an object of great importance1 to procure an exact chemical analysis of every mineral species4 ,hitherto no exact analysis of minerals had been performed by ,french chemists2 for ,sage1 who was the chemical mineralogist connected with the academy1 satisfied himself with ascertaining the nature of the constituents of minerals1 without determining their proportions4 ,but ,vauquelin soon displayed a knowledge of the mode of analysis1 and a dexterity in the use of the apparatus which he employed1 little less remarkable than that of ,klaproth himself4 ,of ,vauquelin's history ,i can give but a very imperfect account1 as ,i have not yet had an opportunity of seeing any particulars of his life4 ,he was a peasant-boy of ,normandy1 with whom ,fourcroy accidentally met4 ,he was pleased with his quickness and parts1 and delighted with the honesty and integrity of his character4 ,he took him with him to ,paris1 and gave him the superintendence of his laboratory4 ,his chemical knowledge speedily became great1 and his practice in experimenting gave him skill and dexterity3 he seems to have performed all the analytical experiments which ,fourcroy was in the habit of publishing4 ,he speedily became known by his publications and discoveries4 ,when the scientific institutions were restored or established1 after the death of ,robespierre1 ,vauquelin became a member of the ,institute and chemist to the ,school of ,mines4 ,he was made also assay-master of the ,mint4 ,he was a professor of chemistry in ,paris1 and delivered1 likewise1 private lectures1 and took in practical pupils into his laboratory4 ,his laboratory was of considerable size1 and he was in the habit of preparing both medicines and chemical reagents for sale4 ,it was he chiefly that supplied the ,french chemists with phosphorus1 c41 which cannot be conveniently prepared in a laboratory fitted up solely for scientific purposes4 ,vauquelin was by far the most industrious of all the ,french chemists1 and has published more papers1 consisting of mineral1 vegetable1 and animal analyses1 than any other chemist without exception4 ,when he had the charge of the laboratory of the ,school of ,mines1 ,hauy was in the habit of giving him specimens of all the different minerals which he wished analyzed4 ,the analyses were conducted with consummate skill1 and we owe to him a great number of improvements in the methods of analysis4 ,he is not entitled to the same credit as ,klaproth1 because he had the advantage of many analyses of ,klaproth to serve him as a guide4 ,but he had no model before him in ,france2 and both the apparatus used by him1 and the reagents which he employed1 were of his own contrivance and preparation4 ,i have sometimes suspected that his reagents were not always very pure2 but ,i believe the true reason of the unsatisfactory nature of many of his analyses1 is the bad choice made of the specimens selected for analysis4 ,it is obvious from his papers1 that ,vauquelin was not a mineralogist2 for he never attempts a description of the mineral which he subjects to analysis1 satisfying himself with the specimen put into his hands by ,hauy4 ,where that specimen was pure1 as was the case with emerald and beryl1 his analysis is very good2 but when the specimen was impure or ill-chosen1 then the result obtained could not convey a just notion of the constituents of the mineral4 ,that ,hauy would not be very difficult to please in his selection of specimens1 ,i think myself entitled to infer from the specimens of minerals contained in his own cabinet1 many of which were by no means well selected4 ,i think1 therefore1 that the numerous analyses published by ,vauquelin1 in which the constituents assigned by him are not those1 or1 at least1 not in the same proportions1 as have been found by succeeding analysts1 are to be ascribed1 not to errors in the analysis1 which1 on the contrary1 he always performed carefully1 and with the requisite attention to precision1 but to the bad selection of specimens put into his hand by ,hauy1 or those other individuals who furnished him with the specimens which he employed in his analyses4 ,this circumstance is very much to be deplored2 because it puts it out of our power to confide in an analysis of ,vauquelin1 till it has been repeated and confirmed by somebody else4 ,vauquelin not only improved the analytical methods1 and reduced the art to a greater degree of simplicity and precision1 but he discovered1 likewise1 new elementary bodies4 ,the red lead ore of ,siberia had early drawn the attention of chemists1 on account of its beauty2 and various attempts had been made to analyze it4 ,among others1 ,vauquelin tried his skill upon it1 in #aghi1 in concert with ,m4 ,macquart1 who had brought specimens of it from ,siberia2 but at that time he did not succeed in determining the nature of the acid with which the oxide of lead was combined in it4 ,he examined it again in #agig1 and now succeeded in separating an acid to which1 from the beautiful coloured salts which it forms1 he gave the name of chromic4 ,he determined the properties of this acid1 and showed that its basis was a new metal to which he gave the name of chromium4 ,he succeeded in obtaining this metal in a separate state1 and showed that its protoxide is an exceedingly beautiful green powder4 ,this discovery has been of very great importance to different branches of manufacture in this country4 ,the green oxide is used pretty extensively in painting green on porcelain4 ,it constitutes an exceedingly beautiful green pigment1 very permanent1 and easily applied4 ,the chromic acid1 when combined with oxide of lead1 forms either a yellow or an orange colour upon cotton cloth1 both very fixed and exceedingly beautiful colours4 ,in that way it is extensively used by the calico-printers2 and the bichromate of potash is prepared1 in a crystalline form1 to a very considerable amount1 both in ,glasgow and ,lancashire1 and doubtless in other places4 ,vauquelin was requested by ,hauy to analyze the beryl1 a beautiful light-green mineral1 crystallized in six-sided prisms1 which occurs not unfrequently in granite rocks1 especially in ,siberia4 ,he found it to consist chiefly of silica1 united to alumina1 and to another earthy body1 very like alumina in many of its properties1 but differing in others4 ,to this new earth he gave the name of glucina1 on account of the sweet taste of its salts2 a name not very appropriate1 as alumina1 yttria1 lead1 protoxide of chromium1 and even protoxide of iron1 form salts which are distinguished by a sweet taste likewise4 ,this discovery of glucina confers honour on ,vauquelin1 as it shows the care with which his analyses must have been conducted4 ,a careless experimenter might easily have confounded glucina with alumina4 ,vauquelin's mode of distinguishing them was1 to add sulphate of potash to their solution in sulphuric acid4 ,if the earth in solution was alumina1 crystals of alum would form in the course of a short time2 but if the earth was glucina1 no such crystals would make their appearance1 alumina being the basis of alum1 and not glucina4 ,he showed1 too1 that glucina is easily dissolved in a solution of carbonate of ammonia1 while alumina is not sensibly taken up by that solution4 ,vauquelin died in #ahbi1 after having reached a good old age4 ,his character was of the very best kind1 and his conduct had always been most exemplary4 ,he never interfered with politics1 and steered his way through the bloody period of the revolution1 uncontaminated by the vices or violence of any party1 and respected and esteemed by every person4 ,mr4 ,chenevix deserves also to be mentioned as an improver of analytical chemistry4 ,he was an ,irish gentleman1 who happened to be in ,paris during the reign of terror1 and was thrown into prison and put into the same apartment with several ,french chemists1 whose whole conversation turned upon chemical subjects4 ,he caught the infection1 and1 after getting out of prison1 began to study the subject with much energy and success1 and soon distinguished himself as an analytical chemist4 ,his analysis of corundum and sapphire1 and his observations on the affinity between magnesia and silica1 are valuable1 and led to considerable improvements in the method of analysis4 ,his analyses of the arseniates of copper1 though he demonstrated that several different species exist1 are not so much to be depended on2 because his method of separating and estimating the quantity of arsenic acid is not good4 ,this difficult branch of analysis was not fully understood till afterwards4 ,chenevix was for several years a most laborious and meritorious chemical experimenter4 ,it is much to be regretted that he should have been induced1 in consequence of the mistake into which he fell respecting palladium1 to abandon chemistry altogether4 ,palladium was originally made known to the public by an anonymous handbill which was circulated in ,london1 announcing that palladium1 or new silver1 was on sale at ,mrs4 ,forster's1 and describing its properties4 ,chenevix1 in consequence of the unusual way in which the discovery was announced1 naturally considered it as an imposition on the public4 ,he went to ,mrs4 ,forster's1 and purchased the whole palladium in her possession1 and set about examining it1 prepossessed with the idea that it was an alloy of some two known metals4 ,after a laborious set of experiments1 he considered that he had ascertained it to be a compound of platinum and mercury1 or an amalgam of platinum made in a peculiar way1 which he describes4 ,this paper was read at a meeting of the ,royal ,society by ,dr4 ,wollaston1 who was secretary1 and afterwards published in their ,transactions4 ,soon after this publication1 another anonymous handbill was circulated1 offering a considerable price for every grain of palladium made by ,mr4 ,chenevix's process1 or by any other process whatever4 ,no person appearing to claim the money thus offered1 ,dr4 ,wollaston1 about a year after1 in a paper read to the ,royal ,society1 acknowledged himself to have been the discoverer of palladium1 and related the process by which he had obtained it from the solution of crude platina in aqua regia4 ,there could be no doubt after this1 that palladium was a peculiar metal1 and that ,chenevix1 in his experiments1 had fallen into some mistake1 probably by inadvertently employing a solution of palladium1 instead of a solution of his amalgam of platinum2 and thus giving the properties of the one solution to the other4 ,it is very much to be regretted1 that ,dr4 ,wollaston allowed ,mr4 ,chenevix's paper to be printed1 without informing him1 in the first place1 of the true history of palladium3 and ,i think that if he had been aware of the bad consequences that were to follow1 and that it would ultimately occasion the loss of ,mr4 ,chenevix to the science1 he would have acted in a different manner4 ,i have more than once conversed with ,dr4 ,wollaston on the subject1 and he assured me that he did every thing that he could do1 short of betraying his secret1 to prevent ,mr4 ,chenevix from publishing his paper2 that he had called upon1 and assured him1 that he himself had attempted his process without being able to succeed1 and that he was satisfied that he had fallen into some mistake4 ,as ,mr4 ,chenevix still persisted in his conviction of the accuracy of his own experiments after repeated warnings1 perhaps it is not very surprising that ,dr4 ,wollaston allowed him to publish his paper1 though2 had he been aware of the consequences to their full extent1 ,i am persuaded that he would not have done so4 ,it comes to be a question whether1 had ,dr4 ,wollaston informed him of the whole secret1 ,mr4 ,chenevix would have been convinced4 ,another chemist1 to whom the art of analyzing minerals lies under great obligations1 is ,dr4 ,frederick ,stromeyer1 professor of chemistry and pharmacy1 in the ,university of ,gottingen4 ,he was originally a botanist1 and only turned his attention to chemistry when he had the offer of the chemical chair at ,gottingen4 ,he then went to ,paris1 and studied practical chemistry for some years in ,vauquelin's laboratory4 ,he has devoted most of his attention to the analysis of minerals2 and in the year #ahba published a volume of analyses under the title of ,untersuchungen ber die ,mischung der ,mineralkrper und anderer damit verwandten ,substanzen4 ,it contains thirty analyses1 which constitute perfect models of analytical sagacity and accuracy4 ,after ,klaproth's ,beitrage1 no book can be named more highly deserving the study of the analytical chemist than ,stromeyer's ,untersuchungen4 ,the first paper in this work contains the analysis of arragonite4 ,chemists had not been able to discover any difference in the chemical constitution of arragonite and calcareous spar1 both being compounds of ,lime #ce ,carbonic acid #bge ,yet the minerals differ from each other in their hardness1 specific gravity1 and in the shape of their crystals4 ,many attempts had been made to account for this difference in characters between these two minerals1 but in vain4 ,mr4 ,holme showed that arragonite contained about one per cent4 of water1 which is wanting in calcareous spar2 and that when arragonite is heated1 it crumbles into powder1 which is not the case with calcareous spar4 ,but it is not easy to conceive how the addition of one per cent4 of water should increase the specific gravity and the hardness1 and quite alter the shape of the crystals of calcareous spar4 ,stromeyer made a vast number of experiments upon arragonite1 with very great care1 and the result was1 that the arragonite from ,bastenes1 near ,dax1 in the department of ,landes1 and likewise that from ,molina1 in ,arragon1 was a compound of #if carbonate of lime #d carbonate of strontian4 ,this amounts to about thirty-five atoms of carbonate of lime1 and one atom of carbonate of strontian4 ,now as the hardness and specific gravity of carbonate of strontian is greater than that of carbonate of lime1 we can see a reason why arragonite should be heavier and harder than calcareous spar4 ,more late researches upon different varieties of arragonite enabled him to ascertain that this mineral exists with different proportions of carbonate of strontian4 ,some varieties contain only #b per cent41 some only #a per cent41 and some only #jge1 or even #je per cent42 but he found no specimen among the great number which he analyzed totally destitute of carbonate of strontian4 ,it is true that ,vauquelin afterwards examined several varieties in which he could detect no strontian whatever2 but as ,vauquelin's mineralogical knowledge was very deficient1 it comes to be a question1 whether the minerals analyzed by him were really arragonites1 or only varieties of calcareous spar4 ,to ,professor ,stromeyer we are likewise indebted for the discovery of the new metal called cadmium2 and the discovery does great credit to his sagacity and analytical skill4 ,he is inspector-general of the apothecaries for the kingdom of ,hanover4 ,while discharging the duties of his office at ,hildesheim1 in the year #ahag1 he found that the carbonate of zinc had been substituted for the oxide of zinc1 ordered in the ,hanoverian ,pharmacopia4 ,this carbonate of zinc was manufactured at ,salzgitter4 ,on inquiry he learned from ,mr4 ,jost1 who managed that manufactory1 that they had been obliged to substitute the carbonate for the oxide of zinc1 because the oxide had a yellow colour which rendered it unsaleable4 ,on examining this oxide1 ,stromeyer found that it owed its yellow colour to the presence of a small quantity of the oxide of a new metal1 which he separated1 reduced1 and examined1 and to which he gave the name of cadmium1 because it occurs usually associated with zinc4 ,the quantity of cadmium which he was able to obtain from this oxide of zinc was but small4 ,a fortunate circumstance1 however1 supplied him with an additional quantity1 and enabled him to carry his examination of cadmium to a still greater length4 ,during the apothecaries' visitation in the state of ,magdeburg1 there was found1 in the possession of several apothecaries1 a preparation of zinc from ,silesia1 made in ,hermann's laboratory at ,schnebeck1 which was confiscated on the supposition that it contained arsenic1 because its solution gave a yellow precipitate with sulphuretted hydrogen1 which was considered as orpiment4 ,this statement could not be indifferent to ,mr4 ,hermann1 as it affected the credit of his manufactory2 especially as the medicinal counsellor1 ,roloff1 who had assisted at the visitation1 had drawn up a statement of the circumstances which occasioned the confiscation1 and caused it to be published in ,hofeland's ,medical ,journal4 ,he subjected the suspected oxide to a careful examination2 but he could not succeed in detecting any arsenic in it4 ,he then requested ,roloff to repeat his experiments4 ,this he did2 and now perceived that the precipitate1 which he had taken for orpiment1 was not so in reality1 but owed its existence to the presence of another metallic oxide1 different from arsenic and probably new4 ,specimens of this oxide of zinc1 and of the yellow precipitate1 were sent to ,stromeyer for examination1 who readily recognised the presence of cadmium1 and was able to extract from it a considerable quantity of that metal4 ,it is now nine years since the first volume of the ,untersuchungen was published4 ,all those who are interested in analytical chemistry are anxious for the continuance of that admirable work4 ,by this time he must have collected ample materials for an additional volume2 and it could not but add considerably to a reputation already deservedly high4 ,there is no living chemist1 to whom analytical chemistry lies under greater obligations than to ,berzelius1 whether we consider the number or the exactness of the analyses which he has made4 ,jacob ,berzelius was educated at ,upsala1 when ,professor ,afzelius1 a nephew of ,bergman1 filled the chemical chair1 and ,ekeberg was magister docens in chemistry4 ,afzelius began his chemical career with considerable clat1 his paper on sulphate of barytes being possessed of very considerable merit4 ,but he is said to have soon lost his health1 and to have sunk1 in consequence1 into listless inactivity4 ,andrew ,gustavus ,ekeberg was born in ,stockholm1 on the #afth of ,january1 #agfg4 ,his father was a captain in the ,swedish navy4 ,he was educated at ,calmar2 and in #aghd went to ,upsala1 where he devoted himself chiefly to the study of mathematics4 ,he took his degree in #aghh1 when he wrote a thesis ,de ,oleis ,seminum expressis4 ,in #aghi he went to ,berlin2 and on his return1 in #agij1 he gave a specimen of his poetical talents1 by publishing a poem entitled ,tal fver ,freden emellan ,sverige och ,ryssland 7,discourse about the ,peace between ,sweden and ,russia74 ,after this he turned his attention to chemistry2 and in #agid was made chemi docens4 ,in this situation he continued till #ahac1 when he died on the #aath of ,february4 ,he had been in such bad health for some time before his death1 as to be quite unable to discharge the duties of his situation4 ,he published but little1 and that little consisted almost entirely of chemical analyses4 ,his first attempt was on phosphate of lime2 then he wrote a paper on the analysis of the topaz1 the object of which was to explain ,klaproth's method of dissolving hard stony bodies4 ,he made an analysis of gadolinite1 and determined the chemical properties of yttria4 ,during these experiments he discovered the new metal to which he gave the name of tantalum1 and which ,dr4 ,wollaston afterwards showed to be the same with the columbium of ,mr4 ,hatchett4 ,he also published an analysis of the automalite1 of an ore of titanium1 and of the mineral water of ,medevi4 ,in this last analysis he was assisted by ,berzelius1 who was then quite unknown to the chemical world4 ,berzelius has been much more industrious than his chemical contemporaries at ,upsala4 ,his first publication was a work in two volumes on animal chemistry1 chiefly a compilation1 with the exception of his experiments on the analysis of blood1 which constitute an introduction to the second volume4 ,this book was published in #ahjf and #ahjh4 ,in the year #ahjf he and ,hisinger began a periodical work1 entitled ,afhandlingar i ,fysik1 ,kemi och ,mineralogi1 of which six volumes in all were published1 the last in #ahah4 ,in this work there occur forty-seven papers by ,berzelius1 some of them of great length and importance1 which will be noticed afterwards2 but by far the greatest part of them consist of mineral analyses4 ,we have the analysis of cerium by ,hisinger and ,berzelius1 together with an account of the chemical characters of the two oxides of cerium4 ,in the fourth volume he gives us a new chemical arrangement of minerals1 founded on the supposition that they are all chemical compounds in definite proportions4 ,mr4 ,smithson had thrown out the opinion that silica is an acid3 which opinion was taken up by ,berzelius1 who showed1 by decisive experiments1 that it enters into definite combinations with most of the bases4 ,this happy idea enabled him to show1 that most of the stony minerals are definite compounds of silica1 with certain earths or metallic oxides4 ,this system has undergone several modifications since he first gave it to the world2 and ,i think it more than doubtful whether his last co but he has taken care to have translations of them inserted into ,poggensdorf's ,annalen1 and the ,annales de ,chimie et de ,physique4 ,in the ,stockholm ,memoirs1 for #ahai1 we have his analysis of wavellite1 showing that this mineral is a hydrous phosphate of alumina4 ,the same analysis and discovery had been made by ,fuchs1 who published his results in #ahah2 but probably ,berzelius had not seen the paper2 at least he takes no notice of it4 ,we have also in the same volume his analysis of euclase1 of silicate of zinc1 and his paper on the prussiates4 ,in the ,memoirs for #ahbj we have1 besides three others1 his paper on the mode of analyzing the ores of nickel4 ,in the ,memoirs for #ahba we have his paper on the alkaline sulphurets1 and his analysis of achmite4 ,the specimen selected for this analysis was probably impure2 for two successive analyses of it1 made in my laboratory by ,captain ,lehunt1 gave a considerable difference in the proportion of the constituents1 and a different formula for the composition than that resulting from the constituents found by ,berzelius4 ,in the ,memoirs for #ahbb we have his analysis of the mineral waters of ,carlsbad4 ,in #ahbc he published his experiments on uranium1 which were meant as a confirmation and extension of the examination of this substance previously made by ,arfvedson4 ,in the same year appeared his experiments on fluoric acid and its combinations1 constituting one of the most curious and important of all the numerous additions which he has made to analytical chemistry4 ,in #ahbd we have his analysis of phosphate of yttria1 a mineral found in ,norway2 of polymignite1 a mineral from the neighbourhood of ,christiania1 where it occurs in the zircon sienite1 and remarkable for the great number of bases which it contains united to titanic acid2 namely1 zirconia1 oxide of iron1 lime1 oxide of manganese1 oxide of cerium1 and yttria4 ,we have also his analysis of arseniate of iron1 from ,brazil and from ,cornwall2 and of chabasite from ,ferro4 ,in this last analysis he mentions chabasites from ,scotland1 containing soda instead of lime4 ,the only chabasites in ,scotland1 that ,i know of1 occur in the neighbourhood of ,glasgow2 and in none of these have ,i found any soda4 ,but ,i have found soda instead of lime in chabasites from the north of ,ireland1 always crystallized in the form to which ,hauy has given the name of trirhomboidale4 ,i think1 therefore1 that the chabasites analyzed by ,arfvedson1 to which ,berzelius refers1 must have been from ,ireland1 and not from ,scotland2 and ,i think it may be a question whether this form of crystal1 if it should always be found to contain soda instead of lime1 ought not to constitute a peculiar species4 ,in #ahbf we have his very elaborate and valuable paper on sulphur salts4 ,in this paper he shows that sulphur is capable of combining with bodies1 in the same way as oxygen1 and of converting the acidifiable bases into acids1 and the alkalifiable bases into alkalies4 ,these sulphur acids and alkalies unite with each other1 and form a new class of saline bodies1 which may be distinguished by the name of sulphur