1\IINER ALOG 1C h L CHEMISTRY.IT is impossible to begin a report on the progress of MineralogicalChemistry during the past year without making brief reference to thegreat loss this brauch of science has sustained in the untimely deathof S. L. Penfield. Equally happy as a theorist and as an experimenter,he has left in his work an enduring monument behind him. A sympa-thetic biographical notice, accompanied by a bibliography, has beencontributed by L. V. Pirrson to the pages of the American Joui-nal ofScience. I I n the person of H. A. Ward, America has also lost aveteran who, by his untiring energy as a collector, did good service inadvancing our knowledge of meteorites. By the death of W. Meyer-hoffer at the early age of forty-two, van’t Hoff has been deprived ofa fellow-worker and our science of one who did much to introduce tomineralogists and petrologists those ideas and met hods of physicalchemistry, the application of which promises such rich results in thefuture.It is, in fact, along these lines that the most important workhas been done during the past year, and it is therefore fitting that thisbranch of the subject should occupy the first place in our survey.General und Physical Chemistry of Minemls.Isalt Deposits.-J. H. van’t Hoff and his pupils have carried ontheir investigations with unabated energy. Number x l ~ i of the ‘‘ Re-searches on the Formation of Oceanic Salt Deposits ” appeared earlyin the year, and was devoted to a discussion of the conditions ofoccurrence at 83’ of anhydrite, CaSO,, syngenite, CaK2(S04),,H20,glauberite, CaNaz(S04)z, and penta-salt, Ca5K,(80,),,H20; the forma-tjon of calcium chloride and tachhydrite, CaCI;, 21\IgC12,1 BH,O, were alsoconsidered.In number xlvii the examination of the naturally occur-ring calcium compounds was brought to a conclusion by a study of therelations at 8 3 O of the triple sulphates, polyhalite, Ca,K2Mg(S0,),,2H20,and krugite, Ca,K2Mg(S0,)6,dH,0.Work on the borates was begun last year, and the relations ofAqner. J. Sci., 1906, [iv], 22, 353.3 SitmngsBer. K. Akad. W’isss. Beylin, 1906, 218, 412, 566, 653, 689MI N E R A LO G I C A TA C H E M T STRY . 295tincal and octahedral borax elucidated. The more difficult andcomplex problem presented by the double borates of calcium andmagnesium with a univalent ion has now been attacked, and therange of existence and the dissociation of NaCaB50,,8H,0 boron-atrocalcite f ally determined.'It has been shown in number xlviii that this substance splits intothe individual borates a t about S 5 O , and that i t probably was notformed in nature a t a temperature higher than 70".Incidentallypandermite, Ca,B,,O,,, 15H,O, was prepared artificially for the firsttime, together with a new substance, tricalcium borate, Ca,Bl,0,,,9H,0,not as yet obserred as a mineral. The mutual transformations of thehydrates of calcium monoborate, CaB,O,, are the subject of a separatepaper ; and number xlix of the series is concerned with the conditionsfor the artificial preparation of colemanite, (CaO)2( B20&5H,0, wbichit is shown can bc formed from the corresponding heptahydrate andsodium chloride a t 83", o r from boronatrocalcite in the same mediuma t 70".Mutua I Relution, of Fused Silicates.-The past year has witnessedgreat activity in this line of research, and the entry of Americanworkers into the field has resulted in a notable increase of ourknowledge of the calcium and magnesium silicates. I n the first place,E. T. Allen and W. P. White have succeeded in preparing artificialwollastonite having properties identical with those of the natumlmineral, and have also made a careful examination of the hexagonalcalciuni metnsilicate, termed by them pseudo-zuolkcbstonite, and ofthe relations between these two substances.They find that wollas-tonite can be readily obtained from the glass made by melting,together, a t a temperature of over 1500", molecular proportions ofquartz and calcium carbonate in a platinum crucible, which is thenrapidly chilled by placing it in water. On heating this glass to about800' to 1000" i t crystallises directly and rapidly into wollastonite,identified by its optical characters. The specific gravity is 2,915.When heated to about 1180° wollastonite changes into pseudo-wollastonite. This change is an enantiotropic one, and under properconditions reversible. The point of transformation mas determined byheating wollastonite in contact with the other form for definite perigdsa t various temperatures, and also by observing the rate of rise oftemperatureas heat was supplied to the mass, a slight absorption OCheat being noticed a t the transition point.The volume changeaccompanying the transformation is so slight that it is doubtful whichis the denser form. The reverse transformation is not so easilyeffected, and does not take place when the two forms are merelyheated in contact a t temperatures between 900' and llOOG, even if theAmer.. J. Xci., 1906, [iv], 21, 89296 ANNUAL REPORTS ON THE PROGRESS OF CHEMTSTRTheating be continued for many hours. It can, however, be broughtabout by the aid of a solvent. Calcium vanadate proved suitable, andit was found that the change into mollastonite was complete if5 grams of the silicate were heated with 1 gram of the vanadate forsome days a t a temperature of 800" to 900".Beautiful transparentcrystals were produced in this way. Analysis proved them t o benearly pure CaSiO,, and the mean specific gravity 2.913, crystallo-graphic characters 1 and optical properties, agreed with those ofwollastonite. This inversion also takes place readily in mixturescontaining excess of lime or silica, as shown by Day and Shepherd.Pseudo-wollastonite is usually considered to be hexagonal, but F. E.Wright, who has made a careful optical study of Allen and White'spreparations, thinks that it is more probably pseudo-hexagonal, its realsymmetry being that of the monoclinic system. The melting point is1 5 1 2 O , and on cooling the liquid almost invariably crystallises above1 200' as pseudo-wollastonite.The fact that the transformation takesplace at 1 180° has an important geological bearing, for it fixes an uppeklimit of temperature above which wollastonite cannot possibly havebeen formed, and neither pseudo-wollastonite nor paramorphs ofwollastonite after pseudo-wollastonite have been met with in nature.The work on wollastonite has been extended by A. 1,. Day and E. S.Shepherd2 to embrace the whole series of combinations of lime andsilica, They began by studying the properties of the two oxides.The melting point of lime is too high for any satisfactory measure-ments to be made, It can, however, be fused in the electric furnace,and on cooling crystallises with well-marked cubic strncture. Themean specific gravity is 3.316 a t 25".Silica, either in the form ofquartz, glass, or precipitated silica, when heated for a sufficient lengthof time at temperatures above 1000°, changes into tridymite. Thechange proceeds most rapidly in the case of the precipitated silica, afine state of division being favourable to the transformation. I n orderto determine the transformation temperature as accurately as possible,quartz-glass mas heated with vanadic acid, sodium tungstate, or amixture of 80 per cent. potassium chloride with 20 per cent. lithiumchloride. Below 760' quartz crystals were obtained. At 800' andhigher tridyrnite was the only product. Inversion occurs therefore atabout 800°, and the melting point of silica is really the melting pointof tridymite, although by very rapid heating quartz can sometimes bemelted without first changing into tridymite.Owing to the viscosityof the substance, it is exceedingly difficult to fix this point, but it seemsprobable that pure silica begins to melt a t about 1600".To obtain a general idea of the behaviour of mixtures of limeand silica, small portions of finely-ground mixtures of known com-1 Two crystals were measured. Anzer. J. Sci., 1906, [iv], 22, 265position were placed in A row on platinum or iricfiuin strip. Thestrip was gradually heated electrically and t'he order of melting noted.In this way two compounds ancl three eutectics were discovered.Mixtures containing more than 75 per cent. or less than S2i- per cent.of lime could not be investigated, owing to the refractory nature of thooxides.The compoonds formed are the metasilicate and the ortho-silicate of calcium ; the analogue, 4Ca0,3Si02, of tokermanite, and thetricalcic silicate, SCfaO,SiO,, could not be detected, although specialefforts were made to prepare them.Theorthosilicate, 2CaO,SiO,, melts a t about 2080", and exists in threepolymorphic forms which stand in enantiotropic relation to oneanother. The a-form, which crystallises in the monoclinic system, isthe only modification stable in cpntact with the fusion. Its specificgravity is about 3.27. Below 1410" the a-form changes into the/3-form. This unstable modification is orthorhombic, and has aboutthe same density as the a-form ; i t turns into the monoclinic y-varietya t about 675' with great increase of volume, the specific gravity ofthe latter being 2.974.The disintegration which takes place whenthe orthosilicate is cooled is thus explained. The ortliosilicate isreadily attacked by water, and this is probably the reason why it isnot found as a mineral. The three eutectics a r e : tridymite a n dpseudo-mollastonite a t 37 per cent. of lime, melting a t 1417' ;pseudo-mollastonice and a-orthosilicnte at 54 per cent. of lime,melting at 1430'; a-orthosilicate and lime a t 67; per cent. of lime,melting at 2015'.The preliminary investigation having demonstrated the existence oftwo compounds and three eutectics, the melting points of 100 gramcharges mere determined by means of a thermo-junction, or for highertemperatures by the Holborn-Kurl baum pyrometer.The results,which were plotted, fully confirmed the preliminary observations. Itwas found incidentally that pseudo-wollastonite appears to be capableof taking up small quantities of silica and of orthosilicate in solidsolution.The very important results obtained in the course of the investiga-tion of the felspars ancl of the calcium silicates naturally led theworkers in the geophysical laboratory at Washington to turn theirattention t o the compounds of magnesia :and silica, and thanks tothe labours of E. T. Allen, F. E. Wright, and J. K. Clement,l wenow possess a very complete knowledge of the metasilicate, MgSiO,.This substance can exist in four distinct cryst,il forms.I. The first crystallises in the inonoclinic system, and is the productusually obtained from fusions.It was first prepared by Ebelmen, andAmw. J. Sci.,11906, [iv], 22, 385.The properties of the metasilicate have been already clescribed298 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is found in nature in certain meteorites. It can be made (1) bymelting together magnesia and silica in the proper proportions andallowing the liquid to crystallise; (2) by allowing the glassobtained by rapidly cooling the fusion to crystallise at 1300O ; (3) byheating any of the other forms t o temperatures from 1150" upwards ;(4) by fusing amorphous silica with magnesium tellurite or chloride ;(5) by recrystallising magnesium silicate from a flux of magnesiumchloride or vanadate, calcium vanadate or tellurium dioxide.Thefirst method is most suited for preparing the substance in quantity;the last yields the best crystals, the most satisfactory results beingobtained when the silicate is fused with magnesium chloride in acurrent of dry hydrogen chloride. The crystals resemble in somerespects those of a monoclinic pyroxene, having the characteristiccleavage angle 92O, but the ratio b : c = 0.77 is very different from thatof diopside b : c = 0.5894. They are characterised by the low extinctionangle on b (OlO), c :t= 21.So, and by polysynthetic tvinning parallelto a (100). The specific gravity is 3.192 a t 25O. The monoclinic pyroxenemet with in the Bishopville meteorite has the same properties.11. The second form is orthorhombic and identical with enstatite.It is best prepared by heating the glass to between 1000° and 1100';if the latter temperature is exceeded the first variety appears as well,often in parallel intergrowths.Obtained in this way, the substanceforms fibrous aggregates of specific gravity 3.175. The angle betweenthe optic axes is smaller than that of natural enstatite, a fact as yetunexplained, On heating to temperatures above 1260' this formpasses slowly into the monoclinic variety.111. The third form is a monoclinic amphibole, and is the leastclearly defined of the four. Its identification as a separate varietyrests on its extinction angle, maximum value ll', and on its meanrefractive index, which is much lower than that of I. It is sometimesmet with in fusions which have been rapidly cooled, and appears