,transcriber's ,notes3 ,underscores 80 before and after a word or phrase indicate italics in the original text4 ,equal signs 80 before and after a word or phrase indicate bold in the original text4 ,small capitals have been converted to ,,solid capitals4 ,footnotes have been moved so they do not break up paragraphs4 ,old or antiquated spellings have been preserved4 ,typographical and punctuation errors have been silently corrected4 ,a ,,new ,,system ,,of ,,chemical ,,philosophy4 ,,part ,,first4--,,vol4 ,,ii4 ,,reproduced ,,in ,,facsimilie ,,by ,,william ,,dawson ,,sons ,,ltd4 #ajb ,,wigmore ,,street1 ,,london1 ,w4#a ,,and ,,printed ,,by ,,henderson ,,spalding ,,sylvan ,,grove1 ,,old ,,kent ,,road1 ,,london1 ,s4,e4#ae ,,this ,,edition ,,is ,,limited ,,to #a1jjj ,,copies ,a ,,new ,,system ,,of ,,chemical ,,philosophy4 ,,part ,,first ,,of ,,vol4 ,,ii4 ,,by ,,john ,,dalton1 ,f4,r4,s4 ,president of the ,literary and ,philosophical ,society1 ,manchester4 ,corresponding ,member of the ,royal ,academy of ,sciences1 ,paris1 ,member of the ,royal ,academy1 ,munich1 and of the ,csarean ,natural ,history ,society1 ,moscow2 ,honorary ,member of the ,royal ,medical ,society1 ,edinburgh1 and of the ,philosophical ,societies of ,bristol1 ,cambridge1 ,leeds1 ,sheffield and ,yorkshire4 ,manchester3 ,printed by the ,executors of ,s4 ,russell4 ,,for ,,george ,,wilson1 ,,essex ,,street1 ,,strand ,,london4 #ahbg4 ,,to ,,john ,,sharpe1 ,,esq4 ,f4 ,r4 ,s4 ,,of ,,stanmore1 ,,middlesex1 7,late of ,manchester17 ,,as ,a ,,testimony ,,of ,,his ,,friendly ,,regard1 ,,and ,,of ,,his ,,liberal ,,encouragement ,,given ,,to ,,the ,,promotion ,,of ,,chemical ,,science3 ,,and ,,to ,,peter ,,ewart1 ,,esq4 ,vice-,president of the ,literary and ,philosophical ,society of ,manchester1 ,,on ,,the ,,score ,,of ,,friendship1 ,,but ,,more ,,especially ,,for ,,the ,,able ,,exposition ,,and ,,excellent ,,illustrations ,,of ,,the ,,fundamental ,,principles ,,of ,,mechanics1 ,,in ,,his ,,essay ,,on ,,the ,,measure ,,of ,,moving ,,force1#a ,,this ,,work ,,is ,,respectfully ,,inscribed ,,by ,,the ,,author4 ,footnote #a3 ,manchester ,memoirs1 ,vol4 ,,ii4 7second series47 ,,preface4 ,the work now submitted to the public was begun to be printed in #ahag2 and the #acth and #adth sections1 containing the oxides and sulphurets1 were printed off before the end of ,october of the same year4 ,the printing of the rest of the work to the appendix was finished in ,september1 #ahba4 ,one sheet of the appendix was printed at the end of #ahbc2 but no addition was afterwards made till ,may1 #ahbf2 when the printing was resumed1 and has been continued to the present time4 ,it may be asked1 what were the motives for such a plan of procedure4 ,to this it may be replied1 that soon after the publication of the first volume 7in #ahaj71 ,i began to prepare materials1 and to institute experiments1 relating to the oxides1 c41 with occasional diversions into other departments of chemistry1 as circumstances arose4 ,as a great portion of my time was always necessarily engaged in professional duties1 and as that part of the work ,i was about to commence was one running into detail1 ,i thought it would be best to print it as ,i proceeded1 whilst the train of thought and of experiments was fresh in view4 ,the advantage in this case was expected to be partly at least counterbalanced by the loss of discoveries and improvements likely to be made in the interval between the printing and publishing of the several articles4 ,this ,i was aware of2 but as a principal object ,i had in view was to give the results of my own experience1 in the various departments of chemical science1 rather than to form the best compilation of ,chemistry at the period1 this object was most likely to be obtained by the proposed plan4 ,it is true the time the work has been in the press has far exceeded my expectation2 notwithstanding this ,i am not conscious of any very material alterations or additions1 which ,i should wish to make at the present moment4 ,it affords me great pleasure to acknowledge the assistance ,i have had during the progress of this volume1 from a valuable selection of chemical apparatus1 for which ,i am indebted to the generosity of ,mr4 ,sharpe2 also the continued and friendly intercourse with ,dr4 ,henry1 whose discussions on scientific subjects are always instructive1 and whose stores are always open when the promotion of science is the object4 ,my present design is to add a second part to this volume1 and with that to finish the work4 ,it will consist of the more complex compounds4 ,acids1 and other products of the vegetable kingdom1 ,salts1 c41 will form principal parts4 ,already ,i have a stock of experiments on these subjects2 but ,i am not satisfied without exploring this region afresh4 ,august1 #ahbg4 ,,contents ,,of ,,vol4 ,,ii4 ,part ,first4 ,page4 ,,chap4 ,v4--,,compounds ,,of ,,two ,,elements4 ,,section #ac4 ,metallic ,oxides #a ,oxide of ,gold #e ---- ,platina #aa ---- ,silver #ag ,oxides of ,mercury #ai ,oxide of ,palladium #bd ,oxides of ,rhodium1 ,iridium1 and ,osmium #bf ---- ,copper #bf ---- ,iron #bh ---- ,nickel #cd ---- ,tin #cf ---- ,lead #ci ,oxide of ,zinc #ea ,oxides of ,potassium #ec ---- ,sodium #ef ,oxide of ,bismuth #eg ,oxides of ,antimony #eh ,oxide of ,tellurium #fb ,oxides of ,arsenic #fc ---- ,cobalt #fh ---- ,manganese #ga ---- ,chromium #hj ---- ,uranium #hf ---- ,molybdenum #hg ---- ,tungsten #ij ---- ,titanium #ia ---- ,columbium #ib ---- ,cerium #id ,,section #ad4 ,earthy1 ,alkaline1 and ,metallic ,sulphurets #if ,sulphurets of ,lime #ii ,sulphuret of ,magnesia #aaa ,sulphurets of ,barytes #aab ---- ,strontites #aad ---- ,alumine1 ,silex1 ,yttria1 ,glucine and ,zircone #aad ---- ,potash #aaf ---- ,soda #aai ,sulphuret of ,ammonia #abj ,sulphurets of ,gold #aba ,sulphuret of ,platina #abc ,sulphurets of ,silver #abf ---- ,mercury #abg ,sulphuret of ,palladium #aca ---- ,rhodium #acb ---- ,iridium #acb ---- ,osmium #acb ,sulphurets of ,copper #acc ---- ,iron #acd ---- ,nickel #ach ---- ,tin #aci ---- ,lead #add ---- ,zinc #adf ---- ,potassium and ,sodium #adh ---- ,bismuth #adi ---- ,antimony #aea ,sulphuret of ,tellurium #aec ,sulphurets of ,arsenic #aec ,sulphuret of ,cobalt #afj ,sulphurets of ,manganese #afb ,sulphuret of ,chromium #afc ---- ,uranium #afd ---- ,molybdenum #afd ,sulphuret of ,tungsten #afd ,sulphurets of ,titanium1 ,columbium1 and ,cerium #afe ,,section #ae4 ,earthy1 ,alkaline1 and ,metallic ,phosphurets #aff ,phosphuret of ,hydrogen #afi ,phosphurets of ,carbon and ,sulphur #ahd ,phosphuret of ,lime #ahd ---- ,barytes #ahh ---- ,strontites #aij ---- ,gold #aia ---- ,platina #aid ---- ,silver #aie ---- ,mercury #aig ---- ,palladium #aih ---- ,copper #aii ---- ,iron #bja ---- ,nickel #bja ---- ,tin #bjb ---- ,lead #bjc ,phosphurets of ,zinc and ,potassium #bjd ---- ,sodium and ,bismuth #bjg ---- ,antimony and ,arsenic #bjh ,phosphuret of ,cobalt #bji ---- ,manganese #baj ,,section #af4 ,carburets #baa ---- of ,iron 444 steel #bab-bad ,,section #ag4 ,metallic ,alloys #bah ,alloys of ,gold1 with other metals #bbb ---- ,platina1 with other metals #bbf ---- ,silver1 with other metals #bbh ---- ,mercury1 and other metals3 amalgams #bcj ,triple1 ,quadruple1 c4 amalgams #bcf ,alloys of ,copper1 with other metals #bch ---- ,iron1 with other metals #bec ,alloys of ,nickel and ,tin1 with do4 #bed ---- ,lead1 with do4 #beh ,triple ,alloys1 ,solders2 fusible metal1 c4 #bfc ,,appendix4 ,abstract of ,de la ,roche and ,berard's essay on the specific heat of gases #bfh ---- ,dulong and ,petit's essays1 ,on the expansion of air1 mercury1 glass1 iron1 copper1 and platina1 by heat #bgb ,on the capacities of certain bodies1 for heat #bgd ,on the laws of refrigeration #bgg ,on the specific heats of certain bodies #bhj ,remarks on the above essays #bhb ,new ,table of the forces of vapours #bih ,table of the expansion of air1 and the force of aqueous and therial vapour1 adapted to atmospheric temperatures #bii ,applications of the above table #cjj ,formul for determining the proportions of combustible gases1 in mixtures #cje ,heat produced by the combustion of gases #cji ,absorption of gases by water #cji ,fluoric acid--deutoxide of hydrogen #caa ,muriatic acid--oxymuriatic acid #cac ,nitric acid--compounds of azote and oxygen #cae ,on ammonia #cbh ,decomposition of ammonia by nitrous oxide #ccj ---- ---- ---- by nitrous gas and oxygen #ccb ,volume of gases from the decomposition of ammonia #cce ,decomposition of ammonia by a red heat #cce ,decomposition of ammonia by oxymuriatic acid#cce ,sulphuret of ,carbon #cch ,potassium1 ,sodium1 c4 #cdj ,alum #cda ,new table of the relative weights of atoms4 #ceb ,,addenda4 ,steel2 mixed gases2 expansion of liquids by heat #ced ,,new ,,system ,,of ,,chemical ,,philosophy4 ,,chap4 ,v4 ,,section #ac4 ,,metallic ,,oxides4 ,all the metals are disposed to combine with oxygen1 but the combination is effected more easily with some than with others2 the compound is usually called an oxide1 but in some instances it is also called an acid4 ,the same metal combines with one1 two1 or perhaps more atoms of oxygen1 forming compounds which may be distinguished according to ,dr4 ,thomson1 by the terms protoxide1 deutoxide1 tritoxide1 c4 ,such however is the repulsion of oxygen to oxygen that we rarely find three atoms of it retained by a single atom of any kind2 and there are not many instances of metals capable of holding two atoms of oxygen4 ,various modifications of the proportions of metals and oxygen arise from the combinations of the oxides themselves one with another and with oxygen1 so as to lead some to imagine that an atom of metal in some instances combines with #c1 #d1 or more of oxygen4 ,this is altogether improbable3 ,it is much more simple to suppose that one atom of oxygen connects two or more atoms of protoxide1 #a of protoxide unites to #a or more of deutoxide1 c4 ,these intermediate oxides are in few if any instances found to combine with acids like the other two oxides4 ,there is no reason that ,i am acquainted with for disbelieving that oxygen combined with a metal is still repulsive of oxygen1 and that by the same law as particles of an elastic fluid2 that is1 the repulsion is inversely as the distance of the centres of the atoms4 ,hence it may be demonstrated that it requires twice the strength of affinity to form a deutoxide as a protoxide1 three times the strength to form a tritoxide as a protoxide1 c4 ,on this account it is1 in all probability1 that deutoxides are not numerous1 and tritoxides are rarely if ever found4 ,the quantity of oxygen that combines with any metal to form an oxide may be investigated by several methods4 #ast4 ,by combustion2 a given weight of the metal may be burned and the oxide produced may be collected and weighed2 when the increase by combustion will appear4 #b4 ,by solution in an acid and precipitation by an earth or alkali2 in this case a given weight of the metal is dissolved and precipitated2 the precipitate collected and sufficiently dried shews the increase by oxygen4 #c4 ,by transferring the oxygen from an oxide to another metal2 in this case the metal in question is usually immersed in a saline solution of the other metal2 this latter metal gives up its oxygen to the former and is itself reformed or revived as it is termed4 #d4 ,by determining the proportion of hydrogen gas evolved during the solution of a given weight of metal2 then allowing half of that volume for its equivalent of oxygenous gas1 the weight of it shews the oxygen united to the metal2 it being now well understood that water furnishes the two elements of hydrogen and oxygen in such case4 #e4 ,the higher oxides are conveniently determined by the application of the solution of oxymuriate of lime to the lower oxides in solution4 #f4 ,the quantity of oxygen in several oxides may be found from the quantity of nitrous gas evolved during the solution of a given weight of metal in nitric acid4 ,the first four methods have been used by chemists for several years past2 the two last ,i have added from my own experience1 having found them very useful assistants in various instances4 ,the last method by nitrous gas1 has indeed been proposed before1 and labour bestowed on it both by others and myself1 but without reducing the results to any certainty1 till lately2 the principal cause of this want of success has arisen from misunderstanding the nature and constitution of nitric acid4 ,most chemists seem with me to have mistaken nitrous acid for nitric2 the former is composed of #a atom of azote and #b of oxygen2 or perhaps of #b azote and #d oxygen2 the latter of #b azote and #e oxygen1 or #b nitrous gas and #c oxygen2 the weight of the former is #ai1 or its double #ch1 on my scale1 and that of the latter #de4 ,my reasons for adopting the above conclusion respecting nitrous acid1 which is at variance with that in ,,vol4 #a1 p4 #cca1 will be given hereafter4 ,when therefore a metal is oxidized by nitric acid1 #c atoms of oxygen 7 #ba7 go to the metal1 and #b atoms of nitrous gas 7 #bd7 are disengaged4 ,hence of the weight of nitrous gas evolved is the weight of oxygen combined4 ,it sometimes happens however that the nitrous gas is partly or wholly retained by the residue of nitric acid2 but in this case the oxymuriate of lime can be applied to convert the nitrous gas into nitric acid1 and from the oxygen imbibed the quantity of nitrous gas may be inferred4 #a4 ,oxide of ,gold4 ,some difficulties have been found in ascertaining both the number and proportions of the oxides of gold2 hence the differences in the results of authors4 ,gold does not burn by exposure to heat1 but gold leaf and gold wire may be deflagrated by electricity and galvanism2 a purple powder is the product1 which is considered by some as the protoxide of gold2 but others1 after ,macquer and ,proust1 conceive with greater probability that this powder is nothing but gold reduced to its ultimate division4 ,solutions of gold which are of a fine yellow1 give a purple stain2 and gold deoxidized by green sulphate of iron is precipitated blue1 which precipitate gradually assumes a yellow colour as the particles become united4 ,the very weak affinity of gold for oxygen is shewn by the difficulty with which it is oxidized and the ease with which the oxygen is expelled again by heat2 these facts seem to preclude the idea of gold combining with oxygen in high temperatures4 ,protoxide4 ,gold is scarcely affected by pure sulphuric1 nitric or muriatic acid2 but it is easily oxidized and dissolved by nitro-muriatic acid 7that is1 a mixture of nitric and muriatic acids7 when assisted by a temperature of #aej or #bjj4 ,caustic potash being put into the solution and heated1 a brownish black precipitate is obtained2 but a part of the oxide remains in solution combined with the muriate of potash1 according to ,vauquelin2 and ,proust has observed that the oxide cannot be washed and dried in a moderate heat without a portion of the gold being revived2 hence the difficulty of ascertaining in this way the weight of oxygen combining with gold4 ,i have succeeded1 as ,i apprehend1 in determining the relative weights of gold and oxygen1 by two methods1 which mutually corroborate each other4 ,the first is by means of the nitrous gas generated by the solution of gold2 and the second is1 by finding what quantity of green oxide of iron is converted into red by precipitating a given weight of gold in solution4 ,ten grains of guinea gold of the sp4 gr4 #ag4c1 were repeatedly dissolved in a small excess of nitro-muriatic acid2 the quantity and purity of the nitrous gas generated were duly observed and allowance made for the loss occasioned by a small portion of common air originally in the gas bottle4 ,the volume of nitrous gas corrected as above was always found between #aajj and #abjj grain measures1 the weight of which may be estimated at #a4f grains1 corresponding to #a4d grains of oxygen4 ,the small portion of alloy 7_/7 known to be in standard gold is chiefly copper with a small part silver2 now it will be seen in the sequel that copper takes of its weight of oxygen2 hence if we allow 4#h of a grain for copper and 4#b for the oxygen combining with it1 we shall have #i4b gold united to #a4b oxygen1 or #ajj gold with #ac oxygen1 which is nearly the same as ,berzelius has determined by precipitating the gold by mercury4--,again1 #aj grains of gold were dissolved as above 7 #i4b pure7 and precipitated by a solution of pure green sulphate of iron of the sp4 gr4 #a4aha and which ,i had previously proved to contain #i grains of green oxide in #ajj measures4 ,they converted #abj measures of this green sulphate into yellow1 which was carefully precipitated afterwards by lime water1 dried and weighed4 ,the gold precipitated was found very nearly #i grains2 and the yellow oxide of iron mixed with oxide of copper was nearly #ac grains4 ,now #abj measures sulphate iron contain #aj4h grains green oxide1 and these require _/ of their weight of oxygen 7see the oxides of iron7 to be changed into yellow oxide1 or #a4b oxygen4 ,hence it appears that the oxygen combined with the gold was transferred to the iron unchanged in quantity4 ,it is to be observed however that green oxide of iron not only deoxidates the gold but it semideoxidates the copper also2 so that 4#a of the transferred oxygen above might be said to be derived from the copper1 and the rest1 or #a4a from the #i grains of gold2 this would give #ajj gold to #ab4b oxygen1 which is still nearer to the determination of ,berzelius4 ,upon the whole ,i am inclined to adopt the proportion of #h to #a or #ajj to #ab4e as that which appears the most correct approximation and at the same time a ratio easily remembered and adapted to facilitate calculations4 ,we are now to consider whether the above is the protoxide4 ,as no other oxide has been clearly shewn to exist1 and as this combines with muriatic acid1 with ammonia1 with the oxide of tin1 c4 and is wholly deoxidated by green sulphate of iron and by a moderate heat1 there seems every reason to conclude it is a combination of the most simple kind1 or #a atom of metal to #a of oxygen4 ,hence the atom of oxygen being #g1 that of gold must be #ef1 and not #adj or #bjj1 as stated ,,vol4 #a1 p4 #bej4 ,berzelius seems to consider the above as the tritoxide1 or three atoms of oxygen to one of gold2 but it is extremely improbable that gold1 which is allowed to have a weak affinity for oxygen1 should be able to restrain the violent repulsion of three atoms of oxygen1 and should on every occasion lose them all at once1 and not by degrees1 as is usual with other high oxides4 ,subjoined are the results of various authors in regard to the oxide of gold1 but generally given with diffidence as to their accuracy4 gold oxygen ,bergman #ajj #aj ,proust -- #h4eg to #ca4 ,oberkampf -- #aj ,berzelius -- #ab 7#d suboxide7 ,my results -- #ab4e ,since writing the above ,i have had an opportunity of repeating the experiments on the oxide of gold by an improved nitrous gas apparatus1 calculated almost entirely to exclude atmospheric air2 ,i find less nitrous gas produced during the solution than stated above1 sometimes by 1 and that it is variable according to the excess of nitric acid2 also that the solution requires a portion of oxymuriatic acid as an equivalent for the nitrous gas retained4 ,i prefer1 however1 the method of oxidizing the green sulphate of iron2 by putting a small excess of the green sulphate and precipitating1 first the red oxide and then the green1 ,i obtained very distinct results4 ,on the whole ,i am inclined to think my results preceding these have rather overrated the oxygen1 and that it would as nearly be stated at #aa on the hundred4 ,this would be nearly a mean of those in the above table1 and would require the atom of gold to be #fc1 and that of the oxide #gj4 ,between the two extremes of #ef and #fc it is most probable the true weight of the atom of gold will be found4 ,it may be proper to add that ,i have found #ajj grain measures of muriatic acid 7#a4af71 and #be of nitric 7#a4ce71 are sufficient to dissolve #dj grains of standard gold2 and ,i have reason to think the acids are in due proportion nearly1 though different from what is usually recommended and employed4 #b4 ,oxide of ,platina4 ,platina exhibits greater difficulties than gold in the investigation of its compounds with oxygen4 ,it is not oxidized by heat2 but by the explosion of an electric battery it is converted into a black powder1 which is most probably the metal in extreme division1 though it has been considered by some as the protoxide4 ,platina is capable of being oxidized and dissolved by nitro-muriatic acid1 but less easily than gold2 it requires more acid1 as high or higher temperature and long continued digestion2 nitrous gas is given out1 during the solution1 but sparingly4 ,when lime or an alkali is added to the solution with a view to precipitate the oxide1 a triple compound is usually formed of the acid1 the oxide and the alkali1 which is in most instances precipitated4 ,this weighty compound renders the valuation of the oxygen in it very uncertain4 ,chenevix has made some observations on the oxides of platina1 7see ,nichols4 ,journ4 #g4 p4 #agh47 ,he finds two oxides3 the one consists of #ic platina and #g oxygen2 the other of #hg platina and #ac oxygen2 but the experiments on which these results rest are not quite satisfactory4 ,mr4 ,e4 ,davy in the #djth vol4 of the ,philos4 ,magazine1 states his having reduced the oxide of platina in solution by means of hydrogen2 and that he finds the oxide to consist of #hd platina and #af oxygen nearly4 ,i could not succeed at all in effecting the reduction of the metal in this way4 ,berzelius has lately given us the results of his investigation on this subject4 7,an4 de ,chimie #hg--abf47 ,according to this distinguished chemist there are two oxides of platina2 the first consists of #ajj metal and #h oxygen1 and the second of #ajj metal and #af oxygen1 nearly4 ,in order to understand his process it may be proper to premise that when nitro-muriatic acid has dissolved as much platina as it can1 there is still a great excess of one or both of the acids1 which is unnecessary for the existence of the solution1 and which may1 and in general ought to be expelled by evaporation2 by exposing the solution to a heat of #ajj or #aej the excess of both acids is in great part driven off and a dry red mass is obtained1 without smell1 but very deliquescent4 ,it is equal to or rather more than twice the weight of the platina4 ,it consists of water1 muriatic and nitric acids1 oxygen and platina2 it is still an acid salt4 ,by exposing the dry mass again to a heat of #djj or #ejj1 it liquifies1 exhales acid fumes having the odour of oxymuriatic acid1 and becomes again a dry mass of an olive colour1 exhaling fumes as the heat increases1 and loses about of its weight4 ,it is still soluble in water1 except a few atoms of black powder1 continues acid to the tests1 and may be considered as a supermuriate of platina4 ,if this olive powder be again heated almost to red1 it exhales a visible smoke in the open air1 which has the smell of oxymuriatic acid1 and becomes a light brown powder1 having lost a little weight4 ,it is then neither deliquescent nor soluble in water except in a small degree so as to give the yellow colour4 ,in this state it has been considered as a neutral muriate4 ,by a moderately bright red heat this powder is decomposed and leaves a black spongy mass which is found to be pure platina4 ,the insoluble muriate of platina according to ,mr4 ,e4 ,davy1 contains #gb4e per cent4 of platina1 and ,berzelius finds #gc4c2 the loss is considered as oxymuriatic acid2 hence from the known proportions of this acid ,berzelius infers the constituents of #ajj muriate #gc4c platina1 #f4jge oxygen and #bj4fbe muriatic acid2 or #ajj platina take #h4c oxygen4 ,the near agreement of the above authors is favourable to the accuracy of their results2 but ,i have found some difficulty in obtaining the insoluble muriate free from the soluble one1 and at the same time from reduced platina because the precise degree of heat requisite to produce it is neither well known nor easily attained2 and it is desirable that a certain weight of platina should be dissolved and the same weight reproduced as a confirmation of accuracy4 ,from a train of experiments on the soluble and insoluble muriates of platina1 the salts being obtained from the purified laminated metal1 ,i am disposed to consider the above results as good approximations to the truth4 ,in order to obtain the other oxide1 ,berzelius digests mercury in a solution of the supermuriate of platina2 a black powder is thrown down1 which is found to be platina1 and mercury is taken up1 being oxidized at the expence of the platina4 ,it was found that #af4g grains of mercury had precipitated #h4e of platina2 and the mercury being calculated as in the state of deutoxide1 contained1 from the known proportions of this metal1 #a4d oxygen2 hence #h4e platina must have yielded #a4d oxygen2 and if #h4e #a4d #ajj #af4d2 so that #ajj platina must have had #af4d oxygen in the supermuriate1 or twice the quantity it had in the insoluble muriate4 ,this conclusion appears to me premature2 the mercurial oxide should at least have been precipitated and a corresponding quantity have been found and proved to be the red oxide4 ,even had this been the case1 it is not easy to determine what quantity of it might be due to the residue of nitro-muriatic acid4 ,but ,i have not found that the common yellow or red oxide of mercury is precipitated by lime water in such case2 the precipitate is brown1 and evidently contains both mercury and platina4 ,proust had found in his excellent essay on platina 7,journ4 de ,physique #eb--dcg1 #ahja7 that mercury decomposes muriate of platina1 that an amalgam of platina with a little calomel1 and much mercury in powder1 were precipitated2 exposed to heat1 a fine black powder was left which had the characters of platina4 ,into a solution of pure platina that had been evaporated to dryness in #aej and redissolved1 ,i put #i grs4 of mercury1 and boiled it for #aj minutes in a glass capsule1 till there was apparently no further change2 the liquor filtered was as yellow as at first2 the mixture of black powder and running mercury remaining on the filter1 when dried1 weighed #f grains2 this heated to a low red in an iron spoon1 left #a grain of fine black powder2 the liquid saturated with lime water1 yielded #b grains dry black powder insoluble in cold nitric acid2 after this1 protomuriate of tin threw down #e grains of the compound oxides of platina and tin4 ,the solution at first contained #c4c grains of platina4 ,in another experiment #b parts of calomel were put to #a of platina in solution2 when heated to boiling1 the calomel was dissolved and a little black powder was precipitated1 which did not amount to half the weight of the platina4 ,lime water threw down from the liquid1 a yellowish olive or brown precipitate1 partially soluble in cold nitro-muriatic acid2 and after this1 muriate of tin yielded a brown precipitate4 ,these experiments shew that the action between muriate of platina and mercury or the mercurial salts1 is of a complicated nature1 and is not limited to the decomposition of the oxide of platina and the substitution of the deutoxide of mercury in its place4 ,the difficulties abovementioned have led me to investigate the oxygen combining with platina by means of the nitrous gas yielded upon its solution in nitro-muriatic acid4 ,by three distinct experiments ,i found that #aj grains of pure platina by solution yielded nearly #gej grain measures of nitrous gas1 which may be considered as #a grain in weight2 of which 4#hge for oxygen2 this would give #h4ge oxygen per cent4 ,but from a subsequent experiment made under circumstances calculated to preclude as much as possible every source of fallacy1 ,i obtained #gij measures of nitrous gas from #aj grains of platina2 and the solution afterwards took #fj measures of oxymuriatic acid gas before a permanent smell of the gas was produced4 ,these #gij measures #a4je grain1 of which 4#ib1 to which add 4#jd for the oxygen acquired from the oxymuriatic acid1 and we have 4#if oxygen for #aj platina2 or #ajj platina take #i4f oxygen4 ,but if #i4f #ajj #g #gc1 for the weight of an atom of platina1 and #hj for that of the protoxide1 as ,i apprehend it to be1 and the only oxide of platina we can at present form4 7,the atom of platina in ,vol4 #a1 page #bdh1 was estimated at #ajj47 #c4 ,oxide of ,silver4 ,when silver wire is exploded by electricity in oxygen gas1 a black powder is produced1 which is the oxide of silver4 ,if silver be dissolved in nitric acid and precipitated by lime water1 an olive brown powder falls which becomes black when exposed to the light4 ,this black powder is the only oxide of silver with which we are acquainted4 ,the proportion of silver and oxygen has been investigated by various chemists2 the results are as under4 silver oxygen ,wenzel #ajj #h4e ,proust #i4e ,bucholz and ,rose #i4eb ,gay ,lussac #g4fc ,berzelius #g4ibe ,footnote #b3 #g4i when duly corrected4 ,annal4 de ,chimie1 #gh--aad4 ,footnote #c3 ,memoirs d',arcueil #b--afh4 ,from the solution of #agj grains of standard silver ,i obtained nearly #cj oz4 measures of nitrous gas #ah grains1 corresponding to #af oxygen4 ,this would give #i4d oxygen upon #ajj silver4 ,but as of the metal or #ag grains was copper1 and this takes of its weight of oxygen1 we shall have #aei silver and #aa oxygen1 or #ajj silver and #g4g oxygen nearly4 ,if we adopt #g4h as the proper quantity of oxygen on #ajj silver1 we shall have #g4h #ajj #g #ij nearly1 which represents the weight of an atom of silver1 and #ig that of the oxide4 #d4 ,oxides of ,mercury4 ,two oxides of mercury have been long known and are well distinguished from each other4 ,they may be obtained by exposing mercury to a heat not exceeding #fjj1 in contact with oxygen gas or atmospheric air1 and due agitation2 but this method is rarely adopted in practice4 ,a high degree of heat decomposes the oxides again4 ,protoxide4 ,to obtain the protoxide1 mercury must be slowly dissolved in dilute nitric acid without heat1 and an excess of mercury must be used4 ,if to #ajjj grain measures of nitric acid1 #a4b sp4 gr4 be put #ejj grains of mercury1 by occasional agitation the requisite solution will be obtained in #bd hours4 ,a portion of this solution must be treated with a small excess of lime water or caustic alkali1 when a black powder will be thrown down1 which is the oxide containing a minimum of oxygen1 and hence may be considered the protoxide4 ,deutoxide4 ,if to #ajjj measures of nitric acid1 #a4b sp4 gr4 be put #cej grains of mercury1 and the mixture be boiled till the mercury disappear1 a solution will be obtained containing the deutoxide4 ,a portion of this being treated as beforementioned with lime water1 a yellowish red powder is precipitated1 which is the oxide of mercury containing a maximum of oxygen2 all the later authors agree that it contains just double the quantity of oxygen to a given portion of mercury that the former does1 and may therefore be called the deutoxide4 ,these two oxides combine with most acids and form salts1 some of which exhibit remarkable differences occasioned by the oxides2 thus1 muriatic acid with the protoxide forms protomuriate of mercury1 commonly called calomel1 an insoluble salt2 with the deutoxide it forms deutomuriate of mercury1 commonly called corrosive sublimate1 a soluble salt4 ,the proportions of metal and oxygen in the two oxides may be found by precipitating a known weight of mercury reduced by solution to either of the oxides1 then drying and weighing the oxides1 when the increase of weight by the addition of oxygen may be observed4 ,this method is less accurate with regard to mercury than to other metals1 on account of the very great weight of the atom1 by which a small error in the gross weight of the oxide will be a great one as it respects the oxygen4 ,this circumstance will partly account for the differences of authors on this subject4 ,one fact has been for some time known which demonstrates the oxygen in the red oxide to be double that in the black4 ,corrosive sublimate may be reduced to calomel by adding to it as much mercury as the sublimate contains1 and triturating the mixture well1 the oxygen of the red oxide 7as well as the acid7 becomes equally divided amongst the mercury and forms the black oxide1 which is a constituent of calomel4 ,hence it follows that if the oxygen in one oxide can be ascertained1 that of the other becomes known4 ,or if we can find how much oxygen must be added to the black oxide to change it to the red1 we shall know the oxygen in both4 ,conformably with this last idea ,i have found a very accurate and elegant method of ascertaining the oxygen required to convert the black to the red oxide by treating protomuriate of mercury1 mixed with water and a little muriatic acid1 with oxymuriate of lime in solution2 this must be gradually added till the protomuriate is dissolved1 or rather converted to the deutomuriate4 ,the quantity of oxygen in a given solution of oxymuriate of lime is most conveniently found by a solution of green sulphate of iron1 as will be shewn under the oxides of that metal4 ,the oxides of mercury may be investigated by the nitrous gas produced during solution4 ,when mercury is dissolved without heat1 as mentioned above1 no nitrous gas is liberated4 ,the solution has a strong nitrous smell and requires a great quantity of oxymuriate of lime to saturate both the oxide and the acid4 ,when heat is employed to accelerate the solution1 nitrous gas is liberated4 ,i dissolved #aed grains of mercury in nitric acid1 #a4b sp4 gr41 by the application of a gentle heat from a lamp4 ,about excess of acid remained in the solution2 the nitrous gas obtained was #ab oz4 measures #g4e grains1 corresponding to #f4e oxygen1 which gives nearly #d oxygen or #ajj mercury4 ,this would have led me to suppose ,i had obtained the black oxide in solution2 it was however entirely the red1 as it gave no precipitate by common salt1 and exhibited the red oxide by lime water2 but it required as much oxymuriate of lime as contained #f4e oxygen to saturate the nitrous gas in the solution before any oxymuriatic acid was liberated4 ,it was clear therefore that only of the nitrous gas was evolved1 and the other was retained in the solution1 though it had been exposed to boiling heat4 ,the following are the proportions assigned by the several authors for the oxides of mercury4 ,mercury4 ,oxygen4 ------------------ black4 red4 ,bergman#d #ajj #d -- ,lavoisier#e -- -- #g4ge to #h ,chenevix#f -- #ab #ah4e ,taboada#g -- #e4b #aa ,fourcroy ,thenard#h -- #d4af #h4ba ,sefstrom#i -- #c4ii #g4ii ,my results give -- #d4b #h4d ,footnote #d3 ,kirwan's ,mineralogy4 ,footnote #e3 ,annals of ,philosophy1 ,vol4 #c1 p4 #ccc4 ,footnote #f3 ,philos4 ,trans4 #ahjb4 ,footnote #g3 ,jour4 de ,physique4 #ahje4 ,footnote #h3 ,mem4 d',arcueil1 ,vol4 #b4 p4 #afh4 #ahji4 ,footnote #i3 ,annals of ,philosophy1 ,vol4 #b4 p4 #dh4 ,though the relative weights of oxygen and mercury may be investigated as above1 yet it is from the weight of mercury and the acids in the salts of mercury1 some of which are of a very definite character1 such as the muriate and the deutomuriate1 that the relative weight of the atom of mercury is best investigated4 ,from these ,i first deduced the weight of an atom of mercury to be #afg about #aj years ago1 and subsequent experience has not induced me to change the number1 though it probably may admit of some correction4 ,if the atom of mercury be denoted by #afg1 that of the protoxide will be #agd1 and that of the deutoxide #aha2 which makes #ajj mercury take #d4b and #h4d oxygen for the oxides respectively1 as in the above table4 #e4 ,oxide of ,palladium4 ,the discoverer of this metal1 ,dr4 ,wollaston1 has given us its distinguishing chemical properties2 but we are indebted to ,berzelius and ,vauquelin for the proportions of oxygen and sulphur which combine with the metal 7,vid4 ,annal4 de ,chimie1 #gg and #gh47 ,few chemists have had an opportunity of making experiments on this metal1 owing to its great scarcity and the consequent high price of it 7#a shilling per grain74 ,it does not seem desireable that any but those skilled in the more delicate chemical manipulations should operate upon articles such as the present4 ,berzelius treated the muriate of palladium with mercury1 which abstracted the oxygen and left an amalgam of palladium and mercury2 from the quantity of mercury dissolved he calculates that #ajj palladium combine with #ad4b oxygen4 ,this conclusion was corroborated by the circumstance that #ajj palladium were found to take #bh of sulphur1 or double the quantity of oxygen1 which frequently happens with the metals4 ,vauquelin precipitates the oxide of palladium from the muriate by potash2 it appears of a red brown colour1 and is probably a hydrate2 when washed and dried in a moderate heat1 it becomes black1 it loses #bj per cent4 by a red heat and becomes metallic4 ,this would give #be oxygen on #ajj metal2 but as he finds the sulphuret to be #ajj metal with #bd or #cj sulphur1 nearly agreeing with ,berzelius1 it is very probable that a moderate heat does not free the oxide from water1 and that consequently a part of the #bj per cent4 loss is water4 ,i dissolved #c grains of palladium in a small excess of nitro-muriatic acid and obtained #bdj grain measures of nitrous gas2 the same quantity was obtained a second time1 and to the solution 7slightly acid7 were added by degrees #bjj measures of oxymuriatic acid gas2 after agitation no smell was perceived1 but by increasing the quantity of gas a permanent smell of oxymuriatic acid was produced1 and when #bjj more had been added the smell was sensible for some days in an open jar1 a presumption that no higher oxide is to be obtained4 ,now #bdj nitrous gas 4#cb of a grain1 corresponding to 4#bh of oxygen1 and #bjj oxymuriatic acid 4#fd of a grain1 corresponding to 4#ae oxygen2 the sum of the two portions of oxygen 4#dc1 which must have combined with #c grains of palladium2 if 4#dc #d #g #ej nearly4 ,or #ajj metal combine with #ad oxygen1 as determined by ,berzelius4 ,i find the sulphuret to accord with this determination2 and by carefully saturating the excess of acid in the nitro-muriate of palladium and then finding the quantity of lime water necessary to precipitate a certain weight of palladium1 as well as the quantity of test muriatic acid necessary to dissolve the precipitated oxide1 ,i am confirmed in the opinion that the atom of palladium must weigh #ej nearly1 and its oxide #eg1 which there is every reason to believe is the protoxide4 #f1 #g1 and #h4 ,oxides of ,rhodium1 ,iridium1 and ,osmium4 ,nothing certain has yet been determined respecting the oxygenation of these very rare metals4 #i4 ,oxides of ,copper4 ,there are two oxides of copper according to the results of ,proust1 ,chenevix1 ,berzelius and others1 the proportions of which are given nearly the same by all1 and so as to leave no reasonable doubt concerning their accuracy4 #a4 ,protoxide4 ,this oxide is orange1 and contains #ab oxygen on #ajj copper3 it is obtained by precipitating a portion of copper from the solution of any cupreous salt1 by means of iron1 then mixing this copper with a rather greater portion of the deutoxide and triturating them well4 ,this being done1 the mixture is to be dissolved in muriatic acid1 and the orange oxide may then be precipitated by an alkali4 #b4 ,deutoxide4 ,this oxide is black2 it contains #be oxygen on #ajj copper3 the black oxide is obtained by dissolving copper in nitric or sulphuric acid1 then precipitating by lime water or an alkali1 and heating the dried precipitate red hot4 ,it may also be obtained by exposing copper to a red heat for some time in common air or oxygen gas1 removing the scales and exposing them in like manner1 till at length the black oxide is formed4 ,by dissolving #aab grains of copper turnings in #ajjj grain measures of #a4af nitric acid1 ,i obtained #dh oz4 measures of nitrous gas1 #cj grains2 by oxymuriate of lime ,i found #b grains of nitrous gas in the solution1 making in all #cb grains #bh grains of oxygen4 ,if #bh #aab #ad #ef1 for the weight of an atom of copper2 hence the protoxide #fc and the deutoxide #gj4 ,these weights ,i adopted in #ahjf1 and have not seen any reason to modify them since4 #aj4 ,oxides of ,iron4 ,two well known and well distinguished oxides of iron are now universally admitted2 the one contains #bh oxygen on #ajj iron1 the other #db on #ajj4 #a4 ,protoxide4 ,this is always formed when iron is dissolved in dilute sulphuric or muriatic acid2 it may be precipitated from these solutions by the pure alkalies or earths2 it appears at first of a dark green1 being then a hydrate or combined with water2 on a filtre it soon becomes yellow at the surface by attracting oxygen2 when dried in a heat of #bjj or upwards it becomes black4 ,the quantity of oxygen in it is best ascertained from the hydrogen generated during the solution of the iron4 ,all the authorities ,i have found nearly concur in their results as under4 #ajj grains of iron dissolved in dilute sulphuric or muriatic acids yield hydrogen1 according to ,cavendish 7#agff7 #aee cubic inches4 ,priestley1 from #adg to #afb ,lavoisier #afc ,vandermonde1 ,berthollet1 max4 #agf and ,monge ,vauquelin #afj to #agi ,dr4 ,thomson #afc ,my own ,experiments give #afj ---- ,mean #afd #hb oxygen #bg4i grains4 ,by precipitating the oxide1 and drying it1 nearly the same result may be obtained1 as #ajj iron will yield #abh oxide4 ,this oxide is magnetic4 #b4 ,intermediate or red oxide4 ,this oxide may be obtained in various ways4 ,first by calcining the sulphate or nitrate of iron4 ,second by precipitation from old solutions of the salts of iron2 the precipitate is yellow at first1 being perhaps a hydrate2 but when dried and heated it becomes brown-red4 ,third1 by calcining iron or repeatedly exposing iron filings to a red heat1 and trituration4 ,fourth1 by treating a solution of the sulphate or other salt of the protoxide with oxymuriatic acid1 or oxymuriate of lime till oxymuriatic acid is evolved2 then precipitating the oxide which is thus converted into the red4 ,fifth1 by agitating water containing the green oxide recently precipitated1 with oxygen gas4 ,the red oxide is not sensibly magnetic4 ,the quantity of oxygen in the red oxide may be investigated in various ways1 and it is generally allowed that they all concur in giving #db on #ajj iron4 ,the one which ,i have used peculiarly1 and prefer both for ease and accuracy1 is to find the quantity of oxymuriatic acid gas necessary to saturate a given portion of the green sulphate4 ,i take for instance #ajj measures of #a4adi green sulphate1 which ,i know to contain #h grains of black oxide2 this ,i find absorbs nearly #ac hundred measures of oxymuriatic acid gas before the acid smell is developed2 the oxygen corresponding to this quantity of acid is known to be near #ffj measures1 4#hh grain4 7,see ,,vol4 #a1 p4 #cjh47 ,hence1 if #h 4#hh #abh #ad2 or #abh black oxide acquire #ad or become #adb when converted into the red oxide4 ,this fact being established1 ,i find it very convenient to make use of the oxymuriate of lime instead of the acid gas1 adopting the solution of green sulphate of iron as a test of the quantity of oxymuriatic acid in a given volume of any solution of oxymuriate of lime4 ,the quantity of oxygen in the red oxide of iron may be inferred1 but not so satisfactorily1 from the nitrous gas obtained during the solution of iron in nitric acid4 ,in order to obtain the most gas from a given quantity of the materials1 they should be so proportioned as to produce saturation nearly4 ,if an excess of acid be used1 it absorbs the nitrous gas in part2 and if an excess of iron1 it is not all dissolved4 ,i took #ej grains of iron filings and #fjj measures of #a4ae nitric acid2 these were put together in a gas bottle and by the assistance of a little heat a quantity of nitrous gas was obtained equal to #ab grains in weight1 allowing the sp4 gr4 of the gas to be #a4jd 7air being #a72 all the iron was dissolved except a few atoms1 and the solution was slightly acid2 the whole of the oxide was red when precipitated by lime water4 ,now #ej grains of iron take #ba of oxygen to form the red oxide1 and these correspond to #bd of nitrous gas1 which is just twice the quantity obtained2 one half of the gas generated then remains in combination with the iron1 even when the constituents of the salt are proportioned so as to produce mutual saturation4 ,i was in expectation that the quantity of nitrous gas retained might be converted into nitric acid by oxymuriate of lime1 and hence might be determined2 but in this ,i was disappointed4 ,when oxymuriate of lime is added to the liquid1 a pungent gas is liberated1 the nature of which ,i have not determined4 ,thinking it might in part be owing to the iron1 ,i transferred the acid to soda1 by decomposing the nitrate of iron by the carbonate of soda2 this nitrate of soda however1 when treated with oxymuriate of lime1 exhibited the same phenomenon as the nitrate of iron4 ,when an acid is added the oxymuriatic acid itself is given out4 ,these results will require further consideration4 ,at present ,i am inclined to think the pungent gas is one atom of nitrous and one of oxygen or what ,i formerly considered as nitric acid4 7,see ,,vol4 #a1 plate #d1 fig4 #bg47 ,some authors have found as they conceive1 other oxides of iron1 containing less or more of oxygen than the above2 thus ,darso finds by calcination from #ae to #ef oxygen on #ajj1 7,nicholson's ,journ4 ,,vol4 #ag72 but there is great reason to believe that uncertainties must exist in his mode of experimenting sufficient to account for the anomalies observed4 ,this author has suggested some doubt whether the oxygenous gas naturally contained in water has any effect on the salts with green oxide of iron4 ,i have ascertained that point by repeated experiments1 and can assert that the oxygen in water immediately unites to the green oxide of iron to convert it into red1 and that the green sulphate may be used as an accurate test of the quantity of oxygen in water4 ,when pure green sulphate of iron is dropped into water and then the oxide precipitated by a gradual addition of lime water1 it falls down yellow in proportion to the oxygen in the water1 which may be increased #c or #d times by artificial impregnation4 ,if the oxygen of the water be previously saturated with nitrous gas1 then the oxide is wholly precipitated green4 ,gay ,lussac1 in the #hjth ,,vol4 of the ,annal4 de ,chimie1 asserts that an oxide of iron containing #cg4h oxygen upon #ajj iron is always obtained when iron is burned in oxygenous gas1 and still more effectually when iron is oxydized by water or steam4 ,if this oxide exist in the proportions stated1 it must be a compound of #a atom of the protoxide and #b of the red oxide1 which would give #cg4c oxygen on #ajj of iron4 ,from the above facts and observations it is evident the atom of iron must be considered as weighing #be1 7and not #ej as already given1 ,,vol4 #a1 page #beh72 the protoxide is #cb1 and the intermediate or red oxide is #b atoms protoxide and #a of oxygen #ga4 #aa4 ,oxides of ,nickel4 #a4 ,protoxide4 ,it appears to be ascertained from the experiments of ,proust 7,journ4 de ,physiq4 #fc--ddb71 ,richter 7,nichols4 ,jour4 #ab471 ,tupputi 7,an4 de ,chimie #gh471 and ,rolhoff 7,an4 of ,philos4 #c--cce471 that the protoxide of nickel consists of #ajj metal and from #be to #bh oxygen4 ,my experiments on the solution of nickel in nitric acid give me #ad grains nitrous gas1 corresponding to #ab oxygen1 in the solution of #dd grains of nickel2 this gives #ajj nickel to #bg oxygen1 which ,i adopt as agreeing with the mean of the beforementioned results4 ,this oxide may be obtained by precipitation from a solution of nitrate of nickel2 it is at first white1 being then a hydrate2 when dried in a moderate temperature it becomes yellowish2 after this1 being heated to a cherry red1 it loses from #bj to #bd per cent4 of water and becomes of an ash grey colour3 this is the only oxide of nickel soluble in acids1 and must therefore be deemed the protoxide3 hence we have #bg #ajj #g #bf1 nearly1 for the weight of an atom of nickel2 and not #be or #ej1 as estimated at page #beh4 ,,vol4 #a4 ,intermediate oxide4 ,thenard discovered a second oxide of nickel by passing oxymuriatic acid through a solution of nickel and then precipitating2 it is a black powder2 when treated with sulphuric or nitric acid it gives out gas1 being the excess of oxygen above the protoxide2 but with muriatic acid it gives oxymuriatic acid gas4 ,rolhoff was induced to believe1 but ,i do not know upon what evidence1 that this oxide contained #a or #a times the oxygen of the protoxide4 ,by means of oxymuriate of lime ,i find the protoxide recently precipitated1 takes half as much oxygen as it had previously1 to form the black oxide2 and that it cannot be formed1 like the red oxide of iron1 by agitation with water mixed with common air4 ,the white oxide treated with oxymuriate of lime becomes almost instantly blue1 growing darker till it gradually passes into brown1 and finally black in about half an hour4 ,it contains #dj oxygen on #ajj nickel1 and is most probably constituted of #a atom of oxygen holding #b of protoxide together1 more especially as it is not found in combination with acids4 ,the method ,i prefer to procure the black oxide is to precipitate a known weight of oxide by lime water2 then pouring off the clear liquid1 ,i put as much liquid oxymuriate of lime to the moist hydrate as contains of the weight of the oxide of oxygen1 and stir frequently for half an hour2 the point of saturation is found when more oxide put to the clear liquid is not discoloured on one hand1 and when more oxymuriate of lime does not affect the colour1 but remains in the clear liquid on the other hand4 #ab4 ,oxides of ,tin4 ,there are two oxides of tin1 which have been carefully investigated by several chemists1 and appear to be ascertained with great precision4 ,the protoxide is grey1 and contains #ac oxygen on #ajj tin2 the deutoxide is white1 and contains #bg oxygen on #ajj tin4 #a4 ,protoxide4 ,there are two methods of obtaining the constitution of this oxide4 ,the first is by dissolving a certain weight of tin filings in muriatic acid1 precipitating by lime water or carbonated alkalies and drying the oxide in a moderate heat2 this is liable to some uncertainty2 the precipitate being a hydrate1 requires to be exposed to heat to expel the water2 but if the heat approaches to red1 the oxide takes fire and is converted into the deutoxide4 ,the second method is to dissolve tin in muriatic acid and carefully collect the hydrogen gas evolved2 this was first done by ,mr4 ,cavendish1 with his usual accuracy1 and published in #agff2 he found #a oz4 of tin yield #bjb oz4 measures of hydrogen gas4 ,i have frequently tried this experiment and always found a proportional quantity1 or very nearly #bjj measures for each grain of tin4 ,this mode of investigation appears to me unexceptionable4 ,now #bjj hydrogen unite to #ajj oxygen1 and #ajj grain measures of oxygen 4#acd grain in weight2 hence if 4#acd oxy4 #a tin #g oxy4 #eb nearly for the weight of an atom of tin1 on the presumption this is the protoxide4 #b4 ,deutoxide4 ,this may be obtained by heating tin till it takes fire1 and the produce of the combustion is the oxide required2 but to ascertain the proportions of tin and oxygen two other methods are preferable2 the one is to treat tin with nitric acid of the sp4 gr4 #a4b to #a4d2 a violent effervescence and great heat ensue and the tin is converted into a white powder4 ,this being dried in #ajj gives about #afj grains for #ajj of tin4 ,it consists of the deutoxide united to a little acid and water2 these two may be driven off by a low red heat1 and #abg grains of the deutoxide remain in the state of a white powder4 ,the other method is to treat a solution of the protoxide of tin with oxymuriate of lime till it is saturated2 this will be found when #ei grains of the protoxide have acquired #g grains of oxygen1 or #aac grains of the deutoxide have acquired #ac grains of oxygen1 which corroborates the result by the #ast method4 ,this oxide containing just twice as much oxygen as the former1 may justly be considered as the deutoxide4 ,no higher oxide of tin has been obtained4 ,the two oxides1 though both white when precipitated1 may be distinguished from their different appearances2 the first is curdy1 the second1 gelatinous4 ,it may be proper to subjoin authorities for these oxides3 ,tin ,protoxide ,deutoxide ,cavendish1 from the hydrogen #ajj #aac4e -------- ,proust 7,journ4 de ,physique #ei-cda7 #ajj #aae #abg4abhaj ,gay ,lussac 7,annal4 de ,chimie #hj-agj7 #ajj #aac4e #abg4baa ,berzelius 7,annal4 de ,chim4 #hg-ee7 #ajj #aac4f #abg4bab ,my own1 as above #ajj #aac4d #abg ,footnote #aj3 ,by nitric acid1 the result of #c experiments all agreeing for the deutoxide2 the protoxide is by calculation and less certain4 ,he afterwards adopts #ac4f from ,berzelius4 ,journ4 de ,phys4 ,aug4 #ahad4 ,footnote #aa3 ,the protoxide from hydrogen by solution2 the deutoxide by transmitting steam over the metal at a red heat4 ,footnote #ab3 ,the #b;d4 by oxydizing the sulphuret of tin by nitric acid2 the #ast4 by inference only1 one half of the oxygen of the #b;d4 #ac4 ,oxides of ,lead4 ,there are three oxides of lead now generally recognized1 the yellow1 the red1 and the brown1 the proportion of oxygen in each of which has been investigated by several chemists whose results do not well accord with each other4 ,i shall treat of them under the following names1 namely the protoxide1 the