salts4 ,this subject has been since carried a good deal further by ,m4 ,h4 ,rose1 who has by means of it thrown much light on some mineral species hitherto quite inexplicable4 ,thus1 what is called nickel glance1 is a sulphur salt of nickel4 ,the acid is a compound of sulphur and arsenic1 the base a compound of sulphur and nickel4 ,its composition may be represented thus3 #a atom disulphide of arsenic #a atom disulphide of nickel4 ,in like manner glance cobalt is #a atom disulphide of arsenic #a atom disulphide of nickel4 ,zinkenite is composed of #c atoms sulphide of antimony #a atom sulphide of lead2 and jamesonite of #b atoms sulphide of antimony #a atom sulphide of lead4 ,feather ore of antimony1 hitherto confounded with sulphuret of antimony1 is a compound of #e atoms sulphide of antimony #c atoms sulphide of lead4 ,gray copper ore1 which has hitherto appeared so difficult to be reduced to any thing like regularity1 is composed of #a atom sulphide of antimony or arsenic #b atoms sulphide of copper or silver4 ,dark red silver ore is composed of #a atom sulphide of antimony #a atom sulphide of silver2 and light red silver ore of #b atoms sesquisulphide of arsenic #c atoms sulphide of silver4 ,these specimens show how much light the doctrine of sulphur salts has thrown on the mineral kingdom4 ,in #ahbh he published his experimental investigation of the characters and compounds of palladium1 rhodium1 osmium1 and iridium2 and upon the mode of analyzing the different ores of platinum4 ,one of the greatest improvements which ,berzelius has introduced into analytical chemistry1 is his mode of separating those bodies which become acid when united to oxygen1 as sulphur1 selenium1 arsenic1 c41 from those that become alkaline1 as copper1 lead1 silver1 c4 ,his method is to put the alloy or ore to be analyzed into a glass tube1 and to pass over it a current of dry chlorine gas1 while the powder in the tube is heated by a lamp4 ,the acidifiable bodies are volatile1 and pass over along the tube into a vessel of water placed to receive them1 while the alkalifiable bodies remain fixed in the tube4 ,this mode of analysis has been considerably improved by ,rose1 who availed himself of it in his analysis of gray copper ore1 and other similar compounds4 ,analytical chemistry lies under obligations to ,berzelius1 not merely for what he has done himself1 but for what has been done by those pupils who were educated in his laboratory4 ,bonsdorf1 ,nordenskild1 ,c4 ,g4 ,gmelin1 ,rose1 ,whler1 ,arfvedson1 have given us some of the finest examples of analytical investigations with which the science is furnished4 ,p4 ,a4 ,von ,bonsdorf was a professor of ,abo1 and after that university was burnt down1 he moved to the new locality in which it was planted by the ,russian government4 ,his analysis of the minerals which crystallize in the form of the amphibole1 constitutes a model for the young analysts to study1 whether we consider the precision of the analyses1 or the methods by which the different constituents were separated and estimated4 ,his analysis of red silver ore first demonstrated that the metals in it were not in the state of oxides4 ,the nature of the combination was first completely explained by ,rose1 after ,berzelius's paper on the sulphur salts had made its appearance4 ,his paper on the acid properties of several of the chlorides1 has served considerably to extend and to rectify the views first proposed by ,berzelius respecting the different classes of salts4 ,nils ,nordenskild is superintendent of the mines in ,finland3 his ,bidrag till nrmare knnedom af ,finland's ,mineralier och ,geognosie was published in #ahbj4 ,it contains a description and analysis of fourteen species of ,lapland minerals1 several of them new1 and all of them interesting4 ,the analyses were conducted in ,berzelius's laboratory1 and are excellent4 ,in #ahbg he published a tabular view of the mineral species1 arranged chemically1 in which he gives the crystalline form1 hardness1 and specific gravity1 together with the chemical formulas for the composition4 ,c4 ,g4 ,gmelin is professor of chemistry at ,tubingen2 he has devoted the whole of his attention to chemical analysis1 and has published a great number of excellent ones1 particularly in ,schweigger's ,journal4 ,his analysis of helvine1 and of the tourmalin1 may be specified as particularly valuable4 ,in this last mineral1 he demonstrated the presence of boracic acid4 ,leopold ,gmelin1 professor of chemistry at ,heidelberg1 has also distinguished himself as an analytical chemist4 ,his ,system of ,chemistry1 which is at present publishing1 promises to be the best and most perfect which ,germany has produced4 ,henry ,rose1 of ,berlin1 is the son of that ,m4 ,rose who was educated by ,klaproth1 and afterwards became the intimate friend and fellow-labourer of that illustrious chemist4 ,he has devoted himself to analytical chemistry with indefatigable zeal1 and has favoured us with a prodigious number of new and admirably-conducted analyses4 ,his analyses of pyroxenes1 of the ores of titanium1 of gray copper ore1 of silver glance1 of red silver ore1 miargyrite1 polybasite1 c41 may be mentioned as examples4 ,in #ahbi he published a volume on analytical chemistry1 which is by far the most complete and valuable work of the kind that has hitherto appeared2 and ought to be carefully studied by all those who wish to make themselves masters of the difficult1 but necessary art of analyzing compound bodies4#f #f ,an excellent ,english translation of this book with several important additions by the author1 has just been published by ,mr4 ,griffin4 ,whler is professor of chemistry in the ,polytechnic ,school of ,berlin2 he does not appear to have turned his attention to analytical chemistry1 but rather towards extending our knowledge of the compounds which the different simple bodies are capable of forming with each other4 ,his discovery of cyanic acid may be mentioned as a specimen4 ,he is active and young2 much1 therefore1 may be expected from him4 ,augustus ,arfvedson has distinguished himself by the discovery of the new fixed alkali1 lithia1 in petalite and spodumene4 ,it has been lately ascertained at ,moscow1 by ,m4 ,r4 ,hermann1 and the experiments have been repeated and confirmed by ,berzelius1 that lithia is a much lighter substance than it was found to be by ,arfvedson1 its atomic weight being only #age4 ,we have from ,arfvedson an important set of experiments on uranium and its oxides1 and on the action of hydrogen on the metallic sulphurets4 ,he has likewise analyzed a considerable number of minerals with great care2 but of late years he seems to have lost his activity4 ,his analysis of chrysoberyl does not possess the accuracy of the rest3 by some inadvertence1 he has taken a compound of glucina and alumina for silica4 ,i ought to have included ,walmstedt and ,troll-,wachmeister among the ,swedish chemists who have contributed important papers towards the progress of analytical chemistry1 the memoir of the former on chrysolite1 and of the latter on the garnets1 being peculiarly valuable4 ,but it would extend this work to an almost interminable length1 if ,i were to particularize every meritorious experimenter4 ,this must plead my excuse for having omitted the names of ,bucholz1 ,gehlen1 ,fuchs1 ,dumesnil1 ,dobereiner1 ,kupfer1 and various other meritorious chemists who have contributed so much to the perfecting of the chemical analysis of the mineral kingdom4 ,but it would be unpardonable to leave out the name of ,m4 ,mitcherlich1 professor of chemistry in ,berlin1 and successor of ,klaproth1 who was also a pupil of ,berzelius4 ,he has opened a new branch of chemistry to our consideration4 ,his papers on isomorphous bodies1 on the crystalline forms of various sets of salts1 on the artificial formation of various minerals1 do him immortal honour1 and will hand him down to posterity as a fit successor of his illustrious predecessors in the chemical chair of ,berlin--a city in which an uninterrupted series of first-rate chemists have followed each other for more than a century2 and where1 thanks to the fostering care of the ,prussian government1 the number was never greater than at the present moment4 ,the most eminent analytical chemists at present in ,france are1 ,laugier1 a nephew and successor of ,fourcroy1 as professor of chemistry in the ,jardin du ,roi1 and ,berthier1 who has long had the superintendence of the laboratory of the ,school of ,mines4 ,laugier has not published many analyses to the world1 but those with which he has favoured us appear to have been made with great care1 and are in general very accurate4 ,berthier is a much more active man2 and has not merely given us many analyses1 but has made various important improvements in the analytical processes4 ,his mode of separating arsenic acid1 and determining its weight1 is now generally followed2 and ,i can state from experience that his method of fusing minerals with oxide of lead1 when the object is to detect an alkali1 is both accurate and easy4 ,berthier is young1 and active1 and zealous2 we may therefore expect a great deal from him hereafter4 ,the chemists in great ,britain have never hitherto distinguished themselves much in analytical chemistry4 ,this ,i conceive is owing to the mode of education which has been hitherto unhappily followed4 ,till within these very few years1 practical chemistry has been nowhere taught4 ,the consequence has been1 that every chemist must discover processes for himself2 and a long time elapses before he acquires the requisite dexterity and skill4 ,about the beginning of the present century1 ,dr4 ,kennedy1 of ,edinburgh1 was an enthusiastic and dexterous analyst2 but unfortunately he was lost to the science by a premature death1 after giving a very few1 but these masterly1 analyses to the public4 ,about the same time1 ,charles ,hatchett1 ,esq41 was an active chemist1 and published not a few very excellent analyses2 but unfortunately this most amiable and accomplished man has been lost to science for more than a quarter of a century2 the baneful effects of wealth1 and the cares of a lucrative and extensive business1 having completely weaned him from scientific pursuits4 ,mr4 ,gregor1 of ,cornwall1 was an accurate man1 and attended only to analytical chemistry3 his analyses were not numerous1 but they were in general excellent4 ,unfortunately the science was deprived of his services by a premature death4 ,the same observation applies equally to ,mr4 ,edward ,howard1 whose analyses of meteoric stones form an era in this branch of chemistry4 ,he was not only a skilful chemist1 but was possessed of a persevering industry which peculiarly fitted him for making a figure as a practical chemist4 ,of modern ,british analytical chemists1 undoubtedly the first is ,mr4 ,richard ,philips2 to whom we are indebted for not a few analyses1 conducted with great chemical skill1 and performed with great accuracy4 ,unfortunately1 of late years he has done little1 having been withdrawn from science by the necessity of providing for a large family1 which can hardly be done1 in this country1 except by turning one's attention to trade or manufactures4 ,the same remark applies to ,dr4 ,henry1 who has contributed so much to our knowledge of gaseous bodies1 and whose analytical skill1 had it been wholly devoted to scientific investigations1 would have raised his reputation1 as a discoverer1 much higher than it has attained2 although the celebrity of ,dr4 ,henry1 even under the disadvantages of being a manufacturing chemist1 is deservedly very high4 ,of the young chemists who have but recently started in the path of analytical investigation1 we expect the most from ,dr4 ,turner1 of the ,london ,university4 ,his analyses of the ores of manganese are admirable specimens of skill and accuracy1 and have completely elucidated a branch of mineralogy which1 before his experiments1 and the descriptions of ,haidinger appeared1 was buried in impenetrable darkness4 ,no man that ,great ,britain has produced was better fitted to have figured as an analytical chemist1 both by his uncommon chemical skill1 and the powers of his mind1 which were of the highest order1 than ,mr4 ,smithson ,tennant1 had he not been in some measure prevented by a delicate frame of body1 which produced in him a state of indolence somewhat similar to that of ,dr4 ,black4 ,his discovery of osmium and iridium1 and his analysis of emery and magnesian limestone1 may be mentioned as proofs of what he could have accomplished had his health allowed him a greater degree of exertion4 ,his experiments on the diamond first demonstrated that it was composed of pure carbon2 while his discovery of phosphuret of lime has furnished lecturers on chemistry with one of the most brilliant and beautiful of those exhibitions which they are in the habit of making to attract the attention of their students4 ,smithson ,tennant was the only child of the ,rev4 ,calvert ,tennant1 youngest son of a respectable family in ,wensleydale1 near ,richmond1 in ,yorkshire1 and vicar of ,selby in that county4 ,he was born on the #cjth of ,november1 #agfa3 he had the misfortune to lose his father when he was only nine years of age2 and before he attained the age of manhood he was deprived likewise of his mother1 by a very unfortunate accident3 she was thrown from her horse while riding with her son1 and killed on the spot4 ,his education1 after his father's death1 was irregular1 and apparently neglected2 he was sent successively to different schools in ,yorkshire1 at ,scorton1 ,tadcaster1 and ,beverley4 ,he gave many proofs while young of a particular turn for chemistry and natural philosophy1 both by reading all books of that description which fell in his way1 and by making various little experiments which the perusal of these books suggested4 ,his first experiment was made at nine years of age1 when he prepared a quantity of gunpowder for fireworks1 according to directions contained in some scientific book to which he had access4 ,in the choice of a profession1 his attention was naturally directed towards medicine1 as being more nearly allied to his philosophical pursuits4 ,he went accordingly to ,edinburgh1 about the year #agha1 where he laid the foundation of his chemical knowledge under ,dr4 ,black4 ,in #aghb he was entered a member of ,christ's ,college1 ,cambridge1 where he began1 from that time1 to reside4 ,he was first entered as a pensioner2 but disliking the ordinary discipline and routine of an academical life1 he obtained an exemption from those restraints1 by becoming a fellow commoner4 ,during his residence at ,cambridge his chief attention was bestowed on chemistry and botany2 though he made himself also acquainted with the elementary parts of mathematics1 and had mastered the most important parts of ,newton's ,principia4 ,in #aghd he travelled into ,denmark and ,sweden1 chiefly with the view of becoming personally acquainted with ,scheele1 for whom he had imbibed a high admiration4 ,he was much gratified by what he saw of this extraordinary man1 and was particularly struck with the simplicity of the apparatus with which his great experiments had been performed4 ,on his return to ,england he took great pleasure in showing his friends at ,cambridge various mineralogical specimens1 which had been presented to him by ,scheele1 and in exhibiting several interesting experiments which he had learned from that great chemist4 ,a year or two afterwards he went to ,france1 to become personally acquainted with the most eminent of the ,french chemists4 ,thence he went to ,holland and the ,netherlands1 at that time in a state of insurrection against ,joseph ,,ii4 ,in #aghf he left ,christ's ,college along with ,professor ,hermann1 and removed with him to ,emmanuel ,college4 ,in #aghh he took his first degree as bachelor of physic1 and soon after quitted ,cambridge and came to reside in ,london4 ,in #agia he made his celebrated analysis of carbonic acid1 which fully confirmed the opinions previously stated by ,lavoisier respecting the constituents of this substance4 ,his mode was to pass phosphorus through red-hot carbonate of lime4 ,the phosphorus was acidified1 and charcoal deposited4 ,it was during these experiments that he discovered phosphuret of lime4 ,in #agib he again visited ,paris2 but1 from circumstances1 being afraid of a convulsion1 he was fortunate enough to leave that city the day before the memorable #ajth of ,august4 ,he travelled through ,italy1 and then passed through part of ,germany4 ,on his return to ,paris1 in the beginning of #agic1 he was deeply impressed with the gloom and desolation arising from the system of terror then beginning to prevail in that capital4 ,on calling at the house of ,m4 ,delametherie1 of whose simplicity and moderation he had a high opinion1 he found the doors and windows closed1 as if the owner were absent4 ,being at length admitted1 he found his friend sitting in a back room1 by candle-light1 with the shutters closed in the middle of the day4 ,on his departure1 after a hurried and anxious conversation1 his friend conjured him not to come again1 as the knowledge of his being there might be attended with serious consequences to them both4 ,to the honour of ,delametherie1 it deserves to be stated1 that through all the inquisitions of the revolution1 he preserved for his friend property of considerable value1 which ,mr4 ,tennant had intrusted to his care4 ,on his return from the continent1 he took lodgings in the ,temple1 where he continued to reside during the rest of his life4 ,he still continued the study of medicine1 and attended the hospitals1 but became more indifferent about entering into practice4 ,he took1 however1 a doctor's degree at ,cambridge in #agif2 but resolved1 as his fortune was independent1 to relinquish all idea of practice1 as not likely to contribute to his happiness4 ,exquisite sensibility was a striking feature in his character1 and it would1 as he very properly conceived1 have made him peculiarly unfit for the exercise of the medical profession4 ,it may be worth while to relate an example of his practical benevolence which happened about this time4 ,he had a steward in the country1 in whom he had long placed implicit confidence1 and who was considerably indebted to him4 ,in consequence of this man's becoming embarrassed in his circumstances1 ,mr4 ,tennant went into the country to examine his accounts4 ,a time and place were appointed for him to produce his books1 and show the extent of the deficiency2 but the unfortunate steward felt himself unequal to the task of such an explanation1 and in a fit of despair put an end to his existence4 ,touched by this melancholy event1 ,mr4 ,tennant used his utmost exertions for the relief and protection of the family whom he had left1 and not only forgave them the debt1 but afforded them pecuniary assistance1 and continued ever afterwards to be their friend and benefactor4 ,during the year #agif he made his experiments to prove that the diamond is pure carbon4 ,his method was to heat it in a gold tube1 with saltpetre4 ,the diamond was converted into carbonic acid gas1 which combined with the potash from the saltpetre1 and by the evolution of which the quantity of carbon1 in a given weight of diamond1 might be estimated4 ,a characteristic trait of ,mr4 ,tennant occurred during the course of this experiment1 which ,i relate on the authority of ,dr4 ,wollaston1 who was present as an assistant1 and who related the fact to me4 ,mr4 ,tennant was in the habit of taking a ride on horseback every day at a certain hour4 ,the tube containing the diamond and saltpetre were actually heating1 and the experiment considerably advanced1 when1 suddenly recollecting that his hour for riding was come1 he left the completion of the process to ,dr4 ,wollaston1 and went out as usual to take his ride4 ,in the year #agig1 in consequence of a visit to a friend in ,lincolnshire1 where he witnessed the activity with which improvements in farming operations were at that time going on1 he was induced to purchase some land in that country1 in order to commence farming operations4 ,in #agii he bought a considerable tract of waste land in ,somersetshire1 near the village of ,cheddar1 where he built a small house1 in which1 during the remainder of his life1 he was in the habit of spending some months every summer1 besides occasional visits at other times of the year4 ,these farming speculations1 as might have been anticipated from the indolent and careless habits of ,mr4 ,tennant1 were not very successful4 ,yet it appears from the papers which he left behind him1 that he paid considerable attention to agriculture1 that he had read the best books on the subject1 and collected many facts on it during his different journeys through various parts of ,england4 ,in the course of these inquiries he had discovered that there were two kinds of limestone known in the midland counties of ,england1 one of which yielded a lime injurious to vegetation4 ,he showed1 in #agii1 that the presence of carbonate of magnesia is the cause of the bad qualities of this latter kind of limestone4 ,he found that the magnesian limestone forms an extensive stratum in the midland counties1 and that it occurs also in primitive districts under the name of dolomite4 ,he infers from the slow solubility of this limestone in acids1 that it is a double salt composed of carbonate of lime and carbonate of magnesia in chemical combination4 ,he found that grain would scarcely germinate1 and that it soon perished in moistened carbonate of magnesia3 hence he concluded that magnesia is really injurious to vegetation4 ,upon this principle he accounted for the injurious effects of the magnesian limestone when employed as a manure4 ,in #ahjb he showed that emery is merely a variety of corundum1 or of the precious stone known by the name of sapphire4 ,during the same year1 while endeavouring to make an alloy of lead with the powder which remains after treating crude platinum with aqua regia1 he observed remarkable properties in this powder1 and found that it contained a new metal4 ,while he was engaged in the investigation1 ,descotils had turned his attention to the same powder1 and had discovered that it contained a metal which gives a red colour to the ammoniacal precipitate of platinum4 ,soon after1 ,vauquelin1 having treated the powder with alkali1 obtained a volatile metallic oxide1 which he considered as the same metal that had been observed by ,descotils4 ,in #ahjd ,mr4 ,tennant showed that this powder contains two new metals1 to which he gave the name of osmium and iridium4 ,mr4 ,tennant's health1 by this time1 had become delicate1 and he seldom went to bed without a certain quantity of fever1 which often obliged him to get up during the night and expose himself to the cold air4 ,to keep himself in any degree in health1 he found it necessary to take a great deal of exercise on horseback4 ,he was always an awkward and a bad horseman1 so that those rides were sometimes a little hazardous2 and ,i have more than once heard him say1 that a fall from his horse would some day prove fatal to him4 ,in #ahji he was thrown from his horse near ,brighton1 and had his collar-bone broken4 ,in the year #ahab he was prevailed upon to deliver a few lectures on the principles of mineralogy1 to a number of his friends1 among whom were many ladies1 and a considerable number of men of science and information4 ,these lectures were completely successful1 and raised his reputation very much among his friends as a lecturer4 ,he particularly excelled in the investigation of minerals by the blowpipe2 and ,i have heard him repeatedly say1 that he was indebted for the first knowledge of the mode of using that valuable instrument to ,assessor ,gahn ,fahlun4 ,in #ahac1 a vacancy occurring in the chemical professorship at ,cambridge1 he was solicited to become a candidate4 ,his friends exerted themselves in his favour with unexampled energy2 and all opposition being withdrawn1 he was elected professor in ,may1 #ahac4 ,after the general pacification in #ahad he went to ,france1 and repaired to the southern provinces of that kingdom4 ,he visited ,lyons1 ,nismes1 ,avignon1 ,marseilles1 and ,montpellier4 ,he returned to ,paris in ,november1 much gratified by his southern tour4 ,he was to have returned to ,england about the latter end of the year2 but he continued to linger on till the ,february following4 ,on the #aeth of that month he went to ,calais2 but the wind blew directly into ,calais harbour1 and continued unfavourable