20 ABSTRACTS OF CHEMICAL PAPERS. Miner a 1 o gical Chemistry . Dopplerite. By C. CLAESSEN (Jahrb. f . Min., 1899, i, Ref., 424 ; from Chem. Zeit., 1898, 523).-Analysis of dopplerite from an Olden- burg moor gave : C. H. 0. Ash. Total. 52.96 4-67 34.1 0 8.27 100~00 New Zealand Coal and Ambrite; Barbados Manjak. L. J. s. By P. PHILLIPS BEDSON (Tvans. Fed. Inst. Mining Eng., 1899,16,388-390). -Coal from New Zealand gave analysis I (by A. Dodds); the com- position of the dried ash-free coal is given under Ia; 10-13 per cent.MINERALOGICAL CHEMISTRY. 21 of the coal is soluble in pyridine. Ambrite, a brown, transparent resin, associated with this coal, gave T I (Dodds). An asphalt from Barbados, locally known as manjak, gave I11 (by R. L. Treble) ; it resembles albertite in appearance, but is completely soluble in pyr- idine.Fixed carbon. Volatile matter. Moisture. Ash. S. I. 46.44 47.80 4.66 1.10 0.54 11. - - 0*59 0.18 c 111. 36.52 61.90 1.58 c C. H. 0. N. - I I U . 80.95 9.87 9.1s - IIICC. 81.18 8.43 10.39 - ICC. 74.32 9-67 20.0 1 L. J. S. Identity of Binnite with Tennantite : Composition of Fahl- em. By GEORGE T. PRIOR and LEONARD J. SPENCER (iwin. Mag., 1899, 12, 184--213).-The small, briIliant crystals of ‘ I binnite” are of rare occurrence in the white, saccharoidal dolomite of the Binnenthal in Switzerland. They are cubic and hexakistetrahedral, and the formula usually assigned to them is 3Cu2S,2As,S,. It is now shown that they are crystallographically, physically and chemically identical with the less perfectly developed crystals of Cornish tennantite.Analysis I was made on eleven crystals (weighing 0.3101 gram), of which the streak is chestnut-brown ; thin splinters are translucent and crimson by transmitted light. This analysis gives the formula 3Cu2S,As2S,=Cu3AsS,. Analysis I1 is of crystals, of which the streak is black, and which, in thin splinters, are opaque; formula [S(Cu,Ag),S,As,S,] + g3[ GFeS,As,S,]. The variation in the colour of the streak of the mineral depends on the amount of iron present. Analyses I--V by G. T. Prior. I n each case, detailed descriptions are given of the crystallographic and physical characters and of the associations of the material analysed. Cu. Ag. As. Sb. Bi. Fe. Zn. Pb. S. Total. Sp. gr. r. 49.83 1-87 19.04 - - 1.11 - 0-17 27.60 99-62 4’62 11.44’12 4.77 [20.49] - - 3’68 - - 26‘94 100*00 4.598 1x1. 45.39 - trace 28735 - 1’32 - 0.11 24’48 100.15 4‘921 IT. 41.55 - trace 28.32 0.83 1.02 2.63 0‘62 24.33 99.30 4.969 V. 30’56 15-26 trace 27.73 - 3’51 trace 0’05 23.15 100’26 5.047 The results of these analyses of ‘ I binnite,” as well as the published analyses of Cornish tennantite, differ considerably from the figures required by the accepted formula for fahlerz (tetrahedrite and tennant- ite), namely, 4R”S,R”’,S,, where R” = Cu,, Ag,, Fe, Zn, and R ” = As, Sb, Bi. Very few of the published analyses of fahlerz agree with this formula, and minerals which have given the formula 3R”S,R”,S, have often received new names. Three new analyses were therefore made of specially pure tetrahedrite crystals free from copper pyrites, blende and pyrites which are usually so intimately associated with fahlerz ; the fracture of these crystals was smooth and conchoidal and with a brilliant lustre,22 ABSTRACTS OF CHEMICAL PAPERS.Analysis 111 is of material from a large crystal of octahedral habit from Fresney d’oisans, Dauphine ” ; the streak is dark brown ; after deducting the iron as pyrites, the formula is 3Cu,S,Sb2S, = Cu,SbS3. Analysis IV is of the well-known brilliant crystals from Horhausen, in Rhenish Prussia; very thin flakes are crimson by transmitted light, and the streak is dark brown. Analysis V is of tetrahedral crystals, probably from Wolfach, Baden; the streak is