alsoto be produced by the action of water a t 375-475' on the nextvariety.IV.This form is orthorhombic, and is identified by the authorswith n naturally occurring amphibole to which some writers havegiven the name of kupfferite. To prepare this variety the mixtureshould be heated well above the melting point and then cooled asquickly as is possible withoui; forming glass. Measurable crystalshave not been obtained, and the identification with kupfferite restson the optical properties and the indication of cleavage a t 120".The mean specific gravity is 2.857 at 25". This variety changes intoI on heating. These four modifications stand in monotropic relationto one another, the order of increasing stability being orthorhombicamphibole, monoclinic amphibole, enstatite, monoclinic pyroxeneBI IN ER A LOG I C A 1, C H E JZ I S'I'R 17.299That this is so is shown by the fact that enstntite and the amphiboleswhen heated pass over into the monoclinic pyroxene, which cannot bechanged back without passing through the amorphous state. Further,it is found that although the first three forms can all be dissolved insuitable fluxes at comparatively low temperatures, yet they crystalliseout as monoclinic pyroxene. Lastly, it has been shown by aningenious application of Frankenheim's method that the first threeforms change into the monoclinic variety with evolution of heat. Theexistence of a monotropic relation between the two great groups ofamphiboles and pyroxenes is i n accord with the work of other experi-menters, and the formation of amphiboles in nature instead ofpyroxenes may perhaps have been due to the viscosity of the magmafrom which they crystallised, while the presence in the Bishopvillemeteorite of intergrowths of pyroxene and enstatite suggests that i twas rapidly cooled from a high temperature.Certain meta- and ortho-silicates have also been studied from a some-what different point of view by V.Paschl,' who has prepared mixedcrystals by melting the constituents together. Thus he finds thatartificial diopside and hedeiibergite from Elba mix in all proportions.The melting point curve corresponds to Roozeboom's type I, but is notquiteregular and tho specific gravities of the mixtures do not in allcases lie between those of the components.Experiments with enstatiteand diopside indicate that these substances form an isodimorphous series,with n gap exteuding from 40CaMgSi,O,, 60Mg,Si,O6, to 50CaMgSi,O,,SOMg,Si,O,. The case is similar to that of the mixed sulphates ofiron and magnesium, and the specific gravities are lower for the rhombicthan for the nionocliiiic form. The melting point curve is of type V.Artificial mixtures of the isomorphous orthosilicates, Mg,SiO, andFe,SiO,, do not give a continuous series, the gap extending from65Mg,Si0,,35Fe2Si0, to 3Mg,SiO4,97Fe,SiO,. The melting pointcurve is of type 1, but is not a straight line. Artificial mixtures ofMg,SiO, and Cs,SiO, give results indicating t h a t these substances areisodimorphous.The conditions under which quartz and tridymite crystallise fromsilicate fusions have also been studied by P.D. Quensel,, who has arriveda t conclusions in the main much the same as those reached by Day andShepherd. He found that when a mixture of 74 parts of oligoclase and26 parts of amorphous silica mas fused with small quantities of tungsticoxide, or in the presence of water supplied by driving a current of super-heated steam through the fusion, small quartz crystals were formed.The effect of adding tungstic oxide was to lower the melting point andCentr. &fin., 1906, 571.Ccntr. Xi?z., 1906, 657, 728; see also R paper by Cosmo Johiis, Geol. Mag.,1906, 3, 118300 AXNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,viscosity, and to increase the size and rapidity of formation of thecrystals.On fusing silica with excess of sodium t ongstate, tridymitewas obtained, a fact previously noticed by Hautefeuille. As thereseemed reason to think that the ainountl of '' mineraliser ') present (inthis case tungstic oxide o r sodium tungstate) had an important influenceon the result, fresh experiments were undertaken in which the oligo-clase-silica mixture or pure silica were fused with from one to five partsof sodium tungstate. It was found, however, that quartz was alwaysobtained from the oligoclase-silica mixtnre at temperatures below lOOO",while if silica alone was used, tridymile or glass were formed, accordingas the temperature was kept above or below 1000°, the amount ofsodium tungstate present being unimportant.Quensel therefor0 con-cludes that the factors which determine the products are, the presenceof co-solutes, the concentration, and the existence of chemical equili-brium, and explains the forination of quartz as due to the influence ofthe constituents of oligoclase on the equilibrium between the alkalisand silicic acid. I n the case of tridymite a sodium silicate or possiblya silicotungstate is perhaps first forined, and this being unstable a t hightemperatures the silica separates dit ectly as tridymite. The rare occur-rence of tridymite in eruptive rocks, in spite of the fact that the tem-perature conditions mould favour its formation, he explains as due tothe special conditions required to produce this form, the presence ofother substances interfering with its crystallisation.Quensel finds that the melting point of tridymite is about 156G0, andconcludes from his own work and from that of his predecessors thatabove 900" i t is the stable form of silica. It can, however, exist at tem-peratures as low as 300" to 400".Quartz, on the other hand, can exist upto 1000°, but is unstable above 900'. Below 200' the hydroxides areperhaps to be considered the stable form, though quartz can exist as well.While the Americans have been breaking fresh ground in the studyof pure silicates, C. Doelter has been very active in the field he hasmade especially his own. Many pages of the numerous and lengthypapers for which he and his pnpils are responsible are occupied byadverse criticism of the views held by Vogt and of the resrilts obtainedby Day and Allen, but a certain ilmoant of fresh work along the licesalready familiar has been accomplished. Thus Doelter himself hasredetermined the melting points of a number OF nntuial felspars, and hasobtained results lower than those given by Day and Allen in their workon the artificial compounds.Further, he has reiterated his belief thatwhen silicates are melted they dissociate to a very considerable extentinto oxides, and has laid p e a t stress on the part played by viscosity,Wien. Sitxungsbe~., 3906, 115: 723 ; ililoitntsh., 1906, 27, 438 ; 2'sch. Mia.Uitt., 1906, 25, 79 and 206 ; Zeit. Eieklrocltcm., 1906, 12, 413 ; CcnfT.ililin., 1906,193MINERALOGICAL CHEMISTRY. 301crystallising power, and velocity of crystallisation in determining theparticular compounds which separate from a magma.The relation between the cornposition of the_ii;ixture and that of theeutectic is regarded by him as oE very minor importance. This pointhas been specially studied by M. VuEnik,l who has attempted to testVogt’s view in the case of certain binary mixtures, a s for instanceanorthite and fayalite, or anorthite and olivine. No eutectic structurewasobserved, but that mixture had the lowe>t melting p d u t for whichthe composition was that required by theory for the eutectic. M.V u h i k and H. H. Reiter 2 have also examined the eifect of f iising :tnumber of ternary mixtures such as anorthite, hedenbergite, andolivine; leucite, olivine, and achmite ; labradorite, aegerine, and elaolite ;albite, augite, and magnetite, &c. As can readily be imagined, theresults obtained are complex, and substances like spinel and hematitenot present in the original mixture crystallise out on cooling.Suchfacts as these they regard as evidence that dissociation of the originalsilicates has taken place. The general conclusion drawn from theexperiments is that from fusions of tLis kind minerals separate in thefollowing order : spinel, hematite, magnetite, olivine, magnetite (2),augite, magnetite (3), nepheline, plagioclase. This order is conditionedby the chemical reactions accompanying the dissociation of the silicates,as well as by the composition of the mixture and its relation to thatof the eutectic.That supersaturation may play an important part isto be gathered from the fact that magnetite can appear at more thanone stage, while viscosity, velocity of cooling, and power of crystal-lisation all have a share in determining the result. They find in theseexperiments no confirmation of Vogt’s views tts to the importanceof the eutectic in determining the order of crystallisation.J . H. L. Vogt himeelf, on the other hand, continues to insist mostvigorously that the laws of physical chemistry established by thestudy of solutions aye directly applicable to mixtures of moltensilicates, which he regards as but slightly, if at all, dissociated. Hehas recently contributed a niasterly exposition of his views to thepages of Tschernmk’s il.linernlogische ill itteilu n,g en.This begins witha brief riszcnzS of the Inws goveruitig the solidificatiou of binary andternary mixtui es, aiicl includes an account of Roozeboom’s classificationof mixed crystals. The application of these principles to slags is nextdiscussed, and van’t Hoff’s law of molecular freezing point depressionshown to hold for such cases as Akermanite and augite, melilite andanorthite, diopside and olivine, melilite and olivine. Incidentally theconviction is expressed that Doelter’s experiments in this direction arenot calculated t o throw much light on the subject.C’67ztP. jIi?t., 1906, 132. Jdrb. Nia. 1906, Beit. Bd., 22, 1%. ’ 1906, 24, 437-542302 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n a Eucceeding paragraph the mixed crystals formed by Mg,SiO,and Fe,SiO, are shown to belong to type I of Roozeboom’s classification,and the importance of zonal structure as indicating a slight degree ofsupersaturation is pointed out.Arguments are also adduced to showthat the mixed crystals formed by enstatite and diopside fall underRoozeboom’s type IV. The results obtained by Day and Allen areutilised in the elaborate discussion of the felspars which occupies thesecond half of Vogt’s paper and is devoted mainly to the considerationof mixed crystals composed of orthoclase, albite, and anorthite. Itis shown that whereas the binary mixture, albite and anorthite,belong to type I, the mixtures of orthoclase with albite or anorthitebelong to type V and fotm eutectics.The ternary mixture in whichall three components are present is also discussed and illustrated by adiagram. Further, the work of Schreinemakers 1 is applied to the casein which the mixture of orthoclase and albite is present with someindependent component such as quartz or olivine. Such a case mustfall either under Schreinemakers’ type d or type e, and i t is stated thatthe combination quartz, orthoclase, albite belongs to the second ofthese, and yields as final product a ternary eutectic mixture of quartzand the two kinds of mixed crystals. A full discussion of some ofthe latter points is to be given in a continuation of the paper.Deposition of Quartz from Aqueous SoZutio?zs.-J.G. Konigsbergerand W. J. Muller have attempted to throw light on the conditionsunder which quartz and other vein minerals have been deposited, moreespecially in the case of those found in the biotite-protogine of theAar. Assuming that these minerals have crystallised from solutionshaving approximately the composition of the incliisions found inthe quartz crystals of the district (see page 323) a t temperaturesbetween 120’ and 500°, they have attempted to imitate the conditionsof their formation by heating glass and obsidian with water and czrbondioxide in a steel bomb lined with platinum-iridium. The bomb washeated in an electrical oven i n which i t could be shaken and inverted.On inversion a filtering arrangement came into action which enabledthem to examine separately the crystals deposited from the solution oncooling.The composition of the glass (I) and obsidian (11) was :-SiO,.A1,0,. Fe,O,. MgO. CnO. K,O. Na,O. H,O.1. 69’21 2.48 0’45 0.52 9-84 1-98 14*91 -11. 74’3 13.0 2.6 0.3 1 -00 4’6 3 .s 0’3The glass was completely decomposed on heating with water to 360°,and quartz crystals and some opal mere found to have separated fromthe solution. The residue in the tube consisted chiefly of amorphousZeii. p7iysikal. CIWIL., 1905, 51, 569.Centy. Aliia., 1906, 339, 353MINERALOGICAL CHEMISTRY. 