tar to ees . nd a ania vo tet AD ‘ P ten : Boyan ee athens ate Rector ents taste m sions # . rs Tm ite hy At lar Fiat in toe emlen gaits i 9 le ee | ned totem” be No, Me fate Seale | - FS RL et tee te Lathe Paste teed ere Bete A At A Me Frnt nd Aha to Amt aniline BY nee. Rae Rar Mato eMac Mae Sls! Seaaeeeten m~ Vat | tate ig any Phe a te te tet Raa Be tte ah ne Ba fire Ns OO a ei ax" eb ry a er ens he ect a an eon Bae het oP tn Btn bin Se aN Satin hn a geetahatdn' ee NT ee arene erary er pert vr ea ee ree RAR Aare A Mahan ihe er _ eet pear a *9 eer erar were Woche Pathe tintin tan an an tian intestine = SCT eT TO ee aa Rl Re A. Gothnlte Yn tie Pte ti Ol it ala A Ho Ts ee le — a 2 ~ ee ene ns " pong th PR ec dy tM Ne em te tpl Or ee ll a aah Rika tg A Tht tn ay Ngee. 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Gig nae Nt BaF San = Mate meee Be stele abate = =Te** SS ae roan a et a a ee te eh we A “ any rater Oe ne eres Garr Phas Ge he FR IS Lan _ ase “ +a.” oa = ste a) oie ~~ Spe se tehNV te te an aa, a Re te 8 apace Oe RR ie te RT me AER ON A ah teats ier i See at « Sn -* ~ — ~~ mn .* Perera eee ee ie 8 A Sek hn Shree ANE Me = ws Peruperrerartre oS are a _ eon oo - ee TGR ce Reet Rae Ae eee OP —— ee —~ a a ee a eo eT re cpap ae Pat Ti eet AAAS 9 i afdinda : : te ; my ee ws Be SP ~~ ee Ae “ +s here er + ee . = a 7 DAMS Peceerurar er ee = 3 - Sam Nate ts tl re Pe erent oi ; we a a ae Fis"& 7 er - ~* . at ana Vu © se — i —~o- 4 gta TS eee ee ee Me Ratich. Te —* rae om ae tt aa! 7 th ro ae ' i - ay | 7 ps : = : - ee rere wand %, wet Roe re er ** Par “ amok, - a aan - ~ ” me gee. «0 +, 85 x ‘he oe ste Ate ee oe Pc dea ad Bee | - : i t oo ™ x. * - +s Se Ot ie tantant ° " at Am = . > . ~ Cae Oe ee 4 ° = : ~ . ~ ae * ~~ : a a! 7 - . a ~ ~ * te Oe a “ . TAPE Hae LS Ba Et 7 - * ~ ~*~ a ~ - ne a, x a “ *~- a. - - e ™, * Ne ~ a ” » >. ue i ae* ° 7 . x “ &. ~ me Pr wa a aed “ ~* = FA ~ ca = * * tad _ a H ; aoe : whut Sa Ee een Satna Se ee : 3 : - ps pe . Ak : = Sonn mak om or . — = ~ oe - ae TNS aa ag aT amin AE TD se RS “Se . i ” = mm Be aki ~* : = i ; = : Par Z - <0 meee Ne ® . ~ a+ _” . - x = « A ee ie Re Soles, * — wens c | : — +s . a nay ; 7 ; : . .* . - = ~ ~ —*e ; : : e . al ~ . < ‘ ay | . ; - A ea : ~ vi in om 7 ° - _ - : - : : = \ a = 7 7 ; | | . ) - : s en) ames 4 - 7 z | | . % | . . | ” ry hn ’ “8 ac: ox - : | eiabo ue ee - ~ * ~~ ; . | ~ ‘ . > 7 : n u F _—— | : | oe | | a are ars . ‘es oe — a - ~ > ad fe fn aloo Rete Oe at aoe e ro x : . nee 8S) 3 oe = -*, ant ~ om mar nr wren SARL : : - = . Peon . . ’ ml — a .* * Rem Sete © . ™ An ae oe BN na as oa SS igpmeecye Sree gery ye eren tn Oe ta pe ee ee ~~ <4 tt - 4 parte yn a h: - - é ‘ ——_—_ 7” a . ea) a ee ee Tle wet: ngs Te Bee gn Ay Pee d “ as ~— see, , — = “s eines = . ea —. *e 2* CN See ee a A tit oS Ke Face rma imate sy PY ‘ A “ “* . ~ aioe fe ? ”~ tenet 50 «aves hates 4 - ™ ~ 7 = * ~P ee oa © oan Weeeses Metiecnl rbe wns eee anita a = ; on ae : ~ “ a eeiaieties => Dearne cert ee een ; La . “s Pane - a oer gh. Ha ' s a) i mur af > ay iy t + ‘ a a ‘aay | 1 aks tai * ahs + gir Wie as y ” i E~= ) oF —- SILO. Fo TH ie AMERICAN JOURNAL OF SCIENCE. Epitorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or CampBripce, Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPHIA, Proressor HENRY S. WILLIAMS, or IrwHaca, Proressor JOSEPH S. AMES, or Battimore, Mer. J. S. DILLER, or Wasuinerton. FOURTH SERIES VOL. XIX—[WHOLE NUMBER, CLXIX.] WITH TWO PLATES. NEW HAVEN, CONNECTICUT. 1905 SZANIAN INSTI 777 =. a 8) “ers yy RS vi ‘ 2, ‘ ’ THE TUTTLE, MOREHOUSE & TAYLOR COMPANY. fi N 2 1905 CONTENTS TO VOLUME XIX. Number 109. Page Arr. 1.—Submarine Great Canyon of the Hudson River; by PNM SUN Omer te sue AN dee eo a 1 IJ.—Radio-activity of Underground Air; by H. M. a LADD WETTER ASP LAA ae Ne et ea 16 IIl.—Types of Limb-Structure in the Triassic Ichthyosauria ; at OEE RDAM@g eo Wire oS ee ee 8 IV.—Interaction of Hydrochloric Acid and Potassium Per- manganate in the Presence of Ferric Chloride; by J. PestcemnpNe oe Sh ET AS IST Site GUE cree Serene 31 V.— Crystal Drawing ; by S. L. PENFIELD.....-..----.--- 39 VJ.—Anemiopsis Californica (Nutt.) H. et A. An anatomi- Eres eiiye yet EhOUM oO Se ee 76 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Production of Pure Sodium Hydroxide for Labora- tory Uses, F. W. Ktster: Production of Magnetic Alloys from Non- Magnetic Metals, R. A. HaprieLD: Ozobenzol, HARRIES and WEIss, 83.—- Concerning Emanium, GiesEL: School Chemistry, E. Avery: Application of Some General Organic Reactions, Lassar-Coun, 84.—Influence of Glass Walls of Geissler Tubes on Stratified Discharges in Hydrogen, KE. GEHRCKE : Phosphorescence, P. Lenarp and V. Kuatr: Color Changes in Gold Pre- parations, fF. KiRcHNER and R. ZsicmMonpDy : Spectra of Hydrogen, Helium, Air, Nitrogen, and Oxygen in the Ultra-Violet, J. ScHNIEDERJOST, 85.— Pressure of Light, A. Bartroni: Notes on X-Light, W. Rowuins, 86. Geology and Mineralogy—Indiana Geological Survey, W. S. BLATCHLEY, 87. —Geological Map of Indiana, T. C. Hopkins: Geological Survey of New Jersey, H. B. Ktmmet: Recent Seismological Investigations in Japan, DarrRoxu Kixvucai, 88.—EKarthquakes, in the Light of the New Seismology, C. E. Dutron: Minerals of Japan, T. Wana, 89.—Brief notices of some recently described Minerals, 90. Miscellaneous Scientific Intelligence—Annual Report of the Regents of the Smithsonian Institution: Bulletin of the Bureau of Standards, 91.— National Academy of Sciences: American Association for the Advance- ment of Science, 92. s lV CONTENTS. Number: 110. Page Art. VIJ.—Isomorphism and Thermal Properties of the Feldspars; by A. L. Day and E. T. Auten. (With Plate I) . cect hee ae eye er 93 VIII.—Progress of the Albatross Expedition to the Eastern Pacifics by A. AGASSIZ (220s ee 143 IX.—Measurement of Self-Inductance; by J. B. WuirraEapD and H, a). CALS See ee Sictee Veer ee a 149 X.—Climatic Features in the Land Surface ; by A. Pmencx - 165 XJI.—Preliminary Results with an Objective Method of Showing Distribution of Nuclei Produced by the X-rays, for Instance ; by C. BaRus 2252.22 5e0.).2 175 XII.—Radio-active Measurements by a Constant Deflection Method ;.*by HL. BRONSON(@224. 202 > eee 185 XIII.—Convenient Apparatus for Determining Volatile Sub- stances by Loss of Weight; by J. L. Kremer __-_-_-- 188 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Canyon Diablo Meteorite, Moissan: Metallic Cal- cium, K. Arnpt, 191.—Use of Dried Air in Blast-furnaces, LE CHATELIER : Trisulphoxyarsenic Acid, McCay and Fosrmr, 192.—Hlectrolysis of Solid Electrolytes, Haeer and ToLtLoczKo: Determination of Fluorine in Wine and Beer, TREADWELL and Kocu: Direction and Velocity of Hlectric Discharges in Vacuum Tubes, J. Jamus, 193.—Extinction of the Hlectric Spark, J. Kocu: Exhaustion of Geissler Tubes by the Electric Current, E. Rrecke, 194.—N-rays, A. Broca: Recent Development of Physical Science, W, C. D. Wuerrsam, 195.—Outlines of Physiological Chemistry, 8. P. BEEBE and B. H. Buxton, 196. Geology and Mineralogy.—Geological Survey of Canada: Iowa Geological Sur- vey, 196.—Glaciation in South Africa, M. EK. Frames: Ueber Untersilur in Venezuela, F. Drevermann, 197.—Devonian Fauna of Kwataboahegan River, W. A. Parks, 198.—Ueber den Bau und die Organisation der Lyttoniidz Waagen, F. Nortiinc, 199.—Tower of Pelée: New Studies of the Great Voleano of Martinique, A. HEILprin, 200.—Jiingeren Gesteine der Ecuatorianischen Ost-Cordillere, F. TANNHAUSER: Alteren Gesteine der Ecuatorianischen Ost-Cordillere, F. von Wotrr: Ueber die Chemische Zusammensetzung der Eruptivgesteine in den Gebieten von Predazzo und Monzoni, J. RomBerG : Heptorit, ein-hauyn-monchiquit aus dem Siebenge- birge am Rhein, K. Busz, 201.—Kristallinen Schiefer, I, Allgemeiner Theil, U. GruBenMANN: Yttrium and Ytterbium in Fluorite, W. J. Humpurevys : Hamlinite from Brazil, 202. Miscellaneous Scientific Intelligence. —Publications of A Yale Observatory : Publications of the Yerkes Observatory, Vol. II, 1908, 203.—How to Know the Starry Heavens; a Study of Suns and Worlds, K. Irvine: Jefferis Mineral Collection : The Chemical Engineer, 204. Obituary—DR. BENJAMIN W. FRAZIER. e CONTENTS. Vv Nema ber 111. Page Arr. XITV.—Optical Constants of the Human Eye for differ- emtse@olors jby.C. 5. HASTINGS 22) 23. 22 bel eee 205 XV.—Notice of the Discovery of a New Dike at Ithaca, REE myo kis DARNEPT OS sec oe lle eae 210 mee —Damortierite : by W. T. SCHALLER ;..-_-..- ac-s-.. 211 XV II.—Crystallography of Lepidolite ; by W. T. Sogn ae 225 XV Iil—Machine-Made Line Drawings for the Illustration Beaccientine Eapers:: by WK. A. DALY {2.202.522.2222 227 XIX.—Iodobromite in Arizona; by W. P. Braxz.---_---- 230 XX.—Anutophytography : A Process of Plant Fossilization ; pe rgidkeny\ HERE Sima ay hae See eo ea lll ese 231 XXI.—Oxidation of Sulphites by Iodine in Alkaline Solu- eee Oy bese belle NSH Vays ee oe Ms Ue 937 XXII.—Billings Meteorite: A new Iron Meteorite from Southern Missouri; byiH. A. WARD 2. 2222 -2.2222- 240 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Atomic Weight of Iodine, G. P. BaxtER: Double Silicides of Aluminium, Mancuot and KIEsER: Europeum, URBAIN and LacomBe, 243.—Use of Calcium Carbide as an Explosive in Mining, GUEDRAS: Silicon-fluoroform, Rurr and ALBERT: Double Cyanides of Copper, GROSSMANN and Forst, 244.—Occurrence of Radium and Radio- active Earths, F. GirsEL: N-Rays, E. GEHRcKE: Photography of N-Rays, G. Weiss and L. Buti; Spectra of Electric Discharges in Cooled Geissler ’ Tubes, E. GoupstEe1n : Dependence of the Ultra-Réd Spectrum of Carbonic Acid upon Pressure, C. SCHAEFER, 245.—Hlectromagnetic Waves in the Visible Spectrum, F. Braun: Damping Galvanometer Deflections, W. EINTHOVEN: Possible Variation in Solar Radiation, 246.—Terrestrial Mag- netism, L. A. BAveER, 248.—Introduction to the Study of Spectrum Analysis, W. M. Warts, 249.—Reflecting Telescope : Theory of Optics, A. ScHUSTER, 200.—Elektrische Bogenlicht, W. B. von CzupNocHOwSEI, 251. Geology and Mineralogy—Treatise on Metamorphism, C. R. Van Hissz, 251. —United States Geological Survey: Geology of Perry Basin in South- eastern Maine, G. O, Smita and D. WHITE, 206.—Preliminary Report on the Arbuckle and Wichita Mountains of Indian Territory and Oklahoma, J. A. Tarr, 207.—Oldest Sedimentary Rocks of the Transvaal, F. H. HatcH: Maryland Geological Survey, 258.—Palezgntologia Universalis : Melting Points of Minerals, A. Brun, 259.—Mineral Resources of the United States, 1903, D. T. Day, 260.—Elements of Mineralogy, Crystallography and Blowpipe Analysis, A. J. Mosrs and C. L. Parsons, 261. Miscellaneous Scientific Intelligence—Report of S. P. Langley, Secretary of the Smithsonian Institution : Report of the Superintendent of the Coast and Geodetic Survey, 261.—Scottish National Antarctic Expedition: Nat. Academy of Sciences : Amer. Museum Journal, 262.—Reflections suggested by the new Theory of Matter, A. J. BaLFour: Ideals of Science and Faith, J. EK. Hanp: Long-range Weather Forecasts, E. B. GARRIOTT: English Medicine in the Anglo-Saxon Times, J. F. Payne, 265.—Studies in Gen- eral Physiology, J. Lors: Early Stages of Carabidae, G. Dimmock and F’. Knap, 264. Obituwary—ALPHEUS SPRING PACKARD. v1 CONTENTS. Nama ex) dd 2k Page Art. XXITI.—Bearing of Physiography upon Suess’ Theo- ries; by W. M. Davis. 265 XXIV. bye ogress of the Albatross Expedition to the Basten Pacific ; : by A; AGASSIZ 2... 2. Se 274 X XV Renleemens of Quartz by Pyrite and Corrosion of Quartz Pebbles ; by C. H. Smyru, Jr. (With Plate II) 277 XXVI.—Occurrence and Distribution of Celestite-Bearing Rocks by WH. H. Kraus... 2.1033 204 286 XXVIL. cane on Interference with the Bi-Prism; by W. Mo@inmmane 2.030 lac B22 294 — XXVIII.—Doughty Springs, a Group of Radium- ears Springs, Delta County, Colorado; by W. P. HeappEn~ 297 XXIX.—Hrror of Collimation in thie! Human Eye; by C.S. HASTINGS: 220 UL ee ee oe 310 XX X.—New Form of Electrode for Lead Storage Came by He MM. DavovURIaAN 220022. 325 ee 315 XX XI.—Chrysoberyl from Canada; by N. N. Evans.----- 316 XX XII.—Souesite, a native iron-nickel alloy occurring in the auriferous gravels of the Fraser, province of British Columbia, Canada; by G. C. Horrmann.....---.----- 319 XX XIITI.—Absence of Helium from Carnotite; by EH. P. ADAMS: 202240022230 02 Se 321 SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Properties of Methane, Morssan: Silicide of Carbon in the Cafion Diablo Meteorite, Morssan: New Process for Detecting Ammonia in Water, TRILLOT and TuRCHET, 323.—Radio-tellurium, MARcK- WALD: Conversations on Chemistry, Part I, General Chemistry, W. OstTWALD, 324.—Text-book of Organic Chemistry, H. LErrmMann and C. H. LaWAuLu: Electric Inertia, S. H. BurBury: Double Refractions, F. BRAUN, 020.—Emission Spectra of the Metals in an Hlectric Oven, A. S. Kine, 326.—Dynamics of Particles and of Rigid, Elastic, and Fluid Bodies, A. G. WEBSTER: Experimentelle Untersuchung von Gasen, M. W. TRAVERS, 327.—Dynamical Theory of Gases, J. H. Jeans, 828.—Optical Pyrometry, C. W. WartpNneER and G. K. BurGEss, 329. Geology and Mineralogy—Cambrian Brachiopoda with Descriptions of New Genera and Species, C. D. Watcort, 829.—Occurrence of Mastodon humboldtii in Northern Mexico, C. SHELDON: Petrography and Geology of the Igneous Rocks of the Highwood Mts., Montana, L. V. PIRSson : Red Beryl from Utah, W. E. HiLiesranp, 330.—Nickel and Copper Deposits of the Sudbury Mining District, Ontario, Canada, A. E. BARLow, del. Miscellaneous Scientific Intelligence—Studies in General Physiology, J. LOEB: Birds of North and Middle America, R. RipGway: British Museum Catalogue, 352. CONTENTS. Vil Number 1138. : Page Art. XXXIV.—Physiographic Improbability of Land at pice Norine tole) by do W . SPENCER. 20 fo24 cae 333 XXXV.—Bibliography of Submarine Valleys off North eM ea UVnI NUE SPENCER © 0800 os lly lut ee 84 XXX VI.—Interesting Variety of Fetid Calcite and the Cause Oits, Odor. by 1: 7J HARRINGTON 2215022220225 0222 345 XXXVII—Alternations of Large and Small Coronas observed in Case of Identical Condensations produced in Dust-free Air saturated with Moisture ; by C. Barus 349 XXXVIII.—New Circular Projection of the Whole Earth’s pubiace.; Dy A. J. VAN DER. GRINTEN — 2.2.22. .-.~---- 357 XXXIX.—Progress of the Albatross Expedition to the Macicnusreaciiers by A AGASSIZ. 25-02. ole. SSS 367 XL.—Note on the Names Amphion, Harpina, and Platyme- mapuen Over. WAYMOND. 2 05220 25 oe 8 XLI.—Bragdon Formation ; by J. 8. Dimumr __-. _-------- 379 SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Preparation and Properties of Tantalum, W. von Botton: Gravimetric Determination of Nitric Acid, M. Buscn, 388.— - Unity of Thorium, R. J. Meyer and A. GUMPERZ, 389.—Nitroxyl Chloride, GuTsierR and Lonpmann; Heusler Magnetic Alloys, E. Gumiicu: High Frequency Alternator, W. DuppEtL, 390.—Deviation during Free Fall, De SpaRRE: Polarized Réntgen Radiation, C. G. Barkua, 391. Geology and Mineralogy—Plans for Obtaining Subterranean Temperatures, G. K. GitBert, 393.—Vermont Geological Survey: Big ‘‘ Cullinan” Dia- mond from the Transvaal, F. H..Hatcw and G. S. CorstorpHine, 395.— Moissanite, a Natural Silicon Carbide, G. F. Kunz, 396.—Occurrence of Palladium and Platinum in Brazil, E. Hussax, 397.—Platinum Resources in the United States, 398.—Beitrige zur Mineralogie von Japan, T. Wapa, 399. Miscellaneous Scientific Intelligence—National Academy of Sciences, 399.— Astronomical Observatory of Harvard College: Journal of Agricultural Science, 400. Vill CONTENTS. Number 114. Page Art. XLII.—Group of Visual Phenomena depending upon Optical Errors of the Human Eye ; by C. S. Hastrnes. 401 XLIII.—Natural Iron-Nickel Alloy, Awaruite ; by Gere JAMIESON 2.50080 Cae hho d TO ae 413 XLIV.—Hy opsodide of the Wasatch and Wind River Basins; by &. B. Loomis sf. o.0 2s oe 416 XLV. Bono of Late Mineral Research in Llano County, — Texas; by W..B. HxppEen J. _2 2) 2) oo 425 XLVL—New Allotr ope of Carbon and its Heat of Combus- tion ; by W.-G. Mixter if 0.3.02) 50 0 oer XLVIL—Reflection of Light by Colored Papers; by H. D. MEN OHEN 42 602 oO A ee a 445 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—New Experiments in Preparing Diamonds, MorIssan: Atomic Weights of Soditm and Chlorine, T. W. RicHarps and R. C.° WELLS, 451.—Origin of Radium, B. B. Botrwoop: Marceli Nencki, Opera Omnia—Gesammelte Arbeiten von M. Nencxk1, 452.—Manual of Chemical Analysis as Applied to the Assay of Fuels, Ores, Metals, Alloys, Salts, and other Mineral Products, E. PRost: Radiation Pressure, PoyNTING, 453. Spontaneous Ionization of ’Air in closed Vessels and its Causes, A. Woop : Radio-activity and Chemical Change, N. R. CAMPBELL : Helium Tubes as Indicators of Electric Waves, E. Dorn: Specific Heat of Water and the Mechanical Equivalent of Heat, C. DizTERIcI: Photograph of the Solar Corona without a Total Eclipse, "M. A. Hansky: Kristallinische Fliissig- keiten und Fliissige Kristalle, R. Scumnox, 454.—‘‘N” -Rays, R. BLonpLor: EKlektrische Bogenlicht, seine Entwickelung und seine physikalischen Grundlagen, voN CzuDNOCHOWSKY, 455.—The New Knowledge, R. K. Duncan: Percentage Tables for Elementary Analysis, L. F. Gurtrw ann, 456. Geology and Mineralogy—United States Geological Survey, 406.—Contribu- tions to Devonian Paleontology, H. 5S. Wintrams and EH. M. Kinpuez, 460. Structure of some Primitive Cephalopods, R. RurpEMANN, 463.—Notes on the Siluric or Ontaric section of Eastern New York, C. A. HARTNAGEL : Trilobites of the Chazy Limestone, P. E. Raymonp ; Contributions to the Fauna of the Chazy Limestone on Valcour Island, Lake Champlain, G. H. Hupson: Ueber Pteraspis dunensis, F. DREvERMANN: Notice of a new Crinoid and a new Mollusk from the Portage rocks of New York, R. P. WHITFIELD, 464.—Fossils of the Bahama Islands, with a list of the non- marjne mollusks, W. H. Datu: Relations of the Land and Fresh-water Mollusk-fauna of Alaska and Eastern Siberia, W. H. Dati: Geological Survey of Ohio: Bahama Islands: La Montagne Pelée et ses Eruptions, A. Lacrorx, 465.—-Recherches géologiques et pétrographiques sur l’Oural du Nord, L. Duparc et F. Pearce: Einleitung in die chemische Krystal- lographie, P. GrotH: Grundziige der Krystallographie, C. M. Vroua, 467. Miscellaneous Scientific Intelligence—Ascent of Water in Trees, A. J. Ewart, 468.—Problems of the Panama Canal, H. L. Axssot, 470. — Primer of Forestry, G. Pincnot: Field Operations of the Bureau of Soils, 1905, M. Watney ; Mechanism, S. Dunkeriny, 471.—British Museum of Natural History, Birds, W. R. Octrvis-Grant: Catalogue of the Lepidoptera Phalznz in the British Museum, G. F. Hampson: Geographen-Kalender, Haack: Publications of the Carnegie Institution, 472.—Cold Spring Har- bor Monographs, M. E. SmaLuwoop: Science Bulletins of the Brooklyn Insti- tute of Artsand Sciences: Project for the Panama Canal, L. W. Bates. Obituary—Henry R. Mepuicotr: PROFESSOR PreTRO TACCHINI: PROFESSOR Otro STRUVE, 473. InpEx TO Vou. XIX, 474. Dr. Cyrus Adler, — poe | Tem- | Time |N SE aaa ho tore dines pera- | diges- 19 M2020. | fo cole Riteo em3, em3, cm. tion. ture | tion. cm3, em. digestion. | em3. C°. min. | em:, 100'| 9:91 |... | 9-91 | 50 | 60 | 9:91) 7 15-80 lmmeeee LOO ROOK Baa: 9°91 ie aE 9°91 lovalett 4:77 100 9°91 Nu 9°91 pei os 9°91 15°15 4°81 100 9°91 BPs 9°91 ey oe 9°91 en bay(0)7/ ES) 100 9°91 wee 9°91 “e a 9°91 15° 4°79 100 9°91 Wiis 9°91 is Es 9°91 WEP Wy 4°73 100 | 9°91 Buk: 9°91 ie ele OSOy: 15:08 4°74 100 | 9°91 ied 9°91 ee re 9-91 15°02 4°68 100 9°91 Pot One oe cl 9°91 14°85 4°51 LOO) 29791 ee 9-91 Kes al hee 9-91 14:40 4-06. 100 | 9:91 eps 9°91 ag ee 9°91 15:05 Act 100 ie 9°91 9°91 we as 9°91 15°60 5°26 LOOM See a 9°91 9°91 ee rf 9°91 15°35 5°01 100 Bye 9.91 9°91 us of 9°91 15°32 4:98 ROO ce 9.91 9-91 of ee 9°91 15°88 5°64 100 saith 9°91 9:91 oe 2 9°91 15°42 5:08 100 hee 9°91 9°91 cig 63a O&O 15°45 511 100 Ry 9°91 9°91 as gl 9°91 15°95 5°61 100 En 9°91 9°91 ce ue 9:91 15°41 5:07 100 es 9°91 9°91 fe Oe 9°91 15°95 5°61 100 pay 9°91 9°91 oh Be 9°91 16°65 6°31 100 eee: 9°91 9°91 WG of 9°91 15°75 Ol 100 Re 9°91 9°91 ee ae 9°91 15°79 5°45 . The experiments of Table I were conducted, as outlined by Wagner, in the following manner : To a 250° flask were added 100°™ of normal hydrochloric acid (that is a solution contain- Permanganate in the Presence of Ferric Chloride. 38 ing 36°4575 grams of the acid to the liter), and in addition either 9-91 of tenth normal hydrochloric acid (prepared by diluting 100° of the normal solution to one liter) or 9°91°™ of tenth normal ferric chloride. Of approximately twentieth normal potassium permanganate, carefully standardized against ammo- nium oxalate, 9° 91°" were then added, and the flask, fitted in a ground joint to a return-condenser 60% in length and with a bore approximately 3° in diameter, was heated for one hour in the Ostwald thermostat at a temperature of 50° C. Of tenth normal oxalic acid, 9:-91°"" were then added to the digestion liquid and a measured volume of the same perman- ganate solution as was added before digestion was run in to color. The difference between the total permanganate used (that is the permanganate added before digestion plus that added to bring about final coloration against the oxalic acid) and the permanganate equivalent of the oxalic acid added gives, accord- ing to Wagner, the permanganate reduced during the diges- tion. The results of these experiments are recorded in the above table. Here it may be seen that although in general more perman- ganate is required to bring about final coloration in those experi- ments in which ferric chloride was used than in its absence, the results show at best wide variation among themselves, and the amounts of permanganate apparently destrc oyed during the diges- tion are atall events consider ably greater than in the experiments conducted by Wagner under similar conditions. In the experi- ments recorded in Table I, in the average 4°73°™ of per- manganate were apparently destroyed where ferric chloride was not used, and 5°37" in the presence of ferric chloride; while in Wagner’s experiments 0°96 of permanganate was appar- ently reduced without use of ferric chloride and 1:41°™* in its presence. Since, as has been noted above, the permanganate color entirely ‘disappear ed in the experiments of Table I, long before the termination of the hour’s digestion, while only small amounts of hydrated oxides of manganese varying in color from brown to black were visible in the ¢ digestion liquid, it seemed probable that more permanganate was really reduced during the digestion than is indicated in these experiments. Moreover a strong odor of chlorine was noticeable in these experiments and it seemed probable that some of the chlorine, formed by the interaction of the potassium permanganate and hydrochloric acid during the digestion, remained to take part in the oxidation of the oxalic acid introduced, and that, therefore, on running in permanganate solution to color, less of the latter was required than corresponded to the oxalie acid left unoxidized by the residual oxides of manganese. It was, therefore, decided to AM. Jour. Sc1.—Fourtu Series, Vou. XIX, No, 109.—January, 1905. 3 SES OO———— i i i i a 34 Brown— Hydrochloric Acid and Potassium remove if possible this chlorine, and to this end a vigorous eur- rent of carbon dioxide or air was passed through the digestion liquid while heating. In this way the chlorine was readily removed and starch and potassium iodide paper held in the current of carbon dioxide or air gave no test for chlor- ine. The experiments of the following table (II), in which no fer- ric chloride was used, were conducted precisely as were those of Table Labove, except that a vigorous current of carbon dioxide generated in a Kipp generator by action of hydrochloric acid on marble, and washed and dried by passing first through a bottle filled with water and then through a calcium chloride tube, was passed through the liquid during the process of digestion. Because also of the greater ease of measuring out accurately 9°90 rather than the 9-°91°™ used by Wagner and in the experi- ments of Table [ above, the former volume of reagents was sub- stituted for the latter in the experiments to follow. It will readily be seen that in the case of tenth normal hydrochloric acid 0-01" is negligible as compared with the large amount of hydrochloric acid used in the experiments. The results of these experiments are recorded in Table II. TABLE IT. | | KMnO | KMn0O, Time | Brareyre | N Tem- f Mn pp * HCl | Ws iges! ia diges- H2C204 to Cale sone em:, |. em’. tion. qo tion. oe em3 during | cm’. * | min. digestion. | cms. N [9:90°™3 approximately 10 H.C.0, =23°02 -™? KMnO,] I | 100 | 9-90 | 9-90 | 50 | 60 | 9:90 | 2ei9 | {Bby i OO OSD | OOd | oes. & 9:90 | 22-10 8-48 1 | 100 | 9-90 | 990 | « | « 9:90 | 2215 | 8:53 ne OO) | God | OS 68 26 9°90 || 22-48 | 8-49 [9:90°™? approximately es H.C.04 = 23°65¢"? KMn0O,] VY { 100 | 9:90. 99-90 | 50%) 607 | Vo-90 alee 2 ats 8-40 VI 100 | 9°90 9:90 ee i 9:90 | 21:79 8:04 VIL | 1009) 9:90 4) 9-900 |) ce o-oo te ieee 8-49 VITL | 100; 5) 9:90 7) 9-90 | ee 4 ao 0a eee ona 8-46 ox 100. | 9:90) 9) 9:90 aN 0 0 melee eee 8-49 x 1009] 9:90) 1) 9:90 || i 7) {eR Moron a ee aees 8-48 xl: 100 | 9°90 | 9-90..)) |) al eeoFo0 ears 8-50 KIL | 100 | 9:90:..\ 9-90 5) OOO ea aes 8-40 XUI-j 100 | 9:90 | t9-g0 [9 | I Qyo0 Ol 9: iia metres XIV | 100 | 9°90 7 19-80 |“ | “<9 to-90 "| d9°s3 05 ieiaags XV | 100 | 9:90 | 50-0 ec | 195-00. | 44°53 aieearen XVI | 100 | 9:90 | 50-0 MT #651 95-00 | 44:4 eae XVII | 100 | 9:90 | 50:0 co) 95°00 || 44-44 re XVIII | 100 | 9:90 | 50-0 co] ee "95-00 | 44:58) Weadage Permanganate in the Presence of Ferric Chloride. 35 From these results the conclusion may be drawn that the low indications of the amount of permanganate apparently reduced during digestion in the experiments recorded in Table I, at least so far as concerns those experiments in which no ferric chloride was used, were in all probability due to the oxidizing action of the unexpelled chlorine on the oxalic acid, and that the large variations in results were due to the greater or less retention of the chlormme. In experiments XIII to X VIII itis seen further that amounts of permanganate very much greater than those used in Wagner’s experiments and in the experi- ments of Table I above can be reduced by the same amount of hydrochloric acid, and under ihe same conditions of tempera- ture and time as in those other experiments; for, in these. last experiments, also, the permanganate color entirely disappeared during the, digestion. In order to ascertain if a current of air is equally as effective in removing the chlorine as is carbon dioxide, and also because of the greater availability of the former, the experiments recorded in Table III were conducted in a manner identical with those of Table II, except that a current of air dried and puri- fied was substituted for the carbon dioxide. When also the success of the air current was apparent, ferrie chloride was again used and the effect noted. Results are outlined in the following table. TABLE IIT. N [9:90°™3 approximately 10 H.C.20, = 20:09°™3 KMnO,, | | | | KMnO | | | Residual | appar- ee ree |e geo JRMRO* ncantea a fe ow efore |pera- | 0 olor est | mt 10 eee ‘10 ACS) aioe: are: diges-| after after | cm3. | color. | during em3, em’. | cm’, | tion. C°. | tion.| dlges- diges- cm, diges- em3, min.| tion. tion. tion | | cm. 100 = 990 om 9-90 | 50 | 60 | none | none 9:90 | 18°88 8°69 100 | 9-90 one 9-90 i ye eS | ee | 9:90 | 18°87 8°68 100 | 9°90 zx? 9°90 sy RS EY ie oe | 9:90 | 18°80 8°61 100 | 9-30). | 9-90 os et as Se | 9:90 | 18°81 8°62 TJ aS 9-90 a ae Ne a | : | 9:90 | 18°80 8°61 400" 9-90 Ee 9°90 oa SP a ese kc s | 9:90 | 18°82 8°63 100 SOR = 217) 990 Ge Aeros, Tnmces 4 os ee OO aadocd i 8:58 100 | 9-90 | eee 9-90 hs es | i doubtful 9:90 | 18°70 8°51 fo | 9-90.) 90h tape eee te o90,. 18-70.) 8:51 100 9°90 ak 9°90 ‘ oe alPacee oe | 9°90 18°68 8°49 | 100 Lis 9-90 9-90 eae ate : none | 9:90 | 18°87 8°68 100 Bee 9°90 9-90 oe oe ue as | 9°90 | 18°85 8°66 100 Lpee 9°90 9-90 ; Y ; Ls | 9°90 | 18°81 8°62 100 er: 9-90 9°90 ee ; ‘ a | 9°90 | 18°81 8°62 100 ee 9-90 9:90 a Sets te Kae RG | 9:90 | 18°87 8°68 100 nai 9°90 | 9-90 a | peceazaal borne tts o | 9°90 | 18°85 8°66 100 ae 9°90 9°90 ul SOaite ie re | 9°90 | 18°80 8°61 i) aoe 9°90 9°90 ef se | oe doubtful 9‘90 | 18°72 8°53 meee te FA). 9°90) |) 4 |. aa |“ Pe i 9°90: |18 6a. | eae Mee a FO 9:90.10 fo el cers} 9:90! | 18:67 1 8:48 36 Brown—fydrochlorie Acid and Potassium Here again may be noted the concordance of results when the chlorine is al! removed before the addition of oxalic acid, as well as the fact that under these conditions substantially the same amount of permanganate is required to bring about the end reaction, whether ferric chloride is present or not; and _ that consequently as much permanganate is reduced during the digestion in the latter case as in the former. Also by a com- parison of experiments VIII-X and XVIII-XX, in which a slight trace of chlorme remained, with experiments I-VI and XI-XVI, in which the chlorine was entirely removed, we again see the oxidizing effect of the residual chlorine on the oxalic acid ; for even in the former sets of experiments, in which the digestion was carried on only fifteen or thirty minutes, the permanganate color had entirely disappeared at the end of the digestion. The variations in the amount of permanganate apparently reduced during the digestion in the experiments . recorded in Table I are, therefore, doubtless due to the interfer- ing action of the residual chlorine held in solution. The ‘““K MnO, apparently reduced during digestion” in the experi- ments of Table IJ, and in those of Table III in which the chlorine was entirely removed during the digestion, represents the amounts of permanganate entirely reduced to manganous chloride, while the differences between these amounts and the ‘“ K MnO, betore digestion” represent the residual oxides of manganese. Similar differences in the experiments of Table I, and in those of Table III in which the chlorine was only par- tially removed, represent the residual oxides of manganese and the chlorine retained in solution. The amount of chlorine held in solution when no means are employed to remove it, depends largely on the form and size of the flask used to contain the solutions during digestion, also on the dimensions of the return-condenser, and will vary according to the greater or less amount of shaking to which the flask is subjected during the entire course of the experi- ment. It is, therefore, evident that Wagner’s experiments are in no way indicative of the relative amounts of potassium per- manganate reduced in the presence or absence of ferric chloride other conditions being constant, but are an indication simply of the greater or less retention of chiorine in solution in the form of apparatus used by him; for it has been shown that im all experiments conducted within the limits proposed by Wagner the permanganate is entirely destroyed and that any variations in the amount of permanganate apparently destroyed during digestion disappear when the chlorine is entirely removed from the sphere of action. The possibility of any interfering action of ferric chloride in titrations of oxalic acid by potassium per- manganate is excluded by the results of the experiments of Permanganate im the Presence of Ferric Chloride. 37 Table III, in which we find no variations in results whether ferric chloride is present or not. The cause of the apparently greater destruction of potassium permanganate in those experl- ments of Table I in which ferric chloride was used than in those in which ferric chloride was not used, is now under investiga- tion. TABLE IV. Vol- Time |Residual Deane KMn0O, ume |Tem-| of | KMnO, Cl KMn0z | ently re- N yc Naa before H,O |during|pera- |diges-| color test | H2C,0, to duced 10 diges- |em3,| diges-|ture.| tion | after | after cm3. color. | quring em3. | em3, | tion. tion. | C°. |min. | diges- | diges- cm$. |qjcestion. em’. | cm$. tion. tion. “cm3. N [40cm 10 (HiN)2C20, = 37°64cm3 KMnO, 100e™3 H.C.O, = 101°40¢™? KMn0O, | 100 | 9°90 | HOO Re elle moO) | 60 | none | faint 100 59°52 | 58°12 100 | 9°90 | 100 oe | 210 20) Si eS 100 | 58°44 | 57:04 N [409 = (H.N),C.0, = 18°35°™? KMn0, N ages 5 H2C204 = 49-26"? KMn@,. | 100 | 9°90 QE 160° 50) 60 |ynone |) mone aD Bee | 31-46 100 | 9°90 50 ele OU) oe ss pis Balas Soa 50 | 30°75 | 31°49 100 | 9°90 50 ERE AGO e Sateen cars ea Ea ut 50 | 30°76 | 31°50 100 | 9:90 D0 ok Se AG) e Pea oatts bees ass 00 | 30°78 | 31°52 100 | 9°90 50 Ee se LOO PS a RR I na AR ea 50 = 30°88 | 31-62 100 | 9:90 50 00 | 210 eyo ale keri, paint Te I iS as earitsis) 100 | 9-90 50 50 | 210 a ce xe oe 50 =| 27°92 | 28°66 100 | 9°90 50 50 | 210 Pare eee. tad me 50 =| 28°52 | 29°26 100 | 9:90 | 50 00 | 210 THe ele ig e 50 | 28°54 | 29-28 100 | 9°90 50 50 | 210 ee Sey ear Ne US 50 =| 29°14 | 29°88 100 | 9°90 50 00. 210 ae eee es me 50. =| 28:98 | 29°72 100) 9°90: | 50 00 | 210 Ke mers es x 50 | 28°56 | 29°30 100 | 9°90 50 00 | 210 es ee af ¥ 50 | 29°96 | 30°70 100 | 9:90) 50 | 50/| 210 | “ | 85 | none | p% | 50 | 29°96 | 30-70 100 | 9°90 |. 50 50 210 «| 60 faint faint 50. =| 80°22 | 30:96 100 | 9-90 v6) Se eto oO eet none marked| 50 20°72 | 46°46 100 | 9°90 50 | 50 | 210 ‘* | 120 | none | none 50 | 30°31 | 31:05 100 | 9-90 100 Tee ld ‘¢ | 60 |marked marked; 60 | 19°58 | 60°47 HOO 9°90. | 75 50. 285 ‘¢ | 220 | none | faint d0 | 21°84 | 47°58 100 | 9:90} 100 | 50 | 260 | ‘* | 180 Imarked'marked| 60 | 10:18 | 51:07 = Hel 50 | mn SOS (110g (Pedfnone taint |, 50 | 80°23. 30°97; 50 | 9°90 iy ==) too a | 60 Segegiiaricedipe fet) [ui ae Ss eS a a Se Nao ie Sy i oe 00. =| ~380°69 06°43 Since in all experiments thus far conducted the permanganate color has been entirely destroyed, the experiments of Table IV 38 Brown—lydrochloric Acid, ete. were made to ascertain if possible how much permanganate can be destroyed by the amount of hydrochloric acid used in the experiments of ‘Table I, II, and II], under the same conditions of time and temperature, and also during greater periods of time. It will readily be seen from the evident oxidation of oxalic acid by chlorine in previous experiments that an exact measure of the maximum amount of permanganate reduc- tion during a given period of time can be. obtained only when all the chlorine is removed and at the same time the per- manganate color just disappears—a condition difficult to attain. The results recorded in Table IV should therefore be regarded as approximate only. Thus it may be seen that the same amount of hydrochloric acid as was used in the experiments of Table I, II, and III is capable of breaking down approximately thirty. times as much permanganate as was used in those experiments and in the experi- ments of Wagner, conditions of time and temperature being the same. Changes of volume are of course involved in the use of varying amounts of permanganate but an increase in volume would in all probability be attended by a decrease in the relative amount of permanganate reduced by a constant quantity of hydrochloric acid. In any case the results show a more exten- sive reduction than is indicated in Wagner’s experiments and in those of Tables I, II, and III above. The conclusion must be drawn, then, that Wagner’s experi- ments in no way show the catalytic effect of ferric chloride in the interaction between hydrochloric acid and potassium per- manganate, nor do they furnish evidence in support of the assumed formation of chlor-ferrous acid. They afford simply an indication of the greater or less retention of chlorine in solution, ana the greater or less oxidizing action of this chlorme on the oxalic acid in the presence or absence of ferric chloride. The author is indebted to Prof. F. A. Gooch for much advice and assistance in the preparation of this paper. S. L. Penfield—Crystal Drawing. 39 Arr. V.—On Crystal Drawing; by S. L. PEnrrexp. Introduction.—The methods commonly employed for repre- senting crystals consist in drawing their edges as they appear when projected upon a plane. A peculiarity of the methods used is that the eye, or point of vision, is regarded as being at an infinite distance from the object, so that all edges which are parallel on a crystal appear as parallel lines in the drawing. Thus true perspective, whereby parallel edges would appear in a drawing as lines approaching one another in the distance, is lost sight of. Furthermore, two kinds of projection are employed : orthographic, where the lines of projection fall at right angles, and clinographic, where they fall at an oblique angle on the plane upon which the drawing is made. Most of the figures found in works on mineralogy and crystallography are drawn in clinographic projection. The data generally employed in constructing a erystal figure are the inclinations and lengths of the axes and the symbols of the forms, while interfacial angles are not made use of directly, other than as they may have been employed for determiniug the axial relations and the symbols of the several faces. To be really successful in drawing, it is essential that one should have a thorough understanding of the form or combi- nation to be represented, and that every step in the process of constructing a figure should be fully comprehended. The reason for offering the present communication is the hope entertained by the writer, that by developing the subject of erystal drawing in a manner somewhat different from that generally adopted, the processes involved may be compre- hended more readily and the work accomplished with greater facility and accuracy. Projection of the Axes of the Isometric System.—It is believed that figures 1 to 4 will make clear the principles upon which the projection of the isometric axes are based. Figure 1 is an orthographic projection (a plan, as seen from above) of a cube in two positions, one, @ 6 ¢ d, in what may be ealled normal position, the other, A 6 CD, after a revolution of 18° 26’ about its vertical axis. The broken-dashed lines throughout represent the axes. Figure 2 is likewise an ortho- graphic projection of a cube in the position A LCD of figure 1, when viewed from in front, the eye or point of vision being on a level with the crystal. In the position ‘chosen, the appar- ent width of the side face B C B’ C” is one-third that of the front face A B A’ 6G’, this being dependent upon the angle of revolution 18° 26’, the tangent of which is equal to 4. To 40 S. L. Penfield—Crystal Drawing. construct the angle 18° 26’, draw a perpendicular at any point on the horizontal line, as at o figure 1, make op equal one- third Qo, and join O and p. The next step in the construe- tion is a change from orthographic to clinographie projection. In order to give figures the appearance of solidity it is sup- posed that the eye or point of vision is raised, so that one looks down at an angle upon a crystal which is figured; thus, in the case under consideration, figure 3, the top face of the cube comes into view. The position of the crystal, however, is not changed, | and the plane upon which the projection is made remains ver- tical. From figure 1 it may be seen that the positive ends of the axes a, and a, are forward of the line X Y, the distances a, # and a,y being as 3:1. In figure 2 it must be imagined, and by the aid of a model it may easily be seen, that the extremities of these same axes are to the front of an imaginary vertical plane (the projection of XY Y above) pass- ing through the center of the erys- tal, the distance being the same as a, @ and a,y of the plan. In fivure 4 the distance aw is drawn of the same length as a, of the plan, and the amount to which it 1s supposed that the eye is raised, indicated by the arrow, is such that a, instead of being projected horizontally to a, is projected at an inclination of KF ce Pees one et ihe 9° 28’ from the horizontal to w, reaptite ne Ae aitts ie the distance xw being one-sixth jection. . of ax; hence the angle 9° 28 is such that its tangent is 4. Looking down upon a solid @t an angle, and still making the projection on a vertical plane, may be designated as clinographic projection ; accordingly, to plot the axes of a cube in elino- graphic projection in conformity with figures 1, 2 and 4, draw the horizontal construction line Ax, figure 8, and cross it by four perpendiculars in vertical alignment with the points d,,—a, and @,,—a, of figures 1 and 2. Then determine the (i) 4 S. L. Penfield—Crystal Drawing. 41 extremities of the first, @,, —@, axis by laying off distances equal to ew of figure 4, or one-sixth a, « of figure 1, locating them below and above the horizontal line Ak. The line a,, —a, is thus the projection of the first, or front-to-back axis. In like manner determine the extremities of the second axis, a,, —d., by laying off distances equal to one-third xw of figure 4, or oue-sixth a, y of figure 1, plotted below and above the line Ad. The line @,, —a@, is thus the projection of the second, or right- to-left axis. It is important to keep in mind that in clino- graphic projection there is no foreshortening of vertical dis- tances. This is evident from figure 5, where c, —c is supposed to represent a vertical axis and 1 Y the trace of a vertical plane on which the projection is made. The parallel lines of sight, indicated by the arrows, project the axis c, —¢ to c’, —c¢’ without change of length. In figure 3 the axis @,, —@, is somewhat, and a,, —@, much foreshortened, yet both represent axes of the same length as the vertical, @,, —@,, and of the plan above, when plotted in clinographic projection. The completion of the cube about the clmographic axes, as indicated by the construction lines, figure 3, is too simple to need special comment. It is wholly a matter of choice that the angle of revolution shown in figure 1 is 18° 26’, and that the eye is raised so as to look down upon a crystal at an angle of 9° 28’ from the hori- zontal, as indicated by figure 4. Also it is evident that these angles may be varied to suit any special requirement. As a matter ct fact, however, the angles 18° 26’ and 9° 28’ have been well chosen and are established by long usage, and prac- tically all of the figures in clinographic projection, found in modern treatises on crystallography and mineralogy, have been drawn in accordance with them. The development of the axes as indicated by figures 1 to 4 yields the same result as that obtained from following the scheme found in almost all text- books of crystallography, accredited to Naumann.* It will be observed that figures 1 and 8 are in vertical align- ment, and one of the chief features of this communication will be to emphasize the value and importance of two projections, orthographic and clinographic. The object of the upper figure or plan is twofold: (1) it may be employed as a help in the construction of the more complex clinographic projection below, and (2) it serves to make clear certain relations which * Lehrbuch der Krystallographie, 1830, Band II, p. 400. 42 S. L. Penfield—Crystal Drawing. at times are only with difficulty, if at all, comprehended from a clinographic projection alone. Figures 2 and 4 have been introduced merely as helps in the development of the clino- graphic projection. It is also worthy of note that in the major- ity of cases a plan and its accompanying clinographic projection may be drawn more readily than a single figure in che projection alone. No originality is claimed for the idea of making use of a plan in connection with a clhnographic projection. The prin- ciples are those commonly made use of in mechanical drawing, though generally in dealing with that subject orthographie projection alone is employed. In Kokscharow’s Atlas accom- panying his “ Mineralogie Russlands” it will be found that a plan accompanies almost every figure drawn in clinographic projection, while Miller in his “Treatise on Mineralogy ” employs orthographic projection almost exclusively. Lastly, students of crystallography may use an orthographic and its accompanying clinographic projec- tion much as a carpenter or builder uses a plan and its accompanying ele- vation. The one supplements the other. Projection of the Anes of the Hea- agonal System.—For projecting the hexagonal axes exactly the same prin- ciples may be made use of as were employed in the construction of the isometric axes. Figure 6 is an ortho- graphie projection, a plan, of a hex- agonal prism in two positions, one of them, @,, @,, ete., after a revolution of 18° 26’ from what may be called normal position. In figure 7 the ex- tremities of the horizontal axes of figure 6 have been projected down 5 upon the horizontal construction line hk, and a,, a, and —@, which are Fics. 6,7 and 8.—Develop- forward of the line XY in figure 6 ment of the axes of the hex: are located below the line #2amanme agonal system in orthographic and clinographic projection. Clinographic projection, the distances from Ak being onesixth of aw, ay and —a,z of figure 6. Figure 8 is a scheme for vetting the distances which the extremities of ie axes are dropped. The vertical axis in figure 7 has been given the same length as the axes of the plan. i I ! ! ' 4 ' ' ' 1 ’ 1 ' 1 1 t ' 1 1 ‘ ' / ' 1 ! - 1 ea a a Be me 28 oo — S. L. Penfield—Crystal Drawing. 43 Engraved Awves.—For the purpose of facilitating crystal drawing the writer has had the isometric and hexagonal axes engraved, and impressions of them made on good quality of drawing paper have been found very useful. To insure accu- racy they were plotted on a large scale (the vertical axis 28™ in length) and they are shown very much reduced in figures 9 and 10. Each axis from the center is divided into thirds, and generally the lengths marked 1, when taken as unity, will give a figure of convenient size for drawing. In figure 9 an ortho- graphic and a clinographic projection of a dodecahedron are shown, and in figure 10 corresponding projections of a combi- nation of prism m and pyramid p of apatite, c= 0°735. As is ' evident from the figures, the upper axes are for orthographic, 9 10 Fies. 9 and 10.—Scheme of the engraved axes of the isometric and hex- agonal systems, one-sixth natural size. the lower for clinographic projections. The sections of the axes marked 2 and 3 are lengths most frequently needed in the construction of complex figures. Printed on each sheet is a scale which will be referred to as the scale of decimal parts. Its length is equal to that of wnity on both the vertical axis and the axes for orthographic projection. As printed on the original sheets the scale is divided into one hundred parts. Axes of the Tetragonal and Orthorhombic Systems.—For drawing tetragonal and orthorhombic erystals the engraved isometric axes may be used, after changing certain lengths. The vertical axis for both systems is changed by taking the desired length from the scale of decimal parts, referred to in the previous paragraph. For an orthorhombic crystal the length of the brachy, or d, axis is first laid off on the front-to- 44 S. L. Penfield—Crystal Drawing. back axis of the orthographic projection above by means of the scale of decimal parts, and is then projected down upon the front-to-back axis below by means of a vertical line. ‘Thus with facility and accuracy the engraved isometric axes may be modified to suit the requirements of any tetragonal or ortho- rhombie erystal. 3 Fre. 11.—Protractor for plotting crystallographic axes; one-third natural size. Projection of the Axes of the Monoclinic and Trictinic Systems.—These axes are obtained from those of the isometric system by giving the lines suitable inclinations, and varying their lengths. Instead, however, of using the methods gener- ally employed for inclining the axes, it occurred to the writer S. L. Penfield—Crystal Drawing. 