black. IV and V give the formula [ ~ ( C U , A ~ ) ~ S , S ~ , S , ] ;t &[G(Fe,Zn)S,Sb S 3.These analyses suggest the new formula 3R ,S,R”’?S3 + x[6R”E!,$”’,S,], where R’ = Cu, Ag ; R” = Fe, Zn ; R ” = As, Sb, Bi ; and x is a small fraction, often =2G and 1 but rising to in the case of the highly ferriferous tetrahedrite ’‘ coppite.” I n this formula, the group (Fe,Zn),S,, and not (Fe,Zn),Sp, is isomorphous with Cu,S3. Only in those cases where iron and zinc are absent does the simple formula SRS,R”’,S, hold good. Numerous previous analyses are discussed and found to agree with the new formula. L. J. 5. Melonite (?), Coloradoite (?), Petzite and Hessite. By WILLIAM F. HILLEBRAND (Arner. J. S’ci., 1899, [iv], 8, 295-298).--MeZonite? -Impure material from the Melones mine, in the Mother Lode region, California, gave the results under I ; after deducting a little hessite and tellurium, this gives the formula NiTe,, I n colour and cleavage, the material agrees with Genth’s melonite from the same locality; Genth, however, gave the formula Ni,Te3. Coloradoite ?-One small specimen from the Norwegian mine in the same district showed dolomite, petzite, hessite, and a mercury telluride, which is probably coloradoite.Petxite.-Analysis of pure material from the Norwegian mine gave 11, agreeing with the formula Au;J!e,3Ag2Te. ETessite.-Material from San Sebastian, Jalisco, Mexico, gave analysis 111; sulphur, iron and zinc are also present. Te. Ni. Ag. Au. Se. Mo. Pb. Total. Sp. gr. 11. 33.21 - 41.87 25.16 trace 0.08 - 100.32 8.925. I. 80.75 18.31 0.86 - - - - 99.92 - 111. 36.11 - 61.16 - - - 1.90 99.17 8.24. L. J. S. Langbeinite from the Punjab Salt Range.By FREDERICK R. MALLET ( M h . Mag., 1899, 12, 159--166).-A potassium magnesium sulphate occurring as a lenticular stratum in the ‘ kallar’ (impure rock salt) of the Mayo mines, Punjab, India, was discovered and analysed in 1873. The material has now been more completely examined, and found to be the same as the cubic mineral langbeinite, 2MgS0,,K2S0,, recently described from the Prussian salt deposits (Abstr., 1898, ii, 168). The Indian mineral is associated with salt, sylvite and kieserite, and sometimes encloses these. It is colourless and transparent, and optically isotropic. The powder is slowly but completely soluble in water. Sp gr. 2.84 ; H = 4. Analysis gave :MINERALOGICAL CHEMISTRY, 23 K,O. MgO. so,. NaCl. H,O.Total. 22.23 19.08 57.27 0-41 0.84 99-83 On exposure to the air, the powder absorbs water, and there is an increase in weight of nearly 57 per cent. ; the decomposition therefore takes place in accordance with the equation : 2MgS04,K2S0, (langbein- ite) + 13H20 = K2S0,,MgS04,6H,0 (picromerite) + MgS04,7H20 (epsomite). Lnngbeinite, as isotropic octahedra , may be artifically produced by fusing together magnesium and potassium sulphates in the proper proportions. L. J. S. Formation of Oceanic Salt Deposits, particularly of the Stassfurt Beds. XIII. Evaporation of Sea Water a t 25'. By JACOBUS H. VAN'T HOFF and W. MEYERHOFFER (Chem. Ceiitv., 1899, ii, 76 ; from Sitxungsbev. Aknd. Wiss. Bedin, 20, 372--383).-The most recent and trustworthy analyses of sea water show that on an average 1000 parts contain NaCI, 47 ; KC1, 1.03 ; NgC12, 7-26 ; and MgSO,, 3-57, When sea water is evaporated at 25', the salts separate out in the following order :-( 1) NaCl ; (2) NaCl + MgS04,7H,0 and NaCl+ MgS04,6H20 ; (3a) NaCl + MgS04,6H20 + KC1 and NaCl + MgS0,,5H20 + KCI ; (371) NaCl + MgSO4,4H2O + MgCl2,KCl,6H2O ; (4) NaCl + MgSO4,4H,O + MgCI,,KCl,GH,O + MgC1,,6H20, and in the following relative quantities : NaCI.MgSO,. KCI. MgCI,, KC1,6H20. BfgC1,. 1. 94.5 2. 2.39 1.63 3cc. 0.59 1-42 0.72 36. 0.50 0.22 1-27 4. 