intermediate oxides1 and the deutoxide1 for reasons which will appear4 #a4 ,protoxide4 ,the yellow oxide of lead is the only one capable of forming salts with acids4 ,lavoisier found the oxygen of this oxide combined with #ajj lead to be #d4dg2 ,wenzel1 #aj2 ,proust1 #i2 ,thomson1 #aj4e2 ,bucholz1 #h2 ,berzelius1 #g4g4 ,this last accords best with my own experience2 but it is chiefly from the other combinations of lead1 that the weight of its atom as well as that of the protoxide are determined and confirmed1 as lead forms several very definite compounds with acids1 c4 ,the quantity of oxygen in the protoxide may be found by several methods1 as under4 #ast4 ,by dissolving a given portion of the oxide in acetic acid1 and precipitating the lead by another metal1 as zinc2 in this case the oxygen of the lead goes to the zinc which becomes dissolved1 and from the loss of weight of the zinc and the proportion of oxygen in zinc oxide being previously known1 and the weight of the precipitated lead being found1 we have data for determining the oxide of lead4 ,i took #bjj measures of acetate of lead solution 7#a4adb71 which ,i knew contained #bg grains of oxide of lead2 this being diluted with an equal volume of water1 the lead was precipitated by a rod of zinc2 in #f hours an arbor saturni was formed which was collected and well dried2 it weighed #ba grains1 and the zinc rod had lost #g grains3 care must be taken in performing this experiment that all the lead be not precipitated1 otherwise the oxide of zinc begins to fall1 and the result is uncertain4 ,in the residuary liquid ,i got #d grains of sulphate of lead by sulphuric acid4 ,here then we have the oxygen of #ba lead transferred to #g zinc2 but if #g #ba #bi #ij nearly4 ,now it is known that #bi parts of zinc take #g of oxygen1 therefore #ij lead take #g of oxygen1 and the atom of lead #ij1 and the protoxide #ig4 ,i formerly stated the atom of lead #ie4 ,,vol4 #a1 page #bfj4 #b4 ,by dissolving #ahj grains of lead in nitric acid in a small thin capsule1 and heating it till the salt was quite dry1 ,i got #bhh grains of salt1 weighed in the capsule2 #cf grains of this salt yielded #bd yellow oxide by a low red heat #bb lead4 ,this gives #ij lead to #g oxygen4 #c;d4 ,again1 #cf grains of the above salt1 dissolved in water1 precipitated by ammonia1 and well washed on a filter1 gave #bc grains of oxide separated from the filter1 and this had acquired #a grain1 making #bd grains of oxide from the #bb lead as before2 the residue of liquid gave no signs of lead by hydrosulphuret of ammonia4 ,the same quantity of salt precipitated by an excess of lime water gave only #bb grains of oxide2 but hydrosulphuret of ammonia precipitated #b grains of sulphuret of lead from the clear liquid4 ,,ii4 ,intermediate oxide or oxides4 ,minium or red lead1 c4 ,minium is an article of commerce used as a pigment and for various other purposes4 ,it is made by exposing the yellow or protoxide of lead finely pulverized to a low red heat in a current of air1 and constantly stirring the oxide so as to expose fresh particles to the air4 ,in two days the yellow oxide is converted into the red4 ,several authors observe that red lead usually contains #a1 #b1 or more grains per cent4 of impurities insoluble in nitric and acetic acids2 the specimen ,i used however was so pure as not to leave more than of a grain per cent4 of insoluble matter after being heated red and treated with dilute nitric acid4 ,some of the most remarkable properties of red lead are1 #ast4 ,it is never obtained in combination with any acid2 #b;d4 ,it yields oxygen gas when exposed to a bright red heat or when treated with concentrated sulphuric acid1 and is in both cases reduced to the protoxide2 #c;d4 ,when treated with dilute nitric acid it is dissolved in part1 but constantly leaves an insoluble brown residuum1 which is the deutoxide1 as will be shewn2 the weight of the deutoxide obtained is by my experiments #bj per cent4 and the part in solution is found to be the protoxide2 #dth4 ,when treated with muriatic acid1 muriate of lead is formed and oxymuriatic acid given out2 #eth4 ,when treated with dilute acetic acid or cold concentrated acetic acid1 of the oxide is dissolved and the remainder is still red1 its colour being rather improved2 if concentrated acid be used and boiling heat applied1 then of the whole oxide is dissolved and remains of brown oxide1 the same as with nitric acid4 ,some of the above facts are new1 and may contribute to elucidate this most curious oxide1 which scarcely has a parallel4 ,proust is the only author ,i know who has given a plausible conjecture concerning the peculiar nature of this oxide4 ,he supposes it a compound of the yellow and brown oxides4 ,this ,i believe is the fact2 but it will be found ,i apprehend to be a compound of #a atom of oxygen with #f of the yellow oxide1 as will appear from what follows4 ,respecting the quantity of oxygen in the red oxide1 ,lavoisier finds #i oxygen to #ajj lead1 ,thomson #ac4f1 and ,berzelius #aa4ee4 ,this last is partly from experience and partly from a supposed analogy1 that the successive oxides of the same metal contain oxygen as #a1 #a and #b respectively2 and having found 7,i believe7 correctly1 that the brown oxide contains just twice as much oxygen as the yellow1 this ingenious and generally accurate author adopts the theoretic inference in this instance at least prematurely1 and concludes the red oxide is the mean between the yellow and the brown4 ,but we must appeal to experience4 ,it has already been stated that when red lead is exposed to heat1 oxygen gas is given out1 and it may be added1 a small trace of water2 and yellow oxide remains4 ,this experiment requires considerable skill4 ,if too great a heat is used1 a part of the lead is reduced or revived as it is termed2 if too little heat1 then a part of the red lead remains unaltered4 ,in performing this experiment ,i use a small clean iron spoon to hold the red lead1 and cover it by another iron spoon2 the whole is then held by a pair of tongs in a red fire till the spoon exhibits a uniform moderate red1 and some time after4 ,it is then withdrawn and cooled1 and the oxide weighed4 ,the average loss of weight is nearly #b grains per cent4 ,if only #a grain or less1 a considerable portion of red oxide remains mixed with the yellow2 if #c or more grains1 then the margin of the oxide exhibits particles of lead amounting to 1 less or more1 of the original weight2 this can be easily separated from the oxide if necessary1 but it is apt to adhere to the iron2 when red oxide remains1 it is so mixed with the yellow as not easily to be separated1 but its quantity may be determined by nitric acid1 which dissolves the yellow1 and of the red1 leaving a residuum of brown oxide1 from which the quantity of red is inferred4 ,now if the loss of weight of #ajj red oxide be only #b grains1 and a part of that be water1 it is impossible that #aae4ee should lose #c4he grains of oxygen1 according to ,berzelius4 ,another experiment1 equally decisive of the question1 is to determine the quantity of oxygenous gas to be obtained by heat or acids from a given weight of red lead4 ,in one experiment made with great care1 #ejj grains of red oxide gave #f grains of oxygenous gas by sulphuric acid2 in another1 #bjj yielded #b grains4 ,in order to vary the mode of determining the quantity of oxygen1 into #baj measures of test green sulphate of iron solution1 7#a4aef7 #af4h green oxide1 put #afj grains of minium2 to this was added dilute muriatic acid more than sufficient for the minium3 ,the oxymuriatic acid from the oxygen of the minium was instantly seized by the oxide of the iron1 the whole of which was found by precipitation to be changed from green to red and an excess of oxymuriatic acid appeared4 ,now #af4h oxide would require #a4hf oxygen to become red1 which it must have acquired from #afj of red lead2 or #ajj red lead yielded #a4b oxygen1 the same proportion as by sulphuric acid4 ,these experiments point out #a4b oxygen in #ajj red lead as the excess which converts the yellow to the red oxide4 ,were any doubt to remain on the subject1 the experiment with nitric acid and red oxide will remove it4 ,if the red oxide contained a mean of oxygen between the yellow and the brown1 when it is treated with nitric acid more than #ej per cent4 of brown oxide would be obtained instead of #bj1 which is contrary to all experience4 ,it must be observed that ,berzelius informs us he extracted the yellow oxide1 mechanically mixed 7as he conceives7 with the red oxide1 by digestion with dilute acetic acid2 but he does not inform us how much per cent4 his minium was reduced by this operation4 ,from what is stated above1 it appears that about of the whole is thus dissolved4 ,the remaining half would then contain double the quantity of oxygen and brown oxide per cent4 that the original did4 ,still these quantities are inadequate to explain the phenomena4 ,besides it cannot be admitted that a red and a yellow powder can be intimately mixed in equal quantities and the mixture not be distinguishable without difficulty from the red one1 and be altogether different from the yellow4 ,we must then conclude that the minium of commerce 7such as ,i have used7 is a true chemical compound4 ,grounding our reasonings upon the preceding facts1 there are but two suppositions that can be considered as plausible1 respecting the constitution of the red oxide4 ,it may be #a atom of oxygen and #e of yellow oxide1 or #a atom of oxygen and #f of yellow oxide4 ,the former would give #a4d per cent4 extra oxygen in #ajj red oxide1 and #ba brown oxide2 the latter would give #a4b per cent4 extra oxygen and #ah brown oxide4 ,i adopt the latter supposition2 because it agrees with experiment in regard to oxygen1 and gives the brown oxide a little lower than experiment1 as may be expected on two accounts2 first1 the residue of brown oxide contains the insoluble dross of the red oxide 7which was very small however1 as stated above72 and1 second1 unless a considerable excess of nitric acid be used1 or long digestion1 a small portion of the red oxide escapes decomposition4 ,another and still more important consideration1 as to the question whether #e or #f atoms1 is the equal division of the red oxide by the operation of cold acetic acid2 it reduces the #a oxygen and #f yellow oxide to #a and #c atoms2 whereas if we adopt the other1 we must conclude it reduces the #a and #e to #a and #b1 a position that cannot well be reconciled to the atomic theory4 ,according to this conclusion then the red oxide of lead or minium of commerce is constituted of #a atom of oxygen holding #f atoms of yellow oxide together2 or it is composed of #ajj lead and #i4jg oxygen4 ,when it is digested in cold acetic acid the residuum constitutes another oxide consisting of #a atom of oxygen and #c of yellow oxide1 or #ajj lead and #aj4d oxygen1 possessing the same colour as the former1 but distinguishable by its not being acted on by cold acetic acid1 and by its containing twice as much brown oxide and extra oxygen as minium4 ,no doubt the other intermediate oxides of #a to #d and #a to #e exist1 and are all alike red2 but have not perhaps any remarkable distinctions besides their containing different proportions of oxygen and brown oxide4 ,whether an oxide consisting of #a oxygen and #b yellow oxide exists1 ,i have not discovered2 but that #a oxygen and #a yellow oxide are found united1 appears below4 ,,iii4 ,deutoxide4 ,this is the flea-brown oxide mentioned above4 ,it may also be obtained by treating solutions of salts containing the yellow oxide by oxymuriate of lime1 in which case the oxide is precipitated1 leaving the acid in the liquor1 a proof that it is insoluble in acids4 ,its more remarkable properties are3 #ast4 like the red oxide1 when heated to a low red1 or treated with sulphuric acid1 it yields oxygenous gas1 and more copiously2 it is thus reduced to the yellow oxide3 #b;d4 with muriatic acid it yields oxymuriatic acid in great plenty and muriate of lead3 #c;d4 it detonates when rubbed with sulphur in a mortar4 ,the quantity of oxygen in the brown oxide is stated by ,thomson at #be oxygen to #ajj lead1 by ,berzelius at #ae4f to #ajj4 ,this last is very nearly right by my experience1 and being just double of the oxygen in the protoxide1 it warrants us in denominating it the deutoxide4 ,berzelius finds #ajj of the brown oxide lose #f4e by a red heat so as to reduce it to the yellow2 ,dr4 ,thomson finds the loss #i grains4 ,this difference is easily accounted for2 it loses1 ,i find1 from #g to #aj grains per cent4 according to the previous degree of dryness2 when exposed to a moist atmosphere it attracts humidity2 when dried in a temperature of #bjj and exposed to red heat immediately after1 it does not lose more than #f4e or #g per cent4 ,this is corroborated too by the oxygen expelled by sulphuric acid4 ,from #ajj grains of brown oxide and sulphuric acid in a gas bottle1 ,i obtained by the heat of a lamp #h4c oz4 of oxygenous gas #e4c grains2 about #abj grains of grey sulphate of lead were left in the bottle4 ,the oxygen is rather less than was expected2 but it must be remembered that #ajj grains of brown oxide1 obtained in the ordinary way1 have the insoluble dross of #ejj red oxide in them1 which must have some influence in diminishing the production of oxygen4 ,though the above might be deemed sufficient to demonstrate the proportion of oxygen in the brown oxide1 ,i was desirous to corroborate the results by oxymuriate of lime4 ,i found repeatedly that #ajj grain measures of acetate of lead 7#a4adb7 #ac4h yellow oxide1 required #djj measures of oxymuriate of lime #a oxygen1 to precipitate the whole of the oxide in a brown state4 ,now if #ac4h #a #ig #g4 ,again1 into #bdj measures of test green sulphate of iron 7#a4aef7 #ai oxide1 were put #dj grains of brown oxide of lead1 together with a sufficient quantity of muriatic acid to saturate the lead1 and discharge the oxygen2 after due agitation sulphate of lead was precipitated1 and the whole of the oxide of iron was found1 when precipitated1 to be yellow4 ,but #ai grains oxide of iron require #b of oxygen to become yellow2 hence the #dj grains brown oxide of lead must have furnished #b grains of oxygen to form oxymuriatic acid1 which transferred it to the oxide of iron4 ,if #dj #b #ajj #e oxygen1 for the excess or second dose of oxygen in #ajj brown oxide1 such as is obtained by nitric acid along with its impurities2 which agrees with the results obtained by the other methods4 #ad4 ,oxide of zinc4 ,when zinc is exposed to a strong heat it burns with a brilliant white flame1 and a white powder sublimes1 which is the oxide of the metal4 ,when dilute sulphuric acid is poured on granulated zinc1 hydrogen gas is produced in great abundance and purity2 the metal is oxidized at the expence of the water and dissolved in the acid1 the oxide may be precipitated by an alkali2 it is white both when precipitated and dried1 and when heated does not differ from that obtained by combustion4 ,by a violent heat it runs into glass4 ,the quantity of oxygen in zinc oxide is1 ,i think1 best estimated by the hydrogen gas produced during the solution2 it may also be obtained by direct combustion1 or by solution in nitric acid and calcination4 ,dr4 ,thomson determines the oxygen by comparison of the weights of real sulphuric acid and metallic zinc in a solution of sulphate of zinc1 along with the consideration that the proportion of sulphuric acid and oxygen in the metallic sulphates is known2 ,mr4 ,cavendish obtained #cef oz4 measures of hydrogen from #a oz4 of zinc by solution4 ,i dissolved #di grains of zinc in dilute sulphuric acid and obtained hydrogen1 after the rate of #cfc grain measures for #a grain of zinc #ahb measures of oxygen 4#bd grain of oxygen4 ,the following are the principal authorities for the quantity of oxygen in zinc oxide1 in the order of time4 ,zinc4 ,oxygen4 #agff4 ,cavendish #ajj #bc4c #aghe4 ,lavoisier -- #ai4f #agij-ahjj4 ,wenzel and ,proust -- #be #ahja4 ,desorme and ,clement -- #ba4g ,davy -- #ba4ie ,berzelius -- #bd4d ,gay ,lussac -- #bd4d ,thomson -- #bd4db ,my own -- #bd ,now if #bd oxy4 #ajj zinc #g oxy4 #bi zinc1 nearly1 which is therefore the weight of an atom of this metal1 on the supposition that the oxide is #a oxygen and #a metal2 and the atom of oxide #cf4 ,i formerly estimated the atom of zinc at #ef 7,,vol4 #a1 page #bfj74 ,this was occasioned by taking the above as the deutoxide instead of the protoxide4 ,by violently heating the oxide of zinc in a close vessel1 ,desorme and ,clement reduced the oxygen nearly one half1 so as to afford a presumption that an oxide with half the oxygen of the common one subsisted4 ,since that time some observations of ,berzelius seem to shew that a suboxide of zinc exists4 ,it does not appear however1 that such oxide is ever found in combination with acids2 and1 granting the accuracy of the observations1 it is rather to be presumed to be the semi-oxide1 or #a atom of oxygen and #b of metal1 than the protoxide4 ,no higher oxidation of zinc than the above has yet been obtained1 and probably does not exist4 #ae4 ,oxides of potassium4 ,since writing the articles 8potassium and sodium10 in the former volume1 a very important essay relating chiefly to these subjects has been written by ,gay ,lussac and ,thenard 7a copy of which they were so good as to send me71 entitled 8,recherches ,physico-chimiques1 c40 in #b ,,vol4--,many of the most interesting experiments of ,davy have been repeated on a larger scale1 and a great number of original ones added2 these ingenious authors endeavour to sum up the evidences for and against the two hypotheses concerning potassium and sodium1 namely1 as to their being metals or hydrurets1 and upon the whole incline to the former1 allowing however1 that the facts afford great plausibility to both4 ,one thing they seem to have discovered and established1 that the new bodies or metals admit of various degrees of oxidation1 and of course these products have a claim to be classed amongst oxides in general though the nature of their bases may still be an object of dispute4 ,they find three oxides of potassium2 the lowest degree is obtained by exposing potassium to atmospheric air in a small bottle1 with a common cork2 a gradual oxidation takes place2 a blueish grey brittle product is obtained2 there does not appear however1 to be any proper limit to this oxidation besides that which they admit as characterizing the second degree or potash1 which degree of oxidation may always be immediately obtained by placing potassium in contact with water4 ,this ,i think should be called the protoxide and considered as #a atom of potassium1 and #a of oxygen2 before this point it is potassium and potash mixed or perhaps combined4 ,besides these there is another obtained by burning potassium in oxygen gas at an elevated temperature2 this oxide is yellow1 fusible by heat1 and crystallizes in lamina on cooling2 it contains three times as much oxygen as potash2 put into water it is suddenly decomposed1 giving out of the oxygen in gas and becoming potash4 ,very probably an oxide containing twice as much oxygen as potash might be formed with some mark of discrimination1 by uniting #ah parts potassium with #ef of yellow oxide1 but this has not yet been done4 ,according to these conclusions the weights of the oxides of potassium may be stated as under4--,potassium #ce1 protoxide or potash #db1 deutoxide 7supposed to exist7 #di1 and the yellow or tritoxide #ef4 ,hence we have ,potassium4 ,oxygen4 ,protoxide 7potash7 #ajj #bj ,gay ,lussac ,thenard #ai ,davy ,deutoxide #ajj #dj 7unknown7 ,tritoxide #ajj #fj ,gay ,lussac ,thenard ,one feels unwilling to admit of a tritoxide1 7and that perhaps the only one existing17 when the deutoxide is unknown1 were it not upon good authority4 ,the obscurity on this subject may be removed by future experiments4 ,it may be proper to add that ,gay ,lussac and ,thenard concur with ,davy in assigning a much greater saturating power to potassium and sodium than to the fused hydrates of potash and soda of equal weights4 ,from the table1 ,recherches1 ,tom4 #b1 p4 #bad1 it may be deduced that #ce potassium require as much sulphuric acid to saturate them as #ej or more of the hydrate of potash2 and that #ba sodium are equivalent to #cf or #cg hydrate of sodium4 ,if these results are accurate1 the weights of potassium and sodium1 considered as hydrurets1 cannot be as we have deduced them at pages #dhf and #ejc1 ,,vol4 #a1 namely1 #dc and #bi respectively1 but #ce and #ba1 as at page #bfb4 #af4 ,oxides of sodium4 ,gay ,lussac and ,thenard find a suboxide of sodium in the same way as that of potassium1 and it is probably a compound of soda and sodium3 the remarkable oxidation which produces soda is1 ,i should imagine1 the protoxide or one atom to one1 as obtained by placing sodium in contact with water4 ,a higher oxide is obtained as with potassium1 by burning sodium in oxygen gas with a vivid heat4 ,it resembles the yellow oxide of potassium in its appearance and properties4 ,the degree of oxidation varies in the different experiments from #a to #a times the oxygen of soda4 ,it is probably a combination of the protoxide and deutoxide4 ,hence the oxides of sodium may be as under2 reckoning the atom of sodium #ba1 and soda #bh4 ,sodium4 ,oxygen4 ,protoxide 7,soda7 #ajj #cc ,intermediate oxide #ajj #ej #ag4 ,oxide of bismuth4 ,only one oxide of bismuth is known1 and the proportion of its parts has been gradually approximated by ,bergman1 ,lavoisier1 ,klaproth1 ,proust1 and others4 ,berzelius mentions a purple oxide obtained by exposing bismuth to the action of the atmosphere2 but as no experiments have been made upon it1 we cannot adopt it at present4 ,according to ,klaproth and ,proust1 #ajj bismuth unite with #ab oxygen2 but by the more recent experiments of ,mr4 ,j4 ,davy and ,lagerhjelm #ajj bismuth take #aa4a or #aa4c oxygen4 ,if we adopt this last1 which is doubtless near the truth2 we shall have #aa4c #ajj #g #fb for the weight of the atom of bismuth1 on the supposition that the compound is the protoxide or #a atom of metal to #a of oxygen4 ,my former weight of bismuth was #fh 7page #bfc71 which is clearly too high4 ,bismuth is best oxidized by nitric acid4 ,part of the oxide combines with the acid and part precipitates in the state of a white powder2 if the whole be gradually heated1 the acid is driven off1 and at a low red the oxide remains pure2 it is fused into glass and of a red or yellow colour1 according to the heat employed4 ,bismuth may also be oxidized by heat in open vessels2 yellow fumes arise which may be condensed and are found to be the oxide4 #ah4 ,oxides of antimony4 ,considerable difference of opinions exists with regard to the oxides of antimony4 ,proust finds two oxides which he determines to consist1 the first1 of #ajj metal #bb or #bc oxygen2 the second of #ajj metal #cj oxygen4 ,thenard finds #f oxides3 ,j4 ,davy two oxides1 namely1 #ajj metal #ag4g oxygen1 and #ajj #cj oxygen4 ,berzelius infers from his experiments that there are #d oxides of antimony1 the first containing #d4fe oxygen1 the second #ah4f1 the third #bg4i1 and the fourth #cg4b of oxygen on #ajj metal4 ,he admits however that the oxide obtained by boiling nitric acid on antimony and expelling the superfluous acid by a low red heat1 consists of #ajj metal #bi to #ca oxygen1 as determined by ,proust and others4 ,this is certainly the most definite of the oxides1 next to that which is obtained from the solution of antimony in muriatic acid4 ,this last may be had by pouring water into a solution of muriate of antimony2 a white powder precipitates1 which is the oxide with a little muriatic acid2 the acid may be abstracted by boiling the precipitate in a solution of carbonate of potash4 ,this oxide is a grey powder1 and fusible at a low red heat4 ,it enters exclusively into various well known compounds1 as the golden sulphur of antimony1 antimoniated tartrate of potash1 c4 ,its constitution1 according to ,proust1 is #ajj metal #bc oxygen2 but ,j4 ,davy finds only #ag4g oxygen1 and ,berzelius #ah4f4 ,as this oxide possesses the most distinct features1 and besides is the most important1 it is desirable its constitution should be ascertained without doubt4 ,from several experiments ,i made on the precipitation of antimony by zinc1 ,i conclude the oxide contains about #ah oxygen on #ajj metal4 ,i took the common muriate of antimony with excess of acid1 and immersed a rod of zinc into it1 covering the whole with a graduated bell glass4 ,hydrogen gas was produced by the excess of acid1 and its quantity was ascertained2 the antimony was in due time precipitated1 and when the operation ceased1 the loss of zinc and the weight of antimony were found4 ,for instance1 to #ej measures of #a4fi mur4 ant4 #fj water were added1 no precipitation was observed2 a zinc rod was put in and the whole covered by a bell glass1 over water2 in a few hours the operation had ceased1 and there appeared #cdhj grain measures of hydrogen gas generated2 the dried antimony weighed #be grains1 and the zinc had lost #bi grains4 ,now #cdhj hydrogen require #agdj of oxygen #b4c grains in weight4 ,but #bi zinc require #g oxygen2 therefore the zinc must have got #d4g oxygen from the antimony2 that is1 #be4e antimony were found united to #d4g oxygen2 this gives #ajj antimony #ah4d oxygen4 ,i conclude then that the error is with ,proust2 and this appears to be confirmed by the consideration that ,proust himself obtains only #hf oxide of antimony from #ajj sulphuret1 which he allows to contain #gd antimony2 now if #gd #ab #ajj #ag nearly4 ,i am therefore inclined to adopt #ah for the oxygen which combines with #ajj antimony to form the grey oxide4 ,whether this is the protoxide or deutoxide may be disputed2 and the facts known concerning the other oxide or oxides will scarcely determine the case3 but the proportions of the muriate and sulphuret of antimony accord much better with the former supposition4 ,now if #ah #ajj #g #ci1 for the weight of the atom of antimony2 ,i prefer the weight #dj1 deduced from the sulphuret1 as announced in ,,vol4 #a1 page #bfd4 ,the oxide which contains #cj on #ajj must be #b atoms of the deutoxide and #a of the protoxide united4 ,what ,berzelius calls the white oxide or antimonious acid1 may be #a atom of each oxide united1 containing #bg oxygen on the #ajj4 ,the oxide supposed to contain #cf or #cg oxygen on #ajj1 and which must be considered as the deutoxide1 has not been proved to exist separately4 ,my efforts to procure it have failed as well as those before mine3 by treating muriate of antimony with oxymuriate of lime ,i have obtained oxides of #cj on the #ajj1 but never much higher4 ,whenever a greater proportion of oxymuriate of lime is added1 the smell of the gas becomes permanent4 ,antimony exposed to a red heat in a current of common air or oxygenous gas takes fire1 and white fumes arise formerly called flowers of antimony2 this oxide contains #bg or #cj oxygen on #ajj metal4 ,antimony thrown into red hot nitre is oxidized rapidly2 the remaining powder1 washed in water1 is found to be a compound of oxide of antimony and potash4 ,berzelius calls the oxide the antimonic acid1 and the salt the antimoniate of potash4 ,it consists1 according to his experience1 of #ajj acid and #bf4e potash4 ,a similar salt formed between the antimonious acid and potash is constituted of #ajj acid and #cj4e potash4 #ai4 ,oxide of tellurium4 ,we are chiefly indebted to ,berzelius for the proportions in which tellurium combines4 ,he finds #ajj tellurium unite to #bd4h oxygen4 ,also that #bja4e tellurate of lead gave #aeg sulphate of lead4 ,this last contains #aaf oxide of lead1 which must therefore have combined with #he4e of the oxide of tellurium4 ,hence #ig oxide of lead would combine with #ga4e oxide of tellurium #eg tellurium #ad oxygen4 ,whether this oxide of tellurium is the protoxide or deutoxide1 is somewhat uncertain4 ,the atom of tellurium will weigh #eg in the latter case1 but only #bh or #bi in the former4 ,the analogy of the oxide to acids favours the notion of a deutoxide2 but the facility with which the tellurium is volatilized by hydrogen is in favour of the lighter atom4 ,the oxide is a white powder2 it is produced by dissolving the metal in nitro-muriatic acid and precipitating by an alkali4 #bj4 ,oxides of arsenic4 ,there are two distinct combinations of arsenic and oxygen2 the one has been long known as an article of commerce under the name of arsenic4 ,it is a white1 brittle1 glassy substance1 obtained during the extraction of certain metals from their ores4 ,its specific gravity is about #c4g4 ,according to ,klaproth boiling water dissolves from #g to #h per cent4 of the oxide of arsenic2 but on cooling it retains only about #c per cent42 and this ,i find is gradually deposited on the sides of the vessel till it is reduced to #b per cent4 or less in cold weather1 and by some months standing4 ,water of #fj or under dissolves no more than per cent4 of the oxide4 ,at the temperature of about #djj the oxide sublimes4 ,this oxide combines with the alkalies1 earths1 and metallic oxides somewhat as the acids do1 but does not neutralize them1 and in other respects it is destitute of acid properties2 as for instance1 it does not affect the colour tests4 ,it is extremely poisonous4 ,the other oxide is obtained by treating either the white oxide or pure metallic arsenic with nitric acid and heat4 ,one hundred grains of white oxide require two or three times their weight of nitric acid1 of #a4c1 to oxidize them4 ,the new oxide is produced in a liquid form2 from which the excess of nitric acid may be driven by a low red heat1 and the oxide is obtained pure in the form of a white opake glass1 which soon becomes liquid by attracting moisture from the atmosphere4 ,this oxide1 discovered by ,scheele1 has all the properties of acids in general1 and is therefore denominated arsenic acid4 ,when just fluid by attracting moisture it has the sp4 gravity #a4fe nearly4 ,it is represented as equally poisonous with the white oxide4 ,the proportions of the elements in these two oxides have been investigated with considerable success4 ,proust finds the white oxide constituted of #ajj metal and #cc or #cd oxygen1 and the second of #ajj metal with #ec or #ed oxygen3 with these results those of ,rose and ,bucholz nearly agree4 ,thenard finds #ajj #cd4f for the white oxide1 and #ajj #ef4be for the acid3 and ,thomson #ajj #eb4d for the acid4 ,berzelius however1 infers from his recent experiments that the oxide consists of #ajj metal #dc4f oxygen1 and the acid of #ajj #ga4c2 these last results ,i have little doubt are incorrect from my own experience4 ,it appears that when arsenic is oxidized by nitric acid1 #ajj parts yield from #aeb to #aef of acid1 dried in a low red heat4 ,the differences may in part be owing to the metal being partly oxidized at the commencement of the operation4 ,on this account ,i should suppose #ee or #ef to be the proper quantity of oxygen united to #ajj metal to form the acid4 ,proust and ,thenard both found that #ajj white oxide1 when converted into acid by nitric acid1 gave #aae or #aaf4 ,i have found the same4 ,now if #aaf #ajj #aef #acd2 hence the white oxide of arsenic must contain #ajj metal to #cd oxygen1 if the data be correct2 or the metal and oxygen are as #c to #a nearly4 ,it is highly improbable that any inferior oxide subsists1 as no traces of such have been found1 if we disallow a conjecture of ,berzelius on the subject4 ,the white oxide of arsenic must then be considered as the protoxide1 and the atom of arsenic must weigh #ba nearly1 and that of the protoxide #bh4 ,it is plain the other is not the deutoxide1 as it does not contain twice the oxygen of the protoxide2 but as the proportion of oxygen in it is to that of the protoxide1 as #e #c1 it may be a compound of #b atoms of deutoxide1 and #a of protoxide2 that is1 it may be the superarseniate of arsenic1 if we consider the deutoxide as the acid1 and the protoxide as the base4 ,according to this view1 the compound oxide1 or arsenic acid of ,scheele1 is constituted of two atoms of the deutoxide1 weighing #gj1 and #a atom of the protoxide weighing #bh1 together making #ih1 for the weight of an atom of arsenic acid1 #fc arsenic #ce oxygen3 and #ajj arsenic take #ee4e oxygen to form the acid1 agreeably to the above recited experiments4 ,singular as this conclusion may appear1 the truth of it is put beyond doubt1 ,i think1 by the following experiments4 ,i have repeatedly found that #bh parts of white oxide in solution are sufficient to throw down #bd parts of lime1 from lime water1 so as to produce #eb parts of arsenite of lime1 and leave the water free from both elements4 ,this confirms the notion of the atom of protoxide weighing #bh4 ,if to #bd parts of lime dissolved in water we put #ih parts of dry arsenic acid1 the compound remains in solution1 and is perfectly neutral to the colour test1 but so that the addition of a small quantity of either ingredient disturbs the neutrality4 ,if to this solution #bd parts of lime dissolved in water be added1 the compound remains a limpid solution1 but is very limy to the test4 ,if to this we put in like manner1 #bd parts more of lime1 the whole compound is thrown down1 and yields1 when dried1 #agj parts of arseniate of lime1 the liquid being now free from both elements4 ,here we see first1 two atoms of the deutoxide1 neutralized by two atoms of base1 namely1 #a of arsenic oxide1 and #a of lime2 but 7second71 when one atom more of lime is added1 an union of #b deutoxide1 and #c of base is effected1 which of course is an alkaline salt2 when 7third7 more of lime is added1 the #b deutoxide and the #a protoxide each attach #a of lime1 and form a still more alkaline salt1 which being insoluble1 is wholly thrown down1 most probably in a compound state of #ih parts arsenic acid1 combined with #gb parts lime4 ,in like manner1 ,i find that #db parts of potash1 #bh of soda1 and #ab of ammonia1 severally neutralize #ih parts of arsenic acid4 #ast4 #bd lime #cb4g arsenic acid insoluble arseniate #b;d4 -- #di ------------ soluble arseniate #c;d4 -- #ih ------------ neutral arseniate ,it is a remarkable fact1 that when neutral arseniate of potash and nitrate of lead are mixed together to mutual saturation1 the precipitate is found to consist chiefly of arsenic acid and oxide of lead1 in proportion of #a of acid to two of oxide1 7that is1 #ih #aid1 or #ajj #aih72 which does not differ much from the determination of ,berzelius4 ,i find however1 only one fourth of the nitric acid in the residuary liquid in a free state2 which leads me to suspect that the precipitate is a compound of subnitrate and arseniate of lead1 in which the arsenic acid and lead are in due proportion1 or #ih acid1 to #ig oxide4 ,this consideration may be properly resumed hereafter4 ,hence we conclude1 the atom of arsenic weighs #ba 7and not #db1 as at page #bfd1 ,,vol4 #a71 that of the protoxide of common white arsenic1 #bh2 and that of arsenic acid #ih1 being a compound of #b atoms of deutoxide1 and #a of protoxide4 ,or1 #ajj ,arsenic #cc4c oxygen #acc4c protoxide -- #ee4e ---- #aee4e arsenic acid #ba4 ,oxides of cobalt4 ,there are at least two oxides of cobalt1 the one blue1 the other black4 ,authors differ as to the proportions of the elements4 ,proust states the blue oxide to consist of #ajj metal1 and #ai or #bj oxygen1 and the black of #be or #bf oxygen4 ,klaproth finds in the blue1 #ajj metal and #ah oxygen4 ,but ,rolhoff according to ,berzelius1 finds #ajj metal and #bg4c oxygen in the blue oxide1 and #dj4i in the black4 ,i have taken some pains to investigate these oxides1 and have been able to satisfy myself in a good degree1 respecting their constitution4 ,the blue or protoxide consists of #ajj metal and #ai oxygen1 and the black oxide of #ajj metal1 and #be or #bf1 very nearly as ,proust determined4 ,protoxide4 ,by repeated trials ,i have found1 that if #cg parts of metallic cobalt be treated with the due quantity of nitro-muriatic acid1 and a heat of #aej1 a rapid solution takes place1 and a disengagement of pure nitrous gas2 this being carefully collected1 it will be found to weigh #h grains1 and of course corresponds to #g grains of oxygen2 hence #cg cobalt1 unite to #g oxygen1 to form #dd of the blue oxide2 and as this is the only oxide that combines with acids1 it must be considered as the most simple or protoxide1 being #a atom of metal 7#cg71 and #a of oxygen 7#g74 ,the estimation of the atom of cobalt at #ej or #fj1 7page #bfe71 must therefore be corrected4 ,compound oxides4 ,when the blue oxide of cobalt is precipitated from a solution1 by an alkali or lime water1 and oxymuriate of lime is gradually dropped in1 the precipitate changes colour rapidly2 it passes from blue to green and olive1 thence to a dark bottle green1 and finally becomes black2 oxygen gas is given out copiously when an excess of oxymuriate of lime is used4 ,i find the additional oxygen requisite to convert the blue to the black oxide is what ,proust states it1 namely1 of that necessary to form the blue2 hence it must be considered as a compound of #a atom of oxygen and #c of the protoxide4 ,probably the other coloured oxides are #a to #d1 #a to #e1 c4 ,the protoxide is blue when precipitated1 but it is supposed to contain water1 or to be a hydrate2 as it is dark grey when heated4 ,the blue oxide in a short time after precipitation being still under water1 changes to a yellowish or dead-leaf colour2 which also appears to be a hydrate of the protoxide1 as it dissolves in acids without giving out gas1 and yields the blue oxide by an alkali4 ,according to ,proust1 this hydrate contains #bj or #ba per cent4 water4 ,if we suppose the blue to be #a atom oxide1 and #a water1 the yellow hydrate may be #a water and #b of the proto-hydrate2 or #hh oxide1 and #bd water1 which will be nearly #ba per cent4 water4 ,the black oxide gives out oxygen gas by a red heat1 and is reduced to the grey oxide3 it forms oxymuriatic acid1 with muriatic acid1 and the protoxide remains in solution4 7,see ,tassaert4--,an4 de ,chimie #bh2 ,thenard1 #db2 and ,proust1 #fj47 #bb4 ,oxides of manganese4 ,one of the oxides of manganese being a natural production1 and sometimes of great purity1 and the metal not being obtainable without skill and labour1 it may be most convenient to adopt the inverse method in our investigations2 that is1 to trace out the atom of metal from its oxides4 ,native oxides of manganese4 ,of late1 ,i have met with excellent specimens of this oxide2 they are in masses of a grey1 crystalline appearance1 sp4 gr4 #d1 easily pulverizable into a greasy1 shining1 dark grey powder4 ,they are nearly pure oxide2 but the more common sort is blacker1 and contains less or more of siliceous earth4 ,some specimens are very harsh1 require an iron mortar to pulverize them1 and contain #ej or upwards per cent4 of siliceous earth4 ,of the common sort when pulverized1 the black inclining to blue1 is generally preferable to the black inclining to brown4 ,i have not observed any earthy carbonates mixed with the oxide of manganese4 ,amongst various specimens ,i obtained the following analyses4 ,oxide4 sand and insoluble matter4 #a4 ,grey1 crystallized oxide #ajj ---- #b4 ,pulverized black oxide1 from #hj #bj a bleacher1 reputed good #c4 ,another specimen1 in the lump #gg #bc #d4 ,a light brown oxide #dg #ec #e4 ,a sparry oxide1 abounding with #bg #gc flint2 black brown when pulverized ,some of the chemical characters of the native oxide of manganese are1 its giving oxygen gas by a red heat1 its insolubility in nitric and sulphuric acids1 and its solubility in muriatic acid1 but with the accompanying circumstance of disengaging oxymuriatic acid4 ,all these facts shew that it is of the higher order of oxides1 or analogous to the brown and red oxides of lead4--,the muriatic acid solution abovementioned1 contains an oxide of an inferior degree1 which is soluble in all acids1 and which is the only oxide of manganese that appears to be soluble in acids4 ,if this be considered1 7as it may with the greatest probability71 the protoxide1 then it will appear from what follows1 that the common native manganese is the deutoxide1 and that there is an intermediate one1 which contains a mean quantity of oxygen4 ,protoxide4 ,this may be obtained in solution with muriatic acid as above1 from the native oxide4 ,or the black oxide may be mixed with sulphuric acid into a paste1 and heated in an iron spoon to redness2 the mass being lixiviated1 a solution of the protoxide in sulphuric acid is obtained1 generally with a slight excess of the acid2 in this process heat and the presence of sulphuric acid1 expels the redundant oxygen of the black oxide1 and reduce it to the protoxide1 which hence becomes soluble4 ,if in either of these solutions any oxide of iron be present1 whether from the manganese1 or acquired during the manipulation1 it is easily discovered and separated1 as ,i have frequently found4 ,into any solution containing a mixture of the oxides of manganese1 the green oxide of iron1 and the red oxide of iron1 let lime water be gradually poured2 the red oxide of iron will be first precipitated1 next the green oxide1 and lastly the oxide of manganese1 which may hence be separated from each other4 ,iron may also be discovered and separated by carbonate of potash1 which must be dropped into the solution as long as any coloured precipitate appears2 as soon as it has subsided1 the snow-white carbonate of manganese succeeds4 ,this white carbonate may be very conveniently used for obtaining solutions of pure manganese in any of the acids4 ,when a solution of pure manganese is treated with lime water1 or ammonia1 a light buff oxide1 not much differing in appearance from the yellow oxide of iron1 is obtained4 ,this oxide is soluble in all acids1 when recently precipitated2 but1 such is its avidity for oxygen1 with moderate agitation of the liquid it acquires oxygen and becomes brown1 when it ceases to be totally soluble2 if dried in the air quickly1 it becomes brown and obtains considerable oxygen4 ,the buff oxide recently precipitated1 is probably a hydrate2 for1 when the white carbonate of manganese is heated gradually to red1 the water and the acid are both expelled1 and a grey powder remains2 this is quite black on the surface of the mass1 if exposed to the air during the process4 ,probably this grey powder is the pure protoxide2 it is soluble in acids1 except the black powder at the surface2 perhaps but for the oxygen of the air1 the protoxide would be nearly white4 ,from its combinations with sulphuric and carbonic acids1 ,i find the weight of an atom of the protoxide to be #cb1 or the same as that of iron4 ,dr4 ,john1 a ,german chemist1 who seems to have investigated these salts with more attention than any other person1 has deduced nearly the same results4 7,annals of ,philos4 #b-agb74 ,he finds #cc sulphuric acid #ca oxide1 and #cd4b carbonic acid #ee4h oxide2 that is1 when reduced to compare with my results1 #cd sulphuric acid #ca4c oxide1 and #ai4d carbonic acid #cb oxide4 ,this near agreement may be considered as a confirmation of the accuracy of both4 ,dr4 ,john finds1 as ,i have done1 three distinct oxides of manganese1 the greyish green1 the brown1 and the black4 ,the first of these is the only one that combines with acids2 but we differ materially as to the quantity of oxygen in each4 ,he found manganese decompose water at the ordinary temperature2 by oxidizing the metal this way1 #ajj metal acquired #ae oxygen to constitute the protoxide2 according to this1 #bh metal #d oxygen would make #cb protoxide2 but this conclusion would be so contrary to all analogy1 that it cannot be admitted as satisfactory4 ,the probability is1 that the manganese must have contained a little oxygen at the commencement of the experiment4 ,the general analogy of manganese to iron1 lead1 c4 requires that #cb protoxide should contain #g oxygen4 ,if this be allowed1 we have the atom of manganese #be1 and not #dj1 7as at page #bff1 ,,vol4 #a71 the same as that of iron3 and this conclusion is corroborated by what follows4 #b4 ,intermediate or olive brown oxide4 ,this may be formed by combining oxygen directly with the buff or protoxide recently precipitated1 and still remaining in the liquor2 simple agitation in oxygenous gas or common air for a few minutes1 is all that is requisite4 ,or it may be instantly formed by treating the same moist protoxide with liquid oxymuriate of lime4 ,or it may be had by exposing the purest black oxide to a bright red heat for some time1 when it will lose #i or #aj per cent4 and there will remain the olive brown oxide4 ,to find the proportion of oxygen absorbed1 ,i precipitated #c4b grains of the protoxide by lime water2 the liquid containing the oxide was put into a well stoppered bottle of oxygen gas2 on agitation the oxide changed colour fast1 from buff to brown2 in a short time it absorbed #bfj grain measures of gas 4#ce of a grain in weight1 and then ceased to absorb4 ,in another experiment1 #c4b grains of precipitated protoxide1 took #ajj measures of a solution of oxymuriate of lime1 containing 4#ce per cent4 of oxygen1 7that is1 #a4de oxymuriatic acid74 ,hence as #cb take #c4e1 #fd must take #g2 which shews the brown oxide to be a compound of #a atom of oxygen1 and #b of the protoxide4 ,the characters of this oxide are1 its olive brown colour1 its insolubility in nitric and sulphuric acids1 without heat or deoxidation1 and its solubility in muriatic acid after the evolution of oxymuriatic acid4 ,by long exposure to the air1 it is gradually changed1 in all probability into the black oxide4 #c4 ,deutoxide4 ,in order to determine the quantity of oxygen deducible from the purest native oxide of manganese1 to convert it into protoxide1 ,i have successfully adopted the two following methods4 #ast4 ,let #ci or #dj grains of the oxide be mixed with #fj common salt2 to this add #hj grains of water1 and #abj grains weight of strong sulphuric acid1 in a gas bottle4 ,the heat must be gradually raised to boiling1 and the oxymuriatic acid gas may be received in a quart of lime water4 ,this will be found sufficient to convert #hjj measures of test green sulphate of iron 7#a4aef7 into red2 that is1 it will produce #bi grains of oxymuriatic acid1 which will cause #g grains of oxygen1 to unite to the green oxide of iron4 ,now #ajj measures of #a4aef sulphate1 according to some recent experiments of mine1 contain #h grains of green oxide1 7,i estimated the sp4 gr4 of test sulphate1 heretofore at #a4adi72 hence #hjj contain #fd oxide1 and these require just #g grains of oxygen to be united to them1 to form the red oxide1 as has been shewn1 page #cd4 ,in the above experiment1 the #ci grains of oxide1 will be found to vanish or be dissolved1 if pure1 and to yield #cb grains of protoxide1 making up with the #g grains of oxygen1 the original weight4 ,hence we have #ci grains of the oxide resolved into #cb protoxide1 and #g oxygen4 ,if then we allow #cb protoxide1 to contain #g oxygen1 it appears that #ci grains of the native oxide1 consists of #a atom manganese 7#be71 and two atoms of oxygen 7#ad72 or it is the deutoxide of the metal4 #b;d4 ,a more direct and expeditious method1 of transferring the oxygen from the manganese to the iron1 is as follows3 ,let #ci grains of pure grey shining oxide1 be mixed with #hjj of test green sulphate of iron2 to this mixture let #be or #cj grain measures of strong sulphuric acid be added3 after stirring the mixture for #e minutes1 the oxide of manganese will be completely dissolved1 and1 on precipitating the oxide of iron gradually1 by lime water1 it will be found to be wholly yellow or buff2 shewing that #g grains of oxygen have been transferred from the oxide of manganese to that of iron4--,if more green sulphate of iron be used1 then the surplus of the oxide will be thrown down green2 the order of precipitation being the yellow oxide of iron1 the green oxide of iron1 and lastly1 the yellow or buff oxide of manganese1 as has been stated4 ,this affords an easy and elegant method of appreciating the different oxides of manganese of commerce2 and it was in this mode1 the valuations of the specimens in the above table were made4 ,the proportions of the three oxides are then as under3 ,manganese ,oxygen ,protoxide #ajj #bh -- buff2 soluble in acids4 ,intermediate oxide -- #db -- brown2 insoluble4 ,deutoxide -- #ef -- black2 insoluble4 ,it may be proper to subjoin the results of others1 who have investigated the oxides of manganese4 ,bergman finds #c oxides1 containing #ajj metal #be1 #ce1 and #ff4f oxygen2 ,dr4 ,john finds #c oxides1 containing #ajj metal #ae1 #be1 and #dj oxygen3 ,berzelius finds #e oxides1 containing #ajj metal #g1 #ad1 #bh1 #db1 and #ef oxygen2 and ,davy finds #b oxides1 containing #ajj metal #bf4f1 and #ci4i oxygen1 respectively4 #bc4 ,oxides of chromium4 ,there appear to be at least two oxides of chromium1 one or other of which is found in combination with the oxides of lead or iron1 but hitherto so very sparingly that few chemists have had an opportunity of investigating the proportions of chrome and oxygen1 in the oxides of chromium4 ,the chief sources for information on this subject1 are essays by ,vauquelin1 ,an4 de ,chimie1 ,,vol4 #be and #gj2 by ,tassaert1 ibid4 #ca2 by ,mussin ,puschin1 ibid4 #cb2 by ,godon1 ibid4 #ec2 by ,laugier ibid4 #gh1 and by ,berzelius1 ,annal4 of ,philosophy1 #c4 ,the oxides of chromium1 as might be supposed1 are distinguished for the colours which they possess and impart to the compounds into which they enter4 ,one of the oxides is green2 it gives colour to the emerald4 ,the other is yellow1 dissolved in water1 but deep red when crystallized1 and possesses the characters of an acid2 it unites with alkalies1 earths1 and metallic oxides2 it was first found in ,siberia1 in combination with the oxide of lead1 a salt now denominated chromate of lead1 of a splendid yellow colour1 inclining to orange or red4 ,since then1 the chromate of iron1 has been found in ,france1 ,america1 and ,siberia1 with a prospect of greater abundance4 ,in order to investigate the weight of the atom of chromic acid1 it is necessary to attend to such of the chromates as have been carefully examined4 ,the chromates of potash1 barytes1 lead1 iron1 and mercury1 are those with which we are best acquainted4 ,vauquelin has given us the components of the native chromate of lead by analysis1 and those of the artificial chromate by synthesis2 the results do not accord very nearly3 for1 according to the analysis corrected by the modern science1 ,chromate of lead #fb acid #ig oxide ,by synth4 chromate of lead #eg -- #ig -- ,berzelius however1 has more lately given us the results of his experience1 both analytical1 and synthetical2 and he finds both to give chromate of lead nearly #dd acid #ig oxide4 ,chromate of barytes 7,vauq47 #dg4h acid #fh barytes ,ditto 7,berz47 #dd -- #fh -- ,native chromate of iron 7,vauq47 #de acid #ce oxide ,ditto 7,laugier7 #ee -- #ce -- ,having received a small portion of chromate of potash in solution1 from a chemical friend 7,j4 ,sims71 ,i endeavoured to satisfy myself1 as far as my materials would go1 as to the nature and proportions of the chromates4 ,the solution was of the sp4 gr4 #a4jfa1 and consequently in #ajj measures contained nearly #f4g grains of chromic acid and potash1 c4--,the liquid was a beautiful yellow2 it was alkaline by the colour test4 ,by the usual tests1 ,i had reason to believe1 that the solution contained as under per cent4--namely1 #b4b gr4 chromic acid #b4 potash 4#h uncomb4 potash #a4d carb4 potash 4#c sulphate of potash --- #f4g ,with this liquid neutralized by nitric acid1 ,i formed the chromates of lead1 barytes1 iron1 and mercury2 and ,i am inclined to believe these salts are nearly constituted as under3 ,neutral chromate of potash #df acid #db potash -- -- of barytes #df -- #fh barytes -- -- of lead #df -- #ig oxide -- -- of iron #df -- #cb oxide 7black7 -- -- of mercury #df -- #agd oxide 7black7 ,according to these results1 the atom of chromic acid weighs #df2 it is made #dd by the results of ,berzelius1 and from #de to #fb by those of ,vauquelin2 ,i would not be understood to place great confidence in the above results of mine1 though ,i am persuaded they will be found good approximations4 ,is the chromic acid the deutoxide1 or the tritoxide of chromium8 ,the determination will evidently be affected by the question1 how much oxygen must be abstracted from the chromic acid to reduce it to the green oxide4 ,vauquelin finds #df acid to lose #f oxygen1 and ,berzelius #aj1 when converted into green oxide by heat4 ,from the former of these1 one would infer chrome to be #cb1 the green or protoxide of chrome to be #ci1 and the acid or deutoxide #df3 from the latter1 chrome #be1 protoxide #cb 7unknown71 the green oxide #a protoxide and #a deutoxide united #ga #ej chrome #ba oxygen 7#be chrome #aj oxygen7 #b #ce #b the deutoxide #ci1 and the tritoxide or chromic acid #df4 ,i have not had an opportunity to perform any experiment that appears to me decisive as to the accuracy of one or other of these views2 but shall make a few remarks relative to them4 ,the green oxide being the most prominent compound next to the chromic acid1 being commonly produced from it by any deoxidizing process1 being the lowest oxide known1 and combining with acids1 is on these accounts entitled to the consideration of the protoxide2 indeed there does not seem an instance where the protoxide of a metal is unknown1 whilst the deutoxide and compound oxides are known4 ,there is however1 another oxide observed by ,vauquelin and by ,berzelius1 which is obtained by heating the nitrate1 or combination of nitric acid and the green oxide1 to dryness and expelling the acid2 this oxide is brown1 and gives oxymuriatic acid when