45 that both time and accuracy might be gained by constructing a suitable protractor, which is shown one-third its natural size in figure 11. At the top is a graduated circle, X, two of the diameters of which inclined at 18° 26’ to the vertical and hori- zontal, represent unit lengths of the a and 6 axes in orthographic projection. The uses of the circle and its graduation will be explained later. The three large ellipses are the clinographic projections of three circles uniting the ends of the isometric A, —A; B, —B and C, —C axes; they represent, therefore, the paths which the extremities of the axes would follow if the latter were revolved in the three axial planes. The ellipses may also be regarded as the clinographic projection of three great circles of a sphere; an equator, crossed by two meridians at 90° to one another. The ellipses and their graduation were plotted with much care, and the engraving was skillfully exe- cuted by Messrs. Bormay & Co. of New York. Each axis is divided into thirds, and a scale giving decimal parts of the vertical axis accompanies the protractor. The quadrant of a small ellipse # has a radius equal to one-third that of the large ellipse. It is intended for getting one-third the length of an inclined @ axis, but it has not proved to be of much value. Printed on cardboard, the protractor may be used for a long time, it being intended that the axes shall be transferred to a sheet of drawing paper by superimposing the protractor and puncturing the unit lengths of the axes with a needle point. The axial protractor has been in use in the writer’s laboratory for four years, and has been found very convenient, not only for plotting axes of the monoclinic and triclinic systems, but, also, for constructing the axes of twin crystals. It may be said of the protractor and also of the engraved axes that they have proved to be not only time-savers, but they have also helped to make the work of crystal drawing more accurate and better understood. Students frequently encounter difficulties in crys- tal drawing because the axes with which they are working have not been plotted with accuracy, but by the use of the engraved axes this difficulty, at least, is eliminated. A few examples will serve to illustrate the methods of using the axial protractor in plotting inclined axes. In both the monoclinic and triclinic systems the same method is used for plotting the @ axis at the inclination 8, hence one example in the triclinic system will serve for the two classes of crystals. The example chosen is rhodonite, and the data needed are as follows: a3 OU e014 se3 Ook a=103° 18’; B=108° 44’. arb, 100A 010=94° 26’. 46 S. L. Penfield—Crystal Drawing. The projection of the @ axis, which is the same for both the monoclinie and triclinic systems, will first be explained: When @ is not at right an gles to ¢, it must appear somewhat foreshortened in orthographic pro- jection, as shown in figure 12, which represents the relations of the @ and c¢ axes of rhodonite: AY being the trace of the hori- zontal plane on which the ortho- graphic projection is made, the a axis, length 1:073, will appear fore- shortened to the length Oda’. Applying the foregoing principle to the upper circle of the pro- tractor, figure 13, draw a radius at the inclination 8, 108° 44’, making use of the graduation of the circle, lay off on this a i a= =—E—\ ess | oe a we, ars =o 6 radius the length of the @ axis (1:073 in figure 13) using the scale of decimal parts, and then project at right angles to the direction a, —a, as indicated by the arrow, thus determining S. L. Penfield—Crystal Drawing. 47 the length of the foreshortened @ axis. For the clinographic projection locate 8, 108° 44’, on the graduation of the ellipse passing through A and (, draw a diameter through the center and fix the length of @ by projecting down vertically from a of the orthographic axis above. If one does not wish to make use of the orthographic axes, draw the diameter of the ellipse at the inclination #, and find the length 38a by laying off a distance equal to 3a on the vertical axis (3-219 in figure 13), using the scale of decimal parts, aud then transpose the length thus found to the inclined @ axis by drawing a line parallel to B, —C, as shown in the figure: One-third of the length thus determined is the desired length of the @ axis. Two processes are involved in plotting the d axis of a tri- clinic crystal. (1) The vertical plane in which the d and ¢ axes are located is revolved about the ¢ axis so as to conform to the measurement @ab, 100,010. Care must be taken to note the direction in which the plane of the 6 and ¢ axes is turned: (1) As shown in figure 14, since 10UA010 (angle between normals) is 94° 26’ in rhodonite, the right-hand end of the 6 axis is first swung forward 4° 26’ in the plane of the equator. Carrying out the fore- going process in figure 13, a point p is located on the equator, 94° 26’, measured from — A, and likewise 6 of the orthographic projection above is brought forward to a position 94° 26’ from —a@. (2) The horizontal 6 axis, in its new position, must next be inclined to the vertical axis at the angle a, which in rhodo- nite is 103° 18’. For the orthographic projection above, this inclination of the 6 axis causes some foreshortening, which is determined by laying off two points o and o’, figure 13, 13° 18’ (103° 18’ —90°) on either side of where the 6 axis intersects the divided circle, and projecting through the points thus formed at right angles to the direction 0, —d, as indicated by the arrows. To give the } axis of the clinographic projec- tion its proper inclination, the value of a, 103° 18’, is laid off on two, or preferably three, of the vertical ellipses, as at a, y and z, figure 13, measured from C. Next draw three chords, Ap, —Ap and &p, on the plane of the equator, and parallel to them, respectively, the chords zx’, yy’ and zz’. The com- mon intersection of the three chords determine a point 3), on the surface of an imaginary sphere and on a meridian Je passing through p. The point 36 is 13° 18’ below the equator and 103° 18’, that is a, from C. 49 —3a;6b; and —c, and —3e are laid off both on the orthographic and clnographic projections of the axes, and the twinning plane —3a:56:—3c¢ drawn. The value of ¢, 54° 37’, is laid off at p on the equator, measuriug in the direction of the arrow from 6, and the radius from the center O to p makes an angle of 90° at / with the line —ga:6. The twinning axis, a line from the centre at right angles to the twinning plane, is now plotted on the clinographic axes by finding a point 7, on the meridian through p, 60° 31’ (the value of p) from the south pole of an imaginary sphere. This is done by locating x, y and z on the graduated ellipses at 60° 31’ from the south pole, and drawing the chords #2’, yy’ and zz’ parallel, respectively, to chords on the plane of the equator through p and the inter- sections of the a and 6 axes with the equator. The intersec- tion of the three chords determine the desired point 7’ at the Am. Jour. Sci.—FourtTH Seriks, Vou. XIX, No. 109.—Janvuary, 1905, 4 50 S. L. Penfield—Crystal Drawing. surface of an imaginary sphere on the meridian through p, and OT is the twinning axis. The point ¢, where the twinning axis pierces the twinning plane, is determined by the intersec-. tion of the twinning axis OZ’ with a line drawn from —3e to P. The points p, P and ¢of the orthographic projection are in vertical alignment with corresponding points on the lower axes, and need no further explanation. Having found ¢ on both the chnographie and orthographic axes, the ends of the axes, —3a, 6 and —3c, are shifted respectively to —3 A, Band —3C, equidistant from ¢, as would result from a revolution of 1% 18 i 180° about the twinning axis. Lines from the centers of the two projections through —3A, 6 and —3C are the axes in twin position. In figure 17 the axes are shown without con- struction lines, @ and 6 being one-third as long as in figure 16, and in figure 18 two projections of interpenetrating prisms, 772,. terminated by basal planes, c, are shown. A problem encountered by W. E. Ford and the writer in the study of twin crystals of calcite from Union Springs,. N. Y.,* may be cited as a second example for illustra- ting the uses of the axial protractor in plotting the axes of twin crystals. It was desired to represent a scalenohedron, twinned about the rhombohedron /f (0221), so drawn that the. * This Journal (4), x, p. 237, 1900. S. L. Penfield— Crystal Drawing. 51 twinning plane should be vertical and have the position corre- sponding to that of the side pinacoid 6 (010) of an orthorhom- bie erystal. The solution depends upon the angle of base on twinning plane, ¢ ~,f = 638° 7’, from which the inclination of the vertical axes, 53° 46’ from one another, or 26° 53’ from the twinning plane placed in vertical posi- tion, as shown in figure 19, is derived. As indicated by figure 20, the 7 ne of the vertical axes, ¢ and C26" D from the perpendicular, are ee by the graduation of the vertical ellipse through LB. Also the intersections of the planes of the horizontal axes with the same ellipse are located at X and X’, and Y and Y’, 26° 53’ from Band —B. In order to have the twinning plane cor- respond with the side pinacoid 010 of the orthorhombic system, it is necessary to make one of the horizontal axes —4a,, @, of the hexagonal system correspond with the front and back or @ axis of the orthorhombic system. The 1g 52 S. L. Penfield— Crystal Drawing. other hexagonal axes, therefore, must intersect vreat circles pass- ing through —a,and_X, and —a@,and 3’, at 60° from —a, and q,. To find the desired intersections on the great circle at right angles to one of the twinned axes, ¢; through the 60° gradua- tion points on the horizontal ellipse to the left, figure 20, draw the chords ve’ parallel to a chord through —4 and X; like- wise through the 60° points on the horizontal ellipse to the right draw the chords yy’ parallel to a chord through B and X. The intersections of the chords xa’ and yy’ determine the extremities of the horizontal axes a@,, —a,, and a,,—a,. To make the drawing somewhat more real, a hexagon at right angles to the twin axis cc has been constructed, by uniting the ends of the horizontal axes. Following a similar process 91 29 (drawing chords parallel to BY and — 6 ¥ through the 60° grad- uation points of the horizontal ellipse) the extremities of the horizontal axes at right angles to the twinned axis C’ would be found, but it has not seemed best to complicate the figure by carrying out this construc- tion. The length of the vertical axis of calcite is 0°854, and this is plotted on the vertical axis by laying off three times 0°854 (2562) on the perpendicular, using the scale of decimal parts, and proportioning the length on the twinned ¢ axis by con- structing the parallel lines pp and p’p’, as indicated in figure 20. Figure 21 represents the scalenohedron w {2131} of calcite drawn on the twinned axes, and figure 22 is a development like that observed on the crystals from Union Springs, N. Y., where the re-entrant angle is obliterated by the extension of four of the faces, resulting in a peculiar spear-head shaped development. Use of T-square and special Triangles.—A. T-square may be used to advantage in connection with the engraved axes, figures 9 and 10, the paper PP, figure 23, being adjusted on a drawing board 68 so that the blade of the T-square is parallel with the right-to-left or 6 axis of the clinographie pro- jection. If an ordinary rectangular drawing board is used, the paper may be fastened somewhat askew upon it, and it is not at all necessary to have a board with its right-hand edge cut at a special angle, as shown in figure 23. Special triangles have also proved to be very convenient. One of these is a truncated triangle /, figure 23, so made that when its lower edge is against the blade of the T-square its upper edge is parallel to S. L. Penfield—Crystal Drawing. 53 the right-to-left of 6 axis, and its left-hand edge parallel to the front-to-back or @ axis of the orthographic projection. A sec- ond triangle 77 is shown in two positions in figure 28; Ila, when its shorter edge is against the blade of the T-square its right-hand edge is parallel to the vertical axis, and, 116, when one of its longer edges is against the blade of the T-square its upper edge is parallel to the front-to-back or @ axis of the clinographic projection. A third triangle ///, figure 23, is for the hexagonal system, and is so made that when its longer edge is against the blade of the T-square its upper left- hand edge is parallel to the @,, —q@, axis, and its upper right- hand edge parallel to the a,, —a, axis of the clinographic pro- jection; compare figure 10. Thus with T-square and triangles, the axial directions, the essential ones in the construction of a erystal figure, may be had almost instantly, excepting, of course, some of the directions of the monoclinic and triclinic systems. Uses of the Linear or Quendstedt Projection.—In drawing crystals various methods may be employed for finding the 54 S. L. Penfield— Crystal Drawing. direction of an edge made by the meeting of any two faces, but the principle depends generally upon locating two points, common to both faces, where they intersect certain axial planes. A line through the points thus found gives the direction of the edge. In general it will be found best to adopt some system for determining the direction of crystal edges, and to adhere to it rather strictly, and the writer has found the method based upon the linear or Quenstedt projection most useful. The projection is too well known to erystallographers to need discussion ; as far as it relates to crystal drawing, how- on ever, it will be treated briefly in order to add to the completeness of the present article. ae. The principle upon which the projec- tion is based is very simple: Hvery face of a crystal (shifled if necessary, but without change of direction) 1s made to intersect the vertical axis at UNIT Y, and then its wntersection with the hori- zontal plane, or the plane of the a and b axis is indicated by a line. When it is desired to find the direction of an edge made by the meeting of any two faces, the lines representing the lmear projec- tion of the faces are first drawn, and the point where they intersect is noted. Thus a point common to both faces is determined, which is located in the plane of the a and 6 axes. 2a eciie M 77° 16’ and 7 85°; also the angles made by the great circles Bpr and Ls with the equator, 44° 40’ and 26° 20’, respec- tively. The cotangents of the meridians of the several poles are laid off on the orthographic A axis atm’, p’, a’, s’, Mand 7, and projected down on the clinographic A axis. The linear projections of the faces of the prismatic zone are vertical lines through m’, a’ and AZ’; those of p and 7 are lines throngh p’ and 7’, parallel to the direction from A to the point on the vertical axis marked cot. 44° 40’; and that of s the line through s’, parallel to the direction from A to the point on the vertical axis marked cot. 26° 20’. All of the intersections of the figure in clinographic projection are parallel to limes drawn from 6B to points of intersection on the linear projection, indicated by the lettering. Thus the orthographic and clinographic figures of axinite were made wholly without reference to the lengths and inclinations of the triclinic axes and the symbols of the faces. Figure 57 represents a cut stone (brilliant) as seen from above, and figure 58 as seen from below in orthographic pro- jection, while figure 59 is a clinographic projection of the same. ‘These drawings were made from two-circle goniometer measurements plotted in the stereographic projection. The object measured was a glass model of the Regent or Pitt diamond. S. L. Penfield—- Crystal Drawing. 75 57 59 It is scarcely necessary to state that drawings may be made from gnomonic¢ as well as from stereographic projections, with but slight modifications of the methods just described. It is the writer’s belief that the average student will find it easier to draw crystals from axes and the symbols of erystal faces, as set forth in the earlier part of this paper, than from the stereographic projection. Cases may arise, however, in which the:latter methods may be found useful, as, for example, in finding the intersections between faces of twin crystals, or in representing some odd shapes which can not be referred to the axes of the crystal systems. Mineralogical Laboratory of the Sheffield Scientific School of Yale University, | New Haven, Conn., November, 1904. Notre.—If any desire to make use of the Engraved Axes, page 43, the Protractor for plotting Crystallographic Axes, page 44, or the Special Triangles, page 53, the writer will be glad to answer any communications and see that the necessary articles are supplied from his laboratory. 76 T. Holm—Anemiopsis Californica. Art. VI.—Anemiopsis Californica (Nutt.) H. et A. An anatomical study; by Turo. Horm. (With six figures in the text drawn by the author.) Wirth Bentham and Hooker Anemropsis H. et A. and Gyrotheca Desne. are included in Houttuwynia Thunbg., but they all have been kept separate by Hichler* on account of their floral structures. /outtuynia is described as possessing only three stamens opposite the three carpels, while in Anemz- opsis and Gyrotheca the flower has six stamens and three ear- pels in the former, but four in the latter; the ovary is, more- over, perfectly inferior in Gyrotheca. The arrangement of the stamens in Anemiopsis is somewhat peculiar, as already described by Payer, there being two in front and two behind the ovary, with one on each side of this; this position of the stamens was, also, observed by the writer in the several inflo- rescences examined. Furthermore, DeCandollet has treated our genus as distinct from the others. Anemiopsis Californica does not seem to be very well known anatomically, and since the writer has lately received some fresh and carefully collected specimens from California through our friend Mr. Thos. H. Kearney, we have examined the plant and offer now the following notes as a small contri- bution to the knowledge of this peculiar genus. The thick rhizome is horizontal with several strong and quite fleshy roots; its ramification is monopodial, the apical bud being purely vegetative, while the stolons and flower-bear- ing stems are all lateral , proceeding from the axils of the leaves, which form an open rosette, While, as already pointed ont by Eichler (1. ¢.), the flowers are destitute of prophylla, such occur at the very base of both the stolons and flower-bearing stems, thus representing clado-prophylla.t These leaves are two in number and situated to the right and left of the stems; they are membranaceous, scale-like and prominently carinate, but simply one-nerved. The flower-bearing stems are often branched, there being one terminal and two or three lateral inflorescences pr eceded by one or two green leaves. The stolons show the same structure, but with vegetative shoots instead of inflorescences. Considered from an anatomical viewpoint the Piperacea§ have always attracted a good deal of attention, and they figure * Bliithendiagramme, vol. ii, 1878, p. 6. + Prodromus, vol. xvi, 1869, p. 237. {Compare Casimir DeCandolle: Mémoire sur la famille des Pipéracées. (Mém. Soc. phys. Geneve, vol. xviii, 1865, p. 254.) § The anatomy of the order has been described in Dr. H. Solereder’s work: Systematische Anatomie der Dicotyledonen. Stuttgart, 1899, p. 779. T. Holm—Anemiopsis Californica. 17 prominently in works upon géneral anatomy. Not less than four types of stem-structure are described by Dr. Solereder (Il. e.), and characteristic of the tribe Saururee, to which our eenus belongs, is one normal ring of collateral mestome-bun- dles. In regard to the leaf-structure the stomata are said to be confined to the lower surface; in Anemiopsis, however, we observed these to be present also on the upper, and even more numerous. Most peculiar is the development of a hypoderm, so very prominent in Peperomia, besides the hydathodes. Secreting cells abound in the leaves and stems of both Piperee and Saururee, while secreting ducts are only known from some species of Piper. Very little seems, however, to be known about Anemiopsis, thus we take the opportunity to describe herewith the structure of the various organs in detail. The leaf-blade. The cuticle of both surfaces is quite thick and prominently wrinkled, which is especially distinct when we examine the epidermis from above (fig. 1). Epidermis consists of relatively small cells with the outer wall moderately thickened except in the secreting cells (SC in fig. 2). For, as may be seen from this figure, secreting cells oceur, also, in the epidermis; they are thin-walled thr oughout, much larger than the or dinary epi- dermis-cells and sunk below the level of these, thus forming round depressions in the leaf-surface. Long hairs abound on the lower surface and consist of from eight to twelve cells in one row with the enticle thin and smooth. As stated above, we observed stomata on both surfaces, and they appeared even to be most numerous on the upper; they have no specialized subsidiary cells, but are surrounded by a somewhat indefinite number of ordinary epidermis cells, from four to six, as may be seen from our “fig. 3; viewed in transverse sections, the stomata are level with epidermis (fig. 4). A hypoderm of one layer of cells (/ in fig. 2) is developed on both faces of the blade, but of different structure; the cells are very large and cone- shaped on the upper face with the point towards the pali- sade-tissue; on the lower face the hypodermal cells are rela- tively smaller and of a roundish outline (fig. 2). The leaf is dorsiventral and possesses a distinct palisade- tissue of several layers on the upper tace, interrupted here and there by secreting cells; the palisades are rich in chlorophyll and surround the conical, hypodermal cells, but without reach- ing the epidermis. A pneumatic tissue of irregular, oblong cells, with wide intercellular spaces, occupies the dorsal part of the blade. The mestome- bundles, except the mediane, are small and completely imbedded in the mesophyll; they are surrounded by a colorless parenchyma-sheath. The midrib is 78 T. Holm—Anemiopsis Californica. quite broad and projects on the lower surface, where it borders on a large mass of thin-walled, colorless parenchyma. It is composed of seven separate mestome-bundles, each with a parenchyma-sheath and having a support of several layers of stereomatic tissue, especially on the leptome-side. Anemiopsis Californica. Fie. 1.—A cell of epidermis from the leaf, showing the wrinkled cuticle, seen from above. Fie. 2.—Transverse section of the leaf; C=cuticle; Hp = epidermis ; SC = secreting cell of epidermis ; H = hypoderm. Fic. 3.—Epidermis with stomata of the leaf, seen from above. Fic. 4.—Transverse section of leaf, showing a stoma. Fie. 0.—Epidermis with twin-stomata, seen from above. Fic. 6.—Transverse section of a part of the central-cylinder of the root; L=leptome, outside a secondary vessel V; C=cambial layers; H= the primordial rays of hadrome ; P= pith: Cp =secondary cortical parenchyma. The petiole. The cuticle shows the same structure as described above ; the epidermis possesses stomata, but no hairs, and is rather small-celled. A hypoderm is, also, developed here, but it is uniform and consists only of one layer of roundish cells. The T. Holm—Anemiopsis Californica. 79 cortical parenchyma, at least the peripheral strata, contains chlorophyll, and is very open from the great width of the inter- cellular spaces; secreting cells occur, also, here, but are not very frequent. Separating the cortex from a central group of parenchymatic tissue, a pith, is a circle of twelve collateral mestome-bundles, each with a thin-walled parenchyma-sheath, and surrounded besides by strata of stereomatic tissue. The stereome, however, is confined to the periphery of the mestome- bundles themselves, and does not connect these as a continuous ring of mechanical tissue as is the case with the stem. Char- acteristic of the mestome-bundles in the petiole is their ellipti- eal outline in cross-section with the leptome, forming a narrow, linear group in contrast to the broad group of hadrome with numerous, narrow vessels. The prophylla. As already mentioned, the stolons and flower-bearing stems are axillary; they bear at their base two scale-like, membra- naceous fore-leaves, the structure of which is as follows: The cuticle is very distinctly wrinkled on the outer, the dorsal face, but smooth on the inner, the ventral. Epidermis is thin-walled and consists of relatively small cells throughout with neither trichomes or stomata; the outermost portion of the margins is merely composeél of epidermis in two layers corresponding to the dorsal and the ventral. The mesophyll is very poorly represented except in the sharp keel; it is quite open and does not contain chlorophyll, neither is it differentiated as a palisade or pneumatic tissue, but constitutes a homogeneous tissue of roundish, thin-walled cells. There is only one mestome-bun- dle, which is located in the keel; it has a support of two or three layers of slightly thickened stereome and contains mostly leptome. The involucre. The involucral leaves at the base of the inflorescence are very conspicuous, being large and white ; they are prominently papillose on the ventral face, each epidermal cell being extended into an obtuse papilla, while the dorsal face is per- fectly smooth. Stomata and secreting cells occur in the dorsal epidermis. A hypoderm of large, roundish cells is developed underneath the epidermis on both faces of the mvolucre. The mesophyll is almost destitute of chlorophyll ; it is homogeneous and traversed by wide, intercellular spaces, besides by several very small mestome-bundles. The floral bracts. The cuticle and the epidermis exhibit exactly the same struc- ture as observed in the involucre, while the hypoderm is absent 80 T. Holm—Anemiopsis Californica. from the ventral face and but slightly differentiated on that of the dorsal. The homogeneous, somewhat open mesophyll con- tains a little chlorophyll, and about seven very small mestome- bundles are located in the middle of this tissue. The stem. The long stolons above ground and the flower-bearing stems show the same structure. They are nearly cylindric, slightly hairy, but perfectly smooth. We notice, also, here a wrinkled cuticle, covering an epidermis of relatively small cells of which the outer wall is distinctly thickened; none of the epidermal cells were transformed into secreting cells. Underneath the epidermis is a hypoderm of only one layer of very large, roundish celis, much larger than those of the adjoining cortex. This tissue, the cortex, consists of about fifteen strata, of which only the peripheral contain chlorophyll; the innermost layer is differentiated as a thin-walled endodermis, surrounding a continuous ring of about fifteen layers of very thick-walled stereome. Directly bordering on the stereome is a circle of twenty-four collateral mestome-bundles separated from each other by broad medullary rays; they are oval in cross-sections and contain both leptome and hadrome, the latter consisting of a few, but wide vessels. But there is no parenchyma-sheath and no mechanical support on the sides of ‘these mestome- bundles or around the hadrome. The central pith is very thin- walled and open. Secreting cells abound in the cortex and in the pith. Lhe rhizome. The horizontal rhizome is cylindric, glabrous and smooth ; towards the apex it is densely covered with sheathing, green leaves, and is not exposed to the light. Its free portion, behind the rosette of leaves, becomes soon deprived of both the epidermis and hypoderm, but protected by many layers of cork. The cortical parenchyma consists of about fifteen layers with wide intercellular spaces; the cells are filled with starch or contain a secretion of a reddish brown color. The very numerous mestome-bundles are narrow oblong in transverse sections, and are nearly all arranged in a cirele separated from each other by rays of the very broad, central pith, which con- tains starch. The leptome occupies only a small portion of the mestome-bundles, and between this and the very prominently developed hadrome are several strata of cambium. The root. All the roots were so far advanced that they showed only a secondary stage of growth. By the increase in thickness the T. Holm—Anemiopsis Californica. 81 tissues from epidermis to pericambium had been thrown off and replaced by some, five to six, layers of cork and a very . large parenchyma of secondary cortex, filled with starch or sometimes interspersed with secreting cells. Towards the central cylinder the cells of the cortex decrease in size and the innermost layer shows somewhat the structure of a secondary endodermis by its darker color and its power to resist the effect of concentrated sulphuric acid. The central cylinder, how- ever, shows a part of its original structure, viz: a circle of nine short hadromatic rays, each consisting of a few, narrow vessels (/7 in figure 6). These rays alternate with nine col- lateral mestome-bundles in which the vessels are quite wide ( V in fig. 6), and mostly more thin-walled than the primordial. Several layers of cambial tissue (Cin fig. 6) are developed out- side the old vessels and inside the groups of leptome, where the secondary hadrome has become developed. A broad and compact pith occupies the inner part of the central cylinder, thus the structure of the root corresponds very well with that of the stem, if it were not for the presence of the primordial rays of hadrome between the collateral mestome-bundles. Summary. Being an inhabitant of moist, saline localities our plant may, perhaps, be regarded as a Halophyte. The structural pecu- harities of this category of plants has been studied to some extent, but as yet too little has been ascertained to enable us to draw the line between Halophytes and Xerophytes or even the Hydrophytes. Moreover, there are certain orders of plants in which the structural peculiarities appear as characteristic of the order and to some extent inherited, rather than being an expres- sion of a certain mode of adaptation, such as the epharmonic characters. Now in regard to Anemiopsis Californica, it certainly appears as if the structure may be defined more properly as simply ‘“‘ piperaceous” than either halophilous or xerophilous. The most conspicuous characters—the prominently developed hypoderm and the abundance of secreting cells throughout the various tissues—are in conformity with the general structure of the order rather than with the Halophytes, for instance, and these characters are very important. Then when we compare the tables of ‘“leaf-anatomy of salt-marsh species” in Mr. Kearney’s interesting paper on this subject,* we notice several points by which our plant differs from his salt-marsh species. * The plant covering of Ocracoke Island. Contrib. U. S. Natl. Herb., vol. v, Washington, 1900, p. 310. Am. JouR. Scl.—FourtTH Serizs, Vou. XIX, No. 109.—Janvuary, 1905. 6 82 T. Holm—Anemiopsis Californica. Most of the species examined by this author possess isolateral leaves; several of these have hypodermal collenchyma or the mestome-bundles are supported by real stereome. On the other hand, Mr. Kearney observed a wrinkled cuticle and a like distribution of stomata on both leaf-surfaces, both of which characters, as we remember, are also to be observed in Anemi- opsis. A similar result is reached when we compare the species examined by Professor Warming,* none of which pos- sess such striking peculiarities as those characteristic of the Piperacee, nor do the features of his Halophytes in general agree with those of our plant; only a few points and of no particular interest or of seemingly great importance may be found common to both. As stated by Professor Warming, the lack of stereome seems to be characteristic of the Halophytes, so far as concerns their leaves, and only these have been exam- ined. In this respect Anemzopsis would show some likeness to the Halophytes, since the leaves contain very little stereome and only near the midrib. But if we compare the other parts of the plant, the stem and the petiole for instance, we then observe this tissue to have reached a very high development, especially in the flower-bearing stems and the stolons. It would, thus, appear as if Anemzopsis so far as concerns the structure, gives a better illustration of one of the several types of the P2peracee than of any specialized type modified in accordance with the environment, halophilous for instance. Brookland, D. C., October, 1904. * Halofyt-Studier, Kgl. Danske vid. Selsk. Skr., 6th series, vol. viii, Kj6- benhavn, 1897, p. 175. Chemistry and Physics. 83 Seren TEFEPC FRVELLTGEN CE. I. CHEMISTRY AND PHYSICS. 1. The Production of Pure Sodium Hydroxide for Laboratory -Uses.—On account of the danger in dissolving any considerable amount of metallic sodium directly in water, because of the very violent explosions that are likely to take place from an unex- plained cause, even with bright metallic sodium, F. W. Ktstrer has devised a method for effecting this solution slowly by the help of moist air, and has thus obtained a very satisfactory and cheap caustic alkali solution. He places a bell-jar in a large, flat dish in which there is sufficient water to make a water-seal, and under the ball-jar he places a platinum, silver, or nickel dish, cru- cible, or wide-necked flask, as a receptacle for the caustic solution. Above the receptacle is placed upon a tripod a piece of nickel wire gauze, bent into a conical shape with its apex downward, and in the cone pieces of sodium are placed after the outer crust has been cut off. The sodium begins at once to deliquesce while bubbles of hydrogen escape through the water-seal, and the resulting sodium hydroxide solution drops as a very concentrated, oily liquid from the point of the cone into the dish below. The operation goes on until all the sodium has been used up, and at last certain impurities of the sodium remain upon the wire-gauze, so that this process gives a purer product than direct solution. The solution thus obtained is of about 40 per cent strength, and it may be kept absolutely free from carbonate.—Zeitschr. anorgan. Chem., xli, 474. H. L. W. 2. The Production of Magnetic Alloys from Non-Magnetic Metals.—R. A. HapvFizeLp, who has produced the well-known non-magnetic alloy of iron and manganese known as ‘manganese steel,” calls attention to the interesting fact that a magnetic alloy can be produced from the non-magnetic metals, copper, alumin- ium, and manganese. A sample of this alloy, which appears to have been prepared by Dr. F. Heusler, contains 60 per cent cop- per, 25 to 27 per cent manganese, 12 per cent aluminium, 6 to 7 per cent silicon, 0°5 to 1 per cent carbon and probably 0°5 per cent iron ; but samples containing absolutely no iron had exactly the same magnetic properties. It has been found that no alloy of copper and aluminium is magnetic, hence it appears that the magnetic properties of the alloy are due to manganese, which, curiously enough, produces the non-magnetic alloy with iron. It is to be observed, however, that the alloy under consideration requires the presence of a cer tain amount of aluminium in order that it may be magnetic, and that with fairly constant contents of manganese amounting to 25 to 28 per cent, the maximum ‘“magnetizability ” is reached when 14 per cent of aluminium is present.— Chem. News, xc, 180. H, L. W. 3. Ozobenzol.—A product of the action of ozone upon benzol 84 Screntific Intelligence. was named and described by Renard a number of years ago, and the formula C,H,O, was then ascribed to it. Harries and Weiss have recently re-investigated this substance and find that its for- mula is C,H,O, ; that is, three molecules of ozone attach them- selves to benzol, presumably at the points of double linking, according to Kekulé’s theory. The compound forms a gelatinous mass when ozonized oxygen is allowed to act at 5-10° upon ben- zol. It is fearfully explosive, resembling iodide of nitrogen in this respect. When ice-cold water is placed upon the amorphous substance it assumes a crystalline modification which is also exceedingly explosive. It appears that the formation of this compound is a support to Kekulé’s benzol theory.— Berichte, XXXVil, 3431. H. L. W. 4. Concerning Hmanium.—Some time ago GIESEL announced that he had found a new radio-active substance related to lan- thanum, which was characterized by its remarkable action upon the blende screen. He has recently been able to compare the action of this “emanium” with Debierne’s actinium, which is related to thorium, and finds that the two substances show no dif- ference with the screen. He is still inclined to believe, however, that there may be a difference in the substances, on account of an apparent slight difference in the rates of decay of their induced activity, and also on account of the fact that three lines which the phosphorescence of his substance shows in the spectroscope have not been found with actinium.— Berichte, xxxvii, 2963. He save 5. The School Chemistry ; by Etroy Avery. 12mo., pp. 423. American Book Company, 1904.—This new text-book for high schools and academies is noticeable for being more extensive in its scope, both in the descriptive and theoretical parts of the subject, than is usual with books of this class. The experiments introduced are numerous, more than 300 being given, and they appear to be very well chosen for the purposes of instruction. A particularly good feature of the book is the number and variety of arithmetical problems, and other thought-inducing questions, that are presented. Although the book is well up-to-date in its facts, since such recent topics as radio-activity are discussed, the treatment of chemical theories may be considered as somewhat old-fashioned. For instance, there appears to be no mention of ionization, although many electrolytic experiments are given, and although the “changing places” of atoms or groups in reactions is frequently alluded to. A few inaccurate or mislead- ing statements have been noticed in the book, but these do not appear to be unduly numerous. It is to be hoped, since hydrogen was solidified several years ago, that the characterization of lithium as the lightest solid known will soon disappear from our text-books, because it is about seven times heavier than solid hydrogen. : | H. L. W. 6. Application of Some General Organic Reactions ; by Dr. -Lassar-Coun. Authorized Translation, by J. Bisnop TINGLE. Chemistry and Physics. 85 12mo., pp. 101. New York, 1994 (John Wiley & Sons).—The topics discussed in this book are “ Fixation of Hydrogen Atoms,” “Modification of Reactions,” “Improvement in Conditions of Reactions,” and “influence of Atoms and Atomic Complexes.” These subjects are of importance, and have not received sufficient attention in other works. The simple and entertaining manner in which the book is written should make it of interest not only to the experienced chemist, but also to the beginner in organic research. TBs J. 7. Influence of Glass Walls of Geissler Tubes on Stratified Dis- charges in Hydrogen.—E. Grurcxk®E, of the Reichsanstalt, finds that the glass walls exert a marked influence on the length of such stratifications. Not only the curves drawn from measurements but the appearance of the stratifications in suitable tubes show this influence. To make the effect evident to the eye oue side of the inner wall of a Geissler tube was covered with silver ; this had the effect of changing the length of the stratifications. The inner walls were also covered in another case with a layer of phosphoric pentoxide, with the same result. The author refers the stratifications observed in open space in flames to an effect of secondary cathodes. The stratifications in Geissler tubes appear to be a chain of cathodes with dark spaces and light spaces; the potentials of which seem to form an arithmetical series, and each stratification hands on to the next as much negative electricity as it received from the previous one. Foundation for a suitable mathematical theory is discussed.— Ann. der Phys., No. 13, 1904, pp. 509-530. Jaan 8. Phosphorescence.—P. LeNaRv and V. Kiarr continue their researches on this subject. Among their interesting conclusions is the following: Stokes’s law that the waves of excited light are always longer than those of the exciting hght has not been sus- tained by analysis of the sixty-four fluorescent bands examined. If the range of the exciting and the produced light are compared, it is seen that the exciting light and the fluorescent bands often approach each other very nearly; sometimes coincide, but never overleap each other. Study was made of momentary and more or less permanent fluorescence and of their dependence on exciting conditions.— Ann. der Phys., No. 13, 1904, pp. 425-484. 9 3.7. 9. Color Changes in Gold Preparations.—The theory of elec- trical resonance has been applied by various observers to account for the phenomena presented by colloidal preparations of gold in reference to color. EF. Kircuner and R. ZstamMonpy have had in view especially Planck’s work in this direction. Their results support in general Planck’stheory. There were, however, notice- able lacunz between the theory and the observations.— Ann. der Phys., No. 13, 1904. TEE: 10. Spectra of Hydrogen, Helium, Air, Nitrogen, and Oxvygen in the Ultra Violet.—With the aid of a quartz spectroscope, J. ScHNIEDERJOST has made a study of these gases. Comparison lines of platinum were employed. Two new lines of helium at 86 Scientific Intelligence. wave-lengths 2653°1 and 2644'9 were discovered which belonged to the first main series. Deslandres’ nitrogen group which lies between wave-lengths 3009°6 and 2205°3 was investigated, and Deslandres’ results confirmed. Seventy new lines of the line- spectrum of nitrogen were also measured. A number of new lines of oxygen were also discovered.—Diss. Halle, 1904. Beiblitter, Ann. der Phys., No. 22, 1904. Tighe 11. Pressure of Light.—In a sealed communication to the R. Accad. dei Lincei in 1882, opened at the meeting of February 1, 1903, A. Barrott relates that certain experiments conducted in the year 1876 appeared to show that the pressure of light apparently con- firmed by late experimenters does not really exist, and that there arises a certain resistance which a reflecting body encounters in a region of radiation, and which in the movement of a reflecting body would be shown in the body without a normal component in consonance with the second law of thermodynamics. He sus- pects further that the work for overcoming this resistance is changed into electric currents in the reflecting metal. These currents should be of measurable size. This suspicion was appar- ently confirmed by experiment. He mounted a strong cir- cular disc upon the axis of a solid lathe. This disc had a circular highly-reflecting band which was insulated by dry wood soaked in oil. The band was cut and the two ends were connected to two rubbing insulated contacts and to a sensitive galvanometer. The velocity of revolution of a point on this band was 240-410 meters per second. When sunlight fell on the silvered band the thermo-electric effect was only 2°3™™ deflection if the disc was at rest. When the disc rotated in the dark there was no reflection. As soon as sunlight fell on the rotating disc the galvanometer gave a deflection of 42™™, and this deflection persisted while the sunlight remained. It disappeared when the sunlight was re- moved. When the revolution was reversed the deflection was reversed to —32™™. A half speed gave a deflection of 20™™. These experiments were made in August and September, 1880, in the Technical Institute of Florence, and were so far as is known never resumed.— Beibldtter, Ann. der Phys., No. 22, 1904. esis 12. Notes on X-Light ; by Wit.itam Routitns. Pp. 400, plates 150, Boston, 1904.—This beautifully printed volume contains the arduous researches of a professional man who has devoted his evenings to what is perhaps the most baffling and trying of all physical research, experimentation on gases at low vacuo— trying both to physical endurance and to the spirit; for just as nature seems to be inclined to open her mysterious chambers, the glass apparatus and the mechanical apparatus employed in producing such vacuo breaks, and the course of experimenta- tion has to be begun anew. The expenditure of time and money, in giving freely to physicians and surgeons the best means of producing and employing the X-rays, shown by this book is remarkable, especially when one reviews the history of the use of these rays and sees the endless effort to secure all e Geology and Mineralogy. 87 improvements in tubes or processes of regulation by patents. Following the method adopted by Faraday, the author relates both positive and negative results of his experiments. In the subject of rarified gases, especially at low pressures, this method in the present uncertainty of our knowledge is most useful ; for, like the story of the Alpine climber who relates his attempts to scale some most difficult aiguille, it stimulates the imagination and leads to a consideration of all possible paths in the hope of finding, even through failure, a way to the summit ; and in ulti- mate success, the first path-breaker should not be forgotten. In reading the list of contents of this volume one Is surprised at the richness of suggestion.. Every form of X-ray tube, of regulators _and of exciters for such tubes, receives thought, and it is recog- nized by those who have followed Dr. Rollins’ work that the present forms of the most enduring and most efficient tubes are the result of his work. Makers of such tubes have eagerly taken up his suggestions and by (we will charitably say) unconscious cerebration have taken credit to themselves. This is true also of the open construction of Ruhmkort coils which the author fully describes in his book, and the employment of a hinged Faraday ring in the primary of such coils.. This is a most efficient construction of a transformer both for X-ray work, for spectrum analysis, and for wireless telegraphy. No onein America appears to have had the experience of Dr. Rollins in exhausting X-ray tubes to their point of greatest efficiency. He points out many phenomena of absorp- tion and occlusion of gases by the various terminals he employed, and by the glass walls of the enclosure which are now being studied quantitatively by various observers. This occlusion or absorption can under certain conditions reduce the pressure in an X-ray tube from one-thousandth of a millimeter to one two- thousandth. The mechanical skill shown in the plates of appli- ances for the employment of X-rays in surgery, which are collected at the end of the volume, would suffice alone to make this a notable work and a monument of altruism. ay ae IJ. GroLocy AND MINERALOGY. 1. Indiana Geological Survey.— W. 8. Buatcuiey, State Geologist. 28th Annual Report, 1903, 553 pp., with plates, maps and figures.—In addition to the statistical reports of the mine inspector, the gas supervisor, etc., the Indiana Survey Report for 1903 contains articles by T. C. Hopkins and A. F. Foerste on the Topography and Geological Formations of the state accompany- ing the new Geological Map ; and a paper on the Stratigraphy and Paleontology of ‘the Niagara, by E. M. Kindle. There is also a valuable table of contents of all of the geological literature published by the state of Indiana. The report of the state gas supervisor brings clearly to mind the great waste that has been caused by the careless treatment of the natural gas supply. ‘The people of the state have finally been convinced that the gas sup- 88 Seientific Intelligence. ply is not inexhaustible. It is fast declining and the end is not far off. Most of the present drilling is done in territory aban- doned years ago, and the average well now drilled would have been considered a failure ten years ago. The price of gas has increased fivefold in ten years and at the present time more pipe- line is being taken out of the ground than put init. Two large gas companies have entirely abandoned the city of Indianapolis. 2. Geological Map of Indiana. — A new geological map of Indiana has been published under the direction of W. 8. Blatch- ley, state geologist, on a scale of four miles to the inch. This map is a compilation of all the stratigraphic work done in the state from 1895 to 1903 inclusive, while the actual work of prep- aration is by T. C. Hopxins. Accompanying the map is a short. description (77 pp.) of the topography of Indiana and of the chief geologic formations of the state. No attempt has been made to represent the rock structure underneath the heavy glacial deposits covering the northern part of the state for a distance of about forty miles. 3. Geological Survey of New Jersey; Henry B. Kiuaret, State Geologist. Vol. VI, 533 pp., 56 pls., 41 figs.