for several days4 ,after waiting till the #bjth he went to ,boulogne1 in order to take the chance of a better passage from that port4 ,he embarked on board a vessel on the #bb;d1 but the wind was still adverse1 and blew so violently that the vessel was obliged to put back4 ,when ,mr4 ,tennant came ashore1 he said that it was in vain to struggle with the elements1 and that he was not yet tired of life4 ,it was determined1 in case the wind should abate1 to make another trial in the evening4 ,during the interval ,mr4 ,tennant proposed to his fellow-traveller1 ,baron ,bulow1 that they should hire horses and take a ride4 ,they rode at first along the sea-side2 but1 on ,mr4 ,tennant's suggestion1 they went afterwards to ,bonaparte's pillar1 which stands on an eminence about a league from the sea-shore1 and which1 having been to see it the day before1 he was desirous of showing to ,baron ,bulow4 ,on their return from thence they deviated a little from the road1 in order to look at a small fort near the pillar1 the entrance to which was over a fosse twenty feet deep4 ,on the side towards them1 there was a standing bridge for some way1 till it joined a drawbridge1 which turned on a pivot4 ,the end next the fort rested on the ground4 ,on the side next to them it was usually fastened by a bolt2 but the bolt had been stolen about a fortnight before1 and was not replaced4 ,as the bridge was too narrow for them to go abreast1 the baron said he would go first1 and attempted to ride over it2 but perceiving that it was beginning to sink1 he made an effort to pass the centre1 and called out to warn his companion of his danger2 but it was too late3 they were both precipitated into the trench4 ,the baron1 though much stunned1 fortunately escaped without any serious hurt2 but on recovering his senses1 and looking round for ,mr4 ,tennant1 he found him lying under his horse nearly lifeless4 ,he was taken1 however1 to the ,civil ,hospital1 as the nearest place ready to receive him4 ,after a short interval1 he seemed in some slight degree to recover his senses1 and made an effort to speak1 but without effect1 and died within the hour4 ,his remains were interred a few days after in the public cemetery at ,boulogne1 being attended to the grave by most of the ,english residents4 ,there is another branch of investigation intimately connected with analytical chemistry1 the improvements in which have been attended with great advantage1 both to mineralogists and chemists4 ,i mean the use of the blowpipe1 to make a kind of miniature analysis of minerals in the dry way2 so far1 at least1 as to determine the nature of the constituents of the mineral under examination4 ,this is attended with many advantages1 as a preliminary to a rigid analysis by solution4 ,by informing us of the nature of the constituents1 it enables us to form a plan of the analysis beforehand1 which1 in many cases1 saves the trouble and the tediousness of two separate analytical investigations2 for when we set about analyzing a mineral1 of the nature of which we are entirely ignorant1 two separate sets of experiments are in most cases indispensable4 ,we must examine the mineral1 in the first place1 to determine the nature of its constituents4 ,these being known1 we can form a plan of an analysis1 by means of which we can separate and estimate in succession the amount of each constituent of the mineral4 ,now a judicious use of the blowpipe often enables us to determine the nature of the constituents in a few minutes1 and thus saves the trouble of the preliminary analysis4 ,the blowpipe is a tube employed by goldsmiths in soldering4 ,by means of it1 they force the flame of a candle or lamp against any particular point which they wish to heat4 ,this enables them to solder trinkets of various kinds1 without affecting any other part except the portion which is required to be heated4 ,cronstedt and ,engestroem first thought of applying this little instrument to the examination of minerals4 ,a small fragment of the mineral to be examined1 not nearly so large as the head of a small pin1 was put upon a piece of charcoal1 and the flame of a candle was made to play upon it by means of a blowpipe1 so as to raise it to a white heat4 ,they observed whether it decrepitated1 or was dissipated1 or melted2 and whatever the effect produced was1 they were enabled from it to draw consequences respecting the nature of the mineral under examination4 ,the importance of this instrument struck ,bergman1 and induced him to wish for a complete examination of the action of the heat of the blowpipe upon all different minerals1 either tried per se upon charcoal1 or mixed with various fluxes2 for three different substances had been chosen as fluxes1 namely1 carbonate of soda1 borax1 and biphosphate of soda2 or1 at least1 what was in fact an equivalent for this last substance1 ammonio-phosphate of soda1 or microcosmic salt1 at that time extracted from urine4 ,this salt is a compound of one integrant particle of phosphate of soda1 and one integrant particle of phosphate of ammonia4 ,when heated before the blowpipe it fuses1 and the water of crystallization1 together with the ammonia1 are gradually dissipated1 so that at last nothing remains but biphosphate of soda4 ,these fluxes have been found to act with considerable energy on most minerals4 ,the carbonate of soda readily fuses with those that contain much silica1 while the borax and biphosphate of soda act most powerfully on the bases1 not sensibly affecting the silica1 which remains unaltered in the fused bead4 ,a mixture of borax and carbonate of soda upon charcoal in general enables us to reduce the metallic oxides to the state of metals1 provided we understand the way of applying the flame properly4 ,bergman employed ,gahn1 who was at that time his pupil1 and whose skill he was well acquainted with1 to make the requisite experiments4 ,the result of these experiments was drawn up into a paper1 which ,bergman sent to ,baron ,born in #aggg1 and they were published by him at ,vienna in #aggi4 ,this valuable publication threw a new light upon the application of the blowpipe to the assaying of minerals2 and for every thing new which it contained ,bergman was indebted to ,gahn1 who had made the experiments4 ,john ,gottlieb ,gahn1 the intimate friend of ,bergman and of ,scheele1 was one of the best-informed men1 and one whose manners were the most simple1 unaffected1 and pleasing1 of all the men of science with whom ,i ever came in contact4 ,i spent a few days with him at ,fahlun1 in #ahab1 and they were some of the most delightful days that ,i ever passed in my life4 ,his fund of information was inexhaustible1 and was only excelled by the charming simplicity of his manners1 and by the benevolence and goodness of heart which beamed in his countenance4 ,he was born on the #agth of ,august1 #agde1 at the ,woxna iron-works1 in ,south ,helsingland1 where his father1 ,hans ,jacob ,gahn1 was treasurer to the government of ,stora ,kopperberg4 ,his grandfather1 or great-grandfather1 he told me1 had emigrated from ,scotland2 and he mentioned several families in ,scotland to which he was related4 ,after completing his school education at ,westers1 he went1 in the year #agfj1 to the ,university of ,upsala4 ,he had already shown a decided bias towards the study of chemistry1 mineralogy1 and natural philosophy2 and1 like most men of science in ,sweden1 where philosophical instrument-makers are scarcely to be found1 he had accustomed himself to handle the different tools1 and to supply himself in that manner with all the different pieces of apparatus which he required for his investigations4 ,he seems to have spent nearly ten years at ,upsala1 during which time he acquired a very profound knowledge in chemistry1 and made various important discoveries1 which his modesty or his indifference to fame made him allow others to pass as their own4 ,the discovery of the rhomboidal nucleus of carbonate of lime in a six-sided prism of that mineral1 which he let fall1 and which was accidentally broken1 constitutes the foundation of ,hauy's system of crystallization4 ,he communicated the fact to ,bergman1 who published it as his own in the second volume of his ,opuscula1 without any mention of ,gahn's name4 ,the earth of bones had been considered as a peculiar simple earth2 but ,gahn ascertained1 by analysis1 that it was a compound of phosphoric acid and lime2 and this discovery he communicated to ,scheele1 who1 in his paper on fluor spar1 published in #agga1 observed1 in the seventeenth section1 in which he is describing the effect of phosphoric acid on fluor spar1 ,it has lately been discovered that the earth of bones1 or of horns1 is calcareous earth combined with phosphoric acid4 ,in consequence of this remark1 in which the name of ,gahn does not appear1 it was long supposed that ,scheele1 and not ,gahn1 was the author of this important discovery4 ,it was during this period that he demonstrated the metallic nature of manganese1 and examined the properties of the metal4 ,this discovery was announced as his1 at the time1 by ,bergman1 and was almost the only one of the immense number of new facts which he had ascertained that was publicly known to be his4 ,on the death of his father he was left in rather narrow circumstances1 which obliged him to turn his immediate attention to mining and metallurgy4 ,to acquire a practical knowledge of mining he associated with the common miners1 and continued to work like them till he had acquired all the practical dexterity and knowledge which actual labour could give4 ,in #aggj he was commissioned by the ,college of ,mines to institute a course of experiments1 with a view to improve the method of smelting copper1 at ,fahlun4 ,the consequence of this investigation was a complete regeneration of the whole system1 so as to save a great deal both of time and fuel4 ,sometime after1 he became a partner in some extensive works at ,stora ,kopperberg1 where he settled as a superintendent4 ,from #aggj1 when he first settled at ,fahlun1 down to #aghe1 he took a deep interest in the improvement of the chemical works in that place and neighbourhood4 ,he established manufactories of sulphur1 sulphuric acid1 and red ochre4 ,in #aghj the ,royal ,college of ,mines1 as a testimony of their sense of the value of ,gahn's improvements1 presented him with a gold medal of merit4 ,in #aghb he received a royal patent as mining master4 ,in #aghd he was appointed assessor in the ,royal ,college of ,mines1 in which capacity he officiated as often as his other vocations permitted him to reside in ,stockholm4 ,the same year he married ,anna ,maria ,bergstrom1 with whom he enjoyed for thirty-one years a life of uninterrupted happiness4 ,by his wife he had a son and two daughters4 ,in the year #aggc he had been elected chemical stipendiary to the ,royal ,college of ,mines1 and he continued to hold this appointment till the year #ahad4 ,during the whole of this period the solution of almost every difficult problem remitted to the college devolved upon him4 ,in #agie he was chosen a member of the committee for directing the general affairs of the kingdom4 ,in #ahaj he was made one of the committee for the general maintenance of the poor4 ,in #ahab he was elected an active associate of the ,royal ,academy for ,agriculture2 and in #ahaf he became a member of the committee for organizing the plan of a ,mining ,institute4 ,in #ahah he was chosen a member of the committee of the ,mint2 but from this situation he was shortly after1 at his own request1 permitted to withdraw4 ,his wife died in #ahae1 and from that period his health1 which had never been robust1 visibly declined4 ,nature occasionally made an effort to shake off the disease2 but it constantly returned with increasing strength1 until1 in the autumn of #ahah1 the decay became more rapid in its progress1 and more decided in its character4 ,he became gradually weaker1 and on the #hth of ,december1 #ahah1 died without a struggle1 and seemingly without pain4 ,ever after the experiments on the blowpipe which ,gahn performed at the request of ,bergman1 his attention had been turned to that piece of apparatus2 and during the course of a long life he had introduced so many improvements1 that he was enabled1 by means of the blowpipe1 to determine in a few minutes the constituents of almost any mineral4 ,he had gone over almost all the mineral kingdom1 and determined the behaviour of almost every mineral before the blowpipe1 both by itself and when mixed with the different fluxes and reagents which he had invented for the purpose of detecting the different constituents2 but1 from his characteristic unwillingness to commit his observations and experiments to writing1 or to draw them up into a regular memoir1 had not ,berzelius offered himself as an assistant1 they would probably have been lost4 ,by his means a short treatise on the blowpipe1 with minute directions how to use the different contrivances which he had invented1 was drawn up and inserted in the second volume of ,berzelius's ,chemistry4 ,berzelius and he afterwards examined all the minerals known1 or at least which they could procure1 before the blowpipe2 and the result of the whole constituted the materials of ,berzelius's treatise on the blowpipe1 which has been translated into ,german1 ,french1 and ,english4 ,it may be considered as containing the sum of all the improvements which ,gahn had made on the use of the blowpipe1 together with all the facts that he had collected respecting the phenomena exhibited by minerals before the blowpipe4 ,it constitutes an exceedingly useful and valuable book1 and ought to make a part of the library of every analytical chemist4 ,dr4 ,wollaston had paid as much attention to the blowpipe as ,gahn1 and had introduced so many improvements into its use1 that he was able1 by means of it1 to determine the nature of the constituents of any mineral in the course of a few minutes4 ,he was fond of such analytical experiments1 and was generally applied to by every person who thought himself possessed of a new mineral1 in order to be enabled to state what its constituents were4 ,the ,london mineralogists if the race be not extinct1 must sorely feel the want of the man to whom they were in the habit of applying on all occasions1 and to whom they never applied in vain4 ,dr4 ,william ,hyde ,wollaston1 was the son of the ,reverend ,dr4 ,wollaston1 a clergyman of some rank in the church of ,england1 and possessed of a competent fortune4 ,he was a man of abilities1 and rather eminent as an astronomer4 ,his grandfather was the celebrated author of the ,religion of ,nature delineated4 ,dr4 ,william ,hyde ,wollaston was born about the year #agfg1 and was one of fifteen children1 who all reached the age of manhood4 ,his constitution was naturally feeble2 but by leading a life of the strictest sobriety and abstemiousness he kept himself in a state fit for mental exertion4 ,he was educated at ,cambridge1 where he was at one time a fellow4 ,after studying medicine by attending the hospitals and lectures in ,london1 and taking his degree of doctor at ,cambridge1 he settled at ,bury ,st4 ,edmund's1 where he practised as a physician for some years4 ,he then went to ,london1 became a fellow of the ,royal ,college of ,physicians1 and commenced practitioner in the metropolis4 ,a vacancy occurring in ,st4 ,george's ,hospital1 he offered himself for the place of physician to that institution2 but another individual1 whom he considered his inferior in knowledge and science1 having been preferred before him1 he threw up the profession of medicine altogether1 and devoted the rest of his life to scientific pursuits4 ,his income1 in consequence of the large family of his father1 was of necessity small4 ,in order to improve it he turned his thoughts to the manufacture of platinum1 in which he succeeded so well1 that he must have1 by means of it1 realized considerable sums4 ,it was he who first succeeded in reducing it into ingots in a state of purity and fit for every kind of use3 it was employed1 in consequence1 for making vessels for chemical purposes2 and it is to its introduction that we are to ascribe the present accuracy of chemical investigations4 ,it has been gradually introduced into the sulphuric acid manufactories1 as a substitute for glass retorts4 ,dr4 ,wollaston had a particular turn for contriving pieces of apparatus for scientific purposes4 ,his reflecting goniometer was a most valuable present to mineralogists1 and it is by its means that crystallography has acquired the great degree of perfection which it has recently exhibited4 ,he contrived a very simple apparatus for ascertaining the power of various bodies to refract light4 ,his camera lucida furnished those who were ignorant of drawing with a convenient method of delineating natural objects4 ,his periscopic glasses must have been found useful1 for they sold rather extensively3 and his sliding rule for chemical equivalents furnished a ready method for calculating the proportions of one substance necessary to decompose a given weight of another4 ,dr4 ,wollaston's knowledge was more varied1 and his taste less exclusive than any other philosopher of his time1 except ,mr4 ,cavendish3 but optics and chemistry are the two sciences which lie under the greatest obligations to him4 ,his first chemical paper on urinary calculi at once added a vast deal to what had been previously known4 ,he first pointed out the constituents of the mulberry calculi1 showing them to be composed of oxalate of lime and animal matter4 ,he first distinguished the nature of the triple phosphates4 ,it was he who first ascertained the nature of the cystic oxides1 and of the chalk-stones1 which appear occasionally in the joints of gouty patients4 ,to him we owe the first demonstration of the identity of galvanism and common electricity2 and the first explanation of the cause of the different phenomena exhibited by galvanic and common electricity4 ,to him we are indebted for the discovery of palladium and rhodium1 and the first account of the properties and characters of these two metals4 ,he first showed that oxalic acid and potash unite in three different proportions1 constituting oxalate1 binoxalate1 and quadroxalate of potash4 ,many other chemical facts1 first ascertained by him1 are to be found in the numerous papers of his scattered over the last forty volumes of the ,philosophical ,transactions3 and perhaps not the least valuable of them is his description of the mode of reducing platinum from the raw state1 and bringing it into the state of an ingot4 ,dr4 ,wollaston died in the month of ,january1 #ahbi1 in consequence of a tumour formed in the brain1 near1 if ,i remember right1 the thalami nervorum opticorum4 ,there is reason to suspect that this tumour had been some time in forming4 ,he had1 without exception1 the sharpest eye that ,i have ever seen3 he could write with a diamond upon glass in a character so small1 that nothing could be distinguished by the naked eye but a ragged line2 yet when the letters were viewed through a microscope1 they were beautifully regular and quite legible4 ,he retained his senses to almost the last moment of his life3 when he lay apparently senseless1 and his friends were anxiously solicitous whether he still retained his understanding1 he informed them1 by writing1 that his senses were still perfectly entire4 ,few individuals ever enjoyed a greater share of general respect and confidence1 or had fewer enemies1 than ,dr4 ,wollaston4 ,he was at first shy and distant1 and remarkably circumspect1 but he grew insensibly more and more agreeable as you got better acquainted with him1 till at last you formed for him the most sincere friendship1 and your acquaintance ended in the warmest and closest attachment4 ,,chapter ,v4 ,,of ,,electro-,,chemistry4 ,electricity1 like chemistry1 is a modern science2 for it can scarcely claim an older origin than the termination of the first quarter of the preceding century2 and during the last half of that century1 and a small portion of the present1 it participated with chemistry in the zeal and activity with which it was cultivated by the philosophers of ,europe and ,america4 ,for many years it was not suspected that any connexion existed between chemistry and electricity2 though some of the meteorological phenomena1 especially the production of clouds and the formation of rain1 which are obviously connected with chemistry1 seem likewise to claim some connexion with the agency of electricity4 ,the discovery of the intimate relation between chemistry and electricity was one of the consequences of a controversy carried on about the year #agij between ,galvani and ,volta1 two ,italian philosophers1 whose discoveries will render their names immortal4 ,galvani1 who was a professor of anatomy1 was engaged in speculations respecting muscular motion4 ,he was of opinion that a peculiar fluid was secreted in the brain1 which was sent along the nerves to all the different parts of the body4 ,this nervous fluid possessed many characters analogous to those of electricity3 the muscles were capable of being charged with it somewhat like a ,leyden phial2 and it was by the discharge of this accumulation1 by the voluntary power of the nerves1 that muscular motion was produced4 ,he accidently discovered1 that if the crural nerve going into the muscles of a frog1 and the crural muscles1 be laid bare immediately after death1 and a piece of zinc be placed in contact with the nerve1 and a piece of silver or copper with the muscle2 when these two pieces of metal are made to touch each other1 violent convulsions are produced in the muscle1 which cause the limb to move4 ,he conceived that these convulsions were produced by the discharge of the nervous energy from the muscles1 in consequence of the conducting power of the metals4 ,volta1 who repeated these experiments1 explained them in a different manner4 ,according to him1 the convulsions were produced by the passage of a current of common electricity through the limb of the frog1 which was thrown into a state of convulsion merely in consequence of its irritability4 ,this irritability vanishes after the death of the muscle2 accordingly it is only while the principle of life remains that the convulsions can be produced4 ,every metallic conductor1 according to him1 possesses a certain electricity which is peculiar to it1 either positive or negative1 though the quantity is so small1 as to be imperceptible1 in the common state of the metal4 ,but if a metal1 naturally positive1 be placed in contact1 while insulated1 with a metal naturally negative1 the charge of electricity in both is increased by induction1 and becomes perceptible when the two metals are separated and presented to a sufficiently delicate electrometer4 ,thus zinc is naturally positive1 and copper and silver naturally negative4 ,if we take two discs of copper and zinc1 to the centre of each of which a varnished glass handle is cemented1 and after keeping them for a short time in contact1 separate them by the handles1 and apply each to a sufficiently delicate electrometer1 we shall find that the zinc is positive1 and the silver or copper disc negative4 ,when the silver and copper are placed in contact while lying on the nerve and muscles of the leg of a frog1 the zinc becomes positive1 and the silver negative1 by induction2 but1 as the animal substance is a conductor1 this state cannot continue3 the two electricities pass through the conducting muscles and nerve1 and neutralize one another4 ,and it is this current which occasions the convulsions4 ,such was ,volta's simple explanation of the convulsions produced in galvanic experiments in the limb of a frog4 ,galvani was far from allowing the accuracy of it2 and1 in order to obviate the objection to his reasoning advanced by ,volta from the necessity of employing two metals1 he showed that the convulsions might1 in certain cases1 be produced by one metal4 ,volta showed that a very small quantity of one metal1 either alloyed with1 or merely in contact with another1 were capable of inducing the two electricities4 ,but in order to prove in the most unanswerable manner that the two electricities were induced when two different metals were placed in contact1 he contrived the following piece of apparatus3 ,he procured a number 7say #ej7 of pieces of zinc1 about the size of a crown-piece1 and as many pieces of copper1 and thirdly1 the same number of pieces of card of the same size4 ,the cards were steeped in a solution of salt1 so as to be moist4 ,he