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' ' +6 Ce ee oT] a a Et esi ot eek) be eee ed ped ‘ ;. bie ‘ ! i : - ‘. a ‘ Rises + Ss ep bw ee Rye ae ' ‘ ' ‘ ‘ tet aaa f a eS He COCR FUER TOE PE AE Rite ore 4. ; ay ot ett C4 GO betwee cid emer de Hew ni og fee " hese oe Deas mee oe rer, 15 Pe td Np bed i kaek Gs ee ee er ee ed we Bark 5 Bebe a tee oe alt a Se ee or Vere er See tea ee ieee eee er Pe rr rT) . a of so ee BD spe aes Mette ee honed 6 Feed ar Tejee Vode) Asem wy Me eke weet et he a eee etede at yp deh 4 yb ey bed # ate Wedet md ge hoe oes easy @ dain eed re ee oy weed “4 =H os bot voir dhs a8 see pa we he bee Lis, Baad ‘ , ‘ ae oe eee ee ae er ee re a a ee er er cee rt ar) Wy ana eme errr Seen ren On t1e Hie seme as pi sen Pee erie a ere fr for | nt ate teal ood F wernt ete ot? eae ee oe ee eee te et te Pe Cee ey nn ne Sd be oa - ponve t +463) anh, . Pt ie be oe eet alee & Ce ee Pe Ce ee La rhok, oe sean eB eget tere ie ee 4 Cd ode? Uo tietehe 0 dese Gade TO cn oed ot beta ae - ee eee ne Wie y ee ery ess ia aswete rl a4 ns git cee EE pete ee Fo ee om mehr Be os serio we =e 4 yp sae only ee Sr a * tee ty by: fom) oe See eee ae ‘ Wn OL0 pebiaca th cae deh be oko atten oct eter a arte Ce ee a Patt ae ae wet de lak 6b ole er ft au aetw a pi Coed | sone we eons ‘ a ew enone ees os wed dee arrears Mery esr Te | ” tae el ei Ce ee eh ed ile Ce oo eee A tat Beude A ot we bd ant “Hamee ye int 84 Cr aren ee ace Carnie Ree arr ar te Were had & a Jelace ase be Et dd ba reine pw ee tel ate oe wid oi a: peewee see G “ne ey fe ree darbhes oe woo peer eee Rage ae « Aa eek uch val <4 6 nei bre andes caf ‘at a by edt ot ere ett me ed Gace ay Can oe weep tea d dete 6 Cr ee ¥ Se . . rahontanees oe nes + @ Fed AP eee est oh LA waPee awry e ar Saas » pint THE eM ay LOA IN Epirorn: EDWARD S. DANA. ASSOCIATE EDITORS. Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camprince, Proressorss ADDISON E. VERRILL, HORACE L. WELLS, ~ LOUIS V. PIRSSON, HERBERT E. GREGORY AND HORACE S. UHLER, or New Haven, Proressorn HENRY 8S. WILLIAMS, or Ituaca, Proressor JOSEPH S. AMES, or Batrimmore, Mr. J. S. DILLER, or Wasuinecron. FOURTH SERIES VOL. XXXVI—[WHOLE NUMBER, CLXXXVJ]j. WITH TEN PLATES. NEW HAVEN, CONNECTICUT. noel Ss . £2 Cet THE TUTTLE, MOREHOUSE & TAYLOR COMPANY NEW HAVEN CONTENTS TO VOLUME XXXVI Number 211. Page Art. I.—Investigation of the Prehistoric Human Remains found near Cuzco, Peru, in 1911; by H. Brneuam .--- 1 II.— Vertebrate Remains in the Cuzco Gravels; by G. F. Pinan ee ences Ry a Ne eR es 3 II1.—Gravels at Cuzco, Peru; by H. E. GRecory.--. -.-. 15 1V.—Simple Model for Illustrating the Symmetry of Crys- DeEmenrera Ef HILEEPS 206 ote 8 ee 30 V.—Chemical Composition of the Alkaline Rocks and its Significance as to their Origin; by C. H.Smyru,Jr.--. 33 VI.—Solid Solution in Minerals. III. The Constant Compo- sition of Albite; by H. W. Foote and W. M. Braprey 47 VIi.—Triplite from Eastern Nevada; by F. L. Hess and mpebRieie rrr. (ee ee ee oe oe. OB VIlI.—Heat of Formation of the Oxides and Sulphides of Iron, Zine and Cadmium, etc. ; by W. G. Mixrsr --_--- 55 1X.— —Deep Boring in Bermuda Island ; by L. V. Prrsson PN ieran PY gO X.—Preparation of Telluric Acid and Test for Associated Tellurous Acid ; by P. E. Brownine and H. D. Minnie 72 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Compounds of Trivalent’and Quadrivalent Tung- sten, O. OLsson: New Oxide of Carbon, H. Meyer and K. STEtner, 73.— Examination of Waters and Water Supplies : Gas Analysis: Chemical Analysis for Students of Medicine, 74.—Per-Acids and their Salts: Prac- tical Physiological Chemistry, 75. "Influence of Dissolved Salts on the Absorption Bands of Water, 76. Geology and Natural Histor y—United States Geological Survey, 77.—Bureau of Mines, United States: Geological Survey of “New Jersey, 78.—Map of West Virginia, showing Coal, Oil, Gas, Iron Ore and Limestone Areas: Living and Fossil Flora of West Virginia: Wisconsin Geologieal and Natural History Survey: Iron making in Alabama: Canada Department of Mines, 79.—Underground Water Resources of the Coastal Plain Province of Virginia: Geology of the Columbus Quadrangle, 80.—State Geological Survey of Wyoming, Bulletin 3, Series B: Coal, and the Prevention of Explosions and Firesin Mines: New Zealand Department of Mines, 81.— Geology and Ore Deposits of the Monarch and Tomichi Districts: Devonian and Mississippian formations of N.E. Ohio, 82.— Fossil Coleoptera from the Wilson Ranch near Florissant, Col.: Lower Siluric shales of the Mohawk valley, 83.—Introduction to Zoology: Malaria, Cause and Con- trol : Publications of the British Museum of Natural History, 84.—Annual Report of the Director of the Field Museum of Natural History, 86. Misceilaneous Scientific Intelligence—-General Index to the Chemical News, Vols. 1 to 100, 86.—Journal of Ecology: Annual Report of Superintendent of Coast and Geodetic Survey. 87.—Hurricanes of West Indies: Die Zersetz- ung und Haltbarmachung der Eier: Publications of Comitato Talasso- grafico Italiano, 88.—Publications of Allegheny Observatory of University of Pittsburgh: Publications of Detroit Astronomical Observatory of the University of Michigan: Carothers Observatory: Bibliotheca Zoologica IT, 89.—Chemical and Biological Survey of Waters of Illinois : Mining World Index of Current Literature, Vol. Ii, 90. Obituary—E. Kitt: J. G. MacGrecor: Lorp AveBuRY: W. Hattock, 90. 1V CONTENTS. Number: 202 Page Art. XI.—Velocities of Delta Rays; by H. A. Bumstmap 91 XII.—Banded Gneisses of the Laurentian Highlands of Canada; by M. E. WiusoN 22224322. 25_ 324) 109 XIII.—Deep Wells at Findlay, Ohio; by D. D. Conprr ... 123 XIV.—Note on the Temperature in the Deep Boring at Findlay, Ohio; by J JonNston o> 122 233 131 XV.—Are Spectrum of Tellurium; by H. 8. Unter and R. A, PATTERSON. .-....-2.2525.2255)22) rr 135 XVI.—La Paz (Bolivia) Gorge ; by H. E. Grmcory ______ 141 XVIL—Some Kilauean Formations; by F. A. Perrer_---- 151 XVITI.— Marked Unconformity between Carboniferous and Devonian Strata in Upper Mississippi Valley ; by C. R. KEYES". goose doe. es Re ee XIX.—Meteoric Iron from Paulding County, Georgia ; by T. L. WATSON 2. 0). eee a8 fe oe ere X X—Pyroxmangite, a New Member of the Pyroxene Group and its Alteration Product, Skemmatite; by W. E. Forp and W. M BrapLny __._<2_-. 2.52 12522 169 XXI.—New or little known Paleozoic Faunas from Wyo- ming and Idaho; by HE. BLACK WELDER_ »._ = 2223 32eeem 174 XXII.—Solid Solution in Minerals. IV. The Composition of Amorphous Minerals as illustrated by Chr yeena by H. W. Foor and W. M. Braviny )-2>22) See 180 SCIENTIFIC INTELLIGENCE. Miscellaneous Scientific Intelligence—History of the first Half-Century of the National Academy of Sciences, 1863-1913, 185.—United States Geological Survey, 186. Obituary—E. Houzapre., 186. CONTENTS. Vi Number 213. Page Arr. XXIII.—Geologic Sketch of Titicaca Island and Adjoining Areas; by H. E. Gregory. (With Plate I) 187 -XXIV.—Experiments on Columnar Ionization; by E. M. Reemrscrand J. W. WoopRoW 2.2.2.2 4.22.54 5-2. 214 XXV.—Geology of the New Fossiliferous Horizon and the Wnderlying Rocks, in. Littleton, N. H.; by F. H. re SUE ae iin ek Selene ne We ae oe ens 28 XXVI.—HLiassic Flora of the Mixteca Alta of Mico ,—Its Composition, Age and Source ; by G. R. WIELAND... 251 XXVII—Age of the Sere of Kokomo, nee by PSP OUNDI YG 22. 22 ee ie Wes tps ate Ee 8D XXVIII.—Two Vanadiferous Atgirites from Libby, Mon. tana ; by E. 8. Larsen and We HY Serre uO ega9 XXIX.—Method of Increasing and Controlling the Period in Vertical Motion Seismographs; by F. A. Perret... 297 XX X.—Action of Sodium Paratungstate in Fusion on Salts of the Halogen Acids and Oxy-halogen Acids ; by 8. B. en DT TATE) AS aes pe 0 ne cep eo 301 XX XI.—Use of the Sodium Paratungstate and the Blowpipe Flame in the Determination of the Acid Radicals of Chlorides, Chlorates, Perchlorates, Bromides, Bromates iaeeiuordes > by 8. Bi: Kuzigian..--- 0222 ...2----- 305 SCIENTIFIC INTELLIGENCE. Miscellaneous Scientific Intelligence.—Atlas der Krystallformen, V. Goup- SCHMIDT: Dybdeboring i Grdndals eng ved Kébenhavn 1894-1907 og dens videnskabelige Resultater, E. P. BoNNESEN, O. B. BOGGILD og J. P. Ravn, 313.—Das Problem der Vererbung ‘‘ Erworbener Eigenschaften ”’, R. Semon: Principles of Economie Zodlogy ; Part I, Field and Laboratory Guide, L. S. Darguerty and M. C. DaucHerty: The Modern Worship, E. L. Atwoopn, 314. al CONTENTS. Number 214. t Page Art. XX XII.—Distribution of the Active Deposit of Radium in an Electric Field (II); by E. M. Wetiisca ___.___- 315 XX XITI.—Adjustment of the Quartz Spectrograph; by C. C. Huresins.. bo222- 4522382262 2 3 ee XXXIV.—Stability Relations of the Silica Minerals ; by C. N. Fenner 222.5..0 20) i 2 eee XX XV.—Custerite : A New Contact Metamorphic Mineral; by J. B. Ump.esy, W. T. Scuarimr, and E. 8. Larsen 385 XXXVI.—Ordovician Outlier at Hyde Manor in ae Vermont ; by oT 3N. Darn 2 ee eee i! XXX VIL — Preparation of Tellurous Acid and Copper Am- monium Tellurite; by G. O. OpeRHELMAN and P..E. BROWNING... 22-50-4222 /2+-5 022 12-2 rr XXX VIIT.—Determination of Water of Ceyatallie ae in Sulphatess by S. B. KuzIRIAN _-_. ._.- 2.22.) 233 XX XIX.—Paleozoic Section in Northern Utah; by G. B. RICHARDSON «2 oe oe es eee SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Volatile Oxide of Manganese, F. R. LANKSHEAR: Detection of Bromine and its Distribution in Nature, I. GuarzEscut, 416.— Calcium Hydride, MOLDENHAUER and RoLL-HAnsen: Analysis of Special Steels, S Zrnperc, 417.—Qualitative Chemical Analysis, A. A. Novus: New Fluorescence Spectrum of Iodine, J. C. McLennan, 418.—Inter- ference of Gamma Rays, A. N. SHaw, 420 —Experimental Researches on the Specific Gravity and Displacement of Some Saline Solutaons, J. Y. BucHanan, 421.—Elektrischen Higenschaften und die Bedeutung des Selens fiir die Elektrotechnik, C. Rims: Photochemische Versuchstechnik, J. PLotnixow, 422.—First Course in Physics, R. A. MrxuiKan and H. G. GaLE: Materialien fiir eine wissenschaftliche Biographie von Gauss, F. KuEIn and M. BRENDEL, 423.—Descrizione di una Macchinetta Elettro- Magnetica, A. Pacinotrr: L’attraction universelle considérée comme fonction du temps, A. N. Panorr, 424. Geology and Mineralogy—Publications of the United States Geological Sur- vey, 424.—Report of the State Geologist on the Mineral Industries and Geology of Vermont, 1911-12: Cretaceous deposits of Miyako, H. YABE and §. YEHARA, 425.—Die Antike Tierwelt, O. Ketter: A Manual of Petrology, F. P Mrnneuu, 426.—Supposed new occurrence of Plattnerite in the Coeur d’Alene, E. V. SHANNON, 427. Miscellaneous Scientific Intelligence—Miiller’s Serodiagnostic Methods, te. WHITMAN : Planetologia, E. CortEss, 428. CONTENTS. Vil Number 215. Page Arr. XL.—Upper Devonian Delta of the Appalachian Geo- Pamelinen DY. J. DARBENE) 8203 le. el. se --. 429 XLI.—Optical Bench for Elementary Work; by H. W. | EMER NDE ere EN aoe aa a le ATS XLIL—Volcanic Research at Kilauea in the Summer of 1911; by F. A. Perrer; with Report by A. BRun__-- 475 XLII.—Observations on the Stem Structure of Psaronius Peeenonsic "oy O. A. Dirpy 22.20.2222 -s2e--.-- 2 489 XLIV.—Fauna of the Florissant (Colorado) Shales ; by T. eA. COCKERELL.-_.--- SM ph i Do ol ci eee Mie ag he ee 498 XLV.—The Photoelectric Effect ; by L. Page _-__-.--_-__- 501 XLVI.—Graphical Methods in Microscopical Petrography ; by EF. E. Wrieut. (With Plates II to 1X)_---.--_._. 5.09 XLVII.—A Graphical Plot for Use in the Microscopical Determination of the Plagioclase Feldspars ; by F. E. Peeper umes (ouvaitie Flaite, Nj 9 ee eS ee 540 XLVII.—On the Influence of Alcohol and of Cane Sugar upon the Rate of Solution of Cadmium in Dissolved Todine; by R. G. Van Name and D. U. Hitz _-_-- ---- 543 XLIX.—Comparative Studies of Magnetic Phenomena. IV. Twist in Steel and Nickel Rods due to a Longitudinal Magnetic Field; by S. R. Wiziiams .-----. Epona, Ce 555 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Hydrides of Boron, A. Stock: Metallic Beryllium, FICHTER and JABLOZYNSKI, 562.—General Chemistry, Theoretical and Applied, J. C. Buaxe: A Dictionary of Applied Chemistry: General and Industrial Organic Chemistry, 563.—Chemistry and its Relations to Daily Life: Studies in Valency: Deviation of Rubidium Rays in Magnetic Fields, K. BerGwirz, 564.—Researches in Magneto-Optics, P. ZEEMAN : A New Element, Uranium X: Mechanics and Heat, 565.—Practical Physies for Secondary Schools: Beyond the Atom, 566.—Physikalische - Chemie der homogen und heterogenen Gasreaktionen, 567. Geology—Virginia Geological Stirvey: Sixteenth Annual Report of the Geological Commission, Cape of Good Hope, Department of Mines, 1911 (1912), 568.—Sixth Annual. Report (New Series) of the New Zealand Geo- logical Survey, Session IT, 1912: Geological Survey of Western Australia, 1912, 569.—Recurrent Tropidoleptus zones of the Upper Devonian in New York: Grundztige der geologischen Formations- und Gebirgskunde : Igneous Rocks, J. P. Ipprnes, 571.—Introduction to the Study of Igneous Rocks, G. I. Finuay, 573.—Der Vulcanismus, 574. Miscellaneous Scientific Intelligence—Publications of the Carnegie Institu- tion of Washington, 579.—The Mining World Index of Current Literature, 576. Obituary—C,. G. Rockwoop: J. R. Hastman: A. MAcFaRLANE: J. MILNE: W.N. Harttey: H. MarsHauz: P. L. Scuater: H. CREDNER: H. Las- PEYRES: H. WEBER, 576. Vill CONTENTS. Number 216. Page Art. L.—Some Lavas of Monte Arci, Sardinia; by H. S. W ASGHINGTON 2 22) ,e2t -L..J.. J. 332 577 LI.—On the Use of Sealing ee asa Source of Lime for the Wehnelt Cathode; by Nettie N. Hornor._..__-.___ 597 LII.—Dehydration and Recovery of Silica in Analysis ; by F, A. Goon, F. C. Recxerr and 8. B. Kuzirian -___- 598 LILI.—The Ascent of Lava; by F. A. Perret .__._...__. 605 LIV.—Solar Radiation ; by F. W. Very __.-___. 2) 733g LV.—A New Occurrence of Cuprodescloizite; by R. C. BB 04 Ve een ge Shep Ree ta SC) ee LVI.—On the Crystallization of Wales ; by C. Patacue and R. P. D. Granam __-........_/5.) or SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Action of Sulphur Trioxide uponSalts, W. TrauBsE, 644.—Volumetric Determination of Fluorine, A. GrEeEF: Behavior of Hydrogen towards Palladium, GUTBIER. GEBHARDT, and OTTENSTEIN: A New Era in Chemistry, H. C. Jones, 645.—Experiments Arranged for Students in General Chemistry, E. F. Smira and H. F. KELLER: Chemical German, F.C PHILuips: Spectrum of the Aurora Borealis, L. VeGarp. 646.—To Produce a Continuous Spectrum in the Ultra-violet, V. Henrr: The Gyroscope, F. J. B. CorpErro, 647.—Medizinische Physik, O. FiscHER: Wonders of Wireless Telegraphy, J. A. FLemine, 648.—Principles and Methods of Geometrical Optics, Second Edition, J. P. C. SouTHat.: Physical Measurements, A. W. Durrand A. W. EweLL: Uber kausale und konditionale Weltanschauung und deren Stellung zur Entwicklungs- mechanik, W. Roux, 649.—Annals of the Astrophysical Observatory of the Smithsonian Institution, 650. Geology and Mineralogy—Research in China, 650.—Fosseis Devonianos do Parané, 652.—Monograph of the Terrestrial Palzozoic Arachnida of North America, 653.—The Heart of Gaspé; Sketches in the Gulf of St. Lawrence: Ninth Report of the Director of the Science Division, 654.— New Trilobites from the Maquoketa Beds of Fayette County, lowa: New Paleontologic Periodical— Palaeontologische Zeitschrift: Petrology of the alkali-granites and porphyries of Quincy and the Blue Hills, Mass., 655.— Geology and Ore Deposits of the suas ie Quadrangle, Montana : Gems and Precious Stones in 1912, 656. Miscellaneous Scientific intelligence Natiouel Antarctic Expedition, 1901-- 1904 ; Meteorology, Part Il, 656.—Annual Report of the Board of Regents of the Smithsonian Institution, showing the operations, expenditures, and condition of the Institution for the year ending June 30, 1912: Report on the Progress and Condition of the U. S. National Museum for the year end- ing June 30, 1912, 657.—Publications of the British Museum of Natural History: Publications of the Museum of the Brooklyn Institute of Arts and Sciences: National Academy of Sciences, 658.—Hlements of Bacterio- logical Technique, 659. Obituary—A. R. WALLACE: W. H. PREECE, 659. aed ot WOL. XXXVI. JULY, 1913. Established by BENJAMIN SILLIMAN in 1818. THE | AMERICAN JOURNAL OF SCIENCE. Epitrorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, ae G. FARLOW AND WM. M. DAVIS, or CamBrmwnce, Proressors ADDISON E. VERRILL, HORACE L. WELLS, LOUIS V. PIRSSON, HERBERT E. GREGORY anp HORACE S. UHLER, or New Haven, Proressor HENRY S. WILLIAMS, or Iruaca, ProFessor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or WasuinerTon. f FOURTH SERIES VOL. XXXVI—[WHOLE NUMBER, CLXXXVIj. Moet FLY, 1913, 5 onal [mown CML iicais Bite? PAS F S f | Novi4 1918 \ NOV i4& Lose NEW HAVEN, CON EOTICUT. aK , ational Must Pots. THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. Published monthly. Six dollars per year, in advance. $6.40 to countries in the Postal Union ; $6.25 to Canada. Remittances should be made either by money orders registered letters, or bank checks (preferably on New York banks). : NEW DISCOVERIES AND NEW FINDS. BEAVERITE, A NEW MINERAL. This mineral, which was fuliy described in the December, 1911, number of this Journal, I have been fortunate enough to secure the whole output of. It was found at the Horn Silver Mine in Utah and is a hydrous sulphate of © copper, lead and ferric iron. It was found at a depth of 1600 feet. in appearance it resembles Carnotite. Prices 75¢ to $2.00. PSEUDOMORPHS OF LIMONITE AFTER MARCASITE. These remarkable Pseudomorphs, which have never before been found in such clear cut specimens, was described and illustrated in the last number of this Journal. I have secured the majority of the finest of these speci- mens. They vary in size from 2 inches to 6 inches. In color they run from brown to glossy black and they have met with favor from all who haye seen them, Prices from $1.00 to $10.00. . CHIASTOLITES. Of these remarkable specimens, which are generally known as lucky stones, I have secured the finest lot ever found at Madera Co., California. They are — cut and polished and sold singly and in collections from 25¢ to 50¢ for single — specimens ; 9 specimens all marked differently for $5.00, and 18 specimens, — all different markings, for $18.00. Matrix specimens, polished on one side showing many crystals, from $2.00 to $8.00. ‘ SYNTHETIC GEMS. It is remarkable the interest that has been taken by scientists in these wonderful scientific discoveries. The Corundums are now produced in Pigeon blood, Blue, Yellow, Pink and White. Also the new Indestructible Pearls in strings with gold clasps. These are identical in hardness and rival in color and lustre the real gems. They can be dropped and stepped on without injury and are not affected by acids. My collection of the above is unrivalled, and prices of the same are remarkably low. ; OTHER INTERESTING DISCOVERIES AND NEW FINDS Will be found in our new Catalogues. These consist of a Mineral Catalogue of 28 pages; a Catalogue of California Minerals with fine Colored Plates; a Gem Catalogue of 12 pages, with illustrations, and other pamphlets and lists. These will be sent free of charge on application. . Do not delay in sending for these catalogues, which will enable you to secure minerals, gems, etc., at prices about one-half what they cam be secured for elsewhere. ALBERT H. PETEREIT 261 West 71st St., New York City. AN Agtely AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.] +0 Arr. 1—The Investigation of the Prehistoric Human Re- mains found near Cuzco, Peru, in 1911; by Hiram BincHaM.* | Iy the American Journal of Science for April, 1912, the present writer made a brief report on “ The Discovery of Pre- Historic Human Remains near Cuzco, Peru.” Published in connection with this report was a paper by Prof. Isaiah Bow- man on the “ Geologic Relations of the Cuzco Remains,” and another paper by Dr. G. F. Eaton, entitled: “ Report on the Remains of Man and of Lower Animals from the Vicinity of Cuzco, Peru.” It will be remembered that a small collection of vertebrate remains had been found interstratified with the gravel bank in the Ayahuaycco Quebrada, not far from Cuzco; and that these bones were brought to New Haven for study. It was a keen disappointment to us that we were not able in 1911 to spend more time in Cuzco. I concluded my report as follows: “ Notwithstanding my great interest in these prehis- toric human remains, | felt it was wiser to carry out the plans originally adopted for the Expedition, although that meant a hurried departure from Ouzco without doing more than is shown by the results presented herewith. It seems to me extremely desirable to continue the work of exploration and excavation in and about Cuzco, for it is highly probable that important as bearing on Inca and pre- -Inca civilization may be obtained nere.”’ + Chiefly owing to the interest shown in this discovery, and in others made on the same expedition, by the National Geo- graphic Society and by certain friends of Yale University, it was possible to return to Peru in 1912 and make a thorough * Director of the Peruvian Expedition of 1912. + This Journal (4), xxxiii, p. 305. Am. JOUR. mo SERIES, VoL. XXXVI, No. 211.—Juty, 1918. 2 Bingham— fesults of the Peruvian Expedition of 1912. investigation of the Ayahuaycco Quebrada and of the Cuzco Valley. The Expedition of 1912 reached Cuzco in June and left at the end of November. Nearly three months were spent in a careful topographic survey of the Cuzco Valley. A portion of that map is published at this time. The remainder will appear in connection with the complete geological report of the Expe- dition. | Remembering that I had seen many bones in position in various parts of the vicinity, and feeling that it would be entirely impracticable to bring home all this bone material without knowing its value, I persuaded Dr. Eaton, who had reported on the bones brought home in 1911, to accompany the Peruvian Expedition of 1912 in the capacity of osteologist. The approved plan for his work included: (a) a careful search for bone deposits in the cliffs of the Ayahuaycco Quebrada and in other similar cliffs in the vicinity wherever located within easy reach of trails; (b) search for bone deposits at heights not easily accessible from trails,—such deposits rarely coming within the category of human burials, and such search requiring the use of rope slings; (c) especial attention to be paid to the occurrence of remains of pre-Hispanic and Hispanic animals, including domestic poultry, horses, asses, mules and cattle ; (d) examination of skeletons of contemporary bovines, to determine the value of the peculiar characteristics noted in the fragmentary bovine rib found in 1911; and, (e) an exami- nation of the so-called ‘‘ Cuzco ash-deposits,” to determine their origin and true character. It also seemed to me that it was essential to have a geologist make a far more comprehensive study of the geology of the Cuzco Basin than had been possible in the few days at Prof. Bowman’s disposal in 1911. Moreover it seemed advisable that these geological studies should be made by an independent and impartial observer, who should be in no wise influenced by any necessity for substantiating the previous findings, nor by any desire to discredit them. As the previous work had been done by a Yale man, it seemed to me most appropriate that. the proposed studies should also be done by a member of the same Faculty, and I accordingly considered myself most fortu- nate in being able to persuade Prof. Herbert E. Gregory, Silliman Professor of Geology in Yale University, to accept the commission of Geologist of the 1912 Expedition, and to go to Cuzco and make a special study of the Cuzco gravels. His report on this subject and Dr. Eaton’s on the vertebrate remains which he found in the Cuzco gravels are presented herewith. While the results are not as exciting as some people wish they were, it is a great satisfaction to me to have been able to get to the bottom of this interesting problem. Eaton— Vertebrate Remains in the Cuzco Gravels. 3 Arr. Il.— Vertebrate Remains in the Cuzco Gravels; by GrorceE IF. Earon.* Tur Yale Peruvian Expedition of 1911 collected human remains in the Ayahuaycco Quebrada of Cuzco, Peru, under conditions that called for a more critical investigation than was possible at the time of the discovery. So much interest attaches to the question of the existence of Man during the Glacial Period of geological time that it seemed desirable to make every effort to. obtain some decisive evidence regarding the antiquity of the fragmentary remains popularly known as the Cuzco Man. Accordingly the plans for osteological work by the expedition of 1912 not only provided for a general search for bone deposits in the alluvium of the Cuzco Valley, but also included a special study of the gravels of the Ayahuaycco Quebrada. It will be recalled by those who read the preliminary reports on this subject? that neither the geological evidence nor that derived from a strictly osteological study of the bones them- selves was to be relied on in determining the age of the deposit, only the barest indications of great antiquity being observed in the remarkably bisontic form of a bovine rib associated with the human bones. Had it been possible to identify this rib positively as that of an extinct species of Bison, a claim to great antiquity for the “Cuzco Man” would have been almost unas- sailable ; but believing that the premises did not warrant such a conclusion, I made the following statement in the prelimi- nary report on the bones: “ It cannot be denied that the mate- rial examined suggests the possibility that some species of Bison is here represented, yet it would hardly be in accordance with conservative methods to differentiate Bison from domestic eattle solely by characters obtained from a study of the Ist ribs of a small number of individuals.” From what I was able to learn of the beef industry in and about Cuzco, practically all the beeves slaughtered for the Cuzco trade are raised on the elevated pastures within one day’s drive of that city ; and one of the first steps taken toward solving the problem under consideration, after the arrival of the expedition at Cuzco, was to examine the first ribs of carcasses of beef animals offered for sale in the public markets. This con- vinced me that under the life-conditions prevailing in this part of the Andes, and possibly in correlation with the increased action of the respiratory muscles in the rarefied air, domestic cattle occasionally develop 1st ribs closely appr oaching the form observed in Bison. Therefore, apart from purely geological * Osteologist of the Peruvian Expedition of 1912. + This Journal (4), xxxiii, p. 332, April, 1912. 4 Eaton— Vertebrate Remains in the Cuzco Gravels. considerations, no reason remains for supposing that the bovine rib, found with the human bones in the Ayahuayeco Quebrada in 1911, belonged to a Bison; and any theory attributing great antiquity to the ‘ Cuzco Man, ” based on such a supposition, is rendered untenable. When preparing my contribution to the preliminary report of the Expedition of 1911, I preferred to limit myself to a strictly osteological discussion of the material submitted to me, without any recourse to the geological relations of the discoy- ery. Now that I have visited the locality where the material was collected, the problem may be treated more broadly, and utilized as fully as possible in connection with the further study of the bone-deposits of the region. In June, 1912, the shallow excavation, made in the north- east wall of the Ayahuayceco Quebrada by the Expedition of 1911, was revisited. It was apparently just as it had been left eleven months before. Not even had the little mound of gravel, thrown out by the excavators, been washed away from the side of the trail by the showers of the past rainy season. The original collectors had done their work so carefully and completely that nothing recognizable was to be found, by sift- ing this fallen material, except a sternal segment, referable to Canis sp., and a fragment of the labial cusp of a human upper premolar. These two small specimens probably belong with the bones taken out in 1911. They have little significance beyond making it appear likely that the human and canine remains, deposited in this place, were slightly more complete than they were, at first, reported to be, and to that extent more suggestive of the ancient burial customs of the region. The coarse gravel immediately surrounding the excavation of 1911 was compact and free from cracks or flaws. It had, in fact, every appearance of being an undisturbed integral part of the flat- topped gravel spur that separates the Ayahuaycco and Huatanay (uebradas. To make sure that there was no lack of homogeneity in the gravel at this place it was proposed that a small tunnel, commencing at the excavation of 1911, should be made directly into the face of the cliff. This was accordingly done at a time when Professor H. E. Gregory, the geologist of the expedition, could visit the scene. During the first day’s work I encountered no cracks or fissures in the gravel, and Mr. K. C. Heald, who continued the tunneling, reported that the gravel cut through by him was everywhere extremely firm and without break of any kind. The solidity and firmness of the formation are attested by the fact that, in three days’ time, our laborers were able to penetrate only 11 feet into the cliff, the height and width of the tunnel being 43 feet and 8 feet respec- tively. The gravel exposed within the. tunnel was of precisely the same character as the gravel of the cliff about the entrance. Eaton— Vertebrate Remains in the Cuzco Gravels. 5 If this tunnel with carefully shaped parallel sides had cut through a contact between the basal mass of gravel and an overlying “veneer,” deposited by landslide against its face, some indication, no matter how slight, of the lack of continuity should have been presented. As the tunnel offered a much better opportunity for recognizing a possible break in the gravel than the original excavation offered, I am led to suppose that, if in either period of work at this place, a contact between basal mass and gravel of later deposition was reached, it was not during the tunneling, but in 1911 during the first period of excavation. At the time when the bones were excavated Professor Bow- man was fully aware of the significance such a break would have in determining their age; and the following quotation from his report shows that he actually encountered what, at first view, looked very much like an extensive break in the gravel enclosing the bones: “Tmmediately above the stratum containing the bones was a break in the face of the bluff about four feet long. It rose in a curved line about two feet above the layer in which the bones were disposed and suggested the upper part of a grave, especially as the break exhibited a mould of organic material. After the excavation work was done, as much care was exer- cised in the examination of this break as in the gathering of the bones. Upon excavation of the gravel along the line of the break and forward from it two facts were discovered : (1) the break extended downward but a few inches and merged into hard undisturbed material in which the bedding planes ran apparently without interruption from within the main gravel mass to the outer edge of the bluff; (2) the mould con- sisted principally of a fungus growth mixed with a few species of lichens.’’* It is difficult to advance and maintain any theory at variance with the foregoing careful statement by Professor Bowman regarding the apparent condition of the gravel surrounding the bones; and yet, after studying the form and composition of the walls of the quebrada and examining other deposits of bones both here and elsewhere in the Province of Cuzco, I am led to the opinion that the bones excavated in 1911 were not originally embedded in the basal gravel of the spur at the time when that gravel was itself in process of deposition, but were, in all probability, interred there at a much later time when the northeast wall of the quebrada had assumed more nearly its present contours. The upper part of the Ayahuayceo Quebrada is shown in the accompanying view (fig. 1), taken from the southwest side * This Journal, 1. c., p. 310. 6 Katon— Vertebrate Remains in the Cuzco Gravels. and looking northerly. The point of the arrow marks the place of the excavation of 1911. The view shows also the flat top of the gravel spur, separating the Ayahuayeco and Fig. 1. Fie. 1. View of the northeast side of the Ayahuaycco Quebrada, taken from the opposite cliff. The point of the arrow marks the site of the excava- tion of 1911. Huatanay Quebradas, and certain other features to which I wish to refer. The general course of the upper part of the quebrada is about N. W. and S. E. In the down-stream direc- tion (S. E.) from the excavation of 1911, a cultivated terrace extends along the foot of the cliff for several hundred feet. Eaton— Vertebrate Remains in the Cuzco Gravels. 7 It narrows gradually as it approaches the place of excavation, until it finally ends about 10 feet from this place. In the photograph the foot of the cliff lies in such deep shadow that the extreme prolongation of this terrace is not visible. The terrace appears to be composed, almost entirely, of material that has fallen from above. In the opposite direction CN. W:) from the place of excavation, and about 60 feet distant from it, is a somewhat confused mass of talus material. As this is separated from the previously described terrace by a gap of — only about 70 feet, it is quite possible that these two masses of fallen gravel may have been connected, at some earlier time, by an intermediate portion that has been cut away during recent improvement and widening of the road. In fact the general character of that part of the slope lying between the road and the brook-bed, at the bottom of the quebrada, makes this seem probable. Whether these masses of talus were con- tinuous or not, there must have been, from time to time, con- siderable quantities of gravel falling from the top and face of the cliff over the place where the bones were found. The diagrams, arranged under fig. 2, represent three pos- sible stages of development at the foot of the quebrada wall where the excavation was made. A grave containing human remains may have been left open in the face of the gravel cliff, as indicated in Section I. This seems to have been one form of burial practiced by the Indians of the region. Many open graves of this character were observed in the face of a steep gravel bank in the neighborhood of Urubamba, one day’s ride from Cuzco; and it is interesting to note that none of these graves that I was able to examine contained entire skeletons, merely disarticulated or fragmentary bones. Section I] shows the result of an enlargement of the talus. Gravel deposited at this point would fill the open grave, and would closely simulate the basal gravel of the cliff. The filling would, however, tend to be somewhat less compact at the top of the grave than at the bottom, and a shallow “break” might develop under the roof of the grave when the filling had settled. In section III the trail, known as the lower road to Anta, has been improved and widened by removing a considerable quantity of gravel from the talus and also from the face of the cliff. At this stage the inner portion only of the grave is left; and the greater part of its original contents, already broken and dis- placed by decay and by the impact of the falling gravel, if not by inquisitive and ceremonial visitors, has been “out away by the mattocks of the road-menders. The foregoing explanation of the occurrence of vertebrate remains at this place in the quebrada would apply to almost any time during the three centuries anda half that have elapsed since the Spaniards brought domestic cattle to Peru; 8 Eaton— Vertebrate Remains in the Cuzco Gravels. but it would not otherwise fix the date when the bones were deposited here. Their exact age cannot be determined. In regard to the bones of lower animals accompanying these human remains: it seems to have been an ancient and common practice, in this part of Peru, to place in the human grave, pieces of the flesh of llamas, and occasionally, if the mute Fie, 2. Section II Section I EXPLANATION Secttorn L Grave in foot of clt7r the original gravel being marked A. - Section H, Talus, marked B LECLCME Che Rave: Section I. Profile after road was made along foot of clufr Only the inner portion of the grave ts preserved. Lettering as above. Section II Fic. 2. Diagrams showing possible changes in the profile of the foot of the cliff where bones were excavated in 1911. testimony of the bones can be relied on, a dog’s entire careass. There is no reason to suppose that this ancestral custom would have been discontinued until long after the introduction of European domestic animals; and accordingly there should be nothing surprising in the occurrence of beef bones in human graves, either with or without bones of the native animals. I shall have occasion, a little further on in this paper, to describe a grave where horse bones were interred with the human remains. Eaton— Vertebrate Remains in the Cuzco Gravels. 9 Further search along the walls of the quebrada was rewarded by the discovery of several other bone deposits whose history seems to have been almost as closely connected with recent changes in the contours of the gravels as was the history of the deposit found in 1911. Reference has been made to a mass of talus material at the foot of the northeast wall and about 60 feet distant from the excavation of 1911. In this Ries o: Fic. 8. Near view of a portion of the talus 60 feet N. W. from the exca- vation of 1911. The upturned point of the pick marks the site of a grave. material, by the side of the trail, human bones were found under conditions differing from those that obtained in the interment previously described. Figure 3 is from a photo- graph of the cut bank where these bones were found, the position of pieces exposed at the surface being marked by the upturned point of the pick. Excavation at this place brought to light parts of two human skeletons, a fragment of a llama’s vertebra, a piece of charred bone, a few podial bones of some small unidentified mammal, bits of charcoal, and a small flat piece of bone, about 14 inches long and 4 inch wide, pierced at one end. No pottery was found. The human material shows no departure from the modern Indian type of the region, and possesses little morphological interest except that the iliac por- tion of a left os innominatum has no preauricular sulcus, while the same portions of two smaller and slighter ossa innominata, 10 Katon— Vertebrate Remains in the Cuzco Gravels. right and left, present very deep and well-defined sulci, and are therefore recognized as female. Of the two human indi- viduals, the larger, supposed to be male, was represented by the following bones: a series of ten dorsal and lumbar verte- bree in nearly perfect articulation with each other and with the sacrum, the left ilium still in contact with the sacrum, the distal two-thirds of the left femur, the proximal part of the left tibia, the left fibula in two fragments, the distal half of the right humerus, and a few more or less fragmentary ribs. The smaller individual, female, was represented by only a few bones, namely: the first sacral vertebra, the left ilium, and the articular portion of the right, the left humerus, and the left radius. There were also an incisor tooth, a coccygial vertebra, Fig. 4. Fie. 4. Horizontal arrangement of bones at the face of the talus in the place shown in fig. 3. a patella, and a few podial bones that may belong to either individual. No other human bones were found at this place although the gravel surrounding the bones was excavated freely in the hope of finding more. The position of some of the principal bones, relative to the face of the cut bank, is shown in fig. 4. The series of dorsal, lumbar and sacral verte- bree lay in a nearly horizontal plane with the ventral surfaces uppermost. The unnatural position of the left femur and tibia underneath the pelvis, and the absence of the skull and ante- rior vertebrae, while the rest of the vertebral column is so well preserved, are conditions not lkely to occur in an undis- turbed grave. Although some of the bones may have been removed with gravel cut away by the road-menders, this would not explain the peculiar disarrangement of the rest. The con- ditions described can best be accounted for on the supposition that the original interment was made higher up on the elifi— perhaps at the top—and that subsequently, when one of the small landslips that have built up the talus occurred, the con- tents of the grave were dislodged and carried down to the foot Eaton— Vertebrate Remains in the Cuzco Gravels. 11 of the cliff in such a manner that only a part of the original skeletal material was preserved intact. The cultivated terrace extending along the foot of the north- east wall of the quebrada appears to be composed largely of gravel fallen from the cliff. Scattered irregularly through this terrace, and exposed to view by the roadside, were pot- sherds and fragmentary bones, mostly of llamas, but with an occasional beef- or dog-bone. As these specimens resembled the pottery and fragmentary bones that were found, strewn to a depth of a few inches, in the flat top of the gravel spur, they may have been derived principally from the latter elevation. There was, however, one small area, exposed in section at the face of the terrace, that showed some of the characteristics of a kitchen-midden. It was a stratum of gravel having a large admixture of charcoal and wood-ashes. Potsherds and bones occurred more plentifully here than elsewhere in the terrace. This stratum had a maximum depth of about 18 inches, and could be traced along the face of the terrace, a little above the level of the roadway, for a distance of abont 30 feet. Fig. 5 _ shows a portion of the stratum, though not as clearly as could be desired. From its size and shape and from the general character of its contents this stratum appears to be a midden built upon the talus slope by the accumulation of miscel- laneous débris during some period since the Conquest when little or no gravel was falling from the cliff. Undecorated potsherds, too small to convey any definite idea of complete form, were found here together with fragmentary bones of llama, dog, domestic cattle and deer, and also bits of charred bone and a copper or bronze needle. This last is an inter- esting relic. It is a round needle 4? inches long, and a trifle less than 4 inch in diameter. The eye has been formed by piercing the blunt end, instead of by drawing out the metal and bending it around in the more primitive way sometimes followed. The great quantity of llama bones buried in the Ayahuaycco Quebrada and in other places near Cuzco indicate that after the subjugation of the Cuzco region by the Spaniards, the flesh of the lama still formed the larger part of the meat diet of the natives, and was accordingly considered the most suita- ble, or the most convenient, kind of flesh that could be provided for the supposed needs of the human dead after interment. When domestic cattle became commoner in the region their flesh naturally replaced that of the llama, to some extent, as an article of food for the living Indians, and as a provision for the dead, but I have not yet met with or heard of any instance of the modern Indians of the region eating the flesh of horses or mules. 12 Haton— Vertebrate Remains in the Cuzco Gravels. I have already alluded to a grave containing horse bones. It was located at the foot of the cliff forming the southwest boundary of the quebrada, and was nearly opposite the lower Fic. 5. Fie. 5. View of a portion of the face of the long terrace where a section of a kitchen-midden was exposed. end of the long cultivated terrace. A peculiar circumstance was the position of the grave in an immense block of alluvium, composed of strata of coarse and of fine material, that had Katon— Vertebrate Remains in the Cuzco Gravels. 18 slipped bodily down the face of the cliff from a height of about 30 feet, without being overturned or entirely disin- tegrated. The block of alluvium is shown in fig. 6, the hand Fiae. 6. Fic. 6. Location of a grave in a fallen block of alluvium. Southwest cliff of Ayahuayceco Quebrada. The man’s hand marks the position of the grave. of the man in the view marking the place where the bones lay buried in a stratum of fine material. Most of the bones excavated at this place were fragmentary and in a poor state of 14. Haton— Vertebrate Remains in the Cuzco Gravels. preservation. Portions of six human femora were obtained— showing that no less than three individuals had been buried together. A fragmentary skull was found impaled on the distal end of a femur, the base of the skull being fractured so as to admit the end of the long bone within the brain-chamber. This may have resulted from the compression of the alluvium by the landslip, if the body represented by these two bones was interred in the conventional sitting position with raised knees. Among the other human skeletal parts found here were the left parietal of a second skull, a few crumbling ver- tebree, a pair of innominate bones (male), four tibia, three fibulee, and several podials. Besides the human remains and a few llama bones, the grave contained the upper portions of a horse’s tibia and radius. As these equine bones were associated with human remains in the same way that bones of llama and ox were, in the grave exvavated in 1911, and that llama bones alone were in many graves in other parts of the Inca empire, there can be little donbt that they, or more cor- rectly the flesh attached to them, were also intended to serve asa provision for the supposed needs of the dead. Whether such a use of horse-flesh fully satisfied the local conventions regard- ing human burial, remains a matter of surmise. Ruined. graves were found in two other places in the walls of the quebrada. Their contents were extremely meager, and beyond adding to the total number of graves observed, they were of no special interest. Local traditions, in Peru, are not always reliable, but the meaning of the name Ayahuayeco “valley of the dead ’’—and the tradition, recorded by Professor Bingham,* that it was once used as a burial place for plague victims, seem very appropriate. ; Near the lower end of the quebrada three more middens were observed. Two of them were still being built up with the unsightly debris of the neighboring part of the city. The third was on the right bank near the stone water-tank. Over- lain by the gravel wash of the stream, or of the adjacent slope, it had an appearance of pseudo-antiquity; but after a brief examination, bones of domestic animals of European origin were found in the lower part of the deposit, showing that although this midden may be considerably older than the two others, it belongs to the modern city, and does not date from pre-Hispanic times. Where the middens of the early Inca city are located, and what interesting relics they may contain, are problems that will perhaps not be solved until the government permits extensive work of excavation in the public plazas, and the owners of modern houses, built upon ancient ruins, are persuaded to take a livelier interest in Peruvian archeology than they do at the present time. * This Journal, 1. c., p. 3802. H. E. Gregory—Gravels at Cuzco. 15 Art. Il.—Zhe Gravels at Cuzco, Peru; by Herzert E. GREGORY.” Introduction.—A prominent feature of the Cuzco Valley is a fringe of unconsolidated deposits exhibited as walls or dis- sected slopes. With the exception of a superficial cover of recent sediments these border forms are the remnants of pied- mont alluvial deposits which date from a time when waste prepared through a long period of local disintegration was stripped from the highlands and earried to the central valley below. The bulk of these deposits is assigned to the late Pleistocene on the basis of the interlocking relations which the gravels flanking the lower slopes sustain to the slightly modified glacial drift now occupying the valley heads. The most extensive of these Pleistocene fluvial deposits and those best exposed for study are the fans which mark the mouths of nearly all valleys, even minor ravines and wet- weather channels, which enter the Cuzco basin. Two of these fans, San Geronimo and Cuzco, the former actively aggrading, the latter in a stage of rapid disintegration, are conspicuous among the gravel accumulations of the Cuzco Valley, and are somewhat unusual, both in extent and in thickness, as border features of a valley of such limited dimensions. The Cuzco fan, while presenting no essential features which differentiate it from other examples of its class, is deemed worthy of somewhat extended description in view of twofacts: (1) the city of Cuzco is built on the outer dissected fringe and the terminal bluffs of the fan—a city which probably “marks the site of one of the earliest permanent human settlements on the South American continent. (2) Because these gravels have yielded implements, pottery, the bones of lower animals, and human bones, which on the basis of a preliminary exam- ination were tentatively assumed to date from glacial times.t Topography.—tIn superficial extent the Cuzco gravels are arranged as a wide-open V or triangle whose apex extends to the divide separating the Anta and the Cuzco basins and whose base forms a curved line reaching from the Chunchullumayo Quebrada, where it merges with a second fan, to the lime- stone bluffs one mile due north of the railroad station. (See map, fig. 2.) -In topographic expression it consists of two parts: the lower portion on which the city is built is bounded on the north and northwest by steep-faced ‘bluffs ; on the south and west it grades imperceptibly into the main valley floor. * Geologist of the Peruvian Expedition, 1912. + Bingham : The Discovery of Prehistoric Human Remains near Cuzco, Peru ; and Bowman: The Geologic Relations of the Cuzco Remains. This Journal, vol. xxxili, pp. 297-325, 1912. ‘uRysulg weary Aq ydeisojoyg “punoisetoj 4J0] OY} UL YouorTy poyjem-deeys oy} serdnooo iddvg o1y ey} : eperqend oookenyreAy oy} SI punoasseroj 4YS1I ey} UI AvTVA OY, ‘“Speavrs ooznH ey} Jo uoyazod e Jo Aydeasodoy sovjans ey} SuTMOYsS Koqyea oozZnY) ey} Jo uotyz0d azeddn 04} Jo MeIA ‘TT ‘DIT TDL = Fic. 2. 1 MILE 2000 3000 4000 FEET 1000 1000 S500 fo) | KILOMETER 500 METERS 2 ditions of 1911 and 1912. also areas of bed rock (heavy Von, XXXVI, No. 211.—Juty, 1913. ), g present distribution (light shad- tad) aos om = p4 ou ml m2 & -~ O°en Bos & Cee a) eS a ao Dd oo Bee BOS Oe eS mens SHB BO 4 Od op 26 §, SIS a a mn Nos Sep pie Ey Ep 8 era “a M Am. JouR. Sc1.—FourtH SERIES 18 H. EF. Gregory—Gravels at Cuzco. Its slope is 200’ per mile and its surface is diversified by flat- tened hills much reduced by grading, valley filling, and canal- ization of streams, processes which have been going on since Inca days. The upper portion of the fan (fig. 1) is a nearly level plateau, deeply trenched by the Ayahuaycco Quebrada,* and by gravel-walled canyons tributary to the Hnatanay.t The Ayahuayeco ravine reaches a depth exceeding 140’. Its northeast wall, cut entirely in gravels and sands, presents slopes of 20° to 60° which increase to 60° to 80° at the base (see fig. 1, p- 6; fig. 6, p. 13); its southwest wall is of gentler slope, and consists in part of bed rock. ‘The five western tributaries of the Huatanay are sharply cut gravel canyons ending in box heads, —the southernmost one, leading to a flat 240’ above the river, is confined between banks with an average slope of 70°, and at one point presents a vertical wall 110’ high. In fact at certain points in these canyons the walls are undercut ten to fifteen feet without, however, interfering with the stability of the compact gravel mass. Such canyon faces, built entirely of coarse unconsolidated sediments, are made possible by the dis- tribution of calcareous cement among the finer constituents, and by exceptional conditions controlling ground water circu- ation. To reach the upper gravel flats from the city requires an ascent of 400’. Throughout the entire area covered by the fan gravels, rock is exposed only in the bed of the Huatanay and at a few places in the Ayahuaycco and its tributaries. (See map, fig. 2.) Structure.—Speaking broadly, the Cuzco fan is built of thick, widespread deposits of gravel within which are included lenses of fine sand. Most of the gravels are very coarse, ap- proximately one-half of their bulk consisting of pebbles exceed- ing an inch in diameter. Stratification in the gravels is nowhere well developed, but may be detected in large exposures by the relatively high per cent of flattened pebbles which tend to assume horizontal positions. However, many portions of the quebrada walls 1000-2000 square feet in area appear equally well stratified vertically and horizontally and a photograph of such banks reveals essentially the same structure regardless of the position from which it is viewed. (See p. 1, fig. 6.) In fact the difference between the unmodified fan deposits composed exclusively of gravel and the slides, artificial gravel heaps, or the bowldery floor of the present torrential streams is to be detected only by the closest scrutiny. In brief a large part of the materials of the fan constitute a heap of unassorted * Quebrada is a Spanish-American term applied to narrow steep-walled water courses regardless of dimensions. As used locally the term includes both arroyos and canyon. Ayahuaycco signifies, ‘‘Valley of the Dead.” +The Huatanay consists of the Rio Sappi and its affluents. H. &. Gregory—Gravels at Cuzco. 19 Fic. 3. Fig. 4. a b c ad a, 14 ft., horizontally bedded sand with a, soil and debris. slight cross-bedding. b, 4ft., adobe with lenses and stringers b, 4ft., gravel and sand interbedded. of gravel. c, 44 ft., fine sand cemented. c, 10 ft., coarse gravel with masses of d, 1% ft., gravel and sand interbedded. adobe. : e, fine sand cemented. d, 4 ft., sand with thin-gravel beds in Jj, sand with stringers of gravel. upper part. g, coarse gravel. h, 5ft., sand with two clay lenses. Fie. 3. Section Il, west bank of Ayahuaycco Quebrada at mouth of canyon portion of valley. DipS. W. Z 2°. Fie. 4. Section li], Ayahuaycco Quebrada, 200 feet from mouth. Note absence of gradation between strata. Bowlders six to eight inches in diam- eter rest directly upon the smoothed surface of adobe. Gravels traverse adobe masses vertically and horizontally. 20 HT, BE. Gregory—Gravels at Cuzco. bowlders of various sizes between which finer materials have been irregularly deposited. The sand beds consist of fine well- washed quartz grains which in places are bound together by films of calcareous mud. Through the body of the fan the sand is displayed as lenses rarely exceeding 2’ in thickness, and usually dying out laterally within a distance of 100’. The largest bed observed is six feet in thickness and extends for about 225’. Near the upper surface of the fan the sand lenses are more abundant and have a somewhat wider extent; at one point constituting nearly 1/5 of the material exposed. At the outer edge of the fan where its deposits interleave with silts and calcareous muds of an ancient water body, sands and adobe assume the leading role, the gravels playing a minor part. There is here also a much more frequent alternation of beds and a much greater change in short horizontal distances. The stratified phases of the Cuzco gravels Fig. 5. slope in general southward at various degrees of inclination. At the mouth of the canyon _ portion of the Ayahuaycco the well-stratified beds of sand included within the gravel mass ‘| dip south at an angle of 38°-5°. At the edge $71 of the bluffs facing the city and on the slope northwest of Santa Ana church dips of 8°-10° south were measured, while the strata (aV.G2| which cap the deposits along the Anta road Ss een are practically horizontal. Oross-bedding otk Sioee though present is not a conspicuous feature, g.9. Section 3 ee IV, Detail of gravel doubtless being obscured by the prevailing shown in section IIT; unstratified condition of the gravels, but size and orientation eyt and fill channels trending in various of pebbles drawn to ; 5 : aie: directions are revealed in nearly every sec- tion. The accompanying sections (sec. I and figs. 8-9) illustrate the structure and arrangement of beds in selected portions of the delta. Section I. Mouth of Ayahuaycco Quebrada. Dip 4° south. Feet 1. Soil, red-brown, sandy, with bands of brown adobe, streaked with calcareous bands and penetrated by root. tubes:.2. 22st Lo eee ee 10 2. Gravel, composed of subangular pebbles 1 to 6 inches in diameter, of brown and grey sandstone, rarely limestone; ; par tially cemented by calcareous films. Bottom. rests unconformably on the channeled surface of No.3) 222.204 eee + Hf, EF. Gregory—Gravels at Cuzco. 21 Feet 3. Sand, coarse, mingled with clay-adobe, firmly cemented with lime; dull yellow on weathered surfaces, brown and white beneath 9.52.2. 2.1240 5) 22. 3 4, Gravel, composed of flattened subangular pebbles of grey and brown sandstone, 1 to 6 inches in length. Many pebbles partially decomposed. Contains mresular lenses Of Coatse sand. 2.2252 52-. 22. 5 For Sections II- VIII see accompanying figures. Fie. 6. ne ie a, 15 ft., very coarse gravel. b, 1 ft., fine sand, stratified. c, 50 ft., very coarse gravel, massive. a, 30 ft., coarse gravel, with lenses of sand. b, 120 ft., coarse gravel, massive. Fie. 6. Section V, North bank of Rio Sappi at mouth of tributary descend- ing from the Cuzco-Anta divide, Fic. 7. Section VI, Bank of tributary to Rio Sappi, descending from the Cuzco-Anta divide. Composition. Source of Material. The highlands which contributed material to the Cuzco fan consist, on the northeast, of grey-blue limestone through which protrude small knobs of greenish igneous rock (altered diabase) 22 H. E. Gregory—Gravels at Cuzco. along the Huatanay and on the Anta divide. The contributary area on the west and northwest is underlaid by brown and gre: sandstone, chiefly the former. Sandstone furnished the bulk of the material, and in the Ayahuaycco Quebrada fully 95 per cent of the pebbles have this origin, igneous pebbles being nearly absent. Along the Huatanay tributaries the sandstone is still dominant, but limestone makes up about 10 per cent and diabase 3 per cent to 5 per cent. Bowlders of limestone exceeding 5 feet in diameter are found in this area. The rel- ative scarcity of large bowlders of sandstone appears to be due to the fact that closely spaced intersecting joint-planes break up this rock into cubes of a few inches on a side. That brown sandstone should rank first as the source of material is due (1) to the more precipitous slopes on the west border of the fan ; (2) to the more abundant fragmental waste resulting from the weathering of sandstone as compared with limestone ; (3) to the fact that those portions of the fan where limestone and diabase bowlders were formerly most abundant (e. 2., along the Hua- tanay river) have been most completely removed by stream erosion. It was noticed that limestone fragments are more abundant in the topmost beds of the fan—a natural consequence of the fact that the limestone occupied southern slopes and was more or less protected by a cover of snow and ice during the early part of the period of excessive aggradation. So far as observed, coarse, sandstone gravel forms the layer immediately in contact with bed rock. Three types of material are represented in the fan: gravel, coarse to very coarse; sand, fine, compact; and adobe. The structure and composition of the gravel and sand have been dis- cussed. Brown adobe occupies about an acre on the west bank of the Ayahuaycco Quebrada, where it attains a thickness of thirty feet and includes three bands of white lime silt. The material lies in horizontal beds, is impalpably fine but firm and compact. The adobe and associated beds are alike highly eal- careous and are traversed by vertical root tubes encrusted with lime. This deposit, as well as the less extensive accumulations near Santa Ana church and at the mouth of the Ayahuayceo, differ inno essential from the beds of adobe and unconsolidated limestone abundantly displayed in the Cuzco Valley beyond the border of the fan. ‘They are believed to represent the shores of ephemeral lakes which existed contemporaneously with the gravel-bearing streams. Age of Deposits. As previously stated, the Cuzco gravels are believed to have reached their greatest extent and thickness in late Pleistocene times. More recent deposits have, however, been superposed. HH, E. Gregory—Gravels at Cuzco. 23 Bie. 8. Fic. 9. a 6 ec U a ah u = Ne ae e es Eee, : yy is eoeeesss wu St ad U g U h t a, 2 ft., soil and adobe. b, 2 ft., fine shell limestone. ec, 5 ft., gravel, coarse and fine, hori- a, 40 ft., gravel, massive. zontal. _ ; 6, 4ft., fine sand. d, 6 ft., massive adobe, with lenses ce, 7 ft., gravel, massive. of gravel. : d, 6 feet, compact clay adobe. e, 4ft., fine sand with gravel patches. e. 20 ft., coarse gravel, massive. f, 10 ft., adobe with thin lenses of gravel. g, 2 ft., compact adobe. A, 2 ft., fine sand and clay. i, 3 ft., adobe with thin band of shell limestone. u, unconformity. wu, uncontormity. Fic. 8.—Sec. VII, Bank of unnamed tributary to Rio Sappi opposite the Rodadero. Fie. 9.—Section VIII, Bank of the Chunchullumayo, near junction with Rio Huatanay. Surface wash from the bordering slopes, controlled in amount and character by climatic changes, has probably been accumu- lating continuously since glacial times, and has greatly increased since human occupation began. Soil wash resting unconform- ably on the surface of the fan may be observed at favorable localities. On the lower sandstone slopes bordering the Cuzco 2+ — ALE. Gregory— Gravels at Cuzco. fan, where the fields may have been cultivated for five or six centuries, soil wash and associated deposits have accumulated to depths of ten to twenty feet at the base of the slopes. A section exposed on the bank of the Ayahuayeco Quebrada pre- sents the following order of stratification : Recent deposits northwest bank of Ayahuaycco Quebrada. Feet 1. Wash from hill slope and cultivated field, red-brown in tone, composed of sand and clay with inclosed rock pebbles and earth clods __.._..-. =. 22232 2 Ash, cross-bedded in layers 1/4 to 1 inch, composed of alternating bands of black charcoal, burnt grass, etc., and grey wood ashes. Fragments of bones, teeth, also of ancient pottery, are abundant. Near the base pebbles of sandstone and thin bands of sand are found __.../22-2:-..) (32 eee 10 3. Gravel, rudely stratified, composed of pebbles one to four inches in diameter; also scattered bones and iS) sherds 22...05.0 ¢22.02. 2.5 eS 8 4, Sandstone ledge, on top of which lie two large lime- stone bowlders not of local origin -.--.--.------ 4 The thickness of cover over deposits of ashes varies from one to eight feet within a distance of 300 feet along the Ayahu- ayeco Quebrada. The thickness and position of deposits of human origin is likewise variable. The recent date of the wood ash and overlying strata is plainly shown by the pres- ence of sherds and of bones of modern types and by a compari- sion of the ash shown in section along the quebrada with that exposed in a bank 300 feet further east. In structure and composition the two are essentially alike, although one is the present city dump and the other is definitely interbedded with gravels and soil wash. An even more striking illustration of ageradation is the presence along the lower Ayahuaycco of a wall of Incaic or pre-Incaic design which had been buried by four to eight feet of gravel, partly stream-laid, partly washed from the slopes. This buried wall was exposed (about 1870) in cutting an artificial channel for the wet-weather stream which drains the quebrada. The original wall, resting on what is believed to be an eroded portion of the fan, is com- posed of hewn limestone blocks of excellent workmanship and has been continued upward by a poorly constructed retaining wall of stone and adobe which serves as a border for the fields below.* Similar buried walls were noted at other localities, * For further details regarding this wall see Bowman: ‘‘ A Buried Wall at Cuzco and its Relation to the Question of a pre-Inca Race,” this Journal, vol. xxxiv, pp. 497-509, 1912. Bowman concludes that the burial of this wall may date from 2000 B. C. to 4000 B. C. Although such antiquity is possible, yet the geological conditions are satisfied on the basis of a much shorter period of time. H. E. Gregory—Gravels at Cuzco. 25 and at a point south of San Sebastian such a wall buried beneath the soil of a cultivated field is exposed in the valley of the Huatanay, where it stands plastered against the bank of Figs LO: Fie. 10. Buried wall exposed in the bank of the Rio Huatanay. the stream, twenty feet above the bed, like an ornamental border on wall paper (fig. 10). This wall, probably built to protect the fields from the summer overflow of the Huatanay, 26 Hl. EF. Gregory —Gravels at Cuzco. has remained in place, while the canalized stream has entrenched itself in the sands and gravel bordering the Cuzco basin. Ground Water.—A large proportion of the water which falls on the surface of the Cuzco fan is rapidly absorbed, and percolating downward through the porous gravels to a depth of 100 to 400 feet, emerges as springs along water courses and on the periphery of the fan. Springs are numerous in the lower part of Cuzco, and many open wells within the city reveal permanent supplies at a depth of fifteen to twenty-five feet. On the northeast border of the fan the direction of ground-water flow is southwest, following the rock slope beneath a thin superficial cover; on the west border, where similar relations exist, the flow is east. The high content of lime in well and spring waters is due to the presence of tiny fragments of limestone widely disseminated through the gravels in quantities sufficient to furnish calcareous cement for the par- tial consolidation of portions of the mass. One result of ground-water action, which has also an archeological bearing, is the presence of numerous small caves and pockets and shelves in the steeply inclined gravel walls,—cavities which mark the position of ephemeral seeps and areas of less consolidated material. The floor of these caves is covered with stratified sands and they appear to have been used extensively as sepulchres. Landslides and creeps resulting from the action of ground water may be observed at numerous places along the ravines which trench the Cuzco gravels, where the conditions for their formation are exceptionally favorable. The alluvium rests on steep rock surfaces, coarse gravels overlie lenses of fine sand and adobe, the water courses follow deep, narrow canyons, cut in unconsolidated deposits, the amount ot ground water is relatively large, and markedly fluctuating in response to peri- odic showers. Foliowing an ordinary storm accompanied by a heavy downpour, the writer observed six small slides and numerous seeps along the Chunchullomayo in positions where vertical, dry gravel walls had been noted on previous days. In the heavier gravel masses trenched by gravel-walled canyons the effect of slidesis chiefly to give the valleys an unsymmetri- cal shape with the steeper wall on the side toward which ground water flows. In valleys where one bank is gravel and the other gravel underlaid by rock, the lack of symmetry is” very pronounced,—a perpendicular wall of gravel facing a moderate slope of gravel, decomposed rock and miscellaneous slide debris. Slides, mostly of small or of moderate dimen- sions, are conspicuous along the Sappi and the Ayahuayeco where they extend to the stream bed or remain as plasters attached to the walls. The southwest bank of the canyon por tion of the latter stream is almost continuously faced with ——. H. EF. Gregory—Gravels at Cuzco. yi slides like an artificial revetment. The northeast wall is marked by two slides, one immediately above and one immedi- ately below the locality from which bones were excavated by the expedition of 1911. Moreover this wall is capped by a sloping terrace with an escarpment at its inner face, indicating that a mass of gravel 30300150 feet has slid downward ten feet toward the valley axis. An examination of old slides as well as of those which have occurred within the last few years shows that except where decomposed rock forms the slipping plane there is no clean break between the gravel in place and the transported portion or between different portions of the slide material itself. Where sand or adobe lenses have been involved it is easy to determine both the fact and the amount of displacement, but in the massive gravel where evi- dence of stratification is absent, it is impossible to determine with assurance which is slide and which is original bank, espe- cially after the low top escarpment has been obliterated by further sliding and soil creep. ‘Iwo artificial trenches were cut into gravels across a plane, which on independent evidence is known to mark the contact of slide gravel with the original valley wall. In these cases neither the orientation of pebbles, nor a ragged contact, nor open spaces, nor effects of ground water gave evidences of displacement. A tunnel eleven feet long and with a cross section 443 feet was sunk into the steep gravel wall of the Ayahuayeco Quebrada at the exact point from which human bones were taken by the members of the Peruvian Expedition of 1911. The section exposed is entirely gravel, consisting of pebbles of brown sandstone (90 per cent), gray sandstone (9 per cent), hmestone and igneous fragments (1 per cent), ranging in size from one-half inch to four, rarely six inches, and so firmly packed that no timbering of the tunnel was required. The material is uniform in tex- ture, contains no bands or lenses of sand, no division planes, or other unmistakable evidences of stratification. Even the peb- bles are variously oriented and about a third of them, includ- ing many thin, flat slabs, slope at angles between 60° and 90° to a horizontal surface. The relation of landslides to the gravels in which human bones were found by the Expedition of 1911 is discussed by Doctor Eaton (see p. 5) and need not be fur- ther considered here. In certain of the slides the gravel pebbles appear to have moved differentially among themselves, to have assumed an angle of repose by internal readjustment, somewhat analogous to the movement of particles involved in glacier motion. It would therefore appear impracticable to determine the position and dimensions of landslides and slumps in the unassorted portions of the Cuzco gravels. Evidence of dis- placement indicates the presence of landslides, but unfortu nately the absence of such evidence does not prove the absence of landslides or “ creep” at any given point. 28 HI. EF. Gregory—Gravels at Cuzco. The lower Ayahuayeco Quebrada furnishes evidence of the manner in which slides modify valley form and aid in the burial of extraneous matter. The stream has occupied this portion of its valley since about 1870, when an artificial read- justment of drainage was effected. During these forty years the stream has cut a ravine twenty to thirty feet deep and about twenty feet wide. Three slides are visible within one hundred feet. The one nearest the stream’s mouth covers about twenty square feet and is pasted against the vertical wall as a patch two feet thick. In this case stratification is well marked, but the break is so completely healed that, without the discordance in bedding, the displacement could not be detected. The second slide blocked the stream, which, rising to the crest of the dam, cut downward and formed a new floor. Later trenching developed a terrace 12 x 20 feet, the edges of which reveal material identical with the gravel in the original bank. The material of the slide, the material deposited by the stream, the material fallen on the terrace, and the material of the standing wall are indistinguishable in structure, texture and composition. The fact of the slide is demonstrated by a broken lense of sand revealed by an artificial trench. From the gravels of the slide midway between top and bottom were excavated two pieces of imported pottery, relics carried by the stream or fallen from the top of the bank. A deeper cutting of the channel, accompanied by smoothing of the slope, would have left those fragments of household furniture firmly embedded in a wall of gravel beneath twenty feet of sediment, all so like the gravel of the original fan as not to be differenti- ated with certainty. It seems reasonable to suppose that much greater thicknesses of sediment forming much higher banks of gravel may have passed through similar stages. Erosional History.—The present position and structure of the Cuzco gravels and the general physiographic relations of the area suggest the outline of the original deposits as indi- cated on the map (fig. 2). The dissection of the fan probably began with the establishment of permanent drainage in the Sappi, whose relatively large watershed and its fall of about 400 feet per mile gave it considerable erosive power over the gravels marking its path. Coincident with the cutting of the Sappi canyon, but at a slower pace, its tributaries were cut and the front of the fan was developed into cliffs by headward erosion of short, steep, wet-weather streams assisted by ground- water activities. The Ayahuaycco probably originated as a line of drainage at the western edge of the fan and worked progressively north and east, following the rock slope down- ward and maintaining, approximately, the present relation of one bank on or near rock and the other bank cut in gravel. That the dissection of the Pleistocene and recent gravels has H, EB. Gregory—Gravels at Cuzco. 29 not been progressively continuous, is shown by the terraces along the upper Huatanay (Sappi) and still more plainly by the well-developed terraces, two to five in number, flanking the streams entering the Cuzco valley beyond the limits of the fan. No well-marked terraces persist in the upper Ayahuaycco Quebrada, a location unfavorable for their preservation. The canyon is narrow, the banks are of gravel or of gravel on rock, and the stream is fed by wet-weather torrential tributaries with gradients of over 1500 feet per mile. Here, as along other streams entering the Cuzco valley, terraces may have been buried and re-excavated many times in response to minor climatic fluctuations during historic as well as prehistoric times, the evidence for which is conclusive. It is unprofitable, from a geological standpoint, to work out the details of ero- sional history in and about Cuzco, because of the extensive moditication of slopes and terraces resulting from cultivation and flood-water irrigation. However, the evidence indicating periodic destruction and building of terraces, even within the past one hundred years, removes the necessity of ascribing great antiquity to animal bones, parts of human skeletons, and fragments of pottery found along stream banks and which may have been deposited on terraces or on banks, or in the numer- ous sinall cave-like openings in the gravels, to be transported, buried, or reéxposed during alternating processes of deposition and degradation. It is interesting to note that in the canyoned tributaries of the Sappi and of streams leading from the lime- stone plateau and from the sandstone highlands bordering the Cuzco basin on the south,—valleys from which terraces and slides have been removed and whose banks offered no tempta- tion to occupation, valleys whose present precipitous gravel walls are clearly of glacial age,—no traces of human occupa- tion were revealed by careful search. From these same gravels, however, mastodon bones have been collected, on the Huanearo and in the lower Cuzco valley. The fact that these bones from the Ayahuaycco gravels are of modern types (see article by Eaton, p. 5) obviously corroborates this view of depositional history, and also indicates important climatic changes since the Spanish conquest. Tt will be noted that the explanations civen in this paper are chiefly of negative value so far as archeological research is concerned. That man existed in South America in glacial or preglacial times, and that the human. bones discovered in the Ayahuayceco Quebrada “appear to be from 20,000 to 40,000 years old” as tentatively held by Bowman,* is not definitely disproven by the field studies of the present writer. On the other hand, the geologic data do not require more than a few hundreds of years as the age of the human remains found in the Cuzco gravels. * This Journal, vol. xxxiii, p. 221, 1912. 30 A. A. Phillips—Symmetry of Crystals. Art. 1V.—A Simple Model for Illustrating the Symmetry of Crystals ; by ALEXANDER H. Puixures. For several years past I have been using in my class work a model, of very simple construction, to illustrate the symmetry of the various types of crystals. It has been very helpful and HMivel,, 1 most effective in simplifying some of the points in crystallog- raphy, which have always seemed most dithcult for the ordi- nary student to grasp without a demonstration. The model as shown in the figure is constructed of a horizon- tal disk of tin, representing the plane of the lateral axes or the equator, in the equatorial types. At right angles to this disk and at right angles to each other are two semicircular disks ; these three planes divide space in the northern hemisphere into the usual four quadrants, as in those systems in which the axes are at right angles and represent the axial or diametral planes, the intersections of which will represent the axes a:b;c. At the center of the model a socket is cut in the A. H. Phillips—Symmetry of Crystals. 31 stand and holes in the disks, large enough to allow easy motion to a lead ball, of an inch and a half in diameter, which forms a universal joint; into this lead sphere a knitting needle of proper size is set in the direction of the radius and upon the end a small card, P, is placed which represents the position and inclination of the crystal face under consideration. The lead ball bemg so much heavier than the needle, the pole may be placed in any position whatever within the quadrant and remain stationary. At b, the vertical disk is not soldered to the equatorial disk, but a slot is cut wide enough to allow the pole to pass to the right back quadrant. The pole thus, in the prism zone, has a range of 180 degrees and any face in this zone may be repre- sented by the pole. There is a similar slot at ec, which allows the pole to pass from the right to the left front quadrants, allowing a range of 180 degrees in each dome zone. The only quadrant not accessible to the pole is the back left. The right front quadrant is lined with mirrors, which represent planes of symmetry ; by placing the pole in the required position any erystal face is represented, and if wished, a card may be cut and placed in the mirrors, when the exact shape of the form will be reflected. The model in the figure represents the holo- hedral orthorhombic class ; with the pole in any position within the quadrant, not in contact with a mirror, will represent a pyramid, as the eight reflected poles may be counted, represent- ing the eight possible faces of the form. When the pole is moved in contact with one of the mirrors (the lead ball should be placed a little eccentric in favor of the octant in which the mirrors are placed to permit of this), it will be seen that two poles will be in contact, indicating that two faces of the most general form, the pyramid, will coincide, yielding a form of four faces, a dome or prism, according to the position of the ole. When the pole is placed in any one of the three angles of the octant, it will be seen that four of the eight poles of the pyramid coincide forming the pinacoids of two faces, which are also shown as fixed in forms, as there is but one position for the pole in the angle. For the tetragonal system an intermediate mirror may be placed at 45 degrees to the one containing the crystallograph- ical axes; the ditetragonal pyramid will be reflected by the mirrors, when a ecard is placed between them, as in the figure, and 16 poles may be counted. For the hexagonal sys- tem the intermediate mirror is placed at 30 degrees, when 24 reflections may be counted. For the isometric system three pieces of tin are cut and soldered at their intersection, the tri- gonal axis of the system, so as to divide the octant symmetri- 32 A. H. Phillips—Symmetry of Crystals. cally into eight similar triangles, representing the six diagonal planes of symmetry of the system, three of which are repre- sented in an octant. If when this set of three planes is placed in the octant, one of the six triangular spaces is lined with mirrors and the pole placed within it, 48 reflections may be counted or the hexoctahedron is illustrated. The remaining six forms may be represented by placing the pole in the six possible positions, the three sides and the three angles of the triangle. If desired, the disks may be graduated and marked off in degrees, when any particular dome or prism may be illustrated. The model is also most convenient for illustrating the method of the two-circle goniometer, as the equatorial disk represents the vertical circle of the instrument and the vertical disk of the model the meridian of reference. The relation. of the two angles measured on the instrument, to the pole of the face, is simply shown in the model, as one corresponds to the longitude and the other to the complement of the latitude. In the gnomonie projection the plane of projection would be tangent to the two vertical disks of the model at c, and the intersections of these two disks with this plane would be the lines along which the two angular codrdinates x and y of any face is measured; the face being represented by the point of intersection of the pole with this tangent plane. The trig- onometrical relations of the coordinates « and y, the point representing the face and the two angles measured on the goniometer, cannot be more simply demonstrated than by this model. Princeton University, May 3, 1913. — oo : Smyth, Jr.— Composition of the Alkaline Locks. 33 Arr. V.—The Chemical Composition of the Alkaline Rocks and its Significance as to their Origin, by C. H.Smytu, JR. As the alkaline rocks constitute one of two closely related groups which, taken together, comprise all igneous rocks, it is evident that any complete discussion of the question of their origin must involve a consideration of the origin of igneous rocks in general, leading, thus, to the largest problems of structural and dynamic geology, even including, in the last analysis, the origin and internal constitution of the earth. This being the case, it is safe to conclude that a final solution of the problem will be attained only by a long series of approxima- ‘tions. Recognizing this fact, and making no attempt at exhaustive treatment, the present discussion deals only with certain phases of the problem, accentuating relations whose significance appears to be greater than has been recognized in earlier contributions. The title of this paper, and of others dealing with the same problem, would seem to imply that, in spite of their broad relations, the alkaline rocks have something distinctive in their character which justifies their more or less independent con- | sideration ; and it need hardly be said that this appears in the facts that they are marked by comparative rarity and by certain peculiarities of chemical and mineralogical composition. The comparative rarity of the alkaline rocks, as contrasted with the subalkaline rocks, has been generally, though often tacitly, recognized by petrologists. Subalkaline rocks are taken as a matter of course, as the normal and expected thing, but every newly discovered occurrence of alkaline rocks is made the object of special study, as something out of the ordinary and of unusual interest. A more precise statement of this quantitative relation has recently been made by Daly,* who, after careful study of the question, concludes that the alkaline rocks make up less than one per cent of all igneous rocks. This is a fact of much importance in its bearing upon the origin of the alkaline rocks, and, as shown by Daly, points dis- tinetly to the conclusion, supported by many other hnes of ae that they are derivative in their nature, products of a special variation of the normal subalkaline magma. In other words, the earth’s crust is composed essentially of rocks which are pr ‘oducts of the normal differentiation of subalkaline magmas, and which constitute 99 per cent of the 95 per cent *R. A. Daly: The Origin of Alkaline Rocks, Bull. Geol. Soc. Am., xxi, pp. 87-118, 1910. Am. Jour. Scl.—FourtTH SERIES, VoL. XXXVI, No. 211.—Juty, 1918. 3 34. = =Smyth, Jr.—Composition of the Alkaline Rocks of igneous rocks of which Clarke* estimates the lithosphere to consist. The remaining igneous rocks, amounting to only one per cent, are derived from the same magmas, but are products of some ‘exceptional conditions of differentiation, which find their expression in the peculiar chemical and mineralogical composition of the resultant alkaline rocks. These relations may, perhaps, be made clearer, so far as the major constituents of rocks are concerned, by a com- parison of the composition of igneous rocks in general with that of alkaline rocks. The mean composition of igneous rocks has been estimated by averaging the results of large numbers of analyses, and, on the basis of somewhat different data, Clarke, Harker Pid Washington have arrived at the results given below, in I, II and III, the figures in each case being recalculated, by Clarke, to one hundred per cent, on a water free basis. I II III IV V S10, Cait ck 61°82 60°76 58°96 59°19 62°46 TiO, fa Na SEN 278) 75) 3) 1-05 2 Ol "06: AT OL. ia chit 15°51 15°87 15-99 16°51 18-07 Fe,0, -- Ds he eee 2°67 4°99 eid Bt 2°24 BRe@ 2a pees 3°45 2°78 3°93 4:17 2°31 MnOi. os aes epee Ss hk eee =i ‘08 MeO: 4:02 3°82 3°87 3°93 “97 CaO tae ns 4°96 4°97 5°28 6°47 patra NaLO cee encr ae 3°51 3°28 3°96 3°39 5°58 K,O Serie hoe aka 2 3°04 2°55 3°20 Pps Wy? ay yd PIO Ae ere 2 29 37 26 14 —>_—— _— — 100°00 100°00 100°00 100°00 L00°00 I Average Igneous Rock, Clarke, F. W., Data of Geochemis- try, Bull. 491, U. 8. Geol. Survey, p. 25, 1911. II Average Igneous Rock, Harker, A., Tertiary Igneous Rocks of the Isle of Skye, Mem. Geol. Survey United Kingdom, p. 416, 1904. III Average Igneous Rock, Washington, H. §8., Chemical Analyses of Igneous Rocks, Prof. Paper, U.S. Geol. Sur- vey, No. 14, p. 106, 1903. IV Average Composition of 89 Diorites, Daly, R. A., Average Chemical Composition of Igneous Rock Types, Proc. Am. Acad. Arts and Sci., xiv, p. 238, 1910. V_ Average Composition of 23 Alkaline Syenites, Daly, RAs; Op. cit.; p220: The agreement of these estimates is sufficiently close to war- rant the conclusion that they must afford a fair approximation * Clarke, F. W.: The Data of Geochemistry, Bull. 491, U. S. Geol. Survey, PD. OlaouL: q 7 | and its Significance as to their Origin. 35 to the truth, while the nature of the data used by Clarke is such as to inspire particular confidence in his results. The figures of I, then, may be taken as representing the mean composition of the j igneous rocks, or the average magma, including not only the abundant subalkaline rocks, but the less common alkaline rocks. Indeed, since the latter, as stated above, always receive special attention, it is probable that a disproportionately large number of their analyses are used in making up the average, thus tending to bring the results slightly closer than they should be to the average for alkaline rocks. But whether or not this is so, it is evident that the mean composition, as given, is distinctly subalkaline in charac- ter, as is clearly shown by comparison with Daly’s average of the composition of eighty-nine diorites, given in IV, and representing a typical subalkaline magma, slightly less siliceous than the average rock, and with corresponding differences in other respects, ‘but, on the whole, showing fairly close agree- ment with I. On the other hand, the same writer’s average of twenty- three alkaline syenites, given in V, while having nearly the same silica content as the average rock, differs from it markedly in other respects, particularly in having higher alumina, lower magnesia and lime and much higher alkalies, features generally characteristic of alkaline rocks. In view of the fact, stated above, that the alkaline rocks are included in the gener al mean, it is clear that, if the figures of V are at all typical, the alka- line rocks must exist in comparatively small qnantity, while it is equally clear that the average magma must be distinctly subalkaline. The latter magma is, obviously, of world-wide extent, while the former occurs in relatively limited amount, but at widely scattered poimts. Differing from the average rock only in the relative percentages of elements common to both, the alkaline rocks are to be regarded as derivatives of the subalkaline magma rather than as “something essentially dis- tN CH. In view of the small amounts of alkaline rocks, it is evi- dent that the moderate concentration in them of such abundant constituents as alumina and the alkalies would not materially affect the composition of the greatly preponderant average magma, while less abundant constituents may exist in the latter in such small quantities as to escape detection, and yet be markedly concentrated in the derivative alkaline frac- LOR): Quite different from this conception of the derivation of alkaline from subalkaline magmas is the view of Becke,* who suggests that the constituents of the two types of magma were * Becke, F.: Die Eruptivgebiete des bohm. Mittelgebirges und der amerik. Andes, Tschermak’s Min. und Petr. Mitt., xxii, p. 247, 1903. 36 Smyth, Jr.—Composition of the Alkaline Locks separated by gravity, during a gaseous stage of the earth, into an upper, subalkaline, and a lower, alkaline, layer which furnish the respective ‘types of rock, ‘as well as intermediate varieties due to mixing. Jensen* advances the hypothesis ‘that alkaline rocks are derived from . . . Archeean saline beds which, by chemical attacks on the adjacent sediments, have given rise to an alka- line magma in the process of metamorphosis. This magma has been squeezed laterally into continental areas and has undergone differentiation, or it has mixed with other magmas, chiefly basic. and then differentiated.” Daly,+ as previously stated, regards alkaline magmas as derived from subalkaline magmas, but finds the cause of differ- entiation in. the assimilation of limestone, both the carbon dioxide of the latter, and the lime, being active agents. ‘These agents he views as disturbing the chemical equilibrium of the magma, thus tending to differentiation and the resultant pro- duction of the alkaline rocks. Harkert differs from Daly in seeking the chief cause of the special differentiation that produces alkaline rocks in mechan- ical, rather than chemical, conditions and, noting an association of this “ branch” of rocks with the Atlantic type of structure, as defined by Suess, concludes that both are products of the same mechanical conditions. Thus, the hypotheses mentioned explain alkaline magmas as primordial or as due to melting of saline sediments, with some assimilation, to assimilation and consequent differentiation, or to differentiation caused by crustal disturbances. As already stated, the present writer considers the alkaline magmas to be der ived from the subalkaline magmas, as indicated not only by the relatively small amount and local occurrence of the former, but also by the association of the two types, the existence of intermediate varieties and the successive appear- ance of both in a givenregion. ‘This view is further supported by certain peculiarities of chemical composition of the alkaline rocks which, taken in conjunction with their small quantity, are thought to be very suggestive as to the agents and condi- tions of their origin. As their name implies, and as shown by the analyses given ~ above, the alkaline rocks are, as a rule, high in alkalies, par- ticularly sodium, but, for the present purpose, attention is directed, not to the dominant constituents, but rather to those * Jensen, H. I.: The Distribution, Origin and_ Relationships of Alkaline Rocks, Proc. Linn. Soc. N. 8. Wales, xxxiii, pp. 585-586, 1908. + Daly, R. A.: Origin of the Alkaline Rocks, Bull. Geol. Soc. Am. Pee este pp. 87-118, 1910. Harker, A.: The Natural History of Igneous Rocks, pp. 102 and 330 | et seq, 1909. TP -oelieel oe ake and its Significance as to their Origin. 37 which, thongh small in amount, are thought to possess a peculiar s significance. The data in regard to these minor chemical constituents of rocks have been summarized by Washington*® in an exceedingly interesting and suggestive paper. With reference to the rarer elements, he concludes that, in the alkaline rocks, there is a greater relative abundance of lithium, beryllium, cerium, yttrium, and other rare earth minerals, zirconium, uranium, thorium, sulphur as SO,, fluorine, chlorine, barium and perhaps tin. In the subalkaline rocks, on the other hand, there is a concentration of titanium, vanadium, manganese, ‘nickel and cobalt, chromiun, platinum metals and, possibly, phosphorus. A tabulation of W ashington’s somewhat more detailed state- ment, giving the elements concentrated in sodic, potassic, ferriferous, magnesian and calcic magmas, respectively, is as follows : Alkaline | Subalkaline Sodium Potassium Iron Magnesium Calcium Magmas Magmas Magmas Magmas Magmas Li Ba | Ti Cr Cr? Be . Va Pt Pe Ce | Mn Yt Ni Zr | Co Ur | Th | Se(asroO,) | * | B | Cl | Sn ? | The contrast between the two main sections of the table is striking. ‘The elements of the second section, those concen- trated in subalkaline magmas, are such as occur in ultrabasic segregations, nearly always in basic igneous rocks. On the other hand, the elements of the first section, those concentrated in alkaline. magmas, fall into two groups :—elements character- istic ot, and largely confined to, pegmatites, and “ mineral- 1zers.’ The frequent association of these two latter classes of elements In pegmatites is generally recognized as having a direct genetic * Washington, H. S.: The Distribution of the Elements in the Igneous Rocks, Trans. Am. Inst. M. E. , XXXix, pp. 730-764, 1909. 38 Smyth, Jr.