14 ABSTRACTS OF CHEMICAL PAPERS.M i n e r a1 o g i c a1 C h e m i s t r y.The Fundamental Forms of Crystal Species. By A. KEKY-GOTT (J07u-b. f. A&-, 1878, 337-349).-1t is of course an acknow-ledged rule, that in “ derivation-forms ” the axial relations of theprimary or fundamental forms are modified by means of “ derivation-coefficients,” expressed as rational numbers. This assumption thatthe “ derivation-coefficients are rational nuubers,” is open to a ques-tion, viz. : “ Is i t mathematically true that these coefficients arerational numbers ? ” C. F. Naumann, in his Lehrbuch (7e.1. ~civen zmdaugezvnndten K~ystctllogrupirie, Band I, says, “ a very remarkable butthoroughly confirmed natural law for the derivation of forms is thatthe ‘ derivation-coefficients ’ are always rational numbers.This fun-damental law must be considered as the result of all methods ofderivation.” The results of measurements of angles certainly alwayslead to rational numbers, but the above-mentioned law cannot be saidto rest upon a proved mathematical basis. A second question may beasked, viz. : “ Are the numbers expressing the lengths of the axes ofthe fiindamental forms rational or irrational ones ? ” The author con-siders that they are irrational numbers (the numbers in the regularsystem belong neither to the rational or irrational, because the axialrelations of the octohedron are expressed t,hus: 1 : 1 : 1, or by t h eformula a : a .- a, thus merely showing that t’he axes are of equallength). I n the quadratic and rhombic systems, however, the numberswhich express the axial ratios of the primary pyramids must beirrational, for this reason, viz., if the “ derivation-coefficients ” areassumed to be rational numbers, the resulting axial ratios obtainedexpressed in rational numbers, lead inevitably to the derivation of theregular octohedron from a quadratic or rhombic pyramid.A thirdquestion may be asked, viz. : “ Is the choice of a primary form alimited one, or in other Fords, do the values expressing the lengthsof the axes of non-regular primary forms lie between certain limits ? ”The choice of a primary form in all the systems except the regularsystem, is optional, falling either upon one of the forms actually 011-served, or upon one obtained by calculation from the observed forms.It is often observed that a different primary form (in the samemineral species) is chosen by different observers, and also that theaxial lengths obtained by calculation do not agree.The latter circum-stance is due, in most instances, to the varying qualities of thegoniometers used, and occasionally also to physical defects or abnor-malities on the crystals themselves. I n order to diminish the errorsarising from such differing observations, the author sugqests thatcrystallograpers should give the angles obtained by measurement orcalculation of the primary form, and the resulting axial lengkhs of theprimary forms, giving a t the same time similar observations of othercrystallographers for comparison; just as it is the rule to give theanalyses of a substance by different chemists side by side. Naumann,in his Leluhuch (already referred to), says for example in regard tothe quadratic system, that every form whose parameters have thMISERALOGICAL CHEitIISTRT.15finite relationship cc : 1 : 1, can be chosen as a geometrical primaryform ; but as normal quadratic pyramids can alone be said to fulfilthese conditions, they must therefore be chosen as primary forms. Apyramid P (of undetermined dimensions, with the parameter of thevertical axis standing to the parameter of a lateral axis in the rela-tionship of " a : 1 ") is chosen as the primary form. Opinions aredivided as to whether this relationship is a rational or irrational one ;Hauy, Weiss, and Mohs expressing " a " as a square root, whilstHreithaupt has endeavoured to show that this number is rational, andis always a multiple of the coefficient TQc, the other lateral axis, or theintermediate axis being taken as unity.It is, however, immaterial forthe independence of the quadratic sjstem whether the one or the otherof these opinions is the correct one, as the distinctive feature of thequadratic system is the contrast exhibited by one axis in regard to theother two axes, thus making a passage of quadratic forms into regular(tesseral) forms impossible.This opinion of Naumnnn is a t variance with that of the author, whohas already stated above that the numbers cannot be rational ones, asthe " derivation-coefficients " would in that case lead to the produc-tion of a regular octohedron, and not of it normal quadratic pyramid.As a proof of this opinion, the author points out that the axial rela-tion n : 1 : 1 cannot be chosen in the derivation of the primary form ofn " species," because the regular octohedron would probably occur inthe series of normal pyramids obtained, and would with equal justicebe chosen as the primary pyramid.It is impossible for a quadratic species to exhibit the axial relationa* : b2 = 2 : 1, as the faces of the primary pFramid P would intersectin a terminal edge a t an angle of 101" 32' 13", and in a lateral edge atan angle of 126" 52' 12", consequently the pyramid Px, would haveequal lateral and terminal edge angles, and be a regular octohedron.In regard to the hexagonal system, i t is evident, from its close simi-larity to the quadratic system, that the parameters of the lateral axesmust differ in length from that of the vertical axis, although as Nau-mann states in his Lehdmch, i t is theoretically possible to have nprimary hexagonal pyramid in which all the axes are of equal length.The author agrees with Naumann in considering such a form to be;L purely theoretical one, because the close analogy existing betweenthe quadratic and hexagonal systems in the characteristics of theirforms, the laws relating to their hemihedry and tetartohedry andtheir physical properties, point to a similarity in their axial relations;whence i t is safe to conclude that the length of the vertical axis of ahexagonal pyramid must differ from the lengths of its lateral axes.As;t proof of this opinion, the author gives the folIoaing examples, viz. :" a normal hexagonal pyramid with the axial relation a : b = 1 : 1,mould have an interfacial angle over a terminal edge of 135" 35' 5",;ind over a lateral edge of 98" 12' 48" ; the Corresponding ho???bohedmtwould have a terminal edge angle of 98" 12' 48", and the correspond-ing trigonuZ pyramid would have equal terminal and lateral edgeangles, vis. : 98" 12' 48". The di(fgonaZ pyramid corresponding withthis normal pyramid would have a terminal edge angle of 138" 35' 25",and a lateral edge angle of go", and the corresponding dingonaZ rhom16 ABSTRACTS OF CHEMICAL PAPERS.bohedroit would have a terminal edge angle of 104" 28' 39".Besidesthe above improbable axial relation (which would include every pos-sible rational angle-relation obtained through rational " derivationcoefficients"), the two axial relations a' : b2 = 3 : 2 and 2 : 1 are im-possible, as will readily be seen from the following, viz. : " the axialrelation a2 : b2 = 3 : 2 furnishes a normal hexagonal pyramid, havinga terminal edge angle of 131° 48' 3G", and a lateral edge angle of109" 28' 16" ; the corresponding rhombohedron is the cube, and thecorresponding normal trigonal pyramid has a terminal edge angleof 90" and a lateral edge angle of 109" 43' 16", whilst finally thediagonal hexagonal pyramid of the normal pyramid has a terminaledge angle of 134" 25' 37", and a lateral edge angle of 101" 32' 13",and the diagonal rhombohedron derived from the last-mentioned formhas a terminal edge angle of 55" 4 4 21".The axial relation a2 : 6?