—The latest volume of the New Jersey survey deals with the Clays and Clay Industry of New Jersey, and is written by Heinrich Ries and H. B. Ktimmel, assisted by G. N. Knapp. The report deals with the occurrence, chemical and physical properties of clays, the stratigraphy of the clays and the method of their manufacture. A very complete set of fire brick tests has been made, particu- larly in reference to its refractoriness. A striking commentary upon the efficiency of the New Jersey survey is the fact that the clay maps of 1878 are found to be accurate in spite of the great development of the industry since that time. 4, Recent Seismological Investigations in Japan; by Baron Datroxu Kixucui, Emeritus Professor of Mathematics Tokyo Imperial University, Member and former President of the Im- perial Earthquake Investigation Committee. Pp.ix+120. 54 illustrations. ‘Tokyo, 1904.—This volume, stamped ‘for private circulation only,” was distributed at the Japanese exhibit of the recent exposition in St. Louis. As stated in the introduction, Japan is preéminently the land of earthquakes, and following the great Mino-Owari earthquake of October, 1891, in which over 7000 people were killed, the Imperial Earthquake Commission was established with a twofold object. First, to imvestigate whether there are any means of predicting earthquakes ; and, secondly, to determine how to reduce the disastrous effects to a minimum. With characteristic Japanese insight and thorough- ness the commission decided that the best way to attain its objects was first, possibly for many years, to study earthquakes in every relation, even such as might appear to have little or no bearing upon the immediate objects. The results of these investigations are given in sixteen publications in foreign languages, a list of which is given in the back of this volume. Among the more Geology and Mineralogy. 89 noticeable features of the present volume are charts giving the time, distribution and periodicities of Japanese earthquakes for over a thousand years, and studies in the variations in magnet- ism, latitude and other physical changes as possibly having rela- tions with the occurrence of severe earthquakes. For more than a decade astronomers have been familiar with the fact, rendered evident by long continued and refined astronomic observations in several parts of the world, that the earth’s axis of rotation is not absolutely fixed, but that, on the contrary, the poles wander through a period of years in a complex path within a circie of a few hundred feet radius. Among other results the commission has found that the seismic activity of Japan presents a period of six and one-half years, and in the past nine years all the destructive earthquakes occurred exactly or very nearly when the latitude was at a maximum or minimum. Je Bs 5. Harthquakes, in the Light of the New Seismology ; by CuaRENCE Epwarp Dutton, Major U. 8. A. Pp. xxii+314, with 63 illustrations. New York (G.P. Putnam’s Sons), London (John Murray), 1904.—This is volume 14 of “The Science Series,” and while clear and readable throughout, nevertheless enters into all the chief problems related to earthquakes and is a volume which should be read by every teacher of physical geology. Previous to 1870 the studies published were with few exceptions little more than narratives of disasters. Since that time, largely through the labors of Ewing and Milne, who have more recently been joined by many other investigators, the subject has grown into an exact science which not only reveals the location of regions of unstability whether at the antipodes or even under the ocean, but which is throwing light upon such problems as the density and solidity of the earth’s interior. After discussing the nature and causes of earthquakes, the author devotes 48 pages to the subject of earthquake instruments, obviously an important topic since it is from these refined instru- ments that nearly all of our modern knowledge has come. Following this are 119 pages on the nature of earthquake waves and the deductions from them. ‘This statement gives some idea of the complexity of the record and the involved messages it brings from the earth’s interior and which are still far from being completely understood. The last part of the book discusses earthquake distribution and seaquakes. ae, Bs 6. Minerals of Japan, by TsunasHiro Wana, translated by Taxupzi Ocawa. Pp. 144 with thirty plates. Tokyo, 1904.—Not- withstanding the comparatively limited extent of Japan and the fact that its resources are as yet only partially developed, the coun- try has afforded a large number of mineral species, many of them of peculiar interest either because of their rarity or of the beauty of their crystallization. The volume before us gives an excellent summary of this subject and deserves careful study by all interested. Concise accounts of the species identified are given, with exact statement of locality and numerous analyses ; a series 90 Scientific Intelligence. of fine heliotype plates give representations of notable specimens, for example, of the well known quartz twins, also the fine stibnite and topaz crystals. Among other Japanese minerals of especial interest may be mentioned crystallized danburite containing a considerable amount of magnesia (7°67 p. ¢.); datolite at Nobori, Hyuga Pr.; chalcopyrite of varied and unusual habit ; axinite, etc. A new species, naégite, is also described, as noted below. 7. Brief notice of some recently described Minerals—N aiGitE is a new silicate of uranium and thorium collected with fergu- sonite from the placer tin washings near ‘Takayama, Mino province; it is described by T. Wada on p. 49 of the Minerals of Japan (1904, see above). It occurs in small spheroidal aggregates, also rarely in small crystals of pseudo-dodecahedral habit ; these are probably tetragonal and isomorphous with zircon. The color varies be- tween dark pistachio-green, greenish gray and brown or reddish brown; under the microscope it is transparent, grass-green and highly refractive, though also often nearly isotropic. The hard- ness is about 7°5 and the specific gravity 4:09; it has marked radio-activity. An analysis by T. Tamura afforded: SiO. UO, ThO, TazO; Nb2O; CeOz Fe2.0; CaO MgO H,.O 34°89 28°27. 16:50 7:00 -4:10- 1°59 1:60 (1:71 0:57 a2 98a The name is from the locality where the new mineral has been found, viz. Naégi near Takayama. TEALLITE is a new sulpho-stannate of lead from Bolivia, exact locality unknown; it is described by G. T. Prior. It occurs in thin inelastic, flexible and cleavable folia showing crystals face on the edges; the angles afforded by these proved that the mineral is orthorhombic and somewhat related in form to nagy- agite. The hardness is 1 to 2 and the specific gravity 6°36 ; luster metallic, color blackish gray, streak black. The mean of two analyses gave: 8 16°29, Sn 30°39, Pb 52:98, Fe 0°20=99°86. This yields the simple formula PbSnS, or PbS.Sn8,. Teallite is named after Dr. J. J. Harris Teall, Director-General of the Geological Survey of Great Britain and Ireland, The same author has also analyzed carefully selected samples of franckeite and cylindrite, both from Poopd, Bolivia, the locality from which teallite may also very probably have been derived. The result is to give for franckeite the formula Pb,FeSn,Sb,S,, or 3 PbSnS, _Pb, Hesbiss5 «onl Cylimolrtie miss FeSn 50,9 eon 3 PbSnS,. SnFeSb,S.. Min. Mag., Xv, pp. 21-27, Oct. 1904. PALMERITE is a new hydrated phosphate of aluminium and potassium described by EKugenio Casoria from a deposit of guano found in a large cavern at Monte Alburus near Controne, province of Salerno, Italy. It occurs in a white, amorphous pulverulent form, unctuous to the touch and resembling purified kaolin. An analysis yielded : P.O; Al,O; KO Na,O H,0(100°) ign. Fe.0; NH, SiOz oP) ee Oo, 8704.5 O0iS 7:87 21:29 “tar 0:61 «0: asain The calculated formula is HK, Al,(PO,),4+7H,O. Att. Aecad. Georgofilé (5), 1, July 3, 1904. yd Miscellaneous Intelligence. 91 IIL. MIscELLANEOUS SCIENTIFIC INTELLIGENCE. 1. Annual Report of the Regents of the Smithsonian Institution, S. P. Lanexiey, Secretary, showing the operations, expenditures, and condition of the Institution for the year ending Sune 30, 1903. Pp. xi, 376 with 124 plates. Washington, 1904.—This volume contains the usual account of the administrative activity of the Smithsonian Institution in its different directions. The work in one of these in particular, the International Exchange Service, is presented in a very interesting form. In an Appendix a striking exhibit is made of the extent to which this service has been developed ; upwards of 150,000 packages were sent out to all parts of the world between July, 1902, and June, 1903, this work having nearly doubled in six years. The value of this ser- vice to the science of the country can hardly be overestimated. Another Appendix describes the additions to the National Zoo- logical Park, with some interesting illustrations; still another gives a report of the work of the Astrophysical Observatory for the year ending June 30, 1903. It is interesting to note here that the bolographic work carried on showed the earth’s atmos- phere to have been more opaque than usual, the direct solar radia- tion having been reduced about 10 per cent on an average through the entire spectrum. It is also shown to be probable that the radiation has been decreased outside of the earth’s atmos- phere. A new determination of the temperature of the sun, based upon the distribution of the solar radiation in the spec- trum, has yielded the result of 5,290° Centigrade above the abso- lute zero. As usual, the larger part of the volume of about 800 pages is given to the republication of a well-chosen series of scientific papers, showing the progress made in all departments of science. ‘These are fully illustrated and form a most interesting series, which ought to be accessible to all intelligent people. 2. Bulletin of the Bureau of Standards ; 8. W. Stratton, Director. Vol. I, No. 1, pp. 124. Washington, 1904 (Depart- ment of Commerce and Labor).—The Bureau of Standards, estab- lished some four years since, in addition to its regular testing work, the value of which is now thoroughly appreciated in the country, has recently undertaken the publication of occasional Bulletins. These will contain the results of investigations and researches carried on in connection with the Bureau, and which are likely to be of general interest in the country, either on the scientific or technical side. The Bulletins will be issued as often as they are required to present papers which are ready for publi- cation. The first number, issued November 1st, contains eight articles. L. A. Fischer discusses a recomparison of the United States prototype meter; K. EK. Guthe gives a study of the silver voltameter, and also describes fibers resembling quartz made from asbestos (amphibole) and steatite; F. A. Wolff discusses the so-called international electrical units; P. G. Nutting has papers on the spectra of mixed gases, on secondary spectra, and 92 Scientifie Intelligence. on new rectifying effects in conducting gases; C. W. Waidner and G. K. Burgess give results of determinations of the temper- ature of the are varying from 3690° to 3720° C., according to the form of pyrometer employed. National Academy of Sciences.—The autumn meeting of the National Academy was held in the buildings of Columbia University, New York city, on November 15 and 16. The fol- lowing is a list of papers presented : W. K. Brooxs: On the affinities of the Pelagic Tunicates. W. K. Brooks and S. Rrirrennouse: The life history of Turritopsis. W. K. Brooks and R. P. Cowires: Phoronis architecta, its anatomy, life history, and branching habits. JOHN TROWBRIDGE: On the electrical resistance of a vacuum. Franz Boas: Psychic associations in primitive culture. M. I. Pupin: Time electrical impulses. C. Barus: The occurrence of maxima and minima of atmospheric nucle- ation in approximate coincidence with the winter and summer solstices respectively. L. A. BaverR: The system of magnetic forces causing the secular varia- tion of the earth’s magnetism. R. H. CuirrenpDEN: The influence of low proteid metabolism on the formation and excretion of uric acid in man. Epwarp M. Mortey: Note on the theory.of experiments to detect the second power of the aberration of light. Also, Report of a repetition of the Michelson-Morley experiment on the drift of the earth through the lumin- iferous ether. C. S. Perrce: On topical geometry. N. Yatsu: An experimental demonstration of the formation of centro- somes cle novo. T. H. Moreaan: An analysis of the phenomena of organic polarity. E. B. Winson: Experiments on prelocalization in the annelid ovum. C. E. MEnDENHALL: The absolute value of the acceleration of gravity determined by the ring-pendulum method. R. S. Woopwarp: The double suspension pendulum for measuring the acceleration of gravity. Toro. Horm: The genus Claytonia,—morphological and anatomical studies. CHARLES S. Hastines: A determination of the dispersive power of the human eye. Cuas. F. CHANDLER: The air in the Subway in New York. W.H. Dati: Biographical memoir of Charles Emerson Beecher. Ep@ar F, Smita: Biographical memoir of Robert H. Rogers. 4. American Association for the Advancement of Science.— The fifty-fourth annual meeting of the American Association was held in Philadelphia, in the buildings of the University of Penn- sylvania, during the week from Dec. 27 to 31. The various affiliated societies also held their meetings at the same time and place. This is the third “Convocation week” that has been observed at this season of the year. «, Cyrus Adler, Pa Lee er or Ay M ae ee ae - Librarian U. S. Nat. Museum. Les ye ES i ae " ‘ Poot dist So Bet Tt ee bk ee : a: Ie FS a : ial ae Yr . is a Me Hy ae Beir, > aw f, zt whe " x ; “ly eae eta FEBRUARY, 1905. THE | AMERICAN | ‘| JOURNAL OF SCIENCE. | Eprror: EDWARD S. DANA. ASSOCIATE EDITORS ; ‘| Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camprinvce, Proressors ADDISON FE. VERRILL, HORACE L. WELLS, L. V. PIRSSON anv H. E. GREGORY, or New Haven, - Proressor GEORGE F. BARKER, or PHiInapEeLpHia, Proressor HENRY S. WILLIAMS, or Iruaoa, Proressor JOSEPH S. AMES, or Batrtimore, Mr. J. S. DILLER, or Wasuinerton. FOURTH SERIES. VOL. XIX—[WHOLE NUMBER, CLXIX.] No. 110.—FEBRUARY, 1905. WITH PLATE I. NEW HAVEN, CONNECTICUT. 1905 ‘atl \nslitutio 17s * 4 Zo 8 THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, _ Published monthly. Six dollars per year, in advance. “$6.40 No thenaht ids. ‘the tal Union. Remittances should be made either by money—or precistered s, or bank checks (preferably on New York banks). eperies at reasonable a Our material ig care of nearly thirty years. e actual comparison, it) is : that of any other three mineral dealers combined. As in the a we shall continue to supply collections. By laboratory material sold ty weigh - a ap he disappointment. ee Eas FOOTE MINERAL co, a ee Established by Dr. uke E, Foote, 1876. . = W. M. Foors, a z | 18317 Arch Street, Philadelphia. THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.] —_—_++e—_____ Art. VII.— The Lsomorphism and Thermal Properties of the Feldspars ; by Artuur L. Day and EH. T. ALien. (With Plate I.) Tue investigation here recorded is the first chapter in a rather comprehensive plan for the study of the rock-forming minerals at the higher temperatures. In its broader outlines at least, it is by no means a new plan. Mr. Clarence King and Dr. George I’. Becker were inspired by a desire to reach the mineral relations from the experimental side, which is recorded in the very earliest records of the U. 8. Geological Survey, and much of the remarkable ground-breaking work of Professor Carl Barus was undertaken in furtherance of a care- fully prepared scheme of research along these lines. The matter bas been advanced but little m the imtervening years. The present renewal of the effort in this direction is again due to Dr. Becker and has the benefit of his wide field experience and enthusiastic and effective codperation throughout. In October, 1900, one of the authors was called from the Reichsanstalt to equip a laboratory in the U. 8. Geological Sur- vey in which the exact methods and measurements of modern physics and physical chemistry should be applied to the minerals. The ultimate purpose was geological, to furnish a better basis of fact for the discussion of the larger problems of geology, but it appeared highly probable also that a quantita- tive study of the thermal phenomena. in this class of substances would offer new relations of intrinsic interest and of considera- ble theoretical value. This inference has been happily sub- stantiated quite recently through the publication by Tammann of an extended treatise on melting and erystallization,* in which * Tammann, ‘‘ Krystallisiren und Schmelzen.” Leipzig, 1903. Am. Jour. Sct.—Fourtsa Series, Vou. XIX, No. 110.—Fesrouary, 1905. 7 94 Day and Allen—TIsomorphism and Thermal he offers some very interesting speculations on the conditions of equilibrium for substances above and below the melting temperature under different pressures. The behavior of crys- talline minerals, which melt at temperatures considerably higher than he was able to command, offers peculiarly advantageous opportunities for verifying the truth of his inferences and of contributing further to the knowledge of this most important change of state of matter. Temperature Measurements.—lt is only a short time since it became possible to measure even moderately high tempera- tures with certainty and to express them in terms of a well-— established scale. Temperature is a peculiar function in that it is not additive. Two bodies, each at a temperature of 50°, can not be united to obtain a temperature of 100°, nor can any number of bodies, at a temperature of 50° or below, give us information about the temperature 51° or above. Further- more, temperature is not independently measurable: we can only measure phenomena like the expansion of gases or the conductivity of platinum wire or the energy of thermal radia- tion, which we have good reason to suppose will vary with the temperature uniformly or according to a known law. The measure of temperature now generally accepted as standard is the expansion of hydrogen gas between the melting point of ice and the normal boiling point of water, divided into 100 equal increments or degrees. Temperatures above this point* have been determined ‘by continuing the expansion of hydrogen or nitrogen in the same units, as far as it has been found possible to provide satisfactory containing vessels for the expanding gas. Such determinations are then rendered permanent and available for general use by establishing fixed points, such as the melting temperatures’ of easily obtainable pure metals, at convenient intervals. Beyond 1150° no trust- worthy gas measurements have been made and we have there- fore no standard scale. [or higher temperatures it is usual to select some convenient phenomenon which is measurable up to the temperature desired, to compare it with the gas seale as far as the latter extends and then to continue on the assump- tion that the law of its apparent progression below 1150° will continue to hold above that point. In this way we obtain degrees which, if not identical with the degrees of the gas scale, approximate very closely to them and can receive a small correction if necessary, whenever the gas scale shall be extended or another scale substituted. * To 600°, Chappuis et Harker, Travaux et mémoires du bureau inter- national des poids et mesures, xii, 1902. To 1150°, Holborn and Day, Ann. der Physik, ii, 505, 1900; English translation, this Journal [4], x, 171, 1900. — Properties of the Feldspars. 95 The application of measurable high pressures at the higher temperatures has never been successfully accomplished, and until something can be done in this direction, our knowledge of the rock-forming minerals and in fact all the generalizations relating to equilibrium between the states of matter, which have been established for moderate temperatures, must be regarded as more or tess tentative and subject to eventual re- vision. We have been accustomed to assume, both in geology and physics, with rather more confidence than scientitic exper- ience justifies, that established relations for ordinary tempera- tures and pressures will hold in comparable ratio for the higher temperatures and pressures also. Experimentation under extreme conditions is slow and technically difficult, and it is therefore not strange that simple relations which are verifiable within easily accessible conditions should now and then be accorded the dignity of natural laws without sufficient inquiry into the more remote conditions. General Plan.—Our plan on entering this field was to study the thermal behavior of some of the simple rock-making min- erals by a trustworthy method, then the conditions of equili- brium for simple combinations of these, and thus to reach a sound basis for the study of rock formation or differentiation from the magma. Eventually, when we are able to vary the pressure with the temperature over considerable ranges, our knowledge of the rock-forming minerals should become suffi- cient to enable us to classify many of the earth-making pro- cesses in their proper place with the quantitative physico- chemical reactions of the laboratory. Relation to Geological Research.—The relation which this plan bears to general geological research may perhaps be expressed in this way. Geological field research is essentially a study of natural end-phenomena, of completed reactions, with but a very imperfect record of the earlier intermediate steps in the earth-making processes. The records of the splendid laboratory experiments in rock synthesis which have already been made are also of this character. The final product has been carefully studied, but the temperatures at which partic- ular minerals have separated out of the artificial magma, and the conditions of equilibrium before and after such separation, have not been determined. In fact, except for a limited num- ber of determinations of the melting points of natural minerals, no exact thermal measurements upon minerals or cooling mag- mas have been made, and it is in this direction that a beginning is to be attempted. The temperatures of mineral reactions under atmospheric pressures are nearly all within reach of existing laboratory apparatus and methods. 96 Day and Allen—TIsomorphism and Thermal Existing Methods.—Furthermore, the methods which have been used in determining these mineral melting points seem to the authors to be open to serious objection both in principle and in application. They depend, almost without exception, upon the personal judgment of the observer and not upon the actual measurement of any physical constant. For this reason perhaps more than any other, the results obtained by different observers upon the same mineral from the same source do not agree within considerable limits, much larger than can be pr roperly ascribed to impurities in the specimens. Familiar examples will best illustrate this point. Among the deter- minations of the mineral melting points, two have received much more general acceptance than others ; ;—those ot Joly* and of Doelter.+ The melting temperatures which they obtained for some of the typical feldspars are as follows: Meldometer Measurement. Thermoelectric Measurement. Gas Furnace. Electric Furnace Joly, 1891 ; Cusack, 1896. Doelter, 1901. Doelter, 1902. Microcline LS 1169° 1155 5 OT ies Albite 1175 2 1108 1110 Oligoclase 1220 1110 1120 Labradorite 1230 1235 1119 1125 Anorthite To) 11382 The determinations agree in recording higher melting points toward the calcic end of the series, but the differences between corresponding melting points by the two methods is greater than the observed differences between different feldspars. Joly’s method was novel. He stretched a thin strip of care- fully prepared platinum foil between suitable clamps. placed a few grains of the powdered mineral upon it and mounted a small microscope above, so as to be readily trained on any part of the strip. The foil was then heated by an electric current which could be very gradually increased, and the temperature measured from the linear expansion of the strip at the moment when the observer at the microscope noticed the first signs of melting. The author of this method was able to obtain con- cordant results with it to within about 5° C., but differences several times greater than 5° appeared in the observations made by one of ust with the Joly apparatus, unless the grains were prepared with the greatest care and all the observations made by the same observer. The size and form of the grains, the care used in locating them exactly in the middle of the *J. Joly, Proc. Royal Irish Acad., iii, 2, p. 38, 1891. R. Cusack, Proc. Royal Irish Acad., iii, 4, p. 399, 1896. + C. Doelter, Tschermak, Min. u. Petr. Mitth, xx. p. 210, 1901s sexpe 23, 1902. t Day. Properties of the Keldspars. 97 strip, every draught of air, but most of all the judgment of the observer as to when the substance appeared to melt, all entered into the result to a very considerable degree. And there is another source of error with which we afterward became familiar, which may serve to account for the very large differences between J oly’s results and our own later values with some of the well-known miner als, though not with all. In certain of the minerals, after melting, the resistance to change of shape due to viscosity is of the same order of magnitude as that due to the rigidity of the crystal just before melting, a fact which may well have led to large errors of judgment in this method of detecting melting points. The possibility of working very expeditiously with minute quantities of a substance led us to study this method with great care, and we were fortunate enough to possess an instru- ment of Prof. Joly’s own model made by Yeates & Son, Dublin, but the results obtained with it, even under most favor. able conditions, are more in the nature of personal estimates than of exact measurements of the change of state. Its value for qualitative study, and in cases where only a very minute ‘quantity of a substance is available, is unquestioned. Doelter has employed electric furnaces modeled after that in use at the Reichsanstalt by Holborn and Day for the deter- mination of the melting points of the metals, measured his temperatures with thermoelements, and used several grams of material in his determinations, but he also judged of the approach of the melting point by the appearance of the charge and usually recorded two temperatures, the first approach of viscous melting, and the point where the material appeared to become a thin liquid. Detailed Plan.—We determined from the first to get rid of this personal factor. However carefully such observations may be made, and however well supported by the reputation of a particular scientist for skillful and exact work, they can not have a permanent value. Melting points of pure minerals are not different, in principle at least, from the melting points of other chemical compounds or of metals. They occur at less accessible temperatures and involve some complicating phenomena, as we shall see presently, but the change of state of a solid erystalline mineral to a liquid must of course be defined by an absorption of heat. Whether the appearance of the mineral charge in the furnace will offer a trustworthy index through which to locate this absorption, may well be expected to differ with different substances.’ Nearly all observers have recorded the fact that many substances of this class remain very viscous after melting and that the transition is not well marked in the appearance of the material. 98 Day and Allen—Isomorphism and Thermal We therefore planned an apparatus* which should be as sensitive as possible to heat changes over a long range of tem- peratures, and then prepared to examine the thermal behavior of simple minerals of natural or artificial composition when gradually heated or cooled. Changes of erystalline form (Umw andlungen) or of state (melting and solidifying) must involve a more or less sharply marked absorption or release of heat and be recorded as breaks in a smooth curve in the same way as in the determination of metal melting points or the singularities of any of the well-known chemical compounds at lower temperatures. first Group of Minerals Investigated.—The particular group of minerals chosen for the first investigation was the soda-lime feldspar series, and orthoclase (microcline). The reasons for this choice will be fairly obvious. Aside from its being altogether the most important group of rock-forming minerals, unusual interest has been attracted to it through Tschermak’s theory that these feldspars bear a very simple relation to one another, that they are (orthoclase excepted of course) in fact merely isomorphous mixtures of albite and anorthite. This hypothesis has given occasion for serious and extended study both from the optical and thermal sides. A complete review of the literature of the feldspars will not be attempted here. Although opinion is still somewhat divided,t it is probably tair to say that the optical researches have failed detinitely to establish or disestablish the isomor- phism of the albite-anorthite group, and that it is somewhat uncertain whether conclusive evidence will be obtained by optical means alone. Investigation from the thermal point of view has been even less satisfactory by reason of the subjective methods employed, to which reference has already been made, though the recorded results indicate with reasonable unanimity that the melting point of anorthite is above that of albite and that the intermediate feldspars will probably fall between the two.{ Beyond this conclusion, the great body of evidence is more or less contradictory and sometimes controversial in character. Orthoclase (preliminary i) 2 Comentat unluckily, our meas- urements began with natural orthoclase (microcline) from * For a detailed description of this apparatus see Day and Allen, Phys. Rev., xix, p. 177, 1904. + Fouqué et Lévy, Synthése des Minéraux et des Roches, p. 145, 1882. C. Viola, Tschermak’s Min. u. Petr. Mitth., xx, p. 199, 1901. Lane, Journ. Geol. XII, ii, p. 83, 1904. J. H. L. Vogt — Die Silikatschmelzl6sungen. Christiania, 1903. tJ. H. L. Vogt, loc. cit., p. 154, expresses the opinion that the soda-lime feldspars will be found to fall under Type III of Roozeboom’s types of iso- morphous series, with a minimum between anorthite and albite. (See p. 134, seq.) Properties of the Heldspars. 99 Mitchell Co., North Carolina, a quantity of which was placed: at our disposal by the U. 8. National Museum. The material was powdered so as to pass readily through a 100-mesh sieve, and placed in 100° or 125° platinum crucibles, some- times open and sometimes covered, in charges of from 100 to 150 grams. These charges were heated slowly in the electric furnace from 600° to above 1400° C., but, although the thermal apparatus was sufficiently sensitive to detect an unsteadiness of a tenth of a degree with certainty, not the slightest trace of an absorption or release of heat was found. The charge at the beginning of the heating was a dry erystalline powder, which was prodded from time to time with a stout platmum wire to ascertain its condition as the heating progressed. At about 1000° traces of sintering were evident, at 1075° it had formed a solid cake which resisted the wire, at 1150° this cake had softened sufficiently to yield to continued pressure and at 1300° it had become a viscous liquid which could be drawn out in glassy, almost opaque threads by the wire. Under the micro- scope the opacity was seen to be due to fine, included bubbles, the material being entirely vitreous. The cooling was equally uninstructive ; the vitreous mass solidified gradually without recrystallization or the appearance of any thermal phenomenon. Frequent repetition with fresh charges and varied conditions added nothing to our knowledge of the melting temperature, and the matter began to look very unpromising. We also reheated charges of the resulting glass which was sumetimes repowdered and sometimes in the cake as it had cooled. But except to observe that the glass powder began to sinter earlier (800°), no new facts appeared.* Then we tried by various means to recrystallize the melted orthoclase. We mixed crystalline powder with the glass, we applied successive quick shocks to the cooling liquid for several hours with an electric hammer below the crucible, we varied the rate of cooling and even tried rapid see-sawing between 800° and 1300°. We arculated air, water vapor, and car- bonie dioxide through the charge throughout the _heat- ing, and finally introduced a rapid alternating current sent directly through the substance while cooling, but no trace of crystallization resulted. An extremely viscous, inert mass always remained which gradually hardened into a more or less opaque glass. It appeared somewhat translucent if very high temperatures had been reached, but was never clear. Following orthoclase, a number of specimens of natural albite were tried under similar conditions and with entirely similar results. * These sintering temperatures varied within considerable limits with the fineness of the material and therefore serve only in a very rough way to define the state of the charges. 100. Day and Allen—Lsomorphism and Thermat Later on, when more experience had been acquired, these minerals were taken up again and a satisfactory explanation for their behavior was found. But for the moment all the defin- ing phenomena appeared to be so effectively veiled by some property, presumably the viscosity, that we were constrained to look about for some simpler compound which should give us « better insight mto the behavior of mineral glasses and their thermal relations, and to lay aside the feldspars until they could be more successfully handled. This outline of our unsuccessful experiences is given here in some detail, in order to show the actual difficulties which con- front the student in working with the feldspars, in the face of which it is certainly not surprising that uncertain and contra- dictory conclusions have been reached. Borax.—The substance chosen for this preliminary work was ordinary anhydrous borax (sodium tetraborate). We chose this merely because it was a simple glass and unlikely to undergo chemical change. It is easily obtainable pure and its thermal phenomena are within easy reach. The study of borax proved to be most instructive. It gave us an effective insight into the behavior of this class of substances, and in particular served to define the phenomena of melting and solidifying in substances which undergo extreme undercooling and which recrystallize with difficulty or of borax were therefore of much interest in themselves and were given in a paper before the National Aca- demy of Sciences at its spring meet- ing in Washington last year (April 21, 1903), but were not printed at that time. The borax glass upon which our measurements were made was pre- pared in the usual way by heating the crystals until the water of crys- tallization had been driven off and the viscous mass was reasonably free from bubbles. If the borax is pure, Me. a. the anhydrous product, when cooled, is a brilliant, colorless a 180- tropic, of conchoidal fracture, and specific gravity 2°37. The specific gravity was determined in the fraction of kerosene boilmg above 185° C. About 100 gr. of this glass were then broken up and placed in a platinum crucible in the electric furnace. The thermoelement was placed in position PtRh & i cS | = not atall. The results of this study ~ Properties of the Feldspars. 101 as indicated in fig. 1, the heating current properly regulated and observations of the temperature made at intervals of one minute, while the glass softened and passed gradually over into a thin liquid (800°). Then the current was reduced and the cooling curve observed in the same way. These observations gave an unbroken curve both for the heating and cooling, as in the case of all the glasses,* without a definite melting or Pre: solidifying “ although the arrangements for detecting an absorption or release of heat were very sensitive. Prodding at intervals with a platinum rod showed the change to be per- fectly gradual from a clear, hard cake through all degrees of viscosity to a fairly thin liquid and back again. This observa- tion is of considerable interest as showing that the absence of bounding phenomena between the cold glass which fulfils the mechanical conditions for a solid very perfectly, and the liquid, is not confined to mixtures of complicated chemical composi- tion, but is exhibited also by true chemical compounds of undoubted purity. It is therefore not conditioned by compo- sition but by the physical nature of the substance. Having verified this behavior of anhydrous borax by several repetitions of the experiment, various disturbing influences were applied to the slowly cooling liquid in the hope that some temperature *See Tammann, loc. cit., also Roozeboom ‘‘ Die heterogenen Gleich- gewichte, etc.” Braunschweig, 1901. . 102 Day and Allen—Lsomorphism and Thermal or range of temperature would be found within which the vitreous condition would prove unstable and crystallization be precipitated. ‘The jar produced by an electric hammer pound- ing upon the outside of the furnace during cooling proved to be sufficient to bring down the entire charge as a beautiful crystalline mass of radial, fibrous structure, brilliant luster, rather high refractive index and increased volume. The pho- tograph (tig. 2) will give some idea of the appearance of the anhydrous er ystalline borax in the crucible. Its specific grav- ity proved to be 2°28 as compared with 2°37 for the glass, a Ce ee ances LO ee BE Pamenyeeeee PL ee eee Ja oS ete eee ee ECE HERGEEAeeee Time. 1 divy.=10 minutes. 6900 (765°) 6800 6700 6600 (740°) 6500 Temp. in microvolts. Fie. 3. somewhat unusual relation,* which may in part account for the quasi-stability of the vitreous form during cooling. Observations were then undertaken upon the crystalline borax with a thermoelement as before, to determine the melting temperature and solid modifications if such existed, but none of the latter were found. The charge melted uniformly at 742° and the melting point was well defined. A curve showing the minute-to-minute observations on the crystalline borax between the temperatures 660° and 765° is shown in the adjoining figure (fig. 8 oO, a). Having determined the melting point of er ystalline anhydrous borax satisfactorily, we examined more closely into the condi- tions under which it solidified. As has been said, if the melted charge was allowed to cool slowly, undisturbed, no return to the crystalline state occurred. It merely thickened into a- transparent glass without releasing the “latent” heat which it *Tammann. Loc. cit., p. 47 et seq. Properties of the Feldspars. 103 had taken on in melting (fig. 5, 6). If it was subjected to the jarring produced by the electric hammer on the furnace wall, it cooled down a few degrees below the melting point and then began to crystallize, the heat of fusion was set free and a rise in temperature or hump imme- Re 4 ee aa 000 joes diately appeared upon the cool- 37> g ing curve as shown in the figure Coe ieslias| y (fig. 3, 6, ¢, d@). Up to this point ee eee y, the phenomenon differs but little ( from the usual behavior of liquids which undercool in solidi- fying. We then varied the experiment by first cooling quiet- ly to about 100° below the melt- ing point and then introducing a few crystal fragments or start- ing the pounding. Crystalliza- tion and release of the latent heat followed at once. In fact over a range of some 250° im- mediately below the melting Seals point it proved to be within our : Fie eed power to precipitate the crystalli- no zation of the undereooled mass __ ;o99 eae eae entirely at will. It was even cael lege possible to cool the melted charge [ Piel aaa quietly down to the temperature ae [sei a of the room and remove it from _ | soa the furnace as a clear glass, then, £ 4500 2 NS on a subsequent day, to reheat© =~ 77774 ae to some point in this sensitive = 7" zone and pound judiciously,§ Ty V al when crystallization would at # | . once begin, marked by thei) 2040-6080 release of the latent heat of the eed previous fusion as before (fig. 4, tel a and 6). The accompanying curves show the situation clearly. Curves aa’ and 60’ (fig. 5), were obtained from charges of crystalline and vitreous borax, respectively, of exactly equal weight, which were cooled and reheated in the same electric furnace under like conditions. The radiation from the furnace for like temperature conditions will also be practically the same, so that the more rapid rate of cooling and of reheating in the -erystalline charge indicates a much smaller specific heat than for the vitreous form. . From the point of view of the usual definition of the solidi- fying point of a substance, a difficulty confronts us here: (1) 104 Day and Allen—Isomorphism and Thermal we were able to vary the beginning of solidification (erystalli- zation) at will over a range of 250°, and (2) the temperature to which the charge rose after the undercooled liquid had begun to crystallize did not reach the melting point although once otter , 7 crystallization was induced only el : 1 7-7F] 10° below it in a furnace of con- | ea stant temperature. The rapidity | with which the crystallization and the accompanying release of the latent heat go on, depends in part upon the rate of cooling and the character of the disturbance which has been applied, i. e., upon acci- dental rather than characteristic conditions. It thus happens that the amount of the heat of fusion and its slow rate of liberation in the case of liquids which can be greatly undercooled and become very viscous, may be such as to deprive it of its usual significance as defining a solidifying point. | It is, of course, a consequence of the phase rule that the soliditying temperature of an undercooled liquid is established, if only equi- librium between solid and liquid (and vapor) is reached before + complete solidification is accom- | plished, but equilibrium 7@s not necessarily attained during solidi- fication, and the devices usually ;employed (sowing with erystals, —+7— agitating’) are often totally inade- - 3500) 4 7 "quate 2 bring it about. The | | temperature to which a erystalliz- Lele 2a | |_| ing liquid rises after undercooling COIN O oe Pee ATs CO apa) ee OO cea not necessarily constant or In anal any way related to the melting we point, and is therefore not, in general, entitled to be regarded as a physical constant. We then endeavored to ascertain whether the unstable domain had a lower limit also. For this purpose we mixed a quantity of the crystals with the glass and powdered them together to about the fineness represented by a 150-mesh sieve and heated them very slowly. In this condition the glass proved to be very unstable and erystallized readily with a rapid release of its latent heat at about 490°. Very slow heat- IL ; 7 Temperature (MY), Properties of the Keldspars. 105 ing (10 min. per 1°) gave a temperature a few degrees lower, but such variations as could be applied within the period of a working day did not suffice, under the most favorable condi- tions, to change this temperature materially. The first evi- dence of molecular mobility in borax glass, shown in the sticking together of the finest particles (sintering), and the first traces of crystallization and release of latent heat, appeared consistently at about 490-500°. Still a third phenomenon attracted our attention to this temperature. On every occa- sion when borax glass was heated rapidly, either powdered or in the solid block, a shght but persistent absorption of heat appeared in this same region and continued over some 20°, after which the original rate of heating returned. We were entirely unable to explain an absorption of heat in an amor- phous substance under these conditions except by assuming an actual change of state to exist between amorphous glass and its melt, in which case the absorbed heat would reappear some- where upon the corresponding cooling curve,—which it failed to do. We then reasoned that any assumed change in the molecular structure which would account for an absorption of heat would also be likely to cause an interruption in the con- tinuity of the curve of electrical conductivity, and the relative conductivity was determined throughout this region; but no such interruption appeared. : Finally the matter was abandoned. The evidence did not appear sufficient to establish any discontinuity in the cooling curve of the glass, so long as no crystallization took place. When these relations had been clearly established, we turned again to the feldspars. It became clear very early in the investigation that only artificially prepared and chemically pure specimens would be adequate for our purpose. Each of the end members of the series, anorthite and albite, as found in nature, is always inter- mixed with some quantity of the other, while the intermediate members generally contain iron and potash, and all are lable to inclusions. There was nothing new in this plan: Fouqué and Lévy* had demonstrated the possibility of making pure feldspars by chemical synthesis and had studied their optical properties some years ago. We undertook to prepare much larger quantities than they (200 grams), and to make a careful study of their heating and cooling curves under atmospheric pres- sure, the conditions under which anorthite and the plagio- clases crystallize, the relations between the amorphous and erystalline forms, the sintering of crystalline and vitreous pow- ders, in short, their entire thermal behavior, as we had done with the borax. At the same time it was our purpose to make * Synthese des Minéraux et des Roches, loc. cit. 106 Day and Allen—TLsomorphism and Thermal careful determinations of the specific gravities of both the vitreous and the crystalline products, analyses of such portions as might be of special interest, and also to prepare microscopic sections wherever they were likely to throw lght on the rela- tions involved. The latter, after preliminary examination, were very thoroughly studied by Prof. J. P. Iddings of the University of Chicago, whose large petrographic experience with mineral crystallites makes his judgment of exceptional value.* 3 The constituents used in our syntheses were precipitated calcium carbonate, anhydrous sodium carbonate, powdered quartz (selected crystals) and alumina prepared by the decom- position. of ammonium alum. None of these contained more than traces of impurities, if we except the quartz, in which 0°25 per cent of residue, chiefly oxide of iron, was found after treatment with hydrofluoric and sulphuric acids. All but the calcium carbonate were carefully calcined and cooled in a desiccator before weighing. To obtain a homogeneous pro- duct, the weighed constituents were mixed as thoroughly as possible mechanically, and heated in large covered platinum crucibles (100° capacity) in a Fletcher gas furnace.t| After some hours heating, during which the temperature usually reached 1500° or more, the product was removed from the furnace, cracked out of the crucibles, powdered, passed through a “100-mesh” sieve and then melted again. ‘This process probably gives a fairly homogeneous mixture, though a third fusion in the resistance furnace was generally made before determining the constants. We prepared in this way albite (Ab), anorthite (An) and the following mixtures of the two: Ab,An,, Ab,An,, Ab,An,, Ab,An,, Ab,An,, Ab,An,. All of these were obtained in wholly or partially crystalline form, by crystallization from the melt, except albite. The syntheses were controlled by analyses of a number of the products, the results of which are appended. ANALYSES OF ARTIFICIAL KF ELDSPARS. An Avo Aun Ab, Ane Ab,An, Caleu- Calcu- Calcu- Calecu- Found. ited: Found. inhoa. Found. lated: Found. iste SiO, 43°33 43°28 47°10 47°18 251306 51-30 “GU;0IR >on ALO, 36°21 36°63 34:23 34°00 “31°50 31:21 " 24°055) 2omay PeO, 29. vehi eds) eke 7 eee ee CaO 20:06 20:09 17:00 16°93 13°65 13°68 7:09 6:98 Na,O TL LTA. 87 8881 879 a ee 100-00 100°22 100711 100°13 * See Pt. Il of the complete paper, Publications of the Carnegie Institution of Washington. + Buffalo Dental Company, No. 41A. A Fletcher furnace of this type, with ordinary city gas pressure and a small blast motor, will melt all of the feldspars. Properties of the Feldspars. 