— Composition of the Alkaline Rocks cause, the mineralizers being the active agents, which, through their ‘affinity for the rarer elements, with which they form mobile compounds, concentrate the latter in the magmatic extracts which furnish the materials for pegmatitic intrusions. As a result of this process, the rarer elements of a normal magma, which may originally have been so diffused through the mass as to be hardly perceptible, become concentrated in a comparatively small amount of magma, which, being tapped off separately, solidifies as a rock different in composition from that representing the original: magma, and characterized by the presence, in relatively large amounts, of the rare elements and mineralizers, although, as a rule, the latter are in large part dissipated. Indeed, but for this process, many of the rare elements would doubtless be unknown to us. Even with such a method of concentration in existence, radium, in spite of its striking properties, was discovered only through the exercise of extra- ordinary skill and patience; and there can be little doubt that_ there are other elements with such limited tendency toward natural concentration as to put their detection beyond our present means of accomplishment. Thus, there is a very general tendency in magmas toward the segregation of the rare elements and the mineralizers in a distinct part, usually erupted separately and always in much smaller quantity than the average magmas. The composition of the latter, moreover, is not perceptibly changed by the withdrawal of the rarer elements, since,-compared with the total mass, their quantity is entirely negligible. This, how- ever, is not necessarily true of the gaseous constituents, as they may have been present in considerable amount, and subse- quently dissipated. Between these phenomena and those presented by the alka- line and subalkaline rocks as a whole, the analogy is too strik- ing to be accidental, in spite of the great difference in order of magnitude. This difference of scale is such that no close asso- ciation, either in time or in space, can be expected in the case of the two groups of rocks, like that existing between pegma- tites and their associated rocks, but contemporaneous or successional association of the two branches, though less inti- mate, is practically universal; while the quantitative relation between the alkaline and subalkaline rocks on the one hand, and the pegmatites and their associated rocks, on the other, are analogous, just as are the chemical relations. With reference to the latter, it is true that definite analytical data, as to the quantities of the rarer elements mentioned above, are meager, but, so far as they exist, they justify the conclusion reached ; and substantiation is afforded by field relations, the rare ele- and its Significance as to their Origin. 39 ments occurring in pegmatites associated with alkaline rocks in whose parent magmas the elements in question must have occurred in a state of relative concentration as compared with their amounts in subalkaline magmas. Referring to cerium, yttrium, and other rare earth metals, together with thorium and uranium, Washington® says: “ Min- erals containing them are commonly associated with acid peg- matites, which, judging from occurrences in Norway, Green- land and elsewhere, are most apt to be sodic, though the few determinations available of the rare earths are in highly potassic igneous rocks.” Thus, while here, as elsewhere in the paper, Washington distinguishes between sodic and potassic magmas, he refers the elements in question to one of the two, or in other words, to alkaline magmas. He states that lithium favors the sodic rather than the potas- sic magma, while beryllium has similar associations. ‘ Few analyses exist of such beryl-bearing rocks and beryllia has seldom been estimated separately from alumina in rock-anal- ysis, but such data as are available and the common mineralog- ‘ical association of beryllium and sodium point to the conclusion that the element is most at home in sodic magmas.” Zirconium, he says, ‘‘may be considered to be a characteristic minor chemical constituent of the sodic rocks, whether the silica be so high that quartz is present, or whether it be so low that nephelite is abundant, as in the nephelite-syenites and phonolite.”’ : In the ease of fluorine “there seems to be a marked ten- dency on its part to favor especially rocks which are high in soda. ‘This is seen in the fact that fluorite is frequently present as an original constituent of such highly sodic rocks as nephe- lite-syenite, phonolite and tinguaite ; the association of fluorine and sodium in certain rare minerals, as leucophanite, meliphan- ite, johnstrupite, rinkite, ete., which are almost always found in sodie rocks; and by the recent discovery by Lacroix of sodium fluoride in nephelite-syenite of West Africa.” “Chlorine resembles fluorine in being a pneumatolytic consti- tuent, and is present in igneous rocks, chiefly in the minerals sodalite and noselite, which are almost wholly confined to sodic rocks and especially those which are low in silica, in this resembling the occurrence of SO,.” These extracts from Washington’s paper serve to make clear the general abundance of rare earths and related elements, and of the mineralizers, in the alkaline rocks, as compared with the subalkaline rocks. These elements may be perceptibly abun- dant throughout large masses of alkaline rocks, or they may appear only in the associated pegmatites as a result of concen- * Loe. cit. 40 Smyth, Jr.—Composition of the Alkaline Locks tration from the main magma by a process in which the min- eralizers are universally recognized as having played a leading art. Not only are the rare elements thus concentrated in the peg- matites, but the alkalies themselves appear in muscovite, lepi- dolite, microcline, albite, etc. In other words, the elements whose relative abundance is a characteristic feature of the alka- line rocks in general, are concentrated in pegmatites through the agency of tinenalioiee in virtue of the power of the latter to unite with these elements and yield mobile compounds which, from their distinctive phy sical character, are capable of being segregated from the average alkaline magma. Now, since the alkaline rocks, as a whole, ‘differ from the subalkaline rocks in containing larger pr oportions of these same elements, is it not a reasonable conclusion that the same agents have effected the concentration in both cases? In other words, the facts stated above suggest that the alkaline rocks represent magmas ot exceptional composition derived from ordinary subalkaline magmas through the agency of mineralizers, and, thus, the relation between the two branches of rock i is, to some extent, analogous to that existing between a local magma and its peg- matitic phases. According to this view, the pegmatites of an alkaline region represent a final stage in the process of concentration of certain elements, which started in a subalkaline magma, and was effected through the agency of mineralizers. The power of these agents is due to their own mobility, which enables them to permeate a magma, together with their capacity to form mobile com- pounds with certain elements. As a result of these two proper- ties, the mineralizers are able, under favorable conditions, to extract these elements from the magma and to transfer them elsewhere. The elements peculiarly subject to such extraction are clearly shown by the pegmatites, and the same elements are extracted to form alkaline rocks. So far as the abundant elements of the alkaline rocks are con- cerned, there is no difficulty in accepting their concentration as the result of diffusion, fractional crystallization, gravity or what- ever agents may effect the usual differentiations of magmas. But such an explanation of the concentration of the rare ele- ments in alkaline magmas seems wholly inadequate, and we are forced to have recourse to some agent capable of extracting minute quantities of rare elements from the subalkaline magmas and concentrating them in the alkaline magmas. The high atomic weights of many of these rare elements and their extreme deer ee of dilution would both, presumably, tend to prevent differentiation by diffusion, and the only agents appar- ently capable of performing the task are the mineralizers. ee ee ee 4 bagi he «] \ and its Significance as to their Origin. 41 The simultaneous concentration of the rare elements and the alkalies can hardly be fortuitous, and if the mineralizers accom- plished the former there can be little doubt that they did the latter as well, but to a smaller degree. While the essential features of the production of pegmatites are generally accepted as established, many details remain to be worked out, particularly on the mechanical side. If this is true of, relatively, so small an operation, it is not surprising that one. of the magnitude here under consideration should be wrapt in obscurity. Even if the probability of the hypothesis advanced be admitted, it constitutes only one step in a long series of most complex problems. One of these problems may be referred to on account of the importance that has been ascribed to it from the genetic standpoint. First emphasized by Iddings* in his classic paper on the origin of igneous rocks, the distribu- tion of the alkaline and subalkaline rocks has nee been made the basis of the broad generalization that, so far as may be judged by the conditions of “Tertiary and recent time, alkaline rocks -oceur in regions of radial dislocation, the “Atlantic” regions of Suess, while subalkaline rocks occur in regions of tangential dislocation, “ Pacific’ regions of Suess. This weneralization, first made by Harker} and later, inde- pendently, by Becket and by Prior,$ has, as already indicated, been taken by the former as the basis of a mechanical hy pothesis to account for the distribution of alkaline and subalkaline rocks. Without trying to determine details, he concludes that distinct types of differentiation are effected by the two types of crustal disturbance, the one, radial, giving alkaline rocks, the other, tangential, giving subalkaline rocks. The differentiation takes place chiefly in a horizontal direction and, as a result, very extensive regions are underlaid, during a single igneous epoch, by alkaline, or subalkaline, magmas, as the case may be, which determine the type of igneous rocks for the region and epoch. Asa result of changing type of crustal disturbance, a given region may be underlaid by alkaline magmas at one time and by sub- alkaline magmas at another, with corresponding changes in its igneous rocks. The writer’s conception is quite different, since it regards the subalkaline magmas as of world-wide extent, and the alka- line magmas as derived from these, when local conditions are * Iddings, J. P.: The Origin of Igneous Rocks, Bull. Phil. Soc. Washing- ton, xii, pp. 89-202, 1892. + Harker, A.: The Natural History of Ignecus Rocks: I. Their Geographi- tse Cae ey Distribution, Science Progress, vi, pp. 12-33, 1896. § Prior, G. T.: Contribution to the Petrology of British East Africa, Min- eralogical Magazine, xiii, pp. 228-263, 1903. 42 ees Jr.— Composition of the Alkaline Locks fronts without any regional transfer of magma in a hori- zontal direction. If this conception is right, it may still be true that the final determining factor for the genesis of alkaline rocks is a mechanical one, and, perhaps, as suggested by many occurrences, the necessary local conditions for the derivation of alkaline from subalkaline magmas most often exist in regions of radial dislocation. As to the precise character of such mechanical control, it is, of course, impossible. to speak with even an approach to certainty, for we are here brought face to face with the still unsolved fundamental problems of vuleanism. It may be that, in very unstable regions, with belts of intense lateral thrust in which vulcanism is greatly developed, subalka- line rocks are intruded and extruded without opportunity for the associated mineralizers to effect the differentiation neces- sary to produce alkaline magmas. Whatever the mechanical conditions needful to cause solid, but potentially molten, rocks to become liquid (a much discussed problem wholly transeend- ing the limits of this paper), in regions of such instability, intrusion and eruption may follow so rapidly upon melting that no opportunity is afforded for the separation of alkaline fractions. Instead, over vast areas, we find a monotonous assemblage of basalts, andesites, etc., typical subalkaline rocks. In the more stable regions, on the ‘other hand, where, instead of typical mountain-making due to lateral thr ust, radial dis- placement prevails, magma basins may remain, for long periods, undisturbed by external agencies, and, if the proper conditions of pressure, temperature and viscosity exist, the mineralizers have the opportunity to exert their selective influ- ence and extract from the mass those constituents with which they readily form mobile compounds. In other words, alka- line magmas may be formed under relatively stable conditions which admit of a long continued delicate adjustment of equi- librium. Such conditions must necessarily be rare, a fact with which the comparative rarity of alkaline rocks is in harmony. Iddings* holds that stable conditions may prevent differen- tiation, and this is doubtless true for some types of differentia- tion, but where it is a process of magmatic extraction, such as is here considered, stability of conditions may be more favor- able. The inagmas formed under these conditions are tapped off by vertical fissures and give rise to intrusions and extrusions of alkaline rocks. Presumably, too, the vertical fissures some- times play an important role in permitting the active circula- tion of mineralizers through relatively rigid and, thus, but for the mineralizers, stagnant, bodies of magma. * J. P. Iddings: Igneous Rocks, i, p. 292, 1909. and its Significance as to their Origin. 43 In this connection, it is of interest to note that Suess* says: “ Thus the cuestion arises whether diminution of calcium and magnesium in the Atlantic hemisphere may not stand in some connection with the progress of consolidation.” These suggestions, whose exceedingly hypothetical nature ean not be too strongly emphasized, obviously are based upon the view, adopted throughout the discussion, that, in every region of,alkaline magmas, large reservoirs of subalka- line magmas exist from which the former were derived. Whether or not intrusion and extrusion of such subalkaline magmas would precede the formation of the alkaline magmas would depend upon local conditions. A period of active mountain-making, with attendant intrusion and extrusion of subalkaline rocks, might be followed by a period of relative stability with the delicate adjustment of conditions necessary for the elaboration of alkaline magmas. Or, on the other hand, it might equally well happen that the subalkaline mag- mas would remain at depth, while the alkaline magmas reached higher levels. In dealing with phenomena of such a large order of magnitude, involving not only great bodies of magma, but, also, long periods ot time, determinable relationships can hardly be expected. In brief, the association of alkaline and subalkaline rocks, with distinct types of crustal disturbance, in so far as it may exist, is ascribed to the presence or absence of opportunity for the mineralizers to exert their influence as agents of differen- tiation. The mineralizers are regarded as the fundamental factor in the process, the mechanical conditions as affording secondary control, which, though perhaps in part subject to Harker and Becke’s generalization as to distribution, may ulti- mately prove wholly independent of it. Much more thorough investigation is required before the extent and nature of the relations between petrologic and tectonic types can be estab- lished, and, while some connection doubtless exists, there can be no question that the relation is less direct and vastly more complicated than is implied by the foregoing bald statement or than could be expressed by any statement at the present time. If, as here maintained, the magmas contain, within them- selves, the essential agents of differentiation, it must follow that when these agents are allowed, by surrounding conditions, ° to operate, their effect is cumulative and, thus, intensified with the passage of time. The separation of an alkaline fraction from a subalkaline magma implies a concentration, in the for- mer, of the agents which cansed the differentiation. It neces- sarily results that the derivative magma has a greater tendency to differentiate than the original subalkaline magma had. 2g. Cit, Ivy p. 590. 44 Smyth, Jr.— Composition of the Alkaline Rocks Thus, the alkaline magmas must tend more than the subalka- line magmas, to separate into fractions of diverse composition and, in view of the elements which concentrate in alkaline magmas, some of these fractions will naturally contain rare minerals. Moreover, the production of small fractions excep- tionally high in alkalies necessarily implhes the production of corresponding fractions of complementary composition, and therefore high in other constituents. How chosely these con- clusions are in harmony with well-known facts, it is hardly necessary to say, since the great range of chemical and miner- alogical composition shown by alkaline rocks in limited areas, the frequent occurrence, in them, of rare minerals and the not uncommon presence of highly. calcic rocks, are among the familiar facts of petrology. Of interest in this connection is Vogt’s* statement that, in so far as limited miscibility may play a part in magmatic differ- entiation, it would be most hkely to occur in rocks rich in mineralizers. Thus, we arrive at the conclusion that the pegmatite dikes of such a region as the alkaline province of Christiania are but the last step in a somewhat discontinuous but still causally connected series of operations, differing vastly in degree rather than in kind, starting in the normal subalkaline magma and effected primarily through the agency of mineralizers, subject to secondary mechanical “control. It is hardly necessary to say that this hypothesis has much in common with the views promulgated by the French petrologistst in so far as the potency of mineralizers in igneous activities, and especially in connection with magmatic differentiation, is concerned. On the other hand, it differs materially from Becke’s hypoth- esis of a primordial gaseous separation, in a vertical sense, of alkaline and subalkaline materials. rom Harker’s hypothesis, it differs essentially in ascribing the chief function to mineral- izers rather than to mechanical conditions and in regarding alkaline magmas as local derivatives of the universal subalkaline magma, instead of assuming separation of the two types by a horizontal differentiation of regional magnitude. Jensen’s hypothesis is based upon melting of early alkaline and saline sediments, with some assimilation and mixing, and is, thus, essentially different from the views here advanced. Daly’ . hypothesis has much in common with the writer’s, though based upon assimilation, but the assimilation postulated is of limestone and it is to the carbon-dioxide of this rock that *J. H. L. Vogt, Die Silikatschmelzlésungen, II, p. 229, 1904. +Cf. A. Michel-Levy: Note sur la classification des Magmas des Roches Eruptive, Bull. Soc. eo France (3), xxv, pp. 326-377, 1897. and its Significance as to their Origin. 45 the chief function is ascribed, while in certain cases it is con- sidered probable that magmatic carbon-dioxide may have been effective, in the absence of limestone. It need hardly be said that the present hypothesis is not offered in controversion of any of those above mentioned, but merely as a suggestion arising from viewing the problem from another standpoint. As a matter of fact, the several hypotheses have certain features in common, ‘despite great differences of emphasis, and it is entirely possible that all the various agencies appealed to may play a part in the complex operations under consideration. While not explicitly stated, the writer has, throughout the diseussion, implied the belief that the mineralizers are mag- matic or “ ‘OGL ‘OIF ‘d SArxx “[puvyiog ‘wWjoyyooIG ‘1 ‘uot “Joos, “1vaT ‘plohysuepsoN yoyorgolss|y evi['y *¢ ae : ) ‘cO6L “6ST “A ‘1 + -qaqepe sonon § OGL ‘Zh *d “Axx “[pueqigg ‘Woy IG “I ‘UaIQT "Joo “foxy “oroquueyy ‘duojodmnayg “7 < ‘POST ‘06e ‘d Sttox “YO “ud “Pf “[joqoyy “A “pleAUuExOR[TpPS “€ % ‘epg—ap9 ‘dd ‘taxxx “qskry ‘yz : 0061 ‘oge ‘d {{ “IUY—Y “Sojooy “yy Ya A CA*D UYOL “VUUaLA “Z iS ‘098l ‘Tge‘d “YO ‘UI, ‘Stoqsjomtuvy ‘(op[OSOIM7) SIeUUUOpPOg *T § < DUNC maa Ma cermin co eee eae es ee dhl VOR Gy be ROR) | BOs e = COOrL Ae ep e bela. 1 Be ee a ar 5 See Wee gee wie UE eee wee OSE be ile Vc omgiObae a We Crme ane La) : - ‘— Seales tae re di sete Ay ons PARE NES eG igs ahGe), os a pea ONG: 1 OVC 1 Oral Oia uta 7 6&- TOT ag Re CoE: moet EI. WAR V6-V ne! 9V-P 8-1 06-81 ¢9.9s 9 S &8&-POT L&- ee 16. Ol- 8I- REG G8 OFF O1-G €6-GE = PBI C0-6& a Se €4-601 91-6 &&- 86+ G61 LT: OV-& 96-9 6&1 08. 09-66 8F-0G &&-6& ave = 8I-rOL es “IY = tie fre eh Pete ae O1-8 G0.& 06°G 00-08 86-96 GREE S SS ca (Ore ANNE cone Gh. GG. aie: pat td op LAU-8 “ly OFel G0. LE €0-16 66-18 6 D Ry 00-LOT oars et po ay ac, ig nS 00-9 a es G66 GP-Ib &8&-08 aL [POL "O*1V O'x O'8N O°H “O'S "OO ut O71 0%) =: OUN Oo sel 54 Hess and Hunt—Triplite from Eastern Nevada. If, in the above analyses, those constituents representing either adhering matrix or altered material intimately mixed with the triplite are disregarded, the greatest variation is to be found in the proportion of FeO to MnO. Inasmuch as the ‘percentage of FeO varies from 41°42 to 1°68 with a corre- sponding increase in the MnO from 23°25 to 57:63, we have unquestionably isomorphous replacements of these elements in all proportions and the term triplite must be considered to include not only those phosphates of manganese high in iron, but likewise those in which the iron content is practically negligible. The material from Nevada would seem to represent the manganese end member of this iron-manganese series. Blowpipe and physical properties.—Triplite is soluble in acids. Before the blowpipe it fuses readily to a black globule and becomes slightly magnetic, and gives a manganese reaction with the borax bead. The color of triplite given in texts as various shades of brown and black, seems to correspond to those varieties rich in FeO or those possessing considerable included and oxidized material ; the mineral here described was apparently unaltered, possessed a vitreous luster and light salmon-pink coior. Streak white. H—=4W—43. Cleavage in two directions, one very prominent. Sp. gr. 3°79. Optical properties —The material was entirely massive and the indices were determined by immersion in oils by E. S. Larsen as follows: a =1°650 8 =1°660 y = 1°672, all + 005. The birefringence is about (020. The optic axis emerges per- pendicular to one of the cleavages. A very large optical angle is shown by the extremely slight curvature of the bar observed on this interference figure. Optically +, dispersion p>v. Under high magnification some of the fragments reveal dark colored rounded or fibrous aggregates of included material. Similar inclusions were reported by Lazarevic* in a brown variety and Stelznert is of the opinion that the dark color of triplite is to be explained by the unusually large quantities of these inclusions. Whether or not this supposition is correct, in the Nevada material, which is apparently unaltered and con- tains a comparatively small number of inclusions, we have a variety which is not brown but salmon-pink in color. * Centr. Min., 385, 1910. Min. Mitth., 222, 1873. Minter Oxides and Sulphides of Iron, ete. 55 ‘Art. VIIl.— The Heat of Formation of the Oxides and Sul- phides of Iron, Zine and Cadmium, and Ninth Paper on the Heat of Combination of Acidic Oxides with Sodium Oxide; by W. G. Mrxter. [Contributions from the Sheffield Chemical Laboratory of Yale University. | THERE is comparatively little known about the heat of for- mation of minerals and the anhydrous oxides and sulphides of the metals. The hydrated compounds have, however, been more fully investigated. The object of the work was the study of some minerals. Some other compounds were also investigated. Except ina few cases the only way known of finding the heat of formation of a mineral is by fusion with sodium peroxide. The method involves the heat effect of a mineral and its components reacting with the peroxide. The Oxides of Iron. The heat of formation of the oxides of iron has been deter- mined in the present investigation by the sodium peroxide method, and that of the magnetic oxide by burning the metal in oxygen. ‘Two lots of sodium peroxide were used, one of which gave with 1 gram of rhombic sulphur 5270° and the other 5240°, and hence different heat effects of sulphur are given in the tables of results. The peroxide was passed through a $™™ mesh and only the fine powder used, since it gives quicker, combustion and consequently higher temper- atures than the coarse powder. After completing a series of determinations, the work was repeated with new preparations except in case of ferrous oxide. For brevity both series are put together in the tables. Iron.—The metal was obtained by heating ferrous oxalate gradually in hydrogen to a red heat. When cold it was passed through a 47" mesh and heated again in hydrogen. The preparation is indicated as “A.” The determination of iron as ferric oxide gave 99°9 per cent. The sample contained a trace of carbon. Preparation “ B,” containing 99°8 per cent of iron, was from the reduction of pulverulent ferric oxide by hydrogen. Both lots of iron were free from hydrogen and yielded no water when burned in oxygen. In the following experiments ‘A ” was used in 1, 2 and 38, and “ B” in 4. A little iron remained unburned in 3, hence the result is not included in the final value, 1719°. For 2 gram atoms of iron reacting with sodium peroxide it is 1719° K 111°68 == 192000°. 3 56 Miuter— Heat of Formation of the 1 2 3 4 icon? Woes Ste roche 2°550 1754, 1754 3°000 grms: SSIEUY DNOWTE PAM aay SNe Ce 1°500 1°500 1°500 1°500 Sodium peroxide..-- 20° 1bs)° 20° 22° Water equivalent of Si SUM G22) tie ole 3080 3078 3188 4108 Temperature interval 4:016 3°573 3°423 3°180° leat elect = - = ae. 12369 10998 10912 ‘TadGae Heat effect of sulphur — 7905 — 7905 — 7905 — 7860 s “ignition i AU ee a ee — 80 — 80 — 60 — 45 4384 3018 2947 5158 Heat effect of 1 grm. | Re ages Fes Se il es Wg) 1718 1680 1719 Ferric Oxide.—Ferric oxide was made by heating the hydroxide to a faint red. When cold it was pulverized and sifted. Each portion used was heated again to a dull red before weighing to drive off hydroscopic water. Further heating was found not to change the weight. All heating was in an electric furnace where there was no liability of reduc- tion. The following table contains all of the calorimetric results with ferric oxide. The fusions of 1 and 2 were dark colored and gave with cold water ferric hydroxide and red solutions containing sodium — ferrate. From the water solution of 2 barium ferrate precip- itated on adding barium chloride. The fusions 3 and 4 were black on tep but white below, and the remaining were white throughout. The water solutions of all except the first two were white and free from iron, proof that ferrate was not formed. In 1 and 2, where the temperature due to the redc- tions was lower than in the others, both ferrate and ferrite were formed, and hence the results are without value. Of the remaining experiments the last three are to be regarded as better than 3 and 4, since larger amounts of ferric oxide and smaller quantities of sulphur were taken. The average of 5, 6 and 7 is 863°. For 1 gram molecule of ferric oxide combining with sodium oxide the result is 58000°. Van Bemmelen and Klobbie* prepared sodium ferrite, Na,Fe,O,, by heating a mixture of ferric oxide and sodium hydroxide. They found it to be slowly decomposed by water. Hilpert and Kohlmeyert+ consider that calcium orthoferrite, 3CaO.Fe,O,,. is formed at 1410°. It is not possible to decide whether orthosodium ferrite, Na,FeO,, or meta ferrite, “J, Prac, Ch, xlvi, 497, 1892: + Ber d. deutsch. Chem. Gesell., xlii, 4581, 1909. 57 Oxides and Sulphides of Iron, ete. 99E 6861 68+ oo ae 0984— 06916 oS G&-S 6vIP -04 00¢-1T SUIVIS 96Z-¢ L eog- 9481 Tet Sis 0984 — O&L6 6GE.G LEIP -61 00G-T G1I1-S 9 19€ 6961 08 + Sh ree 0984— 8416 SLE-G GIP -06 00g.T S0P-G G V6E SGél PoA.lasqo jou 10% "© Off FOoWUIe 1 yy 55 coy BOW eae es "OC. 94f JO Woe VEOFT OV GE a ae heuer ag ois = paqaosqe “+ 901f 908 “Cy, 55 » (Ca eee OIIM Oi] 5, 955 . OUGCSS Se aaah ae G JO 5 355 GS SS later ee Serie > rien Sd SS pOoTfo JOA, NE9-[ ~"777 77 [eAdoqut ommjesodwa y, 8168 “mass Jo juareamba 19}8 AA 06 ~~"" "77 727 eprxosed wmtpog OOO. =o See eee ae ee inydyng O18 692s = -OpIxOOLIag I 58 Misxter—Heat of Formation of the Na,Fe,O,, is formed in the sodium peroxide fusions, but since the heat of the reaction of ferric oxide and sodium oxide is much greater than that of alumina and chromium sesquioxide, it is probable that sodium orthoferrite istormed. The formula wNa,O.Fe,O, is used in equations to indicate that the composi- tion of the ferrite is not known. For the heat of formation of ferric oxide we have oFe + 3Na,0, = «Na,O.Fe, O, + ¢@Na.O + _ 2.0 192, 000° 3Na,O + 30 = 3Na,0, foe ede lee te 1 oFe + 30 + wNa, o= -aNa, 0.FeO, 4). 250,200 Fe,O, + #Na,O = 2Na,0.Fe,0, aL St 58,000 9Fe-+ 80 = Fe,O,.4 2.9) 3) 192,200 ferrous Oxide.—The various products obtained by heating ferrous oxalate for the purpose of making ferrous oxide are described in a note on p. 68. The substance used in the fol- lowing calorimetric work was a mixture of ferrous oxide and metallic iron, containing 16°27 per cent of the latter. It was free from carbon. Substance (FeO 3°349, Fe 0°651)._-_- 4:000 4:000 grams. SU ow eis Ne ae ee ee 2000 2°000 Sodium peroxddenys as se eereee eee 26" 26° — effect 0 ele en eae 14023° 14027 es re Ok sulphur fo ae See ae 10480 10480 ce OL iE OTINd © Kas Cxmitnoraeae see 40 40 oS Of" Gol germ sora h ee mer 1119 1129 9 > Ob 3734 0vorm. oF he On nmin se 4 2388 eo Ob elon lorie ORS mamueurs 712 713 For 2 gram molecules of ferrous oxide we have 712° x 143°68 = 102300°, and for the heat of oxidation the following : 20eO +: NaO) + @NalOwss lee ee eee 102,300° Na,O --- OO = 2.22 222 ee ee ee 2FeO Or cea, Oe) i ee eee ee - 121,700 Fe,O, + a@Na,O se ee 2FeO 40cm pl and for the heat of formation of ferrous oxide a + 80) — (2FeO + O) = 2(Fe + O) =. 128500° and Fe + O = FeO + 64300° Ferrous Ferrie Ovide.—Attempts to burn iron completely were not successful, hence the heat effect of oxygen taken up was found. The iron, preparation ‘“ B,” was placed in the hemispherical bottom of a steel bomb, which was then repeat- edly exhausted and filled with dry oxygen, fairly free from nitrogen, and finally at a pressure of 12 to 15 atmospheres. Oxides and Sulphides of Iron, ete. 59 The ignition was by means of an iron wire heated by electric- ity. Most of the product of a combustion was in one button which contained a few cavities indicating dissociation of ferric oxide. The contents of the bomb were collected and weighed. Then it was washed and the few decigrams of dust collected were ignited and weighed. The experiments were as follows : u 2 5) id 8105 8499 8°609 grams emanet 2. 22. LK 11°202 11°676 11°757 Oxygen combined ---.- 3°097 S°ETT 1:148 Heat effect ....-..- om ao 12685 13167 13067° ie of 1 grm. Se OMyeren 2... 4096 4144 4150° The average is 4125°. While the product of a combustion is a mixture of iron and oxides it is mostly ferrous ferric oxide as shown later. Moreover, the heat effect of an atom of oxygen in the different iron oxides is nearly the same. Hence the _ error is insignificant in the value derived for 3Fe+4O, which is 4125°x* 64 = 264,000° at constant volume and 265,200° at constant pressure. The products of the experiments were united, pulverized and sifted. About 0°2 gram of iron was picked out and a small portion of the substance remaining on the sieve contained metallic iron. The powder appeared to be free from metal, as it gave no gas when dissolved in hydrochloric acid. The iron in the powder, determined as ferric oxide, was found to be 72°14 and 72-07, mean 7271 per cent; oxygen by difference 27-9 per cent. The corresponding formula is Fe,O.,.... Magnetite.—Magnetite from a large crystal, excluding 0°27 per cent of silica, was found to have the following composition : = Calculated I II Mean for Fe3;04 LOC 72°74 [72°65 | 2-7 72°36% Oxygen Ps a NS [27°36] Qiao 253 27°64% The iron in I was determined as ferric oxide, and the oxygen in II by loss on heating 2°6481 grams of the substance in hydrogen. The mineral contained no aluminum, manganese, calcium or magnesium. The composition is expressed by the formula Fe,O,,.,,. The calorimetric fusions were treated with water, and dilute nitric acid was added to dissolve the ferric hydroxide formed and the magnetite left was collected and weighed. The follow- ing are the results obtained with magnetite and the magnetic oxide described above: 60 _ Miater—Heat of Formation of the Magnetic Oxide, Magnetite, Fe;03.94 Fe, Ouene — a —_ -—eoooo ~ Substance. ee ee) 5 el 6°056 5°615 5°910 gers. oe LIS 6 cpa telaly aes 0°285 0°457 0°520 0°620 ee combined (a). 4°876 5599 5:095 5290 SoM. se ed low 1°500 1°500 1°500 Sodium peroxide .....- 20° 20° 20° 20° Aiea ee aR 10104 10473 10087 10174¢ of S........ —7860 — 7860 — 7860 ~ —7860. ee Tira ahd ghrevedapee ke uhh mic ale) Pe 45 — 45 — 45 ec UE OL set. free + 32. +: 51 + Ti eG IME RET CD) Ve, 2 2931 2619 2959 9875 « «1 orm, es, 468 443 449 a The mean for the magnetite is 462° and for the magnetic oxide 446°. For the oxidation of the magnetite we have 2Fe,O.,.,, + 1:12 O= 3Fe,O,. The mass of 2Fe,O,,,, is, in terms of atomic weights, 461° 12. The heat effect of N a,O,— O is —19,400° and — of 1:12 O —21,700°, hence | 9Fe.O,.;. +) eNaiO, = 469° x 46112 =) ee 218,800° 1:12 NaO 141190 j= pe 2Fe.0,,,. + 1120 4 @Na,O = fo 0222) 3Fe,0,. +: @Na,O = ole eb ee 2Fe,0,,. + 1120 = aie ele 2Fe.0, +.0 = 61000 = 1:12. = 22....2)... eee For the heat of union of ferrous with ferric oxide we have (2FeO + O) — (2Fe,0, + O) = 9,200° and for the heat of formation of magnetite (2Fe + 30) + (Fe + O) + (FeO + Fe,O,) = 265,700° From the heat of the reaction of fused magnetic oxide with sodium peroxide is derived 3Fe + 40 = 264,600°, which accords well with 265,200°, found by burning iron in oxygen. The ectlhe of Berthelot* and LeChateliert are included 1 in the following summary: ~ B. _) tee: Fe + O = FeO (900’) + 64,300°8 _- 64,600°S 2¥e + 30 = FeO, (faintred) -+ 192,2008.. . 198,400 § 3Fe + 40 = Fe,O, (magnetite) + 265,700 8.. 3Fe + 40 = Fe,O, (fused) + 265,200 f.. 268,800§ 2FeO + O = Fe,0, + 63,700§_- 65,200 § 2F¥e,0, + O= oh e,0, + 54,500 §-- FeO + Fe,0O, = Fe,O, (magnetite) + 9,200§.- Fe,O, + EO) = «Na,0.Fe,0, + 58,000 f-- * Ann. Chim. Phys. (5), xxiii, 118. tC. R., exx, 625: ¢ Experimental result. § De rived result. Oxides and Sulphides of Iron, ete. 61 Berthelot derived his result from the heat of solution of a readily soluble magnetic oxide in hydrochloric acid. LeChate- lier burned in oxygen mixtures of ferrous oxide and carbon and of ferric oxide and carbon, and based his calculations on B’s heat of formation of magnetic oxide. The heat effect in the different stages of oxidation of one atom of oxygen is nearly the same, as LeChatelier observed, thus : | Fe or Ou 64,300° 2FeO + O = 63,700 ewe SONG. C4100 ee 1: 4 166.400 The figure for the last is higher than the others because of the considerable heat of combination of ferrous with ferric oxide. This heat effect confirms the view that magnetite is meta-ferrous ferrite. After the foregoing work was finished the paper of Ruff and Gersten,* Ueber das Triferro-carbid, came to the writer’s notice. In the investigation they obtained for the heat of formation of Fe,O, 267,100° + 200° and FeO 60,400 + 1800°. Ferrous Sulphide. — Allen, Crenshaw and J ohnston+ state that by heating iron in hydrogen sulphide an iron sulphide is formed, having approximately the composition of FeS. The writer’s preparation, prepared by this process, contained 1°7 per cent excess of sulphur, equivalent to 3:2 per cent of FeS,. The following are the results: Ferrous sulphide. ._....-- 3°308 3°502 3°698 grams Pedim peroxide ...:. .-- 20° 20° 20° Water equiv. of system.--. 3110 3171 3170 Temperature interval ...-. _. 2°994 3°141 33070 eamvettect. 2/2252 -25-- 9311 9960 10483° a Set Ol TOM: «otis aes 50 50 50 7 “OE SSI EN che openers 9261 9910 10433 = oe hr oram - hes 2800 2830 28292 The mean is 2817°. Allowing for 0:032 gram of FeS, with a heat effect of 106° we have 2801° for 1 gram of ferrous sulphide, and for 1 gram molecule 246,200°. The heat of formation is derived as follows : S + 3Na,0, = 169,000° Fe + 14Na,0, = 96,000 Hel or Shee ‘44Na,0, = 265,000 FeS +. 43Na,0, = 246,200 Fe + 8 (chombié) == Kes (amor) :==-: 18,800 * Ber. d. Chem. Ges., xlvi, 394, + Zeit. £. Anorgan. Chem., Ixxvi, 224. 62 Mixter— Heat of Formation of the Pyrite and Marcasite-—Pyrite from Danbury, Conn., was found to have very nearly the composition of 5FeS, +FeS, Very likely the mineral had lost sulphur as dioxide when pulverized. The average of three combustions was 3241° and, allowing for ferrous suiphide present, 5321° for 1 gram of FeS,. “At the time this result was not regarded as satisfactory because of the composition of the substance used. Hence another crystal of pyrite, locality unknown, was analyzed and also marcasite from Joplin, Mo., with the following results: Pyrite Marcasite Theory, FeS. Tron aie eee 471 47°] 46°54 Slo lie 52°6 52° 53°46% Insoluble ... 0:1 0°2 piel es) BS) 100°00 The results of the combustions were as follows: Pyrite Marcasite. PS SSS i a Deis ee se eae 4°011° 4:059 4:030 4:070 grms. Sodium peroxide ROLE aie 24° 24° one 27° Water equiv. of system. 4045 4085 4147 4180 Temperature interval_.. 3°301 3°316 3:233 3:251° Pleat) Cireety aes 0 elas 13352 18545 138407 13589° i (Ok: awomiam aber —40 —50 —40 —40 i OK eS, ----, 13812 18496) eae 7 lees oh Fe) (Of Mona eases 3325 ~ 3317 3329 The results indicate that the heat of formation of the two minerals is the same. Allen, Crenshaw and Johnston* find that pyrite is more stable than marcasite, and suggest that the latter may have a lower heat of formation than the former. In their papert in the Zeitschrift fir Anorganische Chemie, they notice that Carazzit found the heat of combustion of pyrite and marcasite to be the same, namely, 1550°. If the two crystalline forms of iron disulphide differ as suggested the difference is small. | The average of the results obtained with sodium peroxide is 3322°. For the gram molecule it is 398,500°. From this num- ber the heat of formation of FeS, is derived as follows : Be -) Th Nia, O70 re nee ee es sae ene me 96,000° 25) + GNaO! (52709 cas 2 nOnin eee 338,000 Fe + 28 + Ta NaO ee ee ee aot! 2 oa) Brae FeS, + 74Na,0, i oleae ramepanaame tawny, (QC) Fe + 28 = Fes, (crys. ) aes etl sony 0 35,500 * This Journal, xxxiii, 169. + Loc. cit. { Rend. Accad. Bolona, N. S., ii, 205, 1898. Oxides and Sulphides of Iron, ete. 63 For the heat effect of one and two atoms of sulphur we have | Be + S = FeS (amor.) +. 18,800° FeS (amor.) + S = FeS, (crys.} + 16,700 This accords with the oxides of iron where one atom of oxygen combining with iron produces but little more heat than - when combining with ferrous oxide. Line Sulphide.—The zinc blende was a honey yellow, trans- lucent piece with brilliant cleavage planes. The zine found in it was 67-10 per cent; theory 67:14 percent. Zinc sulphide was prepared as follows: zine oxide was heated gradually to a bright red heat in a current of dry hydrogen sulphide and allowed to cool in the gas. After pulverizing it was heated again in the gas to about 500°. A determination of zine in this sulphide gave 67°19 per cent. Under the microscope a few bright surfaces were visible in the apparently amorphous powder. One would expect it to be crystalline since its heat of formation is the same as that of blende, and also because ~ Deville and Troost* obtained crystalline zine sulphide by heat- ing the amorphous in hydrogen sulphide, probably hotter or longer than the writer did. The fusions were treated with water and the zinc hydroxide formed was dissolved by acetic acid. The zinc sulphide left was collected and weighed. The results are given on the following page. The average of the results for the blende is 2005°._ For the gram molecule it is 195,3800°. The heat effect of Zn + S is derived thus : MomreNOnr es eh Pe = 67,600°} SEIN @ Pah = 169,000 ees ANaO, 2) 2.2882... = 236,600 Me Na ON = 195,300 fae oS (thombic) = ZnS.(crys.)-.--.-.. = (41,300 The average of the results for the zine sulphide made is 1992°, which gives 42,500° for Zn + 8. If we exclude the lowest result, 1970°, the mean of the other two is 2003° and we have 41,300°. Evidently the artificial sulphide has the same heat of formation as zinc blende. Cadmium.—Cadmium chips which passed through a $”™ mesh were used in the work. An analysis of the sample gave Cd 99-96. per cent, Fe 0°005. The metal, as is well known, oxidizes slowly and superficially in ordinary air. In a desicca- tor, however, it remains bright. On page 65 are the data obtained from combustions with sodium peroxide. oOo. lit, 920; 1861. + This Journal, xxx, 199. if the “on O Mixter—Heat of Format 64 610% L861 OL61 3968 S614 990¢ OF OF OF 0 ies) 181 06068 GE8q 1899 oS LL:S 696-1 196-6 0908 8863 £963 ST SI rl 0 0 00-0 260-4 916-6 19-6 710-0 660-0 0 SUILIS 901-7 800-8 LLG.3 313 3 Pt b bé Seen ces 1 gram CdO— ......---- 583 49 While the results agree well they are to be regarded as approximations since the heat effect of the cadmium oxide is only 2°5 per cent of the total effect of the combustion. The mean is 51° and for one gram molecule of cadmium oxide it is 51 XK 128-4 = 6548°. Meunier* observed that cadmium oxide dissolved in molten sodium hydroxide, but failed to isolate the compound formed. The writer has found that the oxide did not dissolve if the hydroxide is first heated until free from water. When, how- ever, a little water is added to the sodium hydroxide it dis- solved cadmium oxide on heating. The fused mass was white. When treated with a very small quantity of water and filtered, the filtrate on dilution yielded a very little cadmium hydroxide. The fusions in the bomb were yellow and for reasons already stated the color is not due to cadmium sulphide. The difference in the condition of the two kinds of fusion may account for the difference in color. In the first case the reac- tion is with molten hydrated sodium hydroxide; in the second with sodium oxide at a high temperature. The writer found when a mixture of sodium peroxide and cadmium oxide was heated that oxygen came off freely and that the sintered mass left in water only reddish oxide and no white cadmium hydroxide. Evidently the temperature was not sufficient to effect combination of the two oxides. Cudmium Sulphide.—Cadmium sulphide, precipitated by hydrogen sulphide from a hot solution of the sulphate, after washing and drying was heated to redness in a current of dry hydrogen sulphide and then left to cool inthe gas. After pul- verizing it was heated again as before. Cadmium found, TUTA per cent: CdS has 77:80 per cent. Under the micro- scope it appeared as an amorphous powder containing a very few minute crystals. The following are the experimental data : Cadmium sulphide .---.------- 5°470 5:209 5°220 grams SLD gS oe ee ag baie 0-0 0°500 0°500 Padrm peroxide... 6224.22... oes 20° 20° Water equivalent of system... 3942 3988 3984 Temperature interval__-.___-- 1°715 2°291 2.°283° #0, R., Ixiii, 330. 68 Mixter—Heat of Formation of the Heat chteehul- 2 ane ees 6760 9136 9095° ae EVOL sulphur #2. S22 0 2620 2620 < Ce SOIR Eee yg ek 50 50 50 6¢ GOTT TCEN GINS ese tr eel ae 6710 6466 6425 Es ie hl ora Cdesses 1227 1241 1231 The average is 1233° for the heat of reaction of 1 gram of cadmium sulphide with sodium peroxide. For 1 gram mole- cule it is 178,100°. For the heat of formation of cadmium sulphide we have Od NajQicck 2:2 5h Gae ee eee = 44,100° So SNe Oe ale ee ee = 168,000 Cd i+ S. + ANaOi eee eee = 212,100 CdS 4. 4Na.00 0 ee = 178,100 Cd + S(rhombic) = CdS(crys.)..-.----- = 34,000 Summary. Cd ae Na" (Oe an ee 44,100¢ * Na:0" 000) U0? ae i eae Cd°+ 0. +) NarQuikee oe eee eee 63,500 CaO +iNa © oe cies Lar eee eee 6,500 * approx. Cd +) 0% = CdO(amor)e2e22 =. t 57.000 t « Cd + O = CdO(mostly crys.) ---- 63,000 * Cd + S(rhombic) = CdS(crys.)-- - 34,000 + Thomson found Cd,O,H,O = 65,800°, and Cd,S,H,O = 32,350°. HW WN a Note on Ferrous Oxide. A quantity of ferrous oxide was needed and it appeared from the statements in Moissan’s Traité de Chimie best to make it from ferrous oxalate. In the first attempt the oxalate was heated rapidly to a red heat in a bulb with a narrow neck, the end ot which passed into water. After gas ceased to come off the neck was closed and the bulb allowed to cool. The product was found to have very nearly the per cent of iron in ferrous oxide. It was, however, a mixture of metallic iron, ferrous and ferric oxides and contained sufficient carbon to render it useless for the calorimetric work. When ferrous oxalate is heated rapidly the reduction product first formed from the oxalate in contact with the hot sides of the containing vessel is exposed to the action of the oxides of carbon and water vapor from the decomposing oxalate. Under these conditions carbon separates, since, as is well known, carbon monoxide at 1000° dissociates thus : 2CO waz COFaC: To avoid separation of carbon or formation of iron carbide ferrous oxalate was heated in a current of pure dry nitrogen. The temperature was raised gradually and at the end of four * Experimental result. + Derived result. Oxides and Sulphides of Iron, ete. 69 hours was about 520° and carbon dioxide had ceased to come off. Then the temperature was raised to about 900°. At this temperature a very little carbon dioxide was given off. After an hour the bulb was sealed. The product was gray and dis- solved in hydrochloric acid with evolution of hydrogen. It was free from carbon. A determination of iron as ferric oxide gave an atomic ratio, Fe 1:253 to O1. The oxygen, determined by loss on heating the substance in hydrogen, gave a ratio of Fe 1:°240 to O1. The mean is 1°25 of iron to 1 of oxygen and hence Fe,O, represents the composition of the sub- stance. The atomic ratio very likely is adventitious and the substance should be regarded as a mixture of 4 molecules of ferrous oxide and 1 atom of iron. Such a mixture contains 16°27 per cent of metallic iron. A number of investigators have described different ways of making ferrous oxide, but apparently no one has analyzed the product except Ruff and Gersten.* They tried to make it by passing a mixture of equal volumes of hydrogen and carbon dioxide over a mixture of equal parts of iron carbonate and ferrous oxalate at a red heat. They found that the product contained FeO, Fe,O,, CO, (as FeOO,) and amorphous carbon. Note on the Volatilization of Cadmium Oxide. The writer has observed that cadmium oxide loses weight at about 900° when heated in an electric furnace with platinum resistance. One experiment was made with the preparation described on p. 66. The weighed portion was in an unglazed porcelain crucible. The temperature at times was as high as the melting point of silver, 962°, but usually lower. The weight of the cadmium oxide after heating to redness and cooling in a desiccator was 3°050 grams. The weights observed after successive heatings were: 3:036, a few minutes; 3°029, time not noted; 3°025, 1 hr.; 3-016, 2 hrs.; 3:007, 3 hrs.; 3°001, 6 hrs. ; 3°000, 4 hrs. The total loss was 1°66 per cent. The reddish brown oxide had changed to a black sintered mass showing some crystalline structure. About the top of the crucible was a reddish deposit. In another experiment 28-088 grams of commercial cadmium oxide were heated successive times, in all 96 hours. The total loss was 0°641 gram, or 2°28 per cent. The temperature in this test was much of the time somewhat higher than it was in the first. The results show that reddish brown amorphous cadmium oxide volatilizes or dissociates slowly at 900° to 1000° and that the rate of loss is less as the oxide becomes denser and erystal- line. Apparatus has not been available for the determination of the melting point or for the investigation of the vapor or dis- sociation pressure of cadmium oxide. * Loe. cit. r 70 Pirsson and Vaughan—Deep Boring in Bermuda. Art. [X.—A Deep Boring in Bermuda Island, by L. V. Pirsson and T. WAyLanp VAUGHAN. In April 1912 one of the writers (L. V. P.) was in Bermuda and lodging at the Princess Hotel. Through the courtesy of one of the managers, Mr. F. Howe, he learned that the hotel company had engaged in the project of putting down a deep well in the island in the hope of obtaining a more adequate water supply, and he was given the opportunity of seeing this well and of inspecting the material brought up from it. Later, owing to the kindness of Mr. Howe, he was furnished with a carefully taken and labelled set of samples, showing the char- — acter of the rocks at about every 40 feet in depth. | What process of reasoning or matter of experience led th projectors of this enterprise to hope to obtain a large supply of fresh water by boring into a conical mass, rising from the floor of the ocean’s abyss, and whose summit alone projects into the region of any rainfall, it is difficult to conjecture. It may be said here, that the problem of a fresh-water supply in a thickly settled island like Bermuda, especially when needed in quantities in a large modern hotel, is a difficult one. In spite of its insular position the average rainfall. is not high, running to two or three inches a month, with, generally, twice that quantity during some one month in the year. Springs and streams are a negligible quantity, while ordinary wells are poor, unreliable, and shunned for sanitary reasons. The ordi- nary supply is rain water, caught from the roofs of houses and stored in cisterns. Where a larger amount is needed, a slop- ing hillside is cleared of its vegetation and soil, down to the white chalk-like limestone, which having been cleaned and smoothed forms a watershed whose drainage is collected and led to the cistern. It is quite evident that no mere surface rainfall would supply any underground reservoirs in a small oceanic island like Bermuda, to be tapped by deep boring, and the projectors of the well realized this, but hoped that water of “ volcanic origin” might in some way be met with. It is, perhaps, needless to say that this hope was not fulfilled. But while the enterprise from the commercial side was a failure, its interest and value from the scientific standpoint is very great. Fortunately, it was perceived by Mr. Howe that this would be the case, and it was owing to his foresight that records were kept and samples taken at each stage of the work. One set of these has come into possession of the United States National Museum, and it is due to the courtesy and permis- sion of Dr. Richard Rathbun, assistant secretary in charge, " Pirsson and Vaughan—Deep Boring in Bermuda. 71 that we have been given the opportunity of using this material in addition to our own. Situation and Nature of the Boring.—The site of the bor- ing is in the parish of Southampton, on the slope of a hill nearly a mile west of the lighthouse on Gibb’s Hill. The spot selected is about 200 feet above sea-level. The method of boring was not that of the diamond drill by which a solid core is obtained, but by the use of a drill which is raised and dropped, a method commonly used in boring oil wells. In this case, the material is removed in the form of a coarse powder. Fortunately, in placing the casing, occasional chips of the rocks are eee off and obtained, and this has furnished some material of a size sufficient for the making of thin sec- tions, and thus for petrographic study in the usual manner. At the time when the well was visited by one of us, the boring was down 800 feet ; since then it has been continued over 600 feet more, making a total depth of over 1400 feet. Summary of Results—Very briefly stated for this prelim- inary paper, it may be said that of the 1400 feet penetrated by the boring, the first 360 feet are in the limestones of the usual character known in Bermuda. Below them for 200 feet, soft yellowish to brown, often clay-like rocks are met, whose nature indicates that they are more or less decomposed volcanic tufts. Below them blackish to gray compact volcanic rocks are found, of andesitic and basaltic appearance. The study of the section made from a chip indicates that this is a lava, and, though con- siderably altered, an augite-andesite. This rock continues without essential ‘change in character for the further 800 feet penetrated. The geographical situation of Bermuda in the Atlantic basin, distant as it is from other islands and the continental mass, “together with its isolation as a coral island, renders any new fact which we may obtain of its geology a matter of par- ticular interest and value in several directions. The data which our investigation may be expected to furnish will have a bearing on the origin of coral islands and certain limestones ; while a knowledge of the nature of the underlying lavas of the volcano will contribute material toward a better under- standing of the problem of the distribution and relation of igneous rocks in the Atlantic basin. In addition, Mr. Joseph A. Cushman is studying the foraminifera for a report on the paleontology. The object of this paper is merely to give a preliminary notice of this investigation and of our being at work in this field. New Haven and Washington, June 10th, 1913. 72 Browning and Minnig—Preparation of Tellurie Acid. Art. X.—A Wote on the Preparation of Tellurie Acid and a Test for Associated Tellurous Acid; by Putiie E. Browntine and H. D. Mrynice. [Contributions from the Kent Chemical Laboratory of Yale Univ.—cexlvi.] Or the various methods suggested for the preparation of telluric acid, two only seem to be in general use: first the oxi- dation of tellurous acid by chromic acid,* and the precipita- tion of the telluric acid by nitric acid after the concentration of the solution ; and second, the oxidation of an alkali tellurite by hydrogent dioxide, followed by the precipitation of the telluric acid by nitric acid. While both of these methods give quite satisfactory yields, the difficulty of washing out the chromium salt{ in the first method, and of removing the alkali salt in the second method is apparent. Berzelius formed tellu- rates by passing chlorine into an alkaline solution of a tellurite, but here also the precipitation of the telluric acid would have the same disadvantage in the inclusion of alkali salts. The work to be described was undertaken to study the effect of free chlorine upon elementary tellurium suspended in water. The element in the form of an amorphous powder weighing several grams was suspended in water and subjected to the action of a current of washed chlorine gas. After about an hour the tellurium had dissolved, and a portion of the solution, made alkaline and then acidified with acetic acid, remained clear, showing the complete oxidation to telluric acid. It was found by experimentation with solutions of tellurates and tellurites that this method of testing would detect a milli- gram of tellurous acid in the presence of between one and two hundred milligrams of telluric acid, in a volume of 5°, When the solution was thoroughly saturated with chlorine and the complete oxidation was shown by this method of test- ing, the solution was evaporated to small volume, tested to be sure that no reduction had taken place, and again treated with chlorine if necessary. The concentrated solution was then treated with acetone or ethyl alcohol to the complete precipita- tion of a beautifully crystalline product of satisfactory yield. This product was washed with acetone or alcohol until the washings gave no test with silver nitrate for hydrochloric acid. The telluric acid obtained was readily soluble in water ; moreover, the solution gave no indication of the presence of tellurous acid on treatment with an alkali hydroxide and acetic acid, and was not reduced by stannous chloride except on warming. * Staudenmaier, Zs. anorg. Chem. x, 189; Gutbier, xxix, 22. + Gutbier, Zs. anorg. Chem., xl, 260. ¢{ Kothner, A., cccxix, 39. Browning and Minnig—Preparation of Tellurie Acid. 73 After concentration of the telluric acid solution, the acid may be precipitated by nitric acid, washed with the same reagent to remove the hydrochloric acid and then with acetone or ether to remove the nitric acid. This modification of the process, however, appeared to have no advantage in the purity of the product. The absence of contaminating salts is practically assured by the method described if the elementary tellurium used is rea- sonably pure. June, 1913. SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. Compounds of Trivalent and Quadrivalent Tungsten.— That tungsten forms compounds of at least one lower state of oxi- dation than tungstic acid, WO,, has been well known for a long time, as the beautiful blue color produced by its reduction has been extensively used as a qualitative test for the element, but heretofore little has been known in regard to the nature of the reduction products. O. Otsson, however, has recently succeeded in preparing several well-crystallized compounds of trivalent and quadrivalent tungsten. By reducing strong hydrochloric acid solutions with metallic tin he obtained the double salts K,W,Cl, and (NH,),W,Cl,, which show the existence of WCl, in combina- tion. The analogous thallium, calcium and rubidium salts, T1,W,Cl,, Cs,W,Cl,, and Rb,W,Cl, were prepared also. These salts are greenish yellow in color, they are fairly stable in the air in the dry solid condition, but in their preparation it was neces- sary to protect the solutions with an atmosphere of carbon diox- ide. By using less complete reduction by means of tin the author has been able to obtain a single dark green salt, which appears to contain quadrivalent tungsten, with the formula K,W(OH)Cl.. — Berichte, xlvi, 566. He Ws 2. A New Oxide of Carbon.—H. Meyer and K. Sterner have succeeded in preparing the anhydride, C_,O,, of mellitic acid. This is a benzol derivative, each of the six carbons of the benzol ring being combined with a CO group, and the three adjacent pairs of CO groups being connected by an oxygen atom. The compound is peculiar in containing precisely 50 per cent each of carbon and hydrogen. It forms brilliant, colorless crystals which are very stable, and may be dried at 160° ©. without change. The sub- stance begins to darken when heated above 320° C., and it burns 74 . Scientific Intelligence. with a smoky flame in the air, but it may be sublimed by heating in a vacuum. It is almost insoluble in cold water, but upon warming with water it forms mellitic acid, C,,H,O,,.— Berichte, xiva, 813. H. La Wes 3. The Hxamination of Waters and Water Supplies; by Joun C. ToresH. Second Edition. 8Vvo, pp. 644. Philadelphia, 1913 (P. Blakiston’s Son & Co. Price $5.00 net).—This is an admirable treatise, dealing with all the aspects of the subject under conditions existing in England. ‘The author emphasizes the importance of the examination of sources of water supply, and gives an excellent discussion of this topic. The methods of water examination are very fully treated, and the results of many analyses, useful for comparison, are given. There are 34 plates illustrating microscopical objects found in water. It may be mentioned that the author employs an ingenious and appar- ently novel device for eliminating the error due to the excess of the reagent necessary to produce the end-reaction in connection with certain volumetric determinations. For example, in deter- mining hydrogen sulphide with centinormal iodine solution it was found that 500° of the water required 9° of the iodine solu- tion to give a blue color with starch ; then 8°° more of the water itself removed the blue color. It was assumed that the true end- point lay half way between 500 and 508° of water, so that 504° was the amount used for the calculation. The same plan is used in determining chlorine by means of silver nitrate with a chro- mate as indicator. In a few operations the author recommends the use of weighed paper filters where the employment of the Gooch filter is to be preferred. H.. Li, WG 4. Gas Analysis; by L. M. Dennis; 8vo, pp. 434. New York. 1913 (The Macmillan Company. Price $2.10 net).— This very full and satisfactory text-book on gas analysis will be welcomed by all who are interested in teaching or practising this branch of analytical chemistry. In its general plan the book fol- lows the author’s well known translation of Hempel’s work, but much new materia] has been added, and many of the older methods have been modified or omitted, so that the book is actually a new and original work. While the greater part of the book is devoted to rapid methods of technical gas analysis, descriptions are given also of certain methods of exact analysis that are adapted to specific determinations. The manipulation of the-more generally used types of apparatus is very fully described, the illustrations are excellent, and in general the book deserves the highest praise. Hy To Wee 5. Chemical Analysis for Students of Medicine, Pharmacy, and Dentistry; by Expert W. Rockwoop ; 8vo, pp. 247. Phila- delphia, 1913 (P. Blakiston’s Son & Co.).—The fact that this is the fourth edition shows that the book is extensively used. After an introduction dealing with operations and a few general principles, a course of inorganic qualitative analysis is taken up, which is fairly extensive. Then comes a chapter on the qualita- au and Physics. 75 tive reactions of organic compounds, dealing with a number of substances important in medicine, including a few of the vegeta- ble alkaloids. The second part of the book deals with volumetric analysis and gives a number of important methods. ~The last part takes up the sanitary examination of water, the detection of poisons, and blowpipe analysis. While some of the practical parts of the book are very brief, they appear to be well adapted to the purpose of serving as an introduction to the subjects. It would seem desirable to provide this class of students with some practice in gravimetric analysis, which is not included in this book... H. L. W. 6. Per-Acids and Their Salis; by T. SLATER PRICE ; 8vo, pp. 123. London, 1912 (Longmans, Green & Co.).—-This is one of a series of ‘‘ Monographs on Inorganic and Physical Chemis- try,” edited by Alexander Findlay. It deals very fully with an important branch of modern chemical research, gives very exten- sive references to the literature, and it is a very useful book for advanced students and for teachers of chemistry. Hols W: 7. Practical Physiological Chemistry ; by Puinie B. Hawx. Fourth Edition. Pp. xx, 475. Philadelphia, 1912 (P. Blakis- ton’s Son & Co.).—The fourth edition of this useful manual of practical physiological chemistry has been greatly enlarged by the addition of much new material with a thorough revision of the old. Its usefulness has been greatly increased by the addi- tion of references to the original literature, the lack of which in previous editions has limited its value as a reference book. The chapter on urine analysis contains a description of the newer methods such as Van Slyke’s amino nitrogen method, and the microchemical methods of Folin and his coworkers for urea, ammonia, and total nitrogen. To the chapter on enzymes has been added a reference table of enzymes, their classification and properties. A description of the discovery, optical properties, and chief source of the amino acids occurring in proteins in tabular form has been added to the chapter on proteins. As in previous editions, the excellent illustrations are conspicuous. The book asa whole is admirably suited “for use in courses in practical physiological chemistry in schools of medicine and science,” one- half of the contents being devoted to a study of the urine. The main fault, if any, in this manual lies in too great a wealth of material rather than in toolittle. In the description of many of the various qualitative tests, it would seem that some selection of a few of the more important tests from among the many described, which vary only in some slight detail from each other, might well be made. The detailed description of some of the less important determinations such as the determination of fecal amylase and fecal bacteria should be relegated to more complete reference manuals. More space should be devoted to an account of the mode of origin of the aporrhegmas and other products of intestinal putrefaction, an account which in the present edition is limited to a statement of their primary source, proteins, with no more complete explanation. H. B. L. 76 Scientific Intelligence. 8. The Influence of Dissolved Salts on the Absorption Bands of Water.—Some important facts bearing on the theory of solu- tions have been discovered by H. C. Jonus, J. S. Guy and E. J. SHAEFFER. The fundamental piece of apparatus used was a specially constructed radiomicrometer of short period. A Nernst glower produced the radiations, The region of wave-lengths investigated extended from 0°710p to 1°445y, since the infra-red absorption bands of water fall within this interval. The experi- mental method may be made clear by the following concrete example. The deflection of the radiomicrometer was observed when a chosen wave-length had passed through a cell containing a layer of solution 1™™ deep. Then the deflection was read when the same radiation had passed through a cell containing 11™™ of the same solution. The ratio of these two deflections measures, in a certain sense, the absorption which would be produced by a layer of the solution 10™™ thick. The object in using two depths was to eliminate the effects of the ends of the cells. Next the percentage by volume of water in the solution was calculated from the specific gravity of the solution and from its coneentra- tion. This percentage may be formulated as 100s — O-lkm where s denotes specific gravity, & means the multiple of normal, and m stands for the molecular weight of the dissolved substance. This method of calculation assumes that the solvend and solvent are present in the solution quite independently of each other. If the specific gravity of a 6X normal solution of potassium chloride is 1°236 the per cent calculated would be 78:9, (A = 6, m = 74°, $s = 1236). Consequently the cell was set at a depth of 1™™, filled with pure water, and the deflection noted. Then the micrometer reading corresponding to a depth of 8°89™™ of pure water was taken. As before, the ratio of these two deflections is a measure of the absorption caused by a column of water 7:89™™ deep, that is, due to a column equivalent (on the assumption of independence of solvent and dissolved salt) to the water present in 10™™ of solution. For each salt studied two curves are plotted on the same diagram. ‘The abscisse are wave-lengths and the ordinates are proportional to the ratios of intensities as explained above. One curve pertains to pure water and the other corre- sponds to the aqueous solution. The dissolved substances were chosen so as to have no appreciable absorption in the region of the infra-red absorption bands of water. For the chlorides and nitrates of ammonium and potassium the curves for the solutions and for the equivalent depths of water were practically coinci- dent. This means that the dissolved substance and the solvent are effectively independent in solution, so far as the absorption of light is concerned. On the other hand, when the salts dis- solved were calcium chloride, or magnesium chloride, or alumin- ium sulphate the solutions were far more transparent than the equivalent depths of pure water. This experimental fact is very striking. ‘The last three salts have been shown by Jones to be the most strongly hydrated substances known, hence the obvious Geology and Natural Mistory. ae explanation is that a certain percentage of water molecules have formed complexes or “ hydrates” with the dissolved salt and that only the remaining water molecules are free to absorb as they would do if no dissolved substance were present. There are, of course, other ways of explaining the important fact mentioned above.—Amer. Chem. Jour., vol. xlix, April, 1913, p. 265. #7 8211 /Uh II. Grotogy anp Natura History. 1. United States Geological Survey ; GrorcE Oris SMITH, Director.—Recent publications of the Geological Survey are noted in the following list (continued from vol. xxxv, p. 329) : Toprocrapuic ATLas.—Fifty-nine sheets, including a large. map of the island of Kauai, Hawaii. : Fortos.—No. 184. Kenova Folio: Kentucky—West, Virginia— Ohio; by W. C. PHaten.. Pp. 16; 13 figs., one chart, 3 maps. No. 186. Apishapa Folio: Colorado ; by GroreE W. SToss. —Pp. 12; 20 figs., 3 maps, 13 pls. Minera Resources of the United States, Calendar Year, 1911. Part I. Metals. Pp. 1018; 16 figs. Bui.etins.—No. 502. The Eagle River Region, Southeastern Alaska ; by ApotpH Knorr. Pp. 61; 5 pls., 3 figs. No. 503. Iron-Ore Deposits of the Eagle Mountains, Cal- ifornia; by Epmunp C. Harprr. Pp. 81; 18 pls., 4 figs. No. 527. Ore Deposits of the Helena Mining Region, Mon- tana; by ApotpH Knorr. Pp. 143; 7 pls., 4 figs. No. 529. The Enrichment of Sulphide Ores; by Wiuriram H. Emmons. Pp. 260. No. 537. The Classification of the Public Lands ; by GrorGE Otis SmirH and others. Pp. 197; 8 figs. WatTER Supply Paprrs.—No. 297. Gazetteer of Surface Waters of California. Part III. Pacific Coast and Great Basin Streams. Prepared under the direction of Joun C. Hoyt, by B. D. Woop. Pp. 244. No. 300. Water Resources of California. Part III. Stream Measurements in the Great Basin and Pacific Coast River Basins. Prepared under the direction of Joan C. Hoyt, by H. -D. McGuasuHan and H. J. Dean. Pp. 956; 4 pls. No. 310. Surface Water Supply of the United States 1911. Part X. The Great Basin. Prepared under the direction of M. QO. Lereuton; by F. F. Hensuaw, H. D. McGuasuan, and E. A. Porter. Pp. 210; 4 pls. No. 313. Water Powers of the Cascade Range. Part II. Cowlitz, Nisqually, Puyallup, White, Green, and Cedar Drainage Basins; by Frep F. Hensuaw and Guenn L. Parker. Pp. 170; 16 pls., 12 figs. No. 316. Geology and Water Resources of a portion of South-— Central Washington ; by Grratp A: Warine. Pp. 46; one plate, one fig. 78 Scientific Intelligence. No. 317. Geology and Underground Waters of the Wichita Region, North Central Texas; by C. H. Gorpon. Pp. 88; 2 lates. : A disastrous fire in the basement of the Geological Survey building, on May 18, destroyed most of the “reserve stock” of the Survey publications and some of the folios and topographic maps ; the total loss is estimated at $75,000. Fortunately a recent transfer to the Government Printing Office saved a large part of the publications from destruction and thus prevented a much larger loss. A new fireproof building, to cost about $2,500,000, is in prospect, but unfortunate delays in Congress have postponed the beginning of the construction for another year. 2. Bureau of Mines, United States.—Recent publications include the following (see vol. xxxv, p. 330) : BuLuetins.—No. 48. Selection of explosives used in engineer- ing and mining operations; by CiareNce Hatt and §. P. Howey. Pp. 50; 3 pls., 7 figs. No. 52. Ignition of mine gases by the filaments of incandes- cent electric lamps ; by H. H. Crarx and L. C. Instzy. Pp. 31; 6 pls., 2 figs. No. 54. Foundry-cupola gases and temperatures; by A. W. BELDEN. Pp. 29; 4 pls., 16 figs. No. 55.. The commercial trend of the gas-producer in the United States ; by R. H. Fernarp. Pp. 92; 1 pl., 4 figs. No. 62. National Mine-Rescue and First-Aid Conference, Pittsburgh, Pa., September 23-26, 1912; by H. M. Witson. No. 68. Sampling coal deliveries, and types of Government specifications for the purchase of coal ; by G. S. Popr. Pp. 68, 3 pls., 3 figs. No. 65. Oil and gas wells through workable coal beds ; papers and discussions ; by G. 8. Ricz, O. P. Hoop, and others. Pp. 101, 1 pl. Also Technical Papers, Nos. 14, 31, 36, 38, 40, 46, 48, 52, 53. 3. Geological Survey of New Jersey ; Henry B. KtUmMMEt, State Geologist.—Bulletins 8 and 9 have recently appeared. No. 8 contains the annual administrative report of the State Geologist for 1912, and two Appendixes. The first appendix describes the improvements of Shark River Inlet as ordered by the legislature of May 1, 1911; thisis by C. C. Vermevute, Consulting Engi- neer. Appendix B gives a list of new bench marks in some eight counties. ‘ Bulletin 9, compiled by ALANSoN SKINNER and Max ScuRa- BISCH, 1s a preliminary report of the archeological survey of the State. The first chapter describes the types of Indian remains found in New Jersey, and the following chapters the Indian camp sites and rock shelters in different parts of the State. A map accompanies the report, showing the distribution of archzo- logical remains. Geology and Natural History. 79 4. Map of West Virginia, showing Coal, Oil, Gas, Iron Ore and Limestone Areas ; published by the West Virginia Geological Survey and the State Semi-Centennial Commission ; I. C. Wuirg, State Geologist, assisted by Ray V. HENNEN and C. E. Kress. Morgantown, W. Va., 1913.—This new edition contains a thorough revision of the coal, oil, and gas develop- ments, several anticlinals being added, and others corrected from later observations. The valuable iron ore deposits of the State are also indicated on this map, and all the special features of pre- vious editions corrected and brought up to date, showing the approximate areas of the several coal series, operating mines and their post office addresses, as well as the oil and gas pools. Scale, 8 miles to the inch. Price by mail, 50 cents each. 5. West Virginia Geological Survey; I. C. Wuirs, State Geologist. Volume V (A), Zhe Living and Fossil Flora of West Virginia. Pp. xiii, 491. Wheeling, 1913.—This volume consists of two parts. Part I, The Living Flora, by Dr. C. F. Mittspavenr. This is a complete revision of the “ West Virginia Flora” published in 1896, with many additions and new species brought up to date. It is invaluable for students and teachers of Botany. Also Part II, the Fossil Flora, by Dr. Davin Waite. A complete list of the fossil plants associated with each of the great coal beds, thus constituting a much-needed guide to corre- lation. 6. Wisconsin Geological and Natural History Survey. E. A. Birer, Director; W. O. Hotrcuxiss, State Geologist—An im- portant map of the State of Wisconsin has recently been issued | showing both the Geology and Roads. This has been prepared by W. O. Hotchkiss and F. T. Thwaites and is issued in two parts on a scale of 6 miles to the inch. It is based upon the work of the present Survey, that of 1873-9 under 'T’. C. Chamber- lin and of other organizations. A concise outline of the geolog- ical history of Wisconsin is added in the second sheet, which gives also three structure sections. 7. Geological Survey of Alabama; EuGENE ALLEN SMITH, State Geologist. Jron-making in Alabama. Third edition; by W. B. Parties. Pp. 254; 31 pls. 2 figs—This is the third edition of a work first published in 1896. The years that have elapsed since then have seen very great advance in the produc- tion of iron ores, and the manufacture of iron and steel, in Ala- bama. This whole subject is presented in detail, with a large number of interesting plates. There has also been issued: Map of the Coosa Coal Field with vertical and horizontal sections ; by Witiiam F. Proury, Assistant State Geologist. 8. Canada Department of Mines.—Recent publications of the Canada Department of Mines (see vol. xxxv, p. 550) are as follows: (1) GzoLogicaL Survey Brancu; R. W. Brock, Director. Memoirs. No. 17, E.—Geology and Economic Resources of the Larder Lake District, Ontario: and adjoining portions of 80 Scientific Intelligence. Pontiac County, Que.; by Mortey E. Wirson. Pp. vii, 62; 11 pls., 5 figs., 2 maps. ye No. 35. Reconnaisance along the National Transcontinental Railway in Southern Quebec; by Joun A. Drusszer. Pp. vii, 42; 6 pls., 3 figs. (2) Mines Brancu; Eucene Haanet, Director. An Investigation of the Coals of Canada with reference to their Economic Qualities. In six volumes; by J. B. Porter and R. J. Durtry, with assistants. Vol. V, pp. 318, 17 charts; vol. VI, pp. 120; 3 pls., 6 figs. Annual Report on the Mineral Production of Canada during the Calendar Year 1911. Joun McLeisn, Chief of the Division of Mineral Resources and Statistics. Pp. 316. The Magnetic Iron Sands of Natashkwan, Saguenay, Quebec ; by G. C. Macxrnziz. Pp. 49; 22 pls., 9 figs., 3 maps. | Butuetin, No. 8.—Investigation of Peat Bogs and Peat Indus- try of Canada, 1910-11; by A. Anrep. Pp. 533; 19 pls., 1 fig.; 12 maps in separate pocket. 9. Virginia Geological Survey ; T. L. Watson, Director. Bulletin No. V, Zhe Underground Water Resources of the Coastal Plain Province of Virginia ; by SAMUEL SANFORD (pre- pared in codperation with U.S. Geol. Survey). Pp. 361, figs. 8, tables 11, map in pocket. Charlottesville, 1913.—Bulletin No. V forms a companion volume to the previously published ‘ Physiog- raphy and Geology of the Coastal Plains Province of Virginia” (this Jour., xxxili, 594), 1912, and deals exhaustively with the underground water problems of this portion of the coastal plain. Plenty of water is to be had in this area. and the position and character of the Cretaceous, Tertiary and Pleistocene beds are so well known that the depth required to secure artesian flows can be determined within fairly narrow limits. Following a general discussion of principles and recommendations regarding well con- struction, sanitation, etc., the ground water conditions in thirty- © eight counties included within the area are treated in detail,—a most commendable feature, since the report is designed to be of direct use to farmers and municipalities. The tables of well data (pp. 297-353) furnish a convenient summary. In the opinion of the reviewer there is no better expression of the economic value of geologic science than is to be found in the volumes issued by the Federal and State Surveys dealing with water resources. H. E. G. 10. Geological Survey of Ohio; J. A. BownocKsr, State Geologist. ourth Series, Bulletin 14 (in codperation with the United States Geological Survey), Geology of the Columbus Quadrangle. Part I, Historical or Areal Geology, by CLinron R. Sraurrer, pp. 11-50; Part Il, Physiography or Surficial Geology, by Grorce D. Husparn, pp. 51-112; Part III, Economie Geology, by J. A. Bownocker, pp. 113-129. Plates i-xxvill, figures 16, 3 maps in pocket.—The Ohio geological re- ports have taken high rank, particularly along stratigraphic and Geology and Natural Eistory. 81 economic lines, since the establishment of the first Survey. The publications, however, have been of limited use to teachers, students, and general readers because of their technical character. The present volume is designed for students in colleges and teachers in schools and admirably fulfils its purpose. The physio- graphic treatment in particular is adapted to serve as a textbook in itself. It is to be hoped that more volumes of this character will be forthcoming. H. E. G. 11. State Geological Survey of Wyoming, Bulletin 3, Series B, The Douglas Oil Field, Converse County ; The Muddy Creek Oil Field, Carbon County,. by C. E. Jamison, State Geologist. Pp: 50, pls. i-vili. Cheyenne, 1912.—In the Douglas anticline, the exposed beds exhibit a stratigraphic sequence from pre- Cambrian to Quaternary. Oil occurs in the Lower Cretaceous’ and most of the seventy-one wells sunk in this field report “ small amount of oil.” In the Muddy Creek field oil-saturated sand- stone (lower part of Wasatch formation) overlies unconformably 3200-3400 feet of Fort Union sandstones and shales containing numerous beds of coal. H. E. G. 12. Coal, and the. Prevention of Explosions and Fires in Mines ; by JouN Harcer. Pp. 183. London, 1913 (Longmans, Green & Co. ).—The character of this admirably written volume and its evident field of usefulness is sufficiently indicated by its contents. The principal chapters deal with: Combustion, respira- tion, mechanism of explosions, the réle of dust in explosions, prevention of explosions, gob fires—their phenomena. and treat- ment. H. E. G. 13. New Zealand Department of Mines, Geological Survey Branch; P. G. Morean, Director. Bulletin No. 15 (New Series), The Geology of the Waihi-Tairua Subdivision. Hauraki Division; by James Macxrytosa Bett and Comyn FRaser. Pp. 192, pls. i-x, 10 diagrams, 18 maps and sections. Welling- ton, 1912.—The publication of maps and descriptions of the Waihi-Tairua subdivision completes the geological survey of the Hauraki peninsula,—an area prevailingly volcanic. No sedi- mentary formations occur in the region under discussion, the suc- cession being: Eocene (?), andesitic and dacitic lavas and breccias ; Miocene, similar to Eocene; Pliocene. rhyolitie and dacitic tuffs, breccias, agglomerates and flows. Dikes of andes- ite, dacite and rhyolite of post-Pliocene and earlier dates traverse the rock complex. Mineralization through hydrothermal action is especially pronounced in the Eocene and Miocene rocks. At- tention is called to the similarity in origin and occurrence between the gold deposits of Hauraki and those of Washoe, Cripple Creek, Tonopah, etc., in the United States. Detailed dis- cussion of mines and prospects, illustrated by analyses and maps, constitutes the major part of the report. The region has pro- duced over $50,000,000 worth of gold and silver bullion from quartz veins. H. E. G. Am. Jour. Sct.—Fourts Series, Vout. XXXVI, No. 211.—Juty, 1913. 6 82 a Scientific Intelligence. 14. Geology and Ore Deposits of the Monarch and Tomichi Districts, Colorado ; by R. D. Crawrorp. Pp. 317, 25 pls., 15 figs. Bulletin 4, Colorado Geological Survey, 1913.—The area described in this bulletin is situated in the southwestern por- tion of Chaffee County and the adjacent southeastern portion of Gunnison County, the Monarch District lying on the eastern and the Tomichi District on the western slope of the Sawatch Moun- tain Range. The region is one of high relief, ranging from an altitude of 6000 feet to the summit of Shavano Mountain, 14,239 feet. The pre-Cambrian rocks include gneisses and schists into which a granite batholith is intruded. ‘These rocks were exposed to erosion for a long period and after the land surface was reduced to almost a peneplain there followed a period of subsi- dence and the deposition of a series of sedimentary rocks. Sedi- ‘mentation was interrupted from time to time by periods of elevation and erosion. The important sedimentary rocks are a late Cambrian quartzite, an Ordovician limestone, a parting quartz- ite, an Upper Devonian limestone, a black dolomite of Missis- sippian time and Upper Carboniferous shales and sandstones. Following this period of sedimentation the region was subjected to strong compressive forces which threw the strata into a series of anticlines and synclines and developed many faults. Probably in Tertiary time much of the region now occupied by the Sawatch Range was invaded by a huge batholith of quartz monzonite whose southern limits are within this area. This intrusion was preceded and followed by intrusions of granular rocks in stocks and by minor intrusions of porphyry. The ore deposits were formed probably immediately after and as a consequence of the intrusion of the quartz monzonite. The first discovery of ore in the Monarch District was in 1878. The various mines have produced since then approximately $10,000,000 worth of ore. The deposits are of various types, including: (1) Replacement deposits in limestone, (2) filling of fault fissures in the sedimentary rocks with replacement of the wall rocks, (3) fissure veins in igneous rocks, (4) contact deposits. The greater part of the ores have been silver-bearing lead carbonate. Lead, gold and zinc have also been produced. The Tomichi District was discovered in 1879. Its ores have produced gold, silver, lead, zinc, copper and iron in commercial quantity, silver and lead being, however, by far the most important. W. E. F. 15. The Devonian and Mississippian formations of northeastern Ohio ; by Cuarites S. Prosser. Geological Survey of Ohio, J. A. Bownocksr, State Geologist. Fourth series, Bull. 15, 574 pp., 33 pls., 1 text fig., 1912.—The author here describes in great detail and with their essential fossils the many sections of: the uppermost Devonian and basal Mississippian formations of north- eastern Ohio and northwestern Pennsylvania. It is the work of many years, done between professorial duties. The writer for the present holds that the’ black shales of the Huron, Cleveland and Bedford, when traced eastward through Ohio, change into Geology and Natural History. 83 the more fossiliferous Chagrin formation with its distinctly Che- mung fauna. The difference in sedimentation is thought to be due to distance from the shore line. Therefore all of these forma- tions appear to be more naturally referred to the Devonian period, while the Mississippian is begun with the Berea of Ohio and the Cussewago of Pennsylvania. The contact of these upper sand- stones upon the underlying shales is often an irregular erosion line and is always disconformable. A number of brachiopods are described in detail, and much valuable pale ontologic work is scat- tered throughout the work. The volume is a most important contribution toward the final adjustment of the Devono-Carboniferous line of separation, which has been under discussion more or less vigorously for the past thirty-five years. Cc. 8. 16. Fossil Coleoptera from the Wilson Ranch near Florissant, Colorado ; by H. ¥. Wickuam. State University of Iowa, Bull., Vol. vi, No. 4, 29 pp., 7 pls., 1913.—In this pamphlet are described five new genera (Creniphilites, Cychramites, Protoncideres, Pythoceropsis, Xyleborites) and forty new species. The author states that the Florissant strata have now yielded 377 species of described beetles, but that about 200 new forms still await description. All of these are derived from Miocene deposits of an area nine miles long and two miles wide, with a maximum thickness of fifty feet. In a quarry twenty feet long and six feet deep the author collected ninety-five species. He says, however: “Tt may be worth mentioning that a stroll along the beach of Lake Superior after a favorable night wind would show a much more striking assemblage of beetles, as far as size and structure are concerned, than seems to have been present about the shores of the ancient Lake Florissant ”’ (6). Cc. 8. 17. The Lower Siluric shales of the Mohawk valley ; by RupotF RuEDEMANN. N. Y. State Museum Bull. No. 162, 151 -pp., 10 pls., 30 text figs., 1912.—A most valuable and interesting study showing how the Trenton limestone in passing eastward into the Hudson valley changes into a shale (the Canajgqharie and Schenectady formations) with markedly different faunal assem- blages. The Utica and Frankfort formations are shown to be absent in the Hudson valley, though the latter formation is in part represented in the east by the Indian Ladder formation, deposited in a different trough, a long and narrow one belonging with the Green Mountain foldings. Verily, the supposedly reli- able New York “Standard of Correlation” is hardly yet trust- worthy ! As the distinguishing of these various faunas depends upon an accurate knowledge of the combinations of known forms and new species, the author here describes essentially all of the previously undefined or poorly understood forms, more than fifty in num- ber. A new genus of marine alga is also proposed, Sphenophycus. C..:35 84 Scientific Intelligence. 18. An Introduction to Zoology, with Directions for Practical Work (Invertebrates); by Rosariz Luntuam. Pp. xv, 457, with 328 figures and 5 plates by V. G. Sheffield. London, 1913 (Mac- Millan and Co.).—The recent trend of biological teaching away from anatomical details and toward a return to the Natural His- tory studies which characterized the science a half century ago is well illustrated by this new book, prepared for use in British schools. The Introduction consists of a well-written and well-illus- trated account of the external structure and habits of British invertebrate animals, with anatomical descriptions sufficient only for an understanding of the general structural plan of the dif- ferent groups. The subject matter is divided into twenty-seven chapters, each of which takes up for discussion a single group of animals. At the end of each chapter is a brief survey of the classification of the principal animal forms belonging to the group under discus- sion, with directions for their collection and study. The writer wisely selects for description the forms of common occurrence or popular interest. The marine forms receive less attention than those of the lakes and fields; 243 pages, or more than half the book, are devoted to the insects. The majority of the illustra- tions were drawn especially for this work and are of distinct merit. W. Ba@: 19. Malaria, Cause and Control, by Witi1am B. Hers. Pp. xi, 163, with 39 figures. New York, 1913 (The Macmillan Co.).—This is a practical guide to the control of one of the dead- liest enemies of the human race, the malarial mosquito. The writer has had wide experience in the conduct of public campaigns against this pest, and gives here the methods which he has found most successful in protecting the individual and the community from its attacks. The economic importance of the malarial para- site, its life history and means of transmission, the different kinds of mosquitoes, essentials of control, results accomplished by public crusades, advice as to the management of mosquito cam- paigns, expenses involved, and desired legislation are some of the practical features which comprise the various chapters. This book will furnish the information necessary for the guidance of public health officers in this most important sanitary problem. W. R. C. 20. Publications of the British Museum of Natural History.— The following important volumes, based upon the collections in the British Museum, have recently been issued : The History of the Collections contained in the Natural History Departments of the British Museum, Vol. Il. Appendix. By Dr. ALBERT GUNTHER. Pp. ix, 109.—This appendix to the sec- ond volume of the history of the Museum collections gives a record of the development of the zoological section from 1856 to 1895, when the author retired. Previous to the earlier date, this section had been recognized simply as a “ Branch” of the Natural History Department of the originally undivided British Museum. Geology and Natural History. 85 Thirty years ago, however, in 1882-83, the collections were re- moved to the new building at South Kensington, where they are now preserved. The total number of specimens increased from about 1,000,000 im 1868 to 2,245,000 in 1895. Much information of special interest to those concerned with museum administration is given in this volume. Catalogue of the Mammals of Western Europe (Kurope exclu- sive of Russia); by Gerrit 8. Mintzer. Pp. xv, 1019; 2138 figures.—In the preparation of this catalogue, the Museum has been so fortunate as to have the services of Mr. Gerrit 8. Miller, of the U.S. National Museum at Washington. He, as earlier noted (June No., p. 642), has already published a similar work on North American Land Mammals. The European collection of Jand mammals in the British Museum consists of about 5,000 specimens, of which 124 are types. It has been chiefly brought together during the past thirty years, and the sources from which material has been derived are noted in the introduction. Free use has been made of the specimens in other museums, so that the total number on which the work is based approximates to 11,500. Catalogue of the Collection of Birds’ Eggs. Vol. V. Carinatze (Passeriformes completed). By W. R. Ocinvie-Grant. Pp. xxiii, 547 ; 22 plates—With this volume the catalogue of birds’ eggs is brought to a conclusion. Its appearance has been delayed through the unfortunate death of Dr. R. Bowlder Sharpe at the end of 1909. It concludes the order Passeriformes of the sub-class Carinate. Catalogue of the Lepidoptera Phalene, Vol. XII. Catalogue of the Noctuide ; by Sir Grorcs F. Hameson. Pp. vi, 626; 134 figures.—The earlier volumes of this work have been repeat- edly noticed in this Journal. In the present volume 63 genera and 648 species of the Catocalinz are represented. The remainder of this sub-family, with two other small sub-families, will appear in volume XIII, in which the key to the genera and the phylogeny will be reprinted. The Atlas, embracing plates 192-221 to illus- trate the above volume, is about to be issued. Catalogue of the Chetopoda. A. Polycheta: Part I—Areni- colide. By J. H. Asnwortu. Pp. xii, 162; 68 figures, 15 plates. —An introductory survey of the history and classification of the Cheetopoda, and in particular of the Polycheta, is-introduced in - this volume, which is especially devoted to the Arenicolide. No definite provision for the continuation of the volumes on the Chetopoda has been thus far made, but it is anticipated that the work now begun by Dr. Ashworth will be continued from time to time. Catalogue of the Heads and Horns of Indian Big Game bequeathed by A. O. Hume, C.B.; by R. LypEeKxKer. 'Pp. xvi, 45; 16 figures and portrait.—The present catalogue describes what are stated to be the finest specimens of the heads of the big game of India ever brought together ; they were bequeathed to 86 Scientific Intelligence. the British Museum by Mr. Hume. He had earlier given an impor- tant series of Indian mammals, and also some thirty years ago a collection of skins and the eggs of birds from the Indian Empire, ageregating about 82,000 specimens. A Revision of the Ichneumonidae with descriptions of new genera and species. Part II. Tribes Rhyssides, Echthromor- phides, Anomalides and Paniscides; by CuraupE Moruzy. Pp. vill, 140 ; one plate.—This is a continuation of the revision com- menced by the author in 1912. 21. Annual Report of the Director of the Field Museum of Nat- ural History, FREDERICK J. V. SkirF, to the Board of Trustees for the year 1912. Pp. 184-273. Plates OOK LOEU IT Chicago, 1913. —Dr. Skiff’s report of the Field Museum shows the rapid work there being accomplished in the way of installations in ethnology and zoology. Some of the last, including large bird and animal groups, of very attractive character, are illustrated in the present pamphlet. The most important field work in anthropology was that of the Joseph N. Field expedition to Melonesia in charge of Dr. A. B. Lewis ; this is in its fourth year and has yielded a large amount of valuable material. Numerous contributions, particu- larly in paleontology and botany, are also noted. The Museum appeals largely to the people of Chicago, and an increased attend- ance in 1912 of some 15,000 is remarked upon. The total amount expended in the direct work of the Museum was about $240,000. III. Muiscetnuanrous Screntiric INTELLIGENCE. 