= 2 : 1 is equally impossible, as i t also leads to the cube as a hexagonalfoi-m. From the above, therefore, it appears that a quadratic pyramidcannot exist having the same interfacial angle on a terminal edge ason a lateral edge, because it would in that case be a regular octohe-dron ; and further, a rliombohedron cannot have the same angle on aterminal edge as on a lateral edge, because i t would then be a cube.The author also considers it impossible for a normal hexagoiial pyra-mid to have equal termirial and lateral edge angles. A normal hexa-gonal pjramid having the interfacial angle 126" 52' 12" on a terminaland lateral edge, requires the axial relation a2 : b2 = 3 : 1 ; its rhom-bohedron would have a terminal edgc angle of 78" 27' 47", its trigonalpyramid the terminal edge angle 78" 27' 47", and lateral edge angle126" 52' 12".The relative diagonal pyramid would have a terminaledge angle of 128" 40' 56", a lateral edge angle of 120°, and its rhombo-hedron (diagonal) would have a terminal edge angle of 8P 49' 9". Adiagonal hexagonal pyramid haring the same interfacial angle on itsterminal and lateral edges, viz., 126" 52' 12", and whose diagonalrhombohedron has a terminal edge angle of 78" 27' 47", requires theaxial relation a2 : b2 = 4 : 1, or n : 21 = 2 : 1. The relative normalliesagonal pxramid would have a terminal edge angle of 125" 22' 36",a11d a lateral edge angle of 133" 10' 25", its rhombohedron a terminaledge angle of 74" 44' 33", and its trigonal pyramid a terminal edgeangle of 74' 44' 33", and EL lateral edge angle of 133" 10' 25".Theaxial relation CL : I, = 2 : 1 would give the relative normal pyramid asa " derivation form " of the pyramid with the axial rclation a : b =1 : 1. If the latter form is found to be inadmissible, it follows thatits '' deiaivation forms " must also be inadniissible, and to this cate-gory belongs the pyramid 2P2, which has equal terminal and 1ater:Lledge angles. The axial relation 2 : I,2 = G : 1, is also inadmissible, aswill be seen from the following, viz. : the corresponding normal hexa-goiial pyramid would have a terminal edge angle of 123" 44' 56", anda lateral edge angle of 141" 3' 27", its I*homl)ohedron would have aterminal edge angle of 70" 31' 44", and this form combined with CtRin a pioper proportion would become a regular octohedron.Thetrigorla1 pyramid corresponding with the above-mentioned normalhexagonal pyramid would also be a regular octohedron. Fromthediagonal pyr'tmid corresponding with the above-mentioned norma3IINERALOGICAL CHEMISTRY. 17pymrnid, a diagonal rhombohedron is obiairled, which in reality is acubc. I t seems, therefore, from what has already been stated, thatallowing primary forms to have rational ’‘ derivation coefficients ”and irrational axial lengths, it still does not follow that any kind ofirrational axial relation will furnish a primary form, because certainforms mentioned above are excluded.The author concludes by statingt,hat the values of the axial relations of the possible primary formsmust oscillate between certain limits. C. A. B.Hetaerolite. A New Mineral. By G. MOORE (Jalirb. f. illin.,1878, 210--211).-This mineral occurs in botryoi’dal radio-fibrousmasses, always accompanying (dmipo?) chalkophanite in brown-ironochre, a t the Passaie zinc-mine, Sterling Hill, N. Jersey. Hetseroliteis black, has a semi-metallic lustre, a brownish-bIack streak, is infusiblebefore the blowpipe, and evolves water on being heated in a closedtube. H. = 5 . Sp. gr. = 4.933. Its chemical composition correspondswith the formula ZnO.MnO.MnO,, whence it appears to be a zinc-hausmannite.The chalkophnnite is rhombohedral, and occurs indruses in thin laminae or stnlactitic aggregates. Colour bluish-black.Jliistre metallic. H. = 2. SD. pr. 3.907. I t s chemical comDositioncorresponds with the formula, !2M\02 + (MnZn)O + 2H20. AC. A. B.The Origin of some Ores of Copper. By C . A. BURGHARDT(Chem. News, 37, 215).-hmmite. - The author considers thismineral to have had in most cases an aqueous and not an igneousorigin, o w h g to the more common occurrence of globular and stalac-titic atacamite ; the crusts of atacamite in volcanic neigh bourhoods(arising from the action of hydrochloric acid gas upon copper com-pounds) being comparatively scarce and insignificant in quantity.Natural atacemite is known to occur in three statos of hydration, t}iechemical composition of each being as follows, viz.:-(1.) Afacainite jiwn Algodon Bay, Bolivia (von Bibra, Jahesb., 1855,740)-cu. c1. 0. H20.59.25 16.1 1 12.51 12.13 = 100.00,the formula corresponding with the above being Cu40,C12 + 3H20.( 2 . ) Atacamite f r o i n Copiapo, Chili (Field, Journ. Chem. S’oc. [‘LJ, 3,193)-c u . c1. 0. HZO.56.38 14-95 10.78 17.89 = 100.00.Formula = Cu,0,C14 + 9HzO or (Cu*O,Cl,), + 9H20.(3.) Botnllnb Atacccnzite ( a ) (Church, Jouru. Chem. SOC. [2], 3,212)-Cobija Atcicai?zitc ( b ) (Berthier, Ann. cles Mines. [3], 7, 542)-c u . c1. 0. H,O.(a.) 52.90 14-76 10.4 9 22.4.5 = 100.00(b.) 53.26 14-92 9.37 22.24 = 100.00Formula = Cu,03C12 + 6H20.voL.xxxv~. 18 ABSTRACTS OF CHEMICAL P9PERS.Field (Phil. Mug. [4], 24, 1862, 124) prepared an apple-greenatacamite, corresponding with Berthier's atacamite from Cobija, byadding a solution of calcium hypochlorite to an excess of cupric sul-phate. The author obtained (in addition to cuprite and chalcotrichite)very small quantities of a green substance resemhling atacamite, byheating in one case cuprous chloride crrstals with water in a sealedtube a t a temperature ranging from 160-180"; in another case, byheating cuprous oxide with a strong solution of sodium chloride in itsealed tube a t a temperature ranging from 150-180". After numerousexperiments, it was found that large quantities of atacamite werereadily formed by simply covering cuprous oxide with a concentratedsolution of sodium chloride, and exposing this mixture to the air.Thecuprous oxide dissolves in the sodium chloride solution, forming avery concentrated solution of cuprous chloride, and the latter, onexposure to the air, rapidly decomposes, a green insoluble substanceseparating out. This substance was dried over calcium chloride untilits weight was constant, then analysed, and found to have the follow-i n g chemical composition-cu. c1. 0. H?O.56.25 14.29 10.95 18.51 = 100.00,from which it will be seen that it agrees closely with the Copiapoatacamite. The first stage of the above reaction niay be expressed bythe following equation, viz. :-3Cu2C12 + 0, = CuC1,.3CuO + 2CuC12,the cupric oxychloride thus formed becoming eventually hydrated.I n a former paper (Proc.Lit. Phil. Xoc. illmcl~ester~ 18, 27-36)the author expressed an opiiiion that most of the ores of copper arethe products of the decomposition of cuprous oxide ; and the resultsdetailed above seem to confirm this view, more especially as atacamiteis nearly always intimately associated with cuprite, chalcedony, quartz,&c., occurring in diorite and syenite. C. A. B.Uranium Pitchblende from Joachimsthal. By E. REICHARDT(Arch. Pharnz. [ 3 ] , 13, 130).