lays upon the table a piece of zinc1 places over it a piece of copper1 and then a piece of moist card4 ,over the card is placed a second piece of zinc1 then a piece of copper1 then a piece of wet card4 ,in this way all the pieces are piled upon each other in exactly the same order1 namely1 zinc1 copper1 card2 zinc1 copper1 card2 zinc1 copper1 card4 ,so that the lowest plate is zinc and the uppermost is copper 7for the last wet card may be omitted74 ,in this way there are fifty pairs of zinc and copper plates in contact1 each separated by a piece of wet card1 which is a conductor of electricity4 ,if you now moisten a finger of each hand with water1 and apply one wet finger to the lowest zinc plate1 and the other to the highest copper plate1 the moment the fingers come in contact with the plates an electric shock is felt1 the intensity of which increases with the number of pairs of plates in the pile4 ,this is what is called the ,galvanic1 or rather the ,voltaic pile4 ,it was made known to the public in a paper by ,volta1 inserted in the ,philosophical ,transactions for #ahjj4 ,this pile was gradually improved1 by substituting troughs1 first of baked wood1 and afterwards of porcelain1 divided into as many cells as there were pairs of plates4 ,the size of the plates was increased2 they were made square1 and instead of all being in contact1 it was found sufficient if they were soldered together by means of metallic slips rising from one side of each square4 ,the two plates thus soldered were slipped over the diaphragm separating the contiguous cells1 so that the zinc plate was in one cell and the copper in the other4 ,care was taken that the pairs were introduced all looking one way1 so that a copper plate had always a zinc plate immediately opposite to it4 ,the cells were filled with conducting liquid3 brine1 or a solution of salt in vinegar1 or dilute muriatic1 sulphuric1 or nitric acid1 might be employed2 but dilute nitric acid was found to answer best1 and the energy of the battery is directly proportional to the strength of the nitric acid employed4 ,messrs4 ,nicholson and ,carlisle were the first persons who repeated ,volta's experiments with this apparatus1 which speedily drew the attention of all ,europe4 ,they ascertained that the zinc end of the pile was positive and the copper end negative4 ,happening to put a drop of water on the uppermost plate1 and to put into it the extremity of a gold wire connected with the undermost plate1 they observed an extrication of air-bubbles from the wire4 ,this led them to suspect that the water was decomposed4 ,to determine the point1 they collected a little of the gas extricated and found it hydrogen4 ,they then attached a gold wire to the zinc end of the pile1 and another gold wire to the copper end1 and plunged the two wires into a glass of water1 taking care not to allow them to touch each other4 ,gas was extricated from both wires4 ,on collecting that from the wire attached to the zinc end1 it was found to be oxygen gas1 while that from the copper end was hydrogen gas4 ,the volume of hydrogen gas extricated was just double that of the oxygen gas2 and the two gases being mixed1 and an electric spark passed through them1 they burnt with an explosion1 and were completely converted into water4 ,thus it was demonstrated that water was decomposed by the action of the pile1 and that the oxygen was extricated from the positive pile and the hydrogen from the negative4 ,this held when the communicating wires were gold or platinum2 but if they were of copper1 silver1 iron1 lead1 tin1 or zinc1 then only hydrogen gas was extricated from the negative wire4 ,the positive wire extricated little or no gas2 but it was rapidly oxidized4 ,thus the connexion between chemical decompositions and electrical currents was first established4 ,it was soon after observed by ,henry1 ,haldane1 ,davy1 and other experimenters1 that other chemical compounds were decomposed by the electrical currents as well as water4 ,ammonia1 for example1 nitric acid1 and various salts1 were decomposed by it4 ,in the year #ahjc an important set of experiments was published by ,berzelius and ,hisinger4 ,they decomposed eleven different salts1 by exposing them to the action of a current of electricity4 ,the salts were dissolved in water1 and iron or silver wires from the two poles of the pile were plunged into the solution4 ,in every one of these decompositions1 the acid was deposited round the positive wire1 and the base of the salt round the negative wire4 ,when ammonia was decomposed by the action of galvanic electricity1 the azotic gas separated from the positive wire1 and the hydrogen gas from the negative4 ,but it was ,davy that first completely elucidated the chemical decompositions produced by galvanic electricity1 who first explained the laws by which these decompositions were regulated1 and who employed galvanism as an instrument for decomposing various compounds1 which had hitherto resisted all the efforts of chemists to reduce them to their elements4 ,these discoveries threw a blaze of light upon the obscurest parts of chemistry1 and secured for the author of them an immortal reputation4 ,humphry ,davy1 to whom these splendid discoveries were owing1 was born at ,penzance1 in ,cornwall1 in the year #aggh4 ,he displayed from his very infancy a spirit of research1 and a brilliancy of fancy1 which augured1 even at that early period1 what he was one day to be4 ,when very young1 he was bound apprentice to an apothecary in his native town4 ,even at that time1 his scientific acquirements were so great1 that they drew the attention of ,mr4 ,davis ,gilbert1 the late distinguished president of the ,royal ,society4 ,it was by his advice that he resolved to devote himself to chemistry1 as the pursuit best calculated to procure him celebrity4 ,about this time ,mr4 ,gregory ,watt1 youngest son of the celebrated improver of the steam-engine1 happening to be at ,penzance1 met with young ,davy1 and was delighted with the uncommon knowledge which he displayed1 at the brilliancy of his fancy1 and the great dexterity and ardour with which1 under circumstances the most unfavourable1 he was prosecuting his scientific investigations4 ,these circumstances made an indelible impression on his mind1 and led him to recommend ,davy as the best person to superintend the ,bristol ,institution for trying the medicinal effects of the gases4 ,after the discovery of the different gases1 and the investigation of their properties by ,dr4 ,priestley1 it occurred to various individuals1 nearly about the same time1 that the employment of certain gases1 or at least of mixtures of certain gases1 with common air in respiration1 instead of common air1 might be powerful means of curing diseases4 ,dr4 ,beddoes1 at that time professor of chemistry at ,oxford1 was one of the keenest supporters of these opinions4 ,mr4 ,watt1 of ,birmingham1 and ,mr4 ,wedgewood1 entertained similar sentiments4 ,about the beginning of the present century1 a sum of money was raised by subscription1 to put these opinions to the test of experiment2 and1 as ,dr4 ,beddoes had settled as a physician in ,bristol1 it was agreed upon that the experimental investigation should take place at ,bristol4 ,but ,dr4 ,beddoes was not qualified to superintend an institution of the kind3 it was necessary to procure a young man of zeal and genius1 who would take such an interest in the investigation as would compensate for the badness of the apparatus and the defects of the arrangements4 ,the greatest part of the money had been subscribed by ,mr4 ,wedgewood and ,mr4 ,watt3 their influence of course would be greatest in recommending a proper superintendent4 ,gregory ,watt thought of ,mr4 ,davy1 whom he had lately been so highly pleased with1 and recommended him with much zeal to superintend the undertaking4 ,this recommendation being seconded by that of ,mr4 ,davis ,gilbert1 who was so well acquainted with the scientific acquirements and genius of ,davy1 proved successful1 and ,davy accordingly got the appointment4 ,at ,bristol he was employed about a year in investigating the effects of the gases when employed in respiration4 ,but he did not by any means confine himself to this1 which was the primary object of the institution2 but investigated the properties and determined the composition of nitric acid1 ammonia1 protoxide of azote and deutoxide of azote4 ,the fruit of his investigations was published in #ahjj1 in a volume entitled1 ,researches1 ,chemical and ,philosophical2 chiefly concerning ,nitrous ,oxide1 or ,dephlogisticated ,nitrous ,air1 and its ,respiration4 ,this work gave him at once a high reputation as a chemist1 and was really a wonderful performance1 when the circumstances under which it was produced are taken into consideration4 ,he had discovered the intoxicating effects which protoxide of azote 7nitrous oxide7 produces when breathed1 and had tried their effects upon a great number of individuals4 ,this fortunate discovery perhaps contributed more to his celebrity1 and to his subsequent success1 than all the sterling merit of the rest of his researches--so great is the effect of display upon the greater part of mankind4 ,a few years before1 a philosophical institution had been established in ,london1 under the auspices of ,count ,rumford1 which had received the name of the ,royal ,institution4 ,lectures on chemistry and natural philosophy were delivered in this institution2 a laboratory was provided1 and a library established4 ,the first professor appointed to this institution1 ,dr4 ,garnet1 had been induced1 in consequence of some disagreement between him and ,count ,rumford1 to throw up his situation4 ,many candidates started for it2 but ,davy1 in consequence of the celebrity which he had acquired by his researches1 or perhaps by the intoxicating effects of protoxide of azote1 which he had discovered1 was1 fortunately for the institution and for the reputation of ,england1 preferred to them all4 ,he was appointed professor of chemistry1 and ,dr4 ,thomas ,young professor of natural philosophy1 in the year #ahja4 ,davy1 either from the more popular nature of his subject1 or from his greater oratorical powers1 became at once a popular lecturer1 and always lectured to a crowded room2 while ,dr4 ,young1 though both a profound and clear lecturer1 could scarcely command an audience of a dozen4 ,it was here that ,davy laboured with unwearied industry during eleven years1 and acquired1 by his discoveries the highest reputation of any chemist in ,europe4 ,in #ahaa he was knighted1 and soon after married ,mrs4 ,apreece1 a widow lady1 daughter of ,mr4 ,ker1 who had been secretary to ,lord ,rodney1 and had made a fortune in the ,west ,indies4 ,he was soon after created a baronet4 ,about this time he resigned his situation as professor of chemistry in the ,royal ,institution1 and went to the continent4 ,he remained for some years in ,france and ,italy4 ,in the year #ahba1 when ,sir ,joseph ,banks died1 a very considerable number of the fellows offered their votes to ,dr4 ,wollaston2 but he declined standing as a candidate for the president's chair4 ,sir ,humphry ,davy1 on the other hand1 was anxious to obtain that honourable situation1 and was accordingly elected president by a very great majority of votes on the #cjth of ,november1 #ahba4 ,this honourable situation he filled about seven years2 but his health declining1 he was induced to resign in #ahbh1 and to go to ,italy4 ,here he continued till #ahbi1 when feeling himself getting worse1 and wishing to draw his last breath in his own country1 he began to turn his way homewards2 but at ,geneva he felt himself so ill1 that he was unable to proceed further3 here he took to his bed1 and here he died on the #bith of ,may1 #ahbi4 ,it was his celebrated paper ,on some chemical ,agencies of ,electricity1 inserted in the ,philosophical ,transactions for #ahjg1 that laid the foundation of the high reputation which he so deservedly acquired4 ,i consider this paper not merely as the best of all his own productions1 but as the finest and completest specimen of inductive reasoning which appeared during the age in which he lived4 ,it had been already observed1 that when two platinum wires from the two poles of a galvanic pile are plunged each into a vessel of water1 and the two vessels united by means of wet asbestos1 or any other conducting substance1 an acid appeared round the positive wire and an alkali round the negative wire4 ,the alkali was said by some to be soda1 by others to be ammonia4 ,the acid was variously stated to be nitric acid1 muriatic acid1 or even chlorine4 ,davy demonstrated1 by decisive experiments1 that in all cases the acid and alkali are derived from the decomposition of some salt contained either in the water or in the vessel containing the water4 ,most commonly the salt decomposed is common salt1 because it exists in water and in agate1 basalt1 and various other stony bodies1 which he employed as vessels4 ,when the same agate cup was used in successive experiments1 the quantity of acid and alkali evolved diminished each time1 and at last no appreciable quantity could be perceived4 ,when glass vessels were used1 soda was disengaged at the expense of the glass1 which was sensibly corroded4 ,when the water into which the wires were dipped was perfectly pure1 and when the vessel containing it was free from every trace of saline matter1 no acid or alkali made its appearance1 and nothing was evolved except the constituents of water1 namely1 oxygen and hydrogen2 the oxygen appearing round the positive wire1 and the hydrogen round the negative wire4 ,when a salt was put into the vessel in which the positive wire dipped1 the vessel into which the negative wire dipped being filled with pure water1 and the two vessels being united by means of a slip of moistened asbestos1 the acid of the salt made its appearance round the positive wire1 and the alkali round the negative wire1 before it could be detected in the intermediate space2 but if an intermediate vessel1 containing a substance for which the alkali has a strong affinity1 be placed between these two vessels1 the whole being united by means of slips of asbestos1 then great part1 or even the whole of the alkali1 was stopped in this intermediate vessel4 ,thus1 if the salt was nitrate of barytes1 and sulphuric acid was placed in the intermediate vessel1 much sulphate of barytes was deposited in the intermediate vessel1 and very little or even no barytes made its appearance round the negative wire4 ,upon this subject a most minute1 extensive1 and satisfactory series of experiments was made by ,davy1 leaving no doubt whatever of the accuracy of the fact4 ,the conclusions which he drew from these experiments are1 that all substances which have a chemical affinity for each other1 are in different states of electricity1 and that the degree of affinity is proportional to the intensity of these opposite states4 ,when such a compound body is placed in contact with the poles of a galvanic battery1 the positive pole attracts the constituent1 which is negative1 and repels the positive4 ,the negative acts in the opposite way1 attracting the positive constituent and repelling the negative4 ,the more powerful the battery1 the greater is the force of these attractions and repulsions4 ,we may1 therefore1 by increasing the energy of a battery sufficiently1 enable it to decompose any compound whatever1 the negative constituent being attracted by the positive pole1 and the positive constituent by the negative pole4 ,oxygen1 chlorine1 bromine1 iodine1 cyanogen1 and acids1 are negative bodies2 for they always appear round the positive pole of the battery1 and are therefore attracted to it3 while hydrogen1 azote1 carbon1 selenium1 metals1 alkalies1 earths1 and oxide bases1 are deposited round the negative pole1 and consequently are positive4 ,according to this view of the subject1 chemical affinity is merely a case of the attractions exerted by bodies in different states of electricity4 ,volta first broached the idea1 that every body possesses naturally a certain state of electricity4 ,davy went a step further1 and concluded1 that the attractions which exist between the atoms of different bodies are merely the consequence of these different states of electricity4 ,the proof of this opinion is founded on the fact1 that if we present to a compound1 sufficiently strong electrical poles1 it will be separated into its constituents1 and one of these constituents will invariably make its way to the positive and the other to the negative pole4 ,now bodies in a state of electrical excitement always attract those that are in the opposite state4 ,if electricity be considered as consisting of two distinct fluids1 which attract each other with a force inversely1 as the square of the distance1 while the particles of each fluid repel each other with a force varying according to the same law1 then we must conclude that the atoms of each body are covered externally with a coating of some one electric fluid to a greater or smaller extent4 ,oxygen and the other supporters of combustion are covered with a coating of negative electricity2 while hydrogen1 carbon1 and the metals1 are covered with a coating of positive electricity4 ,what is the cause of the adherence of the electricity to these atoms we cannot explain4 ,it is not owing to an attraction similar to gravitation2 for electricity never penetrates into the interior of bodies1 but spreads itself only on the surface1 and the quantity of it which can accumulate is not proportional to the quantity of matter but to the extent of surface4 ,but whatever be the cause1 the adhesion is strong1 and seemingly cannot be overcome4 ,if we were to suppose an atom of any body1 of oxygen for example1 to remain uncombined with any other body1 but surrounded by electricity1 it is obvious that the coating of negative electricity on its surface would be gradually neutralized by its attracting and combining with positive electricity4 ,but let us suppose an atom of oxygen and an atom of hydrogen to be united together1 it is obvious that the positive electricity of the one atom would powerfully attract the negative electricity of the other1 and vice vers4 ,and if these respective electricities cannot leave the atoms1 the two atoms will remain firmly united1 and the opposite electrical intensities will in some measure neutralize each other1 and thus prevent them from being neutralized by electricity from any other quarter4 ,but a current of the opposite electricities passing through such a compound1 might neutralize the electricity in each1 and thus putting an end to their attractions1 occasion decomposition4 ,such is a very imperfect outline of the electrical theory of affinity first proposed by ,davy to account for the decompositions produced by electricity4 ,it has been universally adopted by chemists2 and some progress has been made in explaining and accounting for the different phenomena4 ,it would be improper1 in a work of this kind1 to enter further into the subject4 ,those who are interested in such discussions will find a good deal of information in the first volume of ,berzelius's ,treatise on ,chemistry1 in the introduction to the ,trait de ,chimie appliqu aux ,arts1 by ,dumas1 or in the introduction to my ,system of ,chemistry1 at present in the press4 ,davy having thus got possession of an engine1 by means of which the compounds1 whose constituents adhered to each other might be separated1 immediately applied it to the decomposition of potash and soda2 bodies which were admitted to be compounds1 though all attempts to analyze them had hitherto failed4 ,his attempt was successful4 ,when a platinum wire from the negative pole of a strong battery in full action was applied to a lump of potash1 slightly moistened1 and lying on a platinum tray attached to the positive pole of the battery1 small globules of a white metal soon appeared at its extremity4 ,this white metal he speedily proved to be the basis of potash4 ,he gave it the name of potassium1 and very soon proved1 that potash is a compound of five parts by weight of this metal and one part of oxygen4 ,potash1 then1 is a metallic oxide4 ,he proved soon after that soda is a compound of oxygen and another white metal1 to which he gave the name of sodium4 ,lime is a compound of calcium and oxygen1 magnesia of magnesium and oxygen1 barytes of barium and oxygen1 and strontian of strontium and oxygen4 ,in short1 the fixed alkalies and alkaline earths1 are metallic oxides4 ,when lithia was afterwards discovered by ,arfvedson1 ,davy succeeded in decomposing it also by the galvanic battery1 and resolving it into oxygen and a white metal1 to which the name of lithium was given4 ,davy did not succeed so well in decomposing alumina1 glucina1 yttria1 and zirconia1 by the galvanic battery3 they were not sufficiently good conductors of electricity2 but nobody entertained any doubt that they also were metallic oxides4 ,they have been all at length decomposed1 and their bases obtained by the joint action of chlorine and potassium1 and it has been demonstrated1 that they also are metallic oxides4 ,thus it has been ascertained1 in consequence of ,davy's original discovery of the powers of the galvanic battery1 that all the bases formerly distinguished into the four classes of alkalies1 alkaline earths1 earths proper1 and metallic oxides1 belong in fact only to one class1 and are all metallic oxides4 ,important as these discoveries are1 and sufficient as they would have been to immortalize the author of them1 they are not the only ones for which we are indebted to ,sir ,humphry ,davy4 ,his experiments on chlorine are not less interesting or less important in their consequences4 ,i have already mentioned in a former chapter1 that ,berthollet made a set of experiments on chlorine1 from which he had drawn as a conclusion1 that it is a compound of oxygen and muriatic acid1 in consequence of which it got the name of oxymuriatic acid4 ,this opinion of ,berthollet had been universally adopted by chemists1 and admitted by them as a fundamental principle1 till ,gay-,lussac and ,thenard endeavoured1 unsuccessfully1 to decompose this gas1 or to resolve it into muriatic acid and chlorine4 ,they showed1 in the clearest manner1 that such a resolution was impossible1 and that no direct evidence could be adduced to prove that oxygen was one of its constituents4 ,the conclusion to which they came was1 that muriatic acid gas contained water as an essential constituent2 and they succeeded by this hypothesis in accounting for all the different phenomena which they had observed4 ,they even made an experiment to determine the quantity of water thus combined4 ,they passed muriatic acid through hot litharge 7protoxide of lead72 muriate of lead was formed1 and abundance of water made its appearance and was collected4 ,they did not attempt to determine the proportions2 but we can now easily calculate the quantity of water which would be deposited when a given weight of muriatic acid gas is absorbed by a given weight of litharge4 ,suppose we have fourteen parts of oxide of lead3 to convert it into muriate of lead1 #dfbe parts 7by weight7 of muriatic acid would be necessary1 and during the formation of the muriate of lead there would be deposited #aabe parts of water4 ,so that from this experiment it might be concluded1 that about one-fourth of the weight of muriatic acid gas is water4 ,the very curious and important facts respecting chlorine and muriatic acid gas which they had ascertained1 were made known by ,gay-,lussac and ,thenard to the ,institute1 on the #bgth of ,february1 #ahji1 and an abstract of them was published in the second volume of the ,mmoires d',arcueil4 ,there can be little doubt that it was in consequence of these curious and important experiments of the ,french chemists that ,davy's attention was again turned to muriatic acid gas4 ,he had already1 in #ahjh1 shown that when potassium is heated in muriatic acid gas1 muriate of potash is formed1 and a quantity of hydrogen gas evolved1 amounting to more than one-third of the muriatic acid gas employed1 and he had shown1 that in no case can muriatic acid be obtained from chlorine1 unless water or its elements be present4 ,this last conclusion had been amply confirmed by the new investigations of ,gay-,lussac and ,thenard4 ,in #ahaj ,davy again resumed the examination of the subject1 and in ,july of that year read a paper to the ,royal ,society1 to prove that chlorine is a simple substance1 and that muriatic acid is a