303silica, together with tridymite and zt little quartz. The glass was alsodecomposed if the water contained small quantities of carbon dioxide,but if much was present the glass was less readily attacked.Obsidiantreated with water was more resistant than glass, but on adding sodiumbicarbonate decomposition took place and quartz was formed. Whenheated to 420’ with a solution of the composition of the quartzinclusions, obsidian was partially converted into a substance identi-fied with aegirine-augite. Zeolites were not observed in theseexperiments. Quartz, muscovite, and adularia were all more or lessattacked by water a t 350’, and dissolved completely when heated tothe same temperature with a 20 per cent. solution of sodium carbonate,carbon dioxide escaping from the tube, which mas not quite tight. Onthe other hand, water contailling both carbon dioxide and sodiumcarbonate had very little action on quartz, adularia, sphene, muscovite,biotite, calcite, or fluorite a t 370”.The action of alkali carbonatesfirst becomes considerable a t those temperatures a t which they arestrongly hydrolysed. The addition of carbonic acid diminishes thehydrolysis, and in consequence the action of the alkali. This is inharmony with the experiments of Spezia, who found that the action ofa solution of borax on quartz was diminished by the addition of boricacid. The most important conclusion arrived a t by t’he authors is thatin the system composed of silicic acid, alkalis, and a weak acid such ascarbonic acid or boric acid in aqueous solution, the deposition ofquartz can only be explained by a change in the equilibrium point ofa reversible reaction, the acidity of the silicic acid increasing withgreater rapidity as the temperature rises than it does in the case ofthe other weak acid present.They also point out that the simul-taneous production of quartz, tridymite, opal, and chalcedony is inharmony with van’t Hoff’s rule that high valence favours the existenceof labile compounds.The Silicic Acids.-G. Tschermakl and his pupils have carried outa good deal of new work on the lines described last year, and be!ievethat they have established the existence of several new silicic acids,and thereby thrown light on the constitution of a number of minerals.Ilvaite, anorthite, and olivine all yield rnetasilicic acid, H,SiO,, andmust therefore be regarded as metasilicntes. Willemite and monti-cellite are orthosilicates. Pectolite and wollastonite both yieldH6Si,0,, and wollastonite is therefore Ca,Si,O,.Meerschaum fromAsia Minor also gave an acid, H6Si,0,. Massive and foliatedserpentine and also chrysotile were found to have the compositionH,Mg,Si,O,, but whilst the latter gave an acid, Hl,,Si4013, the former1 W i e i i . Bilximgd~cr., 1906, 115, i, 217, 697 ; Amcigcr K. Aknd. 1Viss. lVie?~.,1906, 19, 339304 AKNUAL REPORTS ON THE 1'ltOGRESS OF CHEIIISTRP.gave H8Si4012, and the same substance was obtained from thepseudomorphs of serpentine after olivine from Snarum. Chrysotile istherefore to be written l€4(MgOH)4( MgOMg)Si,O,,, ancl serpentineH,(MgOH),Si,O,,. From datolite and gadolinite a new pulverulent acid,H,Si,O,, was obtained.Heulandite, taken to be H12CaA12Si6022, gaveail acid, H,,Si,017, and must be written H,(Cr202Al,0,H2)Si~O~7,H20,the bivalent group HOAlOCaOAlOII being present. They find, more-over, that heulandite lost calcium when exposed to the action of aconsiderable quantity of water, and therefore conclude thvtt i t wasprobably deposited from a concentrated solution.to the ex-periments of F. Zambonini on heulandite and on thomsonite, by whichhe attempted to throw light- on the vexed question of the part playedby water in these compounds. The conclusion to which he then camewas that these minerals are comparable to the hydrogels described byvan Bemmelen. H e has been confirmed in this view by his recentresearches,2 which have been conducted on lines similar to thosealready described.Thus he finds that the dehydration of, and thereabsorption of water by, gelatinous silica prepared froin potassiumsilicate follows much the same course as in the case of the zeolites.The amorphous nickel ore garnierite, (Mg,Ni)SiO,,nH,O, fromNoumea, New Caledonia, on the other hand, exhibits a very differentbehaviour from heulandite and thomsonite as regards its capacity forreabsorbing water after partial dehydration a t various temperatures.This substance is probably a solid solution, and it is therefore hardlylikely that the zeolites are to be regarded as having the same con-stitution. Further, he concludes that the water taken up again byzeolites after they have been heated is more loosely held than thewater originally present, and he bases this statement on the dehydra-tioii curves of the rehydrated zeolite. Lastly, observations made ondioptase lead him to the somewhat remarkable conclusion that in thecase of this mineral we meet with a n example of solid solution.The constitution of certain silicates has also been discussed byH. C.9tLN~i1,~ who, continuing the line of research begun byF. W. Clarke, has examined the behaviour of various minerals whentreated witli strong solutions of hydrochloric acid and sodiumcarbonate both before and after ignition. H e finds that talc whichhas been strongly heated contains one-fourth of its silica in a formsoluble in sodium carbonate, the residue being completely decomposedby hydrochloric acid. He concludes that talc contains both a n ortho-and a tri-silicate radicle, and that the latter on iguition turns into anSi,O, group.Yyrophyllite he regards as a true acid metasilicate.C'unstitution of Zeolites.-Reference was made last yearAWL. Ileprt, 1905, 271. " ilIem. 12. Bccnd. Liwcci, 1906, 6, 102.J. AVLLI*. ChciiL. SOC., 1906, 28, 590MlNERALOGICAL CHEMISTKY, 305The results obtained with kaolin accord with the supposition that it isan orthosilicate, HOAl(OSiO,H,)( OSiO,Al), converted, on heating, intoA1,Si,O7 and water. Halloysite on ignition also gives Al,Si,O,,and may be regarded as kaolin combined with one molecule ofwater. McNeil has also carried out some experiments on zeolites,on the lines of those made by Steiger, but instead of using sealedtubes he has fused the minerals with various chlorides in platinumcrucibles, As the result of experiments in which chabazite, stilbite,and thomsonite were fused with sodium chloride, he believes that thesesilicates belong to the same class and have the following generalformula :R"[XR"{ Al(X Al)(XH,*AlO,H,)j],.I n thomsonite X is chiefly SiO, in stilbite Si,O,, and in chabazite amixture of both these groups.iMutua1 Relations of Fused C'hZorides.-Some fresh light has beenthrown on the m'inerals of the cerargyrite family by the work ofK.Mi;nkemeyer,l who has studied the freezing point curves of binarymixtures of AgCl, AgBr, and AgI. These three substances melt at4 5 2 O , 422O, and 552' respectively. The two former crystallise in theholohedral class of the cubic system, but the iodide is dimorphous, thecubic form being stable above 1464", whilst below that temperaturethe substance forms hexagonal crystals.I n the case of the mixtureAgC1-AgBr, the freezing point curve is of type I11 of Roozeboom'sclassification. A continuous series of mixed crystals of the same kindis formed, and a minimum freezing point lying below the meltingpoint of the more fusible constituent is reached. The minimum 4 1 2 Owas found to correspond to the mixture containing 35 per cent. ofsilver chloride. The mixtures of bromide and iodide also conform totype 111, the minimum value of the freezing point being 37i0,corresponding to the mixture containing 73 per cent. of silver bromide.I n this case the phenomena are further complicated by the transforma-tion of cubic into hexagonal crystals conditioned by the presence of theiodide. This transformation falls under type IA of Roozeboom'sscheme, the mixed crystals forming a continuous series before andafter the change, only one component being dimorphous.I n the caseof the chloride and iodide mixture the freezing point curve is of typeV. The series of mixed crystals is interrupted, and a eutectic occurscontaining 42 per cent. of silver chloride and solidifying at 211". Thechloride is only capable of taking up very small quantities of iodide,while the latter will mix with as much as 13 per cent. of chloride. Thetransformation into hexagonal crystals conforms to type III'A. Theview suggested by L.J. Spencer's study of miersite, that silver iodideJahrb. 2cl.i.l~. 1906, Bed-Bd,, 22, 1.VOL. 111. 306 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is trirnorphous, has not received any confirmation from these experi-ments.Water of Crpta1Zisation.-The difficult question as to the manner inwhich the elements of water are cpmbined in minerals has beenattacked by W. W. Cobientzl in an ingenious way. The infra-redabsorption spectrum of water exhibits well-marked bands at theapproximate wave-lengths 1.5, 2, 3, 4.75, and 6p, those at 3 and a t 6being especially strong. Coblentz has therefore examined a largenumber of minerals to see if those containing so-called “water ofcrystallisation” show the water bands. I n the case of selenite,CaS0,,2H20, he found that these bands were strongly marked, withthe exception of that a t 4.75, the place of which was taken b y a strongband at 4.55.Anhydrite, CaSO,, on the other hand, did not show thewater bands, although in this case d s o the band at 4.55 mas prominent.This band was subsequently found t o be well shown by anglesite,barytes, and celestine, as well as by glauberike, kieserite, andthenardite; it is doubtless due to the SO, ion. Opal, heulandite,stilbite, natrolite, and scolecite all showed the water bands. Onexamining hydroxides the water bands were found to be wanting, withthe exception of that a t 3, which appears to be characteristic of thisclass of substances, This wits found to hold for manganite, gothite,bauxite, turquoise, lazulite, hydrargyllite, and diaspore.I n the case ofdatolite and azurite the band a t 3 was slightly displaced, while brucitcexhibited a complex band with maxima a t 2.5, 2.7, and 3. Tourmalineshowed bands at 1.28 and 2.82. The examination of chloritoid,clinochlore, pennine, the micas, and talc revealed no indication of thepresence of hydroxyl. On the other hand, this group probably existsin serpentine, which shoms a well-marked band a t 3p.Ne w ilii n e r CL Z s.BeZZite.-This mineral has been described by W. F. Petterd.2 Itoccurs in delicate tufts and velvety coatings lining cavities in a softiron-manganese-gossan at Nagnet silver mine, Magnet, Tasmania.Minute hexagonal scales are sometimes met with. The colour is brightcrimson to orange-yellow. Sp.gr. 5 . 5 .The following analysis is by J. D. Rlillen :8i0,. PbO. C1.0;;. SO,. As,O,. Y205. TzO,. A1,0,. C1. Total.(’09 61.6s 22.61 0.05 6.55 0.04 0.11 0.01 0.52 99.16Cl~Zo~)izaizganoh.aZite.-A preliminary account of this mineral hasbeen given by H. J. Johnst~n-Lavis,~ who found i t in the form ofcanary-yellow rhombohedra associated with halite inside a block ejected8-rI Pl~ysiunl X e x i c u , 1906, 23, 125.TaPmniiin.Noltcrc, 1906, 74, 103.IZcpovt of Xecmkwy for J1iite.c .fw 1904. Hobrirt, 1905. 83.See also A. l m r o i x , L‘o?i~pL. T W ~ . , 1906, 142, 1249MINERALOGICAL CHEMISTRY. 30'7from Vesuvius. Analysis shows that the mineral is essentially adouble chloride of manganese and potassium containing 38.97 per cent.of MnCl,,dH,O and 57.71 per cent.of KCI.ChZornatrokalite.--This name has been given by Johnston-Lavis l toa sylvite containing 12 per cent. of NaCl, found associated withchlormanganokalite.It occurs in brownpebbles, so-called "favas," in the diamond sands of Brazil, and hasbeen described by E. Hussak.2 Omitting silica (present as includedquartz grains), ferric oxide, and TiO,, the two following analyses byG. Florence lead t o the formula Ba0,2A120,,P,0,,5H,0, a portion ofthe barium being replaced by calcium and cerium, and occasionally bystrontium :SiO,. TiO,. BnO. CaO. G O . Al,O,. Fe,03. P,O,. H,O.1. 1 5 5 0.67 15'42 3.55 1-55 35.00 4.10 22'74 14.6211. 6.5 0.75 15.30 2.24 2.35 35'20 1.67 21.47 14'73Harttile.-E. Hussak has assigned this name t o a strontiumnluminium sulphato-phosphate found in flesh-coloured '' favas " in thediamond sands of Brazil.The mineral is related to svanbergite,SSr0,3A1,0,,P,0,,2S03,6 H,O, and has been analysed by G. Florence,with the following results :TiO,. A1,03. SrO. CaO. CeO. P,O,. SO,. H,O.1'42 33-66 16.80 2.80 1.02 21.17 11'53 12'53These numbers lead to the formula (Sr,Ca)0,2A1,0,,P,0,,S03,5H,0.lfyclrated Calcium CaTbonak-A deposit from the neighbourhoodof Novo-Alexandria, looking much like mould or a thin layer ofcotton-wool, has been examined by L. L. Ivanoff,* who finds that itconsists of very thin, colourless, transparent, monoclinic or triclinicneedles. When kept over calcium chloride a t 22", it loses 37.56 percent.of water, leaving practically pure calcium carbonate behind. It isto be regarded as a hydrate, CaCO,,nH,O, where n, is not less than 3.I~ertschenite.