-The sp. gr. of this mineral is 5.328 ; thecolour brown-black with an ochrey coating; its composition is asfollows :-Si. S. A1,03. Fe,OR. CaO. MgO. MnO. Pb.3.680 0.788 0.313 4.161 0.499 0,034 0.180 3.8880.261 0.068 0.072 0.578 83.918 trace = 98.440Polydymite.By A. KENNGOTT (Jnhrb. f. &fin., 1878, 183-185).-Laspeyres described this new mineral ( J r h b . f. X n . , 1877,206), stating its composition to be as follows, viz. :-As. Sb. p205. CUO. u203. Bi.E. w. P.Ni. CO. Fe. S. As. Sb.53.508 0.606 3.844 40.270 1.041 0,508 = 99.777,the formula corresponding with this analysis being NiS.Ki,S,, thusplacing the mineral in the same class as musenite, which containMISERALOGICrVI CHEMISTRY. 19both Ni and Co. The small amount of arsenic and antimony presentpoints to a slight intermixture of gersdorffite and ullmannite with thepolydymite. Further, Laspeyres was of opinion that the nickel-bismuth-glance (snynite, eriinauite) analysed by von Kobell, was amixture of polydymite with bismuthine, galena, and chalcopyrites(copper-pyrites), and this opinion is considered by Kenngott to bewell founded, as he obtained the formnla NiS.Ni& on deducting theseveral percentages of bisniuthine, galena, and chalcopyrites obtainedby calculation from von Kobell's analysis.Yellow Dolomite from Bleiberg.Ry V. TON ZEPHAROVICH(Juhrb. f. Ifin., 1878, 315).-This dolomite occurs fine-grained andmassive, with a sulphur-yellow to brownish-yellow colour, and oftenenclosing yellowish- brown zinc-blende. The yellow colour of the dolo-mite is most, intense in the neighbourhood of the enclosed zinc-blende,Small drusy cavities occur in the dolomite containing zinc-blende,which are filled with hemimorphite crystals, accompanied by yellowish-white calcke rhomhohedrons.A microscopical examination showedthe doloniite to be homogeneous (excluding of course the zinc-blendeenclosures). Sp.. cr. = 2.87. An analysis showed it to have thefollowing composltlon, viz. :-C. A. B.CaCO3. MgC03. ZnC03. FeC03. ZnS. CdS. FeS2. SiOP79-48 16.71 2.4'2 0-30 0-31 0.25 0.08 0.03 = 99.58.The formula correspondirig nearly with the above is 4CaC03 +MgCO,. The yellow colour is due to the presence of cadmiumsulphide. C. A. B.A Boron Mineral from Chili. By E. RErCHARDT (Arch.Plmrrn. [ 3 ] , 13, 131).--In the Chili saltpetre beds, together withcalcium borate and boronatrocalcite, a mineral is found in powderhaving the composition-Water ....................Silica. .....................Ferric oxide and alumina ....Lime ......................Sodium chloride ............Potassium chloride ..........Sodium biborate ............Sand and clay ..............Magnesium chloride ........Calcium sulphate............18.10715.0560.0 700-8400.7271.1093.7631.31032.24726.611-I99.840E. W. P.Deposits of Calcium Phosphate in the Vosges. BY P. GUYOT(Cornpt. rend., 87, 333). At Damblain and Blevaincourt, in theVosges, are found kidney-shaped masses of calcium phosphate from2 to 10 centimeters in dimeter. A sample from Damblain yielded76-99 per cent. of tribasic phosphate ; one from Blevaincourt 77.74 percent . R. R.c 20 ABSTRACTS OF CHEMICAL PAPERS.New Minerals from Fairfield Co., Connecticut. By G. J.BRUSH and E. S. DANA. First Paper (Amer.Jour. Sci. [ 3 ] , 16, 39-46).-These minerals were found in a vein of albitic granite, asso-ciated with a large number of others ; six new species were identified.Those described in the following paper occur associated in the mostintimate manner, although distinct crj-stals can be obtained.Eosphorite occurs in prismatic crystals, often of considerable size,more generally massive. Hardness = 5. .Sp. gr. (mean) = 3.134.Lustre vitreous to subresinous; of the massive mineral often greasy.Colour of the crystals pink, yellow, and grey ; of the massive mineralpale pink, greyish, bluish-, and yellowish-white and white, some-times greenish, owing to admixture of dickinsonite. Transparentto translucent. Streak nearly white. Fracture uneven to sub-conchoidal.The crystals are prismatic in habit, showing but one terminatedextremity, and belong to the orthorhombic system.The surfaces ofthe crystals are often covered with drusy quartz and with apatite ;the prismatic planes almost always, and the pyramidal planes veryoften, are finely striated, giving rise to rounded barrel-shaped crptals.The crystals are c_losely analogo_us to those of, childrenite. Observedplanes: m p m , mPm, mP, mP2, P, +@+, 2P2. Axial ratio, a': 8 : c(vert.) = 1 : 1.28732 : 0.66299. Angle, P : P (in the terminal edges)= 61" 1' 54' ; P : P (in the basal edges) = $6" 27' 45"; mP : COP= 75" 36'; ~ogijoo : mP = 52" 12' : m P : P = 49" 55'.The three axes of elasticity coincide with bhe crystalline axes ; theoptical axes lie in the macrodiagonal section or plane of cleavage.The axial angle is (approximately) 2E = 54" 30' (for red rays) andUlo 3cl' (blue rays).The dispersion of the axes is strong v>p ; thecharacter of the double refraction is negative. A parallelopiped, cutwith its edges parallel to the three crystalline axes, showed a distincttrichroism. The mean composition is as follows :-P,O,. A1,03. FeO. MnO. CnO. Na,O. H,O.31.05 22-19 7.40 23.51 0.54 0.33 15.60 = 100.62,corresponding with the formula ~A12P201,.4H20, or AI,P,O, + 2H,R02 + 2Aq. Eosphorite differs from childrenite in containiiig a largerproportion of manganese and a smaller proportion of iron. It is essen-tially a phosphate of aluminium and manganese, childrenite being ;tphosphate of aluminium and iron.In a closed tube eosphorite decrepitates, whitens, gives off water,and turns black, grey, and then brown with metallic lustre, andbecomes magnetic.Before the blowpipe, it cracks open, colours theflame pale green, and fuses to a black magnetic mass. It dissolvescompletely in the ordinary fluxes, giving iron and manganese reac-tions.TripZoidite.-This mineral occurs in crystalline aggregates, whichare parallel-fibrous to columnar or divergent, sometimes confusedlyfibrous to nearly massive. Occasionally distinct crystals are foundimbedded in quartz, from which they cannot be separated withoutbreaking into small pieces ; rarely crystals may be found projectinginto cavities in the massive mineral.It is soluble in hydrochloric and nitric acidsMISERALOGICAL CHEJIISTRY.2 1The hardness of triploidite is 4.5-5" ; sp. gr. 3.697. Lustre vitreousto greasy-adamantine ; colour yellowish- to reddish-brown ; crystalstopnz- to wine-yellow and sometinies hyacinth-red. Streak nearlywhite ; transparent to translucent ; fracture sub-conchoidal.The crystals belong to the monoclinic system and are homeomor-phous with wagnerite ; they are much striated and occasionally exhibitfalse planes. Of the two axes of elasticity which lie in the plane ofsymmetry, one nearly coincides with the vertical axis, the other isalmost normal to the orthopinacold. The mean chemical compositionis as follows:-P.,Oj. FeO. MnO. CsO. H20.32-11 14.88 48.45 0.33 4.08 = 99.85,leading to the formula R4P209.H20, or R,P,O,.H,RO,, where R =Mil : Fe = 3 : 1.Triploidite is therefore related in composition tolibethenite, olivenite, and lazulite, none of which, however, havesimilar crystalline forms. I n crystalline form it resembles wagnerite,which again is analogous to triplite in composition, thus showing arelation between triplite and triploidite. Observed planes : OP,aSm, mFm, CCP, Pm, 242. Axial ratio, u : b : c (vert.) =1 : 0.33846 : 0.80367. Angle, UP : mP m = 54° 48'; ocf 00 : cmP= 60° 27'; mPm : OP = 71" 46'; OOP: XP = 59" 6'; mP00 : OP= r l d5'.In a closed tube, triploidite gives off water, turns black, andbecomes magnetic. Fuses quietly in the naked flame, and before theblowpipe in the forceps colours the flame green.Dissolves in thefluxes, giving reactions for manganese and iron. Soluble in acids. c. w. w.c o tThe daikest specimens contain the most iron.Thaumasite, a new Mineral Species. By NORDENSKIOLD(Compt. r e d . , 87, 313).