1. General Index to the Chemical News, Vols. 1 to 100. Pp. 712. London, 1913 (Chemical News Office).—More than fifty- three years have elapsed since the Chemical News was established by Sir William Crookes, the first number bearing the date Dec. 10, 1859. Since that time, it has appeared regularly as a weekly periodical. The current volume is the one-hundred and eighth and a total of about 2800 numbers have been issued. It is hardly necessary to remark upon the very large amount of original mat- ter which has found publication in this valuable journal ; in addi- tion, each number has contained a résumé of the progress in chemistr y and allied sciences, particularly on the industrial side, with notices of books and important memoirs. - It is interesting that the name of the gifted veteran chemist should still appear as editor, while Mr. Walter 8. Crookes is manager. A great service has been now performed for the active chores in making this mass of material easily accessible through a gen- eral index. This index embraces volumes 1 to 100 (1859- -1909) and occupies more than 700 pages, closely printed in fine type, and arranged in three columns to the page. It is evident that no pains have been spared to make this work as complete and accurate as possible. The decision has been wisely reached to Miscellaneous Intelligence. 87 include the subject matter and authors’ index in a single vocabu- lary. Various methods have been employed to insure the maxi- mum degree of conciseness, as in printing the titles belonging toa single subject in one paragraph, clearness being attained by the use of heavy-faced type for the volume number. Other points may be noted, thus references to the different Acips are brought together under the single word, sub-divided, as far as practicable; upwards of twenty pages are required for this portion of the work. The titles of reviews and notices of books are also grouped together under “ Booxs,” which cover some thirty-six pages ; in addition, the author’s name in each case appears in the vocabulary independently. Numerous cross references have been inserted which will insure a prompt finding of the subject desired. All those interested, particularly in chemistry and chemical industry, will be grateful to the management of Chemical News for bringing to completion this great work. 2. The Journal of Ecology ; edited for the British Ecological Society by Frank Cavers. Vol. I, No. 1, May 5, 1913 (Cam- bridge University Press).—The plan of the new Journal is thus stated by A. G. Tansley: “The aim of the Journal of Ecology istwofold. In the first place, as the organ of the British Ecolog- ical Society, it will endeavor to foster and promote in all ways the study of ecology in these islands. In the second place it will endeavor to present, by critical articles and reviews, by full notices of recent ecological publications, and by full lists of current eco- logical literature, a record of and commentary on the progress of ecology throughout the world.” The editor adds further, that contributions (in English, French, or German) are invited; pref- erence will as a rule be given to short articles and notes (not exceeding about 2000 words) and those with a general ecological bearing. Editorial communications should be addressed to Dr. Cavers, Goldsmiths’ College, London, S. E. ; subscriptions should be sent to the Manager, Cambridge University Press, Fetter Lane, London, E. C. The articles in this first number are, as follows : Some remarks on Blakeney Point, Norfolk; by F. W. Oliver. Raunkiaer’s “ Life- Forms” and statistical methods; by Wilham G.Smith. A univer- sal classification of Plant- Communities; by A. G. Tansley. Also the briefer articles: The relation of the present plant population of the British Isles to the glacial period; by Clement Reid. The nature reserve movement in Great Britain; by Wilfred M. Webb. In addition, pages 47-78 are given to a series of notices in part general but chiefly on work bearing on British and on foreign vegetation. 3. Annual Report of the Superintendent of the Coast and Geo- detic Survey, O. H. Tirrmann, for the Fiscal Year ended June 30, 1912. Pp. 106; 10 illustrations including pocket maps. Washington, 1913.—This report with its atlas and series of maps gives the usual summary of the progress of the Survey for the year ending June 30, 1912. Several parties were engaged in the 88 Scientific Intelligence. interior states and territories on primary and secondary triangula- tion. Magnetic observations were made at five observatories, in addition to which there were six parties engaged in this work on land, and observations were also made by the Survey vessels at sea. In this way the magnetic elements were determined at upward of 300 stations, while 60 stations were reoccupied for the purpose of determining the secular change of the elements. The international boundaries between the United States and Canada and between Alaska and Canada have also made important pro- ress. The Superintendent has also published a report to the seven- teenth General Conference of the International Geodetic Asso- ciation on the geodetic operations in the United States, 1909-1912. The California—W ashington Arc of Primary Triangulation ; by A. L. Batpwin. Special Publication No. 13. Pp. 78; 7 illus- trations. 4. Hurricanes of the West Indies. Prepared, under direction of Witiis L. Moorz, by Oxrtver L. Fassic. Pp. 28; 4 tables, 25 plates. Washington, 1913. U.S. Department of Agricul- ture, Weather Bureau Bulletin —This important memoir dis- cusses the areas and tracks of West Indian hurricanes ; their frequency (&8 per cent in August, September and October); pro- gressive movement; duration and intensity ; origin, and allied points. The storm of August 7-20, 1899, so destructive in Porto Rico, is described in particular detail. This general subject becomes of vital interest in connection with the development of navigation in West Indian waters likely to result from the open- ing of the Panama canal. | | 5. Die Zersetzung und Haltharmachung der Hier ; by Prof. Dr. ALEXANDER Kossowicz. Pp. vi, 74. Wiesbaden, 1913 (J. F. Bergmann).—The monograph includes a detailed review of the literature relating to the occurrence of bacteria, yeasts, and moulds in eggs under various conditions of preservation, along with the author’s experimental observations bearing on this ques- tion. In contrast with the contentions of certain American inves- tigators he finds that fresh eggs rarely contain bacteria within them. However in the course of time micro-organisms readily find their way into the interior through the intact shell. This is particularly true of the putrefactive type. In discussing the problems of preserving eggs the author emphasizes low tempera- ture, lime-containing mixtures, and water glass solutions. L. B. M. 6. Publications of the Comitato Talassografico Italiano, Venice, 1912.—The Commission for the investigation of the Italian Seas, which began its work in 1910 (see vol. xxxi, p. 581), continues to be highly active in its many departments. A bi-monthly bulle- tin is published, the last received being No. 20 for the months of November and December, 1912. In addition, a series of twenty memoirs have been given to the public dealing with 1 great vari- ety of subjects. These include the temperature and composition of the sea water ; meteorological conditions over the sea deter- Miscellaneous Intelligence. 89 mined, for example, by balloons; the life of the sea, and the fish- eries, as those for sponges on the African coast. A large amount of important material is thus being brought together, having to do with the Adriatic and Mediterranean. 7. Publications of the Allegheny Observatory of the University of Pittsburgh ; edited by Frank ScuLEsincER, Director. These include the following : Volume II, Title Page and Contents. Vol. HI, No. 1. Irregularities in Atmospheric Refraction ; by FRANK SCHLESINGER. fp. 10. No. 2. The Orbit of U. Sagittze; by Mary Fow er. Pp. bt 15. No. 3. A Description of Eighteen Spectrograms ot Nova Geminorum; by Franx C. Jorpan. Pp. 17-22. Description of the Mellon Spectrograph: A Correction. Pp. 197-199. Index, p. 199. The addresses given in connection with the dedication of the new Allegheny Observatory on August 28th, 1912, are printed in a special pamphlet of 39 pages with 3 plates—Misc. Sci. Papers, Mes. vol. n, No. 2. 8. Publications of the Detroit Astronomical Observatory of the University of Michigan ; Witu1am J. Hussey, Director. Volume I. Pp. 72; 13 plates. Ann Arbor, 1912.—This in- cludes a general illustrated account of the Observatory by the Director ; also papers on the single-prism spectrograph by R. H. Curtiss, and on the registration of earthquakes from Aug. 16, 1909 to Jan. 1, 1912, by W. M. Mircwett. 9. Carothers Observatory—private astronomical, Houston, Texas.—Bulletin No. 1 discusses the ‘Central Law of the Weather :” localized ‘long range” forecasts in actual operation, a comparison with U.S. Weather Bureau’s local forecasts ; by W. F. CarorueErs. 10. Bibliotheca Zoologica II. Verzeichniss der Schriften tiber Zoologie Welche in den periodischen Werken Enthalten und vom Jahre 1861-1880 selbstindig erschienen sind, etc.; bearbeitet von Dr. O. TascueNsBerRG. -Achtzehnte Lieferung. 5515-5800. Leipzig, 1910 (Wilhelm Engelmann, Mittelstrasse 2). —The opening parts, I and II, of this valuable and exhaustive work were noticed in 1887 (see vol. xxxili, p. 245). During the years that have elapsed, nineteen parts have been published, of which seventeen belong to the work proper in its different divisions. Part XVIII (as also XIX, vol. xxxv, p. 558), are sup- plementary in nature; the one now in hand contains corrections and additions, dealing first with literature, books, and periodicals, and, second; with the subjects of aquariums, museums, zoological gardens, laboratories and microscopes, and finally with works dealing with the history of natural sciences and allied subjects. The fact that the work as a whole has run to 6,000 pages, with from twenty to twenty-five references on each page, indicates its extraordinary completeness. 90 Scientific Intelligence. 11. Chemical and Biological Survey of the Waters of Lll- nois. Report for year ending December 31, 1911. Epwarp Bartow, Director. Pp. 173; 20 plates. University of Illinois Bulletin. Vol. 9, No. 20. Urbana, Illinois.—This report has much more than a local value, since the subject with which it deals is of vital importance to all communities situated on the banks of any one of our great rivers. The whole subject of stream pollution in its various aspects is taken up in detail, and much information is given as to the analytical work done, with special details as to individual localities. 12. The Mining World Index of Current Literature, Vol. LI. Second Half Year 1912; by Gro. E. Sistey, Associate Edi- tor Mining and Engineering World. Pp. xxiv, 234. Chicago, 1913.—The Mining World Index, planned to cover the world’s current literature in mining metallurgy and the allied industries, and since 1911 published weekly in the Mining and Engineering World, is now presented in book form, covering half a year ; this second volume concludes 1912. The promptness of its appearance makes it particularly valuable to all immediately con- cerned with the field here covered. OBITUARY. Dr. Ernst Kirti, the well-known Austrian paleontologist, died on May 1, 1913, at the age of 59 years. He was professor in the Royal Technical High School, and Paleontologist and Director of the Geological Department of the Royal Natural History Museum, Vienna. His work was especially along the lines of the faunas of Triassic time. PRoFESSOR JAMES GorDOoN MacGrecor, of Edinburgh Uni- versity, died on May 21 at the age of sixty-one years. He was born at Halifax, was graduated at Dalhousie College and had devoted himself with signal success to investigations in physics. Lorp AvEsuryY, better known as Sir John Lubbock, died on May 28 at the age of seventy-nine years. Many readers have gained pleasure and inspiration from his able writings on flowers and insects. Dr. Wirt1amM Hautocg, professor of physics in Columbia Uni- versity, died on May 21 in his fifty-sixth year. He was gradu- ated at Columbia in 1879 and received the degree of Ph.D. from the University of Wiirzburg in 1881. From 1882-91, he was connected with the U.S. Geological Survey as physicist, and in this capacity did much important research work. He became associate professor of physics at Columbia in 1892, professor in 1902 and was dean of the Faculty of pure science from 1906 to 1909, ‘ . P, , ‘ i New Circulars. 84: Eighth Mineral List: A descriptive list of new arrivals, rare and showy minerals. « 85: Minerals for Sale by Weight: Price list of minerals for blowpipe and laboratory work. 86: Minerals and Rocks for Working Collections: List of common minerals and rocks for study specimens; prices from 1% cents up. Catalogue 26: Biological Supplies: New illustrated price list of material for dissection; study and display specimens; special dissections; models, etc. Szxth edition. Any or all of the above lists will be sent free on request. We are constantly acquiring new material and publishing new lists. It pays to be on our mailing list. Ward's Natural Science Establishment 76-104 CoLnecr AveE., Rocursrer, N. Y. Warns Naturat Science EstaBlisHMENT A Supply-House for Scientific Material. Founded 1862. . Incorporated 1890. DEPARTMENTS: Geology, including Phenomenal and Physiographic. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. Invertebrates, including Bielogy, Conchology, ete. Zoology, including Osteology and Taxidermy. Human Anatomy, including Craniology, Odontology, ete. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Wards Natural Science Establishment, 76-104 College Ave., Rochester, New York, U.S. A. SS ae aia ann a esses =~ FT ee ee oe SET ESS OAT ICL | CONTE N-Tg¢ Page | Arr. I.—Investigation of the Prehistoric Humah Remains found near Cuzco, Peru, in 1911; by H. Binecuam __7 3 9 IJ.—Vertebrate Remains in the Cuzco Grayels; by G. F. HATON L222 22 eee Oe aS Ill.—Gravels at Cuzco, Peru ; by H. E. Gregory .-2.” ee 1V.—Simple Model for Illustrating the Symmetry of Crys- tals ; by A. H. Pears.) -. cases ee 30 V.—Chemical Composition of the Alkaline Rocks and its Significance as to their Origin ; by C. H. Smyrna, Jr..._ 38 VI.—Solid Solution in Minerals. ILI. The Constant Compo- sition of Albite; by H. W. Foote and W. M. Brapiey 47 VII.—Triplite from Eastern Nevada; by F. L. Hess and W. B. UNT 5 ee eo ee ee 51 VIlI.—Heat of Formation of the Oxides and Sulphides of Iron, Zinc and Cadmium, ete. ; by W. G. Mixrsr __--- ob. : 1X. — — Deep Boring in Bermuda Island ; by L. V. Pirsson and: TeV VAUGHAN Cob ee oi oe ae 10 X.—Preparation of Telluric Acid and Test for Associated Tellurous Acid; by P. E. Brownine and H. D. Minnie 72 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Compounds of Trivalent and Quadrivalent Tung- sten, O. Olsson: New Oxide of Carbon, H. Meyer and K. STEtnerR, 73.— Examination of Waters and Water Supplies : Gas Analysis: Chemical Analysis for Students of Medicine, 74.—Per-Acids and their Salts: Prac- tical Physiological ee 75.—Influence of Dissolved Salts on the Absorption Bands of Water, Geology and Natural Hoe ee States Geological Survey, 77.—Bureau of Mines, United States: Geological Survey of New Jersey, 78.—Map of West Virginia, showing Coal, Oil, Gas, Iron Ore and Limestone Areas; Living and Fossil Flora of West Virginia: Wisconsin Geological and Natural History Survey: Iron making in Alabama: Canada Department of Mines, 79.—Underground Water Resources of the Coastal Plain Province of Virginia: Geology of the Columbus Quadrangle, 80.—State Geological Survey of Wyoming, Bulletin 3, Series B: Coal, and the Prevention of Explosions and Firesin Mines: New Zealand Department of Mines, 81.— Geology and Ore Deposits of the Monarch and Tomichi Districts : Devonian and Mississippian formations of N.E. Ohio, 82.—Fossil Coleoptera from the Wilson Ranch near Florissant, Col.: Lower Silurie shales of the Mohawk valley, 83.—Introduction to Zoology: Malaria, Cause and Con- trol: Publications of the British Museum of Natural History, 84.—Annual Report of the Director of the Field Museum of Natural History, 86. Miscellaneous Scientific Intelligence—-General Index to the Chemical News, Vols. 1 to 100, 86.—Journal of Ecology : Annual Report of Superintendent of Coast and Geodetic Survey, 87.—Hurricanes of West Indies: Die Zersetz- ung und Haltbarmachung der Hier: Publications of Comitato Talasso- grafico Italiano, 88,—Publications of Allegheny Observatory of University of Pittsburgh: Publications of Detroit Astronomical Observatory of the University of Michigan : Carothers Observatory: Bibliotheca Zoologica IL, 89.—Chemical and Biological Survey of Waters of Illinois: Mining World Index of Current Literature, Vol. Il, 90. | Obituary—E. Kirtt: J. G. MacGregor: Lorp AveBuRY: W. Haxook, 90. Gs od VOL. XXXVL AUGUST, 1913. Established by BENJAMIN SILLIMAN in 1818. AMERICAN JOURNAL OF SCLENCE, Epirorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW ann WM. M. DAVIS, or CamsBrince, Proressors ADDISON E. VERRILL, HORACE L. WELLS, LOUIS V. PIRSSON, HERBERT E. GREGORY anD HORACE S. UHLER, or New Haven, Proressor HENRY S. WILLIAMS, or ItHaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or WasuHincTon. FOURTH SERIES | VOL. XXXVI—[WHOLE NUMBER, CLXXXVIJ}J. No. 212—AUGUST, 1913. NEW HAVEN, CONNECTICUL [92S 1913. 3 THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. Published monthly, Six dollars per year, in advance. $6.40 to countries in the Postal Union ; $6.25 to Canada. Remittances should be made either by money orders, registered letters, or bank checks (preferably on New York banks). NEW DISCOVERIES AND NEW FINDS. BEAVERITE, A NEW MINERAL. This mineral, which was fuliy described in the December, 1911, number of this Journal, I ‘have been fortunate enough to secure the whole output of. It was found at the Horn Silver Mine in Utah and is a hydrous sulphate of copper, lead and ferric iron. It was found at a depth of 1600 feet. In appearance it resembles Carnotite. Prices 75¢ to $2.00. PSEUDOMORPHS OF LIMONITE AFTER MARCASITE. These remarkable Pseudomorphs, which have never before been found in such clear cut specimens, was described and illustrated in the last number of this Journal. I have secured the majority of the finest of these speci- mens. They vary in size from 2 inches to6 inches. In color they run from brown to glossy black and they have met with favor from all who have seen them. Prices from $1.00 to $10.00. CHIASTOLITES. Of these remarkable specimens, which are generally known as lucky stones, I have secured the finest lot ever found at Madera Co., California. They are cut and polished and sold singly and in collections from 25¢ to 50¢ for single specimens; 9 specimens all marked differently for $5.00, and 18 specimens, all different markings, for $18.00. Matrix specimens, polished on one side showing many crystals, from $2.00 to $8.00. SYNTHETIC GEMS. It is remarkable the interest that has been taken by scientists in these wonderful scientific discoveries. The Corundums are now produced in Pigeon blood, Blue, Yellow, Pink and White. Also the new Indestructible Pearls in strings with gold clasps. These are identical in hardness and rival in color and lustre the real gems. They can be dropped and stepped on without injury and are not affected by acids. My collection of the above is unrivalled, and prices of the same are remarkably low. OTHER INTERESTING DISCOVERIES AND NEW FINDS Will be found in our new Catalogues. These consist of a Mineral Catalogue of 28 pages; a Catalogue of California Minerals with fine Colored Plates; a Gem Catalogue of 12 pages, with illustrations,.and other pamphlets and lists. These will be sent free of charge on application. Do not delay in sending for these catalogues, which will enable you to secure minerals, gems, ete., at prices about one-half what they can be secured for elsewhere. ALBERT H. PETEREIT 261 West 71st St, New York City. etl fe E AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.] Arr. XI.—On the Velocities of Delta Rays; by H. A. BuMSTEAD. gi Tue name “delta rays” was given by Sir J. J. Thomson in 1905 to the slow electrons which he found to be emitted by polonium, and which had previously masked the positive charge of the a-rays. Shortly afterward, and independently, Ruth- erford discovered a similar emission from radium and showed that it was not confined to the source of a-rays, but took place from any body which was struck by them. Some writers have made a distinction between these two phenomena, restricting the name delta rays to those which are emitted by the source of a-rays and calling the others secondary rays. There appears, however, to be little ground for this distinction ; there is no appreciable difference between the two kinds of rays, and every- thing goes to show that Rutherford was right in his original suggestion that all é-rays are secondary phenomena, due to the impact of a-rays upon matter. In the present paper, therefore, the name will be used in this sense. The question of the velocity of the 6-rays has been attacked by a number of investigators.* They have all agreed that a - large proportion of the rays have velocities which are small, as electronic velocities go, not very different, in fact, from those which are observed in the photo-electric effect. The estimates by different observers of the maximum velocity of the rays have en discordant; they have varied from zero to 3-9 x 10° — , the latter corresponding to a fall of potential of about 49 sles * For a historical sketch of the subject see Campbell, Jahrb. d. Radio- aktivitat und Elektronik, ix, p. 419, 1912. Am. Jour. Scl.—FourtTH SERIES, VOL. XXXV, No. 212.—Aveust, 1913. 7 92 H. A. Bumstead— Velocities of Delta Rays. Last year it was shown by Dr. McGougan and the present — writer * that electrons were present in a beam of 6-rays which had much greater velocities than any of the above estimates ; an opposing potential difference of 1700 volts was not sufficient to stop all of them, and very marked effects were produced by electrons having velocities corresponding to several hundred volts. The present paper contains the results of some further experiments upon these swifter rays. It will be seen that there- is no gap between the swifter and the slower electrons, but that all intermediate speeds are found between the highest and the lowest. It seems reasonable, therefore, to include under the name ‘delta rays” all the electrons which are projected from the atoms of bodies by the direct action of the a-rays, the recently discovered swift ones as well as the slower ones previ- ously known; this nomenclature will be adopted in the present paper. It is, however, to be observed that some, at least, of the slower electrons (under 10 volts) must be caused, not directly by the a-rays, but by the swifter d-rays. When there is occa- sion to refer to these they will be called tertiary rays. It is impossible at present to make a sharp distinction between the slower 6-rays and the tertiary rays which come from the source of 6-rays, or to determine the proportion of each; so that in all numerical estimates the tertiary rays must be included among the 6-rays. § 2. Tertiary electrons are emitted also by any body on which é-rays fall and in numbers considerably in excess of the swifter 6-electrons which cause them. When an electric field is used to hold back the slower 6-electrons, this is the most conspicuous effect of the remaining swift rays; for the field which opposes the é-rays assists the tertiary electrons to escape, and their ° larger number magnifies the experimental effect. The unsus- pected presence of this phenomenon has undoubtedly had an influence upon the results obtained in previous experiments — upon 6-rays, and helps to explain the discrepancies which have appeared in the work of different investigators. Unfortunately this effect, which is easy to observe and meas- ure, does not lend itself readily to a quantitative study of the swifter 6-rays. The number of secondary electrons, due to a single incident electron, varies markedly, and not in a very simple way, with the speed of the latter.t In a beam of 6-rays one has a complex of electrons of many different speeds, and when the opposing electric field is, for example, increased, the *Bumstead and McGougan, this Journal, xxxiv, 309, 1912; Phil. Mag., xxiv, 474, 1912. + Gehrts, Ann. d. Phys., xxxvi, 1000 et seq., 1911. aot H. A. Bumstead— Velocities of Delta Rays. 93 slower of these are eliminated and all the remaining ones have their velocities reduced ; under these circumstances it appears quite impossible to draw any conclusions as to the variation in the number of incident 6-rays from observations upon the ter- tiary electrons. | In attempting to determine the distribution in velocity of the swifter 6-rays, the essential thing, therefore, is to eliminate the effects due to the tertiary electrons. The first method by which I attempted to do this was to receive a beam of 6-rays in a Faraday cylinder, the whole arrangement being in a very high vacuum. ‘Two different forms were tried for the source of the 6-rays; (A and B, fig. 1). In both of these the a-rays from Hires i. ‘At ff f§fyr ERS WAG \ == i 2 CENTIMETERS the polonium, P, struck the inner walls of a small brass cham- ber; a hole in this chamber was placed so as to allow some of the d-rays to escape but none of the a-rays. The beam of é-rays issuing from this hole was caught in a Faraday cylinder after passing through an opposing electric field; there were ‘suitable diaphragms and earthed screens about the Faraday cyl- inder. But although I had in the neighborhood of a millicurie of polonium, the arrangement was not sensitive enough to do more than indicate the presence of the swifter rays, certainly not to measure them. Only a small fraction of the 6-rays gen- erated in the chamber escaped through the hole, and, even so, the beam was so divergent that the Faraday cylinder had to be rather large (5°5 x 4™); thus its electrostatic capacity was considerable and one could not gain any advantage by substi- tuting a sensitive electroscope for the quadrant electrometer. The next attempt was by insulating the source (either A or B) from the case and connecting it to the measuring instru- ment; as its capacity was small, an electroscope could now be used to advantage. A negative potential applied to the case would send back to the source all the electrons whose kinetic 94 #H. A. Bumstead— Velocities of Delta Rays. energy was not sufficient to overcome the opposing potential difference. Here the difficulty was to prevent the tertiary electrons, set up by the impact of the d-rays upon the case, from being carried to the source by the electric field. I first tried to obviate this by means of a magnetic field. A long cylindrical case was used (the one shown in fig. 2), with the source of d6-rays near the top and the rays striking the bottom and the lower part of the sides of the case. A magnetic field of about 50 gauses was applied to this part of the case. To prevent this field as much as possible from having an effect upon the emission of the 6-rays themselves, the source was inclosed in a sort of upper chamber made of a plate and a ring of soft Norway iron, 1°5° thick; (this is not shown in fig. 2). A tapered hole in the plate allowed the beam of 6-rays to pass into the lower chamber ; both chambers were coated with soot. Preliminary measurements of the magnetic field in the upper chamber by means of a swinging needle showed that, with a field of 50 gausses near the bottom of the case, the field near the source was not more than 0°5 gauss. This method was not wholly unsuccessful. In a charcoal vacuum which had been maintained for several days, the source lost negative electricity in the face of an opposing potential of 300 volts, but beyond that it acquired a negative charge. The form of the relation between current and potential for the lower voltages was quite similar to those obtained later with the final form of apparatus; with potentials over 250 volts, however, the effects of the tertiary electrons began to be con- spicuous. Moreover, on account of the limited beam of 6-rays the values of the currents were small‘and necessitated the use of a very sensitive, and consequently troublesome, electro- scope. § 3. The final form of the apparatus is shown in fig. 2. The source of é-rays is the shallow, open, cylindrical box, B, made of brass; in some of the later experiments, in which a mag- netic field was used, the box was surrounded by a flat ring of brass, as shown in the figure, giving to the source the shape of a sailor’s hat. Below, and opposite the middle of this box, a thin brass arm supported a cylindrical copper plug, P, with a deposit of polonium on its upper surface, which was 4™™ in diaineter.* The end of this plug projected into the box so that none of the a-rays escaped, but fell upon the top and *JT am again indebted to Professor Boltwood for the polonium used in these experiments. For three successive years he has most kindly supplied me with the annual crop of polonium grown from a preparation of radio-lead in his possession. a . “- x > H. A. Bumstead— Velocities of Delta Rays. 95 sides of the box; the open character of the latter and the smallness of the obstacle presented by the polonium and its support enabled a large proportion of the 6-rays and tertiary rays to get away. ‘This source was enclosed in a large, cylin- drical brass case which could be highly exhausted by the help of charcoal and liquid air; the charcoal bulb was placed be- tween the evacuated chamber and the pump and gauge, and Goitepe 14 Se CENTIMETERS was so constructed as to free the chamber of mercury vapor by its distillation into the cold bulb. Within the case and $™ from its walls was a cylindrical cage of bronze wire-gauze which was insulated from the case and could be separately charged by means of an external electrode. It was found to be important that the insulators supporting the cage should not be struck by the é-rays; if they were, they acquired charges which gave rise to erratic resuits. Accordingly the cage was supported by three small pieces: of ebonite near the 96 HI. A. Bumstead— Velocities of Delta Lays. top, and out of the path of the éd-rays. The gauze had 5°5 meshes to the centimeter; of its entire area 83 per cent was open, the remaining 17 per cent was occupied by the wires. The rod which supported the source, B, was insulated from the case and provided with an earthed guard-tube in the usual manner. It was connected to the gold-leaf of a sensitive elec- troscope of the Hankel type which has been previously described.* The magnitude of the effects obtained, even when all the slower 6-rays were stopped, was such that the electroscope could be used at the very moderate sensitiveness of 200 divisions per volt. Under these circumstances the deflections were strictly proportional both to potential and current over the whole range of the eye-piece scale in the microscope (100 divisions); the sensitiveness remained quite constant, so that there was no need of continual checking up by means of a potentiometer. When changes in the zero | position occurred they were slow and steady and could easily be taken into account, and they caused no alteration in the sensitiveness ; often the zero would not vary more than one or two divisions in an entire half-day’s work.t On account of the emission of 6- and tertiary rays, the source as soon as it is insulated acquires a positive charge which increases with the time. When there is no opposing field this charge is far too great to be measured with the arrangements described above. When the case and cage are both charged to the same negative potential, all the electrons, whose kinetic energy is less than the work which this potential can do upon an electron, are returned to the source and only the swifter ones escape; thus the rate at which the source ac- quires a positive charge is diminished. When, however, the negative potential applied to the gauze and case is more than about 25 volts, the source begins to acquire a negatiwe charge, which (as the negative potential is increased) soon reaches a maximum and then steadily decreases; this continues up to, and beyond, 2000 volts. This effect has been shown to be due to the emission of tertiary electrons by the case when struck by the swifter 6-rays; the tertiary electrons are returned to the source of 6-rays by the field, and, as they exceed in number the 6-rays which produce them, the source acquires a resultant negative charge, which falls off, however, as more and more d-electrons are restrained from reaching the case.t * Bumstead, this Journal, xxxii, 403, 1911; Phil. Mag., xxii, 910, 1911. + In order to secure fair steadiness of the zero reading, it is necessary to. protect any sensitive electroscope against sudden changes of tempera- ture. With the electroscope mentioned, satisfactory protection is given by covering it with felt about 144 inch thick, and by setting it up in a wooden box (with an open front), to keep off drafts in some degree. A glass win- dow in the back of the box admits light to the gold-leaf. { Bumstead and McGougan, 1. ¢., § 3. H. A. Bumstead— Velocities of Delia Rays. oT It was for the purpose of eliminating, if possible, this com- plication that the wire-gauze cage was introduced as a substi- tute for the magnetic field mentioned in$ 2. Retarding fields may be set up by putting negative potentials on the gauze while the case is kept grounded. As the tertiary electrons have small velocities, those which are set up at the surface of the case, bythe 6-electrons which have surmounted the field and passed through the meshes of, the gauze, will not get back to the source on account of the field between the gauze and the case.* The electric force is much greater between gauze and case than between gauze and source, (though the potential difference is the same) because of the smaller distance; thus a considerable fraction of the tertiary electrons which originate on the wires of the gauze itself will be captured by this field and will not get to the source of é-rays. As the case and source are always kept at zero while the potential of the gauze - is changed, the shape of the lines of force, in the neighbor- hood of the wires of the gauze and within its meshes will not change, and it seems reasonable to assume that a nearly con- stant fraction of the tertiary rays originating upon the gauze will be captured in this way, and that the number which get back to the source in any case will be a small part of the total — set up by the 6-rays on case and gauze together. § 4 With the case grounded and with various negative potentials on the gauze cage, readings of the electroscope gave the charge acquired by the source in a given time, usually one minute. It was soon evident that the readings thus obtained varied greatly with the time which had elapsed since the pro- duction of the vacuum. ‘Three hours after the liquid air had been applied to the charcoal bulb, a negative potential of 40 volts on the gauze was sufficient to give a slight negative charge to the electrode (the source of d6-rays, B, fig. 2); and larger negative potentials caused a marked increase in this negative current. (See Curve I, fig. 3). As time went on, however, these effects were much altered; positive currents were observed with negative potentials on the gauze greater than 300 volts, and the negative currents at’ the higher poten- tial were much diminished in magnitude. The results of four series of observations are given in Table I and shown graphi- cally in fig. 3. * This method has been several times used to prevent the reflection of slow electrons in experiments upon cathode rays and on the photo-electric effect. v. Baeyer, Phys. Zeitschr., x, 174, 1909. 98 H. A. Bumstead— Velocities of Delta Rays. TABLE I. Volts | I (3 hrs.) |II (22 hrs.) |III (46 hrs.)|IV (66 hrs.)) II-T | 11-1 | Iv- — 40 |— 0:3 +63°6 +72°7 + 76° 63°9.\ deg 76°3 — 80 |—39°7 +21°%5 + 33° +84°5 | 61°2 | 72°7 | 74:2 —120 |—54°7 + 83 +18: +20°5 | 63°0 | 72°77 %a-e —160 |—61°'3 + 1°4 + 10° +13°5 | 62°7) 71°3 | 74°8 —200 |—67°5 eed = 16- + 9° 64°0 | 73°5 | 76°5 —240 |—70° = 02 + 17 +°5°5 | 63°81 Ties — 280 —10° — 1°0 + 2°8 —320 |—7A4° —10°7 — 2°8 0° 63°3 | 71°2 | 74: — 360 —13°4 — |" —400 |—78'4 | —14°5 — 7 =) Er 63°9 | 71°4 | 75°4 — 440 — 16° — 4: —480 |—82°'2 —17°8 — 9 — 6° | 64°4 | 71°2 | 76°2 —520 |—79°7 —19°6 — 7 60°1 72°77 —560 —21°4 —11° — 8 — 600 | —22°2 — 9° —640 |—85 —21°5 —13°2 —10°5 | 68°5 | 71-S(aiees In the table, the first column gives the negative potentials applied to the gauze cage; the second, third, fourth, and fifth give the currents (in arbitrary units) observed at 3, 22, , 46, and 66 hours, respectively, after the application of the liquid ale the remaining columns give the differences between these currents. < 3 -CURRENTS Fie. 3. 0 600 NEGATIVE VOLTS ON GAUZE H. A. Bumstead— Velocities of Delta Rays. 99 It will be observed that these differences are constant, and that the four curves of fig. 3 have the same form and are merely shifted vertically on the diagram. Itis quite clear that we have here the resultant of two effects, the first independent of the time since the vacuum was made, and depending upon the applied potential, while the second is independent of the potential, but does vary greatly with the time. The first effect is plainly due (at least in great part) to the escape from the source, B, of the swifter 6-rays, thus giving it a positive charge, which is decreased as larger opposing potentials are applied to the gauze. The second phenomenon causes the source to gain negative, or to lose positive, electricity at a rate which is independent of the potential beyond 40 volts ; and its variation with the time shows that it must be due to residual gas—either that which occupies the volume of the chamber, or that which is condensed upon its walls and on the electrode. It seemed desirable first to investigate the nature and cause of the second effect. When the apparatus was in the condition which gave the upper curve (LV) in fig. 3, the liquid air was removed from the charcoal, and a small quantity of air admit- ted to the chamber so that the pressure rose to 0:2"™. This was allowed to remain for about 15 minutes, when exhaustion was recommenced, while the charcoal bulb was heated in the usual manner. When the pressure had fallen to :003™™, the liquid air was again applied. Three hours later a series of measurements was taken, the results of which were between those represented in Curves II and III, fig. 3. This shows that the effect in question is not due to a volume ionization of the residual gas. For the amount of gas in the chamber three hours after the application of the liquid air could not have been very different from that which was present when Curve I was taken. On the other hand, the surface films on the metals might well be different after a brief exposure to a pressure of 0-2™™ from what they were after a prolonged exposure to atmospheric pressure. In another experiment, air at atmos- pheric pressure was allowed to stand in the chamber for two days ; upon re-exhaustion, the same behavior was observed as that shown in fig. 3. It seems clear therefore that the effect is due to the presence of surface films which are removed only very slowly in a high vacuum and probably not completely removed in any case. The next question to be considered was whether the negative charge upon the electrode was due to electrons coming to it from the gas film on the case and gauze or to positive ions lost by the film on the electrode itself. To determine this a magnetic field was employed. The core of the magnet was a bar of soft iron 2 inches square in section, bent so as to form 100 H. A. Bumstead— Velocities of Delta Rays. three sides of a rectangle. One side of this rectangle, 21™ long, was surrounded by the magnetizing coil; the other two sides, 18 long, embraced the case, as shown in fig. 2, and formed long, narrow pole pieces. Along these pole pieces, from their ends nearly to the magnetizing coil, the field was fairly uniform, not varying more than 10 per cent, when measured by a fluxmeter. In the other two directions at right angles to this, the variation of the field was rapid on account of the spreading out of the lines of force in the large air-gap. With a current of 5 amperes, for example, the field near either pole-piece was 530 gausses, while half-way between them, and in their plane, it was 250. The field at any one point was nearly proportional to the current in the coil from 1 to 8 amperes. Before using the magnetic field, the brass box which served as the electrode and the source of 6-rays was provided with the brass ring shown in fig. 2 (forming the brim of the “hat”), which had not been present in the preceding experiments. Its purpose was to catch the 6-electrons, originating near one side of the box when they were bent by the magnetic field toward that side. The addition of this ring, by increasing the capacity of the electrode, decreased some- what the readings of the electroscope. With the magnetic field, the electrode charged up negatively, the rate reaching a maximum value with a current of 3 amperes on the magnet and not changing when the current was increased to 9amperes. It was independent of the potential applied to the gauze from —40 volts to —1200, but it did vary with the time after the vacuum was made in the same manner as the results obtained previously. For example, with —40 volts on the gauze, and a magnetic field of 250 units, the fol- lowing values of the current were obtained at different times after the application of the liquid air to the charcoal : 1‘ houretCMt is aes 126 divisions per minute. 3 hours aaa 72 si cS oe 94 $69)! UL REG ie en 25 (75 66 66 48 660 8 12 (15 6 66 D) 66) oun heh 9 cé 66 66 We are, I think, justified in concluding that the carriers of this current are not electrons, but ions of atomic mass. Thus, in a magnetic field of 250 gausses, an electron whose velocity was as great as that corresponding to 1600 volts would be curled into a circle of only half a centimeter radius, and could scarcely reach the electrode even if it started from the case with that velocity ; and there is no evidence that any swift electrons start from the case at all. On the other hand, a HT. A. Bumstead— Velocities of Delia Rays. 101 hydrogen ion whose velocity was due to a fall of potential of only 9 volts would move in a path whose radius of curvature is 1:7", and might escape from the electrode, while an oxygen atom -with a single charge certainly would, as its radius of curvature would be 6:7. Assuming, then, that the negative current is carried by such positive ions from the gas film upon the source, it seems unnecessary to suppose that they are emitted with an appreci- able velocity, as any of the electric fields used in the preceding experiments would be sufficient to take them through the mag- netic field. It seems more probable that it is simply an ioniza- tion of the gas film by the a-rays. When the current in question is reduced to its minimum value by three or four days duration of the vacuum, the charge carried by it is from 5 to 10 per cent of that carried by all the a-rays from the polonium. (See $6.) If the ions have lost a single electronic charge, this means that only one out of ten (or one out of five) of the a-particles, in its passage through the surface film, pro- duces a positive ion which can get away. When the surface film is not so much reduced by long exposure to a high vacuum, this number may be considerably increased. It is possible that negative ions of atomic size may also be produced, but the present apparatus is not adapted to decide this question for the following reasons. The magnetic field is by no means parallel to the electrode and some of the lines of force meet the surface of the electrode, though not at very large angles. A small proportion of the 6-electrons from any point of the electrode will leave in paths making only a small angle with the magnetic field and will hence escape. Now when a positive potential is applied to the gauze, the current of elec- trons leaving the source without a magnetic field is more than 500 times the ionic current under consideration. If a fraction of one per cent of these escape along the lines of force, it will be sufficient to cover up the possible small current due to neg- ative ions. That this is the case will be seen in the following section. Effects have been observed by other investigators which, I believe, indicate the presence of ions from gaseous surface films. Thus in the recent, very careful determination by Danysz and Duane* of the charge carried by a-rays, the screen which limits the beam of a-rays and the opening of the Fara- day cylinder which receives them are both covered with thin aluminium foil, the two foils being parallel and 0°8™ apart. A magnetic field of 8000 units parallel to these foils is used to curl up the @- and 6-rays. Even with this field, the authors foundt that a difference of potential of only 2 volts between * This Journal, xxxv, 295, 19138. {i ci, p. 302. 102 H. A. Bumstead— Velocities of Delta Rays. the foils increased the charge received by the Faraday cylinder by 2°5 per cent or diminished it by 0°8 per cent according to the direction of the electric field; a potential difference of 1800 volts, they find, may affect the current as much as 8 per cent. It is very difficult to believe that these results can be due to a “drift” of the 6-electrons as the authors suppose ; in their magnetic field, the radius of curvature of the path of an electron, moving with a velocity corresponding to 2 volts, Fie. 4. a NEGATIVE VOLTS. would be about :0005"; with a velocity corresponding to 1800 volts about 02°". In neither case does it seem possible that an electron would be able to traverse the 0°8°™ between the two foils. In fact, with 2 volts, it appears that it would require a very heavy ion to get through the magnetic field ; with 1800 volts, an oxygen ion should get through. 8 5. An estimate of the reliability of the present measurements of the distribution in velocity of the swifter d-rays will be facilitated by a consideration of fig. 4, which will also serve to give a clearer idea of the somewhat complicated phenomena which appear when a-rays fall upon a metal in a high vacuum. The figure shows graphically the results of measurements, all H. A. Bumstead— Velocities of Delta Rays. 103 of which were made on the same day, after the vacuum had been maintained for eight days. Curve I shows the currents received by the electrode, with the case grounded and with negative potentials between 20 and 1200 volts on the gauze cage. Curve II represents the currents when both case and gauze are charged alike. Curves I’ and II’ give the currents observed under similar electrical conditions as in I and II respectively, but with a magnetic field sufficient to give its maximum effect. Ourve I is similar to those plotted in fig. 3 except for the change in scale due to the altered capacity, and for the fact that it begins at 20 volts instead of 40. Accord- ing to the views advanced in § 4, an ordinate of this curve represents (with more or less accuracy) the number of elec- trons whose energies are greater than that represented by the abscissa; these ordinates, however, are to be measured, not from the axis, but from a line below it representing the con- stant negative current received by the electrode. This cor- rected zero line may coincide with I’, or it may fall below it, since it is not certain that all the carriers of this current get _through the magnetic field. Curve Il represents the resultant of the current of 6-electrons from the source, and the current of tertiary electrons from the case: at 20 volts the 6-ray current predominates, but at higher potentials the tertiary electrons are in the majority. Their number decreases, however, as higher negative potentials are applied, owing to the decreased number of 6-electrons which reach the case. Their presence ean still be detected, however, at 2000 volts. The course of II shows that the gauze cage acts as an entanglement to the tertiary electrons even when there is no field between it and the ease; for when the cage is absent the tertiary current reaches a maximum at 40 volts, while with the cage (as shown in [J), the maximum occurs at 150 volis. On the view advanced in the preceding section, the negative ordinates of I’ and II’ represent the current carried by positive ions generated by the a-rays in the gas film upon the electrode. I have been unable to find an explanation for the difference between the two curves. _ Considered as representing the distribution in velocity of the swifter 6-rays, the measurements represented by Curve I (or by the curves of fig. 3), are subject to certain sources of error, of which the following appear to be most important. 1. Some of the 6-electrons, whose velocity is nearly but not quite great enough to get through the electric field, may approach near enough to the gauze to be captured by the auxiliary field between it and the case. A consideration of the electric field in the neighborhood of the gauze shows, how- ever, that to be so captured, an electron must approach fairly 104 H. A. Bumstead— Velocities of Delta Rays. near to the gauze; thus at any given voltage, the electrons improperly captured must lie between narrow limits of velocity and would form a small fraction of the total not returned to the electrode. Moreover, since the shape of the lines of foree near the gauze remains the same, this fraction would not vary much for different potentials. The principal effect, therefore, of this error would be to increase each ordinate of the curve in nearly the same proportion, which would not seriously affect its accuracy. : 2. Some of the tertiary electrons, set free by the 6-rays which strike the gauze, may be returned to the electrode. In a preceding section reasons have been given for supposing that these will form a nearly constant fraction of all the tertiary electrons from both gauze and case. If this is so, Curve I lies below its true position, each ordinate having subtracted from it a fraction of the corresponding ordinate of IJ. This would alter the course of 1, depressing it most between 100 and 200 volts, and less at higher potentials. This correction, however, cannot be large. The wires of the gauze occupy only 17 per cent of its total area, and certainly most of the tertiary elec- trons which originate upon it must be captured by the auxiliary field. It is quite improbable that this correction can amount to more than 1 or 2 per cent of the ordinates of Curve II. 3. Some of the 6-rays originating upon the sides of the box-source will cross its opening obliquely, and will be deflected, so as to strike the box, by fields too small to stop them. Thus at any given potential, some electrons which should get away will not do so, and the ordinates of Curve I will be thereby diminished. But the number thus improperly stopped at any voltage must be a nearly, or quite, constant fraction of those which should escape, so that the effect would be merely to change the scale of the curve. ; We may reasonably conclude, I think, that the measure- ments given represent a fair first approximation to the distri- bution in velocity of the swifter d-rays. It will probably be possible to improve the accuracy of the determination by using. a more intense source of a-rays and receiving a restricted beam of 6-rays ina Faraday cylinder. A suitable source of a-rays for this method is not at present at my disposal. § 6. The preceding measurements have had to do only with 6-rays whose velocities exceeded 20 volts. By reducing the sensitiveness of the electroscope to somewhat less than one- eighth of its former value, measurements could be taken with smaller negative potentials on the gauze cage. A series of H. A. Bumstead— Velocities of Delta Rays. 105 observations made in this manner is represented in fig. 5. It is within this region that all previous measurements of the velocities of d-rays have been, so far as I know, confined. Most, if not all, of such measurements have been, I believe, to a considerable extent vitiated by two circumstances: lack of knowledge of the existence of the swifter rays and of the ter- tiary rays which they produce; and the fact that the a-rays were allowed to pass through the field, thus giving two sources CURRENTS 35 NEGATINE VOLTS ON GAUZE of 6-rays, and of tertiary rays, with much consequent confusion of the results. Among neither the swifter, nor the slower, rays is there any approach to the Maxwellian exponential distribution; if it were so, the integrated curves (those of figs. 3, 4, and 5) would also be exponential. This is not true in either case ;* the diminution in the ordinates is too rapid at the lower potentials and too slow at the higher. If we plot / V instead of V, thus making the abscisse proportional to velocities *In the curves of figs. 3 and 4, allowance must be made for the depression of the zero line ; but no reasonable adjustment of this sort will bring the curves near to an exponential form. 106 IH. A. Bumstead— Velocities of Delta Rays. instead of to kinetic energies, the result is still very far from an exponential curve The form of the curves, however, for both the swifter and the slower electrons suggests an equation of the form ya" = C. In fact, a very fair agreement between the observations from 30 to 500 volts, and this equation may be obtained by using nm = 0°75, as may be seen from Table II. In this table the observed currents have been increased by 12 units to allow for the ionic current discussed above. TABin eld, yx? = n = 0°75 x (volts) y(obs + 12) y (calc. ) Diff. 20 108: 89° 19° 40 00" 53° O° 80 ‘ap ome B1°2 — 02 120 23°5 Te "2 + 0°3 160 19° 18°7 + 0°3 200 16°7 15°8 + 0°9 240 14°6 13°8 + 0°8 Z80 1128 12°3 — 0'd 320 11°4 laleea + 0°3 360 Pa el ON) 10°2 + 0°3 400 9°5 9°4 + Ol 480 8°5 8°2 + 0°3 600 6°2 6°9 ‘— O07 800 4° 5°6 - — 1°6 1000 2°6 4°7 — 2°1 1260 1°3 4°1 — 2°8 The departure of the observations from the equation at the higher voltages. may or may not be of significance, since the currents under these conditions were small and could not be very accurately measured, and the placing of the zero line is uncertain. At the lower potentials, however (beginning at 20 volts), the equation does not fit at all. This may well be due to the large admixture of tertiary electrons at these potentials, while above 40 volts there can be few, if any, of these. An approximate representation of the distribution of the slower electrons may be obtained with an equation of the same form, but with a larger value of , between 1°5 and 2. In order to get an idea of the relative magnitudes of the currents observed under various conditions, a rough series of comparisons was made by altering the sensitiveness of the elec- troscope, and introducing a small mica condenser. The results were as follows: H. A. Bumstead— Velocities of Delta Lays. 107 Klectronie current at — 40 volts_.2__ 22. 2- AS (13 (1 66 ae () 66 Maite ic reeset 100: 6¢ (73 CO) ee 9 URI Gn eta a ates ree 1700: (74 6¢ 6¢ O SLi Lat UES Rea 2700° 66 66 ie ett A (i 6s guanylate G2 BOO" Corrent.carried by, a-Tay se. sts ae = Se 5. 200° NimimivMsoOnie) Curbenibis.. 3&2 ee 10° It will be seen that the swifter electrons with which we have been principally concerned form only a small part of the total number which leave a metal when it is struck by a-rays. But the fact that a-rays can cause electrons to be projected with such speeds is undoubtedly a fact of considerable import- ance, whether these electrons be few or many; it must have some bearing upon the theory of ionization by a-particles and _of their passage through matter. It is not altogether surpris- ing that a-particles should cause electrons to be projected with velocities corresponding to some hundreds of volts. Accord- ing to the theory of Einstein, the energy of electrons projected under the influence of ultra-violet light is a linear function of _ the frequency of the light. This theory has been extended with some degree of success to the electronic emission caused by Roéntgen rays, taking, instead of the frequency, the time occupied by the pulse in passing over an electron, and esti- mating this as well as can be done in the present state of knowledge. If we assume that the effective field about an a-particle has the diameter of an atom, 10~*™, then, since its Coe Cs) yar velocity is about 2 x 10° its time of passage over an elec- tron will be 4 X 10-" seconds. The frequency of ultra-violet light is about 2 x 10-’° seconds, so that we might expect the maximum energy of the 6-rays to be of the order of 100 times that of photoelectric electrons. It has been shown that the number of slow 6-electrons varies with the speed of the a-rays in much the same manner as the number of ions produced in a gas. I have not yet been able to determine whether this is so with the swifter d-rays, nor how their distribution in velocity varies (if at all) with the speed of the a-rays. Knowledge of this sort might throw considerable light upon the relations between the electrons of various speeds, and upon the mechanism of ionization by a-rays, about which very little is known at present. Summary. 1. When a-rays fall upon a metal, electrons are emitted with velocities varying continuously from a -very small value to more than 2°7 x 10° —, which corresponds to a potential differ- Am. Jour. Sct.—FourtH SERIES, VoL. XXXV, No. 212.—Aveust, 1913. 8 108 H. A. Bumstead— Velocities of Delta Rays. ence of 2000 volts. It is proposed to include under the name “ d-rays,” all the electrons which owe their origin to the direct action of the a-rays,—the swifter ones as well as the slower ones previously known. 2. Evidence is given for the view that, in addition to the 6-rays, positive ions are also produced when a-rays impinge upon a metal in a very high vacuum; these ions appear to come from the layer of adsorbed gas upon the metal. By maintaining the vacuum for several days, the current carried by these ions may be reduced to a small value,—from 5 to 10 per cent of that carried by the a-rays themselves. The pres- ent experiments do not determine whether or not these ions leave the plate with an appreciable velocity in the absence of an electric field; but there is some evidence that the velocity is, at all events, small. 3. When the swifter d-rays fall upon a solid it emits elec- trons of slow speed which, in the present paper, are referred to as tertiary electrons. Their number is considerably greater than the 6-rays which produce them. The existence of the tertiary electrons makes it difficult to determine with accuracy the distribution in velocity of the é6-rays. A large number of tertiary electrons come from the source of 6-rays itself, and their presence in the beam of 6-rays makes it impossible to draw valid conclusions as to the number of true 6-electrons of slow speed (less than 10 or 20 volts). 4, The distribution in velocity of the 6-rays between 20 and 1200 volts has been determined, and reasons are given for believing that the measurements represent a fair approxima- tion to the true distribution. The number of electrons having a given kinetic energy is not an exponential function of either the energy or the velocity. Between 30 and 500 volts, the results are approximately represented by an equation of the form ya" = c¢ where y is the number of electrons whose kineti¢ energy is equal to or greater than w and n=0-75. It is impossible to say whether or not the departure of the measure- ments from this equation at potentials higher than 500 volts is significant ; the quantities measured are small and their values are rendered somewhat uncertain by the presence of the posi- tive ions and of the tertiary electrons. On the other hand, the fact that the slower electrons (under 20 volts) do not follow the same law of distribution in velocity as the swifter ones is — to be expected; the presence of tertiary electrons from the source, in the beam of d-rays, should greatly increase the numbers of the very slow electrons, as is, in fact, found to be the case. Sloane Laboratory, Yale University, April 15, 1913. a en * M. EF. Wilson—Laurentian Highlands of Canada. 109 Art. XII.—The Banded Gnetsses of the Laurentian High- lands of Canada; by Morztey E. Witson. Introduction. Tue larger part of the Pre-Cambrian oldland of northeastern Canada is composed of a complex of banded gneisses, which, in accordance with the designation of Sir William Logan, is generally called Laurentian. It is now generally believed that these gneisses, for the most part, originally constituted huge batholithic masses of magma and that the foliated structures which they possess originated as a result of deformation. But -the investigation of the origin and structures of the gneissic complex has not been carried beyond these generalizations. During the summer of 1912, in making a geological recon- “naissance across the Laurentian highlands of Quebec, an opportunity was afforded the writer to study the Laurentian banded gneisses in some detail, and to collect additional data bearing on their mode of origin and their relationship to the structural history of the Laurentian plateau. In the following pages is embodied a brief account of this investigation. Geological Relationships of the Banded Gneisses. The Pre-Cambrian rocks occurring in northeastern Ontario and western Quebec may be divided stratigraphically into two strikingly different divisions: an older complex and a younger group of slightly disturbed Huronian sediments which occur as erosion remnants scattered here and there over the surface of the basement upon which they were deposited. Since the banded eneisses are confined entirely to the basement complex, it is their relationship to the other rocks of that division of the Pre-Cambrian that is of special interest in this connection. Near the southern border of the Laurentian plateau the banded gneisses have their greatest development in a wide belt . which extends continuously from Georgian bay to the Gulf of St. Lawrence. To the south of this belt, the gneisses intrude and include bands and masses of crystalline limestone and other sediments, the masses and bands gradually decreasing in size and number towards the north until finally replaced entirely by the banded gneisses. To the north of the gneissic belt, in the vicinity of Lake Timiskaming and extending westward to the north shore of Lake Huron and eastward to Lake Mis- tassini, a belt of volcanic flows and sediments occur in the base- ment complex which like the sediments of the southern belt are intruded by granite and gneiss and like the sediments of the 110 M, FE. Wilson—Banded Gneisses of the southern belt gradually disappear when traced (southward) in the direction of the central belt of gneisses. Throughout western Quebec and northeastern Ontario, therefore, there is everywhere a basal Pre-Cambrian complex, the surface rocks of which (sediments and volcanic flows) may be divided lithologically into two provinces, a southern limestone belt known as the Grenville series, and a northern belt of voleanic flows and sediments to which the writer has given the name Abitibi group. Between the Grenville series and the Abitibi group intervenes the central belt of Laurentian banded oneisses. Geological investigation throughout the world has shown that wherever mountains have been greatly denuded, batho- lithic masses of rock are generally found at their centers, and since the Laurentian banded gneisses occur in a central belt intervening between belts of folded surface rocks, it is inferred that the Laurentian gneissic complex in this locality originally formed the core of a Pre-Cambrian mountain chain and con- stitutes a geanticlinal axial belt intervening between geosyn- clines formed by the rocks of the Abitibi group and the Gren- ville series. But denudation was carried to so profound a depth in Pre-Cambrian time that not only were all the roof rocks stripped from the central geanticlinal mass but the geo- synclines were truncated so close to their bottoms that they also are intruded by batholiths of granite and gneiss. Adams and Barlow have concluded from their areal work in eastern Ontario, that these smaller batholiths are. anticlinal in their relationship to the Grenville series.* Whether this relation- ship also holds in the case of the batholiths intruding the Abitibi group is as yet unknown. It is of historical interest in this connection to note that Logan, in his report on the geology of the Ottawa river,} regarded the metamorphic series, which he afterwards named Laurentian, as forming the axis of an anticlinal arch lying between north- _ ern and southern troughs of Huronian and Paleozoic sediments; a conception analogous to that suggested in the foregoing par- agraph. ‘The two conceptions differ, however, in that Logan assumed the anticlinal relationship to exist between the base- ment complex (Laurentian), and the Huronian and Paleozoic rocks, whereas in the present paper the anticlinal relationship is regarded as existing, not between the basement complex and younger series, but within the basement complex itself. Definition of Laurentian. The name Laurentian was first used by Sir William Logan to designate the great complex of gneisses and associated rocks * Memoir No. 6. G. S. Dept. of Mines, Can., p. 16, 1910. t+ Ann. Rep. G.S.C., p. 40, 1845. Laurentian Highlands of Canada. 111 which oceur so extensively throughout the northern part of the St. Lawrence basin. As a result of the investigations carried on by Logan and his associates during the early years of the Canadian Geological Survey, it was concluded that the Pre-Cambrian rocks of eastern Canada fell naturally into two main stratigraphical divisions; an older complex, the Lauren- tian, and a younger series, the Huronian. Logan further attempted to subdivide the basement complex into an Upper Laurentian, consisting of anorthosite and anorthosite gneiss, and a Lower Laurentian composed of two groups, the younger of which consisted largely of limestone, and the lower of gneiss. Logan’s conception of the Pre-Cambrian succession may thus be tabulated as follows: ( Huronian | Azoic ( Upper Laurentian, Labrador, anorthosite (Pre-Cambrian) { Laurentian | or Norian series. | ; ( Grenville series. | Lower Laurentian j L L | Ottawa gneiss. Although Logan included the rocks of the Abitibi group in his Huronian instead of placing them in the Laurentian where they actually belonged, and thus went astray in applying his Pre-Cambrian classification, yet the work of later years has shown that, theoretically, his classification of the Pre-Cambrian into Laurentian and Huronian was wholly in accord with the facts. Unfortunately, the importance of the great strati- graphic break which. separates the Huronian from the basal complex and the consequent necessity for a group name ‘to include all the rocks of the older complex was not generally recognized, and in subsequent years it became customary to limit the term Laurentian to merely the granite and gneiss.* It is with approximately the latter significance that the name is here used by the writer to include all the acid plutoni¢ rocks of the basement complex regardless of possible difference in age. Defined in terms of geological relationships, the Lau- rentian includes the granite and gneiss which intrude the Grenville series and the volcanic complex (Abitibi group) of the Lake Mistassini- Lake Timiskaming-Lake Huron re- gion. It would also include any granite or gneiss which might le unconformably beneath either the Grenville series * Report of the Special International Committee on the Correlation of the Pre-Cambrian Rocks of the Adirondack Mountains and the ‘‘Original Laurentian Area” of Eastern Ontario, Jour. of Geology, vol. xv, pp. 191- 217, 1907. 112 M. EF. Wilson—Banded CGneisses of the or the Abitibi group. The upper limits of the Laurentian are defined by the erosion surface that separates the basement complex from the Huronian, or defined more locally, the plane which separates the Cobalt series from the older complex, in the Timiskaming region, and the original Huronian rocks from the basement complex, on the north shore of Lake Huron. It is probable, according to this definition, that the anorthosites (Logan’s Upper Laurentian) should be classed as Laurentian for these rocks are in part transformed into gneiss and prob- ably belong essentially to the basement complex.* Lithological Character. The rocks of the Laurentian complex may be classified (1) according as to whether they are massive or foliated, and (2) according to their mineralogical composition. To the mas- sive rock types belony nearly all of the small batholitic masses which intrude the northern voleanic complex (Abitibi group) and, to a much more limited extent, some of the batholiths which intrude the southern limestonet complex (Grenville series). The foliated rocks, on the other hand, include nearly the whole of the central gneissic belt which separates the Abi- tibi group from the Grenville series. Classified according to mineralogical composition, the rocks of the Laurentian com- plex include the following types: granite, syenite, granodiorite, diorite, pegmatite, aplite, pyroxenite, amphibolite, and garnet- iferous mica schist. Granite and Granite-gneiss.—The granite and granite-gneiss of the Laurentian complex are granular, fine- to coarse-grained rocks consisting essentially of quartz and alkalic feldspar (orthoclase, microcline, albite, and oligoclase), with biotite or hornblende or biotite and hornblende together as ferromagne- sian constituents. The biotite granite and granite gneiss is, however, much more common than the hornblende variety. The common accessory minerals present are titanite, epidote, muscovite, garnet, apatite, zircon, and magnetite, but allanite, tourmaline, rutile, graphite, cyanite, arfvedsonite, and egirine have also been found in some thin sections of the granite gneiss.{ From the microscopic examination of the granite and eranite oneiss it is seen that, in some places, the constituent minerals are remarkably fresh while, in others, the feldspars are largely replaced by sericite, and the hornblende and biotite by chlorite. Between these two extremes an intermediate rock * Adams, F. D.: ‘‘Uber das Norian oder Ober-Laurentian von Canada” ; Neues Jahrbuch fir Mineralogie, etc., pp. 419-498, 1892. + According to Adams and Barlow, Memoir No. 6, G. S. Branch, Dept. of Mines, Can., 1910. + Barlow, ‘A. H., Ann. Rep. G. S. C., p. 871, 1897. Wilson, M. E., Sum. . Rep., G.S. Dept. of Mines, Can., 1913. ey I. Laurentian Highlands of Canada. 113 type is also common in which sericitized feldspar occurs en- closed in a matrix of fresh, granular quartz and microcline. In some thin sections the minerals show by their undulatory extinction and granulated character that they have been sub- _ jected to intense mechanical deformation. In others, however, all these evidences of deformation are entirely wanting. Syenite and Syenite-gneiss.—The syenite and syenite gneiss are commonly a grey to rusty red rock which, in most localities, shows a remarkable tendency to disaggregate into its constitu- ent mineral grains on the weathered surface. They consist essentially of orthoclase, albite, microperthite, egirine, and dark brown biotite. The accessory constituents observed are titanite, apatite, zircon, epidote, and magnetite. Under the microscope it can be seen that the disaggregation on the weath- ered surface arises from irregular fractures which traverse the rock along the contacts of the mineral grains. The cause of the fractures is not apparent, but they are most probably rela- ted in their origin to the expansive pressure which no doubt accompanied the slight decomposition which has occurred in the eegirine. Granodiorite and granodiorite-gneiss.— The granodiorite and granodiorite-gneiss are rocks of similar appearance to the granite and granite-gneiss, but their mineralogical composition shows them to occupy an intermediate position between diorite and granite. They contain much less quartz and orthoclase than the granite and correspondingly more plagioclase, and biotite is replaced by hornblende as the dominant ferromagne- - sian constituent. The accessory mineral constituents, mineral alterations and evidence of mineral deformation are the same in the granodiorite as in the granite and granite gneiss. Dorite und diorite-gneiss.—The diorite and diorite-gneiss are dark rocks containing an abundance of glistening crystals of hornblende. Examination under the microscope shows most of the rocks of this class to consist essentially of blue-green hornblende and plagioclase, either albite, oligoclase or andesine, but in some thin sections the proportion of plagioclase becomes so small that the rock might be more appropriately called a hornblendite. The common accessory minerals observed are garnet, magnetite, biotite, titanite, epidote, and zircon. The hornblende and biotite are generally more or less altered to chlorite, and the plagioclase in some thin sections is entirely replaced by sericite and epidote. Pegmatite and aplite.—These rocks are among the most common in the Laurentian gneissic complex occurring, in part, as thin lenses in the banded gneiss and, in part, as dikes trans- verse to the foliation and banding. They consist largely of quartz and alkalic feldspar (orthoclase, microcline and albite), 114 M. EF. Wilson—Banded Gneisses of the but muscovite, biotite, garnet, epidote, and titanite are also commonly present. Other minerals less commonly present are cyanite, molybdenite, graphite, and allanite. Like the other rocks of the complex, the pegmatite and aplite have undergone some mineralogical and mechanical alteration, the evidences of deformation being particularly apparent. Pyroxenite, amphibolite, and amphibolite-gneiss. — The rocks in this subdivision of the Laurentian have been grouped together because they are largely composed of lime silicates, and hence are similar in chemical composition, although miner- alogically somewhat different. They occur chiefly as small lenticular masses in the banded gneiss, and are largely limited to a few localities near the south side of the central belt of gneisses. The pyroxenite consists chiefly of diopside, while the amphibolite is largely composed of either hornblende or trem- olite. Other minerals observed in these rocks were biotite, scapolite, garnet, a carbonate, and serpentine, the latter occur- ring as an alteration product from the diopside. Garnetiferous mica-schist. — Within the central belt of banded gneisses, particularly near their northern border, there are areas ot fine-grained garnetiferous mica schist very similar in appearance to some of the mica schist of sedimentary origin occurring in the Abitibi group farther to the northward. This mica-schist consists of biotite quartz, orthoclase, albite, and either pink or red garnet and possesses a mosaic-like texture very similar to the crystalloblastic texture of the paragneisses. Structural Features. Foliation.—By tar the larger part of the rocks comprising the Laurentian complex are foliated and for this reason are largely classed as gneisses. This foliation has been brought about, for the most part, by the parallel orientation of biotite plates and hornblende prisms but also, in some eases, by the flattening of the feldspar and quartz in the same plane. Very commonly the biotite of the biotite gneiss is seen to “ eye” around small lense-shaped fragments of feldspar, giving rise to the characteristic augen structure, which results from deforma- tion. The trend of the foliation, like that of the banding, indicates that it has the form of anticlines and synclines simu- lating the structure of folded sedimentary rocks in every respect. Banding.—The most striking and the most characteristic structural feature of the central belt of Laurentian gneisses is the banding which is everywhere developed. The extreme complexity of the structures exhibited by these bands and the heterogeneity of the rocks which they contain even in a single Laurentian Highlands of Canada. 115 rock outcrop are scarcely capable of description, yet when examined over broad areas this complexity and heterogeneity is so uniform that it becomes monotonous. The banding of the gneisses may arise either from (1) a variation in the proportion of minerals present in the same rock or (2) by the alteration of bands of different rock. Thus, one of the most common types of banding is brought about by the alternation of bands of bio- tite gneiss, containing varying proportions of biotite so that a light band, in which little biotite is present, alternates with a dark band containing a large proportion of biotite. In a sim- ilar manner, variations in the proportion of hornblende in the hornblende granite gneiss, the granodiorite-gneiss or the diorite- gneiss result in a banded structure. The second type otf banded structure, in which the alternate bands are composed of different rocks, may also be combined with bands of the first types, and in this way an almost infinite variation in the composition of the bands may occur. The commonest rock of the banded gneiss is the biotite, or biotite hornblende granite gneiss; but pegmatite and aplite are also important, composing not less than 15 per cent of the whole. The proportion of other rocks is small, so that the central belt of Laurentian gneisses, considered as a whole, is granitic rather than dioritic in composition. The width of the bands may vary from a frac- tion of an inch to hundreds of feet. When followed along the strike they are found to pinch out as though they were, in reality thin lenses. This lenticular character is particularly evident in the case of the pegmatite, which commonly occurs in a succession of lenses around which the foliation in the sur- rounding gneiss bends in a manner very similar to that which occurs on asmall* scale around the augen of feldspar in the augen gneiss. tae Granulation.—That granulation has occurred to a large extent in the banded gneisses is apparent from the abundance of augen gneisses and from the evidences of strain and frag- mentation seen in some thin sections. Recrystallization has followed granulation in many cases, however, for in many rocks which have very evidently suffered granulation, the granular quartz and feldspar which surrounded the lense of the augen contain a large proportion of microcline and are much fresher in appearance than the central core. Folding and Faulting.—The study of the structure of the banded gneisses indicates that they have been folded in a manner very similar to that exhibited by deformed sedimentary rocks. While the bands are not continuous over wide areas like sedimentary beds, yet, all the various types of folds are present on a small scale and, in places, anticlines and synclines nearly a half-mile in cross section, can be recognized. These 116 M. FE. Wilson—Banded Gneisses of the folds are generally pitching and since the strike of the bands is dominantly in a northeasterly- southwesterly direction, it is inferred that the banded gneiss has been folded into pitching | anticlines and synclines having a northeasterly-southwesterly trend. In some places the biotite has been smeared out along the contacts of the bands, giving a slickensided appearance which has evidently resulted from differential movements. accompanying the folding. In describing the structure of* the Laurentian gneisses* occurring in eastern Ontario, Adams and Barlow note that the foliation of the gneiss near the border of the batholith corre- sponds to the strike of the surrounding sedimentary rocks and conclude that the batholiths are anticlinal in their relationship to the Grenville series, the anticlinal axes trending N. 30° E. They also point out that the trend of the foliation and band- ing in the batholiths is commonly oval or elliptical in form, and while no further statement is made by the authors as to structure of the gneiss, it seems apparent, from the trend of the foliation indicated on their maps, that the gneiss in that locality also has a folded structure similar to that of the central belt of gneisses of the Laurentian complex. On the whole, faulting has been subordinate to folding in the Laurentian banded gneisses, but faults of both the over- thrust and normal types are present. The pegmatite and aplite dikes which are transverse to the banding of the gneiss have been very commonly intruded along fault ‘planes, for the bands on opposite sides of many of the dikes have been rela- tively displaced. Origin. A discussion of the possible modes of origin of the Lauren- tian gneissic complex resolves itself into two problems : (1) Are the banded gneisses sedimentary or igneous in origin, and (2) in what manner did the rocks become banded, folded and foli- ated into their present condition. Sedimentary or Igneous Origin.—The early Canadian geol- ogists, in common with geologists working in other par ts of the world, generally assumed that banded gneisses owed their bedded-like structure to subaqueous deposition.t In the case of the Laurentian banded gneisses, this seemed particularly obvious, for they were bedded and folded like stratified sedi- ments, and were intimately associated with limestone and other rocks which were undoubtedly sedimentary in their origin. 3ut with the application of petrographical and chemical inves- * Memoir No. 6, Geol. Surv., Dept. of Mines, Can., 1910. + Geology of Canada, p. 29, 1863. Sterry Hunt, Royal Society of Canada, vol, ii, 1884. Laurentian Highlands of Canada. Taly tigation to the problem, the sedimentary hypothesis was grad- ually abandoned—as regards the major part of the Laurentian complex—in favor of the igneous hypothesis, which is now generally accepted.* In describing the lithological character of the gneissic com- plex it was noted that within the axial belt particularly near its northern border, garnetiferous mica schists occur which are probably of sedimentary origin. Likewise, along the southern border of the central Laurentian gneissic complex, fine-grained rusty gneisses and amphibolites occur which are believed from their lithologica! character and chemical composition to, be altered sediments, the former being a mashed quartzite or arkose and the latter a metamorphosed limestone.t Thus it is probable that the proportion of sediments associated with the Laurentian is somewhat larger than is generally supposed, yet the characteristics of the major part of the complex is such as to point conclusively to an igneous origin. The evidence upon which this conclusion is based may be summarized briefly as follows :— 7 (1) The complex is largely composed of granite, diorite, granodiorite and pegmatite, and hence is composed of rocks having the mineralogical and chemical composition{ and tex- ture which belong to rocks of igneous origin. | (2) Pegmatite constitutes a large and essential portion of the Laurentian complex and occurs not only in parallel bands but as dikes transverse to the banding. (8) The bands in the gneiss pinch out when followed along the strike, whereas sedimentary beds composing uniformly stratified series are generally continuous for long distances. (4) The extreme local heterogeneity of the Laurentian com- © plex and the uniformity of this heterogeneity over many thous- and square miles is not characteristic of sedimentary rocks. (5) The dominant sediments which result from the decom- position of igneous rocks are argillaceous, and since the Lau- rentian banded gneisses have an areal extent in Canada of not less than 2 million square miles, it might be expected that a considerable proportion of the complex would consist of slates, but on the contrary it is almost entirely composed of rocks approaching the composition of arkose or quartzite. It may therefore be assumed as unquestioned that the banded gneisses of the Laurentian plateau, in their most typical develop- ment, are of igneous origin. : * Adams, F: D., Jour. of Geol., vol. i, pp. 325-340, 1893. Barlow, A. E., Ann. Rep., CO. G.S:, p. ol, 1, 1897. + Adams, F. D., this Journal, vol. 1, pp. 58-69, 1894. Adams, F. D., Ann. Rep., G. S. C., vol. viii, 1895. Adams and Barlow, Memoir No. 6, Geol. Surv., Dept. of Mines, Can., 1910. ¢ Barlow, A. E., Ann. Rep. G. S. C., p. 55, I, 1897. 118 M. EF. Wilson— Banded Gneisses of the Banding, folding and foliation.—lIt the banded gneisses of the Laurentian complex are igneous in origin, then it becomes necessary to frame an hypothesis which will account for the development of a banded, folded and foliated structure in rocks which originally constituted a batholithic magmatic mass. The various ways by which a banded structure might develop in an igneous rock are the following :—(1) by the flattening out of fragments of the invaded rock forming the batholithie root ; (2) by lit par lit injection,—that is, by the intrusion of dikes parallel the foliation of a gneiss; (3) by the deformation of (a) a heterogeneous complex of igneous rocks in the zone of flowage long after consolidation; (b) a heterogeneous magma during or immediately after consolidation. (1) The development of a banded structure along the con- tact of the Laurentian batholiths by the flattening out of xeno- liths has been advocated by a number of Canadian geologists,* and is undoubtedly an important mode of origin for the strue- ture in some places, but this method alone cannot account for the banded structure of the Laurentian axial complex because the composition of the bands is, for the most part, wholly dif- ferent to that of the rocks constituting the batholithic roof. (2) A banded structure may originate by lt par lit injection, wherever a magia intrudes a rock which, because of its bedded or foliated structure, possesses a prominent cleavage. Thus, where the Laurentian rocks intrude some of the sedimentary schists of the Abitibi group, the granite, aplite and pegmatite commonly occur, as sheets or dikes paralleling the foliation. There are also some sharply defined dikes of pegmatite and aplite in the gneissic complex which parallel the foliation of the gneiss and were probably intruded in this way, but it is scarcely possible that the banded structure of the Laurentian gneisses has originated to any great extent by /zt par lit injec- tion for if such were the case, the bands formed by intrusion (1) should be connected in places by dikes transverse to the foliation, (2) should be sharply defined on their contacts, and (3) should be continuous for considerable distances when foi- lowed along the strike. Instead of these features being pres- ent, the bands were never seen to connect transversely, the con- tacts of the bands are generally poorly defined; the mineral grains interlocking across the line of junction, and the bands commonly pinch out in short distances when followed in the direction of their trend. | (3) The third hypothesis to explain the origin of the banded gneisses has been divided into two subdivisions according to *Lawson, A. C., Ann. Rep. G.'S. C., vol. iii. Part:1, p. 1lasH fee. Adams, F. D., and Barlow, A. E., Memoir No. 6, Geol. Surv. Dept. of Mines, Can., 1910. Miller, W. G., and Knight C., Ann. Rep., Bur. of Mines, Ont., vol. xx, pp. 280-284, 1911. Laurentian Highlands of Canada. 119 the time at which the deformation occurred, that is, according to whether it took place at the time of intrusion or long after consolidation. Wherever the Laurentian gneiss and granite have been observed in contact with rocks of the Abitibi group and the Grenville series, they are always intrusive into the latter, yet the presence of conglomerate containing granite pebbles in the Abitibi group and the occurrence of siliceous sediments in the Grenville series indicate that older granitic rocks were at one time widely present in the region and it might be possible that this ancient granite comprises a consider able part of the Lau- rentian gneissic complex. However, no evidence was observed anywhere throughout the gneissic complex of the presence of granite or gneiss of two distinct periods of intrusion, and if such occurred, the evidence of their presence has been entirely obliterated by deformation. On the other hand,—if it be assumed that the banding of the banded gneisses originated as a result of deformation,—it is apparent that the larger part of the simplex was undergoing consolidation at the time the band- ing was being developed ; for pegmatite and aplite were being given off from the magma during stages in the development of the bands, as shown by the occurrence of dikes of these rocks transverse to the banding and in all stages of deforma- tion, some being exceedingly crumpled and others undisturbed. In a paper published in 1887 ‘On the Origin of Certain Banded Gneisses,” J. J. Teall* coneluded that banded oneisses might originate by the deformation of a heterogeneous plutonic mass, the evidence for this conclusion being (1) that plutonic rocks are commonly heterogeneous and (2) that a plutonic igneous mass may undergo deformation during intrusion or later as a result of mountain-buildinyg stresses. It is proposed in this paper to suggest that the Laurentian banded gneisses, in the particular locality studied by the writer, not only originated by the deformation of a heterogeneous plutonic mass but that the heterogeneity was itself developed, to a large extent, as a result of the deformation and that the deformation was related to mountain-building stresses which acted upon the magma during and following its consolidation. Plutonic masses of rock when examined over areas of con- siderable extent, are generally found to be heterogeneous. This heterogeneity must obviously be due to either assimilation of foreign rock, or to differentiation within the magma itself. That assimilation occurred in the case of the Laurentian com- plex is evident from the occurrence of partially assimilated fragments of both the Abitibi group and the Grenville series along the batholithic border, but whether this process was of * Geol. Mag., vol. iv, pp. 484-492, 1887. 120 M. FE. Wilson— Banded Gneisses of the great importance or not, is unknown. It is also probable that basic and acidic aggregations and other variations were present in the Laurentian as in other plutonic masses, but it is doubtful whether all of these differences, as developed in normal plutonic rocks, would account for the excessive -heterogeneity which would have to be present to result in such variability in com- position as occurs in the Laurentian complex. | Throughout the northern geosynclinal belt formed by the rocks of the Abitibi group, small batholiths of granite occur which are presumably offsets from the main Laurentian mag- matic mass. These, because of their small size, would no doubt consolidate much more quickly than the larger central complex, so that, in them, we should expect to find the record of the early stages in the series of events which resulted in the development of the Laurentian banded gneisses. On mak- ing an examination of these northern batholiths, it is found that although they consist largely of granite instead of gneiss they also are exceedingly heterogeneous and the heterogeneous portions are similar in composition to the most common bands of the banded gneisses. ‘Thus, in some places in the small batholiths, a granite containing very little biotite may be seen to cut across another granite in which this mineral is more abundant, or a biotite granite may cut a hornblende granite in a similar manner. Long schlieren of granite very rich in biotite are also common. These variations are generally poorly defined and are gradational from basic to acidic in composition from which it is inferred that they are differentiated parts of the same magmatic mass. This differentiation was evidently assisted by deformation which, in some cases, caused movements in the viscous magma, thus dragging it out into long schlieren and, in other cases, broke up the magma after it had become solid so that the central magma of more acid composition flowed in to fill up the fractures. By this process of deformation during consolidation, a magmatic mass originally homogeneous might continue to become more and more heterogeneous as the knead- ing process continued, material of progressively more salic composition being squeezed out through fractures from the in- terior.* Not only would heterogeneity be developed by this process, but the variations in the magma would, as consolidation continued, be flattened out mto thin lenses which, because of their different competency, would behave like sedimentary beds and assume a folded structure. In discussing the geological relationships of the banded gneisses it was pointed out that they apparently formed the truncated base of a Pre-Cambrian mountain chain, and since mountain building is generally accompanied by deformation it * Harker, A., The Natural History of Igneous Rocks, 1909. Laurentian Highlands of Canada. 