107 Anorthite.—Of the whole series of feldspars, this member is in many respects the simplest to deal with. It is of rela- tively low viscosity when melted and crystallizes easily, very rapidly, and always in large, well developed crystals. A 100- eram charge crystallized completely in ten minutes. Sudden chilling gave a beautiful clear glass entirely free from bubbles, somewhat slower cooling usually resulted in a partial crystal- lization from few nuclei, the crystals being always large. In appearance it resembles the natural mineral in every respect. Its hardness is also equal to that of natural anorthite. Thin sections show good cleavage, and twinning according to the albite law is frequent. The extinction and other microscopic characteristics are as well marked as in natural specimens. The heating curve of crystalline anorthite is perfectly smooth except for the single break which marks the melting point. No trace of a second crystalline form (Umwandlung) appeared in this or any other of the feldspars within the temperature range of the observations (800°-1600°). Some undercooling always occurs in solidification even if the rate of cooling is slow, but it is less, under like conditions, with anorthite, than with any other member of the series. The heating curve of the glass shows a strong evolution of heat which may occur as low as 700°, when crystallization takes place. The melting point of crystalline anorthite was deter- mined by three different thermoelements upon two different mineral preparations. It will be seen from the appended table that the determinations agree remarkably well. ANORTHITE. First Preparation. ; E.M.F. Tem- Date. Element. in MV. perature. Remarks. Oct. 7,1903 A 15939 1534° solid charge, open crucible. eteaies co ACE Da OA a3 2 “ SF arn. < A 15878 1530 covered crucible. eee, NO, 3 16074 1533 5 : “6 66 66 3 16058 1532 66 Ce eee 3 16068 1532 S 6¢ “e 74 y) 16095 1532 66 66 Mean 1532° Second Preparation. A 15860 1532° covered crucible. A 15864. 1532 pec No. 3 15960 (153838 Seliad “o ee 2° 16102-5352 2 16092 15382 Mebs3st, 3 15932 1531 1st & 2d preparations together. : Mean 1532° Melting temperature 1532°. 4 “ce oe 108 Day and Allen—Lsomorphism and Thermal The close agreement of these determinations -is of very considerable significance with reference to the method of temperature measurement employed. It will be remnembered that the established temperature scale ends at 1150° and that temperatures beyond that point are extrapolated with the help of some trustworthy phenomenon which varies with the tem- perature. We chose for this purpose the thermoelectric force developed between pure platinum and platinum alloyed with 10 per cent of rhodium. Now the constants of. such thermo- elements will usually differ among themselves and require to be determined for each element by calibration with the gas thermometer or with the melting points of the metals.* It therefore offers an excellent test of the value of the extrapo- lation if some sharp melting point can be found in the extra- polated range to serve as a point of reference. The melting point of crystalline anorthite serves this purpose exceedingly well, and separate determinations of it with three separate thermoelectric systems gave identical values within the limits of error of observation. Our confidence that the extrapolation for these 375° is reasonably correct would therefore appear to be justified. Until the gas scale can be extended over this range, the melting point of pure anorthite (1532°) determined in this way will serve as a useful point in thermometry. Ab,An,.—This feldspar decidedly resembles anorthite in its relatively low viscosity, the readiness with which it crystallizes, the well marked break in the heating curve at the melting point, and in its tendency to form comparatively large crystals. In general we may say that all these characteristics are some- what less marked than in anorthite. Our determinations of the melting temperature follow: AB,AN5 First Preparation. Electromotive Temper- Date. Element. Force in MY. ature. Remarks. Dec. 9, 1 A 15501 1504° slow heating. ih 11, A 15363 1493 rapid ‘ St ali ae No. 3 15507 1498 a ef en lvoe ef 5) 15599 1505 oe i 66 CC (15 3 15594 1505 66 (14 OO a ee 3 15604 1506 slow “ (<4 6G 6¢ A 15518 1505 6¢ 6 Mean 1502° Second Preparation. : Apr. 9,1904 No.3 15520 1499 slow heating. ee areata 2 15637 1497 ie ng Mean 1498°. Melting temperature 1500°. * Day and Allen, loc. cit. Properties of the Feldspars. 109 In one instance, while cooling the molten mass at a rapid © rate, we obtained a result which has a most important bearing on the relation of the feldspars to one another, which will be referred to again in the concluding discussion of the experi- mental data. When the charge had cooled, it was found to consist of a compact mass of rather large crystals, radial m_ struc- ture, at the bottom of the crucible (fig. 6), and a beautiful, transparent glass above. It was easy to separate the crystalline por- tion from the glass and to analyze the two separately. The composition of the two portions is practically identical, save for a slightly higher percentage of iron in the erystals.* In harmony with this latter circumstance the color of the crystals was a decided amethyst brown, while the glass was but slightly tinted. The analyses fol- low: AB,ANs Glass Residue Crystalline Cake Found. Found. S10, Sees 47°46 47°34 JAN OSS Se eee 33°56 30°51 Be Ones aae a2 5. “29 "47 Oe cd JN So 16°99 16°84 ING) EY Samet 1°87 1°89 100:17 100°05 It is at once clear from these determinations that the solid . phase has the same composition as the liquid phase, so far as it is within the power of chemical analysis to establish it. Ab,An,.—In this feldspar we observe the same characteris- tics as in the two preceding, but they are still less sharply marked. The viscosity is greater, both solidification and melt- ing take place more slowly, and the undercooling is so per- sistent that the furnace must be cooled slowly or the charge will come out wholly or partly vitreous. * A small quantity of iron was contained in the quartz used in preparing the feldspars. Am. Jour. Sc1.—FourtH Series, Vor. XIX, No. 110.—FEBRuARY, 1905.° 8 110 Day and Atlen—TIsomorphism and Thermal AB, ANo. First Preparation. K.M.F. Temper- Date. Element. in MV. ature. Remarks. Oct. 16, 1903 A 14895 1459° rapid heating. EC Ja Ake No. 3 15142 1460 slow a ch ai BS 3 15101 1457 rapid 3 2c Sue peace 3 35220 1466 extremely slow heating. Coie as ae 3 15204 1465 rapid heating. Me eS ee 3 15160 1462 Deceit sy 3 15116 1467 powdered charge, open crucible. 3 15103 1466 ditto, slower. 3 15109 1467 solid cake, covered. : 3 15044 1462 very fast. < CO aes 3 15040 1462 same slower. A 15035 1467 Mean 1463° Second Preparation. Feb. 19, 1904 A 14945 1460° _—_ covered, slow. eee DOR NC No. 3 15096 1466 ditto, faster. AS) 5S 2 15239 1467 fast. Mean 1464° Melting temperature 1463°. Here again we made an attempt to discover a possible dif- ference in composition in the first portions to crystallize out of the melt, this time by optical means. We first cooled the charge so rapidly that only a relatively small portion erystal- lized out in fine, reddish-brown spherulites at the surface and - near the wall of the crucible. Without disturbing these, the crucible was then replaced in the furnace and slowly reheated until (about 5 hours) the remaining vitreous material had also become completely crystallized. Upon removing from the fur- nace, the charge presented a singular appearance. The reddish- brown stars remained undisturbed, while the later crystals were perfectly white. But though so different in appearance, the microscopic examination of slides cut from the different por- tions showed the two to be optically identical. We have here another instance of the tendency of the iron to concentrate in the crystals which first form, a tendency which was frequently noticed, throughout our work. It also appeared to matter little whether the first crystals formed at the surface or at the bottom of the charge. It is possible that this phenomenon may have significance in ore deposition, but we have not thus far been able to give it adequate attention. Properties of the Keldspars. fen Ab,An,.—With this member of the feldspar group a diffi- | eulty in effecting crystallization in the molten mass becomes noticeable. Undercooling will continue until the vitreous melt becomes rigid, unless the cooling is slow or some special effort in the way “of mechanical disturbance or the introduction of nuclei is applied. Furthermore, when once precipitated, crys- tal formation goes on slowly, even when the charge is finely powdered, and the crystals are always small. Of the feldspars at least it is possible to say that the, size of individual crystals varied chiefly with the viscosity; the thinner, calcic feldspars always gave large individuals, while Ab,An,, Ab,An,, Ab,An, and Ab,An, crystallized in closely interwoven, increasingly smaller fibers, which gave much difficulty in microscopic study. In comparison with this apparent effect of the viscos- ity, the rate of cooling was altogether insignificant in deter- mining the size of individual erystals. Several days were required to complete the crystallization of 100 grams of Ab,An, under the most favorable conditions which we were able to bring to bear upon it. The melting temperature of the crystalline feldspar was still fairly well marked, however, and crystallization began in the powdered vitreous material as low as 700°. The melting point of this feldspar is: AB,AN,. K.M.F. Tem- Date. Element. in MV. perature. Remarks. Feb. 9,1904 A 14402 1416° covered charge, heating rapid. Pee A 1A4004 1416 Sele No, 3514529 . 1421) very rapid. ie... Dae Teal Reta, seir gS 2 14709 1426 very small charge. Mean 1419° Melting temperature 1419°. Ab, An,.—To effect the complete crystallization of this sub- stance, it is best to reduce it to a fine powder and heat very slowly, holding the temperature for many days at 100—200° below the melting point. When thoroughly crystallized, it has a melting temperature which is determinable with reasonable certainty, but neither this nor any of its thermal phenomena approach the more calcic feldspars in sharpness. For this reason a considerably greater variation will be noticed in the melting points tabulated below. Remarks. very rapid heating. poor. covered. (4 Gs covered. Melting temperature 1367°. eee pf P| yy 112 Day and Allen—ILsomorphism and Thermal AB, AN}. First Preparation. de ML em- Date. Klement. in MV. perature. Dee. 10, 1908 A 13726 1362 > ele to) aes A 13887 1374 sees) Som A 13969 1381 SSO ELOR EAS A 13728 1362 Jan. 18, foes No: 3 13967 1376 Feb. 29, 3 138] 2 1363 Pe he Open 3 13854 1366 Mean 1369° Second Preparation. Feb. 5, 1904 No. 2 13990 1369° Third Preparation. Mch. 25, 1904 5) 13752 1358 ES AIO inne 2 13995 1370 NE. Oe 3 13756 1358 Mean 1362° Ta ; iz = A 2 eae am Ca toe doe SU a ea E fp Time 1 div, 1595 0000018 INVeL. 7 Properties of the Feldspars. 113 From here on to the albite end of the series, viscosity becomes very troublesome in restraining crystallization. The breaks which mark the melting temperature on the heating curve of Ab, An, are so slight as to make the determination difficult and somewhat uncertain. It is not that temperature measure- ment is less accurate here than elsewhere, for these tempera- tures are more accessible than the melting point of anorthite, to which reference has been made in this connection. These ultra-viscous materials do not melt at a constant temperature but over a considerable range of temperature, as we shall undertake to show in some detail, with illustrations from pho- tographs, in the discussion of albite. A glance at a series of curves (fig. 7) plotted from our observations upon metallic silver and the feldspars An, Ab,An,, Ab,An, and Ab,An, im such a way as to bring their melting points together, will show clearly the nature of this dithicnlty. The melting point of the metal is sharp, but with anor thite a change in the character of the phenomenon is noticeable. Its poor conductivity for heat and its viscosity, which, though small compared with the other feldspars, is very great compared with silver, have rounded off the corners until a really constant temperature for a period of a minute or more during the melting is nowhere to be found. The nearest approach to a melting point is where the rise in temperature is slowest, and this will occur when the por- tion nearest to the thermoelement (see fig. 1) melts. A series of melting point curves containing a typical one for each of the observed feldspars, is reproduced here exactly as observed (see page 114). The numbers represent the electromotive force of the thermoelements at intervals of one minute, together with a column of differences at the right of each record. The E.M.F. will be seen to approach a minimum as melting progresses and to increase again when it is complete. This mimimum rise in the temperature of course indicates the maximum absorption of heat. For purposes of rough orientation 10 MV may be con- sidered equivalent to one degree. There is no circulation in these viscous melts and nothing to assist in distributing the heat uniformly. The melting point is therefore not marked by a constant temperature but by the point of greatest inclination of the tangent to the curve, with a limit of error which increases with increasing viscosity. With Ab,An, it was barely discernible and with Ab,An, all trace of the heat of fusion was lost.* Slow heating or rapid * Only a small portion of the charge could be crystallized. The relatively small heat of fusion of the crystallized portion was therefore superposed upon the larger specific heat of the glass. This, together with the effect of the viscosity, destroyed all record of the melting 114 Day and Allen—Lsomorphism and Thermal TIME CURVES (in Microvolts as observed). An Ab, Ans Ab, Ane Ab, An, Ab,.An, Ab;An, MV AV MV AV MV AV MV AV MV AV MV AV 15050 13530 11700 13400 12480 12754 15206 jor 13830 45, 19210 7. 13489 ¢) 12533 2 gaan 15841 55) 14180 545 12655 45, 13573 ,, 12590 -, 12834 |. 15441 “4, 14870 555 12960 5,, 18647 4, 12648 22 oe 15526 4, 14560 j,, 138236 5), 138715 6, 12701 -) 12916 4. 15594, 14718 54, 138441 5,, 18778 -, 12752 (2 eae 15650 4, 14888 ,5, 13595 15, 18836 -, 12797 ,, 12989 2, 15697 4, 14942° ,, 13722 555 18891 ,) 12840) 15738 4, 15028 ,, 18832 }), 18942 ,, 12881 4, 13053 54 15773 49 5101 6, 189382 “9, 18991 4, 12917 ,. 13082 6, 15802 4, 15164 ,, 14022 ,. 14038 ,, 12952 4. 13109 5 - 15829 5, 15218 4, 14107 ,, 14083 ,, 12987 4, telat. 158535, 15264 4, 14186 -,, 14125 (7 13020 egies 15875 5, 15803 4, 14256 ,, 14166 ,, 18053 52 iste 15891 5, 15389 5, 14823 ,,) 14206 5, 18088 4, 13207 55 15906 5, 15371 5, 143938 (, 14245 4, 13121 4, 138229 55 15920 5, 15398 5, 14456 . 14284 (0 13154) ee 1593838 55 15483 5, l4sl4 ., 14303 (| 1806) oe 15945 5, 18447 4, 14571 1g «14863 4g «= 18215 eee 18956 4 15468 5, 14620 -, 14402 (5 13248): ee 15965 4 15488 5, 14670 |, 14444 (7 132837 15974 4 15504 |, 147d 4, 14488 (5 8818 ee 15983 4 15521 3, 14759 4, 14588 4, 18355 4, 18854 59 15992 6 «15537 yn 14797 «40 = 14605 5, = 13888 4, 13878 5) D998 7 8 eda? eso ee ere 18421 4, 18898 6, OOS a SO i MSIE ve 13451 2 ee Hog lees a Lge 13483 4, 18439 5, 160208 tsb) 4 ie oe 13516 ,, 138466 5, 16025" 9 S608) ne Seas 13547 54 18498 5, 16033, 15622 5, 15013 4, 13576 5, 18520 64 OU UN OCD ye OTE 13602 5, 18548 94 MOE | tone ie eee a. 13627 5) 18576 MOUS ys C7 as MOIS 13648 7, GOCE) 63a sary Coro0 es 13664 || OU GE ey oT ee aR a 13675 5) MOOT ye IDE S08 © oa 13696 5. 16087 4, 15419 13724 2) 16099 43 13758 3, 16110) =, 13794 34 16122 15 13833 45 OUD 13873 4, 161499045 13914 45 16163 54 13954 4) 16181 J, 13998 16197 3, 14050 ~~ 16213 4 16232 Properties of the Keldspars. 15 heating merely acts to change the general inclination of the - eurve but not to emphasize the absorption of heat. By way of conveying a concrete impression, it may be added that Ab,An, just above its melting temperature resists the intro- duction of a stout platmum wire (1°5"™ diameter) unless the cold wire is thrust in very quickly and vigorously. If the wire is first allowed to become hot in the furnace, it will give way itself instead. No acceleration of the melting process tending to sharpen the break in the curve appears to be possi- ble without the introduction of new substances or new con- ditions (water vapor under pressure for example) which would take the experiment outside the definition of a “dry melt.” We have undertaken some preliminary experiments in these directions, but they belong to another phase of the subject. A number of efforts were made to locate the melting tem- perature of Ab,An,, which are given in the list below. Although two days were required to erystallize each charge of the material sufficiently for a determination, the recorded numbers possess but little significance, as will be clear from the foregoing. AB3AN, First Preparation. Hlectromotive Temper- Date. Klement. Force in MV. ature. Remarks. Nov. 23, 1903 A eh eb LS BE~ Oe alla A 13415 1336 ore a A 13698 1359 Dee. 726;°°* A 13319 1328 Jan, 14, 1904 No. 3 13893 1370 Mean 1344° Second Preparation. Mch. 11, 1904 A 13218 1320 “co dags ag No. 3 13469 1335 i 32On Approximate melting temperature 1340°. Ab,An,—With Ab,An, a third proof of the identity of composition of the first crystals to separate and the vitreous residue was obtained. ‘The optical identification of this feld- spar is absolute. If we could obtain crystals at all in a melt of this chemical composition, therefore, it would offer a crucial test of the relation of the solid and liquid phases in a part of the curve where no melting point or specific gravity determi- nation upon crystals was possible. After some days of nearly continuous heating at a temperature somewhat below its assumed melting point, a few crystals of Ab,An, were obtained and identified. 116 Day and Allen—Isomorphism and Thermal Albite.-—From the experiments upon natural albite and orthoclase, which have been described, and after observing the effect of the increasing viscosity as we approached the albite end of the artificial plagioclase series, we had no expectation of finding a melting point for either in the ordinary sense. Nor did we in fact succeed in locating a point of any real significance in this connection. The various trials which were made were simply calculated to throw all the light possible upon the character of the change from (crystalline) solid to liquid in such extremely viscous substances. The return change or recrystallization of such substances from the melt (solidifying point) without the introduction of modifying con- ditions has never been accomplished. The time required to do it is certainly very great, probably much greater than the demonstration is worth at the present stage of experimentation in this field. Crystalline albite has been produced under exceptional con- ditions several times—by Hautefeuille,* by heatmg a very alkaline alumino-silicate with sodium tungstate for 30 days at 900°-1000°; by Friedel and Sarasin,+ using an atmosphere of water-vapor under high pressure and a moderately high tem- perature (an aqueo-igneous fusion); by J. Lenaréié,t at ordinary pressure and high temperature by crystallization out of a mix- ture of melted albite and magnetite (1 part magnetite, 2 parts albite by weight), and by others. It may be noted in passing that, entirely apart from the solution relations, the last mentioned process reduces the viscosity to an entirely differ- ent order of magnitude from that of pure albite; magnetite melts to form a thin liquid almost of the consistency of water and even in 1:10 solution with albite forms a fairly mobile liquid. We endeavored to repeat portions of the work of Hautefenille and Lenarcit, but were obliged to postpone a systematic inquiry into the conditions of crystallization which involved the addition of other components or extraordinary pressures, until our plant could be somewhat extended. Hautefeuille describes his successful preparation as a “solu- tion” of the alkaline alumino-silicate in sodium tungstate out of which the albite slowly crystallizes after long heating, but he remarks that the crystallization does not take place if the mixture is heated sufticiently to melt the components of the charge into a homogeneous glass. In that case he obtained only a vitreous white enamel. The case does not appear, therefore, to be one of simple solution, out of which the same ee Annales de l’Ecole Normale Supérieure, 2d series, ix, p. 363, + Friedel and Sarasin, Bull. Min., clvili, 1879; Ixxi, 1881. t J. Lenaréit, Centralblatt f. Min., xxiii, 705, 1903. Properties of the feldspars. LEE solid phase always reappears upon reproducing given condi- tions of temperature and concentration. On the contrary, as Hautefeuille describes the experiment, the components of the albite remain as independent solid phases, which are then assembled in some manner through the intermediary action of the melted tungstate. Notwithstanding the fact that our interest was confined for the moment to the mere production of a small quantity of chemically pure crystalline albite, we ventured to proceed along the lines of Hautefeuille’s unsuccessful trial. We first prepared a chemically pure albite glass, i. e., we melted the components into a homogeneous mass before adding tungstate. This glass was then finely powdered, thoroughly mixed with an excess of powdered sodium tungstate and maintained con- tinuously for 8 days at 1100°. Upon removing from the furnace at the close of the heating, both albite and tungstate were found to have been completely melted and to have separated into two distinct layers according to their specific gravities, the albite glass being above, and showing no trace of erystallization. A second charge was then prepared with only 50 per cent of the tungstate, powdered and mechanically mixed as before, and maintained at a temperature of 900° for 17 days. This time we were successful. After the sodium tungstate had been dissolved away with water, the albite appeared as a powder of about the fineness to which it had originally been pulverized, except that the fragments were now crystalline and apparently homogeneous albite. In thin section, under the microscope, to our considerable surprise, it appeared that the original glass fragments were unchanged in form. The bounding surfaces were all conchoidal fractures, as they came from the hammer, and evidently had not been in solution with the tungstate at all. Its optical properties showed it to be undoubted albite and the specific gravity was 2°620. The preparation of albite which we had synthesized by heat- ing with an equal weight of sodium tungstate was first purified by thorough washing with warm water, but this was not suth- cient to remove all the tungstate. A determination of tung- stic acid showed 0-62 per cent still present, which is equiva- lent to 0°78 per cent of sodium tungstate. After removing the water by heating carefully to a dull redness, the product was submitted to a microscopic examination, which showed it to be entirely crystalline and apparently homogeneous. Determina- tions of the specific gravity gave 2°620 (see table, p. 128). If this is corrected for 0°78 per cent of sodium tungstate of spe- cific gravity 4°2, we obtain 2°607. A portion of this preparation was then purified further by fusing for a few minutes with acid sodium sulphate (Haute- 118 Day and Allen—Isomorphism and Thermal feuille) at as low a temperature as practicable, after which the excess of sulphate was extracted with water and the product dried (the temperature was raised to a dull red heat to remove all water) and analyzed. Found. Calculated. SiO ore tera. 68-74 68°68 Al,O. and ji ; Fe.0, 1 Nd a AE 19°56 19°49 Na,O Wh. WN Ek. Mair gate Wahers3 11°83 SOn ae eae 02 WI SEE ee 16 100°21 The specific gravity of it was 2°604, which may be corrected as before for the remaining trace of tungstic acid assumed to be in the form of the sodium salt. The value then falls to 2-601. A, second portion of the same albite was purified by another precess. Insteaa of fusing with acid sodium sulphate, the powdered sample was first digested for a short time with dilute hydrochloric acid (1:1), which set free tungstic acid. The excess of hydrochloric acid was removed with water, the tungstic acid with ammonia, aud finally the excess of reagent and the ammonium tungstate by further washing with water. When dried at a low red heat, the preparation had the follow- ing composition : Found. Calculated. SiO gee ae 68-91 68°68 ae = neo ein ate ae 19°13 19°49 NO py ee NGlOMEA nite ag 11°59 11°83 WO, ra) 29 EO) Sw 13 99°98 The specific gravity determination gave 2°615, which when corrected for a small amount of sodium tungstate becomes 9612. If, as is possible after the above treatment, the tungstic acid is present as the anhydride, sp. gr. 71, the cor- rection would lower the value to 2°605, in excellent agreement with the other determinations. The products of both methods of purification were carefully scrutinized by the microscope, but no conclusion could be reached as to which was the purer. Neither the sodium sul- Properties of the Keldspars. mg pee fusion nor the digestion with acid and ammonia appeared to have changed the particles in the slightest degree. Diligent search was made for opaque or amor phous matter on the sur- face of the grains, or any other indication of decomposition, but none was found. While the chemical analysis indicates a rather higher purity for the first product, purified by fusion, the differences are nearly within the limits of error and ther e- fore hardly conclusive. Both powders were ground finer than usual for the specific gravity determinations to avoid errors introduced by a spongy structure. Reverting now to Hautefeuille’s directions, it is clear that glass of albite composition crystallizes homogeneously under substantially the conditions which he obtained, as well or better than the mechanically mixed component parts; but the part played by the tungstate requires some further experimental study before a conclusion can be reached. Except for the specific gravity, the experiments upon crys- talline albite and orthoclase which follow were made upon natural specimens from well-known localities (a fragment of the Mitchell Co. albite is shown in Plate I, 1), for which we are indebted to Dr. G. P. Merrill of the National Museum and Dr. Joseph Hyde Pratt, State Mineralogist of North Carolina. The specimens were selected with great care, but like all natural specimens, they contained other feldspars and inclusions. The analyses follow: Albite. Albite. Microcline. (Amelia Co., (Mitchell Co., cMiten ell Co Va.-Nat. Mus.) Calculated, N.C. -Pratt.) Calculated, N.C.-Nat . Mus.) Calculated, Found. Anhydrous. Found. Anhydrous. Found. Anhydrous. Si0, fs 68°22 68°71 66°03 66°42 65°49 65°83 AipOre- 19:06 — (19°20 = 20°91 OEY | POE aks Oe (es Oe "15 "15 "18 "18 "36 "36 CaQ.. - “40 “4() 2°00 2-00 “49 “49 Na,O = 11°47 11°53 9°97 10°08 2-29 2°30 KO ae °20 ‘20 “70 ‘70 EOS oO? ST aa 69 bags mg) wre ‘51 ised 100°19 100°38 100°00 It will be remembered that in the preliminary experiments (p. 98) the heating curve of these natural feldspars did not show an absorption of heat which we were able to detect; our first step was therefore to find out what manner of process it was by which a charge of crystalline albite or orthoclase became amorphous without leaving a thermal record behind. We prepared a charge of albite glass from a previous melt powdered to “100-mesh.” In this glass powder a small crystal fragment (perhaps 2x5x10™™), from the same original speci- 120 Day and Allen—Isomorphism and Thermal men and therefore of the same chemical composition, was imbedded beside the thermoelement as indicated in fig. 8. This charge was heated slowly to exactly 1200°, slowly cooled again and several thin sections prepared from the crystal frag- ment and its immediate neighborhood. What the microscope showed can best be seen from the accompanying illustrations (Plate I, 2 et seq.)—groups of crystal fragments of miero- scopic size, preserving their original orientation (extinction) pertectly but with narrow lanes of glass where cleavage and other cracks had been, forming a perfect network without a trace of disarrangement. Considerable melting had taken place but no flow. Neither had the charge as a whole made any movement to take the form of the containing vessel after sintering together (fig. 9). Surmising that we had accidentally hit upon the approxi- mate melting temperature, a fresh charge of like material was RaG= oO! prepared, and the same experiment carefully repeated except that the temperature was carried up to 1206° and maintained there for 30 minutes. Instead of showing the melting to be complete, the slides (Plate I, 3) looked precisely like the first save that the lanes of glass were somewhat wider and the crystal fragments relatively smaller than before. Further trials under precisely the same conditions with the tempera- ture increased to 1225° (Plate I, 4) and 1250° (Plate I, 5) respectively, for like periods of time, showed only more advanced stages in the same process. In the latter case the Am. Jour. Sci., Vol. XIX, 1905. Plate |. 1. Original Albite (Mitchell Co.), x10. 2. Fragment of same heated to 1200°, x20. 3. Another fragment, 1206°, x20. 4. Another, 1225°, x20. 5. Another, 1250°, x20. 6. Another (x 800) four hours at 1125°. 7. Another, bent at 1200°, x10. 8. Microcline bent at 1200°, x10; note the direction of cleavage (cf. dotted line), All the photographs were made through crossed nicols, vitreous areas are therefore black. Properties of the Feldspars. 121 remaining crystal fragments were relatively very small com- pared with the separating lanes of glass, but the orientation of the tiny particles still remained perfectly undisturbed. The evidence contained in this series of slides shows plainly that we have here an unfamiliar condition—a case of a erys- talline compound persisting for a long time above its melting temperature for a given pressure. Albite or orthoclase glass sin- ters tightly at 800°. At the temperature when melting began, therefore (below 1200°), the charge consisted of erystal frag ments of microscopic size imbedded in a large vitreous mass of the same composition and known temperature. These fragments melted so slowly over the 50° included between the first slide (Plate I, 2) and the last (Plate I, 5), with the rate of heating slow (1° in 2 min.), and the upper temperature-continued for 30 minutes, as to leave considerable portions unmelted at the close. Furthermore the extreme viscosity, of which further evidence will be given directly, and the absence of any dis- turbance in the orientation of the particles indicating flow, assured us that the lanes of glass represented actual melting and not an inflow of glass from without. Finally, the per- fectly homogeneous character of the glass and the unchanged appearance of the crystals as heating “progressed, gave no hint of any chemical decomposition. In the hope of obtaining a point of value for comparison with the melting points of the other feldspars, some time and patience were expended in trying to locate the lowest tempera- ture at which certain evidence of melting appeared. We did not extend any single trial beyond a single day, so that our results can not pretend to establish the lowest point at which albite melts. Such an effort with a natural specimen known to contain impurities would yield nothing of value. Mitchell County albite showed signs of melting after four hours at 1100°. Under a high power the erystal edges appeared weathered or toothed—strongly resembling the incipient melt- ing of the ice on a frosted window pane. These extremely fine teeth could be followed through the slide on exposed edges. At 1125° (Plate I, 6, x 300) a four-hours heating gave unmistakable glass in tiny pockets and lanes. The above experiments with the Cloudland albite were com- pleted before we obtained the Amelia County material, but the latter proved to be so much nearer to the type of pure soda feldspar that nearly all the experiments were repeated with it except that the crystal blocks were imbedded in powdered crystals. We did not develop any new fact, however; the effects noted above reappeared in the same order except per- haps that melting went on a little faster in the Amelia County specimen. As much melting was found after one-half hour at 122 Day and Allen—Lsomorphism and Thermal 1200° with the Amelia County sample as the Cloudland (Mitchell County) showed in the same time at 1225°, which is readily enough explained by the relatively large quantity of lime (anorthite) im the latter. Since both time and temperature enter into the delimitation of the metastable region, further trials at temperatures above 1250° did not seem likely to add anything to the knowledge already obtained. And if the heating were very rapid, the temperature differences within the charge would be considerable. A few isolated crystalline fragments were found in an ortho- clase melt which had been heated as high as 1400° for another purpose. Another which had reached nearly 1500° showed no orthoclase, but one or two minute quartz inclusions still remained undissolved. We made a rough attempt to get a more tangible idea of the viscosity of these feldspars at their melting temperature in the following way. A long, slender sliver (perhaps 30x2x1™™) of albite and one of microcline were chipped from larger por- tions, spanned across small empty platmum crucibles, and placed side by side in the furnace. These exposed crystals © were heated to 1225° for three hours. When removed, they were completely amorphous (melted) but retained their posi- tion with hardly a trace of sagging. After this a number of similar slivers were prepared, mounted in the same way, and heated to temperatures of from 1200° to 13800° for a few moments. At their highest tempera- ture a platinum rod was inserted through a hole in the top of the furnace and allowed to rest as a load upon the middle of the crystal bridges. Under this load the partially melted slivers gradually gave way, and were taken from the furnace in the various forms shown in the illustrations. Slides cut from these showed no squeezing out of the melted portion between the crystal fragments on the side toward the center of curvature, or open cracks on the outer side (Plate I, 7, 8.) On the other hand, a variable extinction angle in an unbroken crystal fragment frequently gave unmistakable evidence of the bending of the erystal as well as the vitreous portion. From these. qualitative experiments it seems possible to assert with confidence that the order of magnitude of the viscosity of the molten portion (glass) is the same as the rigidity of the crystals at these temperatures. Plate I, 7, shows a piece of Mitchell Co. albite heated to 1200° under load. The sagging is indicated by the curved cleavage cracks. Plate I, 8, shows a sliver of microcline which has been heated to 1200° under load. The sagging is shown by the curvature of the crystal edges and the cleavage cracks. Properties of the Feldspars. 123 The black portions are glass. It is interesting to observe that while the erystal has melted completely across, there has been no displacement of the cleavage plane. The preceding experiments gave a clear idea of the phe- nomena attending the melting of albite and orthoclase, and convinced us that the absorption of heat accompanying — fu- sion, which we had searched for in vain upon the heating curves in the earlier experiments, had eluded us merely because it was ex- tended over so long a stretch of the curve as not to be notice- able. Some very exact measurements of the temperature change from minute to minute were therefore made in the hope that a more intelligent search might be more suc- cessful. Separate charges of glass and of crystals of the same composition and of equal weight were prepared and successively heated in the same furnace with the same cur- rent. The specific heat is of course not identical in the two 12000 11500 11000 (1135°) 10500 Temperature (MV). 9500 = [: (10002) 0 20 40 60 80 100 120 140 160 Time (minutes), re. 10! cases, but the curves were comparable in form. Above 1100° we felt sure that one of the curves must contain an absorp- tion of heat which would be absent from the other. Such 124 Day and Allen—Lsomorphism and Thermal a pair of curves, I, taken from the microcline measurements, is reproduced in the adjoining figure (fig. 10), and appears to show such an absorption clearly, extending from 1135° to 1275°. The dotted line shows the course of the curve without the absorption, as inferred from the glass curve. The same figure contains two other curves (II, In), similarly treated, which were made upon fresh charges of the same material, but with different rates of heating. It will be noticed that the absorption begins to be noticeable at a slightly lower temperature if the heating is slower. This peculiar behavior shown by compounds which melt to form hyperviscous liquids seems not to have been observed before and to contain features of more than ordinary interest. Here are evidently crystalline substances which not only can exist for considerable periods of time at temperatures far above their melting temperatures, but which melt with extreme slow- ness in the lower portion of this range of instability. It would certainly be no exaggeration to say that the albite with which we worked would require some weeks to reach the amorphous state if maintained at a constant temperature of 1125°. ~ An interesting question arises here as to the state of the crystalline material at temperatures above its melting point. It is easily conceivable that the crystals are merely superheated without loss of any of their properties as solids, and that they thus present an analogy to superheated liquids. In the trans- formation (Umwandlung) of a solid crystalline substance into another crystal form, such superheating has long been known. The change is dependent upon temperature and pressure like ordinary fusion, but it is possible to pass the transformation temperature in either direction. This must be due to the unfavorable opportunity for molecular motion which solids afford, and the latter should differ in no essential particular from ultraviscosity. On the other hand, it does not seem a violation of any known principle to conceive cases of unstable equilibrium in which the molecules of a liquid are oriented as in a crystal. Maxwell’s demons might arrange them much like a school of fish and there is no apparent reason why the fluidity should be destroyed thereby. Were such an arrangement one of mini- mum potential, the mass would be a liquid erystal. In the supposed case such a substance would possess a melting point dependent upon the temperature and pressure, above which Maxwell’s definition*® of a true solid—that its viscosity be infinite—would no longer obtain, although deorientation might not become apparent, in the face of extreme viscosity, for a * Maxwell’s Scientific Papers, vol. ii, p. 620. Properties of the Keldspars. 125 considerable time afterward. Such a melting point would be determinable only with the greatest difficulty, for all the func- tions—mechaniceal, thermal or electrical—which usually become suddenly discontinuous at the melting point would be equally powerless to define a change of state in the face of such extreme molecular inertia. In substances like these, which are still viscous at the tem- perature of the electric arc, the sharpness of a minimum due to heat absorption, for example, is not dependent upon the magnitude of that absorption entirely, but also upon the rapidity with which the change which involves it proceeds. In albite and orthoclase, the velocity of this change is very small. Specific Gravity.—The study of the specific gravities yielded one interesting result which was not anticipated. The arti- ficial feldspars, being chemically pure and homogeneous, gave a perfectly definite specific gravity which could be determined with great accuracy if the specimen was completely crystal- lized. If vitreous inclusions were still present, the results were of course variable and were all too low. It was anticipated that the density of pure glasses, transparent and free from bubbles,-as they were in the more calcic members of the series, might yield values varying more or less with the rate of cool-’ ing, or after annealing, but this did not prove to be the case. Our results did not vary more than two units in the third decimal place in the same preparation even with the more calcic feldspars which required to be very rapidly chilled in order to cool the melt without crystallization. The determination of specific gravities is a trite subject, but we have found the common methods liable to such grave errors that we venture to give some useful details. The error due to the evaporation of water about the stopper of the pyc- nometer is very much less with finely ground stoppers than with coarse grinding, and if the stopper is slightly vaselined just before the final weighing, the error from this cause will hardly affect the third decimal place with 25° pycnometers. The simplest form of flask with a small capillary opening in the stopper, is, in our judgment, far superior to one carrying a thermometer. ‘The temperature should be made sure by the use of the thermostat. For removing the air from a powdered charge, we used the device of G. E. Moore,* slightly moditied, as indicated in the accompanying sketch. The bulb A contains boiled water. *G. E. Moore, Jour. prakt. Chem., ii, p. 319, 1870. Am. Jour. Sct.—FourtH Series, Vout. XIX, No. 110.—FEBRuaRY, 1905. 9 126 Day and Allen—ILsomorphism and Thermal When the apparatus is exhausted, the water is allowed to flow back into the pyenometer containing the charge ; then by tap- ping and warming with water at 40—-50° to produce boiling within, the air is effectively removed. The material projected from the flask, if the boiling is violent, is then washed back from the tube 4 with boiled water and any small particles remaining are washed into a tared dish and finally weighed. It is very important that not the smallest grain of material should get into the ground joint between the neck and stopper of the pycnometer. To obviate this, wipe out the neck with filter paper before stoppering and burn it in the tared dish. Asp rator iDinees. LIL If the powder is very fine it is advisable to allow the filled pycnometer to stand for some hours in the thermostat, in order that suspended material may settle. With a 25° pycnometer and 5 to 10 grams of material, this method usually yields con- cordant results to the third decimal place, and the error from all causes should never be greater than two units (+ 1) in the third place. A determination of this accuracy is of course sub- ject to a correction for buoyancy, and all the numbers which follow have been thus corrected. There is another error to which accurate specific gravity determinations upon powdered minerals will be subject unless suitable precaution is taken. The exposure to the air during the period of grinding the samples gives opportunity for the condensation of sufficient atmospheric moisture upon the grains to affect the weight in air. The amount varies measurably with the size of the grains, as will be seen from the accompanying data, and probably with the degree of saturation of the atmos- phere and the time of exposure. Properties of the Feldspars. 127 DETERMINATION OF MOISTURE IN 1 GR. OF POWDERED MINERAL UPON EXPOSURE TO THE AIR. Mineral. Fineness (mesh), Moisture, Orthoclase (natural glass) 120 0010 Ab, An, ( ce glass) < 100 >120 0007 es cryst. ) 120 "0010 Ab (natural ~*~ ) coarse "0006 Ab (ae ce) <150 “0069 Orthoclase (natural cryst.) < 120 >150 "0011 gr. es (same sample ) <150 0031 5 Gait ) stili finer 0059 Orthoclase (artificial glass) everything <100 ~~ 0065 ier. eS (portion of same) >150 0022 <= finer than >= coarser than In the last two groups, note that the moisture in selected portions of the same sample varies with the fineness. We also veritied the conclusion of Bunsen* that this adsorbed moisture is not removed at temperatures only slightly above 100° but requires 600° to 800°—equivalent to a low red heat. Several samples for which the moisture had been determined were laid away in corked test tubes for a number of weeks, after which redetermination gave exactly the former value. It is worth noting in this connection that these measured quantities of adsorbed water are of the same order of magni- tude as those usually obtained for the water content in feldspar analyses,t where again, of course, the finer the sample is ground for the analysis, the greater the possible error from this cause. It may be that a part and occasionally all of the moisture usually found in these analyses is adsorbed and the significance of its presence there mistaken. | The number of feldspars of which specific gravity deter- minations could be made was limited only by the possibility of obtaining complete crystallization within a reasonable time. Thus Ab,An, was reheated many times before a constant value was reached. Ab,An, required 17 days and Ab,An, was not completely crystallized in any of our attempts. Crystalline albite was produced under other conditions. The specific gravities of the glasses and of so many of the crystalline mixtures as we could obtain are tabulated below : * Wied. Ann., xxiv, p. 327, 1885. + Dana, System of Mineralogy, 6th ed., p. 314 et seq. 128 Day ond Allen—ILsomorphism and Thermal SPECIFIC GRAVITIES OF ARTIFICIAL CRYSTALLINE FELDSPARS. Ab, An; Ab, Ane Ab, An, Ab2An, Ab;An, Ab (First Deter- mination) "764 2°734 2°710 j 2°680 2°660 2°650 e, 2°620 “165 ( 2°734 2°708 ( 2°680 2°660 2°648 2°620 2°660 ‘167 2-732 2°710 2°679 2°659 4 ( 2-614 a) 2°732 D 2°710 D 2677 D 2°660 a) 2-615 a 2734 | e 2-604 ‘765 2733 2-710 2°679 2660 2-649 » SPECIFIC GRAVITIES OF FELDSPAR GLASSES. 2:647 1 (23593 eee | 2482 9°458 2383 2649 | 2°594 9°534 2-489 2-459 2°382 2-648 9°59 1 a W485 2-647 9°591 2-648 2590 2649 i 2°588 ( 2°647 ) 2°647 Mean 2°700 2648 O59. | 25533 9-483 2-458 9382 Determinations in duplicate are enclosed in brackets. a. Another preparation. 6b. Same materia! reheated for several days at temperatures about 150° below the melting point. ce. Contained about 0°8 per cent of sodium tungstate. d. Purified by warming with dilute hydrochloric acid, then with water, and afterwards with ammonia. é. Purified by fusion with acid sodium sulphate. Jj. Assuming the residual tungsten to be present as Na, WO,,. g. Assuming the residual tungsten to be present as WO.,. Sintering.—Incidental to this work upon the relation between the feldspars, we made a great many observations upon the sintering of powdered minerals, both crystalline and vitreous, of natural and artificial composition. While the results have not enabled us to offer positive conclusions of importance, they are worth a note in passing, Powdered glasses sinter slowly or rapidly several hundred degrees below the melting temperature of crystals of the same composition. When the viscosity is relatively slight (anorth- ite) crystallization begins at a low temperature and proceeds very rapidly, the sintering probably being due to the inter- weaving of the crystal fibers during their formation. In vis- cous glasses (albite) sintering also begins at low temperatures,— Ab (Cor- rected) 2°607 2°601 Ff 2612 J 2°605 2°605 * Properties of the Feldspars. 