treated with muriatic acid2 on this account it would seem to be intermediate between the green oxide and the chromic acid2 it is probably a combination of the two1 or the chromate of chromium4 ,on the other view however1 it must be considered as the deutoxide4 ,what corroborates the notion of the green oxide being #ci1 is the fact which ,i have observed1 of #df parts of chromic acid combining with #fd of the green oxide of iron to form #aaj of chromate of iron2 in this combination the oxide of iron may be said to borrow #a atom of oxygen from the chromic acid1 and the compound may then be considered as the union of the green oxide of chrome1 and the red oxide of iron4 ,when this precipitate is subjected to the action of muriatic acid1 a green solution is obtained containing the oxide of chrome1 and red oxide of iron is precipitated1 as ,vauquelin has observed4 ,to form the above chromate 7or rather subchromate7 of iron1 let a given portion of neutral chromate of potash be treated with green sulphate of iron1 and lime water be added1 sufficient to saturate the sulphuric acid1 a brown red precipitate is obtained2 more sulphate and lime water must be gradually added to the clear liquid till the precipitate become green1 when the proportions will be found as above stated4 ,this artificial compound seems a subchromate2 whereas the native compound seems to be a chromate4 ,that there is some uncertainty in decomposing a chromate by heat with a view to obtain the green oxide1 ,i have reason to suspect from having decomposed #e grains of chromate of mercury by a moderate red heat2 this compound contained #a4a chromic acid1 and it yielded only 4#f of green oxide1 whereas it should have been 4#i or 4#h at least4 ,upon the whole ,i think the evidence is in favour of the opinion that the atom of chrome is #cb1 the green or protoxide #ci1 and the deutoxide or chromic acid is #df4 #bd4 ,oxides of uranium4 ,there appear to be two oxides of uranium from the experiments of ,klaproth1 ,bucholz1 and ,vauquelin2 but the proportions of metal and oxygen have not been very nearly ascertained1 from the great scarcity of the minerals containing this metal4 7,vid4 ,bucholz1 ,an4 de ,chimie1 #ef--adb4 ,vauquelin1 ibid4 #fh--bgg2 or ,nicholson's ,journ4 #be--fi74 ,the oxides are obtained by precipitation from solutions of the minerals in the nitric or muriatic acid1 the foreign substances being first separated4 ,the protoxide of uranium precipitates dark bottle green by caustic alkalies1 and forms crystallizable salts with acids2 the other1 probably the deutoxide1 precipitates orange yellow1 and forms uncrystallizable salts with acids2 in these respects the oxides bear a near resemblance to those of iron4 ,bucholz estimates the yellow oxide at #ajj metal from #be to #cb oxygen2 as it yields oxymuriatic acid when treated with muriatic1 it is most likely to be the deutoxide2 now if we take #bh for the oxygen combined with #ajj metal1 the protoxide must consist of #ajj metal #ad oxygen1 or of #ej metal #g oxygen1 and the atom of uranium #ej4 ,from his account of the sulphate and nitrate of uranium the weight of the atom might be inferred to be double of the above or #ajj4 ,these different conclusions can only be elucidated by future experiments4 #be4 ,oxides of molybdenum4 ,the latest and as it should seem most accurate experiments on the oxides of molybdenum were made by ,bucholz4 7,vid4 ,nicholson's ,journal1 #bj1 p4 #aba74 ,there appear to be #c oxides or combinations of molybdenum and oxygen1 namely1 the brown1 the blue1 and the white or yellow4 ,the two last have the character of acids1 and none of them seem to form salts with acids1 like oxides in general4 ,bucholz ascertained the above gradation1 and that the white oxide or molybdic acid contains of its weight of oxygen2 7which has since been corroborated by ,berzelius72 he also found that the blue was best formed by mixing1 triturating1 and boiling in water #c parts of brown oxide1 and #d of white1 or one of metal1 and two of acid2 and that it has acid qualities as well as the white4 ,bucholz also found #c parts of liquid ammonia of the sp4 gr4 4#ig dissolve #a of molybdic acid2 now #c parts of ammonia 4#ahf real 7,,vol4 #a1 p4 #dbb72 and #a 4#ahf #fd #ab1 the quantity of ammonia usually saturated by one atom of acid2 and ,berzelius found #ajj molybdic acid saturate #aee oxide of lead1 or #fc acid to #ig oxide4 ,the native sulphuret of molybdenum 7the state in which this metal is usually found7 was analyzed by ,bucholz and found to consist of #fj metal and #dj sulphur4 ,the molybdic acid may be obtained by roasting the sulphuret in a crucible and stirring it frequently2 the sulphur in great part escapes in the form of sulphurous acid and the metal becomes oxidated3 carbonate of soda in solution may be added to the residuum as long as any effervescence is observed2 molybdate of soda remains in solution and the acid may be precipitated by nitric acid4 ,the brown oxide is best obtained by heating molybdate of ammonia to red2 the ammonia and part of the oxygen are expelled1 and the brown oxide remains4 ,there are two views with which the preceding results may be reconciled2 namely1 #ast4 supposing the atom of molybdenum to weigh #ba2 and #b;d1 by supposing it to weigh #db or twice that number4 ,in the first case the brown oxide will weigh #bd 7#di7 being supposed #b atoms of metal and #a of oxygen1 the blue or protoxide will weigh #bh1 and the white oxide or molybdic acid will weigh #fc1 being a compound of the protoxide and deutoxide1 molybdena or native sulphuret will then be as usual1 the protosulphuret1 consisting of #ba metal and #ad sulphur1 or #fj metal and #dj sulphur4 ,in the #b;d4 case the brown or protoxide will weigh #di1 the blue or deutoxide #ef1 and the acid or tritoxide #fc4 ,the native sulphuret1 molybdena1 must in this view be the deutosulphuret1 or #db metal and #bh sulphur4 ,the former of these views exhibits the oxides somewhat complicated1 but agrees well with the sulphuret2 the latter shews the oxides in a more regular train1 but does not appear so probable from the sulphuret2 besides1 the notion of a metallic tritoxide is rather singular1 especially in a metal that is rarely if ever found in combination with oxygen4 ,upon the whole ,i prefer the former view2 but it must be considered as problematical only4 ,the atom of #fj 7see page #bfg ,,vol4 #a7 must doubtless be erroneous4 #bf4 ,oxides of tungsten4 ,from the experiments of ,d',elhuiarts1 ,bucholz#ac and ,berzelius#ad it seems very probable that the tungstic acid is composed of about #ajj metal #be oxygen4 ,it is a yellow powder of the sp4 gr4 #f4ab1 and is best obtained from the native tungstate of lime 7a scarce mineral74 ,one part tungstate of lime and four of carbonate of potash are fused together1 dissolved in water1 and then the tungstic acid may be precipitated by nitric acid4 ,there is an inferior oxide that is black or dark brown2 ,berzelius reduced the yellow oxide to a flea-brown colour1 by sending a current of hydrogen gas through it in a glass tube heated red hot4 #ajj parts of this oxide burnt be #ajg yellow oxide4 ,hence #ajj metal must combine with about #af or #ag oxygen to form this oxide1 which is of that in the yellow or tungstic acid4--,upon the whole it does not seem improbable1 considering the great sp4 gravity of this metal1 that it forms three oxides and that the acid or yellow oxide is the #c;d4 ,hence the atom of tungsten must be #hd1 that of the protoxide #ia1 the deutoxide #ih1 and the tritoxide or tungstic acid #aje4 ,the native tungstate of lime1 if pure1 according to this would be #ha4d acid #ah4f lime1 which is not far from ,klaproth's analysis2 he having found #ah4g lime in one specimen2 nor from that of ,berzelius1 he having found #hj4d tungstic acid and #ai4d lime in #ii4h tungstate of lime4#ae ,footnote #ac3 ,an4 of ,philos4 #f--aih ,footnote #ad3 ,an4 of ,philos4 #c-bdd ,footnote #ae3 ,an4 of ,philos4 #h--bcg ,there is another view however1 which would accord with the experiments and perhaps will be found preferable in other respects2 that is1 to suppose the tungstic acid to be composed of #a atom deutoxide and #a atom protoxide united2 in this case the atom of tungsten #db1 that of the protoxide #di1 that of the deutoxide #ef1 and the tungstic acid #aje as before4 #bg4 ,oxides of titanium4 ,nothing certain is known respecting the oxides of titanium4 ,an observation of ,richter1 quoted by ,berzelius 7,an4 of ,philos4 #c--bea71 if it could be relied upon1 furnishes an important fact1 namely1 that a solution of muriate of titanium containing #hd4d oxide1 gave #aej muriate of silver4 ,now #aej muriate of silver contain #bh acid2 hence #bh acid must have combined with #hd4d oxide2 but if #bh #hd4d #bb #ff nearly for the weight of an atom of the oxide4 ,this would indicate #ei for an atom of the metal4 #bh4 ,oxides of columbium4 ,the white oxide or acid of columbium is found in combination with the oxides of iron and manganese in proportion nearly as #d of the acid to #a of the aggregate oxides4 ,the two minerals1 columbite and tantalite1 though yielding these substances nearly in the same proportions1 are found to differ remarkably in specific gravity1 the former being about #e4i and the latter about #g4i4 ,dr4 ,wollaston concludes however1 from the agreement of the white oxides extracted1 that they must be the same4 ,the white oxide of columbium is insoluble in the mineral acids2 it unites with potash by fusion1 and may be precipitated by most acids4 ,some of the vegetable acids1 the oxalic1 the tartaric1 and the citric dissolve the white oxide4 ,when the alkaline solution of columbium previously neutralized by an acid is treated with infusion of galls1 an orange precipitate is produced which is characteristic of columbium4 ,nothing certain has been determined respecting the proportions of metal and oxygen2 but from the great proportion of the columbic acid found with the oxides of iron and manganese1 together with the great sp4 gravity of the compound1 one may pretty clearly infer the great weight of the atom of columbium4 ,supposing the white oxide or acid to consist of #a atom metal #c oxygen and that the columbite is formed by #a atom of acid to #a of oxide1 we should have #abh acid #cb oxide4 ,this would give #ajg for the weight of an atom of metal1 and #abh for that of the tritoxide or columbic acid2 but it is unnecessary to dwell upon such conjectures4 ,in a recent memoir of ,messrs4 ,gahn1 ,berzelius1 and ,eggertz 7,an4 de ,chimie1 ,octo4 #ahaf71 it is maintained as probable that there is only one oxide of columbium or tantalum1 and that #ajj metal take #e4dhe oxygen1 or #aba metal take #g oxygen4 ,if this be correct1 the atom of columbium must be #aba and the protoxide #abh4 7,see also ,an4 de ,chimie1 #dc--bga2 ,philos4 ,trans4 #ahjb2 ,nichols4 ,journ4 #b--abi2 ibid4 #c--bea2 ibid4 #be--bc74 #bi4 ,oxides of cerium4 ,the mineral cerite is of the sp4 gr4 #d4ec1 and constituted of #ej or #fj per cent4 of oxide of cerium1 with silex1 lime1 and iron4 ,this mineral being calcined and dissolved in nitro-muriatic acid1 the solution is to be neutralized by caustic potash1 and then treated with tartrate of potash4 ,the precipitate1 well washed and afterwards calcined1 is pure oxide of cerium4 ,this oxide1 which is white1 when calcined in the open air becomes red and acquires more oxygen4 ,these oxides1 particularly the white1 are soluble in most acids2 the red oxide with muriatic acid gives oxymuriatic acid4 ,the experiments hitherto made on this subject scarcely enable us to decide respecting the proportions of metal and oxygen1 nor the relative weights of these oxides4 ,both ,vauquelin#af and ,hisinger#ag agree that the protocarbonate of cerium1 when exposed to a red heat1 yields #eg or #eh oxide1 which the former says is the red oxide1 being changed by the calcination4 ,hisinger finds the percarbonate to consist of #cf4b acid and #fc4h oxide3 also that the muriate of cerium consists of #ajj acid and #aig4e oxide2 but ,vauquelin remarks that the sulphate1 nitrate1 and muriate of cerium are always more or less acid1 however dried2 and he found the protoxalate of cerium to yield #de4f red oxide by calcination1 on a mean of #c experiments not much differing from each other4 ,supposing all these facts accurate1 they may be reconciled by a few suppositions by no means improbable4 ,let the atom of cerium be #bb1 the protoxide #bi1 and the red oxide #cb 7that is1 #a oxy4 #b protox4 #fe72 and let the protocarbonate be #a atom of acid1 #a of oxide1 and #a of water2 the percarbonate1 #a acid #a oxide2 the oxalate1 #a acid 7#dj7 and #a oxide2 and the muriate1 saturated with base1 #c oxide and #b acid4 ,then it will be found that1 ,footnote #af3 ,an4 de ,chimie1 #ed--bh ,footnote #ag3 ,an4 of ,philos4--#d--cef ,the decomposed protocarbonate will yield #eg4e red oxide2 ,the decomposed percarbonate will yield1 #cf4g acid1 #fc4c oxide2 ,the decomposed oxalate will yield #dg red oxide2 and ,the muriate will yield #ajj acid 7#bb71 and #aig4g oxide4 ,all of which agree very nearly with the results above obtained4 ,hence it appears to me very probable that the several atoms of the metal and the oxides are as stated above2 and that1 #ajj cerium #ca4h oxygen #aca4h protoxide1 white4 ---------- #dg4g ------ #adg4g intermediate1 red4 ,hisinsger1 from some of the same data united to other hypothetical facts than those assumed above1 deduces the two oxides very different2 viz4 #ajj metal #ag4d oxygen for the protoxide1 and #ajj #bf4a for the peroxide4 ,,section #ad4 ,,earthy1 ,,alkaline ,,and ,,metallic ,,sulphurets4 ,the sulphurets exhibit a very important class of combinations of two elements4 ,many of the metals are found chiefly in the state of native sulphurets1 and are extracted by particular processes4 ,artificial combinations of sulphur and the metals1 and of sulphur and the earths and alkalies are commonly practised1 and are found useful in chemical investigations4 ,the alkaline and earthy sulphurets will scarcely be allowed perhaps to be combinations of two elements only2 but their analogy with the other compounds is such as to induce us to treat of them under this head1 especially as they are agents occasionally in the formation of metallic sulphurets1 and these cannot be so well understood without some knowledge of the other4 ,for like reasons the compounds of three elements1 sulphur1 metal1 and oxygen1 called sulphuretted oxides1 and sulphuretted sulphites1 and those of four elements1 sulphur1 metal1 oxygen and hydrogen1 called hydrosulphurets1 may be considered at the same time1 having an intimate relation with the sulphurets strictly so called1 or the compounds formed with sulphur and the undecompounded bodies4 ,sulphur may be combined with the earths1 alkalies and metals1 by heat1 of various degrees according to the nature of the subjects4 ,the union is attended in many cases with a glowing ignition1 indicating the evolution of heat4 ,the metallic oxides and sulphur when heated together commonly produce a sulphuret of the metal1 whilst the oxygen escapes with part of the redundant sulphur in the form of sulphurous acid1 and the rest of the sulphur sublimes4 ,in the humid way sulphur may be combined with earths1 alkalies1 and metals1 by means of sulphuretted hydrogen1 hydrosulphurets 7that is1 sulphuretted hydrogen united to other alkaline or earthy bases71 and hydroguretted sulphurets 7a name given to certain earthy and alkaline sulphurets formed mostly by boiling mixtures of the respective bases and sulphur in water47 ,the sulphuretted hydrogen may be used in this state of gas or combined with water2 the hydrosulphurets and hydroguretted sulphurets are best applied in their watery solutions4 ,the metals are to be used in this case in the state of salts1 that is1 oxides united to acids1 and in solution2 or their oxides may in some instances be precipitated previously to the addition of the sulphur compound2 the alkalies and earths are sometimes directly sulphurized in the state of hydrates1 and at other times by double affinity1 in the state of salts or combined with acids4 ,the phenomena in the case of sulphurets formed in the humid way1 are various and often complicated1 and the true results are not always to be obtained without considerable difficulty and uncertainty4 #a4 ,sulphurets of lime4 ,when pounded lime and sulphur are mixed together1 and heated in a crucible scarcely any union takes place2 the sulphur sublimes or burns away and leaves the lime unaltered4 ,if for lime we substitute carbonate of lime1 it also remains unaltered4 ,but if hydrate of lime and sulphur are heated together in equal weights1 the hydrate is decomposed1 and the lime unites to a portion of the sulphur1 whilst the excess of sulphur sublimes or burns and escapes at a low red heat4 ,the residue1 about #fj per cent4 of the original weight1 is a yellowish white powder1 composed of sulphur and lime4 ,if this be again treated with sulphur and heated1 it undergoes no material change2 the last sulphur entirely escaping1 leaves the sulphuret unaltered1 and hence shews that it must be a true chemical compound4 ,now if #cb parts hydrate of lime1 which consist of #bd lime and #h water1 be mixed with #cb sulphur and heated as above1 they will yield #ch parts sulphuret1 which must be composed of #bd lime and #ad sulphur1 or sulphur and water2 but it appears from the analysis hereafter to be given1 that the whole of this last part is sulphur2 therefore the compound is formed of #a atom of lime1 and #a of sulphur1 and is the protosulphuret of lime4 ,when #cb parts of common hydrate of lime and #ef sulphur1 are boiled together in #ajjj parts water for half an hour1 or more1 occasionally adding water to supply the waste1 a fine yellow liquid is obtained1 with a few grains of residuum containing both lime and sulphur nearly in the original proportion with a few grains of alumine4 ,this liquid of course contains in solution1 a combination of #a atom of lime1 or perhaps hydrate of lime1 and #d atoms of sulphur2 and may therefore be called a quadrisulphuret of lime4 ,if more sulphur or lime than the above proportion be used1 the surplus will remain in the residuum uncombined1 shewing that by this process no other than a quadrisulphuret can be formed4 ,a similar solution may be obtained in cold water by frequent agitation2 but it is much slower in producing the effect4 ,the strength of liquid quadrisulphuret depends upon the relative quantity of the ingredients4 ,i have boiled it down till the water was only #e times the other materials1 which appears to be its maximum strength in the common temperature2 its specific gravity was #a4adf2 but in general ,i have used it of less than #a4jg density4 ,it may be proper to remark here that ,i find the decimals multiplied by #d express very nearly the number of grains of lime in #ajjj grains measures of the solution1 and multiplied by #i those of the sulphur2 on this account a solution of the sp4 gravity #a4jf facilitates the calculations1 as #ajj measures of it contain #b4d grains of lime1 and #e4d or #e4f of sulphur nearly4 ,it is rather surprising that no bisulphuret nor trisulphuret of lime should be formed this way4 ,one would suppose that the sulphuret of lime in its progressive changes would have passed through the forms of bisulphuret1 c4 till it had obtained its maximum of sulphur when that was in excess2 but1 as has been observed1 the quadrisulphuret is the only one formed1 whatever may be the proportions of the ingredients4 ,i imagine the reason to be1 that the sulphur has to decompose the hydrate of lime1 and that no fewer than #d atoms of sulphur are adequate to that effect2 it is known that water adheres so strongly to lime as to require a red heat to separate it4 ,when therefore we mix lime water with quadrisulphuret of lime1 it must be considered as a mere mixture of the two1 and that the lime does not divide the sulphur equally4 ,consistently with this reasoning1 whenever the lime is in excess in forming quadrisulphuret of lime1 we ought to consider the liquid solution as lime water holding quadrisulphuret of lime4 ,this distinction will be of some importance when the solution is weak1 because then the lime in the lime water will be considerable1 compared with the lime combined with sulphur4 #a4 ,protosulphuret4 ,the properties of this compound are2--about #a grain is soluble in #ajjj water2 this water1 as well as the powder itself1 tastes like the white of an egg2 salts of lead are thrown down black by the solution2 weak nitric and muriatic acids dissolve the lime1 and leave the sulphur2 #ajj parts of test acid require #ai of the powder1 and yield #g of sulphur2 indicating the compound to be #ab lime and #g sulphur4 ,the same conclusion may be obtained by means of a solution of lead2 if water containing #a4i grains of the powder be precipitated by nitrate of lead1 it will require #g grains of the salt #b4b acid and #d4h oxide1 or #d4e lead1 and about #e or #e grains of sulphuret of lead will be formed1 and the liquid will contain #c4d grains of neutral nitrate of lime4 #b4 ,quadrisulphuret4 ,this combination has been long known1 and some of its properties observed2 but ,i have not found in authors any determination of its proportions4 ,it is of a beautiful yellow or orange colour1 and #a grain imparts very sensible colour to #ajjj of water2 it has a disagreeable bitter taste2 when evaporated down1 it crystallizes or rather perhaps solidifies into a yellowish mass2 but its properties are affected by the process from the acquisition of oxygen4 ,this mass when dried1 burns with a blue flame and loses #dj per cent42 the remainder is a white powder1 a mixture of sulphite and protosulphuret of lime4 ,liquid quadrisulphuret exposed to the atmosphere soon becomes covered with a white film which arises from the sulphur displaced by oxygen gas2 this film being broken subsides1 and another is formed1 and so on successively till at length the acquisition of oxygen ceases with the deposition of sulphur1 and the liquid remains quite colourless4 ,it is intensely bitter1 and contains lime1 sulphur and oxygen in proportions to be presently determined4 ,this colourless liquor undergoes a gradual change by being kept for years in a bottle with a common cork2 a deposition of some sulphur and sulphate of lime takes place1 but whether from a further acquisition of oxygen gas or from some internal chemical action1 ,i have not had an opportunity of observing4 ,from the above observations it is obvious that to form pure quadrisulphuret of lime the atmospheric air should be excluded1 as the agitation by ebullition would promote the oxidizement of the compound4 ,i mixed #afh grains of sublimed sulphur with #if hydrate of lime1 which by previous trials ,i had found to consist of #gj lime including #b or #c grains of alumine1 and #bf water2 the mixture was put into a small florence flask1 which was then filled with water up to the neck and loosely corked4 ,this was immersed in a pan of water and boiled for #b or #c hours1 the flask was continually turned round to agitate the mixture and promote the solution4 ,after the undissolved part had subsided the clear liquor was decanted and found to be #bhjj grain measures of the sp4 gr4 #a4jef2 the residuum moderately dried weighed #cd grains2 it was found to contain #h of lime and alumine1 and #be of sulphur4 ,hence the liquid contained #fb lime and #adc sulphur1 or #b4b lime and #e4a sulphur per cent42 that is1 after the rate of #bd lime to #ef sulphur1 or #a atom of lime to #d of sulphur1 and its weight #hj1 the atom of sulphur being supposed #ad4 ,here then we have a synthetic proof of the composition being a quadrisulphuret4 ,innumerable other experiments1 though made with less rigid accuracy1 had convinced me that the liquid is essentially the same whatever the proportions of the ingredients1 and that the residuum only varies in such cases4 ,i have made many experiments occasionally since #ahje1 on the quantities of oxygen absorbed and sulphur deposited by quadrisulphuret of lime4 ,they all concur in establishing the same conclusion2 namely1 that each atom of the compound takes #b of oxygen and deposits #b of sulphur1 in its transformation from the yellow to the colourless state4 ,for instance1 #ajj measures of the above #a4jef took #ijj of oxygen gas #a4bb grains1 and let fall #b grains of sulphur1 besides a small portion which adhered to the bottle1 which was estimated at a few tenths of a grain4 ,the method is to put #ajj measures into a graduated and well stoppered bottle filled with oxygen2 to agitate briskly for half an hour1 occasionally opening the stopper a little under water to admit its entrance into the place of the oxygen absorbed4 ,whenever the agitation has been continued for five minutes without any sensible increase in absorption1 and the liquor1 after standing to let the sulphur subside1 appears colourless1 the experiment is finished4 ,this new combination then consists of #a atom lime1 #b sulphur1 and #b oxygen #ff2 it will be necessary to give it a name3 ,i propose calling it sulphuretted sulphite of lime1 as it is an atom of sulphur united to sulphite of lime2 and the rather1 as it will appear in the sequel that other neutral salts do combine occasionally with an atom of sulphur4 ,this sulphuretted sulphite may be boiled down to the sp4 gr4 #a4a before it precipitates3 the liquid then contains about #ab per cent4 of the salt1 or #e sulphur1 #b oxygen1 and #d lime4 ,the salt precipitates from the liquid by evaporation in the form of a white powder2 it burns with a feeble blue flame1 and loses about #bj per cent42 the remainder is sulphite of lime4 ,when #ajj grain measures of the liquid sulphuretted sulphite 7#a4a7 are saturated with oxymuriate of lime1 they acquire #e grains of oxygen1 and then yield #ab grains of sulphuric acid 7containing #e sulphur and #g oxygen71 as may be found by the barytic tests4 ,the point of saturation is known by the smell of oxymuriatic acid being given out permanently4 ,if however we oxidize the quadrisulphuret of lime by oxymuriate of lime1 the results are somewhat different4 ,as soon as an atom of the quadrisulphuret has received two atoms of oxygen it becomes colourless as before1 but of the sulphur is thrown down instead of 2 and when more oxymuriate is added1 so as to impart #c atoms of oxygen to one of the salt1 a complete sulphate of lime is formed4 ,the point of saturation is determined by adding a small portion of muriatic acid to the liquid1 which develops the oxymuriatic acid as soon as it becomes in excess4 ,this method excels in the analysis of the alkaline and earthy sulphurets in general4 ,when quadrisulphuret of lime is treated with an alkaline carbonate1 a reciprocal change takes place2 the carbonic acid takes the lime1 and the alkali the sulphur1 leaving however #a atom of sulphur with the carbonate which precipitates4 ,hence a sulphuretted carbonate of lime is obtained and a trisulphuret of the alkali4 ,the sulphur burns off from the carbonate below a red heat and leaves #ge per cent4 of carbonate of lime2 this affords an excellent analysis of quadrisulphuret of lime as far as lime is the object4 ,thus #edj of the above #a4jef quadrisulphuret took #ajj test carbonate of potash 7#a4be71 and gave a precipitate of #bi grains1 which burned blue and left #bb grains #ab lime1 and #aj acid2 but if #edj #ab #ajj #b4b1 as above determined synthetically3 moreover1 #ab lime1 #aj acid1 and #g sulphur1 are as #bd lime1 #bj acid1 and #ad sulphur2 the composition of an atom of sulphuretted carbonate of lime1 which is analogous to the sulphuretted sulphite of lime1 as found above4 ,when quadrisulphuret of lime is treated with as much sulphuric acid as is sufficient for the lime1 the sulphur is in part precipitated1 but it is in union with the sulphate of lime1 or at least they are not separable by mechanical means4 ,this compound is sold in the shops under the name of precipitated sulphur4 ,it is about one half sulphate of lime1 and the other half sulphur4 ,the nitric and muriatic acids precipitate the sulphur partially from quadrisulphuret1 but the sulphur assumes a viscid form and exhales sulphuretted hydrogen1 and the proportion of the elements of quadrisulphuret are not easily obtained by any of these acids4 ,the mutual action of quadrisulphuret of lime1 and the metallic salts is curious and interesting2 for instance1 with nitrate of lead4 ,let a solution of nitrate of lead1 containing #ig oxide1 be treated with a solution of quadrisulphuret of lime by degrees1 as long as a black precipitate appears1 marking the exact point of saturation2 this will be found when #cf parts of lime have entered1 and #hd of sulphur2 the sulphuret of lead will fall1 and when dried will weigh #ade parts1 and contain #ij lead1 and #ee sulphur2 that is1 #a atom of lead1 and #d of sulphur1 and is consequently a quadrisulphuret of lead4 ,the liquid remains clear and colourless1 and contains the nitric acid1 lime1 oxygen of the lead1 and of the sulphur2 each atom of nitric acid combines with one of lime1 which retains one of the #d atoms of sulphur1 forming a sulphuretted nitrate of lime1 consisting of #de acid1 #bd lime1 and #ad sulphur2 the #g parts of oxygen unite with #g of sulphur to form sulphurous acid1 which require #ab parts of lime to saturate them and #g of sulphur1 forming a sulphuretted sulphite of lime3 hence we see that #bh parts of sulphur remain in the liquor1 and the rest 7#ef7 unite with the lead4 ,if now we add gradually more nitrate of lead1 a silvery white precipitate appears1 increasing till half the original quantity is added1 and then the liquid is saturated4 ,this white precipitate is sulphuretted sulphite of lead2 when heated it soon grows black and loses #ae or #bj per cent41 being then a protosulphuret of lead4 ,the liquid now contains sulphuretted nitrate and simple nitrate of lime2 nitrate of lead has no effect1 but nitrate of mercury precipitates a black sulphuret4 ,quadrisulphuret of lime saturated with oxygen1 as has been observed1 contains sulphuretted sulphite of lime in solution1 and deposits sulphur3 the liquid treated with nitrate of lead1 gives as above the white1 silvery sulphuretted sulphite of lead as a precipitate1 and holds nitrate of lime in solution4 ,hydrosulphuret of lime4 ,this compound may be formed by passing sulphuretted hydrogen into lime water2 the water assumes a brownish colour1 but the point of saturation is not easily found1 as the lime water is not neutralized so as to shew by the colour test1 and water of itself absorbs above twice its volume of the gas4 ,by means of a neutral solution of nitrate of lead it may be found that #ajjj lime water in volume1 require about #fjj sulphuretted hydrogen1 because then a mutual saturation is observed by double affinity2 that is1 sulphuret of lead and neutral nitrate of lime are formed2 but otherwise the liquid remaining is either acid or alkaline4 ,hydrosulphuret of lime1 as well as the other hydrosulphurets1 has a peculiar bitter taste4 ,it forms a useful reagent in regard to metals1 but is apt to be spoiled by keeping1 owing to the acquisition of oxygen4 #b4 ,sulphuret of magnesia4 ,i have not succeeded in endeavouring to combine sulphur and magnesia in the dry way2 but a liquid sulphuret is easily formed by the action of double affinity4 ,let a quantity of the liquid quadrisulphuret of lime be treated with a solution of sulphate of magnesia1 so that the sulphuric acid may be sufficient for the lime2 by digesting in a moderate heat1 the sulphate of lime is precipitated1 carrying with it one fourth of the sulphur1 and a trisulphuret of magnesia remains in solution4 ,i have not observed any remarkable feature of distinction between this sulphuret and that of lime1 except as above noticed in the proportions of their compounds4 ,hydrosulphuret of magnesia4 ,this compound may be formed by pouring sulphuretted hydrogen water into recently precipitated magnesia2 it does not differ much from that of lime4 ,one atom of sulphuretted hydrogen 7#ae71 combines with one of magnesia 7#ag71 and the compound is soluble in water4 #c4 ,sulphuret of barytes4 ,protosulphuret4 ,the protosulphuret of barytes may be procured the same way as that of lime1 by heating hydrate of barytes and sulphur till the mixture becomes red4 ,it is very little soluble in water1 and accords in other respects with the like compound of lime4 ,it consists of #fh barytes and #ad sulphur1 or #ajj barytes and #bj sulphur4 ,quadrisulphuret4 ,the quadrisulphuret of barytes may be formed the same way as quadrisulphuret of lime1 by boiling the hydrate of barytes and sulphur together4 ,a yellow solution of the compound is formed1 not distinguishable in appearance from that of lime2 and it appears to be analogous to it in most of its properties4 ,by acquiring oxygen it becomes colourless sulphuretted sulphite of barytes1 and crystalizes in needles2 in this last respect it differs from that of lime4 ,the maximum density of liquid quadrisulphuret ,i have not had an opportunity of ascertaining2 it is #a4jg or upwards2 that of the liquid sulphuretted sulphite is much less than that of lime2 the crystals are found in a liquid so low as #a4jjd sp4 gr4 ,they have a fine silky lustre when dry1 and a yellowish colour2 heated they burn with a blue flame and leave a white mass of sulphate preserving the same crystalline appearance as before1 and lose about #bj per cent4 of weight4 ,ten grains of the crystals of sulphuretted sulphite1 when treated with liquid oxymuriate of lime to saturation1 require #b grains of oxygen and yield #h grains of sulphate of barytes1 together with an excess of sulphuric acid which with muriate of barytes gives #h grains more of sulphate4 ,from these facts it may be concluded that the sulphuretted sulphite consists of one atom barytes1 #b sulphur1 #b oxygen1 and #b water1 and that #d more of oxygen are derived from the oxymuriatic acid to convert the sulphurous oxide into sulphuric acid4 ,the sulphuretted sulphite of barytes seems to pass into sulphate by length of time4 ,the weight of the atom of quadrisulphuret of barytes is #abd2 the compound in mass consists of #ajj barytes and #hb sulphur4 ,hydrosulphuret of barytes4 ,this compound may be formed in the same manner as that of lime1 and is found to have similar properties4 ,the proportions for mutual saturation are1 ,i find1 as in the case of lime1 #ae sulphuretted hydrogen to #fh barytes by weight1 or one atom of each4 #d4 ,sulphurets of strontites4 ,the protosulphuret and quadrisulphuret of strontites may be formed in the same way as those of lime and barytes4 ,from a few experiments made on these compounds ,i have not observed any remarkable feature of distinction between them and the corresponding ones of the other earths4 ,hydrosulphuret of strontites4 ,this compound may be formed in the same way as that of lime2 the proportions to produce mutual saturation will be #a atom of each1 or #ae parts sulphuretted hydrogen1 to #df strontites by weight4 #e1 #f1 #g1 #h1 and #i4 ,sulphurets of alumine1 silex1 yttria1 glucine1 and zircone4 ,i made several unsuccessful attempts to combine alumine and sulphur4 ,when alumine and sulphur mixed together are heated1 the sulphur sublimes chiefly1 and leaves the alumine with traces of sulphate of alumine4 ,in the humid way1 recently precipitated and moist alumine mixed with sulphur and boiled in water1 give a liquid with some traces of sulphuric acid1 but no sulphuret of alumine2 the sulphur and alumine both subside1 and when the sulphur is either sublimed or burnt1 the alumine remains much the same as at first4 ,when a solution of alum is treated with sulphuret of lime1 sulphate of lime is precipitated along with the greatest part of the sulphur in a kind of feeble union rather than mechanical mixture1 it should seem2 the alumine is at the same time precipitated probably in mechanical mixture2 there remain in solution a little sulphuret of potash and sulphate of lime4 ,sulphuret of silex is not known1 ,i apprehend1 to exist4 ,when silicated potash in solution is treated with quadrisulphuret of lime1 a copious dark brown or black precipitate instantly appears2 the liquid when filtered is of a pale yellow colour1 and seems to contain about one half of the sulphur and potash1 whilst the other half is thrown down in union with the lime and silex4 ,this black compound is probably #a atom of lime1 #b of sulphur1 #b of potash1 and #b of silex2 it cannot therefore be accounted a sulphuret of silex4 ,sulphurets of yttria1 glucine1 and zircone1 are as yet1 ,i presume1 unknown4 #aj4 ,sulphurets of potash4 ,potash has a strong affinity for sulphur and unites with it in various ways and proportions4 #ast4 ,in the dry way by heat4 ,when either pure potash or the carbonate 7salt of tartar7 is heated in a covered crucible with sulphur1 a chemical union of the two principles takes place4 ,eight parts of dried hydrate of potash unite to six or seven of sulphur3 a heat of #d or #ejj of ,fahrenheit is convenient for the purpose4 ,if the carbonate of potash be used1 then #ab parts dried in a low red heat will require #h of sulphur for their complete saturation3 in this case a higher degree of heat is requisite in order to expel the carbonic acid2 a low red heat seems sufficient from my trials4 ,when the heat does not exceed #c or #djj a partial union takes place2 the carbonate of potash1 without losing any acid1 unites to of the sulphur1 and the rest of the sulphur remains uncombined2 when intermediate degrees of heat are used1 ,i have found the result a mixture of the pure sulphuret and the carbonated sulphuret1 with more or less of sulphate of potash4 ,a high degree of heat and exposure to the atmosphere produces a sulphate instead of a sulphuret4 ,the sulphurets obtained this way are in fusion till poured out and cooled2 they are of a liver colour1 and hence were formerly called livers of sulphur4 ,they are largely soluble in water1 and give a brownish yellow solution4 #b;d4 ,in the humid way by solution4 ,pure caustic potash in solution when boiled with sulphur dissolves it largely1 #db parts of real potash being saturated with about #ef of sulphur4 ,if we boil a solution of carbonate of potash with sulphur1 for an hour or more1 a brown liquor is obtained1 which consists of #fj parts carbonate of potash and #ad sulphur in chemical union4--,it has already been observed that a trisulphuret of potash may be obtained by double affinity from quadrisulphuret of lime and carbonate of potash1 together with sulphuretted carbonate of lime4 ,from what has been stated we may infer at least three varieties in the compounds of sulphur and potash1 viz4 #ast4 ,sulphuretted carbonate of potash4 ,this consists of #a atom carbonate of potash 7#fa7 with #a atom of sulphur 7#ad74 ,its analysis may be effected as follows3 the quantity of carbonic acid may be found by the lime water necessary to saturate it2 the potash may be known from the quantity previously entering into the mixture2 and the sulphur in the same manner1 or from the quantity of sulphuretted carbonate of lead that it forms4--,the sulphur may also be known1 from the quantity of oxygen it requires by means of oxymuriate of lime to produce saturation2 this ,i find to take place when the oxygen is half the weight of the sulphur1 or one atom to one of sulphur2 it soon happens1 that one atom of sulphur deprives two others of their oxygen1 and sulphuric acid is formed whilst the other two atoms of sulphur join the carbonate of lime and are precipitated along with it4 ,as it may frequently happen1 that the sulphuretted carbonate is mixed with common carbonate of potash1 the proportions may be found by means of nitrate of lead1 which being cautiously dropped into the solution1 lets fall first the brown sulphuretted carbonate of lead1 and then the common white carbonate of lead4 ,the sulphuretted carbonate of potash absorbs oxygen and precipitates metals much the same in appearance as the other sulphurets2 but essential distinctions are observable1 some of which are noticed above1 and others will appear in the sequel4 #b and #c4 ,the trisulphuret and quadrisulphuret of potash so nearly resemble the quadrisulphuret of lime in their properties1 as not to require any additional remarks4 ,hydrosulphuret of potash4 ,this combination1 when duly proportioned1 consists of #ae parts sulphuretted hydrogen1 and #db potash by weight1 or one atom of each4 ,it may be formed by directly uniting the two elements1 or by decomposing hydrosulphuret of lime by carbonate of potash4 ,its properties agree with those of the other hydrosulphurets4 #aa4 ,sulphurets of soda4 ,i have repeated most of the experiments on the sulphurization of potash with soda1 and have not found anyone remarkable feature of distinction1 besides those which arise from the weights of the atoms4 #a4 ,sulphuretted carbonate of soda consists of #a atom of carbonate of soda united to #a of sulphur2 or of #dg parts of the former and #ad of the latter4 #b4 ,trisulphuret of soda consists of #a atom soda 7#bh7 and #c of sulphur 7#db74 #c4 ,quadrisulphuret of soda consists of #a atom soda 7#bh7 and #d atoms of sulphur 7#ef74 ,hydrosulphuret of soda4 ,this compound consists of one atom of each of the elements1 or #ae sulphuretted hydrogen1 and #bh soda4 ,in other respects it agrees with hydrosulphuret of potash4 #ab4 ,sulphuret of ammonia4 ,the best way which ,i have found of procuring sulphuret of ammonia1 is to treat quadrisulphuret of lime with the carbonate of ammonia as long as any precipitate takes place2 the precipitate is sulphuretted carbonate of lime1 #c atoms of sulphur to #a of carbonate of lime4 ,the liquid is of a pale yellow1 and contains ammonia and sulphur united in the ratio of #a atom 7of #f7 to #a of sulphur3 it may therefore be denominated the protosulphuret of ammonia4 ,the carbonate of ammonia is best procured by heating the common subcarbonate of ammonia1 first pulverized1 in a temperature of #ajj for half an hour1 or exposing it for a few days to the atmosphere4 ,what remains of the salt is almost without smell2 it should consist of #ai parts acid1 #f ammonia1 and #h water nearly3 the ammonia is usually however a small degree in excess4 ,hydrosulphuret of ammonia4 ,this compound may be formed in the dry state by combining the two gases of sulphuretted hydrogen and ammonia over mercury2 it is of a white crystalline appearance1 and very soluble in water1 and forms a fuming liquor of a very pungent smell4 ,it may also be obtained by passing sulphuretted hydrogen into a vessel containing liquid ammonia4 ,i find about #aaj or #abj measures of sulphuretted hydrogen require #ajj of ammoniacal gas4 ,hence it is #a atom of sulphuretted hydrogen 7#ae71 that unites to #a of ammonia 7#f74 #ac4 ,sulphurets of gold4 ,there exist at least two sulphurets of gold1 the nature and proportions of which are easily ascertained2 though several authors assert that no combinations of gold and sulphur are known2 amongst these it is surprizing to find ,proust3 indeed most of the others have probably been led by his authority to adopt the opinion without examination4 ,it is not very easy to account for his deception4 ,obercampf1 in the ,annal4 de ,chimie1 tom4 #hj4 #ahaa1 is the first author ,i have seen who distinctly maintains the existence of one or more sulphurets of gold1 though it seems to have been admitted previously by ,bucholz4 ,the last author finds #hb gold unite to #ah sulphur1 and the former #hj to #bj nearly4 ,protosulphuret of gold4 ,this compound is formed whenever a solution of muriate of gold is agitated with sulphuretted hydrogen gas1 or with the same united to a base1 as lime or alkali4 ,a black or deep brown powder falls down by the addition of more gas1 till the whole of the gold is precipitated4 ,the oxide of gold loses one atom of oxygen1 and receives one of sulphur in its place1 whilst the hydrogen of the gas is carried off along with the oxygen of the oxide4 ,the sulphuret dried and heated1 burns with a blue flame1 leaving the gold nearly pure4 ,this compound consists1 ,i find1 of #ha gold and #ai sulphur per cent42 or #ajj gold unite to #bc sulphur4 ,trisulphuret of gold4 ,this compound is obtained whenever quadrisulphuret of lime is gradually dropped into a solution of muriate of gold2 it is a black powder1 not quite so deep as the former4 ,care must be taken to saturate the excess of acid previously by lime water1 to prevent any uncombined sulphur precipitating4 ,trisulphuret of gold being heated1 burns with a blue flame1 and leaves the gold nearly pure2 it loses from #aj to #de per cent4 by the process4 ,it is constituted of #a atom gold and #c sulphur1 or #fj gold and #db sulphur1 nearly2 or #ajj gold combine with #gj sulphur4 ,from several experiments ,i am led to conclude that each atom of oxide of gold takes #c of sulphur1 and parts with #a of oxygen to the remaining sulphur2 thus a trisulphuret of gold is formed1 and an oxide of sulphur2 the liquid1 being afterwards treated with oxymuriate of lime1 is found to require twice the oxygen of the gold for its saturation1 when a corresponding portion of sulphuric acid may be precipitated by muriate of barytes4 #ad4 ,sulphuret of platina4 ,sulphur may be combined with platina in several ways1 and probably in different proportions2 but the combination is not so easily and elegantly effected as with many other metals1 and hence some uncertainty still remains on the subject4 ,when a salt of platina is treated with sulphuret or hydrosulphuret of lime1 or sulphuretted hydrogen water1 the liquid slowly and gradually grows dark brown and finally black2 after agitation and standing a few hours1 the liquid is semitransparent1 and a black flocculent precipitate appears at the bottom4 ,sometimes after violent agitation1 the liquid on standing a few minutes becomes a transparent brown1 but soon grows turbid again4 ,in the course of a few days1 and by occasional agitation1 the liquid finally becomes clear and nearly free from platina1 and the precipitate may be collected on a filter and dried4 ,this circumstance of slow and indolent precipitation cannot be prevented by any means ,i have found1 such as saturating the excess of acid1 c4 ,mr4 ,edmund ,davy1 in the #djth ,,vol4 of the ,philos4 ,magazine1 has given us the results of his experiments and observations on the sulphurets of platina1 containing some useful and original information4 ,he combines platina with sulphur by heating the ammonia-muriate of platina with sulphur2 also by heating platina and sulphur in an exhausted tube2 and by sending sulphuretted hydrogen gas or water into a solution of muriate of platina2 this precipitate he calls hydrosulphuret of platina4 ,he has just noticed the precipitate formed by sulphuret of potash with muriate of platina1 but gives no opinion as to the compound obtained this way4 ,he determines three sulphurets1 namely1 ,subsulphuret1 #ajj platina #ai sulphur ,sulphuret1 #ajj ---- #bh4b ---- ,supersulphuret1 #ajj ---- #ch4h ---- ,i have obtained the sulphuret of platina in five ways3 #ast4 ,by pouring sulphuret of lime solution by degrees into muriate of platina1 and agitating the mixture well or till it grew black each time2 after digesting for some days1 repeated filtering1 and drying1 a black powder is obtained3 #b4 ,instead of sulphuret1 hydrosulphuret of lime was used2 the precipitate was obtained under like circumstances3 #c;d4 ,sulphuretted hydrogen water was used1 and the precipitate obtained in like manner3 #dth4 ,ten grains of ammonia-muriate of platina were treated with sulphuretted hydrogen water2 by continued agitation the yellow powder disappeared1 the liquid looked uniformly black1 and at length a precipitate was formed2 by repeated filtration and addition of sulphuretted hydrogen water1 the whole of the platina was thrown down1 and the liquid remained colourless2 but it is difficult to discover the exact quantity of sulphuretted hydrogen requisite for any weight of the ammonia-muriate from the tediousness of the operation2 #f grains of well dried black powder were obtained1 besides perhaps #a grain of loss on the filters3 #eth4 ,ammonia-muriate of platina was heated in a covered crucible along with sulphur till it was judged that all the uncombined sulphur was sublimed or dissipated4 ,all these sulphurets appear to me to be the same when dried in a moderate heat4 ,when exposed to a low red heat they yield water and sulphurous acid1 and lose about of their weight4 ,the subject however1 requires further investigation4 ,the sulphurets of platina appear of a complex nature1 and the proportions of their elements are not yet determined with precision4 #ae4 ,sulphurets of silver4 ,silver combines with sulphur in two different proportions1 and forms two sulphurets1 both of them black or dark brown4 #a4 ,protosulphuret of silver4 ,this may be formed either by the dry or humid way3 if thin lamina of silver be heated with sulphur1 they combine and form this sulphuret2 a higher degree of heat expels the sulphur again4 ,it is formed too by passing sulphuretted hydrogen or a hydrosulphuret through a solution of silver in nitric or other acids4 ,the atom of silver unites with that of sulphur1 whilst the hydrogen unites with the oxygen4 ,of course this compound is composed of #ij silver1 and #ad sulphur1 and the atom weighs #ajd2 or #ajj silver unite with #ae4e sulphur4 ,klaproth finds #ajj silver and #ag4f sulphur2 ,wenzel #ajj silver1 and #ad4g sulphur2 ,berzelius #ajj silver1 and #ad4i sulphur2 and ,vauquelin #ajj silver1 and #ad sulphur4 ,trisulphuret of silver4 ,this compound is formed whenever neutral nitrate of silver is dropped into a solution of quadrisulphuret of lime or alkali4 ,mutual saturation seems to take place when eight atoms of nitrate meet with seven of quadrisulphuret4 ,trisulphuret of silver is constituted of #ij silver1 and #db sulphur2 or of #ajj silver1 and #df4e sulphur4 ,its colour is not so dark as that of the protosulphuret4 ,the residuary liquid contains sulphurous acid1 which is easily converted into sulphuric by the addition of a portion of lime2 and the quantity of acid may then be determined by muriate of barytes4 #af4 ,sulphurets of mercury4 ,mercury combines readily with sulphur both in the dry and humid way1 and that in several proportions1 as under3 namely1 #a4 ,protosulphuret of mercury4 ,this is most conveniently formed by passing sulphuretted hydrogen gas through a solution of the protonitrate of mercury1 or by pouring hydrosulphuret of lime1 c4 into the same solution4 ,the protosulphuret falls down in the state of a black powder4 ,it consists of #afg mercury1 and #ad sulphur2 or of #ajj mercury1 and #h4d sulphur4 ,the theory of its formation is the same as that of silver4 #b4 ,deutosulphuret of mercury4 ,this is formed in the humid way whenever sulphuretted hydrogen or a hydrosulphuret in excess is mixed with the deutonitrate or deutomuriate of mercury 7corrosive sublimate72 a brown powder is precipitated which is the deutosulphuret4 ,if the sulphuretted hydrogen be only one half what is sufficient to form the deutosulphuret1 then we obtain no sulphuret1 but instead of it a protonitrate or protomuriate1 as was first intimated by ,proust2 ,i find however1 the atom of sulphur adheres to the atom of salt1 and that it is therefore a sulphuretted protonitrate or muriate1 whilst #a atom of oxygen unites with the hydrogen4 ,the brown precipitate does not change to yellow1 orange1 and red1 when left undisturbed for a few days1 in my experience2 though this is stated to have been observed by ,mr4 ,accum4 ,notwithstanding the difference in colour1 this deutosulphuret must be the same nearly as the cinnabar and vermillion of commerce1 if ,proust and others are right in their analysis of these articles4 ,the combination of the elements of sulphur and mercury when intended to form cinnabar is made in the dry way by trituration1 and a moderate heat3 the compound1 at first black1 is afterwards sublimed by a duly regulated heat and becomes red4 ,this compound must consist of #ajj mercury and #ag sulphur nearly4 #c4 ,quadrisulphuret of mercury4 ,this compound is formed when a solution of protonitrate of mercury is treated with quadrisulphuret of lime1 added by degrees till the clear liquid no longer gives a dark coloured precipitate4 ,the oxygen of the mercurial salt unites1 it should seem1 to part of the sulphur1 and forms sulphuric acid1 whilst the rest of the sulphur unites to the mercury4 ,this sulphuret is a black or dark brown powder1 and when heated burns with a blue flame4 ,it consists of #ajj mercury1 and #cc or #cd sulphur1 as appears to me from the synthesis4 ,when the insoluble muriate of mercury 7calomel71 is triturated in liquid quadrisulphuret of lime1 it is soon decomposed2 quadrisulphuret of mercury is formed1 with muriate of lime and sulphuric or sulphurous acid4 ,when the soluble muriate 7corrosive sublimate71 has quadrisulphuret of lime dropped into it by degrees2 at first a yellowish white precipitate is obtained1 which increases till it is one half saturated2 after this1 by continually adding more sulphuret1 the precipitate grows darker1 and ends in being quite black4 ,it is at least as high as quadrisulphuret4 ,much sulphurous acid is found in the liquid4 ,the deutonitrate of mercury1 produces a copious yellow precipitate with quadrisulphuret of lime4 ,exposed to the sun1 it grows black in a few minutes on the light side1 but continues yellow on the opposite side of the jar2 at the same time1 an effervescence and disengagement of oxygen gas are observed4 ,finally1 the precipitate becomes the common quadrisulphuret1 and the liquid contains sulphurous and sulphuric acids4 ,the recently precipitated and washed oxides of mercury act upon quadrisulphuret of lime4 ,the black oxide seems to take #d atoms of sulphur and part with its oxygen to another portion of sulphur2 but the red oxide becomes