121 follows that if the mountain deformation continued until the axial complex began to consolidate, it would also be deformed. The action of the mountain-building stresses on the magmatic central mountain mass thus affords a complete explanation of - the cause which brought about not only the folding, foliation and granulation in the banded gneisses but also explains how the differentiation of the magma was brought about so that a banded structure was made possible. During the final stages of deformation, the gneissic complex had evidently passed, for the most part, from the zone of flowage to the zone of fracture ; for slickensiding between the bands, granulation and fracture became the dominant deformational processes. Summary. In the foregoing pages, the geological relations, lithological character, and structural features of the banded gneisses of the Laurentian highland of Canada have been briefly described, and from these data it has been concluded that the gneisses com- plex was originally the magmatic center of a Pre-Cambrian mountain chain and that mountain-building stresses acted upon this axial magmatic mass during its consolidation with the re- sult that it (1) underwent differentiation aided by deformation during consolidation and (2) by further deformation, the differen- tiated portions became flattened out into bands which were then crumpled into their present folded structure. This hypothesis is supported not only by observations in the field where the various stages in the process may be seen, but also by the fact that it affords a complete explanation of the heterogeneity, banding, foliation, folding and other characteristic features of the gneissic complex. Moreover, it postulates only such con- ditions as are generally accepted by geologists the world over, and assumes only such effects as must necessarily result wher- ever such conditions arise in the earth’s crust. | Stated more fully, the conclusions with regard to the rela- tions, character, and origin of the banded gneisses occurring in the southern part of the great Pre-Cambrian Canadian oldland are as follows: (1) The Pre-Cambrian basement complex occurring through- out northeastern Ontario and western Quebec may be divided into three divisions, a northern geosynclinal belt consisting of highly folded sediments and voleanic flows (Abitibi group), a southern geosynclinal belt chiefly composed of crystalline lime- stone (Grenville series), and an intermediate geanticlinal zone of Laurentian banded gneisses. (2) The banded gneisses are largely igneous in origin. (3) From the geographical and structural relationship of the eneissic complex to the rocks of the Abitibi group and Gren- 122 M. EF. Wilson—Laurentian Highlands of Canada. ville series, it is inferred that the banded gneisses originally constituted the magmatic centre of a Pre-Cambrian mountain chain. (4) As regards the origin of the folded, banded and foliated structure of the gneisses, it is concluded that these are all genetically related in the Laurentian mountain-building de- formation which acted upon the magmatic axial mass during its consolidation. While it is recognized that heterogeneity in a magma may be caused by the stopping off and partial assimi- lation of fragments of the batholithic roof, it is concluded from the field evidence that the principal factor in bringing about the heterogeneity of the Laurentian complex was dif- ferentiation aided by deformation during consolidation. By this process, the magmatic mass was constantly being broken up, and the residual fluid magma of slightly different composition squeezed out to fill the fractures around the broken fragments. The variations in the complex produced in this way were then flattened out and crumpled into a folded structure resembling that assumed by deformed sedimentary beds. ‘Thus by the action of mountain-building stresses on a magmatic axial mass a folded and banded gneissic complex such as that occurring in the Laurentian plateau may be developed. D. D. Condit—Deep Wells at Findlay, Ohio. 128 Art. XIII.— Deep Wells at Findlay, Ohio; by D. Date Conpit.* Frypray lies in the midst of the “Trenton” oil and gas field of northwestern Ohio and has been in the foreground as a pro- ducer for over thirty years. Until recently all of the produc- tion has come from near the top of the so-called “ Trenton” limestone, but at Tiffin and other localities considerable oil is now being found at a horizon 600 or more feet lower strati- graphically. During the summer of 1912 the citizens of Find- lay formed a company with the object of testing the deeper strata and determining the “ thickness of the Trenton.” Drill- ing was commenced on the D. L. Norris farm in section 38, Marion Township, about three miles northeast of the city. A test well was also started by the Ohio Oil Company on the J. H. Grubb farm in section 9, Liberty Township. In November, when the Norris well had been drilled to a depth of nearly 3000 feet, Mr. J. E. Fennerty of Findlay informed the United States Geological Survey by telegram: “ Well now about 200 feet below Trenton, and drillings indicate granite formation, very hard and drill slow.” Dr. J ohnston, who through the courtesy of the Carnegie Geophysical Laborator y has been coéperating with the U. 8. Geological Survey in deep-well obser- vations, went at once to Findlay and recorded temperatures in the Norris well, the results of which are set forth in the follow- ing article. The writer also visited the locality and obtained the log of the well and samples of the drillings. In the Norris well no samples were saved until the “bottom of the Trenton” was reached at a depth of 2755. The samples from the sue- ceeding 225 feet were donated by Mr. J. B. Maxwell, one of the drillers. Information concerning the higher str ata was derived from the Grubb well, which reached a depth of 2470 feet. Credit is due Mr. J. E. Dougherty, the driller, who saved a complete set of samples which were given to the Sur- vey. A duplicate set was also furnished by Mr. Berry of the Ohio Oil Company. Thanks are extended to Mr. Casterline, and especially to Mr. Fennerty of Findlay, for their courtesy and assistance. The combined records of the Norris and Grubb wells are of unusual geologic interest as the drill passed below the base of the Paleozoic and penetrated pre-Cambrian rocks, concerning which nothing has been known heretofore in this part of the United States. There is given below a geologic section, which represents the combined well records. All but the lower 610 feet of the section presents data derived mostly from the Grubb * Published by permission of the Director of the U.S. Geological Survey. Am. Jour. Sc1.—Fourts Srries, Vou. XX XV, No. 212.—Aveusr, 19138. 9 . 124 =D. D. Condit—Deep Wells at Findlay, Ohio. well record, with depths adjusted so as to coincide with those in the Norris well. This seems permissible, for the distance between the two wells is only a few miles. The question as to the age and relations of the various beds was discussed with Dr. E. O. Ulrich, of the U.S. Geological Survey, and the cor- relations used in the section are those suggested by him, adapted to the nomenclature and classification in current use by the U.S. Geological Survey. Limestone of Niagaran age forms the surface in the vicinity of Findlay. This is generally covered with 10 to 100 feet of glacial drift. In the Grubb well this limestone was found 311 feet thick. The underlying strata in descending order are shale and brownish gray limestone of either Clinton or upper Medina (Ohio “ Clinton’) age; then gray and red shale, prob- ably to be correlated with the lower Medina on the one hand and the Richmond on the other, underlain in turn by gray and brown shales with a thickness of 732 feet, representing the lower formations of the Cincinnatian series. The top of the oil-bearing limestone, generally known as Trenton, was struck at 1165 feet and the drill continued in limestone and shaly beds, probably of Black River, Lowville, and Stones River age, to a depth of 1894 feet, giving a thickness of 729 feet for these strata. Then comes 406 feet of white, granular quartzose lime- stone and sandstone, all of which probably represents St. Peter sandstone. At 1135 feet below the top of the “Trenton” is a dark, glauconitic, dolomitic limestone 60 feet thick that is re- ferred tothe Upper Cambrian. Beneath this is garnetiferous, ark- osic sandstone, which was penetrated only 10 feet in the Grubb well. Its thickness, as shown by the Norris record, is 395 feet. All of it is probably Upper Cambrian. At the base of the sandstone is 15 feet of red, green, and gray clay, which rests upon granite. Drilling was discontinued after the granite had been penetrated to a depth of 210 feet.* *The ‘‘ Trenton” limestone was found at a depth of 1165 feet in the Norris well, and the base of the garnetiferous sandstone (bottom of the Grubb well) at 2755 feet. As has already been stated, no samples were saved in this portion of the well, but the drillers report a uniform, gray grit throughout the interval. The belief that the lower 395 feet of the sec- tion is entirely sandstone is corroborated by the mineralogical examination of samples collected from the sand cone back of the derrick where the pump- ings were dumped. Acut was made through this cone and thus a condensed section showing the principal beds in inverted order was obtained. Imme- diately underneath the granite drillings were the thin films of gray, green and red clay, mentioned ; then came several inches of rusty gray sand which corresponds to the thick Upper Cambrian sandstone. The greater part of this was clean and contained a few accessory minerals. A little deeper in the sand cone was a dark band which represented the dark Upper Cambrian dolomite. D. D. Condit—Deep Wells at Findlay, Ohio. 125 Geologic section of wells at Findlay, Ohio. Depth Thick- in feet ness Rema teale Cle iiet ye Sac ea ARs alert oe Eee eae aera 0-87 87 Silurian : Niagaran strata : (c) Limestone, dark gray, slightly dolo- mitic, dense textured_......-.---- 87-134 47 (0) Limestone, gray, crystalline, slightly Slants 07s ot eet oe a 134-195 61 (a) Limestone, dark, minutely crystalline 195-245 50 Strata of Medina or Clinton age : (ey Shale, calcareous 222). ss252. 22) (245—255 10 (a) Limestone, pinkish, brownish, and gray ; minutely granular texture (probably Ohio ‘Clinton”’) _-_.--- 255-343 88 Ordovician : Cincinnatian series : Strata probably equivalent to Richmond and lower Medina : oasiales erayish “oe ee ok 343-399 56 eo paoiialewmed 8s Wee S022) 8 id * 399-433 34 Strata of Maysville, Eden, and Utica age: (2) Shale, a gray to dark eray, unusually pure clay shale. Some parts resem- ble flint clay. Grit is almost want- ing. Scattered particles of marcasite present. A slight flow of gas report- ed at 770 feet in Norris well. No fossils were seen. (Maysville and TEMPERA Goma eeeerte cele) oon. re 433-965 532 (a) Shale, dark brown, calcareous, very fossiliferous. A species of Dalma- nella was the only form recognized. The age of the beds is probably Utica Anh paet Ment: sat fo. Ler Bae 965-1165 200 Mohawkian series : (c) Limestone (Trenton? or Galena ?), highly dolomitic, brownish gray, granular texture, having numerous cavities lined with crystals of dolo- mite and marcasite. In the Grubb well there was a show of oil 23 and 46 feet below top and salt water at 40 feet which rose 200 feet. This is the “Trenton oil rock” of northwest- ern: Olio ses eee a Se SoH Cay or 1165-1233 68 (6) Limestone, slightly dolomitic, vary- - ing from dark gray to nearly black, dense textured. Some shaly beds. Fossils are plentiful, and indicate iblgekehuivemacernes 606 ok" 2 12338-13825 92 °126 =D. D. Condit—Deep Wells at Findlay, Ohio. (a) Limestone, light gray to dark gray, minutely crystalline; no fossils seen, but probably of Lowville age-.---. Lower Ordovician series : Strata of probable Stones River age : (e) Limestone, dense textured, dark ---- (d) Limestone, light gray, minutely crys- talline |.) cea egy Oe Bie eee ee (c) Limestone, dense textured, dark, be- coming brownish near base. Some shaly beds present. Show of oil near top in Grubb well. These limestones are devoid of fossils and vary from hight dove color to dark bluish. The texture is smooth. Some portions are argillaceous and resemble litho- oraphie limestowe Wes eee tee ae (6) Shale, bluish green, slightly calcare- QUIS Pree ne = eg: uy eee Ne ee a (a) Limestone, dark gray .--.-.------- Strata of probable St. Peter age: _(z) Limestone, dolomitic, white, granu- ular with quartz grains in lower portion. In the Norris well a little oil was found distributed through the rock at a depth of 1900 to 1960 feet, and at 1990 feet was the “ Blue Lick” water which rose 1200 feet: - (h) Sandstone, calcareous, white. Quartz grains well rounded and assorted - - - (g) Limestone, white, slightly dolomitic, (7) minutely granular. Some quartz orains present Var gee wee ae Fae Sandstone, with calcite, microcline and orthoclase as prominent acces- Sony COnstibMents sees eee eee (ec) Limestone, slightly dolomitic, white, siliceous, minutely granular ---- --- (7) Sandstone; with much calcite. Quartz grains rounded, average di- AMVCTCI Aras = ayaa ace ey ee Fe ee ae es (c) Limestone, dolomitic, dark gray, Ramadliy: Se Wesel) eine LS) hee Ahk Le (6) Clay, e@ieenis Reeest Fx. seynce loi ciate (a) Sandstone, with few accessory min- erals besides calcite. Quartz grains show secondary enlargement _-_.- .- Depth in feet 1325-1401 1401-1637 1637-1675 1675-1850 1850-1875 1875-1894 1894-2085 2085-2105 2105-2155 9155-2195. 2195-2229 2229-2239 2239-2255 2355-2260 | 2260-2300 Thick- ness 76 236 38 175 19 191 40 pa D. D. Condit—Deep Wells at Findlay, Ohvo. 127 Depth Thick- in feet ness Upper Cambrian : (c) Limestone, dolomitic, dark, minutely granular. Much green glauconitic material and some quartz. Basal portion sandy and brownish gray. Some of the rock particles have vein- letstel emilee ous ru 52 aks 2300-2360 60 (6) Sandstone, impure, arkosic in upper portion. Garnet, orthoclase, micro- celine, and plagioclase are plentiful. Usual diameter of grain 0°3 to 0°5™™, Samples from the Norris well show a white sand of angular grain that drilled fine, indicating a quartzite_. 2360-2755 395 (a) Clay, top portion red, middle green, fii and base gray ---- - [eekcgeit 2 SIS as 2755-2770 15 Pre-Cambrian : | Granite, probably gneissoid. Biotite and green hornblende principal acces- sory minerals, with a considerable amount of titanite and apatite and a lesser amount of garnet .---.---- Di) 208 0 eae A deep well drilled at Waverly in southern Ohio is of inter- est in this connection, and a condensed section with major headings omitted is given for comparison, The record was studied by R. 8. Bassler, whose description appears in volume xxxl of this Journal, pages 19-24. Geologic section of the Waverly well. Thickness Wh in feet Depth Fine grained drab sandstone, forming lower part Daameniveseries, ses os. ase 35 0-35 Bituminous, fissile black Ohio shale ..-.____- 450 35-485 Mainly white, fine-grained sandstone with traces of white limestone. Red and brown calea- reous sandstones of Clinton age in basal PORMOMM ea tee eee Sah lee 415 485-900 Blue shale and fragments of blue limestone, Richmond and Maysville age, with proba- : bly upper Eden shales represented ----- - 1065 900-1965 Blue shales containing Middle Eden fossils --. 55 1965-2020 Unfossiliferous blue and greenish shale, prob- aplylower Uden aud Wigica ~~ 5. 22. 2 - 80 2020-2100 Blue clay and shale with a few fragments of blue | limestone. Lower Trenton fossils noted-. 125 2100-2225 White, clayey, and dove-colored unfossilifer- ous limestones and blue argillaceous lime- stone at bottom (Lowville and Stones River) 600 2225-2825 128 =D. D. Condit—Deep* Wells at Findlay, Ohio. Thickness in feet Depth White, saccharoidal sandstone (St. Peter) -... 175 2825-3000 White, dolomitic limestone. Fragments of igne- ous Tock ‘at base! ii) ae oe ee 320 3000-3320 The following section is regarded by Dr. Bassler as repre- sentative of the region near Cincinnati. It was taken from a -well drilled at Oxford, described by Joseph F. James in volume x of the Journal of the Cincinnati Society of Natural History. The correlations are inserted in brackets by Bassler in the article cited, and the original classification of James is omitted. Geologic section of well at Oxford, Ohio.* Thickness in feet Blue limestone anal shale [Richmond and Maysville] 360 Blue shale [Maysville and Eden] ..--.--.----..-- 380 Dark limestone [Trenton] 2222-222. 222255 a 50 White limestone with magnesia [Lowville and Stones River|i¢czec ses eee: Bee 495 White, arenaceous limestone [St. Peter] -.-------- 40 It is pointed out by Dr. Bassler that the Maysville and Richmond do not vary greatly in thickness across the Cincin- nati arch, but that the great variation in thickness of the Cin- cinnatian series is probably due to an increasing thickness of Utica shale away from the apex of the axis. He also says :t “The same eastward increase in thickness for the Trenton rocks may be stated with less doubt. At Cincinnati the lower 50 feet of the Trenton are exposed with the thin Utica shale resting upon its eroded surface. Proceeding southeast along the Ohio River, this thickness increases to over 100 feet, in a distance of 30 miles, by the addition of higher beds of the formation. The occurrence of 125 feet of Trenton strata at Waverly 80 miles east, 1s, therefore, in line with the idea that the Trenton and the Utica are alike in having a minimum thickness along the Cinein- nati axis.” The thickness of the lower formations of the Cincinnatian series at Findlay and other localities in northwestern Ohio, is shown by well records to range from 700 to 1000 feet, being 732 feet at Findlay, and over 950 feet at Carey in W yandot County. Records in Van Wert, Allen, Hancock, Wyandot, and Wood counties, all show a bluish oray shale in the upper portion and beneath this a calcareous, brown, fossiliferous shale which everywhere varies only a little from 300 feet in thick- ness. It seems probable that this brown shale is the equiva- lent of the Utica and at least a portion of the Eden shale of the Cincinnati region. * This Jour., 4th ser., vol. xxxi, p. 22. t Op. cit., p. 23. D. D. Condit—Deep Wells at Findlay, Ohio. 129 There is nothing in the Findlay well records which proves the presence of the Point Pleasant formation as developed in southern Ohio, which contains a Trenton fauna. The oil-bearing limestone underlying the Utica (?) shale and popularly known as the ‘T'renton may be the equivalent of the Galena limestone which is of early Trenton age. The rock is a brown, crystal- line, open-textured dolomite with numerous voids. These are lined with dolomite crystals and marcasite, which appears to be the latest mineral introduced. This open-textured oil- and water-bearing dolomite has a thickness of 68 feet. Beneath it is a dense, dark gray limestone having numerous fossils. A diminutive variety of Dalmanella testudinaria is especially significant, and Black River is indicated as the probable age of the beds. The drillers report sharp sands which cut the drill, at depths of 85 and 180 feet below the top of the “Trenton,” but an examination of the samples showed but little quartz within those limits. The limestone of Black River age has some shale beds. The limestones considered to be of Stones River age are more or less argillaceous and even textured, and vary from light dove color to nearly black. They appear to be devoid of fossils. There is some shaly limestone in the lower portion. The white Be initilar limestone immediately under the lime- stone last described occupies the position usually assigned to the top of the St. Peter. The samples from the upper por- tion contain little quartz and the first sandstone bed penetrated lies 150 feet lower. The succeeding 190 feet consist of alter- nating layers of siliceous limestone and white sandstone, with athin layer of clay near the base. This gives the unusual thickness of 406 feet for the St. Peter. Some oil was found in the Norris well in the interval rang- ing from 1,900 to 1,960 feet in depth. This may have come from the lowest bed tentatively assigned to the Stones River, but it seems more probable that the horizon belongs in the St. Peter. No oil was reported at this horizon in the Grubb well. The “Blue Lick” water, a bittern characteristic of the St. Peter, was found about 30 feet lower than the oil. There is little doubt that the dark dolomitic limestone found at 2,300 feet is Upper Cambrian. No recognizable fossils were discovered, but the rock has an abundance of glauconite. The underlying sandstone having a thickness of 395 feet rests on pre-Cambrian rock. The pre-Cambrian rock was penetrated to a depth of 210 feet. The water from the overlying sandstone was cased off, and it was necessary to pour in water to facilitate drilling. Progress was slow in the hard rock which played havoc with the drill. The bailer was run four times each day giving 130 =D. D. Condit—Deep Wells at Findlay, Ohio. samples at intervals of three or four feet, which were painstak- ingly washed by the driller thus losing all of the mineral powder. No rock particles were obtained. The samples, fifty-five in number, are fairly uniform as to mineral composition except the ones from near the bottom of the hole, which consist largely of flakes of iron and heavy minerals. Quartz and feldspars are the principal constituents. The feldspars are principally orthoclase, microcline and acid plagioclase. A few microperthitic intergrowths were seen. The quartz has inclusions of rutile. Green hornblende and biotite are next to quartz and feldspar in order of abundance. These are not uniformly distributed, being abundant in some samples and practically wanting in others. Such irregularity in their occurrence may signify a banded gneissoid structure for the rock, but it must be remembered that the sand bailer is not an accurate sampling device, and in dumping, mica and hornblende would be the most likely materials to be washed away and/lost. Minerals present in lesser amounts are titanite, apatite, garnet, muscovite, zircon, and a mineral probably diop- side, together with chlorite, sericite, kaolinite, and other alter- ation products. There are several rusty oxidized samples from various depths which evidently came from shear zones or joint planes, but aside from these decomposition is not advanced even in the upper portion. Garnet is found rather sparingly in the upper portion, but the samples at and near the bottom of the hole have much gar- net, together with zircon, titanite and other heavy minerals. Titanite is more plentifully and uniformly distributed through- out the rock, and in some samples probably constitutes as much as four per cent. Muscovite is present in only a few samples. One sample, lacking hornblende and having considerable mus- covite and little biotite, may have come from a pegmatite dike. The information at hand does not warrant sweeping conelu- sions as to the relations of this rock, but it is believed that its composition is consistent with that of granite. In the upper portion the rock is typical hornblende granite. Toward the bottom the quantity of dark minerals becomes larger, but is not prohibitive, and it is doubtful whether the name grano- diorite should be used even for this most basic portion. The somewhat abundant occurrence of titanite and garnet might be regarded as militating against the conclusion that the rock is igneous, but these minerals may be accounted for by suppos- ing that sedimentary masses were caught up and blended with the granite magma. This view is supported by the fact that these minerals are more or less localized. It is probable that the rock has a gneissoid structure. No evidence of this was noticed in the microscopic examination of the samples, but there is an alteration of light and dark samples which suggests a banded rock. Johnston— Temperature in Deep Wells at Findlay. 131 Arr. XIV.—Wote on the Temperature in the Deep Bor- ing at Findlay, Ohio,;* by Joun JounsTon. At the instance of the U.S. Geological Survey the writer went to Findlay, Ohio, in order to make a series of measure- ments of the temperature at various depths in the bore-hole, the geology of which is discussed in the preceding paper by Mr. Condit. The results obtamed are communicated in the present note. The temperatures were measured by means of maximum- reading thermometerst which, with a scale extending from 0°—100° C., were divided into single degrees, the length of each of which was about 1-4™™. These thermometers had been previously calibrated at the Bureau of Standards and found 2x0t to be in error by more than 0°1°C., which is the limit of practicable accuracy with such thermometers and is moreover ample for the present purpose. Now if only a single ther- mometer is used, accidental jarring of the thermometer sus- tained while it is being raised to the surface may lead to errors the existence of which might not be detected; in order to eliminate this possibility of error, three thermometers were always used together. As a matter of fact the readings of all three thermometers were in each case concordant, showing that freedom from jarring was attained by means of the ther- mometer cage made use of. This cage consists essentially{ of a thin-walled open copper tube, slightly constricted at the lower end, suspended between two spiral springs which were fastened to a sort of cage made of stout wire; this in turn was attached top and bottom, by means of open links, to 100 foot lengths of one-eighth inch steel wire cable. The thermometers, which in this case were armored, were held fast in the copper tube by short pieces (1 inch) of rubber tubing of appropriate size slipped about one-half inch over either end of each thermometer and kept in compression between the constricted lower end of the copper tube and a kind of hinged lid at its upper end. The lower thin steel cable carried a weigh ; the upper was attached to the bottom of the bailer, which in turn hung as usual on the sand line and was raised and lowered by means of the engine. The use of a weight is advisable, as in its absence there is likely to be considerable jarring of the thermometers; the weight must * Compare the preceding paper by Mr. Condit. + Obtained from H. J. Green, 1191 Bedford Avenue, Brooklyn, N. Y. {A full description of the apparatus, and a discussion of methods of accurately determining temperatures in bore-holes, will be published later. 132 Johnston—Temperature in Deep Wells at Findlay. of course be so far below the thermometers that the heat absorbed by it is not abstracted froin the zone the temperature of which is desired. Likewise the thermometers should be a considerable distance below the bailer, which is a convenient: means of minimizing any convection currents which might perchance be present. There are a number of circumstances which affect the tem- perature of bore-holes; we cannot discuss them here, but shall point out one or two of the more common conditions likely to cause errors. Temperatures at the bottom of a hole should Eres: 1000 2000 3000. DEPTH Peet Fic. 1. Curve showing the relation between observed temperature and depth in the bore hole at Findlay, Ohio. not be taken until at least twenty-four hours have elapsed since drilling was discontinued or since water was poured in the hole; otherwise it is uncertain if the temperatures observed really represent the temperature of the rock at the depth in question. Moreover the temperature of water brought up in the bailer is no certain criterion of the temperature down below, for if the bailer is raised quickly, the friction against the casing may be sufficient——in deep wells, especially—to pro- duce a temperature actually higher than that obtaining down at the bottom of the hole. But the factor which perhaps in- tervenes most frequently and most seriously in the attempted determination of the temperature of the rock (as distinct from that of the air or gas in the hole) is the flow of gas, which in Johnston—Temperature in Deep Wells at Findlay. 133 expanding cools itself off.* Its influence is evident in the present series of measurements, which, therefore, do not Temperature at Various Depths in the Borehole at Findlay, Ohio. 770 | 1165 1165 i Period ! of im- mersion | of ther- * |\mometer Hours. 18 1Z 13 1f 1; 1 18 Temperatures Corrected aver- observed. age temperature. ieee Remarks, mometer| Reading: | Centi- | Fahren- number, |Degrees C.| grade. | heit. 1 11:0 2 11-0 11°0 51°8 5) 11:0 4 13:0 9) 13°2 13°71 50°6 6 13°1 4 14°5 9) 14°6 14:5 58°1 | Level of gas in 6 14°5 flow. + bee eal! 5 19°5 19°5 Gr saan) 6 19°6 | lope Obs / 4 aren _4 19°3 [ee -Comr, 2 5 19°4 19°4 66°9 | J 6 19°5 ib 22°5 2 22°5 22°5 72°5 | Indications of oil. 5) 22°4 + 20°4 4) 25°95 20°D 77-9 | 100 ft. above bot- 6 25°6 tom of Cambrian sandstone. 1 26°5 2 26°5 26°5 79°7 | 50 ft. below bot- 3 26°4 tom of Cambrian sandstone. 4 27-8 4) 27-9 27°8 82-1 | Bottom. 6 208 represent the temperatures of the rock at horizons above that of the gas in flow. * It is, of course, self-evident that no definite conclusions of value can be drawn from temperature measurements in wells in which there is a flow even a small flow—of oil or water. 134 Johnston—Temperature in Deep Wells at Findlay. The actual results are presented in the above table. The depths were determined by measuring down the sand line, a method which is of ample accuracy for the present purpose. The first trial was made at a depth of 1165 feet, the~ ther- mometers being left at that level for one and one-half hours, and in a second trial for one hour only; the concordance of the results thus obtained shows that, with the form of apparatus used,* a period of one and one-quarter hours sufficed substan- tially for the attainment by the thermometers of the tempera- ture of the zone in which they were placed. This is confirmed by the agreement between the ‘measurements made with a period of one and one-quarter to one and one-half hours and those in which the thermometers were left overnight in the hole; as is evident from the figure, in which temperatures have been plotted against depths. The figure shows very plainly the general regularity of the results, apart from the marked discontinuity which was observed, as might be expected, at the point at which Bas appears. The temperatures observed at depths less than 770 feet do not represent the temperature of the surrounding rock, but that of the atmosphere in the well, which is cooled by the flow of gas between the outer and inner casing of the well. The temperature gradient in the sedimentary rocks from the “Trenton” limestone downward is about 0°41°C. (0°74° FE.) per 100 feet ; that in the crystalline rocks appears to be some- what higher, but the data are insufficient to enable one to draw any very certain conclusions from Une phenomenon. Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., June, 1913. *The period required for the practical attainment of temperature equili- brium between thermometers and the surrounding rock depends of course upon the form and weight of the cage surrounding the thermometers and _ should always be determined by actual trial. Uhler and Patterson—Are Spectrum of Tellurium. 135 Art. XV.—The Arce Spectrum of Tellurium; by H.S. Unuer and R. A. Patterson. TuHE object of the present paper is to give an account of the results of our experimentation upon the are spectrum of tellurium and to place on record the wave-lengths of the are lines on the basis of the international system. The attention of the senior author was directed to the interesting and appar- ently anomalous behavior of tellurium with respect to the Mendeléeff table during the winter of 1910-11 by Professor Philip E. Browning at the time when Doctor William R. Flint was working, in the Kent Chemical Laboratory, on the problem of the complexity and atomic weight of tellurium. At that time the primary object in the spectroscopic work was to test the purity of Flint’s material. In order to avoid gas lines and to obtain the spectral lines as sharp as possible the electric arc was used instead of the spark. Also to save the metal and to prevent oxidation the arc was formed in a specially - constructed brass cylinder through which a current of carbon dioxide gas was kept flowing. The grating then employed had a radius of curvature of about ten feet, 14,436 lines per inch, and it was ruled by Schneider on one of Rowland’s engines. Since the mass of each of Flint’s most important by-products was small, a little preliminary work showed that the spectro- graph was too large for the object then in view. Consequently the problem of testing spectroscopically the composition of these by-products was deferred until more suitable apparatus could be obtained. Nevertheless, it may be stated that the are between comparatively pure electrodes of metallic tellurium could not be maintained continuously at about 110 volts in hydrogen, or in carbon dioxide, or in air. In fact, the carbon dioxide seemed to be partly reduced because the spectrograms showed all the strong lines of carbon and a black deposit, which may have been finely divided graphite, was formed on the electrodes. Especial care was not taken to purify the car- bon dioxide as was made evident by the presence on the nega- tives of the band at 23590, which is usually ascribed to cyanogen. | Since the time mentioned above we have been so fortunate as to obtain two concave gratings ruled by Professor John A. Anderson on Rowland’s remodelled engines. The smaller grating is the best we have ever seen and the larger one is of the highest grade. The former has a radius of curvature of one meter and 18,159 lines in the space of 460°. It is mounted in essentially the same manner as was the grating set 136 Uhler and Patterson—Arc Spectrum of Tellurium. up by one of us to obtain the data for the “ Atlas of Absorp- tion Spectra”’*. The larger grating has a radius of curvature of about 21°5 feet and 15,000 lines per inch. It is mounted according to Rowland’s plan. With these two spectrographs we have been able to test Flint’s material successfully and to investigate the are spectrum of tellurium. The latter problem being the more important and fruitful will be taken up first. With the smaller instrument films sensitized by the “ Pan- chromatic B” emulsion of Wratten and Wainwright were used. We found these films to be uniformly sensitive from about A 2300 to 76500. With long exposures or with very intense radiations it was possible to photograph between the limits A 2000 and 27200. With the larger apparatus Cramer “Crown” and “Instantaneous Isochromatic” plates were employed. The simple hydrochinone developer as formulated by Jewell was used throughout. When the work was begun we could only find four are lines of tellurium recorded. These were measured by Exner and Haschek. When the sixth volume of Kayser’s ‘“ Handbuch der Spectroscopie ”’ reached us it added three more arc lines, as determined by Eder and Valenta. ‘These seven lines are all in the ultra-violet above 2800 and yet the are produced by bringing in contact and quickly separating two rods of metallic tellurium is so intensely bright as to suggest the existence of radiations in the visible region of the spectrum. The hypo- thesis that this light was due entirely to incandescent solid or liquid tellurium did not seem adequate. For this reason, as well as on account of the fact that certain articles in chemical journals imply that some of the tellurium lines coincide exactly with the lines of other elements, we decided to investigate the are spectrum as if nothing were known about it in advance. The problem consisted, therefore, in two parts, first, the deter- mination of all the lines which pertain to the are spectrum of tellurium and only to this substance and, second, the measure- ment of the wave-lengths of the are lines in terms of the inter- ferometer standards. Obviously, the meter-radius grating was employed to attack the first part of the problem. To have a sure foundation of comparison, negatives were taken of the arc spectra of all the . metals, 17 in number, which were likely to occur as impurities in the metallic tellurium or in the oxides and nitrates of this element. Selenium does not give an are spectrum and hence it presents no difficulty as far as the lines of tel- lurium are concerned. On the other hand, selenium affords an example of a substance which would. escape detection if the are alone were used in analyzing spectroscopically *H.S. Uhler and R. W. Wood, Carnegie Publication No. 71 (1907). Ad Leal ee Uhler and Patterson—Are Spectrum of Tellurium. 137 a mixture which might contain it. The metals or suit- able salts were placed in shallow holes which had been drilled in the lower, positive, carbon electrodes. The carbon rods were made and regraphitized by the Acheson Com- pany of Niagara. Although these electrodes contained only slight traces of impurities, “blank” exposures were taken for each rod. Six negatives were taken on each film. Fifteen lines have been absolutely identified as belonging to the are spectrum of tellurinm. All of these lines are in the ultra- violet above 13200 and they have all been observed in the spark spectrum by other investigators. To avoid repetition of the wave-lengths the lines will be referred to by the arbitrary numbers in the first column of the following table. No. | Wave-lengths Intensity Character 1 3175°130A 9 sharp, narrow reversal 2 2769°653 9 . ae ke 3 2530°734 a is “eae se + 2431°771 1 fine, sharp 5) 2420°122 1 = be 6 2385°783 10 broad, wide reversal 7 2383°268 10 ee oF ss 8 2265°515 5 sharp, narrow reversal 9 | 2259°02 8 broad, wide $s 10 |. 2255°50 5 sharp, narrow “ 11 2208°88 6 f 12 2160°12 6 s 13 2147°33 8 s 14 2143°0 9 broad, wide reversal 15 2081°8: 8 sharp By means of the meter grating, limes 1 and 2 were readily proved to belong to tellurium, although they seemed to coin- cide with the lines 1 3175:044 and 2 2769-939 of tin and antimony respectively. In other words, lines 1 and 2 were always present in the arc spectrum of tellurimm when not the slightest trace of the strongest lines of tin and antimony could be seen on the negatives. Since line 1 is not very wide, since its wave-length differs from that of the tin line by only 0-086 A, and since the tin line in question is one of the most intense and broad arc lines of this element, it is not surprising that line number 1 has been overlooked by earlier investigators. When the fuzzy spark lines are photographed, the quartz spectrographs employed by K6thner and others 138 UWhler and Patterson—Are Spectrum of Tellurium. would probably not’ suffice to separate the antimony line from line 2, the interval being about 0°29A. [2 3175-044 is accord- ing to our measurements whereas A 2769°939 is quoted from volume VI, page 440, of Kayser’s “ Handbuch.” It was measured by Schippers. A In the later work we were given such large quantities of especially purified metallic tellurium by Professor Browning as to enable us to dispense with the enclosed-are apparatus and to work in air in the usual manner. Between 45 and 110 volts D. C. it was not possible to maintain an are between rods of pure tellurium. The small spectrograph showed that, in addition to the ultra-violet lines, the arc formed at the instant of breaking the circuit radiates a continuous spectrum between the limits » 3300 and >A 4800. This accounts in part only for the visible light mentioned above. It seems to come from the vapor and not from the electrodes directly. However, we have not fully proved this point. If this continuous spectrum is really made up of bands then they are too fine and uniform to be resolved by the small grating. The intensity of the con- tinuous spectrum was not sufficient to justify trying to record it with the largest spectrogr aph. With this instrument the are was always obtained by putting lumps of the metal in a shal- low hole in the lower, positive, graphite electrode. The are would not burn between the pointed lower end of the negative electrode and the large, spheroidal globule of tellurium but it would wander around the peripheral line of contact of the lower electrode and the globule. The arc is intensely white and it shows the various arc-regions (core, mantle, ete.) very clearly and beautifully. Of course, when using an are of tellurium in the manner just mentioned, special precautions have to be taken to avoid breathing the fumes which are inju- rious and very irritating to the nose, throat and lungs. Lines 1 to 10 inclusive were photographed in the second order of the largest grating. The iron spectrum was always impressed simultaneously with that of tellurium, and care was taken to have the grating entirely filled with light. Also, each line was photographed at the center of curvature of the grating in order to have the interferometer iron lines dis- tributed nearly linearly. The spectrograms for lines 1 to 10 inclusive were measured either two or three times in one direc- tion and then an equal number of times when reversed. The same lines were measured on different plates by the two obser- vers and the means of the separate wave-lengths are given in the above table. In general, the results agreed very closely, but, because some of the interferometer lines used have only been determined by Fabry and Buisson and also because there exists at the present time some doubt as to the constancy of Ohler and Patterson—Are Spectrum of Tellurium. 189 the wave-leneths of the iron lines, we are of the opinion that 0:005 A is a fair estimate of the possible error of our results for lines 1 to 8 inclusive. Lines 9 and 10 were so faint in the second order as to preclude the possibility of measuring them closer than 0°01 A. Their wave-lengths were checked up in the first order. Line 11 was also measured in the first order of the largest grating, whereas lines 12 to 15 could only be obtained with = Lumiere plates in the first order of the 10 ft. grating and with Panchromatic films in the same order of the meter spectrograph. | As to the are lines themselves the following remarks may not be superfluous. By using some metallic tellurium which contained a trace of tin as an impurity an excellent negative was obtained, in the second order of the largest grating, which showed the iron, tin and tellurium lines very sharp and fully resolved. The wave-lengths are 3175°044, 3175°130 and 3175°447 for tin, tellurium and iron in the order named. This removes all doubt as to the independence of the tin and tellu- rium lines. In like manner the antimony and tellurium lines at 2769°94 and 2769°653 were differentiated. Lines 6, 7, 9, and 14 were broadly and symmetrically reversed, in general, and they seem to belong to a class by themselves. Line 6 was always wider and a little more intense than line 7. Lines 4 and 5 were never obtained reversed or double with the two larger gratings. Strange to say, when the films were examined with a compound microscope each of these lines appeared to be double. The duplicity seemed to be due to self-reversal because the separation of the components varied from film to film. The reversal is asymmetric, but im some cases the longer wave-length component is the weaker, and in others just the opposite holds. The reversal was wider when a pure salt was tamped in the lower electrode than when the metal alone was used. Salts were not used with the largest grating. Lines 11, 12, 13, and 15 never appeared reversed on the negatives. All the remaining lines were easily obtained with fine, symmetri- eal, axial self-absorption. As might be expected, the reversal of any one line is widest at the end corresponding to the posi- tive, lower electrode. Because other investigators have been unable to repeat the work of Flint in such a manner as to obtain his low value for the atomic weight of tellurium, it may not be superfluous to state the results of our spectroscopic analysis of the specimens which he left with one of us in the spring of 1911. The white needles which corresponded to the atomic weight 127-45, when vaporized in the arc, showed only slight traces of anti- mony and copper. It must be remembered, however, that some elements such as selenium do not give lines in the elec- Am. JouR ScIl.—FourtTH SERIES, VOL. XXXV, No. 212.—Avueusrt, 1913. 10 140 Ohler and Patterson—Are Spectrum of Tellurium. trie are. The crystals in the vial labelled ‘ alpha sub. 8., at’ w’t. 126°6” seemed to be as pure as the 127-45 material. The same statement applies to the sample marked “ 'TeO,.124°3 Redistilled fraction 10”. One negative showed more copper for 124°3 than for 127-45, but another negative did not. Con- sequently the discrepancy must be ascribed to slight, unavoid- able changes in the conditions of the are. The orange-yellow erystals (“ beta. P’ p’t. by NH,OH and boiling ”’) gave a fairly complete spectrum of iron. From the spectroscopic stand- point we would say that a great deal of iron was present. The usual trace of copper was recorded. At our request Professor Browning subjected some of the yellow crystals to a delicate chemical test for iron and found this metal to be present, thus verifying our analysis. However, he did not think that the percentage of iron was at all great. The test seems to have been definite but not pronounced. These results are at vari- ance with Doctor Flint’s statement that “ No shghtest traces of either iron or copper can be discovered by the usual tests”*. There was no discernible difference between the metallic tellu- rium which had been distilled once and twice in hydrogen. The lines of sodium were very strong and there were some lines of antimony, iron, and lead. Copper was not at all strong. It would seern, therefore, that the particular process of distilla- tion used by Flint is illusory. In conclusion we desire to state that our work on the spec- troscopic properties of tellurium will be continued during the next academic year. Also we desire to express our sense of deep indebtedness to Professor Browning-for having supplied us with the large quantities of tellurium. Sloane Physical Laboratory, Yale University, New Haven, Conn., June, 1913. * This Journal, vol. xxx, p. 219, Sept., 1910. HI. EF. Gregory—La Paz (Bolivia) Gorge. 141 Art. XVI.—TZhe La Paz (Bolivia) Gorge; by Hersurr E. Gregory.* From the shores of Lago Pequeno, the nearly enclosed south- eastern portion of Lake Titicaca, the surface of the interior plateau of Bolivia (the altiplano or altiplanicie of the Spanish Americans) ascends toward the Cordillera Real. From Guaqui to Viacha, forty-two miles, the rise is 120 feet and the railroad, after following the irregular course of the Rio Tiahuanaco and Fie. 1. Fie. 1. View from Alto looking eastward toward the Cordillera Real. The position of the gorge, on the floor of which the city of La Paz rests, is indicated by the arrow. passing a group of low, mature hills, crosses the shallow valleys of the Rio Colorado and the Rio Viacha. From Via- cha to Alto, the terminus of the steam railroad, the floor of the altzplano is remarkably flat, and slopes westward at the rate of forty feet per mile.t The drainage of this portion of the plateau is sluggish and frequently interrupted by shallow * Geologist of the Peruvian Expedition of 1912. + Distances and elevations are as shown on the Mapa General of the Ferro Carril del Sur del Peru, a blue print of which was kindly furnished by T. A. Corey, Chief Engineer. 142 H. E. Gregory—La Paz (Bolivia) Gorge. depressions. No hills rise above the gravel-strewn floor which appears to extend as an unbroken surface to the foot of majes- tic Ilampu. At Alto a surprise awaits the traveler, for here, without preliminary warning in change of slopes or eastward- flowing streams, one finds himself on the brink of a canyon eut entirely in alluvial deposits to a depth of over 1500 feet. At the foot of the canyon wall lies the city of La Paz, whose red tile roofs, cathedral spires and threads of streets, broken by parks and traversed by streams and irrigation ditches com- pose a unique picture of singular beauty. Fic. 2. Qe oe ee s a, gravel,sand. 0b, tuff. c,sands, gravel, clay. d, lignite. e, sands, gravel, clay. Fig. 2. Generalized section of La Paz gorge, not drawn to scale. As shown in the view (fig. 1), looking from Alto station across the La Paz valley, the landscape gives no suggestion of the presence of such a chasm and one is reminded forcibly of the Colorado Plateau of Arizona, where impassable canyons of great depth are revealed only when one is standing on their rim. On descending the canyon walls it is found that the floor is by no means flat, but is cut by streams which flow in gorges one hundred feet and more in depth, between and over which, resting on hills and terraces, the city is built. The larger part of the buildings are distributed along two more or less dissected terraces whose position with respect to the valley walls is shown diagrammatically in fig. 2. Between San Jorge and Obrajes the La Paz river has sunk its bed into sands and clays whose eroded strata exhibit minia- ture “bad land” forms. Lymg unconformably above these finer deposits at San Jorge and northward through the city are deposits of gravel which stand as nearly vertical walls fifty to one hundred and fifty feet high. The material is exces- sively coarse and contains bowlders of white granite six inches to six feet in diameter. Above the gravel terraces, forming the knobs and benches and ridges of the western part of the H. FE. Gregory—La Paz (Bolivia) Gorge. 143 city as well as the walls of the valley, and extending nearly to the ievel of the a/tiplano, are beds of gravels and sands and clays eroded into a bewildering maze of forms. Needles in groups or singly, columns unadorned or fluted or capped by tables, rise five to fifteen feet on steep slopes and five to fifty feet on knife-edged, dividing ridges. Innumerable sharply- cut, miniature canyons with sheer “walls five to two hundred feet in height together with tunnels and pits in great variety furnish passage for water. Landslides with slopes as great as 50°, frequently accompanied by open cracks, are numerous. Here and there benches and tables composed of cemented gravels and brown concretions project from vertical surfaces or form the capping of columnar masses. The whole deposit is ash-gray in general tone, but is beautifully striated by gray, brown, light pink, bright yellow, purple and white bands from a few inches to one hundred feet in thickness. Vegetation is absent except for patches of wiry grass and tough shrubs which find a foothold on the little flat-topped tables and gen- tler slopes. The beds in general dip slightly to the south. A closer examination of the strata exposed reveals the presence of the following materials: (1) Sand, mostly fine, some coarse, composed chiefly of quartz grains, and arranged in beds several hundred feet in extent, or in short lenses. All the strata are more or less cross-bedded, with laminae dipping 0°—25°. (2) Gravel, composed of rounded pebbles from the size of a small pea to three inches in diameter, arranged as lenses which exhibit marked and sudden variation in position and size both horizontally and vertically. The gravels are everywhere cross-bedded and frequently inclose lenses of sand. The component materials in the upper part of the section were found to consist approximately of sedimentary fragments 75 per cent, igneous 15 per cent, metamorphic 10 per cent. The following types of rock were recognized : gray sandstone, brown sandstone, white granite, granite-gneiss, diorite-gneiss, carneti- ferous granite-gneiss, black slate, mica or chlorite slate, gray quartzite, brown quartzite. Quartz pebbles are rare and no limestone or volcanic material was observed. All the pebbles are worn, about half of them well-rounded, and a few are faulted and veined. The gravel increases in amount and becomes coarser toward the top, and along the electric railway from La Paz to Alto contains angular, sub-angular and rounded bowlders four inches to one and one-half feet in diameter. At this locality the gravel forms beds of considerable thickness or occurs as lenses embedded in finer gravels, sands and clays, and resembles morainal deposits except for the irregular strati- fication. (3) Clays, rarely pure, usually highly arenaceous, generally distributed as lenses within the finer sands. In the eS; 144 . E. Gregory—La Paz ( Bolivia) Gorge. localities studied by the writer, clay is relatively small in amount, the larger beds being 100 to 200 feet in length and of inconsiderable thickness. (4) Carbonaceous shale and two Hie? 3) Fie. 3. View of deposits in La Paz gorge, about one mile west of the American Institute. layers or lenses of impure lignite three to six inches thick, composed of comminuted plant remains too fragmentary for determination. (5) Volcanic ash, eight to fifteen (at one point twenty or more) feet thick, extending as a continuous white H. EF. Gregory—La Paz (Bolivia) Gorge. 145 band for over two miles on the west side of the valley and reappearing on the east side at an elevation of about 12,600 feet. Microscopic examination shows the ash to be dacitic. Ines 2S So Fic. 4. View of deposits in La Paz gorge, about one and one-half miles west of the American Institute. The general appearance of the deposits and the arrangement and alternation of strata are shown in figs. 3 and 4, with “which, for purposes of comparison, is inserted a typical view of the Dakota bad lands (fig. 5). 146 Hl. E. Gregory—La Paz (Bolivia) Gorge. The texture and structure of a portion of the beds taken about midway between the top and bottom are shown in fig. 6. Figs. 7 and 8 exhibit details and are fairly representative of a large number of occurrences. The profound gorge of La Paz with its great accumula- HTGE so: Fie. 5. View of Bad Lands, South Dakota. Photo by Darton, U. S. Geological Survey. tion of unconsolidated sediments and striking erosion features has naturally attracted the attention of scientists and travelers alike. D’Orbigny* speaks of the La Paz deposits as “allu- vial,” and uotes that sandstone pebbles were more abundant in the upper beds. He also recognized kaolin deposits at Mira- flores,—a suburb not visited by the writer. Forbest assigns * Voyage dans Amérique Méridionale, Tomo III, 1842, partie 8, p. 120. + Report on the Geology of South America, Quar. Jour. Geol. Soce., vol. xvii, 1860. Hi. EF. Gregory—La Paz (Bolivia) Gorge. 147 to these beds a thickness exceeding 2000 feet. The band of “trachytic tuff” “300 feet below the surface of the plain,” HIe=— Os a, 15 ft., fine sand with thin lenses of gravel. b, 4 ft., cross-bedded gravel. ¢, 24 ft., fine sand, consolidated in places and lenses of gravel. d, \4 ft., cross-bedded gravel, with lenses of finesand. e. 20ft., finesand. /, 8 ft., cross-bedded gravel with lenses of A ee g, 200 ft., thin-bedded sands with gravel lenses ; portions of sand firmly cemented. Fie. 6. Section of a portion of the west wall of the La Paz gorge. Drawn to scale. 148 H. EB. Gregory—La Paz (Bolivia) Gorge. “90 to 80 feet in thickness,” Forbes considered as part of a wide-spread ‘ diluvial formation,” occupying a basin between the Silurian rocks of the high Andes and the low Devonian hills to the west, and believed the impure lignite to be an extension of the carbonaceous strata exposed at the foot of Illimani and also near Poto-poto. The material composing eee Pe Fic. 7. Portion of gravel lens; extent and thickness of gravel and sand and orientation of cross-bedding laminz drawn to scale. igs os a, Sand with irregularly distributed gravel. 6b, gravel with two lenses of clay. Fie. 8. Section on line of Arica-La Paz railroad, showing contact between gravel and sand. Drawn to scale. these beds has its source, according to Forbes, in the Silurian strata of the Cordillera Real; with the exception of the vol- eanic ash, which he assumes had been carried by streams from Achacachi on the shores of Lake Titicaca. Zundt* assigns the * Appendix to Spanish edition of D’Orbigny, La Paz, 1907. H, EF. Gregory—La Paz (Bolivia) Gorge. 149 granite bowlders to the Cordillera Real at the north, the quartz to the same area, and also to the mountains near Viacha and Colquencha to the west, clays to the Ramos formation (Terti- ary?) underlying the altiplano, and the ash to the Letania mountains. As to the condition of deposition of these deposits, D’Or- bigny and Forbes appear to have held no definite views. Evans* expresses the opinion that “‘the enormous deposits of alluvium ... represent not the alluvium of a lake, but the infillings of a longitudinal valley.” Zundtt speaks of the ash deposit as carried by wind, dropped into a lake or sea and spread by the waves. Minchin speaks of lake beds, a part of the floor of ancient Titicaca, now covered by glacial gravels. D’ Arlach§ speaks of floods induced by earthquakes which cut the La Paz gorge and drained an interior sea. Posnansky| apparently considers the base of the La Paz beds as marine- built, the upper portion deposited in an ancient sea detached from the Pacific by uplift. Zundt, whose previous views involved the existence of a salt sea, considers the deposits in the La Paz gorge as lacustrine,—the fillings of a temporary lake formed by blocking an ancient river which drained the interior basin. The upper end of the La Paz gorge is believed by this writer to have been excavated by glaciers. Bowman" recognized the fluviatile origin of the La Paz beds, but in speaking of the deposits as ‘“‘ the coarsest alluvium, the sort of material that mountain torrents carry,” evidently had in mind the upper beds of the section and the material forming the banks of the present stream, rather than the fine-textured, stratified deposits to the west and south of the city. From the general and detailed sections described and figured above it appears that the deposits which line the La Paz gorge are in no way typical of lacustrine formations. The absence of continuous beds of thinly laid clays, silts and the finest sands of uniform texture, the presence of cross-bedding and channeling and the rapid alternation of gravels and sands both horizontally and vertically argue against deposition in the quiet waters of a lake. All the phenomena disclosed by the study of the sections may be accounted for on the theory that the region was traversed by low grade, piedmont streams. Such streams with a shifting net-work of distributaries and interlaced chan- nels alternately depositing and cutting in a capricious manner * Geog. Jour., vol. xxii, pp. 634-35, 1903. t Loe. cit, 1907. ¢{ Geog. Jour. vol. xxxvi, pp. 396-7, 1910. § Bol. Oficina National de Estadistica, No. 64-66, p. 756, La Paz, 1911. | Bol. Oficina National de Estadistica, No. 64-66, pp. 689-702, 1911. §] This Journal, vol. xxviii, p. 400, 1909. 150 H. E. Gregory—La Paz ( Bolivia) Gorge. in response to seasonal rainfall would produce just such sedi- ments as the strata under discussion. Temporary lakes,— annual or lasting for decades,—are normal features of such a piedmont flood plain and are ample to account for the lenses of clay and the thin, short bands of carbonaceous material oceur- ring in the section. The geologic history of the La Paz gorge can not be written on the basis of the data at hand. The significance of the inner gravel terrace pointing to a second, or perhaps a third, cycle of filling and erosion, the conditions under which the remarkably coarse upper beds were deposited, the character of the floor on which the finer sediments were laid down, the extent of the deposits and the pre-glacial history of the La Paz river itself, are problems which will repay detailed physiographic research. — F. A. Perret—Some Kilauean Formations. 151 Art. XVII.—Some Kilauean Formations; by Frank A. PERRET. Tue floor of the great pit crater of Kilauea has an area of more than ten million square meters, every one of which—on the surface, or immediately below it—reveals something of interest or importance to the investigator. To say, therefore, that a month might profitably be devoted to its exploration 1s almost to state an absurdity—a lifetime would be more appro- priate and it is more than probable that, in such an interval, a new floor will have been laid, with fresh interests for the visitor at every step. The larger portion, by far, of this great area is composed of pahoehoe lava which has overflowed from Halemaumau or welled up through more ephemeral vents—its smoothly undnu- lating, glassy surface glistening with that satiny sheen which is responsible for the peculiarly expressive Hawaiian name. Here and there, however, a long, high-standing AA flow, hav- ing a jagged, dark red surface contrasting sharply with the surrounding plain, has made its way along some slight decliv- ity from a now hidden vent from which it had issued tumultu- ously, hissing with gas at every pore. And, between these extremes, there may, in places, be found an intermediate type passing by insensible degrees from the most superficially inco- herent AA to a form so smooth and plate-like as almost to merit the appellation ‘‘ ultra-pahoehoe.” In the opening sentence ot the present paper a hint is con- veyed of interesting things beneath the surface and that these exist is due to the fact that this great crater floor is composed chiefly of lava flows. A stagnant pool of the Kilauean lava will, in cooling, solidify from the surface to the bottom into a continuous and homogeneous mass of rock, but a flowing stream drains away, after the solidification of its surface layers, leaving a tunnel with an arched roof. The gases which con- tinue to be emitted from the inner, flowing lava, undoubtedly assist in supporting the roof during consolidation and may even form expanded. chambers at intervals along the line of a flow. On the crater floor the visitor is thus walking over caverns and tunnels of whose existence he is unaware, excepting in the comparatively few instances where the roof has foundered and revealed the “cave” below. The larger of these are pro- vided with a ladder giving access to the interior and have been given fantastic names, such as “ Pele’s Dining Room,” etc. In certain cases they have been observed by the writer to ter- minate upward in a prismatic cupola almost—and, in some 152 FF. A. Perret—Some Kilauean Formations. instances, quite—perforating the roof. If this oceurs in the earlier stages of the flow, an active vent is formed, emitting much gas and a little lava in spatters or driblets which build up a “blowing cone” over the orifice. When the action is violent, and especially if the cone has formed at or near the lava’s point of issue on the crater floor, it will take the form of an open cylinder, as in the case of the so-called “ Little Beggar” (fig. 1), and the lava stream will then have the appear- HG ol; Fic. 1. The ‘‘ Little Beggar” blowing cone. ance of flowing from the base of the cone. A more moderate activity forms a simple “driblet cone” (fig. 2) in which the central conduit may be closed at the top by the last splashes emitted therefrom. These spatter cones have always constituted a conspicuous feature of Kilanean volcanism and testify to the importance of the gaseous emanations from the active lava, upon which there has been so great a tendency to cast doubt. They are also interesting as demonstrating that the same, ultra basic lava which, flowing continuously, produces a cone with declivities so gentle as not to exceed, in some cases, four or five degrees will, if ejected intermittently i in splashes which cement together and have time to cool, result in a construction whose sides may even attain the vertical and thus exceed the repose angle of the F. A. Perret—Some Kilauean Formations. 153 most chaotic of fragmentary ejecta from more acid and explo- sive voleanoes. The cones often appear upon the newly formed “shore” of the Halemaumau lava lake and are then of the greatest value to the investigator as offering a means—by the introduction of a tube through an oritice of the blow-cone—of Fic. 2. Fic. 2. A typical spatter cone. collecting the gases emanating directly from the active lava and before their modifications by contact with the air.* Closely allied to the above-mentioned gas-expanded cham- bers along the line of a flow—and, in some instances, identical * As has already been shown in preceding papers of the present series, these gases burn on coming in contact with the atmosphere. 154 F. A. Perret—Some Kilauean Formations. with these-—are the intumescent formations for which the late Dr. Benedict Friedlaender proposed the appellation ‘‘ Schollen- dom ” (fig. 3). In many instances these also are gas-expanded or, at all events, gas-supported, during solidification, and Mr. Immanuel Friedlaender has informed the writer of having observed these formations covering vegetation at the bottom of Kilauean-iki. Green has shown* how the characteristic sub- spherical shape may also result from the simple flowing out of pahoehoe lava in spheroidal masses, after the manner “of por- ies, a Fig. 3. A typical ‘‘ Schollendom.” ridge, upon which the surface cools over until the inner lava forces a way out at the lower side to flow on and form other spheroidal accumulations along the line of the flow. On cooling, the mass is fissured by contraction and a central block is frequently separated from the rest and founders, revealing the dome in section—often as a comparatively thin roof arching over a void, but frequently also as a monolithic mass as deep as the dour itself (fig. 4). It is, therefore, incorrect to state that these formations are intumescent by reason of the intrusion of fresh lava beneath a crust already formed and fractured—the Schollendom is a pri- mary formation and is fissured by contraction in cooling. Intrusive lava often does uplift the flat slabs of the crater floor, the which are then incorporated with the resulting driblet mound, * Wm. Lowthian Green : ‘‘ Vestiges of the Molten Globe,” vol. 2, page 173. FE. A. Perret—Some Kilauean Formations. 155 as could be shown photographically were the present paper not already overcharged with illustrations, but such a construction is not a true Schollendom. The writer has also seen already- Fie. 4. Fic. 4. Interior section of a ‘‘Schollendom.”’ formed Schollendoms invaded by fresh lava from below but, in such cases, the dome is deformed and its gracefully lenticu- lar outline destroyed. Am. Jour. Sct.—Fourts Suries, Vout. XXXV, No. 212.—Aveusr, 1913. 11 156 FE. A. Perret-—Some Kilauean Formations. The general subject of lava tunnels must be left to a future paper and the same is to be said of those interesting tunnel products, the stalactites and stalagmites, the consideration of which would require much space and which are here mentioned as constituting a curious—if small and secondary—Kilauean formation. Notwithstanding all that has been written of these characteristic little forms, the main question, viz., their mode of formation, remains wholly unanswered ; the various theories Fig. 9. Fic. 5. A tree mould of the projecting type. being indefinite and inconclusive or else incompatible with the revealed characteristics of the product. The subject requires further study and the devoting to it of a separate paper. Lava flows outside the great crater have, in some localities, produced the very interesting formations known as “ ‘Tree moulds.” These are divergent in type according to the condi- tions of the flow of lava. If this has invested a forest of trees, or some great unit in the midst of a plain, and then, in great part, flowed away, a casing of lava—solidified by contact with the cold tree-trunk—will be left surrounding this to a height corresponding with the greatest depth attained by the stream at that point. This remains, therefore, as the salzent, or pro- F. A. Perret—Some Kilauean Formations. 157 jecting type of tree mould, standing above the surrounding plain as a monument to the original tree which, even if not at once destroyed by the igneous flood, has since suffered that decomposition and transmutation which is inevitable at the hand of time. (Fig. 5.) In the swnken or ground type the lava has invaded low ground and has remained at virtually its full height around the stricken trees, of whose substance no vestige now remains Rie. 6: Fie. 6. Tree moulds of the sunken type. but whose form, to the most minute detail, is preserved in last- ing stone. The visitor sees a number of cylindrical openings in the ground (lava) descending to the depth of the original flow which, in the cases observed by the writer, was from three to five meters. (Fig. 6.) It is most interesting to note that, at and near the surface, where the lava was not pressed with force against the tree and was also free to slightly shrink away upon cooling, the impression is of the grosser details only, such as the circular or elliptical form of the trunk with the more prominent corrugations while, the farther one descends, the more nearly perfect becomes the imprint of the bark. Near the bottom, where the lava pressed the tree with a force corresponding to the depth of the flow—and which we may 158 F. A. Perret—Some Kilauean Formations. estimate as one kilogram per square centimeter—the impres- sion is as reproduced in fig. 7, than which nothing more exquisitely precise can be imagined. It is a true “ pressure casting,” so faithfully recording the finest detail that, from it, a naturalist may readily classify the original tree, of which the lava has thus formed so perfect a matrix. The reader will marvel that the tree was not marred by its baptism of fire before such an impression could be obtained, iG ae Fic. 7. Specimen from a tree mould. but, if we except the resinous varieties, a growing tree-trunk, massive and full of moisture, will resist carbonization for a time sufficient to permit of the formation of a solidified layer or shell in contact with its surface and which—to make use of an expression almost hackneyed—is “a poor conductor of heat.” Something more than this, however, is required to account for the greater marvel that this mere shell is not then re-melted and destroyed by the flood of liquid lava at full tem- perature which continues to flow against it and the fact that it is not so re-fused can be explained, the writer believes, in but one way. Careful examination of the mould shows that not even the contact surface is vitreous and it is, therefore, obvious that the consolidation has taken place rather slowly, i. e., it F. A. Perret—Some Kilauean Formations. 159 was not a matter of a very few seconds but of many minutes, as indeed we should infer, considering the backing of a mass of liquid at full heat. The result, then, is a shell of crystal- line rock, deposited molecule by molecule after the manner of an electrotype, and whose fuszon point is higher than the tem- perature of the liquid from which it consolidated. We may believe, therefore, that there is no power in the flow to re-fuse the crystalline shell deposited therefrom as the lava—especially in the case of a stream—will not possess a sufficient degree of superheat to accomplish this; the shell, instead, will progres- sively increase in thickness. The writer believes that failure to appreciate this most important fact, viz., that the fusion point of the crystalline rock is above the temperature at which the original lava will remain fiuid, has frequently resulted in an exaggerated evalua- tion of the temperature of liquid lava through the practise of taking the melting point of the consolidated crystalline product as marking the lower limit of the liquid lava’s temperature. The Halemauman lake, for example, is liquid and active at 1050° C., but the rock of its consolidation—according to recent tests by Dr. E. S. Shepherd—melts at 1150° C. It is the principle—truly universal in its distribution—of relaxation resulting in products which are then with difficulty removable. In the field of volcanism it is this which gives to the crater ledges their stability, to the floating island its span of existence, and which for a time ensures the growth and preservation—as it must eventually set the seal of closure and extinction—of and to no less a formation than the volcanic edifice itself. | Posillipo, Naples, May 6, 1913. 160 Keyes— Carboniferous and Devonian Strata. Arr. XVIIL—WMarked Unconformity between Carboniferous and Devonian Strata in Upper Mississippi Valley ; by Cuaries R. Kayes. Arter half a century’s controversy the final adjudication of the Chemung problem in the Upper Mississippi region seems at hand. Exact determination of the stratigraphic horizon of a marked plane of unconformity which may be properly regarded as delimiting the base of the Carboniferous rocks of this province gives answer to a number of long standing questions. In the delimitation and correlation of geologic terranes the superior value of diastrophic, or orogenic, criteria over all other lines of evidence has been recently urged by a number of wri- ters,* notably Chamberlin} and Willis, while orogenic criteria aided by fossils are urged by Suess,§ Schuchert,| and Ulrich. As is well known, the most striking expression of orogenic movement is the unconformable relations of strata. Recently, during the progress of certain investigations for city water supplies in Lowa, Missouri, and L[llinois, it became necessary to make some rather nice calculations on the thick- ness and extent of sundry geologic formations. In the course of this work a number of facts were disclosed bearing directly upon the vexed problems mentioned. There are given us for the first time definite data upon the actual stratigraphic rela- tions existing between the rocks of the two distinct geologic ALES. : The general geologic section of the Devono-Carboniferous rocks of southeastern Iowa and northeastern Missouri is as follows : General Geologic Section. Feet Burlinoton limestone 22)... ai SO | Chouteau limestone, 2°22) 2-2 eee 10 CARBONIFEROUS < Hannibal shales ee ee Sees 15 \ Loutsiana: limestone === 225.2 =e 50 averton ue) shales SLi oe 50 bes (blue) shales ** | ‘Grassy (black) shales 2222272255 .0e—= 40 Unconformity. Lime Creek (blue) shales _.-_..._-__- 125 DATOS ooo 1 Cedar, limestone>....222 22.0 =25eee aye * American Geologist, vol. xviii, p. 289, 1896. + Das Antlitz der Erde, vol. ii, p. 15, 1888. + Journal of Geology, vol. xvii, p. 685, 1909. § Bull. Geol. Soc. America, vol. xx, p. 447, 1910. || Science, N. S., vol. xxxi, p. 243, 1910. §] Bull. Geol. Soc. America, vol. xxii, p. 394, 1911. ** This name is the local one usually applied to the blue shales lying be- tween the Grassy black shales and the Louisiana limestone as well exposed at Saverton station, in Ralls county, Missouri. The formation probably attains a maximum thickness of at least 75 feet. Keyes— Carboniferous and Devonian Strata. 161 The stratigraphic relations of the several terranes are best shown in cross-section as they are plotted along the line of the Mississippi river from Louisiana, Missouri, to Muscatine, Iowa (fig. 1). Detailed vertical sections I have given in another place.* At this time the shales lying at the base of the Louisiana limestone were little considered, since at the town of Louisiana they were only two feet thick and the northern local- ities were not yet carefully studied.+ Comparisons of the Lowa and Mis- souri sections are made in the report on the geology of Des Moines county.t At one time§ it seemed that upon faunal grounds the Kin- derhook shales as exposed at Louis- jana could just as well be included in the Devonian section, but this old view long since gave way to the stratigraphic evidence. The Chouteau limestone is quite thin on the Mississippi river, but rapidly becomes thicker to the west- ward. At Louisiana the Hannibal shales are 75 feet thick; at Keokuk, 65 feet; at Burlington about 50 feet of the blue shales in the base of the river-bluffs are assignable here. The Louisiana limestone, which is 50 feet thick at the type-locality, becomes gradually thinner northward, until at Keokuk it is only 10 feet in thick- ness, and soon vanishes altogether as shown by well-sections. This per- mits the overlying and underlying shales of Missouri to come together in Iowa and form one continuous shale-section. Immediately beneath the Louis- iana limestone at the original locality are two feet of blue shales. This ap- parently insignificant layer is usually included in the Grassy black shales below.|| It now seems to have much greater importance. Northward * Bull. Geol. Soc. America, vol. iii, p. 283, 1892. + American Geologist, vol. x, p. 384, 1892. ¢ Iowa Geol. Surv., vol. iii, p. 486, 1894. S aus Louis Acad. Sci., vol. vii, p. 369, | Proc. Iowa Acad. Sci., vol. v, p. 66, 1898. HANNI BAL FT. MADISON KEOKUK F303 Grassy. Shales 1 BURLINGTON Lime Creek Shales MORNING SUN Limestones See Des Moines. Sha MUSCATINE Fic. 1. Geologic cross-sec- tion along Mississippi River. 162 Keyes— Carboniferous and Devonian Strata. from Louisiana these shales rapidly become thicker. At Han- nibal they measure 20 feet in thickness ; at Keokuk, probably not less than 50 feet; beyond, they merge with the Hannibal shales. The Grassy black shales* are only four feet thick at Lonis- iana. They attain a greater vertical measurement northward. Before disappearing below river-level in the Keokuk syneline, they reach a thickness of 30 feet. In well-sections at Keokuk they have not been definitely recognized or separated from the associated shales. At Morning Sun, north of Burling- ton, they are distinctly present in a number of deep-well sections. They have been traced farther north to beyond Muscatine, where Uddent has given them the title of Sweet- land beds. Here they are 45 feet thick; rest in notable uncon- formity upon the Cedar limestones; and have resting upon them unconformably the Des Moines coal measures. Below the black shales there are still other blue shales. They are not exposed above river-level at either end of the syncline ; but as shown in deep-well sections, at Keokuk, there are at least 125 feet referable to them; at Burlington, about 100 feet ; and at Morning Sun, 50 feet. When the lowat and Missouri§ reports were printed it was surmised that this part of the great shale section at Burlington rested directly upon, or was an integral portion of the shales called farther north the Lime Creek formation. Since that time this view has proved to be really correct. The shales in question actually continne in full development to the Minnesota boundary. They rest on the Callaway limestone in Missouri, which appears to be the exact equivalent of the Cedar limestone in lowa. The Grassy shales are of exceptional interest since, in spite of their associated faunal affinities, they probably represent the basal member of the Carboniferous section of the Upper Mississippi region. At Louisiana these shales recline directly upon Silurian limestones. A few miles away they lie im- mediately upon the Callaway (Devonian) limestone. Farther on the Lime Creek shales are found immediately beneath. At their base, therefore, a marked unconformity exists, which is also well displayed at the north, above Muscatine. The present correlation of the Grassy black shales seems to set at rest several moot questions. They, doubtless, represent the Chattanooga black shales which in the south constitute, according to Schuchert,| the base of the Mississippian section. They are not to be regarded as Devonian in age, as suggested * Proc. Iowa Acad. Sci., vol. v, p. 60, 1898. f lowa Geol. Surv., vol. ix, p. 289, 1899. t Iowa Geol. Surv., vol. i, p. 55, 1898. § Missouri Geol. Surv., vol. iv, p. 56, 1894. | Bull. Geol. Soc. America, vol. xx, p. 548, 1910. Keyes—Carboniferous and Devonian Strata. 163 by Udden.* They are not a local development of uncertain affinities as stated by Calvin ;+ nor do they underlie the Lime Creek shales as indicated in his general geologic section of Iowa.t It appears that Owen and Norwood§ in drawing the line of separation of the Devonian and Carboniferous strata in the Mississippi valley at the black shale, displayed phenomen- ally keen insight into the real geologic succession in the region. Particularly noteworthy the Burlington section remains. When discussing the Devonian Interval in Missouri] I was inclined to regard the entire shale-section between the Cedar limestone and the Chouteau limestone as a distinct unit, Devonian in age, and having intercalated the lens of Louisiana limestone. This conclusion was based largely upon faunal grounds and especially upon the Gomphoceras fauna then newly found high up in the section at Burlington, and after- wards especially noted by Weller.4| This fauna was discovered by me at the time that the report on Des Moines county was being printed ;** and six years later the fossils were turned over by Dr. Calvin to Professor Weller for critical examina- tion. Asa result Weller was led to correlatet} the lithographic limestone (bed 4) of the Chouteau formation, at Burlington, with the Louisiana limestone at the typical locality, and to regard the fossils of the shales as constitutmg the oldest Kinderhook fauna. Stratigraphically there seems to be no doubt whatever that Bed 4 at Burlington cannot possibly be the continuation of the Louisiana limestone. Yet there is really no serious faunal discrepancy in Weller’s determinations. That the older fauna —a fauna of marked Devonian aspects—should occur at a stratigraphic horizon higher than that of the Louisiana lime- stone is not remarkable. It is easily explained. At Burling- ton the shale succession from the Grassy formation to the Chouteau limestone is uninterrupted; at Louisiana a thick limestone divides the shales. In the north the fauna of the Grassy black shales continued upward unbroken. The Gom- phoceras fauna from the shales 40 feet below the Burlington limestone at Burlington is probably the characteristic fauna of the Hannibal shales, although the latter at the typical locality have thus far proved unfossiliferous. *Towa Geol. Surv., vol. ix, p. 301, 1899. + Journal of Geology, vol. xiv, p. 572, 1906. ¢{ Iowa Geol. Surv., vol. xvii, p. 192, 1907. § Researches on the Protozoic and Carboniferous Rocks of Central Ken- tucky during the year 1846, 1847. || Bull. Geol. Soe. America, vol. xiii, p. 267, 1902. “| lowa Geol. Surv., vol. x, p. 69, 1900. ** Tbid., vol. iii, p. 483, 1895. +t Ibid., vol. x, p. 70, 1900. 164 Keyes—Carboniferous and Devonian Strata. The blue shales below the Grassy shales and above the Cedar limestone show in deep-well sections a thickness of at least 125 feet. They are without doubt a continuation of the Lime Creek shales. Along the Mississippi river they become attenuated towards the northeast; and some little distance south of Muscatine and to the south of Hannibal they fail altogether. Fifty miles southwest of the last mentioned place, near Fulton, they appear to be fully represented by the 50 feet of Snyder shales which immediately overlie the Callaway . limestone. From Burlington to the northwest they are recognizable as far as Marshall county and characteristic Lime Creek fossils have been taken from well-drillings in this dis- trict. From Marshall the belt swerves to the east somewhat, and in Floyd county the Kinderhook blue shales directly cover them. In the delimitation of geologic formations I place far more weight on the stratigraphic evidence of a well-marked uncon- formity than on the occurrence of a fauna of Devonian aspects high up in the thick shale-succession. To me unconformity means more than any other classificatory or correlative criterion.* * Americar Geologist, vol. xviii, p. 289, 1896. Watson—Meteoric Iron from Paulding County. 165 Arr. XIX.—A WMeteoric Iron from Paulding County, Georgia ; by THomas L. Watson. THE iron described below was obtained by the writer about twelve years ago from a party who reported having found it in the northern part of Paulding County, northwest Georgia. Neither the date of find nor the exact locality from which the iron came can be given, nor is anything known regarding its fall. Excepting the extreme northwest corner, all of Paulding County hes within the crystalline province of the state, but nothing is known of the natural conditions SHEETS the find of the iron. When secured by the writer the mass was deeply coated with a thickness of oxidation products, small fragments of which could be readily broken from the surface. Since being in the possession of the writer, it has been kept carefully wrapped in several thicknesses of paper in a tightly closed box at room temperature. During this time the mass has under- gone rapid oxidation and much of it has crumbled into small and large fragments of yellow to reddish brown color, resem- bling much of “the ordinar y brown hematite (limonite). Natur- ally, the fragments are of irregular shapes and some exhibit a rudely shaly or platy structure. The total weight of the mass (1912), meluding the fresh iron and the detached oxidized small and large fragments that had crumbled from it, was 725°1 grams. As _ separately weighed the two parts of the iron (unoxidized or fresh, and oxidized or altered) gave the following results: Grams Pre snaIONM, ae cape oS tem Xe kes 18443 Oxidized iron, including fragments of vari- ale sIZe-am@e Welo Mtn a: 2-225 2.5-2-h5 2-22 590°8 INOUE ies akties Dt ag Aeon oe pe me 725°1 Five of the largest fragments of the oxidized portion of the iron gave, when separately weighed, 110-4, 64:0, 52-8, 20-0, and 13°8 grams, respectively —a fotal ‘weight of 261-0 grams. The remainder of the oxidized portion of the iron (329°8 grams) was composed of smaller fragments of irregular outline and a goodly amount of very fine material of almost dustlike particles. A fractured surface shows the mass to be somewhat porous and the cavities lined with deep red oxide of iron (hematite). Other pieces show much admixed deep red oxide with blue-black surfaces. Practically all of the oxidized material reacted strongly magnetic, most of the particles showing polarity. 166 Watson—WMeteoric Lron from Paulding County. The maximum diameters of the fresh portion of the iron are 6 by 3-7" by 2°2™ (fig. 1); weight 134°3 grams. Its general outline is irregular and ‘when examined in detail is quite ragged in places. The sawn and polished surface exhibits several minute fractures with oxidation apparent along most of these. In structure the iron is a coarse (broad) octahedrite, the lamellee being mostly 1°5 to 2™™ in width (fig. 2). ine, it | Hig Through the courtesy of Doctor George P. Merrill, the writer was afforded opportunity for comparing the Paulding County iron with other irons from Georgia and the adjoining states in the collections of the U. S. National Museum. The results were uncertain and of slight value, because of the very small surface of the available Paulding County i iron, but so far as could be judged it resembled more closely the Cherokee County (Canton), Georgia, iron, and the following two from Tennessee: Cleveland (East Tennessee) and Cooperstown, Rob- ertson County. In neither case, however, was the resemblance close, but only very general, and so far as the comparison has value it must be concluded that the Paulding County iron is different from any yet found in Georgia and adjoining states in the collections of the U. 8. National Museum. It is of interest to note that of the three irons mentioned above, which most closely resemble the Paulding County iron, Farrington* groups the one from Georgia (Canton, Cherokee Connty) with “ coarsest octahedrites” and the two from Ten- nessee (Cleveland and Cooperstown) with ‘‘ medium octahe- drites.” The analysis of the Canton Georgia iron (coarsest octahedrite) is given in column IT below for comparison, with that of the Paulding County iron. The two irons are quite similar in composition. Analyses of the Cleveland and * Farrington, O. C.: Analyses of Iron Meteorites Compiled and Classified, Field Columbian Museum, Publication 120, Geological Series, 1907, vol. iii, No. 5, pp. 72-73, 78-79. Watson—Meteoric Iron from Paulding County. 167 Cooperstown Tennessee irons show lower iron and higher nickel than the Paulding County, Georgia, iron, which alone is sufficient to distinguish them. A separate chemical analysis was made of (a) the fresh iron and (6) the oxidized portion of the mass by Mr. Wm. M. Thornton, Jr., of Yale University. The results are given below. For purposes of comparison there is given in column II an analysis by Doctor H. N. Stokes* of the Canton octahe- drite (coarsest) from Cherokee County, Georgia. I II Per cent Per cent Hinonang(ie) Pate oes ce ellos 83 93°26 91°96 Nek elGNG) a 20s). kee Sas ates 6°34 6°70 Wobvalite CO se as 52 Soe a ss oe 0°50 0°50 @apper (Cu). 225204. 8 bees 2se Trace 0°03 itesphorus:(E")) 5.2. 4220.2: He0223 Onl @imorme: (Cl) 23.2.2 os-225..* 0°01 Be Salou (Seo se 8 None 0-01 SMe OM (DN So5cn2. 2. cS eee None ‘Trace War won (CO) bees yee ee Sk Trace ? . 100°34 99°31 Specm@eravity. = 24 -.- 7°886 Te, Paulding County, Georgia, fresh iron, Wm. M. Thornton, Jr., analyst. II. Cherokee County (Canton), Georgia, iron, H. N. Stokes, analyst. The analysis shows nothing unusual in the composition of the Paulding County iron. Because of the limited amount of the fresh iron available for analysis, no search was made for the rarer elements frequently reported in minute quantity in many octahedrites.t, In the preparation of the oxidized portion of the iron used for analysis, all coarse fragments were sorted out and discarded, no fragments or particles being broken or crushed. The remainder of the mass (143°8 grams) was thrown on a sieve of 20 meshes to the linear inch. Out of the 143°8 grams, 32 grams passed through which still contained small cores of metallic iron. It was therefore quartered and the portion thus obtained gently ground in an agate mortar and passed through silk bolting cloth of about 100 meshes to the linear inch. This process was repeated upon the residue until practically no powder passed through the sieve. The sifted portions, after being mixed together, made up the sample for chemical analysis. * Howell, E. E., this Journal, vol. 1, p. 252, 1905. + Merrill, Geo. P.: Minor Constituents of Meteorites, this Journal, vol. XXXV, pp. 009-525, 1913. 168 Watson—Meteoric [ron from Paulding County. Of the 382 grams which passed through the 20-mesh sieve, 25°9 grams were strongly magnetic; the residue (6-1 grams) was essentially nonmagnetic. Of the 111°8 grams that did not pass the 20-mesh sieve, 109 grams were strongly mag- netic, 2°8 grams being nonmagnetic or essentially so. The analysis by Mr. Thornton of the above pci of the oxidized iron is as follows: Analysis of oxidized portion of Paulding County, Georgia, iron. (Wm. M. Thornton, Jr., analyst.) Per cent FeO. eh an pine oe eID PeOon eo iee ce ae he oe Cee NOs ie 2k se ee 6°57 CoOres mace Saeko eat ae em (A CuQ* 2 ee SE eee. Ss a eee DIO) wiz Leia te = sy ses eas ee 0°26 PhO. 5 Dene oe) * eae eee ero oee 0 aegypti Ye A et a(t Td aa oe Deon HO (at Ine) eo H © G@boye 1107 ©) 23 eee 28 99°38 A most extraordinary feature of this analysis which the writer cannot explain is the very abnormally high chlorine content. So far as the writer has been able to ascertain from an examination of many hundreds of analyses of meteoric irons from all parts of the world, it is enormously excessive, being many times greater than for any published analysis. In light of this fact the analyst, Mr. Thornton, at the request of the writer, redetermined the chlorine in a second portion of the oxidized iron with the following result : Per cent HO at TOC eee eee Set Chlorine (C)) ae ae epee IO When these results are compared with the same constituents in the analysis above, it will be observed that a difference is shown, but on recalculating the two chlorine determin- ations to the same (moisture free) basis the figures are in fairly close agreement. Concerning these results, Mr. Thornton in a recent personal communication to the writer says: “The material is hygro- scopic and the moisture content very variable; ... I think it improbable that my first determination of chlorine (see above) in the first drawn sample is too high.” Brooks Museum, University of Virginia. Ford and Bradley—Pyroxmangite. 169 Art. XX.—Pyroxmangite, a New Member of the Pyrouene Group and its Alteration Product, Skemmatite ; by W. E. Forp and W. M. Bravery. . TuE minerals to be described in this paper were found four and one-half miles east of Iva, Anderson county, South Caro- lina, by Mr. George Letchworth English, of Shelby, N. C., who kindly submitted them to the Mineralogical Laboratory of the Sheffield Scientific School for investigation. On preliminary examination one of them proved to be essen- tially a silicate of manganese and ferrous iron with the general characteristics of a pyroxene. It was at first thought to be a schefferite, but further study proved it to be quite distinct from that species. It differs from schefferite in that it contains only a little lime, no magnesia, and much higher percentages of iron and manganese oxides. Further, the crystallographic and opti- eal properties show that it is triclinic. As far as the analysis goes it might be a highly ferriferous rhodonite, for the analysis given below does not differ materially from that of a rhodonite from Vester Silfberg given by Weibull and quoted by Dana as analysis 9, page 380, of the System of Mineralogy. The crystallographic and optical characters of the two minerals do not, however, agree as shown below. The cleavage angle of pyroxmangite differs from that of rhodonite by about half a degree. The extinction directions of the two minerals differ by angles ranging from 10 to 13 degrees. The axial angle of pyroxmangite is small and its optical character is positive, while the axial angle of rhodonite varies between 72° and 76° and it is optically negative. Pyroxmangite differs markedly in its composition from that of babingtonite. The conclusion, therefore, is that it is a new member of the Pyroxene Group, belonging in the triclinic section. It was found only in cleavable masses, no indication of erystal forms being observed. It is triclinic as proved by the character of its cleavages and its optical structure. It shows two cleavages, one of which is quite good while the other is rather poor. The difference in the quality of the two cleay- ages 1s very distinct. The average of a number of measure- ments gave the angle between the two cleavage planes as 91° 50’. A parting plane, occupying the position of the crystal face 6 (010) was occasionally to be .observed. The angle between this plane and the better cleavage was measured as 45° 14’, giving the angle between it and the poorer cleavage as 42° 56’, The hardness is 5°5-6. The specific gravitv was determined as 3°80. The luster is vitreous, inclining to resinous. Its color 170 ford and Bradley—Pyroxamangite. is amber, yellowish brown, reddish brown to dark brown, the darker colors predominating. It is translucent to opaque. It fuses quietly about 3 to a black and magnetic globule. It gives the manganese color reactions with the fluxes. It is insoluble in acids. | The mineral was poorly adapted for optical observations and measurements, but the following facts were established. It is biaxial and optically positive. A section cut in the prism zone and making an angle of 44° 5’ with each of the cleavages Iuiey ell Artificial Plane Artificial Plane (i. e., a section near the position of the parting plane, b (010)), showed an extinction angle measured to the trace of the pris- matic cleavage of about 5°. A’ section cut parallel to the parting plane showed an extinction practically parallel to the lines of cleavage. The axial plane is normal to the parting plane, 6(010). A section cut in the prism zone at right angles to the first section mentioned above and making an angle of 45° 55’ with both cleavage planes, showed an extinction angle of approximately 45° with .the trace of the cleavage. The refractive index was measured by immersion of fragments of the mineral in high refracting liquids and by applying the Becke test to them it was found to range between 1°75 and 1:76. The optical angle was measured under the microscop land Ford and Bradley—Pyroxmangite. 