compound of chlorine and hydrogen4 ,this was introducing an alteration in chemical theory of the same kind1 and nearly as important1 as was introduced by ,lavoisier1 with respect to the action of oxygen in the processes of combustion and calcination4 ,it had been previously supposed that sulphur1 phosphorus1 charcoal1 and metals1 were compounds2 one of the constituents of which was phlogiston1 and the other the acids or oxides which remained after the combustion or calcination had taken place4 ,lavoisier showed that the sulphur1 phosphorus1 charcoal1 and metals1 were simple substances2 and that the acids or calces formed were compounds of these simple bodies and oxygen4 ,in like manner1 ,davy showed that chlorine1 instead of being a compound of muriatic acid and oxygen1 was1 in fact1 a simple substance1 and muriatic acid a compound of chlorine and hydrogen4 ,this new doctrine immediately overturned the ,lavoisierian hypothesis respecting oxygen as the acidifying principle1 and altered all the previously received notions respecting the muriates4 ,what had been called muriates were1 in fact1 combinations of chlorine with the combustible or metal1 and were analogous to oxides4 ,thus1 when muriatic acid gas was made to act upon hot litharge1 a double decomposition took place1 the chlorine united to the lead1 while the hydrogen of the muriatic acid united with the oxygen of the litharge1 and formed water4 ,hence the reason of the appearance of water in this case2 and hence it was obvious that what had been called muriate of lead1 was1 in reality1 a compound of chlorine and metallic lead4 ,it ought1 therefore1 to be called1 not muriate of lead1 but chloride of lead4 ,it was not likely that this new opinion of ,davy should be adopted by chemists in general1 without a struggle to support the old opinions4 ,but the feebleness of the controversy which ensued1 affords a striking proof how much chemistry had advanced since the days of ,lavoisier1 and how free from prejudices chemists had become4 ,one would have expected that the ,french chemists would have made the greatest resistance to the admission of these new opinions2 because they had a direct tendency to diminish the reputation of two of their most eminent chemists1 ,lavoisier and ,berthollet4 ,but the fact was not so3 the ,french chemists showed a degree of candour and liberality which redounds highly to their credit4 ,berthollet did not enter at all into the controversy4 ,gay-,lussac and ,thenard1 in their ,recherches ,physico-chimiques1 published in #ahaa1 state their reasons for preferring the old hypothesis to the new1 but with great modesty and fairness2 and1 within less than a year after1 they both adopted the opinion of ,davy1 that chlorine is a simple substance1 and muriatic acid a compound of hydrogen and chlorine4 ,the only opponents to the new doctrine who appeared against it1 were ,dr4 ,john ,murray1 of ,edinburgh1 and ,professor ,berzelius1 of ,stockholm4 ,dr4 ,murray was a man of excellent abilities1 and a very zealous cultivator of chemistry2 but his health had been always very delicate1 which had prevented him from dedicating so much of his time to experimenting as he otherwise would have been inclined to do4 ,the only experimental investigations into which he entered was the analysis of some mineral waters4 ,his powers of elocution were great4 ,he was1 in consequence1 a popular and very useful lecturer4 ,he published animadversions upon the new doctrine respecting chlorine1 in ,nicholson's ,journal2 and his observations were answered by ,dr4 ,john ,davy4 ,dr4 ,john ,davy was the brother of ,sir ,humphry1 and had shown1 by his paper on fluoric acid and on the chlorides1 that he possessed the same dexterity and the same powers of inductive reasoning1 which had given so much celebrity to his brother4 ,the controversy between him and ,dr4 ,murray was carried on for some time with much spirit and ingenuity on both sides1 and was productive of some advantage to the science of chemistry1 by the discovery of phosgene gas or chlorocarbonic acid1 which was made by ,dr4 ,davy4 ,it is needless to say to what side the victory fell4 ,the whole chemical world has for several years unanimously adopted the theory of ,davy2 showing sufficiently the opinion entertained respecting the arguments advanced by either party4 ,berzelius supported the old opinion respecting the compound nature of chlorine1 in a paper which he published in the ,annals of ,philosophy4 ,no person thought it worth while to answer his arguments1 though ,sir ,humphry ,davy made a few animadversions upon one or two of his experiments4 ,the discovery of iodine1 which took place almost immediately after1 afforded so close an analogy with chlorine1 and the nature of the compounds which it forms was so obvious and so well made out1 that chemists were immediately satisfied2 and they furnished so satisfactory an answer to all the objections of ,berzelius1 that ,i am not aware of any person1 either in ,great ,britain or in ,france1 who adopted his opinions4 ,i have not the same means of knowing the impression which his paper made upon the chemists of ,germany and ,sweden4 ,berzelius continued for several years a very zealous opponent to the new doctrine1 that chlorine is a simple substance4 ,but he became at last satisfied of the futility of his own objections1 and the inaccuracy of his reasoning4 ,about the year #ahbj he embraced the opinion of ,davy1 and is now one of its most zealous defenders4 ,dr4 ,murray has been dead for many years1 and ,berzelius has renounced his notion1 that muriatic acid is a compound of oxygen and an unknown combustible basis4 ,we may say then1 ,i believe with justice1 that at present all the chemical world adopts the notion that chlorine is a simple substance1 and muriatic acid a compound of chlorine and hydrogen4 ,the recent discovery of bromine1 by ,balard1 has added another strong analogy in favour of ,davy's theory2 as has likewise the discovery by ,gay-,lussac respecting prussic acid4 ,at present1 then1 7not reckoning sulphuretted and telluretted hydrogen gas71 we are acquainted with four acids which contain no oxygen1 but are compounds of hydrogen with another negative body4 ,these are ,muriatic acid1 composed of chlorine and hydrogen ,hydriodic acid iodine and hydrogen ,hydrobromic acid bromine and hydrogen ,prussic acid cyanogen and hydrogen4 ,so that even if we were to leave out of view the chlorine acids1 the sulphur acids1 c41 no doubt can be entertained that many acids exist which contain no oxygen4 ,acids are compounds of electro-negative bodies and a base1 and in them all the electro-negative electricity continues to predominate4 ,next to ,sir ,humphry ,davy1 the two chemists who have most advanced electro-chemistry are ,gay-,lussac and ,thenard4 ,about the year #ahjh1 when the attention of men of science was particularly drawn towards the galvanic battery1 in consequence of the splendid discoveries of ,sir ,humphry ,davy1 ,bonaparte1 who was at that time ,emperor of ,france1 consigned a sufficient sum of money to ,count ,cessac1 governor of the ,polytechnic ,school1 to construct a powerful galvanic battery2 and ,gay-,lussac and ,thenard were appointed to make the requisite experiments with this battery4 ,it was impossible that a better choice could have been made4 ,these gentlemen undertook a most elaborate and extensive set of experiments1 the result of which was published in #ahaa1 in two octavo volumes1 under the title of ,recherches ,physico-chimiques1 faites sur la ,pile2 sur la ,preparation chimique et les ,proprits du ,potassium et du ,sodium2 sur la ,dcomposition de l',acide boracique2 sur les ,acides fluorique1 muriatique1 et muriatique oxygen2 sur l',action chimique de la ,lumire2 sur l',analyse vegetale et animale1 c4 ,it would be difficult to name any chemical book that contains a greater number of new facts1 or which contains so great a collection of important information1 or which has contributed more to the advancement of chemical science4 ,the first part contains a very minute and interesting examination of the galvanic battery1 and upon what circumstances its energy depends4 ,they tried the effect of various liquid conductors1 varied the strength of the acids and of the saline solutions4 ,this division of their labours contains much valuable information for the practical electro-chemist1 though it would be inconsistent with the plan of this work to enter into details4 ,the next division of the work relates to potassium4 ,davy had hitherto produced that metal only in minute quantities by the action of the galvanic battery upon potash4 ,but ,gay-,lussac and ,thenard contrived a process by which it can be prepared on a large scale by chemical decomposition4 ,their method was1 to put into a bent gun-barrel1 well coated externally with clay1 and passed through a furnace1 a quantity of clean iron-filings4 ,to one extremity of this barrel was fitted a tube containing a quantity of caustic potash4 ,this tube was either shut at one end by a stopper1 or by a glass tube luted to it1 and plunged under the surface of mercury4 ,to the other extremity of the gun-barrel was also luted a tube1 which plunged into a vessel containing mercury4 ,heat was applied to the gun-barrel till it was heated to whiteness2 then1 by means of a choffer1 the caustic potash was melted and made to trickle slowly into the white-hot iron-filings4 ,at this temperature the potash undergoes decomposition1 the iron uniting with its oxygen4 ,the potassium is disengaged1 and being volatile is deposited at a distance from the hot part of the tube1 where it is collected after the process is finished4 ,being thus in possession1 both of potassium and sodium in considerable quantities1 they were enabled to examine its properties more in detail than ,davy had done3 but such was the care and industry with which ,davy's experiments had been made that very little remained to be done4 ,the specific gravity of the two metals was determined with more precision than it was possible for ,davy to do4 ,they determined the action of these metals on water1 and measured the quantity of hydrogen gas given out with more precision than ,davy could4 ,they discovered also1 by heating these metals in oxygen gas1 that they were capable of uniting with an additional dose of oxygen1 and of forming peroxides of potassium and sodium4 ,these oxides have a yellow colour1 and give out the surplus oxygen1 and are brought back to the state of potash and soda when they are plunged into water4 ,they exposed a great variety of substances to the action of potassium1 and brought to light a vast number of curious and important facts1 tending to throw new light on the properties and characters of that curious metallic substance4 ,by heating together anhydrous boracic acid and potassium in a copper tube1 they succeeded in decomposing the acid1 and in showing it to be a compound of oxygen1 and a black matter like charcoal1 to which the name of boron has been given4 ,they examined the properties of boron in detail1 but did not succeed in determining with exactness the proportions of the constituents of boracic acid4 ,the subsequent experiments of ,davy1 though not exact1 come a good deal nearer the truth4 ,their experiments on fluoric acid are exceedingly valuable4 ,they first obtained that acid in a state of purity1 and ascertained its properties4 ,their attempts to decompose it as well as those of ,davy1 ended in disappointment4 ,but ,ampere conceived the idea that this acid1 like muriatic acid1 is a compound of hydrogen with an unknown supporter of combustion1 to which the name fluorine was given4 ,this opinion was adopted by ,davy1 and his experiments1 though they do not absolutely prove the truth of the opinion1 give it at least considerable probability1 and have disposed chemists in general to adopt it4 ,the subsequent researches of ,berzelius1 while they have added a great deal to our former knowledge respecting fluoric acid and its compounds1 have all tended to confirm and establish the doctrine that it is a hydracid1 and similar in its nature to the other hydracids4 ,but such is the tendency of fluorine to combine with every substance1 that hitherto it has been impossible to obtain it in an insulated state4 ,we want therefore1 still1 a decisive proof of the accuracy of the opinion4 ,to the experiments of ,gay-,lussac and ,thenard on chlorine and muriatic acid1 ,i have already alluded in a former part of this chapter4 ,it was during their investigations connected with this subject1 that they discovered fluoboric acid gas1 which certainly adds considerably to the probability of the theory of ,ampere respecting the nature of fluoric acid4 ,i pass over a vast number of other new and important facts and observations contained in this admirable work1 which ought to be studied with minute attention by every person who aspires at becoming a chemist4 ,besides the numerous discoveries contained in the ,recherches ,physico-chimique1 ,gay-,lussac is the author of two of so much importance that it would be wrong to omit them4 ,he showed that cyanogen is one of the constituents of prussic acid2 succeeded in determining the composition of cyanogen1 and showing it to be a compound of two atoms of carbon and one atom of azote4 ,prussic acid is a compound of one atom of hydrogen and one atom of cyanogen4 ,sulpho-cyanic acid1 discovered by ,mr4 ,porrett1 is a compound of one atom sulphuric1 and one atom cyanogen2 chloro-cyanic acid1 discovered by ,berthollet1 is a compound of one atom chlorine and one atom cyanogen2 while cyanic acid1 discovered by ,whler1 is a compound of one atom oxygen and one atom cyanogen4 ,i take no notice of the fulminic acid2 because1 although ,gay-,lussac's experiments are exceedingly ingenious1 and his reasoning very plausible1 it is not quite convincing2 especially as the results obtained by ,mr4 ,edmund ,davy1 and detailed by him in his late interesting memoir on this subject1 are somewhat different4 ,the other discovery of ,gay-,lussac is his demonstration of the peculiar nature of iodine1 his account of iodic and hydriodic acids1 and of many other compounds into which that curious substance enters as a constituent4 ,sir ,h4 ,davy was occupied with iodine at the same time with ,gay-,lussac2 and his sagacity and inventive powers were too great to allow him to work upon such a substance without discovering many new and interesting facts4 ,to ,m4 ,thenard we are indebted for the discovery of the important fact1 that hydrogen is capable of combining with twice as much oxygen as exists in water1 and determining the properties of this curious liquid which has been called deutoxide of hydrogen4 ,it possesses bleaching properties in perfection1 and ,i think it likely that chlorine owes its bleaching powers to the formation of a little deutoxide of hydrogen in consequence of its action on water4 ,the mantle of ,davy seems in some measure to have descended on ,mr4 ,faraday1 who occupies his old place at the ,royal ,institution4 ,he has shown equal industry1 much sagacity1 and great powers of invention4 ,the most important discovery connected with electro-magnetism1 next to the great fact1 for which we are indebted to ,professor rstedt of ,copenhagen1 is due to ,mr4 ,faraday2 ,i mean the rotation of the electric wires round the magnet4 ,to him we owe the knowledge of the fact1 that several of the gases can be condensed into liquids by the united action of pressure and cold1 which has removed the barrier that separated gaseous bodies from vapours1 and shown us that all owe their elasticity to the same cause4 ,to him also we owe the knowledge of the important fact1 that chlorine is capable of combining with carbon4 ,this has considerably improved the history of chlorine and served still further to throw new light on the analogy which exists between all the supporters of combustion4 ,they are doubtless all of them capable of combining with every one of the other simple bodies1 and of forming compounds with them4 ,for they are all negative bodies2 while the other simple substances without exception1 when compared to them1 possess positive properties4 ,we must therefore view the history of chemistry as incomplete1 till we have become acquainted with the compounds of every supporter with every simple base4 ,,chapter ,,vi4 ,,of ,,the ,,atomic ,,theory4 ,i come now to the last improvement which chemistry has received--an improvement which has given a degree of accuracy to chemical experimenting almost approaching to mathematical precision1 which has simplified prodigiously our views respecting chemical combinations2 which has enabled manufacturers to introduce theoretical improvements into their processes1 and to regulate with almost perfect precision the relative quantities of the various constituents necessary to produce the intended effects4 ,the consequence of this is1 that nothing is wasted1 nothing is thrown away4 ,chemical products have become not only better in quality1 but more abundant and much cheaper4 ,i allude to the atomic theory still only in its infancy1 but already productive of the most important benefits4 ,it is destined one day to produce still more wonderful effects1 and to render chemistry not only the most delightful1 but the most useful and indispensable1 of all the sciences4 ,like all other great improvements in science1 the atomic theory developed itself by degrees1 and several of the older chemists ascertained facts which might1 had they been aware of their importance1 have led them to conclusions similar to those of the moderns4 ,the very attempt to analyze the salts was an acknowledgment that bodies united with each other in definite proportions3 and these definite proportions1 had they been followed out1 would have led ultimately to the doctrine of atoms4 ,for how could it be1 that six parts of potash were always saturated by five parts of sulphuric acid and #fge parts of nitric acid8 ,how came it that five of sulphuric acid always went as far in saturating potash as #fge of nitric acid8 ,it was known1 that in chemical combinations it was the ultimate particles of matter that combined4 ,the simple explanation1 therefore1 would have been--that the weight of an ultimate particle of sulphuric acid was only five1 while that of an ultimate particle of nitric acid was #fge4 ,had such an inference been drawn1 it would have led directly to the atomic theory4 ,the atomic theory in chemistry has many points of resemblance to the fluxionary calculus in mathematics4 ,both give us the ratios of quantities2 both reduce investigations that would be otherwise extremely difficult1 or almost impossible1 to the utmost simplicity2 and what is still more curious1 both have been subjected to the same kind of ridicule by those who have not put themselves to the trouble of studying them with such attention as to understand them completely4 ,the minute philosopher of ,berkeley1 mutatis mutandis1 might be applied to the atomic theory with as much justice as to the fluxionary calculus2 and ,i have heard more than one individual attempt to throw ridicule upon the atomic theory by nearly the same kind of arguments4 ,the first chemists1 then1 who attempted to analyze the salts may be considered as contributing towards laying the foundation of the atomic theory1 though they were not themselves aware of the importance of the structure which might have been raised upon their experiments1 had they been made with the requisite precision4 ,bergman was the first chemist who attempted regular analyses of salts4 ,it was he that first tried to establish regular formulas for the analyses of mineral waters1 stones1 and ores1 by the means of solution and precipitation4 ,hence a knowledge of the constituents of the salts was necessary1 before his formulas could be applied to practice4 ,it was to supply this requisite information that he set about analyzing the salts1 and his results were long considered by chemists as exact1 and employed by them to determine the results of their analyses4 ,we now know that these analytical results of ,bergman are far from accurate2 they have accordingly been laid aside as useless3 but this knowledge has been derived from the progress of the atomic theory4 ,the first accurate set of experiments to analyze the salts was made by ,wenzel1 and published by him in #aggg1 in a small volume entitled ,lehre von der ,verwandschaft der ,krper1 or1 ,theory of the ,affinities of ,bodies4 ,these analyses of ,wenzel are infinitely more accurate than those of ,bergman1 and indeed in many cases are equally precise with the best which we have even at the present day4 ,yet the book fell almost dead-born from the press2 ,wenzel's results never obtained the confidence of chemists1 nor is his name ever quoted as an authority4 ,wenzel was struck with a phenomenon1 which had indeed been noticed by preceding chemists2 but they had not drawn the advantages from it which it was capable of affording4 ,there are several saline solutions which1 when mixed with each other1 completely decompose each other1 so that two new salts are produced4 ,thus1 if we mix together solutions of nitrate of lead and sulphate of soda in the requisite proportions1 the sulphuric acid of the latter salt will combine with the oxide of lead of the former1 and will form with it sulphate of lead1 which will precipitate to the bottom in the state of an insoluble powder1 while the nitric acid formerly united to the oxide of lead1 will combine with the soda formerly in union with the sulphuric acid1 and form nitrate of soda1 which being soluble1 will remain in solution in the liquid4 ,thus1 instead of the two old salts1 ,sulphate of soda ,nitrate of lead1 we obtain the two new salts1 ,sulphate of lead ,nitrate of soda4 ,if we mix the two salts in the requisite proportions1 the decomposition will be complete2 but if there be an excess of one of the salts1 that excess will still remain in solution without affecting the result4 ,if we suppose the two salts anhydrous1 then the proportions necessary for complete decomposition are1 ,sulphate of soda #i ,nitrate of lead #bjge ------ #bige and the quantities of the new salts formed will be ,sulphate of lead #ai ,nitrate of soda #ajge ----- #bige ,we see that the absolute weights of the two sets of salts are the same3 all that has happened is1 that both the acids and both the bases have exchanged situations4 ,now if1 instead of mixing these two salts together in the preceding proportions1 we employ ,sulphate of soda #i ,nitrate of lead #bege ,that is to say1 if we employ #e parts of nitrate of lead more than is sufficient for the purpose2 we shall have exactly the same decompositions as before2 but the #e of excess of nitrate of lead will remain in solution1 mixed with the nitrate of soda4 ,there will be precipitated as before1 ,sulphate of lead #ai and there will remain in solution a mixture of ,nitrate of soda #ajge ,nitrate of lead #e ,the phenomena are precisely the same as before2 the additional #e of nitrate of lead have occasioned no alteration2 the decomposition has gone on just as if they had not been present4 ,now the phenomena which drew the particular attention of ,wenzel is1 that if the salts were neutral before being mixed1 the neutrality was not affected by the decomposition which took place on their mixture4#g ,a salt is said to be neutral when it neither possesses the characters of an acid or an alkali4 ,acids redden vegetable blues1 while alkalies render them green4 ,a neutral salt produces no effect whatever upon vegetable blues4 ,this observation of ,wenzel is very important3 it is obvious that the salts1 after their decomposition1 could not have remained neutral unless the elements of the two salts had been such that the bases in each just saturated the acids in either of the salts4 #g ,this observation is not without exception4 ,it does not hold when one of the salts is a phosphate or an arseniate1 and this is the cause of the difficulty attending the analysis of these genera of salts4 ,the constituents of the two salts are as follows3 #e sulphuric acid #i sulphate of soda #d soda1 #fge nitric acid #bjge nitrate of lead #ad oxide of lead4 ,now it is clear1 that unless #e sulphuric acid were just saturated by #d soda and by #ad oxide of lead2 and #fge of nitric acid by the same #d soda and #ad oxide of lead1 the salts1 after their decomposition1 could not have preserved their neutrality4 ,had #d soda required only #ege of nitric acid1 or had #ad oxide of lead required only #d sulphuric acid1 to saturate them1 the liquid1 