-This substance, obtained from a mine atAreskustan, has been analysed under the aut,hor's direction, withresults leadiiig to the formula CaSi03.CaS04.CaC03 + 7H20.R. R.Some Minerals from Laangban. By A. E. NORI)ENSKI~LD(Jahrb. f. N i i z . , 1878, 206--209).--Atopite T TO TO^ = unusual), a newmineral, c:rystallises in predominating regular octohedrons, in combi-nation with the cube and rhombic dodecahedron and indications ofthe trapezohedron and tetrakis- hexahedron. Yellowish- brown to resin-brown, resinous lustre, semi-transparent.Sp. gr.= 5.03. On heating it in the oxidising flame before the blowpipe,no change is observable ; i t gives a deposit on charcoal and leaves aninfusible slag-like residue after the volatilisation of all the antimony ;gives a faint trace of Mn on treating i t with carbonate of soda andnitrate of potassium. Soluble in microcosmic salt without separationof silica, the bead being yellow when hot and colourless when cold ;insoluble in acids.H. = 5.6 to 6.Chemical composition as follows, viz. :-Sb,O,. CaO. FeO. MnO. K,O. Na20.72-61 l i . 8 5 2.79 1-53 0.86 4-40 = 100.0422 ABSTRACTS OF CHEMICAL PAPERS.Formula 2R0.Sb20,. From the above i t would seem that atopiteresembles very closely nionimolite and romei te, differing howeverfrom the former in the absence of lead and a higher amount ofantimonic oxide, and from the latter in a double amount of bases, thecrystal form, and the different state of oxidation of the antimony pre-sent. Atopite occurs mostly disseminated in very fine veins anddeposits of hedyphane, which penetrates rhodonite.M o n imolite isfound a t Laangban in brown crystals and grains in calcite-drusesenclosed in rhodonite and tephroide.A'kdemite (cKErjpoS = absent, foreign), a new mineral, coarse-crys-talline, foliated, monoaxial, with a distinct basal cleavage. Lightyellow with a greenish tinge, translucent in thin splinters, resinouslustre on broken surfaces, on cleavage-planes a strong vitreous lustre.H. = 2.5-3. Sp. gr. 7.14. Brittle. Decrepitates in a closed tubeand crumbles to powder, a yellow fused mass separating out witah ease,and a t the same t'ime a sublimate of lead chloride.Heated on char-coal it furnishes a lead-bead and a deposit of lead oxide and chloride.Arsenic is also present. Soluble in nitric acid and warm hydro-chloric acid. An analysis of this mineral proved it to have the follow-ing composition, viz, :-PbO. Pb. C1. A S , ~ ~ .58.25 23.39 8.03 10.60 = 100.24.The formula corresponding with the chemical composition is 5Pb0As203,2PbC1,.HZl~~ocsrussite.-Hydrated carbonate of lead surrounding nativelead. White by transmitted light ; colourless, quadratic lamine,having a very distinct foliation. Decrepitates in the closed tubeand becomes yellowish-brown. Yields a lead-bead on charcoal.Solublein acids with eflorescence. Rather soft, The author considers itscomposition to correspond with the formula 2PbOC02,H20.Hyalotekite (3uXos = glass, and ~ ~ X E L V = melt, fuse).-A newmineral. Occurs in coarse crystalline masses, exhibiting two direc-tions of foliation which intersect each other at an angle of about !)O".H. = 5 to 5.5. Sp. gr. = 3.81. Vitreous to resinous lustre; whiteto pearl-grc7 ; semi-translucent ; brittle ; fuses easily before the blow-pipe to a clear colourless bead, which becomes black on heating it inthe reducing flame owiiig to the reduction of lead. Gives the reactionfor silica with microcosmic salt, and a lead-bead on reducing a por-tion of the mineral with sodium carbonate, also a yellow deposit whenheated aIone on charcoal.Insoluble in hydrochloric and sulphuricacids. An incomplete analysis furnished the following results, viz. : -Si02. PbO. BaO. CaO. Loss on ignition Al,03, K,O, &c.39-62 25-30 20.66 7.00 0.82HIyalotekit(e is accompanied by hedyphane and schefferite, and gener-ally resembles a greyish-white Pelspar.Occurs massive,accompanied by tephroite, which it cIosely resembles; in fact, it isoften necessary to resort to the blowpipe in order to distinguishGunonzolite (+m~pua = lustre) .-A new mineralBIISERALOGTCAL CHEMISTRY. 23between them. Cleavage indistinct. Strongly double refracting,colourless, whit'e t o greyish-white, strong resinous lustre, translucent.H. = 4. Sp. gr. 4.98. Fuses before the blowpipe to a clear bead,which become black on the surface in the reducing flame. Givesa lead-bead and a yellow deposit.Easily soluble in nitric acid, withseparation of gelatinous silica. An analysis gave the following results,viz. :-Si02. PbO. MnO. CaO. MgO. Alkalis and loss.34.55 34.89 20-01 489 3.68 1.86.Jacobsite.-This mineral which is st~ongly magnetic, has the fol-lowing chemical composition, via. :-Fe203. Mn203. MnO. MgO. CaO. PZO,. Pb. residue.58.39 6.96 29.93 1-68 0.40 0.06 1.22 2.17 = 100.81.InsolubleThe formula corresponding with the above is MnO(Fez03Mnz03).C. A. B.Magnetite from Monte Mulatto, South Tyrol. By V. VONZEPHAROVICH (Jahrb. f. Min., 1878, 310).-The crystals clothe drusyhollows in a tier-like mass of magnetite.Their size is sometimes 5 to8 mm. They exhibit the combination 000.50$. 303.0. Similar formswere observed by %-on Kokscharow, occurring on the magnetite ofAchmatowsk, and by Struve on the Albanese magnetite.C. A. B.The Mirabilite from Aussee. By V. vox ZEPHAROVICH(Jahrb. f. Nh., 1878, 314).-Some crystals of mnirabilite from the saltmines of Aussee exhibited the following forms in combination, viz. :-- i P , - 2 P ; the latter two forms being new to this mineral. Theorthopinacold generalIy predominates, whilst the faces of the clino-diagonal zone occur only in a secondary position. Most of the crystals(particularly the largest) exhibit an unusual " habit," on account of anabnormal vertical development, their height varying from 7 t o 10 cm.,and their width from 3 to 24 cm., and they are generally terminatedby OP or pyramids. Short tabular crystals through a r m are com-paratively rare.C. A. B.The Sericite Rocks of the Taunus. By A. WICHMANN (Jahd.f. Min., 1878, 264--275).-The author shows plainly that the con-clusions of K. A. Lossen (Zeits. Dezk G'eol. Ges., 1867, 1877) are erro-neous. Judging from the presence of a certain percentage of soda inthe Taunus rocks, Lossen endeavours to prove albite as a constituent ;but a microscopical examination of these rocks proved the absence ofunsymmetrical felspar. Albite is observed to occur on11 in bands orstreaks, but never as a rock-constituent, and the percentage of soda isrefcrable to a sodium-aluminium silicate, which constitutes the ground-mass of the slatey-rocks of the Taunus.Examination of Lithia-Mica from Paris (Maine), Rozena,and Zinnwald.By F. BERwEEtTH (Jahrb. .f. Mn., 1878, 316).-UP, mrm, mEm, -+l?Cr,+Pm,3?m, zm, 2.E?o@, mP, -P, P, +,P,C. A. B24 ABSTRACTS OF CHEMICAL PAPERS.The author analysed the lithia-mica from the above localities, takingperfectly pure material furnished by Tschermak for the purpose.A. Lithia-mica, from Paris (Maine) ; B. Ditto from Rozena ; C. Dittofrom Zinnwald.PpO,. F1. Si02. A1203. Fe03. FeO. MnO. I<@.A . . . . -- * 5.15 50.39 28-19 - - trace 12.34B . . . . 0.05 7.88 50.98 27.80 - 0.95 trace 10.78C . . . . 