171 by the drawing table method of Becke and was determined as approximately 2V=30°. The above facts are shown graph- jeally in fig. 1. It is to be understood that because of the lack of crystal ‘faces the exact orientation of the cleavage pieces is impossible, and therefore the position of the extinction direc- tions might be the reverse of that shown in the figure. _ The mineral was intimately associated with a black iron- manganese oxide, a description of which will be found beyond. This oxide is evidently an alteration product. The material used for analysis was selected from the purest specimen. It was crushed and the fragments sifted to an uniform grain. By experimentation it was “found that the pyroxmangite was not attacked by hydrochloric acid, even at boiling temperature, but that the black oxide was compietely soluble under such con- ditions. Consequently the powdered material was boiled in dilute hydrochloric acid until the decanted acid showed no fur- ther test for iron. After such treatment the grains of pyrox- mangite, when examined under a lens, appeared of an uniform character, showing bright and unetched surfaces. The method of analysis was briefly as follows. Water was determined by the direct method of Penfield.* Silica was determined as usual. The sesquioxides were separated by the basic acetate precipitation, dissolved in nitric acid and reprecip- itated by ammonium hydroxide. The filtrate from the basic acetate and that from the ammonium hydroxide precipitations were evaporated separately and any further precipitates col- lected. The manganese was precipitated in the combined filtrates by means of bromine water, dissolved by strong sul- © phur dioxide water and again precipitated by acid sodium phosphate. Calcium was precipitated as the oxalate in the filtrate from the first manganese precipitation. No magnesium was found. Total iron and alumina were determined as usual. Careful qualitative tests proved that the iron was all ferrous in valence. The results of the analyses by Bradley follow: I II Average Ratios Subtract ratios equivalent to RO. Al203. SiOz. BO AULT AT11 47°14. 0°78 —0°023 = 0°757 = 1:00 MnO 20°72 20°55 20°68 0°29 FeO 28°30 28°38 28°34 0°394 $0717 —0°023 = 0-694 = 0°917 CaO 1:85 1:91 1:88 0-033} Al,O, 2°50 2°26 2°38 0-023. —0:023 Ee) 0:37. 0:29! 0338 100°91 100°50 100-70 * This Journal, xlviii, 31, 1894. Am. Jour. Sci.—FourtH SERIES, Vout. XXXVI, No, 212.—Aveust, 1918. 2 172 Ford and Bradley—Pyroamangite. The analysis yields molecular ratios that agree with the accepted type of a pyroxene formula. The small amount of water was disregarded. It was probably due to incipient alter- ation. The alumina was presumed to be present in the combi- nation RO.AI,O,.SiO,. After subtracting the proper amounts from the silica and protoxide ratios to satisfy this formula, the resulting ratios $10, : RO reduce to 1:00: 0-917 which gives ‘the metasilicate formula, RSiO,. The name pyroxmangite was given to the mineral in order to indicate that it is a manganese pyronene. As stated above, there was a black oxide of iron and manga- nese intimately associated with the pyroxmangite. The oxide Fig. 2. is unmistakably an alteration product. It surrounds the unaltered silicate, occurring on the outside of the specimens. The change from one substance to the other while confined to a small space is nevertheless gradual, there being no sharp dividing line between the two. In certain instances prominent cleavage and parting planes, which were evidently formed before the alteration took place, could be traced unbrokenly from one mineral into the other. Fig. 2 represents the change as shown in a thin section under the microscope. The alteration penetrates the pyroxmangite first along the cleavage cracks. The beginning of the alteration is shown in the section by a darkening of the color of the silicate to brown, which gradually intensifies until the substance becomes black and opaque. This oxide is metallic in luster, giving a dark chocolate- brown streak. It is fusible about 4 to a black magnetic glob- ule, Its hardness is between 5:5 and 6-0. When heated in the closed tube it yields abundant water and also gives off Ford and Bradley—Pyroxmangite. 173 oxygen gas. It gives manganese reactions with the fluxes. It is readily soluble in hydrochloric acid, giving off chlorine gas. The method of analysis was as follows. The mineral was erushed and then dissolved in hydrochloric acid, the weight of the insoluble residue being deducted from that of the original portion. The sesquioxides were separated by the basic acetate precipitation and determined as usual. The manganese was determined as outlined above in the case of pyroxmangite. The available oxygen in the manganese oxide was determined by means of the oxalic acid method. The iron was proved to be all ferric in valence. The water was determined by the Penfield direct method. The results of the analyses by Bradley follow: : I II Average ud Ea ee 31°71 31°96— 31°84 “SAD ARMR see aee ee 6°50 6°56 6°53 Fe,O, 5 Se Pees a 43°67 44°24 43°95 eS 7) a _ 2°43 1°49 1°96 od Sees oe Sea 15°57 15°55 15°56 99-92 99°76 99°84 The ratio of the manganous oxide to the available oxygen is as 0-448: 0-408 or as 1:0°910. This indicates that the oxide of manganese present must be almost wholly the dioxide, MnO,. In the ealeulations to follow it has been assumed that the sum of the percentages of manganous oxide and available oxygen represent the percentage of manganese dioxide present. Considered in this way the analysis becomes as follows: Theoretical Average Ratios Composition MnO..---- 38°36 0-441 or 1°48 or 3°00 37°88 Mee)... 43°95 l 46°44 3 2 . ae ao. 1:96 | 0°298 1°00 2°00 Bee! 2 15°57 0°865 2°90 6°00 15°68 99°83 100-00 From the ratios given above is derived the following for- mula, which closely expresses the composition of the mineral, 3Mn0O,.2Fe,O,.6H,O. The theoretical percentage composition corresponding to this formula is given in the last column above and agrees closely with the results of the analysis. Although many oxides of manganese have been described, no one of them agrees with this “mineral in its composition. Two new oxides of manganese from India, vredenburgite, 174 Ford and Bradley—Pyrowmangite. 38Mn,O,.2Fe,O,, and sitaparite, 9Mn,O,.4Fe,O,. MnO.3CaO, have been recently described by Fermor.* They contain ferrie oxide in considerable amounts, but do not correspond in other respects to this mineral. Consequently, if this material is to be taken as a distinct species it must be considered as new. The grave question arises, shali a mineral which is so obyi- ously an alteration product, and which shows no crystal form, be dignified by a species name? The close agreement of the analysis with the assumed formula is an argument in favor of its being a distinct species, but yet such an agreement might very well be accidental. Other analyses of material from the same locality, or better, of material from some other oceur- rence, would help to settle the problem. In order, however, that the above description and analysis be not overlooked in any future work on similar minerals, the name skemmatite, derived from the Greek, oxéupa, a question, is proposed for the material. Mineralogical Laboratory of the Sheffield Scientific School of Yale University, New Haven, Conn., May 6th, 1918. Art. XX1.—Wew or little known Paleozoie Faunas from Wyoming and Idaho ; + by Exror Buackwerper. Wiruin the past three years the writer has had occasion to collect fossils from many localities and horizons in the moun- tains of western Wyoming and a few in southern Idaho. Among these collections there are three or four which throw new light upon some questions of Rocky Mountain strati- graphy, and so it appears worth while to publish a brief account of them here in advance of the more detailed official reports, the preparation of which will require several years. Ordovician graptolites from the Wood River valley, in southern Idaho.—The region about Hailey, on the northern border of the Snake River lava plain, has long been known as — an important mining district. Geologists have studied the valley in more or less detail with special reference to the ore deposits, but they have found the sedimentary rocks almost entirely devoid of fossils. The few specimens thus far discov- ered appear to be of Carboniferous age. * Mem. Geol. Survey, India, xxxvii, 1909. + Published with the consent of the Director of the U. S. Geological Survey. Blackwelder—Litile known Paleozoic Faunas. 175 In June, 1912, the writer, while on a brief visit to this local- ity, was fortunate enough to find a zone of black slates which are crowded with well-preserved specimens of graptolites. Owing to the lack of time and facilities only a small collection was obtained, but in this material Mr. E. O. Ulrich has identified the following list of species : Didymograptus extensus Hall. Didymograptus cf. nitidus Hall. Didymograptus cf. planus E. and W. Didymograptus cf. tornquisti Rued. Didymograptus caducens (Salter) Rued. Didymograptus nanus Lapw. Didymogruptus bifidus Hall. Tetragraptus similis Hall. Dichograptus ct. octobrachiatus Hall. Phyllograptus n. sp. aft. P. angustifolius. Hall. Lingula sp. undet. | Hexactinellid sponge spicules. Of this collection he says: ‘“ It probably represents an horizon intermediate between the Zetragraptus and the Didymograptus bijidus zones of the ‘Canadian’ as worked out by Dr. R. Ruede- matin, in New York.” This seems to prove that there are rocks of Lower Ordovician age in this part of Idaho. The fossils were found about a mile south of the pass on the Trail Creek road northeast of Ketchum. The detailed stratigraphy and the relations of the strata in which they were found still remain to be worked out. Fossils from the Amsden formation in the Gros Ventre Lange, Wyoming.—The series of soft sandstones, shales, and limestones which overlie the well-known Madison limestone, have been given the name Amsden formation by Darton.* It ean be followed with more or less confidence clear across the state from the Black Hills to Idaho. Very few fossils have been found therein, and the majority even of those were poorly preserved or of doubtful significance. Some of them indicated Pennsylvanian age, while others were doubtfully referred to the Mississippian. In 1911 fossils were found by the writer and C. W. Tomlin- son at several horizons in the Amsden formation along the erest of the Gros Ventre Range, and were later submitted to Dr. G. H. Girty for study. Nearly all the specimens were found in a thin group of limestone beds a little below the middle of the formation. Dr. Girty has recognized two some- what unlike faunules. The more widespread of the two con- sists. almost entirely of brachiopods, with a few bryozoans, * Darton, N. H., U.S. Geol. Survey, Prof. Paper 51, Geology of the Big Horn Mts., Wyoming ; and other papers. 176 Blackwelder—Little known Paleozoic Faunas. echinoderms, etc. The other is an assemblage of mollusks, with a few brachiopods. The former occurs in the blackish to drab-gray limestones mentioned above, while the latter was found at the horizon about 60 feet lower in a dense, olive-gray limestone mottled with purple. It is thus evident that the environment of the two faunules in life was somewhat differ- ent. In the upper, or brachiopod faunule, the most character- istic species are Productus cora, Composita subtilita, and Chonetes geinitzcanus. The lower or mollusk faunule is char- acterized especially by Composita subtilita, Spirifer rocky- montanus, and a number of small gastropods and pelecypods. The full quota of spectes recognized in each zone is given below: Fossils of the upper or brachiopod zone. Echinocrinus sp. ‘Schizophoria aff. resupinoides. Crinoidal plates. ‘Chonetes Geinitzianus. - Batostomella sp. . Chonetes granulifer. Batostomella ? sp. Productus cora. Rhombopora lepidodendroides? Productus semireticulatus. Stenopora sp. Productus nebraskensis. Lingula umbonata ? Spirifer rockymontanus. Lingula carbonaria. Composita subtilita. Lingulidiscina sp. Conocardium sp. Derbya robusta. Fish plate. Fossils of the lower or mollusk zone. Large crinoid stems. Pleurophorus 2 sp. Spirifer robkymontanus ? _ ~ Bucanopsis ? sp. Squamularia perplexa ? Huphenus ? sp. Composita subtilita ? Pleurotomaria sp. Myalina sp. Naticopszs sp. Cypricardinia sp. Euomphalus sp. With reference to the age and correlation of these faunules, Dr. Girty says that the upper zone is “ pretty clearly of Penn- sylvanian age. They are also probably early Pennsylvanian.” The lower faunule “evidently presents a different facies The preservation of most of the species is poor and none of them are very diagnostic, but there is at least a possibility that this collection may prove to be of Upper Mississippian age.” The remark may be added here, however, that both faunules occur in a single formation of distinctive and unified character, separated from the known lower Mississippian limestone by a distinct unconformity. ‘Therefore, unless there is strong evi- dence to the contrary, it seems probable that both faunules belong to the same period. Blackwelder—Little known Paleozoic Faunas. Lei Marine Permian (?) fossils from the Wind River Range. ‘From the Black Hills of South Dakota west to the eastern boundary of Idaho there are two prominent and relatively con- stant formations of late Paleozoic and early Mesozoic age. One of these, the Tensleep sandstone, is characteristically a massive, buff-colored sandstone which makes prominent cliffs, hogback ridges, and dip-slopes, wherever it appears. The upper terrane is the Chugwater formation, the brilliant color of which makes it the most easily recognized member of the entire sedimentary column. These two prominent terranes— _the one apparently Pennsylvanian, the other usually referred to the Triassic—are separated almost invariably by 300-500 feet of shale, limestone, sandstone, and chert. This is the Embar formation of Darton.* At almost any of its outcrops, this formation may yield a few fossils, but most of those which have been collected are pelecypods, difficult to determine and of doubtful significance even when well preserved. This meager fauna has led paleontologists to refer the Embar to the Permian, the * Permo-Carboniferous,”’ or the Pennsylvanian, and always with a large element of doubt. In 1877 Orestes St. John of the Hayden Survey found some richly fossiliferous beds in a formation which is evidently the same as the Embar, near Bull Lake on the northeast side of the Wind River Range. In his report,t he gave an admirable detailed section ot the beds and referred to some of the fossils generically. Apparently the names were given as the result of rough field identifications, rather than after a critical study of collections in the laboratory. So far as I am able to learn no collections were brought home by St. John from this remark- able locality,—doubtless, because of the difticulty of transport- ing them more than 200 miles to the railroad,—and for many years no attention was paid to the find. Within the past decade, the same beds with similar fossils more or less well preserved have been visited by Darton and Woodruff along the north slope of the Wind River Range. Their published - reports,t however, suggest that they made but small collections and obtained material some of which was not in a satisfactory state of preservation. In 1910 a party in charge of the writer examined many of the canyons on the northeast slope of the Wind River Range in some detail, and there made careful stratigraphic sections and tolerably complete collections of fossils from many hori- * Darton, N. H. Op. cit. Fethonsy Geog. and Geol. Survey of the Territories, F. V. Hayden in charge, 1878, vol. xii, part 1, pp. 242-248. t Darton, N. H., Paleozoic and Mesozoic of Central Wyoming, Bull. Geol. Soc. Am., vol. xix, 1908, pp. 403-474. Woodruff, BGs The Lander oil field, U. S. Geol. Survey, Bull. 452 1911, pp. 12-14, 178 Blackwelder— Little known Paleozoic Kaunas. zons. Mr. J. M. Jessup was the indefatigable worker through whose efforts the bulk of the material was obtained. Some of the specimens were collected by Mr. C. L. Breyer and the writer. The general report* on this trip, which has already been issued, contains a complete section of the Embar forma- tion. It is the writer’s expectation soon to publish in a bulletin of the U. 8. Geological Survey a more detailed description of the stratigraphy of the north slope of the Wind River Range. This will include the Embar formation. Dr. G. H. Girty, of the U. S. Geological Survey, to whom the collections were submitted, reports over 60 species belonging to at least 45 genera. Although most of the fossils are brachiopods and pelecypods, there are also bryozoans, crinoids, scapbopods, gastropods, protozoans, and fishes.t The preliminary list of species identified in the 1910 collections from the lower half of the Embar formation follows : Foraminifera (indet.) Crinoids Septopora ? sp. Phyllopora n. sp. Stenopora sp. Fhonbopora sp. Fenestelia sp. Lingula aff. carbonaria Lingulidiscina Utahensis Derbya sp. Derbyan. sp. Meekella sp. Chonetes aff. geinitzianus Productus nevadensis Productus subhorridus Productus cora Productus multistriatus Aulosteges n. sp. Heterelasma ? n. sp. Pugnaz utah Dielasma ? sp. Dielasmina n. sp. Spirifer aff. cameratus Spirifer cameratus var. Spiriferina pulchra Spiriferina pulchra ? Composita mexicana Batostomella sp. Batostomella n. sp. Batostomella ? sp. Lioclema n. sp. Polypora sp. Pseudomonotis aft. hawni Pseudomonotis sp. Myatlina aff. wyomingensis Myalina sp. Euchondria neglecta Solenomya sp. Pteria sp. Allerisma terminale ? Allerisman. sp. Pleurophorus aft. subcostatus Pleurophorus? 3 sp. — Parallelodon sp. Schizodus ? sp. Astartella sp. Leda obesa Plagioglypta canna / Bellerophon aff. crassus Bellerophon sp. Bellerophon ? sp. Patella n. sp. Patella sp. Euphemus subpapillosus *Blackwelder, Eliot, Reconnaisance of the phosphate deposits in west- ern Wyoming. U.S. Geol. Survey, Bull. 470-H, 1911, pp. 108-109. 'o_.w 9 + The fisb fauna of the Embar has recently received notice from Mr. E. B. Branson, in a paper read at the Washington meeting of the Geological Soci- ety of America in December, 1911. Blackwelder—TLittle known Paleozoic Faunas. 179 Composita subtilita Euphemus ? sp. Hustedia meekana Patellostium ? sp. Acanthopecten coloradoensis Pleurotomaria sp. Aviculopecten coreyanus ? Pseudomelania ? sp. Aviculopecten aff. whiter Enchostoma sp. Aviculopecten sp. Nautilus? sp. Pseudomonotis n. sp. Fish remains Girty has already shown* that the Embar formation, as limited by Darton, contains two quite distinct faunas. Of these the hitherto better known is found in the upper half of the formation, and consists of large numbers of Lingulas and pelecypods, representing, however, only a few species, and even those seldom identitiable with confidence. The lower fauna, which is the subject of this note, may well be known as the Spiriferina pulchra fauna, after one of its most easily recognized and most widespread brachiopods. This fauna, in greatly impoverished state, occurs near Thermopolis and is known also from the Phosphoria formation of western Wyo- ming and southeastern Idaho. Of this lower Embar fauna, Girty says, “the age of the Spiriferina pulchra tauna is probably Permian. This is sug- gested by such Permian types as Phyllopora and Audlosteges, together with the peculiar character of other species when compared with congeneric types in other western Pennsylva- nian faunas.” There is little in common, however, between the Spirzferina pulchra fauna and that of the Guadaloupe group of Texas, or of the -beds commonly referred to the Permian in Kansas. There are some things about it suggestive of the fossils which have been described from the Productus limestone of the Salt Range in India and from the Schwagerina limestone of the Ural Mountains in Russia. The former of these has generally been considered Permian and the latter upper Pennsylvanian. It is evident that the whole subject of correlation of the latest Paleozoic formations the world over is in a most unsatisfactory and unsettled state. Madison, Wisc., March 25, 1913. * See paper by Woodruff, noted above, p. 13. 180 Foote and Bradley—Solid Solution in Minerals. Arr. XXII.—On Solid Solution in Minerals. IV. The Composition of Amorphous Minerals as Illustrated by Chrysocolla ; by H. W. Foorz and W. M. Branptey. At the present time a definite chemical formula is ascribed to nearly every well-known mineral. The variations in com- position which actually occur can in most cases be satisfactorily explained by assuming isomorphous replacement. Usually this consists in one or more metals being partly substituted for the metal in the ideal compound, or, what amounts to the same thing, a molecule of the ideal compound is substituted by a molecule of another similar in type. This common case occurs when potash replaces soda in albite. In rarer cases, compounds or radicals of different type appear to be isomor- phous, or capable of forming solid solutions. For instance, in the plagioclases anorthite replaces albite, in nephelite there is a variable excess of silica,* and in pyrrhotite an excess of sulphur.t The minerals which appear to present the greatest difficulty in the relation between actual composition and formula are those which commonly occur in the amorphous condition, but in these cases, as with well-crystallized minerals, definite for- mule are commonly given in all reference works on the subject. An examination of the facts will show, however, that in many amorphous minerals the actual composition found may differ very widely indeed from the theoretical value required by the formula. As an illustration of this type of mineral, we have chosen chrysocolla, to which the formula CuSiO,.2H,O is commonly assigned. We give below the ratios for SiO,.CuO and H,O calculated for this mineral from the analyses given in Dana’s Mineralogy and Hintze’s Handbuch. The numbers are those given in the two reference books mentioned. We have omitted from Hintze’s list the ratios of analyses as given by both Dana and Hintze. In considering these ratios the fact must be taken into account that some of the analyses are undoubtedly inaccurate and the material used was impure. Too much weight, therefore, cannot be laid on the above results. Taking the results as they are, however, only nine of the thirty-one silica ratios show satis- factory values between 0°90 and 1:10. Six ratios are under ‘90 and sixteen above 1:10. Of the ratios for water, three only are between 1°80 and 2°20, eight are under 1°80 and twenty * This Journal, xxxi, 25, 1911. + Allen, Crenshaw and Johnson, ibid., xxxiii, 169, 1912. 5 Foote and Paces olid Solution in Minerals. 181 TABLE I. Ratios calculated from Analyses of Chrysocolla. Dana Hintze No.-~ SiOz CuO H.0 No. SiOz CuO H.20 1 1°20 1°00 2°23 4 2°60 100 3°40 2 1°05 : 1:86 5 81 Ss 2°48 3 1°33 = 3°59 6 1:07 ne 2509 4 1°08 2 1°66 8 IES ee 2°32 3) 1°06 Fe 2°58 9 rel s 3°70 6 Sal ae 1°47 10 1°03 se 2°95 7 2°68 os 5°06 BE Ek a 2°16 8 1°35 4°21 14 1°23 is 1°65 £ 1°89 ta 4°40 22 1°88 - 3°91 10 2°13 a 2°62 23 "94 i 2°74 ey 1°60 me Loe 24 2°33 . 2'50 12 3°54 1 1°03 25 *39 “i 1:28 13 1°62 = 90 26 i ie sf 270 14 "97 rie 2°24 . 15 33 = 49 16 °88 2°66 17 1°07 5S 3°63 18 1°37 Bs 4°19 are above 2°20. To put the results in another way, only 12 out of 62 ratios, or less than 20 per cent, are reasonably close to the theory for chrysocolla. So far, then, as the evidence goes which can be derived from the analy ses given, there is _ little to support the formula CuSiO,.2H,O. On the other hand, there is just as little evidence in support of any other single formula. To obtain further evidence, we have analyzed three speci- mens of chrysocolla. The main difficulty in determining the composition of chrysocolla is in obtaining pure material. By this we mean material which is homogeneous. For if different specimens of chrysocolla are each homogeneous and not mechan- ical mixtures, and show the essential characteristics of the min- eral, we can see no reason why they must not all be regarded as this mineral even if the composition varies in the different specimens in a manner which is not of the character of ordi- nary isomorphous replacement. The samples of chrysocolla chosen for our work were picked from exceptionally fine large specimens. We were unable, however, to use heavy solutions for final purification. Potassium mercuric iodidé solution, which was first tried, reacted with the mineral. Acetylene tetrabromide could apparently be used and a sample of the mineral was obtained by its means of specific gravity 2°336. We soon found, however, that this material had absorbed the tetrabromide in sucha manner that it could not be removed by 182 Foote and Bradley—Solid Solution in Minerdls. washing with solvents. After such treatment, when heated in a closed tube, the mineral gave off not only its water, but also an oily liquid, presumably the tetrabromide or a decom- position product. We were therefore forced to abandon this method of purification. The fact that the tetrabromide is absorbed is interesting, however, as it suggests a comparison with some of the hydrogels like silicic acid, which also absorb various organic liquids. Our only means of purification, there- fore, was by most careful picking. Small lumps of material which appeared pure, or nearly so, were broken up, sifted to uniform size, and separated under a magnifying glass. The material was afterward examined more carefully under a higher power microscope. Nos. 1 and 3 were almost perfectly pure and uniform in appearance. No. 2 was very slightly mottled in color. The method of analysis was as follows: The mineral was decomposed with hydrochlorie acid and silica separated by two evaporations, as usual. It was tested for impurities by evaporation with hydrofluoric acid. In the filtrate from silica, copper was precipitated as sulphide and weighed as Ou,S. The other bases were determined in the filtrate in the usual manner after remuving hydrogen sulphide. Water was deter- mined directly by Penfield’s method.* The results obtained are given in Table II. TABLE II. New Analyses of Chrysocolla (by Bradley). I : IT Locality, Arizona Locality, Montana 1 2 Average 1 2 Average - UO) aaa areas 38°16 38°12 38°14 50°32 50°57 50°45 CuO tak ss ees 36°71 36°77 36°74 87°77, 88:12 Agee HO 4 ae ul S°6%. 18°79 18°73 11°22 611:00>) iia PEO) hg see ae 5°56 5°75 5°66 eee — ae CAIOWY 2c agit 86 coy ec eo “Oil "90 oy eo 99°99: 100-344 OO Al 99°31 99°69 “9950 III Locality, Arizona 1 2 Average SiO, ios |e 88 Bde aes tee oeee CuQ See ake 0is 39:97 308 |g A Os) ONE 19°88 19°86 19°87 AL) One tas tose “91 1:04 "98 Ca! aie sia ri bee "84 ‘78 99°80 100°03 99°92 * This Journal, Ixviii, 30, 1894. Foote and Bradley—Solid Solution in Minerals. 1838 The ratios, caleulated from the averages given above, are in Table ILI. TaBLeE III. Ratios of Analyses given in Table II. I soa HE Ill SU hee ee egies 1°36 1°75 1°26 Wee 2 28 SL 1:00 1:00 1 00 Oe ai 2-25 1°29 2°19 ALO: 2 ine ee See “12 pahsk "02 71) [Ss eel 04 ei. 08 So far as leading to any definite formula is concerned, these ratios are just as unsatisfactory as those in the longer list pre- viously given. If allowance be made for the alumina as allo- phane, the ratios are not improved. By assuming a mechanical mixture with a hydrated silica or opal of empirical composi- tion, the residues in Nos. I and III could be forced to agree in composition with the formula usually assigned to chrysocolla, but this could not be done in No. II, where silica and water are both low. 7 It has seemed to the authors that the composition of this mineral, and probably of many other amorphous minerals, may, however, be regarded in a very simple manner by classifying them with the artificial hydrogels or gelatinous precipitates _such as silicic acid or ferrie hydroxide. It bas been shown in numerous articles by Van Bemmelen and others, that these substances when freed from that part of the water which is present as a mechanical mixture, show values for vapor pres- sure which continually diminish as the substance is dehydrated. In other words, the vapor pressure of a hydrogel is a function of its composition. This leads to the conclusion that hydrogels are not mechanical mixtures of two definite hydrates, but the material is a homogeneous phase of variable composition, com- parable in this respect to a solution of salt in water. If a hydrogel were a mechanical mixture of two definite hydrates, its vapor pressure at a given temperature would be constant, independent of its composition. This is the case, as is well known, with a mixture of two crystallized hydrates of a salt, the vapor pressure remaining constant as the mixture is dehy- drated. These hydrogels, which appear to be homogeneous substances, have been called “adsorption compounds” by Van Bemmelen, but they may equally well be regarded as solid solutions of water in the oxide or in some lower hydrate.* The composition of these substances is not fixed, as in the case of a chemical compound, but is variable, depending on the conditions. The composition of an artificial silicic acid, for * Jour. Amer. Chem. Soc., xxx, 1388, 1908. 184 Foote and Bradley—Solid Solution in Minerals. instance, is not of necessity H,SiO, or H,SiO,, but homogen- eous material containing more or less water may equally well be obtained, depending on the method of preparation. Looked at in this way, the composition of chrysocolla is very simple. The mineral is not a chemical compound and no for- mula should be assigned, but a solid solution of copper oxide, silica and water as essential components, whose composition depends on the conditions of formation. This is, of course, not in accord with the view that every mineral is a definite chemical compound, but it accounts for the facts regarding composition, in a way that no definite formula can do. The possibility of there being chemical combination between the components of the solid solution is not excluded, just as a salt dissolved in water may be chemically combined with the iatter, but we have no means, any more than with other types of solution, of determining the nature of this combination. This tentative view of the composition of chrysocolla, if generally adopted, should logicaily be extended to a large number of the minerals which commonly occur in the amor- phous condition. The fact that some of them occur occasion- ally in a more or less erystalline condition appears to be no | objection to assuming solid solution. Poorly developed erys- tals are rather evidence of this. For instance, when ammonium chloride is pure, it is well crystallized. When it forms solid solutions with a variety of other chlorides of different types, such as nickel chloride, the crystals are distorted and imperfect. A calculation of the ratios of 144 analyses of the various ferric hydrate minerals, given in Dana’s Mineralogy and Hintze’s Handbuch, indicates that with these minerals, as with chrysocolla, there are no definite compounds in the series, but that all may be considered as solid solutions of water either in ferric oxide or in some, as yet undetermined, lower hydrate. Chemical and Mineralogical Laboratories of the Sheffield Scientific School of Yale University, New Haven, Conn., May, 1913. Miscellaneous Intelligence. 185 SCIENTIFIC INTELLIGENCE. I. Miscernanrovus ScrentiFic INTELLIGENCE. 1. A History of the first Half-Century of the National Academy of Sciences, 1863-1913. Pp. xi, 399 ; with 8 portraits and 4 plates. Washington, 1913.—The Committee, with -Dr. Arnold Hague, recor ding secretary of the National Academy, as chairman, which was charged four years ago with the prepara- tion of the semi-centennial volume here noticed, is to be con- gratulated on the promptness with which,its work has been completed, on the handsome form of the printed volume, on the careful and studious arrangement of its contents, and hence especially on the appointment of Mr. F. W. True, assistant secre- tary of the Smithsonian Institution, as author and editor. Itisa good thing thus to place on record in concise and consecutive form an account of so dignified an organization as the National Academy of Sciences, regarding which many American scientists know so little. The opening dispies (pp. 1-24), on the founding of the Acad- emy, contains some interesting reminiscences about the prelimi- nary discussions in which Secretary Henry, Superintendent Bache, Admiral Davis and Professors Louis Agassiz and Benjamin Pierce of Harvard appear to have been particularly active, and which led to the incorporation of the Academy by Act of Congress and its formal organization in the spring of 1863. As is often the case in such matters, no full account of the steps then taken has been preserved ; what is now presented has been industriously gleaned from various sources. The second chapter (pp. 25-102) presents a running account of the peripatetic meetings in the autumn and of the Washington meetings in the spring, from which one may gather a good impression of the characteristic activities and interests of the assembled members, and of the subjects which have most attracted their attention; but as is proper enough in a volume © such as this, no indication is given of the greater attention shown _by members in the business sessions for the election of new col- leagues than in the scientific sessions for the presentation and discussion of learned papers. It was hoped that a list of the two thousand communications thus far presented might have been appended, but this was found impossible. One of the most important records concerns the growth of bequests and trust funds committed to the care of the Academy, chiefly for the support of scientific research, and now exceeding $200,000 ; but the chief moral of this record is the surprising one that so dis- tinguished a body of scientists should have been so seldom selected by generous testators as administrators of their scientific benefactions in a country as rich as ours. 186 Scientific Intelligence. Biographical sketches of the fifty incorporators of the Academy are given in the third chapter (pp. 103-200) with excellent por- traits of the seven presidents, Bache, Henry, W. B. Rogers, Marsh, Gibbs, Agassiz and Remsen, who have served until this year; these sketches are for the most part condensed from the seven volumes of Biographical Memoirs, which constitute the most continuous and in that respect the most successful series of publications that the Academy has issued. Only eleven volumes of scientific Memoirs have been published, and periods varying from one to eighteen years have elapsed between the dates of imprint in the successive numbers ; these eleven volumes contain only 68 titles, from which it is evident that the members of the Academy usually ee to print their essays in some other medium than the A’cademic publications. The Academy’s work as scientific adviser to the Gover nment is treated at length in the fourth chapter (pp. 201-334), from which it appears that, in the fifty years here considered, 32 reports have been requested by Congress or by governmental officials, and made by special committees of the Academy. The number of these reports in successive decades is 14, 2, 9, 4, 3. In view of the enormous increase in the scientific activity of the Government in the same fifty years, this showing is distinctly disappointing ; indeed, in view of the indifference of Congress to the last two reports, the showing is so discouraging that the Academy might fairly ask to be excused from further trouble of this sort. A report on scientific exploration of the Philippine Islands, requested by President Roosevelt in 1902, was made in 1903, but did not reach Congress till 1905; it was then referred to a committee and ordered to be printed, “but was not reported back.” In 1908 a report was asked for by Congress on “ the methods and expenses of conducting scientific work under the government ”; the report was carefully prepared by five academicians of high ability and eminent position, and submitted in January, 1909; but its recommendations ‘have not yet been adopted by Congress.” The Act of Incorporation of the Academy provides that the actual expenses entailed in making these reports shall be paid ; but that the members of the Academy ‘shall receive no compen- sation whatever for any services to the Government of the United States.” This provision seems to be becoming more literally true than might have been anticipated when it was worded. W. MoD; 2. United States Geological Survey.—A civil service examina- tion for an editorial clerk (male) in the U. 8. Geological Survey (salary $1500 to $1800) will be held on August 6, 7. The sub- jects embrace: English ; French and German footnotes (transla- tion into English) ; proof-reading and indexing ; elementary Geology and Geological nomenclature, For further information apply to Geo. McLane Wood, U.S. G. 8., Washington. OBITUARY. Professor Epuarp Houzaprer, the well-known Professor of Geology in the University of Strassburg, died on June 11, 1913, at the age of 59 years. iene _ ~~ ee AS eae Warps Natura Science EstaBlisHMENtT A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS: Geology, including Phenomenal and Physiographic. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. Invertebrates, including Biology, Conchology, etc. _ Zoology, including Osteology and Taxidermy. 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GReGory ------ XVII.—Some Kilauean Formations; by F. A. PERRET.---- X VIII.—Marked Unconformity between Carboniferous and Devonian Strata in Upper Mississippi Valley ; by C. R. KOBYES 2 J obese Oe oe ge XIX.—Meteoric Iron from Paulding Cena Georgia ; by T. L. WarTsone 350900. oo ee ee XX—Pyroxmangite, a New Member of the Pyroxene Group and its Alteration Product, Skemmatite; by W. E. Forp and W.-M. BRADLEY 9%) e252 eee XXI.—New or little known Paleozoic Faunas from Wyo- ming and Idaho ; by EH. BLACK WELDER. -2_.-222- 2558 XXII.—Solhid Solution in Minerals. IV. The Compadiaae of Amorphous Minerals as illustrated by Chrysocolla ; by H. W. Footr and W. MM; Geaniey 22) eee SCIENTIFIC INTELLIGENCE. Page 91 109 123 Miscellaneous Scientific Intelligence—History of the first Half-Century of the National Academy of Sciences, 1863-1913, 185.—United States Geological Survey, 186. Obituary—E. HoLzaPre., 186. VOL. XXXVI. SEPTEMBER, 1913. Established by BENJAMIN SILLIMAN in 1818. THE eewl AAT © AN JOURNAL OF SCIENCE. Epirorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camsprince, Proressors ADDISON E. VERRILL, HORACE L. WELLS, LOUIS V. PIRSSON, HERBERT E. GREGORY AND HORACE S. UHLER, or New Haven, Proressor HENRY S. WILLIAMS, or Itwaca, Proressor JOSEPH S. AMES, or Batrimore, Mr. J. S. DILLER, or Wasuinerton. FOURTH SERIES VOL. XXXVI—[WHOLE NUMBER, CLXXXVIJ. — No. 213—SEPTEMBER, 1913. WITH PLATE I.. cone" ! om =~ NEW HAVEN, CONNECTICUT. ¥ ysou National Wyse" 1913. ne THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. Published monthly. Six dollars per year, in advance. $6.40 to countries in the Postal Union ; $6.25 to Canada. Remittances should be made either by money orders, registered letters, or bank checks (preferably on New York banks). NEW DISCOVERTES AND NEW FINDS. BEAVERITE, A NEW MINERAL. This mineral, which was fully described in the December, 1911, number of this Journal, I have been fortunate enough to secure the whole output of. It was found at the Horn Silver Mine in Utah and is a hydrous sulphate of copper, lead and ferric iron. It was found at a depth of 1600 feet. In appearance it resembles Carnotite. Prices 75¢ to $2.00. PSEUDOMORPHS OF LIMONITE AFTER MARCASITE. These remarkable Pseudomorphs, which have never before been found in such clear cut specimens, was described and illustrated in the last number of this Journal. Ihave secured the majority of the finest of these speci- mens. They vary in size from 2 inches to 6 inches. In color they run from brown to glossy black and they have met with favor from all who have seen them. Prices from $1.00 to $10.00. CHIASTOLITES. Of these remarkable specimens, which are generally known as lucky stones, I have secured the finest lot ever found at Madera Co., California, They are cut and polished and sold singly and in collections from 25¢ to 50¢ for single specimens ; 9 specimens all marked differently for $5.00, and 18 specimens, all different markings, for $18.00. Matrix specimens, polished on one side showing many crystals, from $2.00 to $8.00. SYNTHETIC GEMS. It is remarkable the interest that has been taken by scientists in these wonderful scientific discoveries. The Corundums are now produced in Pigeon blood, Blue, Yellow, Pink and White. Also the new Indestructible Pearls in strings with gold clasps. These are identical in hardness and rival in color and lustre the real gems. They can be dropped and stepped on without injury and are not affected by acids. My collection of the above is unrivalled, and prices of the same are remarkably low. OTHER INTERESTING DISCOVERIES AND NEW FINDS Will be found in our new Catalogues. These consist of a Mineral Catalogue of 28 pages; a Catalogue of California Minerals with fine Colored Plates; a Gem Catalogue of 12 pages, with illustrations, and other pamphlets and lists. These will be sent free of charge on application. Do not delay in sending for these catalogues, which will enable you to secure minerals, gems, etc., at prices about one-half what they can be secured for elsewhere, ALBERT H. PETEREIT 261 West 71st St., New York City. THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.] oe Arr. XXII.— Geologic Sketch of Titicaca Island and Adjoin- iny Areas; by Herzpert E. Grecory.* With Plate L Introduction. THE great Andean Plateau of southern Peru and northern Bolivia, the “ altiplano,” has a width in the Titicaca region of approximately 50 miles. Though possessing in itself relief exceeding a thousand feet, its plateau features are well brought out when the lofty ranges of the Cordillera Real and the Maritime Andes, between which it is hung, are taken into view. The bordering range on the northeast maintains a height of over 17,000 feet for a distance of 200 miles and reaches at Sorata (Illampn) a point 21,520 feet (Conway) above sea level. The western border of the platean is a wide moun- tainous highland crossed by the railroad at 14,666 feet, and maintaining an average elevation in southern Peru of nearly 14,000 feet. As shown by Bowman, the Maritime Andes is a dissected peneplain and represents a mountain range which may have exceeded in height the present eastern Cordillera. Occupying an irregular depression in the high plateau, between lat. 15° 20’ S. and 16° 35’ 8S. hes Lake Titicaca at an elevation of 12,500 feet above sea level. The lake is roughly rectangular in shape, one hundred miles long, and with an extreme breadth of thirty-eight miles.t+ Its superficial area, calculated by planimeter from the best available maps, is approximately 4,000 square miles, and the length of the shore line probably exceeds 500 miles.t Properly speaking, there are two lakes, connected by the rock-walled straits of Tiquina, five-eighths of a mile wide. The lower * Geologist, Peruvian Expedition of 1912. + The figures are from LeMaire. No complete instrumental survey of the lake has yet been undertaken. ¢ The figures given by Paz Soldan (270 miles) and by certain other writers are manifestly too small. Am. Jour. Sct.—FourtH SERIES, VoL. XXXVI, No. 2138.—SEPTEMBER, 1913. 188 H. FE. Gregory— Geologic Sketch of lake (Lago Pequeno) is shallow, with gently sloping bottom flats and large areas of low shore from which rise rock knobs and hogbacks of moderate height. The main lake (Lago Grande) reaches a depth of over nine hundred feet and is bordered by abruptly descending under-water shelves. Twenty- five tributaries, all small and greatly fluctuating in response to seasonal precipitation, supply the lake. Its surplus waters are earried by the Desaguadero into the salt Lake Poopo, thus forming a chain of fresh- and salt-water bodies like the Sea of Galilee—Jordan River—Dead Sea of Palestine and Utah Lake— Jordan River-Great Salt Lake of Utah. Thirty-six islands rise above the surface. The largest of these, Titicaca, has given its name to the lake,and as the Island otf the Sun, shares with Koati (the Island of the Moon) and Tiahuanaco, a posi- tion as a center for archeeological and historical research. Physiography. The Lake Floor.—The soundings made by LeMaire* and by Agassiz,+ supplemented by scattered data, are sufficient for the. construction of a bathymetric map of the basin now occupied by the waters of ditieded)s (Seema, Wei lavems It will be noted that Lago Pequeno is, properly speaking, not a part of the depression holding the waters of Titicaca. Its floor is remarkably flat, less than one-tenth of its area reaching a depth exceeding 20 feet ; and a fall of ten feet in water level would expose about one-fifth of its bed, and effectively impede navigation. Lago Grande is seen to occupy a rectangular basin with abruptly ascending edges on three sides, and with a slope from southwest to northeast. The southeastern extrem- ity partakes of the nature of a canyon,—Tiquina is a sharp-cut valley included between steeply sloping rock walls. The islands of Titicaca (fig. 2), Koati, and Soto are mountains, rising respec- tively 1,400, 1,500, and 1,300 feet above the basin floor, while the archipelago facing the coast at Escoma includes stacks and pin- nacles, erosion remnants, rising above a slightly submerged platform. There are no indications that the tiny islands adjoin- ing Titicaca Island form steps in a submerged causeway unit- ing Copacabana with the Bolivian mainland at Huaicho, as surmised by Bandelier, and no proof that the straits of Tiquina have been opened by faulting or torrent erosion since the lake attained its present dimensions, as is implied by various writers. How much of the shallowness of the bays of Puno, Rames and Achacache and of Lago Pequeno is due to waste furnished by * Les Lacs des Hauts Plateaux de L’Amérique du sud, Paris, 1906. + Hydrographic sketch of Lake Titicaca, Proc. Am, Acad. Arts and Sci., vol. xi, 1875-76. Titicaca Islund and Adjoining Areas. 189 the tributary streams, and how much to original depression, is impossible to determine, but it is significant that bays of great depths and precipitous shore fronts as Yampupata, Tiquina, Huaicho, Conina, and Huaneane do not furnish an outlet for debris-laden streams of large size. Soundings so far avail- able fail to indicate under-water channels or canyons whose orientation may be determined. That the basin, somewhat extended, is a warped, downfaulted area, is suggested by the Fie. 2. S ® 2} 3 Titicaca 2 § flere K e Ss at Fic. 2. Section across Lake Titicaca from Carabuca to Pomata showing mountainous character of Titicaca Island. rectilinear quality of shore and island borders. It would appear also, from the character of the under-water slopes, that the topography had reached a stage of early maturity before the advent of structural movements which prepared the basin for filling by water. The floor of the lake basin, in its deepest part and frequently near shore, was found by Agassiz® to be covered with “ thick mud, the finest possible sreenish black silt containing few frag- ments of shells—the mass being probably several feet thick.” In a few localities sandy, shelly, and rocky bottom was found. The bed of Lago Pequeno appears to be covered with sand. Professor Thoulet analyzed three samples obtained by LeMaire, the first from Lago Pequeno near shore at Chillilaya, the second from a depth of 741 feet, the third from near shore at Huaicho on Lago Grande. The gray slime from Chillilaya contained microscopic fragments of siliceous spicules and dia- toms, black, ferruginous, combustible specks (coal?), brick- colored particles, minute angular quartzes, black magnetic grains and sparsely distributed obsidian, pumice, hornblende, olivine, pyroxene, and mica. Percentage calculations of these samples gave: sand and plant fragments 13; calcareous slime 3 ; non- calear eous siime 13; calcareous mud 59: organic residue 12. Both entire and fragmentary shells were ‘recovered. The sample from deep water gave in parts per 100: sand, ete. 3; * Proc. Am. Acad., vol. xi, p. 284, 1875-76. 190 H. EF. Gregory— Geologie Sketch of slime 78; caleareous mud, a trace; organic residue 18; inde- terminable 2. This sample contained the same minerals as were found in Lago Pequeno and differs only in the absence of lime and greater abundance of globular diatoms. From the Huaicho dredging were obtained iron-coated grains of quartz “resembling the sands of Sahara,” and a few volcanic frag- ments. Thoulet’s studies show that the deeper parts of Titi- eaca are mantled with organic materials, chiefly diatoms, mingled with siliceous and calcareous (in Lago. Pequeno) grains, minute fragments of minerals either wind-worn or vol- canic, rarely meteoric. Near shore sand, plant fragments, and small shells occur. As pointed out by Agassiz, the peculiar physical conditions of the lake bottom combined with high elevation and high temperature of water should tend to the specialization of genera,—a result which does not oceur. The absence of unique forms and the poverty of species are remarkable. The two genera of fish and the mollusks belong to widely distributed fresh-water types. The Crustacea, however, have for their nearest relatives marine forms. An interesting fact pointed out by Orton is that one of the fishes, Z’rzchomycterus dispar, occurs also in the Rimac and Guayaquil rivers. Lake Water.—The temperature of the water, under the influence of the tropical sun and of the rarefied atmosphere, is remarkably uniform at all depths. Of thirty-four measure- ments made by Agassiz in which the temperature of the water at the bottom was compared with that at the surface and that of the air, the difference between bottom and surface was 3°-4°; the bottom temperature being 54°-55° (one reading’ 51° at 618 feet), while the surface temperatures were 56°57". Only one much larger range, 6°5°, was noted. At the same time (January Ist to March 5th) the temperature of the air ranged from 42°-44° early morning to 55°-63° during the hottest part of the day ; extremes of 47° eloudy) and 67° “(very bright) were observed. The mean of twenty-nine records taken by LeMaire from depths between 11 feet and 925 feet* give a value of 51°51° F., the highest reading being 59°52° F. at 79 feet and 607 feet, and the lowest 48:92°F. at 11 feet, 49°64° I’. at 160 feet, and 49°46° F. at 740 feet. A erouping of LeMaire’s thermometric observations indicates an increase from surface to 492 feet, reaching a maximum between 500 and 650 feet, followed by a slight decrease to the lowest depths. The temperatures of * This is the greatest depth obtained by soundings. In Marie R. Wright’s elaborate book ‘‘Bolivia” (1906) is an illustration of the loose statements frequently found in print: ‘‘Its depth varies from 250 feet to 1500 feet, and there are places where it is unfathomable” (p. 243). Titicaca Island and Adjoining Areas. 191 the surface waters during July, during the time the above deep water temperatures were recorded, gives a mean of 52°06° F. The mean temperature of the air, including all hours of the day during the same period, was 45°32°F. It thus appears that the temperature of the surface water averages higher than that of the overlying air in summer as well as in winter. These records of water and air, though manifestly inadequate for meteorological discussion, are sufficient to show that freez- ing temperatures are rare, that ice forms only in narrow bays and then infrequently, and that accordingly the effect of frost in disintegrating rock either in contact with waves or with air is reduced to very low terms. Moreover the diurnal range of temperature is insufficient to aid greatly the disruption of rock masses, conditions which do not hold for the surrounding alti- plano. The water of the lake is fresh and palatable. Raimondi’s analysis showed but a trace of saline matter and the analysis of three samples by Malliere gave 1-07 grams per liter of mineral content, of which -465 of a gram was chloride of sodiuin. The slightly disagreeable taste of samples taken near shore is due, according to Barraneca, to the presence of magnesium and bicarbonate of lime formed by the action of carbonic acid liberated by the decomposition of Myriophillum and totora, which flourish in the shallower bays. The water is clear, even in the rainy season when mud from streams discolors shore areas, and its transparency is little less than Geneva and Tahoe. The outflow of the lake (the Desaguadero, 45 meters wide, two ‘to seven meters deep) is, according to Reck,* 4°822 cubic meters per minute. Evaporation amounts to five millimeters per day.t Fluctuation im Level—The dimensions of the present Titicaca are, as previously stated, one hundred miles by thirty- eight miles, with a superficial area of approximately 4000 square miles. That it formerly had a somewhat greater ex- panse seems to be sufficiently attested by historical and geo- logical observations. Tovart observes that cultivated fields now occupy small portions of exposed lake bottom at Guarisco, Acora, and Llave, that disputes regarding the ownership of reclaimed land at “Capachica and Pusi are listed in local court records, and that in 1877 the waters of the lake reached the suburbs of Puno, now five “cuadras” (city blocks or squares) distant. The ancient ports of Huanecavé, Moho, Couima, Ancoraimes, and Achachaci are now two to three el ommecens * Geog. Soc. de Lima, Tomo X. + Prado, Bol. Soc. Geog. de Lima, Tomo I, 1892. { Bol. Soe. Geog. de Lima, Tomo I, 1892. 192 H. EF. Gregory— Geologie Sketch of inland. Agassiz states* that Lake Arapa and several lakes near the west shore are outliers of an ancient water body, and that the plain north of Lampa ‘only 100-150 feet above the lake ... was one sheet of water.” “The terraces of the former shores are still very distinctly seen.” Tovar also records the tradition that Lake Umayo, now fifteen miles distant and fifty feet more or less above the Titicaca level, was formerly part of Titicaca and that the plains about the north- west end of the lake were formerly less extensive. Viscarrat states that within historical times the peninsula of Copacabana was an island. La Puente,t Zundt,$ Posnansky,| Markham,% and Conway** accept the general view first stated by Orton,tt that the waters of the lake were vastly more extensive and sur- rounded Tiahuanaco within historical times.tt When the Titicaca coast is examined it appears that the data presented by Tovar have little significance. Most of the places mentioned adjoin very shallow waters which are gradually being reclaimed by stream-borne sediments (fig. 3). This is particnu- larly true of the areas mentioned by Agassiz, in which the Lampa and Rames are aggrading their beds and carrying sedi- ment forward to form deltas. Squier appreciated this fact and remarks that “the region around the mouth of the Rames is a kind of delta, very low and level, interspersed with shallow pools as if but recently half rescued from the lake by deposits from the river.” That the lake level has been eight to twelve feet higher than to-day is shown by the whitish band of deposited salts and discolored rock which decorates the bases of rock islands. While in part the evidence of the height reached by breakers, this horizontal band strongly suggests a former level below which the waters have sunk within prob- ably a few decades. The annual fluctuation in lake level is approximately 4 feet, and so shallow is the bottom in places that hogs may feed several hundred feet from shore. In the absence of quantitative measurements and of definite locations of ancient shore lines, the conclusion of Tovar that the lake is “regularly diminishing” in a “surprising manner” is not justified. * Proc. Am. Acad. Arts and Sci., vol. xi, 1875-76. + Copacabana de los Incas, La Paz, 1901. t Bol. Soc. Geog. de Lima, Tomo I, 1892. S Op-cits | Bol. oficina Nacional de Estadistica de Bolivia, 1911. “| Geog. Jour., October, 1910. ** Climbing and Explorations in the Bolivian Andes, 1901. +t The Andes and the Amazon, 1876. tt In a paper presented by Professor Bowman before the Association of American Geographers, December, 1912, and later to be published, the role played by Lake Titicaca in the history of ancient Tiahuanaco is discussed in detail. Titicaca Island and Adjoining Areas. 193 Berglalund reports* that durmg twenty-three years’ residence at Desaguadero the annual fluctuation reached five or six feet and that the level in 1906, following four years of deficient rainfall, was considerably lower than in 1909. Such variations are not uncommon in lakes of the world, even in humid regions Hie. 3- Fie. 3. Bay of Puno, showing a typical portion of the deitas extending into Lake Titicaca from the northwest. marked by climatic regularity. A seasonal or cyclical change in climate, taken in connection with river-borne sediments, is sufficient to account for all authentic facts so far reported, without involving a hypothesis regarding the geological history * Geog. Soc. de Lima, Tomo X. 194 H. E. Gregory—Geologic Sketch of of the lake. Until long-term, continuous records are available, it seems best to assume that Titicaca, in common with other water bodies, rises and falls in response to the increased and decreased precipitation which characterizes climatic cycles, the existence of which has been demonstrated for other parts of the world. The hypothesis of progressive diminution through centuries of time would accordingly be discarded. Former Extent.—That Titicaca is the diminished represen- tative of a vast interior sea which covered the altiplano in northern Bolivia and southern Pern, is claimed by nearly all students of this region. Thus, Agassiz states,* ‘“ Lake Titicaca itself must have, within a comparatively very recent geological period, formed quite an inland sea. The terraces of its former shores are everywhere most distinctly to be traced, showing that its water level must have had an elevation of 300 or 400 feet at least higher than its present level.” Le Mairet accepts Agassiz’s conclusions, supplemented by the existence of an ancient beach line in the Poopo basin, first observed by Mus- ters,t and concludes that Titicaca and Poopo are parts of one interior sea covering the region between 15° and 21° south lat- itude, including La Paz and Oruro. The outlet was supposed to be through the present La Paz river into the Atlantic. “The largest lake in the world fed the largest river in the world.” ‘ Within historical times the Desaguadero has been reduced from a wide strait to its present dimensions.” La Puente§ holds the same view but mentions no evidence bearing on this point. Posnansky| believes that Titicaca is a remnant of an enormous salt sea separated from the ocean by uplift and drained through the eastern Cordilleras by a passage prepared by a cataclysmic rupture of its barrier. As if this were not sufficient proof of the power of the “ titanic forces of nature,” Posnansky states that the region was again flooded by waters from Lagunillos freed by the rupture of massive rock walls,—a disaster which destroyed the civilization represented by Tiahuanaco! Zundt’s original views{{ were in harmony with those of Posnansky and required the elevation of strata to a height of 13,000 feet without destroying their horizontal- ity. The steep faces of the mesas were considered the work of waves. Zundt’s later interpretation** is based on the hypoth- esis of a late Tertiary river, “ Rio Titicaca,” which extended from Sicuani, Peru, to Illimani, Bolivia, via La Paz. This * Proc. Am. Acad. Arts and Sci., vol. xi, 1875-76, p. 288. + Lagos de Los Altiplanos, pp. 153-154. La Paz, 1909. t{ Geog. Jour., xlvi, 1871-77. § Op. cit., 1892. | Bol. officina Nacional de Estadistica de Bolivia, 64-66, La Paz, 1911, pp. 689-702. “| Appendix, D’Orbigny, 1907. ** Bol, Estadistica, 67-69, 1911, and 70-72, 1912. Titicaca Island and Adjoining Areas. 195 ancient channel was blocked by alluvium and glacial debris, thus isolating the present Titicaca. The ancient level of the original lake was not much above the present, and is marked on the rocks at the straits of Tiquina. Duefias* expresses the view that ancient Titicaca may have extended into the Depart- ment of Cuzco. These views are only less extreme than the conclusion of Orton} that the ‘ depression holding Lake Titi- caca is apparently a voleanic basin; fragments of lava, porphyry, and jasper are scattered around and towers of igneous rock protrude through the sedimentary strata.” It will be noted that the conclusions of Le Maire, Posnansky, and others rest on the assumption that the hypothetical Titicaca had its outlet through the La Paz canyon, an assumption neg- atived by the fact that the deposits at La Paz are of later date than the lake basin, and the gorge itself is in large part post- glacial and recent. The existence of the hypothetical ‘‘ Rio Titicaca” of Zundt, flowing in a wide valley or canyon sunk 1000 feet below the altiplano, is supported by no evidence from the lake bed, the altiplano, the valley of La Paz river, or from the upper part of the supposed valley now exposed to view in the region between Huaneani and Sicuani. The enor- mous lake which is supposed to have occupied the basin between the two Andean ranges is believed by Posnansky to have been a detached portion of the sea elevated 12,000 to 13,000 feet without affecting the attitude of the Mesozoic strata. Points urged by Posnansky in favor of the marine origin of the basin are deposits of salt at several localities, deposits of sediments at La Paz and on the altiplano, and the marine affinities of the fauna of the lake. The first two points have little signifi- cance, since salt is a constituent of the country rock, and the sediments at La Paz are river deposits, not marine or even wholly lacustrine. | The lake fauna exhibits in part a marine facies, but is not necessarily of direct marine origin.§ The fish are fresh-water forms, with marine affinities; the mollusks, copepods, Daph- nids, and ostracods are fresh-water forms ; the amphipods pre- sent a marine aspect, but nothing definite may be said of their origin. The only true marine species mentioned by Posnansky, the hippocampus, is not found in the extensive collections of Agassiz and Le Maire. The presence of this species in the lake, a conclusion based on a specimen given to Posnansky by an Indian fisherman, and now in the private museum of the collector, requires further confirmation. * Bol. Cuerpo de Ing. de Min., No. 58, Lima, 1907, p. 25. -+ The Andes and the Amazon, 1876. {See Gregory: The La Paz Gorge, this Journal, vol. xxxvi, pp. 141-150. § For data concerning the habitat of the Titicaca fauna, I am indebted to my colleague, Professor Petrunkevitch. 196 Hl. L. Gregory— Geologic Sketch of In this connection Agassiz’s statement, quoted above, that “the terraces of its [Titicaca] former shore line are everywhere most distinctly to be traced,” at ‘“‘an elevation of 300 or 400 feet at least higher than its present level,” deserves attention. Such high level terraces were not observed by the writer at Puno, Guaqui, Tiquina, Yampupata, or on Titicaca Island,—a fact which surprised me not a little, since I had assumed that such evidences of higher level were to be found on all sides. The shale, sandstone, and limestone, tilted at various angles and of different degrees of firmness, fretted by waves of considerable power, especially during the southern winter, would be expected to produce unmistakable rock benches, and the low-lying bor- ders of parts of the lake offer favorable opportunities for beach- making. Moreover, the conditions for preserval of the shore forms in a semi-arid climate and where freezing is unusual are favorable. This does not prove, of course, that no such evi- dences of high-water level exist, for no detailed survey has as yet been made; but raised terraces are not “ distinctly to be traced.” In fact, no rock shelf or raised beach has been mapped or described, and there is no direct evidence of former high levels except for the relatively slight fluctuations discussed above. It is significant that La Puente, who stoutly affirms the former existence of a vast interior sea, made a traverse of the lake borders and visited many islands without recording the presence of ancient shore forms, and that Bowman in 1908 saw no signs of raised terraces.* It will be noted that the argument against the presence of an ancient interior sea of vast dimensions rests chiefly on evi- dence of a negative value, and in the absence of topographic maps and of detailed physiographic studies must remain so. The problem involves the unraveling of the geologic history of the entire plateau region. From the data at hand it appears that the great interior depression, itself a plateau, owes its existence to faulting as implied by Bowman,t and that the downfaulted area was givev its relative position after uplift and peneplanation of both the eastern and the Maritime Cor- dilleras in early Tertiary time. It is also probable that the floor of the sunken area was further modified by warping and selective faulting which produced a number of secondary depressions at considerable depths below the general floor. It is reasonable to suppose that such a downfaulted, warped surface would be oceupied by a number of lakes, whose extent and permanency and degree of salinity would bear direct rela- tions to the original topography, abundance of waste and climatic fluctuations. * Private communication. + This Journal, vol. xxviii, 1909. ley Titicaca Island and Adjoining Areas. 197 Titicaca Island.—TViticaca Island is a representative of a large class of elevations including hogbacks, eroded folds, mesas, igneous masses, and probably fault blocks, which pro- ject above the general floor of the great interior basin or pla- teau. In common with its companions it has reached a mature stage of development and is, in brief, a residual prominence now partly submerged in the waters of a lake. In outline Titicaca Island is very irregular (fig. 8). Five large bays set deeply into the land, in addition to ten or twelve other bays of one-fourth mile or less in width which scallop the island’s border. Although the island has an area of 102 square miles, with an extreme length of only seven miles, and width nowhere exceeding three miles, the length of the coast line is 85 miles. Only at the southwest, where the sandstone ridge of Kakayo-Kéna forms an unbroken wall for nearly five miles, does the coast assume a rectilinear quality. The dominating feature of the island’s surface is a backbone or central ridge, extending from Bilcokyma to Sicuyo, a distance of about seven miles, and following the direction of strike of the sedimentaries which compose it. On the northeast the Kea Kollu dome, extending far into the lake, assumes a com- manding position, and on the southwest the long, straight ridge of Kakayo-Kéna, culminating at Chullun-Kayani with an elevation of 800 feet, constitutes a conspicuous feature of the landscape. At the north the peninsula of Marcuni, tied to the land by the low isthmus of Challa, is a prominent feature when viewed from the lake. Approximately two-thirds of the island maintains a height of 400-500 feet, a few small areas are over 700 feet, and at Palla~-Kasa a barometer reading of 15,330 feet, 830 feet above lake level, was obtained. This is probably the culminating point on the island, and Squier’s figure, 2,000 feet, for the hills back of Challa is clearly an error. Back from the shore the surface has little sharp relief ; clifis and precipices and deeply cut chasms, except those formed by differential erosion of strata, are absent. Rounded ridges, flattened domes, flat saddles, and graded slopes form the surface, but not to the exclusion of minor steep rock slopes developed on the edges of tilted strata. In fact dip slopes and cuesta fronts in many places determine the topog- raphy and point to structural control of subordinate features. The valleys separating the rounded heights are broad V-shaped, frequently nearly flat, and the divides are everywhere incon- spicuous. Only in their lower courses do the stream channels become steep-walled ditches and then only where wave-worn headlands have destroyed previously established grades. In short, the topography is mature or post-mature and youthful features are exceptional. (See figs. 4, 5 and 6.) 198 H. E. Gregory—Geologic Sketch of The coast shows everywhere signs of vigorous erosion ; head- lands of bare rock, rising 100-800 feet above water, are numer- Fie. 4. Hie. 4. General view of the Peruvian shore of Lake Titicaca. Fie. 5. te Le Oe (he Titicaca Island and Adjoining Areas. 199 ous, and the short stretches of crescent beach are piled high with gravel. (Figs. 6 and 7.) The longer beaches, as at South Yumani and Challa, are built of fine materials with flat oradi- ents and in more sheltered places luxuriant fields of reeds Fie. 6. Fie, 6. Kona Bay at South Yumani, showing beach, hill slope, and quality of the short drainage channels. (totora) are found. The Marcuni peninsula is tied to the land by a double-faced, wave-made beach. .) a 200 4. Limestone; thin-bedded; hard -_-_..-.----------2.120 @ 5. Sandstone ; medium- _grained ; pebbles, red and white : matrix, and general color, green; soft, thin-bedded, cross- bedded in places; three bands of dove-colored limestone 35 6. Limestone; hard, blue-gray and soft yellow; top bed dove-colored ; beds 6-1’; fossiliferous ...----.------ 65 7. Sandstone; coarse, clear and white, well-rounded grains 40 8. Sandstone; medium-grained; gray to green; rounded, clear, green and red grains ; massive; hard to medium. Dip NE. LAB? oo eee Re 22 eee 9. Sandstone; soft; medium to coarse; purplish to gray, top greenish; quartz grains, clear, red, green, and black, be- sides specks of lime. Bed of ‘lime (4') in middle. Spar- ingly fossiliferous. At top sandstone is harder and includes zone of brecciation”—22-- 4-4-2. -25- 2s. 150 10. Sandstone; massive; medium-grained quartz, clear, green, red and black; also lime specks; all in green cement; soft, but forms cliff face .-.2. see nes uss. 2. 11. Shale; maroon, in part gray-green ; bed of soft sand- stone at 50’; some seams of limestone running across strike so Wo. oe.) 2cie ye eee 100 12, Shale, eray-ereen. 321.05 26453 eee eee 16 a 13. 23. 24, 26: 27. Titicaca Island and Adjoining Areas. Sandstone ; massive; medium-grained ; quartz, lime and limonite, and a green stone in purple cement; crumbles on weathering; dip 34° in 30’ (probably fault between POELEAE LIS) ll: 0 Ui) Ae eel ee 0d eee na ee Shale; maroon and gray-green; one 2’ pinkish bed ; TSWSSS Cl) CORUNA eR ace eee tee ne!) ho goa eee . Sandstone ; or arenaceous limestone; medium-grained; beds 1'-3’; hard, weathers in checks. Dip N. E. 7 45° Coal (bloom); clean; strike N. 25° W. ; dip N.E. 747° . Limestone, gray; thin-bedded; with drab shale---_------ . Shale; gray-green; talus-covered .__-__----- Dae itl ei . Limestone; impure; has plant fragments._-..--------- . Shale; argillaceous; drab-gray; capped by 2’ of arena- ceous shale filled with plant remains.__-._--.-------.- . Sandstone; fine-grained; rounded quartz pebbles; calca- reous; general color gray-white; included beds and cap of gray-green ; soft, thin, even beds; one belt of gray shale; very few round, pea: limonite concretions. Dip N.E. De OSE spees 10 RE Pe Ss Rae Ne eek ee ne . Sandstone; white; coarse to medium, with clear, suban- gular quartz pebbles. Some bands almost a conglomer- ate. Soft, massive, weathers in rounded knobs. Hard to tell from No. 13 at contact, but No. 13 is finer and has esr Or sale. 6a ee PS EERE Ste A bn Coal. Four feet bone in middle ; weathered rave bale Breanna Oo Newn SO erase eee ee ye Limestone; thin-bedded, grading into sandstone at top; interbedded with shale : much checked or broken ; weathers gray or ISG) TE ss ean ne gee . Sandstone; fine grain; clear quartz, well-rounded and white flakes ; more lime near top than bottom. Color white with some buff-yellow bands; massive ; many cracks across bedding. Like No. 33 except for absence at specks of carbonaceous matter ._._...-.2.-.------- Sandstone; fine-grained; clear quartz, rounded and white flakes; weathers yellow-brown; fresh buff-gray. Even- bedded 1”-3'. One soft lens of buff-brown; at top is a mcllomewandvot, Inmonttes £2 63 ne. Like No. 29, but limestone grades into a sandstone with fine, rounded quartz grains at top; brownish gray; mica Grebeddimompliames 2 oO at . Gray shale; contains lenses of limestune like No. 32 from 3" to 1' thick ; has two seams of coal, one 14” about 11’ from bottom, the other 13”; very clean bloom at top . Limestone and shale; limestone like No. 30. Slate green- ish gray; very thin-bedded; mica on bedding planes... -- . Sandy limestone; buff-gray; weathers mottled gray and nee _-prown.. linim> Kreowlanibeddime 2222. ...5..-.---- . Shale; gray; with 2' red-brown limestone 8’ from bottom, 209 Feet 85 30 70 35 210 H. FE. Gregory—Geologic Sketch of 32. Limestone; begins as limy sandstone and ends as lime- stone; first beds buff to gray; last beds blue-gray (fresh fractured) ; beds even; 2’’-3’; heaviest beds near bot- tom; much mica on bedding planes; fracture uneven and often breaks in rounded forms; between beds a parting of gray shale. Top contains limonite concretions like No. 33, and is weathered brown ___-.------.----2 33. Sandstone; frie grained at top, medium at bottom; quartz 0 IS grains rounded, not colored; a few tiny muscovite flakes and occasional black ’ specks of carbonaceous matter. Much white lime or decomposed feldspar. Rare pea-sized pebbles of quartz; gray-white on weathered sur- faces ; soft, weather-rounded ; bedding massive; cross- bedding poorly developed ; contains seams of limonite- stained rock; one little streak of quartz showing garnet; round limonite concretions, size of pinhead to small pea; at 130’ bed of shale about 32’ thick. Shale is gray-drab to drab; contains carbonaceous matter, clear quartz grains, and occasional flakes of mica. Strike N. 24° W.; dip N. Bi 44308. ee ese ee Oe SECTION C. Tauana Bay. Strike N. 45° W, dip N. &. 2 50°. White, cross-bedded sandstone..-.__.- .--- ---.----- 54 Shale and thin sandstone ; a few very thin carbonaceous layers: .... Sede eee Bie he a) Ss ee Sandstone ; white, er Gas bedded. }y trea ae Eis , Sandstone and sandy shales; thin- bedded ; with. plant fragments irregularly distributed 0...) Shale, carbonaceous ; coal in wavy lenses constitutes about 4+ of the stratum ; the remainder consists of lignite inti- mately mixed with shale and sandstone ; coal appears to be of good quality =. 3 2). 5. 3 Shee pe ee Drab shales and sandstone like No; 8-2-4525.) > Carbonaceous bed, one-half shale ; abundant pyrite_ --- . Sandstone, gray, thin-bedded, $’—2"; shales, black and drab ; wavy, cross-bedded ; concretionary ; with ripple- marks arranged in overlapping patches a few inches in diameter ; contains muscovite and a few plant ne es- SIONS ~~. oe ee Feet 50 Feet 10 20 60 40 Lo Om 200 The interleaving lense character of the coal is well shown here ; 500’ distant, across a little bay, numbers 5 and 8 are scarcely cr resented and shale occupies nearly the whole section. = bo ee tS 10. x. 13. Titicaca Island and Adjoining Areas. Section D. North end of Copacabana Peninsula, measured along the lake shore. Strike N. 40° W, dip #.Z80°. . Shales and thin sandstones with three beds of carbona- ceous shale, 3’, 4', 4’ in thickness. Approximately one- half of each bed consists of coal of commercial value_- -- . Sandstone ;_gray-white ; cross-bedded_-..--------.--- Shales, sandy ; alternating with very thin (4'-14") beds of drab and gray sandstone ; rare streaks of carbonaceous BME A 5 oY i ee ee ts ee nee 0 LINE a Shales, black ; alter nating with ¢ gr ray- -brown sandstone in lenses, and cross-bedded shale, in part carbonaceous ; with some thin ($”+-) lenses of true coal. At top is 1’+ PeemimTC RC Oils we ele ieee Ls oes cis wea a 2 ay ees ik eds Shale ; black, lumpy, in part stained by limonite ; breaks in flakes ; contains lenses of gray-brown sandstone ---- Sandstone ; yellow-gray ; in 6’-10" beds.-------. .--- pmater: black to drab ; like No.9... js. 2222 2--222-2 s5-- Samsoones Vellow-Cray. <. 52.22.2222 2-0ue.d Set Le Shales ; drab ; thin-bedded (4) concretionary with wavy i Sandstone ; yellow-brown ; thin bedded (1’—4”) ; cross- bedded, micaceous, lumpy, with mud concretions and sun-cracks ; surface of sandstone wavy and beautifully ripple-marked. Shales ; drab, sandy, lumpy, intricately MOM CUO LMTAIHINLS Scaler sae eee a Sandstone ; yellow; in beds 4-10” thick ; interbedded with drab, ‘arenaceous shales. Bedding very uneven and surface of each stratum reveals overlapping flakes ...._- . Shales; brown, yellow and drab; with uneven, flaky STUPLEICS a a Se Re Ye 2 ie a aed spe enn ee Sandstone ; white to gray ; cross-bedded ; medium-fine grain ; in bets = eae 20 7. Shale and thin-bedded limestone ; transverse seams stained waite limonites: 22.2... 5 eee ee -- 22...) 175 8. Sandstone ; medium-grained quartz, clear, subangular to rounded ; occasional large grains ; some lime ; gray- white with limonite stains ; cross-bedded ; thin to heavy ; some rare spots of conglomerate :-_!-__-2_ 2.) ae 267 9. Sandstone ; fine-grained, rounded quartz; much stained , by limonite ; even-bedded ; mica on bedding planes____- 50 10. Shale ; drab with lenses of yellowish limestone_._..___- 4 11. Limestone‘; oray, sandy = 6022-2 3 ee 4 12. Coal, with 2" band of sandstone. Coal of fair quality and with little “bone”. 2 :)0.). 116. 2122) ee 13. Shale; gray to drab with purple streaks iota: rootlets i. vol Wiis eis tee de ae _ i 14. Sandstone ; fine-grained, with clear, rounded, quar tz peb- bles, white flakes and limonite ; even, heavy beds ; toward top assumes greenish tone and contains much mica and. lime ..2. 1.225 .2525, -20 ee ee 20 15, Shale; sray tovpurples 2) |- 2. Ue ee ee 30 16. Sandstone ; fine, with well-rounded quartz grains, and white specks ; some muscovite ; thin, even bedding_ ---.- 6 17. Shale ; gray, with thin beds of limestone 2.5/2) 18. Sandstone ; fine, with clear, well-rounded quartz grains and white specks. Mica on bedding planes ; weathers gray-white ; some raised veins of harder, dark rock ; bed- ding fairly even; some cross-bedding ; some twisted beds ; caleareousat top... 2_ 2.7 See eee 135 19. Limestone and shale ; the latter predominate; shale is drab; limestone is gray, to a limonite yellow; cross- bedded and twisted ; has much mica on bedding planes. 55 20. Sandstone ; fine, with rounded, clear grains of quartz, and numerous blotches of lime or other white mate- rial ; general weathered color gray-white with spots and bands of yellow ; medium hard ; even-bedded ; massive ; occasional small, rounded concretions of limonite. Strike N’ 46° W-; dip Ney Aor 30 Bibliography. Adams, G. I.: An Outline Review of the Geology of Peru. Report of the Smithsonian Institution for 1908, pp. 385-480. Agassiz, A.: Hydrographic Sketch of Lake Titicaca. Proc. Am. Acad. ‘Arts and Sci., Vol. XI, 1875-76, pp. 283-292, with map. ‘* and §. W. Garman: Exploration of Lake Titicaca. Bull. Mus. Comp. Zool. Harv. Coll., Vol. III, 1871-76, pp. 274-285. Bandelier, A. F.: The Islands of Titicaca and Koati, pp. 1-858. The His- panic Society of America, 1910. The most exhaustive study yet made of any portion of the Titicaca region. While chiefly archeological, the volume contains valuable geographic data. Basadre, Modesto: Los Lagos de Titicaca. Bol. Soc. Geog. de Lima, Tomo III, 1894. Titicaca Island and Adjoining Areas. 213 Bowman, Isaiah : The Physiography of the Central Andes. This Jour., Vol. XXVIII, pp. 197-217, 373-402, 1909. Conway, Martin: Climbing and Exploration in the Bolivian Andes. New York, 1901. Dereims : Excursiones Cientificas, 1901-04. Anexo de la Memoria de Gobi- erno y Fomento. La Paz, 1906. D’Orbigny : Voyage dans L’Amerique Meridionale, Tomo III, Pt. III, Paris, 1842. Spanish edition translated and annotated by Victor E. Marchant, La Paz, 1907. Forbes : On the Geology of Bolivia and Southern Peru. Quart. Jour. Geol. Soc., Vol. XVII, 1861; Spanish translation by Edmundo Solo- guren, Sociedad Geographica de La Paz, 1901. Le Maire, Dr. M. Neveu: Les Lacs des Hauts Plateaux de L’Amerique du Sud. Paris, 1906. Spanish translation by Dr. B. Diaz Romero, Direcion Genera! de Estadistica y Estudios Geograficos, La Paz, 1909. A study by modern methods of the lake and its waters. Markham: The Land of the Incas. Geog. Jour., Vol. XXXVI, pp. 381-396, 1910. Orton: The Andes and the Amazon, 1873. Posnansky, A.: Lorenzo Zundt y la Geologia Boliviana. Bol. Oficini Na- cional de Estadistica, Nos. 70-72, pp. 288-295, 1912: El Clima del Altiplano y la Extension del Lago Titicaca. Bol. Oficina Nacional de Estadistica, No. 64-66, La Paz, 1911. Puente, Ygnacio la: Estudio Monografico del Lago Titicaca bajo su aspecto fisico e historico. Bol. Soc. Geog. de Lima, Tomo I, 1892. Salter, J. W.: On the Fossils from the High Andes, collected by David Forbes. Quart. Jour. Geol. Soc., Vol. XVII, 1861. Squier, E. G.: Peru: Incidents of Travel and Exploration in the Land of the Incas. Steinmann: A Sketch of the Geology of South America. Am. Naturalist, 1891, pp. 855-860 ; also, Rosenbusch Festschriften, 1906, pp. 300-368. se und Hoek: Das Silur und Cambrian des Hochlandes von Bolivia. undihre Fauna. Neues Jahrbuch fir Mineralogie, Vol. XXXIV, 1912. Tovar, Augustin: Lago Titicaca: Observaciones sobre la disminucion pro- gresive de sus Aguas. Bol. Soc. Geog. de Lima, Tomo I, 1892. Short articles and statistical reports issued by the Bolivian and Peruvian governments. Ulrich ; Paleozoische Versteinerungen aus Bolivia. Neues Jahrbuch, Vol. VII, 1892. Various articles and notes in the Bolletin Sociedad Geographica de Lima. Visearra : Copacabana de los Incas. La Paz, 1901. Zundt, Lorenzo: El Lago Titicaca. Bol. Oficina Nacional de Estadistica, Nos. 70-72. La Paz, 1912, pp. 222-226: Appendix, Estudios sobre la Geologia de Bolivia por A. D’Orbigny. La Paz, 1907, pp. 65-104. 914 Wellisch and Woodrow—Columnar Ionization. Arr. XXIV.— Experiments on Columnar Ionization; by E. M. Wetutscsw, Assistant Professor of Physics, Yale University, and J. W. Wooprow, Ph.D., Yale University. INTRODUCTION. 1. In their experiments on the distribution of the active deposit of radium in an electric field, Wellisch and Bronson* found that the fraction of the total amount of active deposit. that settled on the cathode increased with the potential-differ- ence in a manner quite similar to the increase of the electric current which passed through the gas during the process of activation. The curve connecting the cathode activity and the potential-difference exhibited the characteristic ‘ lack of satura- tion’ which had previously been investigated by Bragg, Moulin, and others in the case of the electric current due to alpha-ray ionization. This experimental result suggested the probability that the electric current would attain its saturation value only when all the active deposit settled on the cathode ; or more generally, that the cathode activity was a measure of the degree of the saturation of the.electric current. On investigating experimentally the activity distribution when the radium emanation was present in air at a pressure of 260™™, it was found that for potentials above 80 volts the cathode activity did not perceptibly increase; but the curves connecting the percentage of cathode activity and the ioniza- tion with the potential-difference had the characteristic hori- zontal portion which suggests that saturation has been attained. On the other hand, the measurements showed that there was still about 17 per cent of the active deposit which failed to reach the cathode. These experimental results appeared to indicate that the saturation obtained for alpha-particle ionization at pressures below about one-half of an atmosphere was only apparent: the results were most suitably explained on the supposition that part of the electric current observed at one atmos- phere was due to the ionization by collision with molecules which, though electrically neutral, had been brought into an unstable condition by the action of the alpha particle. These ‘neutrons’ would be in the most favorable position for ioniza- tion when the electric field was parallel to the alpha-ray column and also when the pressure was not too low. On this view, the characteristic upward slope of the curve connecting the electric current with the field for alpha particle * Wellisch and Bronson, Phil. Mag. (6), xxiii, p. 714, May, 1912. Wellisch and Woodrow—Columnar Ionization. 215 ionization is due in part to the extra ionization thus obtained. We should expect, therefore, that when the electric force is sufficiently great the electric current would be slightly greater when the field is longitudinal or parallel to the alpha-particle column than when it is transverse or perpendicular to it. The present paper describes a series of experiments which were devised to compare the ionization resulting from a longitudinal and transverse field for the case of a single alpha-particle column. The results of the experiments confirm the accepted view of the phenomenon as advanced by Langevin and Moulin,* namely that the ‘lack of saturation’ of the ionization current is due to the columnar recombination, and no evidence was obtained which would indicate the existence of unstable atoms in the alpha-r ay columns. In Section 5, some theoretical considerations based on Lan- gevin’s theory of recombination are given in which the subject is treated from a slightly different standpoirt from that adopted by Moulin. DESCRIPTION OF THE EXPERIMENTAL METHOD. 2. It was first shown by Moulin that lack of saturation does not come into evidence when the field is transverse to the alpha-ray column nor, at low pressures, when the field is lon- gitudinal. This experimental fact formed the basis cf the method employed for the comparison of the ionization result- ing from the application of a longitudinal and a transverse- field to a single alpha-particle column. Consider a single alpha-particle column formed in air (1) ata pressure of one atmosphere, (2) at a pressure p which is a small fraction of an atmosphere, say about one-third. Let 7z, and 4, denote the number of ions due to a small portion of the ‘path (in the present case this was 4" in length) for the two pressures respectively. This ionization may be measured with either a longitudinal or a transverse field. Let when the ionization is measured in a longitudinal and trans- verse field respectively. In general, 7, will be different from 7,: this arises from the fact that the current at one atmosphere when measured in the longitudinal field depends upon the electric field over a wide range, while in the other the currents readily assume values which are independent of the field. * Moulin, Comp. Rend., exlviii, p. 1757, 1909. 216 Wellisch and Woodrow—Oolumnar Ionization. On the hypothesis of Wellisch and Bronson it was to be ex- pected that 7, would be greater than 7, for large values of the field ; whereas on the Langevin-Moulin theory 7, should be less than 7, except when saturation was attained, in which case we should have 7, = 7; In order to determine the value of r, corresponding to any value of the field, the ionization currents due to the alpha rays from a polonium source were measured in a longitudinal field for air at one atmosphere and for air at a lower pressure p. The ratio of these currents gives the value of 7, and is inde- pendent of the-actual number of alpha particles entering the 1M 1 To — ToPump & Gauge IE measuring apparatus and also of the electrical capacity of the system : in fact it is the ratio which would be obtained for the ionization due to a single alpha particle. The ratio 7, was obtained in a similar manner by obtaining the corresponding currents in the transverse field. Description of Apparatus and Experimental Procedure. 3. By the kind permission of Prof. Bumstead we were en- abled to avail ourselves of the ionization vessel which had pre- viously been employed by Wheelock* in his experiments on alpha-ray ionization, A general idea of the apparatus and me general scheme of connections may be obtained from fig. 1 For the vertical lon oitudinal field the ionization vessel consisted of a wire gauze B, 4 *5°™ in diameter, situated 4™™ below a eir- * Wheelock, this Journal (4), xxx, p. 283, 1910. Wellisch and Woodrow—Columnar Ionization. 217 cular brass plate A, which was connected to one pair of quad- rants of a Dolezalek electrometer. The lower gauze G was inserted as usual, to avoid disturbances due to diffusion of ions into the region AB. For the horizontal transverse field two brass plates were employed, one C (8°5 X 2°5°) connected to the battery, and the other D (7-2 x 0:4), which connected with the electrom- eter. The latter electrode was surrounded by an earthed plate E, which served as a guard ring. Both the longitudinal and the transverse fields were so con- structed that they could be inserted in the same containing vessel, as shown in the diagram. A thin film of polonium deposited on a copper plug, 4mm in diameter, which had been prepared previously by Prof. Bolt- wood, was employed as the alpha-ray source. This plug was placed on the carrier R, which could be moved vertically by a screw, S. A scale and divided head enabled one to make a very accurate determination of the distance of the poloniam from the center of the ionization vessel. A narrow beam of alpha-rays was always employed; this was obtained by placing over the polonium a fine slit or a series of fine ‘ canals’ as de- seribed below. The electrometer was of the Dolezalek pattern with a plati- num suspension, and had a sensibility of 140™™ per volt with 84 volts on the needle. In most of the experiments a potentiometer arrangement was employed so that the reading of the ionization current might be made with the zero of the instrument at the center of the swing. It was found that this method gave very con- sistent and accurate readings, which was of especial importance when small potentials were employed. The whole apparatus could be rendered gas-tight by the use of a heavy stop-cock grease. Experimental Results. 4. In the first set of observations a fine slit 5™™ long and 0-5™" in width was placed 1° above the surface of the polo- nium. |: 2°68 x 1077) eee 232 0°73 O65 waite a 280 ae 112 261 0°84 Qapes oy epsiope. 1 2-6 ee 1:13 284 0-92 OBI) Sie Daa D-Saatee ial Bi ral ean eo IEA as CER YS 2913 ae eke 4.00 1°36 1213 ce Ae a0 30 ee ag 446: |. hei L308 a0 me Sree Sm 112 506° 1 25 1:99> uBeniaeee Bese Jelis 1:23 160..|. .Blbe ie 2S 415 Masry. yen C3 It is worthy of mention here that experiments were per- formed to determine the shape of the ionization curve in the longitudinal field at pressures of about 10" of mereury when the electric field was sufficiently increased to produce ioniza- tion by collision. The curve obtained was that to be expected from Townsend’s theory and no evidence of any anomalous ‘behavior was observed. Having proved to our satisfaction that the characteristic shape of the ionization curve for the longitudinal field was to be ascribed entirely to the effect of recombination of i ions, it became a point of interest to ascertain if possible the relative effects of columnar and volume recombination. Moulin* has already given a method for determining the shape of the current-field curve when volume recombination is absent, that is, when no recombination takes place between ions formed in different columns. Moulin’s method consisted in determining the effect of volume recombination by comparing the curve obtained for a transverse field with that obtained by using X-rays as the ionizing source. The ideal curve corresponding to absence of volume recombination in a longitudinal field was obtained by means of a series of calculations referred to the ideal curve of the transverse field. In the present experiments a more direct method was employed to obtain these ideal curves for a longitudinal field. This method consisted in determining how the fraction (2/1) of the saturation current (1) which corresponds to any given value of the electric field depends upon the value of this saturation current. Three sources of polonium were employed and a fourth determination was possible as a result of an appreciable decay of the weakest of these sources. In fig. 4 are * Moulin, Ann. Chim. Phys. (8), xxii, p. 26, 1911. Wellisch and Woodrow—Columnar Ionization. Ce given curves which show how @/I varies with I for different values of X in the longitudinal field. The curves are plotted from the values given in Table VII. These curves are pro- duced so as to intersect the axis of ordinates: the ordinates thus cut off represent the fraction of the saturation current (Die. ds FH =. Saturation Current I. which would be obtained by the corresponding field in the absence of any recombination between ions of different columns. Jt might be expected that as there are only four points on each curve it would be very difficult to produce the curves as TABLE VII. Longitudinal Field ; d=2°6 cm.; p=760 mm, xX. | 0-4 1:0 2°0 4°0 10 20 105 | 420 f. a a6) 520605.) 658 71001: 76 "86. «| 94 | 0°12 Bal.) 33 "50° | °595 654 | °708 "76 ‘86 ae 0°13 aks |: 19 "34 “548 635 "704 "76 "86 "96 0°78 i / 1. ‘15 "29 "498 623. | °704 °76 °86 ‘O4 2°39 Transverse Field; d=2°'6 cm.; p=760 mm. XxX, 0-4 08 2°0 4:0 10 26 40 I. ple 25 44 | -"68' 1) “77a. 67872. "| 94 98 0°44 Baits |) 09 16 SO wrotoe S16" | 93 ‘97 2°40 ELS - 705 10 25h 4 02788 "92 ON 6°99 224. Wellisch and Woodrow—Columnar Ionization. stated above, especially those curves corresponding to small values of the field: however those points which were of the most importance for our subsequent calculations were those which were most readily obtained by this method. Moreover other considerations made it highly probable that the curves corresponding to the small values of the electric field inter- sected the axis of ordinates at points close to one another. In fig. 5 the limiting values of Ria Shean Sree 244 MDEes Gren TOT se ee eee ee 8 244 piueiureand- Correlation 22 oes ee Sek cl ok 246 Devonian fossiliferous horizon = 2.55... 522.2222... 247 Introduction. In August, 1912, the writer published a notice of the discoy- ery of a new fossiliferous horizon near Littleton, New Hamp- shire.