after decomposition1 would have contained an excess of acid4 ,as no such excess exists1 it is clear that in saturating an acid1 #d soda goes exactly as far as #ad oxide of lead2 and that1 in saturating a base1 #e sulphuric acid goes just as far as #fge nitric acid4 ,nothing can exhibit in a more striking point of view1 the almost despotic power of fashion and authority over the minds even of men of science1 and the small number of them that venture to think for themselves1 than the fact1 that this most important and luminous explanation of ,wenzel1 confirmed by much more accurate experiments than any which chemistry had yet seen1 is scarcely noticed by any of his contemporaries1 and seems not to have attracted the smallest attention4 ,in science1 it is as unfortunate for a man to get before the age in which he lives1 as to continue behind it4 ,the admirable explanation of combustion by ,hooke1 and the important experiments on combustion and respiration by ,mayow1 were lost upon their contemporaries1 and procured them little or no reputation whatever2 while the same theory1 and the same experiments1 advanced by ,lavoisier and ,priestley1 a century later1 when the minds of men of science were prepared to receive them1 raised them to the very first rank among philosophers1 and produced a revolution in chemistry4 ,so much concern has fortune1 not merely in the success of kings and conquerors1 but in the reputation acquired by men of science4 ,in the year #agib another labourer1 in the same department of chemistry1 appeared3 this was ,jeremiah ,benjamin ,richter1 a ,prussian chemist1 of whose history ,i know nothing more than that his publications were printed and published in ,breslau1 from which ,i infer that he was a native of1 or at least resided in1 ,silesia4 ,he calls himself ,assessor of the ,royal ,prussian ,mines and ,smeltinghouses1 and ,arcanist of the ,commission of ,berlin ,porcelain ,manufacture4 ,he died in the prime of life1 on the #dth of ,may1 #ahjg4 ,in the year #agib he published a work entitled ,anfansgrnde der ,stochyometrie2 oder1 ,messkunst ,chymischer ,elemente 7,elements of ,stochiometry2 or1 the ,mathematics of the ,chemical ,elements74 ,a second and third volume of this work appeared in #agic1 and a fourth volume in #agid4 ,the object of this book was a rigid analysis of the different salts1 founded on the fact just mentioned1 that when two salts decompose each other1 the salts newly formed are neutral as well as those which have been decomposed4 ,he took up the subject nearly in the same way as ,wenzel had done1 but carried the subject much further2 and endeavoured to determine the capacity of saturation of each acid and base1 and to attach numbers to each1 indicating the weights which mutually saturate each other4 ,he gave the whole subject a mathematical dress1 and endeavoured to show that the same relation existed1 between the numbers representing the capacity of saturation of these bodies1 as does between certain classes of figurate numbers4 ,when we strip the subject of the mystical form under which he presented it1 the labours of ,richter may be exhibited under the two following tables1 which represent the capacity of saturation of the acids and bases1 according to his experiments4 #a4 ,,acids4 ,fluoric acid #dbg ,carbonic #egg ,sebacic #gjf ,muriatic #gab ,oxalic #gee ,phosphoric #igi ,formic #ihh ,sulphuric #ajjj ,succinic #abji ,nitric #adje ,acetic #adhj ,citric #afhc ,tartaric #afid #b4 ,,bases4 ,alumina #ebe ,magnesia #fae ,ammonia #fgb ,lime #gic ,soda #hei ,strontian #acbi ,potash #afje ,barytes #bbbb ,to understand this table1 it is only necessary to observe1 that if we take the quantity of any of the acids placed after it in the table1 that quantity will be exactly saturated by the weight of each base put after it in the second column3 thus1 #ajjj of sulphuric acid will be just saturated by #ebe alumina1 #fae magnesia1 #fgb ammonia1 #gic lime1 and so on4 ,on the other hand1 the quantity of any base placed after its name in the second column1 will be just saturated by the weight of each acid placed after its name in the first column3 thus1 #gic parts of lime will be just saturated by #dbg of fluoric acid1 #egg of carbonic acid1 #gjf of sebacic acid1 and so on4 ,this work of ,richter was followed by a periodical work entitled ,ueber die neuern ,gegenstande der ,chymie 7,on the ,new ,objects of ,chemistry74 ,this work was begun in the year #agib1 and continued in twelve different numbers1 or volumes1 to the time of his death in #ahjg4h #h ,i have only seen eleven parts of this work1 the last of which appeared in #ahjb2 but ,i believe that a twelfth part was published afterwards4 ,richter's labours in this important field produced as little attention as those of ,wenzel4 ,gehlen wrote a short panegyric upon him at his death1 praising his views and pointing out their importance2 but ,i am not aware of any individual1 either in ,germany or elsewhere1 who adopted ,richter's opinions during his lifetime1 or even seemed aware of their importance1 unless we are to except ,berthollet1 who mentions them with approbation in his ,chemical ,statics4 ,this inattention was partly owing to the great want of accuracy which it is impossible not be sensible of in ,richter's experiments4 ,he operated upon too large quantities of matter1 which indeed was the common defect of the times1 and was first checked by ,dr4 ,wollaston4 ,the dispute between the phlogistians and the antiphlogistians1 which was not fully settled in ,richter's time1 drew the attention of chemists to another branch of the subject4 ,richter in some measure went before the age in which he lived1 and had his labours not been recalled to our recollection by the introduction of atomic theory1 he would probably have been forgotten1 like ,hooke and ,mayow1 and only brought again under review after the new discoveries in the science had put it in the power of chemists in general to appreciate the value of his labours4 ,it is to ,mr4 ,dalton that we are indebted for the happy and simple idea from which the atomic theory originated4 ,john ,dalton1 to whose lot it has fallen to produce such an alteration and improvement in chemistry1 was born in ,westmorland1 and belongs to that small and virtuous sect known in this country by the name of ,quakers4 ,when very young he lived with ,mr4 ,gough of ,kendal1 a blind philosopher1 to whom he read1 and whom he assisted in his philosophical investigations4 ,it was here1 probably1 that he acquired a considerable part of his education1 particularly his taste for mathematics4 ,for ,mr4 ,gough was remarkably fond of mathematical investigations1 and has published several mathematical papers that do him credit4 ,from ,kendal ,mr4 ,dalton went to ,manchester1 about the beginning of the present century1 and commenced teaching elementary mathematics to such young men as felt inclined to acquire some knowledge of that important subject4 ,in this way1 together with a few courses of lectures on chemistry1 which he has occasionally given at the ,royal ,institution in ,london1 at the ,institution in ,birmingham1 in ,manchester1 and once in ,edinburgh and in ,glasgow1 he has contrived to support himself for more than thirty years1 if not in affluence1 at least in perfect independence4 ,and as his desires have always been of the most moderate kind1 his income has always been equal to his wants4 ,in a country like this1 where so much wealth abounds1 and where so handsome a yearly income was subscribed to enable ,dr4 ,priestley to prosecute his investigations undisturbed and undistracted by the necessity of providing for the daily wants of his family1 there is little doubt that ,mr4 ,dalton1 had he so chosen it1 might1 in point of pecuniary circumstances1 have exhibited a much more brilliant figure4 ,but he has displayed a much nobler mind by the career which he has chosen--equally regardless of riches as the most celebrated sages of antiquity1 and as much respected and beloved by his friends1 even in the rich commercial town of ,manchester1 as if he were one of the greatest and most influential men in the country4 ,towards the end of the last century1 a literary and scientific society had been established in ,manchester1 of which ,mr4 ,thomas ,henry1 the translator of ,lavoisier's ,essays1 and who distinguished himself so much in promoting the introduction of the new mode of bleaching into ,lancashire1 was long president4 ,mr4 ,dalton1 who had already distinguished himself by his meteorological observations1 and particularly by his account of the ,aurora ,borealis1 soon became a member of the society2 and in the fifth volume of their ,memoirs1 part ,,ii41 published in #ahjb1 six papers of his were inserted1 which laid the foundation of his future celebrity4 ,these papers were chiefly connected with meteorological subjects2 but by far the most important of them all was the one entitled ,experimental ,essays on the ,constitution of mixed ,gases2 on the ,force of ,steam or ,vapour from water and other liquids in different temperatures1 both in a torricellian vacuum and in air2 on ,evaporation2 and on the ,expansion of ,gases by ,heat4 ,from a careful examination of all the circumstances1 he considered himself as entitled to infer1 that when two elastic fluids or gases1 ,a and ,b1 are mixed together1 there is no mutual repulsion among their particles2 that is1 the particles of ,a do not repel those of ,b1 as they do one another4 ,consequently1 the pressure or whole weight upon any one particle arises solely from those of its own kind4 ,this doctrine is of so startling a nature and so contrary to the opinions previously received1 that chemists have not been much disposed to admit it4 ,but at the same time it must be confessed1 that no one has hitherto been able completely to refute it4 ,the consequences of admitting it are obvious3 we should be able to account for a fact which has been long known1 though no very satisfactory reason for it had been assigned2 namely1 that if two gases be placed in two separate vessels1 communicating by a narrow orifice1 and left at perfect rest in a place where the temperature never varies1 if we examine them after a certain interval of time we shall find both equally diffused through both vessels4 ,if we fill a glass phial with hydrogen gas and another phial with common air or carbonic acid gas and unite the two phials by a narrow glass tube two feet long1 filled with common air1 and place the phial containing the hydrogen gas uppermost1 and the other perpendicularly below it1 the hydrogen1 though lightest1 will not remain in the upper phial1 nor the carbonic acid1 though heaviest1 in the undermost phial2 but we shall find both gases equally diffused through both phials4 ,but the second of these essays is by far the most important4 ,in it he establishes1 by the most unexceptionable evidence1 that water1 when it evaporates1 is always converted into an elastic fluid1 similar in its properties to air4 ,but that the distance between the particles is greater the lower the temperature is at which the water evaporates4 ,the elasticity of this vapour increases as the temperature increases4 ,at #cb it is capable of balancing a column of mercury about half an inch in height1 and at #bab it balances a column thirty inches high1 or it is then equal to the pressure of the atmosphere4 ,he determined the elasticity of vapour at all temperatures from #cb to #bab1 pointed out the method of determining the quantity of vapour that at any time exists in the atmosphere1 the effect which it has upon the volume of air1 and the mode of determining its quantity4 ,finally1 he determined1 experimentally1 the rate of evaporation from the surface of water at all temperatures from #cb to #bab4 ,these investigations have been of infinite use to chemists in all their investigations respecting the specific gravity of gases1 and have enabled them to resolve various interesting problems1 both respecting specific gravity1 evaporation1 rain and respiration1 which1 had it not been for the principles laid down in this essay1 would have eluded their grasp4 ,in the last essay contained in this paper he has shown that all elastic fluids expand the same quantity by the same addition of heat1 and this expansion is very nearly #a-dhjth part for every degree of ,fahrenheit's thermometer4 ,in this last branch of the subject ,mr4 ,dalton was followed by ,gay-,lussac1 who1 about half a year after the appearance of his ,essays1 published a paper in the ,annales de ,chimie1 showing that the expansion of all elastic fluids1 when equally heated1 is the same4 ,mr4 ,dalton concluded that the expansion of all elastic fluids by heat is equable4 ,and this opinion has been since confirmed by the important experiments of ,dulong and ,petit1 which have thrown much additional light on the subject4 ,in the year #ahjd1 on the #bfth of ,august1 ,i spent a day or two at ,manchester1 and was much with ,mr4 ,dalton4 ,at that time he explained to me his notions respecting the composition of bodies4 ,i wrote down at the time the opinions which he offered1 and the following account is taken literally from my journal of that date3 ,the ultimate particles of all simple bodies are atoms incapable of further division4 ,these atoms 7at least viewed along with their atmospheres of heat7 are all spheres1 and are each of them possessed of particular weights1 which may be denoted by numbers4 ,for the greater clearness he represented the atoms of the simple bodies by symbols4 ,the following are his symbols for four simple bodies1 together with the numbers attached to them by him in #ahjd3 ,relative weights4 oxygen ,oxygen #fe hydrogen ,hydrogen #a carbon ,carbon #e azote ,azote #e ,the following symbols represent the way in which he thought these atoms were combined to form certain binary compounds1 with the weight of an integrant particle of each compound3 ,weights4 oxygenhydrogen ,water #ge oxygenazote ,nitrous gas #aae carbonhydrogen ,olefiant gas #f azotehydrogen ,ammonia #f oxygencarbon ,carbonic oxide #aae ,the following were the symbols by which he represented the composition of certain tertiary compounds3 ,weights4 oxygencarbonoxygen ,carbonic acid #ah oxygenazoteoxygen ,nitrous oxide #afe carbonhydrogencarbon ,ether #aa hydrogencarbonhydrogen ,carburetted hydrogen #g oxygenazoteoxygen ,nitric acid #ah ,a quaternary compound3 oxygenazoteoxygen ,oxynitric acid #bde oxygen ,a quinquenary compound3 oxygen azote azoteoxygen ,nitrous acid #bie oxygen ,a sextenary compound3 carbonoxygencarbon ,alcohol #bce hydrogencarbonhydrogen ,these symbols are sufficient to give the reader an idea of the notions entertained by ,dalton respecting the nature of compounds4 ,water is a compound of one atom oxygen and one atom hydrogen as is obvious from the symbol oxygenhydrogen4 ,its weight #ge is that of an atom of oxygen and an atom of hydrogen united together4 ,in the same way carbonic oxide is a compound of one atom oxygen and one atom carbon4 ,its symbol is oxygencarbon1 and its weight #aae is equal to an atom of oxygen and an atom of carbon added together4 ,carbonic acid is a tertiary compound1 or it consists of three atoms united together2 namely1 two atoms of oxygen and one atom of carbon4 ,its symbol is oxygencarbonoxygen1 and its weight #ah4 ,a bare inspection of the symbols and weights will make ,mr4 ,dalton's notions respecting the constitution of every body in the table evident to every reader4 ,it was this happy idea of representing the atoms and constitution of bodies by symbols that gave ,mr4 ,dalton's opinions so much clearness4 ,i was delighted with the new light which immediately struck my mind1 and saw at a glance the immense importance of such a theory1 when fully developed4 ,mr4 ,dalton informed me that the atomic theory first occurred to him during his investigations of olefiant gas and carburetted hydrogen gases1 at that time imperfectly understood1 and the constitution of which was first fully developed by ,mr4 ,dalton himself4 ,it was obvious from the experiments which he made upon them1 that the constituents of both were carbon and hydrogen1 and nothing else4 ,he found further1 that if we reckon the carbon in each the same1 then carburetted hydrogen gas contains exactly twice as much hydrogen as olefiant gas does4 ,this determined him to state the ratios of these constituents in numbers1 and to consider the olefiant gas as a compound of one atom of carbon and one atom of hydrogen2 and carburetted hydrogen of one atom of carbon and two atoms of hydrogen4 ,the idea thus conceived was applied to carbonic oxide1 water ammonia1 c42 and numbers representing the atomic weights of oxygen1 azote1 c41 deduced from the best analytical experiments which chemistry then possessed4 ,let not the reader suppose that this was an easy task4 ,chemistry at that time did not possess a single analysis which could be considered as even approaching to accuracy4 ,a vast number of facts had been ascertained1 and a fine foundation laid for future investigation2 but nothing1 as far as weight and measure were concerned1 deserving the least confidence1 existed4 ,we need not be surprised1 then1 that ,mr4 ,dalton's first numbers were not exact4 ,it required infinite sagacity1 and not a little labour1 to come so near the truth as he did4 ,how could accurate analyses of gases be made when there was not a single gas whose specific gravity was known1 with even an approach to accuracy2 the preceding investigations of ,dalton himself paved the way for accuracy in this indispensable department2 but still accurate results had not yet been obtained4 ,in the third edition of my ,system of ,chemistry1 published in #ahjg1 ,i introduced a short sketch of ,mr4 ,dalton's theory1 and thus made it known to the chemical world4 ,the same year a paper of mine on oxalic acid was published in the ,philosophical ,transactions1 in which ,i showed that oxalic acid unites in two proportions with strontian1 forming an oxalate and binoxalate2 and that1 supposing the strontian in both salts to be the same1 the oxalic acid in the latter is exactly twice as much as in the former4 ,about the same time1 ,dr4 ,wollaston showed that bicarbonate of potash contains just twice the quantity of carbonic acid that exists in carbonate of potash2 and that there are three oxalates of potash2 viz41 oxalate1 binoxalate1 and quadroxalate2 the weight of acids in each of which are as the numbers #a1 #b1 #d4 ,these facts gradually drew the attention of chemists to ,mr4 ,dalton's views4 ,there were1 however1 some of our most eminent chemists who were very hostile to the atomic theory4 ,the most conspicuous of these was ,sir ,humphry ,davy4 ,in the autumn of #ahjg ,i had a long conversation with him at the ,royal ,institution1 but could not convince him that there was any truth in the hypothesis4 ,a few days after ,i dined with him at the ,royal ,society ,club1 at the ,crown and ,anchor1 in the ,strand4 ,dr4 ,wollaston was present at the dinner4 ,after dinner every member of the club left the tavern1 except ,dr4 ,wollaston1 ,mr4 ,davy1 and myself1 who staid behind and had tea4 ,we sat about an hour and a half together1 and our whole conversation was about the atomic theory4 ,dr4 ,wollaston was a convert as well as myself2 and we tried to convince ,davy of the inaccuracy of his opinions2 but1 so far from being convinced1 he went away1 if possible1 more prejudiced against it than ever4 ,soon after1 ,davy met ,mr4 ,davis ,gilbert1 the late distinguished president of the ,royal ,society2 and he amused him with a caricature description of the atomic theory1 which he exhibited in so ridiculous a light1 that ,mr4 ,gilbert was astonished how any man of sense or science could be taken in with such a tissue of absurdities4 ,mr4 ,gilbert called on ,dr4 ,wollaston 7probably to discover what could have induced a man of ,dr4 ,wollaston's sagacity and caution to adopt such opinions71 and was not sparing in laying the absurdities of the theory1 such as they had been represented to him by ,davy1 in the broadest point of view4 ,dr4 ,wollaston begged ,mr4 ,gilbert to sit down1 and listen to a few facts which he would state to him4 ,he then went over all the principal facts at that time known respecting the salts2 mentioned the alkaline carbonates and bicarbonates1 the oxalate1 binoxalate1 and quadroxalate of potash1 carbonic oxide and carbonic acid1 olefiant gas1 and carburetted hydrogen2 and doubtless many other similar compounds1 in which the proportion of one of the constituents increases in a regular ratio4 ,mr4 ,gilbert went away a convert to the truth of the atomic theory2 and he had the merit of convincing ,davy that his former opinions on the subject were wrong4 ,what arguments he employed ,i do not know2 but they must have been convincing ones1 for ,davy ever after became a strenuous supporter of the atomic theory4 ,the only alteration which he made was to substitute proportion for ,dalton's word1 atom4 ,dr4 ,wollaston substituted for it the term equivalent4 ,the object of these substitutions was to avoid all theoretical annunciations4 ,but1 in fact1 these terms1 proportion1 equivalent1 are neither of them so convenient as the term atom3 and1 unless we adopt the hypothesis with which ,dalton set out1 namely1 that the ultimate particles of bodies are atoms incapable of further division1 and that chemical combination consists in the union of these atoms with each other1 we lose all the new light which the atomic theory throws upon chemistry1 and bring our notions back to the obscurity of the days of ,bergman and of ,berthollet4 ,in the year #ahjh ,mr4 ,dalton published the first volume of his ,new ,system of ,chemical ,philosophy4 ,this volume consists chiefly of two chapters3 the first1 on heat1 occupies #adj pages4 ,in it he treats of all the effects of heat1 and shows the same sagacity and originality which characterize all his writings4 ,even when his opinions on a subject are not correct1 his reasoning is so ingenious and original1 and the new facts which he contrives to bring forward so important1 that we are always pleased and always instructed4 ,the second chapter1 on the constitution of bodies1 occupies #gj pages4 ,the chief object of it is to combat the peculiar notions respecting elastic fluids1 which had been advanced by ,berthollet1 and supported by ,dr4 ,murray1 of ,edinburgh4 ,in the third chapter1 on chemical synthesis1 which occupies only a few pages1 he gives us the outlines of the atomic theory1 such as he had conceived it4 ,in a plate at the end of the volume he exhibits the symbols and atomic weights of thirty-seven bodies1 twenty of which were then considered as simple1 and the other seventeen as compound4 ,the following table shows the atomic weight of the simple bodies1 as he at that time had determined them from the best analytical experiments that had been made3 ,weight of atom4 ,hydrogen #a ,azote #e ,carbon #e ,oxygen #g ,phosphorus #i ,sulphur #ac ,magnesia #bj ,lime #bc ,soda #bh ,potash #db ,strontian #df ,barytes #fh ,iron #ch ,zinc #ef ,copper #ef ,lead #ie ,silver #ajj ,platinum #ajj ,gold #adj ,mercury #afg ,he had made choice of hydrogen for unity1 because it is the lightest of all bodies4 ,he was of opinion that the atomic weights of all other bodies are multiples of hydrogen2 and1 accordingly1 they are all expressed in whole numbers4 ,he had raised the atomic weight of oxygen from #fe to #g1 from a more careful examination of the experiments on the component parts of water4 ,davy1 from a more accurate set of experiments1 soon after raised the number for oxygen to #ge3 and ,dr4 ,prout1 from a still more careful investigation of the relative specific gravities of oxygen and hydrogen1 showed that if the atom of hydrogen be #a1 that of oxygen must be #h4 ,every thing conspires to prove that this is the true ratio between the atomic weights of oxygen and hydrogen4 ,in #ahaj appeared the second volume of ,mr4 ,dalton's ,new ,system of ,chemical ,philosophy4 ,in it he examines the elementary principles1 or simple bodies1 namely1 oxygen1 hydrogen1 azote1 carbon1 sulphur1 phosphorus1 and the metals2 and the compounds consisting of two elements1 namely1 the compounds of oxygen with hydrogen1 azote1 carbon1 sulphur1 phosphorus2 of hydrogen with azote1 carbon1 sulphur1 phosphorus4 ,finally he treats of the fixed alkalies and earths4 ,all these combinations are treated of with infinite sagacity2 and he endeavours to determine the atomic weights of the different elementary substances4 ,nothing can exceed the ingenuity of his reasoning4 ,but unfortunately at that time very few accurate chemical analyses existed2 and in chemistry no reasoning1 however ingenious1 can compensate for this indispensable datum4 ,accordingly his table of atomic weights at the end this second volume1 though much more complete than that at the end of the first volume1 is still exceedingly defective2 indeed no one number can be considered as perfectly correct4 ,the third volume of the ,new ,system of ,chemical ,philosophy was only published in #ahbg2 but the greatest part of it had been printed nearly ten years before4 ,it treats of the metallic oxides1 the sulphurets1 phosphurets1 carburets1 and alloys4 ,doubtless many of the facts contained in it were new when the sheets were put to the press2 but during the interval between the printing and publication1 almost the whole of them had not merely been anticipated1 but the subject carried much further4 ,by far the most important part of the volume is the ,appendix1 consisting of about ninety pages1 in which he discusses1 with his usual sagacity1 various important points connected with heat and vapour4 ,in page #ceb he gives a new table of the atomic weights of bodies1 much more copious than those contained in the two preceding volumes2 and into which he has introduced the corrections necessary from the numerous correct analyses which had been made in the interval4 ,he still adheres to the ratio #a3g as the correct difference between the weights of the atoms of hydrogen and oxygen4 ,this shows very clearly that he has not attended to the new facts which have been brought forward on the subject4 ,no person who has attended to the experiments made on the specific gravity of these two gases during the last twelve years1 could admit that these specific gravities are to each other as #a to #ad4 ,if #a to #af be not the exact ratio1 it will surely be admitted on all hands that it is infinitely near it4 ,mr4 ,dalton represented the weight of an atom of hydrogen by #a1 because it is the lightest of bodies4 ,in this he has been followed by the chemists of the ,royal ,institution1 by ,mr4 ,philips1 ,dr4 ,henry1 and ,dr4 ,turner1 and perhaps some others whose names ,i do not at present recollect4 ,dr4 ,wollaston1 in his paper on ,chemical ,equivalents1 represented the atomic weight of oxygen by #a1 because it enters into a greater number of combinations than any other substance2 and this plan has been adopted by ,berzelius1 by myself1 and by the greater number1 if not the whole1 of the chemists on the continent4 ,perhaps the advantage which ,dr4 ,wollaston assigned for making the atom of oxygen unity will ultimately disappear3 for there is no reason for believing that the other supporters of combustion are not capable of entering into as many compounds as oxygen4 ,but1 from the constitution of the atmosphere1 it is obvious that the compounds into which oxygen enters will always be of more importance to us than any others2 and in this point of view it may be attended with considerable convenience to have oxygen represented by #a4 ,in the present state of the atomic theory there is another reason for making the atom of oxygen unity1 which ,i think of considerable importance4 ,chemists are not yet agreed about the atom of hydrogen4 ,some consider water a compound of #a atom of oxygen and #b atoms of hydrogen2 others1 of #a atom of oxygen and #a atom of hydrogen4 ,according to the first view1 the atom of hydrogen is only #a-afth of the weight of an atom of oxygen2 according to the second1 it is #a-hth4 ,if1 therefore1 we were to represent the atom of hydrogen by #a1 the consequence would be1 that two tables of atomic weights would be requisite--all the atoms in one being double the weight of the atoms in the other3 whereas1 if we make the atom of oxygen unity1 it will be the atom of hydrogen only that will differ in the two tables4 ,in the one table it will be #jabe1 in the other it will be #jjfbe3 or1 reckoning with ,berzelius the atom of oxygen #ajj1 we have that of hydrogen #abe or #fbe1 according as we view water to be a compound of #a atom of oxygen with #a or #b atoms of hydrogen4 ,in the year #ahji ,gay-,lussac published in the second volume of the ,mmoires d',arcueil a paper on the union of the gaseous substances with each other4 ,in this paper he shows that the proportions in which the gases unite with each other are of the simplest kind4 ,one volume of one gas either combining with one volume of another1 or with two volumes1 or with half a volume4 ,the atomic theory of ,dalton had been opposed with considerable keenness by ,berthollet in his ,introduction to the ,french translation of my ,system of ,chemistry4 ,nor was this opposition to be wondered at2 because its admission would of course overturn all the opinions which ,berthollet had laboured to establish in his ,chemical ,statics4 ,the object of ,gay-,lussac's paper was to confirm and establish the new atomic theory1 by exhibiting it in a new point of view4 ,nothing can be more ingenious than his mode of treating the subject1 or more complete than the proofs which he brings forward in support of it4 ,it had been already established that water is formed by the union of one volume of oxygen and two volumes of hydrogen gas4 ,gay-,lussac found by experiment1 that one volume of muriatic acid gas is just saturated by one volume of ammoniacal gas3 the product is sal ammoniac4 ,fluoboric acid gas unites in two proportions with ammoniacal gas3 the first compound consists of one volume of fluoboric gas1 and one volume of ammoniacal2 the second1 of one volume of the acid gas1 and two volumes of the alkaline4 ,the first forms a neutral salt1 the second an alkaline salt4 ,he showed likewise1 that carbonic acid and ammoniacal gas could combine also in two proportions2 namely1 one volume of the acid gas with one or two volumes of the alkaline gas4 ,m4 ,amde ,berthollet had proved that ammonia is a compound of one volume of azotic1 and three volumes of hydrogen gas4 ,gay-,lussac himself had shown that sulphuric acid is composed of one volume sulphurous acid gas1 and a half-volume of oxygen gas4 ,he showed further1 that the compounds of azote and oxygen were composed as follows3 ,azote4 ,oxygen4 ,protoxide of azote #a volume volume ,deutoxide of azote #a #a ,nitrous acid #a #b ,he showed also1 that when the two gases after combining remained in the gaseous state1 the diminution of volume was either #j1 or 1 or 4 ,the constancy of these proportions left no doubt that the combinations of all gaseous bodies were definite4 ,the theory of ,dalton applied to them with great facility4 ,we have only to consider a volume of gas to represent an atom1 and then we see that in gases one atom of one gas combines either with one1 two1 or three atoms of another gas1 and never with more4 ,there is1 indeed1 a difficulty occasioned by the way in which we view the composition of water4 ,if water be composed of one atom of oxygen and one atom of hydrogen1 then it follows that a volume of oxygen contains twice as many atoms as a volume of hydrogen4 ,consequently1 if a volume of hydrogen gas represent an atom1 half a volume of oxygen gas must represent an atom4 ,dr4 ,prout soon after showed that there is an intimate connexion between the atomic weight of a gas and its specific gravity4 ,this indeed is obvious at once4 ,i afterwards showed that the specific gravity of a gas is either equal to its atomic weight multiplied by #aaaa4a 7the specific gravity of oxygen gas71 or by #jeee4e 7half the specific gravity of oxygen gas71 or by ,o#bgg4g 7#a-dth of the specific gravity of oxygen gas71 these differences depending upon the relative condensation which the gases undergo when their elements unite4 ,the following table exhibits the atoms and specific gravity of these three sets of gases3 ,i4 ,sp4 ,gr4 ,atomic ,weight #aaaaa ,atomic ,sp4 weight4 gravity4 ,oxygen gas #a #aaaaa ,fluosilicic acid #cbe #cfaaa ,,ii4 ,sp4 ,gr4 ,atomic ,weight #jeee4e4 ,atomic weight4 ,sp4 gravity4 ,hydrogen #jabe #jjfi4d ,azotic #age #jjgb4b ,chlorine #de #be ,carbon vapour #jge #jdaf4f ,phosphorus vapour #b #aaaa4a ,sulphur vapour #b #aaaa4a ,tellurium vapour #d #bbbb4b ,arsenic vapour #dge #bfch4h ,selenium vapour #e #bggg4g ,bromine vapour #aj #eeee4e ,iodine vapour #aege #hge ,steam #aabe #jfbe ,carbonic oxide gas #age #jigb4b ,carbonic acid #bge #aebg4g ,protoxide of azote #bge #aebg4g ,nitric acid vapour #fge #cge ,sulphurous acid #d #b4bbb4b ,sulphuric acid vapour #e #bggg4g ,cyanogen #cbe #ahje4e ,fluoboric acid #dbe #bcfa4a ,bisulphuret of carbon #dge #bfch4h ,chloro-carbonic acid #fbe #cdgb4b ,,iii4 ,sp4 ,gr4 ,atomic ,weight #jbgg4g4 ,atomic weight4 ,sp4 gravity4 ,ammoniacal gas #babe #jeijb4g ,hydrocyanic acid #ccge #jicge ,deutoxide of azote #cge #ajda4f ,muriatic acid #dfbe #abhdg4b ,hydrobromic acid #ajabe #bhabe ,hydriodic acid #aehge #ddjigc ,transcriber's ,note3 ,the numbers within thus 4#b represent numbers with a dot above them in the original4 ,when ,professor ,berzelius1 of ,stockholm1 thought of writing his ,elementary ,treatise on ,chemistry1 the first volume of which was published in the year #ahjh1 he prepared himself for the task by reading several chemical works which do not commonly fall under the eye of those who compose elementary treatises4 ,among other books he read the ,stochiometry of ,richter1 and was much struck with the explanations there given of the composition of salts1 and the precipitation of metals by each other4 ,it followed from the researches of ,richter1 that if we were in possession of good analyses of certain salts1 we might by means of them calculate with accuracy the composition of all the rest4 ,berzelius formed immediately the project of analyzing a series of salts with the most minute attention to accuracy4 ,while employed in putting this project in execution1 ,davy discovered the constituents of the alkalies and earths1 ,mr4 ,dalton gave to the world his notions respecting the atomic theory1 and ,gay-,lussac made known his theory of volumes4 ,this greatly enlarged his views as he proceeded1 and induced him to embrace a much wider field than he had originally contemplated4 ,his first analyses were unsatisfactory2 but by repeating them and varying the methods1 he detected errors1 improved his processes1 and finally obtained results1 which agreed exceedingly well with the theoretical calculations4 ,these laborious investigations occupied him several years4 ,the first outline of his experiments appeared in the #ggth volume of the ,annales de ,chimie1 in #ahaa1 in a letter addressed by ,berzelius to ,berthollet4 ,in this letter he gives an account of his methods of analyses together with the composition of forty-seven compound bodies4 ,he shows that when a metallic protosulphuret is converted into a sulphate1 the sulphate is neutral2 that an atom of sulphur is twice as heavy as an atom of oxygen2 and that when sulphite of barytes is converted into sulphate1 the sulphate is neutral1 there being no excess either of acid or base4 ,from these and many other important facts he finally draws this conclusion3 ,in a compound formed by the union of two oxides1 the one which 7when decomposed by the galvanic battery7 attaches itself to the positive pole 7the acid for example7 contains two1 three1 four1 five1 c41 times as much oxygen1 as the one which attaches itself to the negative pole 7the alkali1 earth1 or metallic oxide74 ,berzelius's essay itself appeared in the third volume of the ,afhandlingar1 in #ahaj4 ,it was almost immediately translated into ,german1 and published by ,gilbert in his ,annalen der ,physik4 ,but no ,english translation has ever appeared1 the editors of our periodical works being in general unacquainted with the ,german and other northern languages4 ,in #ahae ,berzelius applied the atomic theory to the mineral kingdom1 and showed with infinite ingenuity that minerals are chemical compounds in definite or atomic proportions1 and by far the greater number of them combinations of acids and bases4 ,he applied the theory also to the vegetable kingdom by analyzing several of the vegetable acids1 and showing their atomic constitution4 ,but here a difficulty occurs1 which in the present state of our knowledge1 we are unable to surmount4 ,there are two acids1 the acetic and succinic1 that are composed of exactly the same number1 and same kind of atoms1 and whose atomic weight is #fbe4 ,the constituents of these two acids are ,atomic weight4 #b atoms hydrogen #jbe #d carbon #c #c oxygen #c ---- #fbe ,so that they consist of nine atoms4 ,now as these two acids are composed of the same number and the same kind of atoms1 one would expect that their properties should be the same2 but this is not the case3 acetic acid has a strong and aromatic smell1 succinic acid has no smell whatever4 ,acetic acid is so soluble in water that it is difficult to obtain it in crystals1 and it cannot be procured in a separate state free from water2 for the crystals of acetic acid are composed of one atom of acid and one atom of water united together2 but succinic acid is not only easily obtained free from water1 but it is not even very soluble in that liquid4 ,the nature of the salts formed by these two acids is quite different2 the action of heat upon each is quite different2 the specific gravity of each differs4 ,in short all their properties exhibit a striking contrast4 ,now how are we to account for this8 ,undoubtedly by the different ways in which the atoms are arranged in each4 ,if the electro-chemical theory of combination be correct1 we can only view atoms as combining two by two4 ,a substance then1 containing nine atoms1 such as acetic acid1 must be of a very complex nature4 ,and it is obvious enough that these nine atoms might arrange themselves in a great variety of binary compounds1 and the way in which these binary compounds unite may1 and doubtless does1 produce a considerable effect upon the nature of the compound formed4 ,thus1 if we make use of ,mr4 ,dalton's symbols to represent the atoms of hydrogen1 carbon and oxygen1 we may suppose the nine atoms constituting acetic and succinic acid to be arranged thus3 hydrogencarbonhydrogen oxygenoxygenoxygen carboncarboncarbon ,or thus3 carbonhydrogencarbon oxygenoxygenoxygen carbonhydrogencarbon ,now1 undoubtedly these two arrangements would produce a great change in the nature of the compound4 ,there is something in the vegetable acids quite different from the acids of the inorganic kingdom1 and which would lead to the suspicion that the electro-chemical theory will not apply to them as it does to the others4 ,in the acids of carbon1 sulphur1 phosphorus1 selenium1 c41 we find one atom of a positive substance united to one1 two1 or three of a negative substance3 we are not surprised1 therefore1 to find the acid formed negative also4 ,but in acetic and succinic acids we find every atom of oxygen united with two electro-positive atoms3 the wonder then is1 that the acid should not only retain its electro-negative properties1 but that it should possess considerable power as an acid4 ,in benzoic acid1 for every atom of oxygen1 there are present no fewer than seven electro-positive atoms4 ,berzelius has returned to these analytical experiments repeatedly1 so that at last he has brought his results very near the truth indeed4 ,it is to his labours chiefly that the great progress which the atomic theory has made is owing4 ,in the year #ahad there appeared in the ,philosophical ,transactions a description of a ,synoptical ,scale of ,chemical ,equivalents1 by ,dr4 ,wollaston4 ,in this paper we have the equivalents or atomic weights of seventy-three different bodies1 deduced chiefly from a sagacious comparison of the previous analytical experiments of others1 and almost all of them very near the truth4 ,these numbers are laid down upon a sliding rule1 by means of a table of logarithms1 and over against them the names of the substances4 ,by means of this rule a great many important questions respecting the substances contained on the scale may be solved4 ,hence the scale is of great advantage to the practical chemist4 ,it gives1 by bare inspection1 the constituents of all the salts contained on it1 the quantity of any other ingredient necessary to decompose any salt1 and the weights of the new constituents that will be formed4 ,the contrivance of this scale1 therefore1 may be considered as an important addition to the atomic theory4 ,it rendered that theory every where familiar to all those who employed it4 ,to it chiefly we owe1 ,i believe1 the currency of that theory in ,great ,britain2 and the prevalence of the mode which ,dr4 ,wollaston introduced1 namely1 of representing the atom of oxygen by unity1 or at least by ten1 which comes nearly to the same thing4 ,perhaps the reader will excuse me if to the preceding historical details ,i add a few words to make him acquainted with my own attempts to render the atomic theory more accurate by new and careful analyses4 ,i shall not say any thing respecting the experiments which ,i undertook to determine the specific gravity of the gases2 though they were performed with much care1 and at a considerable expense1 and though ,i believe the results obtained approached accuracy as nearly as the present state of chemical apparatus enables us to go4 ,in the year #ahai ,i began a set of experiments to determine the exact composition of the salts containing the different elementary bodies by means of double decomposition1 as was done by ,wenzel1 conceiving that in that way the results would be very near the truth1 while the experiments would be more easily made4 ,my mode was to dissolve1 for example1 a certain weight of muriate of barytes in distilled water1 and then to ascertain by repeated trials what weight of sulphate of soda must be added to precipitate the whole of the barytes without leaving any surplus of sulphuric acid in the liquid4 ,to determine this ,i put into a watch-glass a few drops of the filtered liquor consisting of the mixture of solutions of the two salts3 to this ,i added a drop of solution of sulphate of soda4 ,if the liquid remained clear it was a proof that it contained no sensible quantity of barytes4 ,to another portion of the liquid1 also in a watch-glass1 ,i added a drop of muriate of barytes4 ,if there was no precipitate it was a proof that the liquid contained no sensible quantity of sulphuric acid4 ,if there was a precipitate1 on the addition of either of these solutions1 it showed that there was an excess of one or other of the salts4 ,i then mixed the two salts in another proportion1 and proceeded in this way till ,i had found two quantities which when mixed exhibited no evidence of the residual liquid containing any sulphuric acid or barytes4 ,i considered these two weights of the salts as the equivalent weights of the salt1 or as weights proportional to an integrant particle of each salt4 ,i made no attempt to collect the two new formed salts and to weigh them separately4 ,i published the result of my numerous experiments in #ahbe1 in a work entitled ,an ,attempt to establish the ,first ,principles of ,chemistry by ,experiment4 ,the most valuable part of this book is the account of the salts2 about three hundred of which ,i subjected to actual analysis4 ,of these the worst executed are the phosphates2 for with respect to them ,i was sometimes misled by my method of double decomposition4 ,i was not aware at first1 that1 in certain cases1 the proportion of acid in these salts varies1 and the phosphate of soda which ,i employed gave me a wrong number for the atomic weight of phosphoric acid4 ,,chapter ,,vii4 ,,of ,,the ,,present ,,state ,,of ,,chemistry4 ,to finish this history it will be now proper to lay before the reader a kind of map of the present state of chemistry1 that he may be able to judge how much of the science has been already explored1 and how much still remains untrodden ground4 ,leaving out of view light1 heat1 and electricity1 respecting the nature of which only conjectures can be formed1 we are at present acquainted with fifty-three simple bodies1 which naturally divide themselves into three classes2 namely1 supporters1 acidifiable bases1 and alkalifiable bases4 ,the supporters are oxygen1 chlorine1 bromine1 iodine1 and fluorine4 ,they are all in a state of negative electricity3 for when compounds containing them are decomposed by the voltaic battery they all attach themselves to the positive pole4 ,they have the property of uniting with every individual belonging to the other two classes4 ,when they combine with the acidifiable bases in certain proportions they constitute acids2 when with the alkalifiable bases1 alkalies4 ,in certain proportions they constitute neutral bodies1 which possess neither the properties of acids nor alkalies4 ,the acidifiable bases are seventeen in number2 namely1 hydrogen1 azote1 carbon1 boron1 silicon1 sulphur1 selenium1 tellurium1 phosphorus1 arsenic1 antimony1 chromium1 uranium1 molybdenum1 tungsten1 titanium1 columbium4 ,these bodies do not form acids with every supporter1 or in every proportion2 but they constitute the bases of all the known acids1 which form a numerous set of bodies1 many of which are still very imperfectly investigated4 ,and indeed there are a good many of them that may be considered as unknown4 ,these acidifiable bases are all electro-positive2 but they differ1 in this respect1 considerably from each other2 hydrogen and carbon being two of the most powerful1 while titanium and columbium have the least energy4 ,sulphur and selenium1 and probably some other bodies belonging to this class are occasional electro-negative bodies1 as well as the supporters4 ,hence1 when united to other acidifiable bases1 they produce a new class of acids1 analogous to those formed by the supporters4 ,these have got the name of sulphur acids1 selenium acids1 c4 ,sulphur forms acids with arsenic1 antimony1 molybdenum1 and tungsten1 and doubtless with several other bases4 ,to distinguish such acids from alkaline bases1 ,i have of late made an alteration in the termination of the old word sulphuret1 employed to denote the combination of sulphur with a base4 ,thus sulphide of arsenic means an acid formed by the union of sulphur and arsenic2 sulphuret of copper means an alkaline body formed by the union of sulphur and copper4 ,the term sulphide implies an acid1 the term sulphuret a base4 ,this mode of naming has become necessary1 as without it many of these new salts could not be described in an intelligible manner4 ,the same mode will apply to the acid and alkaline compounds of selenium4 ,thus a selenide is an acid compound1 and a seleniet an alkaline compound in which selenium acts the part of a supporter or electro-negative body4 ,the same mode of naming might and doubtless will be extended to all the other similar compounds1 as soon as it becomes necessary4 ,in order to form a systematic nomenclature it will speedily be requisite to new-model all the old names which denote acids and bases2 because unless this is done the names will become too numerous to be remembered4 ,at present we denote the alkaline bodies formed by the union of manganese and oxygen by the name of oxides of manganese1 and the acid compound of oxygen and the same metal by the name of manganesic acid4 ,the word oxide applies to every compound of a base and oxygen1 whether neutral or alkaline2 but when the compound has acid qualities this is denoted by adding the syllable ic to the name of the base4 ,this mode of naming answered tolerably well as long as the acids and alkalies were all combinations of oxygen with a base2 but now that we know the existence of eight or ten classes of acids and alkalies1 consisting of as many supporters1 or acidifiable bases united to bases1 it is needless to remark how very defective it has become4 ,but this is not the place to dwell longer upon such a subject4 ,the alkalifiable bases are thirty-one in number2 namely1 potassium1 sodium1 lithium1 barium1 strontium1 calcium1 magnesium1 aluminum1 glucinum1 yttrium1 cerium1 zirconium1 thorium1 iron1 manganese1 nickel1 cobalt1 zinc1 cadmium1 lead1 tin1 bismuth1 copper1 mercury1 silver1 gold1 platinum1 palladium1 rhodium1 iridium1 osmium4 ,the compounds which these bodies form with oxygen1 and the other supporters1 constitute all the alkaline bases or the substances capable of neutralizing the acids4 ,some of the acidifiable bases1 when united to a certain portion of oxygen1 constitute1 not acids1 but bases or alkalies4 ,thus the green oxides of chromium and uranium are alkalies2 while1 on the other hand1 there is