0.02 0.30 0.07 6.02 These quantities, however, are only obtained when the separate crystailisations are removed from the mother liquor. By ERNALD G. J. HARTLEY (Min. Mag., 1899, 12, 152--158).-The formula of pharmacosiderite is uncertain ; it is based on an analysis by Berzelius (1821), and no analysis has since been made.The present analyses mere made on selected green crystals from Uornwall; sp. gr. 2.798. A green crystal placed in ammonia solution very soon becomes red throughout without alteration of the optical characters; on placing such a red crystal in dilute hydro- chloric acid, the green colour is restored to the whole crystal. Two preliminary analyses (I and 11) show a deficit, which mas afterwards found to be due to the presence of potassium. This element is present in all the Cornish specimens examined, but in variable amount (2.68 and 4.12 per cent. K20), and in two specimens from Hungary only traces were found. About 10 per cent. of water is lost a t 100'; at 130', the crystals begin t o turn brown and opaque, and about 14.18 per cent.is lost (= 5H20 in the formula given below). A complete analysis made on another specimen is given under 111. E. W. W. Pharmacosiderite. AszO,. P,O,. Fe,O,. K,O. H,O. Total. I. 37.53 2.04 39.29 - 19.63 98.49 11. 36.85 2.06 38.61 - [19*63] 97-35 111. 37-16 1.20 37.58 4.54 18.85 99.3324 ABSTRACTS OF CHEMICAL PAPERS, The ratios between the iron, arsenic acid and water are fairly constant, and give the formula 3Fe,0,,2As2O,,13H,O = 2FeAsO4,Fe(OH),,5H,O. The potassium is assumed to replace hydrogen in the hydroxyl, and the formula is finally written as 2FeAsO4,Fe[O(H,K)],,5H,O. [Chabaxite] from North Carolina. By JULIUS H. PRATT (JaAr6. f. Min., 1899, i, Ref. 229-231; from JOUY. EZisha Mitchell Sci. Soc., 1897, 14, 61--83).-Analyses by C.Baskerville are given of the small crystals of chabazite associated with wellsite (Abstr., 1897, ii, 565) in the Buck Creek corundum mine, Clay Co., North Citroliua. The simple and twinned rhombohedra occur on felspar, hornblende and corundum. The material for analysis was separated into two portions by means of a heavy liquid ; anal. I on material of sp. gr. 2.147-2.203 ; 11 of sp. gr. 2.203-2.244. SO,. A1,0,. FeO. CaO. RaO. MgO. K,O. Na20. H20. Total. I. 45-08 19-68 2-00 7-22 0'18 0.23 4.34 3.35 18-00 100*08 11. 46'15 20'74 2.00 6'92 0'24 0'22 4.10 3 35 16'30 100-02 This variation in composition and specific gravity supports Streng's hypothesis as to the composition of chabazite. Other minerals from North Carolina, described in this paper, have already been noticed (Abstr., 1898, ii, 342, 606).Constitution of Pectolite, Pyrophyllite, Hemimorphite and Analcite. By FRANK W. CLARKE and GEORGE STEIGER (Amey. J. Sci., 1899, [iv], 8, 245-257).-1n continuing the investigation of the constitution of natural silicates, special importance is attached to the two following reactions : (l), when talc is ignited there is a liberation of one-fourth of the silica (Abstr., 1890, 948) ; this suggests that other acid metasilicates may behave in a similar way ; (2), dry ammonium chloride, a t its temperature of dissociation, acts differently on different minerals (Abstr., 1892, 772). I'ectoZite.-The material used in the experiments was from Bergen Hill, New Jersey ; analysis gave the results under I, agreeing with the accepted formula HNaCa2Si309.Only a small portion of the water is given off below a dull red heat. After igniting the mineral, sodium carbonate solution takes up 8.68 per cent. of silica, or one-sixth of the total amount. This, it is considered, indicates that the mineral is an acid metasilicate as expressed by the above formula. Before ignition, sodium carbonate solution, or even distilled water, has a slow, decom- posing action on the mineral, both silica and bases being withdrawn ; the action is, however, not one of simple solution. PyrophyZZite.