light brown and retains the colour when dried4 ,it seems to take the same sulphur as the black1 but whether it retains any of the oxygen1 ,i have not ascertained4 ,the action is more slow than when the nitrates are used1 and more quadrisulphuret of lime is expedient4 ,mercury and sulphur combine in the dry way by trituration and by heat1 forming a black powder2 but the species of compounds and quantities of the ingredients combining in this mode1 have not been ascertained4 #ag4 ,sulphuret of palladium4 ,berzelius exposed #ae grains of palladium filings mixed with as much sulphur to a heat sufficient to expel the uncombined sulphur4 ,the increase of weight was #bh per cent4 upon the palladium3 when exposed afresh with sulphur to heat1 no addition was made to the weight4 ,vauquelin heated #ajj parts of the triple salt of palladium with an equal weight of sulphur1 and obtained #eb parts of a blueish white sulphuret1 very hard1 and when broken exhibiting brilliant plates in its fracture4 ,he had previously found that #ajj salt contained #dj to #db of metal3 hence #ajj metal combined with from #bd to #cj of sulphur4 ,this agrees nearly with the above results of ,berzelius4 ,a very high degree of heat expels the sulphur and oxidizes the metal2 but a more moderate heat leaves the palladium of a silver white colour and nearly pure4 ,according to this the atom of protosulphuret of palladium must consist of #ej palladium1 and #ad sulphur4 #ah4 ,sulphuret of rhodium4 ,vauquelin found that #d parts of the ammonia-muriate of rhodium 7containing #bh or #bi per cent4 of metal7 being mixed with an equal weight of sulphur1 and heated1 a blueish white button was obtained1 weighing #a4d4 ,hence #ajj metal seem to take #be of sulphur2 and allowing this to be the protosulphuret of rhodium1 the atom must consist of one rhodium #ef1 and one sulphur #ad1 making the whole weight #gj4 #ai4 ,sulphuret of iridium4 ,according to ,vauquelin1 #ajj parts of the ammonia-muriate of iridium heated with as much sulphur1 yield #fj parts of black powder resembling the other metallic sulphurets2 but #ajj parts of the salt were found to yield from #db to #de of metal4 ,now supposing the last number the most correct1 it should seem that #c parts iridium take #a sulphur1 or #ajj take #cc4 ,this being supposed the protosulphuret1 the atom of iridium must be #db1 and that of the sulphuret #ef4 #bj4 ,sulphuret of osmium4 ,it is as yet unknown whether any combination of sulphur and osmium exists4 #ba4 ,sulphurets of copper4 ,copper readily unites with sulphur both in the dry and humid way4 ,when #c parts of copper filings are mixed with #a part of sulphur1 and heat applied1 a brilliant combustion ensues1 which indicates the union of the two bodies4 ,copper leaf burns in the fumes of sulphur1 as ,berzelius has observed1 with great brilliancy4 ,the protosulphuret of copper obtained by these similar methods1 when pulverized1 is black or dark coloured2 it has been analyzed by various authors1 who nearly agree in their results4 ,proust finds #ajj copper unite with #bh sulphur2 ,wenzel1 #ajj copper and #be sulphur2 ,vauquelin1 #ajj copper and #bg sulphur2 and ,berzelius #ajj copper and #be sulphur4 ,if the atom of copper be #ef1 and that of sulphur #ad1 the atom of protosulphuret of copper will be #gj2 which gives just #ajj copper and #be sulphur4 ,the protosulphuret may also be formed in the humid way1 by sending sulphuretted hydrogen gas or a hydrosulphuret into a solution of protomuriate of copper1 or amongst the recently precipitated protoxide of copper4 ,deutosulphuret of copper4 ,this compound is formed whenever sulphuretted hydrogen gas or a hydrosulphuret is sent into a solution of salt containing the deutoxide1 or into the deutoxide just precipitated from any acid4 ,it is a dark brown powder not differing much in appearance from the protosulphuret4 ,it consists of #ajj copper and #ej sulphur2 the weight of the atom is #hd4 ,quadrisulphuret of copper4 ,this compound is formed by mixing quadrisulphuret of lime with a salt of the deutoxide of copper1 and diluting the solution4 ,a light brown precipitate falls immediately1 which is the quadrisulphuret of copper4 ,it burns with a blue flame1 and leaves the protosulphuret4 ,the atom consists of #ef copper and #ef sulphur1 or weighs #aab2 and hence the sulphuret consists of equal parts copper and sulphur4 ,the blue hydrate of copper recently precipitated from a salt of copper and washed1 acts upon quadrisulphuret of lime2 the results1 according to my experience1 is quadrisulphuret of copper1 and the oxygen unites with the sulphur remaining in the liquor4 #bb4 ,sulphurets of iron4 ,sulphur may be united to iron either by the dry or humid way1 and that in various proportions4 ,protosulphuret of iron4 ,this compound may be formed by passing a hydrosulphuret into a solution of the green oxide in any acid4 ,it is a black powder4 ,it may also be formed by rubbing a highly heated bar of iron with a roll of sulphur2 the two unite in a fluid form and soon congeal into a brownish black mass4 ,it is too a natural production1 though not very common2 excellent analyses of it1 as well as of the common pyrites1 were some time ago given by ,mr4 ,hatchett4 7,see ,nicholson's ,journ4 ,,vol4 #aj47 ,the protosulphuret is magnetic in a considerable degree2 it is soluble in acids1 and yields sulphuretted hydrogen4 ,it is proper to notice that the sulphuret of iron is not precipitated from solutions by sulphuretted hydrogen simply or without a base4 ,according to ,mr4 ,hatchett this sulphuret consists of #ajj iron1 and #eg sulphur1 which corresponds with #a atom iron #be1 and #a of sulphur1 #ad1 nearly4 ,deutosulphuret of iron4 ,this is a natural production frequently met with1 and in various forms2 it is called pyrites1 or iron pyrites2 it is a yellowish mineral and often appears when broken1 of a radiated texture1 but sometimes it is crystallized in cubes or dodecahedrons4 ,acids have little effect upon it1 except the nitric1 which when diluted attacks both the sulphur and iron2 much nitrous gas is produced1 the iron is dissolved1 and the sulphur chiefly converted into sulphuric acid4 ,this sulphuret consists1 according to ,proust1 of #ajj iron1 and #ij sulphur1 and with this ,bucholz recently agrees 7,nichols4 #bg--cef72 but ,hatchett makes it #ajj iron1 and #aab sulphur4 ,from an experiment of my own on the radiated pyrites1 ,i found nearly equal parts of iron and sulphur4 ,one atom of iron 7#be17 and two of sulphur 7#bh17 would give #ajj to #aab2 but if the atom of sulphur be only #ac1 it gives #ajj iron to #ajd sulphur4 ,mr4 ,hatchett unfortunately calculating the proportions of the ingredients in #ajj sulphuret1 instead of on #ajj iron1 did not notice that the sulphur in the common pyrites is just double of that in the magnetic pyrites4 ,quinsulphuret of iron4 ,this combination consisting of #e atoms of sulphur with #a of iron1 is formed by mixing a solution of green sulphate of iron with quadrisulphuret of lime in due proportion4 ,i found #ej measures sulphate #a4afh saturate #caj of #a4je sulphuret diluted so as to become #f oz42 this yielded #ad grs4 dried sulphuret of iron #c4f iron1 known to be in the sulphate1 and #aj4d sulphur2 the liquid contained #b sulphur combined with the lime and oxygen of the oxide2 for it took #b4c oxygen by means of oxymuriate of lime to convert the sulphur into sulphuric acid together with #a from the oxide1 making #c oxygen1 which unites to #b sulphur to constitute #e sulphuric acid2 and this quantity of acid was found to exist by muriate of barytes together with five more brought in by the sulphate of iron4 ,this sulphuret is a yellowish brown powder2 it readily exhales sulphur by heat and is reduced to the protosulphuret2 but in the open air it burns with a blue flame and leaves the protosulphuret partially1 as ,i apprehend1 oxidized4 ,the theory of the formation of quinsulphuret seems to be this3 #c atoms of quadrisulphuret of lime are requisite to saturate #b of sulphate of iron2 the #b atoms of sulphuric acid seize #b of lime1 three fourths of the sulphur unite to the iron1 and one fourth to its oxygen1 forming #b atoms of oxide of sulphur1 which attack the #c;d atom of sulphuret and decompose it1 giving its sulphur to the iron1 and neutralizing the lime 7for the liquid is found neutral74 ,in this way #aj atoms of sulphur are united to #b of iron1 and #b of sulphur to #b of oxygen1 with one of lime1 which last compound remains in solution1 and the oxide of sulphur may be converted into sulphuric acid immediately by the application of oxymuriate of lime4 ,it is remarkable that neither the green nor the yellow oxides of iron1 even when recently precipitated and not dried1 seems capable of decomposing quadrisulphuret of lime4 ,it is probable that trisulphuret and quadrisulphuret of iron may be formed2 but ,i have not ascertained the truth of this opinion4 #bc4 ,sulphurets of nickel4 ,protosulphuret4 ,according to ,proust1 nickel unites to sulphur by heat1 so that #ajj take #df or #dh2 the sulphuret is of the colour of common pyrites4 7,journ4 de ,physique1 #fc and #hj74 ,according to ,mr4 ,ed4 ,davy #ajj nickel take #ed sulphur4 ,by saturating a solution of nitrate of nickel with hydrosulphuret of lime ,i obtained #dj grains from #cc protoxide or #bf metal4 ,this was evidently the protosulphuret2 it was a fine black powder1 and consists of #ajj metal and #ed sulphur4 ,quinsulphuret4 ,this compound may be obtained from nitrate of nickel and quadrisulphuret of lime1 in the same manner as that of iron4 ,it is a deep black powder1 and consists of #ajj nickel1 and #bae sulphur4 ,by exposure to heat1 the greatest part of the sulphur burns off1 and the rest may be expelled by an increase of temperature4 ,probably intermediate sulphurets may be formed2 but ,i have not pursued the investigation4 #bd4 ,sulphurets of tin4 ,sulphur and tin unite both in the dry and humid way1 and in various proportions4 ,protosulphuret4 ,this may be readily formed in the dry way as follows2 let #ajj grains of tin be fused in a small iron ladle and heated to #f or #h hundred degrees ,fahrenheit2 let then small pieces of sulphur of #aj or #bj grains be successively dropped into the fused metal3 a copious blue flame will instantly arise each time1 and a glowing heat will take place1 when the sulphur and tin are in contact2 as soon as this ceases1 another fragment of sulphur must be dropped in1 and this two or three times repeated1 heating it at last to a perfect red2 the mass may then be taken out and pounded in a mortar2 a great part of it will be a pulverulent powder1 but some portions of malleable metal will still be mixed with it1 which may be separated by a sieve4 ,this must be again heated and treated with sulphur as before1 and the whole mass will be converted to a sulphuret4 ,i find that #ajj parts of tin become in this way #abg grains2 which is the due proportion of #eb tin and #ad sulphur1 so that no loss of tin is sustained by the process when duly managed4 ,according to ,wenzel1 #ajj tin take #ah sulphur2 ,bergman1 #be2 ,pelletier1 #ae to #bj2 ,proust1 #bj2 but ,dr4 ,john ,davy and ,berzelius find nearly #bg as above stated1 and ,i have no doubt it is near the truth4 ,the protosulphuret of tin is a dark grey shining powder1 with a streak like molybdena or plumbago2 it is not much different in colour and appearance from native sulphuret of antimony1 only less blue4 ,it is soluble in muriatic acid by heat1 and yields sulphuretted hydrogen and protomuriate of tin4 ,deutosulphuret4 ,this compound is better known than the former3 it may be formed in various ways2 one is by heating a mixture of deutoxide of tin and sulphur in a retort almost to a red heat2 sulphur sublimes and sulphurous acid is disengaged1 and there remains a yellow1 light shining1 flaky mass at the bottom of the retort which is the sulphuret4 ,it was formerly called aurum musivum or mosaic gold4 ,pelletier and ,proust were of opinion that this product is a sulphuretted oxide of tin2 but ,dr4 ,john ,davy and ,berzelius have rendered it more probable that it is a true deutosulphuret1 consisting of #ajj tin and #ed sulphur4 ,it is insoluble in muriatic or nitric acid1 but slowly soluble by the compound of the two acids2 it is also soluble in potash by heat4 ,by exposing it to a bright red heat1 it burns with a blue flame and leaves a yellowish powder which dues not seem to differ much from protosulphuret4 ,berzelius distilled a mixture of protosulphuret and sulphur at a low red heat1 and obtained a mass of a yellow grey colour and metallic lustre1 which consisted of #ajj tin1 and #ad sulphur1 which is just the mean sulphur between the other two4 ,this would seem to indicate that a compound of the two sulphurets1 #a atom to #a1 is capable of being formed4 ,hydrosulphuret of tin minor4 ,this compound is formed according to ,proust1 when sulphuretted hydrogen1 or an alkaline or earthy hydrosulphuret is passed into a solution of protomuriate of tin4 ,it is of a brown or dark coffee colour when precipitated1 and black when dried4 ,by heat it yields water and protosulphuret4 ,from some experiments ,i am inclined to believe1 that it is formed of #a atom protosulphuret and #a of water3 or1 which is the same1 #a atom protoxide of tin and #a of sulphuretted hydrogen4 ,if this be right it may be said to be a compound of #ajj tin1 #bg sulphur and #ae water4 ,hydrosulphuret of tin major4 ,this name is given by ,proust to the yellow compound thrown down by sulphuretted hydrogen or by hydrosulphurets from solutions of the deutoxide of tin4 ,when dried moderately1 the precipitate is of a dull yellow colour1 and vitreous fracture1 but ,i find it is almost black1 dried in a heat of #aej or upwards4 ,by moderate heat it yields water1 sulphurous acid1 sulphur1 and the residue is deutosulphuret of tin according to ,proust4 ,i heated #d parts of the above previously dried so as to become a black vitreous powder2 it burned feebly with a blue flame1 and after being made moderately red1 left nearly #c parts exactly resembling the artificial protosulphuret4 ,i believe the dried precipitate will be found to be constituted of #a atom tin1 #b sulphur and #a water2 that is1 #ajj tin1 #ed sulphur and #ae water #afi by weight2 and that it loses #bg sulphur and #ae water by a red heat1 which reduces the weight just one fourth4 ,quinsulphuret of tin4 ,this is obtained in the humid way1 by first precipitating the oxide1 and then putting quadrisulphuret of lime or potash to the liquid containing the precipitate1 till the liquid after agitation and subsidence of the precipitate continues of a yellowish colour4 ,i found that #ca measures of protomuriate of tin of #a4cgg #g grains acid1 #g4e tin and #a oxygen1 precipitated by #aj oz4 lime water1 required #dej measures of #a4dj sulphuret of lime1 containing #af sulphur and #g4b lime1 for their saturation4 ,the residuary liquid was nearly colourless1 and the precipitate dried in an oven of #ajj or more1 for #aj hours1 weighed #ag grains besides loss in the operation4 ,it was a yellow1 vitreous mass1 and when pulverized and heated1 burned with a blue flame1 and lost #dj per cent4 in weight2 the residue was a yellow grey colour1 and seemed to be like the intermediate sulphuret of ,berzelius2 it would not give sulphuretted hydrogen by hot muriatic acid4 ,now if #eb 7#a atom tin7 #gj 7#e atoms sulphur7 #g4e tin #aj sulphur2 hence the sulphuret should have weighed #ag4e grains1 which was the observed weight1 allowing grain for loss4 ,according to this1 #ajj tin combine with #ace sulphur1 and when burnt1 the #bce are reduced to #adj1 the weight observed by ,berzelius in the instance alluded to4 ,the liquid required #e grains of oxygen from oxymuriate of lime1 to convert the sulphur into sulphuric acid1 and the weight of this acid1 found by muriate of barytes1 was #aa grains1 indicating #d4d sulphur4 ,it may be observed that the #d4d grains1 and #aj grains1 do not make up the whole 7#af7 of the sulphuret of lime2 but the reason ,i apprehend was1 that the quadrisulphuret was old1 and did not contain the full share of sulphur1 it being usual for a small part to fall by time4 ,the deutomuriate of tin1 precipitating the oxide in like manner1 yielded a sulphuret rather lighter yellow than the above2 about #aj tin gave #be grains of sulphuret dried in a temperature of #hj to #ajj4 ,this compound still contained water1 and ,i suspect it will be found constituted of #a atom tin1 #e sulphur1 and #b water4 #be4 ,sulphurets of lead4 ,lead combines with sulphur in various proportions1 some of which are natural productions of great purity4 ,protosulphuret4 ,this is a natural production which is called galena2 it is of lead grey colour and metallic appearance1 and is found both in masses and crystallized2 its sp4 gr4 is about #g4e4 ,it may be formed artificially by heating lead or its oxide with sulphur2 also by treating a solution of lead with sulphuretted hydrogen or with a hydrosulphuret4 ,authors are well agreed as to the proportions of the ingredients2 #ajj lead combine with from #ae to #af sulphur4 ,that is1 #ij lead with #ad sulphur2 or #a atom of lead with #a of sulphur4 ,deutosulphuret4 ,dr4 ,thomson mentions a natural production or species of galena which contains twice the quantity of sulphur of that above4 ,i have reason to believe that this compound is easily formed in the humid way1 by treating the precipitated oxide with the due quantity of quadrisulphuret of lime4 ,trisulphuret and quadrisulphuret4 ,these compounds1 ,i find1 may be formed by means of quadrisulphuret of lime or potash4 ,when a solution of any salt of lead or the recently precipitated and moist oxide1 is treated with the requisite quantity of quadrisulphuret of lime1 a combination consisting of #a atom of lead and #c of sulphur is formed4 ,it is a black powder not differing much in appearance from the protosulphuret2 it is lighter and more spongy4 ,it consists of #ajj lead and #df or #dg sulphur4 ,the due proportions of the elements to form the above compound are1 lead #ajj parts in solution1 and sulphur1 #fb parts2 of the sulphur is retained by the lime1 and may be converted into sulphuric acid instantly by the addition of as much oxymuriate of lime as contains oxygen equal in weight to the sulphur1 as it has already as much oxygen as converts it into sulphurous oxide1 derived from the oxide of lead4 ,quadrisulphuret of lead is to be obtained in the same way2 only we must have an excess of the sulphuret of lime1 or more than #hj sulphur for #ajj lead in solution1 as part of the sulphur at least is retained by the lime4 ,the quadrisulphuret is a black powder like the others2 it burns with a blue flame and loses nearly #dj per cent41 the residue being still black4 ,it consists of #ajj lead and #fb sulphur4 ,i have not ascertained whether any higher sulphuret of lead is capable of being formed this way4 ,it has been already noticed 7page #aji71 that a beautiful white1 silvery sulphuretted sulphite of lead is formed and gradually precipitated1 when nitrate of lead is dropped into a solution where as much black quadrisulphuret of lead has been just thrown down as the sulphuret of lime can form4 #bf4 ,sulphurets of zinc4 ,zinc and sulphur are scarcely to be united directly by heat2 but by heating the oxide of zinc and sulphur together1 a combination is effected2 part of the sulphur carries off the oxygen in sulphurous acid1 and part combines with the zinc4 ,mineralogists give the name of blende to a mineral which is chiefly the protosulphuret of zinc3 its colour is yellowish1 brown1 or black almost like galena3 its specific gravity is usually #c4i or #d4 ,protosulphuret4 ,the above artificial compound1 or the mineral1 may be taken as examples of the union of #a atom zinc and #a sulphur4 ,but the most correct and convenient way of forming it for the purpose of chemical investigation is1 to drop a given portion of some salt of zinc into a dilute hydrosulphuret4 ,a white precipitate falls1 which when dried becomes a dark cream colour4 ,it is found to consist of #b parts zinc and #a of sulphur nearly2 that is1 of #bi parts zinc and #ad sulphur4 ,deutosulphuret1 trisulphuret1 c4 of zinc4 ,these combinations may be made1 up to the #eth or quinsulphuret1 in the humid way by quadrisulphuret of lime1 c4 ,the oxide may be first precipitated by lime water1 or not1 as we please1 and then treated with quadrisulphuret according to the degree of sulphuration required4 ,i found #ajj measures of #a4bi nitrate of zinc with #bejj of #a4jbf sulphuret of lime yield #dj grs4 dry sulphuret zinc1 of a yellowish white colour2 the liquid was found to retain #ac or #ad grains of sulphur1 by converting it into sulphuric acid by means of oxymuriate of lime4 ,the nitrate contained #aa zinc and #b4h oxygen2 so that about #bh sulphur had combined with the zinc1 and about #ad remained in solution1 or of the whole1 as has been already explained4 ,by proportion1 if #aa #bh #bi #gj2 or #a atom of zinc 7#bi7 combines with #e atoms of sulphur 7#gj74 ,the intermediate combinations ,i have not particularly examined2 they do not differ much in appearance from the one just described2 they burn blue and are reduced by it to the protosulphuret2 and they give sulphuretted hydrogen by muriatic acid4 #bg and #bh4 ,sulphurets of potassium and sodium4 ,according to ,davy and ,gay ,lussac1 potassium and sodium unite with sulphur by heat with vivid combustion4 ,the compounds appear to be protosulphurets1 that of potash being nearly as #ce potassium to #ad sulphur1 and that of sodium as #ba sodium to #ad sulphur4 ,when potassium and sodium are heated along with sulphuretted hydrogen1 an union likewise takes place2 two atoms of gas unite to one of the metals1 except that #a atom of hydrogen is liberated1 corresponding of course in quantity to that liberated by treating them with water4 ,when the compound thus formed is treated with muriatic or sulphuric acid1 the same quantity of sulphuretted hydrogen nearly is liberated that was originally combined4 ,so that the compound may be regarded as sulphuretted hydrogen united to the protosulphurets4 ,the colour of these sulphurets varies from grey to yellow or reddish4 #bi4 ,sulphurets of bismuth4 ,protosulphuret4 ,bismuth combines with sulphur by heat1 in the manner already described in the account of tin sulphurets4 ,i found #ajj parts bismuth in this way combine with #bb sulphur after #d operations3 this is therefore the protosulphuret or #a atom bismuth 7#fb7 with #a of sulphur 7#ad74 ,it may also be formed by substituting the oxide of bismuth for the metal4 ,it has a dark brown or black metallic appearance1 much like that of tin4 ,it yields sulphuretted hydrogen in heated muriatic acid4 ,hydrosulphuret of bismuth4 ,when a solution of bismuth in nitro-muriatic acid is dropped into hydrosulphuret of lime1 a black powder precipitates1 which1 when dried in the common temperature1 appears to be hydrosulphuret of bismuth1 or one atom sulphuretted hydrogen and one oxide of bismuth4 ,it yields sulphuretted hydrogen by cold muriatic acid4 ,but if the precipitate be dried in a heat of about #bjj1 the atom of water seems to be expelled1 and there remains only the protosulphuret4 ,thus ,i found #fi parts oxide of bismuth unite to #ae sulphuretted hydrogen to form #hd hydrosulphuret of bismuth1 when dried in the air2 but upon being heated a little1 it lost #h parts of water and was reduced to the protosulphuret1 retaining in great part the same appearance as before4 ,deutosulphuret and trisulphuret of bismuth with oxygen4 ,when nitro-muriate of bismuth is thrown into water the oxide is precipitated2 if the acid water be decanted1 quadrisulphuret of lime be put to the moist oxide and due agitation be used1 the oxide abstracts sulphur from the lime so as to obtain #b or #c atoms for each one1 if the sulphur be sufficient in quantity4 ,to #f oz4 water ,i put #ajj grain measures of #a4bhf nitro-muriate1 which ,i knew from its formation contained #bj oxide2 after the precipitate had subsided ,i poured off #e oz4 of acid water1 and to the remaining precipitate diluted with water ,i put #cjj of #a4jef sulphuret of lime and agitated for #aj minutes4 ,there were obtained #cc grains of brownish black sulphuret of bismuth dried for some hours in a temperature of #abj4 ,i put the above #cc grains into a gas bottle with #ajj muriatic acid and boiled it2 there were obtained only #b or #c cubic inches of sulphuretted hydrogen1 the oxide was dissolved and sulphur liberated2 the sulphur collected and dried weighed #i grains1 and the oxide precipitated again from the muriatic acid by water and dried1 weighed #ag grains1 besides loss4 ,from this it is evident the oxygen of the oxide must have been chiefly retained in the compound1 and must have united to #b1 and in great part to #c1 atoms of sulphur4 ,for #bj oxide would require #ab sulphur to form trisulphuretted oxide2 and there was evidence of its having nearly1 if not wholly1 that quantity4 #cj4 ,sulphurets of antimony4 ,protosulphuret4 ,this is a natural production1 and found in the state of a dark grey mineral of metallic appearance1 and of the sp4 gr4 #d4b4 ,it may also be formed artificially by uniting metallic antimony and sulphur by heat4 ,most authors nearly concur in assigning to it #gd parts antimony and #bf sulphur1 per cent4 ,that is1 #a atom antimony 7#dj7 and #a of sulphur 7#ad74 ,it yields sulphuretted hydrogen by muriatic acid and heat1 and a solution of the metallic oxide is obtained4 ,hydrosulphuret4 ,when antimony is precipitated from a solution1 by sulphuretted hydrogen or a hydrosulphuret1 or from an alkaline solution of the sulphuret by an acid1 it appears in the form of an orange yellow powder1 denominated golden sulphuret4 ,it is constituted of #a atom sulphuretted hydrogen and #a of protoxide of antimony2 it readily yields sulphuretted hydrogen by muriatic acid1 and the oxide combines with this acid4 ,exposed to heat1 water is expelled and protosulphuret left4 ,it is constituted of #dj antimony1 #g oxygen1 #ad sulphur and #a hydrogen2 or of #ed protosulphuret and #h water4 ,bisulphuretted1 trisulphuretted and quadrisulphuretted oxide of antimony4 ,when crystallized muriate of antimony is agitated along with dilute quadrisulphuret of lime1 an orange yellow compound is formed1 consisting of the oxide and sulphur4 ,to #cej quadrisulphuret of lime1 diluted with lime water1 ,i put #bb grains moist crystals of muriate1 and agitated well for some time4 ,got #bf grains dry yellow sulphuret1 which heated burned blue1 and left from #ac to #ad black grey sulphuret1 equal to #aj antimony nearly2 hence it must have been a quadrisulphuret1 or rather sulphuretted oxide2 for1 by heating this compound in muriatic acid1 a solution is obtained and sulphur liberated without the extrication of gas4 ,less of the sulphuret of lime would have produced a sulphuret of the same colour1 but containing less of sulphur2 so that it is evident various proportions may exist in combination4 ,instead of the crystallized muriate1 the recently precipitated oxide1 nearly free from acid1 may be used to produce these compounds4 #ca4 ,sulphuret of tellurium4 ,tellurium unites with nearly its weight of sulphur1 by heat1 according to ,davy4 ,it is probable that as usual in such cases1 a protosulphuret is formed4 ,this would lead to the conclusion that the atom of tellurium is only equal in weight to that of sulphur2 which does not accord with results from the other combinations of tellurium1 and hence the above fact may not perhaps be sufficiently ascertained4 #cb4 ,sulphurets of arsenic4 ,arsenic may be combined with sulphur by exposing a mixture of the metal and sulphur or of the white oxide and sulphur1 to a heat approaching to redness4 ,in the latter case more sulphur is required1 because the oxygen is carried off in the shape of sulphurous acid4 ,three parts of arsenic with two1 three or more of sulphur may be used2 the heat should be less if a greater proportion of sulphur is intended to be united4 ,as both the elements are volatile in a moderate heat1 and that in unequal degrees1 considerable difficulty occurs in ascertaining by the synthetic mode1 the proportions of the elements combined2 if too little heat be used1 only a mechanical mixture is obtained1 of any proportions we please2 if too much heat be used1 part of the arsenic as well as part of the sulphur sublimes1 and the sulphuret itself sublimes at a heat not much exceeding that required for their union4 ,hence in a great measure we have the discordant results of those who have taken the synthetic method4 ,the analytic method is to be preferred1 and those who have taken it have succeeded the best2 but even this is attended with greater difficulties than with most of the other sulphurets4 ,the artificial sulphurets of arsenic constitute two varieties chiefly1 and these are also found native in various parts of the earth4 ,protosulphuret4 ,native sulphuret of arsenic1 called orpiment1 is found in ,turkey and elsewhere in considerable masses2 when broken it exhibits a foliated structure1 somewhat flexible1 and of a brilliant golden yellow colour4 ,its specific gravity is usually about #c4b2 at least that was the case with the specimen ,i used4 ,when heated so as to be near melting1 its surface reddens1 probably by the loss of sulphur4 ,the same sulphuret is procured artificially in the humid way whenever a solution of the oxide of arsenic in water1 c4 is treated with sulphuretted hydrogen1 or a hydrosulphuret1 and afterwards with an acid2 or when this or any other species of sulphuret of arsenic is dissolved in an alkali and the solution treated with an acid4 ,kirwan in #agif states1 that it is generally thought to consist of #ajj arsenic and #aa sulphur1 but that ,westrumb says it contains #ajj arsenic and #djj sulphur1 which ,kirwan thinks more probable2 they are both however very wide of the truth4 ,thenard1 in the #ei ,,vol4 of the ,an4 de ,chimie1 #ahjf1 asserts that it consists of #ajj arsenic and #ge sulphur2 but he does not point out the experiments on which this result rests2 and it is not very near the truth4 ,laugier in the same ,an4 ,,vol4 #he1 for #ahac1 in a paper of great merit1 finds the native orpiment to contain #ch per cent4 of sulphur2 his method is to dissolve the orpiment in warm dilute nitric acid2 to precipitate the sulphuric acid by nitrate of barytes1 and from the sulphate of barytes infer the sulphur2 the rest he considers as arsenic1 not knowing how to detach the arsenic acid from the nitric acid so as to determine the arsenic by experiment4 ,i have pursued this method with the advantage of being able to determine the arsenic as well as the sulphur3 ,ten grains of orpiment in fine powder were dissolved in #ajj measures of #a4cdf nitric acid diluted with as much water1 by digesting in a heat so as to keep a constant moderate effervescence for about #b hours4 ,the liquid obtained1 being diluted1 yielded #ecf measures of #a4jfa4 ,by carefully and gradually dropping in muriate of barytes ,i found #aej measures of #a4afb just sufficient to saturate the sulphuric acid1 and the sulphate of barytes produced dry was #bh grains1 the loss ,i estimated #a grain3 now one third part being sulphuric acid1 and of the acid being sulphur1 we have _/ of #bi #c4hg1 or #c4i for sulphur4 ,the residuary liquid was then treated with lime water till an excess was manifest1 and produced no farther precipitate2 the arseniate of lime was collected and dried1 and gave #af grains4 ,now ,i had determined by experiments hereafter to be related1 that _/ of arseniate of lime are acid and of the acid are arsenic2 hence _/ of #af #f4a for the arsenic1 which added to #c4i sulphur1 make up the #aj grains of orpiment4 ,when this orpiment is treated with caustic alkali1 it is completely dissolved2 it is thrown down by acids ,i find unaltered4 ,if #fa arsenic combine with #ci sulphur1 #ajj must take #fd nearly2 which corresponds with #a atom of each1 or #ba arsenic #ac or #ad sulphur4 ,subprotosulphuret4 ,sulphur and arsenic are found native in certain places1 combined in masses of a brownish red or orange colour and glassy fracture3 this combination is called realgar1 and is also manufactured in large quantities in ,saxony1 chiefly for the use of calico-printers4 ,its constitution and specific gravity vary considerably1 owing chiefly ,i imagine to the greater or less heat to which it is exposed1 and to the proportions of the elements in the first mixture4 ,i have specimens of #c4c and #c4g sp4 gr42 and it is probable these are not the extremes2 the heaviest is the darkest colour4 ,of course the heaviest contains the most arsenic1 and ,i have reason to believe that the sp4 gr4 is nearly as good a test of the proportions of the elements as chemical analysis4 ,realga when pulverized is of an orange colour3 it is much sooner dissolved in dilute nitric acid and requires less1 than the same weight of orpiment4 ,caustic alkali dissolves it partially1 taking up the protosulphuret and leaving the excess of arsenic1 the quantity of which may hence be ascertained4 ,ten grains of realgar took #hj measures of #a4cdg nitric acid1 diluted with as much water2 digested in a heat of about #aej it was all dissolved in #a hour1 and yielded #ecf liquid of #a4je sp4 gravity4 ,this treated as before gave #bd sulphate of barytes #c4b sulphur1 and #ah arseniate of lime #f4i arsenic4 ,this result agrees nearly with ,laugier's in regard to the sulphur in native realgar3 but the artificial realgar1 which he made by combining arsenic and sulphur1 yielded him #dj per cent4 sulphur by my estimation and #db by his own3 the sp4 gravity of his artificial realgar is not given4 ,westrumb estimates realgar at #ajj arsenic and #be sulphur1 and ,thenard at #ajj arsenic and #cc sulphur4 ,but from the above it must be concluded to contain #ajj arsenic and #de to #ej of sulphur4 ,one hundred parts of the same realgar heated in caustic potash were resolved into #gh orpiment taken up by the liquid and #bb arsenic precipitated4 ,it appears to me most probable that a true subsulphuret would be most convenient for the printers' use1 or one containing #ajj arsenic and #cb sulphur1 that is1 #b atoms arsenic and #a sulphur4 ,the object being to deoxidize indigo and obtain it in solution in a green state1 we may suppose that #a atom arsenic takes the oxygen from the indigo and then forms arseniate of lime which precipitates1 whilst the other atom in union with the sulphur1 takes the green indigo and unites it to the potash1 making a quadruple compound of arsenic1 sulphur1 green indigo and potash in solution4 ,if this view be right the heaviest and darkest coloured realgar of commerce must be the most advantageous for this purpose4 ,some printers however prefer the protosulphuret4 ,deutosulphuret4 ,proust1 by heating #ajj arsenic with #cjj sulphur in one instance got #bbb parts1 and in another #bcd parts of a transparent deep greenish yellow sulphuret1 7,jour4 de ,phys4 #ei--p4 #djf4 #ahjd74 ,now it is very remarkable that if we take the atom of sulphur at #ac and that of arsenic #ba1 one of this and two of the former will be found as #ajj to #abd1 together #bbd2 but if sulphur be #ad1 then the proportion will be #ajj to #acc1 together #bcc4 ,it seems more than probable that ,proust had accidentally used that degree of heat in the combination which is requisite for forming the deutosulphuret4 ,it is probable too that ,laugier always used a higher heat1 as he uniformly obtained the same 7lower7 sulphuret whatever were the proportions1 the excess of either being sublimed or separated by the heat4 ,trisulphuret1 quadrisulphuret1 c4 ,when a solution of the oxide of arsenic is treated with quadrisulphuret of lime1 little precipitate appears2 but if muriatic acid be dropped in1 a fine yellow precipitate is formed4 ,this ,i have reason to think is sometimes a trisulphuret1 and at other times a quadrisulphuret or higher2 but it is difficult to investigate these compounds1 and on that account ,i speak with some uncertainty4 #cc4 ,sulphuret of cobalt4 ,sulphuretted hydrogen does not precipitate cobalt from solutions containing that metal2 but hydrosulphurets precipitate it4 ,protosulphuret4 ,this compound is obtained whenever a neutral solution of cobalt is treated with hydrosulphuret of lime1 c4 or it may be obtained from any acid solution by first precipitating the blue oxide by an alkali1 and then introducing sulphuretted hydrogen into the mixture4 ,by this last method ,i found a solution previously known to contain #dd parts by weight of protoxide to absorb #ae parts of sulphuretted hydrogen2 when filtered and dried in a heat of #ajj it yielded #ea parts of protosulphuret4 ,in appearance it resembles many of the other black sulphurets4 ,it consists of #ajj cobalt and #ch sulphur2 ,proust finds #dj sulphur1 but he considers it only an approximation4 ,the same sulphuret may be formed by heating the oxides of cobalt and sulphur together to a red heat2 at least a combination is effected as ,proust observed1 but ,i have not investigated the proportions4 ,sulphur does not seem to combine with the metal in this way4 ,deutosulphuret 444 dodecasulphuret4 ,when the recently precipitated and moist oxide of cobalt1 the neutral muriate1 or acid muriate of cobalt1 as well as other salts of the same1 are treated with dilute quadrisulphuret of lime1 sulphurets of cobalt are formed in various proportions according to the ingredients1 from the deutosulphuret to the dodecasulphuret3 these precipitates are all black and not easily distinguished in appearance2 but there is reason to believe they are true chemical compounds4 #cd4 ,sulphurets of manganese4 ,though sulphur and manganese do not unite directly1 they can be brought into union by intermediate bodies1 both in the dry and humid way4 ,protosulphuret4 ,this compound may be formed by heating to a low red1 a mixture of the oxide of manganese and sulphur1 or of the white carbonate of manganese and sulphur2 or it may be formed by treating a solution of manganese by a hydrosulphuret1 7sulphuretted hydrogen not producing any precipitate72 this last method seems to produce a dry hydrosulphuret of manganese1 which being heated to red nearly1 parts with water and a little sulphur and there remains the protosulphuret4 ,the protosulphuret is of a snuff brown colour2 but the hydrosulphuret1 when recently precipitated is of a light drab colour1 which grows deeper when exposed to the air1 and when dried becomes brown like the protosulphuret2 when heated1 the colour is not much changed4 ,the hydrosulphuret of manganese gives sulphuretted hydrogen by cold muriatic acid1 and the protosulphuret gives the same by the acid heated4 ,the proportion of the elements in the protosulphuret may be inferred from the fact that the black oxide yields its own weight of protosulphuret2 that is1 #aef grains1 composed of #ajj metal and #ef oxygen give #aef of sulphuret2 hence the atom of metal1 #be1 unites with one of sulphur1 #ad4 ,i found #cb of the protoxide in solution unite to #ae of sulphuretted hydrogen to form #dg hydrosulphuret dried in #ajj4 ,this lost about #h parts or rather upwards by heat4 ,deutosulphuret1 trisulphuret and quadrisulphuret4 ,these may be formed by treating neutral solutions of manganese1 or the recently precipitated oxide1 by quadrisulphuret of lime4 ,they are formed somewhat slowly and by considerable agitation with a smaller or greater proportion of the lime sulphuret4 ,they are all light drab1 and are reduced to the protosulphuret by heat4 #ce4 ,sulphuret of chromium4 ,i have not had an opportunity of ascertaining whether chromium or its oxides combine with sulphur or not1 though several attempts were made for that purpose4 #cf4 ,sulphuret of uranium4 ,from the experiments of ,bucholz it would seem that uranium may be combined with sulphur1 but the proportions have not been ascertained4 7,an4 de ,chimie4 #ef--adb47 #cg4 ,sulphuret of molybdenum4 ,from ,bucholz and ,klaproth's analyses of molybdena it would seem that the native sulphuret consists of #fj metal and #dj sulphur2 but it does not appear whether this should be considered as the protosulphuret or the deutosulphuret4 ,if it is the protosulphuret the atom of molybdenum weighs #ba1 but if the deutosulphuret1 the atom of metal weighs #db2 and the atom of the sulphuret or molybdena must weigh either #ce or #gj4 #ch4 ,sulphuret of tungsten4 ,according to ,berzelius1 a sulphuret of tungsten may be obtained1 by heating a mixture of tungstic acid and sulphuret of mercury in the proportion of #a to #d1 in a crucible4 ,the mixture in his experiment was covered with charcoal and the crucible inclosed in another containing charcoal2 the whole was then exposed to the heat of a furnace for half an hour4 ,the sulphuret obtained was a greyish black powder2 it was found to consist of #ajj metal and #cc sulphur1 or about #c metal to #a sulphur4 ,hence this must be the deutosulphuret if we consider the atom of tungsten to be #hd2 but considering the high degree of heat to which it was exposed1 it would seem more likely to be the protosulphuret2 if so1 the atom of tungsten must be considered as #db only1 or half of the other number4 #ci4 ,sulphuret of titanium4 ,no compound of titanium and sulphur has been formed4 #dj4 ,sulphuret of columbium4 ,this combination is unknown4 #da4 ,sulphuret of cerium4 ,this combination is also unknown4 ,,section #ae4 ,,earthy1 ,,alkaline1 ,,metallic ,,and ,,other ,,phosphurets4 ,phosphorus like sulphur is capable of being combined with several of the earths and metals as well as with other bodies2 but the combination is not so easily effected1 and the products are less interesting than those of sulphur3 from considerations of these circumstances together with those of the expence and danger in making experiments on phosphorus we may account for1 this class of bodies being as yet imperfectly known4 ,margraf in #agdj attempted to combine phosphorus with many of the metals2 but his experiments were mostly unsuccessful4 ,gengembre in #aghc endeavoured to unite phosphorus with the alkalies2 in this he failed of success1 but discovered the phosphuret of hydrogen1 or the spontaneously inflammable gas now denominated phosphuretted hydrogen4 7,journal de ,physique1 #aghe47 ,in #aghf ,mr4 ,kirwan published some experiments on phosphuretted hydrogen1 7,philos4 ,trans472 he ascertained that water impregnated with this gas had the property of precipitating various metals from their solutions4 ,the ingenious and indefatigable ,pelletier has more merit than any other person in his investigations of the phosphurets4 ,an important memoir of his on the manufacture of phosphorus in the large1 is given in the ,journal de ,physique for #aghe2 in this he states that #d or #e lbs4 sulphuric acid are commonly requisite for #f lbs4 calcined bones2 and that from #ah lbs4 calcined bones he obtained by the usual process1 #ab oz4 of phosphorus4 ,in #aghh he read an essay on the phosphurets of gold1 platina1 silver1 copper1 iron1 lead and tin4 7,an4 de ,chimie1 #a--ajf74 ,in #agij he published an essay on the combinations of phosphorus with sulphur4 7,ibid4 #d--a74 ,an additional memoir was published in #agib on the same metallic phosphurets2 and another on the phosphurets of mercury1 zinc1 bismuth1 antimony1 cobalt1 nickel1 manganese1 arsenic and the other metals4 ,m4 ,raymond in the ,an4 de ,chimie1 #agia1 recommends1 instead of potash1 moist hydrate of lime and phosphorus in order to obtain phosphuretted hydrogen with greater facility2 and in the same ,annals for #ahjj he asserts that water absorbs a considerable portion of phosphuretted hydrogen1 and becomes capable of precipitating metals from their solutions in acids1 and of forming phosphurets1 in this respect resembling sulphuretted hydrogen4 ,mr4 ,tennant discovered in #agia that carbonic acid combined with the earths and alkalies is capable of decomposition by phosphorus1 in a red heat2 and ,dr4 ,pearson1 following up the discovery1 found that pure or caustic lime may be united to phosphorus by heat so as to form phosphuret of lime2 and that this dry compound when put into water is decomposed and gives out bubbles of phosphuretted hydrogen gas1 which as usual explode spontaneously on reaching the surface of the water and coming into contact with the air4 ,in #ahaj ,i published the method of analysing phosphuretted hydrogen by ,volta's eudiometer2 having found that this gas and oxygen may be mixed together in a narrow tube without explosion and afterwards exploded as other similar mixtures by an electric spark4 ,dr4 ,thomson published an essay on phosphuretted hydrogen in the ,annals of ,philosophy for ,august1 #ahaf4 ,he agrees with me very nearly as to the constitution and properties of this gas1 as far as ,i have gone2 but he has ascertained several additional properties of the gas1 which ,i shall advert to in the sequel4 ,sir ,h4 ,davy and ,gay ,lussac have investigated several compounds of phosphorus1 particularly with muriatic and oxymuriatic acids1 and with the new metals potassium and sodium1 which ,i shall have to notice in their proper places4 ,other authors have written on phosphurets besides those ,i have mentioned1 but they do not require to be particularly distinguished in this enumeration4 ,we shall therefore proceed to describe the phosphurets more particularly4 #a4 ,phosphuret of hydrogen4 ,from recent experiments which ,i have made on phosphuretted hydrogen gas1 ,i find the account already given 7,,vol4 #a4 page #def7 is deficient1 and in several respects inaccurate2 ,i shall therefore substitute the following1 as more perfect and correct4 ,phosphuretted hydrogen may be obtained nearly pure1 by the methods recommended by ,dr4 ,thomson4 ,phosphuret of lime that has been carefully secluded from the atmosphere1 may be put into a small phial filled with water1 acidulated by muriatic acid2 into this a cork with a bent tube must be immediately put under water1 so that the phial and tube are both full of water2 gas soon begins to appear1 which rising to the top of the phial1 expels a corresponding portion of water1 and in due time the gas itself comes over and may be received as usual3 if the phial in which the gas is generated be warmed to #adj or #aej1 the gas is given out more readily4 ,a half ounce phial with #bj grains of phosphuret in small lumps1 will produce #c or #d cubic inches of gas4 ,if the phosphuret of lime has been previously exposed for a few hours to the atmosphere1 the gas is more abundant1 but consists chiefly of hydrogen1 mixed with a little phosphuretted hydrogen4 ,pure phosphuretted hydrogen is distinguished by the following properties3 #a4 ,it explodes when coming into the atmosphere in bubbles1 and a white ring of smoke subsequently ascends3 #b4 ,it is unfit for respiration1 and for supporting combustion3 #c4 ,its specific gravity is #a4a nearly1 that of atmospheric air being unity3 #d4 ,water absorbs fully of its bulk of this gas1 which is expelled again by ebullition or by agitation with other gases1 but not without some loss3 #e4 ,a small portion being electrified for some time1 deposits abundance of phosphorus1 and expands from one volume to #a nearly1 which is found to be pure hydrogen3 #f4 ,liquid oxymuriate of lime absorbs phosphuretted hydrogen1 converting it into phosphoric acid and water1 and leaves any free hydrogen that may be present2 hence we are enabled to ascertain the proportion of free hydrogen in any such mixture1 an important point as far as regards this gas3 #g4 ,one volume of pure phosphuretted hydrogen1 requires two volumes of oxygen for its complete combustion by an electric spark1 in ,volta's eudiometer2 7the gases must be previously mixed in a tube not more than _/ of an inch in diameter1 to prevent an explosion in the act of mixing1 after which they may safely be transferred into any other vessel72 the result of the combustion is phosphoric acid and water3 #h4 ,one volume of phosphuretted hydrogen1 mixed with from #b to #f volumes of nitrous gas1 may be exploded by electricity in ,volta's eudiometer2 or it may be exploded by sending up a bubble of oxygen1 without electricity2 in like manner1 may the mixtures of phosphuretted hydrogen and oxygen be exploded by a bubble of nitrous gas3 #i4 ,one volume of phosphuretted hydrogen1 mixed with #d1 less or more1 of nitrous oxide1 is also explosive by electricity1 but the mixture undergoes no change without electricity1 at least in a day3 #aj4 ,mixtures of phosphuretted hydrogen and nitrous gas have a slow chemical action1 by which in from #a to #ab hours1 the phosphuretted hydrogen is burnt and the nitrous gas decomposed into nitrous oxide and azotic gas3 #aa4 ,according to ,sir ,h4 ,davy and ,dr4 ,thomson1 phosphuretted hydrogen gas being heated along with sulphur in a dry tube1 the gas is decomposed and a new gas1 sulphuretted hydrogen1 is formed1 and the phosphorus unites with the sulphur4 ,davy says the gas is doubled in volume by this operation2 but ,thomson says it remains the same2 some doubt therefore exists respecting this fact3 #ab4 ,when phosphuretted hydrogen gas is let up to oxymuriatic acid gas1 a quick combustion with a yellow flame is observed1 and the result varies according to the proportions3 when one volume phosphuretted hydrogen is put to #c or #d of acid gas1 both of the gases disappear1 and muriatic and phosphoric acids are produced4 ,as these properties differ in many respects from those hitherto assigned to this gas1 it will be necessary to enlarge upon them4 ,the sp4 gr4 of this gas has already been adverted to1 7,,vol4 #a471 and its great variation from 4#c to 4#he2 more recently ,dr4 ,thomson finds it about 4#i4 ,in all these instances it was1 ,i have no doubt1 contaminated with less or more of hydrogen2 at least it was so in my own instance2 for1 ,i have the proportion of oxygen which it required for its complete combustion1 both before and after it was weighed4 ,it was what ,i then thought pure gas3 that is1 #ajj volumes required nearly #aej of oxygen2 but ,i am now convinced that gas of this description contains of its volume of free hydrogen2 hence the correction of the sp4 gravity4 ,davy estimates the sp4 gr4 of the gas which he denominates hydrophosphoric at 4#hg or #ab times that of hydrogen2 this gas1 as will appear from this and other properties1 is in all probability phosphuretted hydrogen gas1 nearly pure4 ,the absorption of this gas by water1 has been stated variously4 ,in #agii ,m4 ,raymond found that water absorbs rather less than of its volume of this gas3 in #ahjb1 ,dr4 ,henry rates its absorption at _/ only2 in #ahaj ,i found it _/2 in #ahab1 ,davy found it 7hydrophosphoric gas7 to be 2 in #ahaf1 ,dr4 ,thomson found it to be _/2 ,i now estimate it as stated above at 4 ,these enormous differences may be partly accounted for by varieties in the gas2 and partly from the theory of the absorption not being understood2 but these are scarcely sufficient excuses in all the cases4 ,i find that my early experiments on the absorption of phosphuretted hydrogen by water1 were made prior to the discovery of the method of analysing the gas by electric combustion2 consequently they were deficient in regard to the quality of the gas1 both before and after agitation2 the best gas that ever ,i had1 was such as took #aej oxygen per cent4 for its combustion1 exclusive of any common air2 and it was often such as to require considerably less4 ,the bottle which ,i used for the purpose in #ahaj contains #bgjj grains of water2 at first ,i charged water with hydrogen3 into this #abj grain measures of phosphuretted hydrogen were put1 and the whole well agitated3 there were left #ih measures2--this proved that the gas was more absorbable than hydrogen3 into the same water were put #ih more phosphuretted hydrogen and agitated2 out1 #hj2 this confirmed the proof3 ,into the same water were put #ig hydrogen and agitated well2 out #aje3 ,this shewed that the hydrogen had expelled a part of the gas again1 and was less absorbable of the two4 ,as the phenomena were much the same as if oxygen had been used instead of phosphuretted hydrogen1 it was concluded to have the same absorbability4 ,in the present instance1 however1 ,i have been more circumstantial2 after repeatedly agitating water with pure azotic gas1 so as to saturate it and expel the oxygen1 ,i then put in #aaj grain measures of phosphuretted hydrogen composed of #ajj pure gas1 #e hydrogen1 and #e azotic gas or rather atmospheric air4 ,after due agitation1 all was absorbed but #ce2 this was mixed with a known portion of oxygen and exploded2 the diminution was #ai measures2 the oxygen remaining was determined by hydrogen2 from which it appeared that #aj combustible gas had taken #i oxygen4 ,now #aj being _/ of #ce1 we may consider the water as _/ impregnated with the phosphuretted hydrogen1 and _/ with azote2 but as there were #aje combustible gas and only #aj left1 #ie must have entered the water and caused it to be _/ charged with the gas2 whence we may infer that #ccb gas would have been a full charge for #bgjj water1 which is almost exactly 1 as stated above4 ,other experiments gave corresponding results4 ,on admitting #ea azotic gas to the water1 and agitating it a good deal for #d or #e minutes1 there came out #ea measures or the same volume3 this was found in the same way to consist of #dc azote and #h combustible1 which took #aj oxygen4 ,again #ea azote was agitated in the water1 and there came out #ea1 of which #e were combustible and took #i oxygen4 ,after this the bottle of water was put into a pan of water which was raised to the boiling heat1 a bent tube filled with water being adapted to the water bottle1 and having its end immersed in water3 by this operation gas was expelled from the water1 and caught in the neck of the bottle2 when it amounted to #bb grain measures it was transferred and was found to consist of #ag azote #e combustible1 which took #aj