* Further field work and subsequent laboratory study have furnished material fora more complete description of the geology of this region.t The town of Littleton is 23 miles nearly due west from Mt. Washington, and is situated on the terraces of the Ammonoo- suc River, about 22 miles from the point where this stream unites with the Connecticut River at Woodsville. Two miles west of Littleton the land rises westward 1000 to 1200. feet above the Ammonoosue River to a ridge known in its northern part as Blueberry Mountain and in its southern as Bald Hill. Blueberry Mountain. has its northeastern end in a valley in which two brooks flow, one northwest to the Con- necticut River; and the other southeast to the Ammonoosuc River (see fig. 1). A relatively small crest (not shown by the contours) at the northern end of Blueberry Mt. is known as Fitch Hill. This hill is just south of Locality 7, as shown in mo 2. * A New Fossiliferous Horizon on Blueberry Mt., in Littleton, New Hampshire, Science, N. S., xxxvi, p. 275, 1912. + This geological investigation was undertaken with the aid of a fund pro- vided through the generosity of Mr. R. W. Sayles, of the Harvard Geological Department. : 232 Lahee—New Fossiliferous Horizon and Underlying The area to be described (fig. 2) is a strip 14 miles wide and 74 miles long, including Fitch Hull, Blueberry Mt., Bald Hill, and the country for four miles southwest of Baid Hill. Blueberry Mt. and its vicinity should be of peculiar interest to the geologist because the rocks there are less metamorphosed than those anywhere else between the Connecticut River and the Franconia range of the White Mountains, and because most of the fossils obtained in northern New Hampshire have come from this locality. In presenting the results of our field work we shall describe _ (1) the petrology, structure, and stratigraphic sequence of the Index Map. r) / 2 o___1__y Scale in miles. ~ Littletdn 7. “a 4 " > / 4 / a 74 | / SS ~~ as 4 S / — be “ = 7 O NM ! ~ = = 72° Wsa' m*4o" Fie. 1. Outline map of the Ammonoosue district in New Hampshire, showing the position of the area (shaded) included in fig. 2. rocks on and near Fitch Hill; (2) the southwestward distri- bution of these rocks; and (8) the new fossiliferous horizon | of Blueberry Mt. Summary. Following is a summary of the essential facts set forth in this paper : 1. A metamorphic igneous rock, herein called the ‘ Fitch Hill granite gneiss,’ outcropping in the township of Littleton, N. H., displays certain variations in mineral composition, which are possibly consequent upon original magmatic differentiation. 71°40" 44? = que jo’ 233 Rocks, in Littleton, New Hampshire. Hig 2: q NS served boundaries SRA RANY Ss < Ean Basic sills =— Ss Ad Hy ly ln “J Y mud .f US Sao BS KB OURE 4 Re diel bel tis) QAy ~ 2 {TT Lyman, Boundaries; loca- schists tion uncertain. AW b | in miles. Scale Fie. 2. map on the left is the upper edge of that on the ri The lower edge of the The positions of the ght. Map of the area described in this report. cross-sections drawn in figs. 8 and 4 are marked by lines lettered A-A, B-B, etc. 4 234 Lahee—New Fossiliferous Horizon and Underlying 2. The Fitch Hill granite gneiss is intrusive into the Lyman schists, but unconformably underlies the Niagaran sediments of Fitch Hill, Littleton, thus demonstrating the presence of a regional unconformity beneath the Upper Silurian strata of the Ammonoosue district in New Hampshire. 3. The limestone near the base of this Upper Silurian forma- tion is, at least in part, a conglomerate composed of roundish pebbles of crinoidal limestone, together with a very few pebbles of granite, in a highly caleareous, argillaceous, coral-bearing aste. 4, Marine fossils of Devonian age—presumably Lower Devo- nian—have been discovered in fine-grained clasties (‘ banded argillites”) about 3000 feet above the base of the Upper Silu- rian in this region. These Devonian strata may be followed for seven or eight miles along their strike, but they grow finer and more metamorphosed southwestward. Fossils have been - found in them at four localities within a distance of five miles along the strike. These fossils confirm the belief, long ago stated, of a seaway situated near the Connecticut River valley: in Devonian times. Geology of the Fitch Hill Section. In fig. 3 is shown a vertical section drawn nearly north and south across the strikes of the Fitch Hill rocks. Its position is indicated in fig. 2 by the line A-A. Its southern end cuts through Fitch Hill. The rocks appearing in this section are the Lyman schists, the Fitch Hill granite gneiss, and a group of strata which may be called the Blueberry Mountain series. The Lyman, schists. —The terms ‘ Lyman schists’ and ‘Lyman group’ were applied by Professor Hitchcock to a body of ‘hydro-mica and chlorite schists’? which in his earlier report* he assigned to the Huronian. Writing 30 years later,t he referred the group to the Cambrian or Ordovician, but not with complete assurance, for the structural relations of the for- mation are obscnre and all possible evidence of fossils has been destroyed by metamorphism. These Lyman schists outcrop in the northern corner of the map (fig. 2). They are highly metamorphosed fine-grained sandstones and mudstones, with a few beds of fine conglom- erate in which the pebbles, all angular and mashed, are hardly distinguishable from the paste. Some of the finer schists are . thinly banded, and these strata bear evidence of great contor- tion. In one place a zone of crush-conglomerate was seen. * Hitchcock, C. H.: Geology of New Hampshire, vol. ii, p. 50, etc., 1877. Tbid. , Geology of Northern New England, p. 12, 1874. + Geology of Littleton, New Hampshire, reprint from the History of Lit- tleton, pp. 11 and 29, 1905. 4 *F Rocks, in Littleton, New Hampshire. 235 The series as a whole is drab or greenish gray in color. Weath- ered surfaces are much lighter, sometimes almost white. The Fitch Hill granite gneiss: Harlier references.—W hile this rock has been mentioned several times in previous writings on the Littleton district, it has never received very thorough consideration, nor have its relations to the adjoining formations been described. In Hitchcock’s works it i: called ‘chlorite,’ * ‘chlorite rock,’ + ‘chloritic foliated granite,’ + and ‘ protogene, § a name given to it by Hawes. Lambert refers to it as a “stratum of igneous rock,’| and also merely as ‘igneous rock.’ 4 Distribution.—The Fitch Hill granite gneiss outcrops in a belt which trends N.E.—S.W., to the south of the Lyman schists, It is widest (3/4 mile) at the northeastern edge of the map, and ean be traced thence for two miles southwestward, beyond which no exposures were seen. The rock is essentially a valley- maker, although it rises half-way up some of the adjacent hills, Fitch Hill being one of these (Sec. A, fig. 3). In the field the eneiss can be followed northeastward for more than a mile beyoud the border of the map. In passing across this belt, one finds that the rock gradually changes from a dark, hornblende-bearing, northern facies to a lighter, hornblende-free, southern facies. The petrology of these two phases will be described separately. Northern phase.—In its northern outcrops the Fitch Hill granite gneiss is a fine-grained (average size of grain, 1/16 inch or less), dark gray or greenish gray rock, composed essentially of quartz, feldspar, and hornblende. The hornblende crystals are black, are more than twice as long as they are wide, and are without definite orientation. The feldspar is of a dirty pale greenish color. Sometimes a few very indistinct pheno- erysts of this mineral are present, and rarely these are pinkish. The quartz is inconspicuous because its grains are small and transparent. Fine chlorite and sericite may be observed, partic- ularly in those outcrops where there has been a little shearing. In thin sections the microscope reveals evidence of crushing. The quartz, which is more or less granulated, has wavy extine- tion. Among the feldspars, orthoclase, microperthite, micro- cline, and plagioclase, ranging from albite to oligoclase, were * Geology of Northern New England, p. 15. Geology of New Hampshire, vol. ii, p. 327, 1877. + Ibid. + New Studies in the Ammonoosuc District of New Hampshire, Bull. Geol. Soe. Am., xv, p, 465, 1904. § Ibid., ’D. 465. Also, by the same author, Geology of Littleton, p. 13. | Lambert, A. E.: In New Studies of the Ammonoosue District of New Hampshire, p. 480. 4] Geology "of Littleton, p. 54. Am. Jour. Sci.—FourtH SERIES, VOL. XXXVI, No. 213.—SEpPTEMBER, 1913. 16 236 Lahee—New FHossiliferous Horizon and Underlying recognized ; but they are nearly always much decomposed. Epidote and sericite, disseminated through the decaying min- erals, are most abundant as alteration products. A little calcite, oo > TB8E a 900 > + + S05] [>= 5} [47 oR % . ~ wu on wy c 4 Rg) GS ke el 3 S b= a us a a Se eas % Q a ~ Wy | yp eay (Sa HIG. 3: +Hetee tt ttt fete ett +t tts +eeeette eet t trt+ + +tr+et + , B-B, C-C, and D-D, the positions of which are indicated on the ma /300-N 1200_ B schislS Contorted EE Limestone 1000 Fie. 3. Sections A-A The horizontal scale is the same as that given in fig. 4. ed sites I) Banded ates which has crystallized between the grains of the rock, may have been derived from the lime-bearing feldspars. Having no sign of decay nor of distortion, and being moulded against or around the quartz and feldspar particles, the hornblende is aoa 237 fiocks, in Littleton, New Hampshire. 'e ‘SY UL Jey} SY OTILS 94} ST SUOTJOOS OS0Y4 OJ puede, CUT, “A-A PUR W- SUOTPO9G ‘Pp “HIY 99} UL I¥OS [eIUOZIIOLY 0002 000/ 0 dew fo ABRAT yynos dong Baa oT Ney) )3 )} HB : : Hi 00/1 CENA NE he a Ogre he ‘7 Old It is often twinned in mul- of decomposed biotite flakes ap- gin. he remains 1 probably of metamorphic ori rE tiple fashion. 238 Lahee—New Fossiliferous Horizon and er pear as bent and twisted shreds of colorless micaceous material, associated with minute grains of quartz and epidote. Southern phase. —The southern phase of the Fitch Hill granite gneiss is of rather coarse grain and is of a medium grayish tone, with light pink or flesh-colored crystals of feldspar. It is lighter in color and coarser than the northern type. Here, — too, the quartz is not conspicuous. Frequently the structure is indistinctly porphyritic, and then the pink feldspars become phenocrysts with blurred edges. Many are twinned according to the Carlsbad law. Chlorite is always present, not as clear- cut individual flakes, but as irregular patches formed by many minute flakes. In some specimens chlorite occurs, together with sericite, as small, separate flakes, both micas being 1 meta- morphic in origin ; and in such cases the chlorite is more abundant the oreater has been the shearing. No hornblende was seen in the southern phase. Many of the features observed in thin sections of thenorthern phase are characteristic of the southern. The quartz shows crushing and straining. The feldspars—orthoclase, micro- perthite, plagioclase, and a little microcline—are much altered. Of these the plagioclase preceded the others in time of develop- ment. Chlorite is in aggregates, accompanied by quartz, calcite, and epidote. Its form suggests derivation from pio- tite rather than from hornblende. Variations in Mineral composition.—Five specimens of the gneiss were selected from as many different localities. Specimen 106 came from Loc. 10 (see fig. 2). Sp. 302 came from Loc. 5. Sp. 245 was taken from an outcrop not repre- sented on the map. It belongs to the southern facies. Sp. 447 was obtained a few feet south of Loc. 2; and sp. 448, belong- ing to the northern phase, came from an outerop northeast of Loc. 2, just off the map. Thin sections of these specimens were examined and the percentage of the constituents was esti- mated by thorough measurements according to the Rosiwal method. To be sure, this kind of analysis, when applied to rocks of low metamorphism, and, therefore, of incomplete recrystalliza- tion, introduces errors which are large compared with chemical analysis; but it does bring out the relative abundance of the minerals clearly enough for general purposes. The feldspars are not here classified by species. They are so much decayed that an attempt to distinguish them speciti- cally, for quantity determinations, would be fruitless. The results of the analysis are tabulated below : Rocks, in Littleton, New Hampshire. 239 Per cent | Per cent |Per cent Per cent iron- = Seas Total. quartz. | feldspar.) calcite. | bearing silicates. eee Southern phase. Sp. 106 | 27°08 52°93 0 Chistes) 7 19-97)" 19°97- | 99-98 Sp. 302} 18-42 61°79 0 |Chlorite: 19°59 Epidote : OASr ie NO 77s 99-98 Sp. 245 26°20 46°20 7°05 Chlorite : 20°54 20°54 =| 99°99 Northern phase. Sp. 448 | 21°16 57°44 -06 =| Chlorite: 1°89 Epidote : 4°84 Hornblende: 14°30 | 21:03 | 99°99 Sp. 447 | 14:98 61:07 “17 | Chiorite : 3°11 Epidote : o°99 Hornblende: 16°66! 23°76 | 99°98 Average for southern phase : | 23°9 | 03°64 | 2°30 Ohisctaeny 20:02 lapidate « 06| 20-09 | 99-98 Average for northern phase: 18°07 59°25 Chlorite : 2°50 Epidote : 4-41 Hornblende: 15°48 22°39 | 99:97 "26 The above table shows that the northern phase has a lower percentage of free quartz than the southern phase, a higher percentage of feldspar, and a slightly greater percentage of iron-bearing silicates, although hornblende comprises the larger proportion of these silicates in the northern type, and chlorite in the southern. Hornblende is quite wanting in the southern facies. These facts suggest a certain amount of magmatic dif- ferentiation in the original granite magma, either by an increase in acidity toward the southern boundary or by an increase in basicity toward the northern boundary. Intrusive contact with the Lyman schists—We can dis- cover in the literature no mention of the relation of the Fitch Hill granite gneiss to the Lyman schists. Although the con- tact is actually exposed in many places, it is so obscure on account of metamorphism and weathering that its study requires more detailed search than was possible under the con- ditions of the earlier geological surveys. When carefully examined, this contact is seen to be very irregular. The granite gneiss projects into the schists in the form of blunt apophyses or as short, narrow dikes. Most of these intrusive tongues are of fine grain; but a few are peg- matitic, sometimes with quartz and feldspar crystals an inch or two across. Angular fragments of the schist are occasionally seen entirely included within the gneiss. Add to these state- ments the fact that the oneiss usually grows finer toward the 240 Lahee—New Fossiliferous Horizon and Underlying schists, and there can be no doubt that this Fitch Hill granite gneiss is intrusive into, and therefore younger than, the Lyman schist group. Onconformable contact with Blueberry Mountain Series. —At the southern contact the conditions are very different from those on the north. Here the gneiss rests against a body of sedimentary rocks which are much less metamorphosed than the Lyman schists. The lower members of this sedimentary series are known to be of Niagaran (Upper Silurian) age.* They were formerly called Helderbergian. While the southern contact region does receive some men- tion in the geological literature, the references are vague. Lambert wrote that the granite gneiss “broke through” the sediments.t Hitchcock in one placet says it ‘‘ cuts off” the “Helderberg.” Elsewhere he says it “may be followed to close contact with the limestone” (Niagaran);$ and again, ‘Below and in contact with the fossils on Fitch Hill the rock is a chloritic foliated granite.” On the same pagel we read, the “‘synclinal in Littleton rests on igneous materials” ; and here, too, we find the suggestion of an unconformity in the words ‘‘ basal limestones,” meaning the Niagaran limestone. We made as minute an examination of this contact as we did of the northern one. No dikes nor apophyses of any sort pass from the gneiss into the sediments, and, while the contact has several broad and often deep jogs or indentations, it is essentially straight. The granite gneiss sometimes remains coarse quite up to the sediments. More often, however, it grades into a somewhat finer rock. In one place where the gneiss adjoined this finer rock, the former seemed to pass into the latter by concentric layers about a roundish projection of fresh gneiss (see fig. 5). There were several such bowlder-like masses of fresh gneiss partly or wholly wrapped in layers of the same material, more and more.weathered outward. From these facts and from a microscopic inspection of the ‘finer rock,’ we have been led to infer that this contact is an uncon- formity ; that the granite gneiss, preceding the deposition of the Niagaran, broke down, by disintegration without much decomposition, into a feldspathic gravel or coarse sand, now an arkose (the ‘finer rock’); and that in some places we have the original spheroidal weathering preserved and bevelled across by the present land surface (fig. 4). Further support of *See Hitchcock’s Geology of Littleton, pp. 4-6, and his New Studies in the Ammonoosuc District, p. 462. + Lambert, A. E.: A Trilobite from Littleton, etc., in Hitchcock’s Geol- ogy of Littleton, p. 34. { Geology of Northern New England, p. 15. S$ Geology of Littleton, p. 17. | New Studies in the Ammonoosuc District, p. 465, , Locks, in Littleton, New Hampshire. 241 these conclusions depends on certain characters of the overly- ing (to the south) Blueberry Mt. sediments, which we shall describe below. Since the northern contact of the Fitch Hill granite gneiss is intrusive in its nature and the southern contact is an uncon- formity, (1) the original differentiation must have been one of increasing basicity toward the margin (northward), and (2) the age of this granite gneiss must be intermediate between that Bre2):! Fie. 5. Fossil concentric weathering. The rock in the right foreground is the Fitch Hill granite gneiss. It is partly surrounded by layers of the disintegrated gneiss, which have been reconsolidated since the time when the weathering was in process. The hammer stands on arkose which was a. from the completely disintegrated products of the gneiss. Photo by of the Lyman schists and that of the Niagaran sediments on the south. The Blueberry Mountain Series on Fitch Hill.—Blueberry Mt. is regarded as a synclinal ridge.* The base of the * Hitchcock : Geology of Littleton, p, 15. 942 Lahee—New Fossiliferous Horizon and Underlying sedimentary series which forms the fold appears in the region above described, where the lower strata rest unconformably on the Fitch Hill granite gneiss. It is interesting to notice that Hitchcock mentions an unconformity on the southeastern side of the syncline about seven miles southwest of Fitch Hill, northwest of the town of Lisbon, where the Blueberry Mt. argillites meet the Swift Water series, a formation supposed to be equivalent to the Lyman schists and associated rocks on the northwest side of the syncline.* In passing southward from the Fitch Hill granite gneiss, crossing the strikes of the strata, one encounters in succession (going upward, stratigraphically) (1) the basal arkose already mentioned, which may grade locally into quartzite beds (2-80 feet thick); (2) limestone carrying fossils of Niagaran age (30-40 feet) ;+ (3) calcareous slate, also with fossils of Niagaran age (6-10 feet ; (4) non-fossiliferous limestone and slate (150 feet)*; (5) basic sill (thickness uncertain ; not great); (6) thick mass of arkose forming Fitch Hill and therefore called the Fitch Hill arkose to distinguish it from the basal arkose (Z00— 300 feet); (7) basic sill (200 feet); (8) banded argillites (450— 500 feet); (9) dark gray sandstone with dark shale layers (to the crest of Blueberry Mt.).t The first four and the sixth members we have called the ‘ basal series.’ Our measurements for the thickness of the basal series, exclusive of the sixth member, amounted to between 150 and 250 feet. Further proof of the unconformity beneath these sediments is presented in the character of the basal arkose. This is a hard, compact, gritty rock, usually without the least indication of stratification. In one or two outcrops, however, a faint streaky appearance, striking and dipping parallel to the strata on the south, suggests that there was a very slight tendency toward sorting of the disintegration products of the granite gneiss in the encroaching Niagaran sea. The feldspar grains, ranging in size up to 3/16” or 1/4” in the longest dimension, are so conspicuous on account of their white color that they often give the arkose a porphyritic look. They are of the same kind as the feldspars in the Fitch Hill granite gneiss (orthoclase, microperthite, plagioclase, and some microcline). The quartz, together with a very little chlorite, constitutes a dark background for the feldspar. In thin sections the quartz is seen to be cracked and strained. Secondary calcite occurs as veinlets and fillings between the other minerals. As arule the feldspar in the basal arkose is nearly as abun- dant as the quartz; but in a few places the latter becomes rela- * Hitchcock : New Studies in the Ammonoosuc District, p. 478, and fig. 8 on plate 42. + Hitchcock’s figures. t Called ‘ dark gray schists’ on the map. In ea ss Rocks, in Littleton, New Hampshire. 243 tively so much more plentiful that the rock must be called a quartzite. It is then very hard and white. Ordinarily such quartzite beds are not more than five or six feet thick and do not extend more than twenty or thirty feet along the strike. They are purely local. Above the quartzite or the arkose, as the case may be, and sometimes very near to the granite gneiss, is the limestone that earries fossils of Niagaran age. This limestone is of a bluish gray color and is crystalline. Since we found that it had cer- tain peculiarities which marked it as different from other lime- stones with which we had been familiar, we studied it carefully. In an outcrop just east of the upper right corner of the map (fig. 2), two types of limestone were observed, one fine-grained and faintly banded and the other coarse-grained. ‘These two kinds occurred as separate, pebble-ike bunches, apparently lying in all attitudes (banding), and enclosed in a thin paste of fossiliferous calcareous shale. So small in quantity was the paste and so similar tne colors of the two types that, with three or four exceptions, the outcrop as a whole seemed to be com- posed of uniform limestone. These exceptions were rounded pebbles of granite, contained, as the limestone ‘ bunches,’ in the fossiliferous shaly paste. The granite of these pebbles looked strikingly like the Fitch Hill granite gneiss. Many of the limestone ‘bunches’ held erinoid stems, but no other fossils. In the shale paste, however, were numerous remains resembling Stromatopora, Syringopora, and Favosites. On Fitch Hill, where Section A is drawn, the conglomeratic nature of the limestone is not so evident; but there are indica- tions of it. In this connection it is interesting to note that there are occasional scattered, lenticular hollows, elongate parallel to the strike of the formation, in the basal arkose, even as much as ten feet below its upper limit. These little hollows (average: 8” long, 2” wide, 5” deep) are isolated pieces of limestone, weathered several inches below the surface of the outcrop. They are identical with the ‘ bunches’ in the eastern outerop just described. | Now, these observations, if correct, point to limestones of two geologic ages in the Ammonoosue district. Indeed, our investigations in other parts of the region have led us to believe. that some of the limestones hitherto mapped as “ Mid-Upper Silurian” * contain crinoid stems, but no fossils distinctly of Niagaran age. This matter will bear more thorough study. The fossiliferous slate (third member) is dark gray and cal- careous. It has no particular importance for us, and will not be described at greater length. Overlying this slate are the non-fossiliferous limestone and * Hitchcock : New Studies, etc., plate 43. 244 Lahee—New Fossiliferous Horizon and Underlying shale beds, concealed for the most part by the vegetation. And stratigraphically above them is the second great mass of arkose, the ‘ Fitch Hill arkose.’ Just what structural relations this rock has to those underlying, we cannot say. Contacts are not exposed. It appears to be in conformity. It is very like the basal arkose,—hard, dense, and spotted with white grains of feldspar which compose about half of the rock. It is more uniform in texture than the basal arkose, its grain averaging 1/15.” No signs of bedding nor of limestone inelu- sions were seen. Microscopically, also, it is similar to the lower arkose. Both of the sills are composed of a coarse, massive, unsheared rock, formerly consisting of hornblende and plagioclase. The hornblende has been replaced .by zoisite, calcite, and chlorite. These intrusions grow much finer toward their upper and lower contacts. In spots they have metamorphosed the sedi- ments. The Fitch Hill arkose is overlain by a thick body of nicely banded mudstones or argillites. The bands, of lighter and darker gray, are from 1/2 inch to 3 inches wide, and may be traced for many yards. The lighter bands are fine argillaceous sandstone, and the darker, medium to fine-grained mudstone. They are very regular, but sometimes show local crumpling on a small scale. Neither this formation nor the overlying dark gray sandstone are of immediate concern for us. Their importance will be explained later. Geology of the Blueberry Mountain Series Southwest of Fitch Hill. Distribution.—We have previously stated that the Lyman schists pass off the map (fig. 2) and that the Fitch Hull granite eneiss narrows and finally disappears southwestward. On the northern side of Fitch Hill the limestone is a valley- maker (not shown by the contours). Without entering into great detail of description; we may say that this limestone is thought to underlie the valley which is just northwest of Blue- berry Mt., Bald Hill, and the hill m the extreme western . corner of the map. This valley contains Young’s Pond. Asso- ciated with the limestone are the other members of the basal series; but there are exceedingly few outcrops of these rocks. Locality 26 (sec. D, fig. 3) is an outcrop of coarse feldspathic grit resembling the Fitch Hill arkose. Half a mile southwest of this a large glacial bowlder of conglomerate, with ten or twelve limestone pebbles in it, was found; and calcareous schist is exposed a few hundred feet away. Limestone and calcareous grits outcrop at Locs. 42 and 43. Here the lime- Rocks, in Littleton, New Hampshire. 245 stone is in thin, long lenses between thin calcareous shale layers. The limestone has been dissolved down several inches below the level of the shale (fig. 6). The sills of Fitch Hill soon disappear and can be traced no farther. The banded argillite of Loes. 8 and 9 cannot Be definitely followed. A similar rock outcrops at 17 and 18, and also at ‘Loes. 25, 28, 29, 30, 31, ete. Locs. 14 and 15 are dark oray slate. Locs. 19 and 20 are coarse conglomerate, traced 200 or 300 yards along the strike, but no farther. Fie. 6. Fic. 6. Differential weathering. The limestone layers have been dis- solved out, leaving the argillaceotis layers projecting as ridges. Photo by MroRy Ww. Sayles. The banded argillites of Locs. 25 and 28 are easily followed southwestward in a belt which runs, parallel to the strikes, along the crest of Bald Hill, to the east of Young’s Pond, and over the hill in the southwest portion of the map. In the northeastern localities this rock is like that in the Fitch Hill section, although perhaps a little coarser. It is similar, too, at Loes. 34-39. At 41, and to a more marked degree at 44 and 45, itis finer; and southwestward beyond the border of the map it becomes very fine. Accompanying this change of texture is also an increase in metamorphism. The more north- ern specimens are hard, but are scarcely sheared. Southwest- ward the content of secondary mica increases until, in the southwest, just off the map, the rock is a fine sericite schist or phyllite. The entire Blueberry Mt. series of sediments dis- 246 Lahee—New Fossiliferous Horizon and Underlying plays, although not always so obviously, the same southwest- ward advance in metamorphism. Structure and correlation.—That Blueberry Mt. is thought to be synclinal in structure has been stated before. This conclusion is based, not so much | upon an inverse succes- sion of well-marked str ata, as upon the exposure of pre- Niagaran rocks which are nearly identical on opposite flanks of the ridge. We are unable at present to locate the axial region of this fold. For some reasons it seems to be in or near the long belt of banded argillites. Dips (which have been omitted from the map) are usually steep, so steep, indeed, that varia- tions in direction within the area mapped are probably due to local contortion rather than to actual synclinal or anticlinal folding on a small scale. Below are listed the dips for those localities where the attitude of the bedding could be obtained : Locality Dip Locality Dip 6 80° southward. 34 80° northward. a He Ge 35 70° southward. 8 TOs : 36 60° ee 9 60° 3 a oe ee 18 60° oe 38 Be ee all 80° ie 39 (aya Oe BD TO- oe : 4] 60° northward. De 85° ue 49, 80° southward. oT 85° cs 43 80° ni 28 70° northward. 44 80° northward. 30 Woe ne 45 80° ee ol om “ As regards the relations of the Fitch Hull exposures of banded argillite, we cannot now say whether they are continuous with the outcrops at Locs. 17 and 18 or with the belt including Loes. 25 and 28. Various conjectures might be made. 22-- 2). =) ee . MIG Sandrock, massive below, but straticulate above, with some clayey seams. Forms prominent ledge on both of Jar@e, stems ol trees! 2.2 eee ote i565 ae MS Shales somewhat nodular below, but not above. Hasily eroded, and because followed by hard shell rocks and limestones above, responsible for sharp turn of barranca at a right angle. [The course of the barranca follows this soft horizon for about 200 meters and then breaks through the harder rocks above along the course of a small fault with a throw of about a meter or less.] Marine Liassic-Odlitic superposition. M. 5 Principal Totals. Meters. Entire thickness of the plant beds by the preliminary measurements with allowances for lesser faults, JZ. 600, the-corrected total being 945227 2= == 22 ee 567 . Height of horizon of the Williamsonia Nathorstii casts above eruptive floor: 2 22232. 2) geo = eee 85 . Height from eruptive base to the principal coal seam horizon with Meggerathiopsis, Otozamites Mandelslohi and other broad short-leafed Otozamitans with Ale- thopterids, éte.. 2.22222) ee ee ee 100 . Base of plant beds up to Otozamites hespera zone and approximate horizon of silicitied Araucarioxylon log... 240 . Approximate thickness of lower plant beds.--=-------- 250 Base to the main Williamsonia horizon....-----.----- 350 * xx ** * ** 2 * * * The interpretation of the foregoing measurements is in the light of the plant occurrences entirely simple. It is obvious that coincident with land emergence there was a more or less G. R. Wieland—On Liassic Floras. 261 differentiated series of oscillatory subsidences, which increased to a maximum at the time of the deposition of the quartzose con- glomerate No.61. Meantime, the subsidences, followed locally by conditions of moderately quiet waters with shore distance and depth suitable to the deposition of plants in fine muds, were very frequent. They were marked by the laying down of abundant plant remains and where pronounced of coal.* With the later sharp encroachment of the odlitic seas following the deep water bed No. 67 the formation of sheil limestones with alternate marine or semi-marine sandstones begins, while later still, the deep Jurassic and Cretaceous oceans entirely transgressed the plant bed region. That the history of the plant beds consists in a single unit is not believed ; even if relatively short, there may have been three, if not four, series of events involved in their deposition. But it seems much the more scientific method to avoid hasty and perforce arbitrary methods of division, whether resting the case on either the plant or the physical record as now known. And it must be far preferable to use, for the time being, the purely tentative demarcation into lower and upper beds and await the accumulation of exact evidence as to the actual course of deposition and floral change. B. Composition, Age, and Source of the Mixteca Alta Flora. In further comparing representative Jurassic flore like those of Italy, Bornholm, Yorkshire, India, and California, it seems that the age usually assigned to the plants of these several regions is in the main correct. That is to say, however uncer- tain in their application, however illy defined and variant may be the methods for determining the succession of the earlier Mesozoic floree, the general mode of procedure is at least fairly enough understood and agreed upon to yield approxima- tions to the true age. But aside from exigencies of fossilization, climatic varia- tions, and rates of migration or dispersal, all comparisons of * Neither the position nor local trend of the land masses which furnished the fossil plants of the Consuelo section has been worked out. The plant beds may indeed lie near toalong, approximately east-west shore line. But, in any event, there is much doubt if the coal seams, always or ever, indicate swamp bottoms. The comminuted condition of much of the plant material of the coal seams may as well indicate flotation of rafts into deeper waters as Swamp bottom conditions ; while the fine clays, which are so generally intermingled and alternate so often, may mostly be the result of sedimenta- tion in deeper waters. Fortunately, we may presently expect some direct information as to the nature of these coals, the Instituto Geoldgice having, through the courtesy of the director, Sefior Villerello, arranged to send a complete series of the Mexican coals to Professor Jeffrey of Harvard for study by the highly effective methods of thin sectioning he has developed. 262 G. R. Wieland—On Liassic Floras. such widely separated floree as those cited are doubtless further obscured by the fact that any given flora may be old or young for the region in which it occurs. A plant facies may be either juvenile or senile. Thus, as will be further cited below, it is strongly suspected that the plants of the Inferior Odlite of the Yorkshire Coast are old, are really a left-over Liassic _..-_Anetic Cnde Cancer . 150° _ Capricorn A : Antarctic Circle ane at Fic. 2. Principal Triassic and Jurassic plant localities of Western Europe and the extra-arctic Americas. [Disks] denote early, and circles later Trias, solid black stars, early, and outline stars later Jura. The arrow points out the newly discovered Mixteca Alta horizons of Mexico, where 600 meters of Liassic strata have been measured and true Triassic plants are also believed to occur. These plant beds are widely extended over the region stretching westwardly from the valley of the Nochixtlan river in Oaxaca to Tlapa in the state of Guerrero (or further), and northwardly into southern Puebla. rather than a typical mid-Jurassic facies. For these plants may readily have been existent during the deposition of the G. R. Wieland— On Liassic Floras. 263 underlying “ Midford sands.” These contain, at their top, the famous Gloucestershire “ Cephalopoda beds,” and do not yield fossil plants. Furthermore, they are recognized as transition beds, and sometimes actually assigned to the Lias. Contrariwise, as will presently appear, the more critical comparison of the Rajmahal Hills flora with that of Oaxaca indicates the latter to be essentially juvenile, there being distinct reason to believe that as the study of this prolitic region for fossil plants goes on, evidence is likely to increase that the plants in the lower portion of the beds were fossilized soon after their incursion from the North or South, or scon following the rapid local development of new species. At least, taking the Mesozoic as a period of marked changes in plant facies, there must be a certain significance in the persist- ence amongst the Oaxacan plants of certain old elements, which in longer established floree might be mostly eliminated. Admittedly, however, the conclusion here reached can only - have a tentative value, since in the absence of inherent evi- dence of geologic age such as many types of Jurassic plants fail to reveal in the present state of our knowledge, it may - even prove uncertain whether given groups of plants which appear most alike, are of the same age or not. All that can be done safely is to surmise or approximate. [or not only are the chances in all cases very great, that any two such widely separated flore are not exactly synchronous; but however strong their resemblance, there is this ever-present possibility that one is old and long established, the other young or recently established, and undergoing change. The lack of various old types in the first case and their retention in the second would, of course, give a clear result if we knew the Jurassic plant succession better. In general it seems clear that the pulsations or waves of plant evolution marking successive epochs must have had their dawn, their high noon, and their eventide, and that extinction, in any period, must also have had its initial, maximum, and minimum phases; though it is even clearer that, locally, the problems of plant age and dispersion soon pass beyond the known facts of homotaxy, and that they involve factors of the utmost difficulty. But without further outlining these obviously severe limi- tations to accuracy in assigning the age of fossil plants, it will be most convenient, as a prelude to such discussion of the age and source of the Oaxacan plants as can be given, to first range the species alongside their nearest old world counterparts, as is done in the appended Table I. 264 G. R. Wieland—On Liassic Floras. Taste L—Recapitulary Table of the Mixteca Alta Flora showing | Kelationships to the most nearly allied previously known Flore. Mrixteca ALTA SPECIES. Anomozamites Lindley- anus var. Cycadeospermum oaza- acensis Cycadolepis mexicana Otozamites cardiopter- OU CS ae Resi seine ee Otozamites hespera. Otozamites hespera var. intermedius. Otozamites hespera var. latifolius. Otozamites paratypus. cy Muandelslohi Otozamites Molinianus var. oaxacense Otozamites obtusus L. é& H. Otozamites n. var. Lias- SUGCUS EN ee eee Otozamites n. var. oax- acense Otozamites Reglet n. var. lucerensis Sree ree ee ae oe Otozamites (William- sonia) Aguilariana __ Otozamites (William- sonia) Aguilerit. Otozamites (William- sonia) Diaz. Otozamites (William- sonia) Juarezit. Otozamites (William- sonia) oaxacensis. Otozamites (William- sonia) tribulosus. Pterophyllum ef. con- liguum ---- oe Pterophyllum Miinsteri Pterozamites phyllum) folia ( Ptero- angustt- RECURRENT SPECIES. AFFILIATED FORMS. Otozamites Mandels- lohi, Lias: Continen- tal Europe. -- ee ee ee ee we et ew eee eK Pterophyllum ~ Miin-- steri, Rhitic, Conti- nental Europe Pterozamites angusti- folium [Early Juras- sic]. Anomozamites Lindleyanus, Lias : Europe, and Sripermatur. Cycadeospermum [or Cycadospa- dix]: Liassic on. Cycadolepis, Lias: India, ete. * Otozamites Beant Brongn., York- shire. Otozamites Molinianus, Lias: Southern Europe and Bornholm. Otozamites obtusus (Lias of York- shire). Otozamnites obtusus var. Odliticus, Lias: Yorkshire. (a) Otozamites Reglei European Lias. (b) Otozamites Hislopi, Jabalpur group. (c) Otozamites terquemt (infra- Lias). Williamsonia gigas, Yorkshire coast and Continental Hurope ; Odlite or older. Pterophyllum contiguum, Rhatic, Europe. Pterophyllum Miinsteri, Rhitic of Tonkin. G. R. Wieland—On Liassic Floras. 265 TasBLE I—(Continwued). Mixteca ALTA SPECIES. RECURRENT SPECIES. Ptilophylium acutifo- lium ef. var. mazxi- 101, S771 a oars ae ce Ptilophyllum acutifo- lium nov. var. minor) Ptilophyllum Te ee eae Stangerites oaxacense - pulcher- Williamsonia [fruit Romes| = 95. 2. .=.- Williamsonia [stem 2h ics Se Williamsonia mexicana Williamsonia Na- oi SS ~ Zamites cf. confusus -- Zamites Rolkeri Araucarioxylon mexi- cCanwuin Phenicopsis sp. ------ His- Neeggerathiopsis lopi Yuecites 1ANUS Schimper- Trigonocarpus RASC ss 52.95 oe SS Rhabdocarpus grandis Alethopteris mexicana - OAxA- Cladophlebis Albertsii _ Coniopteris ef. hymeno- pehyllowdes . 2.02 Dicksonia (Sphenop- teris) ef. bindrabu-| nensis Glossopteris linearis | _- 2eere - ee ee ee ~~ ee ee ee ee ]weeeew-- ee ee ee ee ee ee Lee ewer er ee || - - -- eee ~ ee ee ee ee ee ee ee ee ec ee eH ee ee Zanvites Rolkeri, Trias of Honduras f Neeggerathiopsis His- | lopi. Rhetic of AFFILIATED FORMS. Ptilophyllum acutifolium var. max- imum, Gondwanas of India. Ptilophyllum or Williamsonia pecten, Yorkshire Odlite and Gondwanas of India. Ptilophyllum forms of India. Stangerites McClellandi, Upper Gondwanas and in European Lias 8. Haidingeri. Williamsonia, Yorkshire Oodlite fruit series. Williamsonia, Upper Gondwana stem series. Williamsonia whitbyensis, York- shire Odlite. Podocarya ovulate cone of Buck- land, Lias of Lyme Regis. J Tonkin, and Trias \- o£ -India, “South | America and Hon- | duras. Yuccites Schimperia- nus, Odlite of Eu- rope [Italy]. Cladophlebis Albertsii, European Weaiden. ? Glossopieris linearis, Upper Paleozoic of: Australia i Zamites confusus, mid Jura of Kurope. Otozamites Hislopi, Jabalpur group Upper Gondwanas. Araucarioxylon Lindleyi, Lias of England. Phenicopsis of Kuropean Lias. Trigonocarpus [ Paleozoic]. Rhabdocarpus [Permian]. Alethopteris forms of Huropean Rhatie. Coniopteris hymenophylloides. Dicksonia bindrabunensis, Liassic of Rajmahal Hills. Glossopteris angustifolia, Rhatic of Tonkin. 266 G. R. Wieland—On Liassic Floras. TABLE I—(Continued). MixtTeca ALTA SPECIES. RECURRENT SPECIES. Glossopteris mexicana - Togeopteris (2) eee == | Sphenopteris cf. VUMUSONT 2a oe no oe Sagenopteris rhoifolia var. Mexicana Teeniopteris cf. Dane- oides Tceeniopteris Zeilleri _- we ee - - ee -- ee He Teeniopteris cf. vittata. Equisetites (Calamites) Gimbeli - y= ee eer ew we ewe ew He we ee ew eK KK Laccopteris near L. Miinsteri in Trias of Sonora mje em ee ew ee ee Treniopteris Zeilleri, — Rhitic of Tonkin. Equisetites (Calamites) Gimbeli, Upper Trias of Franconia. AFFILIATED FORMS. Glossopteris indica, Rhiatic of Ton- kin. Laccopteris Mimsteri, Rhatic, Europe. Sphenopteris Williamsoni, Infer- ior Odlite of Yorkshire. Sagenopteris rhoifolia, Rhiatic, Europe. Teniopteris Dancoides, Damuda Division, India. Teniopteris vittata, Yorkshire Lias, Great Oélite. (a) Composition of the Mixteca Alta Flora. In interpreting Table I it is primarily necessary to recall that in the plant beds outcropping on the Barranea Consuelo the most of the coal occurs near the middle of the lower half of the whole thickness of 550 or more meters; while the coal is followed in the upper portions of the lower half of the beds by a well-marked series of alternating ferruginous sands, shales and grits, during the deposition of which changes in the flora seem to have mainly occurred. And it is here that the older types of ferns and the Cordaiteans appear to drop out. At any rate it becomes worth while to further range the plants of the lower half of the beds side by side with those of the upper half, recalling that the greatest comparatively barren stretches in the great section of the Barranca Consuelo plant beds oceur in the initial and final hundred meters. aainle die See the appended On scanning Table II several most interesting facts appear. In the first place it is most surprising that so few of the species ot the lower half of the Consuelo section continue with cer- tainty into the u pper half. And this fact, surely not entirely due to the fortunes of collecting, appears the more unexpected since any division of the beds of the section into a lower and upper series would be quite arbitrary. However there are observable some changes in dip and deposition, and that con- tinuation of study afield which is always urgent may yet reveal more than a single unconformity. Lower 250 METERS. Anomozamites cf. Lindleyanus (T.) | Otozamites hespera. Otozamites hespera var. intermedius. Otozamites Mandelslohi. Otozamites Molinianus. Otozamites paratypus (T.) Otozamites obtusus var. Liassicus (T.) | Otozamites obtusus var. vaxacense. Otozamites (Otopteris) sp. Otozamites Reglet (variety). Otozamites (Williamsonia) tribulosus. Pterophyillum cf. contiquwuin. Pterozamites (Pterophyllum) angusti- folia. Stangerites oaxacense. Williamsonia fructifications : W. Huitzilopochtli (M). W. Mexicana. W. Tlazolteotl. W. Xipe (1M). W. (species). Zamites confusus (var. ]. Zamites Rolkeri{Puebla). | Araucarioxylon mexicanum. Neggerathiopsis Hislopt. Trigonocarpus oaxacense, Rhabdocarpus grandis. Alethopteris mexicana. Laccopteris (?). Sagenopteris rhoifolia var. mexicana. Equisetites (Calamites) Giimbelt. | G. R. Wieland—On Liassic Floras. 267 TABLE I].—Occurrence of Plants in the Rio Consuelo Section.* Upper 300 MeTERs. Cycadeospermum oaxacense. Cycadolepis mexicana. | Otozamites cardiopteriodes. | Otozamites hespera var. latifolius. | Otozamites Reglet var. lucerensis. | Otozamites (Wiliiamsonia) Agutlari- and. | ° . . . ° os | Otozamites (Williamsonia) Diazii. Otozamites (Williamsonia) Juarezii. Otozamites ( Williamsonia) oaxacensis. Ptilophyllum acutifolium var. maxi- mum. Ptilophyllum acutifolium var. minor. Ptilophyllum pulcherrima. Pterophyllum Miinsteri. Williamsonia fructifications : . Centeotl. . Cuauhtemoc. Ipalnemoant, . Nathorstit. Nezahualcoyotl. . Quetzalcoatl, . Texcatzoncatzl, . Tlazolteotl. . Xticotencatl. PEEEEEEEE | (Williamsonian stems). | Pheenicopsis sp. | . . . Yuccites schimperianus. Yuccites schimperianus var. oaxa- cense. Cladophlebis Albertsii. Coniopteris cf. hymenophylliodes. Dicksonia (Sphenopteris) cf. bindra- bunensis. | Glossopteris linearis. Glossopteris mexicana. | Sphenopteris ef. williamsoni. Teeniopterois cf. dancoides. Teeniopteris Zeillert. Equisetites (Calamites) Giimbeli. Secondly, the distinctly greater proportion of cyeads in the initial two-fifths of the section was scarcely to have been expected. But notwithstanding the differences noted, there is a general unity and resemblance in the two series of plants. ‘The most important fact brought out by grouping the plants as in Table II is, of course, this greater proportion of cycads in the lower half. Taking the beds as a whole, they contain the largest cycadophytan element yet reported, and the fact *The only species arbitrarily included in this section are several frond types from the Tlaxiaco River, marked T., fruits from Rio Mixtepec (M.) and one Puebla species. Am. Jour. Sci.—FourtH SERiss, VoL. XXXVI, No. 213.—SEPTEMBER, 1913. 18 4 268 G. R. Wieland—On Liassic a loras. that these plants culminate in numbers low down in the Seccion Consuelo, which is below shown to be typical Liassic, proves that,—wherever we find beds yrelding. 60 per cent or more of cycadophytans in fairly representative collections, we may confidently assign them to the very earliest Lias. I have already pointed out in my recent paper on the Wil- liamsonian Tribe that the Cycadophytan genera culminated in the Lias, and it may now be regarded as clearly established that the beginning of that period witnessed the maximum development of cycadeous plants in both variety and actual numbers. A further thought also comes to mind. While it is fortunate that we can here deal with an actual plant succession on a large scale, and while it is true that the species of the upper half of the beds do not vary greatly in general type from those of the lower, it is none the less reassuring to find that were the two | series found far separated, most paleophytologists would, with little doubt, reach a fairly correct deduction as to the true relative age. The presence of Veggerathiopsis in at least two distinct leaf species would in itself have some weight in favor of the greater age of the plants of the lower beds, while the rather older appearance of the accompanying ferns would scarcely be overlooked. And that such observations should have some value in aiding us to adjudge remotely separated geologic sections is fair to emphasize. Accordingly, the more general group proportions of the plants of the lower and upper half of the section are further compared by percentages in Table III. And following this suggestive table a similar comparison with more widely sepa- rated floree, interesting because of similar age or because of *- geographic position, becomes instructive. ” TABLE III.—Plant Grouping in the Rio Consuelo Section. Species in the Species in the | Entire section oe lower upper % e 250 meters 300 meters direct count Cy cad ‘7-2 7peaee (iS) 72557) (20) == 966 70 Ferns... 23) eel G7) \e 023 18 Cordaites, 2. si peeps 12?) [8] Conifers 22) s5a— Lecce 4 2 Hquisetums. . ---- (1) (lp: 8 2 Total species --| 25+ 30+ G. PR. Wieland—On Liassic floras. 269 In Table III several lesser rectifications are made, the princi- pal one being the cutting out of the most of the cycad fruits of the upper beds. Since but three to four characteristic William- sonian fruit species were found in the lower beds, it is better to take arbitrarily a similar number from the upper beds instead of the eight or ten’ species there found. By so doing, the comparison is made to rest on foliage forms as it mainly should, recovery of fruits being as yet more a matter of chance; while the number of species compared remains about the same because of the passage of Pterophyllum and Otozamites Regler forms from the lower into the upper beds. The great prepon- ‘derance of Cycadophytan frond species in the lower beds is thus brought out. And in fact it seems certain that this excess is more likely to be increased than diminished by future col- lecting. Most of the non-determinable material occurs in the lower beds, and it seems probable that they will always be found to contain from 6 to 10 per cent more cycad species than the upper beds. The apparent suppression of the ferns in the collections from the lower strata ot the plant beds of the Seccion Consuelo is, however, believed to be due solely to the fact that collecting has not progressed far enough to bring to hght as representa- tive a list as in the case of the cycads. That a list of ferns comparable in variety of species to that of the Yorkshire Coast odlites or the Bornholra Lias will yet be obtained, is deemed most likely; but that the cyeads will continue to form over half the recovered flora seems still more probable. They seem even to so sharply thrust the ferns aside as to suggest that be- tween the wane of the older seed ferns and the appearance of the modern fern genera there was an interim distinctly poor in ferns. (6) Relative Abundance of Cycadophytans in the Mixtecan Flora. As just pointed out, the great and dominant feature of the Mixteca Alta flora is its 70 percent of Cycadophytans. In fact these forms are so strikingly abundant that comparisons with other florge, made with direct reference to the cycads, are most desirable. These we shall proceed to give, after remarking that it seems improbable that future collection will markedly change the proportions observed. Indeed, evidence for the presence of various well-marked cycad species additional to those described [in my memoir] was at various times noted in _ the field. And, moreover, in my judgment, a distinctly if not over-conservative method has been followed in referring to a large proportion of the cycads collected as varieties, in order to avoid duplications of species which might later embarrass workers with more extensive material in their hands. Hence 270 G. R. Wieland—On Liassic Floras. I am disposed to give to every single species and variety of cycad foliage, and to every fruit illustrated, a full unit value. That we shall not be seriously misled in so doing is my con- fident belief; for despite all possible duplication of species due to dissociation of fruits from leaves to which they pertained, the abundance of cycadophytansis clearly extraordinary through- out the Mixtecan strata. In fact, without actual count of forms directly from the specimens, a matter of considerable difficulty, the general impression remains that probably 90 per cent of all the forms collected are leaves or fruits of eycadophytans. Whence there can be little doubt that whatever the increase in other tvpes as collection goes on, fully fifty valid species of cycads will be found in the .Mixtecan horizons, and probably many more. Qn listing the various forms so far definitely determined, the following percentages appear : TABLE I1V.—Rhdt-Liassic Flora of Mixteca Alta. Cycadophytans (10% Pterophyllums)...-. 42 forms == ee oes Oldtypess Sask SER Sai ie oe Cre =7Ad Modermmtypes!a2 ota eae: Sa al) Cordartes: 28 oe eee HekCrcr | on Ch ea ae 5+“ = 8 Conifers\(Arancamoxvlon);p 2522 22s 2aee Lee a Hiquisetumy) ccc) 9 aes sae ee eae aL as == He 60 forms 100 In considering Table IV it is to be noted that because of the large proportion of cyead fruits and a relatively poor conser- vation of ferns in most strata of the Consuelo section, already commented on, the fern element appears unduly small. There is probably, therefore, no very strongly marked departure from the usual Liassic fern proportion of about one-third of all the plants. recovered. But the drop from fully, or over, one-half of all plants in the Rhitic is none the less striking ; and although the ferns again seem to reach large relative num- bers with the accession of numerous recent types in the late Jurassic and Wealden, the Liassic displacement of ferns and dominance of cycadophytans is inescapably clear. These rela- tions at once appear from the summary (Table IVa) of the Rhatic flora of Tonkin, as so fully and thoroughly elaborated by Zeilier. TaBLe [Va.—Rheetic Flora of Tonkin. Henas, (mainly older. types) -..2 22 32ers 26 species = 48% Cycads (largely: Pterophyllums) {22 een lee = 33-5 Conifers (Hx. Nayggerathiopsis= Cordaites) 5 “ = 9 EQUUS SOUS eee. Le Bure ==. one GUM OR Pets: ay 2 hg Ls. Let viel = 2 54 species G. R. Wieland—On Liassic Floras. 271 Summarily put: In the Rhatic flora half of the plants are ferns or ‘“ Pteridosperms,” one-third are cycads, one-tenth are modern gymnospermous types; while the dwindling but still distinct Equisetum element forms a twentieth part, and Cor- -daites still persists.* In the Liassic only a strong third of the plants are ferns mostly of markedly modern type, while the cycads increase from 40 to 50 per cent of all plants and Equisetums and Cordaites tend to disappear with the advent of modern coniferous types. Obviously, as already inferred, the later Rhatic and early Lias witnessed some of the most profound changes known in the history of plants. In the Rhatic, then, diversity of Pterophyllums with the com- plete recession of the Equisetums and Cordaitaleans are the dominant features. But the old types of ferns, presumably still including many seed-bearing kinds, still continue to outnumber all other groups, and the displacement of the Cordaitaleans only seems to foreshadow the advent of the conifers, as yet far from abundant or well marked. The course of change as the Liassic advances is well indi- eated by the Borrholm and Yorkshire Coast floree, which are here appended in their proper order, and followed by a resumé in Table V, in which are also included the more recent floree of Graham Land and Oroville, along with the Rajmahal Hills proportions. TABLE I[V6.—Liassic Flora of Bornholm. Ferns (of old and modern type) .----.---- 27 apecies = 85°5% Cycadophytans (one-fifth Pterophyllums)_ 25 a= 38 ve CULL SIE: 2S Rg ASC Gal ad die ie ae ag Ny SPU REC Si ae ge a aoe ee A a Ba aan v5 = 9 MISE mMNNS 23 9s eee See oe So ol Aare = 5 76 species *Tt is instructive to go back a step further and note general proportions in the Lunz of Austria. This highly interesting flora has recently received the attention of Krasser, although yet lacking a final description. The Lunz flora of some 41 determined species consists of 44 per cent ferns, 39 per cent cycadophytans, 2 per cent conifers, 5 per cent Cordaitaleans, and 10 per cent Equisetums and Calamariales. The pre-Jurassic type of this flora is quite apparent when the large Equisetum element is noted, and it is suffi- ciently emphasized that the rather high percentage of cyecadophytans is due to the fact that the Pterophyllums culminate in the Lunz and thus form in that period the crest of the first wave of the Cycadophytan advance in the Mesozoic, which reaches its climax in the Lias. Similarly the litigious genera Ctenis and Pseudoctenis provisionally included in Cycadophytans g go to swell the cycad percentages of the Odlite. To fully understand the percentages one must hold such facts in mind. 272 G. R. Wieland—On Liassic Floras. TaBLE 1Vc.—Inferior Odlite of Yorkshire Coast. Berns {..5.-22-+..--. 2-22-2522 ee 20 sperics ae ne Cycadophytans). 2!» .\2.4).o. 2 eee 23 anaes = 048 CWoniters;and Ginko os -. mee eee De heets = ie Hquisetums .i4.-\. 4... 222 ee Di eae = 4 54 species TABLE V.—Elements of Typical Rhitic—Odélitic Flore. wR fe = os : an) %'s He “3 A Bus 5 SB ee Q felaelae2| Se | do |fe0| 42 18 NO ela eles & |Oom | eels Ferns .s2- |) 42.4 46 ueea7a) Bom ee 18 | 46 ee Cycadeans | 28 | 388 43 | 3838+ | 344 70. Be 40 Conifers -_| 2% | 12 ser sl 8 (2) 9 13 Ginkoos¢e|) =: 4 9 © om 2g 9+ Cordaites _| .- } .- ? ? ? 8 2 24 Equisetums| 2 | ? 4 5 2 2 5° 3 Before passing the comparisons afforded by the preceding tables, it may be mentioned that they show still more clearly the general course of change from Rhiatic to mid-Jurassic times when necessary modifications are borne in mind. Thus the percentage of cycads in the Bornholm flora is relatively lower, because not augmented by fruits; while the Yorkshire Coast cycad percentage would also be higher were the fruits more recently discovered by Nathorst included. In general there is, indeed, much of consonance in these figures, and it will certainly be of interest, as the species are from year to year augmented and revised, to make the necessary corrections as well as to add the statistics of other regions. Having brought to view the general composition of the Mixteca Alta flora and made clear the fact that it contains a relatively more mumerous cycad element than any other, we pass on to a further consideration of the indicated age. (c) Age of the Plant Beds of the Seccion Consuelo. In order to throw into strong contrast the course of change in early to mid-Mesozoic forest components and further illus- G. R. Wieland—On Liassic Floras. 213 trate both the advantages and the limits of the method pursued in determining the age of the Oaxacan plants, it will not be found amiss to take a hasty glance at plant proportions in the Lower Cretaceous—a rapid survey which has been rendered easy by Berry’s recent résume of the Lower Cretaceous floras of the world. | This more distant comparison with the Lower Cretaceous is not without tangible interest and may be given a concise enough form for interpolation. For this purpose Table Va has been prepared to show the main elements of twelve of the more striking Lower Cretaceous floras. TABLE Va.—Twelve Lower Cretaceous Floras. | = Ss = — o.| = & Bea Be Sie 3 om us| ey s alal al 8 elem de RL | b) = } | Ss %'s Ea oe Rel os ae S &p gs |e si aioe Pa e(BiSeiSe| a |Salge| 2 iso el al § SVa Sore sl a Salta eg pas) so | a | s S si/siaaex| = tesi6o| 8 (82 2/8/28] § | S|aj2F,2P] § eo a) 8 Mt) 5 | a] Ss = Paes Me Sa ae i tM) at | ath Werns ...--.- ADlasp or | oo | 40 | 54 | 47 1.32.) 17 145 28 30 | 40° Cyeadeans -.-|47/38| 35 | 33 | 21 | 18 | 10 | 25 | 38 |12 | 8 Sne3 Womrrens=-:__| 7|1t) 11.| 28 | 28 | 21 | 21 | 22 |.17 120 144 | 18 | 22. Pamceeperms= | 2) (2); =. | ...| =. | -- | -. } 17 0 10 + |12(?) Sen eee 70 | 21 | 88 | 88 | 95 1184 © 29 |75 123 | 66 No. of species: 28! 36 Naturally there are sharp limits to accuracy in so compacted a form of presentation. And, of course, the defectiveness of the plant record is much accentuated by the small size and obvious aberrancy of several of the floras more or less arbi- trarily included. Indeed, at first sight such a table appears to have a rather minor value, and one is mainly aware that no one has ventured to present it hitherto; while every paleon- tologist knows well that these general percentages may even be as little accurate for the floras actually recoverable in a given region, as representative of the ancient plant proportions. Nevertheless, there is more than a mere assumption that the inaccuracies so obviously and inherently involved in no incon- siderable degree balance each other. For neither the exigen- cies of fossilization, nor climatic variation, nor yet the varying personal equation involved in the determination of these frag- mentary records from many lands, can wholly obscure the larger outlines of Cretaceous vegetation. Generally consistent and inescapably salient are the following features : 274. | G. R. Wieland—On Inassic Floras. Firstly, Cordaites which still held a fast lessening place in the early Jura leaves behind only a few lingering hypothetical forms like Holirion. Secondly, the Equisetums left over in the Jura—Rhetic groups are now positively reduced to present day scant numbers. Thirdly, the high frequency of ferns represents the culmina- tion of the mid-Mesozoic fern recrudescence due to the spread of the more strictly modern types, as mentioned further on. Fourthly, the persistent presence of conifers in numbers at first sharply increasing and then followed by decline in both the per- centage and actual number of species recovered, is in striking contrast to the moderate numbers of the lower Jura. It may, in fact, be definitely accepted that, taking the world over, a strong fifth of lower Cretaceous vegetation was coniferous. This is the proportion in the English Wealden, in the Potomac, and appar- ently in all the horizons where collecting has been most thorough. The 44 per cent of the Portuguese Aptian and 7 per cent of the Japanese Neocomian balance each other as abnormal proportions unquestionably due to lack of fortune afield. In a word, just as the early Jura was a period of vast reaches of Williamsonians, so quite all the Lower Cretaceous was the time of dominant conifer- ous forests which receded with the advance of the angiosperms. Kifthly, the eycadophytan and coniferous elements quite exactly balance each other, the time when these gymnospermous types are to reverse their Jurassic proportions being near at hand.* The preparation of Table II at once showed that the lower half of the Consuelo plant beds contains elements which any paleobotanist would, as already insisted upon, recognize as belonging to,a slightly older facies than the plants of the upper half. That is to say, even were these two series of plants obtained in widely separated regions, the fact that they bear a successional rather than an equivalent relation would be evident. Nevertheless, the difference is, in the present state of our knowledge of Lower Jurassic floree, not strongly enough pronounced to permit more than fairly taken surmises. Especi- * Where these floree do vary markedly from the expected or average type, restudy in both laboratory and field is urgent. Take for instance the Urgo- nian of Austria-Hungary. If the commonly found ferns and conifers of Urgonian time were arbitrarily added to that list, the normal proportion of about 45 per cent ferns, 20 per cent cycads and 25 per cent conifers would at once be had, and the presumption is strong that either additional ferns can be found in the formations in question, or else we must take the only remaining alternative view that the series is of somewhat aberrant early Wealden type. , Similarly in the Wealden of Germany we may arbitrarily declare that the reverse holds, cycad and conifer collection and determination having failed to keep pace with fern recovery. At least the cases cited offset each other and the burden of proof must primarily rest on any explanation invoking changed local conditions, sufficient to account for such deep-seated varia- tions as would be indicated were some of the German Wealden proportions found approximately true ones. G. R. Wieland—On Liassic Floras. GS ally is this so because of the lack of other sections yielding as abundant and exactly located forms throughout such great thicknesses of strata. In this respect the Rio Consuelo section is so nearly unique that it has been found necessary to regard the plant beds as a unit when attempting comparison with other sections. Consequently in any first effort to determine the relative age of these beds it is safest to fix the attention on a thoroughly simplified list of the plants of the entire section. And such a list of positive value is best obtained by exeluding from Table I the varieties, the sole Equisetum, the Teeniopterids, the doubtful Glossopterids, and most of the cyead fruits which so far have been of much too seldom occurrence for grouping according to age. By thus dealing with the larger features— the irreducible minimum of genera and species to which no one can take exception, rather than resting the case on more or less moot species, the chances for error must be very markedly lessened. The list when condensed is as follows: TaBLE VI.—Condensed list of Mixteca Alta Plants. Gymnosperms ofnon-) Ferns of old and new cycadaceous ancient | types equally divided Cycads = 60% + type = 15%4 + = 20% + Anomozamites Lindleyanus| Araucarioxylon |Alethopteris Cycadolepis Neyggerathiposis | Cladophlebis Cycas (?) Rhabdocarpus | Coniopteris Podozamites sp. Trigonocarpus |Sagenopteris rhotfolia Prtilophyllum Sphenopteris Otozamites obtusus Teniopteris Zeilleri a Reglet cs Molinianus Ki Mandelsohi ee hespera paratypus sé Diazii es Juarezit Pterophyllum cf. contiguum oe mitinstert Pterozamites angustifolium Williamsonia (stems and fruits in profusion) Williamsonia mexicana Lamites Rolkeri 276 G. R. Wieland—On Liassic Floras. Bearing in mind, now, that it is not the new species of a more or less cosmopolitan early to mid-Mesozoic flora, however broadly identified, but the old and better known elements that must in the primary instance afford a basis of comparison, it is well to take both the trouble and the space to give the age usually assigned to the better known elements recurring in the Mixteca Alta flora in a further subjoined table, VIa. TABLE Vla.—Assigned Age of Oaxacan Plants. Rhatic (or Triassic) Liassic Oolitic Lamites Rolkeri| Ptilophyllums Piilophyllums “< confusus| Otozamites obtusus Otozamites ( Williamsonia) Pierophyllum ct. 5 Molinianus | Williamsonia (fruit species) contiguum i Mandelslohi| Yuccites Laccopteris (?) ft Reglei Neggerathiopsis es J uarezia Alethopteris Pterozamites (Ptero- Glossopteris phyllunr) Ptercphyllum (mtin- 7 ster?) Anomozamites Lind- leyanus Cycadolepis Phoenicopsis Stangerites Sagenopteris (Rhat to Lias) It is here seen that when keeping in mind the specimens themselves, as well as lists, about eight of the old elements are upper Triassic or Rhatic, and only four are of somewhat Inferior Odlite stamp, while the great bulk of the forms are “TLiassic.” Lt is, therefore, found that the plant beds of the Et Consuelo section begin at the upper borders of the Lhatic and probably extend through the Liassie near to the lowermost Inferior Oblate. | | And in so far as the position of the plant beds is open to dis- pute and adjudication following the critical study of the inver- tebyates of the great series of superposed marine deposits in the El Consuelo Section, I would first yield by classing the plant beds still more simply as youngest Jurassic. The flora, as already explained, appears to have been but briefly estab- lished rather than old, a fact quite in accordance with the sequence of geologic events leading up to the deposition of the plant beds. G. R. Wieland—On LItassic Floras. (e7 Such is the academical result; for we hold that no part of the plant beds can be Rhatic. As already quoted, Zeiller has shown that a typical Rhatie flora (that of Tonkin) which actually contains some elements found to persist in Oaxaca, is half made up of ferns of the older type, one tenth of the plants being conifers and only one-third cycads.. While on the other hand, there is much more of agreement in the Liassic propor- tions for these forms as already displayed in Tables IV-V. Moreover, we encounter difficulties as soon as an attempt is made to draw close parallels with presumably post-Liassic flore. That from Oroville, California, appears much more recent in type. So does that of Graham Land. (da) Source of the Mixteca Alta Flora. Are these Oaxacan plants northern or southern in origin ? Or, are they essentially equatorial, and such a distinctive part of the more strictly cosmopolitan vegetation of the Jura that no source or original home of the major elements can be dis- cerned ? It is unfortunate that sections through the plant beds of the Argentine or other South American mainland localities yield- ing Jurassic plants have not been made by qualified plant col- lectors; whilst all we so far have from Antarctica is the recently published work of Halle on the Mesozoic flora of Graham Land. A brief note of Nathorst in the Compte Rendu (p. 1449, June 6th, 1904) first made it known that a varied vegetation resembling that of the Jabalpur-Kach beds of India, and, therefore, affiliated with the Northern flore of early to decidedly mid-Jurassic facies, once flourished in Antarctica. And a little later the study of this notable material was taken up by Haile. | Typical Graham Land plants are Cladophlebis, Todites, Coniopteris, Sphenopterids, Otozamites Hislopi, Pseudoctenis, a Pterophyllum Morrissianum equivalent, and a notable group of conifers including Avraucarites cutchensis, Pagio- phylum, Brachyphyllum, and Elatocladus Jabalpurensis (= Palissya), with various other less important species. Evidently many of the most conspicuous plants of early Jurassic and later time were nearly as distinctly cosmopolitan as the Paleozoic types, a fact which must make the unravelling of the course of plant origin and migration in the mid-Mesozoic or “proangiosperm” age an exceedingly complicated if not virtually impossible task. But, needless to say, the difficulty here confronted must. incite paleobotanists to put forth every effort before finally accepting negative results. Meanwhile, such evidence as we do possess at least makes possible various interesting inferences. As already noted, 278 G. f. Wieland—On Liassic Floras. Neggerathiopsis appears to have come from the South; so also any Glossopterids. And while it is difficult to detect other southern elements, there is in Oaxaca the curious absence of conifers of northern type and especially of Genkgo, so far a very distinctly northern form. The more typically Indian net-veined cycad Dictyozamites is also lacking, though spar- ingly found on both the Yorkshire Coast and at Bornholm, and now known to have occurred in the Antarctic realm, as very recently reported by Halle. TABLE VII.—Notable Old World Types not yet Found Recurrent in Oaxaca. India. ‘ Yorkshire. (1) Liassic : Rajmahal Hills flora: (1) Lias : Teeniopteris lata Macroteniopteris lata Cycadites rajmahalensis Pterophyllum Morrissianum Pterophyllum princeps Pterophyllum rajmahalense Pterophyllum crassum Pterophyllum distans Paleozamia bengalensis Dictyozamites falcatus Dictyozamites indicus . Sphenopteris Hislopi Taxodites (?) indicus Palissya conferta Ginkgo crassipes Thinnfeldia indica Cycadites rectangularis. [On Bornholm occurs Dictyoza- mites Johnstrupi. | (2) Inferior Odlite. Oédlite: Kach-Jabalpur : Ginkgo lobata Palissya indica. Palissya jabalpurensis Echinostrobus expansa Ginkgo digitata. Baiera gracilis. Taxites zamioides. Dictyozamites Hawelli. ; Era Nilssonia mediana. Ctenis Nathorstit Ciena dled Ctenis Nathorstii (Bornholm). Matonidium Goppertit. Dictyophyllum rugosum. But we should not make too much of these facts. ar more noticeable is the absence of the large forms of Pterophyllum and especially of Ctenis ; for the recurrence of these major elements of the Indian Lias in the supposedly younger Oro- ville flora of course suggests a long persistent great northern route or rather center of origin. Taking the facts at hand, it appears that the Oaxacan plant beds were not notably indebted to Indian or southern regions. At least this is a fair conclusion from the suprajoined Table VII giving important old world types not yet known to recur G. R. Wieland—On Liassic Floras. 279 in Oaxaca.* The Indian Liassic and Californian plant equiva- lence is as follows: TABLE VIII.—Recurrence of Indian Types in California. Indian Liassic. | California [Odlite. ] Pterophyllum rajmahalense, -..--------- Pterophylluin rajmahalense, Pterophyllum Morrissianum, - - - - - [near] Ctenophyllum densifolium. Pterophyllum crassum, + -------- [near] Ctensis grandifolia. Pterophyllum princeps, Pterophyllum distans, Oyeadsies rajmahalensis, .---.---.----.- [Recurs in North Carolina Trias. | = eters a Regie aS [near] Macrotceniopteris californica. Macroteniopteris lata, To the lists of Table VII could, of course, be added the plants which are new at Bornholm. But it is a trifle more convenient to give these separately as follows : (1) Dicksonia Pingelit Deaer pauciloba Asplenites Cladophleboides Hausmannia acutidens Ctenis Nathorstii Otozamites bornholmiensis — bo — “é Bartholini Otozamites pusillus es tenwuissimus Dictyozamites Johnstrupi Pagiophyllum faleatum c triangulare Taxites subzamioides Carpolithes nummularius bet ee Oe ee ON Hm © pH OO ~ “1 OD ore Ww —— SS ES Oi Se ee ee ee ee a OS a er a Bornholm is only separated from the Yorkshire Coast by 15° of longitude on the approximate 55th parallel of north latitude; and its Lower Jurassic plant beds must be a near * A most interesting habitus feature of the Mexican Ptilophyllums is the number of fronds characterized by a pinnule insertion intermediate between the linear or Pterophyilum and the stemmed or Podozamites type. And this gradual transition, through the uni- or anterolobate, faintly posterolobate and - finally distinctly bilobate insertion, is in distinct agreement with the great variety of stem and floral structure. As these pages go to press, a study of the porcellanous specimens from the Rajmahal Lias by Miss Bancroft comes to hand, and the details brought to view further emphasize how com- pletely the work of the past few years has broken down the barriers between the Cycadeoidez, Williamsonians, and the existing cyeads, bringing to view a varied and vast but homogeneous group. In particular the nodal type of stem brought to definite notice in my paper on the Williamsonian Tribe proves of intermediate type. Growth rings are not found strong, perhaps because the preservation in light color makes their observation difficult ; but even this difference from Dion is now broken down, as I find that some of my sections of Cycadeoidee show the growth rings distinctly. 280 G. R. Wieland—On Liassic floras. succession of the Rhitic of Skone. With the latter the Born- holm flora has nineteen species in common, with the Rhitie of Franconia the same number, with the Rhatic of Poland fifteen, and with the Inferior Odlite of Scarborough about an even dozen. These species common to Bornholm and Scarborough it is of convenience my recapitulate here as follows: EE ae columnaris Sagenopteris Phillipsii Cladophlebis denticulata Coniopteris cf. hymenophylloides Dictyophylium ct. rugosum Laccopteris polypodioides Podozamites cf. lanceolatus Ginkgo cf. digitata Baiera cf. gracilis Czekanowskia ef. Murrayana Otozamites obtusus Dictyozamites cf. D. Hawelli Nilssonia cf. Compta es el eee ec Vea ce ON NY co ce a ce WnNrH CO OM aT Or — OO be Name a a ee ee ee ee Se oe en on foe As the Bornholm plants include Dictyozamites, conifers, and Ginkgo, so far an exclusively northern type, a strong par- allel with the Yorkshire Coast is presented despite a difference inage. But the cycad element of the Bornholm flora also includes the two important species Otozamites Molinianus and O. Mandelslohi characteristic of the Lias of continental Europe and recurrent in Oaxaca. When therefore, the resemblances to the Oaxacan flora to be found at Bornholm and the York- shire Coast, and in continental Europe, are all brought together (cf. Table I) it is found that they much outweigh the resem- blances noted in the Indian series. Moreover, there is a cer- tain unity in the flora of the northern latitudes, which suggests that north and south routes were the ones most travelled by plants in the early Jura, and throws into much doubt the exist- ence of an equatorial Gondwanaland center of origin or route at the time the Oaxacan plants flourished. Such a direct con- nection with the old world should have resulted in far sharper resemblances to some one of the European or Indian floras than any so far detected. In the equable uniform tropic con- ditions of a hypothetic Gondwanaland, plant migration would apparently have been so easy and rapid as to “readily repro- - duce in the early Jura striking conformities such as still char- acterized vegetation at the beginning of the Mesozoic. But with no appr roach to any such unifor mity in evidence, it is far safer to hypothesize northern and southern centers of origin. To rush to the opposed view that, since in all probability the Oaxacan series belongs to the very early Jura, it is the pre- G. R. Wieland—On Liassic Floras. 281 cursor of either northern or southern floras, appears entirely gratuitous. The lack of the cosmopolitan Dictyozamites, together with the apparent absence of conifers and Ginkgos, points the other way. The general movement of plants in more recent time is also against such a view ; and it is perti- nent to iterate here that it has too long been the custom of paleontologists when comparing the fossils of remote horizons to imagine that the similarities observed are due to some con- stant interchange of species, originating locally and more or less by chance. Too often this idea of the crossing of species and the recrossing half way round the globe is hypothesized in terms excluding the polar areas ; for it is only reasonable to suppose that these have always been relatively more instead of less prolific of new species than equatorial regions. Unquestionably, when isolated localities are freshly popu- lated, especially islands, considerable specific variation results. But it is a fair inference that species so produced have much less invasive power than those which result from profounder geologic changes affecting the globe as a unit—or better said, perhaps, those species which mark and form the crests of the greater waves of evolutionary development and change. It is, therefore, a strong inference from the general as well as special facts cited that the Oaxacan flora, though no doubt including many forms or varieties of local development, was preponder- antly northern rather than southern or mainly equatorial in aspect. The very few generalizations tentatively outlined here must, of course, await the results of future field work for their proof or disproof. Nevertheless, it does seem that the overlap of new and old forms in the various Jurassic florze can be satis- factorily dealt with as soon as species are better known. The strong likeness between such widely separated flore as those just considered betokens regularity in the movement and development of Jurassic plant life. It is, therefore, nearly certain that while it may never be possible to trace the full history of genera or families one after the other, the accumu- lation of large aggregates of definitely determined species will be equally effective. Aggregates of species should enable us to determine age with accuracy on the basis of the percentage of the major elements, that is the Cordaitaleans, cycads, con- ifers, ferns and Equisetums, as approximated on Table V. Certainly it seems that eventually it should be possible to establish the curve of frequency for the orders of plants in the several floree, however erratic may have been the devel- opment and spread of some of the genera or families. And so long as such possibility remains open, the incentive to the accurate determination of the Jurassic species is of the strongest. 282 EF. M. Kindle—Age of the Eurypterids of Kokomo. Art. XXVII.—The Age of the EHurypterids of Kokomo, Indiana ;* by E. M. Kinpie. Tuer small but interesting Eurypterid fauna which charae- terizes the Kokomo limestone of Indiana has recently been admirably described and figured by Doctor J. M. Clarke and Doctor Ruedemannt in connection with the Eurypterid faunas of New York. The opinion concerning the age of this remark- able fauna which these authors express, however, invites dis- cussion since it is at variance with the view of some geologists who have a knowledge of the field relations of the beds hold- ing it and of the formation with which it is correlated. The matter seems to be of sufficient importance to justify a brief review of the evidence bearing on the question of the age of the beds. If, as Clarke and Ruedemann state, the Kokomo Eurypterid fauna is of Lockport age, it may well stand in an ancestral relation to the New York Salina Eurypterid faunas which they describe. This is the conclusion which the reader is apt to draw from an inspection of the tables on pages 91, 93, and 431+ and the discussion of the new subgenus Onychopterus from Kokomo. ‘The other elements of the Kokomo fauna and the stratigraphy of the region do not, in the writer’s opinion, bear out this inference. Clarke and Ruedemann correlate the Kokomo limestone with the Noblesville limestone of Indiana and the Lockport of New York, and use indiscriminately the terms Kokomo lime- stone, Kokomo waterlime and Noblesville waterlime.§ This correlation is in harmony with a suggestion made by Schuchert, who, in a review of the writer’s work on the “Stratigraphy and Paleontology of the Niagara of Northern Indiana,” suggested the probable absence “ of the water-lime horizon in Northern indiana.” Schuchert was probably in part influenced in expressing this opinion by the still earlier reference of Conchidiwm colletti, the most conspicuous brachi- opod of the Kokomo fauna, to the Niagara limestone by Hall and Clarke.4| The writer had, at the time Schuchert’s review. appeared, a nearly complete collection of the Kokomo fauna and intended, when opportunity for its illustration offered, to present the strong array of evidence which it furnished against the inferred equivalence of the Kokomo and Lockport faunas. Other duties intervened however, and at a comparatively recent * Published with the permission of the Director of the Geological Survey of Canada. + Memoir New York State Museum, No. 14, vols. i and ii, 1912. + Ibid. S$ Ibid, pp. 320, 351, 215. || This Journal, Dec. 1904, p. 467. {| Pal. N. Y., vol. viii, pt. II, pl. 66, 1894. a E. M. Kindle—Age of the Eurypterids of Kokomo. 283 date most of the Kokomo fauna was described by Dr. Aug. Foerste. Now that both the Kokomo and Niagaran faunas of northern Indiana have been described, it is in order to examine the evidence which they afford regarding the question of their equivalence as advocated by Clarke and Ruedemann, or their suceession as believed by the writer. The Kokomo fauna occurs in a limestone which in the earlier references te it was generally called the “‘ water-lime” beds or Water-lime Group.* The name Kokomo limestone was intro- duced for these beds by. Foerstet in 1904. They are exposed in various quarries in the vicinity of Kokomo, where they lie horizontal and are covered by drift except where uncovered by quarry operations. The character of the beds of this lime- stone and the stratigraphic relations of the eurypterid and non- eurypterid faunas which characterize different parts of them can best be understood by reference to a section of one of the quarries in the Kokomo limestone. The section exposed at the Geo. Defenbaugh quarry on the south side of Kokomo (N. W.isec. 6 T. 23 N. R. 4E.) is as follows: Section of Kokomo limestone. 1. Drab to grey non-magnesian limestone, with chert bands and contaming a brachiopod fauna.__-.--...02-.-.. 4’ 2. Thin-bedded and finely-laminated dark-grey limestone, with eurypterids, and lying in strata 1’—2” thick which on weathering split still thinner. This bed contains occasional pockets of asphaltum and crude oil ------- 6! Gacy limestone (“ cement tock”) 2. 2.-<2-52-2212+-- 4’ Dark-bluish grey argillaceous limestone... ----------- a! Dark grey limestone in even bedded ledges 6” to 8” thick 6’ Very hard thin-bedded strata of brownish grey to bluish RitlesrOUcw i) et a 2 ee et 6! Blue and light grey panded limestone, the ‘layers very thin, smooth, and even bedded and giving a varie- gated appearance. to the stone __-_.-----------.--- Slay D Ov eo ~T a2 Eight or ten feet more of beds similar to those of the section given above are. penetrated by some of the quarries but these were not seen by the writer. As in the water-limes of New York the eurypterid and non-eurypterid faunas appear to be confined to distinct parts of the section. The writer was able to discover no trace of the brachiopod fauna which character- izes bed number one below it, nor have any eurypterids ever *H. W. Claypole, Am. Geol. vol. vi, p. 261, 1890. v, as in ordinary egirite. The extinction on the side pinacoid gave for an average of eight measurements in sodium light 1°4°, for an average of ten measurements in white light 1:2°. The color and pleochroism of the egirite from Libby are its most marked characteristics. The pleochroism is strong: X is dark-brown, Y is lighter- brown, and Z is pale-yellowish brown or amber. Chemical properties.—The material for analyses was first carefully picked out by hand and was later separated from the small amount of admixed quartz, microcline, calcite, and pyrite, by a weak electromagnet. The resulting material was found on microscopic examination to contain a very small amount of impurity. | From a chemical standpoint the chief interest centers about the relatively high content of vanadium. MHillebrand* has called attention to the presence of vanadium in basic igneous rocks (under 60 per cent SiO,), where as V,O, it replaces alu- mina and ferric oxide in pyroxene, hornblende, and _ biotites. In these instances, however, its presence is usually recorded as a few hundredths of one per cent. In one case, that of a bio- tite separated from a pyroxenic gneiss, the vanadium content was somewhat higher, reaching -13 per cent V,O,. In the ros- coelite mica the content of V,O, is much higher. It would seem from this that the content of vanadinm in mafic minerals other than mica rarely exceeds two-tenths of one per cent. The two minerals here described were unusual in this respect : in one specimen the vanadium oxide was present to the extent of almost + per cent, while the second showed a slightly smaller amount. Table 2 gives the chemical analyses of egirite from Libby, Montana, by Hunt, and from Brevig by Doelter;t the two analyses show a somewhat close similarity. In the latter case TiO, was absent and V,O, either absent or else not sought for. Columns 1 and 2 of Table 3 give the molecular ratios cor- responding to the analyses of the Montana egirite. If we deduct from this the equivalent of Na,O.Fe,O,.48iO, (acmite) * Hillebrand, W. F.: The analysis of silicate and carbonate rocks: Bull. U.S. Geol. Survey, No. 422, pp. 20, 24, 149, 1910. + Doelter, Tscherm. Mitth., vol. i, p. 376, 1878; also in Zeitschr. f. Kryst., vol, iv, p. 91. 294 Larsen and Hunt— Vanadiferous Agirites. TABLE III. Analyses of Agirite. Doelter Hunt SIO) abe ae eee ee 51°74 51-91 TO, pce'ot eee ee ‘91 FeO) ocd} eee 26°17 21°79 Ooo 2am ees 3°98% ALO; (cc: /ue nee Euan 38 CaO) 2 Seas 5°07 5°53 MoO 2 Wee eee eee aThe 3°08 HeQ\:,. 8 te eee 3°48 1°48 MnO Meh hae ls ote “46 58 Na,O ape ny ecg eA (Poet) We Lie) 10°46 K,O Bethe Gog 2 Spy: Vay tet "*B4 22 H,O cast PED Rae ee 100°54 "06 EL Oh) Ye PAVE be none SD ee rae ES ihe: OO6 ads. pe peeks trace 100°51 shown in column 3 there remains the molecular proportions given in column 4, which closely approximates CaO.MgO.28i0, (diopside). 1 2 SiO, 502 eee GOs TiO, 0 ae ne eiat OM DR. 1364 NV Of 7 ee ae 0264 1665 ALO. 0o) Oper ye CaO} ceo eae 0986 0986 MeQui si: Leones MeO 20) Depew 0206 1050 MnO x. See ael ye aap 0081 Nia. Or cee 1687 . IOWA balay & Be gy 3 + 6840 "1881 “10 ‘0986 "1050 17) These figures correspond to an isomorphous mixture of about 73 per cent of egirite, where the K,O replaces the Na,O, VO, and AIO, the Fe,O,, TiO, the SiO, ; and 27 pereem diopside, where the MgO is replaced in part by FeO and MnO. A comparison of the analysis with that calculated containing 73 per cent Na,Fe,Si,O . and 27 per cent CaMg(SiO,), shows: * A duplicate sample gave 3°81 per cent. Po Larsen and Hunt— Vanadiferous Avgirites. 295 Analyses Calculated OL (FP Oe eo fail ae 52°82 52°94 Fe,0,( + V,0, seteie: Se 2 02ho 25°26 COR eA er eee hers 5°53 7°00 Mg0O( + FeO + MnO).-.-- 5°14 5°00 Na,0( sf On ares YS OCOS 9°80 While there is a slight variation, the agreement is sufficiently close to warrant the suggestion. VANADIFEROUS AUGIRITE—AUGITE. The vanadiferous eegirite-augite is from the same locality as the egirite and is closely associated with the microcline-rich portions of the veins. It is present in spherulites of radiating fibers up to an inch across. These spherulites are commonly, nearly pure pyroxene ; along their border the pyroxene needles pierce the grains of microcline, quartz, and calcite. The fibers are very small and are closely packed so that no material was available for crystal measurements and even the cleavage angle could not be determined under the microscope. Optical properties.—The pyroxene is grayish green in color lts finely fibrous character made accurate optical measurements impossible, but its optical properties do not differ greatly from those of ordinary egirite-augite. The indices of refraction as measured by the immersion method are a = 1-720 + 0:003 y =1°747+ 0:0038. The axial angle is large, and the extine- tion on cleavage fragments is about 20° (X A ¢). The maximum extinction in the section was 24°. The pleochroism is rather simone: X'— lieht-preen, Y = greenish yellow, and Z = pale- yellow. The specific gravity is 3°42. Chemical properties.—Material for the chemical analyses was carefully selected and the analyses yielded the following . results: Mol. ratio SIO e ea os as 5Be89 “8842 ) cae TTC 3 eee varices 38 0047 ( a LIGNO EEGs Seae eee 12°38 0770 riers 2°36* 0190 1097 Owes e002" 1°40 0137 C20 esate hae 12°18 "2171 S aleg I 4 Nee cle a 7°01 "1738 WeOM Gen 2s 3°70 "0514 "2315 VEN Oo eee ke "45 .0063 Na OU cea aces - 6°26 ‘1009 K Ong Seana 26-0027 pee Cr} Deis Seow trace 1°5508 TOFS Ge, eB ‘07 BO} te ve ok eos 13 100°40 * A duplicate sample gave 2°82 per cent. 296 Larsen and Hunt— Vanadiferous Agirites. If we deduct from the molecular ratios given above the equivalent of egirite, namely, Na,O, Fe,O, 4810,, as follows : a0) 4 °K.) 5 1097 He, +,V.0,. AlOs eee ‘1097 Si0.( 4+ TiO). ae 4388 There would remain S10, (+ TiO) aa 4501 BO e200 eee 2171 MgO( + FeO + MnO) -.----- 2315 As in the egirite the constituents in the residue approximate diopside, CaO.MgO.2Si0,. In this case we are dealing with an isomorphous mixture of about 43 per cent egirite and 57 per cent diopside. A comparison of the analysis with the cal- "6582 "8987 1°5569 culated composition of such a pyroxene shows: Analysis SiOi ION. nee ae 53°70 Fe, 0:4. V0, + ALO) ie 2) Dems a) 2 Be ae Si A ee 12°18 MgO( + FeO + MnO) ----- 11°16 Na, O(- 4 RO) he ae ey ee es Calculated 54°01 14°88 14°78 10°56 5°77 FA. Perret— Vertical Motion Seismographs. 297. Art. XXIX.—A Method of Increasing and Controlling the Period in Vertical Motion Seismographs; by Franx A. PERRET. In order to obtain a satisfactory period of vibration in seis- mographs for recording vertical motion, the designers of such instruments are generally under the necessity of employing, for the suspension of the weight, a long and sensitive spring under strong tension. The use of such a spring, however, introduces a very serious defect in the practical working of the instrument, viz. a lack of stability in the position of rest due to the effect upon the spring of variations of temperature. The result is a continual wandering of the recording lever from its normally central position, creating a difficulty which the most ingenious of compensating devices have not, so far, been able to satisfactorily obviate. Furthermore, it is prob- able that, aside from the effect of temperature changes, a spring of such length and in so delicate a condition of balance will always be more or less subject to slight alterations which, magnified by the multiplying levers, cannot fail to be trouble- some—the difficulty is enherent an the large amount of spring ordinarily required in this type of instrument. It occurred to the writer that the variations of a magnetic field—due to relative motion of the parts of an instrument in action—might be utilized as a counter influence to the other- wise brusque action of a coarse and stiff spring, thus permit- ting the use of one so short and robust as to be free from extreme sensitiveness to temperature and other variations. From materials already at hand in the laboratory the crude apparatus shown in the figure was erected, it is scarcely neces- sary to say aS an experimental instrument for testing the principle, and not, in any sense, as a model for eventual con- struction. A horizontal lever of 20™, pivoted at one end and carrying at the other a weight of 2°5 kilos, is supported, as shown, by a stiff spring. The period of vibration is less than half a second and, once set in motion, the lever continues to oscillate for more than a minute, thus forming, it will be seen, an impossible instrument from the standpoint of modern requirements. If two armatures are now mounted upon the lever and their relative magnets attached to the frame of the instrument above and below, as shown in the figure, the pull of the upper mag- net is counterbalanced by the downpull of the lower one and, statically, the entire system is in precisely the same condition as before. If we now imagine a sudden upward movement, the weighted end of the lever, by its inertia and mode of sus- 298 EF. A. Perret— Vertical Motion Seismographs. pension, tends to remain at rest. But, unfortunately, this involves the stretching of the spring by which means the weight is lifted and set in vibration, and it is precisely for the minimizing of this effect that so long and sensitive a spring must ordinarily be provided. In the present case, however, it will be seen that the rela- tive motion of the different parts of the instrument has altered Bigialy yy VP ee the conditions in the magnetic field, the upper magnet reced- ing from its armature, increasing the *‘ entrefer”’ and decreas- ing the upward pull on the lever while, per contra, the lower “entrefer” has diminished, thus increasing the downward pull. These two effects combine, therefore, to offset and counteract the increased tension of the spring and they may be given any desired value in relation thereto. In the present EF. A. Perret— Vertical Motion Seismographs. 