-The material used was from Deep River, North Carolina, and gave the results under 11. The empirical formula, AlIISi,O,, is apparently that of an acid metasilicate, but after ignition, only about 2 per cent.of silica is liberated. The formula is therefore written as OH*Al:Si,O,, that is, as a basic salt of the acid H,Si,O,. The mineral is very slightly attacked when heated with dry ammonium chloride. Hemimorphite.--White material from Franklin, New Jersey, gave the results under 111. The formula generally accepted represents the L. J. S. L. J. S.MINERALOGICAL CHEMISTRY. 25 mineral as a basic metasilicate, SiO,(Zn*OH),. Here the hydrogen is all combined in one way, and so, too, is the zinc. In all other possible formuh, the hydrogen, as well as the zinc, must be represented a s present in at least two modes of combination. Several experiments were made with the idea of extracting a definite fraction of the zinc or water, but the results were negative and only tend t o support t h e usual formula, Water and sodium carbonate solution have very litble action either before or after ignition of the mineral.By heating with dry ammonium chloride, all the zinc is converted into zinc chloride. AizaZcite.--Crystals from Wasson's Bluff in Nova Scotia gave analysis IV. Temperature. 100". 180". 260". 300". Low redness. Full redness. Blast. Total. H,O percent. 0.58 1'16 3'64 1.57 1.90 0.11 nit 8.96 Before or after ignition very little silica is extracted by sodium car- bonate solution. Heated a t 350' with dry ammonium chloride, about half of the sodium is converted into chloride, and ammonia is retained ; this ammonia is not given off when the residue is warmed with caustic sodium solution. The composition of the residue, after extracting sodium chloride, is given under V, which agrees approximately with H2Na,Al4SiSO2,,NH,.This ammonia derivative suggests that the analcite formula should be quadrupled, namely, Na4A14S~s02,,4H,0. G. Priedel has previously shown t h a t t h e water of analcite may be replaced by ammonia (Abstr., 1896, ii, 48:). An excess of silica over that required by the accepted analcite for- mula, NaA1Si20,1H,0, is shown by analysis I V and by some previous analyses. This is explained by analcite being, not a metasilicate, but a mixture of ortlzo- and tri-silicate, the general formula being NaAlX, H,O, where X = nSiO, + mSi,O,. This explains the alteration of albite, NaAlSi,O,, and nephelite, NaAlSiO,, to analcite. For normal analcite, the formula is finally written as A1,Ns,(Si0,),(Si,0s),,4H20. This is written structurally t o show the relation between analcite, leucite and the garnet-sodalite group.SiO, AI,O,. Fe,O,. CaO. Na,O. H,O. Total. I. 53.34 0'33 - 33'23 9.11 2-97 ; MuO, 0'45 ; CO,, 0.67 100'10 II. 84.73 29'16 0.49 - - 5.35 ; TiO,, 0'73 ; MgO, trace 100'46 111. 24.15 0.19 0.12 - 7.95 ; ZnO, 67.55 99'96 IV. 57.06 21'48 0.13 0.16 12-20 8'96 99'99 V. 62.59 24-34 - 0.18 S ' l l 2 . 3 2 ; NH,, 2'46 100'00 By ERNST A. W~LFING (Bey., 1899, 32, 2214--2224).-Analyses are given of four samples of Keuper marl from the neighbourhood of Tubingen; some were made by the author, the others by Dittrich. The agreement is fairly close, except in the case of alumina and ferric and sodium oxides. The anthoi- separated the iron and aluminium by running the nearly neutral solution of t21e chlorides into excess of a boiling solution of caustic soda (made from the metal), and found more alumina and less ferric oxide than Dittrich, who fused the mixed oxides with pure caustic soda in a silver crucible j the discrepancy in t h e sodium is unexplained, The water is lost as follows : v L.J. S. Analysis of Rocks.26 ABSTRACTS OF CHEMICAL PAPERS. Stress