oxygen4 ,by these experiments we see that the gas is expelled again from the water1 both by ebullition and by other gases1 nearly the same in quality1 but much diminished in quantity1 the reason of which is not very obvious4 ,the liquid now required #cj measures of oxymuriate of lime1 equivalent to #ajj measures of oxygen1 before it was saturated2 that is1 there appeared to be #ej phosphuretted hydrogen remaining in the water4 ,adding a little lime water threw down a very sensible quantity of phosphate of lime4 ,the expansion of phosphuretted hydrogen by electricity is a subject on which there has been as much diversity as on its absorption4 ,in #agig1 ,dr4 ,henry found that it expanded 8equally with carbonated hydrogen40 7,philos4 ,trans474 ,in #ahjj1 ,davy states that phosphuretted hydrogen was not altered in volume by electricity4 7,researches1 page #cjc47 ,in #ahaj1 my experiments led me to adopt the same conclusion4 ,in #ahaa1 ,gay ,lussac found 7,recherches1 page #bad71 that potassium heated in phosphuretted hydrogen gas1 expanded #ajj volumes to #adf2 he infers that the true expansion ought to have been to #aej4 ,in #ahab1 ,davy observes1 that when electric sparks are passed through gases of this kind1 8usually there is no change of volume40 7,elements of ,chem4 ,philos4 p4 #bid47 ,but he adds that when a gas 7sp4 gr4 #f1 hyd4 being #a7 was heated with zinc filings over mercury1 there was an expansion of volume of more than 4 ,also potassium heated in it1 made #b parts become #c or #c1 parts rather more than #d1 7#ahaj72 the residual gas in these cases was pure hydrogen4 ,hydrophosphoric gas 7sp4 gr4 #ab7 yielded #b volumes of hydrogen1 by heating potassium in it4 ,in #ahaf1 ,dr4 ,thomson found that by electric sparks phosphorus was deposited1 and hydrogen remained 8exactly equal to the original bulk of the phosphuretted hydrogen40 ,lastly1 in #ahag1 ,i found by two experiments1 that by electrifying #cj grain measures of phosphuretted hydrogen in a tube over water1 uninterruptedly for nearly #b hours1 ,i produced an expansion of 1 or the gas became #cf measures2 originally the gas contained #b common air1 and the rest was combustible so that #ajj measures took #aij oxygen4 ,by exploding the residue with oxygen1 ,i found that _/ or _/ of the phosphuretted hydrogen still remained undecomposed4 ,taking these observations into consideration along with the fact1 that #a volume of the purest gas requires #b of oxygen for its combustion1 ,i conclude that the true expansion should be 1 or #c volumes of gas should become #d1 and then it will be found that of the oxygen is joined to the hydrogen and to the phosphorus1 which accords with what appears to me the only correct view of the constitution of phosphoric acid1 namely1 #b atoms of oxygen to #a of phosphorus4 ,the action of oxymuriatic acid1 whether free or combined1 on phosphuretted hydrogen1 is curious and interesting2 in both cases it effects a complete and instantaneous combustion of both phosphorus and hydrogen2 when the acid is put to in the state of gas1 it not only burns the phosphuretted hydrogen1 but any free hydrogen that may be present2 but this has a limit3 if the phosphuretted hydrogen be largely diluted 7#ij per cent47 with hydrogen1 this last is wholly left2 the reason seems to be1 the phosphuretted hydrogen burns at a lower temperature2 and hence probably it is1 that liquid oxymuriate of lime burns the phosphuretted hydrogen1 but not the hydrogen gas4 ,the quantity of oxygen necessary to saturate a given volume of phosphuretted hydrogen is easily found4 ,oxygen gas containing a known per centage of azotic gas1 must be used in some excess1 mixed with a due portion of the gas4 ,after exploding the mixture1 the loss must be observed1 and then the remaining oxygen must be found by exploding it with hydrogen4 ,hence the true volume of oxygen spent by the first explosion1 and that of the combustible gas are both determined4 ,the due proportion of oxygen is so nearly #b to #a1 that ,i have not been able to determine on which side the truth lies4 ,dr4 ,thomson says that when phosphuretted hydrogen and oxygen are mixed1 two volumes to one1 a white smoke takes place1 the volume of oxygen gradually disappears1 and there remains behind a quantity of hydrogen exactly equal to the original volume of the phosphuretted hydrogen4 ,i have observed nothing at all like this4 ,a mixture of phosphuretted hydrogen and oxygen stood #bd hours without sensible diminution1 and afterwards being exploded1 #b volumes of oxygen disappeared for #a of phosphuretted hydrogen1 the same as would have done at the moment of mixing4 ,perhaps the temperature may have some influence2 mine was about #ee4 ,i have tried the minimum of oxygen that will consume or dissipate phosphuretted hydrogen gas4 ,it may be exploded with about of its volume of oxygen1 with the same phenomena as ,davy observed of the hydrophosphoric gas4 ,phosphorus is thrown down and a volume of combustible gas is left about #aj per cent4 greater than the original volume of phosphuretted hydrogen4 ,this gas is nearly pure hydrogen4 ,hence the whole gas may be dissipated at #b successive explosions1 by rather less than an equal volume of oxygen4 ,if phosphuretted hydrogen be exploded with an equal volume of oxygen1 phosphorous acid1 water and a little phosphoric acid are formed1 and some hydrogen remains4 ,one of the most remarkable properties of phosphuretted hydrogen1 is that announced by ,dr4 ,thomson1 namely1 its combustion with nitrous gas by electricity2 and the slow combustion by the same gas1 which ,i have mentioned above is a fact still more difficult to explain4 ,i tried the combustion of phosphuretted hydrogen by nitrous gas and electricity in #ahaj1 but did not succeed4 ,the reason was1 the gas was not sufficiently pure4 ,no phosphuretted hydrogen that is not #gj or #hj per cent4 pure1 can1 ,i imagine1 be exploded by nitrous gas2 even the purest requires sometimes more than one spark1 when mixed in the most favourable proportions2 and ,i have known instances in which the mixture has exploded after electrification for a few minutes4 ,an excess or defect of nitrous gas1 occasions oxygen or hydrogen to be found in the residual gas1 just as when we explode with oxygen4 ,one volume of phosphuretted hydrogen requires1 as nearly as ,i can find1 #c of nitrous gas for mutual saturation4 ,the azote developed amounts to #a volumes or rather less1 7due allowances in all such cases being made for that already existing in the two gases47 ,the mutual action of nitrous gas and phosphuretted hydrogen without electricity exhibits one of the most singular phenomena we have in chemistry4 ,nitrous gas seems constantly to be decomposed1 one part producing nitrous oxide and another part azote1 even though an excess of nitrous gas remain undecomposed in the mixture1 and both the phosphorus and hydrogen are completely burnt2 but if the nitrous gas be deficient1 then nitrous oxide1 azote1 and some of the phosphuretted hydrogen are found in the residue1 and the rest of the phosphuretted hydrogen is completely burnt or converted into phosphoric acid and water2 here appears no preference of phosphorus to hydrogen in this case1 nor any partial combustion4 ,from an attentive consideration of the results of several experiments1 ,i am inclined to offer the following solution of this remarkable case3 ,one atom of phosphuretted hydrogen attacks #e of nitrous gas at the same instant2 the atom of phosphorus takes #b of oxygen1 and gives the corresponding #b of azote to the two of nitrous gas1 and thus makes two atoms of nitrous oxide1 while the hydrogen takes #a of oxygen from the fifth atom and liberates the azote2 thus #b measures of nitrous oxide are formed along with #a of azote2 and they are generally found in the residue in that ratio4 ,the azote does not seem to pass through the intermediate state of nitrous oxide2 for1 as soon as the nitrous gas ceases to exist1 there is an end of the combustion4 ,it may be proper to advert more particularly to the hydrophosphoric gas of ,davy4 ,that this gas is the same as that we have been describing1 can hardly admit of a doubt4 ,their near agreement in sp4 gr41 in their absorbability by water1 in the quantity of oxygen requisite for their combustion1 in their moderate expansion by burning with a minimum of oxygen and in their combustibility by oxymuriatic acid1 are circumstances sufficient to warrant their identity4 ,it is said that by heating potassium in this gas1 one volume yields two of hydrogen2 but it has not been found to yield two volumes by electricity1 the more accurate criterion4 ,besides1 both ,davy and ,gay ,lussac find that potassium heated in the more common phosphuretted hydrogen expands it from #a to #a or #a volume1 which common electricity will not do2 it is presumed therefore that the potassium in some way conduces to the production of a portion of the hydrogen4 ,spontaneous ignition or explosion is1 ,i believe1 no distinctive mark of variety in phosphuretted hydrogen2 when this gas is produced1 it is usually explosive from the uncombined phosphorus which it elevates2 but the best and purest phosphuretted hydrogen loses the property wholly or partially by standing a while over water1 though it loses no sensible part of its phosphorus4 ,it is commonly stated that phosphuretted hydrogen deposits phosphorus by long standing4 ,this seems to be true2 but the deposition is slower than ,i imagined4 ,seven years ago ,i set aside a bottle of impure phosphuretted hydrogen which ,i then labeled1 #aj combustible take #ad4f oxygen2 this bottle has not been preserved with special care to seclude the atmosphere2 notwithstanding that1 it is now such1 that #aj combustible take #f4g oxygen1 and hence it still contains some genuine phosphuretted hydrogen4 #b and #c4 ,phosphurets of carbone and sulphur4 ,see ,,vol4 #a4 page #dfd4 #d4 ,phosphuret of lime4 ,this compound may be formed by subliming phosphorus in a glass tube containing small fragments of recently calcined lime1 heated to a low red4 ,the sublimed phosphorus coming into contact with the hot lime1 the two unite with a vivid glow1 and in due time mutual saturation is produced4 ,the result is a dry1 hard compound of a deep brown or reddish colour1 which on cooling must be put into a bottle and well corked1 if not intended for immediate use1 as it soon changes by the action of atmospheric air and moisture4 ,with this precaution1 ,i have reason to think it may be kept unimpaired for years4 ,as far as ,i know1 no experiments have been published relating to the proportion in which phosphorus and lime unite4 ,m4 ,dulong1 in a valuable paper on the combinations of phosphorus and oxygen1 in the ,memoires de la ,socit d',arcueil1 ,,vol4 #c4 7#ahag17 has given some account of his experiments on the earthy phosphurets2 but it is to be regretted that he has given none on the proportions of their elements4 ,in order to ascertain the phosphorus1 ,i put #aj grains of well preserved phosphuret of lime1 into #ajjj grains of liquid oxymuriate of lime1 such that by previous trials ,i knew would impart #c4e grains of oxygen2 to this mixture a quantity of muriatic acid was put1 sufficient to engage the lime2 the phosphuretted hydrogen disengaged1 was of course made to pass through the liquid as it was generated1 and became oxidized1 so as to lose its gaseous form2 the surplus gas was prevented from escaping by an inclination of the bottle2 it was #de grain measures only1 and of this #cj were found to be pure hydrogen1 and the rest atmospheric air detached from the water2 these #cj measures were the free hydrogen1 which would have been mixed with the phosphuretted hydrogen1 in the ordinary way4 ,in due time1 the whole of the phosphuret of lime was dissolved4 ,the liquid was strongly acid1 and manifested no smell of oxymuriatic acid1 a proof that it was all decomposed4 ,to this were added #gj more of the oxymuriate of lime before the smell of it was permanently developed4 ,the liquid was next saturated with lime water1 and the phosphate of lime carefully collected and dried2 when heated to a low red it weighed #ab grains1 and consisted1 according to my estimate of this compound1 of #f-- grains of phosphoric acid and #f grains of lime4 ,the #f-- grains of acid contained #b4d phosphorus and #c4e of oxygen4 ,it must be remembered that #aj grains of phosphuret yield about #ejj measures of phosphuretted hydrogen1 and these contain #fej measures of hydrogen1 which last is also oxidized at the expence of the oxymuriatic acid2 but then there is an equivalent of oxygen from the water1 so that this does not influence the calculation for oxygen4 ,there appears then to be only an excess of 4#bd grains of oxygen unaccounted for1 7arising from the additional #gj of oxymuriate of lime71 which is as little as can be expected in such an experiment4 ,if the phosphorus amount to #bd per cent4 we may reasonably infer that the remainder 7#gf7 is mostly lime1 though ,i have not been able to detect above #fj4 ,now if an atom of phosphorus weigh #i and one of lime #bd1 the due proportion of the protophosphuret of lime would be #bh phosphorus and #gb lime2 but when the article is made for sale1 it is more likely to find a defect than an excess of phosphorus4 ,according to ,dulong1 when the earthy phosphurets are decomposed by water1 phosphuretted hydrogen and subphosphorous acid are formed4 ,i believe this determination is right2 for ,i find at most only of the above proportion of phosphorus in the phosphuretted hydrogen yielded by #aj grains of the phosphuret of lime2 the remaining seem to rest in the liquid in combination with the oxygen and lime2 that is1 #a atom of hydrogen combines with #a of phosphorus1 and #a of oxygen with #b of phosphorus4 ,notwithstanding this1 the phosphoric acid produced from the residue by means of oxymuriate of lime1 does not in general correspond to the above quantity4 ,perhaps this loss may be owing to the phosphorus carried over in mechanical suspension by the gas4 ,m4 ,dulong observes1 that even the earthy subphosphites are very soluble2 this did not appear to me to be the case with that of lime3 #aj grains of phosphate of lime1 that had been exposed for #bj minutes to the air1 were put into a gas bottle filled with #djj grains of water2 this was kept at nearly the boiling heat for an hour1 when #gbe grain measures of gas were produced1 and some phosphorus was carried over with it into the receiving bottle and bason of water4 ,the gas being analysed1 was found to consist of #fb per cent4 phosphuretted hydrogen1 #cc hydrogen and #e common air4 ,the #djj grains of water in the gas bottle treated with oxymuriate of lime1 and then with lime water1 scarcely gave any appreciable quantity of phosphate of lime4 ,the insoluble residue when dried yielded #i grains4 ,this dissolved in muriatic acid left a fraction of a grain of dirty yellow powder1 which indicated some phosphorus2 and the muriate of lime indicated about #f grains of lime4 #e4 ,phosphuret of barytes4 ,the combination of phosphorus and barytes may be effected in the same way as the foregoing1 and the compound has the same appearance4 ,according to ,dulong1 who has examined this phosphuret with particular attention1 it gives out phosphuretted hydrogen when dropped into water1 the same as that of lime4 ,when the gas ceases to be given out1 a powder remains completely insoluble in water1 of a variable colour1 yellow1 grey or brown4 ,it is not altered by the air2 but it gives out a slight phosphoric flame when heated4 ,dilute nitric or muriatic acid1 dissolves nearly the whole with a trace of phosphuretted hydrogen1 and leaves only a few atoms of greenish yellow powder1 soluble in oxymuriatic acid4 ,the part dissolved by the acids being precipitated by ammonia1 gives phosphate of barytes4 ,from these facts he infers that the residue insoluble in water1 consists of a small portion of phosphuret of barytes with excess of base1 and phosphate of barytes4 ,the water in which the phosphuret was decomposed1 contains most of the barytes2 carbonic acid produces a slight precipitate1 and then leaves a neutral liquid containing the subphosphate of barytes1 which appears to be a very soluble salt4 ,sulphuric acid throws down the barytes and leaves the subphosphorous acid in the liquid4 ,nothing certain is determined from experiment respecting the proportion of phosphorus and barytes which combine2 but from analogy it is probable that they combine atom to atom1 or #fh parts barytes with #i of phosphorus2 or #ajj parts of the compound contain #hh of barytes and #ab of phosphorus4 #f4 ,phosphuret of strontites4 ,phosphuret of strontites may be formed as the two preceding articles4 ,it is in all respects similar to the phosphuret of barytes according to ,dulong1 and its properties therefore need not be particularized4 ,from analogy1 ,i should apprehend1 it must be constituted of #df strontites and #i phosphorus1 or one atom of strontites to one of phosphorus2 that is1 #ajj parts of phosphuret should contain #hc strontites and #ag phosphorus4 ,combinations of the other earths and phosphorus have not yet been effected4 ,neither have the alkalies been combined with phosphorus2 the hydrates of these as well as those of the earths1 yield phosphuretted hydrogen when heated with phosphorus1 and probably a phosphate or subphosphate of the base4 ,m4 ,sementini of ,rome is said to have succeeded in combining potash and phosphorus by means of alcohol4 ,his experiments1 however1 appear to me too indefinite to warrant the conclusion4 7,see ,an4 of ,philos4--#g4 p4 #bhj74 ,the compounds of phosphorus with potassium and sodium are described in the sequel1 amongst the metallic phosphurets4 #g4 ,phosphuret of gold4 ,m4 ,pelletier heated together in a crucible1 half an ounce of pure gold1 one ounce of phosphoric glass and of an ounce of powdered charcoal1 the heat was raised sufficiently to fuse the gold4 ,phosphoric fumes arose1 but the whole of the phosphorus was not dissipated4 ,the gold remaining was whiter than natural1 and brittle under the hammer4 ,exposed to a very high heat it lost _/ of its weight1 and resumed the ordinary characters of gold4 ,the same chemist heated #ajj grains of pure gold in filings to a bright red2 he then projected small fragments of phosphorus amongst the gold successively till after it had entered into fusion4 ,the gold preserved its colour1 but became brittle under the hammer and granular in the fracture2 it had increased #d in weight4 ,mr4 ,edmund ,davy1 by heating in a tube deprived of air1 finely divided gold and phosphorus1 effected a combination of them4 ,it had a grey colour and metallic lustre4 ,the heat of a spirit lamp was sufficient to decompose it4 ,it contained about #ad per cent4 of phosphorus4 7,davy's ,chemistry1 page #ddh--;,an4 #ahab74 ,oberkampf and ,thomson have successively observed the precipitation occasioned by water impregnated with phosphuretted hydrogen1 in solutions of muriate of gold4 ,the former of these has some interesting remarks on the phenomena4 ,when a current of this gas is passed through a dilute solution of muriate of gold for a time1 and then suddenly discontinued1 the solution becomes brown and passes soon to a fine deep purple4 ,a yellowish brown precipitate is obtained1 which is metallic gold1 and the liquid1 now become yellow again1 contains muriate of gold and phosphoric acid4 ,the experiment may be continued with the like results4 ,but if the liquid be saturated with gas before any precipitate is suffered to subside1 a black powder is obtained which does not seem to contain any metallic gold1 and the liquor ceases to have any colour4 ,this black powder is the phosphuret of gold2 exposed to heat it inflames and leaves metallic gold1 but its elements are not separable by mechanical means4 7,an4 de ,chimie1 #hj--adf1 for #ahaa74 ,water impregnated with the gas was found to have like effects as the gas itself4 ,whence ,oberkampf concludes that as long as an excess of gold remains in solution1 the phosphuretted hydrogen precipitates the metal only2 but when the gas is in excess1 the phosphorus leaves the hydrogen and unites with the precipitated gold4 ,i should rather suppose that the precipitation of the gold may be1 in part at least1 owing to the free hydrogen which we now know accompanies the phosphuretted hydrogen largely1 in the manner in which this gas was formerly procured2 however that may be1 ,i find that water1 impregnated with the purest phosphuretted hydrogen1 has the property of precipitating the black phosphuret of gold from the muriate of that metal1 in such manner as to effect complete mutual saturation1 leaving nothing in the liquid but the muriatic acid4 ,let a solution containing a known quantity of gold be gradually dropped into water1 containing a known quantity of phosphuretted hydrogen1 as long as any black precipitate is formed4 ,the point of saturation will be found when #fj parts by weight of gold have united to #i of phosphorus1 nearly2 or when one atom of gold has united to one of phosphorus4 ,hence it may be concluded that #ajj grains of the phosphuret of gold contain #ac or #ad of phosphorus1 which agrees very nearly with the results of ,mr4 ,edmund ,davy abovementioned4 #h4 ,phosphuret of platina4 ,m4 ,pelletier succeeded in combining platina with phosphorus by the same methods as with gold4 ,by projecting phosphorus on grains of platina heated to a strong red1 the latter acquired an increase of weight of #ah on the hundred2 but this was probably an excess1 as some vitreous phosphoric acid was found mixed with the mass4 ,in the ,philos4 ,magazine1 ,,vol4 #dj1 ,mr4 ,e4 ,davy has related some experiments made with a view to combine platina and phosphorus2 he effected it by heating platina and phosphorus together in an exhausted tube2 the union commenced below a red heat and was attended with vivid ignition and flame4 ,the compound was of a blueish grey colour and consisted of #hb platina and #ag phosphorus according to his estimate4 ,also by heating the ammonia-muriate of platina with of its weight of phosphorus in a retort over mercury1 muriatic gas was liberated1 and muriate of ammonia and phosphorus were sublimed1 but there remained at dull red heat an iron black or dark grey mass at the bottom1 of the sp4 gr4 #e4bh4 ,it was estimated to consist of #gj platina and #cj phosphorus2 but ,i doubt whether it could consist of these two elements only4 ,phosphuretted hydrogen water scarcely has any effect on muriate of platina4 ,after some time a very light flocculent matter appears1 as ,dr4 ,thomson has observed2 but this seems to me to be nothing but a slight precipitation of phosphorus alone2 ,i apprehend the gas unites with the platina1 but the compound remains in solution somewhat in the same manner as platina and sulphuretted hydrogen4 ,the platina may be precipitated from the clear liquid by muriate of tin1 much the same in appearance as if no phosphuretted hydrogen were present4 #i4 ,phosphuret of silver4 ,when pieces of phosphorus are dropped amongst silver heated to red in a crucible1 the two unite and enter into fusion1 according to ,pelletier2 when the metal is saturated with phosphorus the whole continues in a state of tranquil fusion2 but being withdrawn from the fire1 at the moment of congelation1 a quantity of phosphorus becomes suddenly volatile and burns vividly1 and the surface of the metal becomes uneven4 ,the metal on being cooled1 is found to have gained from #ab to #ae per cent42 and he apprehends that when fluid it contains #aj per cent4 more1 making in all #be phosphorus to #ajj silver4 ,the phosphuret of silver is white and crystalline1 brittle under the hammer1 but capable of being cut with a knife4 ,by a strong heat the phosphorus is dissipated and leaves the silver pure4 ,both ,raymond and ,thomson observe that phosphuretted hydrogen water precipitates silver from its solutions of a black colour4 ,i find that a solution of sulphate of silver containing one grain of the metal1 requires water containing #ij grain measures of phosphuretted hydrogen to saturate it2 the whole of the silver falls readily and leaves nothing but the acid in the water4 ,now the weight of #ij measures of this gas is nearly of a grain2 hence the proportions of metal and phosphorus are as #aj to #a1 which shows that they combine atom to atom1 or #ij silver to #i phosphorus4 ,this is somewhat less of phosphorus than is determined above by ,pelletier4 #aj4 ,phosphuret of mercury4 ,m4 ,pelletier made several attempts to combine phosphorus and mercury4 ,he seems to have succeeded best1 by exposing mercury in an extreme state of division1 to phosphorus under water in a moderate heat4 ,the phosphuret is a black compound1 which is resolved again into its elements by distillation4 ,when nitrate of mercury is treated with phosphuretted hydrogen water1 a copious dark brown or black precipitate is instantly formed1 as ,raymond and ,thomson have observed4 ,this black precipitate1 ,raymond adds1 soon becomes white and crystalline in passing from phosphuret to phosphate1 by attracting oxygen4 ,i have found the black powder when dried in a moderate heat to abound in small shining globules1 which have all the appearance of revived mercury4 ,however this may be1 ,i find that a certain weight of mercurial salt requires a certain portion of gas to saturate it1 so as that the whole mercury shall be precipitated4 ,one grain of mercury requires rather more than _/ of its weight or #ej grain measures of the gas for its saturation4 ,this proves the combination to be the most simple1 or atom to atom2 that is1 #afg mercury take #i phosphorus2 or #ajj mercury take #e phosphorus nearly4 #aa4 ,phosphuret of palladium4 ,when nitrate of palladium is dropped into phosphuretted hydrogen water1 a copious black flocculent precipitate is immediately formed1 which doubtless consists of palladium and phosphorus4 ,into #hjj grains of phosphuretted hydrogen water containing #bj grain measures of gas1 were put by degrees1 #bb grain measures of muriate of palladium 7sp4 gr4 #a4ja7 containing 4#ab acid and 4#ad oxide1 corresponding to 4#ab metal2 mutual saturation was produced1 and a finely distinct black powder precipitated1 leaving the water clear and colourless1 which was found by lime water to contain 4#ab parts of a grain of muriatic acid4 ,the black powder collected and dried1 corresponded as nearly as could be determined in weight to the ingredients4 ,now #bj measures of gas would weigh 4#jbe of a grain1 of which 4#jjbe would be hydrogen and 4#jbbe phosphorus2 whence we have 4#ab metal joined to 4#jbbe phosphorus or #ej to #i nearly1 indicating one atom of each4 ,hence #ajj palladium would take #ah or #ai phosphorus4 #ab4 ,phosphuret of copper4 ,m4 ,pelletier combined copper and phosphorus by the same means as the preceding compounds4 ,one hundred grains of copper united by heat with #ae of phosphorus2 the fused mass when cooled was white and very hard4 ,as part of the copper gets oxidized during the process he thinks it probable1 with ,m4 ,sage1 that copper may acquire #bj per cent4 of phosphorus4 ,in the #c;d ,,vol4 of ,memoirs of the ,society of ,arcueil1 page #dcb1 ,m4 ,dulong converts fine copper wire into phosphuret by heating it to a low red1 and passing the vapour of phosphorus over it in hydrogen gas4 ,in the sequel he observes that #aj grammes of phosphuret of copper contained #a4ig of phosphorus2 that is1 the copper was to the phosphorus as #h4jc #a4ig1 or as #ajj #bd4e4 ,this exceeds much ,pelletier's result1 and is1 ,i think1 too high4 ,for1 he found that the above phosphuret converted into phosphate of copper by nitric acid yielded #ad4dd grammes4 ,now supposing the atom of phosphorus to weigh #i1 that of phosphoric acid #bc1 and that of the black oxide of copper #gj1 we have an atom of phosphate of copper #ic3 and if #ic #i #ad4dd #a4ddd1 for the phosphorus in #aj grammes2 and hence the copper would be #h4eef3 this would give #ajj copper to #ag phosphorus nearly1 which would accord well with ,pelletier's determination1 and very nearly agree with the theoretic result of #ajj copper to #af phosphorus4 ,both ,raymond and ,thomson remark that phosphuretted hydrogen water produces a black or dark brown precipitate in sulphate of copper4 ,i have not found any precipitate from any of the salts of copper by the same means4 ,but if the blue hydrate be first precipitated by lime water1 and then the phosphuretted hydrogen water admitted1 the hydrate is immediately converted into a dark olive1 which in all probability is a phosphuret of copper4 ,from some experiments ,i am inclined to believe that this compound is the deutophosphuret1 or two atoms of phosphorus to one of copper2 and hence the copper is to the phosphorus as #ajj #cc4 #ac4 ,phosphuret of iron4 ,m4 ,pelletier formed a phosphuret of iron by both the methods above described for gold4 ,he describes the phosphuret as very hard1 of a white colour1 striated and magnetic4 ,he estimates1 with some uncertainty1 that #ajj iron may combine with #bj phosphorus4 ,berzelius produced a phosphuret of iron by reducing the phosphate of the metal by charcoal and heat4 7,an4 de ,chimie1 ,july #ahaf74 ,he describes it as having the colour of iron1 brittle and slightly acted upon by the magnet4 ,by his analysis it was constituted of #ajj iron and #cj phosphorus4 ,the true proportion probably would be one atom to one1 or #be iron to #i phosphorus2 that is1 #ajj iron to #cg phosphorus4 ,both ,raymond and ,thomson found that sulphate of iron yields no precipitate by phosphuretted hydrogen water2 and ,i may add1 that the precipitated oxide or hydrate is also unaffected by the same4 #ad4 ,phosphuret of nickel4 ,by projecting phosphorus amongst red hot nickel1 ,pelletier united #bj parts of the former to #ajj of the latter4 ,a part of the combined phosphorus1 he observes1 flies off on cooling1 so that the above proportion may perhaps be too low4 ,theoretically one atom of nickel should combine with one of phosphorus2 that is1 #bf with #i1 or #ajj with #cf4 ,i find that neither the nitrate of nickel nor the hydrate are affected by phosphuretted hydrogen water4 #ae4 ,phosphuret of tin4 ,margraff was the first who combined phosphorus and tin by fusing the metal along with fusible salt from urine 7phosphate of ammonia74 ,pelletier succeeded also in this way1 as well as by the direct one of projecting phosphorus into melted tin4 ,the compound was of a white colour2 it gained #ab per cent4 of weight2 but as part of the tin was oxidized and adhered to the crucible in form of glass1 he conjectures that tin would take from #ae to #bj per cent4 of phosphorus4 ,the atom of tin being #eb1 and that of phosphorus #i1 the due proportion would be #ajj tin to #ah phosphorus4 ,phosphuretted hydrogen water does not seem to precipitate tin from solutions1 nor yet to act upon the precipitated oxide4 #af4 ,phosphuret of lead4 ,lead combines with phosphorus by the same methods as tin2 but it is difficult to ascertain the proportions1 according to ,pelletier1 from the oxidation and vitrification of part of the lead4 ,muriate of lead distilled with fusible salt of urine1 also yielded phosphuret of lead4 ,he conjectures the increase by phosphorus to be #ab or #ae per cent42 but by theory it should only be #aj or #aa per cent4 ,raymond says that the nitrate of lead is decomposed by phosphuretted hydrogen water1 but with less force than salts of silver and mercury2 and that a phosphuret of lead is formed1 of which he gives no character1 except that it becomes in time a phosphate4 ,thomson says a slight white powder is formed by the mixture4 ,this was the case with me2 but ,i suspected that the white powder was merely a little sulphate of lead1 arising from the impurity of the 7rain7 water2 and this was found to be the fact2 for the milkiness was just the same with like water unimpregnated with the gas4 ,besides1 after the phosphuretted hydrogen water has been saturated with nitrate of lead till no more effect is produced1 still the water retains its peculiar smell1 and a copious black precipitate is instantly produced by nitrate of silver or mercury4 ,it appears then that phosphuret of lead cannot be formed this way4 ,neither does phosphuretted hydrogen water seem to have any effect on the recently precipitated oxide of lead4 #ag4 ,phosphuret of zinc4 ,both zinc and its oxide seem to combine with phosphorus1 according to ,pelletier2 but the proportions were not ascertained4 ,by theory1 zinc should take #cb per cent4 of phosphorus4 #ah4 ,phosphuret of potassium4 ,some account was given by ,davy1 of the combination of potassium and phosphorus in essays from #ahjg to #ahaj2 and by ,gay ,lussac and ,thenard in others from #ahjh to #ahaa4 ,according to ,davy1 when potassium and phosphorus are heated together1 they combine in one uniform ratio of #h to #c nearly2 and the compound1 when acted upon by muriatic acid1 gives out from 4#h to #a cubic inch of phosphuretted hydrogen gas1 resulting from one grain of the former and of a grain of the latter substances combined4 ,also be observed that half a grain of potassium decomposed nearly #c cubic inches of phosphuretted hydrogen1 and set free more than #d cubic inches of hydrogen2 the phosphuret seemed to be of the same kind as the former1 or that by direct combination of the two elements4 ,gay ,lussac and ,thenard combined the elements by heat2 the potassium is scarcely fused till the phosphuret is formed4 ,the excess of phosphorus sublimes1 and the phosphuret is always of a chocolate colour2 the proportions were not ascertained4 ,by treating this phosphuret with warm water1 a quantity of phosphuretted hydrogen was uniformly given out1 about #dj per cent4 more than the hydrogen which would have been yielded by the potassium alone in water4 ,but if the phosphuret was treated with dilute acid instead of water1 then less gas was given out than otherwise2 and the stronger the acid the less gas1 so as sometimes to reduce the gas in volume to that yielded by potassium alone4 ,they also found1 as ,davy had done1 that potassium heated in phosphuretted hydrogen decomposed it1 uniting with the phosphorus and producing the same compound as in the direct way4 ,the results of ,davy and the ,french chemists appear to be discordant2 but ,i apprehend they may be reconciled4 ,it appears probable from both1 that the phosphuret of potassium must be a compound of one atom of each1 or #ce potassium and #i phosphorus2 that is1 #ajj potassium and #bg phosphorus nearly4 ,now in ,davy's method of treating the compound with acid1 it is most probable that the atom of potassium takes one of oxygen to form potash1 and the atom of phosphorus takes one of hydrogen to form one of phosphuretted hydrogen2 but #c volumes of pure phosphuretted hydrogen contain #d volumes of hydrogen1 7see page #agh72 and ,davy obtained nearly of the volume of gas which the potassium alone would have produced1 which therefore accounts for the fact as stated by him4 ,on the other hand1 the ,french chemists by treating the phosphuret with hot water1 probably determined the resolution in this way3 the potassium resolved the water into oxygen and hydrogen the last of which was liberated in a free state1 and of course produced the usual volume2 the phosphorus also resolved the water into oxygen and hydrogen1 one half of it taking the oxygen to form phosphorous acid1 and the other half taking the hydrogen to form phosphuretted hydrogen1 which of course would produce phosphuretted hydrogen amounting to of the volume of free hydrogen or #ch per cent4 nearly1 which would make up the volume of gas to #ach1 or nearly #adj1 as observed by them4 ,it is not unlikely that #b or #c per cent4 of hydrogen might be added by the further decomposition of water by the phosphorous acid1 in order to make it into phosphoric acid4 #ai4 ,phosphuret of sodium4 ,no particular experiments having been detailed of this compound1 we must infer it is similar to the last mentioned1 and consists of one atom of sodium1 #ba1 and one atom of phosphorus1 #i2 that is1 #ajj sodium and #dd phosphorus nearly4 #bj4 ,phosphuret of bismuth4 ,if we may judge from ,m4 ,pelletier's experiments1 bismuth has but a weak affinity for phosphorus4 ,by projecting portions of phosphorus amongst melted bismuth1 he succeeded in uniting some of it to the metal2 he estimates the quantity at #d per cent42 whereas by theory it ought to be #ae per cent4 supposing them to unite atom to atom4 ,i do not find that the salts or oxide of bismuth are materially affected by phosphuretted hydrogen water4 #ba4 ,phosphuret of antimony4 ,phosphorus may be combined with antimony1 according to ,pelletier1 by the same means as with the other metals4 ,the phosphuret has a white1 metallic appearance and lamellar fracture4 ,the ratio of the elements was not determined4 ,by theory supposing one atom to unite with one1 it would be #dj to #i1 or #ajj antimony to #bc phosphorus nearly4 ,phosphuretted hydrogen water seems to have no effect on the salts or oxide of antimony4 #bb4 ,phosphuret of arsenic4 ,from the experiments of ,margraff and ,pelletier1 it seems probable that phosphorus unites both with arsenic and its oxide4 ,by distilling a mixture of equal parts of arsenic and phosphorus in a carefully regulated heat1 ,pelletier obtained a residuum of a black shining substance1 containing a good proportion of phosphorus4 ,the same was obtained in the humid way1 by keeping phosphorus in fusion on arsenic under water for some time4 ,the phosphuretted oxide may be obtained by distilling phosphorus and the white oxide of arsenic together1 the phosphuretted oxide sublimes mixed with arsenic and phosphorus in a separate state4 ,it is of a red colour4 ,the proportions in neither case were ascertained4 ,it is probable that the compounds are of the most simple kind1 or one atom to one2 in that case we shall have #ba arsenic and #i phosphorus1 or #ajj arsenic and #dd phosphorus for phosphuret of arsenic2 and #bh oxide and #i phosphorus1 or #ajj oxide and #cc phosphorus for phosphuretted oxide4 ,no precipitation is occasioned by phosphuretted hydrogen water in solutions of arsenic4 #bc4 ,phosphuret of cobalt4 ,cobalt unites with phosphorus in the direct way as well as by being heated with phosphoric glass4 ,the colour of the compound is a blueish white2 it is brittle and crystalline in the fracture4 ,the metal acquires #g per cent42 this is below the theoretic quantity1 which is #be per cent4 if the atom of cobalt be #cg4 ,solutions of cobalt give no precipitate by phosphuretted hydrogen water4 #bd4 ,phosphuret of manganese4 ,this compound may be formed like the preceding ones4 ,it is of a white colour1 brittle and of a granular texture4 ,it is not liable to be altered by the air like the pure metal4 ,the proportions of the compound ,pelletier did not determine4 ,reasoning from theory1 it should consist of #be metal and #i phosphorus2 or #ajj metal and #cg phosphorus4 ,the salts and oxide of manganese are not sensibly affected by phosphuretted hydrogen water4 99 99 99 99 99 ,the combinations of the remaining metals with phosphorus can scarcely be said to have been investigated4 ,,section #af4 ,,carburets4 ,on the supposition that metals combine with charcoal1 the appropriate names for the compounds would be carburets of the respective metals4 ,this combination1 if it exist at all1 seems very rare1 that with iron being the only one generally acknowledged4 ,no combinations of carbone with the earths and alkalies1 have1 as far as ,i know1 been noticed2 and those with the elements oxygen1 hydrogen1 sulphur and phosphorus have been described in the former volume4 ,since that was printed an ingenious experimental essay on the 8,sulphuret of carbon or alcohol of sulphur10 has been published by ,berzelius and ,dr4 ,marcet4 ,some account of this compound1 under the name carburetted sulphur1 has been given 7,,vol4 #a4 page #dfb72 but the additional information is of sufficient importance to require notice here4 ,the pure liquid is of sp4 gr4 #a4bgb2 and the elasticity of its vapour at #ff is equal to #aj4gf inches4 ,it burns with a blue flame and sulphureous odour1 without sensibly depositing water on cold glass exposed to the fumes4 ,it has an acrid1 pungent taste1 and a nauseous smell1 differing from sulphuretted hydrogen4 ,by various experiments it was found to consist of sulphur and carbone in the ratio of #he to #ae nearly2 that is1 #b atoms of sulphur to #a of carbone4 ,from other experiments it did not appear to contain any hydrogen4 ,from some experiments ,i made in ,june #ahah1 on the combustion of the vapour of carburet of sulphur in oxygen gas1 ,i was led to suspect at least1 that an atom of hydrogen attaches to the two of sulphur and one of carbone in its constitution4 ,but not having an opportunity to pursue the subject1 ,i merely make the observation for future experience to determine upon the question4 #a4 ,carburets of iron4 ,there are three distinct substances which are now commonly believed to be constituted of carbone and iron1 known by the names of ,plumbago1 or black lead1 ,cast ,iron and ,steel4 ,plumbago is a natural production1 found in greatest perfection in the ,borrowdale mine1 near ,keswick1 ,cumberland4 ,it is chiefly used in making pencils4--,it seems to be constituted of carbone and iron by the concurrent experience of all who have examined it3 but the proportions are not uniform1 some having found #aj and others only #e per cent4 of iron in it4 ,from this circumstance it would seem doubtful whether iron is an essential element4 ,as carbone is known to be exhibited in various forms of aggregation1 it is not improbable that plumbago may be one of those forms2 it is evidently not a mere mixture of common charcoal and iron1 or its oxide4 ,cast iron or crude iron is the metal when first extracted from the ore2 it usually contains carbone1 oxygen1 phosphorus and silica1 in small proportions1 with perhaps other earths occasionally4 ,it cannot be considered as having these elements united in definite proportions2 for they vary much1 and probably give to crude iron its several modifications4 ,cast iron contains about #hj per cent4 of its weight of iron in a state capable of solution in dilute sulphuric acid1 and yielding a corresponding quantity of hydrogen gas4 ,the residue1 in a specimen ,i examined1 was nearly as magnetic as iron itself4 ,when treated with boiling muriatic acid1 the insoluble part was reduced to #b per cent4 upon the original weight of the iron1 and some hydrogen gas given out4 ,it was then about as magnetic as the common black oxide of iron2 when heated it assumed a glowing red and lost nearly grain2 it was still magnetic1 and boiling muriatic acid extracted more iron from it4 ,the hydrogen gas from dilute sulphuric acid and cast iron contains no carbonic acid in my experience2 neither does it yield any when exploded with pure oxygen gas4 ,the small residuum after treating cast iron with acids was found by ,bergman and others to resemble plumbago1 being constituted chiefly of carbone and iron4 ,from the above it would seem that cast iron consists chiefly of pure iron1 with the addition of very small proportions of oxygen and carbone2 the oxygen may be about #a per cent4 and the carbone about #b4 ,these proportions1 though sufficient to modify the properties of iron to a certain extent1 can scarcely be considered as constituting cast iron a homogeneous mass4 ,steel4 ,this most important modification of iron has engaged the attention of many chemists and metallurgists4 ,it may be procured1 but not equally pure1 by different methods4 ,one is to keep the cast iron for a considerable time in fusion and in a very high degree of heat2 whilst its surface is covered with melted scori1 so as to preclude the contact of the atmosphere with the iron4 ,this1 it is conceived1 gives time for the carbone and oxygen to combine and escape in the form of carbonic acid4 ,this steel is of inferior purity4 ,steel of cementation is made by stratifying bars of pure iron with charcoal powder in large earthen crucibles1 carefully closed up with clay4 ,these are exposed to a high degree of heat in a furnace for #h or #aj days4 ,this is called blistered steel1 from the appearance of blisters on its surface4 ,cast steel is made from blistered steel by breaking the bars and putting them into a large crucible with pounded glass and charcoal4 ,the crucible is closed with a lid of the same ware and placed in an air furnace4 ,when the fusion is complete the metal is cast into ingots4 ,this is the most valuable and probably the purest steel4 ,when steel is heated red and plunged into cold water1 it is hardened2 that is1 it becomes much harder than iron or than steel without this operation4 ,hardened steel is brittle1 and cannot be extended by the hammer or corroded by a file till it is again softened by being heated and then gradually cooled4 ,one of the most remarkable properties of hardened steel is that of being tempered1 as it is called2 by which it is adapted to the different purposes of the manufacturing artists4 ,tempering consists in heating the hardened steel till it acquires a straw colour for edge tools1 a blue colour for watch springs1 and elastic articles in general2 c4 c4 ,hardened steel is qualified to acquire magnetism1 and to retain it so as to become a permanent magnet4 ,this power of retaining magnetism distinguishes steel from pure iron4 ,from the above account of steel1 it is evident there is an essential difference between it and pure iron4 ,that difference consists1 according to the common opinion1 in steel being a carburet of iron1 or carbone and iron united4 ,the fact of the union of carbone and iron in the formation of steel does not seem to me satisfactorily proved4 ,mr4 ,collier asserts that iron gains about _/th of its weight by being converted into steel4#ah ,but ,mr4 ,mushet found that though steel gains weight upon the iron when copiously imbedded in charcoal1 yet it loses weight if the charcoal is only _/ or _/ of the weight of the iron4#ai ,the same ingenious gentleman seems to estimate the carbone in cast steel1 from synthetic experiments1 to be _/th of its weight4 ,footnote #ah3 ,manchester ,memoirs1 ,vol4 v4 page #abj4 ,footnote #ai3 ,philos4 ,mag4 ,vol4 xiii4 ,from analytic experiments1 however1 there does not appear reason to believe that steel contains so much1 if any charcoal4 ,pure steel dissolved in dilute sulphuric acid gives hydrogen gas containing no carbonic acid nor oxide1 neither is there any appreciable residuum of any kind in general4 ,on considering all the circumstances1 ,i am inclined to believe1 that the properties which distinguish steel from iron are rather owing to a peculiar crystallization or arrangement of the ultimate particles of iron1 than to their combination with carbone or any other substance4 ,in all cases where steel is formed1 the mass is brought into a liquid form1 or nearly approaching to it1 a circumstance which allows the particles to be subject to the law of crystallization4 ,we see that great change is made in steel by the mere tempering of it1 which cannot be ascribed to the loss or gain of any substance1 but to some modification of the internal arrangement of its particles4 ,why then may not its differences from iron be ascribed to the same cause8 ,it is allowed that steel1 by being repeatedly heated and hammered1 becomes iron3 that is1 it should seem1 the change of figure disturbs the regular arrangement of the particles4 ,and it may be further observed1 in corroboration of the opinion that cast iron is capable of being made permanently magnetic1 from its having been in fusion more probably than from its near approximation to steel in its component parts4 ,the most powerful artificial magnets1 after being forged of steel1 are said to undergo the operation of steelifying again1 before they are hardened finally to receive the magnetic virtue4 ,,section #ag4 ,,metallic ,,alloys4 ,when two or more metals of different specific gravities are melted together and intimately mixed1 they frequently enter into chemical union and form a new compound1 called an alloy of the metals4 ,these alloys often possess important properties which their constituents singly do not1 and hence become valuable acquisitions to the arts4 ,the metals thus combined may be fused together in any proportion2 but if one of them greatly exceed the other in specific gravity1 their intimate union is sometimes rendered difficult and even impracticable1 partly from the weak affinity and partly from the gravitating principle causing the metal of least specific gravity to arise to the surface4 ,notwithstanding this union of metals in seemingly indefinite proportions1 there are only a few proportions in which the alloys possess peculiar excellences so as to entitle them to the attention of artists4 ,these proportions have in many instances been discovered by experience2 and it only remains for theory to point out the reason for such proportions1 and to suggest other proportions which may bid fair to possess desirable qualities1 and thereby diminish the unsuccessful attempts for improvement in these combinations4 ,that the metals thus alloyed constitute true chemical compounds and not merely mechanical mixtures1 may be inferred from the change made in their primary qualities2 such as #a4 ,tenacity1 hardness1 c4 ,some alloys are much superior to their ingredients in tenacity and hardness1 whilst others affect a kind of medium between them4 ,this last is often the case too in regard to ductility and malleability4 #b4 ,fusibility4 ,several alloys fuse at temperatures intermediate between the fusing temperatures of their ingredients1 but mostly lower than the mean2 there are others which fuse below the temperature of the lowest1 and few if any require a temperature above the mean for their fusion4 #c4 ,colour4 ,in many cases the colour of alloys is such as would be produced by the mixture of the colours of the metals2 but in others1 remarkably different2 for instance1 the alloys of copper and zinc1--forming the various kinds of brass4 #d4 ,specific gravity4 ,this is not always what might be inferred from a mixture of the two ingredients4 ,sometimes it is greater and other times less2 but this is not a decisive mark of chemical union1 as the same metal varies in specific gravity1 by hammering1 rolling1 tempering1 c4 very considerably4 ,besides1 it is more than probable that the differences said to have been observed1 have in some instances arisen from inaccurate experiments2 as it is a delicate operation to find the specific gravity of small pieces of metal with sufficient precision for comparisons of this kind4 ,many of the simple metals1 when fused and exposed to the air for some time1 without a covering of charcoal1 or some similar principle1 acquire less or more of oxygen1 and retain it even in a fluid state1 as is proved from ,mr4 ,lucas's interesting communication in the #c;d ,vol4 of the ,manchester ,society's ,memoirs 7new series74 ,hence by frequent fusions of the same metal its quality becomes impaired in regard to tenuity and other properties4 ,this is more eminently the case with regard to alloys4 ,thus1 zinc at the temperature in which brass melts is combustible2 and hence a portion of it escapes by combustion4 ,hence the proportions of brass are changed less or more at each fusion1 unless fresh zinc be added4 ,the same observation applies to alloys of copper and tin with regard to the tin4 ,the mixtures of lead1 tin1 bismuth and other soft and easily fused metals1 are still more remarkable in this respect4 ,they should be fused under a cover of oil or tallow in order to keep them of the same proportions2 otherwise1 some of them1 particularly the tin1 is liable to great oxidation1 and no two successive fusions will present the same alloy4 ,hence in some degree the use of fluxes in metallurgy which serve to cover the surface of the metals and prevent oxidation from the atmosphere4 ,when an alloy is made1 it seldom happens that the metal is perfect and compact the first fusion2 it is more or less porous1 especially when the two metals fuse at very different temperatures4 ,by a second fusion1 which usually takes place at a much lower temperature than that requisite for the first1 the metal becomes compact and free from pores4 ,this is particularly the case with speculum metal2 and ,i have little doubt it is so with regard to many other alloys4 ,alloys of ,gold with other ,metals4 ,gold unites with many of the metals by heat1 and forms various alloys1 on which it may be proper to make a few remarks4 #a4 ,gold with platina4 ,platina in a small proportion changes the colour of gold towards white4 #a part to #bj gold makes it much paler4 #a to #aa gives it the colour of tarnished silver4 #a part with #d of gold has much the appearance of platina4 ,the colour of gold does not predominate till it becomes _/ of the alloy4 ,the alloy of #a platina and #aa gold is very ductile1 and elastic when hammered4 ,lewis4 ,klaproth4 ,vauquelin4 #b4 ,gold with silver4 ,these two metals may be combined in almost any proportion by fusion and proper treatment4 ,homberg found that when equal parts of gold and silver are kept in fusion for a quarter of an hour and then cooled1 there were two masses1 the uppermost pure silver1 the undermost an alloy of #e parts gold and #a silver4 #a part silver to #bj gold produces a sensible whiteness in the alloy4 #b parts gold and #a of silver are stated to form the alloy of greatest hardness2 this will consist of #c atoms of gold to #a of silver4 #c4 ,gold with mercury4 ,see amalgams4 #d4 ,gold with copper4 ,gold and copper form an alloy by fusion together4 #aa parts gold and #a copper form the alloy used for gold coin4 ,the copper heightens the colour of the gold1 and makes it harder and less liable to wear4 ,the current gold coin1 however1 usually contains both silver and copper1 but the weight of