129 the finer the powder and the slower the heating, the earlier the first traces appear. Long continued heating, even at very low temperatures (700°), yields a perfectly continuous cake (except for the included bubbles) the surface area of which constantly tends toward a minimum. ‘There is no doubt that the sintering of powdered glasses is due to flow in the under- cooled liquid and is a phenomenon in liquid viscosity. All the feldspar glasses sintered readily between 700° and 900°, de- pending on the fineness of the powder and the time. Powdered crystalline feldspars do not sinter readily below their melting temperature. Indeed we were at first inclined to the view that when only pure, dry, stable crystals are pres- ent, they do not sinter however finely they be powdered. We observed the phenomenon in natural albite at 1000° but the erystals were not wholly free from inclusions which may have caused chemical reactions resulting in cementation. Crystal- line fluorite also sinters 300° below its melting point, but here we were able to establish a decomposition. Acid fumes were evolved during the experiment and the sintered cake contained 1 per cent of free lime. Our final experiments with long con- tinued heating for specific gravity determinations, however, showed that the purest feldspars we could prepare, even after they had reached their maximum density, still sinter very slowly. Thus Ab,An, powder, which was shown by a deter- mination of its specific gravity to be holocrystalline, formed a compact chalky mass in four hours at a temperature about 150° below its rnelting point; in three days it was as hard as porcelain. Other feldspars showed the same behavior. It is hardly possible that inhomogeneities sufficient to produce dif- fusion between portions of different concentration, could have existed in these charges. There is considerable indication that some of the crystalline nuclei grow at the expense of others— perhaps through exceedingly slow sublimation—which may account for it. We made repeated attempts to locate some fixed sintering point which should be characteristic of a particular material by means of continuous measurements of the electrical con- ductivity, but they all indicated that no such point existed. The conductivity of a dry powder increases enormously after sintering begins and would therefore seem to offer a most sensitive test, but the phenomenon is altogether gradual even with a cr ystalline feldspar containing only a small percentage of glass. We purpose to extend these observations to other substances Conclusions.—It now remains for us to gather the results together and to draw such conclusions as they appear to justify. (1) If the melting points are now plotted in a system of 130 Day and Allen—Isomorphism and Thermal which they form the ordinates, while the percentage composi- tions of the different feldspars form the abscissas (fig. 12), we discover, within the limits of accuracy of possible measure- ment at these temperatures, a nearly linear relation: the melt- ing point varies very closely with the compositton. We have no maximum, no minimum, no branching of the curve, but from each fusion there separates a solid phase of the same composition as the vitreous matrix. In Ab,An, it will be remembered that this was proved by the separ ation and analysis of the two phases; in Ab,An, partial crystallization was accomplished in the first cooling and the remainder in a subse- wn ® Ea en ® 2 = a. =| iS) a Ab,An, Ab3 A An 100 ‘ 5 37 2671 0 Ab 0 159 32°0 48°5 65°3 73°9 100 quent reheating and cooling, the two groups of crystals prov- ing optically identical ; a small quantity of Ab,An,, which admits of absolute Aleaekeeation optically, was crystallized out of a melt of that composition and readily recognized. More- over, evidence to show that the same phase always separated was likewise presented. Stated in this way, the relation appears to be a simple addi- tive one in which liquid and solid phases of like composition are stable in all proportions of the components and behave like a series of separate feldspars. But as soon as we consider it with reference to the laws of solution and the phase rule, it ean not be explained in this simple way. First of all, the phase rule tells us at once that we can have no true compound here between the components albite and anorthite, for such a compound would mean one more com- ponent and an additional phase in every solution before equi- librium could be established. Moreover, if the mixture had Properties of the Heldspars. 131 been eutectic in character, the component (albite or anorthite) which happened to be in excess would have erystallized out in each case, causing a continual change in the composition of the remaining glass until the eutectic proportion was reached and the resulting charge would have contained only crystals of one (or, in ease of hysteresis, both) of the components and the eutectic. Our curve is continuous and the resulting charges homogeneous for all proportions of the components. Lane’s suggestion™ that the triclinic feldspars from a eutectic series in which the eutectic proportion is at or near Ab, An, is therefore not borne out by our experiments. Laying aside the eutectic mixture, and passing over to solu- tions of components which are miscible in many or all propor- tions, we find a small number of examples, chiefly organic com- pounds, which have been studied as types by Roozeboom, Kiister, Bodlander, Garelli, Bruni, Van Eyk and others, among which our series appears to fall. Laws of Solutions.—From the physico-chemical standpoint, the case we now have in hand closely resembles Ktister’s prob- lem of 1891.+ His measurements were made upon mixtures of organic compounds of low melting point, while ours reached a maximum temperature of 1532° , but we have, between albite and anorthite, an exactly similar ‘series of solid solutions the melting pointst of which change in nearly linear relation to the percentage of the two compounds which enter into their composition. This simple linear relation was called by Kuster perfect isomorphism, and he formulated the “ Rule” which has since borne his name, that the solidifying point of an isomorphous mixture lies on a straight line joining the melting points of the components and can be calculated from the percentage composition of the mixture. If this line proved to be slightly concave or convex, as it did in most cases, imperfect isomorph- ism was assigned as the cause. To this rule an objection was raised by Garelli§ and elaborated by Bodlinder|—if the solid solution behaves like other solutions, a small quantity of com- ponent & added to component A can only lower the solidity- ing point of A when the solid phase is richer in A than the liquid phase. The reasoning is this (Bodliander): let x, (fig. 13) be the vapor tension curve of component A in the liquid state, y, the solidifying point (¢,) of A, and 2, the vapor tension * Lane, Journal of Geology, XII, ii, p. 83, 1904. + F. W. Kiister, Zeitschr. fir Phys. Chem., viii, p. 577, 1891. ¢ Ktister measured solidifying points, but we have pointed out above that such measurements lead to no positive result in liquids of such viscosity as the feldspars in which equilibrium is not established during solidification. Undercooling rarely appeared at all in Kiister’s cases. SF. Garelli, La Gazzetta Chimica Italiana, xxvi, p. 268, 1894. | Bodlander, Neues Jahrb. f. Min., Beilage, Bd. xii, p. 52, 1899. 132 Day and Allen—Isomorphism and Thermal eurve of solid A. Now if a small quantity of B is added and the solid phase which crystallizes out contains the same pro- portions of A and & as the liquid mixture in which it formed, the vapor tensions of the liquid and solid phases must have been lowered equally and the solidifying point will fall at y, with the same temperature as the pure solvent. (Equality of vapor tension in the solid and liquid phases determines the temperature of change of state.) If A erystallizes alone from A + £, the vapor-tension curve will continue on to z, and the temperature of solidification fall to ¢,; while if the solid phase contains both components bnt is richer in A than. the liquid phase, solidification will occur at an intermediate point. Vapor tension —> Temp. —> ee 4, 100A <—Composilion > 100B Hie. 13. igure Tbzh Fig. 14 will serve to show the crucial character of the issue raised. The ordinates represent temperatures, and the abscis- sas percentages of A and &. Kister finds his solid and liquid phases identical in composition within the limits of experi- mental error and the solidifying temperature on the line AB at a point which can be determined from the proportions of the components—at d for example. But the laws of dilute solutions tell us that if the phases are identical in composition, the solidifying point of A + 6 must fall at ¢, i.e. must remain the same as for pure A. The temperatures at which Kister’s observations were made and their painstaking character leave no doubt as to the valid- ity of the experimental fact. Neither can it be objected that Kiister’s solutions were not sufficiently dilute to reveal the true relation, for the observations upon naphthaline and 8-naphthol have been repeated by Bruni* with very dilute solutions of one of the components in the other, and completely verified. Now. the laws of solutions hold for solid solutions even for moderately high concentrations (Bodlinder) when the com- ponents are not isomorphous, and on the other hand even liquid erystals, when isomorphous, follow Kiister’s Rule more nearly than the law of solutions. *G. Bruni, Atti della Reale Accademia dei Lincei, series 5, vii, p. 138, 1898. Properties of the Feldspars. 133 An extended discussion of existing data from this stand- ' point would involve us in unnecessary detail, but there can be no question that Kuster’s Rule represents the data which have been gathered upon isomorphous mixtures—at least approxi- mately—while the laws of dilute solutions appear to fail of application there. On the other side, the Rule admits of no independent theoretical derivation. Van’t Hoff* suggests that judgment be suspended pending the accumulation of further data and intimates that the close similarity of chemical com- position and molecular structure in compounds which form isomorphous mixtures, gives them an unusually close inter- relation, and their influence one upon the other may render a simple theoretical treatment very difficult. Our case is especially interesting when considered from this standpoint, but it distinctly emphasizes the difficulty rather than helping toward its solution: (1) Although the chemical reac- tions of albite and anorthite are not of such a character as to. prove or disprove a close analogy between them, a comparison of their formulas certainly does not suggest an isomorphous rela- tion. If their formula weights represent true molecules, they possess the same number of atoms to the molecule (NaA1IS8i,O,, CaAl,Si,O,) and the group $i,O, in common, but the remaining atoms taken separately are not mutually replaceable. (2) The melting points of the components in the feldspar series are very far apart—more than 300°—while Kiister’s organic mixtures were all included within a narrow temperature interval (2° to 56°). For reasons which will appear presently, both Garellit and Roozeboom have pointed out that the farther apart the melting points of the components, the less probable is the linear relation. (3) The homogeneity of the solid phase is established within 1 per cent by the optical examination of the slides. Moreover separate chemical analyses of the solid and liquid phases of the mixtures Ab,An, in an exceptionally favorable case showed still closer identity of composition. It appears altogether improbable that the laws of solutions can apply in the face of so extreme a controverting case. If it has proved diffienlt to bring the isomorphous mixture within the general laws of solutions, a most satisfactory theo- retical derivation of the conditions of equilibrium in such mixtures has been developed by Roozeboom. No other prin- ciple is required than the second law of thermodynamics as applied to solutions by Gibbs :—A system of substances will be in equilibrium for a par ticular pressure when the thermo- dynamic potential (function) of the system is a minimum. The scheme of representation is the graphical one proposed by *Van’t Hoff, Vorlesungen tb. Theoret. u. Phys. Chem. (Braunschweig 1901.) Part IL, p. 64. + F. Garelli, loc. cit. 134 Day and Allen—Tsomorphism and Thermal van Ryn van Alkemade* and is itself a powerful instrument of analysis in this field. . Roozeboom distinguishes three general classes of isomorphous mixtures : (1) The components are miscible in all proportions from 0 to 100 per cent in both solid and liquid phases. (2) Miscibility is limited to certain concentrations. (3) More than one type of erystal occurs. In the feldspars we are concerned with the first class only, but here also Roozeboom distinguishes three possible types : Type I. Melting (or solidifying) points of the mixtures lie on a continuous curve joining the melting points of the com- ponents and containing neither maximum nor minimum. Type Il. The curve contains a maximum. Type III. The curve contains a mimimum. * Zeitschr. f. Phys. Chem., xi, p. 289, 1898. Except for the suggestions of Vogt to which reference has been made, this method seems not to have been utilized for the study of mineral solutions before. A brief outline of it will therefore be given here. In a system of rectilinear codrdinates (fig. 15) the ordinates may represent the potential of a particular P,T constant system—(Gibbs’ ¢-function, not directly measureable) and the abscissas the num- Y ber of gram-molecules of solvent (water for example) supposed to contain 1 er. d mol. of solute. In other words, every point of the curve represents a solution _ —_ = of which the « codrdinate rE b is concentration and the y = r- coérdinate the potential. ead) (= | The conditions of pressure w and temperature are assumed constant for a par- ticular diagram. Fie. 15. Every such curve for sub- stances soluble in all propor- tions will be convex downward, otherwise there would be some particular point on the curve which would not represent a minimum potential for a particular composition and the solution would tend to separate into two, the mean potential of which would be lower. The condition for equilibrium between such a solution and its solid phase (pure salt) may now be readily found. Lay off on the ¢-axis a distance equal to the potential of the solid salt and from the point su obtained draw a tangent to the curve. This tangent is the locus of minimum potential (stable systems) for any composition. At the point a for example, we have a sat- urated solution containing the number of gr.-mol. of solvent indicated by the * Concentration —> corresponding abscissa and the proportion = of salt, the balance of the salt g remaining in solid phase. At b we have the saturated solution with all the salt included ; to the left of 6b upon the curve, supersaturated solution; and to the right unsaturated solution. With increase of temperature the form of the curve changes and c approaches d, the melting point of the salt. Properties of the Feldspars. 135° These types are for the moment purely hypothetical and are a product of the method of analysis, though they are being rapidly identitied for various isomorphous pairs by pupils of Roozeboom and by others. The method of reasoning which yields these three possible types I will be briefly described with the help of the van Alkemade graphi- Ss eal analysis: If we indicate the potential (¢) € of a particular mixture by the length of the ordinate (fig. 16), aud the number of molecules of ; A and B by subdividing the hori- ae zontal axis (A+ 6=100) in the proper proportion, assuming Lee atmospheric pressure and constant S temperature for each diagram, then See ag every point within the coordinates € represents a particular phase of known composition and potential. Suppose now (Roozeboom) a tem- perature is assumed above the melt- ing point of the higher-melting component, clearly, whatever the composition, only the liquid phase can have a stable existence. If potential difference represents the measure of the tendency to change and the tendency of all change is toward the minimum potential, for this temperature all change will be toward the liquid, and the potential of a solid, if one existed there, would be greater than that of the liquid for all compositions —hence the eurve S (solid) above the curve Z (liquid) throughout. Suppose the potential to be lowered to a point where crys- tallization can begin, the tendency to melt no longer obtains for all compositions, the two curves will be displaced relatively and, being of different form, will intersect. Draw a common tangent to the two curves and apply van Alkemade’s reason- ing above noted. The trend of the potential of both phases between the points of tangency, 1. e. of all mixtures between these limits of composition, is toward the minimum repre- sented by this tangent. Crystallization will then begin at a Hie. 16. 136 Day and Allen—Isomorphism and Thermal (fig. 16, Il) with the mixture richest in the higher melting component, crystals of composition @ will be in equilibrium with the liquid phase 6 in all proportions and solidification (or melting) will not take place at a single temperature but through a range of temperature. If we now plot the length of the abscissa cor- responding to a in a separate dia- gram with the observed tempera- ture range of solidification, adding all the other possible cases which will arise from the continued dis- placement of the C-curves, we arrive at the accompanying dia- gram (fig. 17) of Roozeboom’s type I. Types II and III appear in the same way when the form of the ¢-curves changes as indicated in figs. 18 and 19. The physical side of the system of reasoning is readily inferred from the figures. If we start with a mixture of the composition indicated by m, (fig. 20) and temperature above the melting point, crystallization will begin at a, the separating erystals will have the composition 6, while that of the remain- ing melt approaches d. Upon cooling to e, solidification ends with crystals of this composition. Melting is exactly the reverse operation. Whether these first crystals of composition 6 remain stable as such or undergo solid transformation or wholly or partly redissolve, appears to remain undetermined in any general way by Roozeboom’s theory and may be radically influenced by accompanying phenomena like viscosity and undercooling: if a liquid mixture of composition @ under- cools to e before crystallization begins, crystals of composition e will appear and no others (provided the release of heat of fusion does not raise the temperature above ¢). Such a situa- tion is certainly unavoidable in viscous mixtures like the feld- spars and accounts very well for the homogeneous solidification observed by us. This would classify the feldspars with type I of Roozeboom’s series. A comparison of our melting point curve with figs. 17, 18 and 19 shows this to be the only type under which it could possibly fall. There is no trace of a maximum or minimum in the feldspar curve. Vogt’s expecta- tion that they would fall under type 3 therefore fails of fulfilment from our experiments. That our curve so closely resembles one branch of Rooze- boom’s typical curve is remarkable. The difficulties of obser- vation, in those portions of the curve where the viscosity becomes so disturbing, are too great to enable stress to be laid upon the form which our curve happens to take there, but 1g UA Properties of the Keldspars. 37 i Ss s I ¢ 5 looA looA a b 100B Gan alll g A 1looA ab- looB 3 1ooA 100B looA 100 138 Day and Allen—Isomorphism and Thermal near the anorthite end of the series its slight convexity is unquestionably real. It should be added that Prof. Iddings has found slight traces of inhomogeneity Gess than 1 per cent) in the slides of several of our intermediate feldspars. Crystals have been found which were evidently of the earlest B formation and with one excep- tion were more calcic than the body of the charge, as Rooze- boom’s theory would lead us to ~~ . expect. The exception was an looA<—Composition— 109B occurrence of tiny plates of | Fic. 20. Ab,An, discovered in a charge of “Ab,An,. Tire “extremely small quantity of the optically different feldspar, the fact that it could not be found in all the slides and that in one ease a less ealcic feldspar appeared, suggest that the inhomogeneity may have been of other origin—perhaps merely a consequence of the tremendous difficulty in mixing a homogeneous charge where ultraviscosity precludes stirrmg, for example. The chemical analyses of the solid and liquid phases, it will be remembered, showed identical composition within the limits of experimental error. It is clear that if Roozeboom’s theory is valid, the line of the melting points can not become perfectly straight unless the ¢-curves for the solid and the liquid phases can be superposed point for point throughout, i. e., are identical. This would mean that the energy content per gr.-mol. of solid and liquid phase was the same for all compositions, i. e. that all mixtures, and the components separately should have the same melting point,—a case which is known (Roozeboom, d- and /-camphor oxime) but is certainly confined to optical antipodes. Another reason for supposing the case to be much less sim- ple than a mere linear relation with equilibrium between solid and liquid phases of identical composition, appears at once from a direct application of the phase rule. A necessary con- dition for equilibrium in any mixture is that the number of phases exceed the number of components by two. If the solid and liquid phases are homogeneous, the number of phases (count- ing vapor) is only three and equilibrium can not obtain there. Reviewing this discussion briefly: The triclinic feldspars are solid solutions and form together an isomorphous series. It is a sufficient condition for the latter that the curve of melt- ing points is continuous (Bruni, loc. cit.). Like Kiister’s Tem A ae Properties of the Feldspars. 139° eurves for organic compounds, the curve of melting points does not follow van’t Hoff’s law of dilute solid solutions and does approximate closely to a straight line joining the melting points of the components. The case appears to fall under type 1 of Roozeboom’s theoretical classification of isomorph- ous mixtures, in which ease the line can not become exactly straight unless the melting points of the components are nearly or quite identical, nor the solidification absolutely homo- geneous without reducing the number of phases to three and destroying the equilibrium. The theory also accounts for an absence of sharpness in the intermediate melting points of the feldspars, but the fact that this lack of sharpness culminated in albite instead of terminating there shows that the viscosity was the chief factor in our difficulties from this cause. Albite was clearly shown to melt through a variable range of 150° or more, while the intermediate feldspar bytownite (Ab, An,) melted almost as sharply as anorthite. The fact that practi- eally no differences of composition could be detected in our melts we attribute to the effect of viscosity and consequent undereooling, which resulted in crystallization invariably taking place at much too low a temperature for equilibrium to become established between the solid and liquid phases at any stage of the crystallization process. (2) When the specific gravities are plotted, like the melting points, as a function of the composition (fig. 21), the isomor- phism of the feldspars is strongly confirmed. The curve indicates a perfectly continuous relation which the successful preparation of chemically pure albite enabled us to follow through to the end. The order of accuracy is also extraordi- narily high throughout by reason ot the chemical purity of all the preparations and the consistent effort made to obtain complete crystallization, even with the more viscous feldspars. Several of the charges were treated for two weeks or more consecutively, then removed for a determination, then replaced in the furnace for another week, in order that we might assure ourselves from the consistent reappearance of the same value that a maximum and therefore holocrystallization had been reached. Itis of some practical importance to note in passing, that preparations which appeared completely crystalline in the slides frequently proved not to have reached their maximum specific gravity. It is very difficult to detect the last trace of glass with the microscope. If our confidence in these determinations is justified, the form of the specific gravity curve is very significant. It was pointed out by Retgers* that if the isomorphous mixture is merely a “mechanical aggregate,” the volume of which remains exactly equal to the sum of the volumes of the components, then the specitic volume curve of the mixtures for percentages by weight * J. W. Retgers, Zeitschr. fir Phys. Chem., iii, p. 507, 1889. 140 Day and Allen—TLsomorphism and Thermal of the two components must be a straight line. He also offers a number of isomorphous pairs for which he finds the specific volume curves to be straight lines, in support of his hypothesis that this relation is general. Our values when plotted in this way (tig. 22) also give a straight line with maximum variations amounting to 0°005, which is probably not greater than the ageregate error in the syntheses and in the determinations of the specific gravity. In spite of this apparent corroboration, it does not seem to us that Retgers was quite justified in assuming that this relation is entirely without limitation. The temperature at which the specific gravity is determined is so far below the temperature of solidification (in our case, more than 1,000°) that the density at 25° will depend to a considerable degree upon the coefficient of expansion of the material as well as upon composition or molecular structure. The coefficient of expansion will, in general, differ for different substances, and is not, in general, a linear function of the temperature. Considering Retgers’ generalization in the light of these facts, the relation of the specific gravities at 25° would be necessarily continuous but not necessarily linear. The specific gravities of the glasses are also plotted (fig. 21) to show the divergence from the line of the crystals toward the albite end of the series, i. e., as the percentage of albite increases, the density of the glass is diminished more than that of the crystals. There is nothing new in the conception of isomorphism in the feldspars, but the positive character of our experimental results makes them of more than ordinary interest by reason of the fact that so good authorities on the subject as Fouqué and Lévy have passed upon it adversely on the basis of optical evidence derived from artificial preparations. More recently Viola,* has declared that the optical evidence is insufficient to prove isomorphism in the natural feldspars. The melting points and specific gravities are brought together in a convenient table here. Feldspar An Ab,An; Ab,An, Ab, An, Abe.An, AbsAn, Ab Melting temp. 1532° 1500° 1463° 1419° 1367° 1340° Sp. gr. (crystals) 2°765 2°733 2°710 2°679 2°660 2649 2°605 Sp. gr. (glass) 2°700 2°648 2°591 2°533 2-483 2-458 2-382 (3) In the melting of albite and microcline we appear to have substantial evidence of a phenomenon which is unfamiliar both to physics and to mineralogy. Microscopic crystals of a homo- geneous compound, when slowly heated, were shown to persist for 150° or more above where melting began, the amorphous melt remaining of the same order of viscosity as the rigidity of the erys- * Loc. cit. Properties of the Keldspars. 141 tals. By careful observation, curves were also obtained showing that the absorbed heat of fusion was distributed over this interval. From the experimental standpoint a substance of this kind can hardly be said to have a melting point but passes gradually from crystalline to amorphous at temperatures oe can be Crystals soln aa a eeeoeeeee as Ss |e Glass Se ae eae An Ab, An; Ab 1An, < 1208 AN A ( Revaipenine. ie a 61°83 a, 4 Fe,0, Pers oe ev 236 7°40 S Gaines B,O, APs Ste AD 0°93 1°04 My? 1LoQ)4 H,O aN ME pie 40 h4 1°45 WX i745) 100°84 The ratios agree well with the new formula except for the water content. Remembering, however, that the amount of water present is very small and that a difference of -10 per cent would make a large difference in the ratios, that Ford deter- mined his water by igniting the mineral with lime, thus not weighing the water directly, and that the writer obtained only 1°52 per cent on the same mineral from the same locality, it seems much more preferable to regard the determination of the water in Ford’s analysis as too high rather than to attempt an explanation of it by the assumption of “ isomorphous replac- ment, ete.” Of the third analysis by Ford, of the New York mineral, he says: “It is fully realized that the results are not to be looked upon as being as exact us those of the other analyses.” His analysis is : Ratios. SIO i 2 5 ease eeeaee 31°24 6937 or — 6 >< akon ALO Lee 6126 7-23 8x 90 1 Dies © MAD Saat iM 00) BuO sac hee 6-14 1-06 1 x 1-06 1 0 eee pe 2-09 1:40 1 xX 1°40 W. T. Schaller—Dumortiertte. 923 Again assuming that his water content is somewhat high, the ratios agree well with the new formula. This coneludes the list of analyses of dumortierite which were made on pure material and witb due knowledge of what was to be determined. A number of other analyses will now be given which serve in a general way for the determination of the composition of the mineral, but can not be relied on for exact results. One, which has heretofore not been published, was made by the writer on the Washington dumortierite. About 200 grams of the rock was powdered and by repeated separation with heavy solutions about 4 grams of dumortierite were obtained. The sample was by no means pure. It was found impossible to remove all the andalusite, an unknown but small amount remaining. It was found during the course of the analysis that the sample also contained some titanite (leucoxene) and a very small amount of pyrite. The analysis was made with all the care possible and the following results were obtained : Ratios after deducing titanite. SO gobo. 98-51 597 or 6X -99 PMD ics 59°75 Oe 6 2-48 7°80 8x 97 NCO)? eS See een 95 Be Ope) 819 1°53 1 xX 1°53 Omri a. G. 5-54 1-03 1 X 1:03 COP ee he 68 100°03 Excepting for the high-water content, the analysis agrees very well with the formula. No allowance was made for the small amount of andalusite present, which would slightly alter the ratios. There now remain the analyses of Whitfield and Riggs, of which but one is suitable for any calculation. The analyses are as follows, No. 1 being of the New York mineral, by Riggs, No. 2 of the New Y ork, and Nos. 3 and 4 of the ‘Ari- zona mineral, by Whitfield : 1 2 3 4 SO es ee 34°82 31°44 31°52 27:99 EO OF en ee DOr a0 68°91 63°66 64°49 NEO) re 57 eee "52 tr. FOr sh 1:04 Fal ‘11 ce. INAnOR Ses re 152.4 1°76 bye "37 a iPAQ) ae en eae seen wae Meus 20 RO ee 4-07 tr. 2°62 4-95 ene A 2296 mbt 1°34 172 100°52 100°35 100°14 99°35 224. W. T. Schaller—Dumortierite. The ratios of the last analysis are: SOR Rice enere s BE Oy NOK OS DANO eh 2 abel aa 8°09 8 S< WO BS AQ) eyes Rema Fo 80 IS 80 TOME Aah ee 1592 1 erlb22 Approximately they agree with the formula. The only question of which there seems to be any doubt is whether the water should be 1 or 13 molecule. As, however, the best analyses show but 1 molecule and their evidence is considered as of much more value than a large number of inferior analyses, there is no question in the writer’s mind but that the formula for dumortierite. is - 8Al,0,.1B,0,.1H,0.68i0,, This may be written (Si0,), Al(A1O),(BO)H, which is the same as the formula given by Groth except that for (BO) he puts (AlO). His formula is (Si0,),Al(AIO),H. This may be written in the following form: SiO, — (Al0), NEO, UNO), SiO, — AlO ~~ BO Slab This formula is similar to that of andalusite, which is written SiO All Al — SiO, — Al N\ sid, = (A10), . Dumortierite alters to muscovite. The change can be very well shown by these formule and seems to be entirely in accord- ance with the group of minerals to which it is related. Dumortierite. Muscovite. SiO, — (Al0), oO) el | Al— SiO, = (AIO), = Al —SiO, = Al \ + alumina and boric SiO, — AlO SiO, =k a ~ BO Ee) > The writer’s thanks are due to Mr. John A. Thoman of San Diego, the owner of the California dumortierite property, and to Mr. K. C. Naylor of San Diego, for many courtesies and favors. W. T. Schaller—Crystallography of Lepidolite. 225 Arr. XVII.— Crystallography of Lepidolite ; by WaLpEMAR T. SCHALLER. A croup of lepidolite crystals was collected by the writer in the summer of 1904, at a gem mine about four miles east of Ramona, on the stave road from Ramona to Julian, San Diego County, California. The mine was opened and worked for its gems, such as topaz, tourmaline, garnet, etc. With these are asso- ciated quartz, orthoclase in good er ystals at times several feet long, and muscovite, and, rarely, lepidolite. The minerals in question all occur in the loose dirt, filling “pockets” in a pegmatite dike. The specimen of lepidolite under consideration consists of a group of intergrown crystals which often reach a large size. The group itself is about 5™ thick and the individual crystals measure about 1™ across the base, though ones with a diameter Gi are not rare. The crystals are also proportionally thick, the average being from 2 to 4™™, though a few are somewhat thicker. They are transparent and of a ver y pale, pink color, and, in the direction normal to the vertical axis and _ parallel to the base, of a slightly deeper tint. They fuse easily to a white enamel, coloring the flame an intense crimson. ‘The side faces are usually plain, not rounded nor striated, and of a brilliant polish, giving excellent signals. It is, however, extremely difficult to secure a complete crystal from the group, owing to the perfect basal cleavage which will cause a crystal to split into a number of layers. This will also at times cause part of a erystal to become slightly displaced. In consequence of this dithculty, most of the crystals measured are only parts of the original crystals, and two such pieces measured as separate crystals may, in reality, be parts of one and the same crystal. As may be expected, the erystals of lepidolite are similar to those of muscovite. The interfacial angles are nearly the same and the crystals are naturally referred to the same axes as muscovite. There are three marked differences between these crystals and those of muscovite: (1) the rarity of twins— only one being found in twenty-one crystals; (2) the absence of the characteristic face of muscovite, M = }221 ; and (3) the presence of the a face {100}, occurring on ten out of twenty-one crystals. The crystals are not so striated as the green North Carolina muscovites for instance, and in many cases the faces yielded perfect signals. The common forms are ¢= {001, b= 3010}, a= 3100}, e = {023}, o= §112?, w= {111}, and # = {131}. Besides these, the Aline have een deter nite Aes Be, 2S Ou I 226 =609W. T. Schaller—Crystallography of Lepidolite. = {1303, and possibly several others, as {223}, {221}, {112}. Also a number of forms occurring for the most part as broad faces, giving good reflections but having anomalous indices and which need further study. The most frequent combination is choux, after which comes chouxea. Whenever the angle (001): (010) could be accurately measured, it was found to be exactly 90° 00" in every ease, and the distribution of the faces also indi- cate monoclinic symmetry. It was noticed that the angle between the same forms varied slightly on different crystals. The faces were smooth and highly polished and the angles could easily be measured with an error nor greater than 1’. It is suggested that this varia- tion is real and is due to the fact that lepidolite is an isomor- phous mixture of two end products, and as the ratio of these two products varies, the crystallographic and physical proper- ties of the mineral also vary. Further study on the possible correlation of the various properties of the mineral is under way. This lepidolite belongs to the “second class” of Tschermak or the “brachydiagonal class” of Scharizer, i.e. the axial plane is parallel to the clinopinacoid, and not normal to it. The trace of the axial plane was always parallel to one arm of the percussion figure. ‘The above is only a brief preliminary state- ment ; the detailed crystallography of the mineral will soon be published in a paper on the mineralogy of this entire field of lithium minerals in southern California. The writer’s thanks are due Mr. Pan McIntosh, Jr., of Ramona, the owner of the mine. Chemical Laboratory, U. S. Geological Survey. R. A. Daly—Machine-Made Line Drawings. 227 Arr. XVIII.—Machine-Made Line Drawings for the Illus- tration of Scientific Papers; by R. A. Daty. Ir is safe to say that the majority of persons, who from time to time publish scientific papers, are seriously hampered in the preparation of text illustrations by the difficulty and expense entailed in the tedious drawing of map, section or diagram. Comparatively few authors can command the services of skilled dranghtsmen or have themselves the requisite training to produce satisfactory line drawings. Yet the desirability of ereatly increasing the proportion of such illustrations in the thousands of scientific articles published each year is manifest. That clearness, precision and conciseness in the exposition of a theme are generally enhanced by the use of abundant, appro- priate diagrams is as evident as that the blackboard is the con- stant friend of the teacher of any branch of natural history or philosophy; the printed page needs its blackboard. Ideally, the author should himself be able to make the original drawing quickly, neatly and artistically. The usual execution of drawing with the pen is, to the average author, discouragingly slow and expensive, not always neat, and still less often artistic. The following note relates to some experi- ments made to increase rapidity and neatness in the production of line drawings by the use of a machine. At the outset the experiments were, for obvious reasons, planned without any idea of rivalling the artistic work of the pen in a skilled hand. The aim has been to secure economy of time in execution and clear-cut precision of legend for the drawing. In both these respects enough success has been attained to warrant the recommendation of the machine method to geologists, geogra- phers and others who desire to prepare useful text illustrations at a minimum cost of labor. Some experimental drawings were made and published in the Bulletins of the Museum of Com- parative Zoology at Harvard College, vol. xxxviii, 1902, pls. 11, 12 and 18; in this Journal, August 1903, pp. 118 and 120; and inthe American Geologist, August 1903, p. 66. The machine there used was an ordinary Underwood typewriter fitted with a black record silk ribbon. Recently the Hammond Typewriter Company of New York has constructed, for the Geological Survey Department of Canada, from the writer’s specifications, a typewriter provided with a carbon ribbon and with ninety special characters designed for the preparation of line drawings to accompany geological and geographical papers. ‘The same machine can be similarly used for statistical, engineering and other diagrams of a more or 228 BR. A. Daly—Machine-Made Line Drawings. less mechanical and simple composition. Of course this method should not wholly replace the use of the pen, even, for example, in the differentiation of areas in a geological map or section. The ultra mechanical look of the typewritten legend can often be pleasingly relieved by the easily and quickly applied cross- hatchings, etc., made with an ordinary drawing pen. In com- 1 A Bu DSE F°G Tel d Ki MN OPP OAR Si 1 U> Vai em anes ab cudi"e tie hajek | mun Opec ays nul Vane een es abe dey gh ag kl mn 0p oor St uty eevee Beas Oo pe 9 C 1.2 3 4 56) tenes Locality marks O° Xo eines Triangulation station etc -bkaAaO Samples of general purpose legends SS SMe Nes NOON a ae uie We trehclpyer te a cere ee Bets st 0 cle: DUA IL IHTPE s E EEE SEO EN SES ee Scala Mes Semele tetic ek TIE TTI HIDE A OOS SEES So EE hl So OO Oe ON ONO Oo 6. Oe SO VU e.@¢ «8 © sae e = cat e eo# es @aesea PETTEEE TULLE EEE UU MAMIE 77777777 SSSI tii Addy ccocoos sees TU Volto AALFLPP. ----=-- © eee. |) AA ts +ttttt++ oF + +t XxXxxxxx x x x x XX XX O00 0 FHttttt FE XXXXXXX OK XK. OX XX” O00 +ttt++4++ + + + +: Xxxxxxx x x xX xX X XXX Y9OOYO DNTN/ NIN NINT NW AACA NA AOR TEE ET EE ee ANAAAAAN IS TS IK ANAANANA Ae aa ALA SET URAL SPS FF TININININILINTNS| IN TINGE NS ANANADA Woo Pe RN ek Ena Ge oe ae FP Hoodoo 8 ooo SO AAA A oo oe noo0000 oo as AAA a eae 1700000 oD op 88 Be A Aaa oo oe a AON EE TIN ee Gd eect ara Marleen “0-0-0! eae Be ne he ee ere eer R eure) (eet! Ai IALIAS ALIA TON EOP t cP oR E00 20 saan Seow VVVVVVV VVVVVVV KAA Ge Ba Ne G00) \ VVVVVVV ICES te se i SECO ee YSIS oni) (AR ARR Se SS | en plex diagrams free-hand work may generally be expected to supplement the work of the machine. The subject of each diagram should thus be studied with the end of securing suit- able contrasts of legend along with the maximum economy of pen work; yet some pen work is almost always necessary. The typewriter has its most general application in lettering, that most difficult element in line drawings. The machine used by the writer has the advantage of making it possible to employ a great range of type styles. With the carbon ribbon the writer has found that any one of the one hundred and R. A. Daly-—Machine-Made Line Drawings. 229 twenty-five shuttles made for such a machine (each shuttle bearing ninety characters and including the lettering for one of twenty-six different languages), will give an impression suitable for photographic reproduction. Each shuttle can be placed in the machine ready for work in a few seconds. The usual silk ribbon gives a “woolly” line, and is far less satis- factory than the carbon ribbon. A highly calendered and high-grade linen paper of a medium to heavy weight or a thin Bristol board may be recommended. Often more than one impression of the key is necessary to obtain the required depth of tint for photography ; such repeated impressions can be made at great speed by employing a back spacing key. Care must be taken not to smudge the carbon of the completed printing. 2 W. by N. En lo Sz 1K OUT * RAK IARAIAD TAT AANA RNA A = RMI AK AKIRD SE = i AA NIN AAI NINN omer —_— aK = OOO — ir Yue —— RANI ADIN NN Ip Doerr aR Th I Ie TOU ae = Ue! TE A ma ON NINN TN Ny Nien eR RE — Nee — = EE —s KANN DA ARMIN KEL 7 =— an! AA = — — Cee ea ge — _ ey a — — = REINA ARTUR ae anh AD es ee _— — —_— —_— = = — —_— = AAT INA AMR —_ = AhRNIN AA — a => — ee Cy SS ee ee eu ae Fee Se oe Ber aes eee oe = S MOOV MUYU UNE ——— I AD a cee a Be Fe as eS See ae = UU aN NBD ie ENS DEBE AL AE ie mT NNT NS Da i aN AD GE Fn ES Fig NE BE TOU UE i ea eee Fg pe eee ee arae ih A h —a A A —— AA AMM An = AKA AA es = BE = = = Bo = — ie os LS ee — og OW ae os = = = — —_— — == nee A ——_ AN A KS —— = ee = ee — ag ee LL oe ARAN AED Se Nee ee eee A = —_— ee vA \ SS = FRAN Ae Fe eI oe OE Ne Re iy pht EN ER = — — — — —— = — = — = — — —— mm Basalt a ze ‘AA44 Granophyre Bi AAKK fe) 500 feet 1000 c ns Sea-level —— The accompanying cuts serve to show something of the method as applied to geological diagrams. The diagram (fig. 1) of alphabets and legends has been reduced to four-fifths of its original diameter. The legends are intended to repre- sent a few examples of those possible with the machine. They can be indefinitely increased in number and varied in design by the engraving of new characters on the shuttle, and by using various permutations and combinations of the existing characters. The section (fig. 2) is reduced to about one-half of its original diameter. It was copied from Harker’s section of a composite triple sill published in “ The Tertiary Igneous Rocks of Skye” (Memoir of the Geological Survey of the United Kingdom, 1904, p. 204). The result represents the saving of from seventy-five to ninety per cent of the time required by a draughtsman to duplicate the drawing. It is to be understood, of course, in the preparation of a diagram that an outline drawing is first prepared, and that the spaces thus formed are filled with the symbols shown in the legends, by means of the machine. Ottawa, Canada. 230 W. F. Blake—TIodobromite in Arizona. Art. XILX.— Lodobromite mm Arizona; by Wititam P. BLAKE. THE rare compound of silver, iodine, bromine and chlorine, iodobromite, occurs in thin seams and crusts in a vein of quartz and calcite near Globe, Pinal County, Arizona. The erystalli- zation is obscure. It is soft like tale; luster vitreous; color light lemon-yellow to sulphur- and canary-yellow. Not being able to secure enough for a satisfactory quantitative analysis, the results of the determinative tests are added. The reactions before the blowpipe are remarkably beautiful and interesting. Heated in a closed tube with bisulphate of potash, the min- eral quickly changes color to a dark salmon, or orange-red, heavy brownish-red fumes of bromine are given off and bro- mine condenses in the higher portion of the tube; violet vapor of iodine then appears and crystals of iodine form below the condensed bromine. The fused assay, floating im the flux, is brilliant cherry red, at first very dark red, but on cooling grad- ually loses this color, passing through various shades of red until the normal yellow color is restored. The fused mass then being removed from the tube and reheated until the bromine and iodine are expelled, and treated with carbonate of soda on charcoal, a button of metallic silver is obtained. The fused carbonate of soda dissolved from the coal gives the reaction for chlorine with silver nitrate. In the final reduction of the assay to the metal a slight yellow areola like that from lead was observed and referred to probable shght impurity. Arizona School of Mines, Tucson, Arizona. C. H. White—Autophytography. 231 Art. XX.—- Autophytography: A Process of Plant Fos- silization ; by CHARLES Henry WuHire. Tue evidence for the existence of plant life on the earth in past geological ages is both direct and indirect. We may include in the class of direct evidence all the records of vege- table life in which the form or structure of the plant is in any degree preserved, and in the class of indirect evidence, such as offer no clew to plant form, but merely indicate in a second- ary way, the existence of vegetable life. In this latter class are coal and certain deposits of calcareous and siliceous sinters and bog-iron-ore. The plant records to which attention is espe- cially directed in this paper may be placed in the category of direct evidence, since the trace or outline of the plant is distinctly preserved; but the process by which the outline is recorded in the rocks is wholly different from those processes to which the formation of plant records is usually attributed. The ways usually described by which the plant form is recorded in the rocks may be included in the following three classes. The first class includes those in which the original substance, or tissue, of the plant is, in part at least, preserved. Such remains are often found within, or in close association with, deposits of shale, peat, coal, diatomaceous earth, and the like. The second class of records by which the form is preserved is that in which the plant tissues have been removed by decay or otherwise, leaving only the impress or mould as the record in the rocks. The third class is that in which the mould has been filled by a cast, either after the complete removal of the plant, or by a gradual so-called molecular replace- ment. By the process of plant fossilization here described, the plant undergoing decomposition reproduces itself in outline on the rock surface upon which it rests, or upon the matrix within which it is enclosed, either by the precipitation of colored mineral matter, or by the alteration or removal of the coloring matter already in the rock. In the first of these processes the rock surface receives a deposit of colored mineral matter, a positive picture,—to borrow the language of the photographer,— is made (see figures 1 and 2); and in the second, the uniform coloring matter already in the rock is abstracted where the plant, during growth or decay, has been in contact with it, giving a plant picture in lighter color, a negative (figures 3 and 4). For such plant pictures, or plant writings, in which the traces or outlines of plants are distinguishable by their color, and in which the variation of color from the matrix is due to chemical change brought about by the plant reproduced, 232 CO. H. White—Autophytography. the name autophytograph (avtes = self, dutdv = plant, ypada = write) is proposed. Figures 1 and 2 represent specimens of the positive autophy- tograph that were collected by Dr. John W. White in Decem- ber, 1897, from a bar of gravel on Cub Creek in the town of Wilkesboro, North Carolina, and were presented to the writer in January, 1898. These specimens* are water-worn pebbles of white quartzite that have been slightly stained brownish yellow by hydrated iron oxide, and that have, in recent time, * All the specimens reproduced here arein the Harvard University Museum. Figures 1 and 2 are from two specimens No. 2559, figures 3 and 4 are Nos. 2667 and 2343, of the Geological Laboratory collection ; and figure 0 is from No. 37 of the Students Palaeontological collection. C. H. White—Autophytography. 