6.08 7.94 45.87 22-50 0.66 l l * G l 1.75 10.46Less oxygenNa,O. Li20. H,O. equivalent to fluorine.- 5.08 2.36 = 103.51 - 2.17 = 101.34- 5.88 0.96 = 104'35 - 3.32 = 101.060.42 3.28 0.91 = 10.5'48 - 3.34 = 109.14Rubidium and caesium were detected by the spectroscope.Thesp. gr. of the three lithia-micas A, B, C, were 2.8246, 2.834, and 2.9715respectively. C. A. B.The Crystal-System of Potash Mica. By M. BAUER (Jnhrb.f. illin., 1878, 310).-The author determined the angle which the planeof the axes forms with the basal plane, a,nd obtained values whichcoincide with those obtained by Tschermak. The results werc asfollows, riz. :-(1.) Potash mica is opt'ically monosymmetrical. (2.)The plane of the optical axes is perpendicular to the plane of symmetry,and the bisectrix is situated in the latter. (3.) The angle formed bythe apparent bisectrix with the basal plane = 87" 5') that formed by theupparent bisectrix with the normal to the basal plane = 2" 55', the trueangles being 88" 18' and 1" 42' respectively.Tho direction of thebisect>rix could not be determined. (4.) The angle of the apparentoptical axes is 64" 14', the angle of the true axes being 40" 21'. (5.) Theappare?Lt angle formed by the optical axes with the normal to the basalplane = 32" 14', the true angle being 20" 15'. C. A. B.Occurrence of Disthene in Central Africa. By T. LIEBISCH(Jahb. f. Min., 1878, 313-314).-Disthene is found in the mica-slateof the Baginsc Mountains, in East Niam-Niam-Land, enclosed in quartzcrystals, and accompanied by biotite and muscovite. The disthenecrystals are asparagus-green in colour. There are numerous biotitelamina3 interpolated in the disthene crystals, parallel to the face COP 63.The forms observed were COP 00, COP%, OCP', m'P, 00 P"2 ; the terminalplane was not observed.Some of the crystals were twins, accordingto the law " the twin axis the normal to the macropinacoi'd."C. A. B.Duporthite, a New Asbestiforin Mineral. By J. COLLIXS(Min. Mag., 7, 226).-This mineral occurs in fibrous masses, fillingclefts in serpentine. Greenish to brownish-grey ; silky lustre ; flexible ; heated in a matrass, it evolves water ; andtine fibres fuse before the blowpipe to R black glass. Insoluble inhydrochloric acid. An analysis furnished the following results, viz. :-H. = 2 ; sp. gr. = 2.78MINERALOGICAL CHEXISTRT. 25SiO,. A1203.FeO. MgO. CaO. Na,O. H,O. Hrgroscopic I1,O.49.21 27-26 6-20 11.14 0.39 0.49 3 90 0-68 = 99.27.Considering part of the water to be water of constitution, the formuladerived from the analysis is 3(A1,03Si0,)5( $Mg+Fe&H?)O + SiO,.The mineral approac-hes nearest to the neolite of Dana. The authornamed it from the place where it was found, viz., Dnporth, nearSt. Austell, Cornwall. C. A. B.The Stone of the “Julius Column,’’ the Lavez Zock inthe Upper Engadine, and the Sericite-gneiss in the Bun-dener Alps. By C. W. Gijmmr, ( J u l ~ b . f. Min., 1878, 296-300).-The Julius Column, which dates from the time of the Romans, isremarkable for the freshness of its colour and the total absence of anysigns of weathering. The author examined chemically and micro-scopically some small fragments which had probably been detachedfrom the column by the action of frost.The stone is rather soft,greasy to the touch, of a greenish colour, and a scaly granular strac-ture, which latter peculiarity arises from the occurrence of thin,cleavable, elastic laminae in isolated groups. There C R ~ be no doubtthat this rock is a “ potstone.” A considerable amount of the rock issoluble in hydrochloric acid, the soluble portion consisting of an impuremagnesite (containing calcium and iron carbonates), and a mag-nesium mineral which plays the part of a cement in the rock. Ananalysis gave the following resnlts :-SiOz Al,O,. Fe203. Cr203. MgO. CaO.Complete analysis . . . . . . 46.312 2.105 10.134 trace 36.161 0.251Portion soluble in lIC1 .. 25.15 2.09 14-90 ,, 44.59 -Portion insoluble in HCL 57.96 1-90 5.80 ,, 30.85 1.14Complete analysis . . . . . . 0.0.50 0.920 1.500 4.300 1.202 = 100.935Partion soluble in HC1 . . - - 3 36 7.48 2.09 = 99.66Portioninsoluble in HC1 0.67 2.21 - - - = 100.53K,O. NazO. CaCO,. MgC03. HzO.The iron was mostly present as ferrons oxide; there were alsotraces of titanic acid present. On examining the above results, itwould appear that a serpentine-like mineral inust be present in therock, as the amount of silica in the portion soluble in hjdrochloricacid is very low in comparison with the amount of magnesia. Mag-netic iron was also ascertained to be present in the powdered rock.The portion insoluble in the acid was principally talc, intermingledin varying amounts with chlorite, tremolite, and a sodium-felspar.Aslight trace of chromium also points to the presence of chromite.The microscopical examination of thin sections of the rock supportedthe conclusions drawn from the chemical analysis, as it was found toconsist of (1) fine-fibrous, green portions of varying intensity ofcolour; (2) of broad indented non-fibrous portions. Some of thefibrous portions exhibited distinct dichroism, and were probablychlorite and tremolite, whilst some small, non-fibrous, colourless por-$isms exhibited in polarised light the peculiar reddish shimmer whic26 ABSTRACTS OF CHEMICAL PAPERS.characterises the carbonates. Some colourless portions full of parallelrifts were also observed, pointing to the presence of talc.Betweenthe fibres, and often on the edges of the colonrless laminze, a powderhaving a metallic lustre was observed, which was no doubt magnetite.There were also here and there isolated, roundish-brown granules(putzen), which externally pass almost imperceptibly into the “ ground-mass ” surrounding them, but towards their interior exhibit the reti-culation characteristic of serpentine, so that it may be inferred thatthese granules were orginally olivine. On examining a thin sectionafter treatment with hydrochloric acid, it was found to contain isolatedcavities, thus pointing out the position of the carbonate portions. Ontreating a section witb caustic potash (after the hydrochloric acidtreatment), i t disintegrates into a mass of greenish needles andlamina From the above examination, the author considers the rockto be held together by a decomposible substance, such as serpentine,brucite, and a chloritic mineral.Potstone of Chinvema.-For comparison with the rock just described,sections were prepared of the Chiavenna potstone.This rock re-sembles closely that of the Julius Column, but the brown, roundishgranules are commoner, and consist on their external surface of ahomogeneous fibrous mass, whilst the central portmion consists of acloudy, dark-coloured substance, filled with a great quantity of veryfine black dust, and dark needles running in all directions.I n order to ascertain from whence the Romans obtained the stone ofthe Julius Column, the author examined some specimens closely re-sembling it, which he found in numerous quarries a t Pontresina inthe Upper Engadine.An analysis furnished the following results,viz. :-Si02. AI2O,. Fe20,. Cr203. MnO. CaO. MgO.Complete analysis ...... 35-90 0.89 11.30 0.23 trace 0.67 24.14Portion soluble in HC1 . . 28.77 trace 11-82 0.25 - trace 21.67Portioninsoluble in HCl . 54.80 1.50 7.52 trace - 2-33 50.50Potstone of Chiavenna(Delesse). ........... 36.57 - 5.85 - - 1.44 35.39K20. Ka20. FeC0,. CaCO,. MgCO,. H,O.Complete analysis. .... . U % 1.09 1.20 2.30 17.85 6.10=101.68Portion soluble in HCl . - - 1.70 3.23 25.07 8.42 = 100.91Portion insoluble in HC1 0.80 3.78 - - - - = 101.23Potstone of ChiaveniiaL----J(Delesse) ...........