-At one or two localities in the Kertsch Peninsulathere is found a dark green or almost black mineral. The formula(Fe,Mn,TYfg)O,Fe,O3,P2O5,7H,O has been given to it by S. P. Popoffon the ground of the two following analyses :P,05. FegO,. FeO. MnO. MgO. CaO. H,O. Total.28.19 32-89 9-50 1'99 1-54 0.49 25.04 99'6428'21 32'965 9'19 1'84 1-56 0'46 24.91 99'435itTew Mercury JfiiLeraL-In 1903 A. J. Moses described two newmineral species, eglestonite and terlinguaite, both oxychlorides ofmercury, from the Terlingua district, Texas, and indicated the probableexistence of a third. The last is now under investigation by W.F.Gorceixite is a barium aluminium phosphate.Ncttzsrc, 1906, 74, 174. TscI". X i 7 t . dfttt., 1906, 25, 335.3 Ibid.) 335. Ann. Geol. Mfi?. RICSSZ'P, 1906, 8, 23.CCdI~, illill. IOOC,, 112.Y : 308 ANNUAL REPORI'Y ON THE PKOGKESS OF CHEMISTRY.Hillebrand and W. T. Scha1ler.l The preliminary examination hasrendered i t almost certain that this remarkable substance is a mercur-bmmonium salt. It has so far been shown to contain Hg,N,CI,SO,,probably 0, and possibly H. Further, P. G. Nutting has found thatit gives off a little helium on warming. The full account of this asyet unnamed mineral will be awaited with interest. I n the mean-time we may note that A. Sachs has suggested that the oxychlorideof mercuxy, 3Hg0,HgC12, described by him last year under the nameof kleinite, may be identical with the substance referred to by Hille-brand. He finds, in fact, that both the sulphur-yellow and the orauge-red varieties of kleinite yield small and variable amounts of SO, andammonia, and he suggests that a portion of the chlorine in the aboveformula is perhaps replaced by SO,, whilst oxygen is substituted byNH,.If these views are accepted, the formula of kleinite becomesMoravite.-Under this name F. Kretschmer 3 has described a newinember of the leptochlorite family, found i n considerable quantity inthe neighbourhood of Gobitschau, near Sternberg, Noravia. It occursin scales and lamells, iron-black in colour, and in physical charactersand mode of occurrence it somewhat resembles thuringite, from whichit may be distinguished by its superior hardness and lower specificgravity, as well as by its different composition.The results obtained onanalysis of two different carefully selected specimens were as follows :Si02. A1,0,. Fe,O,. FeO. CaO. MgO. K20-i-Na20. P20,. C. H,O.I. 49-30 22-71 5'04 13.99 trace 1-82 1.10 trace 0'55 4.9511. 50.69 19'62 10'42 8.30 0.84 1.46 ( 1 ) 0.93 ( 1 ) 5.02The otherHg,[ ClA so41 2P(NH,),I 3From I is derived the formula H,(A1,Fe),(Fe,Mg),Si7024.members of the group found at Gobitschau are :Thuringite, H,8(Al,Fe),(Fe,Mg),Si,0,,.Stilpnochlorane, H,,(A1,Fe),o(Ca,Mg)Si,046.Stilpnomelane, HI2( Al,Fe),(Fe,Mg)8Si,,0,7.Nepouite.-Under this name E. Glasser has recently described amineral somewhat resembling Breit haupt's connarite.It occurs inthe form of a crystalline powder a t NQpoui, New Caledonia. Fivedifferent specimens have been analysed, and the results quoted beloware in harmony with the formula 2Si0,,3(Ni,Mg)0,2H20, nickel andmagnesium being mutually replaceable in all proportions :SiO,. KO. IigO. FcO. CaO. Al,O,. H20. Total. Sp. gr.I. 32'84 49.05 3'64 1.90 0-50 0.97 9'64 9854 3'2411. 33.03 46-11 6-47 2'20 traces 1-39 10'61 99'81 3.18111. 35'05 39.99 11-80 1.22 0.58 1.13 10.05 99'82 2.89IV. 40.07 18.21 29'84 0-25 0.53 0.72 11-98 101.60 2'47V. 32.36 50.70 3.00 0.62 traces 0.69 12'31 99-68 3.202 Centr. illin., 1906, 200.4 Coiizpt. re?zd., 1906, 143, 1173.1 A ~ z c r . J. Sci., 1906, [iv], 21, 85.3 Ibicl., 293MINERALOGICAL CHEMISTRY.3090elwnite.-The formula 6Si02,6(1sIg + Fe, Ca)O, H,O has been givenby E. S. Fecloroff to a mineral of the following composition :SiO,. A1,0,. Fe,O,. FeO. MgO. CaO. Na,O. K20. H,O.49.47 6.74 0.25 6'33 16'80 17.74 0.38 0.18 2-41It occurs in the Jenashir district of the Caucasus and somewhatresembles diallage in appearance. It has three rectangular cleavages,(loo), (010): (OOl), the latter being highly perfect, but crystallises inthe monoclinic system as shown by the optical characters. The opticaxes lie in the plane of symmetry, the acute positive bisectrix makingan angle of 55' with the normal to (001).Osannite is a variety of amphibole, intermediate between riebeckiteand arfvedsonite, and is found in the gneissic rocks of Cevadaes,Portugal.The optical characters have been determined by C.Hlamatsch,2 who points out that in the amphiboles these propertiesvary with the ratio A1,03 : Fe203, and also possibly with the amount ofwater present.The aagle 2Vis 63.The following analysis is due to M. Dittrich :SiO,. Ti02. A1,0,. Fe,O,. FeO. MnO. MgO. CaO. Na,O. Ii,O. H,O, Total.49.55 0.34 0.97 16'52 20.38 1.30 0.16 0.90 6'53 0.85 1.85 99.35Otuvite is a basic cadmium carbonate containing 61.5 per cent. ofcadmium, found by 0. Schneider3 as white to reddish crusts liningcavities on two specimens from the Tschumeb mine, Otavi, GermanSouth-West Africa. The crusts consist of minute rhombohedra( r ~ ' = 80' about), which dissolve with effervescence in hydrochloricacid, and exhibit a metallic to adamantine lustre.Parutmamite.-G.F. Herbert Smith4 has proposed this name fora mineral of the same composition as atacamite, CuC12,3Cu(OH),,which he has observed on some specimens from Chili. The crystalsare of two habits, namely, rhombohedra1 and prismatic. They arefrequently twinned, and have a good cleavage parallel t o the rhombo-hedron faces. The specific gravity is 3.74. The refractive index,1.846. On heating the mineral it appears to give up its water rathermore readily than .does atacamite. According to G. T. Prior, thecomposition is :CnO. CU. c1. Ergo.56'10 14-27 15.97 14'10Pc~~~vivianite.-Radiating needle-like crystals, transparent andsomewhat blue in colour, occur in the limonite ore of the KertschPeninsula. The formula (Fe,Mn,Mg),P,O,,SH,O has been found byGorni Jozmtnl, 1905, 264.Festschrift Harry Rosedusch, Stuitgns.i, 1906, 68.3 Centr. Miqt,, 1906, 389.Illin. Mag., 1906, 14, 170310 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.S. P. Popoff 1 to agree well with the analytical results.is present.No ferric ironP,O,. FeO. MnO. MgO. CaO. H20. Sp. gr.27-01 39'12 2.01 1.92 0.48 29-41 2'66Patronite.-Under this name F. Hewett 2 has recently described adark green substance containing vanadium, which appears to occur insome quantity at Cerro de Pasco, Peru. A specimen of the crude oremas found to contain 16 per cent. of vanadium and 54 per cent. ofsulphur, with considerable quantities of silica, alumina, and iron. Itis a t present undergoing examination at the hands of Dr.Hillebrand.Rutherfordine.-This interesting mineral occurs associated withmica in German East Africa, and is an alteration product of pitch-blende. The following analysis by W. Marckmald 3 shows that it isuranyl carbonate, UOz,CO,. I n appearance it resembles uranochre.UO,. CO,. PbO. FeO. CaO. H20. Gangue. Total. Sp. gr.83.8 12.1 1.0 0.3 1'1 0.7 0.8 100.3 4'82XiZicomagnesiojuorite.-This curious mineral has been found as aloose block composed of radiating hemispherical aggregates, grey orgreen in colour, at Luppiko, in the neighbourhood of Pitkiiranta,Finland. It has been examined by P. A. Zemjat~chensky,~ who assignsto it the formula H2Ca4Blg,Si,0,F,o, which he thinks may also bewritten in the form Mg( OH)F,RiIgSiO,,Ca( OH)F,CaSiO, Fz,2 CaF,,MgF,,The fibres show straight extinction and weak positive double refrac-tion.Weinberyerite.-In the course of an examination of the Kodaikanalmeteorite, F.Berwerth5 has found a new silicate in the form ofspherules exhibiting fibrous structure, associated with diopside.bronzite, apatite, and chromite. It appears t o crystallise in theorthorhombic system, and its refraction and double refraction areboth very low. There is reason to believe that it is pseudomorphous.According t o E. Ludwig, the composition is :SiO,. TiO,. P,O,. Fe,03. A1,0,. Cr,O,. h l n 0 . CaO. MgO.42.0 0.70 0.SS 28.75 9'42 0 98 trace 3.87 4'47K,O. Nn,O. II,O. Total.2.57 3-19 2.17 99.0If we assume that the iron was present as FeO, that the wateris not essential, and that P,O, and Crz03 are due to the presence ofapatita and chromite respectively, it will be found that the compositioncan be represented by the formula NaAlSiO, + SFeSiO,, some of theThe specific gravity is 2.9125 at 20".1 Ceidr.Min., 1906, 112.3 Centr. Min., 1906, 761.a Engin. illi-niqg Jom-., 1906, 82, 385.* Zeit. Kryst. Min., 1906, 42, 209,Txh. Mia. JliLt,, 1906, 25, 179MlNERALOGICAL CHEMISTRY. 311sodium being replaced by potassium, and some of the iron by magnesiumand calcium.Ytti*ocaZcite.-A mineral described under this name by E. S. Fedoroff 1in 1905 has proved on further investigation to be identical with fluor-apat ite.2Ytlrocrasite.-This name has been assigned by W. E.Hidden andC. H. Warren a to an yttrium-thorium-uranium titanite. The materialfor analysis was derived from a single crystal weighing some sixtygrams, found about three years ago in Burneb County, Texas, whsrrethe mineral occurs in loose pegmatite. The crystal exhibited ortho-rhombic symmetry and resembled certain yttrotantalites.It was covered with a thin brown costing., the underlying materialbeing black with pitchy lustre. Optical examination of thin slicesshowed that it was not strietly homogeneous, but consisbed of istropicand of feebly doubly refracting portions. Thefollowing are the results of Warren’s analysis :Sp. gr. 4.8043 a t 1 7 O .TiO,. IVO,. UO,. CO,. (Yt,Er)203. Ce,O,, &c. Fe,O,. Tho,. UO,.49-72 1-87 0.64 0’68 25-67 2 92 1.44 8-75 1.98PbO.BInO. CaO. H,O. Total.8-48 6-13 1.83 4’46 100.57A small quantity of Cb,O, together with traces of Ta205, SiO,, and>$gO,were also found, and of the water 0.10 per cent. was hygroscopic.These numbers give the following approximate molecular ratios :H,O : R O : R”’20, : R””O, : TiO, = 6 : 1 : 3 : 1 : 16, where R O is chieflylime, R”,O, chiefly yttrium earths, and IC’”’O2 chiefly thoria. Themineral is therefore essentially a hydrous titanate of the yttriumearths and thorium, but the fact that it contains both water andcarbon dioxide, taken in conjunction with the results of the micro-scopic examination, suggests that i t may be a hydrated alterationproduct of an originally anhydrous species. The radioactivity of thesubstance has been determined by B.B. Boltwood, who finds that itcorresponds t o 10 per cent. of thorium and 2-08 per cent. of uranium.A New Zeolite.-A. Pauly4 has examined the minute grainsscattered through a quartz-sericite rock which occurs in the neighbour-hood of Hainburg. H e finds that they are isotropic and possess a goodcleavage parallel to faces of the cube. The index of refraction is1.507-1-508 for sodium light, and is therefore higher than that of anal-cime. Microchemical tests showed the presence of Na, Ca, Si, Al, andSO,. About 10 per cent. of water was driven off on heating., provingthat the mineral is not a member of the sodalite group. The specificgravity is 2.4-25. The author has been unable so far to obtainPrivate eo~nmzsirication from E.S. Fedoioff.Zeil. Kryst. Min., 1906, 42, 370.1 Borni Journal, 1905, 264.3 Amer. J. Sci., 1906, [iv], 22, 515312 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sufficient material for a quantitative analysis, but thinks that hisresults justify him in concluding that the mineral is new.ArtiJcicd Pownation of Minerals.A number of cases of the artificial production of minerals have beenmentioned incidentally in a previous section, but R few special experi-ments deserve a separate description here.Diamond.-A useful summary of the attempts that hare been madeto obtain this form of carbon has been contributed by A. Koenigl tothe pages of the Zeitschrift f u r EZektrochenaie.obtained Mg,SiO, as a by-productwhen MgSiO, was dissolved in fluxes and allowed to crystallise.Thebest specimens were furnished by magnesium chloride. The crystalswere small, but gave fairly sharp measurements, and agreed in habit,angles, and physical characters with the natural mineral. Periclasewas also observed in some of these experiments in well-formedoctahedra.Nordensll;ioZclite.-Minute but measurable rhombohedra of this sub-stance, CaO,SnO,,B,O,, have been obtained by L. Ouvrard by passiDga mixture of air and stannic chloride vapour over calcium borate a t abright red heat.Northupite, 2 ZMgCO3,2Na2CO3,2NaCl, is probably isomorphous withtychite, 2MgC0,,2Na2CO,,Na,SO,, described by Penfield and Jamiesonlast year. To throw light on this point, A. de Schulten4 has at-tempted to prepare mixed crystals of the two substances.I n this hehas been successful, for by heating mixtures of the chloride andsnlphate of sodium in various proportions with 20 grams Na2C03 and18 grams Mg2S0,,7H,0, dissolved in 350' C.C. of water, he has obtainedcrystals containing 99, 76, 64, 28, and 6 per cent. of tychite re-spectively. He concludes, therefore, that the two substances are'perfectly isomorphous.Quartz has been produced in measurable crystals by Day andShepherd 5 by heating a mixture of ammonium magnesium chloride,sodium metasilicate, and water for three days in a steel bomb at40O-45Oo. The clear, colourless crystals attained a maximum lengthof 2 mm. They were doubly terminated and often barrel-shaped,showing rhombohedron faces passing by oscillatory developments intosteeper rhombohedra, and finally into the prisms which showed thecharacteristk! striae.I n some the + rhombohedron only was present.The angle from prism to rhombohedron was 37'48' instead ofAnter. J. Xci., 1906, [iv]. 