233 received a black deposit on their polished and stained surfaces, reproducing so perfectly the stem and leaves of a small her fr that the species is readily identified. These autophytographs were determined by Mr. M. L. Fernald at the Gray Herba- rium, Harvard University, through the kind intervention of Mr. Walter Deane, of Cambridge, Massachusetts, as having been produced by Micranthemum orbiculatum > Michx., a small creeper that flourishes in low, muddy ground, from Florida to North Carolina. The composition of the pigment of these autophytographs is difficult to determine, owing to the small quantity of material available. It is, however, a black adherent deposit, insoluble in water, but slowly attacked by the mineral acids, yielding solutions which show the presence of iron. No change of color is produced by the flame of the blow-pipe, but the pig- ment becomes strongly magnetic on heating. There is no doubt, therefore, that the colored deposit contains iron, and it is most probably an oxide. ‘wo possible conditions under which it is believed such a deposit could form are suggested. First, the plants of this genus may yield on decomposition a precipitant of iron, peculiar to the genus, which extracts iron from the surrounding solutions and deposits it in a manner analogous to one of the artificial ink-making processes, and on exposure to the air the precipitate is changed to an oxide. The other suggestion is, that the conditions of decay are such that ammonia is liberated in the presence of iron in solution, precipitating the iron on the rock upon which the plant rests 234 : C. H. White—Autophytography. during decay. For the precipitate to remain permanent, ammonia must be produced gradually and in sufficient quantity to neutralize the acid in the iron-bearing solution until the acid ceases to flow to the point of deposition. That vege- table matter undergoing decay will under certain and usual conditions produce acids which take iron in solution, and will under other conditions yield ammonia, is well known and need not be discussed here; but the nicety of adjust- ment of these conditions called for above would necessarily be rare, and,—if this be the correct theory,—would account for the scarcity of autophytographs of this description. In figures 3, 4 and 5 are reproduced autophytographs of the negative type. The specimens represented by figures 3 and 4 are > antophytoor aphs of recent formation that were collected by Professor J. B. Woodworth of Harvard University, and it is through his kindness that they are here reproduced. The specimen represented by figure 3 is a block of sandstone, taken from the Saratogan, or upper Cambrian, formation near Bid- dle’s Crossing, about a mile and three- quarters north of Sciota, Moore’s quadrangle, Clinton County, New York, on which rootlets have in recent time brought about solution of the iron- pigment which stained the sandstone a yellow-brown, giving an autophytograph of lighter color on a dark background. Figure 4 represents a specimen taken from the ploughed sur- face of a lateral moraine at the west base of Bald Hill near Caroline Depot, Tompkins County, New York. This specimen C. H. White—Autophytography. — . 235 differs from the last only in having a darker iron-pigment in the rock, and in the form of the root reproduced, but in neither case is the portion of the plant reproduced sufficiently charac- teristic to identify the species. These autophytographs belong in no sense to a past geolog- ical age. They were formed on or near the present land sur- face and show little evidence of having suffered disintegration and erosion. Granting that in transportation and deposition the probabilities are decidedly in favor of the destruction of these plant records, yet there are conditions of deposition and burial, not at all rare in nature, that would very effectively | preserve such records to future veological ume. While the specimens so far considered belong to the present and have no value as records for the historical geologist or palaeontologist, they well illustrate the process of autophytography and, as just pointed out, lead us to expect fossils of this character in the plant-bearing horizons of past geological time. At the suggestion of Professor R. T. Jackson, the collection of fossil plants in the Harvard Botanical Museum was inspected, and it was found that fossil plants from many horizons partake of the quality of the autophytograph of both the positive and the negative type. Plant impressions in the slates at Solen- hofen, Bavaria, marked out by oxide of iron have been observed 236 O. H. White—Autophytography. by Seward,* and similar impressions in the Buntersandstein of the Vosges were found by Schimper and Mougeott to have either received a deposit of hydrated ferric oxide or to have had the red color of the rock removed from about the plant impression, the intensification or the removal of the coloring depending on the locality and the nature of the rock. In the Harvard collection are representatives of both these types from the Vosges and also from the Solenhofen deposits, as well as from many other localities. There are also examples in which the plant has left no impression or mould on the rock, but, at the same time, has been perfectly fossilized by negative auto- phytography. A fair representative of this class from the Lias of Germany is shown in figure 5. It is a specimen ot Frucoides bollensis, collected at Boll, Wiirtemberg. The various classes of evidence for the existence of plant life may be summarized as follows: Original tissue ( Vegetable substance Carbonized Mould or impression ( Direct ¢ External form only CASE Ae NaC Ose tae Internal structure Evidences | P e,e ; ositive or pussai Iie 4 | Autophytograph --. Negative | Indirect .. Graphite, coal, sinter, bog-iron-ore Harvard University, Cambridge, Mass. * A.C. Seward, Fossil Plants, vol. i, p. 68. + Schimper et Mougeot, Monographie des plantes fossiles du grés bigarré de la Chaine des Vosges, p. 10. Ashley— Oxidation of Sulphites by Lodine. 237 Art. XXI.— The Oxidation of Sulphites by Lodine im Alkaline Solution; by R. Harman Asuury. [Contributions from the Kent Chemical Laboratory of Yale Univ.—ecxxxiv. ] Accorpine to Bunsen, Dupasquer’s method of oxidizing sulphurous acid by iodine in an acid solution, proceeds to com- pletion according to the equation 28O,+ 21,+4H,0=4H1I+2H,80, only when the concentration of the sulphur dioxide does not exceed 0°5 per cent of the solution. When, on the other hand, the proportion of sulphur dioxide exceeds this value, there is a secondary reaction, which according to Volhard, involves the reduction of the sulphur dioxide by the hydriodic acid pro- duced. This difficulty may be obviated, however, as has been shown by Volhard,* if the solution of the sulphurous acid or a sulphite is run with stirring into a solution of iodine in potas- sium iodide, aciditied with hydrochloric acid, to the bleaching of color, using starch as an indicator,—a procedure which is obviously less convenient than direct titration by a standard solution of iodine. It has been recently further proposed by E. Ruppt to accom- plish the oxidation in an alkaline solution, by treating the solu- tion of sulphur dioxide or a sulphite, with an excess of standard iodine in presence of acid sodium carbonate, 1 gr., during an interval of fifteen minutes, and determining the excess of icdine with sodium thiosulphate. Rupp’s analytical examples, three in number, involving amounts of sulphur dioxide approximating 00343 gr., show small errors of excess, and from them the conclusion is drawn that sulphites like arsenites, may be esti- mated in a solution made alkaline with sodium bicarbonate, by the process indicated. This very unusual use of sodium thiosulphate for the deter- mination of free iodine in the presence of an alkali bicarbonate, suggests the question as to whether the sulphite was in reality completely oxidized by the treatment, or whether the appar- ently good results were in fact due to a chance balancing of errors of incomplete oxidization of the sulphite, on the one hand, and on the other hand, of the excessive use. of iodine in the action of the thiosulphate in an alkaline solution, it being generally supposed that in alkaline solutions not only is the expected tetrathionate formed, but that some of the thiosul- phate is oxidized to the extent of forming sulphate rather than tetrathionate exclusively. In the following table of experiments are data of experi- ments upon the action of iodine and sodium thiosulphate in *Ann. Chem., cexlii, 93. + Ber. Dtch. Chem. Ges., xxxv, 3694. Am. Jour. Sco1.—Fourty Series, Vou. XIX, No. 111.—Marou, 1905. 16 238 Ashley— Oxidation of Sulphites by Iodine. alkaline solution. The sodium thiosulphate, approximately NS was standardized against approximately = iodine solution in a neutral solution. Varying amounts of a saturated solu- tion of acid sodium carbonate were used to render the solution alkaline in the experiments recorded. TABLE I. Todine solution = 0°01236 gr. per em?. Sodium thiosulphate solution = 0:01516 gr. per em?. Error in | NazS20s nearly ~ Iodine nearly = pS OTS NaHCO; No. Tet | maa em? | anaes, em? | 8 gr. em? 1.| 11°94 | 0°1451] 15:00 | 0°1854 | +0:0403/ 20 |] 9.| 11:69 | 01421 | 15-00 « +0:0433| 20 || 3,| 11:18 | 0°1359 | 15-00 1 400405 | 40 1 aes 4.| 11°25 | 0°1367] 15-00 “ 4-0°0487| 40° pean 5.| 918 | 0°1116] 11:00 | 0:1360| +0-0244] 1 gr. || 6. 0 U1) OaO7, ial 00 : +0°0253 | 1 gr. |; 7.| 15°00 | 0°1823| 15°98 | 0°1975 | +0°0152| 20 | tod 8.| 15:00 “ 16°31 | 02016 | +-0°0193'| ° 20) 7) eae 9.| 15:00 “ 16°62 | 0:2054] +0°0231/ 40 || Na,S.0, 10. | 15°00 cc 16°65 | 0°2058 | +0°0935| 40 |, It is plainly evident from the table that more iodine is used up in the presence of an alkali bicarbonate, whether the iodine is run into the thiosulphate or the thiosulphate into the iodine, than accords with the theory of the reaction. Experiments were now undertaken for the purpose of con- trasting the results obtained by Rtupp’s procedure with results found by oxidizing the sulphite with iodine in an alkaline solution and determining the excess of iodine by standard arsenite, which, as is well known, acts with regularity upon iodine in the presence of an acid sodium carbonate. The volumes of the solutions at the time of oxidation varied from 25°™* to 50°". The results are given in the following table: Tas Le II. Rupp’s PROCEDURE. Iodine : Todine value Error in Error in value of hee of Na.S.Os pee terms of terms 80, taken. | fan taken. mee Iodine. of SO. or, or, er, er. gr. er. 0°0977 0°2474 0°1492 aft + 0:°0005 +0:0001 0°0977 0'2474 0°1454 ils +0°00438 +0°0011 0°1440 0°2969 0°1528 ile + 0°0001 + 0°0000 0°1440 0°2969 0°1518 ey +0°0011 +0°0003 0°2759 0°4316 0°1582 i —0°0025 —0'0006 0:2759 0°4316 0°1628 te —0'0071 —0°0018 Ashley— Oxidation of Suiphites by Todine. 239 Excrss OF IODINE DETERMINED BY STANDARD ARSENITE. Iodine ; Iodine value Error in irror in value of ee of arsenite BECO: terms of terms SO, taken. : taken. x : Todine. of SO.. er. er. er. er. er. er. 00977 0°2495 0°15438 fs —0'0025 —0:0006 0:0977 0°2495 0°1540 iL — 0°0022 —0°0006 0°1440 0°2984 0°1586 ]° —0°0042 —0°0010 071440 0:3017 0°:1607 i} — 0°0030 —0:°0008 0°2759 0°4354 O:1710 lig —(0°6115 — 0°0029 0°2759 0°4354 Ock742 ie —0°0147 —0°0037 From a comparison of the results in the second section of the table with those in the first section, it appears that under the conditions advocated by Rupp, the sulphite is not com- pletely oxidized by the iodine. It seems that enough of the secondary action, by which the thiosulphate is oxidized beyond the condition of tetrathionate, takes place to counterbalance the error of incomplete oxidation when moderate amounts of sulphurous acid are handied, and more than enough for the smallest amounts, the secondary error predominating in such cases. The results of experiments in which acid potassium carbon- ate was substituted for the acid sodium carbonate gave similar results. . So it appears that when Rupp’s process gives results approx- imating the truth, it is due to the happy balancing of opposed errors. It seems quite possible that the same balancing of errors likewise occurs in the process for the determination of phosphorous acid described by Rupp and Fink.* In conelusion, I would like to thank Prof. F. A. Gooch for many kind suggestions. * Ber. Dtch. Chem. Ges., xxxv., 3691, 1902. 240 HH. A. Ward—Billings Meteorite. Arr. XXITI.—The Billings Meteorite: A new Iron Meteorite Srom Southern Missouri; by Henry A. Warp. A NEW siderite is now added to the six meteorites (four siderites and two aerolites) already found in the state of Missouri. The mass was found on the farm of Geo. Wolf about four miles east of Billings, Christian County, Southwestern Missouri, in breaking new ground in September, 1903. It was taken by Mr. Wolf—who considered it an iron ore,—to a street fair held in Billings in the same month, where it took the first prize as Iron Ore. The attention of J. P. Thomas was called to it, and Billings Siderite, 14 size. he had a horse-shoe nail made from a piece of it and a hole drilled through the edge of the mass to test its quality. Mr. Thomas shipped it with a large number of specimens of iron ore to Kansas City, Mo., where it was bought by Mr. R. E. - Bruner, a gentleman who possesses a fine collection of minerals. Jt remained in Mr. Bruner’s hands until I obtained it from him last November. In general shape the Billings siderite rudely resembles an axe or hatchet, as may be seen from the cut here given. Its extreme length is 154 inches; its greatest breadth 82 inches. The thickness at the larger end is 5 inches, while from the middle the mass flattens out into a blade or wedge, which is about 3 inches thick on a medium line, and slopes off to a blunt rounded edge at the sides and end. This iron has evidently H. A. Ward—Buillings Meteorite. — 241 lain in the ground for a long time since its fall. Its outer sur- face is rusty and covered with flaking scales of oxide. There consequently remains upon its surface no sure trace of “ pit- ting” or other aerial action incident upon its flight and fall through our atmosphere. A single circular concave depres- sion, four inches across by one inch in greatest depth, on one side of the mass may be the remains of an original . pitting on the original surface. The weight of the mass before cutting was 54 lbs. Several slices have been made under my direction which show fine Widmannstatten figures of the octahedral system. Of the structure and composition of the iron alloys inducing these figures [ am indebted to Prof. Oliver C. Far- rington of the Field Columbian Museum of Chicago for the remarks which follow. : The Billings iron is a coarse octahedrite (Og), with lamellee averaging from 1—-2™™ in width. In length many of the lam- Section of Billings Siderite, 14 size. elle extend 2 without interruption. They are as a rule com- paratively straight in outline, but again become irregular and swollen and at times merge into areas where their outlines are so nearly rounded as to give a coarse-granular appearance. The substance of the lameile is sometimes interrupted and some- times shows subdivision longitudinally into narrower bands by more or less continuous films of tenite. The kamacite is coarsely granular in character, and shows oriented sheen. The teenite appears as a dark, narrow line, in general bordering the kamacite, but also not infrequently crossing and anastomosing. In portions of the meteorite, where some decomposition has taken place, the teenite separates out as thin, flexible, magnetic plates of a tin-white color. The meshes (Felder) of the section occupy but small space relatively to the bands (Balken) but are well defined where they occur. They range in size from about 25°1™™ down, and in outline from triangular to trapezoidal. They are filled with a substance darker in color than the kamacite, and are 242 HT. A. Ward— Billings Meteorite. traversed by irregular numbers of delicate plates seen only under a lens, which run now in one and now in several direc- tions. Asarule these plates start in great numbers from the borders of the mesh and thin out toward the center, but in some of the meshes they extend uniformly across. Several nodules of troilite appear in the section examined and as usual occur near its boundary. One of these nodules is irregularly oval in shape and has a diameter of about one centimeter. The others are smaller, and range in outline from nearly circular to con- siderably elongated. None of them has a border of swathing kamacite. A line of irregular parting extends across the sec- tion, following roughly the lamellar planes, except at about the middle of the section, where it runs nearly straight for a distance of about 2°" quite irrespective of the lamellar struc- ture. The parting at this point has a width of about one millimeter, and is filled with a substance of the section. This substance shows a foliated structure parallel with the length of the teenite, others kamacite. The structure is evidently second- ary in character and appears to be a filling subsequent to the individualization of the main mass. The chemical analysis of the iron has been made by Mr. H. W. Nichols, the chemist of the Field Columbian Museum, and is as given below: Analysis of Billings Iron PNG ae Ps OU ap eae 91°99 Dy GUN tum leat ee toe de ee 2 [3S Ore PMN NCCRiccioler oN neers. uae tg 0°42 Clee Sos es Coe iret rateh 0:01 Sr hoe ee Oe 0°08 Bp aL ii ange, DHE, Ail So or 0°15 re RO arms NI tae SN at 0°06 100°09 The larger part of this Billings siderite has taken its place in the Ward-Coonley Collection of Meteorites. Chicago, Illinois. Chemistry and Physics. 243 S@LRNEIEEOC INTHE LIGENCE. I. CHEMISTRY AND PHYSICS. 1. The Atomic Weight of Lodine.—A series of careful deter- minations of this constant has been carried out by G. P. BaxTER of Harvard University. The ratios of silver to silver iodide, silver to iodine, and silver iodide to silver chloride were found in making these determinations, and the average of very closely agreeing results by the three methods were 126°973, 126°977 and 126°975, where oxygen as 16 is taken as the basis. Several other investigators—Scott, Ladenburg, and Kothner and Aeuer— have recently obtained results upon the same atomic weight which agree almost exactly with those of Baxter; hence it appears certain that the atomic weight 126°85 for iodine, which has been accepted for many years on the authority of Stas and of Marignac, is somewhat lower than the truth. In spite of his wonderful skill, it seems that Stas was not quite infallible in his atomic weight determinations. The international committee on atomic. weights, in the table for 1905, has adopted the value 126°97 for the atomic weight of iodine, when oxygen is 16, and the value 126°01, when hydrogen is taken as unity. Both of these numbers, it may be noticed, are curiously close to being confirmations of. Prout’s old hypothesis, which requires, practi- cally, that the atomic weights should be whole numbers.—Zevtschr. anorgan Chem., xiii, 14. H. Li. W. 2. Double Silicides of Aluminium. — Mancnot and Kiser have obtained the crystalline compounds Cr,AISi, and Cr,AlSi, by the fusion of chromium compounds with an excess of aluminium in the presence of potassium silicofluoride, and treatment of the resulting metallic mass with an acid in order to dissolve the aluminium. The compound, Cr,AISi,, forms beautiful slender crystals of hexagonal habit, which are opaque, with a strong metallic luster and white color. The compound is very inactive with most chemical agents. It is insoluble in acids, except hydrofluoric acid ; it remains bright when heated in a stream of oxygen, and is not attacked by fusion with potassium bisul- phate ; but it readily decomposes by fusing with alkalies. The other compound was obtained in‘a similar way in the presence of a larger amount of silicon. It forms smaller crystals, is some- what harder, but otherwise it is like the first compound in its properties. These compounds are the first double silicides to be described.—Ann. der Chem., ecexxxvii, 3538. H. Le W. 3. Huropeun.—This element, occurring in very small quanti- ties among the rare earths and coming between samarium and gadolinium, was described by Demargay several years ago. Ursain and Lacomper have recently confirmed the existence of the earth. They used 610 g. of oxides representing the whole of the europeum group of earths from. about 500 kilos of monazite 244 Scientific Intelligence. sand, and by a long series of fractionations involving some 3000 crystallizations, they obtained several fractions of constant prop- erties and atomic weight, apparently consisting of pure europeum. The amounts obtained indicated that the monazite sand contained about two hundred-thousandths of europeum oxide. The sul- phate has a scarcely visible rose tint, while the oxide prepared: at a low temperature is practically white, although when intensely ignited it is distinctly rose-colored. Closely agreeing atomic weight determinations made with several different fractions gave 151°79 as the result, which the authors believe to be true within 06. Demargay had given the atomic weight as about 151.— Comptes Rendus, cxxxviil, 628. H. Ti Wei 4, The Use of Caleium Carbide as an Explosive in Mining.— GusEpRAS has described a method of utilizing the explosive force of acetylene for mining purposes. A sheet-iron cylinder is used as a cartridge. At its bottom are placed about 50 g. of granu- lated calcium carbide, and above this in a separate compartment is a sufficient amount of water to react with the carbide. ‘There is also an air-chamber containing an electric fuse. The cartridge is placed in the hole to be exploded, the latter is closed with a wooden plug, and an iron rod attached to cartridge for the pur- pose of piercing the water compartment is struck, thus liberating the acetylene. After this has been disengaged for about five minutes, the mixture of air and acetylene is exploded. The explosion causes the rocks to fly about much less than would be expected, but they are thoroughly broken up.— Comptes Rendus, CXKMUXe 2 25) H. L. W. 5. Silicon-fluoroform.—The silicon compound, SiHCl,, silicon- chloroform, is well known, and recently Rurr and ALBERT, by allowing the compound just mentioned to act upon tin tetraflu- oride or titanium tetrafluoride, have succeeded in obtaining the corresponding fluorine compound. Silicon-fluoroform is a com- bustible gas which liquefies at atmospheric pressure at about —90° and solidifies at about —110°. It is decomposed by water and alkaline solutions without change of volume, for the hydrogen produced by the decomposition is equal in volume to the original gas, as is evident from the following equations : SiHF, + 3NaOH+H,0 = Si(OH),+3NaF +H, ; oSiHF,+4H,0 = Si(OH), + H,SiF, +2H,. The preparation of the compound under consideration completes the series SiHF,, SiHCI,, SiH Br,, and SifMI, of analogous halogen compounds.— Lerichte, xxxvili, 53. H. L. W. 6. Double Cyanides of Copper.— A considerable number of these double salts has been prepared and studied by GrossMANN and von DER Forsr. They are all cuprous salts, and contain lithium, sodium, potassium, rubidium, cesium, as well as ammo- nium, calcium, strontium, and barium. Five different types of double salts were noticed ; for instance, omitting water of crys- tallization, I. KCu,(CN),, I. Rb,Cu,(CN),, II. KCu(ON),, IV. Chemistry and Physics. 245 Na,Cu(CN),, V. K,Cu(CN),. The salts of type III were ob- tained in the largest number. It may be mentioned that all of these types occur among the known cuprous double chlorides.— Leitschr. anorg. Chem., xiii, 94. H. L. W. 7. An Occurrence of Radium and Radio-active Harths.—F. GirsEL has found that mud from Fango and soil from Capri possess an activity of about one one-thousandth of that of pitch- blende, and that it is possible to extract radio-active products from them by chemical methods. For instance, from 40 kg. of the Capri soil about half a gram of barium bromide was extracted, which showed distinct spontaneous phosphorescence upon dehy- dration. In neither of the materials could uranium be detected.— Berichte, xxxviii, 132. Hi, be We 8. V-Rays.—E. Grurcke describes at length certain halluci- nations which might arise in the investigation of the so-called N-rays. He finds that any object, the forefinger for instance, moved to and fro behind a phosphorescent screen produced a change in the light of the screen. The effect is not produced if an independent observer moves the object ; and it is therefore a psychological one. The author believes that the phenomenon is analogous to many which arise at the extreme limit of vision. For instance one often believes that he sees a faint image while developing a photographic plate when no such image really exists. The author does not attempt to explain the photographs obtained by Blondlot and he remarks that in whatever way the phenomena of N-rays may be explained, Blondlot has rendered a service in calling attention to interesting phenomena.—/Physikalische Zeit- schrift, No. 1, Jan. 1, 1905, p. 7-8. ID: 9. Photography of N-rays. —G. Weiss and L. Butt have failed to obtain such registration, and remark that Blondlot now concludes that the rays increase or affect visibility and not lumi- nosity.— Comptes Rendus, cxxxix, Dec. 12, 1904, pp. 1028-1029. pees 10. Spectraof Electric Discharges in Cooled Geissler Tubes.— EK. GoipsTEIN describes the distribution of light and the spectra produced by suddenly immersing Geissler tubes in liquid air. The method appears to be of use in obtaining the spectra of metals in great intensity and with sharp lines. It also reveals a difference in the cathode light, according to the kind and nature of the cathode.—Physikalische Zeitschrift, No. 1, Jan. 1, 1905, pp. 14-17. JD 11. The Dependence of the Ultra-Red Spectrum of Carbonic Acid upon Pressure.—CLEMENS SCHAEFER concludes from his investigation on this subject that Arrhenius’ theory in regard to the ice age is erroneous. The latter concluded from his figures that a diminution of the amount of carbonic acid in the earth’s atmosphere would lead to a fall of temperature of the earth, and in consequence of diminished absorption there would be an increased radiation of heat from the earth into space. Thus an ice age might have been caused. Schaefer shows that the con- 246 Scientific Intelligence. clusion that variation in thickness of layer and variation in pres- sure have similar effect upon absorption is not justified. Changes of volume amount of CO, have no influence on the earth’s tem- perature so long as the diminution of carbonic acid remains under 80 per cent of the former quantity.— Amn. der Phys., No. 1, 1905, pp. 98-105. J. T. 12. Hiectromagnetic Waves in the Visible Spectrum.—Many attempts have been made to identify these waves with light waves. Frerpinanp Braun forms suitable resonators or “ Git- ters” by deflagrating very fine wires stretched on glass plates ; and then observing changes of polarization by means of suitable optical devices directed upon the particles of finely divided metal. According to the electromagnetic theory these “ Gitters” should allow little light through if the arrangements of the parti- cles are parallel to the electric vector, and much if they are per- pendicular to it. The author believes that his photographs show a complete analogy between Hertz waves and optical waves. He shows also that the method he employed is of importance in min- eralogical work.—dAnn. der Phys., No. 1, 1905, pp. 1-19. 3. 7. 13. Damping Galvanometer Deflections.—W. EK1NTHOVEN con- tinuing his investigations on his new galvanometer, which consists of a silvered quartz fiber stretched in a strong magnetic field, finds that a condenser attached to the terminals of the fiber is of great use in bringing the oscillations to rest even when they are extremely rapid. It is believed that the method will be of great advantage in acoustical investigations and also in physiological work.—Ann. der Phys., No. 1, 1905, pp. 20-31. Be bs 14. Possible variation in Solar Radiation.—The report of S. P. Langley, Secretary of the Smithsonian Institution, for the year ending June 30, 1904 (noticed on p. 260), contains in the statement of the work accomplished at the Astrophysical Observatory, under the charge of C. G. Abbot, a further discus- sion of the possible variability of the sun first rated in the report of the year preceding, We quote the following paragraphs : “Notable progress has been made with the researches you have initiated on the amount of solar radiation and its absorption in the solar envelope and in our atmosphere. Within the last seventeen months three independent kinds of evidence have been collected here, pointing toward the conclusion that the radiation supplied by the sun may perhaps fluctuate within intervals of a few months through ranges of nearly or quite 10 per cent, and that these fluctuations of solar radiation may cause changes of temperature of several degrees centigrade nearly simultaneously over the great continental areas of the world. Further evidence must, however, be awaited to verify this important conclusion. The three kinds of evidence referred to are as follows: First, on all favorable days the ‘solar constant’ of radiation outside our atmosphere has been determined here, and changes of about 10 per cent in the values obtained have been found which cannot be attributed to known causes. Second, the solar image formed by Chemistry and Physics. 247 the horizontal telescope has been examined with the spectro- bolometer to determine the absorption of radiation within the solar envelope itself. If we grant for argument’s sake that the rate of solar radiation outside our atmosphere fluctuates rapidly from time to time, then as you have observed, the cause of this fluctuation cannot reasonably be a variability of the temperature of so immense a body as the sun itself, but must rather be in a change in the absorption of a more or less opaque envelope sur- rounding the sun. Accordingly the two researches I have men- tioned are intimately associated, for if we find a considerable increase in the rate of solar radiation outside our atmosphere we ought to find a corresponding decrease in the absorbing power of the solar envelope. Such is in fact one of the most notable results of the year’s work. In August, September, and October, 1903, the observa- tions of the ‘solar constant’ of radiation indicated that the rate of radiation was about 10 per cent below that observed in Feb- ruary, 1904. On the other hand, measurements of the absorption of the solar envelope indicated considerably less absorption in February, 1904, than in September, 1903. The third kind of evidence of change in solar radiation 1s based on a study of the temperature of the North Temperate Zone, as indicated by the Internationale Dekadenberichte pub- lished by the Kaiserliche Marine Deutsche Seewarte, and received at the Observatory through the kindness of the Librarian of the United States Weather Bureau. ‘This publication gives the mean temperature at 8 a.m. for each ten days at each one of about one hundred stations distributed over the principal land areas of the North Temperate Zone, and for about ninety of these stations there is also given the normal temperatures for the same ten-day periods, representing the mean of many years. From these data there have been computed here the temperature depar- tures from the normal since January 1, 1903, and these are com- pared graphically in the accompanying chart, Plate VII,* with the measures of the solar constant made in 1903. It will be seen that shortly after the observed fall of solar radiation in March, 1903, a general fall of temperature occurred, which would be a natural result of such a change. It has been shown here, in accordance with the known laws of radiation, that 10 per cent fall in the solar radiation could not produce more than 7°°5 C. fall in terrestrial temperatures, and that several causes, notably the presence of the oceans, would prevent so great a change of tem- perature as this resulting from a temporary diminution of solar radiation of only a few months’ duration. The observed fall of about 2°°5 C. in the mean temperature of the land areas of the North Temperature Zone during April, 1903, seems to be there- fore in good accord with the observations of solar radiation. Owing to the uncommon cloudiness of the first six months of * Shown also in your article on ‘‘ A Possible Variation of the Solar Radia- tion,” Astrophysical Journal, June, 1904. 248 Scientific Intelligence. 1904 few measures of the ‘solar constant’ worthy to be compared with the series of 1903 bave been obtained, but taking the best of the measures it appears that high values of solar radiation in February, 1904, and lower ones in the subsequent months are indicated, as shown in Table II, given below. This appears to be in general accord with the mean temperature observed over the North Temperate Zone, except that it seems probable that the solar radiation was high in January as well as February, but the lack of good observing weather prevented our recognition of it.” The importance of this subject is remarked upon in its bearing upon forecasts of temperature, in case further research serves to confirm the indications now obtained as to a general parallelism between measures of solar radiation and terrestrial temperature. For this work, however, a better station for observation than Washington is needed. 15. Terrestrial Magnetism. Results of Magnetic Observations made by the Coast and Geodetic Survey between July 1, 1903, and June 30, 1904; by L. A. Bauer. Appendix No. 3, Report for 1904. Washington, 1904.—This report* contains the usual detailed statement of magnetic observations made in the United States and outlying territories during the year ending June 30, 1904 ; an interesting feature is the introduction of observations made at sea by the Survey vessels, this is a new departure begun in February, 1903. In the introductory summary of results reached some interesting notes are made, particularly in regard to the changes of magnetic declination in Louisiana. We quote some paragraphs : “The results of this detailed work in Louisiana have been extremely interesting. First, it has been clearly demonstrated that there was a reversal in the expected course of the secular variation which took place about 1898. Past observations made in the vicinity of New Orleans show that the magnetic declina- tion, which is east, reached a maximum amount of about 82° near the year 1830. It then began to diminish, and, in accord- ance with the laws of the secular variation pertaining north and east of the agonic line, 1. e.,in the Atlantic States, where west declination is known to be increasing at present on the average about three minutes per year, a turning point was under ordinary conditions not to be expected before some time about the middle of the present century. Instead, however, it was reached about 1898, so that east declination reached a minimum value of 54° in about seven decades after a maximum value—the shortest inter- val between a maximum and a minimum value thus far revealed anywhere on the earth. East declination is now increasing in Louisiana at the rate of about one and one-half to two minutes per annum. The total change between maximum and minimum at New Orleans, as above stated, was about 34°. The early reversal produced a larger annual change between the years 1860 and 1870—about six minutes—than has generally been experienced in the United States, although elsewhere, as, for * See also p. 261. Chemistry and Physies. 249 example, England, such large annual changes and even greater ones occur. Values of the magnetic declination secured four to five decades ago, if referred to the present time with the aid of secular change values as were expected, in accordance with the experience in other parts of the United States, would be in error one-third to one-half degree. Observations in other States near Louisiana show that this change in the course of the secular variation is manifesting itself in greater or less degree, according to locality, likewise in these States. How permanent the present change may be, i. e., whether it will continue for but a comparatively short period, so that before long another reversal may be expected, after which east declination will begin to diminish once more, can not be stated at present. The magnetic survey of Louisiana has revealed other most interesting features, as shown by the lines of equal magnetic declination, dip, and horizontal intensity, drawn in conformity with the observations. ‘There were noticed marked relations with well-known physiographic features. The curvatures and bend- ings of the lines of equal magnetic declination appear to con- form with courses of principal steams and shore lines of certain bodies of water. Also a marked difference manifested itself in the general direction of these lines in the middle of the southern part of the State, just where there is a dividing line between the newer and older geological formations. It is especially interesting that the irregularities in the distri- bution of the earth’s magnetism, as exhibited by the three sets of lines, occur chiefly in the regions of the alluvial deposits brought down by the Missisippi River. Owing to these irregularities the compass needle is deflected from the direction it would ordinarily have assumed by amounts varying from about 0°'1 to0°°5. They are not local disturbances of such amount which ordinary instru- ments would readily reveal, but they are of such a magnitude as only approved instruments and methods would indisputably expose. This point can not be emphasized too strongly for the sake of geologists who undertake to discover relations between magnetic disturbances and geological formations, employing crude instru- ments, and using imperfect methods. Quite likely these irregularities are to be referred to small local deposits of iron ore brought down from the upper States by the Mississippi River.’ 16. An Introduction to the Study of Spectrum Analysis ; by W. Marsnatt Warts. Pp. vil, 325, 8vo. London and New York, 1904 (Longmans, Green & Co.).—The first impression from a hasty inspection of this work is the extraordinary variation in the character and value of the numerous illustrations contained in it. We recognize some cuts which are familiar in popular works on spectroscopy from as early a date as 1870, and which might have been omitted even then with profit to the reader. VS ~- Vs | TS I OS et liey EN SN ere Ne mite lie may tae, GEST RG SI 7 iN : BEAN eee iy ee 75 LNF 2 - > SMEs! s - i, FST z) a PE ae / aaa Ae SmI Bully Hill volcanics ae Cloud limestone an aird. Carboniferous ST nz ra a a a = g Te SATE Bragdon. Carboniferous Kennet.Devonian Clear Creek volcanics Scale of map, 1 inch = nearly 7 miles. often fossiliferous, while pebbles and coarse sand chiefly of © vein quartz and chert form the matrix between the larger fragments as well as the beds of finer conglomerate. Away from the river, coarse conglomerate is rare. It was noted on the divide, about one and one-fourth miles southwest of High Mountain, called also Nawtawakit Mountain, close to the eastern edge of the Bragdon, where the pebbles of gray sandstone weathering red are sometimes six inches in diameter and very hard. Distribution.—The principal area of the Bragdon, and the one to which, excepting the western border, [ have given special attention, is what Mr. Hershey calls the “ eastern or J. S. Diller—Bragdon Formation. 381 type area.”* As shown upon the accompanying map, it is roughly pear-shaped, constricted in the small part with the longer axis running nearly northeast and southwest. The big- ger end lies near Trinity River from Lewiston to Trinity Cen- ter, while the smaller end is trenched by the Sacramento from Portugese Flat to Morley, and the long broad stem runs north- east from North Salt Creek to the McCloud, a total length of fifty miles and maximum breadth of about twelve miles. The borders are locally irregular and there are a few small outlying masses of Bragdon, but in general this area is remarkable for its continuity from the Trinity River to the McCloud without interruption excepting a small area of Devonian on Little Sugar Loaf Creek and small areas of volcanics on Clear Creek and Dog Creek, as well as several long narrow masses, not shown on the map, east of the Sacramento River. The smaller end of the Bragdon area, including the stem lying east of the Sacramento, is bordered on the one hand by the Carboniferous sediments and on the other by those of Devonian age; but west of the Sacramento, excepting a small bit on Backbone Oreek, the type area of the Bragdon is everywhere bounded by igneous rocks, some vol- canic, others plutonic. It is evident, I think, that the region of greatest promise in studying the taxonomy of the Bragdon is east of the Sacramento, where it comes in contact both above and below with sediments whose horizon is well established by an abundance of fossils. West of the Sacramento we are adrift-among a plexus of igneous rocks whose exact age in most cases is not easily determined. Stratigraphy.—The Bragdon, composed as it is of thin beds, lacks a definite rigid horizon to resist folding. It is easily crumpled, giving a great variety of dips and strikes. In the part of the area east of the Sacramento the dips are sometimes vertical, but for the most part not over sixty degrees, often under thirty and generally to the eastward, and agree fully with the general position of the Jurassic, Triassic and definitely known Carboniferous (McCloud and Baird), all of which le to the eastward and increase in age westward, suggesting that the Bragdon is the oldest and hes beneath the Baird. This view is strengthened by an examination of the eastern limit of the Bragdon where it adjoins the Baird. The limit may be traced for more than twenty-five miles parallel with the Baird and McCloud limestone, within a mile or two west of the latter, and is marked by the disappearance of the characteristic Brag- don conglomerate. It must not be supposed that the same bed of conglomerate can be traced continuously along the east- ern edge of the Bragdon for twenty-five miles. The conglom- erate is in thin lenticular beds with traceable continuity of * Am. Geol., vol. xxxiii, p. 251. Am. Jour. Sci.—FourtuH Series, Vou. XIX, No. 113.—May, 1905. 382 JS. Diller—Bragdon Formation. only afew miles, but farther along in the same horizon the conglomerate comesinagain. This top horizon of the Bragdon will be noted at only two points. On Hirz Creek road the top conglomerate is fine, but west of it a few hundred feet is another that is coarse with fossiliferous Devonian pebbles. The strata are all nearly vertical and for the most part well exposed eastward to the shales full of Baird fossils. On the divide about a mile and a half southwest of High Mountain the characteristic conglomerates are well developed. Most of them are fine, but one is coarse, with many pebbles of sand- stone and some of fossiliferous Devonian limestone. These lenses of Bragdon conglomerate are immediately and conform- ably overlain by sandstone containing Baird fossils. An ~ observer cannot carefully study the contact of the Baird and Bragdon from one end to the other without being convinced on structural grounds alone that the Bragdon and Baird are contormable and that the former is the older. As to the lower limit of the Bragdon, the matter is more com- plex owing to the fact that the basement on which it rests is vari- able, sometimes sedimentary rocks of Devonian age, but more frequently volcanics. The best exposure of the Bragdon resting on the Devonian is along Backbone Creek, three and one-half miles north of Kennet, where over 800 feet of Devonian shales and limestone* are overlain unconformably by a thirty-foot bed of Bragdon conglomerate containing fossiliferous Devonian fragments. To the east and west of this locality the Bragdon beds overlap the Devonian to the vol- canics, but in both directions there soon appear other patches of Devonian lying between the Bragdon and the voleanics. Near- by, on Little Sugar Loaf Creek, a small area of fossiliferous Devonian is completely surrounded by Bragdon. Along this portion of the Bragdon border the small areas of Devonian are remnants left by pre-Bragdon erosion of a once continuous sheet of Devonian and thus exposing the volcanic rocks which lie beneath and were erupted before the Devonian sediments were deposited. To the northward, in the vicinity of Hazel Creek, the Devonian shales and limestone areas are more continuous and may be traced for over ten miles along the western border of the Bragdon. Although the contact is not well exposed, the fact that the basal conglomerates of the Bragdon are at least generally, if not everywhere, composed wholly of debris trom the Devonian sedimentary rocks, clearly indicates an unconformity by erosion between them. It is in this portion of the pear-shaped Bragdon area that its taxonomy is most evident and may be conveniently studied along the trails from the McCloud to Castle Crag and Sims on * This Journal, vol. xv, p. 347. J. S. Diller--Bragdon Formation. 383 the Sacramento. The essential part of the McCloud-Sims section is given below, beginning with the newer beds on the east. The thickness given is only a rough estimate, making allowances for repetition by many small folds and faults. Carboniferous, limestone, (McCloud) ._---..-------------- 2000 “< reddish shales and sandstones with much vol- Canicsmiatebial, (attd).s. 22. 2) Ss. ..-- 1000 Se shales, sandstones and tuffs with siliceous conglomerates (of Devonian pebbles) in- creasing In number and size from the top towards the bottom (Bragdon) ---.-.---- 2900 (Unconformity) Devonian, dak is lan lester es sve eee a Ne les) Voce 100 z limestone ..-.- 2.4. sey ALS) 3 black slaty shales (scarcely any chert) Baie tie 400 ? ee VOLCUIN CESENICS ESN Ray A aks so LT) es ee Relation of the Bragdon to Volcanie Rocks.