is laid upon the necessity that the reagents used in a rock- analysis, including the distilled water, should be pure. C .F. B. Experimental Petrology. By K. BAUER (Jalwb. f. Min., 1899, Beil. Bd. 12, 535-580)- I n continuing the experiments of Doelter and Schmutz (Abstr., 1897, ii, 54, 329) on the artificial production of rockq, the main object has been to test whether different rocks can be formed from the same magma.Powdered rocks-mica-schist, granite, diorite, phonolite, leucite-lava, nepheline-basalt and andesite, or mixtures having the same composition as these-were fused in a platinum crucible with various fluxes. The following will serve as a n example of the several experiments made. A mixture consisting of mica schist, potassium fluoride, sodium fluoride, calcium fluoride, sodium tungstate and potassium tungstate was maintained i n a fused condition at 1400' for two hours, in a plastic condition for seven hours, and allowed to cool slowly for five hours. Under the microscope, the product resembled a mica-andesite, and was seen t o contain plagioclase, biotite, augite, magnetite, scapolite, nepheline and glass, The same mica-schist with other fluxes gave a product resembling a melilite-basalt.Using diorite with various fluxes, the products were quartz-basalt, andesite, melilite-basalt, mica- andesite and phonolite-pitchstone. Phonolite-pitchstone was also produced from mixtures having the compositions of granite and of phonolite. This is taken to indicate that different; rocks may be formed from the same magma, and vice vem2. [The chemical composition of the magmas have, however, been considerably modified by the large amount of fluxes used.] Hornblende was formed in three of the fusions, whilst quartz was formed only once. L. J. S. [Mineral Analyses]. By W. TARASSENKO (Jahvb. f. Min., 1899, i, Ref., 458-475 ; from Mem. X i e f Nnturulists' SOC.(Russian), 1896, 15, 1--347).-The following mineral analyses are given in a petr- ological paper on t h e gnbbro and allied rocks in the districts of Radomysl, gov. Volhynia, and Shitomir, gov. Kieff, Russia. Orthoclase (microperthite) in a labradorite-rock from Poromowka, Shitomir district, gave anal. I ; the material analysed contained spindle-shaped enclosures of plagioclase. Labradorite from the same rock gave I1 and I11 ; the former of sp. gr. 2.692-2.686 ; the latter of sp. gr. 2.686-2.677; this material also contained spindle-shaped enclosures, possibly of ortho- clase, Diallage in a, labradorite-rock from Kamenny Brod, Radomysl district, gave IV (also MnO, trace ; X, 0.15). SiO,. TiO,. A1,0,. Fe,O,. FeO. CaO. MgO. K,O. Na,O. H,O. Total. I. 62.58 0.59 20'83 - - 2'10 - 12'24 2'08 0.41 100.33 11.54.78 0.36 28-16 0.27 0.48 10.35 - 1.45 4.84 0.04 100'73 111. 55.32 0'28 28.16 0.05 0.52 10'05 - 0.97 5.20 0.03 10058 IV. 50'11 2-01 1'69 1.15 15.61 15.20 13.68 - - 0'65 99.15 L, J. 8,MINERALOGICAL CHEMISTRY. 27 Trap-rock of Rocky Hill, New Jersey. By ALEXANDER HAMILTON PHILLIPS (Ainer. J. Sci., 1899, [iv], 8, 267-285).-A dyke of dolerite in the Triassic strata a t Rocky Hill, New Jersey, shows, in its width of half a mile, variations in chemical composition a,nd in structure. Analysis I is of the microcrystalline rock a t the margins ; I11 is of the most coarsely crystalline material towards the centre of the dyke, and I1 is of an intermediate rock, Analyses are also given of material separated from the rocks by means of heavy solutions.IT and V are of the diallage from the rocks I1 and IT1 respectively. VI and VII are of felspar (plagioclase) from the rock 11, the former of sp. gr. >2.69, and the latter of sp. gr. <2-69. VIII and IX are of felspar, sp, gr. >2*69 and <2*69, from rock 111; and X is of felspar (anorthoclase), of sp. gr. ~ 2 . 