both does not much exceed one twelfth of the whole4 ,according to ,muschenbroeck the maximum of hardness is when #g parts of gold and #a part of copper are united4 ,this corresponds nearly to #f atoms of gold and #a of copper1 the atom of gold being estimated at #ff and that of copper at #ef4 ,other alloys of gold besides the above standard is that for watch cases1 which must contain at least pure gold4 ,watch chains1 and trinkets1 are usually made of inferior alloy1 called jewellers gold1 which is under no control4 ,it rarely contains less than #cj per cent4 of pure gold4 #e4 ,gold with iron4 ,gold and iron may be united by fusion in various proportions4 #aa parts gold and #a iron form a ductile alloy which may be rolled and stamped into coin4 ,its specific gravity is #af4hhe4 ,the colour is a pale yellowish gray approaching to white4 ,the alloy is harder than gold4 ,when the iron is three or four times the weight of gold1 the alloy has the colour of silver4 ,this last compound is constituted of #a atom of gold and #h of iron nearly4 ,lewis4 ,hatchett4 #f4 ,gold with nickel4 ,mr4 ,hatchett fused #aa parts gold and #a nickel together1 and obtained a brittle alloy of the colour of fine brass4 #g4 ,gold with tin4 ,gold combines with tin and forms a brittle alloy4 #aj parts gold and #a tin form a pale alloy and less ductile than gold4 ,one fiftieth of tin does not materially injure the ductility4 ,heat1 up to a visible red1 does not impair the alloy2 but beyond that the tin fuses and the alloy falls to pieces4 ,hatchett4 #h4 ,gold with lead4 ,the effect of uniting even a very small proportion of lead to gold is remarkable4 ,when the alloy contains _/ part of lead1 it is brittle like glass4 ,the vapour of fused lead in close vessels is sufficient to injure gold4 ibid4 #i4 ,gold and zinc4 ,these two metals combine in almost any proportion4 ,when #aa parts gold and #a zinc are alloyed1 the compound is of a pale greenish yellow like brass1 and very brittle4 ,equal parts of these metals form a very hard1 white alloy1 susceptible of a fine polish4 ibid4 ,hellot4 #aj4 ,gold and bismuth4 ,gold unites with bismuth1 but the colour is injured and the ductility of the alloy destroyed by a very small portion of the latter metal1 the same as with lead4 ibid4 #aa4 ,gold and antimony4 ,these metals combine and produce a brittle alloy1 much of the same kind as those with bismuth and lead4 ibid4 #ab4 ,gold and arsenic4 ,there seems a considerable affinity between gold and arsenic1 but the volatility of arsenic in the fusing temperature of gold renders it difficult to bring them into contact4 ,a very small proportion of arsenic makes the alloy brittle1 and this property increases with the arsenic4 ,hatchett4 #ac4 ,gold with cobalt4 ,these unite and form a brittle alloy1 even when the cobalt only makes _/ of the compound4 ibid4 #ad4 ,gold and manganese4 ,gold and manganese may be united1 and the alloy is very hard and less fusible than gold4 ,one alloy was found to consist of #g or #h parts of gold and #a of manganese4 ibid4 ,alloys of ,platina with other ,metals4 #a4 ,platina and silver4 ,it does not appear very clear that these two metals combine by fusion2 at least if they do1 the difference in their specific gravities is sufficient to overcome their affinity4 #b4 ,platina and mercury4 ,see amalgams4 #c4 ,platina and copper4 ,these two metals unite with difficulty by a strong heat and form a malleable alloy4 ,this alloy has been preferred for specula for telescopes1 as it is hard1 polishes well1 and is not liable to tarnish4 ,lewis4 #d4 ,platina and iron4 ,platina and soft or pure iron do not seem to be easily combined by heat1 by reason of the infusibility of iron4 ,but it combines with cast iron and steel by heat4 ,the alloy is very hard1 and in some decree ductile when the iron forms of the alloy4 ibid4 #e4 ,platina and tin4 ,equal parts of platina and tin unite by fusion1 and form a dark coloured brittle alloy4 ,but when the platina falls short _/ of the alloy1 the ductility and whiteness proportionally increase4 ibid4 #f4 ,platina and lead4 ,these two metals may be combined in various proportions by heat2 but the compounds are not stable1 part of the platina falling down1 when the alloy is subsequently melted4 ibid4 #g4 ,platina and zinc4 ,platina may be combined with zinc1 by being exposed to the fumes of the metal as reduced from its ore4 ,three parts of platina become four of alloy4 ,it is hard1 brittle1 of a blueish white colour1 and easily fusible4 ibid4 #h4 ,platina and bismuth4 ,platina and bismuth combine readily in a high temperature in almost any proportions4 ,the alloys are brittle4 ibid4 #i4 ,platina and antimony4 ,platina easily combines with antimony by heat4 ,the alloy is brittle4 ibid4 #aj4 ,platina and arsenic4 ,when white oxide of arsenic is projected upon strongly heated platina1 an imperfect union takes place with a partial fusion of the mass2 it is brittle1 of a greyish colour and a loose granulated texture4 ,lewis4 ,alloys of ,silver with other ,metals4 #a4 ,silver with mercury4 ,see amalgams4 #b4 ,silver with copper4 ,silver and copper are easily alloyed in any proportion by fusion4 ,the compound is harder than silver1 and retains its white colour when the copper is half of the alloy or more4--,the silver coin is a compound of #ab silver and #a copper1 which nearly corresponds to #h atoms of silver and #a of copper4 ,the hardest alloy is said to be when #e silver unite to #a copper2 that is1 #c atoms of silver and #a of copper4 #c4 ,silver with iron4 ,the alloys of silver and iron have not been very minutely examined4 ,the two metals are said to unite by fusion1 but the iron still retains its magnetism4 ,the alloy is of a white colour1 hard and ductile4 ,when kept in fusion for some time the two metals separate1 but not entirely4 ,these circumstances shew the affinity between silver and iron to be weak4 #d4 ,silver with tin4 ,silver and tin form a hard brittle alloy1 which is of little if any use4 ,the modifications arising from various proportions have not been particularly investigated4 #e4 ,silver and lead4 ,silver and lead unite in any proportion and form a brittle alloy of a lead colour4 ,the union is not very intimate2 for when urged by heat the lead parts from the silver1 as in the process of cupellation4 #f4 ,silver and zinc4 ,these two unite and form a brittle alloy of a blueish white colour4 ,the proportions have not been particularly noticed4 #g4 ,silver and bismuth4 ,silver and bismuth readily unite by heat4 ,the alloy is brittle and its colour inclines to that of bismuth4 #h4 ,silver and antimony4 ,these metals unite by fusion and form a brittle alloy1 which does not seem possessed of any remarkable properties4 #i4 ,silver and arsenic4 ,these two metals unite according to ,bergman1 the fused silver taking up _/ of its weight of arsenic2 the alloy corresponds nearly to #c atoms silver and #a arsenic4 ,it is brittle and of a yellowish colour4 ,alloys of ,mercury and other ,metals3 ,amalgams4 ,the alloys of ,mercury with the various metals have been commonly denominated amalgams4 #a4 ,mercury and gold4 ,gold amalgamates pretty easily with mercury and forms an alloy much used in gilding metals4 ,for this purpose six parts of mercury may be heated nearly to the ebullition of the liquid1 and one part of pure gold in thin plates may be gradually added4 ,in a few minutes the whole becomes one fluid mass of a yellowish white colour4 ,it is constituted of #a atom of gold and #b of mercury4 ,by squeezing it through leather one half of the mercury is separated nearly pure1 and the other remains combined with the gold1 and forms a soft white mass1 consisting of #a part gold and #b mercury nearly1 which is the alloy of #a atom to #a1 and may be subsequently used for gilding4 ,a ready way of making this amalgam ,i find is to put #c parts of gold1 precipitated by green sulphate of iron1 to #h or #i parts of mercury2 by a few minutes trituration the whole becomes a fine crystalline amalgam4--,when this amalgam of gold is exposed to a heat just below red1 the mercury sublimes and leaves the gold2 hence its use in gilding4 #b4 ,mercury and platina4 ,these two metals may be combined1 but not very easily1 as little affinity seems to exist betwixt them4 ,this is manifest from the circumstance that platina wire may be long immersed in mercury without any sensible effect4 ,an union may be produced by immersing thin platina foil into boiling mercury for some time2 also by triturating the ammonio-muriate of platina with mercury and exposing it to a due heat4 ,the proportions have not been determined4 #c4 ,mercury and silver4 ,silver and mercury have a considerable affinity and are easily combined by putting lamina of silver into heated mercury and agitating the mixture4 ,when #a part silver and #b mercury are mixed as above1 a fluid mass is obtained which being heated to the temperature of boiling mercury1 a little mercury evaporates and the remainder crystallizes into a soft white mass1 which in time grows hard and brittle4 ,a higher heat than boiling mercury expels the mercury4 ,hence this amalgam may be used for giving a thin coating of silver to the surface of metals1 like that of gold4 ,the compound is evidently one atom of silver 7#ij7 with one of mercury 7#afg74 #d4 ,mercury and copper4 ,i have made several unsuccessful attempts to combine mercury and copper4 ,when a plate of copper is kept immersed in mercury for some time1 the mercury adheres to its surface in a small degree and is not easily rubbed off2 the plate is rendered brittle by it and the fracture has a brilliant mercurial appearance2 but a low red heat expels the mercury and the copper resumes its colour and tenacity1 with scarcely any loss of weight1 being only about #e per cent4 in two or three trials4 ,recently precipitated copper in powder1 dried and triturated with mercury1 produced no union4 ,neither did ,dutch-leaf 7which is copper with a very little zinc7 unite with mercury by trituration4 ,mercury precipitated from deutonitrate by a plate of copper gave pure running liquid4 ,the plate of copper appeared as if it had been immersed in mercury1 was brittle with a shining fracture1 but recovered its colour and texture by heat1 and lost scarcely any weight4 ,the method recommended by ,boyle was tried3 #b parts of crystallized verdigris1 #b parts of mercury and #a of common salt1 were triturated together till the mercury disappeared1 the powder was then digested awhile with vinegar over a fire and frequently stirred4 ,the mass was then put on a filter and dried4 ,it contained a little fluid mercury1 but was chiefly composed of acetate of copper and oxide or muriate of mercury4 ,the liquid contained acetate of copper and muriate of soda4 ,from the above it is manifest that mercury has some chemical action upon copper2 but it has not yet been found1 ,i apprehend1 that the two metals unite so as to form a proper amalgam4 #e4 ,mercury and iron4 ,these two metals have little if any affinity for each other4 ,i do not know that any chemical combination of them has ever been formed4 #f4 ,mercury and tin4 ,these two metals readily combine1 especially if assisted by heat4 ,i heated #eb parts of tin and #afg of mercury together1 that is1 #a atom of each1 till they united in a fluid mass4 ,the amalgam crystallized in about #ahj4 ,by hard pressure in the hand nearly #ej parts of fluid mercury were separated from the amalgam when cool1 containing in appearance very little tin4 ,after this an amalgam was formed of #ajd parts of tin and #afg mercury 7#b atoms tin to #a mercury72 this congealed about #bcj1 and remained a hard1 dry1 crystalline substance1 agreeing in appearance with that which adheres to mirrors4 ,for the purpose of silvering mirrors however much more mercury is employed than is indicated by the above proportion2 but after the glass is slid upon the tinfoil previously covered with mercury1 a great pressure is applied1 which expels the superfluous mercury nearly in a state of purity4 #g4 ,mercury and lead4 ,to #ij parts of lead ,i put #afg of mercury 7#a atom of each72 they united in a moderate heat and crystallized in about #ahj4 ,in a few days the mercury partly separated from the amalgam1 and #ef parts were squeezed out1 the whole was then put together with #ij parts more of lead 7now #b atoms lead to #a mercury71 and fused together2 the amalgam crystallized in about #bjj1 and remained in a solid uniform mass4 #h4 ,mercury and zinc4 ,when #bi parts zinc and #afg mercury 7#a atom to #a7 are heated together1 they combine and form an amalgam which crystallizes about #bjj4 ,a little of the mercury may be squeezed out when cold4 ,by putting #bi parts more of zinc 7#b atoms to #a7 we obtain an amalgam which fuses considerably above #bjj1 and when cooled becomes a permanent hard crystalline mass4 #i4 ,mercury and bismuth4 ,when #fb parts bismuth are fused with #afg mercury 7#a atom to #a71 the compound remains fluid at common temperature1 but crystallizes partially by standing2 about of the weight may be poured off like fluid mercury4 ,if we put #fb bismuth more to the whole 7so as to be #b atoms to #a71 the fluid amalgam crystallizes about #aej or #ahj3 the mass is soft however and by pressure one may squeeze out about #bj per cent4 of a fluid amalgam4 ,if we put #fb more bismuth 7so as to be #c atoms to #a71 then the compound crystallizes between #bjj and #cjj into a darkish coloured granular soft mass which continues without any change4 ,higher than this of bismuth ,i have not examined4 #aj4 ,mercury and antimony4 ,antimony is said to form a feeble union with mercury1 which is soon loosened by time4 ,i made several unsuccessful trials to combine these two metals1 which it seems unnecessary to detail1 as the compound when formed is no ways interesting4 #aa4 ,mercury and arsenic4 ,on the authority of ,lewis an amalgam of mercury and arsenic may be made by keeping them over the fire for some time and constantly agitating the mixture4 ,it is grey-coloured1 and composed of #e parts of mercury and #a of arsenic4 ,most of the other metals are incapable1 as far as is known1 of combination with mercury1 excepting potassium and sodium considered as metals1 which combine with mercury2 but these alloys are of little interest1 and the proportions have not been particularly investigated4 ,triple1 quadruple1 c4 ,amalgams4 ,besides those amalgams which are formed of mercury and each single metal1 there are others formed of mercury and alloys of two or more metals1 which in some instances possess properties differing essentially from mere mixtures4 #a4 ,mercury with bismuth and lead4 ,when the amalgam formed of #b atoms bismuth and #a of mercury is mixed with that formed by #a atom of lead and #a of mercury1 in such proportion that the mercury is the same in both1 the two powders1 though dry and crystalline at first1 soon become a permanently fluid amalgam by trituration4 ,the liquid in running along drags a tail after it1 and is disposed to separate into portions less and more fluid1 but the most fluid part is much inferior to pure mercury in this respect4 ,specific gravity of the amalgam1 #aa4 #b4 ,mercury with fusible metal composed of #g bismuth1 #e lead and #c tin4 ,a mixture of #d parts fusible metal with #e parts mercury compose the most fusible amalgam with a minimum of mercury that ,i have found4 ,it is formed of #b atoms bismuth1 #a lead1 #a tin and #b mercury4 ,its specific gravity is #ab4 #c4 ,mercury1 zinc and tin4 ,this amalgam is found the most effectual for the excitation of electric machines4 ,mr4 ,cuthbertson recommends #a part zinc1 #a tin and #b of mercury for the plate machine amalgam4 ,but for a cylinder the best amalgam ,i have made contains more than twice the above portion of mercury4 ,i form an alloy of #eh parts zinc and #eb tin1 7#b atoms to #a74 ,to this alloy ,i add #bej mercury1 and fuse the mixture2 the liquid mass crystallizes about #bbb into a white1 moderately hard amalgam4 ,this is pulverized in a mortar and mixed up with _/ of its weight of hog's lard4 ,a small portion then is spread upon a piece of leather and applied to the machine when in action4 ,it is probable however that a harder and less unctuous amalgam may be better adapted to the plate machine4 ,this amalgam of mine consists of #d atoms of zinc1 #b of tin and #c of mercury4 ,i have tried the amalgams of zinc and tin separately and find that they answer for electric excitation as well as when combined4 ,they ought to be formed of #b atoms zinc and #a of mercury 7#eh parts to #afg71 and of #b atoms tin and #a of mercury 7#ajd parts to #afg74 ,if we choose to combine them1 we have only to take #b parts of the zinc amalgam and #a of the tin amalgam and triturate them together4 ,bismuth amalgam is not good for electric excitation2 lead amalgam is better2 but they are much inferior to those of tin and zinc4 ,alloys of ,copper with other ,metals4 #a4 ,copper and iron4 ,these two metals may be united with difficulty by heat2 but the compound possesses no useful property4 #b4 ,copper and nickel4 ,a white1 hard1 brittle alloy is said to be formed by combining these two metals4 ,the alloy is scarcely known4 #c4 ,copper and tin4 ,the metals of copper and tin1 may be fused together and united in almost any proportion by skilful treatment2 but it is found that only a few of the proportions constitute alloys possessing properties eminently valuable to the arts4 ,the alloys of copper and tin are commonly called bell-metal2 but they receive more particular names according to the purposes for which they are destined1 as bronze1 speculum metal1 gun-metal1 c4 those of them which are yellow are frequently confounded in common language with brass1 as brass guns1 c4 ,indeed the ancient ,greeks and ,romans seem to have been in possession of these two alloys1 under one and the same name4 ,the of the ,greeks1 being used for cutting-instruments1 must have signified bell-metal1 or the alloy of copper and tin as well as brass1 as indeed is proved by the analysis of them4 ,the s of the ,romans seems also to have included the same compound4 ,ancient copper coins too are usually found to contain tin4 ,tin united to copper in certain proportions gives a surprising degree of hardness and tenacity to the alloy1 much superior in these respects to either of the ingredients4 ,in other proportions it makes the compound highly sonorous1 as in bell-metal properly so called4 ,tin also increases the fusibility of the compound in proportion as it abounds1 being itself fusible at the low temperature of #ddj ,fahrenheit4 ,the principal varieties in the alloys of copper and tin are enumerated below1 beginning with those in which the copper is most abundant4 ,the atom of copper is taken at #ef and that of tin at #eb weight1 the hardness of these metals is denoted by #g4e and #f respectively1 by ,kirwan4 7a74 ,gun-metal4 ,the alloy for brass guns or cannon is made of #ajj parts of copper and #aa or #ab of tin4 ,a small portion of iron is found to improve the metal2 this is best added in the state of tin-plate1 as it more readily fuses and unites with the metal4#bj ,this compound is hard and extremely tenacious1 exceeding in this respect any other alloy of the two metals4 ,the addition or subtraction of #a or #b parts of tin materially impairs the tenacity of the alloy4 ,it is constituted of #h atoms of copper and #a of tin4 ,footnote #bj3 ,see a very excellent essay on the alloy of copper and tin by ,m4 ,dussaussoy1 in the ,annales de ,chimie ,physique4 #e--aac4 7b74 ,alloy for edge tools1 printers' cylinders1 c4 ,the best proportion for this compound seems to be #ajj parts copper and #ae or #af tin4 ,when hammered and tempered duly it is fit for making edge tools not inferior to some kinds of steel4 ,it is a compound of greater density than the preceding1 though containing more tin2 the grain is fine and the metal free from blisters and suited for turning in the lathe4 ,it seems to be the best alloy of the kind for printers' cylinders2 but an analysis which ,i lately made of some turnings from one of these cylinders gave me much less tin than the above proportion4 ,the alloy 7b7 is constituted of #f atoms of copper and #a of tin4 7c74 ,alloy for the ,chinese gong1 cymbals1 c4 ,an alloy formed of #ajj parts copper and #bc tin1 appears from ,dussaussoy's experiments to form the compound of minimum density4 ,it is used for making cymbals2 and nearly accords with the composition of the ,chinese gong4 ,it is formed of #d atoms of copper and #a of tin4 ,the ,chinese gong analysed by ,klaproth was composed of #ajj copper and #bh4b tin2 that by ,dr4 ,thomson of #ajj copper and #bc4d tin4 7d74 ,common bell-metal used for casting bells4 ,this alloy is commonly made of #c parts copper and #a of tin2 but to be in due proportion for #c atoms of copper and #a of tin1 it should be formed of #ajj copper and #ca tin4 ,it is hard1 of a white colour1 less malleable than the preceding alloys1 and more sonorous4 ,a specimen ,i analysed consisted of #ajj copper and #cf tin4 ,the exact proportion of #ajj copper and #ca tin is not essential to produce a sonorous alloy4 7e74 ,speculum metal4 ,this compound has been investigated with great care by opticians4 ,according to ,mr4 ,mudge the best proportion is #cb parts copper to #ad4e tin1 but ,mr4 ,edwards finds #ae parts tin1 #a brass1 #a silver and #a arsenic4 ,the slightest variation in the proportions of copper and tin impairs the metal4 ,the alloy is white1 hard and close grained2 it takes a beautiful polish4 ,the use of the minute portions of zinc1 silver and arsenic is perhaps to correct the colour of the alloy2 though it seems in several alloys that very minute portions of metals apparently foreign to the alloy1 improve the density and texture of the metal4 ,it is remarkable with what precision this alloy accords with the atomic combinations of #b copper with #a tin4 ,by calculation #cb copper would require #ad4h tin4 ,mr4 ,mudge finds #cb copper to #ad tin1 and observes that if a part more of tin be added the metal is too hard4 ,mr4 ,edwards indeed says #cb copper and #ae tin2 but then he adds #a part brass1 which containing of a part of copper1 it reduces his proportion to #cb copper and #ad4g tin1 almost exactly that required by the theory4 ,when #cb copper and #ac tin are combined1 ,mr4 ,mudge asserts the metal is too soft4#ba ,footnote #ba3 ,this author obtained the ,royal ,society's gold medal for his essay on the composition1 c4 of specula for telescopes4 ,philos4 ,transact4 #aghg4 7f74 ,copper and tin1 equal parts4 ,this alloy is of blueish white colour1 and of no particular use that ,i am acquainted with4 ,it consists of the union of #a atom of copper with #a of tin4 ,the other alloys of copper with a higher proportion of tin appear to be uninteresting1 and have not been objects of much attention4 99 99 99 99 99 ,not having an opportunity of forming these alloys synthetically1 ,i contented myself with the analysis of several of them4 ,the mode of analysis ,i adopted with compounds of copper and tin1 is simple and easy4 ,the alloy is treated with nitric acid1 which dissolves the copper1 and on being diluted with water throws down the tin in the state of deutoxide4 ,this last is collected on a filtre1 dried1 and heated to a low red2 then _/ of this is allowed for the tin 7the other #g parts being oxygen72 and the rest of the alloy may be considered as copper4 ,but if thought proper the copper may be thrown down by immersing a plate of lead in the solution1 which succeeds better than a plate of iron in nitric solutions of copper4 #d4 ,copper and lead4 ,copper unites with boiling lead and forms a grey brittle alloy of granular texture4 ,this alloy being heated above the melting point of lead1 causes the last metal to run off1 leaving the copper nearly pure4 ,the alloy is scarcely of any use4 #e4 ,copper and zinc4 ,copper and zinc combined form brass1 one of the most useful of all alloys4 ,though this is a general name for such combinations1 yet several of the proportions form compounds to which peculiar names are given1 some of which will be noticed below4 ,it may be proper to remark that copper is estimated by ,mr4 ,kirwan at #g in hardness1 whilst zinc is #f4 ,the former metal is highly tenacious and malleable2 the latter is brittle and malleable only in a small degree4 ,according to ,lewis a very small proportion of zinc dilutes the colour of copper and renders it pale2 when the copper has imbibed _/ of its weight1 the colour inclines to yellow4 ,the yellowness increases with the zinc till the weight of that metal in the alloy equals the copper4 ,beyond this point if the zinc be increased the alloy becomes paler and paler and at last white1 like zinc4 ,the tenacity of brass is greater than that of either copper or zinc according to ,muschenbroek4 ,his experiments give brass nearly twice as strong as copper1 and #ah times as strong as zinc4 ,it seems to me most probable that the tenacity of brass increases with the increase of zinc in the alloy to a certain proportion1 when it becomes a maximum1 and thence diminishes with the further increase of zinc1 but experiments are yet wanting1 ,i presume1 to ascertain what proportion of the two metals must be taken to form the alloy of greatest tenacity4 ,the same observation may be made as to the maximum hardness2 it is not improbable that the two maxima may be found in different kinds of brass4 ,the point of temperature at which copper fuses is stated to be #bg of ,wedgwood's thermometer1 whilst that of zinc is much lower1 namely1 #fhj of ,fahrenheit4 ,common brass is stated to melt at #ba of ,wedgwood4 ,it is very probable that all kinds of brass melt at temperatures intermediate between those of copper and zinc2 and that the more of zinc the lower will be the fusing temperature2 but there have not been direct experiments to ascertain the degrees1 as far as ,i know4 ,in enumerating the different proportions of such alloys as have come under my notice ,i shall begin with that containing the maximum of copper1 and proceed in gradation to that with the maximum of zinc4 7a74 ,brass for the manufacture of plated goods4 ,this alloy is composed1 judging from one specimen ,i analysed1 of #ab atoms of copper and #a of zinc2 or of nearly #bh parts of copper by weight and #a of zinc4 ,the atom of copper is here estimated at #ef and that of zinc at #bi1 or very nearly that of copper4 ,this alloy had much the same qualities apparently as copper itself1 only a little more yellow4 7b74 ,dutch gold1 gilding metal4 ,this is the alloy which may be beaten out into thin leaves1 after the manner of gold leaf4 ,i have not been able to find any proportions for this compound in books4 ,it seems to have been kept as a secret by the manufacturers4 ,by analysis however ,i find it composed of #f atoms of copper and #a of zinc1 or nearly #ab parts copper and #a zinc by weight4 ,this alloy is probably the most malleable of all the kinds of brass4 ,a leaf containing #ab square inches weighs about _/ of a grain4 ,the colour1 as is well known1 makes a good approach to that of gold4 ,it is the composition used for making articles to be gilt1 as buttons1 c4 7c74 ,dipping metal for stamped brass goods4 ,this is a well known article of ,birmingham manufacture4 ,it is an alloy both tenacious and malleable1 as is manifest from the perfection of the articles4 ,it possesses a beautiful gold colour4 ,a specimen was composed1 by my analysis1 of #d atoms of copper to #a of zinc2 or of #h lbs4 of copper and #a of zinc2 or of #d lbs4 copper and #c of common brass2 but it is varied according to the colour wanted4 7d74 ,soft1 fine coloured brass4 ,according to ,m4 ,sage1 a very fine kind of brass may be made by mixing oxide of copper1 calamine1 black-flux and charcoal powder together and fusing the mixture in a crucible till the blue flame disappears4 ,the brass is found to weigh more than the copper resulting from the weight of oxide4 ,he says when the copper retains of zinc the colour is not so fine2 and the excess of zinc will be burned off by heat1 but the zinc cannot be reduced by burning below 2 so that this appears to be a natural limit4 ,hence this compound1 being formed of #f parts copper and #a of zinc1 must be constituted of #c atoms of copper and #a of zinc4 7e74 ,soft brass preferred for watch movements4 ,there is a kind of brass greatly preferred by watch-makers on account of its working well with steel4 ,i have not met with a specimen2 but ,dr4 ,thomson has analysed one and found it to consist of #b atoms of copper and #a of zinc2#bb or #d parts copper and #a of zinc by weight nearly4 ,footnote #bb3 ,an4 of ,philos4 ,vol4 #ab4 7f74 ,common hard brass4 ,this constitutes the great bulk of brass1 as manufactured in the large way4 ,it is made by exposing granulated copper1 calamine1 that is1 a native oxide of zinc1 and powdered charcoal in mixture to a red heat for some hours1 and then increasing the heat so as to melt the compound of copper and zinc1 the charcoal having carried away the oxygen of the calamine4 ,the metal is then cast into ingots or plates as may be required4 ,this is called brass of cementation as distinguished from the other species1 which are usually made from this by fusion with copper or zinc as the case requires4 ,it is found that #djlbs4 of copper with #fjlbs4 of calamine yield #fj lbs4 of brass2 hence a great part of the zinc burns away during the process4 ,the brass thus resulting1 consisting of #b parts of copper and #a of zinc1 is of course constituted of #a atom of each metal united together4 ,common brass is malleable1 when cold1 like the preceding species2 but probably does not possess that property in so high a degree4 ,it seems better adapted for turning in the lathe than any other kind of brass4 ,the specific gravity of this brass before it is hammered or rolled is generally about #h4a or #h4b by my experience4 ,when rolled it receives a great increase of density1 amounting to 4#e according to ,m4 ,dussaussoy#bc1 so that what is #h4b when cast will be #h4g when rolled2 or it is condensed nearly _/ of its volume by the operation of rolling4 ,the same author finds that brass is hardened very considerably by rolling1 but rendered less tenacious2 however by being heated and consequently softened after rolling1 it becomes stronger than ever1 and nearly of an intermediate specific gravity between cast and rolled brass4 ,footnote #bc3 ,an4 de ,chim4 ,physique4 #e--bcc4 7g74 ,prince's metal1 pinchbeck1 c4 ,this compound1 as far as ,i can learn1 is usually formed by combining equal weights of copper and zinc1 or by fusing together #c parts of common brass with #a of zinc4 ,according to ,lewis the yellow colour of brass is a maximum in this proportion4 ,the alloy is brittle1 or at least much less malleable than common brass4 ,i find the composition of spelter solder1 as it is called1 or that used for soldering both brass and copper1 to be nearly equal parts of copper and zinc4 ,hence it appears that #a atom of copper unites to #b of zinc to form this alloy4 ,the other alloys of copper and zinc in which the zinc gradually exceeds the copper1 become gradually paler in colour and more brittle4 ,they do not promise to be of much utility in the arts1 and have not therefore been very particularly investigated by metallurgists4 ,besides the binary combinations of copper and zinc and copper and tin1 there are ternary combinations of these metals1 namely1 alloys of copper1 zinc and tin4 ,for instance1 the metal of which common white buttons are made4 ,i had occasion to analyse a specimen of this metal and found it to be constituted of #d parts copper1 #a of zinc and #a of tin2 or #d atoms of copper1 #b of zinc and #a of tin4 ,it will be proper to subjoin the methods of analysis which ,i adopted in regard to brass4 ,twenty grains1 more or less1 of the particular articles were dissolved in nitric acid1 and the metals were precipitated in the state of sulphurets by hydrosulphuret of lime4 ,the copper is thrown down in the state of a black powder1 and the zinc in that of a white powder turning to grey4 ,great care was taken to add the precipitating liquor gradually in order that the copper might be obtained distinctly from the zinc4 ,the whole of the copper is thus thrown down before any of the zinc precipitate appears4 ,the precipitates were collected and dried in a temperature not exceeding #aej1 and then weighed4 ,in both cases one third of the weight was allowed for sulphur1 and the remaining two thirds were estimated to be metal2 which is agreeable to the known constitutions of these sulphurets4 ,another method ,i sometimes practised1 which also answers very well2 namely1 to throw down the whole or greatest part of the copper by a plate of lead1 then to throw down the lead by sulphuric acid2 after this the liquor was tested by hydrosulphuret of lime to precipitate the copper remaining1 if any2 and lastly to throw down the zinc by hydrosulphuret of lime4 #f4 ,copper and bismuth4 ,the alloy is brittle and of a pale colour4 ,it is not much known4 #g4 ,copper with antimony4 ,copper and antimony unite by fusion and form a violet coloured1 brittle alloy4 #h4 ,copper and arsenic4 ,these metals unite by fusion in a close crucible1 the surface of the mixture being covered with common salt to prevent the oxidizement of the arsenic4 ,the alloy is white and brittle1 and is known by the names of white copper1 and white tombac4 #i4 ,copper and manganese4 ,these may be united by fusion1 and form a red coloured1 malleable alloy1 according to ,bergman4 #aj4 ,copper and molybdenum4 ,these metals may be alloyed in various proportions1 but the compounds exhibit nothing peculiarly remarkable4 ,alloys of ,iron with other ,metals4 #a4 ,iron with tin4 ,these two metals are alloyed with some difficulty by fusion in a close crucible4 ,the difficulty seems to arise from the very unequal temperatures at which the metals individually fuse4 ,bergman always found two alloys when the metals were fused together2 the one composed of #ba parts tin and #a of iron1 that is1 #aj atoms of tin to #a of iron2 and the other of #b parts iron1 and #a of tin2 that is1 #d atoms of iron and #a of tin4 ,the first was very malleable1 harder than tin and not so brilliant2 the second but moderately malleable and too hard to yield to the knife4 ,the formation of common tin-plate is a proof of the affinity of tin and iron4 ,thin plates of iron1 thoroughly cleaned1 are dipped into melted tin1 when the tin adheres to the surface of the iron1 forming with that metal a true chemical union4 #b4 ,iron and lead1 c4 ,iron combines by fusion more or less perfectly with lead1 zinc1 bismuth1 antimony1 arsenic1 cobalt1 manganese1 c4 but the proportions have in few instances been ascertained1 and the compounds are generally of little importance4 ,alloys of ,nickel and other ,metals4 ,nickel and arsenic4 ,as nickel and arsenic are naturally found in combination1 though mostly along with small quantities of other bodies1 it is to be presumed that an affinity subsists between them2 but ,i do not know that the proportions have been ascertained in which they unite1 or the nature of the alloys4 ,alloys of ,tin with other ,metals4 #a4 ,tin with lead4 ,tin and lead unite by fusion in any proportion4 ,this alloy1 according to ,muschenbroek1 is harder and much more tenacious than either tin or lead1 especially when #c parts tin and #a lead are its constituents4 ,i fused various proportions of tin and lead together1 as per the following table1 in order to find some of the more prominent characteristics of the several alloys4 ,the specific gravity of the tin was #g4b1 that of the lead was #aa4bc2 and the portions taken were such as to combine1 #a1 #b1 or more atoms of tin with #a of lead4 ,the several metals were melted and the compounds formed under a few drops of tallow1 otherwise the oxidation is so rapid that the proportions are disturbed and the quantity of pure alloy is not equal to the weight of the ingredients4 ,without this precaution it is no uncommon occurrence in small experiments to obtain only #c parts of fusible alloy from #d of metal4 ,atoms4 ,weights ,sp4 ,gr4 by ,sp ,gr4 by ,fusing calculation4 experim4 ,point4 ,tin4 ,lead4 ,tin4 ,lead4 #a #a 4#eh #a #i4cb #i4ag #dcj #b #a #a4af #a #h4fd #h4gi #cej #c #a #a4gc #a #h4be #h4di #cdj #d #a #b4c #a #h4jj #h4aj #cde #e #a #b4i #a #g4ic #h4jj #cej #f #a #c4dg #a #g4ha #g4ij #cfj ,from the above table it appears that when #a atom of tin is united to #a of lead there is an expansion of volume2 but when more than #a of tin are combined to #a of lead there is a contraction of volume1 or the density is above that by calculation4 ,this increase of density is greatest when #c atoms of tin are combined with #a of lead2 and it is not improbable the tenacity may then be a maximum2 though ,muschenbroek finds it more tenacious when #c parts tin are united to #a of lead1 which answers more nearly to #d atoms tin and #a of lead2 this opinion is countenanced by the fact that tin is much the most tenacious of the two metals taken singly4 ,it is remarkable that the fusing point of these alloys is below those of either tin or lead4 ,the lowest of all 7#cdj7 is when #c atoms of tin are alloyed with #a of lead4 ,common pewter1 ,i find1 is an alloy of #d atoms of tin and #a of lead nearly1 and fuses about #cde or #cej4 ,this is perhaps the best proportion2 it is hard1 tenacious and of a good colour4 ,more of lead would impair the colour1 and more of tin would impair the tenacity and increase the expence1 though it might improve the colour4 ,certain articles for family use1 such as tea-pots1 spoons1 c4 are made of white metal1 which commonly1 though ,i apprehend improperly1 goes by the name of tutenag4 ,this metal in colour approaches more to silver than pewter does4 ,a spoon of this description ,i found to be pure tin4 #b4 ,tin and zinc4 ,this alloy is easily made by fusion4 ,the metals seem to unite in any proportion4 ,i melted together #bi parts zinc and #eb tin 7#a atom of each71 and obtained a white hard alloy of about #f4h specific gravity4 ,when #b atoms tin and #a zinc are united the specific gravity is #f4gg1 which is below the mean4 ,the alloy appears to be very hard and tenacious2 and probably might be put to some use4 #c4 ,tin and bismuth4 ,these metals readily combine by fusion in any proportion4 ,when #eb parts tin and #fb bismuth are fused together 7#a atom to #a71 a fine1 smooth1 hard but brittle alloy is obtained of the specific gravity #h4db4 ,it fuses at #bfj4 ,two atoms tin and #a bismuth give an alloy of #h specific gravity1 which fuses about #cbj4 ,the alloy of #a atom tin and #b of bismuth is of #h4fg specific gravity1 and fuses about #bfj4 ,the alloy of #c atoms tin and #a bismuth is of #g4gc specific gravity1 and fuses at #cej4 ,the alloy of #a atom tin and #c bismuth is of specific gravity #i4ad1 and fuses at #ccj4 #d4 ,tin with antimony4 ,this compound is said to be white and brittle when formed of equal parts4 ,i did not succeed in uniting the two metals by fusion on a small scale4 #e4 ,tin with arsenic4 ,when #ae parts of tin and #a of arsenic are fused together the alloy crystallizes in large plates like bismuth1 according to ,bayen4 ,it is brittle and less fusible than tin4 ,this alloy must be composed of #e atoms of tin and #a of arsenic1 that is1 #cab tin and #ba arsenic4 ,alloys of ,lead with other ,metals4 #a4 ,lead and zinc4 ,these two metals seem to have a weak affinity4 ,they are easily united1 or rather mixed1 in any proportion by fusion under a little tallow4 ,but however they may be mixed there is a strong tendency to separate again1 which no doubt is occasioned in part by their great difference in specific gravity4 ,i have fused lead and zinc together in various proportions1 from #f parts lead to #a of zinc1 to #a part lead to #b of zinc4 ,the compound usually gives a specific gravity rather greater than the mean2 but upon being broken the fracture is often like that of zinc in one part and not so in another2 and the analysis of fragments proves that a great difference exists in their composition4 ,subsequent fusion sometimes improves the combination and at other times the contrary4 ,six parts lead and #a of tin gave a compound as nearly uniform as any4 ,it was #aa specific gravity1 harder and whiter than lead and had much the appearance of pewter1 that is1 the alloy of tin and lead4 #b4 ,lead and bismuth4 ,these metals alloy well4 ,three parts lead and #b of bismuth unite by fusion and form a tenacious alloy which fuses about #cdj4 ,muschenbroek found it ten times stronger than lead4 ,it grows dark coloured soon by keeping4 ,its specific gravity by my observation is #aj4he1 which is rather greater than the mean4 ,it is constituted of #a atom of each metal1 or #fb bismuth to #ij lead4 ,three parts lead and #d bismuth 7#a atom lead to #b bismuth7 fuses at #bej4 ,this is the lowest temperature at which any alloy of two metals fuses4 ,with a little tin it makes the triple alloy which fuses lower than any other metallic compound1 without mercury1 as will be shown in the sequel4 ,the specific gravity of this alloy of lead and bismuth is #aj4g1 which is greater than the mean4 ,the alloy of #a part lead and #b bismuth 7#a atom of lead and #c bismuth71 fuses at #bhj1 and is of #aj4a specific gravity1 or rather less than the mean4 ,the alloy of three parts lead and #a bismuth 7#b atoms of lead and #a of bismuth7 fuses at #dej4 ,the specific gravity is #aa1 or rather greater than the mean4 #c4 ,lead and antimony4 ,these two metals combine by fusion in any proportion4 ,the alloy is of a fine grain and is brittle or flexible as the antimony or lead prevails4 ,the principal use of this alloy1 ,i believe1 is in the formation of printers' types4 ,the small types require a harder alloy or one with more antimony2 the large types have a greater share of lead as being less expensive4 ,on examination of the different types ,i find #c proportions of the alloy principally in use4 ,the smallest types are cast from a mixture which very nearly corresponds with #dj parts of antimony to #ij of lead 7or #a atom to #a74 ,it is hard1 has a fracture like steel and is of the specific gravity #i4d or #i4e nearly1 and fuses about #dhj or #ejj4 ,the proportions were determined both by analysis and by inference from the specific gravity of the metal4 ,the middle sized types are made of metal composed of #a atom of antimony and #b of lead1 or #dj parts antimony and #ahj of lead4 ,this alloy fuses about #dej or #dfj and has the specific gravity of #aj nearly4 ,the largest types or letters of #b or #c inches diameter are made of metal composed of #a atom antimony and #c of lead1 or #dj parts to #bgj4 ,this alloy also fuses about #dej or #dfj1 which is a very remarkable fact4 ,its specific gravity is usually #aj4bb4 ,after several trials ,i could not determine whether the fusing point of this or the preceding alloy was lower2 and equal parts of the two alloys fused together were liquified at the same temperature of #dej or #dfj4 ,all the intermediate sizes of types appear to be made of one or other of the three preceding proportions or of mixtures of them1 the smaller the type the more of antimony being required to give the requisite hardness4 ,the largest types might1 ,i conceive1 be made with a much greater proportion of lead4 ,when #dj antimony and #cfj lead 7#a atom to #d7 are fused together1 the melting point is about #dgj4 ,the specific gravity was found #aj4d1 but probably too low from blisters or air bubbles4 ,the alloy was more flexible than the preceding1 but brittle with a fine grained fracture4 ,forty parts antimony with #dej lead 7#a atom to #e7 fused at #dij1 and gave #aa specific gravity4 ,this alloy bends and breaks with a fine grained fracture4 ,forty parts antimony with #edj lead 7#a atom to #f7 fused at #eaj1 and gave #aj4h specific gravity1 which in all probability was owing to air bubbles4 ,now the alloy soft and malleable4 #d4 ,lead and arsenic4 ,when lead is fused in contact with the white oxide of arsenic under a film of tallow and stirred frequently1 an union of the two metals takes place and the excess of white oxide is partially converted into arsenic and partly driven off1 seemingly taking with it a portion of the lead4 ,a considerable portion of the mass assumes the form of a black spongy compound infusible at the temperature4 ,it contains a portion of the lead and is probably a compound of the metals with oxygen4 ,the fusible alloy has the appearance of lead1 but is brittle1 breaks without bending and exhibits a fracture like that of antimony and lead4 ,the specific gravity of the alloy is #aj4f1 or more if not saturated with lead4 ,by treating it with an excess of nitric acid it is dissolved1 and the lead may be thrown down by sulphuric acid1 and the arsenic acid or oxide by lime4 ,in this way ,i find the alloy is composed of about #i parts of lead with #b of arsenic1 or #a atom of each of the metals4 ,the spongy mass treated with nitric acid yields a similar solution1 accompanied with a precipitation of oxide of arsenic4 #e4 ,lead and cobalt4 ,the alloy of these two metals is not easily obtained1 probably from the great difference of the temperature at which they fuse4 ,gmelin fused #a part cobalt with #a1 #b1 #d1 #f and #h parts of lead respectively4 ,alloys were obtained of the specific gravities #h4ab1 #ab4bh 7query #h4bh871 --1 #i4fe and #i4gh respectively4 ,from these specific gravities it is plain the lead had been in great part dissipated by the heat4 ,for the last or greatest specific gravity corresponds nearly to #b parts lead and #a of cobalt4 7,an4 de ,chimie1 #ai--ceg47 ,triple ,alloys1 ,solders2 ,fusible ,metal1 c4 ,though it may seem premature to treat of triple compounds in the present chapter1 which professedly is limited to compounds of two elements1 yet as the triple alloys are few and so immediately connected with the preceding1 it will scarcely require an apology for introducing them here4 ,soft solders4 ,solders for plumbers and tin-workers1 are required to melt easily1 and yet not too low1 as they should withstand a heat greater than boiling water4 ,the fusing point of the soft solders is usually between #cjj-djj4 ,plumbers' solder ,i believe is commonly formed by mixing equal parts of tin and lead4 ,i procured a specimen of #h4i specific gravity1 and its fusing point was #chj4 ,probably a more perfect compound would be formed by mixing #ajd parts tin with #ij lead 7#b atoms to #a71 which would give a specific gravity of #h4h and the fusing point #cej4 ,tin workers' solder is made rather more fusible than that of the plumbers4 ,a specimen ,i got from the workmen was #h4hg specific gravity and fused at #cde4 ,a mixture of #c parts tin and #b of lead would have formed an alloy of the same fusibility1 but the specific gravity would have been #h4f or #h4g only4 ,probably a rather less proportion of tin with a little bismuth entered into the composition4 ,fusible ,metal4 ,tin1 bismuth and lead are metals which melt at comparatively low temperatures2 and it has been shewn that the alloys of any two of them usually melt at lower temperatures than the mean1 or even than the lower extreme4 ,by analogy it might be inferred that an alloy of tin and lead fused with one of tin and bismuth1 would melt below either of the two ingredients4 ,it has been shewn that proportions of bismuth and lead of easiest fusion are #b atoms bismuth with one of lead2 this alloy melts at #bej4 ,an alloy of #b atoms of bismuth and #a of tin melts at #bfj2 and so does that of #a atom bismuth and #a tin4 ,these alloys being much more easily fused than any other proportions of these metals1 it is from their combinations we are to expect a still further reduction of the fusing point4 ,in fact1 a combination of either of the tin and bismuth alloys1 with the lead and bismuth alloy1 produces almost exactly the same reduction of the fusing temperature4 ,thus if #d atoms of bismuth1 #a of tin and #a of lead be fused together1 the compound melts in boiling water or below #bab4 ,it is equally the case if #c atoms bismuth1 #a of tin and #a of lead1 are fused together4 ,the double alloy next to those above mentioned in regard to easy fusion is that of #b atoms tin1 and #a bismuth4 ,it fuses at #cbj4 ,this alloy1 united to the one of #b atoms bismuth and #a lead1 gives a compound of #c atoms bismuth1 #b tin and #a lead1 which fuses very nearly at the same temperature as the above triple alloys4 ,in reference to weights1 the above proportions for the most fusible metals will nearly be1 ,bismuth #ad parts -- ,lead #e -- tin #c ------- #aj ----- -- ---- #e ------ #c ------- #e ----- -- ---- #b ------ #c ,most of the elementary books have given the proportions of #h bismuth1 #e lead and #c tin2 or #e bismuth #b lead and #c tin1 which nearly agree with some of the above1 and give an alloy fusing below #bab4 ,wishing to investigate this subject more fully1 and it being obvious from the preceding facts that there are only two proportions of tin and lead to be united with bismuth1 to produce the desired effect1 namely1 either #a atom of tin with #a of lead1 or #b atoms of tin with #a of lead1 ,i proceeded as follows3 #a atom tin 7#eb7 #a atom lead 7#ij7 #a atom bismuth 7#fb71 were fused together2 the fusing point was #bgj4 ,the alloy was flexible to a certain degree2 and the fracture very small grained4 ,to this alloy #ca grains of bismuth were added successively till it was evident the alloy was growing less fusible2 the results were as follows3 #a atom tin #a lead #a bismuth2 fuses at #bgj #a -------- #a ---- #a ------ -------- #bce #a -------- #a ---- #b ------ -------- #bje #a -------- #a ---- #b ------ -------- #bjj #a -------- #a ---- #c ------ -------- #aig #a -------- #a ---- #c ------ -------- #bjj #a -------- #a ---- #d ------ -------- #bbj #a -------- #a ---- #d ------ -------- #bje semi fluid4 #a -------- #a ---- #e ------ -------- #bdj semi fluid4 but it retains a little fluidity down to nearly #bjj ,from this it appears that #c parts by weight of tin1 #e of lead1 and any proportion of bismuth from #g to #ad will produce an alloy fusing below #bab2 but of these the best is #aj or #aa parts4 ,again1 #b atoms of tin were combined with #a of lead and #c of bismuth1 by gradually adding one half of the tin4 ,the several alloys fused without any material difference at or below #bjj4 ,a further addition of tin impaired the property as in the above case with bismuth4 ,i did not think it important to mix #b atoms of tin and #a of lead with any other proportion than #c atoms of bismuth4 ,,appendix4 ,since the publication of the second part of the first volume1 7#ahaj7 some important essays on the subject of heat have appeared1 which have a direct bearing upon some points of the doctrine on that subject inculcated in the said volume4 ,it may be proper to state the results1 with such remarks and reflections as have occurred in the consideration of them4 ,in the ,annales de ,chimie for ,january #ahac1 also in the ,annals of ,philosophy1 vol4 #b1 we find a ,memoir on the specific heat of different gases1 by ,m4 ,m4 ,de la ,roche and ,berard4 ,this exhibits a most laborious and refined series of experiments on this most difficult subject4 ,great merit seems to be due to them1 both for invention and execution4 ,it is unnecessary to describe the particulars of the apparatus and the mode of conducting the experiments1 as a description may be found as above referred4 ,it is sufficient to observe that the calorimeter used was a copper cylinder of #c inches diameter and #f in length1 filled with water1 and having a serpentine tube #e feet in length1 running through the interior and opening at both ends on the outside of the vessels4 ,by means of this tube a regular current of any gas of a given temperature 7#bab7 might be passed through the vessel so as to part with its excess of temperature to the water4 ,the quantity of water and the capacity of the vessel for heat were previously determined2 and the quantity of heated gas passed through the calorimeter was determinable at any time1 as well as the temperature of the water1 from the judicious arrangements4 ,it is easy to see that when an apparatus of this kind is at work1 the gas will impart heat1 more or less according to its capacity1 to the water2 and that the temperature of the calorimeter will gradually ascend till it arrives at a maximum2 that is1 till the refrigerating effect of the surrounding atmosphere upon the calorimeter is equal to the heating effect of the current of gas4 ,the following ,table exhibits the results of their experiments4 ---------------------------------------- --------------- ,specific ,heat ,of the same bulk4 ,of the same weight4 ---------------------------------------- -------------- ,air #a4jjjj #a4jjjj ,hydrogen #j4ijcc #ab4cdja ,carbonic ,acid #a4behc #j4hbhj ,oxygen #j4igfe #j4hhdh ,azote #a4jjjj #a4jcah ,nitrous ,oxide #a4cejc #j4hhgh ,olefiant ,gas #a4eecj #a4egfc ,carbonic ,oxide #a4jcdj #a4jhje ,aqueous ,vapour #a4ifjj #c4acfjbd ---------------------------------------- -------------- ,footnote #bd3 ,the result for this last article must be considered more uncertain than any of the previous ones1 the experiment being more complicated4 ,they found the specific heats of equal volumes of air of the pressures #bi4b and #da4g inches of mercury to be nearly as #a #a4bcif1 differing from the ratio of the pressures or densities1 which is #a3 #a4ceh4 ,the above table of the specific heat of the permanent gases 7excluding aqueous vapour7 was corroborated by the results of another series of experiments in which the principle was varied a little3 namely1 to find how many cubic inches of each gas at a given temperature were required to raise the temperature of the calorimeter a given number of degrees1 and inferring the capacities for heat to be inversely as the quantities of gas employed4 ,the differences