299 very small apparatus, and with the crudest of adjustments, the period was readily increased to from two to four seconds and could even—within narrow limits of movement—be made almost absolute, i. e., the instrument could be made aperiodic. The motion in the magnetic field produced a fair amount of damping, so that the application of this magnetic principle may be said to have converted an impossible instrument into one which, for its size, might be considered as a satisfactory vertical motion seismograph. It will be seen that the magnetic apparatus used in this experiment was far from being well adapted to the purpose. The closeness together of the poles of the magnets gives an exceedingly restricted external field, necessitating the locating of the magnetic control near to the pivoted end of the lever instead of at the weighted end, where its efficiency would have been far greater. In the case of a heavy-weight seismograph a battery of long field magnets is indicated, with armatures _ possibly V-shaped to ensure diagonal approach, the magnetic system to be mounted on an outer extension from the weight for greater leverage. but the details of construction must be left to the manufacturer, who will adapt the magnetic aux- iliary to the design of the instrument, the present paper being merely a presentation of the bare principle. It need scarcely be stated that the magnets should be of the best material, strongly charged and then ripened down to the point of perma-- nence, and that their mounting should be provided with fine screw adjustments. Anticipating a possible criticism, the writer would state that he cannot believe that any variations of terrestrial magnetism nor action of telluric currents at the time of an earthquake could adversely affect this appliance. Even supposing that these phenomena had the power to momentarily weaken or strengthen such powerful magnetic fields, both would be affected alike and the only effect upon the seismograph would be a difference in the ratio of the values of magnetic control and spring power. But the failure of even delicate apparatus designed to act as selsmographs by magnetic variation, may serve as a sufficient guarantee of the integrity of powerful _ tields. We have so far considered this magnetic control as applied solely to seismographs for vertical motion, and this for the reason that, on account of the spring suspension, it is here that the need is most apparent. But it is conceivable that, in many cases, a horizontal pendulum would be the better for a more positive self-centering factor in the pendulum per se, the period then being increased to any desired value by the mag- netic control. Am. Jour. Sc1.—FourtH SERIES, VoL. XXXVI, No, 218.—SEPTEMBER, 1913. 20 300 F. A. Perret— Vertical Motion Seismographs. If it shall be found possible to obtain uniform action in all azimuths, the great length of the simple pendulum, now requiring a tower, might be reduced to the dimensions of an ordinary building, and this suggests a somewhat different application in the case of inverted pendulums, viz. to employ the repulsive action of like magnetic poles—uniformly spaced around the magnetized pendulum rod, or magnets mounted thereon—in lieu of springs, for the maintaining of this in its central position. Such an instrument—especially if provided with optical registration—would, by its freedoin from mechan- ical contact with the static mass, closely approach the ideal. The writer has not tried out these last forms experimentally and they are here given simply as constituting a natural line of thought from the first idea. Posillipo, Naples, June 9, 1913. S. B. Kuzirian— Action of Sodium Paratungstate. 301 Arr. XX X.— The Action of Sodium Paratungstate in Fus- ton on Salts of the Halogen Acids and Oxy-halogen Acids ; by S. B. Kuzrrran. _ [Contributions from the Kent Chemical enters of Yale Univ.—cexlvii. | Tue use of sodium paratungstate as a flux in the expulsion of carbon dioxide from carbonates and nitrogen PeuL bate from nitrates has been proved to be sharp and complete.* It is likewise of interest to note the action of this flux on other common salts that have a volatile acid radical. Salts of the Halogen Acids. sodium Fluoride and Silicofuoride.—When a mixture of 0-2 germ. of sodium fluoride with 3 grm. of sodium paratung- state is fused a partial elimination of chlorine takes place slowly. In one experiment the loss of fluorine after ten minutes’ fusion amounted to about fifty per cent of that originally present in the fluoride. On application of heat to a mixture of sodium silicofluo- ride and sodium paratungstate, gaseous silicon tetrafluoride is evolved, but this is immediately attacked by the atmospheric oxygen ‘and water vapor from the source of heat and a white deposit of silica, which does not disappear on further ignition, is formed on the edges of platinum crucible. Sodium Chloride.—The reaction between sodium chloride and sodium paratungstate is likewise slow and incomplete. For example, in one experiment it was found that a twenty- minutes’ fusion of a mixture of 3 grm. of sodium paratungstate and 0°3 germ. of sodium chloride effected the decomposition of the chloride to an amount of only forty-six per cent, and on further heating the reaction proceeded even more slowly and could not be brought to completion with accuracy. Sodium. Bromide.—From the fact that the same conditions prevail in the fusion of bromides with paratungstate as in the ease of chlorides, it is natural to expect that only partial decom- position will take place; and that is due, similarly, to the slow atmospheric action upon the fused mass. In ten minutes’ fusion of a mixture of 3 grm. of sodium paratungstate and 0°3 erm. of sodium bromide, about sixty per cent of the bromide was decomposed, as against a forty-six per cent loss in twenty minutes’ ignition in the case of sodium chloride. After this period the reaction began to proceed much more slowly. Potassium Lodide.—The action of sodinm paratungstate upon iodides is somewhat different from that upon the rest of * This Journal [4], xxxi, 497. 302 S. B. Kuzirian—Action of Sodium Paratungstate. halogen salts. The reaction proceeds to completion without any difficulty, and this flux seems to be capable of expelling the iodine completely from iodides in a gentle ignition of from five to ten minutes. In the case of fluorides, chlorides, and bromides it appears that the action of sodium paratungstate in the expulsion of the hal- ogen element from chlorides is not complete for the reason that the simple elimination of that element will not leave an oxide to combine with the acidic oxide of the flux. If the fusion with the flux were carried 77 vacuo or in an atmosphere free of oxygen there would probably be no marked decomposition. So the observed partial decomposition of the halogen salts with a slow evolution of the halogen is apparently due to the agency of atmospheric oxygen, or moisture, which may serve essentially the end of oxidizing the metal to a basic oxide which combines with the acidic tungstic oxide, thus helping in the expulsion of the halogen. This action, which may be represented by the following equation : 28NaX + 2(5Na,0.12WO,) + 70, = 24Na,WO, + 14X, 14NaX + 5Na,0.12WO,+7H,O =5Na,WO,+7K,WO, + 14HX is slow and incomplete. The complete decomposition of iodides with this flux can be accounted for by the higher susceptibility of these salts to atmospheric action. The disappearance of the beautiful violet color of iodine is a fair indication of the completion of reaction. A wide- bottomed platinum crucible is advantageous in these determi- nations, on account of the large surface exposure of the con- tents to the atmospheric action. It is also desirable to.shake gently the contents of the crucible when the end point is ap- - proached, thus giving a better chance for oxidation. The use of sodium paratungstate in the estimation of iodine in iodides is shown in the following table: Analysis of C. P. KI of Commerce, after Drying. KI = NajoW1204; Loss on Theory taken taken ignition for loss Error No. grm. g1m. erm. germ. grm. 1 0°2000 2° 02170 0°2149 | + 0°0021 2 0°3000 2° 0°2155 0°2149 + 0°0006 3 0°3000 2° 0°2154 0°2149 + 0°0005 4 0°3000 2° 0°2156 0°2149 + 0°0007 5 0°3000 2° 0°2157 0°2149 + 0°0008 6 0°3000 2° 0°2148 0°2149 — 0'0001 te ire vnee S. B. Kuzirian— Action of Sodium Paratungstate. 303 The constancy of weight of the sodium paratungstate is to be tested from time to time by fusing and weighing over again. ‘The iodide may be added to the cooled solid mass and ignited to expel iodine. The flame should be regulated to obviate undue violence of action, which may be a source of mechanical loss. A gentle ignition of from seven to ten minutes was sufficient to obtain the results in the above table. It is of interest to note that with the use of this flux the decomposibility of the halogen salt (the fluoride being an exception) increases with rise in the atomic weight of the halogen. Thus iodine (with an atomic weight of 126-92) is completely expelled from iodides with the use of paratungstate. Bromine (with an atomic weight of 79°94) is decomposed to the extent of 60 per cent approximately. Chlorine (with an atomic weight of 35°46) is decomposed to the extent of 46 per cent approximately. According to this observation it would naturally be expected that fluorine (with an atomic weight of 19) would stand in its proper place, with a less degree of decomposition than chlorine; but instead, it stands between bromine and chlorine, being decomposible under similar condi- tions to the extent of 57 per cent approximately. It seems plausible, however, that the seemingly high susceptibility of the fluoride to atmospheric action was in reality due to the hygroscopic condition of the fluoride when it was submitted to the action of the paratungstate. Salts of Oxy-halogen Acids. The action of sodium paratungstate upon salts of the halo- gens having been shown to be incomplete, with the exception of iodides, it is interesting to note the action of the same flux upon some salts of oxy-halogen acids—namely, chlorates, per- chlorates, bromates and iodates—in a state of fusion. In view of the varying facility with which chlorides, bromides and iodides, respectively, undergo decomposition, it is natural to expect, as proves to be the case, that the order of decomposi-. tion will be the same for the oxygen salts. Under similar conditions of experimentation chlorates were decomposed to about 40 per cent, bromates to 67 per cent and lodates completely, in ten minutes’ fusion. In the case of iodates, a fusion of from four to seven minutes proved to be sufficient to eliminate all the iodine. In the process of fusion oxygen first begins to escape and the evolution of halogen is rapid. When the oxygen of the salt has all been expelled, the reaction proceeds very slowly, as it has to depend upon the atmospheric oxygen or moisture to do the work. The experimental tests showed that neither - — ae 304 S. B. Kuzirian— Action of Sodium Paratungstate. chlorine of the chlorate nor the bromine of the bromate was expelled under the analytical conditions within a reasonable time; while a five-minute fusion, carried out with extreme care to avoid mechanical loss, was sufficient to effect the elim- ination of iodine from the iodate. The use of sodium paratungstate in the estimation of iodine and oxygen in iodates is shown in the following table : Analysis of C. P. Potassium Lodate of Commerce after Drying. KIO; taken No. erm. 0°300 0:3000 0°3000 0°3000 = OS bo to rw wp Na, oW, Oe Loss on taken erm. ignition grm. 0°2335 0°2335 0°2330 0°2330 Theory for loss grm. 0°2339 0°2339 0°2339 0°2339 Error - erm, + 0°0004 + 0°0004 + 0°0009 + 0°0009 It is advantageous to heat the platinum crucible by waving under it a small flame, thus obviating undue violence of action. S. B. Kuzirian— Use of the Sodium Paratungstate. 305 Art. XXXI.—The Use of the Sodium Paratungstate and the Blowpipe Flame in the Determination of the Acid Radi- cals of Chlorides, Chlorates, Perchlorates, Bromides, Bro- mates and Fluorides ; by 8. B. Kuzrrtan. [Contributions from the Kent Chemical Laboratory of Yale Univ.—cexlviii. ] . Introductory. Tue ability of sodium paratungstate to decompose and expel the volatile acid radicals from certain salts like carbonates, nitrates, iodides and iodates has been shown in a previous paper.* It has also been shown that the action upon chlorides, chlorates, bromides, bromates and fluorides under ordinary atmospheric conditions is only partial.t Under such condi- tions only certain portions of the salts are broken up and the reactions then become very slow. The imperfection of the reaction can be accounted for in the ease of chlorides and bromides by the fact that these com- pounds do not contain a basic metallic oxide to unite with the acidic tungsten trioxide, and therefore have to depend upon the gradual action of atmospheric oxygen or moisture to pro- duce a decomposition which is so slow that the reaction cannot be completed within a reasonable time. The results are, how- ever, sharp and accurate in the case of carbonates and nitrates, which are composed of a basic oxide and an easily volatilizable acidic oxide. Chlorates and bromates, having a molecular con- stitution similar to that of nitrates, might be expected to behave similarly on treatment with sodium paratungstate. But on the fusion of potassium chlorate with this flux, the oxygen of the chlorate does not form potassium oxide, while oxygen is liberated before the salt actually begins to be acted upon by the paratungstate, leaving potassium chloride. Bro- mates being unstable like chlorates behave exactly in the same way on similar treatment with the paratungstate. Oxygen is evolved and a bromide is left. So, for the same reason, the expulsion of the halogens from chlorates and bromates is only partial, and the degree in which the halogen is eliminated proves to be almost the same for the same duration of fusion as with chlorides and bromides. Having in view the function of atmospheric oxygen and moisture in partial decomposition of chlorides, bromides, fluo- rides, chlorates and bromates, it was natural to look for a reagent which would accomplish the decomposition more efli- ciently by supplying oxygen while removing the halogen. * This Journal [4], xxxi, 497. + Ibid., xxxvi, 301. 306 S. B. Kuzirian— Use of the Sodium Paratungstate. Superheated steam was found to be the reagent desired. Steam in a superheated state attacks the chlorides and bromides. From sodium chloride and sodium bromide, for example, a metallic oxide is formed and hydrochloric acid and hydrobro- mie acid are evolved. The inconvenience of this reaction is that at sufficiently high temperature the alkali oxide, as well as halogen acids, are volatile, and their products tend to combine again to form NaCl and Nabr. If this reaction takes place in presence of fused sodium paratungstate, the tungsten trioxide will take up the metallic oxide and the acid formed is quickly expelled. The reaction between steam, sodium paratungstate and sodium chloride may be represented as follow: 5Na,0.12W0O,+14NaCl+7HOH = 12Na,WO, +14HCl. _ In preliminary tests the following procedure was used. The steam was led from a flask through a platinum tube to the eru- cible which contained the fused mass of sodium paratungstate and sodium chloride. The platinum tube was heated to red- ness, the steam passing through the red hot platinum tube became superheated, and the interaction between the steam and the chloride resulted in the immediate evolution of hydro- chlori¢ acid. The same effect may be brought about more conveniently and with great accuracy by directing a sharp, thin blowpipe flame upon the surface of the fused mass of sodium paratung- state and chloride, since superheated steam is one of the princi- ple combustion products of illuminating gas. The gaseous carbon dioxide formed in the interaction is completely expelled from the fused mass by the acidic tungstate, as shown in the determination of carbonates, and the water vapor formed is superheated and ready to take part in the reaction. The thin, sharp blowpipe flame serves excellently the double object of keeping the mass in quiet fusion and of furnishing superheated steam to bring about the desired effect. The procedure is as follows: A 20-gram platinum erucible — is weighed, and a specified amount of sodium paratungstate is introduced, fused with a small sharp blowpipe flame from above and kept in fusion for five minutes in order to expel by the action of steam at high temperature any impurities (e. g. chlorine of chlorides) volatile under the conditions. The eru- cible and contents are cooled and weighed. Next a weighed amount of the salt to be analyzed is introduced, and the mate- rial in the crucible is carefully fused with the gentle heat of a burner with care to avoid spattering. Then a very small and sharp flame of the blowpipe is directed upon the surface of the Bi 4, Pa ‘ yaa S. B. Kuzirian— Use of the Sodium Paratungstate. 307 fused mass for a period of five to eight minutes, until a con- stant weight is obtained. The whole determination can be accomplished in a compara- tively short time. | | Sodium chloride.—In the table are given the results which were obtained by the action of superheated steam upon the fused mass of sodium paratungstate and sodium chloride, under the conditions specified. TABLE I. Analysis of C. P. Sodium Chloride, after Drying. NaCl NaioW.i20.: lLosson Theory taken taken ignition for loss Error No. grm. _ grm. erm. germ. erm. ] 0°2000 2 0°0936 0°0940 —0°0004 2 02000 2 0°0938 0°0940 —0°0002 3 0°2000 2 0°0938 0°0940 —0°0002 i 0°2000 2 0°0933 0°0940 —0°0007 Sodium chloride being an extremely stable salt, a prolonged ignition of fifteen to twenty minutes was necessary. It was customary to weigh after each period of five minutes’ ignition with the blowpipe, in the manner already specified. The residue was tested for chlorine with chromic anhydride test* which is sensitive to about 0°5 mlg. of chloride. No indica- tion of chlorine was found. Potassium chlorate.—Table II shows the results obtained when the sodium paratungstate was fused with potassium chlorate in the manner already specified, care being taken to expel volatile material slowly, thus avoiding possible mechanical loss of material due: to violent evolution of oxygen. This was accomplished by applying a gentle heat of a Bunsen burner from beneath the platinum crucible, until quiet fusion took place. Then a small blowpipe flame was applied in the man- ner described. TABLE IT. Analysis of C. P. Potassium Chlorate of Commerce, after Drying. KC1IO; “NaioWi20.: Losson Theory taken taken ignition for loss Error No. germ. grm. erm. erm. germ. 1 0°2000 2 0°1241 0°1231 +0°0010 2 0°2000 2 0°1260 071231 + 0°0029 3 0°2000 2 0°1230 071231 —0 0001 4 0°2000 2 0°12338 0°1231 + 0°0002 3) 0°2000 2 0°1233 01231 + 0°0002 6 0°2000 2 0°1237 071231 + 0°0006 * Gooch and Brooks, this Journal (8), xi, 2838. 308 S. B. Kuzirian— Use of the Sodiwm Paratungstate. In determinations Nos. 1 and 2, the mixtures were ignited with the blowpipe flame for nine minutes without first bring- ing the mixture to quiet fusion with a Bunsen flame and the large positive errors are without doubt due to the consequent mechanical losses. Nos. 3, 4, 5, and 6 were subjected to the blowpipe flame for seven minutes, after observing all the pre- cautions. A chlorocbromic anhydride test of the residue failed to give any indication of chlorine. It is curious to note that the expulsion of volatile matter is accomplished in the case of a chlorate in a shorter time than with chlorides, a fact which can be accounted for upon the assumption that the oxygen of the chlorate is not all liberated in the first stage of reaction, but it remains partially to take part in the interaction, thus shortening the necessary duration of the blast ignition. Sodium bromide.—The decomposition of bromides with the expulsion of the volatile acid radical is achieved with more ease than that of chlorides. As previously shown, the tendency. toward decomposition increases with the rise in the atomic weight of the halogen. Following are some of the results obtained when C. P. sodium bromide was acted upon with the flux in presence of steam produced in the blowpipe flame directed from above upon the mixture : TABLE IIIT. Analysis of C. P. Sodium Bromide of Commerce, after Drying. NaBr NajoWi20.4,; Loss on Theory taken taken ignition for loss Error No. erm. grm. erm. grm. grm. 1 0°1932 2 0°1354 0°1350 + 0°0004 2 0°2000 2 0°1397 0°1398 —0°0001 3 0°2000 2 0°1397 0°1398 —0°'0007 + 0°2000 2 0°1392 0°1398 —0°0006 The actual and theoretical losses agree within the range of experimental error. The average duration of ignition was about nine minutes. All the precautions applicable in the case of chlorides are applied in the treatment of bromides. Potassium bromate.—The analysis of potassium bromate was carried under the same conditions, with all the precautions that were applied to chlorates. The results obtained are shown in Table IV. The average duration of ignition in the above determination was twelve to fifteen minutes. ; Potassium perchlorate.—In the description of the analysis of chlorates with the use of sodium paratungstate, it was shown, Zi S. B. Kuzirian— Use of the Sodium Paratungstate. 309 TABLE IV. Analysis of C. P. Potassium Bromate of Commerce, after Drying in the Air Bath. KBrO; NajoW1201: Loss on Theory taken taken ignition for loss Error No. grm. grm. grm. grm. germ. 1 0°2000 2 0°1437 0°1436 +0:°0001 2 0°2000 2 0°1430 0°1436 — 0°0006 5 0°2000 2 0°1440 0°1436 + 0°0004 = 0°2000 2 - 0°1446 $) 1028436 + 0°0010 that the decomposition was effected in two stages, most of the oxygen being liberated in the first stage of the reaction; a small portion of it, together with the superheated steam, would act upon the fused mass of the mixture of paratungstate ’ and chlorate, and complete decomposition would ensue, with liberation of its volatile acid radical. In connection with this, it was also mentioned that, probably due to the part played by this small portion of chlorate oxygen, the duration of blast ignition was greatly shortened. Perchlorates (e. g. potassium perchlorate) being richer in oxygen than chlorates while the temperature of dissociation is higher, it would be expected that the part played by the oxygen in this substance would be even more pronounced than in the case of chlorates, and so it is in fact. A complete decomposition of the perchlorate could be brought about within five moments with the use of this flux © and superheated steam, under conditions specified. For the amount of substance taken the necessary duration of blast ignition in the case of chlorides is from fifteen to twenty minutes, in chlorates from seven to ten minutes, whereas five ~ minutes will suffice in the case of perchlorates. The rapid in- teraction of perchlorates with the paratungstates is not altogether chargeable to the extra atom of oxygen which the perchlorate has over the chlorate. When the quantity of oxygen present in chlorates and perchlorates is the only agency to effect their decomposition, there should not be such a marked difference in the duration of blast ignition, as there is more than enough oxygen in the ease of chlorates as well as in perchlorates. The higher temperature of dissociation of the perchlorate appears to favor the reaction between the oxygen and the chloride. Perchlorates, unlike chlorates, being more stable do not lose their oxygen in the first stage of reaction, but retain it until thorough decomposition begins. Then the oxygen liberated simultaneously, while the reaction is proceeding, will certainly take part in the interaction, thus shortening the process to a great extent. Another important point well worth mentioning in this connection, is that the 310 8S. B. Kuzirian— Use of the Sodium Paratungstate. melting points of potassium perchlorate and sodium para- tungstate are rather near to each other. First the perchlor- ate melts, and then the paratungstate begins to fuse, with rather a violent interaction, so excessive care is necessary to avoid mechanical loss at this point.* After the violent action ceases then the cover of the platinum crucible 1 is taken off, and the usual blast ignition started. The potassium perchlorate used in the analysis was the ©. P. material of Commerce containing 1°8 per cent potassium chlor- ate as impurity. Results obtaimed- with this potassium per- chlorate are shown in Table V. TABLE V. _ Analysis of Potassium Perchlorate of Commerce, after Drying in the Air Bath. KClO, NaioWi204, Loss on Theory taken taken. ignition for loss Error No. erm. erm. grm. grm. grm. 1 0°3055 3 0°1996 0°2000 —0*0004 2 0°3055 3 0°2004 0°2000 +0°0004 3 0°3055 3 0°2015 0°2000 +0:0015 4 ()°3055 3 0°2006 0°2000 + 0°0006 5) 0°3055 3 0°2015 0°2000 +0°0015 6 0°3055 3 0°2000 0°2000 0:0000 After bringing the mixture of perchlorate and paratungstate ‘ to quiet fusion with a gentle flame of the Bunsen burner waved underneath the platinum crucible, from three to five minutes’ blast ignition sufficed to obtain the results in the table. The reason for choosing a rather odd amount of perchlorate for analysis was because it contained 1°8 per cent potassium chloride and the amount taken in each determination corre- sponds exactly to 0°3000 grm. of the perchlorate. Analysis of hypo salts of halogens was not attempted because of their indefinite composition and the difficulties with which they can be isolated. Fluorides. The observation that the tendency. of the halogen salts to decompose when heated in the atmosphere increases as the atomic weight of the halogen rises, does not hold in the case of fluorine. The atomic weight of fluorine, being the lowest among the halogen atomic weights, it would be expected that this element would show the lowest tendency to decompose ; but in this respect it ranks almost with bromine, and is much above chlorine. But this may be due to the greater hygro- * Precautions to be observed under such conditions have been described in connection with the chlorates and bromates. S. B. Kuzirian— Use of the Sodium Paratungstate. 311 scopicity of the fluoride, and the consequently greater part played by water in ignition. In expelling fluorine from fluorides, with the use of the blowpipe flame, free hydrofluoric acid is evolved, and so the determinations must be carried out under a good draft hood. Being slightly volatile, sodium fluoride may, on ignition with the paratungstate, escape somewhat as such, unless steps be taken to prevent loss by carefully moderating the heat. The author’s method of overcoming this source of error is, to cover the bottom of the platinum crucible with paratungstate, to add the fluoride and cover it with another weighed portion of sodium paratungstate, to fuse with a very gentle flame of the Bunsen burner, and then to apply the usual blowpipe flame. The covering layer of paratungstate serves as a trap to hold back the somewhat volatile fluoride. The paratungstate used must, of course, be free from mate- rial volatile in the ignition, and this condition is easily fulfilled by subjecting the paratungstate to a preliminary ignition in the superheated steam of the blowpipe flame directed upon it from above. The expulsion of the volatile halogen from a fluoride can be completed within less than five minutes. In Table VI are given the results of the estimation of fluorine in sodium fluoride. TABLE VI. Analysis of C. P. Sodium Fluoride of Commerce, after Drying. Nak NaioW120.1 ~~ Loss on Theory taken taken ignition for loss Error No. grm. erm. grm. grm: grm. 1 0°2000 3 0°0531 0°0524 —0°0007 2 0°2000 3 0°0531 0°0524 —0°0007 3 0°2000 3 0°0522 0°0524 +0:0002 a 0°20900 3 0°0526 0°0524 —0°0002 5 . 9°2000 3 0°0528 0°0524 —0°0004 Summary. Sodium paratungstate of the composition 5Na,O.12W0O,, an acidic salt capable of combining with metallic oxides in a state of fusion to form tungstates with the quantitative expulsion of certain volatile acid radicals, is easily prepared by fusing sodium tungstate with an equal weight of tungsten trioxide, the acidic salt thus formed being readily fusible, and not volatile under the conditions of this work. It is not more than ordinarily hygroscopic and can easily be kept dry in a desiccator over sul- phuric acid. The duration of ignition is remarkably short, as compared with the time required in the case of other fluxes 312 S. B. Kuzirian— Use of the Sodium Paratungstate. thus far proposed. It has been previously shown (loe. cit.) that the determinations of the acidic element or oxide of ecar- bonates, nitrates, iodides and iodates can be made with great — accuracy by simple fusion made in the ordinary way. “The present paper shows that the process may be extended to the analysis of chlorides, chlorates, perchlorates, bromides, bro- mates, and fluorides, ‘if the precaution be taken to make the fusion in the presence of superheated steam produced in the direct application of the blowpipe flame to the paratungstate mixture. In view of the experience detailed it is plain that the proper- ties of sodium paratungstate make it an excellent and a very handy reagent for use in the analytical laboratory. | Miscellaneous Intelligence. 313 isernN TIFIC INTELLIGENCE. MisceLLanerous Screntiric INTELLIGENCE. 1. Atlas der Krystallformen; von Victor GoLpscHMIDt. Volume I, in two parts, Adamin—Buntkupferez: Atlas, plates 1-244 ; Text, pp. v1, 248. Heidelberg, 1913 (Carl Winters Uni- versitatsbuchhandlung).—The prospectus of the Atlas of Profes- sor Goldschmidt was noticed at length in the May number of the Journal. Since then the first volume of this great work has been distributed and the promises of the preliminary announcement are more than fulfilled in it. This volume is in two parts: the first is devoted to an Atlas of two hundred and forty-four plates embracing all the mineral species included under the letters A and B. The accompanying volume of text gives the information which is needed to make the plates intelligible. The list of forms is presented after the manner of the well-known Index of the author and the literature citations are as complete as could be desired. . In the preface to the text the author explains the broad stand- point from which he has been led to develop this work, desiring to bring together the material which shall be available for solv- ing many of the problems of crystals and their growth, partic- ularly with respect to the crystal habit, the frequency of occurrence of certain forms and the relative size of the faces. The author’s earlier labors in similar fields, as also his extraordi- nary power for carrying through complex and difficult investiga- tions, fit him peculiarly for a task of this magnitude. The completeness with which the subject is handled will be appreci- ated from the fact that the single species barite is represented by 737 figures, anglesite by 460 and aragonite by 302 ; while the monoclinic amphiboles, apatite, axinite, beryl and bournonite have each from 160 to 186 figures. The reproduction of the figures by the engraver is excellent and the author has shown rare good judgment in taking these figures direct from the origi- nal authors without attempting the enormous task of redrawing. The latter plan must, of necessity, have resulted in another elegant fragment, as that ot Schrauf, while now we may hope, with the author, that his task may be completed by the publica- tion of four or five additional double volumes, one for each year succeeding the present. No student of mineralogy can afford to be without a work of this importance and completeness. 2. Dybdeboring + Gréndals eng ved Kébenhavn 1894-1907 og dens videnskabelige Resultater ; ved EK. P. Bonnesen, O. B. Boeertp og J. P. Ravn. Pp. 106, pls. 8. Udgivet paa Carls- bergfondets bekostning. Copenhagen, 1913.—This volume gives the record of a boring carried to a depth of 2742 feet, 860°6 meters, near Copenhagen. Its depth is much greater than any other boring in the region, and its vicinity to Copenhagen enabled 314 Scientific Intelligence. an exceptional amount of study to be given to it by the professors resident there. The first part is given up ‘to the records of the boring, including a full description of the methods. The tempera- tures were taken at numerous intervals and show a rectilinear temperature gradient of 21°5° per kilometer, beginning with 8°3° at the surface. The rocks penetrated are limestones of the Upper Cretaceous. Lists of the fossils identified are given by Dr. Ravn, who shows also their position in the Upper Cretaceous series from Turonian to Danien inclusive. Thus the underground geology of Denmark, a land whose surface is mostly of Pleistocene and recent formations, is carried to a depth of more than half.a mile. J. B, 3. Das Problem der Vererbung “Hrworbener Higenschaften” ; von RicHarD Semon. Pp. vii, 203. Leipzig, 1912 (Wilhelm Engelmann).—The possibility of transmitting to future gener- ations any of the characters acquired during the lifetime of the individual has been very generally doubted or even denied by many biologists. An increasing mass of evidence from regent experiments has tended to demonstrate the independence of the characters contained in the germ cells from bodily influences. Yet there are still those who hold that under certain circumstances it may occasionally happen that a long continued or violent stim- ulus may so modify the body of an organism as to be transferred to the germ cells and thus cause a similar modification in the future offspring. Semon belongs to this latter class. In this book he presents an impartial and masterful discussion of the problem, and reviews the evidence which leads him to the con- viction that these so-called acquired characters may be trans- mitted. WwW. B. C. 4, Principles of Economic Zoblogy. Part I, Field and Lab- oratory Guide; by L. 8. Daveurrty and M.C. DaveuHeErry. Pp. vi, 276. Philadelphia, 1912 (W. B. Saunders Company).— This is essentially a book of direction sheets for the field and lab- oratory study of selected types of animals. It.is designed to accompany the author’s text-book, Principles of Economie Zool- ogy, Part II. The work of the student consists mainly in answer- ing series of questions so worded as to lead him to discover for himself the important facts and principles of the subject. Alter- nate pages are left blank for recording the answers. W. R. C. 5. The Modern Warship; by Epwarp L. Arrwoop. Pp. vil, 146; 3 tables, 16 figures. Cambridge (University Press), and New York (G. P. Putnam’s Sons), 1913,— Whether regarded as a means of preserving peace or an engine of war, the warship of modern times is a subject of great interest to many people, and those not especially informed in regard to it will find in this little book an excellent summary of the whole matter. It takes up the question of design, the various materials and steps involved in construction, and finally the point of most serious moment to the tax-payers, namely, the cost of this expensive luxury. Warns Naturat Science EstABLisHMENT A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS: Geology, including Phenomenal and Physiographic. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. Invertebrates, including Biology, Conchology, ete. Zoology, including Osteology and Taxidermy. Human Anatomy, including Craniology, Odontology, ete. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Ward’s Natural Science Establishment, 76-104 College Ave., Rochester, New York, U.S. A. Atlas der Krystallformen von Victor Goldschmidt This work will embrace from 25,000 to 28,000 figures of the crystal forms of mineral species, as given by the original authors. Five or six volumes of about 250 plates each are planned with a like number of volumes of text. Price for each volume: Atlas, 20 marks ; Text, 12 marks; 5 marks additional for a permanent binding. Volume I, Adamin to Buntkupferez, is now ready : Atlas, plates 1-244; Text, pp. vi, 248. Carl Winters Universitatsbuchhandlung, Heidelberg. CONTENTS. Page Art. XXIII.—Geologic Sketch of Titicaca Island and Adjoining Areas ; by H. KE. Grecory. (With Plate I) 187 XXIV.—Experiments on Columnar Ionization; by E. M. WELLiscH and J.-W. Wo0pRow 22225... eee 214 XXV.—Geology of the New Fossiliferous Horizon and the Underlying Rocks, in Littleton, N. H.; by F. H. LaAwEE 220 Scllcc eke See ee ee ee XXVI.—Liassic Flora of the Mixteca Alta of Mexico,—Its Composition, Age and Source ; by G. R. Wietand.--- 251 XXVII.—Age of the ges of Kokomo, Indiana ; by K. M. KINDLE, Oe os ee ee 282 XXVIII.—Two Vanadiferous Agirites from Libby, Mon- tana; by E. 8. Larsen and W. EF. Hunt. ._-- 2) eaeeeee XXIX.—Method of Inereasing and Controlling the Period in Vertical Motion Seismographs ; by F. A. Perrer... 297 XX X.—Action of Sodium Paratungstate in Fusion on Salts of the Halogen Acids and Oxy-halogen Acids ; by 8. B. TOUZIBLAN eee Sere ee eee 2 ee 301 XX XI.—Use of the Sodium Paratungstate and the Blowpipe Flame in the Determination of the Acid Radicals of Chlorides, Chlorates, Perchlorates, Bromides, Bromates and Fluorides; by 5.2. KuziniAN 25. 22 oe 305 SCIENTIFIC INTELLIGENCE. Miscellaneous Scientific Intelligence.—Atlas der Krystallformen, V. GoLp- scumipt: Dybdeboring i Grondals eng ved Kébenhavn 1894-1907 og dens videnskabelige Resultater, E. P. Bonnesen, O. B. BOGGILD og J. P. Ravn, 813.—Das Problem der Vererbung ‘‘ Erworbener Eigenschaften ”, R. Semon: Principles of Economic Zodlogy ; Part I, Field and Laboratory Guide, L. S. DactcuEerty and M. C. Daucuerty: The Modern Worship, E. L. Atwoop, 314. VOL. XXXVI. OCTOBER, 1913. Established by BENJAMIN SILLIMAN in 1818. THE AMERICAN JOURNAL OF SCIENCE. Epirorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or CamBrince, Proressors ADDISON E. VERRILL, HORACE L. WELLS, LOUIS V. PIRSSON, HERBERT EF. GREGORY AND HORACE S. UHLER, or New Haven, Proressor HENRY S. WILLIAMS, or Iruaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or WasurnecrTon. FOURTH SERIES c VOL. XXXVI—[WHOLE NUMBER, CLXXXVI}. No. 214—OCTOBER, 1913. Ct a x Sontal NEW HAVEN, CONNECTICUT. fos XT Te 18) THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. ee eee ee Published monthly. Six dollars per year, in advance. $6.40 to countries in the Postal Union ; $6.25 to Canada. Remittances should be made either by money orders registered letters, or bank checks (preferably on New York banks). NEW DISCOVERTES AND NEW FINDS. BEAVERITE, A NEW MINERAL. This mineral, which was fuliy described in the December, 1911, number of this Journal, I have been fortunate enough to secure the whole output of. It was found at the Horn Silver Mine in Utah and is a hydrous sulphate of copper, lead and ferric iron. It was found at a depth of 1600 feet. In appearance it’ resembles Carnotite. Prices 75¢ to $2.00. PSEUDOMORPHS OF LIMONITE AFTER MARCASITE. These remarkable Pseudomorphs, which have never before been found in such clear cut specimens, was described and illustrated in the last number of this Journal. I have secured the majority of the finest of these speci- mens. They vary in size from 2 inches to6 inches. In color they run from brown to glossy black and they have met with favor from all who have seen them. Prices from $1.00 to $10.00. CHIASTOLITES. Of these remarkable specimens, which are generally known as lucky stones, I have secured the finest lot ever found at Madera Co., California. They are cut and polished and sold singly and in collections from 25¢ to 50¢ for single specimens; 9 specimens all marked differently for $5.00, and 18 specimens, all different markings, for $18.00. Matrix specimens, polished on one side showing many crystals, from $2.00 to $8.00. SYNTHETIC GEMS. It is remarkable the interest that has been taken by scientists in these wonderful scientific discoveries. The Corundums are now produced in Pigeon blood, Blue, Yellow, Pink and White. Also the new Indestructible Pearls in strings with gold clasps. These are identical in hardness and rival in color and lustre the real gems. They can be dropped and stepped on. without injury and are not affected by acids. My collection of the above is unrivalled, and prices of the same are remarkably low. . OTHER INTERESTING DISCOVERIES AND NEW FINDS Will be found in our new Catalogues. These consist of a Mineral Catalogue of 28 pages; a Catalogue of California Minerals with fine Colored Plates; a Gem Catalogue of 12 pages, with illustrations, and other pamphlets and lists. These will be sent free of charge on application. Do not delay in sending for these catalogues, which will enable you to secure minerals, gems, etc., at prices about one-half what they can be secured for elsewhere. ALBERT H. PETEREIT 261 West 71st St., New York City. TE AMERICAN JOURNALOF SCIENCE [FOURTH SERIES.] ———~+e Arr. XXXIIL.—The Distribution of the Active Deposit of Radium in an Electric Field (II); by E. M. Wetttscu, Assistant Professor of Physics at Yale University. Introductory. 1. Tur experiments described in the present paper are a continuation of the investigation made by Wellisch and Bron- son* on the distribution of the active deposit of radium in an electric field. In that investigation radium emanation mixed with air was introduced into a cylindrical condenser and the relative amounts of active deposit which settled on the central electrode and on the case were determined after equilibrium had been established for different positive potentials applied to the outer electrode. It was shown that the part of the active deposit which settled on the ease (anode) was due to the diffusion of uncharged car- riers; no evidence was found of the presence of negative car- riers in any appreciable amount. It was found also that, when the applied potential was not too small, the distribution of the active deposit was Independent of the quantity of emanation employed, and that the fraction of the total amount which settled on the cathode in general increased with increasing potentials, although under the most favorable conditions there was still about 10 per cent which was deposited on the case. The passage of Rontgen rays through the gas during the expo- sure was found to be without effect on the distribution except when the applied potential was small, in which case the extra ionization produced by the rays caused increased recombination with the charged active deposit particles and in this manner the cathode deposit was diminished. Finally it was found that for potentials which were not too small the ratio of the equi- * Wellisch and Bronson, Phil. Mag., ser. 6, xxiii, p. 714, 1912. Am. Jour. Sc1.—FourtH Srriss, Vout. XXXVI, No. 214.—OctToser, 1913. 21 316 ££. M. Wellisch—Distribution of the Active Deposit librium ionization currents in the gas for two different poten- tials was equal to the ratio of the corresponding cathode activities. The main object of the present series of experiments was to extend the investigation in various directions ; in particular, it was thought desirable to ascertain the effect on the distribution of employing a containing vessel of different dimensions and of mixing the emanation with gases other than air, and, in addition, to make a detailed investigation of the distribution Rie. As E Ce hh hh bbb hhh bbihhedidikehededideta ’ O—_— $s Ss ~Whie=-== We=——-hh E when small potentials were employed. The main experimental results of the previous research have been confirmed, but the fresh results which have been obtained necessitate a modifi- cation of the theory which was suggested in explanation of the phenomena. Haperimental Procedure. 2. The method employed for ascertaining the distribution of the active deposit was the same as that which had previously been employed. The radium emanation obtained usually from of Radium in an Electric Field. are a quantity of carnotite, or in some cases from an aqueous solu- tion of a radium salt, was passed into the containing vessel and remained there under the desired conditions of potential, pres- sure, etc., until radio-active equilibrium was established ; in general this period was about 3 hours. The emanation was blown out by means of a strong current of air from a force- pump, and the ebonite plug containing the central electrode was then removed. A fresh electrode was suspended in the vessel and the ionization current due to the ‘case’ activity was measured at 10 and 15 minutes after the emanation had been removed; the activity on the central electrode was measured by suspending it in a vessel of construction identical with that which contained the emanation and observing the ionization eurrent at 20 and 25 minutes after the emanation had been removed. The activity when in equilibrium with the ema- nation was then calculated in the usual manner. The diagram of connections is the same as that given in the previous paper and is reproduced in fig. 1; in the present investigation R and R’ were wire resistances of 50,000 and 100,000 ohms respectively. The Dolezalek electrometer had a platinum suspension, and with 120 volts on the needle the sen- sitiveness was 180™™" per volt. C and B represent capacities which could be added to the system by means of the key K, and the total capacity of the system was then increased 21 times. A potentiometer device, not shown in the diagram, was employed when measurements of the ionization current: were made ; this device enabled the range of swing of the electrom- eter needle to be so adjusted that its mid-point coincided with the zero of the instrument, a precaution which was especially necessary, when the applied potential was small. Reference should be made to the previous paper for a more detailed account of the apparatus and method of procedure. Experiments with a Cylindrical Condenser of small diameter. 3. In the previous experiments the greatest amount of active deposit that settled on the cathode was about 90 per cent of the total; this occurred for a potential of 4000 volts. It was of interest to ascertain the effect of applying a large potential across a smaller distance so as to obtain very large values for the electric field. For this purpose two cylindrical vessels were constructed of the following dimensions : ei Dip ere ee bg™ finer diamclesm sae. =) 19 Length of central electrode _...._--_- 101 Radium emanation mixed with air at 1 atmosphere pressure was introduced into one of these vessels, and when a positive potential of 3000 volts was applied to the case it was found 818 FA i. Wellisch—Distribution of the Active Deposit that about 86 per cent of the deposit settled on the cathode. In all probability some part of the cathode activity made its way to the ebonite insulation, but there did not appear to be any gain in the cathode deposit as a result of decreasing the cross-section of the containing vessel. Cathode Deposit in dry Air at different pressures. 4, Throughout the remainder of the experimental investi- gation use was made of the two cylindrical vessels which had been employed in the previous research. These vessels were identical in construction and the dimensions of each were as follows: Height fimside)s: 2.228) ee ae eee eee 140™™ Innérudiametere: 2.) sae ere ee 58 Exposed length of central electrode _._ 132 Diameter of central electrode __.-__-- 1°83 The inner electrodes were made longer than those which had previously been employed, and care was taken that no appreciable part of the active deposit was able to settle on the ebonite insulation. During the course of the present experi- ments a fact was noted which had previously escaped observa- tion. Discrepancies, in general small, occurred in the values for the cathode deposit when the experimental conditions ap- peared to be identical. Repeated attempts to ascertain the cause of the discrepancies were for a long time unsuccessful, but finally it was ascertained that the inconsistent results arose from the presence of small quantities of water vapor in the gas. In the previous research a test had purposely been made to find the effect of neglecting to dry the gas with which the emanation was mixed ; this test appeared to show that the cathode deposit was unaffected by omitting this precaution. However, the fal- lacy of this result was shown by more thorough investigations. The effect of water vapor is to diminish the cathode deposit and is especially marked when the gas pressure is high and the applied potential fairly small; in these circumstances an amount of water vapor which was not sufficient to produce any percep- tible increase in the recombination of the ions present in the gas might easily diminish the cathode deposit by 30 to 50 per cent. Further illustrations of this effect are given later, but in future experiments extreme care was taken to dry the gas with which the emanation was mixed. This was done by passing the gas through several tubes containing P,O, and glass wool before it entered the testing vessel. The following table gives the values obtained for the cathode deposit expressed as a percentage of the total deposit when the emanation was mixed with dried air at pressures of 210™™ and 760"™ and various positive potentials were applied to the case: of Radium man Hlectrie field. ~ ~~ 319 Percentage Cathode Activity Potential in Volts Air at 210 mm. | Air at 760 mm. 20 Burisce 65:3 40 88:7 74:8 160 88°8 83°9 1030 89°2 89°2 2000 88°8 zs 4000 SEN 89°2 These values have been corrected for the amount of un- charged deposit that diffuses to the cathode during the expo- sure; this correction was made by assuming that the uncharged deposit particles were distributed on the cathode and the case in proportion to the exposed areas, which were as 1:50. The figures given represent accordingly the number of positive car- riers of activity expressed as a percentage of the total number of carriers. | ee In order to demonstrate experimentally that the activity which appeared on the anode was almost entirely due to the diffusion of uncharged carriers, several experimental determi- nations were made of the distribution of the active deposit when a large negative potential was applied to the case. As an example of the results obtained in this connection it was found that when the emanation was mixed with dry air at 1 atmosphere and with a negative potential of 160 volts, less than 2 per cent of the total deposit appeared on the central electrode (anode), showing that no appreciable part of the active carriers are negatively charged. 7 For potentials greater than about 40 volts the percentage cathode activity is independent of the amount of emanation employed unless the amount be inordinately large; over the same range of potentials, moreover, it was verified that the ratio of the two lonization currents obtained for any two poten- tials was identical with the ratio of the corresponding percent- age cathode activities. The values obtained for the percentage cathode activity for air at 210™™ pressure are greater than those obtained in the previous research; it is probable that this dis- crepancy was due to the fact that in the previous experiment some of the ebonite insulation was exposed to the emanation so that the central electrode did not receive all the positive carriers. The insulation would probably act as a partial con- ductor, especially at the lower pressures when it would be exposed to the a-radiation proceeding from a considerable dis- tance. In the present experiment this source of error was carefully avoided, and the result appears to be that the same 320 #. M. Wellisch—Distribution of the Active Deposit maximum value is obtained for the percentage cathode activity both for the lower and the higher pressure. In the previous work the assumption was made that 100 per cent was the limiting value which the cathode deposit ap- proached as the potential was increased, and that even at the low pressures the saturation attained was merely apparent. This assumption was made chiefly as a result of the exper- imental observation that the percentage cathode activity was greater at the higher than the lower pressures. Since, however, it has now been shown that the percentage cathode activity has the same value (89:2) at the higher potentials for both pressures, it appears much better to regard this as the true limiting value. The gradual increase of the values for one atmosphere for potentials above 40 volts shows that the phe- nomenon of columnar recombination is present; the active deposit particle recoils into the gas after the expulsion of the a-particle from the atom of emanation and tends to recombine with the negative ions which it forms along its path. Experiments made with a steel instead of a brass central electrode gave the same limiting value for the percentage cathode activity, indicating that this value does not depend upon the nature of the material of which the electrodes are composed. | At low pressures, as is well known, a considerable number of the active deposit particles may reach the walls of the con- taining vessel before their velocity is sufficiently reduced to enable them to be directed. by the electric field. With air at a pressure of 6™" and with 180 volts the percentage cathode activity was found to be 66-7. Experiments with small applied Potentials. 5. The experiments described in the preceding section refer to potentials for which the distribution of the active deposit was independent of the amount of emanation employed. For smaller potentials the distribution depends considerably on the amount of emanation ; this arises from the fact that with these potentials recombination can occur between the positive par- ticles and negative ions which are produced in the volume of the gas, whereas for the larger potentials recombination can only occur to any appreciable extent with negative ions which are present in the same column as the active particle. A number of experiments were performed to ascertain in what manner the cathode deposit depended upon the amount of emanation for any applied potential, and especially to see whether the distribution would vary in the same way as the ionization current which passed through the gas during the exposure. of Radium in an Hlectric Field. B21 In fig. 2 there are given two sets of curves, which rep- resent the results obtained in this series of experiments. The abscissee represent the ionization current in scale divi- sions per sec (with added capacity) due to the emanation and active deposit in equilibrium when a positive potential of 160 volts was applied to the case. Inasmuch as this potential afforded the same percentage (viz. 94:3) of the saturation current whatever amount of emanation was employed, the abscissee (denoted by L,,,) serve as a measure of the saturation current. Fie. 2. | CONTINUOUS CURVES: LONIZATION BROKEN CURVES: ACTIVITY ! ON CURRENT AT 160 VOLTS: Tico ! i 5.00 6-00 7.00 -10 ne 3.00 4.00 t) 1.00 2.00 The continuous curves in fig. 2 have as ordinates I,/I,,,, i. e., the value of the current obtained with V volts applied to the case expressed as a fraction of the current obtained when 160 volts were applied. The broken curves refer to the active deposit and have as ordinates A,/A,,,, i.e., the cathode deposit obtained with V volts applied to the case expressed as a fraction of the cathode _ deposit obtained when a positive potential of 160 volts was ap- plied. As mentioned above, the cathode deposit obtained for a potential of 160 volts was only 83:9 per cent of the total amount, and the maximnm amount obtainable on the cathode for very large potentials was 89-2 per cent of the total. 322 EF. M. Wellisch— Distribution of the Active Deposit By plotting the curves in this manner the two sets become comparable; the continuous curves afford a measure of the fraction of the total number of positive ions which reach the cathode corresponding to any potential V, while the broken curves similarly afford a measure of the fraction of the total number of positively charged particles which settle on the cathode. A very large number of experimental results were used in order to plot the curves; for the sake of simplification the individual results are not recorded in the diagram. The curves in fig. 2 all refer to the values obtained when the air with which the emanation was mixed was thoroughly dried as described in Section 4. The effect of a small amount of water vapor was especially marked when the applied potential was small. In illustration of this point some of the results obtained for dried and undried air are recorded below: Air at 1 atmosphere : V = 8 volts dried with special caution containing slight traces of water vapor It is worthy of notice that the presence of small quantities of water vapor does not appreciably diminish the fraction of posi- tive ions which reach the cathode, whereas the effect on the num- ber of positively charged deposit particles is considerable. It has for some time been known that water vapor is effective in causing increased recombination of ions, but the above results serve to show that the ions are not nearly so sensitive to the presence of vapor as the active deposit ee Referri ing again to the curves of fig. 2, it is seen that in gen- eral the ‘activity’ curve for any given voltage lies below the ionization curve for the corresponding voltage. This is almost certainly to be ascribed to the increased recombination with negative ions which occurs with the active particles as com- pared with the positive ions even when the air with which the emanation is mixed is thoroughly dried. Cathode Deposit for very small quantities of emanation in dry Air. 6. If the curves in fig. 2 are produced so as to intersect the axis of ordinates, we obtain points which afford a measure of the fraction of ions and of positively charged deposit particles which would be obtained by the application of the corresponding | Eclomope ome | | - | of Radium in an Electric Field. 323 potential when the air in the ionization vessel contains only a very small amount of emanation. These points are plotted both for ionization current and activity as separate curves in fig. 3; they may be regarded as limiting curves which corre- spond to the absence of volume recombination in the vessel even at the smallest potentials employed. The upward slope of the curves is due entirely to the fact that increasing poten- tials prevent more and more the recombination of the positive ions or particles with negative ions which are produced inside the a-particle column. It will be seen from the curves that any given potential brings over to the cathode a larger fraction of ions than of pos- FIG. 3: 0 i i ne eee Do ano 9 100. +O 120. 130 +140 +150 160 VOLTS. itively charged deposit particles; at a potential of about 40 volts the two curves practically coincide. The difference be- tween the two curves can be explained by supposing that the negative ions which are produced in the column recombine with the positively charged active particles with greater facility than with the positive ions. Emanation mixed with Carbon Dioxide, Hydrogen, and Kthyl Ether. 7. When the emanation was mixed with dry CO, at various pressures it was found that the maximum value obtained for the percentage cathode activity was 80°7. In order to obtain this value with potentials less than 1000 volts the pressure had to be less than about 150™”. 324 HL. M. Wellisch—Distribution of the Active Deposit When the emanation was mixed with dry hydrogen the max- imum value obtained for the percentage cathode activity was 89:2, the same as that obtained with air. This value could readily be obtained with a potential of 160 volts and with hydrogen at a pressure of 1 atmosphere, showing that there is very little columnar recombination in this gas. Hydrogen was found to be particularly sensitive to the presence of small traces of water vapor; the effect of the water vapor was to in- crease the potential necessary to obtain the same limiting value. Inasmuch as the presence of minute quantities of water vapor resulted in a marked diminution of the amount of active deposit which settled on the cathode, it became of interest to ascertain the percentage of positively charged carriers which would result from mixing the emanation with a vapor. For this purpose ethyl ether was chosen; any gas which remained in the vessel was swept out by a stream of ether which had previously passed through P,O,. The following results were obtained : Pressure Potential Percentage Cathode Activity mm Volts 82 160 6°4 85 1070 9°8 128 do 10:0 235 | do 10°8 At the highest pressure there was a large current passing through the vapor during the activation due mainly to the fact that the ether being near the point of condensation was partly conducting; this conduction current may have been respon- sible for the increased amount of the cathode deposit at the highest pressure. Apart from this it appears that for ether vapor the limiting value of the cathode activity is approxi- mately 10 per cent. Summary and discussion of results. 8. When the emanation is mixed with any gas there appears to be a definite limit to the fraction of the active deposit which settles on the cathode. This limit is independent of the pres- sure of the gas, provided it is high enough to prevent the deposit particles from recoiling on to the walls of the vessel ; it is in general dependent on the nature of the gas. This lim- iting value is in general obtained only with large potentials ; with smaller potentials the fraction of the cathode deposit is — ee: of Radiwm in an Electric Field. 325 decreased as a result of columnar recombination of the posi- tively charged particles with negative ions; and with very small potentials the charged particles recombine with negative ions in the volume of the gas.. Small traces of water vapor have a considerable effect in diminishing the number of posi- tively charged particles ; the water vapor appears to be effec- tive in bringing about increased recombination, both volume and columnar, between the charged particles and the negative ions. It has been shown in Section 5 that even in air which has been thoroughly dried the recombination between the charged deposit particles and the negative ions is greater than the recombination between the positive and negative ions. This result, which is in all probability to be ascribed to the larger size and mass of the deposit particles, is not in accord with the experimental result of H. W. Schmidt,* who came to the con- clusion that as far as recombination and mobility are concerned the active particles behave as positive ions. The process which accompanies the deposit of the active particles on the cathode appears to be most suitably explained in the following manner. At the moment of expulsion of the a-particle from the atom of emanation the residual part recoils into the gas ; in air at a pressure of 1 atmosphere the range of this recoil atom has been shown to be about 4,™™. As it moves through the gas the recoil atom produces a large num- ber of ions and in the act of ionization it is possible that the recvil atom may lose its positive charge. On the other hand recoil atoms which at any time are uncharged may regain a positive charge, so that if we consider a large number of recoil atoms there will at any given moment be a certain fraction which carry a positive charge, the remainder being practically all neutral. The process is in many respects similar to that which is known to occur in the case of canal rays. During the motion of recoil the atom is practically unaffected by any applied electric field, so that initially the relative number of uncharged and charged recoil atoms is independent of the applied potential. However, when the recoil atom has reached the end of its path, if it be positively charged it may lose its charge by recombination with a negative ion formed in the column; this recombination can be prevented by increasing sufficiently the applied potential. Moreover for small applied potentials a positively charged recoil atom may recombine with a negative ion in the volume of the gas. When both columnar and volume recombination are avoided by the application of a sufficiently high potential the distribu- tion of the active deposit on the electrodes is determined *H. W. Schmidt, Phys. Zeitschr., ix, p. 184, 1908. 326 EF. M. Wellisch—Distribution of the Active Deposit entirely by the relative number of charged and uncharged car- riers resulting from the recoil of the atoms of Ra.A in the gas. Under these circumstances we should expect that the distribu- tion should be independent of the pressure of the gas because the recoil atom will meet the same number of gas molecules before it is brought to relative rest. Of course if the pressure is too low an appreciable number of active deposit particles will recoil on to the walls of the vessel and in this manner the cathode deposit will be diminished. Although nothing has been established in this research with regard to the velocity of the recoil atoms when moving under the influence of an electric field, nevertheless there is distinct evidence that, as far as diffusion and recombination are con- cerned, the recoil atoms behave differently from the positive gas ions. It has been shown in Section 5 that, when recom- bination occurs between negative ions on the one hand and positive ions or positive recoil atoms on the other hand, a con- siderably smaller fraction of recoil atoms than of positive ions is received by the negative electrode. This is especially the case with moist gases, but even in gases which had been dried with the utmost care the difference is well marked. An examination of the curves of fig. 3 seems to afford further information in this connection. The curves may be regarded as giving the fraction either of positive ions or of positively charged recoil atoms that is received at the negative electrode jor any given potential, volume recombination being supposed to be entirely absent. It will be noticed that these curves cut the axis of ordinates at the points marked .7 and .4, these points representing respectively 66 per cent of the total num- ber of positive ions and 38 per cent of the total number of positively charged deposit particles. This type of curve has already been treated by Wellisch and Woodrow* for the case of the columnar recombination resulting from a-particle ioniza- tion. It was shown by them that the ordinate of the point of intersection represents the fraction of the total number of ions which escapes from the a-particle column as a result of molec- ular agitation and diffusion. Inasmuch as volume recombina- tion is absent these ions are brought over to the electrodes by a very small electric field. If we draw through the point of intersection a straight line parallel to the axis of potential and if we refer the curve to this straight line as a new axis of potential, then the new ordinates will indicate to what extent the electric potential is effective in preventing recombination between those ions which still remain in the column after the initial diffusion has occurred. If we treat the curves of fig. 3 in a similar manner we see that, whereas in the vessel employed * Wellisch and Woodrow, this Journal, September, 1913. 4 oat Ay of Radium in an Electric Field. 327 66 per cent of the positive ions on the average escaped from the a-particle column, the corresponding figure for the posi- tively charged recoil atoms was only 38 per cent. This slow- ness with which the recoil atoms diffuse is readily ascribable to their relatively large size and mass. Of those ions and recoil atoms which do not escape by diffusion from the column approximately the same fraction is brought over by any given potential; it seems that there is here some compensating influ- ence at work ; probably the greater tendency of the recoil atoms to recombine with negative ions is partly balanced by the smaller number of encounters with these ions. The existence of a definite limiting value to the percentage cathode activity has been ascribed above to a continual process of gain and loss of charge which occurs during the recoil motion of the active deposit particle. It is to be expected that this hmiting value will depend upon the nature of the gas into which the particle recoils ; the experimental determination showed that this was in general the case although the limiting value for hydrogen was within the limits of error the same as that for air. The fact that the value for ether is as small as 10 per cent is surprising and is in all probability to be ascribed to the ease with which the molecules of ether are ionized. 328 Hutchins—Adjustment of the Quartz Spectrograph. Art. XXXIII.—Adjustment of the Quartz Spectrograph ; by C. C. Hurcnrs. Tue most common form of quartz spectrograph is con- structed with a single Cornu prism with simple collimating and camera lenses of right and left rotation, and is the form to which the following remarks apply. It is an extremely use- ful type of instrument for recording the complete spectrum easily accessible to photography, and in the ultra-violet has a resolving power only exceeded by a large grating. It would doubtless find more extended use were it not for the very tedious operation of putting it into perfect adjustment, com- plete directions for which do not seem to be easily accessible. Eder,* who had the advice and assistance of Schumann in the construction of his apparatus, after giving incomplete direc- tions for adjustment dismisses the matter with the remark that: “Die Ermittlung der zweckdienlichsten gegenseitigen Stel- lung von Collimator,: Prisma und Platte ist eine zeitraubende ye DSI One well-known European maker furnishes an instrument ready adjusted for use. The writer has examined and used two of these, both large and expensive instruments, and has found their performance far from satisfactory. The makers have in fact not made use of easily available information in their design. Owners of such instruments will be glad to know that they are capable of great improvement, while those having the type in which all adjustments must be made by the user, will, it is hoped, have their task considerably light- ened by the following directions. Lens focus.—It is important that the lenses should not be of too short focus. For a prism of medium size—say 4°™ high by 5 on the face, plano-convex lenses of 70° focus for yel- low sodium light are correct, and for the following reasons : i. If the optical parts are good that focal length of camera lens is needed in order to realize upon the photographie plate the full resolving power of the prism. ’ 2. With the best adjustment possible the spectrum does not le in a plane but along a diacaustic curve to which the plate must conform, and with a camera lens of 70° focus the result- ing curvature is about as great as the ordinary commercial plate will bear without danger of breaking,—in fact it is safer to sort out any very thick plates and to use them for other purposes. The plate holder.—As is well known, the plate makes an angle of about 25° with the axis of the camera lens, and should * Beitrage zur Spectralanalyse. alot ia. , t Hutchins—Adjustment of the Quartz Spectrograph. 329 be slightly adjustable about that position. Any projecting portions of the plate-holder, at the ends of short waves, that might prevent the oblique rays from reaching the very end of the plate, should be cut away; for, with a focus of 70° the spectrum just occupies the length of a 10-inch plate. The plate should be firmly held by buttons or otherwise and bent over ways along its edges to a curve whose radius is four times the focal length of the camera lens for sodium hight. Bigous of the collimator.—The distance of the slit to the collimator lens should be 87 per cent of the focus of the colli- mator lens for sodium light. Adjustment of the prism.—The collimator and camera lenses should come close up to the prism. Lay off on a sheet of zinc an angle of 55°°3, cut out and file the edges true. Lay one edge of this templet across the front of collimator and rotate the prism until its face fits the other edge of the templet. This adjustment causes light of wave-length about 2025 to pass at minimum deviation, and is a much more ready means of set- ting the prism than is finding the minimum deviation by suc- cessive exposures and rotations of the prism, while at the same time it is sufficiently accurate for all purposes. The angle of the prism is supposed to be 60°; should it be otherwise it is merely required to calculate, in any case, the deviation for dX 2025 and cut the templet accordingly. Adjustment of the camera.—The spark spectrum of copper is excellent for adjusting purposes. The lines are not remark- ably sharp but are numerous and well distributed throughout the spectrum from the red toX 1979. Using a high-tension transformer (Woods’ Cail), large condenser, Seed No. 26 plate, two seconds was found to give a well exposed negative from dr 5000 to A 2150. A valuable addition to the apparatus is a shutter hinged on the inside of the camera, and movable by a handle from with- out. When swung parallel to the plate it covers all but the extreme ultra-violet end of the spectrum and enables giving a long exposure to the shortest waves without over-exposing the remainder. To get the line 1979 from one-half to one minute is required. The camera is supposed to be furnished with some sort of focussing scale, and further, a scale for measuring the plate inclination. An unexposed but fixed plate being placed in the plate- holder it may be focussed at the visible end of the spectrum, which shonid le at the extreme end of the plate. The best focus being found, draw out the camera 3 or 4 millimeters. Now with a plate in the camera make an exposure near the edge of the plate, move the camera in one millimeter at a time 330 Hutchins—Adjustment of the Quartz Spectrograph. and advance the plate each time, so as to secure a succession of images. From an inspection of the resulting negative the point of sharpest focus at the middle of the plate may be found. Ona plate 2 inches wide 6 or 8 exposures may be made. The nega- tive obtained as above will probably also show which way the plate must be inclined in order to bring the ends into focus, which is accomplished by successive small changes of inclina- tion and exposure as outlined above. When the proper incli- nation is found, it is best to go back and change the focus by fractions of a millimeter at a time in order to secure the finest definition possible. The operator is advised to use short expo- sures, as over-exposed lines often present the same appearance as lines out of focus. An improvement in the definition in the region of long waves may often be effected by partial screening of the prism by placing stops over the lenses. With a prism 4™ high and 5° on the face the writer uses stops of 3°5° opening. This opening being greater than the curtate face of the prism, there is no loss of resolving power, and the loss of light is, in all ordi- nary cases, immaterial. With a good optical equipment the above proceeding should result in excellent definition from end to end of the plate, the lines showing sharp under magnification and free from wings. Bowdoin College, Brunswick, Me., July 17. Fenner—Stability Relations of Silica Minerals. 331 Art. XXXIV.—The Stability Relations of the Silica Minerals; by Crarrence N. Fenner. Introduction. Determination of the inversion points between quartz and tridymite and between tridymite and cristobalite. The appearance of unstable phases. Suggested explanation of anomalous results previously obtained. Natural occurrences of tridymite and cristobalite. Effect of pressure upon the quartz-tridymite inversion. Information to be obtained from the study of tridymite-bearing rocks. Physical properties of artificial quartz, tridymite, and cristobalite. Preparation of quartz in aqueous solution. General observations on the quartz-tridymite-cristobalite inversions. Low temperature inversions. Relations of chalcedony to other forms of silica. Fusion of cristobalite and quartz. Summary. INTRODUCTION. Mucu work has been done at various times on the relations between the different forms of silica which are found as natu- ral minerals, and the Jiterature of the subject is extensive. A portion of what has been written has been based upon labora- tory experiments, a portion upon observation of natural occur- rences, and still a third portion upon theoretical considerations. Each method of attack, when properly applied, is a legitimate means of attempting to arrive at a solution of a problem, and in the paper which follows, each will be resorted to to a certain . degree, but chief stress will be laid upon the results attained by experimental investigation. In spite of the work done upon the problem, the results pre- viously attained can hardly be considered to be satisfactory. The conclusions reached from the experimental side were not concordant; those derived from observation of natural occur- rences indicated the relations in a general way, but were not sufficiently explicit and also contained contradictions which no theoretical consideration was able to clear up. For these rea- sons, the Geophysical Laboratory took up the problem several years ago, and the work done at that time resulted in consider- able advance in our knowledge of the relations of the several forms. In the first publication in which the matter was dis- _cussed,* the inversion point between quartz and tridymite was placed at approximately 800° and the melting point of tridy- mite (or, more properly, the change from the crystalline to the amorphous condition) was considered to be about 1600°. At _* The Lime-Silica Series of Minerals, A. L. Day, E. S. Shepherd and F. E. Wright, this Journal, (4), xxii, 265-302, 1906. Am. Jour. Sci.—FourtTH SERIES, Vout. XXXVI, No. 214.—OctoseEr, 1913. 22 382 Fenner—Stability Relations of Silica Minerals. that time the relations were supposed te be much more simple than was found shortly afterward to be the case. This was due principally to the fact that the mineral cristobalite was almost unknown at the time, and only the relations between the two forms, quartz and tridymite, were considered. In reality, the products classed as tridymite consisted at times of tridymite and at other times of eristobalite. The optical properties of the two are so similar that the fact that two different products were obtained was not realized, although it was noted that the index of refraction in some preparations was slightly higher than normal. It may be noted also that the values of refringence and birefringence of cristobalite given in some of the standard mineralogies are in error. By consulting Mallard’s* original paper, from which they are quoted, it is obvious that the value of the index has been mis- printed and that of the birefringence probably misinterpreted. In a second paper from the Geophysical Laboratory,t deal- ing with the matter, attention was called to the maccuracy in some of the statements of the preceding paper, and it was stated: ‘‘ Recent work on the silica problem, at low tempera- tures, has shown it to be much more complicated than was at first supposed. In fact, several phases have now been found to occur in that region which were not disclosed by the first investigation. The problem as a whole is not simple, and has not yet been satisfactorily solved, so that in the following paragraphs only a report of progress can be made.” Through the courtesy of Professor Lacroix of Paris, to whom specimens of the artificial crystals obtained by the devitri- _ fication of silica glass and by heating quartz at high tempera- tures, had been sent, it had been shown that these were probably cristobalite and not tridymite as had formerly been supposed. The acceptance of this view, however, seemed to open up again the whole question, for if this mineral was cristo- balite, what was the position of tridymite in the series? In fact, beyond the determination that tridymite and cristobalite were high temperature forms, nothing seemed certain regard- ing their relations. This uncertainty was increased by the fact that other investigators had reported the artificial production of tridymite and cristobalite under such conditions that it seemed even a question whether they were properly high tem- perature minerals. The manner of their occurrence in nature also suggested the possibility that their field of stability was in the region below 800°. On the other hand, Professor Koenigs- * KH. Mallard, Bull. Soc. Min., xiii, 175, 1890. + The Binary Systems of Alumina with Silica, Lime and Magnesia, HE. S. Shepherd, G. A. Rankin and F, E. Wright, this Journal, (4), xxviii, 293-333, 1909. Fenner—Stability Relations of Silica Minerals. 333 — berger,* in consideration of the evidence which he believed to exist for the precipitation of quartz from magmas at tempera- tures as high as 1000°, had expressed the opinion that the transformation quartz-tridymite might perhaps be monotropic. The low temperature inversion of a into 8 quartz, of a-8 tridymite, and of a-8 cristobalite, was described in the later paper from this Laboratory, to which reference has been made. The velocity with which these reactions occur, compared with the reluctance with which quartz inverts into tridymite or eristobalite, had been noted as a very striking phenomenon, for which no explanation could be suggested. Further investi- gation of these reactions seemed desirable. These problems were held in abeyance by the Laboratory for some time in the stress of other work. At the first oppor- tunity, however, they were again taken up in the hope that with the advantage of the knowledge gained from previous investigations, the problem might be cleared up. The specitic points which were obscure and for which a solution was desired, were the following: 1. Are the relations between the forms chalcedony, quartz, tridymite, and cristobalite monotropic or enantiotropic ? 2. If enantiotropic, what are the fields of stability of each, and what are the inversion points ? 3. What is the explanation of the observed fact that both in natural occurrences and in the results of experimental work, quartz, tridymite, and cristobalite appear to have been formed at times almost simultaneously, or at least under conditions under which not all could be stable ? 4. What is the reason for the remarkable velocity of the a-8 inversions of quartz, tridymite, and cristobalite as com- pared with the slowness of transformation of each of these minerals into one of the others ? 5. To which form of silica does the previously determined melting point belong ? To these may be added a sixth question which arose in the course of the work and, from its theoretical importance, demanded solution. 6. Is the temperature of inversion of a into f cristobalite a fixed point and is its apparent variability due to some such recognized factor as impurity of material or lag, or is it actually a movable point and therefore an extraordinary type of phe- nomenon ? To some of these questions the present investigation has supplied categorical answers. To others the direction in which experimental work points for the explanation brings one upon debatable ground and caution must be used lest positive con- * J. Koenigsberger, Neues Jahrb., Beilageband, xxxii, 113, 1911. 3384. Henner—Stability Relations of Silica Minerals. clusions be arrived at without supplementary evidence. The explanations suggested for these debatable problems must be looked upon merely as contributions toward a final solution of the theoretical questions involved. After the investigation had been under way for some time a preliminary paper was published.* In this a brief outline was given of the chief results obtained up to that time. In the present paper it has seemed desirable to present the results as a consistent whole, so far as possible, and in order to do this all results of importance will be given and their relations discussed without much regard to the previous publication. DETERMINATION OF THE INVERSION PoINTS BETWEEN QUARTZ AND TRIDYMITE AND BETWEEN TRIDYMITE AND CRISTOBALITE. As previous work had demonstrated that the above inversions take place very slowly, and that the minerals may be heated at high temperatures and for long periods with no indication of inversion or with only partial inversion as the result, it was realized at the outset that it was necessary to employ a flux or, catalytic agent of some sort to hasten the process. This should be such a material as would melt at a comparatively low tem- perature and would not be volatilized to a serious degree at high temperatures. It should, moreover, not dissolve silica in large quantity or enter into solid solution with any of the silica minerals. A number of reagents were tried at various times, such as potassium and lithium chlorides, boric acid, and salt of phosphorus, but the one which best fulfilled the requirements was found to be crystallized sodium tungstate (Na, WO,, 2H,O). This possessed the added advantage that it could be removed by simple washing with water. The only difficulty found was that at high temperatures (1400° and over) it dissolves a con- siderable quantity of silica, and if much is used nothing but a glass results. This difficulty was easily overcome by using a- small quantity. For reactions at a high temperature, that is, in the neighbor- hood of the tridymite-cristobalite inversion-point, sodium- potassium silicate may likewise be employed. It offers no spe- cial advantages over sodic tungstate, except that it may. be regarded as more similar in its nature to a magmatic melt. In establishing the inversion points, the method of procedure - was simple in principle but rather tedious in its application because of the slowness with which equilibrium is established. A charge was first prepared by melting sodic tungstate in a small platinum crucible over a Bunsen flame and adding the respective form of silica and mixing with a platinum stirrer. The crucible, to which a short wire “had been fused on each ' *The Various Forms of Silica and their Mutual Relations, C. N. Fenner, J. Wash. Acad. Sci., ii, 471-480, 1912. Fenner—Stability Relations of Silica Minerals. 335 end of a diameter so as to form a sort of bucket, was then sus- pended from corresponding wires hanging from ‘the lower end of a Marquardt porcelain tube. A thermoelement, of the stand- ard material used in the Geophysical Laboratory (pure plati- num against 90 Pt.10 Rh), was run down through the Marquardt tube and into the charge. The thermojunction within the charge was bare, while the upper portions of the wires were insulated from each other by inclosing them within. capillary porcelain tubes. The upper ends of the thermoelement wires were attached to corresponding terminals of the ice-bath, from which copper wires led to the potentiometer in the usual man- ner. Electromotive force was read from a mirror galvanom- eter in connection with the potentiometer, in the usual form adopted by the Geophysical Laboratory, whose details have been fully described in previous papers* and need not be gone into. Full precautions against leakage of electric current into the galvanometer circuit were employed. A check was main- tained on the accuracy of the readings of the thermoelements by occasional calibration by comparison with the melting points of standard substances (MgCa(Si0,),=1391°2°, Li,SiO,=1200°, gold = 1062°4°, Na,SO, = 884°, zinc = 419-4°). By means of the device described, the bucket containing the charge could be inserted into a furnace heated by an electric eurrent passing through a platinum resistance coil, and sub- jected to whatever heat treatment was desirable. If one heats ground quartz in sodic tungstate at 1000° or more for several hours, it is found to have been more or less completely converted into tridymite. On the other hand, if tridymite so prepared is mixed with tungstate and heated at 800° for a long period, innumerable small quartz crystals can be perceived in the resultant product. Somewhere between these two temperatures, therefore, there must lie an inversion- point. At high temperatures the transformation of quartz into tridymite can easily be carried to completion. The reversion of tridymite into quartz can likewise be completely carried out but is more sluggish, and generally no attempt was made to convert the whole charge because of the length of time which would be required. The quantity of quartz increases with the period of heating, but having once established the rever sibility of the process, nothing would be gained by continuing it for excessive periods. It simply remained to deterniine a temper- ature above which tridymite could be recognized as having been obtained from quartz and below which quartz as obtained from tridymite. It was found that within a few degrees of the *A.L. Day, EK. T. Allen, and J. P. Iddings, Publication No. 31, Carnegie Inst. of Washington ; A. e Day, E. S. Shepherd, and F. E. Wright, in this Journal, (4), xxii, 265- 302, 1908; W. P. White, in Phys. Rev., xxv, 334-352, 1907 ; and in this Journal, (4), Xxviii, 459-489, 1909. 336 FHenner—Stability Relations of Silica Mineruls, inversion-point the velocity of transformation was extremely small and a long period of heating was required to insure the appearance of the stable phase, but outside of this range a noticeably less time was required. Fine grinding apparently did not increase the velocity of the reaction. As the range within which the inversion lay was gradually narrowed down great care was exercised in the regulation of furnace temperature. The method of procedure was to hold the charge for a long period at some temperature previously decided upon, keeping close watch to see that some unexpected variation in the strength of the heating current did not cause a departure from this temperature. When necessary to continue heating from one day to the next (as was frequently the case) the current from the generator was replaced by that from stor- age batteries. These batteries possessed very constant voltage and were of such capacity that in a run of fifteen or sixteen hours the temperature of the furnace dropped only 8-10 degrees. A description of several of the more significant experiments follows : No. 82. A mixture of finely ground silica glass with sodic tungstate ; length of heating, 11 hours 20 minutes, during which the temperature was kept very close to 865°, extreme variations 863°-875°. The product was essentially tridymite, but distinct quartz grains were found, often with bipyramidal terminations. (As will appear a little later, the tridymite was an intermediate stage, and the point of significance is the fact that it was changing to quartz at this temperature.) No. 102. A mixture of artificial tridymite and sodic tung- state; length of heating, 734 hours; utmost variation, $54°— 864°; general temperature, 858°. The product was still mostly tridymite, but there were very numerous quartz crystals, mostly as nuclei of tridymite aggregates. No. 103. Ground quartz with sodic tungstate; length of heating, 24 hours; general temperature, 875°; range, 865°- 877°; product, guartz with considerable tridymite in hexagonal plates. 7 Other experiments of the same nature might be described, confirming the above results and fixing the temperature of inversion at a point very close to 870°. Because of the great difficulty of keeping the temperature of the furnace constant for such a length of time, some latitude must be permitted in expressing the temperature of inversion, but it is believed to lie with 10° of 870°. It has not been considered necessary to tabulate the results of experiments conducted much above or below 870°, for at such temperatures quartz changed to tridymite in the one case and tridymite to quartz in the other in an unequivocal manner. a? t's? Fenner—Stubility Relations of Silica Minerals. 387 In determining the inversion-point between tridymite and cristobalite the same general method of procedure was followed, but the details were slightly different. As before, tempera- tures were first found above which tridymite changed to cristo- balite and below which cristobalite changed to tridymite, and the range was gradually brought within narrow limits. For final determination, however, it was not considered advisable to depend upon the constancy of the storage batteries over night, because of the draught which would be imposed upon them by the heavy heating-current. Therefore the charge under treatment was withdrawn at night and quickly cooled, and replaced in the morning at the same temperature and heat- ing continued. No difference in principle was involved in thus breaking up the time of heating into several periods. _ The final experiments were as follows: No. 114. Mixture of cristobalite and sodic tungstate ; length of heating, 4% hours at 1460°+2°; the product is still mostly cristobalite, but there is a very appreciable quantity of tridymite. No. 117. Mixture of tridymite and sodic tungstate; length of heating, 10 hours 25 minutes at 1475° + 2°; product is mostly tridymite, but with considerable cristobalite. No. 122. Tridymite and sodic -tungstate; 214 hours at 1470° + 2°; no cristobalite discoverable. No. 120. Cristobalite and sodic tungstate; 16 hours at 1470° + 2°; no tridymite discoverable. | From these experiments, in connection with many others at higher and lower temperatures, which gave consistent results, we appear to be perfectly justified in placing the tridymite- ceristobalite inversion temperature at 1470° + 10°. The enantiotropic relations were confirmed by numerous experiments, modified in various ways. Starting with quartz either tridymite or cristobalite may be obtained, according to the temperature used. Likewise, tridymite may be converted into quartz or into cristobalite, and cristobalite into quartz or tridymite. Silica glass and amorphous precipitated silica have. likewise been converted at will into any one of the three crystal- line modifications. In all its relations to other forms precipi- tated silica behaves in the same way as silica glass, and may probably be considered as the same chemical substance, differ- ing only in its state of physical division. There can be no doubt that quartz, tridymite, and cristobalite are enantiotropic forms, each with a certain range of stability. Their general equilibrium relations are shown in fig. 1, in which the codrdinates are temperature and_ vapor-pressure. The absolute values of vapor-pressure are, of course, unknown, but we may make use of the principle that the vapor-pressure rises with temperature, and that the vapor-pressure of a stable 338 Lenner—Stability Relations of Silica Minerals. form is less than that of an unstableform. An inversion-point lies at the intersection of two vapor-pressure curves. These same relations apply to the functions free energy and thermo- BiG sel. PRESSURE TEMPERATURE ofll ofl eOLVl oSc9l 's7evinva oSZS 00Z8 Fie. 1. Stability relations of the silica minerals. dynamic potential, and, as absolute values are unknown, the vapor-pressure codrdinate could as well be considered as a coordinate of free energy or thermodynamic potential. Fenner—Stability Relations of Silica Minerals. 