6 0 from the same rock. SiOz. Ti02. AlZO3. Fe20s. FeO. MnO. CaO. MgO. NazO. RJO. + IT. 50.34 1-56 15'23 2.82 11.17 0-14 9.61 5.81 2.93 1.02 111. 56.78 1'44 14'33 5.76 9.27 0.25 5.26 1-58 3.43 1.75 IV. 47.72 - 3'44 5-93 18.34 - 11.40 12.89 0.86 0'37 + V. 48.54 - 5.50 2.77 21.25 - 10.97 7.67 3'10 VJ. 53'84 - 29.30 0.81 - - 10.08 0.28 5.31 1-16 I. 51.46 1'06 13.98 2.66 8.92 - 10.49 7.59 4.75 VIT. 62'26 - 21.87 0.54 - - 6-53 0.15 7.98 1'20 VIII.66.84 - 17.98 2'6C - - 4.02 0.48 5.46 1.72 IX. 71.68 - 15.02 2'48 - - 3.86 0.12 5-52 1.37 X. 66.28 - 16.79 1.60 - - 0.71 0.13 9.76 5'31 P205. HsO. Total. 0-20 0.26 101.09 0-36 0'43 100.64 - - 100'95 - 0.44 101'22 -- 0 3 2 100.85 - 0.72 99'82 - - 100.05 - 0.49 101.07 L. J. S. 0.17 - 101*08 - 0'82 100'62 Analyses of Italian Volcanic Rocks. By HENRY S. WASHINGTON (Amer. J. Sci., 1899, [ iv], 8, 286--294).-Five analyses are given of trachytes from the Phlegman Fields and from Ischia. By LAZARUS FLETCHER (Min. Mag., 1899, 12, 167--170).-This iron was known before 1869 in the neighbourhood of Caperr, Kio Senguerr, Patagonia. It weighs 114 kilograms, and measures 48 x 31 x 27 cm. The structure is octahedral, and the etched surface shows distinct Widmanstatten figures with kamacite, t m i t e and plessite.Schreibersite is embedded in the kamacite. Sp. gr. 7.837. Analysis gave : L. J. S. Meteoric Iron from Caperr, Patagonia. No troilite or silicate was seen. Fo. Ni. Co. P. Cr. Cn. S. Total. 89'87 9-33 0'53 0'24 traco trace nil. 99.97 In composition and structure, this iron resembles the Joel iron from At acama. L. J. S. Cliftonite and Tmnite in the Youndegin Meteoric Iron. By LAZARUS FLETCHER (Min. Nag., 1899,12, 171-1 '74).-Cliftonite is the name given by the author to cubic crystals of graphitic carbon obtained from the meteoric iron found in 1884 in the sub-district of Youndegin, Western Australia. From a fragment weighing 8.32 grams, three milli- grams of cliftonite were isolated (Abstr., 1888, 30). More recently, a larger mass (97.25 grams) of the same iron was dissolved in dilute hydrochloric acid, but no cliftonite was seen.The cliftonite is there-28 ABSTRACTS OF CHEMICAL PAPERS. fore localised in one or more parts of the mass, and not uniformly distributed through it. During the solution of the iron, thin, lustrous, black plates (total weight, 0.0870 gram) were set free; they appeared to be an alloy of nickel and iron belonging to the tzenite group, After being kept for eleven years in a weighing tube, the material had increased in weight and altered in character owing to the formation of a layer of magnetic iron oxide on the surface, Sp. gr. 6-75. An analysis shows the material to be tzenite, with the composition : Fe, 61.87 ; Ni(Co), 38.13. Phosphorus, copper and magnesium were also present in small amount. L. J. S. Fluorine in the Mineral Waters of Portugal and Spain. By ANTONIO J. FERREIRA DA SILVA and ALBERTO D’AGUIAR (Bull. Xoc. CJ~irn., 1899, [iii], 21, 887-890. Compare Abstr., 1899, ii, 501, 602, 675).-The general question of the presence and detection of fluorine in mineral waters is discussed. The Campilho spring at Vidago has been found by one of the authors to contain fluorine equivalent to 0*000942 gram of sodium fluoride per litre, a result which may be com- pared with the corresponding figures for the Gerez spring (0.02288) and for the Spanish mineral waters of Lug0 (0.0242) and Guitiriz (0*0234). According to Gil, the presence of fluorine in many alkaline and sulphurous waters has hitherto been overlooked, owing to the fact that the tests usually applied for this element depend on the formation of hydrogen fluoride, whereas, since silica or silicates are also commonly present, i t is rather silicon fluoride which is produced and should be sought for. N. 1,.