in the results were from #a to #aj per cent41 which may be considered small1 in experiments of such delicacy4 ,the ratios of the specific heats of several gases being found1 it was highly expedient to find the ratio of the specific heat of water1 and that of some one gas1 as common air4 ,this was effected by passing a small current of hot water through the calorimeter1 and comparing the effect of this current with that of the larger one of air1 the requisite care being taken to ascertain the quantity of water passing in a given time and its temperature at the ingress4 ,the result of this experiment was that the specific heat of water is to that of common air as #a 4#be nearly4 ,by two other experiments1 varied from the above1 results not much differing were obtained1 so that the average of the three gave1 water to air1 as #a 4#bffi4 ,reducing the specific heats of the gases to the standard of water as unity1 we have the following ,table of the specific heats of equal weights of the respective bodies3 ,water #a4jjjj ,air #j4bffi ,hydrogen #c4bicf ,carbonic ,acid #j4bbaj ,oxygen #j4bcfa ,azote #j4bged ,nitrous ,oxide #j4bcfi ,olefiant ,gas #j4dbjg ,carbonic ,oxide #j4bhhd ,aqueous ,vapour #j4hdgd ,before we animadvert upon these results1 it will be expedient to give an abstract of the not less interesting experiments of ,messrs4 ,dulong and ,petit1 on heat1 as given in the ,annales de ,chimie and de ,physique1 vol4 #g and #aj4 ,these gentlemen begin by an investigation of the expansion of air by heat4 ,the absolute expansion of air from freezing of water to boiling had been previously determined by ,gay ,lussac and myself to be from #h to #aa nearly3 they however extended the enquiry above and below these points of temperature1 namely to those of freezing and boiling mercury4 ,from the temperature of freezing mercury or thereabouts1 to that of boiling water1 they find the expansion of air to keep pace with that of mercury1 as indicated by the common thermometer2 but from the boiling point of water to that of mercury1 the latter expands somewhat more in a proportion gradually increasing3 as by the following ,table4 ,,table ,i4 ---------------------------------------- ------------------------ ,temperature by an air ,thermometer1 ,temperature by ,mercurial ,corresponding corrected for ,thermometer4 volume of a given expansion of glass4 mass of air4 ,fahrenheit4 ,centigrade4 ,centigrade4 ---------------------------------------- ----------------------- -#cc -#cf #j4hfej -#cf4h #cb #j #a4jjjj #j #bab #ajj #a4cgej #ajj #cjb #aej #a4eegf #adh4gj #cib #bjj #a4gchi #aig4je #dhb #bej #a4iahi #bde4je #egb #cjj #b4jigf #bib4gj #fhj ,m4 boil #cfj #b4cabe #cej4jj ---------------------------------------- ----------------------- ,the absolute dilatation of mercury claims their attention4 ,they quote nine authorities for the expansion from freezing to boiling water temperatures2 the extremes of these nine are1 ,casbois _/ of original volume1 and mine _/ of the same4 ,they determine it to be _/44 ,by doubling and tripling the elevation of the temperature1 they made observations from which are deduced the results of the following ,table4 ,the dilatations are for each degree of the thermometer centigrade1 to which ,i have added the corresponding ones for ,fahrenheit's4 ,,table ,,ii4 ---------------------------------------- ----------------------- ,mean absolute ,temperatures indicated ,temperature by an air dilatations by dilatation of mercury1 ,thermometer4 of mercury4 supposed uniform4#be ---------------------------------------- ----------------------- ,fahr4 ,cent4 ,fahr4 ,cent4 ,fahr4 ,cent4 #cb #j #j #j #cb #j #bab #ajj _/ _/ #bab #ajj #cib #bjj _/ _/ #djj4c #bjd4fa #egb #cjj _/ _/ #eig4e #cad4ae ---------------------------------------- ----------------------- ,footnote #be3 ,that is1 the temperature that would be denoted by mercury inclosed in a vessel having no expansion by heat2 or else in one that expanded in the same rate as mercury4 ,by a series of observations on the apparent dilatation of mercury in glass vessels1 compared with the results in the above tables1 they deduce the absolute dilatation of glass for each degree of the thermometer1 and the temperature that would be indicated by supposing the uniform expansion of a glass rod adopted as the measure of temperature as under3 ,,table ,,iii4 ---------------------------------------- ---------------------- ,mean apparent ,absolute ,temperature by ,temperature by dilatation of dilatation of a ,thermometer an air ,thermom4 mercury glass in made of glass4 in glass4 volume4 ---------------------------------------- ---------------------- ,fahr4 ,cent4 ,fahr4 ,cent4 ,fahr4 ,cent4 ,fahr4 ,cent4 #bab #ajj _/ _/ _/ _/ #bab #ajj #cib #bjj _/ _/ _/ _/ #dae4h #bac4b #egb #cjj _/ _/ _/ _/ #ffg4b #ceb4i ---------------------------------------- ---------------------- ,the absolute dilatations of iron1 copper1 and platina were investigated with great address1 from #j to #ajj and from #j to #cjj centigrade2 and were found as per ,table below1 for each degree of the centigrade thermometer4 ,,table ,,iv4 ---------------------------------------- ------ ,temp4 by,mean dilatation,temp4 by,mean dilatation the air of iron1 iron rod of copper ,therm4 in volume4 ,therm4 in volume4 ---------------------------------------- ------ ,cent4 #ajj _/ #ajj _/ #cjj _/ #cgb4f _/ ---------------------------------------- ------ ------------------------------------- ,temp4 by ,mean dilatation ,temp4 by copper rod of platina platina rod ,therm4 in volume4 ,therm4 ------------------------------------- #ajj _/ #ajj #cbh4h _/ #caa4f ------------------------------------- ,connected with this subject was another important enquiry1 whether the capacities of bodies for heat remain constant at different temperatures1 or whether they diminish or increase as the temperature advances4 ,in other words1 does a body that requires a certain quantity of heat to raise it from #j to #ajj centigrade1 require the same quantity to raise it from #ajj to #bjj1 and from #bjj to #cjj1 c42 or does it require less or more as we ascend8 ,this enquiry involves that of the measure of temperature4 ,they adopt the uniform expansion of air1 or the air thermometer1 as the proper measure1 and find the capacity of iron1 ,from #j to #ajj 4#ajih #j to #bjj 4#aaej #j to #cjj 4#abah #j to #cej 4#abee the capacity of an equal weight of water being #a4 ,the following ,table exhibits the capacities of seven other bodies according to their results4 ,,table ,v4 ------------------------------------- ,mean capacity ,mean capacity between #j between #j and #ajj and #cjj ------------------------------------- ,mercury 4#jccj 4#jcej ,zinc 4#jibg 4#ajae ,antimony 4#jejg 4#jedi ,silver 4#jeeg 4#jfaa ,copper 4#jidi 4#ajac ,platina 4#jcce 4#jcee ,glass 4#aggj 4#aijj ------------------------------------- ,according to this table the capacities of bodies increase with the temperature in a small degree3 and the increase1 though it would still exist1 would be less1 if the common mercurial thermometer were the measure of temperature4 ,also supposing that thermometers made of these bodies and graduated by immersion in freezing and boiling water into #ajj2 if these were all immersed in a fluid in which an air thermometer stood at #cjj4 ,then the relative temperatures of the several thermometers would be as under1 if measured by the absolute quantity of heat acquired1 namely1 ,iron #cbb4b ,silver #cbi4c ,zinc #cbh4e ,antimony #cbd4h ,glass #cbb4a ,copper #cbj4j ,mercury #cah4b ,platina #cag4i ,from these observations they infer that the law which has been promulgated for the refrigeration of bodies1 cannot be strictly true3 namely1 that bodies part with heat in proportion as their temperature exceeds that of the surrounding medium4 ,some animadversions on the general laws relative to the phenomena of heat1 announced in my elements of ,chemical ,philosophy 7page #ac7 then follow1 together with a table drawn up to show the discordance between the air thermometer and the mercurial thermometer1 both being graduated in the manner ,i proposed in the said elements4 ,on these points ,i may have to remark in the sequel4 ,the first part of the ,essay concludes with some remarks to shew why a preference should be given to the air thermometer1 or more strictly1 the thermometer whether of mercury or any other body1 supposed to be graduated so as to correspond with an air thermometer of equal degrees4 ,the ,second ,part of the ,essay is on ,the ,laws of ,refrigeration4 ,adopting the air thermometer as the most eligible measure of temperature1 ,messrs4 ,dulong and ,petit proceed to investigate the laws of the refrigeration of bodies1 under a great variety of circumstances1 in vacuo and in air or gases of different kinds and densities4 ,the inquiry abounds with experiments and observations evincing great skill and acuteness2 but which it will not suit our purpose to detail4 ,it may suffice for us to give a general summary of the ,laws deduced by them from their experiments1 at the same time recommending all those who feel sufficient interest in the subject to peruse the essay at large1 which exhibits a profound philosophical train of experiments1 the results of which are illustrated by the aid of mathematical generalization4 8,law #a4 ,if one could observe the cooling of a body placed in a vacuum1 and surrounded by a vessel absolutely destitute of heat1 or otherwise deprived of the power of radiating heat1 the velocities of cooling would decrease in geometrical progression when the temperatures diminished in arithmetical progression40 8,law #b4 ,the temperature of a vessel containing a vacuum being constant1 and a body being placed in it to cool1 the velocities of cooling for excesses of temperature in arithmetical progression1 decrease as the terms of a geometrical progression diminished by a constant number4 ,the ratio of this progression is the same for the cooling of all kinds of bodies1 and is equal to #a4jjgg40 8,law #c4 ,the velocity of cooling in a vacuum for the same excess of temperature1 increases in geometrical progression1 the temperature of the vessel circumscribing the vacuum increasing in an arithmetical progression4 ,the ratio of the progression is the same as above1 namely #a4jjgg for all kinds of bodies40 8,law #d4 ,the velocity of cooling due to the sole contact of a gas is entirely independent of the nature of the surface of the cooling bodies40 8,law #e4 ,the velocity of cooling due to the sole contact of a gaseous fluid varies in a geometrical progression1 while the excess of temperature itself varies in a geometrical progression4 ,if the ratio of this second progression be #b1 that of the first is #b4ce1 whatever be the nature of the gas and its elastic force40 8,this ,law may be likewise announced by saying that the quantity of heat carried off by a gas is in all cases proportional to the excess of the temperature of the heated body raised to the power whose index is #a4bcc40 8,law #f4 ,the cooling power of a gaseous fluid diminishes in a geometrical progression1 when its tension itself diminishes in a geometrical progression4 ,if the ratio of this second progression is #b1 the rate of the first is #a4cff for atmospheric air2 #a4cja for hydrogen2 #a4dca for carbonic acid2 and #a4dae for olefiant gas40 8,this law may also be presented as follows3 ,the cooling power of a gas1 all other things being alike1 is proportional to a certain power of the pressure4 ,the exponent of this power depends on the nature of the gas1 and is for air #j4de2 for hydrogen #j4cae2 for carbonic acid #j4eag2 and for olefiant gas #j4eja40 8,law #g4 ,the cooling power of a gas varies with its temperature in such a manner that if the gas can dilate so as to preserve the same uniform tension1 the cooling power will be as much diminished by the rarefaction of the gas1 as it is increased by its augmentation of temperature2 so that definitively it depends only on its tension40 99 99 99 99 99 ,another ingenious ,essay was published by ,messrs4 ,dulong and ,petit1 in the ,annal4 de chimie et de physique1 vol4 #aj1 namely1 8,researches on some important points of the theory of heat40--,one object is to ascertain the specific heats of bodies with superior precision4 ,a table of the specific heats of certain metals1 found by their method1 is given1 together with the weights of the atoms of those metals1 and the products of the specific heats and weights of the atoms1 as under3 ---------------------------------------- ------------- ,product of the weight of each ,specific heats1,weights of the atom by the that of water atoms1 that ofcorresponding being #a oxygen being #a capacity4 ---------------------------------------- ------------- ,bismuth #j4jbhh #ac4cjj #j4chcj ,lead #j4jbic #ab4iej #j4cgid ,gold #j4jbih #ab4dcj #j4cgjd ,platinum #j4jcad #aa4afj #j4cgdj ,tin #j4jead #g4cej #j4cggi ,silver #j4jeeg #f4gej #j4cgei ,zinc #j4jibg #d4jcj #j4cgcf ,tellurium #j4jiab #d4jcj #j4cfge ,copper #j4jidi #c4ieg #j4cgee ,nickel #j4ajce #c4fij #j4chai ,iron #j4aajj #c4cib #j4cgca ,cobalt #j4adih #b4dfj #j4cfhe ,sulphur #j4ahhj #b4jaa #j4cghj ---------------------------------------- ------------- ,the inference intended from this ,table is pretty obvious1 namely1 that the atoms or ultimate particles of the above bodies contain or attach to themselves the same quantity of heat1 or have the same capacity4 ,this principle the authors think will apply to the simple atoms of all bodies1 whether solid1 liquid1 or elastic2 but they hold it does not apply to compound atoms4 ,it differs therefore essentially from a suggestion of mine1 made eighteen years ago1 7see ,vol4 ,i4 page #gj17 that the quantity of heat belonging to the ultimate particles of all elastic fluids1 must be the same under the same pressure and temperature4 ,they seem to apprehend1 from experience1 that a very simple ratio exists between the capacities of compound atoms and that of the elementary atoms4 ,they draw another inference from their researches1 that the heat developed at the instant of the combination of bodies1 has no relation to the capacity of the elements2 this loss of heat1 they argue1 is often not followed by any diminution in the capacity of the compounds4 ,they seem to think that electricity developes heat in the act of combination2 but they do not deny that a change of capacity may sometimes ensue1 and heat be developed from this cause4 ,remarks on the above ,essays4 ,results nearly agreeing with those of ,de la ,roche and ,berard1 on the capacity of certain elastic fluids for heat1 were about the same time obtained by ,m4 ,m4 ,clement and ,desormes4 7,see ,journal de ,physique1 ,vol4 #hi--ahai47 ,such results1 impugning some of the most plausible doctrines of heat1 could not be admitted but upon very good authority4 ,i remained doubtful1 in some degree1 till satisfied by my own experience4 ,i procured a calorimeter of the construction of ,de la ,roche's1 and to simplify the experiment1 instead of forcing a given volume of hot air through the calorimeter to impart heat to the water1 ,i drew1 by means of an air-pump1 a certain volume of atmospheric 7or other air7 of the common temperature1 through the calorimeter filled with hot water1 in order to find how much this process would accelerate the cooling4 ,from several experiments of this kind1 ,i am convinced that the capacity of common air for heat is very nearly such as the above ingenious ,french chemists have determined4 ,that is1 it is about _/ part only of what ,dr4 ,crawford deduced from his experiments1 and nearly the same part of what ,i inferred from my theoretic view of the specific heats of elastic fluids4 7,see ,vol4 ,i4 pages #fb and #gd47 ,indeed ,m4 ,m4 ,de la ,roche and ,berard appear to have been puzzled with the admission of their own results4 ,the combined heats of oxygen and hydrogen gases give only 4#fcce for the specific heat of water2 whereas by experiment the heat of water is found to be #a1 notwithstanding an immensity of heat is evolved during the combination of these gases4#bf ,footnote #bf3 ,by recent experiments ,i find the heat evolved in the union of oxygen and hydrogen1 would raise the temperature of the same weight of water #fejj4 8,it is necessary therefore10 they observe1 8to abandon the hypothesis which ascribes the evolution of heat in cases of combination to a diminution of specific heat in the bodies combined1 and admit with ,black1 ,lavoisier1 and ,laplace1 and many other philosophers1 the existence of caloric in a state of combination in bodies40 ,i am not aware of any writer that denies the existence of caloric in a state of combination of bodies4 ,dr4 ,crawford1 who would be thought the most likely to err in this respect1 maintains1 8that elementary fire is retained in bodies partly by its attraction to those bodies and partly by the action of the surrounding heat10 and that 8its union with bodies will resemble that particular species of chemical union wherein the elements are combined by the joint forces of pressure and of attraction40 7,on animal heat1 #b;d edition1 page #dcf47 ,he is perhaps somewhat unfortunate in his instance in the combination of carbonic acid and water2 muriatic acid or ammonia and water would have been more in point4 ,the truth is1 these important experiments shew that in elastic fluids the increments of temperature are not proportional to the whole heat1 compared with the like increments of temperature and whole heat in those bodies when in the liquid and solid states4 ,the specific heats of bodies1 it is well known1 are determined by means of the relative quantities of heat necessary to raise the temperature of those bodies a certain number of degrees4 ,they are expressed by the ratios of those quantities4 ,if the capacities of the same bodies for heat were permanent at all temperatures1 then these ratios would also express those of the whole quantities of heat in bodies4 ,in fact1 most authors represent the specific heats as expressing both the ratio of the total quantities of heat in bodies1 and of the relative quantities to raise their temperature a given number of degrees2 but it is the latter only which they accurately represent1 and the former only hypothetically4 ,in regard to bodies in the solid and liquid forms1 all experience shews that their capacities for heat are nearly if not accurately constant within the common range of temperature2 it seems therefore not unreasonable to infer that the whole quantity of heat in each is proportional to their increments4 ,when1 however1 a solid body by an increase of temperature assumes a fluid form1 and absorbs heat without any increase of its temperature1 its total quantity of heat is thus increased2 and it is contended by the writers on capacity1 that the increments of heat afterwards are increased in the same proportion as the total quantities4 ,this is probable enough2 but it ought to be proved in several instances by direct experiment before it can safely be admitted as a general principle2 more especially now since the analogy in the case of a liquid becoming an elastic fluid is found to fail in this particular4 ,as an instance of uncertainty1 the capacity of ice to water has been found as #i to #aj by one person1 and as #g4b to #aj by others2 such wide difference in the results shows there must be a difficulty in determining the specific heat of ice1 and that it may even be doubted whether the specific heat of ice or water is greatest4 ,from the foregoing detail of experiments on elastic fluids1 it appears evident that such fluids exhibit matter under a form in which it has the greatest possible capacity for heat1 when capacity is understood to denote the total quantity of heat connected with the fluid2 but if the capacity or specific heat is meant to denote the quantity of heat necessary to raise the body a given number of degrees of temperature1 then the elastic fluid form of matter is that which has the least capacity for heat of any known form of the same matter4 ,when therefore we use the terms specific heat as applied to elastic fluids we should henceforward carefully distinguish in what sense they are used2 but the terms may still be indifferently used in the one or the other sense as applied to liquids and solids1 till some more decisive experiments shew that a distinction is required4 ,probably the anomalies that have occurred in investigations of the zero of cold1 or point of total privation of heat1 are in part due to the want of accordance between the ratio of the total quantities of heat in bodies1 and the ratio of the quantities producing equal increments of temperature4 ,the greatest possible quantity of heat which a given weight of elastic fluid can contain is when the dilatation of the fluid is extreme4 ,for1 condensation1 whether arising from mechanical pressure or from increased attraction of the atoms of matter for each other1 tends to dissipate the heat1 by increasing its elasticity4 ,hence increase of temperature1 at the same time that on one account it increases the absolute quantity of heat in an elastic fluid1 diminishes the quantity on another account by an increase of pressure1 if the fluid be not suffered to dilate4 ,this is well known from the fact that condensation produces increase of temperature in elastic fluids4 ,when it is considered that all elastic fluids expand the same quantity by the same increase of temperature1 it might be imagined that all of them would have the same capacity1 or require the same quantity of heat to produce that expansion4 ,the results of ,de la ,roche and ,berard do not seem to admit of this supposition1 though the differences of the capacities of elastic fluids of equal volumes are not very great4 ,there is a remarkable difference too between their results and those of ,clement and ,desormes1 in regard to hydrogen gas3 namely1 4#ijcc and 4#ffdj2 also in carbonic acid gas1 #a4behc and #a4e4 ,the subject deserves further investigation4 ,in reference to the experiments of ,dulong and ,petit1 on the relative expansions of air and mercury by heat1 ,i have no doubt their results are good approximations to the truth4 ,my former experiments were chiefly made in temperatures between #cb and #bab1 and ,i found1 as ,general ,roi had done1 the expansion of air to be somewhat greater in the lower half than in the upper half of that interval1 compared with mercury4 ,on a repetition of the experiments1 ,i think the difference is less than ,i concluded it to be1 and ,i find that the like coincidence of the air scale and mercurial1 continues down to near freezing mercury2 at least the difference will not be so great as my new table of temperature makes it at page #ad4 ,i have made some experiments on the expansions of air above #bab1 which lead me to adopt the results of ,dulong4 ,on a comparison of the air and mercurial thermometer upon the laws which ,i pointed out1 namely1 the former expanding in geometrical progression to equal intervals of temperature1 and the latter expanding as the square of the temperature reckoned from its freezing point1 it appears that in the long range of #fjj from freezing water to boiling mercury1 the greatest deviation of the two thermometers does not exceed #bb4 ,however1 the great deviation of the scales between the temperatures of freezing water and freezing mercury1 is sufficient to shew1 as ,dulong and ,petit have observed1 that their coincidence is only partial4 ,like the scales of air and mercury1 which are so nearly coincident from -#dj to #bab that scarcely any difference is sensible1 though no one doubts of its existence2 yet afterwards the differences become obvious enough1 and the greater the farther we advance4 ,expansion of ,mercury4 ,see page #cd1 vol4 ,i4 ,i have overrated the expansion of glass bulbs 7as will be seen presently17 and hence that of mercury2 my expansion of mercury corrected on account of the glass1 will be _/ nearly1 which leaves it still greater than ,dulong's4 ,the #bnd table of ,dulong is valuable1 on account of its affording us information of the rate of expansion in the higher degrees of temperature1 from a given or standard air thermometer4 ,iron1 ,copper1 and ,platina4 ,expansion of ,glass4--,by the #crd ,table of ,dulong and ,petit1 it appears these ingenious chemists found the expansion of glass for #ahj1 or from #cb to #bab1 very nearly the same as had been determined previously by ,smeaton and others4 ,it also expands increasingly with the temperature1 whether it is estimated by the air or mercurial standard4 ,this was observed by ,deluc1 but more extensively by the present authors4 ,the expansions of iron1 copper1 and platina1 from #cb to #bab as detailed in the #dth table1 agree nearly with the results of others2 but the expansions in the higher part of the scale manifest some remarkable facts not before known4 ,platina not only expands the least of the above bodies1 but its expansion is almost equable2 iron expands more than glass and less than copper1 but the most unequally of any one1 the expansion increasing rapidly as the temperature advances4 ,these facts explain some others which have fallen under my observation4 ,i was formerly surprised to find glass and iron expand so nearly alike 7see vol4 ,i4 page #ca72 but it now appears that iron increases more slowly in proportion than glass about the freezing point4 ,more recently ,i procured a small thermometrical vessel of platina to contain water like those described at page #ca1 vol4 ,i1 and having filled it and treated it as the other metallic vessels1 ,i was again surprised to find that the apparent greatest density of water in this vessel was at #dc1 whereas ,i expected to have found it below #db1 the point for glass vessels4 ,this observation1 in conjunction with ,dulong's1 shews1 that platina expands more than iron at low temperatures1 though for a range of #cjj the whole expansion of the platina is to that of the iron as #b to #c nearly4 ,hence the error 7for ,i now consider it as such7 which ,i was led into with respect to the expansion of glass bulbs1 7see vol4 ,i4 page #cb7 and subsequently into that of the expansion of mercury abovementioned4 ,it is not the expansion of glass which approaches that of iron1 but it is the reverse1 which occasions the two bodies to meet so nearly in the table1 page #ca4 ,this consideration will affect the point of greatest density of water also2 for1 the less the expansion of iron and glass1 the nearer will be the points of real and apparent greatest density of water1 contained in vessels of those materials4 ,my observations on brown earthenware are scarcely to be relied upon from the difficulty of making such vessels water tight3 but the common white ware ,i have verified repeatedly since the publication of that table1 and am satisfied the point of apparent greatest density1 is at or near #dj in such vessels2 hence the real maximum density of water must be below #dj4 ,i am inclined to adopt #ch as the most proximate degree4 ,capacities of bodies for heat4 ,in the #eth table of ,dulong1 we have the specific heats of glass and of six metals1 determined between freezing and boiling water3 that of iron is given before4 ,so far the question does not involve that of the measure of temperature4 ,their results afford no striking differences from those previously determined2 however1 it is desirable to find a greater accordance amongst philosophers in this respect4 ,the experiments which give the specific heats between #j and #cjj centigrade1 are original and interesting4 ,the results go to shew that the capacities of bodies increase in a small degree with the temperature4 ,but supposing that these results may be relied upon as accurate 7which can scarcely be affirmed of any former ones7 still the character of them may be changed by adopting a different measure of temperature4 ,the ,essay of ,m4 ,m4 ,dulong and ,petit1 in the #ajth vol4 of the ,an4 de chimie 7see ,an4 of ,philosophy1 vol4 #adth1 #ahai7 manifests great ingenuity4 ,it does not appear1 however1 so fortunate either in theory or experiment as the former one4 ,it would be difficult to convince any one1 either by reasoning or by experience that a number of particles of mercury at the temperature of -#dj1 whether in the solid11 liquid1 or elastic state1 have all the same capacity for heat4 ,indeed the experiments of ,de la ,roche and ,berard1 if they are to be credited1 demonstrate the inferior capacity of condensed air to rarefied air2 and if the same body changes its capacity in the elastic form1 it may well be concluded that all the three forms have not the same capacity4 ,m4 ,m4 ,dulong and ,petit have themselves shewn1 in their former essay1 7see page #bgf7 that solid bodies vary in their capacities for heat1 and that scarcely any two bodies1 vary alike2 hence it is impossible that the product of the weight of the atom and specific heat of the body should be a constant quantity4 ,their specific heat of certain metals differ greatly from what is found by others4 ,for instance1 they make the specific heat of lead 4#jbic2 the lowest authority ,i have seen is ,crawford1 4#jceb1 and the highest ,kirwan 4#jej2 from repeated trials ,i have lately found it1 upon an average1 4#jcb4 ,the weights of some of the atoms in their table1 differ materially from what are commonly received2 for instance1 bismuth is #ac4c instead of #i2 also copper1 silver1 and cobalt1 are only half the weights of some authors4 ,the gases too are unfortunate examples4 ,oxygen gas gives a product of 4#bcf instead of 4#cge2 azotic gas gives a product 4#aifg1 if oxygen be to azote as #g to #e1 but a product of 4#cic if oxygen be to azote as #g to #aj3 by ,dr4 ,thomson's ratio of oxygen to azote1 #d to #g1 the product will be 4#dhb1 very different from 4#cge4 ,hydrogen will give a product of 4#dg or 4#da instead of 4#cge4 ,all these differences1 it may be said1 are occasioned by errors in the specific heats of the gases2 but if errors of this magnitude can still subsist after all the care that has been taken1 we shall scarcely know what to trust in experimental philosophy4 ,if ,m4 ,dulong would assume all his simple elements in an elastic state and under one uniform pressure1 the hypothesis would then make a part of mine 7vol4 #a4 page #gj71 and there is great reason to believe it would be either accurately true or a good approximation2 but to suppose that some of the bodies should be in a solid state1 having their particles united by various degrees of attraction1 others fluid1 and others in the elastic state1 without any material modifications of their heat arising from these circumstances1 appears to me to be in opposition to some of the best established phenomena in the mechanical philosophy4 ,their observations on the specific heat of compound elements1 on the relation of the heat developed by combination1 as compared with the heat of the elements before and after the combination1 c41 are not supported by a detail of actual experience4 ,heat given out by chemical changes they suppose not to have been previously in a state of combination with the elements4 ,as an argument1 the heat given out by charcoal kept in a state of ignition1 by a current of galvanic fluid1 is adduced4 ,it is true this case is most easily explained1 by allowing that the galvanic fluid is in such circumstances converted into heat4 ,but the charcoal does not undergo any chemical change1 and therefore this is not a case in point4 ,all modern experience concurs in shewing that the heat of combustion is primarily dependent on the quantity of oxygen combining4 ,the heat evolved by the combustion of phosphorus and hydrogen is very nearly1 if not accurately1 in proportion to the oxygen spent4 ,the heat by the combustion of charcoal is not in a much less ratio3 and ,i find the heat in burning carbonic oxide1 carburetted hydrogen and olefiant gas is the same as in burning hydrogen gas1 provided the combining oxygen is the same4 ,one difficulty seems to have occurred to ,m4 ,m4 ,dulong and ,petit4 ,they all along conceive that the specific heats of bodies1 that is1 the heats producing equal increments of temperature1 must necessarily be proportionate to their whole heat4 ,this is purely hypothetical1 till established by experiment4 ,the generality of writers on specific heat had conceived it almost confirmed by experiment4 ,the results of ,delaroche and ,berard have shewn that in elastic fluids the increments of heat are not proportional to the whole quantities1 but on the contrary are less when a body is elastic than when liquid4 ,indeed some writers have argued this should be the case2 because a body nearly saturated with another has less affinity for it left4#bg ,it is plain then that oxygen gas or any other elastic fluid1 may have a small specific heat in the sense above defined1 and yet have an almost unlimited quantity of heat4 ,i am not aware of any one established fact that does not admit of an explanation upon the hypothesis that heat exists in definite quantities in all bodies1 and is incapable of any change1 except perhaps into one of the other equally imponderable bodies1 light or electricity4 ,footnote #bg3 ,see ,dr4 ,henry's note1 ,manch4 ,memoirs1 vol4 #e1 page #fgi4 ,,new ,,table ,,of ,,the ,forces of ,vapours in ,contact with the ,generating ,liquids at ,different ,temperatures4 7,a7 ,temperatures by the common thermometer4 7,b7 ,ether vapour1 ratio #b ,spec4 ,gravity 4#gb 7,c7 ,sulphuret of carbon vapour1 ratio #a4igh 7,d7 ,alcohol vapour1 ratio #b4g ,spec4 ,gravity 4#hb 7,e7 ,acetic acid vapour1 ratio #b4eg 7,f7 ,water1 ratio #b4fjb77 ---------------------------------------- ---- 7,a7 7,b7 7,c7 7,d7 7,e7 7,f7 ---------------------------------------- ---- ,inches ,inches ,inches ,inches ,inches of ,m4 of ,m4 of ,m4 of ,m4 of ,m4 ---------------------------------------- ---- #g #c4ge #c4acd 4#aic 4#aa #ce #g4e #f4bj 4#efj 4#bg 4#bi #fe #ae4 #ab4bf #a4ea 4#fi 4#ge #ig #cj #bd4bf #d4jg #a4gg #a4ie #acc #fj #dh4 #aa4jj #d4ed #e4jg #agc #abj #bi4gj #aa4g #ac4ah #bbj #bdj #hj4b #cj4 #cd4b #bgb #hh4i #cdj #bca ---------------------------------------- ---- ,this is an improved and extended table of the force of vapour1 similar to that at page #ad1 vol4 ,i4 ,it shews that the different vapours increase inforce in geometrical progression1 to certain intervals of temperature1 the same to most or all liquids4 ,these intervals of temperature were presumed in the former table1 to be in reality equal to one another2 but the accuracy of this last notion has been questioned4 ,,table1 ,shewing the expansion of air1 and the elastic force of aqueous and ethereal vapour1 at different temperatures4 ---------------------------------------- ----------------------- ,utmost force of ,temperat4 ,vol4 -------------------------------,weight of #ajj of air4 ,aqueous vapour4,ethereal vapour4 cubic inches ---------------------------------------- ---------- of aqueous -#bh #dbj vapour4 -#bj #dbh ,inches of ,merc4,inches of ,merc4 -#aj #dch ---------------------------------------- ---- #j #ddh 4#jh ,grains4 #aj #deh 4#ab #bj #dfh 4#ag #cj #dgh 4#bd ---------------------------------- #cb #dhj 4#bf #g4jj 4#agh #cc #dha 4#bg #g4ah 4#ahd #cd #dhb 4#bh #g4cf 4#aia #ce #dhc 4#bi #g4ed 4#aig #cf #dhd 4#cj #g4gc 4#bjc #cg #dhe 4#ca #g4ib 4#bji #ch #dhf 4#cb #h4aa 4#baf #ci #dhg 4#cc #h4cj 4#bbb #dj #dhh 4#cd #h4ej 4#bbi #da #dhi 4#ce #h4gj 4#bce #db #dij 4#cg #h4ij 4#bde #dc #dia 4#ch #i4aj 4#bee #dd #dib 4#dj #i4ca 4#bfg #de #dic 4#da #i4eb 4#bge #df #did 4#dc #i4gd 4#bhd #dg #die 4#dd #i4if 4#bic #dh #dif 4#df #aj4ah 4#cjc #di #dig 4#dg #aj4da 4#cac #ej #dih 4#di #aj4fd 4#cbc #ea #dii 4#ej #aj4hg 4#cbi #eb #ejj 4#eb #aa4aj 4#cda #ec #eja 4#ed #aa4cd 4#ced #ed #ejb 4#ef #aa4ei 4#cff #ee #ejc 4#eh #aa4he 4#cgh #ef #ejd 4#ei #ab4ab 4#chd #eg #eje 4#fa #ab4ci 4#cif #eh #ejf 4#fb #ab4ff 4#djb #ei #ejg 4#fd #ab4id 4#dad #fj #ejh 4#fe #ac4bb 4#dbj #fa #eji 4#fg #ac4ea 4#dcb #fb #eaj 4#fi #ac4hj 4#ddd #fc #eaa 4#ga #ad4aj 4#def #fd #eab 4#gc #ad4da 4#dfh #fe #eac 4#ge #ad4gb 4#dhj #ff #ead 4#gg #ae4jd 4#dib #fg #eae 4#hj #ae4cf 4#eji #fh #eaf 4#hb #ae4fh 4#eba #fi #eag 4#he #ae4ij 4#eci #gj #eah 4#hg #af4bc 4#eea #ga #eai 4#ij #af4ef 4#efi #gb #ebj 4#ib #ag4jj 4#ehj #gc #eba 4#ie #ag4ce 4#eih #gd #ebb 4#ig #ag4ga 4#faj #ge #ebc #a4jj #ah4jh 4#fbg #gf #ebd #a4jc #ah4de 4#fde #gg #ebe #a4jf #ah4hc 4#ffb #gh #ebf #a4ji #ai4ba 4#fhj #gi #ebg #a4ab #ai4fj 4#gjj #hj #ebh #a4af #bj4jj 4#gba ---------------------------------------- ----------------------- ,applications of the above ,table4 ,these tables will be found of great use in reducing volumes of air from one temperature or pressure to any other given one3 also in determining the specific gravities of dry gases from experiments on those saturated with or containing given quantities of aqueous or other vapours4 ,as several writers1 and some of considerable eminence1 have given erroneous or imperfect formul on these subjects1 more particularly with regard to the effect of aqueous vapour in modifying the weights and volumes of gases1 it has been thought proper to subjoin the following precepts and examples for the use of those who are not sufficiently conversant in such calculations4 ,the #eth column of the above table1 or weight of aqueous vapour1 is new1 and may therefore require explanation4 ,gay ,lussac is considered the best authority in regard to the specific gravity of steam2 but it would be well if his results were confirmed or corrected1 as they are of importance4 ,according to his experience1 the specific gravities of common air and of pure aqueous vapour1 of the same temperature and pressure1 are as #h to #e1 or as #a to 4#fbe4 ,now ,i assume that #ajj cubic inches of common air1 free from moisture1 of the temperature #fj and the pressure of #cj inches of mercury1 weigh #ca grains nearly4 ,it is an extraordinary fact that philosophers are not agreed upon the absolute weight of a given volume of common air4 ,most authors now assume the weight of #ajj inches #cj4e grains1 whilst according to my experience it is more than #ca grains4 ,if common air be assumed #ca grains1 steam would be #ai grains for #ajj cubic inches1 at the same temperature and pressure1 could it subsist2 but as it cannot sustain that pressure at the temperature of #fj we must deduct according to the diminished pressure1 the utmost force of steam at #fj being 4#fe parts of an inch of mercury1 we have #cj inches #ai grains 4#fe 4#dbj grains the weight of #ajj cubic inches of aqueous vapour at #fj and pressure 4#fe parts of an inch2 which is the number given above in the table4 ,the like calculation is required for any other pressure3 but in addition to this1 there is to be an allowance for the temperature from the #b;d column3 ,thus1 let the weight of #ajj cubic inches of steam at #cb be required4 ,we have #cj inch4 #ai grs4 4#bf inch4 4#afgi grs42 the weight of #ajj inches of steam at #fj2 then if #dhj #ejh 4#afgi 4#agh grs4 weight of #ajj cubic inches of steam at #cb and pressure 4#bf parts of an inch1 the tabular number required4 ,examples4 #a4 ,how many cubic inches of air at #fj are equivalent in weight to #ajj cubic inches at #de8 ,by the column headed volume of air we have this proportion1 if #dic #ejh #ajj inch4 #ajc4jd inches1 the volume required4 #b4 ,how many cubic inches of air with the barometer at #cj inches height1 are equal in weight to #ajj cubic inches when the barometer stands at #bh4i inches8 ,rule4 ,the volume of air being inversely as the pressure1 we have1 #cj #bh4i #ajj inches #if inches the answer4 #c4 ,how many cubic inches of dry air are there in #ajj inches saturated with aqueous vapour1 at the temperature of #ej1 and pressure #cj inches of mercury8 ,here the formula 7p - f7 ----------- p applies1 where p denotes the atmospheric pressure at the time1 and f denotes the utmost force of vapour in contact with water at the temperature4 ,hence p #cj1 f 4#di per table1 and we have 7p - f7 7#cj - 4#di7 #bi4ea ----------- ----------- ----- #ih_/1 or p #cj #cj #ih_/ percent dry air4 #a_/ vapour4 --------- #ajj4 ,if the vapour of ether is assumed1 then f #aj4fd1 and we have 7p - f7 7#cj - #aj4fd7 #ai4cf ----------- ----------- ----- p #cj #cj 4#fde1 444 or #fd per cent dry air4#bh #ce per cent ethereal vapour4 ----- #ajj ,footnote #bh3 ,the aqueous vapour in this case maybe considered as insignificant4 #d4 ,suppose we find by trial the weight of #ajj cubic inches of common air saturated with vapour at #fj1 the barometer standing at #cj inches to be #cj4e grains1 and the weight of hydrogen gas in like circumstances to be #b4aah grains2 query the weights of #ajj cubic inches of each gas free from vapour1 and their specific gravities1 the temperature and pressure being as above8 ,if #cj4e #b4aah #a 4#jfid sp4 gr4 of vapourized hydrogen1 that of vapourized air being #a4 ,subtracting 4#db grs4 7weight of vapour per table7 from #cj4e grs41 leaves #cj4jh grains2 and subtracting 4#fe parts of an inch from #cj inches1 leaves #bi4ce inches4 ,hence #ajj cubic inches of dry air at the pressure of #bi4ce inches1 weigh #cj4jh grains2 and we have #bi4ce #cj #cj4jh #cj4gdf grains1 the weight of #ajj inches of dry air4 ,again1 subtracting 4#db grs4 from #b4aah1 leaves #a4fih grains weight of #ajj cubic inches of hydrogen of #fj and sustaining the pressure of #bi4ce inches2 whence if #bi4ce #cj #a4fih #a4gcf grains1 weight of #ajj inches of dry hydrogen2 and #cj4gdf #a4gcf #a 4#jefde sp4 gr4 of dry hydrogen1 that of dry air being unity4 ,or the results may be exhibited as under3 ,weight of #ajj cubic inches4 ,sp4 ,gravities4 ,vap4 air #cj4e grains #a #ad4d ,vap4 hydrogen #b4aah ---- 4#jfid #a ,dry air #cj4gdf grains #a #ag4g ,dry hydrogen #a4gcf ---- 4#jefde #a ,,formul ,,for ,,determining ,,the ,,proportions ,,of ,,combustible ,,gases ,,in ,,mixtures4 ,it frequently happens1 especially in the decomposition of vegetable substances by heat1 that the product consists of several combustible gases in mixture1 and it is desirable to determine the proportions of each of those which collectively constitute the mixture4 ,the following forms will be found useful for this purpose4 #a4 ,carbonic oxide and hydrogen4 ,let x the volume of carbonic oxide1 y that of hydrogen1 w that of mixture1 and a that of carbonic acid1 produced by exploding the mixed gases with oxygen over mercury4 ,then the carbonic oxide1 or x a1 and the hydrogen1 or y w - a4 #b4 ,sulphuretted hydrogen and hydrogen4 ,let x the volume of sulphuretted hydrogen1 y that of hydrogen1 w that of the mixture1 and g the oxygen spent in the combustion of w4 ,then because x y w1 and #ax y g2 we have x g - w1 and y #aw - g4 #c4 ,phosphuretted hydrogen and hydrogen2 also carburetted hydrogen and hydrogen1 and carburetted hydrogen and carbonic oxide4 ,the notation being as above1 we have x y w1 and #bx y g 7see page #aga73 and1 #b;g - w #dw - #b;g x -----------1 and y -----------4 #c #c #d4 ,olefiant gas and carburetted hydrogen4 ,the notation being as above1 we have x y w1 and #cx #by g2 whence x g - #bw and y #cw - g4 #e4 ,carburetted hydrogen1 carbonic oxide and hydrogen4 ,let x carburetted hydrogen1 y carbonic oxide1 z the hydrogen1 g the oxygen spent in the combustion of w volumes of mixed gas1 and a the carbonic acid produced4 ,then x y z w1 x y z g1 and #bx y a4 whence we have #b;g - w #c;a - #b;g w x -----------1 y ----------------- #c #c and z w - a4 #f4 ,olefiant gas1 carburetted hydrogen and carbonic oxide4 ,let a the olefiant gas1 y the carburetted hydrogen1 and z equal the carbonic oxide1 g the oxygen entering into combination1 and a the carbonic acid produced2 also w the whole volume as before4 ,then we have x y z w1 #cx #by z g1 and #bx y z a4 ,whence x a - w1 y #dw - #e;a #b;g -------------------1 #c and z 7w a - g74 #g4 ,superolefiant gas1#bi carburetted hydrogen1 and carbonic oxide4 ,footnote #bi3 ,a gas found in oil and coal gas4 ,see ,manchester ,memoirs1 vol4 #d 7new series71 page #gc4 ,let x volume of superolefiant1 y volume of carburetted hydrogen1 z volume of carbonic oxide1 g the oxygen combining1 a carbonic acid produced1 and w volume of mixed gas4 ,then x y z w1 #dx #by z g1 and #cx y z a4 ,whence x a - w ----------1 #b y #cw - #d;a #b;g ------------------1 #c and z #cw - #d;g #e;a -------------------4 #f #h4 ,superolefiant gas1 carburetted hydrogen1 carbonic oxide1 and hydrogen4 ,this is the mixture of gases obtained by a red heat from coal and oil1 after being freed from carbonic acid1 c41 by the usual means4 ,this mixture requires a very complicated formula1 in consequence of the specific gravities of the gases entering into the calculus4 ,the importance of the subject however may be an apology for the labour4 ,let x vol4 of superolefiant1 ,s its sp4 gr4 y vol4 of carb4 hydrogen1 its sp4 gr4 z vol4 of carbonic oxide1 c its sp4 gr4 u vol4 of hydrogen1 s its sp4 gr4 ,c specific gravity of the mixture1 g oxygen1 a carbonic acid1 and w whole volume of mixture as before4 ,then we have x y z u w #dx #by z u g #cx y z a and ,sx y cz su ,cw4 ,whence u 7#c,s #e;c - #h7;a - 7#d;c - #d7;g - 7#c,s #f;,c - #f - #c;c7w ---------------------------------------- ---------------------------- #h c - #c,s - #fs4 ,the value of the hydrogen being obtained1 it may be subtracted from w1 and the remainder will be best divided into three portions1 by the preceding formula4 ,,heat ,,produced ,,by ,,the ,,combustion ,,of ,,gases4 ,subsequent experience to that detailed at page #gg1 ,vol4 #a4 has furnished the following more correct results of the heat produced by the combustion of pure gases4 ,hydrogen1 combustion of it raises an equal volume of water #e ,carbonic ,oxide #d ,carburetted ,hydrogen1 or ,pond ,gas #ah ,olefiant ,gas #bg ,coal ,gas 7varies with the gas from #aj to7 #af ,oil ,gas 7varies also with the gas from #ab to7 #bj ,generally the combustible gases give out heat nearly in proportion to the oxygen they consume4 ,see note at the end of ,vol4 #d1 new series of the ,manchester memoirs4 ,,absorption ,,of ,,gases ,,by ,,water1 c4 ,this curious subject has attracted much less attention than it deserves4 ,very little has been published relating to it since the time of ,dr4 ,henry's essays and my own1 now more than twenty years ago4 ,the only author ,i remember is ,m4 ,saussure of ,geneva1 who published a similar essay about twelve years afterwards4 ,see ,thomson's ,annals of ,philosophy1 ,vol4 #f4 ,he investigates the quantities of gases absorbed by various solid bodies1 in a manner which ,i do not fully comprehend2 he then treats of the absorption of gases by liquids1 adverting at the same time to ,dr4 ,henry's experiments and mine4 ,my enquiries were principally confined to one liquid1 water2 but ,i made a few trials with others1 such as weak aqueous solutions of salts1 alcohol1 c41 and observing no remarkable differences1 ,i concluded somewhat too hastily that 8most liquids free from viscidity1 such as acids1 alcohol1 c41 absorb the same quantity of gases as pure water40 ,manchester memoirs1 new series1 ,vol4 #a4 ,m4 ,saussure however asserts that there are considerable differences in liquids in this respect4 ,he finds sulphuretted hydrogen to be more absorbable by water than ,dr4 ,henry and ,i did2 in this ,i find he is right4 ,water takes about #b its bulk of this gas when pure2 and it seldom had been obtained unmixed with hydrogen when ,dr4 ,henry and ,i made our experiments upon its absorption4 ,in regard to carbonic acid1 nitrous oxide1 and olefiant gas1 ,m4 ,saussure nearly agrees with us2 but his results with oxygen gas1 carbonic oxide1 carburetted hydrogen1 hydrogen and azote1 would prove that water absorbs twice the quantities of each that we have assigned4 ,i have no doubt he is wrong in the less absorbable gases4 ,in the case of absorption of mixed gases1 ,saussure has given four examples1 in which he finds the results to militate against my theoretic view1 as stated at page #bja1 ,vol4 #a42 namely1 that water takes the same quantity of each in a mixed state as it would do if they were separate1 and in other respects in like circumstances4 ,but ,i have shewn in the ,annals of ,philos4 ,vol4 #g1 #ahaf1 that his results coincide as near as any one can expect with the views which ,i have all along taken of this subject4 ,it will be seen1 page #agc1 that another gas has been found to coincide with olefiant gas in absorbability2 namely1 phosphuretted hydrogen4 ,,fluoric ,,acid4--,,deutoxide ,,of ,,hydrogen4 ,in treating of ,fluoric acid1 7,vol4 #a1 page #bgg7 we came to the conclusion that this acid was probably constituted of two atoms of oxygen1 and one of hydrogen1 and have figured it accordingly 7,plate #e1 fig4 #ch74 ,subsequent experience however has shewn that deutoxide of hydrogen1 though it can be formed synthetically1 is not the same thing as fluoric acid4 ,we are indebted to ,m4 ,thenard for the discovery of this curious compound1 the deutoxide of hydrogen or oxygenated water4 ,an ingenious memoir on the subject was published by him in #ahah1 in which the formation and the properties of this compound are fully detailed4 ,i had no small satisfaction in #ahbb1 when at ,paris1 in being obligingly favoured by ,m4 ,thenard with a view of the process of the formation1 and of the more distinguishing properties of this singular liquid4 ,the nature of fluoric acid is still enveloped in obscurity4 ,my experience led me to adopt the composition of fluate of lime to be #dj acid and #fj lime per cent4 ,i had not then seen ,scheele's admirable essay on the subject4 ,from the #eth section of his #b;d4 essay on fluor mineral1 #agga1 it may be deduced that fluate of lime is composed of #gb4e lime and #bg4e acid per cent4 ,in #ahji ,klaproth1 and near the same time1 ,dr4 ,thomson found about #fg lime and #cb acid per cent4 in fluor spar4 ,they both erred1 no doubt1 as ,i did1 by not repeating the treatment of the mineral with sulphuric acid often enough4 ,since then most authors1 as ,davy1 ,berzelius1 ,thomson1 c41 agree with ,scheele nearly1 in assigning #bg4e acid1 and #gb4e lime1 in #ajj parts of fluate of lime4 ,my experience in #ahbj gave me #a per cent4 less of lime2 and ,dr4 ,thomson now finds about #a per cent4 more of lime than ,scheele's analysis gives4 ,if we estimate the atom of lime at #bd1 that of fluoric acid must be about #i1 according with the above proportion2 this is much below #ae1 the weight of an atom of deutoxide of hydrogen4 ,should ,sir ,h4 ,davy's view of fluate of lime be found correct1 its atomic constitution would be one atom of calcium1 the metallic substance of which lime is the protoxide1 and one atom of fluorine1 the name he has assigned to the other element1 which with hydrogen is supposed to constitute the fluoric acid4 ,the atom of fluor spar would then be #a atom of calcium1 #ag1 united to one atom of fluorine #af4 ,,muriatic ,,acid4--,,oxymuriatic ,,acid1 c4 ,from the articles muriatic acid and oxymuriatic acid in the former volume1 published now #af years ago1 as well as from the appendix to said volume1 in which sundry animadversions are found on the fluctuating opinions entertained in regard to these acids1 the reader will not be surprised to find some further addition4 ,three notions have been submitted to the public in the last twenty years in regard to the nature of muriatic acid4 ,first1 the gas detached from common salt by sulphuric acid has been thought to be the acid in a state of purity1 and constituted of a certain base or radical united to oxygen2 this was the notion inculcated in the articles alluded to above4 ,second1--it is stated as a fact that when oxymuriatic acid and hydrogen in equal volumes are united by the electric spark1 a volume of muriatic acid gas is the result equal to the sum of both the other volumes1 and that this gas perfectly agrees with the gas obtained from common salt by sulphuric acid2 this suggested the idea that muriatic acid gas is a compound of what has been called real or dry muriatic acid one atom1 and water one atom4 ,and1 third1 it is argued1 that the element we have called oxymuriatic acid gas1 is1 for aught that appears1 a simple body1 and consequently1 that muriatic acid gas is the real acid1 and is constituted as above1 of one atom of hydrogen1 and one atom of oxymuriatic acid 7now called chlorine47 ,it is not intended here to enter into a discussion of the arguments and facts adduced in support of the different conclusions4 ,more experience must be had before all the doubts and difficulties are removed from the subject4 ,but it will be proper to illustrate these different positions by an example4 ,for instance1 common salt1 muriate of soda or chloride of sodium4 ,by the first notion #ej parts of dry common salt will consist of one atom of muriatic acid gas1 #bb1 and one atom of caustic soda1 #bh4 ,by the second notion the same salt will be formed of #cj parts of muriatic acid gas1 and #bh of caustic soda2 but #h parts of water evaporate when the salt is dried4 ,by the third view common salt consists of oxymuriatic acid1 or chlorine and sodium1 or the metal of which caustic soda is the protoxide2 and #ej parts of salt will consist of #bi chlorine and #ba sodium1 or one atom of each4 ,,nitric ,,acid--,,compounds ,,of ,,azote ,,and ,,oxygen4 ,since the account of nitric acid 7,vol4 #a1 page #cdc7 was printed1 a change has universally taken place in estimating the weight of the nitric acid atom1 and of the proportion of azote and oxygen in the same4 ,this has been effected chiefly by a more correct analysis of nitre than existed at that time4 ,nitre is now found to consist nearly of #eb parts acid and #dh parts potash per cent4 ,hence if the atom of potash be #db1 that of nitric acid must be #de2 for1 #dh #eb #db #de1 nearly4 ,that is1 the nitric acid atom consists of #aj azote #ce oxygen by weight2 or of #b atoms of azote 7according to my estimate7 and #e of oxygen4 ,there appear to be two nitrous acids2 namely1 the one which ,i have designated by that name1 which may now be called subnitrous1 or as ,gay ,lussac terms it