22, 390.Forsterite.-Allen and Wright1 &?it. Elcktrochem., 1906, 12, 441.3 Compt. rend., 1906, 143, 315. Ibid., 403.5 Amer. J. Sci., 1906, [iv], 22, 297MINERALOGICAL CHEMISTRY. 3133S013’, this being perhaps due to some ingredient of the mixture heldin solid solution.Some interesting experiments on the crystallisation of quartz havealso been carried out by G. Spezia.l He suspended a long crystal andthree short prisms of quartz cut perpendicular to the axis in thelower portion of a tube containing a 2 per cent.solution of sodiummetasilicate which was kept a t a temperature of about 330’ a t theupper end, whilst the lower end remained a t about 170’. The upperpart of the solution wits in contact with a quantity of powderedquartz. After heating for one hundred days, it was found that aquantity of silica had dissolved arid had been deposited again on theprisms, converting them into more or less perfect crystals. The longcrystal had also increased in size. It was observed that quickcrystallisation appeared to favour the development of a long prismterminated by the faces of one rhombohedron. Slow crystallisation,on the other hand, gave a short prism terminated by the faces oftwo rhombohedra.Mineml Analyses.Many mineral analyses have been published during the past year.I t is only possible here to refer very briefly to some of those whichhave thrown light on the composition of rare or imperfectly describedspecies, or which are of special importance, because made on carefullyselected material of which the crystallographic and physical charactershave also been determined, For the rest, reference should be madeto the Abstracts published by this Society.Apatite.-Crystals from the Rhone glacier have been the subject ofan elaborate crystallographic and optical study by K.Busz.2 Hefinds a : c = 1 : 0.7335, and that for sodium light, W = 1.63558,~=1-63320. A second prism gave slightly different values. Theanalysis quoted below shows that the substance is a pure Auor-apatite.1’?O5. A1,0,.MnO. CaO. MgO. K20. Na,O. H,O. F. Sp. gr.41’44 0-94 0’39 54.80 0.14 0.45 0.53 0.22 2.93 3.195Traces of iron and chlorine were found.Apo,vl~ylZite.-In a preliminary communication F. Cornu 3 announcesthat the extreme members of the leucocyclite type of apophyllite are freefrom fluorine, but contain hydroxyl ; the specimens of the chromocyclitetype, on the other hand, contain fluorine. The former are opticallypositive and possess higher indices of refraction than the latter, whichare negative.Berthierite.-This mineral occurs in some quantity at Charbes, Val1 Atti R. Accnd. Sci. Toriiko, 1906, 41) 158.Ibid., 79.Centr. illin.) 1906, 753314 ANNUAL REPORTS ON THE PROGRESS O F CHENISTRY.de Till6 (Weilerthal), Alsace.gave the following results :A specimen analysed by UngemachS.Sb. Fe. As. SiQ2. Total. sp. gr.28-02 54.06 12'72 traces 5.29 100'09 4 '2 l e 4 '23On subtracting the silica, aumbers are obtained which agree wellwith the formula FeS,Sb,S3.Boleite Group.-G. Friedel 2 has published a comprehensive aceountof this group, based on an examination of specimens preserved at thegcole des Mines de Saint-Etienne, supplemented by some from thelhole des Mines de Paris. He has also been able to study Mallard'smicroscopic sections a u d some of Lacroix's preparations. He recog-nises three distinct species in the group, namely, cumengeite, pseudo-boldite, and boldite. All three cryetallise in the tetragonal system,and their chief properties are summarised below :Cumengeite ......4PbC12,4Cu0,5H@ ............ 1 *625 4.67 0'100Eoleite ............ 9PbCl2,8Cu0,3A~0l,9H~O ... 3'996 5.054 0-020Name. Formula. Parameter c. Sp. gr. Birefringence.l'seudo-boleite ... 5PbCI2,4Cu0,6H,O ............ 2'023 4 *85 0 -03 2The above formulre differ considerably from those hitherto assignedto members of the group, and are based on the following analyses, ofwhich I refers to cumengeite, I1 t o pseudo-boleite, I11 gives the com-position of pseudo-boleite on the assumption that the silver chloride pre-sent is due to admixture with boleite ; IV is the mean of two concordantanalyses of boleite made, one on material derived from the exteriorof the crystals, the other on material from the interior. Under In,IIIa, and IVa are given the theoretical percentages corresponding withthe formuls.As the analysis of pseudo-boleite was made on 0.0948gram only, and as the water yielded by this substance could only beobtained by calculation from an estimation made on a mixture ofboleite and pseudo-boleite, of which the composition was butapproximately known, the formula assigned can only be regarded asprovisional.I. Ia. 11. 111. IIIn. IV. IVn.C1 .................. 19.03 37.13CuO ................. 20'27 20.93 16 5 16.9 17.51 17.18 17'05H,O .................. 5-90 5'93 [5*5] 5.5 5.97 4.35 4.35AgCl .................. - - 1.6 - - 11-59 11.54Breunnerite.-Large rhombohedra have been observed by G. PioltiPb ..................... 54'47 z!:: ). 77.5 76.52 { f;::: 49*930.23 - - Residne ..............0.19 - 0.8 -in serpentine near Avigliana.angle is 72O29'42", whence c = 0.808642.Bzlll. Soc. franc. Min., 1906, 29, 266.The mean value of the rhombohedronThe ordinary index of re-Ibid., 14.3 Atti €2. Aecad. Xci. Torino, 1906, 41, 106631 IN ER A LOG I C A 1, C HE MI STRP , 31 5fraction determined by the Duc de Chaulnes's method is 1,715. Thecomposition is 90.47 per cent. MgCO, and 9.45 per cent. FeCO,.Traces of manganese are present, but no calcium. A specimen from theSylvester mine, Val de Villk, analysedj by Ungemach,l contained 3.1 0per cent. CaCO,, 35.08 MgCO,, 61.25 FeCO,, whilst another specimenfrom the same mine contained 58-65 per cent. CaCO,, 25.47 per cent.MgCO,, and 21.85 per cent. FeCO,, and is therefore ankerite.Two specimens from Frigido, near Massa, analysed by E.Rlanasse,2contained respectively 46.30 and 55.09 per cent. of FeO with 12-18 and5.94 per cent. MgO. The former corresponds to 2FeCO,,RlgC'O3,the latter to 5FeC0,,MgC03.Two other specimens from Bottino, Tuscany, examined by the samen n n l y ~ t , ~ had a composition agreeing with the formula 3FeCO3,I!tgCO,.Caherite.-A measurable crystal found on a specimen from Lauriunihas enabled A. Sachs4 t o determine the constants of this mineral.H e finds that i t is monoclinic, a : b : c = 0.82386 : 1 : 0.77673 ;p=106"29'. The composition of the apple-green crystals is asfollows :As,O,. KiO. COO. FeO. MgO. H,O. Total. Sp. gr.40.45 26.97 trace 1.10 6'16 25% 99.94 3T)104The mineral is isomorphous with erythrite, though the similarity ofangle is not very close.Calcite.-In the course of an interesting investigation into the causeof t h e perbistent phosphorescence exhibited by certain specimens ofcalcite from Fort Collins, Colorado, and from Joplin, Missouri, W.P.Headden 5 has made a very careful analysis of the well-known yellowcrystals from the latter locality. The results are as follows :SiO,. CO,. CaO. MgO. MnO. FeO. ZnO. Ce,O,.0.032 43.950 55,740 0.113 0.045 0'046 0.014 0.007(Di,Sm, La),O,. (Yt,Er)&.0.012 0.012Traces of SO,, P,O,, C1, SrO, A1,0,, Cr203, NH, and Na,O were observed,but no hydrogen sulphide could be detected, and of the gas evolved ondissolving 100 grams of material, all but 10 C.C.was absorbed by causticpotash. The author is inclined to attribute the remarkable phosphor-escence t o the presence of some member of the yttrium group. Speci-mens OP other colours are found with the yellow ones, and those ofBull. Soc. franq. Min., 1906, 29, 279.Men&. ,!70c. Tosc. Sci. Nat., 1906, 22, 81.3 Proc. verb. SOC. Tosc. Sci. Nut., 1906, 15, 20.5 Airier. J, Sci,, 1996, [iv], 21, 301.Ceittr. Min., 1906, 198316 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.purple tint exhibit the absorption bands characteristic of didymia, butnone of them shows the persistent phosphorescence.Celestine.-A dolomite containing considerable quantities of celestineis found at the Woolmith quarry, near Maybee, Monroe CountyMichigan. Fine crystals of the mineral are met with i n cavities in therock, and have been the subject of crystallographic and chemicalexamination by E.H. Kraus and W. F. Hunt.l Axial ratio a : b : c =0.7'781 : 1 : 1.2673. Analysis of clear, trans-parent crystals gave the following result :Sp. gr. 3.979 a t 20.5'.so,. SrO. BaO. " 0 . CaO. (Al,Fe),O,. SiO,. Total.43'58 53.75 1-26 0'1'2 0.4.5 0.15 0.22 99-5343.60 53.78 1-32 0'14 0'47 0'13 0.23 99'67Clzalnaersite. -E. Hussak,2 having received a fresh supply of thismineral from the St. John del Rey mine, has been able t o place 0.0896gram of pure material in the hands of G. Florence for n new analysis,the first having .been made on 0.016 gram only. The results quotedbelow lead to the formula CuFe,S, or Cu,S,Fe,S,.Fe. cu.S. Total.43-13 22'27 35.11 100.51Clintonite and Chlorite Group-E. Manasse has analysed ftcldoritoid (I) from Strettoia, Alpi Apuane, two specimens of ripidolite,from Calci (11) and Verruca (111) respectively, and a clinochlore fromAffaccata (IV). The results are given below :S O 2 . TiO,. Al,03. Fe,03. FeO. MgO. Ka,O. H,O.I. 25.70 0.59 30.95 - 23.44 6.12 - 6.3111. 26-14 - 23.65 - 18.38 19.48 0.5G 11.9321'80 - 28.08 12.82 trace 21.64 111. 24.93 -34.07 -- 12.86 IV. 28.95 - 21'41 3.12 -I n analysis I water was determined by ignition loss, and the iron allcalculated as FeO, although Fe,O, mas also present.DatoZite.-A valuable contribution t o our knowledge of this mineralhas been made by E. H. Kraus and C. W. who have examinedthe excellent crystals found at Westfield, Massachusetts.Thesecrystals are rich in faces, and exhibit monoclinic symmetry with thefollowing constants, a : b : c = 0.63482 : 1 : 1.26567 j p = 90'9'. Carefuldeterminations of the specific gravities of four crystals gave a meanvalue of 3.0058 a t 21.5'. This composition is accurately expressed bythe accepted formula HCaBSi05. Analyses I1 and I11 below weremade on material derived from a single crystal. Under I is giventhe theoretical composition. Crystals of this mineral found at the1 Amw. J. Sci., 1906, [iv], 21, 237.3 Proc. verb. Xoc. Tosc. Sci. Nnt., 1906, 15, 20.4 Airier. J. Xci., 1906, [iv], 22, 21.Ccntr. illis., 1906, 332MINERALOGICAL CHEMISTRY. 317Colebrook mine, Dundas, Tasmania, have been measured by C.Anderson,l who finds that they have the composition given under IV.SiO,. Fe,O,.A1,0,. CaO. MgO. R,O,. H,O. Total.I. 37-63 - - 34.95 - 21-81 5'61 -11. 37.60 0.10 0.14 34-64 0.32 21'76 5.67 100.23111. 37'58 0.10 0'16 34'74 0.31 21.94 5.76 100.59IV. 36.28 0.95 35.21 - 20.48 6'48 99-40Bzcnclasite occurs in white spherical aggregates or in tufts of radiat-ing silky needles associated with allophane and cerussite at WelshFoxdale Mine, Trefriw, Carnarvonsbire. G. T. Prior 2 finds that theanalytical results suggest the foriiiula, PbO,A1,O3,2C0,,4H,O :YbO. AI,O,. Fe,O,. (20,. H,O> 100". H,Oat100". Iiisol. Total. Sp. gr.43.20 21.39 1'61 16.45 13.60 1.41 1.80 99.46 3'25The Welsh mineral is like that from Tasmania, and shows a relation todawsonite, Na,0,A1,03, 2C0,,2H20.Fho&e.-h the course of an elaborate study of fluorescence,H. NT.Morse3 has examined the composition of the gases given offwhen fluorite is heated. I n the case of specimens from Weardalethese consisted chiefly of carbon monoxide, carbon dioxide, hydrogen,and nitrogen, with small quantities of oxygen, The two latter werenot present in the proportions i n which they occur in air, and no argonor helium was found, He concludes that the gases are due t o thedecomposition of some organic colouring matter, but that there isnothing to show that organic substances have anything to do with thefluorescence or thermo-luminescence of the mineral.Gccrizet.-The chemical composition and optical constants of a numberof garnets have been determined by AT.Seebachm4 His results aretabulated below :vI. Qrossular from Xalostoc, Mexico. Pink dodecahedra.IT. Pyrope from Colorado River, Arizona. Blood-red masses.Dark, wine-red grains.Irregular, dark-red fragments.111. Pyrope from Meronitz, Bohemia.IV. Almandine from Ceylon.VI. Melanite from Frascati.Brown-red to wine-red grains.Well-developed, black crystals.V. Alinandine from Jeypoor.VII. Andradite from Dognaczka. Green crystals.VII I. Demantoid from Polemskoi-Zawod, Urals. Rolled masses.Si02. TiO,.I. 4079 -11. 