- - 14.03 4*97=100*00The excess in the complete analysis and the portion insoluble inhydrochloric acid is due to the iron being determined as ferric oxide,whereas it exists in the rock mostly in the ferrous state. The Pon-tresina rock contains a larger amount of carbonates than the rock ofthe Julius Column, but leaving this out, there is a very close analogybetween them, and the Chiavenna rock belongs also to the samegroup.A microscopical examination proved the identity of the rock of theJulius Column with that of Pontresina: hence it may be safelMIXERALOGlCAL CHEEBIISTR Y. 27inferred that the Romans used the latter rock for the erection of thecolumn. C. A. B.The Granite-porphyry of Beucha, near Leipzig. By E.KALKOWSKY (Jalwb. f. Niw., 1878, 276-286).--Zirkel was the firstto make the important discovery that the granite-porphyry fromBeucha contained " glass-enclosures " ( M i c r o s .Utxh. d. &fin. @ Gest.,Leipzig, 1873) .-This was afterwards confirmed by Rosenbusc'h(Micros. Plys., 1877, Bd. 11,s). Zirkel describes the granite-porphyryfrom Beucha and Altenberg thus :- " It is an aggregate of crystallin2minerals, amongst which quartz predominates over felspar. Themicroscopical quartz of the ground-mass is nearly always in sharplydefined crystals, which yield rhombic or hexagonal sections. Thesecrystals are so intimately intergrown with each other and the rec-tangular cloudy orthoclase crystals, that no microfelsitic suhstanceintervenes between them. The larger quartz-crystals are charac-terised further by numerous fine " glass-enclosures," often of a dihex-ahedral form, aud this is the more remarkable as the rock is of a crys-talline constitution throughout, and such enclosures are peculiar torocks in which a portion of the magma is amorphous.There are alsomovable liquid globules observed occasionally in the quartz, and theclear parts of the orthoclase crystals contain numerous rectangular'' glass-enclosures," the latter occurrence being extremely rare inquartz-porphyry, but common in granite. The rock contains alsoliornblende and chlorite, the latter mineral being in all probability asecondary product of the decomposition of the former.Baranowski considered the green substances of this rock to beaugite, and not hornblende ; and allowing the correctness of this COLI-clusion, the granite-porphyry of Beucha is most closely related to theaugitic felsite-porphyry of the neighbourhood of Leipzig described byKalkowsky (Zeits.Deut. Geol. Ges., 26, 1874). Augite-felsite-poi.-phyry is a coal-black to grey rock, having a true felsite porphyryhabit, with porphjritic quartz, felspar, and small black augite crystals.The dark colour is due to the great quantity of magnetic and titaniciron. Biotite constantly accompanies the augite, and apatite and iron-pyrites are accessory constituents ; the ground-mass is perfectlygranular, the grains diminishing sometimes to a scarcely recognisahlesize. The acid-rocks of this series " weather " easily, the felspar bs-coming more clouded and the augite fibrous. The granite-porphyryof Beucha (and the almost identical granitc-porphyry of the banks ofthe Mulden from Trebsen to Wurzen) is connected in a threefoldmanner with the above-mentioned aogite-felsite-porphyry, viz.:-(1 .) Its geological occurrence in the immediate neigh bourhood of theaugitc-felsite-porphyry. (2.) The granite-porphjry of Beucha ismostly of a reddish tint, owing t o the presence of reddish orthoclase,but there are also many degrees of colour observed, viz., from light-red to dark-red, violet, grey-violet, blackish-grey, greyish-black toblack. The porphyritic habit is caused by the occurrence of largered-orthoclase crystals and w bite plagioclase ; wliilst the large por-phyritic quartz-ciystals disappear entirely.On the northern perpen-dicular wall of the quarry, the greyish-black variety occurs, con28 ABSTRACTS OF CHEMICAL PAPERS.taining large colourless felspar crystals, which variety is scarcely dls-tiriguishable from the true augite-felsite-porphyry. There can be nodoubt that i t is the final member of a series of these rocks distin-guishable by colour alone (more compact varieties being pure black),and it gradually passes into the rock containing numerous red ortho-clase crystals. ( 3 . ) The third bond of union between the two rocksis that augite is common to both. Fresh strongly pleochroitic angitewas found by the author in two preparations only, it being generallyfibrous, as in augite-felsite-porphyry. All specimens exhibiting a red-dish tinge contained no fresh augite, but pseudomorphs of chlorite,quartz, and a mineral resembling epidote. No hornblende could bedetected.The secondary quartz in the centre of the pseudomorphsis penetrated by a mass of pores, badly formed and sometimes radi-ating. Small druses in the chlorite contain a light-yellow columnarmineral, which may be epidote. All the quartzes contain fluid enclo-sures, but not in any great number. The large porphyritic quartzcrystals contain numerous glass enclosures ; one cryst,al 0.1 mm. indiameter contained five glass enclosures, whilst another crystal con-tained a glass enclosure which was + to Q of its own bulk. The ortho-clase crystals owe their colour to. hydrated ferric oxide, which hasseparated out.All the plagioclases exhibit a polysynthetical twin-formation. Zirkel observed that orthoclase does not decompose regu-larly,. but that in the centre of the crystal a pellucid adular-like kernelremains, surrounded by clouded orthoclase. The aut,hor found thatall porphyritic orthoclase exhibits a perthite-like intergrowth of mono-symmetrical orthoclase, with a polysynthetically twinned plagioclase,most probably albite. Further, he observed that the orthoclase 6ub-stance undergoes most readily a molecular change where the smallalbite crystals occur, the adular-like portions being completely freefrom interpolated asymmetrical felspars. From the above it appearsthat an interpolation of unsymmetrical f elspars in orthoclase-crystalscauses them to be more susceptible to atmospheric action.Most ofthe porphyritic felspar-crystals are well and sharply defined, and thosehaving a roundish form are often surrounded by a row of small quartzcrystals, attached to each other like pearls in a necklace. The acces-sory minerals of the Beucha granite-porphyry are biotite, magnetite,titanic iron, apatite, and garnet. Biotite was most common in thegreyish-black variety, being rare in the reddish variety. The apatiteoccurs generally in the chlorite-pseudomorphs, but it is also found inthe ground-mass between the quartz and felspar. Red garnet occursseldom, and in small grains. The ground-mass of the Beucha granite-porphyry is a crystalline granular mixture of quartz and felspar,with secondary chlorite, oxides of iron, and some apatite, but not atrace of microfelsitic substance was detected on any of the prepara-tions.It is a curious fact that the diameters of the quartz and felsparcrystals of the ground-mass are about the same, viz., from 0.07 to0.10 mm. The author concludes from his own observations, and those ofother mineralogists, that the augite-granite-porphyry of Beucha mnsthenceforth be classed geologically with the felsite-PorphyFries, and notwith the granites. C. A. BMIXERALOGICAL CHEMISTRY. 