pernitrous2 and the other what ,i considered as nitric acid in the former volume1 composed of #a atom azote1 and #b of oxygen4 ,real nitric acid then is that combination which is effected by uniting oxygen with a minimum of nitrous gas2 or #a measure of oxygen with #a4c nitrous gas1 7,see ,vol4 #a1 page #cbh74 ,the oxynitric acid1 which ,i was led to infer from the last mentioned combination1 7#a azote with #c oxygen7 does not appear to exist4 ,the ,table of nitric acid 7,vol4 #a1 page #cee7 will require some correction4 ,an increase of about #d per cent4 should be made1 ,i apprehend1 on the quantities of acid corresponding to the several specific gravities4 ,since my former volume of ,chemistry was printed1 several essays on the compounds of azote and oxygen have been published1 with some new and some additional experiments1 the chief of which may be seen in ,sir ,h4 ,davy's ,elements of ,chemical ,philosophy1 the ,annales de chimie et de physique1 ,vol4 #a2 ,annals of philosophy1 ,vol4 #i and #aj2 and the ,manchester ,society's ,memoirs1 ,vol4 #d1 second series2 also ,dr4 ,thomson's first principles of ,chemistry4 ,notwithstanding all that has been written on the subject1 there still appears uncertainty as to the number of combinations formed by these two elements1 their relative weights1 and the number of atoms in the several compounds4 ,the results of an experiment ,i lately made on the decomposition of nitrate of potash by heat seem to be worthy of record1 as ,i am not acquainted with those of any other person who has pursued the experiment to the same extent4--,i took an iron retort of #f cubic inches capacity1 and cleaned it as well as ,i could from carbonaceous matter which it had previously contained1 first by heating nitre to redness for an hour or more in it1 and then washing it repeatedly with water till the liquid came out tasteless1 and only mixed with a little red rust2 ,i then put in #dhj grains of purified nitre1 and having secured a copper tube to the retort so as to be air tight1 the retort was put into a fire and gradually raised to a red heat1 and the fire was occasionally urged with a pair of bellows1 in order to keep up a glowing red on the retort for nearly two hours2 the air was received over water in jars2 the first #d or #e inches were thrown away1 and the rest was preserved and transferred to a graduated jar2 the products were examined in successive portions as under1 namely1 ,inches4 #a produce1 #he cubic inches1 #hc per cent4 pure #gj4e #b #e #gg #c4he #c #be #ej #ab4e #d #f #cj #a4h ----- ------- ,total #aba ,oxygen #hh4fe ,oxygen #hh4fe #cj grains4 ------ ,residue #cb4ce #aj grains4 ,about #a per cent4 on the whole gas was carbonic acid1 the rest oxygen and azote1 the weights of which would be nearly as above4 ,towards the last the gas came very slowly1 and being of inferior quality1 the operation was discontinued4 ,the remaining contents of the retort were diluted with water1 and well washed till the water ceased to shew alkali2 the liquid was then concentrated and gave #afjj water grain measures of the sp4 gr4 #a4aec4 ,there were obtained also #fd grains of red oxide of iron from the washing of the retort1 containing #ai grains of oxygen4 ,the liquid was divided into portions and examined2 the original nitre consisted of #bej grains of nitric acid united to #bcj of potash #dhj grains4 ,after the process there appeared to be1 #aj grains of carbonic acid united to #ba grains potash4 #fb grains of subnitrous acid to #hd 0 0 #acd grains nitric acid to #abe 0 0 --- #bcj ,the quantity of carbonic acid was determined by lime water3 the quantity of potash uncombined with nitric acid was found by precipitating it by tartaric acid1 and manifested #aje grains of potash in the bitartrate that combined with the carbonic and subnitrous acids2 from which subtracting #ba1 it was inferred the remainder #hd must have been in union with subnitrous acid1 or else with nitrous acid2 the rest of the potash1 not being acted upon by tartaric acid1 was understood to be combined with nitric acid4 ,the quantity of subnitrous acid given above1 appeared somewhat hypothetical1 till it was confirmed by treating a portion of the liquid with oxymuriate of lime solution of known strength2 it was found that #cb grains of oxygen were required to be combined with the subnitrous acid1 in order to restore it to the state of nitric acid2 that is1 when oxymuriate of lime1 containing that quantity of oxygen1 was added to the liquid1 and this was afterwards rendered acidulous by the addition of sulphuric acid1 neither nitrous vapour nor oxymuriatic gas was perceptible2 but a greater or less quantity of the oxymuriate being applied1 and the liquid made acidulous1 the fumes of the one or the other were abundantly manifest4 ,it remains to account for the oxygen4 ,there were #bej grains of nitric acid at first in the nitre2 of which #bjj grains were oxygen and #ej azote1 nearly4 ,one-fifth part of the oxygen #dj grains1 corresponds to #a atom of oxygen4 ,now the whole of the oxygen derived from the nitre in the course of the experiment1 seems to be #cj grains in gas1 #g grains in the carbonic acid1 and #ai grains in the iron oxide1 together equal to #ef grains4 ,now the azote and oxygen in the gas collected1 were very nearly in the proportion of those elements in nitric acid2 so that a portion of the acid 7about 7 might be considered as completely decomposed1 whilst the rest was only losing a small part of its oxygen3 this is remarkable1 and ,i think indicates that the carbonic acid 7formed from the carbon of the retort1 or from the adhering carbon7 unites to the potash1 expelling the nitrous acid1 which is immediately decomposed into its elements azote and oxygen4 ,this would not however account for the whole of the azote3 for1 #dj grains of nitric acid would be united to #cg potash2 whereas we find only #ba potash with carbonic acid2 and ,i cannot believe that an error in the estimate of carbonate of potash could exist to that amount4 ,the fact1 however1 was1 that the elements of #dj grains of nitric acid were found in the evolved gas1 and hence we have to account for the remainder #baj grains4 ,from this there appears to have been expelled #bf grains of oxygen1 nearly #ai and #g as related above2 of which the #ai grains cannot be correctly estimated by reason of the uncertainty as to the real quantity of oxide formed during the operation3 there might be some left adhering to the retort1 or on the other hand there might be more than the due share1 derived from former experiments4 ,supposing then1 that #bf grains of oxygen were extracted from the nitric acid1 the remaining acid would require the same to be added to re-form the nitric2 but by the experiments with oxymuriate of lime it seemed to require #cb grains of oxygen4 ,this difference wants an explanation2 ,i believe the greater error must belong to the #bf grains2 perhaps the truth might be approximated best by supposing both to be #cj grains4 ,when the liquid decomposed nitre is treated with any acid1 a gas is instantly expelled which produces red fumes in the air2 it is pure nitrous gas1 which joining with the oxygen of the atmosphere1 generates nitrous acid vapour4 ,at the same time1 no doubt1 the subnitrous acid is disengaged from the potash1 but that part of it which is real nitrous acid 7#a atom azote to #b of oxygen7 is retained by the water1 whilst the other part1 7#a atom azote and #a of oxygen7 assumes the gaseous form4 ,in order to be satisfied respecting this point1 ,i made several experiments with the liquid over mercury3 taking a given portion of the liquid1 and sending it to the top of a graduated tube filled with mercury1 ,i passed up as much muriatic acid as was sufficient to engage the potash2 immediately there was a disengagement of nitrous gas and carbonic acid gas1 and afterwards a slow evolution of gas1 evidently arising from the liquid in contact with the mercury4 ,wishing to ascertain the quantities1 ,i sent up #be grain measures of liquid1 and to that nearly half its bulk of muriatic acid2 in #b or #c minutes there was1 #a4a cubic inch of gas4 ,h4 ,m4 #a4d in #j #de #a4e #a #e #a4g #b #de #a4ge #g #de #a4gh #i #de ,the gas was washed in lime water1 and lost 4#cc parts of an inch of carbonic acid2 the rest1 #a4de cubic inch1 was nitrous gas4 ,it is obvious that of the nitrous gas1 together with the carbonic acid1 was liberated instantly2 the rest of the nitrous gas was due to the nitrous acid1 slowly acting upon the mercury4 ,at the end of the process1 there was a little black oxide floating upon the mercury4 ,calculating from this1 the whole quantity of nitrous gas would be #ca or #cb grains1 whereas it ought to have been #dh grains to constitute #fb of subnitrous acid4 ,it is probable that whilst a portion of the subnitrous acid is oxidizing the mercury1 another portion may be forming nitric acid and dissolving the oxide4 ,from some trials1 ,i have reason to think that even carbonic acid will expel nitrous gas from the liquid sub-nitrite of potash4 ,in the essay of ,dr4 ,henry1 already alluded to1 published in the #dth ,vol4 of the ,manchester ,society's ,memoirs1 a new and interesting discovery is made2 namely1 that a mixture of nitrous and olefiant gases1 though not explosive by an electric spark1 may still be exploded by the more powerful impetus of a shock from a charged jar4 ,dr4 ,henry has adduced the results obtained in this way1 as corroboratory of those which shew the constitution of nitrous gas to be #a volume of azote and #a of oxygen united to form #b volumes of nitrous gas4 7,see page #ejg of the ,memoirs47 ,some time ago in repeating these experiments of ,dr4 ,henry1 ,i found some extraordinary circumstances attending them4 ,after determining that #a volume of olefiant gas may be fired with from #f to #aj volumes of nitrous1 ,i found a shock from a jar sometimes inadequate to fire the mixture1 which1 however1 when repeated a second or third time1 succeeded4 ,this is not a novelty2 for1 mixtures of olefiant gas as well as other gases and vapours1 with a minimum of oxygen1 frequently require several sparks before the explosion3 but this case occurs at times with nitrous and olefiant gas1 when they are mixed in the most favourable proportions for exploding4 ,the most remarkable circumstance1 however1 was1 that when a phial was filled with the mixture of the two gases in the proportion of #a volume olefiant to #f or #g nitrous1 7exclusive of small portions of azote71 the decomposition of the nitrous gas and the combustion of the olefiant were scarcely ever perfect2 and what increased the perplexity more1 was1 the results obtained from the same mixture scarcely ever agreed one with the other4 ,after about #cj experiments1 ,i was inclined to adopt the conclusion1 that the uncertainty was occasioned by the oblong form of the eudiometer4 ,the spark or shock1 in my eudiometer1 is imparted at one extremity of a column of air1 which is often #aj times as much in length as in diameter3 it mostly was found that the larger the quantity of mixture exploded at once1 the more imperfect and incomplete was the combustion4 ,i imagine the intensity of heat is not sufficient to carry on the combustion through the length of the column1 owing1 perhaps1 to the cooling power of the sides of the tube4 ,hence it was1 ,i apprehend1 that in one or two instances1 when a small quantity of gas was used1 ,i got nearly complete results1 as ,dr4 ,henry reports his2 but in the majority both gases were found in the residue after the explosion4 ,in pursuing this enquiry into the decomposition of nitrous gas by combustible gases1 ,i found that it might be effected by any combustible gas or vapour3 at least it succeeded in all ,i tried4 ,the method ,i pursued1 and which was suggested by the known properties of phosphuretted hydrogen1 is this3 it has been shewn 7page #aha7 that a mixture of phosphuretted hydrogen and nitrous gas exploded by an electric spark1 the former gas being completely burned in case the proportions are duly adjusted2 now1 it occurred to me1 that as the above combustible gas is usually a mixture of pure phosphuretted hydrogen and of hydrogen1 and that the latter of these is also burned as well as the former1 the effect must be produced through the heat occasioned by the combustion of the former4 ,having some old phosphuretted hydrogen by me1 at the time1 which on examination1 ,i found to be #ia per cent4 combustible gas1 and #i azote2 and the #ia combined with #aef of oxygen1 consequently was #gd pure1 and #ag hydrogen2 ,i tried this mixture with nitrous gas1 when it exploded by the spark1 as usual2 but on trying it with an excess or defect of nitrous gas1 the spark was inefficient1 but the shock instantly fired the mixture4 ,as there did not appear to be any of the pure hydrogen left unburned in these experiments1 ,i proceeded to mix the old phosphuretted hydrogen with hydrogen2 and then this new mixture with nitrous gas4 ,the first experiment was made with #d parts of old phosphuretted hydrogen #af hydrogen #cf nitrous gas #ef total4 ,on this mixture the spark1 of course1 had no effect2 but it exploded the first trial by the jar1 and left #bj measures1 of which #b were found to be oxygen1 and the rest azote4 ,this experiment succeeding so well1 ,i next tried mixtures of phosphuretted hydrogen1 with carbonic oxide1 carburetted hydrogen1 and ether vapour successively1 along with nitrous gas2 and found that all these mixtures refused combustion by the spark1 but were instantly exploded by the shock1 yielding carbonic acid and water1 the same as if the combustion had been effected by free oxygen4 ,in some instances the combustion was complete1 leaving neither combustible gas nor nitrous gas2 but generally there was a residue of one or both of the gases4 ,from these experiments it may be concluded that the heat1 produced by the combustion of phosphuretted hydrogen and nitrous gas or oxygen gas1 disposes other gases1 accidentally in the mixture1 to chemical changes4 ,in conformity with this view1 ,i mixed phosphuretted hydrogen and oxygen1 in the proportion of mutual saturation2 and taking a small proportion of this mixture1 and as much ammoniacal gas as would saturate the phosphoric acid to be formed1 ,i found that causing an explosion over mercury1 the phosphoric acid combined with the ammonia1 and nearly the whole gas disappeared4 ,in this case1 the heat was not sufficient to decompose the ammonia4 ,but in another experiment1 with a portion of the same explosive mixture and a less proportion of ammonia1 after the firing a residue of azote and hydrogen was found1 amounting nearly to the quantity due from the decomposition of the ammonia4 ,here the heat produced1 had evidently decomposed the ammonia4 ,,on ,,ammonia4 ,the constitution of ammonia still remains undecided4 ,the latest experiments on this article are those of ,dr4 ,henry1 in his essay on the analysis of the compounds of nitrogen4 7,memoirs of the ,manchester ,society1 vol4 #d1 #ahbd47 ,by electrifying ammoniacal gas over mercury1 as carefully as could be devised1 ,dr4 ,henry found results as under3 #ast experiment #dd measures became #hh #b;d #aeg #cbj #c;d #fj #abb #dth #abj #bdj ,the evolved gases carefully analysed by combustion with oxygen1 were found to consist of #c volumes of hydrogen and #a of azote4 ,the analysis of ammonia was also effected by exploding it with nitrous oxide1 with the requisite precautions4 ,the results confirmed the previous ones by electricity1 both in regard to doubling the volume of ammonia1 and establishing the ratio of #c to #a in the volume of hydrogen and azote4--,these experiments are highly interesting as far as regards the question of ammonia1 as they exhibit the latest investigations of one who has previously shewn uncommon skill and perseverance in this kind of analysis4 7,see ,philos4 ,transact4 #ahji1 c47 ,dr4 ,henry's analysis of ammonia1 in #ahji1 has been adverted to in our article on the subject1 vol4 #a1 page #dbi4 ,the results of that ,essay are given in a tabular form2 and the mean of six experiments was nearly as we have stated1 namely1 that ammonia consists of #bg measures of azote1 and #gb hydrogen4 ,to this it may be proper to add1 that the two extremes were1 #bf4a azote and #gc4i hydrogen1 and #bh4b azote with #ga4h hydrogen2 also that a small error has crept into the table1 which being corrected1 the average results are reduced to #bg and #gc1 very nearly4 ,subsequently1 both ,dr4 ,henry and ,sir ,h4 ,davy concurred in assigning #bf and #gd for the most approximating numbers4 7,see ,nicholson's ,journal1 #be1 page #aec74 ,the true quantity of gases procured by the decomposition of ammoniacal gas by electricity1 was concluded by both these authorities1 to be #ahj for each #ajj of ammonia1 when the requisite precautions were taken1 as we have related in vol4 #a4 ,from what is stated above1 it is evident the subject is one which requires extraordinary skill and attention4 ,this ,i can attest from my own experience1 which has been frequently renewed and varied2 but the results have not been sufficiently accordant to yield me satisfaction4 ,about ten years ago1 ,i made several experiments on the decomposition of ammonia1 which1 though they are not convincing1 deserve1 perhaps1 to be recorded in their results4--,some more recent experiments are incorporated with them4 ,decomposition of ammonia by nitrous oxide4--,i made many experiments1 by exploding mixtures of nitrous oxide and ammoniacal gases over mercury4 ,the excess of gas was mostly on the side of ammonia1 but the proportions were varied in the different experiments1 from #aj vol4 nitrous oxide to #aa ammonia or to #e1 which are about the extremes capable of being fired by the electric spark4 ,when #aj parts nitrous oxide and #e of ammonia are exploded over mercury1 the residuary gas contains some free oxygen and some nitrous acid derived from the decomposition of the excess of nitrous oxide used2 with #f parts of ammonia there is rarely any free oxygen4 ,when #aj parts of nitrous oxide1 and #g of ammonia are fired1 ,i never found any free oxygen or hydrogen2 but when the ammonia is at or near #h parts1 ,i find from _/ to of the hydrogen from the ammonia in the residuary gases4 ,the two gases appear to be completely decomposed2 the oxygen of the nitrous oxide1 as far as it can1 unites with the hydrogen of the ammonia1 without forming any portion of nitrous acid or of free oxygen1 and the residue contains the azote of both gases1 and the unburnt hydrogen from the ammonia1 as ,dr4 ,henry first observed4 ,this continues to be the case till the ammonia becomes #aa parts1 when the hydrogen amounts to about of the whole quantity which the ammonia yields4 ,from the above it would seem that the proportions for mutual saturation must be #aj nitrous oxide with from #g to #h parts of ammonia4 ,this agrees with the deduction in ,dr4 ,henry's first essay that #ac nitrous oxide require #aj of ammonia2 or that #aj require #g4g3 but according to the theory of volumes #aj would require #f2 and ,dr4 ,henry recommends in his late essay #aj nitrous oxide to #g4g or #h parts of ammonia1 in order to secure a small excess of the last1 and consequently some free hydrogen after the explosion4 ,the former of these proportions would have nearly of the residue hydrogen1 and the latter nearly 1 supposing the gases pure originally4 ,this gives more hydrogen than ,i have ever found2 but the azote in my experience nearly agrees with the doctrine of multiple volumes4 ,decomposition of ammonia by nitrous gas4--,about #cj experiments carefully made on mixtures of nitrous gas and ammoniacal gas gave very discordant results4 ,at one time #aj parts nitrous gas with #ad ammonia gave of hydrogen in excess1 and another time #aj nitrous with #ab ammonia gave excess of hydrogen _/2 generally #aj parts with #f or less gave oxygen1 and #aj with #h or more gave hydrogen in the residue4 ,decomposition of ammonia by oxygen4--,the limiting proportions of oxygen and ammonia which ,i have fired1 are #aj oxygen to #d ammonia for the minimum1 and #aj oxygen to #bb ammonia for the maximum4 ,when #aj oxygen were fired with #d ammonia1 there were _/ of the oxygen left1 and there was a deficiency of azote amounting to _/ of what was expected from the ammonia1 owing no doubt to nitrous acid generated by the explosion4 ,when #aj oxygen to #a4h1 or from that to #b4b ammonia are used1 there is a surplus of about or of the hydrogen contained in the ammonia1 left in the residue of the gas4 ,when the ammonia is between #ac and #ad there is usually a trace of oxygen or hydrogen as it approaches either of these limits4 ,by the theory of volumes1 #aj oxygen should saturate #ac of ammoniacal gas4 ,i have not any instance of hydrogen being left when #ad ammonia were used1 though there ought to be _/ of the whole left2 and much smaller quantities than that are appreciable by well known methods4 ,the azote resulting from the decomposition of ammonia is usually very nearly the volume of the ammonia4 ,on the whole the results from firing ammonia and oxygen gas appear to me more satisfactory than those obtained from nitrous oxide and nitrous gas1 as they are more simple and less perplexed with any theoretic views4 ,it may be proper to remind the reader that when we speak of #aj parts of one gas uniting with #h1 #aj1 or more1 of another in the above and other cases1 it is to be understood of gases absolutely pure2 not that we ever obtain them in that state1 but approximating as near as we can to it1 we mix given portions of such gases as we can obtain1 and then in our calculations of results deduct for the impurities4 ,one source of uncertainty in these experiments on firing mixtures of ammonia1 is that the real quantity of ammoniacal gas operated upon is not known4 ,if a certain measure of ammonia be transferred through mercury ever so dry1 some portion of it gets entangled in the mercury1 and #ajj measures become perhaps #ie3 now in the explosion it is a question whether any part of the #e measures absorbed is decomposed4 ,i have marked this attentively1 and am persuaded that generally speaking1 little if any of that portion is decomposed2 but some trace of it appears mostly afterwards in the residue as it is liberated from the pressure of its own kind of gas1 and hence easily rises into the gaseous mixture4 ,notwithstanding1 when the loss of gas by transfer amounts to #aj or #bj per cent41 ,i have reason to believe that some part of it suffers combustion occasionally4 ,volume of gases from the decomposition of ammonia4--,it has been observed 7vol4 #a4 ,ammonia7 that ,sir ,h4 ,davy obtained #ahj measures of gases1 by means of electricity1 from #ajj of ammonia as the maximum when the operation was performed with great care1 and ,dr4 ,henry in like circumstances1 produced #aha1 whilst ,i found #ahg measures2 since that1 as has been related1 ,dr4 ,henry has found #bjj measures4 ,it is not easy to account for these differences2 ,i am inclined to the opinion that the volume of gases is very nearly doubled1 but probably rather less than more4 ,i find the experiments on the rapid combustion of ammonia agree best with that opinion4 ,decomposition of ammonia by a red heat4--,a short time since ,i repeated the decomposition of ammonia by passing the gas through a red hot copper tube4 ,the proportion of azote to hydrogen1 due allowance being made for a minute portion of atmospheric air1 was upon the average of a number of experiments1 #bf of the former to #gd of the latter4 ,decomposition of ammonia by oxymuriatic acid4--,i have made several experiments on this mode of decomposition since the results published in vol4 #a1 page #dce4 ,it is well known that a solution of oxymuriate of lime decomposes ammoniacal salts2 water and muriatic acid are produced1 azote liberated1 and the acid previously combined with the ammonia is evolved4 ,but this is not all2 an excessively pungent gas or perhaps vapour is produced1 exciting sneezing1 and inducing catarrh2 the constitution of this vapour is not well understood2 it is never formed1 as far as ,i know1 without the presence of both oxymuriatic acid and ammonia4 ,the results of such mixtures are of course complicated and likely to be unsatisfactory2 it may notwithstanding be useful to relate some of them4 ,when clear oxymuriate of lime solution1 and a salt of ammonia are mixed together with a little excess of oxymuriate1 the ammonia is mostly decomposed1 the oxymuriate being converted into muriate of lime by the hydrogen of the ammonia1 whilst the azote is evolved1 and the acid previously combined with the ammonia is liberated2 hence oxymuriatic acid gas is also liberated along with the azote2 and it is required to be taken out before the azote can be estimated4 ,this circumstance may be obviated by previously adding the requisite quantity of pure potash or soda1 to engage the acid1 or by leaving a little undissolved lime in the oxymuriatic solution4 ,i could never obtain a volume of azote equal to half that of the ammonia 7supposed to be in a gaseous state7 though it is universally allowed not to be less than that1 if the whole of the azote be evolved2 on one occasion only ,i got so much as _/ of that quantity4 ,the residue of liquid has the extremely pungent smell2 but the azotic gas after passing through pure water has no smell4 ,when this experiment is made over mercury1 the oxymuriatic acid acts upon it1 and hence the excess of oxymuriate should be such as to leave a portion of that undecomposed at the conclusion4 ,when the object is to ascertain the hydrogen in ammonia1 a portion of salt known to contain a given weight of ammonia is to be treated with oxymuriate of lime solution1 the strength of which is accurately determined by means of green sulphate of iron1 or otherwise4 ,the ammoniacal salt in solution is then to be mixed with a moderate redundance of the oxymuriate liquid1 and with a few drops of caustic potash1 and the mixture must be repeatedly agitated for some time4 ,at length the liquid must be tested by the green sulphate of iron1 and hence the quantity of acid spent upon the ammonia will be determined4 ,i have mostly found the hydrogen this way below the common estimate1 allowing the ammoniacal salts to be correctly determined4 ,,sulphuret ,,of ,,carbon4 ,since the article at page #dfb1 vol4 #a1 was written1 an excellent essay on the sulphuret of carbon has been published in the ,philosophical ,transactions1 7#ahac7 by ,professor ,berzelius and ,dr4 ,marcet4 ,after an extensive series of experiments1 they infer the atom of the sulphuret to consist of #b atoms sulphur and #a of carbon4 ,the investigation did not seem to warrant their including hydrogen in the atom4 ,i have made several experiments on the combustion of the vapour of sulphuret of carbon in oxygen gas by electricity4 ,my method generally was1 to vapourize a given portion of atmospheric air over mercury1 taking care that the vapour was below the maximum for the temperature2 this is easily effected by putting the liquid into a phial of air1 drop by drop1 and inverting it over mercury till the liquid is evaporated4 ,this vapourized air1 ,i find may be transferred through mercury with very little loss1 and even through water several times1 without a total condensation of the vapour4 ,the vapour of ether is much more condensible by water than that of sulphuret of carbon4 ,a given portion of this vapourized air is to be mixed with oxygen gas1 in ,volta's eudiometer1 and then exploded by the electric spark over mercury4 ,one volume of vapour combines with nearly #c of oxygen1 and therefore requires #d or #e times its bulk of that gas before firing1 in order that the combustion may be complete4 ,the results of the combustion are carbonic acid and sulphurous acid2 and ,i suspect a small portion of water2 though ,professor ,berzelius and ,dr4 ,marcet could not detect any4 ,by evaporating a given weight of the sulphuret of carbon1 in a given volume of atmospheric air1 at the temperature of #fj1 ,i find the specific gravity of the vapour to be #b4ge nearly1 air being #a4 ,now if we assume the atom of vapour to be nearly of the same volume as that of hydrogen1 and to consist of #a atom hydrogen1 #b sulphur1 and #a carbon1 it will require #g atoms of oxygen to form water1 sulphurous acid1 and carbonic acid1 which will accord very well with my experience4 ,when vapourized hydrogen gas is electrified for some time1 there is no change of volume1 though there is some appearance of decomposition4 ,probably the hydrogen of the sulphuret is liberated4 ,it is difficult to conceive how so volatile a liquid as the one in question1 could be constituted out of sulphur and carbon without the addition of hydrogen4 ,,potassium1 ,,sodium1 c4 ,two views of the nature of these bodies have been given in vol4 #a1 7see pages #bfj1 and #dhd1 c474 ,in the former they are considered as simple metals2 in the latter1 as compound bodies resulting from the abstraction of oxygen from the hydrates of potash and soda2 or as being constituted of #a atom of hydrogen united to #a atom of pure potash or soda respectively4 ,those who have had the most experience on these elements1 ,sir ,h4 ,davy1 and ,m4 ,m4 ,gay ,lussac and ,thenard1 seem now to concur in the former view1 and it has been adopted by most chemists4 ,part of the objections which we made to this view have been obviated1 it should seem1 by establishing the fact1 that oxymuriatic gas and hydrogen gas united1 form muriatic acid gas4 ,there are still1 however1 difficulties to remove before this view can be considered perfectly satisfactory2 but they are not greater perhaps than would attach to any other explanation of the facts connected with the subject4 ,besides potassium and sodium1 experience as well as analogy would seem to render probable1 if not to establish1 the existence of barium1 strontium1 and calcium as metals1 of which barytes1 strontites1 and lime are the protoxides1 as potash and soda are of the other two metals2 7other oxides of potassium and sodium are stated1 see page #ee-eg72 barium has a deutoxide1 and probably calcium likewise4 ,the rest of the earths1 as magnesia1 alumine1 silex1 c4 are by analogy considered by most chemists as oxides of particular metals1 but the proportions of their elements have not been determined4 ,,alum4 ,at page #eca1 vol4 #a1 we have given the constitution of this important salt1 as under3 since that time ,mr4 ,r4 ,phillips has announced another view of it2 and ,dr4 ,thomson has published one differing from both of these4 ,they are as follow3 ,dalton-- #a atom sulphate of potash4 #d atoms sulphate of alumine4 #cj atoms water4 ,phillips-- #a atom bisulphate of potash4 #b atoms sulphate of alumine4 #bb atoms water4 ,thomson-- #a atom sulphate of potash4 #c atoms sulphate of alumine4 #be atoms water4 ,notwithstanding these differences1 there is a near approximation in all three1 in regard to the quantities of acid1 alumine1 potash1 and water in the salt4 ,this is accounted for partly in the different relative weights of the atoms1 as estimated by the different analysts1 but chiefly in that of alumine4 ,some very curious results occurred to me about #aj years ago in analysing alum2 they were new to me1 but ,i have since found they had been previously discovered by ,scheele4 7,see his essay on silex1 clay1 and alum1 #aggf47 ,as his observations are not to be found in any of our elementary books that ,i have seen1 ,i shall give the particulars of my own experiments here4 ,i take #bd grains of alum and dissolve them in water2 of these #h grains may be allowed for sulphuric acid1 of which #a4f grain #a4a grain of lime #hhj grains of lime water1 such as ,i commonly use4 ,to the solution of alum ,i put #hhj grains of lime water2 a slight precipitate appears which soon becomes redissolved almost completely4 ,the liquid is then acid by the colour test4 ,to this liquid ,i put #hhj more of lime water1 and agitate2 a copious precipitate appears and continues2 after subsidence the clear liquid is still acid by the colour test4 ,another #hhj grains are added1 and the whole is then well agitated2 the agitation is repeated two or three times after the precipitate has partly subsided1 so as to diffuse it equally again through the liquid2 finally1 the clear liquid is found to be neutral by the colour test1 and to contain no alumine2 for1 lime water produces no precipitate when poured into it4 ,another #hhj grains being added1 and the whole stirred well1 the clear liquid after the subsidence of the precipitate is still neutral by the colour test4 ,the fifth portion of #hhj grains being then added1 and the mixture well agitated1 a considerable portion of the precipitate will evidently disappear1 and the mixture become semitransparent2 after a time the clear supernatant liquid is found strongly alkaline2 a little of it touched with an acid becomes milky1 and adding more acid clears it again4 ,the liquid is now #a4jjbe sp4 gr41 or a little heavier than lime water4 ,the sixth portion of #hhj grains being now added to the whole mixture1 and agitated1 the precipitate rather diminishes1 and an increase of specific gravity takes place in the liquid2 it is now #a4jjc4 ,the seventh and last portion of #hhj grains being added to the mixture1 and agitation being continued for some time1 a dense bulky precipitate is formed1 which falls with great celerity1 carrying with it the greatest part of the acid1 the alumine and the lime1 and leaving the liquid of the sp4 gr4 #a4jjab4 ,it is a subsulphate into which acid1 potash1 lime and alumine enter1 as will be shewn4 ,these phenomena appear to me to be best explained by adopting a constitution of alum1 such as to make it consist of #a atom bisulphate of potash and #c atoms of sulphate of alumine2 after which the following explanation will apply4 ,the first portion of lime water saturates the excess of acid4 ,the second portion throws down a correspondent portion of alumine4 ,the clear liquid is acid1 because it contains sulphate of alumine1 which is essentially acid by the colour test1 because alumine is not an alkaline element4 ,the third portion throws down another portion or atom of alumine2 but by continued agitation the two atoms of alumine liberated1 join the remaining atom of sulphate of alumine1 and the whole compound falls down1 being then the common subsulphate of alum4 ,hence the liquid1 containing nothing but sulphate of lime and sulphate of potash1 is neutral by the test1 and yields no alumine by the addition of lime water4 ,the fourth portion of lime water being put in and duly agitated1 the atom of sulphuric acid is drawn from the subsulphate to join the lime1 and then the floating subsulphate of alumine becomes pure alumine1 and the clear liquor is still neutral4 ,the fifth portion of lime water tries to decompose the sulphate of potash1 but is unable of itself2 however1 the floating alumine assists it1 and by double affinity the potash leaves the acid to join the alumine1 and the lime takes the acid4 ,hence as of the alumine enters into solution with the potash1 the precipitate is less copious1 and the liquid is alkaline2 a small portion of acid put into the clear liquid engages the potash1 and liberates the alumine1 but a larger portion redissolves the alumine also4 ,the sixth portion of lime water seems to complete the effect which the fifth commences1 and hence the density of the liquid increases1 whilst the precipitate rather diminishes4 ,the seventh portion of lime1 together with the sixth1 after due agitation and some time1 unite the lime with the alumine1 one atom of each1 and form a precipitate which would fall together1 were no other compound present1 as ,i found1 and ,scheele before me2 but if sulphate of lime be present1 each compound atom of lime and alumine1 unites with one of sulphate of lime1 and the whole descends together1 forming a subsulphate resembling that of alum1 only two atoms of lime are found as substitutes for two atoms of alumine4 ,this subsalt is very little soluble in water4 ,according to this view1 if #b atoms of alum were decomposed1 #d atoms of subsulphate would be formed1 each consisting of #a acid1 #b lime1 and #a alumine2 also #b compound atoms of potash and alumine1 and #f atoms sulphate of lime4 ,but in the final arrangement1 it would seem1 that #b atoms of sulphate of lime are again decomposed1 and sulphate of potash formed1 the #b atoms of lime combining with the #b of alumine1 and then two more atoms of subsulphate are formed1 and the final arrangement is #f atoms subsulphate precipitated1 and #b atoms sulphate of potash1 and #b sulphate of lime remain in solution4 ,the facts above stated appear to me to place the constitution of alum in a clearer point of view than any other ,i have seen4 ,they make no difference in the weights of the several elements in #ajj grains of the salt1 from what we have given in ,vol4 #a2 only the weight of the atom of alumine is here taken to be #bj instead of #ae1 and we have #c atoms of it in #a of alum1 instead of #d1 as in the former account4 ,,on ,,the ,,principles ,,of ,,the ,,atomic ,,system ,,of ,,chemistry4 ,it is generally allowed that the great objects of the atomic system are1 #ast to determine the relative weights of the simple elements2 and #b;d to determine the number1 and consequently the weight1 of simple elements that enter into combination to form compound elements4 ,the greatest desideratum at the present time is the exact relative weight of the element hydrogen4 ,the small weight of #ajj cubic inches of hydrogen gas1 the important modifications of that weight by even very minute quantities of common air and aqueous vapour1 and the difficulties in ascertaining the proportions of air and vapour in regard to hydrogen1 are circumstances sufficient to make one distrust results obtained by the most expert and scientific operator4 ,the specific gravity of hydrogen gas was formerly estimated at that of common air2 it descended to _/41 which is the ratio we adopted in the ,table at the end of ,vol4 #a4 it is now commonly taken to be _/41 and whether it may not in the sequel be found to be _/4 is more than any one at present1 ,i believe1 has sufficient data to determine4 ,the other factitious gases have mostly undergone some material alterations in their specific gravities in the last twenty years1 several of which ,i have no doubt are improvements2 but when we see these specific gravities extended to the #crd1 #dth1 and #eth places of decimals1 it appears to me to require a credit far greater than any one of us is entitled to4 ,in the mean time1 it may be thought a fortunate circumstance1 that the weight of common air has undergone no change for the last thirty or forty years2 #ajj cubic inches bring estimated to weigh #cj4e grains at the temperature of #fj1 and pressure of #cj inches of mercury3 7whether this is exclusive of the moisture ,i do not recollect47 ,it is also a fortunate circumstance1 7provided it be correct7 that this weight is nearly free from decimal figures4 ,i may be allowed to add1 that according to my experience1 the weight of #ajj cubic inches of air is more nearly #ca grains than #cj4e4 ,i apprehend these observations are sufficient to shew that something more remains to be done before we obtain a tolerably correct table of the specific gravities of gases2 the importance of this object can not be too highly estimated4 ,the combinations of gases in equal volumes1 and in multiple volumes1 is naturally connected with this subject4 ,the cases of this kind1 or at least approximations to them1 frequently occur2 but no principle has yet been suggested to account for the phenomena2 till that is done ,i think we ought to investigate the facts with great care1 and not suffer ourselves to be led to adopt these analogies till some reason can be discovered for them4 ,the #b;d object of the atomic theory1 namely that of investigating the number of atoms in the respective compounds1 appears to me to have been little understood1 even by some who have undertaken to expound the principles of the theory4 ,when two bodies1 ,a and ,b1 combine in multiple proportions2 for instance1 #aj parts of ,a combine with #g of ,b1 to form one compound1 and with #ad to form another1 we are directed by some authors to take the smallest combining proportion of one body as representative of the elementary particle or atom of that body4 ,now it must be obvious to any one of common reflection1 that such a rule will be more frequently wrong than right4 ,for1 by the above rule1 we must consider the first of the combinations as containing #a atom of ,b1 and the second as containing #b atoms of ,b1 with #a atom or more of ,a2 whereas it is equally probable by the same rule1 that the compounds may be #b atoms of ,a to #a of ,b1 and #a atom of ,a to #a of ,b respectively2 for1 the proportions being #aj ,a to #g ,b1 7or1 which is the same ratio1 #bj ,a to #ad ,b17 and #aj ,a to #ad ,b2 it is clear by the rule1 that when the numbers are thus stated1 we must consider the former combination as composed of #b atoms of ,a1 and the latter of #a atom of ,a1 united to #a or more of ,b4 ,thus there would be an equal chance for right or wrong4 ,but it is possible that #aj of ,a1 and #g of ,b1 may correspond to #a atom ,a1 and #b atoms ,b2 and then #aj of ,a1 and #ad of ,b1 must represent #a atom ,a1 and #d atoms ,b4 ,thus it appears the rule will be more frequently wrong than right4 ,it is necessary not only to consider the combinations of ,a with ,b1 but also those of ,a with ,c1 ,d1 ,e1 c42 as well as those of ,b with ,c1 ,d1 c41 before we can have good reason to be satisfied with our determinations as to the number of atoms which enter into the various compounds4 ,elements formed of azote and oxygen appear to contain portions of oxygen1 as the numbers #a1 #b1 #c1 #d1 #e1 successively1 so as to make it highly improbable that the combinations can be effected in any other than one of two ways4 ,but in deciding which of those two we ought to adopt1 we have to examine not only the compositions and decompositions of the several compounds1 of these two elements1 but also compounds which each of them forms with other bodies4 ,i have spent much time and labour upon these compounds1 and upon others of the primary elements carbone1 hydrogen1 oxygen1 and azote1 which appear to me to be of the greatest importance in the atomic system2 but it will be seen that ,i am not satisfied on this head1 either by my own labour or that of others1 chiefly through the want of an accurate knowledge of combining proportions4 ,,new ,,table ,,of ,,the ,,relative ,,weights ,,of ,,atoms4 ,at the close of the last volume1 the weights of several principal chemical elements or atoms were given2 but as several additions and alterations have been educed from subsequent experience1 it has been judged expedient to present a reformed table of weights4 ,,simple ,,elements4 ,weights4 ,hydrogen #a ,azote #e1 or #aj8 ,carbone #e4d ,oxygen #g ,phosphorus #i ,sulphur #ac1 or #ad ,calcium #ag8 ,sodium #ba ,arsenic #ba ,molybdenum #ba1 or #db8 ,cerium #bb8 ,iron #be ,manganese #be ,nickel #bf ,zinc #bi ,tellurium #bi1 or #eh8 ,chromium #cb ,potassium #ce ,cobalt #cg ,strontium #ci ,antimony #dj ,iridium #db ,palladium #ej ,uranium #ej1 or #ajj8 ,tin #eb ,copper #ef1 or #bh8 ,rhodium #ef ,titanium #ei8 ,gold #fj ,barium #fa ,bismuth #fb ,platina #gc ,tungsten #hd1 or #db8 ,silver #ij ,lead #ij ,columbium #ajg8 #aba8 ,mercury #afg1 or #hd8 ,,simple ,,or ,,compound8 ,weights4 ,fluoric ,acid #aj8 #ae8 ,magnesia #ag ,alumine #bj ,glucine #bc8 #cd8 ,lime #bd ,oxymuriatic ,acid 7chlorine7 #bi1 or #cj ,muriatic ,acid #cj1 or #ca ,gas ,zircone #de ,silex #de8 ,yttria #ec8 #cf8 #ah8 ,,compound ,,elements4 ,weights4 ,ammonia #f8 #ab8 #ac8 ,olefiant ,gas #f4d8 #ab4h8 ,carburetted ,hydrogen or ,pond ,gas #g4d ,water #h ,phosphuretted ,hydrogen #aj ,nitrous ,gas #ab1 or #bd8 ,carbonic ,oxide #ab4d ,sulphuretted ,hydrogen #ae ,deutoxide of ,hydrogen #ae ,nitrous ,oxide #ag ,nitrous ,acid #ai1 or #ch8 ,carbonic ,acid #ai4d ,sulphurous ,oxide #ba ,phosphoric ,acid #bc ,sulphurous ,acid #bh ,protoxide of ,arsenic #bh ,soda #bh ,hydrate of ,lime #cb ,protoxide of ,iron #cb ,protoxide of ,manganese #cb ,protoxide of ,nickel #cc ,sulphuric ,acid #ce ,sulphuret of ,arsenic 7native7 #ce ,hydrate of ,soda #cf ,oxide of ,zinc #cf ,carbonate of ,magnesia #cf4d ,protosulphuret of ,iron #ci ,deutoxide of ,manganese #ci ,oxide of ,chromium #ci ,muriate of ,magnesia #ci ,protosulphuret of ,nickel #dj ,protosulphuret of ,lime #da ,carbonate of ,lime #dc4d ,protoxide of ,cobalt #dd ,strontites #df ,muriate of ,lime #df ,chromic ,acid #df ,protoxide of ,antimony #dg ,carbonate of ,soda #dg4d ,hydrate of ,potash #ej ,muriate of ,soda #ej ,sulphate of ,magnesia #eb ,sulphuret of ,antimony #ed ,sulphate of ,alumine 7simple7 #ee ,oxide of ,palladium #eg ,sulphate of ,lime #ei ,protoxide of ,tin #ei ,carbonate of ,potash #fa4d ,hydrosulphuret of ,antimony #fb ,nitrate of ,magnesia #fb ,sulphate of ,soda #fc ,protoxide of ,copper #fc ,muriate of ,potash #fd ,deutoxide of ,tin #ff ,protosulphuret of ,tin #ff ,oxide of ,gold #fg ,barytes #fh ,muriate of ,lime #fi ,oxide of ,bismuth #fi ,deutoxide of ,copper #gj ,nitrate of ,soda #gc ,sulphuret of ,gold #gd ,protosulphuret of ,bismuth #gf ,sulphate of ,potash #gg ,oxide of ,platina #hj8 ,nitrate of ,potash #hg ,carbonate of ,barytes #hg ,muriate of ,barytes #ij ,oxide of ,silver #ig ,protoxide of ,lead #ig ,minium #ih ,sulphate of ,barytes #ajc ,deutoxide of ,lead #ajd ,protosulphurets of ,lead and ,silver #ajd ,nitrate of ,barytes #aac ,protoxide of ,mercury #agd8 ,deutoxide of ,mercury #aha8 ,protosulphuret of ,mercury #aha ,alum #bgg ,,addenda4 ,,steel4--,since writing the article at page #bad1 ,i have had an opportunity of analysing the crystalline steel1 formed by ,mr4 ,macintosh's process of cementation by means of coal gas4 ,i dissolved #ba grains of this steel in sulphuric acid1 with only a very slight excess of acid4 ,the whole was dissolved except about of a grain of silvery-like particles4 ,the gas obtained amounted to #bi4f cubic inches4 ,it yielded no trace of carbonic acid4 ,when fired with oxygen it yielded #c per cent4 upon the volume of hydrogen of carbonic acid2 and this arose1 as ,i ascertained1 from the hydrogen containing #c per cent of carburetted hydrogen gas3 it contained no carbonic oxide4 ,supposing the carbone to have been combined with the iron1 it would amount only to about of a grain1 to #ajj grains of iron4 ,whether such a quantity can be deemed an essential or an accidental ingredient of steel1 may be a subject of consideration4 ,by a mistake of the ,printer1 the following paragraphs were omitted after page #cjh4 ,,example4 ,according to the following values of the different specific gravities1 7of the accuracy of some of which there may be doubts7 and referring to my essay on oil gas 7,manchester ,memoirs1 ,vol4 #d1 new series1 page #gi17 we may take the oil gas1 which1 when the incombustible portion was abstracted would be nearly 4#hab sp4 gravity1 and #ajj pure gas give #aeb carb4 acid and take #bdh oxygen2 ,here w #ajj1 a #aeb1 g #bdh1 ,s #a4deh1 4#eee1 c 4#igb s 4#jfid and ,c 4#hab4 ,the value of u reduces to the following form2 u #d4giaf;a - #a;g #a4hgew - #f;,cw ---------------------------------------- ---- #bd4e 4#fbe hydrogen per cent4 of pure combustible gas4 ,hence we have #ge4e volumes left for the #c other ingredients w of the formula2 and abstracting #ab from the oxygen on account of the hydrogen1 g #bcf1 and a #aeb as above4 ,whence x ,superolefiant #ch y ,carb4 hydrg4 #cj4b and z ,carb4 oxide #g ----- #ge4e ,these results differ considerably from those deduced in the above essay2 probably in part from errors in the above estimates of the specific gravities of one or more of the gases4 ,,expansion ,,of ,,liquids ,,by ,,heat4 ,i am not aware of any particular labour that has recently been given to the enquiry how far pure liquids accord with each other in the law which ,i announced as derived from the experiments on water and mercury1 and corroborated by those upon several other liquids4 ,see ,vol4 #a1 ,table of temperature1 page #ad2 also page #cf1 and following4 ,perhaps all liquids should be considered as pure that are subject to uniform congelation at certain temperatures on the one hand1 and on the other are capable of being distilled by heat without any alteration in their constitution4 ,water and mercury will rank in the first place2 alcohol of 4#hb specific gravity and ether of 4#gb2 concentrated sulphuric acid2 nitric acid of #a4db specific gravity3 naphtha and oil of turpentine1 c4 will probably be thought to claim the next place4 ,it is desirable that the temperatures at which these liquids congeal should be ascertained2 also whether any decomposition is effected by the operation4 ,if these expand proportionally to a scale of square numbers for certain given equal or unequal intervals of temperature1 it may point out something relative to the collocation of the ultimate particles in liquids4 ,the apparent coincidence of this rate of expansion in liquids1 with the geometrical progressive force of steams or vapours creates an additional interest4 ,it may be that most or all of these supposed relations are accidental1 and only approximative like that of the rate of expansion of air and mercury1 between the temperatures of -#dj and #bab2 but ,i cannot think this probable4 ,even should they be only approximations1 they are of sufficient utility to be kept in view4 ,,finis4 ,printed by the ,executors of ,s4 ,russell ,,books1 ,,essays1 c41 ,,published ,,by ,,the ,,same ,,author4 ,,meteorological ,,observations ,,and ,,essays4 #ds4 #hvo4 #agic4 ,,elements ,,of ,,english ,,grammar3 or1 a new ,system of ,grammatical ,instruction1 for the use of ,schools and ,academies4 #bs4 #f;d4 #abmo4 #ahja4 ,a few ,copies of these ,works may still be had of the ,london ,booksellers4 ,a ,,new ,,system ,,of ,,chemical ,,philosophy4 ,part ,i4 of ,vol4 ,i4 #gs4 #hvo4 #ahjh4 ,published by ,g4 ,wilson1 ,bookseller1 ,essex ,street1 ,strand1 ,london4 ,,essays1 by the same1 in the ,memoirs of the ,literary and ,philosophical ,society1 ,manchester4 ,,vol4 #e4 ,,part #a4--;,extraordinary facts relating to the vision of colours4 ,,part #b4--;,experiments and observations to determine whether the quantity of rain and dew is equal to the quantity of water carried off by the rivers1 and raised by evaporation2 with an enquiry into the origin of springs4 ,experiments and observations on the power of fluids1 to conduct heat1 with reference to ,count ,rumford's seventh essay on the same subject4 ,experiments and observations on the heat and cold produced by the mechanical condensation and rarefaction of air4 ,experimental essays on the constitution of mixed gases2 on the force of steam or vapour from water and other liquids1 in different temperatures1 both in a ,torricellian vacuum1 and in air2 on evaporation2 and on the expansion of gases by heat4 ,meteorological observations made at ,manchester1 from #agic to #ahja4 ,,vol4 #a4 ,second series4--,experimental enquiry into the proportions of the several gases or elastic fluids constituting the atmosphere4 ,on the tendency of elastic fluids to diffusion through each other4 ,on the absorption of gases by water and other liquids4 ,remarks on ,mr4 ,gough's two essays on the doctrine of mixed gases2 and on ,professor ,schmidt's experiments on the expansion of dry and moist air by heat4 ,,vol4 #b4 ,on respiration and animal heat4 ,,vol4 #c4 ,experiments and observations on phosphoric acid and on the salts denominated phosphates4 ,experiments and observations on the combinations of carbonic acid and ammonia4 ,remarks tending to facilitate the analysis of spring and mineral waters4 ,memoir on sulphuric ether4 ,observations on the barometer1 thermometer1 and rain1 at ,manchester1 from #agid to #ahah inclusive4 ,,vol4 #d4 ,on oil1 and the gases obtained from it by heat4 ,observations in ,meteorology1 particularly with regard to the dew-point1 or quantity of vapour in the atmosphere2 made on the mountains in the ,north of ,england4 ,on the saline impregnation of the rain which fell during the late storm1 ,december #eth1 #ahbb--with an appendix to the same4 ,on the nature and properties of indigo1 with directions for the valuation of different samples4 ,in the ,philosophical ,transactions of the ,royal ,society4 ,on the ,constitution of the ,atmosphere4--#ahbf4 ,in ,mr4 ,nicholson's ,philosophical ,journal4 ,,vol4 #e4 7,quarto7 ,on the constitution of mixed elastic fluids1 and the atmosphere4--#ahja4 ,,vol4 #c4 7,octavo7 ,on the theory of mixed gases4 #e4 ,on the zero of temperature4 #f4 ,correction of a mistake in ,dr4 ,kirwan's essay on the state of vapour in the atmosphere4 #h4 ,on chemical affinity as applied to atmospheric air4 #i4 ,observations on ,mr4 ,gough's strictures on the theory of mixed gases4 #aj4 ,facts tending to decide at what point of temperature water possesses the greatest density4 #ab4 ,remarks on ,count ,rumford's experiments on the max4 density of water4 #ac #ad4 ,on the max4 density of water in reference to ,dr4 ,hope's experiments4 #bh4 ,on the signification of the word particle as used by chemists4 #bi4 ,observations on ,dr4 ,bostock's review of the atomic principles of chemistry4 ,in ,dr4 ,thomson's ,annals of ,philosophy4 ,,vol #a #b4 ,on oxymuriate of lime4--#ahac4 #c4 ,remarks on the essay of ,dr4 ,berzelius1 on the cause of chemical proportions4 #g4 ,vindication of the theory of the absorption of gases by water1 against the conclusions of ,m4 ,de ,saussure4 #i #aj4 ,on the chemical compounds of azote and oxygen1 and on ammonia4 #aa4 ,on phosphuretted hydrogen4 #ab4 ,on the combustion of alcohol1 by the lamp without flame4 ,on the vis viva4 ,in ,phillips's ,annals of ,philosophy4 ,,vol4 #aj4 7new series74 ,on the analysis of atmospheric air by hydrogen4