—The Red- ding quadrangle contains an extensive series of highly fossilifer- ous sediments from the Devonian to the Tertiary inclusive, and affords one of the most complete records of the volcanic phe- nomena of that interval to be found in the state of California. This is not the place to enter into details concerning this record, and yet it is necessary to consider it very briefly in a general way to elucidate the relations of the Bragdon. Devonian sediments show the existence of andesitic and rhyolitie lavas of earlier date, and during the Bragdon and especially the earlier portion of ‘the Baird there was considerable volcanic activity which continued for a long time and culminated about the close of the Paleozoic. A great sheet of lava and tuffs was formed at that time which appears between the Carboniferous and Triassic sediments. Volcanic eruptions continued at inter- vals throughout the Triassic and Jurassic but during the Creta- ceous there was a long interval of quiescence, followed by the great eruptions of the Tertiary. It is not to be supposed that voleanic products were in all cases spread equally over the whole Klamath Mountain area for each volcanic horizon. The eruptions were local, yielding large masses at different places at different times, and to establish the horizon of each it is generally necessary to determine their relation to fossiliferous sediments. Older than the Miocene, one of the largest among half a dozen horizons of volcanic pr oducts in the Redding quadrangle is that on the border of the Paleozoic and Mesozoic. The andesitic and rhyolitic lavas and tufts of that horizon form a prominent ridge to which Bully Hill belongs, and the wkole mass may be conveniently referred to as the “ Bully Hill volcanics.” Con- 384 J. 8S. Diller—Bragdon Formation. cerning the age and structural relations of the Bully Hill volean- ics, all observers practically agree in placing them about the close of the Paleozoic and the beginning of the Mesozoic, but as to the age of the large area of volcanics southwest of Bully Hill, along the Sacramento—the rocks which Mr. Hershey has called his Clear Creek volcanic series, I have but recently come to a definite conclusion. The generally complete absence cf vol- canic material in the typical Bragdon conglomerates, and also the fact that much of the igneous material which appears in the areas of ‘Clear Creek volcanics” cuts the Bragdon, for a long time counterbalanced in my mind the contention of Hershey that the Bragdon is younger than the “ Clear Creek voleanic series” and rests directly upon it. But the discovery of andesitic and rhyolitic material like that of the Clear Creek series in certain Bragdon conglomerates well characterized by fossiliferous pebbles of Devonian limestone, leaves no doubt that in the main the “ Clear Creek volcanics” near the Sacra- mento are, as Hershey maintains, older than the Bragdon. On Backbone Creek, several miles above Kennet among the stratified rocks which appears to belong to the Devonian, there are definite beds of volcanic debris which indicate that ande- sites and rhyolites, like those of the ‘ Clear Creek volcanics,” were exposed to furnish Devonian sediments. The relation of the Devonian limestone and shales in the Kennet region to the “ Clear Creek volcanics ” confirms the same view. The Devo- nian sediments appear in patches completely surrounded by the “Clear Creek volcanics,” at first suggesting that the Devonian sediments are broken up and enclosed by the volcanics. On closer examination, however, the isolated patches of Devonian are clearly seen to be, for the most part, remnants of a once con- tinuous but deformed sheet of Devonian that covered the “ Clear Creek volcanics” of that region, and was cut up by pre-Bragdon erosion into separate patches exposing larger areas of the underlying voleanics. A few miles northwest of Kennet the Devonian patches lie on ridges completely separated by the narrow canyon of Little Backbone Creek, but on Backbone Creek erosion has not yet quite completed the separation of the Devonian masses upon its sides. The “Clear Creek volcanics” of the Kennet area which are beneath the Devonian, Mr. Hershey regards as on top of the Devonian. If his view were correct, they should lie between the Bragdon and the Devonian, which is certainly not true in the Kennet region where all three are well exposed, and in every Devonian outcrop touched by both Bragdon and “ vol- eanics” the former is on top and the latter beneath. This relation is clearly exposed at two points on Backbone Creek, also on Little Sugar Loaf Creek, at the head of Bailey Creek, J. S. Diller—Bragdon Formation. 385 four miles west of Baird and near the mouth of Hazel Creek. It is evident, therefore, that the ‘“Olear Creek volcanics” of Hershey in the Kennet region, being earlier than the middle Devonian, are not equivalent to the Bully Hill volcanics of late Carboniferous and early Triassic age. The fossiliferous tuffs and shales which are interstratified with the lavas of “ Bully Hill voleanics,” showing them to be of submarine eruption, are entirely lacking in the “Clear Creek volcanic series.” The general statements made in this paper apply only to the type areas of the Bragdon and of the “Clear Creek volcan- ics” east of Trinity Mountain, where it is believed their normal relations to Carboniferous and Devonian are better exposed than anywhere else in the Klamath Mountains. Age of the Bragdon.—The Bragdon formation is regarded by Hershey as Jurassic about the horizon of the Mariposa, and he has set forth his evidence in detail.* It is in part lithological but largely structural, in which much stress in laid on the rela- tive position of his “Clear Creek volcanics” regarded as of early Triassic age, but which, as I have already shown, are in part, at least, earlier than the middle Devonian. Upon a geological map of portions of the copper belt of Shasta County, Andersont+ represents the same rocks as Triassic, but the circumstances of publication did not permit him to present the evidence. . A study of the areal distribution of the Bragdon and its stratigraphic relation to the Carboniferous and the Devonian led me several yearst ago to refer it provisionally to the lower part of the Carboniferous. J urther field study has confirmed me in that opinion as already set forth. Fossils recently dis- covered support the same conclusions and will now be consid- ered. Mr. James Storrs, who has collected most of the fossils for my party of the Geological Survey in the Redding Quadran- gle, early discovered that some of the limestone fragments of the Bragdon conglomerate are fossiliferous. I ossils have been collected at various times during four years from the conglom- erate pebbles at twenty-one localities, chiefly along the Sacra- mento and to the eastward close up to the outcrop of the Baird formation, but also to the westward as far as Trinity Mountain and on the northwest to within a few miles of Trinity Center. These fossils were referred at first to Mr. Schuchert and later to Dr. Girty, and all of them as far as determinable, with one possi- ble exception found on Bailey Creek to be mentioned later, were * Am. Geologist, vol. xxxiii, pp. 248-256 and 347-360. + State Mining Bureau, Bull. 23, 1902, on Copper Resources of California. } This Journal, vol. xv, p. 352. 386 J. iS. Diller—Bragdon Formation. reported as Devonian like those already known in the region. The Devonian fossils in the pebbles simply show that the conglomerate is later than the Devonian. . Careful search was made in the paste of the conglomerate as well as in the associated sandstones and shales for fossils of the Bragdon epoch. Fossils were found in eleven localities, enumerated below, at six of which the fossils are in shales and sandstones, associated with the characteristic Bragdon con- glomerate, while at the other five the fossils occur in the paste of the conglomerate, but not in the pebbles. One of the most important occurrences is upon the divide southwest of High Mountaim, where the sandstones conforma- bly interbedded with characteristic Bragdon conglomerate contain shells which Dr. Girty reports as ‘‘ Paleozoic, and without much doubt early Carboniferous, related to the Baird.” The fossils, among which is a large “Spirifer of the Striatus type,’ occur in several beds. The exposures are good and leave no doubt that the fossils are of the Bragdon horizon. Perhaps the most important locality is beside the railroad, one and one-half miles northeast of La Moine, where fossils were found in the sandstone adjoing the Bragdon conglom- erate. From this locality Dr. Girty reports Schizodus sp., Loxonema sp., Plewrotomaria? sp. and Straparollus aff. S. lwxus. ‘There is no room for doubt that these fossils belong to the Bragdon and are not derived from an older formation, and Dr. Girty remarks that if this be admitted “no other con- clusion is possible than that the Bragdon is a Paleozoic forma- tion. Indeed it is fairly safe to say that the horizon is not later than Baird, for the local faunas have many points of resemblance with that of the Baird, and none at all with those of the overlymg Carboniferous formations.” From the shales about two and one-half miles southwest of the mouth of Hirz Creek, and also from shales in an isolated patch of the Bragdon about one and one-fourth miles a little east of south from Bayha, Cephalopods were collected. From the first locality Dr. Girty reports Glyphioceras, and from both a form “of what seems to be a Wawtilocd to which Mr. Stanton recalls nothing similar in the Mesozoic and which is not out of place in the Carboniferous.” Dr. Girty states further that “The little Gonzatite shows only the course of the suture lines, external characters being concealed. The sutures remind me much of those of the sphwricus group of Goniatites (Glyphioceras), and if this is truly the relation of the specimen the age would probably be late Lower Carbon- iferous. Prof. J. P. Smith, who examined the specimen, on the other hand, thinks that it might represent an immature stage of an Ammonite. It seems to me, however, that an J. S. Diller—Bragdon Formation. 387 Ammonitic stage sufficiently immature to show sutures of the simplicity of the present example would be of a size much smaller than it possesses. In my opinion, therefore, the speci- men is a Glyphioceras, but the possibility should not be lost sight of that 1t may be a young stage of a more complicated and later developed type.” We now come to the fossils found in the paste of the Brag- don conglomerate. Dr. Girty identities Lzthostrotion sublaeve, a Baird species, from one and one-half miles east of Portugee Flat, and also on O’Brien Creek, one-fourth mile below the stage road. No other fossils were found at either place. On Hazel Creek, six miles east of Sims, there is a conglomer- ate composed largely of volcanic material with but little chert and therefore not typical Bragdon. It includes what look like fragments of rotten calcareous sandstone which readily disin- tegrates, leaving very distinct and complete impressions of delicate parts of corals against the paste in such a way as to indicate, as pointed out by Dr. Girty, that the fossils are in place and not derived. Dr. Girty recognizes from this locality Laphrentis sp. and Loxonema sp., and the last, it not both, appears to belong to the Baird. The only case in which there is reasonable doubt concerning the relations of the fossils has already been referred to. It is on Bailey Creek, where a Bragdon conglomerate contains Za- phrentis and Loxonema’? in moderately soft sandstone having the form of a small pebbie, while there is a suggestion in the arrangement of the fossils that, as on Hazel Creek, they are contemporaneous, yet the evidence is not clear. If it is a peb- ble, two explanations may be offered. There is the possibility and perhaps probability on the one hand that the forms men- tioned may have begun in the Devonian, and from thence have been derived, or, on the other hand, that they may not be the identical forms of the Baird. In estimating the weight of the evidence afforded by this one doubtful pebble containing more or less questionable forms, it is necessary to remember that the fossils in the sand- stones and shales, as well as the matrix of the Bragdon con- glomerate, point definitely to the conclusion that the Bragdon formation is Paleozoic and is fully in harmony with the strati- graphic evidence which places the Bragdon at the base of the Carboniferous section conformable beneath the Baird. 388 Screntific Intelligence. SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. The Preparation and Properties of Tantalum, — Metallic tantalum has been prepared by Berzelius, Rose, and more recently by Moissan, but always in an impure condition, either as a black powder, or, in Moissan’s case, as a very hard, brittle substance containing carbon. WERNER von Borron has recently suc- ceeded in obtaining tantalum in a practically pure condition, and finds that it possesses some very remarkable properties which promise to make the metal one of great practical importance. Von Bolton has improved the processes of Berzelius and Rose (where a double fluoride is reduced with an alkali metal) and he has purified the product further by fusing it in a vacuum by means of the electric arc. He has also applied an interesting electrolytic process, consisting in passing an electric current through slender rods of the lower oxide in a bulb similar to that of the incandescent lamp, meanwhile pumping away the oxygen formed by the electrolysis as fast as it was formed. Pure tanta- lum when fused forms a brilliant regulus having a platinum-gray color, which can be hammered and drawn out into the finest wire. The specific heat is (0365, and the atomic heat, 6°64, corresponds to Dulong and Petit’s law. The specific gravity of the cast metal is 16°64. Its melting point was found to be 2250 to 2300°, and is far above that of platinum. It remains brillant upon exposure to air, and oxidizes slowly when heated in air or oxygen. The metal shows an extraordinary combination of the properties of malleability, ductility, tenacity and hardness. For instance, when a red hot piece of tantalum is put under the steam-hammer, a plate of the metal is readily formed, which, when repeatedly heated and hammered, attains a hardness equal to the diamond. An attempt to bore such a plate one millimeter thick with a diamond drill with 5000 revolutions per minute had to be aban- doned after three days.and nights of continuous work, as a depres- sion of only one-quarter millimeter was made thereby, and the diamond drill was much injured ; still the plate could be made thinner by rolling, without losing its hardness. Many applica- tions are predicted for this most wonderful metal, one of which is the use of the wire for the incandescent lamp, in which it gives more than double the efficiency of the carbon thread.—Zevtschr. Sir Hlectrochen., xi, 46. I, Le We 2. Gravimetric Determination of Nitric Acid. — M. Buscu has synthesized a base, diphenyl-endanilo-dihydro-triazol, named “Nitron” for the sake of brevity and for commercial purposes, which forms a very insoluble, stable nitrate, and, therefore, furnishes a means for the direct gravimetric determination of nitric acid, as well as for its qualitative detection. The reagent is manufactured on acommercial scale by Merck, and is employed Chenustry and Physics. , 389 in the form of a ten per cent solution in five per cent acetic acid. For qualitative tests five or six drops of the reagent are added to 5 or 6°™ of the liquid to be tested, after the latter has . been acidified with a drop of dilute sulphuric acid. | pe ‘ ~ S L r¢) Let the object move so that its image (fig. 2) in red light shifts its position from 7 ‘to 7’; the corresponding image in blue light will shift from 0 to 6’, while the center of the difiu- sion circle on the retina, supposed to be at 7 for convenience, shifts from 7 to 6’. It is at once obvious that rr’ /bb’=n,r/n,6 ; also bb'/rb,’ = 1,)/7,.7; whence rr /7rb! = np 2.0/1 ae From the table of dimensions given above this ratio is found to equal 1°0072; that is to say, when an object having red points is shifted in the visual field, the red points seem to have an angular velocity and an angular acceleration about three- fourths of one per cent greater than that of accompanying blue points. Thus, when the red surface described in the experiment is suddenly set in motion, the eye, for an imstant fixed, judges of its acceleration and of the less acceleration of . the green; then, following it in its motion until it is arrested, concludes that the more refrangible color is left behind—a false judgment which is corrected by the sense of a gradual approach of the green to its true position of rest, just as when the eyes, observing a procession of points passing fixed points, corrects a false judgment as to the place of the former, when the motion suddenly ceases, by an apparent temporary motion in the opposite direction. Of course, if we gain our notion of the angular velocity of the green areas from sharp visual perceptions of their boundaries, the illusion ought not to appear; it is only when the position of the colored area is recognized by its color alone that the effect becomes striking ; hence the significance of faint illumination. Hastings— Optical Errors of the Human Hye. 409 IV. Binocular Color Relief. This is an optical ilusion not noted in Helmholtz but described and studied at length by W. Einthoven, who was incited to the investigation by Donders.* According to this writer, Professor Donders was the first one to record the fact that red and blue objects in the same plane appear to most observers, when looked at with both eyes, to lie in different planes, especially when on a black background. ‘To him, as well as to Einthoven, the red appears nearer than the biue. The explanation offered by Einthoven can be described by reference to fig. 1 above. Imagine both axes of the vision converged towards a red point which is accompanied bya blue point just above it: the red images would fall on the points of distinct vision, while the centers of the diffusion circles for blue would fall on disparate points of the retinas nearer the median plane, just where sharp images of a more distant red point would fall; hence the interpretaticn of the resulting sensation is that the blue point is in fact more remote. He finds evidence in favor of this view by the ingenious experi- ment of cutting off, by means of movable diaphragms in front of the eyes, first the inner halves of the pupils and then the outer; by this means he enhances or inverts the illusion. His experiments are easily repeated and are highly interesting. t There are, however, serious objections to this explanation, not only as accounting for the observations, but also from theoretical considerations. Of about thirty individuals inves- tigated Einthoven found that nearly one-third were not con- fident at first that there was any sensation of relief, while ultimately about half recognized the relief as did Donders, and the other half inferred an inverted order. This general con- clusion is fairly well supported by my own more limited experiments. According to the theory, we are obliged to con- clude that half of those investigated had the centers of their pupils lying on the nasal side of the axes of vision, and half on the temporal. It is, however, quite certain that a displace- ment of the pupil towards the nasal side of the axis of vision * Stereoskopie durch Farbendifferenz. Graefe’s Arch., xxxi (8). + A convenient and interesting modification of this experiment may be made by observing a flat surface divided into separated areas of saturated colors through a binocular telescope of which the separation of the axes can be varied at will. The familiar prismatic binoculars are best adapted to the purpose, and any mosaic glass window in which the colors are vivid forms a far better object than colored pigments. If the axial separation is a little greater than that of the eyes, a striking relief will be observed in the sense described above, while a smaller separation will invert the relief. 410 Hastings—Optical Errors of the Human Eye. is extremely rare ; consequently there seems to be no escaping the conelusion that similar visual impressions receive, not merely unlike, but opposite interpretations in different indi- viduals. Any acceptable theory must adapt itself to this funda- mental fact. | It seems to me that we can find a probable.explanation in the following considerations. Imagine a number of red points distributed in two parallel planes which lie at right angles to their direction from the observer. If the eyes be fixed upon one of the points in the nearer plane, the images of all the other points in that plane will fall on pairs of congruent points of the two retinas, but the images of the points on the more remote plane, which will be quite sharp if the separation of the planes is moderate, will fall on disparate points of the two retinas. Now consider the case of red and blue points in a single plane. Here, if the eyes be fixed upon one of the red points, all the other red points will have their images on con- gruent points of the right and of the left retina, while the blue points, relatively very diffuse as compared to the images of the more distant red points in the former case, will fall on disparate points. So far there is a formal similarity between the two cases, but it cannot be carried further: in the first case a simple change of convergence of the axes of vision will change the disparate points to congruent, and vice versa, while in the second case no such change can produce such an effect ; but a change of accommodation proper to blue light will do so at once. The resemblances and differences are such, there- fore, that it should hardly surprise us that certain persons recognize the second case as only a confusion of visual images, when others interpret the effect as a sort of chromatic relief ; nor is it astonishing that of the latter group, since there is really no fundamental relation between the two phenomena, some should imagine the red to be nearer than the blue points and others invert the order. It is singular, however, that Einthoven found those whom he observed to be distributed so nearly equally among the three classes. The experiments of restricting the pupils by screens in front of the eyes is by no means conclusive ; indeed, it is questionable whether it has any bearing whatever upon the phenomenon. he screens will, primarily, increase very greatly the separation of the centers of the red and blue areas on the retinas which represent the images of the points; moreover, the areas them- selves will be much decreased. This will become evident from an inspection of fig. 1. But, as is easy to prove by a diagram, any lateral change of the common point of fixation will pro- duce a relative change in the position of the colored areas on Hastings—Optical Errors of the Human Eye. 411 the retinas, which can be compensated by an alteration in the convergences of the axes, and thus the phenomenon is reduced to one which admits of a simple stereoscopic interpretation in complete accordance with the observations. This is because such a shiftng—whether produced by a change in the direc- tion of vision or by a change of place in the object itself— partially uncovers one pupil while increasing the obstructed portion of the other, in short, virtually moves one pupil inwards and the other outwards. The resultant effect is like that pro- duced by placing a thin wedge of glass before one eye, when the red appears in advance of the biue if the thicker edge of the wedge is on the nasal side; a reversal of the wedge inverts the apparent relief. There is, however, one phenomenon which often gives a determining impulse to the interpretation in accordance with the experience of Donders, namely, the relative angular dis- placement of different colors upon the retina. Thus, in my own case, although quite unable to recognize anything like stereoscopic relief among a series of strongly colored figures on a black background when the eyes are fixed pretty steadily upon them, the relief appears very striking when I walk past it, or when the object as a whole is moved to and fro. So too, in the experiment of the fluttering hearts described above, although there is no chromatic relief under ordinary illuminations, such relief is an invariable accompaniment of the fluttering when produced. Ashas been shown above, the angular accelerations and angular velocities of moving objects in the visual field would vary with their color, so that colors of greater refrangi- bility would appear to change their directions from the observer more slowly, exactly imitating in this particular the effect of greater distance. The illusion described would appear of rather abstract scientific interest were I not convinced that the incomparable French artists of the thirteenth century had recognized it and employed it for the purpose of artistic expression. Indeed, it was a casual inspection of the marvelous medieval windows in the great cathedral at Bourges which first turned my attention to the studies embodied in these papers, and which persuaded me that the one essential distinction between these antique windows and their unsatisfactory modern imitations lies in the knowledge, possessed by the old artists, of the effect gained by an ordering of their vivid colors so that the resulting chromatic binocular relief should fit the composition of their pictures. As far as known to me, the most beautiful surviving examples of this lovely art, as well as the most convincing support for the views here presented, are contained in that unapproached 412 = Hastings—Optical Errors of the Human Hye. collection; and not alone in the wonderful achievements of those forgotten artists, but also in the instructive failure which has attended modern restorations.* This is not the place to suggest reasons why so charming an art should hardly have survived the thirteenth century, nor to discuss certain peculiar restrictions to which the artists sub- jected themselves; but were such an extention of this paper desirable, it seems to me that it would add material weight to the explanation, founded upon principles of physiological opties, of the acknowledged superiority of antique mosaic windows over their modern imitations. *In two quadrifoils in the window given by the Guild of Tanners the artist has chosen a red background in place of the almost universal blue ; but he has reversed the order of his colors throughout the composition se that the effect, to my eyes at least, was that of two charming little intaglios. It was this which first suggested to me the distinction between ancient and modern mosaic windows described above and which I thought abundantly verified by subsequent observations. Certain very puzzling contradictions to this theory—I have no means now of determining how many—vwere elimi- nated by a subsequent discovery that considerable areas of some of the win- dows are nineteenth century substitutions for the original designs which had been lost. There was no suggestion of this significant fact in my hands at the time of my visit. Yale University, May, 1905. Jamieson—Natural Iron-Nickel Alloys. 413 Art. XLIII.—On the Natural Lron-Nickel Alloy, Awarwite ; by GrorcE 8. JAMIESON. Two terrestrial iron-nickel alloys from adjoining localities will be described in this paper. One from Josephine Co., Oregon, which has already been investigated by Mr. W. H. Melville,* came through Mr. Maynard Bixby of Salt Lake City, Utah. The other, found at South Fork, Smith River, Del Norte Co., California, was from Dr. David T. Day, Chief of the Division of Mining and Mineral Resources of the United States Geological Survey. Both specimens had been sent to Professor 8S. L. Penfield, at whose advice this investigation was undertaken. The specimens from Josephine County were water-worn, bean-shaped pebbles, varying in size from a few millimeters to two centimeters in diameter and were composed not only of the alloy, but also of more or less siliceous matter. Thin sections showed that the alloy was of a spongy nature, binding together and enclosing particles of silicate, which had the appearance of serpentine and gave the chemical reactions for that sub- stance. In a steel mortar, the pebbles were easily broken into a powder and no mechanical method of making a separation of the metal from the serpentine seemed possible. A chemical separation, however, was easily effected by treating the powder with water and iodine at ordinary temperature. A complete solution of the alloy was thus obtained in about a day, while the siliceous matter was not dissolved by this treatment. The insoluble silicate was filtered on asbestos, air dried, and weighed. Duplicate analyses were made with the following results : Insoluble silicate ._.. -...2_.- 94°15 Q4°55 SEE MMs ee cot para tN Caen Meee 19°17 18°95 PREC gh aye se or tae ce ee 56°30 56°07 cr Sires CRS 8 ieee ae ae Siete i Bll es 35 35 Peliospn@rusee = 2 oa tees 04 04 SCPE Ree So tA oe ‘09 ‘09 100°10 100°08 Deducting the insoluble silicate and recalculating the remain- ing constituents to one hundred parts, the following percent- ages were obtained : (ES PUSS Mie ie Mace 2 as Raine Reagan 25°24 Yat eels pom e eees S Tia a7 74°30 ra rain ener Meee, es 46 46 PGS PHOraS a Il Te “04 “04 SUT Sg CR Io oon Dearie Ba ee ‘09 “09 100°00 100°00 * This Journal [3], xliii, 509. 414 Janieson— Natural Lron-Nickel Alloys. These resuits differ but slightly from those obtained by Melville, who found iron 23°22, nickel 60°45, and 15-83 per cent of other constituents. The metals calculated to 100 per cent equal, iron 27°75, and nickel 72°25. The sample of iron-nickel. alloy which came from Smith River, California, was in the form of grains of remarkably uniform size, about 0°15 millimeters in diameter, with an occa- sional larger grain, up to 1°5 millimeters. The metallic sand, for that is what it appears to be, was obtained from gold washings and was chiefly composed of the alloy, but mixed with magnetite, and a very little chromite. As no mechanical method for separating the alloy from the magnetite seemed to give satisfaction, a separation by chemical means was again resorted to. The size of the grains, which could not be reduced to powder, made the solution in iodine altogether too slow for practical purposes. The alloy was found, however, to be easily soluble in warm dilute nitric acid (one part cone. HNO,: two parts H,O), while the magnetite was not appreci- ably attacked, if at all. Duplicate analyses were made with the following results : Fnsolubleumatier.2ce eee tee eA 9°97 PPO aa eae bes ee 19°21 18°97 IN elge lees Gon pede or ete nea 68°61 68°46 Cobaltec By we aren Vemaian yet 1-07 1:07 COP Pela hel eke ee oe iO 56 PSU YG 0) UH iam Renae ch haba ibs edo ob OS) "05 PHOSPHO: = see ae 2 teehee 04 ‘G4 Silica Sela ke Slr, (eee eee 10 19 Maeneésium oxide 220222922 50 ‘44 99°62 99°75 The specific gravity was found to be 7-45 or, allowing for 9°7 per cent of magnetite, the value 7°85 is obtained for the alloy. Deducting the insoluble matter, consisting of the magnetite, a small amount of chromite and the traces of silica and magne- slum oxide, and recalculating the remaining constituents for one hundred parts, the following percentayes were obtained : 1B os i eaieme ain ati a vata = Ae en Sco 21°45 21:28 IN Chee Srircey eras ee cata 2 oe aie 76°60 76°79 Cobalt. 62 oy ey senna Lae 2G COP Per 23 3 Aes eee eee 66 "63 Phosphorus) 2-22) 03 222-02 soon eee ‘04 Sulphur (2335s. Soe eee ae ‘06 "06 100°00 100°00 In dissolving the alloys in hydrochloric acid, it was noted that there was no odor of hydrocarbons, such as is observed when iron and steel are dissolved, nor was there any evidence of graphitic carbon. Jamieson—Natural [ron-Nickel Alloys. 415 These two iron-nickel alloys are quite similar in composition to those which have already been described from other locali- ties, and for comparison, a table has been arranged to show per- centages of iron and nickel which these various alloys contain. The first analysis is that of an alloy found at Gorge River, which flows into Awarua Bay on the west coast of South Island, : New Zealand, described by W. Skey* in 1885 and to which the name awaruite was given. The second analysis, by A. Sella,t is of an alloy from the gold-bearing sand of the Elvo River, near Biella, Piedmont, Italy. The third analysis, by Melville, is of material from J osephine Co., for which the name J osephinite was suggested. No. 4 is a recent analysis by F. G. Wait, quoted by G. C. Hoffmann,t of a similar Alles from Fraser River, British Columbia, to which Hoffmann has given the name "souesite, as stated by him, “‘to distinguish this find from that of other naturally occurring iron-nickel alloys.” The last two analyses are those of the present writer. Other Locality. Analyst. Fe. Ni. Co. Cu. constituents. 1. New Zealand Skey 31:02) 67-63. - "70° none’ 9°63 2. Piedmont, Italy Mattirolo 26°60 75°20§ -. none -- 3. Josephine Co. Melville 27°41 71°35 65 59 as 4. British Columbia Waite 22°30 76°48 none 1:22 ise 5. Josephine Co. Jamieson 25:24 Welt 465 oo Als 6. Del Norte Co. es 2 Aaa O70) cl 196 595 32 KO Tt is seen from a glance at the analyses of the alloys from the five different localities, that there is a certain uniformity in composition, but that they are not a definite compound of iron and nickel is evident, nor would this be expected; with Fe: Ni=1:3, the percentages are Ke 24:00 and Ni 76-00, to which most of the analyses approximate, while for the ratio 1:2 the values are Fe 32°19 and Ni 67°81. It seems unfortu- nate that so rare a substance should have received three dis- tinct names, awaruite, josephinite, and souesite, and it is urged that awar uite, which has priority, should alone ‘be used. As regards the occurrence of the alloy, its association at J osephine Co., Oregon, with serpentine, and at New Zealand, Piedmont, F razer River, and Del Norte Co., Cal., with chro- mite, suggests that it is a material which has separated from basic peridotite rocks, and, as it seems to have no tendency to deteriorate by oxidation, it is found as a heavy constituent in adjacent river sands. In closing, it is desired to thank Mr. Bixby and Dr. Day for the material which they had sent to the laboratory for investi- gation, and also Professor 8. L. Penfield for his help and valu- able suggestions. Sheffield Scientific School of Yale University, May, 1905. * Trans. N. Zeal. Inst., xviii, 401. +Comp. Rend., exii, 171. ¢ This Journal (4), xix, 319, 1905. § Contains cobalt. 416 Lf. B. Loomis— Hyopsodide. _ Arr. XLIV.— Hyopsodide of the Wasatch ind. Wind River Basins ; by F. B. Loomis. Durine the early summer of 1904, ae ciee st College sent a party into the Wasatch along the Big Horn River, where an unusually complete collection was obtained: later, “eollecting was continued in the Wind River beds, a new and rich locality having been found on the east side of Bridger Creek, about ten miles northwest of Lost Cabin Post Office, Wyoming. In the latter basin, the fauna of which has been but meagerly known, some 400. specimens, distributed among about. 50 species, were found. As a large number of the species are new, the material, together with that of the Wasatch, has been used in a study of the families represented ; reference also having been made to other collections from these horizons, especially those of Cope and the American Museum of Natural History, both being in that museum. Order INsEcTIVORA. Family Aijopsodidce, Schlosser. This family as now known includes two genera, Hyopsodus and Sarcolemur, both from the North American Eocene. The genera were originally classed among the Primates; and so in Cope’s* and Osborn’s} papers are ‘placed under the suborder Mesodonta; or by Schlosser{ under the equivalent Pseudo- lemuroidea. Wortman,$ however, has classed them among the Insectivora, giving the following reasons: 1, the incisors are 3/3; 2, the tympanic bulla is not ossified ; 3, the structure of the molars is not Primate; 4, the enterocarotid circulation is that typical of the Insectivora: 5, the limb bones differ from those of any known Primate; 6, the metapodials are not Pri- mate; 7, the phalanges are short ; 8, the hallux is not opposa- ble. The writer too would place the Hyopsodidee among the Insectivora and in the neighborhood of the genus Hrinaceus. The family may be defined as follows: teeth in a continuous series, cusps more or less pointed; superior molars with inter- mediate cusps (protoconule and metaconule); posterior internal cusp (hypocone) less developed than the other cusps; the lower molars with a low anterior buttress (protolophid) con- necting the two anterior cusps; a second buttress behind the first, connecting the same cusps posteriorly (metalophid) more or less developed ; the entoconid feebly developed (see fig. 1). * Rep. U.S. Geol. Surv., iii, 738, 1884. + Bull, Amer. Museum Nat. Hist. , 178, 1902. ¢ Die Affen, Lemuren, Chiropteren N. SWE ol, 1890. § This Journal, XV, 400, 1903. FB. Loomis—Ayopsodide. 417 Two genera are distinguished by Cope and Osborn on the condition of the metaconid: when simple, Lyopsodus ; if bifid, Sarcolemur. The two genera are certainly distinet but further characters are required to separate them; for several jaws, which, in all other features, are most closely related to [Zyop- sodus, still have the metaconid bifid. This character has also been noticed as occurring in the genus Lohippus, Phenacodus, and Systemodon, and is not, therefore, considered alone enou oh _to separate the two genera. The bifid metaconid is used below to distinguish some of the species of yopsodus. LFTyopsodus is characterized by lower wider teeth, the cusps being blunter; the fourth premolar is wide and not compressed, having fewer and less developed cusps. It occurs in the Wasatch, Wind River and Bridger horizons. In several species there is a tendency to have the metaconid bifid, but it is never as marked as is characteristic of Sarcolemur. Sarcolemur is characterized by narrow trenchant teeth, with pointed cusps; the fourth premolar is much compressed and has the anterior cusps well developed. It is as yet known only from the Bridger, and of the promolars only the fourth is known. Hyorsopus Leidy Lemuravus Marsh, Stenacodon Marsh, Microsus Leidy, Diaco- dexis, Cope. The genus was founded by Leidy* orn an imperfect lower jaw of ZZ. paulus from the neighborhood of Ft. Bridger. The name Microsus} s} was given the same year to a second species differing only in the proportionate depth of the mandibular ramus. Stenacodont was founded by Marsh on what proves to be a last lower molar, the genus being separated on the ground that there was no cingulum. Lemuravus§ was proposed for a species on the basis of the incisor formula being 3/3 which, later, proved to be true for Hyopsodus. Diucodexis| was proposed by Cope for a specimen, including premolars of Eohippus. As yet the only members of the family found in the Wasatch and Wind River horizons belong to the genus Hyopsodus, the skeletal features of which are as follows The skull is elongate with a level top terminating abruptly behind, the rear of the cranium overhanging the occipital con- dyles, somewhat as in Rodent skulls. The zygomatic arches are slender but widely arched. On the deep lower jaw, the anterior border of the surface for attachment of the masseter * Proc. Acad. Nat. Sci., Phila., 110, 1870. + Same cit., p. 113. t This Journal, ii, 210, 1892. § Same cit., vol. iv, p. 239, 1875. || Proc. Amer. Phil. Soc., vol. xxi, 181, 1883. Am. Jour. Sct.—FourRTH SERIES, VOL. XIX, No. 114.—JUnzE, 1905. 29 418 F. B. Loomis—- Hyopsodide. muscle hes just under the last molar. The teeth are in a con- tinuous series but without crowding. In the upper jaw, the hypocone of the last molar is merely a rudiment, indicated by a slightly raised portion of the cingulum. Molars one and three have a small but distinet hypocone, the cingulum running to it. The first and second premolars have a single cusp while the third and fourth each have inner cusps. The canines are moderate and the three incisors simple. Specific characters are found only in the cingulum and size of the form. The lower teeth are more varied, especially the last molar. ‘The general topo- Wy po lophva ‘ Entoconid a te wnetacenid -¢ Ingulum ~Prolo lophyd. | 4 Hy poconulid dsypoconit *Protocowid. Fic. 1. A typical Hyopsodus lower molar. x nat. size. graphy of a lower tooth with the nomenclature here used is given in fig. 1. On the front part of the tooth the protoconid and metaconid are the principle cusps, connected anteriorally by a low curved protolophid. The inner end of this is in some species developed into a tiny cusp, the possible equiva- lent of the paraconid. Behind, these same two cusps are usually united by a metalophid, and the hypoconid is connected to the metaconid by a more or less developed ridge (hypolophid). The entoconid is always feebly developed, and between it and the hypoconid there is a strong hypoconulid. The fourth premolar has the protoconid and deuteroconid well developed, and from the former a ridge runs to the front, while a second ridge runs from the same cusp to the rear, developing in some species one or two cusps on the margin. The third premolar is similar but simpler. Of the milk dentition I have seen nothing which is worthy of note among so many specimens. The skeletal material, while rather fragmentary, gives many of the characters which determine the ordinal position of genus. The stout humerus is widened at the distal end and pierced by a supratroclear foramen (similar to Hrinaceus). F. B. Loomis—Hyopsodide. 419 The olecranon process of the ulna is long (distinctly an Insec- tivor character), and the greater sigmoid cavity is very wide, the less sigmoid cavity being also well marked. The femur is short, thick and flattened, and has a strong third trochanter. (This is not found in Primates, but is especially well marked in Hrinaceus.) Finally, according to Wortman, the metapo- dials are short and stout, and the hallus not Tepsable (both Insectivor features). Hyopsodus simplex sp. nov. The specimens of this, the smallest and at the same time most abundant of the Wasatch species, were referred by Cope to H. vicarius and FH. paulus, both of the Bridger horizon. Osborn* provisionally referred them to H. mzticulus Cope, from the New Mexico Wasatch, but differmg from //. sempiex in being somewhat larger and having a low (“ Esthyonyx-like”’) heel and in having the posterior cusps more developed. For a type, a lower jaw of the left side carrying the fourth premolar and the molars is chosen. All the teeth of “* , the lower jaw are short and wide with wyg.9. yopsodus sim- obtuse cusps. On each there is a trace plex, Leftramus. x2. of a cingulum about the rounded ante- rior outer corner of the tooth and also externally between the cusps. On the wide fourth premolar the protoconid is better developed than the deuteroconid, and behind there is a wide basin, the posterior margin of which is crenulated. On molars one and two the protolophid is well developed, while there is not more than atrace of a metalophid. A strong ridge runs from the hypoconid to the metaconid. The entoconid is weak and has a small tubercle in front of it, very characteristic of the species. On the last molar the heel region consists of a basin bounded behind by a high crenulated rim, on which the hypoconulid and entoconid appear as crenulations, scarcely larger than the others. Each of the upper molars has the cingulum in front, outside and behind. The last of these molars is much reduced and is without a true hypocone. Promolars three and four have each an internal cusp, while the front two are simply cusps. Affinities— 7. simplex is about the same size as HZ. vicarius from the Bridger, but the molars are shorter and more robust, while the hypoconulid is less developed and has an extra tubercle in front of it. HH. paulus is a much larger and better developed species. HH. miticulus is the nearest form, the more specialized and low talonid, and the superior size distinguishing it from AZ. semplex. * Bull. Amer. Museum Nat. Hist., xvi, 188, 1902. 420) Lf. B. Loomis—Hyopsodide. Locality—27 specimens were collected from both the upper and lower beds of the Wasatch on Gray Bull River. They run very uniform in size, the length of the three lower molars being between 10 and 11™™. In a few eases the last lower molar was considerable smaller than the normal. Hyopsodus miticulus Cope.* This form from the New Mexico Wasatch is thus described by Cope: “Parts of several specimens of this species show that the molars are similar in size to H. paulus, but that it has a much smaller last inferior molar, which has such a low heel as to resemble the corresponding tooth of the species of Hsthonya.” The species seems to resemble /7/. simplex most, but is larger and differs in the heel being low, and more developed. The last molar is also proportionally smaller. The two cannot in the writer’s opinion be included in one species. ! Hyopsodus lemoinianus Cope. This species presents several difficulties on account of the large amount of variation in size, and in the development of both the metaconid and the metalophid; but in as much as these variations do not seem to be constant, and as interme- diate forms are found between the widest variations, all these related forms have been.assigned to the one species. /Z. lemow- anus was established by Cope, who figured a left ramus with the molars, on which the metaconid is but slightly bifid. Osborn figures a second specimen with the metaconids also but little twinned. Most of the Amherst specimens have this cusp markedly bifid, as is seen in the specimen figured. The species may be described as follows: There is a cingulum on the front of the tooth, and between the external cusps of the moderately stout teeth. On molars one and two, there is developed on the inner end of ag & the protolophid a small but distinct paraconid, _ which makes the metaconid appear bifid. The Cee ee eee metalophid is either entirely wanting or but x2, moderately developed. The entoconid is small, as is also the hypoconulid. The last lower molar is longer, and similar except that the hypoconuld is_ developed into a prominent heel. On the upper molars the cingulum is well marked and the cusps fairly high. The three lower molars measure 13 to 15™", there being con- siderable variation in size. The nine specimens collected all occurred in the basal beds along the Gray Bull River, Wyoming. * Rep. Vert. Fossils of New Mexico, Appen. F.F., Rep. Chief. Eng., 8, 1874. + Proc. Amer. Phil. Soc., xx, 148, 1881. FF. B. Loomis—Hyopsodide. \ 421 Hyopsodus powellianus Cope.* This, the largest species of the Hyopsodidaw, occurs but infrequently, being known by parts of the lower jaw only. The teeth are low and wide with stout, low cusps and no cingu- lum. The metaconid is simple and w idely separated from the protoconid. The hypo- eonulid is small, even on the last molar. The protolophid is low and the metalophid lacking. On the last molar the entoconid region is occupied by two small cusps. The three lower molars measure to- gether 18". In the Amherst collection the species occurs but twice, both specimens coming from the basal beds of the Wasatch of the Gray Bull River, Wyoming. Fyopsodus laticuneus Cope. t A single specimen represents this species, on which the genus Diacodexis also hangs. The specimen included both upper and lower teeth, but Matthew has removed the lower premolars and assigned them to Lohippus index, leaving the upper molars which are characteristic of the genus Lyopsodus, and a last lower molar which is distinguished by low broad crown with obtuse cusps, lack of an external cingulum and the entoconid region occupied by two small cusps, and lastly by the metaconid being bifid. This last character alone distin- guishes the species from HH. powellianus to which it is equal in size. The specimen came from the Wasatch in the neigh- borhood of Gray Bull River. Fie. 4. Hyopsodus powellianus. x2. In the Wind River horizon, four species are known, three of which are here described for the first time. This horizon is marked by a slight advance in the development of the genus. The hypoconulid is stronger, especially on the last molar, and in the entoconid region there is only a single strong cusp, the entoconid. The metalophid is universally present. In the locality found by the Amherst party the specimens of Hyopsodus formed fully a third of the collection. Hyopsodus wortmani Osborn.t The type specimen (including an upper and a lower jaw) was first figured. by Cope among ZH. vicarius specimens, and was later by Osborn removed and used as the type of this species, the description however being very meager. The teeth are moderately wide with rather low cusps and a cingulum along the front only. On the fourth premolar the protoconid and deuteroconid are connected by a sharp ridge; the basin behind is wide, and on the outer side of the rim is a * Rep. U.S. Geol. Surv., iii, 235, 1884. + Proc. Amer. Phil. Soc., xx, 181, 1881. ¢ Bull. Amer. Museum Nat. Hist., xvi, 185, 1902. 