a compound of oxygen and manganese which possesses acid properties4 ,in such cases it is always the compound containing the least oxygen which is an alkali1 and that containing the most oxygen that is an acid4 ,the opinion at present universally adopted by chemists is1 that the ultimate particles of bodies consist of atoms1 incapable of further division2 and these atoms are of a size almost infinitely small4 ,it can be demonstrated that the size of an atom of lead does not amount to so much as #a_/hhh1dib1jjj1jjj1jjj of a cubic inch4 ,but1 notwithstanding this extreme minuteness1 each of these atoms possesses a peculiar weight and a peculiar bulk1 which distinguish it from the atoms of every other body4 ,we cannot determine the absolute weight of any of them1 but merely the relative weights2 and this is done by ascertaining the relative proportions in which they unite4 ,when two bodies unite in only one proportion1 it is reasonable to conclude that the compound consists of #a atom of the one body1 united to #a atom of the other4 ,thus oxide of bismuth is a compound of #a oxygen and #i bismuth2 and1 as the bodies unite in no other proportion1 we conclude that an atom of bismuth is nine times as heavy as an atom of oxygen4 ,it is in this way that the atomic weights of the simple bodies have been attempted to be determined4 ,the following table exhibits these weights referred to oxygen as unity1 and deduced from the best data at present in our possession3 ,atomic weight4 ,oxygen #a ,fluorine #bbe ,chlorine #de ,bromine #aj ,calcium #be ,magnesium #ae ,aluminum #abe ,glucinum #bbe ,iodine #aege ,hydrogen #jabe ,azote #age ,carbon #jge ,boron #a ,silicon #a ,phosphorus #b ,sulphur #b ,selenium #e ,tellurium #d ,arsenic #dge ,antimony #h ,chromium #d ,uranium #bf ,molybdenum #f ,tungsten #abe ,titanium #cbe ,columbium #bbge ,potassium #e ,sodium #c ,lithium #jge ,barium #he ,strontium #ee ,yttrium #dbe ,zirconium #e ,thorinum #ge ,iron #ce ,manganese #ce ,nickel #cbe ,cobalt #cbe ,cerium #fbe ,zinc #dbe ,cadmium #g ,lead #ac ,tin #gbe ,bismuth #i ,copper #d ,mercury #abe ,silver #acge ,gold #abe ,platinum #ab ,palladium #fge ,rhodium #fge ,iridium #abbe ,osmium #abe ,the atomic weights of these bodies1 divided by their specific gravity1 ought to give us the comparative size of the atoms4 ,the following table1 constructed in this way1 exhibits the relative bulks of these atoms which belong to bodies whose specific gravity is known3 ,volume4 ,carbon #a ,nickel #age ,cobalt ,manganese ,copper #b ,iron ,platinum #bf ,palladium ,zinc #bge ,rhodium ,tellurium #c ,chromium ,molybdenum #cbe ,silica #ce ,titanium ,cadmium #cge ,arsenic ,phosphorus #d ,antimony ,tungsten ,bismuth #dbe ,mercury ,tin #dff ,sulphur ,selenium #ed ,lead ,gold ,silver #f ,osmium ,oxygen ,hydrogen #icc ,azote ,chlorine ,uranium #ace ,columbium #ad ,sodium ,bromine #aege ,iodine #bd ,potassium #bg ,we have no data to enable us to determine the shape of these atoms4 ,the most generally received opinion is1 that they are spheres or spheroids2 though there are difficulties in the way of admitting such an opinion1 in the present state of our knowledge1 nearly insurmountable4 ,the probability is1 that all the supporters have the property of uniting with all the bases1 in at least three proportions4 ,but by far the greater number of these compounds still remain unknown4 ,the greatest progress has been made in our knowledge of the compounds of oxygen2 but even there much remains to be investigated2 owing1 in a great measure1 to the scarcity of several of the bases which prevent chemists from subjecting them to the requisite number of experiments4 ,the compounds of chlorine have also been a good deal investigated2 but bromine and iodine have been known for so short a time1 that chemists have not yet had leisure to contrive the requisite processes for causing them to unite with bases4 ,the acids at present known amount to a very great number4 ,the oxygen acids have been most investigated4 ,they consist of two sets3 those consisting of oxygen united to a single base1 and those in which it is united to two or more bases4 ,the last set are derived from the animal and vegetable kingdoms3 it does not seem likely that the electro-chemical theory of ,davy applies to them4 ,they must derive their acid qualities from some electric principle not yet adverted to2 for1 from ,davy's experiments1 there can be little doubt that they are electro-negative1 as well as the other acids4 ,the acid compounds of oxygen and a single base are about thirty-two in number4 ,their names are ,hyponitrous acid ,nitrous acid8 ,nitric acid ,carbonic acid ,oxalic acid ,boracic acid ,silicic acid ,hypophosphorous acid ,phosphorous acid ,phosphoric acid ,hyposulphurous acid ,subsulphurous acid ,sulphurous acid ,sulphuric acid ,hyposulphuric acid ,selenious acid ,selenic acid ,arsenious acid ,arsenic acid ,antimonious acid ,antimonic acid ,oxide of tellurium ,chromic acid ,uranic acid ,molybdic acid ,tungstic acid ,titanic acid ,columbic acid ,manganesic acid ,chloric acid ,bromic acid ,iodic acid4 ,the acids from the vegetable and animal kingdoms 7not reckoning a considerable number which consist of combinations of sulphuric acid with a vegetable or animal body71 amount to about forty-three3 so that at present we are acquainted with very nearly eighty acids which contain oxygen as an essential constituent4 ,the other classes of acids have been but imperfectly investigated4 ,hydrogen enters into combination and forms powerful acids with all the supporters except oxygen4 ,these have been called hydracids4 ,they are ,muriatic acid1 or hydrochloric acid ,hydrobromic acid ,hydriodic acid ,hydrofluoric acid1 or fluoric acid ,hydrosulphuric acid ,hydroselenic acid ,hydrotelluric acid ,these constitute 7such of them as can be procured7 some of the most useful and most powerful chemical reagents in use4 ,there is also another compound body1 cyanogen1 similar in its characters to a supporter3 it also forms various acids1 by uniting to hydrogen1 chlorine1 oxygen1 sulphur1 c4 ,thus we have ,hydrocyanic acid ,chlorocyanic acid ,cyanic acid ,sulpho-cyanic acid1 c4 ,we know1 also1 fluosilicic acid and fluoboric acids4 ,if to these we add fulminic acid1 and the various sulphur acids already investigated1 we may state1 without risk of any excess1 that the number of acids at present known to chemists1 and capable of uniting to bases1 exceeds a hundred4 ,the number of alkaline bases is not1 perhaps1 so great2 but it must even at present exceed seventy2 and it will certainly be much augmented when chemists turn their attention to the subject4 ,now every base is capable of uniting with almost every acid1#i in all probability in at least three different proportions3 so that the number of salts which they are capable of forming cannot be fewer than #ba1jjj4 ,now scarcely #ajjj of these are at present known1 or have been investigated with tolerable precision4 ,what a prodigious field of investigation remains to be traversed must be obvious to the most careless reader4 ,in such a number of salts1 how many remain unknown that might be applied to useful purposes1 either in medicine1 or as mordants1 or dyes1 c4 ,how much1 in all probability1 will be added to the resources of mankind by such investigations need not be observed4 #i ,acids and bases of the same class all unite4 ,thus sulphur acids unite with sulphur bases2 oxygen acids with oxygen bases1 c4 ,the animal and vegetable kingdoms present a still more tempting field of investigation4 ,animal and vegetable substances may be arranged under three classes1 acids1 alkalies1 and neutrals4 ,the class of acids presents many substances of great utility1 either in the arts1 or for seasoning food4 ,the alkalies contain almost all the powerful medicines that are drawn from the vegetable kingdom4 ,the neutral bodies are important as articles of food1 and are applied1 too1 to many other purposes of first-rate utility4 ,all these bodies are composed 7chiefly1 at least7 of hydrogen1 carbon1 oxygen1 and azote2 substances easily procured abundantly at a cheap rate4 ,should chemists1 in consequence of the knowledge acquired by future investigations1 ever arrive at the knowledge of the mode of forming these principles from their elements at a cheap rate1 the prodigious change which such a discovery would make upon the state of society must be at once evident4 ,mankind would be1 in some measure1 independent of climate and situation2 every thing could be produced at pleasure in every part of the earth2 and the inhabitants of the warmer regions would no longer be the exclusive possessors of comforts and conveniences to which those in less favoured regions of the earth are strangers4 ,let the science advance for another century with the same rapidity that it has done during the last fifty years1 and it will produce effects upon society of which the present race can form no adequate idea4 ,even already some of these effects are beginning to develop themselves2--our streets are now illuminated with gas drawn from the bowels of the earth2 and the failure of the ,greenland fishery during an unfortunate season like the last1 no longer fills us with dismay4 ,what a change has been produced in the country by the introduction of steam-boats6 and what a still greater improvement is at present in progress1 when steam-carriages and railroads are gradually taking the place of horses and common roads4 ,distances will soon be reduced to one-half of what they are at present2 while the diminished force and increased rate of conveyance will contribute essentially to lower the rest of our manufactures1 and enable us to enter into a successful competition with other nations4 ,i must say a few words upon the application of chemistry to physiology before concluding this imperfect sketch of the present state of the science4 ,the only functions of the living body upon which chemistry is calculated to throw light1 are the processes of digestion1 assimilation1 and secretion4 ,the nervous system is regulated by laws seemingly quite unconnected with chemistry and mechanics1 and1 in the present state of our knowledge1 perfectly inscrutable4 ,even in the processes of digestion1 assimilation1 and secretion1 the nervous influence is important and essential4 ,hence even of these functions our notions are necessarily very imperfect2 but the application of chemistry supplies us with some data at least1 which are too important to be altogether neglected4 ,the food of man consists of solids and liquids1 and the quantity of each taken by different individuals is so various1 that no general average can be struck4 ,i think that the drink will1 in most cases1 exceed the solid food in nearly the proportion of #d to #c2 but the solid food itself contains not less than #g-ajths of its weight of water4 ,in reality1 then1 the quantity of liquid taken into the stomach is to that of solid matter as #aj to #a4 ,the food is introduced into the mouth1 comminuted by the teeth1 and mixed up with the saliva into a kind of pulp4 ,the saliva is a liquid expressly secreted for this purpose1 and the quantity certainly does not fall short of ten ounces in the twenty-four hours3 indeed ,i believe it exceeds that amount3 it is a liquid almost as colourless as water1 slightly viscid1 and without taste or smell3 it contains about #c_/ajjj of its weight of a peculiar matter1 which is transparent and soluble in water3 it has suspended in it about #ad_/ajjj of its weight of mucus2 and in solution1 about #bh_/ajjj of common salt and soda3 the rest is water4 ,from the mouth the food passes into the stomach1 where it is changed to a kind of pap called chyme4 ,the nature of the food can readily be distinguished after mastication2 but when converted into chyme1 it loses its characteristic properties4 ,this conversion is produced by the action of the eighth pair of nerves1 which are partly distributed on the stomach2 for when they are cut1 the process is stopped3 but if a current of electricity1 by means of a small voltaic battery1 be made to pass through the stomach1 the process goes on as usual4 ,hence the process is obviously connected with the action of electricity4 ,a current of electricity1 by means of the nerves1 seems to pass through the food in the stomach1 and to decompose the common salt which is always mixed with the food4 ,the muriatic acid is set at liberty1 and dissolves the food2 for chyme seems to be simply a solution of the food in muriatic acid4 ,the chyme passes through the pyloric orifice of the stomach into the duodenum1 the first of the small intestines1 where it is mixed with two liquids1 the bile1 secreted by the liver1 and the pancreatic juice1 secreted by the pancreas1 and both discharged into the duodenum to assist in the further digestion of the food4 ,the chyme is always acid2 but after it has been mixed with the bile1 the acidity disappears4 ,the characteristic constituent of the bile is a bitter-tasted substance called picromel1 which has the property of combining with muriatic acid1 and forming with it an insoluble compound4 ,the pancreatic juice also contains a peculiar matter1 to which chlorine communicates a red colour4 ,the use of the pancreatic juice is not understood4 ,during the passage of the chyme through the small intestines it is gradually separated into two substances2 the chyle1 which is absorbed by the lacteals1 and the excrementitious matter1 which is gradually protruded along the great intestines1 and at last evacuated4 ,the chyle1 in animals that live on vegetable food1 is semitransparent1 colourless1 and without smell2 but in those that use animal food it is white1 slightly similar to milk1 with a tint of pink4 ,when left exposed to the air it coagulates as blood does4 ,the coagulum is fibrin4 ,the liquid portion contains albumen1 and the usual salts that exist in the blood4 ,thus the chyle contains two of the constituents of blood2 namely1 albumen1 which perhaps may be formed in the stomach1 and fibrin1 which is formed in the small intestines4 ,it still wants the third constituent of blood1 namely1 the red globules4 ,from the lacteals the chyle passes into the thoracic duct2 thence into the left subclavian vein1 by which it is conveyed to the heart4 ,from the heart it passes into the lungs1 during its circulation through which the red globules are supposed to be formed1 though of this we have no direct evidence4 ,the lungs are the organs of breathing1 a function so necessary to hot-blooded animals1 that it cannot be suspended1 even for a few minutes1 without occasioning death4 ,in general1 about twenty inspirations1 and as many expirations1 are made in a minute4 ,the quantity of air which the lungs of an ordinary sized man can contain1 when fully distended1 is about #cjj cubic inches4 ,but the quantity actually drawn in and thrown out1 during ordinary inspirations and expirations1 amounts to about sixteen cubic inches each time4 ,in ordinary cases the volume of air is not sensibly altered by respiration2 but it undergoes two remarkable changes4 ,a portion of its oxygen is converted into carbonic acid gas1 and the air expired is saturated with humidity at the temperature of #ih4 ,the moisture thus given out amounts to about seven ounces troy1 or very little short of half an avoirdupois pound4 ,the quantity of carbonic acid formed varies much in different individuals1 and also at different times in the day2 being a maximum at twelve o'clock at noon1 and a minimum at midnight4 ,perhaps four of carbonic acid1 in every #ajj cubic inches of air breathed1 may be a tolerable approach to the truth2 that is to say1 that every six respirations produce four cubic inches of carbonic acid4 ,this would amount to #ai1bjj cubic inches in twenty-four hours4 ,now the weight of #ai1bjj cubic inches of carbonic acid gas is #ahih troy ounces1 which contain rather more than five troy ounces of carbon4 ,these alterations in the air are doubtless connected with corresponding alterations in the blood1 though with respect to the specific nature of these alterations we are ignorant4 ,but there are two purposes which respiration answers1 the nature of which we can understand1 and which seem to afford a reason why it cannot be interrupted without death4 ,it serves to develop the animal heat1 which is so essential to the continuance of life2 and it gives the blood the property of stimulating the heart2 without which it would cease to contract1 and put an end to the circulation of the blood4 ,this stimulating property is connected with the scarlet colour which the blood acquires during respiration2 for when the scarlet colour disappears the blood ceases to stimulate the heart4 ,the temperature of the human body in a state of health is about #ih in this country2 but in the torrid zone it is a little higher4 ,now as we are almost always surrounded by a medium colder than #ih1 it is obvious that the human body is constantly giving out heat2 so that if it did not possess the power of generating heat1 it is clear that its temperature would soon sink as low as that of the surrounding atmosphere4 ,it is now generally understood that common combustion is nothing else than the union of oxygen gas with the burning body4 ,the substances commonly employed as combustibles are composed chiefly of carbon and hydrogen4 ,the heat evolved is proportional to the oxygen gas which unites with these bodies4 ,and it has been ascertained that every #c cubic inches of oxygen which combine with carbon or hydrogen occasion the evolution of #a of heat4 ,there are reasons for believing that not only carbon but also hydrogen unite with oxygen in the lungs1 and that therefore both carbonic acid and water are formed in that organ4 ,and from the late experiments of ,m4 ,dupretz it is clear that the heat evolved in a given time1 by a hot-blooded animal1 is very little short of the heat that would be evolved by the combustion of the same weight of carbon and hydrogen consumed during that time in the lungs4 ,hence it follows that the heat evolved in the lungs is the consequence of the union of the oxygen of the air with the carbon and hydrogen of the blood1 and that the process is perfectly analogous to combustion4 ,the specific heat of arterial blood is somewhat greater than that of venous blood4 ,hence the reason why the temperature of the lungs does not become higher by breathing1 and why the temperature of the other parts of the body are kept up by the circulation4 ,the blood seems to be completed in the kidneys4 ,it consists essentially of albumen1 fibrin1 and the red globules1 with a considerable quantity of water1 holding in solution certain salts which are found equally in all the animal fluids4 ,it is employed during the circulation in supplying the waste of the system1 and in being manufactured into all the different secretions necessary for the various functions of the living body4 ,by these different applications of it we cannot doubt that its nature undergoes very great changes1 and that it would soon become unfit for the purposes of the living body were there not an organ expressly destined to withdraw the redundant and useless portions of that liquid1 and to restore it to the same state that it was in when it left the lungs4 ,these organs are the kidneys2 through which all the blood passes1 and during its circulation through which the urine is separated from it and withdrawn altogether from the body4 ,these organs are as necessary for the continuance of life as the lungs themselves2 accordingly1 when they are diseased or destroyed1 death very speedily ensues4 ,the quantity of urine voided daily is very various2 though1 doubtless1 it bears a close relation to that of the drink4 ,it is nearly but not quite equal to the amount of the drink2 and is seldom1 in persons who enjoy health1 less than #b lbs4 avoirdupois in twenty-four hours4 ,urine is one of the most complex substances in the animal kingdom1 containing a much greater number of ingredients than are to be found in the blood from which it is secreted4 ,the water in urine voided daily amounts to about #ahfflbs4 ,the blood contains no acid except a little muriatic4 ,but in urine we find sulphuric1 phosphoric1 and uric acids1 and sometimes oxalic and nitric acids1 and perhaps also some others4 ,the quantity of sulphuric acid may be about forty-eight grains daily1 containing nineteen grains of sulphur4 ,the phosphoric acid about thirty-three grains1 containing about fourteen grains of phosphorus4 ,the uric acid may amount to fourteen grains4 ,these acids are in combination with potash1 or soda1 or ammonia1 and also with a very little lime and magnesia4 ,the common salt evacuated daily in the urine amounts to about sixty-two grains4 ,the urea1 a peculiar substance found only in the urine1 amounts perhaps to as much as #dbj grains4 ,it would appear from these facts that the kidneys possess the property of converting the sulphur and phosphorus1 which are known to exist in the blood1 into acids1 and likewise of forming other acids and urea4 ,the quantity of water thrown out of the system by the urine and lungs is scarcely equal to the amount of liquid daily consumed along with the food4 ,but there is another organ which has been ascertained to throw out likewise a considerable quantity of moisture1 this organ is the skin2 and the process is called perspiration4 ,from the experiments of ,lavoisier and ,seguin it appears that the quantity of moisture given out daily by the skin amounts to #edhi ounces3 this added to the quantity evolved from the lungs and the urine considerably exceeds the weight of liquid taken with the food1 and leaves no doubt that water as well as carbonic acid must be formed in the lungs during respiration4 ,such is an imperfect sketch of the present state of that department of physiology which is most intimately connected with ,chemistry4 ,it is amply sufficient1 short as it is1 to satisfy the most careless observer how little progress has hitherto been made in these investigations2 and what an extensive field remains yet to be traversed by future observers4 ,,the ,,end4 ,c4 ,,whiting1 ,,beaufort ,,house1 ,,strand4 ,,popular ,,novels1 ,,just ,,published ,,by ,,henry ,,colburn ,,and ,,richard ,,bentley1 ,,new ,,burlington ,,street4 ,i4 ,,philip ,,augustus4 ,by the ,author of ,de ,l',orme1 ,darnley1 c4 #c vols4 post #hvo4 ,,ii4 ,,jacqueline ,,of ,,holland4 ,by the ,author of ,the ,heiress of ,bruges1 ,highways and ,byways1 c4 ,in #c vols4 post #hvo4 ,,iii4 ,,companion ,,to ,,lawrie ,,todd4 ,,bogle ,,corbet2 ,,or1 ,,the ,,emigrants4 ,by the ,author of ,lawrie ,todd1 c4 #c vols4 post #hvo4 ,,iv4 ,,the ,,young ,,duke4 ,by the ,author of ,vivian ,grey4 #c vols4 post #hvo4 ,v4 ,,mothers ,,and ,,daughters4 ,a ,,tale ,,of ,,the ,,year #ahcj4 #c vols4 post #hvo4 ,the best novel of the season--a faithful1 exact1 and spirited picture of the ,aristocracy of this country4--,,spectator4 ,,vi4 ,,wedded ,,life ,,in ,,the ,,upper ,,ranks4 #b vols4 post #hvo4 ,,vii4 ,,the ,,premier666 ,in #c vols4 post #hvo4 ,all the leading ,statesmen of the day1 and all the most influential political characters1 are not only described in this novel1 but brought forward as actors1 speaking in their own proper persons1 and assigning their own reasons for their conduct with a startling fidelity4--,,courier4 ,,viii4 ,,mr4 ,,theodore ,,hook',s ,,new ,,work4 ,,maxwell4 ,by the ,author of ,sayings and ,doings4 ,in #c vols4 post #hvo4 ,the very best of ,mr4 ,hook's productions4--,,examiner4 ,,ix4 ,,the ,,water ,,witch2 ,,or1 ,,the ,,skimmer ,,of ,,the ,,seas4 ,by the ,author of ,the ,red ,rover1 ,the ,borderers1 c4 ,in #c vols4 post #hvo4 ,cooper1 the ,american ,novelist1 has no living superior4--,,scotsman4 ,x4 ,,paul ,,clifford4 ,by the ,author of ,pelham4 ,second ,edition4 ,in #c vols4 post #hvo4 ,the most original of all ,mr4 ,bulwer's works4--,,lit4 ,,gazette4 ,,xi4 ,,the ,,heiress ,,of ,,bruges4 ,a ,tale4 ,by ,t4 ,c4 ,,grattan1 ,esq41 ,author of ,highways and ,byways1 c4 ,second and cheaper edition1 in #c vols4 post #hvo4 ,a love story1 of the most romantic interest4--,,lit4 ,,gazette4 99 99 99 99 99 ,transcriber's ,notes ,obvious typographical errors have been silently corrected4 ,other variations in spelling and punctuation remain unchanged4 ,several elements are represented by symbols in the original4 ,they have been replaced by the name of the element within thus - hydrogen4 ,in chapter ,,vi the final numeral in several of the decimal numbers is surmounted by a point4 ,these are shown thus #aaaa4a4 ,italics are represented thus italic4