43.37 -111. 42.98 -1 v . 37'25 -V. 38-07 -VJ. 34.74 1-54TII. 36'79 -YIII. 35.37 -A1,0,. Cr,03.21-70 -20.99 2-3621.34 2.0619.43 -19-63 -5'43 -1'39 --1-54 1-32Fe,03.FeO.0.18 0'43- 10'210.95 7-803'29 35.452.16 31'5821.95 1'9929'30 0.6925-89 0'52MnO. CaO. hIg0.1.07 35-63 0-390.52 4.54 18.420-50 4-47 20.671'24 2'51 1'131.36 5'03 2-770.65 32'58 1.480.26 31-40 0.770'34 32-26 0.21Total.100.19100'411 0 0 * i i100 -30100'601 O O 3 i100.60100.45Bcc. AiLstmliaii Miis., 1906, 6, 133.Proc. Aii~er. Accid., 1906, 587. lnnug. Diss. Xcidelberq, 1906.Min. Mag., 1906, 14, 167318 ANNUAL REPORTS ON THE PROGRESS OF CHkMISTRY.All the above are the mean of two concordant analyses, with theexception of VI, which is the mean of four analyses. The mineralswere decomposed by fusion with anhydrous boric acid, and the analysesconducted by the methods developed by Jannasch and his pupils.I n the following table are given the specific gravities and opticalconstants of the minerals before fusion, the specific gravities andindices of refraction for sodium light (so far as the latter could bedetermined) after fusion, and the proportion of the fused mineralsoluble in hydrochloric acid.The molecular ratios cztlculated fromanalyses 111, V, and VII agree fairly well with those required by thegarnet formula R”3R”2Si3012, but diverge considerably from thetheoretical values in the case of analyses IV, TI, and VIII.After fosion./-- ---KO. sp. 6’.I. 3.50611. 3’715IJI. 3.679IV. 4.040Ti. 4.026v1. 3.774T1I. 3.660VIII. 3.801Before fnsion.- -.hi____pLi. pxa.1.7319 1.73641.7371 1’74171‘7417 1.74631’7724 1 *77791.7763 1.78151.8471 1.85601.8763 1’88781.8767 1.8884PT1.1’74111 *74631.75051.78251.7862136581.89901.8999sp. gr.2.8663’1903.2513.0093‘2403.2633.1713.335Percentagesolublepsi$. i n HCI.1-6205 all828472741.7667 971.8177 all1.8110 99----A few other analyses of garnet may also be recorded here.OF theseI refers to a bright red spessartite from KgrarFvet near Falun, analysedby C. Benedicksl; I1 gives the composition of a brown variety fromthe same locality ; these garnets are interesting because they containan appreciable quantity of yttria; 111 is a dark brown garnet foundin pegmatite a t Yamano, Hitachi Province, Japan ; I V occurs in brown-red crystals in mica andesite at Anamushi, Yamato Province.Theanalyses were made by Shimizu.2SiO,. A1,03. Yt,O,. FeO. MnO. CaO. IlgO. Total. Sp. gr.I. 35-67 22.50 1-19 19‘17 21-91 traces - 100.44 4‘19711. 35.36 22.34 1’23 22.01 18-80 traces - 99.74 4.068111. 36.39 23-05 - 24.77 14-21 1-57 0.67 100‘66 -IV. 36-74 20.71 - 34‘91 1.67 2.11 3.27 99’41 -GeikieEite.---A number of specimens of ferro-magnesian titanatesfrom Ceylon, including the original geikielite (analysis I below), havebeen examined by T. Crook and B. M. Jones.3 They find that thismineral contains a greater percentage of iron than was a t first recorded,and they suggest that the formula should be written (Mg,Fe)Ti03.The analyses 11 to X indicate a passage to picroilmenite, the com-position of the latter being given under XI and XII.E ~ l l .Beol. liist. Uitiv. Upsnln, 1906 (for 1904-5), 7, 271.Beitraigc 2. Xin. Japnx, 1906, No. 2, 53. Mi)/, ilIq., 1906, 14, 160MINERALOGICAL CHEMISTRY. 3191. 11. 111. IV. r. VI. VII. V l I I . IY. x. XI. XII.TiOz ... 63.77 64.41 64.78 60.02 60's; ClMl F2.25 li3.94 64.03 63'49 57'64 56.06FeO .... 6'34 5-44 5'92 5'bl 6.03 *.& i 1 9 11'5s 10.09 13'14 10.70 16-57 24.40Fe203.. 1.93 2-77 2'32 6.80 <5%9 4.95 - 0'23 - 3.54 10'17 5'433fgO ... 28-50 27'90 27.90 27'79 37.39 26-31 26.03 23'7'3 24'66 23'60 1.3 56 14'1s100.64 100.53 lOO'S.2 100'42 9R'SS 100.65 99'SB 100.07 100% 100'33 !*!)'!I4 1 O O f Nsp. gr. - 3 9 7 3'S9 3.79 3*S7 390 3.91 4.01 4'11 4.01 4.17 4'35GZaserite.-It has been maintained on the one hand that a doublesalt of potassium and sodium sulphate exists of the constant composi-tion K3Na(S04),, so-called glaserite.On the other, i t has been heldthat this name merely covers those members of the isomorphous seriesof mixed crystals formed by the t w o sulphates which contain amaximum of potassium sulphate. J. H. van't Hoff and H. Barschalllhave investigated this point and find no evidence in support of theview t h a t glaserite has a constant composition.G'yroZile.-This rare mineral has been observed by E. Hussak2 inthe form of spherical aggregates composed of thin radial leafletsoccurring in crevices in diabase a t Mogy-guassh, Siio Paulo, Brazil.The specific gravity is 2.409, and the mineral is uniaxial with negativedouble refraction. The composition is very similar to that of gyrolitefrom Skye, as shown by the following analysis of white material madeby G.Florence :__ ~ - - -___ -- -- __SiO,. Al,O,. CnO. R'a,O. K,O. H,O. Total.52-77 0'73 33'04 0.35 0'41 12.5s 99-88Under alumina is included a trace of ferric oxide. A dark greenvariety contained 7.36 per cent. Fe,03 + A1,03 and 0.32 per cent. MnO.We may note here that P. Cornu identifies gyrolite from the Hebrides,Paroc Islands, Greenland, Poonah, and Siio Pnulo with the mineraldescribed by Peli kan uuder the name zeophyllite.Hellunclite has already been the subject of a preliminary notice I)y%I7. C. Briigger, who has now published a full account based on thestudy of more than forty crystals. The mineral was found it1 a quarryopened i n a pegmatite vein on the top of a small hill calledLindvikskollen near Kragerii, Norway.The crystals belong to theprismatic class of the monoclinic system, and are for the most part agood deal altered. The freshest consist of nut-brown material withvitreous lustre, others exhibit various shades of brown, while the mostaltered ones consist of a yellow to white earthy mass. The alteration,which is probably due to hydration, does not seem to have had anyvery great influence on the relative proportions of the constituents.The purest material had the specific gravity 3.6'7 to 3.70, that of thesubstance used for analysis I1 was 3.41 to 3.33. An analysis (I) by0. N. Heiclenreich made on a small quantity of material has already&it. p,hpih.nl.C'lwn., 1906, 56, 212.Cee,Ltr*. M i i t . , 1906, i 9 ." C'mtr. 111i72., 1906, 330.Zcit. K ~ z J s ~ . Nist., 1906, 42, 41'7320 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been published, I1 and 111 are due to L. Andersen-Bars ; tho materialused for 111 was highly altered :SiO,. A1203. Fe,03. Jlu,O,. Ce,O,. Y20,. Er,O,. Tho.,.I. 23.55 10.22 2‘64 5’69 40’1211. 23’66 10.12 2.56 5‘91 1.01 19.29 15-43 0’62111. 27.85 9-67 2.01 3’13 0.37 19.71 13’28 0’30C’aO. RlgC. Na,O. K20. H20. Total.I. 10.05 - 0’26 0.06 7.65 100-1911. 9-81 0’10 0.23 0-06 11-75 100.55\,-111. 9.97 0’13 0.41 13’09 99.93Since some 6 per cent. of the water mas expelled below 500’ and therest only a t red heat, it seemed probable that about 5 per cent.was chemically combined.This was confirmed by an experiment onthe freshest material, when 4.S6 per cent. of water was found.Accepting this value as the true percentage of water, and assumingthat the small quantities of potash and soda are due t o felspar, theratios (calculated from 11) R”O : H,O : RZ’”O3 : MiO, are very accurately2 : 3 : 3 : 4.Ca ,R ;”[ R”’(0H) J3[ 8iOJor of the type Ca,~R”’(OH)],[SiO,],. Of these two possibilities,Brogger is inclined to prefer the first on the ground of certain analogieswhich hellandite shows with guarinite, danburite, andalusite, andtopaz. Accepting this view, the composition of the mineral may berepresented thus : C’;td[$B1$-(RIn,Fe)l3[ (Y,Er,Ce)(OH),],[SiO,],.t1ibschite.-Reference was made to this mineral last year.Adetailed account of its properties and mode of occurrence has recentlyThe formula is therefore either of the typebeen published by F. C0rnu.lHueherite.-Large black crystalsLawrence County, South Dakota, werehave the following composition :\YO3. mlo. PeO.75.12 20‘54 3’01from the Comstock mine,found by W. P. Headden2 toCaO. Total.1-04 99.71Judade and h‘ephrite.-Some very valuable contributions to ourknowledge of these two minerals are to be found in the monumentaltreatise entitled “ Investigations and Studies in Jade,” issued by theexecutors of Reginald Heber Bishop. I n two vast volumes, eachweighing about sixty pounds, are embodied the results of a series ofstudies by leading American experts of the specimens contained in thegreat Bishop collection now preserved in New York.The mineralogicalportion has been edited by G. F. Kunz, and he has had the assistanceof 8. L. Penfield, P. W. Clarke, J. P. Iddings, C. Palache, L. V.Pirrson, and others. On breaking up a specimen of jadeite, whichProc. Colorado ,S’ci. Soc., 1906, 8, 174. Tsch. Mah. Mitt., 1906, 25, 249.Pyivmtcly pirrtcd, Ken. York, 1906MINERALOGICAL CHEMISTRY. 321probably came from Tibet, two small crystals mere found. Theseclosely resembled augite in shape, and enabled Penfield to determine thecrystallographic constants of the mineral. He found a : b : c =1.103 : 1 : 0.613 ; p= 72’444’. The cleavage angle was 92’58‘. Theextinction angle measured on (010) was 34” and the optic axis angle70°, one axis being nearly parallel to the Z axis of the crystal.Thisspecimen had the following composition :SiO,. Al,O,. Fe,O,. MgO. CaO. Na,O. Ii,O. H,O. Total. Sp. gr.58.80 25.37 0.33 0.25 0‘58 14.65 0.05 0’14 100-17 3.3359I n all, fifty-eight analyses of the two minerals are given, and, withtwo exceptions, these were made by P. ‘3.’. Walden and H. W. Foote.I n his discussion of the formulz to be assigned to these minerals,F. W. Clarke advances arguments in support of the view that themolecules of the pyroxenes are more complex than those of theamphiboles, and that jadeite must be represented as Na6A1,Si,,O,,.Further, he holds that it is not to be regarded as a metasilicate, but asa mixture of an orthosilicate and a trisilicate. A t the conclusion of aparagraph devoted to a discussion of the origin of jadeite considered asa lock, Pirrson sags “jadeite is a metamorphosed igneous rock, R,member of the phonolite family.The wh$e varieties are probablymetamorphosed dikes of the aplitic, leucocratic type, belonging in t h i jfamily and the darker green types those containing more iron-bearingdark silicates, like tinguaites.” The mean value of the specific gravityof all the nephrite specimens was 2-9505 ; that of the jadeites, includingsome chloromelanites, was 3.3202.Junosite.-The existence of this mineral as a separate species hasbeen denied by E. Weinschenk,l who on the ground of its opticalproperties has identified it with copiapite. H. Bockh and :K. Emszt,the discoverers of janosite, have, however, reiterated their belief in itsindividuality, laying special stress ou its specific gravity and chemicalcomposition.I n his reply Weinschenk states that a comparison ofjanosite with specimens of copiapite recently received from Copiapofully confirms his previous conclusion. Further, a specimen of janositesupplied by Bockh was found to contain 30.80 per cent. Pe,O, and tohave n specific gravity 2.17, the corresponding values found forcopiapite being 3 1-09 and 2.19 respectively,J~~mesonite.-Imperfect crystals occurring in quartz veins a tSheridan, Pennington County, South Dakota, have been analysed byW. Y. Headden.2 The percentages found are in tolerable harmonywith those required for the ordinarily accepted formula, 2PbS,Sb,S, :S.Sh. Pb. Fe. Cu. Zn. Cod Insol. Total. Sp. gr.18.90 26-99 51.15 1.30 0 2 4 0.05 trace 1’13 99-76 5’81304Ann. il‘eport, 1905, 279 ; Fold. KOzEOwy, 1906, 36, 224, 228, 359,Pr6c. CoZorado Sci. Soc., 1906, 8, 174.VOL. 111. 322 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Malacom-A specimen of this mineral examined by E. S. Kitchinand W. G. Wintersonl proved to be distinctly radioactive and tocontain argon, Taking the radioactivity of uranium oxide as unity,that of the malacon is 0*0161. This value is much greater than canbe accounted for by the iiranium present in the mineral. Afterdecomposition the radioactivity is entirely associated with thezirconium dioxide. On fusion with potassium hydrogen sulphate,100 grams of malacon gave 37.91 C.C.of gas, consisting of 33.24 C.C.of carbon dioxide, 2.82 C.C. of argon, 0.94 C.C. OF helium, 0.57 C.C. ofhydrogen, and 0.34 C.C. of nitrogen. The specific gravity is 3,908,rising to 4.232 after heating. The complete analysis is as follows :ZrO,. SiO,. Fe,Os. MgO. CaO. U,Oa. (Y,Ce),O,. H,O.67-78 22.53 4'93 0.70 0.41 0'33 0'09 1.84If the other constituents are neglected, and zirconia and silica calcu-lated t o 100, the percentages obtained agree well with those requiredfor the formula Zr3Si2010. The analytical results differ a good dealfrom those previously recorded for the substance, and from which theformula 3(Zr0,,Si02),H,0 has been derived.Meneghirnite.