29Mineralogical-petrographical Notes on the Granite-porphyryof Lower Silesia. By 7’. LIEBISCH (Jahrb. f. N i w . , 1878, 311-313).-The granite-porphyry of the Riesengebirge is composed ofthe following minerals : quartz, orthoclase, plagioclase, biotite, potash-mica, hornblende, augite, magnetite, apatite, and orthite.The quartzoccurs in well developed, mostly pyramidal crystals (occasionally ex-hibiting narrow prism-faces), with rouiided edves, and often enclosingmovable globules of liquid, but no microlites. nThe orthoclase crystalsoften occur colourless and transparent, exhibiting an adular-likeshimmer. They are occasionally colourless in the interior only, whilstexternally they hare a reddish colour. Some of them are white, witlia zonal structure. The crystalline fonn varies in different localities ;one form observed on orthoclase crystals from Hermsdorf was 00 P.OP.2F 00. Twins according to the Carlsbad law are very common. Thosize of these crystals varies from a few millimeters to several centi-meters in the direction of the axis c. Enclosures of biotite and quartzcrystals are very common in the orthoclase crystals, although many ofthe colonrless crystals are almost homogeneous.The orthoclase of thegranite-porphyry of the Altarstein (the southernmost rock of theGrabersteine) is penetrated by per thitic plagioclasc, that betweenKirche, Wang, and Briickenberg being enclosed by plagioclaee. In-terpolations of isolated plagioclase crystals are often observed in theorthoclase of the Riesengebirge grauites, occurring parallel with thesecond cleavage plane of both felspars. I n some localities, a consider-able decomposition of the orthoclase is observable, the product beinggreenish or yellowish mica.The plagioclase crystals vary from 1 mm.to 3 cm. in size, and are generally white or yellowish, seldom red.Double twins occur at Hermsdorf and other localities, the twin axisbeing “ the normal to the brachypinacoid ” for the twin, and the twinaxis being “ the normal to the vertical axis in the bracliydiagonal ” for.the double twin. The plagioclase of the granite-porphyry from thequarry between Erdmannsdorf and Stonsdorf exhibits a zonal struc-ture. The plagioclase “weathers” much more easily than theorthoclase, the product being a light-coloured mica. Sometimes agreenish mica occurs in radiating divergent sheaves, which exhibit inpolarlsed light a black “ interference-cross,” and also occasionally areddish-brown substance resembling pyknotrope.Kumerous veins ofquartz penetrate the granite-porphyry at all localities. The biotiteoccurs in well-defined tabular or prismatic crystals of a greenish-blackor black colour, and exhibiting in section a distinct hexagonal outline.Sections made parallel to the axis C are transparent and of a greencolour on their edges, whilst internally the colour is brown, and somesections exhibit alternately green and brown transparent laminae.Hornblende occurs but sparingly as a constituent of the granite-porphyry, the principal locality being westward between Erdmannsdorfand Stonsdorf. At Erdmannsdorf greenish-black augite occurs as anaccessory constituent, and a t the same place and a t Lomnitz orthiteoccurs as an accessory constituent in acicular crystals 4 to 1 em.inlength, with an orthodiagonal development. The ground-mass of allthe Riesengebirge granite-porphyries is massive, and seldom pre-ponderates over the crystallised rock-constituents. It is grey t o reddish30 ABSTRACTS OF CHEMICAL PAPERS.brown in colour, except in the “ sdbands,” when it is black. Quartz,orthoclase, plagioclase, mica, &c., constiti-rte the ground-mass, whichis microcrystalline and coarse-grained. The so-called “ pseudosphEro-lites” of Rosenbusch occur in great beauty, 0.2 to 0.4 mm. indiameter, in a vein between Erdmannsdorf and Stonsdorf, and in thegrani t\e-porphyry of Buschvorwerk. The difference between the con-stitution of n rock from the middle of a vein and from a salband isvery marked in a granite-porphyry vein in a quarry between Erd-mannsdorf and Stonsdorf.The granite-porphyry from the centre ofthe vein contains in the grey ground-mass large white and greenish-white orthoclase and plagioclase crystals, grey quartz crystals, andgreenish-black biotite. These crystals diminish in size as their dis-tance from the centre of the vein increases. The salband rock con-tains in the massive blackish ground-mass only very small orthoclase,plagioclase, quartz, and black biotite crystals. The orthoclase andplagioclase crystals, however, were penetrated by innumerable smallbiotite laminae, and between the latter was a double refracting crypto-crystalline mineral, which could not further be studied. On accountof the band-like arrangement of the fclspar and biotite crystals of theground-mass around the isolated crystalline const>ituents of the rock,the author considers that a fluid structure is indicated.C.A. B.Occurrence of Dioptase on Chrysocolla, from Peru. ByC. A. BURGHARDT (Cham. New?, 37, 223).-The author examinedsome specimens received from Mr. W. M. Hutchings, of Birkenhead,which the latter thought to contain dioptase. The exact locality ofthe mine is unknown; but the chrysocolla was shipped from the portof Pisco, Peru. The specimens exanlined exhibited certain cavitieshere and there, which appeared to have been eaten out of the massby the action of some powerful solvent. These cavities were dividedinto numerous cells by the intersection of thin portions of chrysocollasubstance, and upon these partition walls were attached particularlyfine sheaves and bundles of emerald-green transparent crystals.Thesecrystals were so extremely small that it was almost impossible to makeaccurate measurements, but the forms characteristic of dioptase, viz.,OCI P‘L, -2R, were well defined. No other forms were observed.Sometimes numerous fine acicular sub-individuals growing parallelto each other built up a large individual. Carefully picked crystalsgave all the blowpipe reactions for dioptase. The dioptase crystalswere associated with colourless quartz crystals, the forms +R. -R.on the latter being in equilibrium. This is the first instance observedof the occurrence of dioptase in Peru. Maskelyne (Chem.News, 24,99) mentions some specimens of dioptase in the British Museum, oneof which is said to have come from the Rosario Mine, Chili, another(associated with quartz and eisenkiesel) from the Mina del Limbo delSalado, Copiapo, Chili. Only one of these specimens is associated withchrysocolla. The author is of opinion that the dioptase describedabove has been formed from the chrysocolla by the action of water.Very fine botryoidal malachite occurs associated sometimes withchrysocolla and cuprite, in the same locality in Peru. C. A. BMISERALOGICAL CHEXISTRT. 31On Unghwarite, Nontronite, Gramenite, &c. By A. KFSN-GOTT (Jahrb. f. Min., 1878, 180-185).-A. Scrauf (Jclhrb. .f. ilI;tL.,1877, 2.56) gave the results of two analyses of chloropal from Mugran,Bohemia, which he found to agree with an analysis of .~zontrouite byBerthier ; therefore nontronite was a variety of chloropal.Kenngottobjects strongly to the name chloropal, as the minerals inclnded in theso-called " chloropal-group " of Dana (including unghwarite, nontro-nite, pinguite, bole, and gramenite) are not true opals. Schrauf'sanalyses furnished the following, viz. :-Fe,03. A1,03. CaO. MgO. Alkalis. SiO?. H,O.1. 27.50 4.16 2.97 1.77 traces 43.98 (by diff.) 19.62 = 100.002. 