492 I. B. Loomis—Hyopsodide. small cusp. The protolophid and metalophid are both well developed on the first and second molars but on molar three the latter is very weak. The hypoconulid is small on the first two molars but developed into a prominent heel on the last, the entoconid being tiny. The upper molars are those typical of the genus, having a cingulum in front, outside and behind. The specimens run uniform in size, the three inferior molars measuring 12=—, /On Bridger’ Cr e@iepeer mens were collected and the species occurs also in the other Wind River localities. a. le S HiGs so: mant, x2, HHyopsodus minor sp. nov. Though but one example of this tiny form was found, it differs so materially from //. wortmanz that it is impossible to include it in that species. The type specimen is part of the right ramus with the three molars measuring together 10™™. | The teeth are short, with obtuse but well-separated cusps, and have a cingulum in front and a trace of it between the external cusps. The proto- and meta-conids are set close together and united by both a protolophid and metalophid. The hypoconid has a ise strong ridge running to the metaconid, while Ree as _ the hypoconulid and entoconid are both . Oo. yopsodus minor, x2, strongly developed. The species is distinguished by its small size, presence of a cingulum externally and the strength of the ento- and hypoconulid. The locality is Bridger Cr., Wyoming, in the Wind River horizon. Hyopsodus browni sp. nov. This, the most abundant species in the Wind River beds, is named in recognition of the successful work of Mr. T. C. Brown in collecting these forms. The type is a left ramus with the molars and fourth premolar; while an upper jaw with premolars three and four is associated with it as co-type. A less complete specimen has both upper and lower dentition. The teeth of the lower jaw are short and stout with obtuse cusps, and a cingulum along the front only. On the fourth premolar the deuteroconid is merely indicated by a small cusp, and behind on the proterior margin of the basin, there is a small external cusp. On all the molars the proto- and meta- conids are set close together and united by both a proto- and meta-lophid. The hypoconid is large and connected the meta- conid by a wide ridge. The hypoconulid is rather large on all the molars but does not make a strong heel on the third molar. The upper molars have a cingulum in front, outside and behind; on the which, where it meets the ridge from the para- LF. B. Loomis—Hyopsodide. 423 cone, there is a strong parastyle. The protoconule is closely united to the protocone. The tast molar is large, but still lacks the hypocone. The third and fourth premolars have the parastyle but lack the intermediates and hypo- cone. The species includes the medium sized individuals of the Wind River, the three lower molars measuring 15™”. It compares in size to /7. lemoimanus but lacks the external cingulum, and has a simple metaconid as well as having much more obtuse cusps. There are 45 specimens in the Ambherst collection all from Bridger Cr., Wyoming. “gaurd. 2 Fic. 7. Hyopsodus browni. x 2. Hyopsodus jacksoni sp. nov. In many ways this is the most specialized of the Hyopsodide, and it has been named in recognition of the interest and codp- eration of Mr. E. E. Jackson in the Amherst expeditions. The type is aright ramus with the molars and the fourth premolar, and a third premolar from the left side. The co-type contains three upper molars. The lower molars are rather narrow with moderately high cusps and a cingulum along the front side only. The metaconid is bifid, strongly so on the first molar, and just visibly so on the last. The protoconid and metaconid are widely separated and connected by the protolophid only. The hypoconulid is throughout small; and on the third molar connected by a ridge to the entoconid. ‘T’he fourth premolar is complex, the protoconid and deuteroconid being connected by a ridge; and there are two well-developed cusps behind on the posterior rim. The third premolar is similar but lacks the two posterior cusps. The upper molars are those typical of the genus, with the cingulum well developed on the outside. A distinct parastyle is formed on the anterior external angle of the cingulum. The posterior intermediate is isolated while the anterior one is connected to the protocone. The three lower molars measure together 16". 26 speci- mens were found along Bridger Cr., Wyoming. Fic. 8. Hyopsodus lawsoni. x 2. 96 Sh LE G2 0 LG ed sueutoeds JO “ON IOATY, PULM TOA PUL AA LOA PUT AA IOATY, PUL Youese qyoquese ORES AV een OVS? 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AULD OUT ON, emees, ancl aoaty HAEOE® © ° :UInpNSsuLD | : seovry ‘UINT Pe Nua? eee N [vUIeyXO9 ON |-NSUTO [eULEyXY sId UIs PIuooRjzeUL : PUTA nee aia! 04 paqoeut09 DUO oc ea cea qoyTeuts (QE eIeIOR is prttoooreyneq pruos0104n9(q pruooo1eyneq, Pee a ‘LUOSMBT “FT “TUMOLQ “FT -TOUTUL Ta] “TUERUTAIOA. ‘FT | ‘snounoyry] ‘Y |‘snueyjomod “F])‘snuetutowey “Y) ‘snpnoryiwe yA | ‘xepdurts “y ‘SNdGOSdOAH Hidden— Mineral Research in Llano County, Tewas. 425 Art. XLV.—Some Results of tate Mineral Research in Llano County, Texas; by Witi1am E. Hippen. Tue noted gadolinite locality in Llano County, Texas, known as Barringer-Hill, was reopened* and thoroughly prospected by the writer, during the winter of 1902-03, with very encouraging results. ‘All the old cuts were cleaned out and extended, and a systematic development of the mine was begun at the southeast point of the Ill, and at as low a level as the river terrace would permit. The plan was to remove the hill by blasting and gradually make a dump of 73-lb. mass of Gadolinite in place. it towards the near-by Colorado river. The season proved to be a very propitious one and much good work was accom- plished. Seven years had elapsed since any work had been done upon the property, but in a short time all the old familiar minerals had been rediscovered either m new openings or in extensions of the original workings of Mr. Barringer. * The development was undertaken under the auspices of the Nernst Lamp Company, of Pittsburgh, Pa., to whom all the output was sent. 426 Hidden— Mineral Research in Llano County, Texas. Among the most notable discoveries of ‘‘ Barringer-Hill ” minerals, at this time, were the double erystal of eadolinite that weighed seventy- three pounds and an eighteen-pound mass of yttrialite (see figures 1, 2 and 3); a mass of pure allanite that weighed over three hundred pounds ; about fifty pounds of thoro- gummite, among which were pieces weighing fully a pound and some few wood crystals. Of fereusonite several very pure masses and lar ve ageregations of rough crystals were found, up to five pounds in weight. Of rowlandite one very pure mass weighing just one kilo was obtained ; of nivenite and mackintoshite very little was discovered. The mineral 2 species rich in yttrium-erbium were more particularly sought atter because thorium and uranium were not used in the “olower” of the Nernst Lamp. “Masses of coarsely crystallized fluorite up to four hundred pounds weight were not rare, and some of these had very large faces of the cube and rhombic dodecahedron. Its color varied from dark green to puce and purple, and colorless transparent rough crystals having remarkably perfect cleavage were some- times observed. Some of the fluorite was true chlorophane and exhibited a brilhant green light when strongly heated and viewed in the dark. One mass was self-luminous, at night, Tlidden— Mineral Research in Llano County, Texas. 427 without heating it. Enormous crystals of orthoclase were common, some over five feet in diameter. Quite frequently small veins of very perfect red feldspar crystals (highly- twinned), and upon which albite crystals were attached, were found bordering the fluorite and penetrating it. In the feld- spar, well crystallized menaccanite was sometimes observed, and this mineral is new to the locality. Yellow rutile, of the sagenitic variety, was observed in only one instance and then upon smoky quartz crystals. Polyerase, or an allied species, 5) 18-lb. mass of Yttrialite. was seen implanted upon the gadolinite, this is also new to the region. A cavity into which a horse could have been put was discovered on the river side of the mine, and from it a large erystal of smoky quartz was taken that weighed over six hun- dred pounds. It was forty-three inches high and twenty-eight inches broad and fifteen inches thick. This is now in the University of Texas collection at Austin, Texas. Very fair amethysts were found in the west end of the hill, in cavities in the feldspar. Masses of biotite, four feet across, 428 Hidden—Mineral Research in Llano County, Texas. were met with and always indicated the presence near-by of the rare-earth minerals. Some of the fluorite contained small thin veins of a very dark mineral, which was deep indigo- purple by transmitted lght, and this may, perhaps, betoken the occurrence of a basic fluoride of the yttrium or cerium earths at this mine and in the region generally. In a period of four months there was taken out of the hill enough of the yttrium ores to suffice for the Company’s needs for the balance of the year, and the mine was therefore closed for the season. In the following winter (1903-4) the work was again resumed at Barringer-Hill, and about a dozen workmen were kept constantly employ ed for a period of six months. The scheme of development laid down by the writer in 1902, was carried forward with much energy. Considerable “dead- work” was done in the line of removing “topping” and bringing up the “fall” from the river-side of the hill. New cuts were opened, and the whole top of the hill was blasted away. All the work done at the mine thus far has been of the character of open quarry work, with hand-drilling and the use of powder and dynamite. The mine has been proved to have a deep- seated origin and is only one of a series of so-called “ blow- outs” in a region that is entirely granitic. Deep work at this locality may be expected to bring to light new combinations of the rare earths and of uranium and of thorium, as well as great quantities of the species for which the hill is already famous. All the old species will probably be found in a purer state and perhaps in their normal condition as when first erys- tallized. This last mentioned condition is what we are eagerly seeking for in order to clear up the formulae of many of the species. During last winter’s work all the old minerals, excepting rowlandite, were again found and more than one thousand pounds of. oe pure gadolinite. The seventy-three pound group of crystals (of gadolinite), found in March, 1903, was the greatest “find” of record in this mineral ; but just one year “later, a mass of roughly erystallized oadolinite was found, partly imbedded in the bedrock at the northeast corner of the hill, that measured thirty-six inches long, eleven inches thick at the widest part, and weighed a little over two hundred pounds. It was apparently free from alteration, had specific gravity of 4:28 (taken on a very pure fragment), had a bright green chatoyancy at certain angles, and was like glass in its broad obsidian-like conchoidal fracture. Upwards of a pound of very pure nivenite and not exceed- ing an ounce of mackintoshite, were picked out of the many boxes of mixed cyrtolite, fergusonite and thoro-gummite. Hidden— Mineral Research in Llano County, Texas. 429 Only the density of nivenite saved it from being thrown away as magnetite (very abundant at this mine), and but for its asso- ciations it would be always neglected except by the expert mineralogist. Equally so with the mackintoshite, its resem- blance to the dark cyrtolite and intimate association with lt prevents it from being recognized by the miner or layman. Some day this mine promises to be worked for the two last- named minerals alone and as the main object of mining there, and in the deeper working they should be found abundantly and in a higher state of purity. Tengerite (? )—About ten grams of a white mineral, occur- ring in semi-globular and flat radiated concretions in the cracks and fissures of the gadolinite, were finally obtained after much labor and search. This quantity was the result of detaching the mineral, bit by bit, from over 300 kilos. of fresh gadolinite. Since the composition of tengerite (to which species this sub- stance is tentatively referred) is unknown, I a the rare mineral to Dr. W. F. Hillebrand of the U. Geol. Survey for analysis; his report is given in full ee The surpris- ing feature is the presence of glucina (BeO) in the form of carbonate, which is new to science, and this may perhaps indi- cate a new glucinum mineral mechanically mixed with a basic hydrous carbonate of the rare earths of the yttrium group. Dr, Hillebrand’s Report and Analysis. “The purest material that could be picked out, from that at my disposal, showed some brown admixture with the white. The following results were obtained from °3640 gram of this selected material, after deducting 0262 gram of residue, left after long treatment of the ignited powder with cold and quite dilute nitric acid. YEO) ornoupes 2 40°8 per cent Mol wit, 252255 226 CsO- sroupr sas - 7-0 a eet pee eens 335 Fe 0. hese ea 4°0 : BeO (GIO) oes 7 iy Oh Oo Se lel GR pds 19°6 ne H, O above 105°_ 14°1 9 1 Bs ‘O below 105°_ 3:2 o SiO, PRONE ts) “4 < MgO, Alk.,loss_ 1:2 100°0 s All determinations were made on the one portion, the co, and H,O being directly and simultaneously ascertained by ignition in a tube and collection of the escaping gases. The loss in weight 430 LHidden—-Minerai Research in Llano County, Texas. of the ignited powder agreed with the sum of the CO, and H,O found. “Approximate molecular weight determinations of the earths, separated into two portions by potassium sulphate, gave 335 for the cerium group and 226 for the yttriam group, the last being the molecular weight of yttria itself. It is certain that some, if not all, of the ferric oxide reported is foreign to the car- bonate, but how much it is impossible to say. The calculated ratios lead to nothing definite, except that the white mineral appears to be a hydrous basic carbonate, but whether a double carbonate of the rare earth metals and glucina, or a mixture, there are no present means of deciding.” Radio-activity—All the minerals of Barringer-Hill have been experimented with to ascertain the extent of this form of energy present. As early as September, 1902, the writer was at work upon it and had then made successful radiographs from specimens mined at this locality as far back as 1889. In the order of their activity, as shown by their own radiographs, I here mention the species in which the phenomena were observed. Nivenite (which is a very soluble variety of uraninite) exhibited the most pronounced radio-activity, and beautiful radiographs were made by placing the mineral outside of a photograph plate-holder. Better ones were procured by plac- ing the mineral in direct contact with the sensitive plate— “Cramer’s X-ray.” Twelve hours exposure, in the dark, developed very good interference figures; but with forty- eight hours, and up to five days exposure, the outlines became as sharp almost as are shown in photographs by sunlight. Mackintoshite (which is the parent mineral of thoro-gum- mite) was next in the amount of radio-activity exhibited. It showed about half the intensity of nivenite when compared with equal exposures of the two minerals, side by side, on the same plate. Positive evidence of the occurrence, within mackintoshite, of little crystals having even a higher radio-activity than that shown by the nivenite, was proven by developing the plates used with direct contact. Little bright spots appeared in the field where the less energetic mackintoshite had touched it, and a dull gray border (made. by the thoro-gummite coating) united to make a radiograph having three degrees of intensity from one mineral specimen. With a strong “Jens these bright spots, possibly due to a new species, could be identified upon the flattened surface and they were noticed to be very unlike the surrounding mackintoshite. They resembled galena in color and in metallic luster and were quite evenly distributed over the several flat sections examined. Mackintoshite has given evidence, in thin sections, of being translucent, and of a very dull green color by tr ansmitted light, but as the purest fMidden— Mineral Research in Llano County, Texas. 431 material yet analyzed showed (vide Hillebrand’s analysis) 4°31 H,O present, it is possible that these little bright spots are only the normally pure anhydrous mineral. It is tenable also that these little inclusions, with their high radio-activity, are but a normally pure form ‘of nivenite in which only UO, is present. Since mackintoshite can be rationally interpreted as being a mixture of three parts of thorite with one of uranin- ite (nivenite), the assumption that a new mineral has been dis- covered may not stand. The question is certainly one of unusual interest at this time and merits further investigation. Thoro-gumamite.—Contact radiographs of this mineral, made from a flattened surface after forty-eight hours exposure, ¢n the dark, had much the appearance of ordinary sunlight photo- graphs. ae2 = 0-810 0°392 0°204 The colored paper was substituted for the mirror and adjust- ments of T’ made as before. The following tables give the results for the paper used : (The interrogation poimt denotes some light, but not suffi- cient for a match. 0 means no trace of color noticeable.) Width of T’ when T =:1™., Intensities at T. Paper. Color — a reflected. 0-1 0:2 0°3 0°4 0°5 Rediteere: RS 1°878 2°697 ieee Rs D Mellowme 3: ® ae, Ries ae ae eeP Green _._.- P Cas Becta ee See red Bluesea ? ea Nie ike ce Wicletr ase 0 0) 0) 0 0 Width of T’ when T = 0°2™™, Intensities at T. ——=— Paper. Color = a refiected. 0-1 0:2 0°3 0-4 earn cack 0°460 0°889 ene 1°680 : Yellow __-.- ? Beni: Les Shay a, nee Green __..- 2 ies pe ergs os ive see 9-235 peas ele ae Violet ? ee ‘ae EE iat Width of T’ when T = 0:2™™, Intensities at T. Paper. Color — A—— reflected. 0-1 0-2 0°3 Reds re sae 1°908 ? one Vellow 3522 9°650 e ines Ns Goya. WO eee eS ene” Binge eee 9-122 ? ye Violet 32: 2°418 ? lind * When T’ was narrow a little green was seen, but when T’ was widened for a match all trace of green disappeared. 0-4 0-5 2°009 set 0-5 Minchin—feflection of Light by Colored Papers. 449 Paper. Dull green Paper. Light green Paper. Dark blue Paper. Light blue Width of T’ when T == 0:1™., Intensities at T. woe Color — reflected. 0-1 0-2 0°3 0-4 0:5 we Clete ik 1°424 fe a: Me a MMetOW, 22.6 17302 ie cee nes il Greens oo. 1:056 2091 ? a 2 | BSINE (eh le eee 12215510) DPS ? Lhe Be Warollet es 23 E Pie Be ap as Width of T’ when T = 0°1™. Intensities at T. Color (a reflected. O-1 0-2 0°3 0°4 0:5 ved. 25 1°289 2°120 ie Zoo ea Bees Wellow, 2-5 1ch06 2°204 ? edie set Green _... 0°683 1°299 2°029 ? a i liners ek 782 1°280 1°912 PARE) MOT AKO) Violet 2 - Just a slight trace Width of T’ when T = 0:2™™, Intensities at T. Color aS ae Sa = reflected. Our 0-2 0:3 0:4 0-5 Fed rycsait ec! 1:847 ? ak ie ae BelllOwee = ee: a ae ee Me aie Green cages ? Se eu ie Bis lee ae 4 OCH i ie AGS ae Warol@t= 3 = ons ip ey £3 ue a Width of T’ when T= 0°1™., Intensities at T. Color —— —— a 5 —_ reflected. Onl 0°2 0°3 0°4 fe 05) edemgetirs ele 2°061 iy Bs Tg te oe ee Yellow .._- 1:088 1°980 EB Biaigees be bss Green _-.. 0:936 1684 2°521 ? ase Blie2— 2 0-789 [SOS DOE se ae Wioletiess= «15036 Hele 1°631 BIOL TY 2°886 Discussion of Data. Table [1 shows that approximately one half the incident light was reflected by the mirror. Both Table I and Table II show that as the violet end of the spectrum was approached the width of T’ had to be increased to procure a match. Because of the small amount of light reflected by the papers it became necessary to cut down the intensity of the light admitted at T. Each of the tables gives the greatest inten- sities that could be used and allow the obtaining of a match. The deep red paper reflected red light only, to a sufficient degree to allow of a match. Am. Jour. Sci.—FourtH Series, VoL. XIX, No. 114.—Junz, 1905. 31 450 Minchin—Reflection of Light by Colored Papers. The intensity of the light reflected by the light red paper was very low and it was necessary to narrow T to 0:1™. A match was then obtained for red and blue. The green -papers reflected all colors in considerable amounts. The dark green reflected red and green light about equally, while the light green reflected less of the red and reflected green and blue in about the same amounts, but as the inten- sity of the light admitted at T was increased more blue than green was reflected. The dark blue paper reflected red light of an intensity about two and one-half times the intensity of the blue reflected. The other colors were reflected in very small amounts. With the ight blue paper all the colors were reflected when the intensity at T was 0-1 or 0:2, and with intensities at T of 0-4 and 0°5 a match was obtained with violet light only. A comparison of all the papers used can be made only for an intensity of light admitted at T of 0-1. The following table gives the width of T’ in terms of T for a match in the different colors. For example, in the red when light was admitted directly, T’ was 0°21 times the width of T for match, when the mirror was used T’ was 0°41 times the width of T, ete. \ Tin terms of 2. Colors. Light from. — —--— _ Red. Yellow. Green. Blue. Violet. (Direct. os: 0°21 0°21 0°23 0°28 0:24 Mirior:siacen o. 0°41 0°42 0°46 0°55 0°47 Deep red .__-_-- 6°44 2 q ? ? hichtined == =2ee 4°60 ? ? 22°34 ? Dark joreen) 7252 9°52 13°25 9:05 15°61 12°09 Dull green..-.. 14:24 102 10°56 14°50 5g Light green.... 12°89 11°76 6°83 7°82 ? Dark blue 2223 9°24 2 ? WB)! 15 Light OL Oe ete 10°88 9°36 7°89 10°36 The dark green and the light blue papers are the only papers that reflected all colors sufficiently to obtain a match. The light green and the dull green papers are the next in order, both the latter reflected very little violet light. The light reflected by the dark green and the light blue papers is more nearly white light than that from any of the other papers used. Less than 0:02 of the incident light was reflected by the best paper used, when all conditions were the best possible. The observations embodied in this paper were made in the Physical Laboratory of the University of Michigan, at the suggestion of Professor Reed, to whom thanks are due for his interest and assistance during the progress of the investigation. Physical Laboratory, University of Rochester, January, 1905. Chemistry and Physics. 451 SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. New Experiments in Preparing Diamonds.—In his exam- ination of the Canyon Diablo meteorite, Moissan noticed that the diamonds found in it occurred in fissures containing sulphide of iron, and it seemed possible that sulphur might have had an indu- ence in the formation of these crystals. He has, therefore, made some new experiments upon the formation of diamonds by crys- tallization from iron saturated with carbon in the electrical fur- nace and rapidly cooled with water, and has modified. his experiments of several years ago by additions of sulphide of iron, silicide of iron, or phosphide of iron to the fused metal before cooling. ‘The results showed that the production of dia- monds was somewhat better in the presence of sulphur’ than had formerly been the case without this addition, and silicon appeared also to exert a favorable influence, but in this case more difficulty was encountered in the separation of the diamonds from the ingot, on account of the presence of carbide of silicon. No dia- monds were obtained in two experiments where phosphide of iron was added. Some of the diamonds produced in the presence of sulphur were large enough to be separated with the naked eye by means of a steel point, while the largest of those made in the presence of silicon had a length of :75™™. Their size is of the same order as that of those from the meteorite, and they are practically microscopic objects. Moissan has confirmed his previ- ous conclusion that the artificial substance is actually diamond, and he finds that, like the natural substance, it often shows weak double refraction. He regards the diamond as a form of carbon which has been liquefied under high pressure, since he has shown previously that at ordinary pressure all forms of carbon vaporize without becoming nae and all produce graphite.— Comptes Rendus, cx), 277. H. L. W. 2. Atomic Weights of Sodium and Chlorine.—T. W. Ricu- Arps and R. C. WELLS have made a very elaborate investigation in revising these important atomic weights. As is usual with the work of Richards, the greatest precautions have been taken in purifying materials, detecting sources of error and avoiding or making accurate allowances for them, and in the use of varied methods and materials. The description of the work inspires the utmost confidence in it, as well as admiration for the skill and patience displayed in carrying it out. As a result of their research it appears that the work of Stas on the atomic weights in question was slightly erroneous. From a study of the ratios AgCl: NaCl, Ag: NaCl, and Ag: AgCl, they find that when the atomic weight of silver is taken as 107°920, sodium is 23°008, and chlorine is 35°473, whereas the previously accepted numbers are 23°05 and 35°45. Many other atomic weights are affected, in 452 Scientific Intelligence. their second decimal places, by these changes, and a recalculation of the atomic weights will be necessary soon. Richards suggests, however, that this systematic recalculation be delayed until a few other new data should have been obtained—in particular, new analyses of potassium chloride, silver chlorate, the bromides, sul- phides and sulphates, and similar important compounds. Some of these are already being made, and others will be undertaken at once by Professor Richards.— Carnegie Institution of Wash- ington. Publication No. 28. HH. Lene 3. The Origin of Radiuwm.—A continuation of the investiga- tions of Dr. B. B. Botrwoop upon the relative quantities of uranium and radium in various minerals, an account of which appeared in the preceding volume of this Journal, shows that these quantities are proportional to one another, within the limits of experimental errors, even in minerals containing much thorium and very small amounts of uranium. The more recent experi- ments were the examination of twenty-two specimens of min- erals where the accurately determined percentages of uranium vary from 74 to 0°3 per cent, and in this series allowance is made for the emanation lost at ordinary temperatures by the various samples. The author says that the inevitable and only possible conclusion from the results is that uranium is the parent of radium, and that the participation of thorium in the production of radium, which has been suggested by some, is entirely excluded. He also mentions experiments made to determine whether radium is formed directly from uranium. These showed no evidence of this change after a period of seven months and confirm the results of similar experiments by Soddy, so that it is probable, as suggested by Rutherford, that one or more intermediate changes exist between the uranium atom and the radium atom. Attention is called to the persistent appearance of lead as a con- stituent of uranium-radium minerals as an indication that this metal may be one of the final products of the disintegration of uranium.—Phil. Mag. (6), ix, 599. H. L. W. 4, Marceli Nencki, Opera Omnia—Gesammelte Arbeiten von Prof. M. Nencx1—Erster Band, 1869-1885; Zweiter Band, 1886- 1901. Large 8vo, pp. xlii+840, and xiii+893. Braunschweig, 1905. (Friedrich Vieweg und Sohn.)—These two sumptuous vol- umes, edited by N. Sieber and J. Zaleski, contain a fine portrait of Nencki as a frontispiece, a sketch of his life, a complete col- lection of his scientific writings, as well as numerous articles by pupils working under his direction. The work is an important and useful one, because Nencki’s publications are scattered through many different journals, and because of the scientific value of his researches. Nencki’s work covers a wide field, and the articles have been systematically indexed by the editors. There are many important investigations in pure chemistry—it is said that he took pride in having made over one thousand ele- mentary analyses—but it is well known that his most important work was in the lines of physiological and medical chemistry, and Chemistry and Physics. 4538 the book will be particularly useful to those interested in these branches of science. H. L. W. 5. Manual of Chemical Analysis as Applied to the Assay of Fuels, Ores, Metals, Alloys, Salts, and other Mineral Products ; by Eveéine Prost; translated by J. CRuicksHaNK SMITH. 8vo, pp- 300. London, Maclaren & Sons; New York, D. Van Nos- trand Company, 1904.—The object and scope of this work are set forth in the title. It should serve as a useful book of refer- ence for analytical chemists engaged in technical work, for many of the methods of analysis are well selected and carefully described. A good feature of the book is the introduction of typical analyses of many commercial products, which give the chemist an idea of the ingredients to be looked for as well as the extent to which they are liable to occur. The book may be criti- cized on account of failing to include certain useful and reliable methods. For instance, Drown’s method for the determination of silicon in pig iron is not given, while tared paper filters are recommended for weighing precipitates in cases where the Gooch crucible would give far better service, and other antiquated features from an American point of view are to be noticed. Not all of the methods are described in such a way that they would give a satisfactory degree of accuracy when implicitly followed, and in some cases the directions are decidedly lacking in com- pleteness, or the methods are faulty in principle. The book is, therefore, not a perfect one, although it contains much that is useful. It seems unfortunate that the translator should have employed incorrect chemical nomenclature in some cases; for instance, chloride of soda for sodium chloride. H. L. W. 6. Radiation Pressure.—Professor PoyNnTiINnG discusses simple methods of showing the pressure of light, and applies his theory of the stream of momentum. Theory and experiment seem to indicate that when a source is sending out waves it is pouring out with them forward momentum as well as energy, the momen- tum being manifested in the reaction, the back pressure against the source, and in the forward pressure when the waves reach an opposing surface. The wave train may be regarded as a stream of momentum traveling through space. Radiation pressure has not succeeded in explaining the repulsion of comet’s tails. Pro- fessor Poynting suggests the following explanation of Saturn’s rings: Let us imagine that a small sun while still radiating much energy on its own account has captured and attached to itself as satellite a cometary cloud of dust. Then, if the cloud consists of particles of different sizes, while all will tend to draw into the primary, the larger particles will draw in more slowly. But if the larger particles are of different sizes among themselves, they will have different periods of revolution, and will gradually form a ring all round the planet on the outside. Meanwhile the finer . particles will drift in, and again differences in size will corre- spond to difference in period and they too will spread all around, forming an inner fringe to the ring. If there are several grades 454 Scientific Intelligence. of dust with gaps in the scale of size, the different grades will form different rings in time.— Phil. Mag., April, 1905. sg. ‘7. 7. Spontaneous Lonization of Air in closed Vessels and its Causes.—The conductivity of air and other gases is generally attributed to the presence of free ions, and as these free ions are continually recombining there is some agency which is splitting up the combinations. Ionization in which no artificial ionization agent is employed has been called spontaneous ionization. The hypothesis that the ionization is due to a penetrating radiation constantly passing through the atmosphere has been advanced and is largely adopted. ALEXANDER Woop of Emmanuel Col- lege, Cambridge, believes from a careful inspection of indirect evidence that all matter is radio-active and that the disintegration processes going on in radium and the other radio-active elements are going on also, though to a much smaller extent, in all matter. — Phil. Mag., April, 1905. psy 8. Radio-activity and Chemical Change. —N. R. CamMPpBeti finds that there is no evidence that chemical change is accom- panied by radio-activity ; and that the spontaneous leak increase which has led some investigators to suggest such a connection is due to the heating of the walls of the vessels,— PA7l. Mag., April, 1905. Jee 9. Helium Tubes as Indicators of Electric Waves. — Geissler tubes filled with argon, neon and other gases have been used by various investigators of electric waves along wires. Ernst Dorn finds that tubes filled with helium, °5-5™™ pressure are very sensi- tive and do not require a dark room.—Ann. der Phys., No. 4, 1905, pp. 784-788. Ns 10. The Specific Heat of Water and the Mechanical Equiva- lent of Heat.—The leading article in the Annalen der Physik, No. 4, 1905, by C. DreTEeRrtici, 1s a careful consideration of this subject, and is remarkable for the use the author makes of vessels of amorphous quartz. The method adopted in determining the specific heat of water was to enclose a definite quantity in a. quartz cylinder and after raising 1t to a measured temperature to suddenly immerse it in a Bunsen ice calorimeter. The value erg. 419°25 10° —— was obtained for the mechanical equivalent of heat.—Ann. der Phys., No. 4, 1905, pp. 593-621. Toss 11. Photograph of the Solar Corona without a Total Eclipse. —In the opinion of M. J. Janssen, M. A. Hansxy has succeeded in photographing the corona of the uneclipsed sun. The results were obtained at the observatory of Mt. Blane by the use of the selective absorption of different screens. ‘The direct rays of the sun were shut off by a disc. The negatives show distinct halos around the disc of the sun. Photographs illustrate the paper.— Comptes Rendus, No. 12, 1905, pp. 768-778. Tens 12. Kristallinische Flissigkeiten und Flissige Kristalle ; von Dr. Rupotr ScHenck. 159 pp., 8vo, with 86 figures in the text. —The highly important work of Lehmann on “ Fliissige Kristalle” was published a year ago and presented a large array of interest- Chemistry and Physics. 455 ing and novel phenomena in regard to liquids, which under cer- tain conditions exhibit the phenomena of double-refraction. The present volume is a further contribution to the same remarkable subject in which the observations of the author and his asso- ciates, particularly as the physico-chemical properties of the liquids, are given in detail. These phenomena, in general, are exhibited through a definite interval of temperature included between the point of fusion and the ‘* Klarungs-punkt,” or that at which the transition to the transparent isotropic fluid takes place. The chapter discussing in detail the properties of these two points, their relation to the density, their dependence upon - the pressure, upon the presence of foreign constituents and other related points is of great interest. Another chapter not less important, treats of the viscosity and other properties of the “crystalline ” and isotropic fluids. The author wisely makes free use of the work of Lehmann and by this means is enabled, in a limited space, to present an excellent summary of the entire subject. 13. “ V” Rays: A Collection of Papers communicated to the French Academy of Sciences with additional Notes and In- structions for the Construction of Phosphorescent Screens ; by R. BLronpiot; translated by J. Garcin. Pp. xii, 83; with phos- phorescent screen (frontispiece) and other illustrations. London and New York, 1905 (Longmans, Green & Co.).—The subject of the “ N ”-rays* is one that has excited much attention, although there have been some to raise the question as to the objective reality of the phenomena described. In any case, however, it is a matter of great interest to have the original papers of Professor Blondlot translated and brought together in a single volume ; this work has been well done by M. Garcin. Fifteen papers are in- cluded, all reprinted as they were originally published in the Comptes Rendus of the French Academy. A number of plates are introduced which show the phenomena described, and the frontispiece consists of a phosphorescent screen of calcium sul- phide for use in the observation of the “ N”-rays, and prepared in accordance with the methods described in the closing pages of the volume. 14. Das elektrische Bogenlicht, seine Entwickelung und seine physikalischen Grundlagen ; von W. B. von CzupnocHowskI, Zweite Lieferung, pp. 99-194; dritte Lieferung, pp. 195-290. Leipzig, 1905 (S. Hirzel).—The second and third parts of this exhaustive work on the electric are-light, announced in an earlier number of this Journal, have recently been issued. These are largely devoted to a historical discussion of the development of the are-light from the time of Volta and Davy downto 1900. The subject has now reached so definite and relatively simple a stage that it is interesting to recall the many and varied attempts to solve the problems which had to be made before success was * Named in allusion to the city (Nancy) at the university in which the author is professor. 456 Scientific Intelligence. finally attained. The prominent forms of regulators, devised from time to time, are described fully and in historical order. The various special problems which have arisen, as the division of the electric light, the application of the hght for signals at sea, the relation of light intensity to distance of visibility, and so on, are also treated in detail. ‘The three parts now issued com- plete about one-half of the work as planned. 15. The new Knowledge: A popular Account of the new Phys- ics and the new Chemistry in their Relation to the new Theory of Matter ; by RoperRT KENNEDY DuNcaANn. 263 pp., 8vo. New - York, 1905 (A. 5. Barnes & Co.).—There is no reason why, at the present day, the intelligent laymen should not acquire a reasonably good knowledge of the progress that is bemg made in the different branches of science, for books are not wanting which put before him the facts in a form requiring a minimum of preliminary training. The volume at hand is one having this object, but its scope is broader than usual, and the nature of matter, as now understood, and the light thrown upon the sub- ject by the phenomena of electricity and radio-activity are pre- sented with much system and clearness, and with a style to attract the reader. ‘The closing chapters reach out beyond the earth to some of the problems of the stellar universe. 16. Percentage Tables for Hlementary Analysis ; by Lxo F. GuTrMann, Ph.D. 43 pp. 8vo. New York and London, 1904 (Whittaker & Co.).—These tables, reproduced here from the German edition, will be found most useful by the practical chem- ist, as they give him at once with all necessary accuracy (to four decimal places), from the amount of carbon dioxide and water yielded on combustion by the substance under examination, the percentage of carbon and hydrogen which it contains. A pro- portional table opens the volume and one for the reduction of volumes of nitrogen to grams is added at the end. I]. GroLtocy AND MINERALOGY. 1. United States Geological Survey, Cuartes D. Watcort, Director.—The following publications have been recently re- ceived ; notices of some of them are deferred to a later number. Grotocic Foros. No. 117. Casselton-Fargo Folio, North Dakota—Minnesota ; by C. M. Hatz and D. E. Wiriarp. No. 118. Greeneville Folio, Tennessee—North Carolina; by ARTHUR KauiTu. No. 119. Fayetteville Folio, Arkansas—Missouri; by G. I. Apams and EK. O. Uric. ProreEssionaL Papers. No. 32. Preliminary Report on the Geology and Underground Water Resources of the Central Great Plains; by N. H. Darron. 483 pp. 4to, 72 plates, 18 figures. No. 39. Forest Conditions in the Gila River Forest Reserve, New Mexico; by Turoporer F. Rixon. 89 pp. with folded map and diagram. Geology and Mineralogy. 457 Buuuetins. No. 238. Economic Geology of the Iola Quad- rangle, Kansas; by G.I. Apams, E. Haworts and W. R. Crane. 80 pp., with 11 plates, 13 figures.—The Iola Quadrangle embraces an area of 944 sq. miles in the southeastern portion of Kansas. It lies in the prairie plains region characteristic of the eastern portion of the state, and is of especial interest because of its extensive oil and gas resources. ‘The geological structure and relations of the oil and gas are in general similar to those pre- vailing over the entire Kansas—Indian Territory field, and hence the facts brought out in this bulletin, which is issued in advance of the Iola folio now in preparation, will be found useful by those interested in other portions of the field. Briefly stated, the rocks exposed by outcrops and revealed by | the drillings belong to the Pennsylvanian series of the Carbonifer- ous. This series, known as the Coal Measures, contains beds of workable coal chiefly in the lower portions ; the Boone limestone of the Mississippian series lies below the Coal Measures. The oil and gas of the region are largely confined to the Cherokee shales, which here form the lowest section of the Coal Measures and have a thickness of some 450 feet. ‘The oil and gas reservoirs are associated with beds of sandstone, of varying extent and thickness, and sometimes of very local extent. Many facts of an economic importance are brought out in the bulletin, particu- larly with reference to the gas wells. This region also affords considerable quantities of Portland cement and there are impor- tant brickmaking plants. No. 242. Geology of the Hudson Valley between the Hoosic and the Kinderhook ; by T. Netson Date. 63 pp., 3 plates including a geological map, 17 figures. No. 246. Zine and Lead Deposits of Northwestern [linois ; by H. Foster Bain. 56 pp., 5 plates, 3 figures.—The region covered by this paper lies in the extreme northwestern portion of the state, including a part of Jo Daviess county. Another region, also yielding zinc and lead minerals, is found in the southern portion of the state (in Hardin, Pope and Saline counties) and forms part of the Kentucky—Illinois fluorspar, lead and zine field. The former region, here described, has been known to yield lead since 1700 and mining operations have been carried forward for upwards of one hundred years. Much has been written by different authors as to the mineralogical nature of the deposits, the method of their occurrence and their origin ; the present paper gives a convenient and concise summary of the facts as now known, upon what the writer’s observations have served to throw additional light. No. 249. Limestones of Southwestern Pennsylvania; by Freperick G. Crapp. 52 pp., 7 plates.—The subject developed in this paper is the character and distribution of limestones suitable for Portland cement, or for other economic uses. Six- teen layers of limestone are recognized and named, varying in thickness from 60 to 6 feet; the occurrences are described and the prospective value of each estimated. 458 Scientific Intelligence. No. 250. The Petroleum Fields of the Pacific Coast of Alaska with an account of the Bering River Coal Deposits ; by Grorer C. Martin. 64 pp., 7 plates, 3 figures.—The observations made thus far are preliminary only, but they serve to show that at several points on the Alaska coast, conspicuously near Controller Bay, about 100 miles west of Mt. St. Elias, petroleum occurs in some quantity, and the region may prove to be an important source in the future; explorations thus far made are, however, inconclusive. The best coal thus far found on the Pacific coast is that of Bering river which flows into Controller Bay. Petro- leum fields have also been somewhat developed on the western shore of Cook Inlet and on Cold Bay opposite Kodiak Island. No. 252. Preliminary Report on the Geology and Water Resources of Central Oregon; by IsrarLt C. RusseLy. 138 pp. 24 plates, 4 figures.—This bulletin gives, as the result of a rapid reconnoisance, an interesting and well illustrated account of a little known region in central and eastern Oregon. It includes the extreme northern part of the Great Basin, which has no external outflow, and also a part of the drainage area of the Deschutes and Crooked rivers. Much of it is an arid region, conspicuously the “ Great Sandy Desert,” which has a length of 150 and a width of 30 to 50 miles. Of the hills or mountains of the region, much the greater number owe their origin to volcanic eruptions, the cones being particularly abundant to the west in the neighborhood of the Cascade Mountains. The volcanic rocks are mainly rhyolites, andesites and basalts, the last named being in general the latest, though certain andesites and andesitic tuffs are the youngest of all the lava outflows. In the west- central part of the state an extensive shell of pumice, similar to that about Crater lake described by Diller, forms a thick mantle over the surface. The sedimentary formations consist of soft, or partially consolidated beds, of Tertiary age. Interesting observa- tions, with excellent views, are given of the present glaciers, par- ticularly on the three peaks of the Cascade Mountains known as the Three Sisters. In regard to the extent of former glaciation the writer states “that during a former period, which can be safely correlated with the Glacial epoch, great snow fields covered the summit portion of the Cascade Mountains throughout their entire extent across Oregon, and from this névé region large alpine glaciers flowed eastward down the mountains. Glaciers also occurred on the west side of the range, but no new facts concerning them can be presented at this time. The conditions were of the same general character as existed on the Cascade Mountains in Washington, but the eastward-flowing ice streams were seemingly less extensive. An instructive suggestion in reference to the glaciers on the east side of the Cascade Moun- tains in Oregon is furnished by the fact that in the southern por- tion of the state, in the vicinity of Mounts Scott and Mazama, the eastward-flowing glaciers are larger and of greater length than farther north in the vicinity of the Three Sisters peaks and Geology and Mineralogy. 459 Mount Jefferson. If this conclusion is sustained by future studies, an explanation of it will perhaps be suggested by com- paring the present climatic conditions of the two regions.” No. 258. The Origin of certain Place Names in the United States (second edition); by Henry Gannetr. 334 pp. This paper is a second edition of that published as Bulletin No. 197; it contains a large amount of useful geographical information. No. 259. Report on Progress of Investigations of Mineral Resources of Alaska in 1904; by Atrrep H. Brooks and others. 196 pp., 3 plates, 10 figures.—This bulletin gives an account, by the different geologists at work, of the information gathered dur- ing the last season in regard to the various mineral deposits of Alaska. Nine parties were in the field, five of them engaged in geologic work, two in topographic surveys, one was a combined geologic and topographic party and one studied the methods and costs of placer mining. The larger part of the bulletin is devoted to the gold placers, but an account is also given of the Treadwell ore deposits on Douglas Island, as, too, of the recent develop- ment of tin deposits in Alaska. Further, the coal and petroleum resources of Alaska are discussed in detail (see also Bulletin No. 250). No. 261. Preliminary Report on the Operations of the Coal- testing Plant of the U. 8S. Geological Survey at the Louisiana Purchase Exposition, St. Louis, Mo., 1904; E. W. Parxer, J. A. Houmess, M. R. Campsert, Committee in charge. 192 pp. No. 264. Record of Deep Well Drilling for 1904; by M. L. Fuuver, E. F. Lines and A. C. Veatou. 106 pp.—The work of the Survey, in regard to the accummulation of geological and physical data of deep wells, although only recently inaugurated, is now so well organized that a very large amount of useful material is promptly brought together and given to the public. The paper now issued is the first of the series planned and . presents the material received during the first six months of the work.