-A fibrous mineral found in the Gorham claim nearRochford, Pennington Cobnty, South Dakota, has been analysed byW.P. Headden.2 The ratios obtained are only approximate, butshow that the probable formula is 4PbS,Sb2S, :S. Sb. Pb. cu. Insol. Total, Sp. gr.17-51 18-20 62.85 0 *86 0.49 99.91 6'21Traces of As, Bi, Cd, and Fe are also present.iVaegite.-T. Wada 3 has published some important fresh informationabout this mineral. He states that a crystallographic examination byTakimoto has shown that in habit and angles the mineral is closelyrelated to zircon, whilst Haga has found that it contains a largequantity of zirconia, a constituent previously overlooked, probablyowing to some imperfection in the methods of separation employed.Haga's analysis is as follows :ZrO,. Tho,. SiO? (NbTa),O,. UO,. Y,O,. Total. 8p.gr.55'30 5'01 20-58 7-69 3.03 9'12 100'73 4.091Petterdite,-Under this name there mas described, a few years ago,a mineral from the Zritannia mine, Zeehan, Tasmania, which wassupposed to be a new oxychloride of lead. A careful re-examinationof this substance recently made by C. Anderson has proved that i t ismerely a variety of mimetite.Trans., 1906, 89, 1568.Beikrage z. Nin. Japan, 1906, No. 2, 23,Rec. Australia?t Mics., 1906, 6, 133.PTOC. CoZorndo. ,%i, Soc,, 1906, 8, 174MINERALOGICAL CHEMISTRY. 323Pitchblende.-The pitchblende from which rutherfordine is derived(see p. 310) is 20 per cent. more radioactive than that from Joachims-thal, and has been shown by W. Marckmaldl to have the followingcomposition :U,O,. PbO. CaO. FeO.SiO,. H,O+CO,. Gangue.87.7 7-5 2.1 1.0 0.3 0.5 0.2Plumbogurnmite. --E. Hussak 2 has published the following analysisby G. Florenceof a mineral found in the form of pebbles, “favas,” inthe diamond sands of Brazil :SiO,. PbO. CaO. CeO. Al,O,. P,O,. H,O .0.70 35-50 0.62 0‘16 24‘92 22.50 16.30The corresponding formula, 2(Pb,Ca)0,3A120,,2P,05,10H,0, is near tothat of plumbogurnmite, although it contains 3 molecules more water.Pyrochroite.-This rare mineral occurs a t Lgngban in prisms andneedles with a distinct basal cleavage. The following analysis, giveiiby H. Sjogre~~,~ agrees with the formula Mn(OH), :H,O. Sp. gr.77.3 0.4 trace 1.7 20.9 3,2435MnO. FeO. CaO. MgO.Quartz.-J. C. Konigsberger and W. J. Muller have studied theliquid inclusions in quartz crystals from the biotite-protogine of the Aardistrict, They find that for these crystals there is aconstant relationbetween the volume of the liquid and the volume of the gas in a cavity,a fact first observed by Sorby.On heating a t from 200’ to 230’ thebubbles disappear, the liquid expanding to fill the cavity. They con-clude that the included matter represents a homogeneous portion ofthe liquid phase. Its composition in the case of a specimen fromthe Biichistock appears t o be as follows :H,O. CO,. Na. I<. Li. Ca. C1. SO,. CO:,.83’4 9.5 2.0 0.7 0.2 8 0.3 1‘6 0.5 1-831. Berthelot5 has found that crystals of amethyst from Brazildecolorised by heating to 300’ regain their original tint on exposingthem for a few weeks to the action of radium chloride.He attributesthis change to the reoxidation of traces of manganese present, andsuggests that the colour of amethyst and other minerals may be dueto the action of radioactive substances. On heating smoky quartzand green fluor spar, petroleum is driven off, and in these cases thecolour is due to organic matter.n~odochrosite.-Small rhombohedra { 100) of this mineral have beenCen’entr. Min., 1906, 761.Geol. Foren. Stockholm Forhandl., 27, 37. C&nt,r. 1906, 72.Compt. rend., 1906, 143, 477.Tsch. iWi7z. Mitt., 1906, 25, 335.Y 324 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.found at S. BarthBlemy, Val d'Aosta, by F. Millosevich.1 The cleavageangle is 73"10', and the composition as follows :MllO. FeO. CaO.MgO. C 0 2 (diff.).56.00 2.04 3.33 trace 38.63Rock Xak-The blue colour observed in certain specimens of rocksalt has been the subject of much experiment and speculation in recentyears. As pointed out in a paper by F. Focko and J. Bruckmoser,2 theexplanations offered fall under three main headings. I n the first place,it is held that the phenomenon is a purely physical one due to the pre-sence of very minute fissures, secondly we have the view that it is dueto the presence of some inorganic colouring matter such as the sub-chloride of sodium or a compound of iron, and lastly that it is causedby organic material. It has, however, been shown that the blue colourcan be produced by exposing salt to the action of cathode rays or byheating it with metallic sodium, and the opinion is now widely heldthat the colour is due to the presence of subchloride or of metallicsodium.Though the latter view does not commend itself to Focke andBruckmoser or to E. Pie~zczek,~ who has found a deficiency of chlorineamounting to as much as 0.4 per cent. in the blue portions, it hasreceived strong support from the work of H. Siedeiitopf.4 This authorinvestigated specimens of salt, coloured blue by the action of sodiumvapour with the aid of the ultra-microscope and believes that he hasdemonstrated the presence of metallic sodium deposited in ultra micro-scopic fissures in the salt. These particles of sodium may possibly becovered by a very thin or " molecular " cooling of subchloride whichprotects them from the action of reagents such as chlorine. H e thinksthat since rock salt strongly absorbs Becquerel rays the blue colour ofthe mineral may perhaps be due to the sodium produced by the cumula-tive effect of the radiation absorbed during long periods of time.The gases included in certain specimens of salt from Roumania havebeen the subject of an interesting investigation by N.Costachescu.5The gases were extracted either by dissolving the salt in well boiledwater or by pnlverising it under mercury. The composition of thegases was found to vary a good deal with the method of extractionemployed, but the following points appear to be established. I n thefirst place the quantity of gas contained in a given weight of salt variesgreatly, but there is no relation between the quantity of gas evolvedand the solid impurities in the salt.Secondly, as regards the nature ofthe gases given off, the specimens examined fall into two groups, thosein which hydrocarbons are predominant and those which yield little else.A t t i A. Accad. Liizcei, 1906, [v] 15, i, 317.Tivh. Illin,. Mitt., 1906, 25, 43. Phavm. Zeit., 51, 700.Ann. Sci. Univ. Jnssy, 1906, 4, 3, 4 Phys. Zcit., 1905, 6, 8 5MINERALOGICAL CHEMISTRY. 325but nitrogen, a gas which is invariably present. Oxygen is also alwaysfound, but in smalIer proportion than the nitrogen and there is no con-stant relation between the quantities of these two elements. Carbondioxide is either absent or occurs in very small quantities. Argoncould not be detected.Methane is almost always present, but thehigher hydrocarbons appear to be absent. To account for these factsthe author suggests that the gases have been derived mainly from thedecomposition of the microscopic fauna of the lagoon in which thedeposits were laid down, and to but a limited extent from the atmos-phere through the medium of the solvent. The absence of carbon di-oxide and argon can be explained in this way, but it is difficult toaccount satisfactorily for the oxygen always observed.,S'aarcoEite.-Specimens of this mineral from Vesuvius have been sub-mitted to a careful crystallographic and optical examination byA. Pau1y.l Two pure crystals were used for analysis :SiO,. A1,0,. CaO. MgO. Na,O. K,O. Total. Sp. gr.39.34 21.63 33.70 0.36 4'43 traces 99.46 2.78cheeZite.-The crystals from Traversella have been measuredby L.Colomba who moreover has analysed specimens of differentcolours in order to test Traube's hypothesis that the ratio a : c varieswith the amount of molybdic acid present. His results are asfollows :W03. MOO,. CaO. MgO. Total. a : c.I. Colourless crystals ......... 77.03 3-15 19.73 - 99-91 1.539811. Reddish-brown crystals ... 77-35 2'46 18.33 1.67 99-81 -111. Grcenish-brown ,, ... 78.75 1.47 19.23 0.55 100*00 1.5352IV. Orange ,, ... 79-68 0.72 19.43 trace 99.83 -Since the mean value of c calculated from measurements of crystalsof the composition given under I and 111 falls about midway betweenthose accepted by Traube for pure scheelite and pure calcium molybdaterespectively, this work affords no confirmation of the view that aregular variation takes place.Siderr.ite.-Minute crystals from Prostburg, Maryland, have beenshown by W.T. Schaller3 to be pure ferrous carbonate. An analysismade on 0.1 gram of carefully selected material gave 62.01 per cent.of iron (calc. 62.07 per cent.). MnO, CaO, and MgO were proved t obe absent. A number of measurements of the crystals were made forthe purpose of defining accurately the ratio a : c forpure siderite. Themean value deduced is c=O.8241. This corresponds to a cleavageangle rr' = 73O18.6' and differs considerably from that hitherto adoptedfor the mineral, namely, c = 0.81841, rr' = 73'0'.1 Centr. Min., 1906, 266. Atti 12. Accad. Lincei, 1906, [v], 15, i, 281.3 Anav.J. Xci., 1906, [iv], 21, 364326 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.StibiotantaZite.-This very rare mineral was originally described byG. A. Goyder as occurring in water-worn fragments at Greenbushes,Western Australia. Crystals have been discovered in recent years atMesa Grande, San Diego County, California, associated,with tourmaline,pink beryl, quartz, orthoclase, and lepidolite, and have been the sub-ject of an exhaustive investigation by S. L. Penfield 1 and W. E. Ford.The mineral is an isomorphous mixture of (SbO),Cb,O, and (SbO),Ta,O,,and has a specific gravity varying from 5.98 to 7.37, depending on therelative proportions of columbium and tantalum present, and diminish-ing as the amount of the latter decreases.It crystallises in the hemi-morphic class of the orthorhombic system, though owing to twinning thecrystais simulate holohedral symmetry. I n axial ratio and habit i tshows relations with columbite. Owing to its yellow colour, highindex of refraction, and good cleavage it might be mistaken for blende.I n the following table I is the original analysis of the Australianmineral, I1 and 111 are each the means of two concordant analysesmade on separate crystals of the Mesa Grande material.(Ta,Cb),O,. Sb,O,. Bi,O,. NiO. H,O. Total. Sp. gr.I. 58-69 40.23 0 '82 0'08 0.08 99-90 7.3711. 55-33 44 26 0.33 - __ 99-92 6.72111. 50.30 49'28 0.53 - - 100.11 5-98TapioZite.-A group of distorted crystals found by W. P. Headden 2in granite near Custer City, South Dakota, were shown by S.L. Penfieldto be tetragonal pyramids (111) with small (201) planes. Twoanalyses were made :FeO. Ta,O,. Cb,O,. WO,. SnO,. Cassiterite. Insol. Total.I. 16.85 78.61 4-29 0.11 0.07 0.31 - 100.24v11. 15.60 '18.58 3'90 0 *59 - 1-29 99.96Traces of TiO, were found in analysis I and there is reason to believethat FeO is too high. The formula is FeTa,O,, a portion of the tantalumbeing replaced by columbium and taken in conjunction with the crystal-lographic characters shows that the substance is tapiolite. The specificgravity 7.2185 is low f o r a compound containing so little columbicacid. This point is discussed by Headden, who finds himself unable toexplain it.Tetrahedrite.-In the course of a description of the mines andminerals of the Val de Villd (Weilerthal), Alsace, Ungemach3 hasgiven the results of an elaborate crystallographic investigation of thebeautiful crystals of tetraliedrite found at the Sylvester mine.Twodifferent types of crystals can be readily distinguished. One (analysisI below), rich in arsenic but poor in silver, is met with in the upperportions of the veins; the other, found at greater depths, is rich insilver and poor in arsenic (analysis 11).Amer. J. Sci., 1906, [iv], 22, 61. Proc. Colorado Sci. SOL, 1906, 8, 177.BUZZ. SOC. franq. N n . , 1906, 29, 194MINERALOCIIC AL CHEMISTRY, 327The comparatively large quantities of Zn and Ri present are some-what remarkable, and the author is inclined to believe that they aredue to the presence of native bismuth and of zinc blende.Be this asit may, if the formula is calculated omitting zinc, it is found thatthe ratio R”S : R2’”S3 is 3.07 : 1 for I and 3.21 : 1 for 11.The variety of tetrahedrite previously described under the namescoppite and frigidite has been examined by E. h1anasse.l Threespecimens were analysed. The results, which are given below, analyses111, IT, and V, are in harmony with a formula of the typeTraces of tin were found in I V and V.3R2S,R’2S3 + xGR”S,R’2S3.Cu. Ag. Pb. Fe. Zn. Ni. As. Sb. Bi. S. Total. Spgr.I. 38.15 trace 0.53 3.77 5-05 - 6.75 17.47 1.63 25.58 98-93 4‘8211. 34.15 5.94 - 3.79 4-86 - 1-21 25.24 - 25-22 100-41 5-10111. 37.42 - trace 6.60 1‘72 0.23 trace 29.28 - 25.70 100.95 -1V.37’54 - trace 6’01 1.98 0.14 trace 29-54 - 25’48 100*69 -V. 30’04 - 0’26 9‘83 0.59 3.46 1.50 28.82 - 24-48 98-98 -Thuringite.