28.91 3.19 3.35 2.84 - 42.43 (direct) 28.32 = 99.53If the alumina be considered a vicarious constituent, replacing ferricoxide, and the magnesia a vicarious constituent replacing calciumoxide, and both calculated into the corresponding amounts of ferricoxide and calcium oxide, also if the resulting percentages are thencalculated (the percentage of ferric oxide in each analysis being madeidentical), the composition of the mineral is as follows, viz.:-Fe,03. CsO. Si02. HzO.1. 32.00 5.13 41-44 18.50 = 97.072. 32.00 6.93 40.57 17.31 = 96.81From these calculated percentages i t is evident that the relativeproportions are nearly 10H20, 1R0, 2Fez03, 7SiO?. Schrauf assignedto the mineral the formula C~trMg2A12Fe,4Si,8G84 + 40H20. Theauthor points out that. i t would probably have been more correct hadSchrauf named the mineral from Mugrau, nontronitc. Tf Berthier'sanalysis of nontronite be treated in the same way as the above, resultsare obtained which agree closely with them, with the exception of thepercentages of the RO metals.These differences arc observed in theother allied minerals, whence the author concludes that unghwarite,nontronite, gramenite, pinguite, &c., are only impure varieties of amineral species which is essentially a hydrated ferric silicate, whosetrue composition yet requires to be ascertained. C. A. B.Mineralogical Notices. By S. R. PAIJKULL (Juh~b. J'. Mh.,1878, 209-210) .-Eucrasite, a New Mineral *from Brevig.-Thismineral is found upon one of the small islands in Brevigsf'jord. Crys-talsystem, probably rhombic. H. = 4.5to 5. Blackish-brown, streak brown, uneven fracture, fuses beforethe blowpipe on the edges and becomes lighter in colonr. Borax beadi n the oxidising flame yellow, in the reducing flame violet.Microcos-mic salt dissolves it, leaving a skeleton of silica. Partially soluble inhydrochloric acid, with evolution of chlorine ; completely soluble insulphuric acid.Sp. gr. (at 15" C.) = 4.3'3.Chemical composition as follows, viz. :32 ABSTRACTS OF CHEMICAL PAPERS.SiO,. TiO?. SnOr(?) Zr0,. MnO,. Tho,. CeO,. Ce20,. La?03Di20g.16.20 1.27 1.15 0.60 2-34! 3-5-96 5.48 6.13 2.42YzOs. Er&. Fe203. A1203. CaO. MgO. K20. Na20. H20.4.33 1-62 4.25 1.77 4.00 0.95 0.11 2.48 9.15Formula corresponding with the above (3R0, + +R,O, + $RO)SiO, + 2H20. The author considers it probable that eucrasite isidentical with the polycrase (thorite) from Brevig, of Scheerer andBreithaupt, and with the polymignite of Mollcr.Picrotephyoite froin Lactngban is a light red mineral, and may be con-sidered to be tephroite in which the manganese has been replaced bymagnesium.Its chemical composition is as follows, viz. :-SiOz. MnO. CaO. MgO. Loss on ignition.33.70 51.19 0.95 12-17 0.44 = 98.45.ilIaiaga?iozcs Serpeiztine f row?. Laaizgba~~.-Colour and streak brown ;uneven fracture ; brittle. Decrepitates before the blowpipe, and isscarcely fusible even in fine splinters. Dull on broken surfaces;vitreous lustre. I s found pseudomorphous. Chemical composition asfollows, viz. :-SiO?. PbO(?). Fe203. FeO. MnO. A1203. CnO. MgO.428.40 0.30 ‘7.51 1.84 7.77 0.90 2.80 24.60K,O. Na20. P205. Loss on ignition.0.04 0.47 trace. 10.000 = 98.63.Formula corresponding with the above = 4R0.3SiO2 + 2H20.Homilite.C.A. B.By DESCLOIZEAUX and DAMOUR (Jnhrb. f. illin., 1878,204-205).-This mineral (described by Paijkull, Jahrb. f. Min.,1877, 536) is found a t Stockii, near Brevig, accompanied by melino-phane and erdmnnnite. Descloizeaux found that the mineral crystal-lises in the monosymmetrical system, and exhibits a certain similarityto the forms observed on datolite and gadolinite, the crystals beinggenerally developed irregularly. Inclination of clinoaxis to the ver-tical axis = 90” 39’. The following forms predominate, viz., OOP,$42 m, OP, 00 P 00, F m, -P. H. = 4 5 to 5.Sp. gr. = 3.34. Black vitreous lustre ; transparent in thin fragments ;grey streak. Horizontal dispersion v > p . Some crystals contain agreen double-refracting dichromatic kernel, the outer rind or shellbeing yellowish and refracting light simply.Homilite evolves wateron being heated in a closed tube, fuses easily to a black glass, anddissolves in acid with gelatinisation. An analysis by Damour showedi t to have the following composition, viz. :-Cleavage not apparent.Oxides of Ce,SiO,. Boy. FeO. MnO. CaO. La,andDi. Na,O. H,O.33.00 15.21 18-18 0.74 27.00 2.56 1.01 2.30 = 100.00.C. A. BMISERALOGICAL CHEMISTRY. 33Daubreelite, the New Meteoric Mineral. By J. 11. SJTITA( C o i ~ y f . rend., 87, 338-340).--In the resistance of daubr6elite tothe action of hydrochloric and hydroflnoric acids, the author has foundan easy method of separating i t from troiilite and other impurities.Daubr&lite tlius purified presents itself in small, black brilliant scalcs,of density 5.01. It is not magnetic, and does not fuse before theblowpipe. It gives an intense green coloiir to borax, and is com-pletely soluble in hot nitric acid. The mean of four analyses givesthe following percentage composition : S 42.69, Cr 95-91, Fe 20.10.The mineral is therefore a double sulphide corresponding with chromeiron in which the oxygen has been replaced by sulphur, thus,FeS.Cr,S,. No terrestrial mineral of this composition is known. Theauthor found daubrkelite in several meteorites in which its presencewas not previously known, and he believes that this substance, eithcrin a visible condition, or so disseminated as to be discerned only afterchemical treatment, will be found to be universallypresent in me.teori tes. R. R.The Mineral Spring of "Tenninger Bad," Somvixer Tobel,By R. MEYEII. (Dezit. CJ~enz. Ges. Rer., 11, 1521--1526).-Sp. gr. 1.002582 a t 10.5" compared10,000 parts of waterGrisons.Temperature of the spring 14.3".with distilled water a t the same temperature.contain-Na,O. KZO. (NH,),O. CaO. SrO. MgO. FcO.0.0847 0.0532 0.0273 8.3688 0.0957 1.1428 0.0016AI20, and H,P04. SO,. c1. SiO,. co?.0*0008 13.4723 0-0049 0.198 1.7182Organic matter 1.1130, and traces of MnO, Pb, Cu, Zn (?) andHN03.Although the water a t present contains mere traces of iron, a thickferruginous deposit (containing traces of arsenic) is found a t the sourceof the spring. w. c. w.Presence of Lithium in the Earths and Water of the Solfa-tara at Puzzuoli. By S. DE LUCA (Compt. rend., 87, 174).--Theaiithor allowed 10,000 litres of water, which bad been used to levigate250 cwt. of Solfatara earth, to svaporate spontaneously. From themothcr-liquors he obtained a considerable quantity of amorphousmatter by desiccation. This yielded a hydrochloride, the spectrumof which showed the brilliant lines of lithium distinctly and thesodium lines feebly, showing clearly that the earths of the Solfatar,icontain traces of lithium in the form of sulphate, which can be ex-tracted by means of rain-water. Hot water is found in abundance FLCa depth of from 10 to 12 metres below the surface about, the oldcrater of the Solfatara, containing free sulphuric acid and sever21other substances. The water is formed both by the vapours of thenumerous fumaroles, and by the rain percolating through the poroussoil and dissolving on its way the soluble matter contained in it. OnFOL. sxsv1. 34 ABSTRACTS OF CHEMICAL FM'ERS.treating this water in the manner described above, the same resultswere obtained, as far as the presence of lithium is concerned, showingthat sulphate of lithium is contained in the trachytic earth and in thehot springs of the Solfatera of Puzzuoli. J. M. T