-F. Kretschmer 2 has published further details as tothe occurrence of this mineral at Gobitschau, and has given three newanalyses.Thoriccnite.-In a paper published last year, W. R. Dunstan andG . S. Blake suggested that the intimate association of thoria withoxides of uranium might be a CRSI of isomorphous mixture. This viewhas been confirmed by a series of analyses of thorianite from theGalle district of Ceylon, recently published by W. R. Dunstan andB. M. Jones.3 Their results show that the proportion of the twooxides present in the mineral may vary considerably, as can be seenon comparing columns I to VII of the following table.I gives thecomposition of small crystals from Hinidumpattu, Galle District ;I1 to VI that of large lumps from the same locality, 11, I11 and IVbeing different portions of the same crystal ; VII is an analysis of alarge crystal of the ordinary variety from Balangoda. All the speci-mens contained helium and carbon dioxide. The radio-activity ofspecimen I was compared by R. J. Strutt with that of the mineralthe composition of which was given last year and found to be 1.16times as great. Column VIII contains some determinations of themore important constituents of thorianite made by E. H. Buchner inSir W. Ramsay’s laboratory in the course of an investigation into thedistribution of the radioactivity among the constituents of the mineral.In addition to the elements enumerated, small quantities of copper,tin, antimony, bismuth (?), aluminium, titanium, and zirconium wereestimated, and traces of mercury, arsenic (?), cadmium (1) and phos-Mem.SOC. Tosc. Xci. Nat., 1906, 22, 81.Proc, Boy, Xoc., 1906, 77, A , 546.Cent,.. Min., 1906, 309.Ibid., 78, A , 385328 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.phorus observed. One gram of the mineral yielded 8.2 C.C. of helium.The radioactivity is associated almost entirely with the portion of themineral soluble in nitric acid.I. 11. 111. IV.Tho, ..................... 58.84 62-16 1 66.82 -(Ce,La,Di),O, ......... 0.85 1.841 { -uo, uo, } 32’74 { ii:;:} 28.24 28.68PbO ..................... 2.56 2-29 2’29 2.50Fe,03 ................1.31 1.11 1-22 2.43..........................................CnO ..................... 0.19 0.59 0.54 -H20 ..................... 1’26 1.05 1 .OO --Insol. in HNO, ...... 0.45 0.77 0.56 0.54* u,o*.v.62-322.2427.022.992.280.502-160.87VI.63-361-1627.992.901 -270 ‘851-320.77VII. VIII.78-98 70.961-47 1.9613.40 13’12*2-54 2-420.87 2-050‘91 0.131.28 3.200.47 -Titanile.-F. Zambonini called attention last year to the unsatis-factory state of our knowledge of the composition of titanite. H e hasrecently returned to this question, and has pointed out that the com-position of specimens containing tervalent elements is better expressedby Blomstrand’s formula, 2(R,”R~’0,,TiO)0,SiO2, than by that due toGroth, who regards such titanites as consisting of isomorphousmixtures of CaTiSiO, and R,”’SiO,.Blomstrand’s formula representstitanite as containing titanyl, TiO, playing the part of a cation thus,Ti0:02Si02:Ca, aluminium, iron, yttrium, and cerium eo tering themolecule in the bivalent grouping R,“’O,. As, however, recent workon titanium, zirconium, and tin has shown that these elements readilyform complex anions, Zambonini thinks that it will be more inharmony with what is known of the general chemical character oftitanium if it is regarded RS playing a similar part in titanite. H etherefore proposes to modify Blomstrand’s formula in this sense, andregards the mineral as the calcium salt of a complex silicotitanic acidTiO:SiO,:Ca.The tervalent elements enter the molecule as two uni-valent groupings R”’0, replacing TiO.Zeolites.-Certain zeolites which occur in the amygdsloidal basalt ofthe Debaroa plateau, Eritrea have been described by E. Manasse.2Two specimens of chabtczite had a composition agreeing with theformula CaAl,Si,01,,6H20. Analyses I and 11. I Crystals of apophyllite,measured by G. D’Achiardi, agreed approximately with the formulaH7KCa,(Si0,),,4iH20. Analysis 111. The loss of water a t varioustemperatures and its reabsorption on standing in moist air werestudied in the case of both minerals.E. Manasse has also re-examined the mineral from Montecatinitermed picrothomsonite by Meneghini and A. D’Achinrdi, and has cometo the conclusion that i t is thomsonite.The mean composition derivedfrom two concordant analyses is given under IV below. Associated withAttiB. Accnd. Lincci, 1906, [v], 15, i, 291.Proc. ?:el-6. SOC. [I‘osc. Sci. Arnt., 1906, 15, 65. 3 Ibid., 20MINERALOGICAL CHEMISTRY. 329this substance is another called sloanite by Meneghini.to be identical with ncitrolite.This appearsAnalysis V.SiO,. A1,0,. CaO. Ego. K,O. Na,O. H,O. Total.I. 48.35 19.47 8.77 0.20 trace 1.05 22.13 99'9711. 46.69 20.27 9.72 - trace 0.96 22.80 100'44111. 52.84 trace 24'46 - 5'42 trace 16-48 99.20IV. 36-90 31'36 14'48 0 3 3 0.65 3.81 13.59 101'12V. 46.49 25-47 1-10 trace trace 17'05 9-76 99.87VI. 65-21 11'20 3-77 trace 6.07 14'22 100.47G. D'Achiardi 1 has referred toptilolite, a mineral from San Piero inCampo, Elba, which has the composition given under YI, and hassuggested that the mineral called hydrocastode is possibly identicalwith a pulverulent form of stilbite, containing small quantities of lithium,which he has found at the same locality.He has also given somefurther account of the zeolite which was mentioned last year as pro-bably constituting a new species.22oisite.-Striated prisms associated with prehnite have been foundat the Trace mine, Juarez district, Lower California. The opticalcharacters have been studied by 0. C. Farrington,3 and the mineralhas been analysed by H. W. Nichols.The numbers obtained agree well with the formula H,Ca,A16Si60,7,which is that usually accepted for zoisite with the addition of onemolecule of water.There is good evidence for believing that in thiscase the extra molecule of water is a primary constituent of themineral, and not the result of alteration, and the authors quote othersimilar instances.Analysis 11, which agrees with the ordinary formula, was made byE. M a n a ~ s e , ~ on a specimen from Monte Corchia, Alpi Apuane.-+Analysis I below.Traces of K and Na were also present.SiO,. A1,0,. Fe,O,. MnO. CaO. MgO. H,O. Total.I. 38.15 29.50 4-60 0 5 5 22.71 0.63 3-76 99.9011. 37'86 26'88 7.90 - 24'65 - 2-07 99'36&dioccctivity of h%aera!s.The radioactivity of minerals containing thorium has occupied theattention of several workers.B. B. Boltwood has examined thorianite, thorite, orangite, andmonazite, containing 78.8, 52, 51.1, and 4.66 per cent.of Tho, re-spectively. He has found that the activity of one gram of thoria waspractically the same in each of the four minerals. H e believes thathis results confirm t.he view that radio-thorium is a disintegrationillem. Soc. Tosc. Sci. Nnt., 1906, 22.Field Coolurnhian M i ~ s . Pub., 112 ; Gcol. Ser., 3, No. 4, 55.Proc. wrb. Xoc. Tosc. Xci. Nat., 1906, 15, 20.A?ner. J. Xci., 1906, [iv], 21, 415.Ann. Xeporf, 1905, 282330 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,product of thorium, but that they do not lend any support to theidea that the activity of thorium in a mineral depends on the amountof uranium present. On the other hand, the available data point tothe conclusion that the quantity of actinium in a radioa,ctive mineralis proportional t o the uranium present.Similar conclusions as to theproportionality existing between the activity of thorium minerals andtheir thorium content have been arrived a t by H. M. Dadourian I andby H. N. McCoy and W. H, Ross.2Finding reason to suspect that their former estimate of the amountof radium associated with a given quantity of uranium in a mineralwas too high, E. Rutherford and B. B. Boltwood have repeated theestimation. They now find that approximately 3.8 x 10-7 grams ofradium are associated with 1 gram of uranium, a result about half thatpreviously obtained. They point out that a ton of 60 per cent.uranium ore would carry radium equivalent to about 0.35 gram ofradium bromide.Special Reactions of Minerals.F. Cornu4 has examined and tabulated the behaviour of a largenumber of minerals when finely powdered, moistened, and brought incontact with neutral litmus paper.H e finds that all the minerals ofthe kaolin and pyrophyllite groups show acid reaction, and that thesame is true of opal. On the other hand, olivine, mesolite, and talc reactalkaline. The same writer 5 bases a method of distinguishing betweencalcite and dolomite on the behaviour of these substances towardswater containing phenolphthalein. On shaking the solution with finely-divided calcite a dark red colour is produced, wbilst dolomite givesmerely a faint red tinge. V. Goldschmidtg has called attention tothe ease with which a number of minerals can be determined byfinding the loss of weight they suffer on ignition. Experiments madeunder his direction by P. Hermann on a number of zeolites show thatthese substances can be rapidly identified by heating quantities offrom 30 to 100 milligrams in a platinum spoon over a spirit lamp.Meteorites.The composition of a number of meteorites has been examinedCaiion l)iablo.-A septarian nodule found in t h i s meteorite has beenThe septa are metallic and like the mass of3 l b i d . , 1906, 22, 1.during the past year,studied by W. Tassin.7Among these we may notice the following :dmer. J. Sci., 1906, [iv], 21, 427.Tsch. Min. Mitt., 1906, 24, 417,Jahrb. Min., 1906, i, 16.Ibid., 433.7 Proc. U.X. Nat, IcIus,, No. 1497,Centr. Nin., 1906, 550MINERALOGICAL CHEMISTRY. 331the iron. The interseptal portions are made up of crystalline graphiticand amorphous carbon mixed with troilite. A lustrous motallicsubstance consisting mainly of iron (88-8 per cent.), but containingnickel, silicon, carbon, phosphorus, and a trace of cobalt, is alsopresent.Coon Butte.-This aerolite was discovered in 1905 by D. M. Barringernear Coon Butte, Coconino County, Arizona. There is some evidenceto show that its fall was observed in January, 1904. I t s generalappearance and the results of an optical examination made by G. P.Merrill suggest affinities with the meteorites from Ness County,Kansas, or with the Pultusk meteorite. J. W. Mallet has foundthat it consists mainly of enstatite and olivine, but it also containsmaskelynite and nickel-iron. The composition of all these constituentshas been ascertained, and traces of tin and copper found in the last.~stacudo.-An aerolite fell in 1882 near Estacado, on the stakedplains of north-western Texas. It has been investigated by J. M.Davison,2 who has determined the composition of the metallic portion,which amounts to 16.41 per cent., and of the stony matter, whichappears to be mainly olivine and enstatite.Kangra VccZZey.-An aerolite which is reported to have been seen tofall in the Kangra Valley, Northern Punjaub, has been described byW. N. Hartley.3 The specimen, which weighs 350 grams, appears toconsists of a crystalline ground mass of enstatite and olivine, throughwhich are scattered numerous metallic grains. A spectroscopicexamination of the metallic portion showed the presence of Fe, Ni, Co,Cr, with small quantities of Cu, Ag, Pb, and Ga. Traces of Mn, Ca,K, and Na were also detected. Ca and Mg are the principal con-stituents of the siliceous portion, accompanied by minute quantities ofFe, Ni, Cr, Ga, Sr, Pb, Ag, Mn, K, and Na.KodaikanaZ.-A new silicate, weinbergerite, has been discovered byF. Berwerth in this meteorite (see page 310).Modoc.-A fall of meteorites took place on the night of September2, 1905, in the vicinity of Modoc, a small town in Scott County,Kansas. Fourteen specimens, mostly complete individuals, have beenrecovered, and the largest of these, weighing 4.64 kilos, now in thepossession of the U.S. National Museum, has been described by G. P.MerrilL4 Under the microscope it is seen to consist essentially ofolivine and enstatite, with blebs of metallic iron and troilite. Itbelongs to Brezina’s group of veined chondritic meteorites. Analysesof the metallic portion and of the soluble and insoluble silicates havebeen made by W. Tassin.Amer. J. Sci., 1906, [iv], 21, 347.Tram., 1906, 89, 1566.Ibid., 186 ; 22, 55.J Amer. J. Sci., 1906, [iv], 21, 366332 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Shelburne.-A second stone of this fall has been described by 0. C.Farrington.South Bend.-0. C. Farringtonl has also examined a pallasiteweighing 5& lb., found in 1893 near South Bend, St. Joseph County,Indiana, and refers i t to the Imilac group. The ratio of nickel-ironto chrysolite is 21.4 to 78.6.I n conclusion, it should be noted that a great deal of interestinginformation regarding Japanese meteorites has been brought togetherby K. Jimb6.2A. HUTCHINSON.Field Columb. MISS. Pub., 109 ; Geol. Ser., 3, 2.2 Beitrage 2. Min. Japaib, 1906, No. 2, 30