339 Tue APPEARANCE OF UNSTABLE PHASES. In experiments on the relations of the various forms, certain phenomena were met which were rather puzzling at first, but after their explanation was perceived it was recognized that they threw considerable light upon discrepancies shown in the results obtained in previous work upon the silica minerals, and upon the conditions under which tridymite and cristobalite have been formed in nature. It was found, for example, that if silica glass or precipitated silica was heated with sodic tung- state for a number of hours at 800-850°, not quartz but tridy- mite was first obtained. It was only after much longer heat- ing that quartz crystals began to appear, although this is the stable form at that temperature. It seems that in the passage from the amorphous condition to quartz, the whole is first converted into the intermediate form tridymite, and only secondarily into quartz. Likewise, if either amorphous modification is heated with- out a flux at 1300° or 1400°, cristobalite alone is obtained, although the temperature is within the range of tridymite. The process halts at the cristobalite stage, and can only be carried to completion by the addition of a flux. Similarly, ground quartz heated without a flux at high temperatures but still below the 1470° inversion-point is changed to cristobalite and not tridymite, which might be expected. A striking instance of the formation of unstable phases appeared in a series of experiments in which one or another form of silica was heated with a large excess of sodic tungstate over a Bunsen burner. In one instance in which amorphous precipitated silica was thus heated for 48 hours, quartz, tridy- mite, and cristobalite, all in good crystals, were found in the same melt. In other instances, quartz or tridymite or cristo- balite was similarly employed and two or three of the phases were simultaneously obtained. The crystalline outlines were such as to indicate new formation of even that phase which was added at the beginning. Working in this manner one may start with tridymite and, keeping the temperature in all parts of the crucible within the tridymite range, convert part of the tridymite into cristobalite—a result which at first sight seems impossible. _The production of unstable phases in this manner has con- siderable theoretical importance. In its proper interpretation light may be thrown upon some apparent discrepancies in former work and make possible a reasonable explanation of natural occurrences of tridymite and cristobalite. It also seems to have some bearing upon recent theories of the structure of molecules and crystals. It will, therefore, be dis- cussed at some length and an endeavor made to interpret its significance. 340 Kenner—Stability Relations of Silica Minerals. From the standpoint of the kinetic theory, the question of the formation and appearance of a mineral phase may be looked upon as a function of two variables ; first, the prob- ability of the requisite number of moving particles coming together in the pattern appropriate to the structure of the niuineral in question, and second, the strength of the bonds by which the particles thus assembled are held together under the impact of other particles or under the stress of intramolecular forces. Both of these are again functions of the temperature and pressure, but vary with these according to very different laws. Under this conception, when a number of substances enter into a reaction, or when a single substance is subjected to a change of conditions under which it is no longer stable, a cer- tain assemblage of particles characterized by a simple* pattern may be formed at a given temperature and pressure in great numbers, while a second assemblage characterized by a more complex pattern is formed in the same interval in much less quantity; and the relative velocity of formation and destruc tion of the two may be such that the phase appropriate to the first pattern will appear as a new phase of the system, while the second is present in only infinitesimal quantity; but we may easily suppose that each group of the second phase, when once formed, is relatively indestructible under the given con- ditions, while the groups of the first kind are continually breaking down and reforming. The result will be that the phase which appeared with such rapidity at first will gradually yield place to the second phase, which will then be the stable phase. The second phase may, however, under some condi- tions, be formed with such slowness (on account of the small number of free particles which escape from the phase already formed or because of the complexity of its pattern) that it will not appear in recognizable quantity, and the unstable phase will persist indefinitely. By changing the temperature and pressure, we change the two variables according to different laws, and the results obtained as regards the phases which first appear and as regards the phases which are stable, vary accordingly. At transition points the opposing tendencies are in equilibrium, or in other * Simple and complex, as here used, refer to probability or improbability o the particles coming together in the manner to form the pattern in ques- ion. . R. J. Strutt (Proc. Roy. Soc. London, ser. A, 1xxxvii, 302-9) has made some interesting calculations on this sort of molecular statistics. He con- cludes that probably a single collision with a silver surface is sufficient to destroy a molecule of Os, but that a molecule of active N must collide 500 times with an oxidized Cu surface before it is destroyed, and that two mole- cules of Os at 100° must collide 6 x 10'! times before the right sort of colli- sion occurs for the formation from them of 3 molecules of Og. (Chem. Abstracts, vii, 6, 928, 1913.) Fenner—Stability Relations of Silica Minerals. 341 words, the formation and destruction of each of two phases proceed at the same rate. Below the inversion-point the formation of one of the phases exceeds its destruction ; above it the other phase is thus characterized. Let us apply this conception to the specific case of the simultaneous formation of crystals of quartz, tridymite, and eristobalite in a sodic tungstate melt. In this experiment there is some evidence that a reversible reaction of this kind proceeds : SiO, + Na, WO, =~ Na,Si0, + WO,, going from left to right at igher temperatures and from right to left at lower. In this manner a multitude of SiO, molecules are constantly contributed to the liquid, in which they are in active movement. By chance collisions numbers of these meet in such manner as to form groups of definite patterns, which tend to cohere. According to their arrangement, they form the quartz, tridymite, or cristobalite molecules, each of which appears and disappears in countless numbers at each instant. Under the conditions of the experiment, a stream of ungrouped molecules is constantly added to the cooler portions of the melt by the breaking-up of Na,Si0O, (or by con- vection currents from below), yielding such an_ over- whelming excess over what would occur under more uniform conditions of temperature that all possible configurations of grouping (which seems to mean those appropriate to quartz, tridymite, and cristobalite) are formed, and the number of each kind formed is in great excess over those destroyed. Each sort of crystal is, therefore, deposited from the melt. If none of the crystals settled into the hotter regions below, we should ultimately find that after the exhaustion of the supply of ungrouped molecules, two of the kinds of erystals would pass into the third, as for this the excess of production over destruction would be greater than for either of the other two, and this would be the stable form at this temperature; but under the influence of convection currents, the process con- tinues around and around in a circle indefinitely. In the process thus presented, I have conceived that by regular arrangements of the simple SiO, molecule more complex groups corresponding to quartz, tridymite, and cristobalite molecules are first formed in the liquid, and that these again group themselves in appropriate patterns to form the respective crystals. The question may arise whether such primary groupings occur apart from the crystal groupings. There is abundant evidence, however, from various sources, that simple molecules do form groups of this nature in a liquid, so-called associated moleeules. Moreover, evidence will be presented later that eristobalite crystals at least give phenomena which are best 342 Henner—Stability Relations of Silica Minerals. explained by the assumption of two different kinds of molecules in the same crystals. It seems most probable, therefore, in con- sideration of all the phenomena, that different molecular group- ings of SiO, take place in the melt under the circumstances described, and that when crystallization ensues, these complex. molecules arrange themselves in the appropriate patterns corresponding to the respective crystals. The minerals are regarded, therefore, as being not only polymorphic but poly- meric. The reactions of silica which have been mentioned appear to follow very closely the requirements of the principle which Ostwald enunciated and which is known as Ostwald’s rule, or the law of successive reactions. As formulated by him, it is as follows:* ‘In all reactions the most stable state is not straightway reached, but the next less stable or that state which is the least stable of the possible states.” The reason- ing by which he endeavors to show the necessity of reactions taking this course is based upon a consideration of the diminu- tion of free energy of a system. It seems to imply that because the free energy in passing from a stage A to a lower stage C passes through the level B, the phase corresponding to this level must always appear, but there is no necessity that this should hold. The matter resolves itself into the question whether under wnstable conditions the quantity of free energy in a system defines its state. Expressed in this form, we can answer definitely that it does not, any more than the somewhat parallel functions of vapor-pressure or thermodynamic poten- tial. | Applying a kinetic conception, if we can imagine a sodic tungstate melt saturated with simple ungrouped silica mole- cules at 850°, and then allow such reactions as tend toward equilibrium to take place for a minute space of time, while it is probable that cristobalite groups, because of the relative simplicity of structure usually accompanying high temperature forms, will have been produced in greater numbers than tri- dymite groups, yet at the end of a longer interval it is doubt- ful if this would be the case. The strength of the union holding together the members of each cristobalite group would probably be so slight at this temperature that after the rapid attainment of a certain maximum number, equivalent numbers would be destroyed as rapidly as others formed, while the number of tridymite groups would continually increase until the solvent was saturated and crystals were deposited. In the latter sequence of events, the level of free energy represented by B would be that pertaining to a mixture composed mostly *W. Ostwald, Principles of Inorganic Chemistry ; translation by A. Find- lay, 1904, p. 211. Fenner—Stability Felations of Silica Minerals. 348 of tridymite and unassociated silica instead of that pertaining to cristobalite. ( Thus it seems that whether we regard Ostwald’s principle from a thermodynamic standpoint,. applying the principle of minimum free energy, or whether we use a kinetic conception of the process as a guide, its validity as a general law is ques- tionable. Although the reactions of silica show a number of phenom- ena to which Ostwald’s principle is applicable, exceptions are also found. Thus if a mixture of amorphous silica and sodic tungstate is heated to 800-850°, in a few hours only tridymite ean be found. By much longer heating quartz crystals appear. At no stage can cristobalite, the intermediate form between amorphous silica and tridymite, be detected. Likewise, silica glass or precipitated. silica, heated without a flux at any tem- perature at which devitrification occurs, always gives cristo- balite, but just above 1470° it should first give tridymite if Ostwald’s rule applied. Quartz heated without a flux for a very long period at 1300° gives cristobalite, in obedience to Ostwald’s principle. Heated with a flux for three hours at the same temperature, it gives tridymite with no indication of an intermediate cristobalite phase. SuGGESTED EXPLANATION OF ANOMALOUS RESULTS PREVIOUSLY OBTAINED. - From the results obtained by former investigators of the silica diagram, it had been pretty well established that the quartz-tridymite inversion-point lay between 800° and 900°. The exact temperature was rendered uncertain from the fact that in a number of cases amorphous silica was employed as the initial material, which, as we have seen, in the presence of a flux yields tridymite at temperatures considerably below the true inversion-point. The significance of this has been discussed, and it has been shown that with longer heating the tridymite obtained would have gone over into the stable form quartz. Similarly misleading phenomena appeared in the endeavor to determine the position of cristobalite in the series. By heating either quartz or amorphous silica without a flux, cristobalite will be obtained at temperatures much below its field of stability. . 7 These discordant phenomena may all be interpreted as instances in which Ostwald’s principle applies, and their appearance need give rise to no uncertainty. NATURAL OccURRENCES OF TRIDYMITE AND ORISTOBALITE. The mode of occurrence of natural tridymite and cristo- balite implies that in many cases they have been formed as 344, Henner—Stability Lelations of Silica Minerals. . unstable phases. Cristobalite especially could seldom if ever have been deposited as a stable mineral in the circumstances in which it is now found. Its usual occurrence is in cavities in eruptive rocks, which would certainly have been in a fluid con- dition at temperatures within the range of stability of this mineral. The appearance of the inclosing rocks in many cases, however, suggests that the formation of the cristobalite is to be ascribed to its deposition from mutually reacting vapors or to the decomposition of former silicate minerals or siliceous glass by pneumatolytic processes. In either of such modes of action, unassociated molecules of silica would be set free in quantity from their previous state of combination with other elements, and would probably tend to form groups among themselves corresponding to cristobalite. ‘This is perfectly analogous in principle to the formation of cristobalite in tungstate melts overa Bunsen flame at a comparatively low temperature, which was obtained as a result of direct experiment and for which the explanation has been suggested. It is quite certain that for the deposition of the mineral in question under such condi- tions no excessively high temperature is demanded and its presence in no wise implies that the temperature requirements of stability obtained. Many of the occurrences of tridymite are similar and like- wise suggest the intervention of gases in its production, as has been pointed out in a number of instances by A. Lacroix.* An interesting association of tridymite and quartz in hollow sphern- lites of rhyolite is described by Iddings and Penfield,t and appears to be due to processes of this character. The presence of trapezohedral faces on the quartz crystals shows that it is of the a variety, and therefore formed below 575°. In addition to such occurrences, which point to pneumato- lytic action, tridymite is sometimes found as an essential con- stituent of acid effusives, associated in such manner with other minerals as to imply its separation from the melt as a primary constituent. In such instances the implication is simply that at some period in the previous history of the -magma the temperature was such that the excess of silica not required to form other minerals had formed the molecular groupings corresponding to tridymite, and when rapid cooling ensued these groups crystallized out in the tridymite form. The temperature at the time of crystallization may have been either above or below the 870° inversion-point. If below, the viscosity of the melt acted as an effective obstacle to prevent that rearrangement of the molecules which would be demanded to form quartz. With less rapid cooling and especially with * A, Lacroix, Bull. Soc. Min., xxviii, 56, 1905. t Iddings and Penfield, this Journal, (3), xlii, 39, 1891. = Fenner—Stability Relations of Silica Minerals. 345 decrease of viscosity by the retention of volatile substances (mineralizers)—conditions implying a crystallization of the magma under pressure—tridymite if once formed would become unstable at 870° and would pass over into quartz. This matter will be taken up a little later. Through the kindness of Dr. E. 8. Larsen, of the U. 8. Geo- logical Survey, my attention has been called to an interesting occurrence of cristobalite in a basalt found by Dr. Whitman Cross in the Hawaiian Islands. In the calculation of the norm from the chemical analysis of the rock, no olivine appeared, while examination of thin sections showed abundant olivine. The explanation was found in the discovery of small crystals of cristobalite in cavities. In another set of rocks from Colorado which Dr. Larsen brought to my attention, the flow- structure of acid effusives is well developed-and certain of the bands show innumerable tridymite crystals whose arrangement with respect to the other constituents of the rocks indicates their simultaneous crystallization from the melt. It seems probable that these minerals are not so rare as has been gener- ally supposed and that with careful search they might often be found. Emphasis should be laid upon the fact that the presence of cristobalite or tridymite in a rock does not necessarily imply that at the time of formation of these minerals the temperature was above the respective inversion-points (1470° and 870°). Any set of conditions which will bring together quantities of ungrouped SiO, molecules in such a manner as to favor their rapid assemblage in definite groupings without giving time for perfect equilibrium to be established (as in the reactions of vapors) ; or which will suddenly bring a system in which equi- librium prevails into new conditions, at the same time introduc- ing obstacles to the establishment of a new equilibrium (as in the sudden chilling of a melt), will favor the deposition of unstable forms. It is evident that there will be two factors to be considered ; first, the question of whether change of condi- tions has been too rapid for equilibrium to follow, and second, the question as to what was the previous condition from which the state in question has been reached. Certain phenomena which Lacroix and others* have de- scribed, where quartzose inclusions in voleanic rocks have been partly or wholly transformed to tridymite ‘or to tridymite and eristobalite, seem to show that here the 870° inversion- point has been exceeded. Some uncertainty on this point arises from the observation which Lacroix makes+ that, in the * A. Lacroix, Les Enclaves des Roches Volcaniques, 1893; Bull. Soc. Min., xiv, 185, 1891 ; K. v. Chrustschoff, Tschermak Min. Pet. Mitth., vii, 295, 1886. + Les Enclaves des Roches Volcaniques, p. 570. 346 Fenner—Stability Relations of Silica Minerals. eases which he has observed, such newly formed tridymite seems always to be due in some way to the intervention of mineralizers, and, as previously shown, the reactions of vapors are likely to produce tridymite at a temperature below its range of stability. Nevertheless the most probable explanation for the phenomena which Lacroix describes seems to be that the temperature was sufficiently high to break up the quartz mole- cule and give opportunity for the formation of new groupings corresponding to tridymite and cristobalite. | A reproduction of the essential conditions attending the engulfment of quartzose material by a liquid magma was attempted in one experiment. Potassium carbonate, sodium bicarbonate, and ground basalt were mixed in approximately equal proportions, and eight or nine times as much ground quartz was added. ‘The whole was heated in a Fletcher fur- nace to a high temperature (1500-1600°) and melted to a clear, slightly greenish glass, in which small spherulites had formed on cooling. This glass was then placed in the electric furnace and devitrified by holding at 1000° to 1400° for five hours. It was then found to be filled with a mass of tridymite crystals. A portion of this was mixed with a large excess of quartz and the whole well ground. Heated again tor 22 hours at 1200-1400°, the final result was a mixture of tridymite and cristobalite, although the temperature appropriate to the cristobalite region had never been reached. The results are similar in kind to those observed in the basaltic rocks of Mayen,* where quartz — inclusions have been partly converted into cristobalite and tri- dymite, and is to be ascribed to the breaking-up of the quartz molecules by the high temperature attained, giving oppor- tunity for new arrangements to form, without facilitating rearrangement to such a degree that all the groups reached stability. The question arises, whether in the cooling of a magma quartz may appear outside of its range of stability, as several authors have supposed. The possibility of this is not wholly excluded, but nothing has been found in the experimental work which suggests anything of the kind, and on theoretical grounds it appears inherently improbable. The equilibrium from which the magma has cooled is one corresponding to the presence of tridymite molecules in the solution. It is dittcult to conceive the formation and precipitation of quartz from such a solution above the inversion-point, while the precipitation of tridy- mite below this point is perfectly intelligible when the cooling is rapid. The effect of pressure in shifting the inversion-point itself is not here considered, but will be taken up later. * A. Lacroix, Bull. Soc. Min., xiv, 185, 1891. P. Gaubert, idem, xxvii, 42, 1904. Fenner—Stability Relations of Silica Minerals. 347 A question of considerable importance is, whether the gen- eral absence of tridymite in rocks which have cooled slowly (such as large bodies of deep-seated intrusives) must be under- stood as proving that the temperature of crystallization was below the tridymite-quartz inversion-point. Considered solely from the experimental evidence on the quartz-tridymite rela- tions, it may probably be said that the temperature during the jinai stages of crystallization of the quartz was below this point, but nothing is implied regarding the jirst stages ; for if tridymite were precipitated at an earlier stage, but remained in contact with a fluid portion of the magma after the temper- ature dropped below the inversion-point, it would probably pass over into quartz within a short time (probably within a few days). Examples are not lacking in which traces of such inversion appear to survive. The peculiar form of quartz in some eruptives has been thus explained. Professor Lacroix* has found a number of instances of such relations, and Dr. Per Geijert has recently described others. In the examples just referred to, the peculiar form of the quartz bears testimony to the history through which it has passed, but under different conditions, especially those obtain- ing during the crystallization of a coarsely granular rock, the newly formed quartz would undoubtedly tend to assume its proper crystallographic structure, and no evidence of the inter- mediate steps of the process could be found in the final product. Jt is hardly necessary to consider in detail the various nat- ural occurrences of tridymite and cristobalite which have been deseribed in the literature. So far as I have been able to ascer- tain, the descriptions given bear out the principles of origin which have been outlined. EFFECT OF PRESSURE UPON THE QvuARTZ-TRIDYMITE INVERSION. In the preliminary paper on the silica minerals which the writer published, some inquiry was made into the effect which pressure would have in displacing the inversion point. By em- ploying the Clausius-Clapeyron equation (= == : a »,)) and assuming probable values of L, the heat of inversion, and v,—,, the volume change, a displacement (rise) of 0°10537° per atmosphere was deduced. It is doubtful, however, if a cal- culation of this kind serves any useful purpose because of the lack of certainty of the values assumed and the consequent * A, Lacroix: Sur la tridymite du Vésuve et sur la genése de ce minéral par fusion, Bull. Soc. Min., xxxi, 323, 1908. + Per Geijer: Geol. Foren. Forhandl., xxxiv, 1, pp. 51-80, 1913. Refer- ences are given in this paper to instances cited by other writers. Am. Jour. So1.—FourtH Series, VoL. XXXVI, No. 214.—OctToser, 1913. 23 348 FHenner—Stability Relations of Silica Minerals. unreliability of the results and the danger that they will be misinterpreted. The data for such a. calculation would be of great value, but until they are available, we can hardly make a more positive statement than to say that pressure will raise the inversion-point by some unknown amount. INFORMATION TO BE OBTAINED FROM THE STUDY OF TRIDYMITE- BEARING Rocks. A careful study of the relations and characteristics of the minerals in tridymite-bearing rocks should give us important information on certain problems connected with the processes of voleanic activity. The position of the quartz-tridymite inversion-point is within a critical region as regards the temperatures of vulcanism, and the history of the tridymite, as revealed by petrologic study, may, with the accumulation of evidence, be able to settle a number of debated points. The kind of evidence to which I refer may be illustrated by an example. In the set of rocks from Colorado which Dr. Larsen kindly placed at my disposal, I have found certain very sug- gestive features, which appear to show that quartz phenocrysts which were formed in the magma at depth, became converted into tridymite during the process of extrusion. The nature of the evidence is as follows: When in laboratory experiments ground quartz is converted into tridymite in a sodic tungstate flux, it is frequently found that many of the quartz grains retain their individuality during the process, but’are replaced by an aggregate of tridymite crystals. If the replacement has not been quite complete, very irregular nuclei of quartz remain, corroded by the encroaching tridymite. Similar phenomena have been remarked in the transformation of quartz bricks into tridymite in metallurgical establishments or glass furnaces.* In the Colorado rocks certain tridymite aggregates suggest the same sort of process carried to com- pletion. They are distinctive units, quite sharply set off from the surrounding matrix, which fr equently bends around them in flow lines. They are not spherulites, as the component crystals are disposed at random instead of in a radial form, and are much larger than ordinarily found in spherulites. Perhaps most important of all is the observed fact that in several in- stances the outlines of the nodules are those of slightly rounded hexagons. All inall, the appearance suggests a derivation from quartz phenocrysts. The rocks in which the phenomena occur may be called tridymite-latites; that is, rocks corresponding i in mineralogical make-up to quartz Jatites but in which the role of quartz as an essential constituent is taken by tridymite. *H, Mallard, Bull. Soc. Min,, xiii, 172, 1890; P. J. Holmquist, Geol. Foren. Forhand, 26.6. ail 4, 245— 260, 1911 : cK Endell, Stahl u. Eisen, Nr, 10; 1912. Fenner—Stability Relations of Silica Minerals. 349 This single observation requires support from other direc- tions. If it should be confirmed its interpretation leads to in- teresting deductions. The explanation which first suggests itself is that under great pressure quartz phenocrysts had formed in the magma at a temperature considerably above the 870° inversion-point, and that with relief of pressure accom- panying the movement toward the surface, the position of the inversion-point was lowered to such a degree that tridymite became the stable phase and transformation followed as a natural consequence; but we are not justified in accepting this explanation at once. We cannot focus our attention upon this one phenomenon and neglect the results which would arise among the accompanying constituents, that is, upon the magma as a whole, from relief of pressure. In a mixture of such great complexity as a partly solidified magma, consisting’ of solids, liquids, and dissolved gases, a change of pressure will be accompanied by transformations and reactions among all the components tending toward a new condition of equilibrium. The direction of all such reactions will be governed by a single principle, that the net result shall be an increase of volume of the mass as a whole when the pressure is decreased. Neces- sarily such reactions will be attended by an evolution or absorp- tion of heat, but this factor does not influence the direction of reaction except secondarily, and, moreover, there is no general parallelism between the amount of the volume change and the quantity of heat evolved or absorbed. It is certain that from such internal reactions (neglecting losses of heat by conduction or radiation to the surroundings) the temperature of the magma will either rise or fall, but observations of volcanic phenomena have not yet supplied data from which it is possible to affirm which is the general result. There is, therefore, at least the possibility that in the rise of a magma from the depths the temperature may actually become greater, perhaps even to a notable degree. If this should be the case, the transforma- tion from quartz to tridymite might well be explained from this alone, and the fact that the direction of volume-change in this one constituent is that demanded of the magma as a whole would be a mere coincidence. — | PuysicaAL PROPERTIES OF ARTIFICIAL QuaARTZ, TRIDYMITE, AND ORISTOBALITE. In determining the transition points between quartz and tridymite and between tridymite and cristobalite, it was neces- sary, as previously explained, to use a solvent or catalytic agent in order to cause the transformation to proceed at an appreci- able rate, and sodic tungstate was selected for the purpose. The use of this material is permissible if it gives rise to no 350 Henner—Stability Relations of Silica Minerals. product which enters into solution with one or another form of silica. If such solution occurred, the inversion-points would be displaced and the determinations made would have no special significance. It is necessary, therefore, to show that the artificial products do not represent solid solutions. For this purpose chemical analysis has little value. A number of analyses were made by volatilizing the silica with hydrofluoric acid and weighing the residue. ‘This residue was always rather small (0°19—0°60 per cent.), but its effect depended wholly upon the question as to whether it was mixed with the crystalline silica as a mechanical impurity or whether it had entered into solution with it. To settle this, the determination of physical properties fortunately provides effective criteria. Certain of these properties are of such a nature that they would be even more affected by a slight amount of foreign material in solid solution than would the transition points mentioned. There- fore, by a comparison of the properties of the artificial minerals with those of their analogues in nature, the probability of identity can be established. Outside of this, the physical con- stants are inherently of value and their determinations should be recorded. | Properties of Quartz.—The quartz obtained in sodic tung- state melts seldom exceeds 0°1™™ in length. The erystals appear to be simple combinations of prism and pyramids. Frequently the forms are rounded or distorted, an effect which, with some crystals, can be seen to be due to oscillatory develop- ment of faces. Ordinarily, each crystal is a separate individual, with double terminations, and a general habit similar to quartz phenocrysts in porphyries. Determination of refractive indices was made in sodium light by matching the index of the crystals with that of various oils by the Becke line method, the index of the oil mixture whichematched being immediately deter- “mined on a total refractometer. The agreement with natural quartz was very close. For artificial o=1:544 e—1:551 (temperature 23°), for natural wo = 1°544 «= 1-553. Strong confirmation of its identity with natural quartz was furnished by comparison with the a-8 inversion point of the natural mineral (to be described later). The quantity of heat involved in this transformation is so insignificant (8-4 calories* per gramme, according to unpublished determinations by W. P. White of this Laboratory) that a small amount of material in solution would tend to produce a decided shift. The aver- age of three determinations gave the point as 577:2° on heating and 568°5° on cooling. Within the limits of error of the method, these points coincide with those of natural quartz. * The exact amount of heat change to be considered is variable because of an increase of specific heat just prior to the inversion, which must be taken into account when the displacement is considerable. am Fenner—Stability Relations of Silica Minerals. 351 Properties of Tridymite.—The most frequent form of tridy- mite as obtained by the inversion of quartz in a tungstate melt is as aggregates of crystals of random orientation replac- ing each quartz grain. In addition, large numbers of perfectly formed hexagonal plates are almost always present in the same preparation. Ordinarily the crystals are quite minute, but it is not difficult to produce them at will of such size that individ- ual crystals are plainly visible to the naked eye. The essentials seem to be a long period of heating and a moderately high tem- perature. After one experiment, conducted at 1300° for 23 hours, the crust of the mass in the crucible appeared somewhat fissured and the openings were lined with relatively large, separate crystals of a tabular form. Under a binocular of moderate power their hexagonal form could be distinguished. Interpenetration twinning was developed to a high degree, and although the crystals were too frail for goniometric work, the resemblance to the twins and trillings figured in Dana and Hintze was striking. In another experiment the heating was continued for 140 hours at a temperature varying from 900° to 1200° and still better crystals were obtained. The erystals in random aggregates fr ee show elongated or lath-like shapes, due to their be- ing cross-sections of the thin scales. Fig. 2. In such cases the extinction is par- allel to the elongation, and the 7 elongation has the vibration direc- \/ tion a. In other cases the wedge- like twinning frequently noted in descriptions appears. This has the appearance shown in fig. 2. The hexagonal scales, when of the thinness ordinarily obtained, a appear perfectly isotropic when lying on the base. The larger ones : secured by special effort are found to be divided into slightly birefrin- gent fields, as shown in fig. 38. The acute bisectrix in each distinct area is nor ae to the plate and the optical character is positive. The planes of the optic axes are related to the exterior crystal boundaries in such a way as to be always normal to an edge. The shape of the fields, though quite irregular, is also ‘plainly related to the er ystal outline. The hyperbolic brushes are broad and rather faint, and the value of the axial angle is therefore difficult of accur ate determination. Three measurements gave the following results for 2V :— 32°6°, 38:0°, 35°8°, average 35°5°, or 2E = 58-6". Determination of refractive indices in sodium light by the im- mersion method gave for vibrations parallel to plates (a and 8) 6 352 Henner—Stability Relations of Silica Minerals. 1-469 (difference too small to be determined), perpendicular to plates (vy) 1:473 (temp. 24°). All these characteristics agree closely with those of the natural mineral, as given by Mallard,* whose determinations and descriptions are usually cited. Mal- lard found difficulties in exact determinations of optical con- stants, but gives ee = LATl, y — a= 000185, 20 66° about, and 2V = 48° about. bay A determination of specific gravity was made by the method of Day and Allen.t The value found was 2-270 for tridymite Hic. 3. Fie. 8. Tridymite crystal in basal position ; length about 1:0™™, at 27° referred to water at 27°. Mallard gives 2°28 for the natural mineral. The optical characteristics of the low temperature (a —) form of tridymite indicate orthorhombic symmetry. Each hexagonal plate appears to be made up of several orthorhom- bie individuals whose vertical axes are parallel with the vertical axis of the hexagonal crystals, but which are twinned after a 60° orthorhombic prism coinciding with the 60° hexagonal * KE. Mallard, Bull. Soc. Min., xiii, 161, 1890. + Publication No. 31, Carnegie Inst. of Washington, p. 55, 1900. wae ae aa Fenner—Stability Relations of Silica Minerals. 353 prism. In the transformation from the high temperature to the low temperature form there appears to be but little shifting of the elements of the space-lattice. The low temperature inversion of tridymite has long been known. Further investigation has made it appear that there are in reality two inversions lying less than 50° apart, of which the lower is the one ordinarily observed. The method of deter- mining the temperature of these inversions and their meaning will be discussed later. Only a small energy change is involved in either, and therefore a small amonnt of material in solid solution would probably cause a noticeable shift m their positions. This fact gives to the lower inversion a value as a criterion for judging the identity of the natural and artificial minerals. Mallard* placed the inversion-point of natural tridy- mite at 130°+ 5°. This seems to be the only determination recorded. My own observation on natural tridymite from Cerro San Cristobal in a thermal microscope indicated a some- what lower value, about 112°. With artificial tridymite the average of anumber of closely concordant results obtained by methods in which I place greater confidence, gave 117-4°. On the whole, the physical properties of artificial tridymite show close agreement with those of the natural mineral, and there is little reason to doubt that they are the same substance. Properties of Cristobalite.—It is a little more difficult to prove that the cristobalite obtained trom tungstate melts car- ries no foreign material in solid solution. A peculiar situation arises from the fact that the inversion of a into § cristobalite does not take place at a definite temperature like the corre- sponding inversions of quartz and tridymite, but the tempera- ture for any given preparation depends upon the conditions under which it was formed, and that entirely apart from any question of impurity. This variability eliminates it as a crite- rion. Moreover, the properties of natural cristobalite are rather impertectly known. Efforts were made by this Laboratory to obtain specimens of the mineral from dealers for purposes of comparison, but the material submitted was practically useless. Nevertheless it is possible to establish a strong presumption of the identity of the natural and artificial minerals. The values of the index of refraction and birefringence usually cited in standard works are those of Mallard.t Mallard gives the value of the index as 1:432, which is evidently a mis- print for 1:482, for he immediately states “c’est-a-dire sensi- blement égal, ou peut-étre un peu supérieur 4 celui de la tridy- mite.” P. Gaubertt has called attention to the error, and has made a redetermination, which, however, he did not con- *K. Mallard, Bull. Soc. Min., xiii, 171, 1890. +Ibid., 175, 1890. ¢{P. Gaubert, ibid., xxvii, 42, 1904. 354 Henner—Stability Relations of Sica Minerals. sider entirely satisfactory. ‘The mean index, he says, is near 1:49. For artificial crystals prepared in a tungstate melt I have determined the indices in the manner described for quartz, and obtained y= 1:487 a = 1-484 (sodium light, tem- perature 24°). Mallard determined the value of the bire- tringence as 0°00053. There seems to be here also an error of some kind. At any rate, the artificial crystals show a bire- fringence nearly equal to that of tridymite, probably a little less. M. Bauer, describing the crystals of vom Rath’s* original discovery, speaks of the “ ziemlich kraftige Doppelbrechung.” Determination of the specific gravity by the method of Day and Allen gave 2°333 for cristobalite at 27° referred to water at 27°. Mallard found 2°34 for natural crystals. As ordinarily obtained, the artificial cristobalite shows con- siderable general resemblance to the elongated form of tridy- mite. The difference in indices of refraction, however, while slight, is sufficient ordinarily for discrimination. More- over, the extinction of cristobalite in such aggregates is not parallel to any recognizable crystallographic feature, and again, cristobalite grains frequently show a distinct polysyn- thetic twinning like that of albite, or a plaid effect like micro- cline. It is a fact not without significance in considering the — possibility of material being taken up in solution by cristoba- lite formed in tungstate melts, that cristobalite, unlike quartz and tridymite, can be formed without a flux and the material so prepared does not differ observably from that formed with a flux. Even those preparations obtained by aid of a flux show very little impurity, 0°19-0°35 per cent according to several analyses. The best crystals of cristobalite have been obtained by heat- ing amorphous silica with sodic tungstate over a Bunsen burner. They then show an attempt to develop a definite crystal form, but generally arrive at no better results than the forms illustrated in fig. 4. Many of the dihedral and poly- hedral angles are nearly perfect, but the remainder of the crystal is a mere skeleton framework. At times the principal growth has been in the direction of one axis only, more often along two or three at right angles to each other. Crystals fre- quently show many more branches than those illustrated, but the general form of growth has been the same. | In every case where terminal caps have been developed they appear to be octahedra. It is not possible to get very exact measurements of such small crystals under the microscope, but, as nearly as determinable, the edges make angles of 90° with each other and the plane faces make angles of practically 70°. From the relations of the caps to the axes of elongation, *G. vom Rath and Max Bauer, Neues Jahrb., i, 200, 1887. Fenner—Stability Relations of Silica Minerals. 355 ‘it seems that the direction of elongation is always that of cubic axes. In many cases the direction of growth has been influ- enced by twinning. This is evident at once in such a form as shown at ¢ and is the natural explanation wherever the angles between axes differ from 90°. The best measurements that could be made with the microscope show that angles which do not differ sensibly from 45° and 60° occur. The mode of ie Fic. 4, Cristobalite crystals; size 0°1-0:2™™. twinning which would give such results as regards the direc- tions of the axes and which is in accord with the observed positions of the faces is twinning after the octahedron (111) or spinel twinning. If, after twinning has occurred at some point during the growth along an axis, the same axis continues to grow, an angle: of 60° is formed. If, however, a second axis, which would normally assume a 90° position, starts growth in the twinned position, an angle of 45° results. 356 Fenner Stability Relations of Silica Minerals. The general crystallographic symmetry of cristobalite indi- cates that under the conditions of formation it is actually an isometric mineral, but in cooling to ordinary temperatures it passes through an inversion, by which it becomes birefringent. In the sketches of cristobalite crystals shown in fig. 4, dotted lines indicate the birefringent fields and arrows show vibra- tion directions. Crossed arrows in a circle show that no bire- fringence is perceptible. In the last case, the crystals should be perpendicular to an optic axis, or nearly so, but because of the weak birefringence of the mineral and the small thickness of the crystal, no indication whatever of an interference figure could be perceived in convergent light. The sections which showed maximum birefringence, however, gave a figure appar- ently perpendicular to an optic normal (8). From this it was possible to determine that the acute bisectrix is a and hence the mineral is negative. This agrees with Mallard’s determi- nation on natural crystals. The manner in which the bire- fringent fields are arranged also agrees with Mallard’s observations. The plane of secondary twinning is generally quite sharp and makes an angle of 45° or 90° with the cubic axis which it crosses. In some instances, however, the border of adjacent fields is quite irregular, as inf. The position of the secondary twinning plane and the relations which the vibration directions bear to each other is concordant with the idea of tetragonal or orthorhombic* symmetry of the low-tem- perature form, with twinning after a 45° pyramid parallel to an octahedral edge of the original crystal. During inversion, therefore, the crystallographic space-lattice seems to suffer but little distortion. The tendency to assume skeleton forms agrees with the description of natural crystals, as does the occurrence of twinning after the spinel law.t , PREPARATION OF QUARTZ IN AQUEOUS SOLUTION. Quartz may be prepared without difficulty by heating either silica glass or amorphous precipitated silica with water and sodic carbonate in a silver-lined steel bomb at 400° to 500° for two or three days. The relative proportions of materials need not be very exact; approximately the following were used in several experiments: water 8°, silica 2-3 g., crystallized sodic carbonate 0°7 g., capacity of bomb 16°. Experiments of this kind have been performed a number of times and have no special interest. Of more importance was an investigation as to the possibility of obtaining tridymite or ie Mallard, Bull. Soc. Min., xiii, 175, 1890. A. Lacroix, ibid., xiv, 186, 1G. vom Rath, Neues Jahrb., i, 198, 1887. P. Gaubert, Bull. Soc. Min., xxvii, 242, 1904. Fenner—Stability Relations of Silica Minerals. 357 eristobalite under such conditions. A number of experimenters have reported the formation of these two minerals in aqueous solution and this fact had, in the beginning, given rise to uncertainty in regard to the stability relations of the three. In all my experiments with amorphous silica in alkaline solutions, quartz was obtained. When artificial tridymite or eristobalite was substituted for amorphous silica, quartz was likewise obtained as the end-product. This removed any uncertainty that had been felt as to the relative stability of the three minerals under such conditions and confirmed the results obtained in tungstate melts. ; To obtain as much information as possible on the question, it was thought desirable to repeat several of the experiments cited in the literature, in which tridymite or cristobalite was reported. ; EK. Baur,* in one of his experiments (No. 8) took 5 g. Si0O.,, 4°3 g. AlO,Na (composition between soda leucite and nephe- lite) and obtained quartz, tridymite, and albite. The tridymite was described by Weinschenk as follows: “tablets, made up of countless differently oriented individuals, plainly less refringent than Canada balsam, weakly birefringent, small axial angle, optically positive.’ To repeat this, I placed in a bomb of 16° capacity a thorough mixture of 2°5 g. amorphous precipitated silica and 2°15 g. NaAlO, (the latter made by heating a mixture of Na,CO, and A1,O, in molecular propor- tions to 1400°); 6° of water was added. The bomb was heated to approximately 520° for five hours, then heating cur- rent was turned off and the bomb cooled with furnace over night. The resulting product consisted apparently of two different minerals. The first was in sharp, hexagonal prisms cut off squarely by basal pinacoid, elongation negative, both indices >1°5380 and <1°535. The erystals are attacked by dilute HCl, leaving at times crystalline fragments in an amor- phous material (probably gelatinous SiO,). This conforms to nephelite except for slightly lower index. The second mate- rial was in roundish granules having at times a suggestion of erystal outline, was isotropic and had index just below 1490 ; apparently analcite. This experiment was performed three times, with some vari- ation as to length of heating and rate of cooling. The prod- ucts were always the same. Although these results do not agree with those obtained by Baur, I do not consider that one disproves the other. There can hardly be any question that quartz is the stable mineral under these conditions, but it might well happen that from some combination of circumstances the intermediate form *K. Baur, Zs. phys. Chem., xlii, 567-576, 1902. 358 Fenner—Stability Relations of Silica Minerals. tridymite was first produced and from lack of time did not pass over completely. into quartz. K. v. Chrustschoff,* by heating soluble amorphous silicic acid in an aqueous solution of hydrofluoboric acid for five hours, obtained the following results: at 180-228°, regular crystals, perfectly isotropic, index = 1-58 (possibly a misprint for 1:48), contain 99°78 per cent SiO,; 240-800°: quartz; 310-860°: tridymite with some quartz. The regular crystals were considered to be cristobalite, although the index as quoted is markedly different. No data on the tridymite are given in the German abstract. The writer placed in a bomb of 18° capacity 49. amor- phous precipitated silica, 3° hydrofluoboriec acid, made by saturating a 40 per cent solution of HF with B,O,; and 3° water. These were heated 22 hours at 350-380°. The product was mostly unchanged amorphous silica, with which there were a few small but perfectly formed crystals of quartz. Cristobalite and especially tridymite have been reported as formed similarly in a wet way in numerous instances and natural occurrences due to a similar mode of formation have likewise been reported. There is no reason known why they should not have been deposited as wnstable forms under such conditions, but these two minerals possess such neutral proper- ties that great care must be exercised in identification and other possibilities must be eliminated before reaching a positive conclusion in such instances. GENERAL OBSERVATIONS ON THE QUARTZ-I'RIDYMITE-CRISTOBAL- ITE INVERSIONS. The experimental work which has thus far been described has been concerned principally with establishing the stability relations of the three minerals. During the course of the in- vestigation, however, a considerable amount of data was accumu- lated regarding the conditions under which one form may be converted into another regardless of whether the product was the final or stable form, and regarding the reactions which may be expected under various conditions of treatment. Some of these results are important in establishing points in the unstable fields of the complete silica diagram. ‘The whole may be sum- marized as follows :— Neither quartz nor tridymite has been formed under any conditions in the absence of a solvent. At temperatures below 870° quartz was always produced when any form of silica was heated for a sufficient length of time in a sodic tungstate melt or in aqueous solution. Ina sodic tungstate melt the most favorable temperature seemed to * K. v. Chrustschoff, Neves Jahrb., i, Referate 240, 1897. Fenner—Stability Relations of Silica Minerals. 359 be about §25°. Here the conversion of the whole charge takes about three days. A lower working limit to the use of sodic tungstate is imposed by its solidification at 698°. Although quartz is the stable form below 870°, either amorphous silica or eristobalite first yields tridymite and only after much longer heating does quartz appear. Between 870° and 1470° tridymite is always formed in a tungstate melt. From 1300° upward the reaction is fairly rapid. At high temperatures (1400° and upward) an alkaline silicate glass may be used as a flux. The best crystals of tridy- mite have been obtained in a tungstate melt at 1300° or there- abouts. Within the tridymite range amorphous silica in fused sodie tungstate or alkaline silicate yields at first a mixture of eristobalite and tridymite, which later becomes entirely tridy- mite. From 1470° upward to the melting-point any form of silica heated in a tungstate melt is changed into cristobalite. At 1500° and upward the reaction is fairly rapid. At high temperatures quartz, heated without a flux, changes to eristobalite even below the tridymite-cristobalite inversion- point. The upper limit of this reaction is set by the melting- point of cristobalite. The lower limit is uncertain. B-quartz 575° B-quartz ——> a-quartz 570° a-tridymite ——> £,-tridymite 117° B,-tridymite —~ £B,-tridymite 163° Reversions on cooling not very sharp ( a-cristobalite —> B-cristobalite 274°6° to | 219°7°, depending upon previous heat- | treatment 4 8-cristobalite —> a-cristobalite 240°5° to | 198°1°, depending upon previous heat- | treatment | A study of the remarkable variations in the temperature of inversion of a- into §-cristobalite has led to the conclusion that this mineral is made up of two different molecular species of silica within the same crystal. Various other properties of the silica minerals seem to have considerable bearing upon theories of the structure of molecules and crystals. The nature of the radical differences existing between the two different types of inversion has been discussed in some detail. The melting-point of cristobalite has been found to be close to 1625°. Quartz melts at least 155° lower. The general stability relations are shown diagrammatically in figure 1. | Geophysical Laboratory, Carnegie Institution of Washington, Washington, July, 1913. J. B. Umpleby, ete.—Custerite: A New Mineral. 385 Arr. XXXV.— Custerite: A New Contact Metamorphic Mineral ; by J. B. Umetusy, W. T. Scuarier, and HK. 8S. Larsen. Iniroduction. Tur new mineral here described is a hydrous fluosilicate of ealcium which in thin section, in parallel light, resembles a pyroxene but with crossed nicols suggests albite. It was col- lected by one of the authors (J. B. Umpleby) in the fall of 1912, from a contact zone three and one-half miles southwest of Mackay, Custer County, Idaho. The zone is worked for copper, the ore occurring principally as irregular shoots in granite porphyry, well removed from its contact with the invaded Mississippian limestone. The ore minerals, principal among them chalcopyrite and its oxidation products, are inti- mately associated with garnet, diopside, magnetite, fluorite, and other contact minerals in bodies which are nearly coincident in extent with original limestone inclusions.* In some of these inclusions none of the original limestone remains, though locally its bedded structure is preserved in the garnet-diopside rock, but in others a core of unaltered blue hmestone grades outward through pale-blue, partly recrystallized limestone into white marble and on into a zone made up largely of garnet, diopside, and magnetite. The new mineral was collected from between the garnet-diopside and marble zones which fringe one of these inclusions. . The name custerzte, after the county in which it was found, is proposed for the mineral here described. Occurrence and Genesis. The mineral custerite was found about 200 feet within the margin of a great limestone inclusion which outcrops over an area of about 10,000 square feet on the first divide north of the Empire (formerly the White Knob) mine. It occurs inti- mately associated with magnetite and much less garnet and diopside. Hand specimens of usual size may be secured which show magnetite and custerite in about equal amount, and apparently of contemporaneous origin. The garnet and diop- side occur in irregular scattered crystals many of which are euhedral. The relation of the custerite to these minerals is similar to the relation of calcite to them on the margins ot garnet-diopside areas and suggests that they were developed *This interpretation, which will be amplified in a report on the ore deposits by J. B. Umpleby, is at variance with that advanced by Kemp, J. F., and Gunther, C.G., The White Knob Copper Deposits, Mackay, Idaho: Am. Inst. Min. Eng., Bull. No. 14, pp. 301-328, 14 figs., March, 1907. 386 J. B. Umpleby, etc.—Custerite: A New Mimeral. later than the custerite. This view seems to be supported by the occurrence of the mineral in the transition zone from garnet-diopside rock to marble and its apparent absence about the periphery of included limestone blocks where the meta- morphic action was most intense. The thin sections and field relations therefore suggest that the custerite was formed in the outer part of the wave of metamorphism which passed from the magma into the limestone. It follows that in any given place there appears to have been a rather definite sequence of metamorphism from limestone to marble and thence through custerite into garnet-diopside-magnetite rock. If this sequence held throughout the deposit it is probable that the fluorine of the custerite is in part represented by the fluorite of the garnet-diopside rock. The field observations on the occurrence of custerite in the deposit, however, are so incomplete that further speculation as to its genesis might not even be suggestive. Description of Mineral. Custerite occurs in finely granular masses which may be easily mistaken for greenish marble, although the minute cleavage faces, which under the hand lens glisten in the sun- light, are roughly tabular in shape and chance ones show twinning lamelle normal to the elongation. On weathered surfaces a chalky crust consisting chiefly of carbonate is not uncommon and for a distance of perhaps a millimeter beneath it the mineral is white and porcelain-like. The physical properties of custerite, as determined from the hand specimen where individual crystals cannot be isolated, are as follows: Hardness, about 5; specific gravity 2°91 (cor- rected* for admixed diopside and magnetite) ; luster, greasy to vitreous; streak, white; color, pale greenish gray; tenacity, brittle ; translucent. A. microscopic study of thin sections reveals an aggregate of irregular, diversely oriented interlocking grains, few of which exceed one millimeter in length by a width a little less. Most of the grains, however, are about one-half of a millimeter in diameter. The mineral has three cleavage directions which intersect at angles closely approaching 90 degrees. The cleay- age in each of the three directions is so interrupted that it is impossible to measure accurately their angles of intersection. In two of the directions the cleavage is about equally promi- nent but in the other it is more nearly perfect. Polysynthetie twinning is beautifully developed parallel to this principal cleavage. The lamelle are seldom wider than 0:01 millimeter and are commonly much narrower but are not uniformly dis- *Value obtained =2'96. J. B. Umpleby, ete.—Custerite: A New Mineral. 387 tributed, considerable areas of some of the crystals being untwinned. Sections cut normal to the obtuse bisectrix show the twin lamelle which extinguish symmetrically at 6°-7° from composition plane and the principal cleavage ;_ those par- allel to the plane of the optic axis are also normal to the twin lamellz but the extinction is parallel. Sections cut normal to the acute bisectrix show no twin lamelle. Here the cleavage intersects at angles of approximately 90° and the plane of extinction is diagonally across the squares, or at about 45° to each cleavage direction. From the above relations of the optic properties to the cleavage directions and twinning it appears that the mineral possesses two cleavages, namely (110) and (001), with the twin- ning plane parallel to the latter. The conclusion that the min- eral is monoclinic also seems warranted since the most careful measurements failed to show an inclined extinction of the lamelle in one of the two principal sections normal to them. The accuracy of this observation was confirmed with the aid of the Federow stage on which a crystal was rotated in the plane of the twinning lamelle and extinction angles were measured. The positive acute bisectrix (Z) is nearly normal to the twin- ning lamelle. The obtuse bisectrix (Y) emerges from those sections cut normal to the twinning lamelle which show an extinction (Yaa) of 6°-7°. This section is therefore normal to the crystallographic axis, 0. The optic axial angle measured with the Federow stage in lithium, sodium, and thalium light gave the following average results of readings on each axis by two observers : Measurements of optic angles of custerite. Readings on Federow stage with section inclined 171g degrees. One axis Other axis cm teh Se 32225 34°77 PSO OUUTA Ty, tS GD cae eyecare 31°85 34°65 pliner linia 365 eee Oe 31°25 355 Correcting these readings, which were checked on another sec- tion, for the index of the glass and the tilting of the section, the following values are derived: 2 V,,= 60°5°; 2 V,, = 60°1°; v7 — oo 6 | Eberetore, 2: = 105°. Whe dispersion of the optic axes as observed on the interference figure is rather strong and p >v. Orystals of custerite, as seen in thin section, are commonly almost equidimensional, though there seems to be a tendency toward elongation coincident with X. . The indices of refraction for custerite were determined by the oil-immersion method, the values below being fairly con- stant for different grains: 388 J. B. Umpleby, etc.—Custerite: A New Mineral. a= 19586 + °005 y—-a='012 B = 1°589 + ‘005 Ve ys U0 Vi Lio 8) se n0 Us B—a = ‘008 The birefringence values derived by differences of refrin- gence closely check with the following more accurate direct measurements on orientated sections respectively 0:06 and 0-1 of a millimeter thick : Leg = 6 ‘Ol1+ ‘009+ "004 — oll Ul Dx ~ Custerite is characterized microscopically by its moderate index of refraction, low birefringence, polysynthetic twinning, maximum extinction angle of twin lamelle of 6°—7°, positive optical character, distinct dispersion of the optic axes with pCa which would explain the fact that zeophyllite does not give a strong alkaline reaction with phenolphthaline but seems incon- sistent with the fact that less than one per cent of the water is given off at 110°. Other structural interpretations are, of course, possible. Cuspidine, found originally at Vesuvius, has recently been described from Franklin Furnace by Palache.* At Vesuvius cuspidine was found as well-developed crystals in druses asso- ciated with augite, hornblende, biotite, garnet, sarcolite, davyne, and calcite (derived from altered cuspidine). Granu- lar aggregates—resembling a fine-grained diabase—of cuspi- dine with augite and biotite were also noted. Attention may also be called to the ‘“ cuspidine-like mineral” found+ with green magnesium mica and white sodalite, and occurring in rhombic prisms, apparently different from cuspidine. The composition of this material is not known, though Zamboninit considers it identical with humite. The density of the Franklin Furnace cuspidine is given as 2°965 — 2°989 and that of Vesuvius, as determined by Zam- bonini, as 2°962; average value 2°97. The formula derived by Zambonini, namely, Ca,(CaF),Si,O,, is in perfect accord with his own analysis and with Warren’s analysis of the Frank- lin Furnace material. It may be noted that the presence of only 0°57 per cent of water (not determined according to War- ren’s analysis) in the Franklin Furnace mineral woul¢ suffice to bring the ratio of [F + (OH)]: SiO, to 1:00 instead of 1:00: 0°88 as calculated from his analysis. Structurally the formula of cuspidine can be interpreted as: +2H,0 Ca : Cak Ca 7 21S CaF which does not show any direct relation to that of custerite. * Loc. cit. + Rath von G., Zs. Kryst., vol. viii, p. 45, 1884. { Zambonini, Appendice alla Mineralogia Vesuviana; Att. Accad. Sci., Napoli, vol. xii, p. 44, 1912. 7 va J. B. Umpleby, ete.—Custerite: A New Mineral. 393 Hillebrandite is genetically similar to custerite, being one of the products of contact metamorphism of limestone adjacent to an igneous mass. A sample of hillebrandite kindly furnished for that purpose by Dr. F. E. Wright yielded 0°77 per cent of water at 110° and 9-64 per cent on ignition (calculated 9°45 per cent). The strong alkaline reaction with phenolphthaline, as described by Wright, was confirmed and suggests the presence of the CaOH group. On the basis of these results, the com- position of hillebrandite can be readily interpreted as a meta- silicate with the following structtral formula: CaOH CaOH This formula is identical in type with that of custerite, and suggests at once that custerite is an isomorphous mixture of hillebrandite and a theoretic fluo-hillebrandite,in which all the hydroxy! is replaced by fluorine. This conception is a simple and rational one, but is opposed by other considerations: As euspidine has been found at two widely separated local- ities, the inference may be justified that in the presence of much fluorine and little or no water, a mineral of the cuspi- dene formula, 3CaO.2Si0O,.CaF,, would always form instead of a fluo-hillebrandite with the formula 2CaO.2Si0,.2CaF,. In other words, fiuo-hillebrandite seems to be unstable under the meta- morphic conditions prevailing, judging, however, solely from the fact that at the only two localities where a calcium fluo-silicate occurs, a different type of compound (cuspidine) was formed. It seems likely, therefore, that, considering the isomorphous replacement of fluorine and hydroxyl, the isomorphous series of which hillebrandite is the hydroxy] end, consists of the two end members: (CaOQH),SiO, and (CaF) (CaOQH)SiO, and not of the theoretic end members: (CaOH),SiO, and (CaF),Si0,,. The symmetry of hillebrandite and custerite is apparently different, though some of the properties of hillebrandite could not be as definitely determined as those of custerite. The former mineral is fibrous, orthorhombic, whereas custerite is granular, monoclinic, with a close approach to orthorhombic symmetry, as evidenced by the nearly rectangular cleavages and low extinction angle. The custerite and hillebrandite compounds may both be dimorphous, with only the two non- isomorphous end members of the four possible compounds known. The status of the relationship of these minerals, as far as can be judged by the available evidence, seems to be somewhat as is given below. Si0,< 394. J.B. Umpleby, etc.—Custerite: A New Mineral. ‘Cuspidine — Ca,Si,F,O.. atk EN Ca,Si,F,O, — unstable, non-existent. Custerite — Ca,Si,F,(OH),O,, dimorphous: (1) orthorhom- bic form isomorphous with hillebrandite (not known) and (2) monoclinic. Hillebrandite — Ca,8i,(OH),O,, dimorphous: (1) monoclinic form isomorphous ‘with custerite (not known) and (2) orthorhombic. | Zeophyllite —Ca,Si,H,F,O,,, dimorphous, the known form | not related to the above named minerals. | The close chemical relationship of these four minerals can be shown by writing their formulas so as to keep intact the com- | mon compound, Ca,Si,F,O,. | Cuspidine = anim oO. | Custerite = Ca,8i,F,0,. H,O (or cuspidine plus water). 1 Hillebrandite = Ca, Si, (OH Ne O.. H,0. Zeophyllite = Ca, Si, FO... H, O. SiO, (or cuspidine plus water and silica). These relations suggest nee things — the existence of a hydroxy-cuspidine, Ca,Si,(OH),O,; the derivability of custerite and zeophyllite (or a polymorphic form of the zeophyllite com- pound) from cuspidine by the actual addition of water and silica, ete. The essential properties of the four minerals considered in the preceding paragraphs are briefly tabulated below for pur- poses of future reference. Properties of Custerite and related minerals. Custerite. Zeophyliite. Cuspidine. | Hillebrandite. Composition Ca,Si.-H.F.O; Ca,SizH,F.0,, Ca,Si.F.O, Ca.SieH,0 0 Symmetry Monoclinic Rhombohedral |Monoclinic Orthorhombic Cleavage Two, basal and |One, basal One, basal Prismatic (2) prismatic Hardness o—6 3 5—6 5—6 Density 2°91 2°79 2°97 2°69 Fusibility Difficult Very easy Difficult Difficult Axial plane |Normalto basal|Normal to {010}, normal |Parallel to cleavage cleavage to cleavage cleavage Index y 1°598 TOO 1 (LEM eee Cal eS © 1°612 Index 8 1°389 ol Sele ee alee eo Index a 1°586 0S Pe ema ae in eee 1°605 Birefringence 0:011 a agli ER alm ee re es 007 2H 105° 0—273° 1107 60-80° Dispersion Strong,p>v | pv Sign Positive Negative!) y\c\ ieee Negative Extinction (0) Sot mite PRR nose 5° 0° Twinning Promiment,' an) hae scene Tw. pl. (100) sae Be eyes Elongation \ jy iecees.2. oc) ) 22. . 2 gOS eee eee Z T. M. Dale—Ordovician Outlier at Hyde Manor. 395 Arr. XX XV1.—The Ordovician Outher at Hyde Manor in Sudbury, Vermont (second paper); by T. Nexson Datz.* Sryce the publication of the former paper on this subject + further excavations and core drilling have thrown still more light on the areal and structural relations of the outlier. These later results, together with the former, are embodied in the map and section, fon I. A series of holes (excav. 10, 11, 12) was dug across the sag in the surface west of the outlier, and the location of the bound- ary between the Cambrian schist mass and the Ordovician fos- siliferous limestone west of it was fixed within five feet. Other excavations (13, 14) showed that what had been taken for a minor fold in the main Ordovician mass was really the end of a limestone lens, 41-42 ft. long and up to 5 ft. thick, lying in the Cambrian schist and at one point with an inch or two of the schist actually overlying it. Whether this over- lying schist got there by deposition or by “creep” after the solution of the limestone could not be ascertained. Then another limestone lens, about 7 feet long, was found a little west and south of the other. The age of these lenses is not determined ; but they are probably contemporaneous with the schist and thus Cambrian. A small excavation at the southern apex of the outlier (excav. 15) shows that the limestone there pitches southward under the schist, the foliation of the schist which the micro- scope shows to be bedding, conforming to the limestone surface east of the point but running up against it on the west for at least a foot north. A woodchuck’s burrow a little north of the apex has schist SaaS about it brought up from next to the limestone. Hand-specimens of the limestone from next to the drill hole of 1911 show two foliations, one dipping 30° about E.SE., and the other, marked by sharply undulating and faulted calcite laminee, dipping 55° E.SE. A thin section shows that the first of these foliations consists of undulating laminee of extremely fine particles (probably dolomite) alternating with lamin of coarser particles, probably calcite, containing here and there large calcite grains. The section also shows quartz grains dis- tributed along this foliation. The second foliation, consisting of coarse calcite laming, in sharp folds and faulted, breaks across the first and seems to be secondary. Both foliations are shown on the map at this point but with the same strike, which may not be exact. an ery ae Sse} EXCAV. | Picks So citer es tee “ORDOVICIAN "~ bette ese oe ae “LIMESTONE + 7 EM ESION ESAs OUTLIER | +.” CAMBRIAN SCHIST Pied fir ee 33 a ‘schist Fragments ‘about woodchuck hole Verinorps 1 - ©! OES “| ve POOR LY Net ie. 114 FT BEYOND MAP LI MIT.€ SCHIS 510 20 30 40 50 Feet FOL.ST. N.SZE. DIP. ss SST E. ls BED,STRIKE & DIP | | CLEAVAGE, do ea FOLIATION where. BEDDING UNCERTAIN BED HORIZONTAL ©' Rock EXPOSURE mH CORE DRILL HOLE,I9I. (52 FT. S. OF MAP LIMIT ll d 913. € SCHIST = NSS E. Gi ) at he| Dip. $3° S.39°E. Drill holes: ree 1913 ORDOV. = € A! SCS nd Seto Ps € Schist dip os SM Ft. 4in. T Nelson Dale 22° K. and dips 40° 8. 78° E. is bedding. Therefore the strike of N.10°-15° E. and dip of 45° S. 88° E., seven feet north of apex is very probably that of bedding also. - s T. M. Dale—Ordovician Outlier at Hyde Manor. 397 Strike observations were taken at all the Cambrian schist outcrops nearest to the outlier. Im some the bedding was clearly shown by small lenses or beds of quartzite. In others the course of the bedding could not be fixed. All the data are shown on the map. The conclusion is that Cambrian schist completely surrounds the Ordovician mass and has a bedding strike of N. 35°-60° E., generally N. 40°—50° E., that the limestone at excavation (2) rests unconformably on the schist, and that the bedding strike of the limestone is generally about 10 degrees west of that of the schist. Finally, another drill core was obtained from a point, shown by black square on the map, 13 ft. 6 in. 8. 75° E. of the first one, indicated by a star. The drilling was done with diamonds by the Vermont Marble Co., June 19-24, 1913. By inclining the drill at 45° eastward all possibility of mistake arising from its crossing an exceedingly overturned anticline was excluded. The results of this drilling are given below. The measure- ments are along the inclined drill. 9 feet .--- Limestone. 4° .--- Decomposed limestone and solution cave. ett ..-- Limestone. 5 “ 6in...-. Decomposed limestone and solution cave. =e 6 in, --.. Limestone. a .--- Decomposed limestone and solution cave. Le Limestone. a2 6 e222) “Nchist: ee) FOUN. 2. Decomposed schist and joint space. 1 iia 203 222 SeNIse. eo> te The cores obtained measure: Limestone-- ---- Lbft: 10 m, Selish 2252 23225 - AKG NOLS: me 20 ft. 8:8 in. One of the cores, broken into three parts, measured 30:5 inches, of which the upper two inches are Ordovician lime- stone and the rest, 28°5 in., is Cambrian schist. A thin section of the ordinary size could be furnished from this core which would show the rocks of both periods in contact. A photo- raph of this core wlll be shown in a future publication. The bedding of the limestone, judging from the cores, dips about 55° eastward, and that of the schist about 65° eastward. The general results of the last drilling are shown in the section on fig. 1. 398 37. M. Dale—Ordovician Outlier at Hyde Manor. In view of the fact that the schist dips under the Ordovician on the west side of the outlier at the outcrop next to the north- ern elm, and overlies it on the east side at excavation (1), and again underlies it in the western half of the outlier, 11 ft. 6 in. below the surface, as determined by the drilling of 1911, and, finally, also underlies the Ordovician in the eastern half, 20 ft. vertically below the surface at the eastern edge, as determined by the drilling of 1913, the synclinal character of the outlier, as shown in the former article, is still more completely demonstrated. As the schist overlies the limestone on the east side at excav. (1) with an eastward dip of 35°-45°, the presence of schist below the limestone lower down on the east side, as shown by the core drilling of 1918, is just what would not be expected under the hypothesis of an overturned anticlinal structure. Only a very arbitrarily distorted diagram, contrary to the entire habit of the rocks of the Taconic region, could make the outlier into an anticline. But the syncline proves to be much more elongated along its axial plane than shown in fig. 2 (A) of the first paper, its deepest part on the line of section being 24 feet vertically below the highest part of the outlier. The unconformity between the Cambrian and Ordovician beds, already shown by specimens obtained at the contact at excavation (2),* is again shown in the cores by the difference in bedding dip. The interpretation of the structure as consisting of Cambrian schist thrust over Ordovician limestone and both folded into an overturned anticline, with the subsequent erosion of the Cambrian to form a “ Fenster,” is shut out by ail the laws of probability applied to the conjoint evidence of the outcrops, the excavations, the cores, thin sections, and the habit of the region. 3 The correctness of the conclusions of the first paper as to the general significance of the outlier} is thus made still more probable. The interfolding of the limestone at the northeast corner, excavation (6), and the pitch of the limestone under the schist at excavation (15), taken together, indicate transverse folding quite typical of the Taconic region. The cores will be preserved at the National Museum. Pittsfield, Mass., July 11, 1913. * Op. cit., this Journal, fig. 2 (B). PLDide pp eLOL. 02. Oberhelman and Browning—Tellurous Acid. 399 Art. XX XVII.—On the Preparation of Tellurous Acid and Copper Ammonium Tellurite ; by G. O. OBERHELMAN and P. E. Brownine. : [Contributions from the Kent Chemical Laboratory of Yale Univ.—ccxlix. ] Occasion having arisen to prepare some tellurous acid from . residues from the electrolytic refining of copper,* residues con- taining a high percentage of tellurous oxide together with small amounts of silica, copper, selenium, and several other impurities, it was determined to try the effect of the solvent action of ammonium hydroxide, followed by the precipitation of the tellurous acid from the ammoniacal solution by acetic acid. This procedure, employed on another occasion for the removal of selenium,+ proved satisfactory for the removal of the greater part of the silica,and of those bases which are insoluble in ammonium hydroxide. By dissolving the tellurous acid thus obtained in sodium hydroxide and precipitating the tellurous acid again by acetic acid, copper and many other metals whose hydroxides are insoluble in sodium hydroxide were also removed. If the precipitation of the tellurous acid by acetic acid is brought about without warming the solution, and the product is dried without heating, the tellurous acid obtained is readily soluble in the alkali hydroxides. If, however, the precipitation takes place in hot solution and the precipitate is dried by application of heat, the product tends to be quite insoluble in the alkali hydroxides. After the first treatment of the residues with ammonia in this extraction process, it was observed that a purple crystal- line salt separated from the alkaline solution on standing. The color: suggested a copper compound, and after the removal of this salt by filtration, the filtrate proved to be practically free from copper. It was found that asalt similar in appearance could be produced by allowing anammoniacal solution of tellurous acid containing some copper salt to evaporate over sulphuric acid, and in the presence of soda-lime. The depth of color varied with the concentration of the copper solution from a reddish purple through pink to nearly white. It was found that a salt which appeared to be identical with the compound just mentioned, could be produced by adding slowly, with constant stirring, | acetic acid to an ammoniacal solution of tellurous oxide and cop- perchloride. ‘The precipitate thus obtained proved to be slightly soluble in water but insoluble in acetic acid and in 50 per cent alcohol. A sample of this compound prepared in the manner * Furnished through the kindness of the Baltimore Copper Co. + Browning and Flint, this Journal (4), xxviii, 112, 1909. 400 Oberhelman and Browning—Tellurous Acid. just described, which from its intensity of color was considered to contain the maximum amount of copper, gave the following analysis: TeQ, 35h ie aeons 83°84 CuO ee eae See Aces NA 2 ee eee HO fe fae ee be ee 6°10 99°79 The TeO, was determined by the permanganate method. Copper was estimated colorimetrically by comparing in Nessler tubes ammoniacal copper solutions of known strength with weighed amounts of the compound dissolved in acid and made ammoniacal. ‘This method was found to be accurate to 2/10ths ofamg. ‘The ammonia was determined by distillation from an alkaline solution into standard acid. ‘The water eould not be determined by difference on ignition, owing to aslight reduction of the tellurium. So the compound was heated at 140°, and the residual ammonia was determined after weighing. From the weights of the total ammonia and of the residual ammonia at 140°, together with the total loss on heating at 140°, the weight of the water was determined. The loss of ammonia which resulted from beating at 140° proved to be about constant and amounted to a third of the totalammonia. The color of the substance changed on heating at 140° from reddish-purple to blue. It was thought that compounds of a similar nature containing bases other than copper might be formed in a similar manner. Nickel, cobalt, zinc, cadmium, and silver were tried but with no success. Silver gave a yellow precipitate, but this proved to be the ordinary silver tellurite. Kuzirian— Water of Crystallization in Sulphates. 401 Art. XXXVIII.—Determination of Water of Crystalliza- tion in Sulphates ; by 8. B. Kuzirtan. [Contributions from the Kent Chemical Laboratory of Yale Univ.—ccl.] CrRTAIN substances, e. g. chlorides of barium and calcium, sulphates of sodium, potassium, barium, etc., are completely dehydrated at moderately high temperatures, leaving a definite and weighable compound. Under such conditions, when the substances do not lose anything but water, at a definite tem- perature, the determination of water of crystallization can be made with great ease. _ Certain other substances, like the minerals, tale, topaz, chondrodite, staurolite, do not lose all of the water of crystal- lization by simple ignition at moderate temperatures. The high heat of the blast lamp is in such cases applied for the complete removal of water. This latter step often gives rise to complications, when the material to be blasted changes weight otherwise than by loss of water, e. g. by joss of carbon dioxide, fluorine, chlorine, or by accession of oxygen, as when a ferrous compound is ignited in air. Some other crystalline substances like sulphates and alums of aluminum and chromium are decomposed with loss of material other than water, at temperatures obtainable with an ordinary good-sized Bunsen burner, thus preventing a correct determin- ation of their crystalline water. Various modifications in treatment have been suggested to avoid complication in water determinations. For instance, in the case of minerals, talc, topaz, etc., fusion with pure and dry sodinm carbonate* will expel the water which may be absorbed in sulphuric acid and weighed. — Fusion of such silicates, very finely pulverized, with an- hydrous powdered borax, is another method suggested by Jannasch,+ for the same object. If the silicates are found to contain fluorine, then a retaining layer of granular lead chromate or a previously fused and powdered lead oxide is used in the ignition tube. This process is found objectionable by W. H. Hillebrandt for the reason that silicates on fine grind- ing lose some water. Magnesia§ is another substance mentioned in connection with determination of crystalline water in decomposable compounds * Bulletin 422, United States Geol. Survey, Hillebrand, p. 79. ; + Praktischer Leitfaden der Gewichtsanalyse, Leipzig (1897, 2d ed.). { Bulletin 422, United States Geol. Survey, Hillebrand, p. 83. § F. Stolba, Zeitschr. f. analyt. Chem, vii, 23. 402 Kuzirian— Water of Crystallization in Sulphates. like silico-fluorides. Under definite conditions, this flux seems to give satisfactory results, a correction being necessary when the separated metallic oxide, e. g. ferrous oxide, takes up atmos- pheric oxygen. In the case of decomposable sulphates, how- ever, no attempt has been made to determine their water of orystallization, while retaining all of the acidic oxide. In the investigation of the action of sodium paratungstate upon some salts, containing a volatile acid radical, both in pres- ence and absence of superheated steam, described in previous papers,* it has been shown that this acidic salt is able to expel the acidic oxides of carbonates, nitrates, chlorides, chlorates, etc., completely and with great ease. But sulphates which are stable on simple ignition, for example, the sulphates of sodium, potassium, barium and even calcium and manganese, do not lose appreciably their sulphur trioxide, either in absence or in presence of superheated steam on fusion with the paratung- state. For exainple, 0°2 grm. of sodium sulphate on fusion with the paratungstate did not lose in weight at all. The same amount of manganous sulphate when fused with the same flux lost only 0:0010 grm. of sulphur trioxide. Calcium sulphate on similar treatment lost only 0°0002 grm. and further heating did not occasion further loss. The explanation is that the basic sodium oxide of the sodium paratungstate combines with volatile sulphur trioxide of the sulphates to form the non- volatile sodium sulphate. The presence of a considerable excess of the acidic tungsten trioxide apparently does not | influence the reaction. The following may serve as a typical representation of the reaction : II II : 5MSO, + 5Na,0.12WO, = 5Na,SO, + 5MO.12W0O, Since sodium paratungstate does not expel the volatile sulphur trioxide from sulphates, it should be capable of serving a use- ful purpose as a flux in the expulsion of the water of crystal- lization of sulphates ordinarily decomposable by heat; and any sodium tungstate containing less of this acidic ‘oxide should be similarly serviceable. In the preliminary investiga- tion of this application of the sodium tungstates a nearly neutral sodium tungstate was prepared,t and a portion of the dry mate- rial was weighed and placed in a platinum crucible, a weighed portion of a decomposable sulphate—viz., crystalline copper * This Journal (4), xxxi, 497; xxxvi, 301, 305. + In order to purify the commercial material, which ordinarily contains sodium carbonate, it was fused in a large platinum dish over the blast, and pure tungstic trioxide was added until carbon dioxide ceased to bubble out. Kuztrian— Water of Crystallization in Sulphates. 403 sulphate (CuSO,5H,O)—was mixed well with the tungstate, and the covered crucible heated with a very low flame of a Bunsen burner waving under it. After driving off most of the water, the crucible was heated to low redness and the mixture fused, cooled and weighed. The loss apparently corresponded exactly to the theoretical loss of water in CuSO,.5H,0. The fusion was repeated several times and weighed over again, but no further loss in weight was found. So it appears that, while crystal- line copper sulphate loses some of its sulphur ‘trioxide when heated by itself at the temperature which is necessary for its complete dehydration, no loss of the acidic oxide occurs in pres- ence of sufficient amount of neutral sodium tungstate when the mixture is heated over a Bunsen flame to dull red heat. It is possible to keep the mixture in quiet fusion for fifteen to twenty minutes without losing any sulphur trioxide. Sodium tungstate thus serves excellently to retain the sulphur trioxide at a temperature sufficiently high to dehydrate the sulphate completely. To determine the water of erystallization in sulphates by weighing the water evolved, as well as by loss on ignition, the following procedure was tried. A hard’ glass ignition tube, about 15 inches long and 14 inches in diameter, was placed upon a small furnace; each end was fitted with a perforated (one hole) rubber stopper soaked in hot paraftine for a moment and wiped carefully; and one end of it was connected with a large air-drying apparatus while the other end was joined to a sulphuric acid weighing tube. The sulphuric acid tube was connected to a calcium chloride drying tube to prevent the entrance of any moisture into the weighing tube from cutside, and the calcium chloride tube was connected to an aspirator. The ignition tube was thoroughly dried by heating it for at least forty-five minutes and passing a rapid current of dry air with the aid of the aspirator. ‘The efficiency of the appa- ratus was evident from the fact that when, after such drying, the sulphuric acid weighing tube was connected with the i igni- tion tube and a blank test made, by running the apparatus for one hour, a gain of only 0:0003 er. in the weight of the weigh- ing tube resulted, for which a correction was appled in the subsequent work. After having the apparatus thus in readi- ness, exactly half a gram of the sulphate was mixed well with three grams of sodium tungstate in a porcelain boat, ignited and weighed previously. The boat and its contents, w eighed together, were introduced into the ignition tube. The ignition was started at first very gently by passing a current of hot dry air over the boat, at a rate of 3 bubbles a second, for a period of fifteen minutes. The temperature was carefully and gradu- 404. Kuzirian— Water of Crystallization in Sulphates. ally increased, until the mixture went into clear fusion. By waving a Bunsen flame around the ignition tube, and short delivery tubes, the condensed moisture was volatilized. After the apparent disappearance of all moisture, the remaining traces of it were forced into the sulphuric acid weighing tubes by a more rapid current of dry air, while continuing the heat- ing of the ignition and delivery tubes for at least twenty min- utes. After this period the heating was stopped, while a rapid current of dry air was passed for about ten minutes. The weighing tube was disconnected, stoppered with the glass plugs used as stoppers in the first weighing, brought as nearly as possible to the original temperature (by setting it aside for a few moments), wiped around with a filter paper, and weighed. The gain in weight of the weighing tube was recorded. After disconnecting the weighing tube from the ignition tube, the delivery tube leading into the ignition tube was plugged carefully, to avoid any moisture. ‘The boat was taken out while rather hot, cooled in a desiccator over sulphuric acid and weighed, and the loss in weight was recorded. It was found that if the procedure was carried out with the utmost care, observing all the, precautions, the loss in weight of the porce- lain boat, within experimental error, corresponded to the gain in weight of the sulphuric acid tube, and this corresponded closely to the theory for water in the crystallized sulphates. Repeated fusions of the contents of the boat did not occasion any further loss in weight, thus proving that under the condi- tions there is no loss of sulphur trioxide. The sulphuric acid weighing tube used was a side-neck U-tube filled with glass beads and the ends of the large tube were sealed. The rubber connecters were air tight so that the weighing tubes would not gain in weight over night. It is desirable that the sulphuric acid in the drying apparatus and in the weighing tube should have the same absorbing power ; for this reason the sul- phuric acid in the weighing tube was changed after every four determinations. The determination of the water of crystallization in copper sulphate, and in other sulphates, was carried out under the conditions cited above, with special precaution to avoid loss by decrepitation of the salt while yielding its water. After mixing the sulphate well with sodium tungstate, another portion of the flux was put upon the surface of the mixture to form a trap, and thus avoid mechanical loss, and the mixture was heated with utmost care for a long time at a temperature not exceeding 70° centigrade. Following are some of the results obtained with various sulphates : _ Kuzirian— Water of Crystallization in Sulphates. 405 (UAB Ei Determination of water of crystallization in various sulphates. Loss of the Gain of Dried porcelain . sulphuric sodium boat acid Sulphate tungstate after weighing Difference. taken taken ignition tube erm. erm, + erm, erm. Copper Sulphate. CuS0O.. 5H.O. 0°2000 = 0:0707 0:0701 — 0°0006 0°2000 4 0-0715 0:0712 —0°'00038 Aluminum Sulphate (Al,(S0,).18H.0. Al,(SO.)3.18H.0. 0-2000 4 0°0897 0°0913 +0:0016 0°2000 4 0-0900 0-0894 —0-0006 0°2000 4 0:0907 0°0915 + 0°0008 0°2000 4 070925 0:0935 +0:0010 Nickel Suiphate (NiSO,.6H:0). NiSO,.6H,0. ; 0°2000 3 0°0822 0:0831 +0:0009 -0:2000 3 0-0832 0°0833 +0:0001 0°2000 3 0°0826 0-0825 +0:0001 Chrome Alum (K2SOx,.Cr2(SO.)3).24H20. K.S0.Cr2(SO.1)3.24H20. 0°2000 + 0:0807 0:0800 —0°0007 0°2000 4 0°0755 0°0755 0°0000 0°2000 4 0:0780 0°0794 +0°0014 Potassium Alum (K.SOu.. Al2(SO4)3).24H20. 0°2000 3. 0:0915 0°0923 + 0°0008 0°2000 2 0°0911 0°0929 +0°0018 0°2000 3 0°0910 0°0915 +0°0015 0°2000 3 0°0915 0:0928 +0°00138 From the results detailed in the above table, it is evident that there is no loss other than water during the fusion. Even from aluminum and chromium sulphates which lose their acidic oxide on simple ignition, no sulphur trioxide is volatilized in the presence of sodium tungstate. The water of crystallization of these sulphates may, therefore, be determined in a remark- ably short time and with great accuracy with the use of this flux, and the advantage to be derived is obvious and needs no particular comment. In the case of an acidic sulphate the entire amount of the acidic oxide will be retained by the tungstate, and the water of constitution as well as the water of crystallization will be evolved. The extension of the use of this flux to the estimation of water in salts other than sulphates is, for lack of time, left to some future date. 406 Richardson—Paleazoic Section in Northern Utah. Arr. XXXIX.—The Paleozoic Section in Northern Utah ; | by G. B. Ricuarpson.* Introduction.—One of the most complete Paleozoic sections known in the entire Cordilleran region is exposed in: eine vicinity of Bear Lake, northern Utah. This section embraces more than 14,000 Faas of strata and includes seven Cambrian, three Ordovician, one Silurian, two Devonian and four on boniferous formations. The entire sequence is well exposed ' in the Randolph quadrangle, which was studied in the summer of 1912 by the writer, assisted by Paul V. Roundy, to whom he is indebted for measuring a number of sections and collect- ing many of the fossils. G. H. Girty visited the party during the progress of field work and, in addition to identifying the Carboniferous fossils, was of creat help in making collections. The writer also acknowledges his indebtedness to Messrs. E. O. Ulrich, E. M. Kindle, L. D. Burling and Edwin Kirk for examining the fossils. The table on page 407 summarizes the Paleozoic rocks of northern Utah. Cambrian. The Cambrian section in the Randolph quadrangle is essen- tially that described by Walcott+ as occurring in Blacksmith Fork, Utah, and in the vicinity of Liberty, Idaho, and need not be described here. This section is finely exposed on the eastern flank of Bear River Range west of Garden City, where the thicknesses recorded in the table were measured. There the formations named by Walcott were recognized by their lithology, stratigraphic position and fossils, which latter were examined by L. D. Burling, who assisted Walcott in the study of the type section. In the preparation of the geologic map of the Randolph quadrangle it was found desirable to differen- tiate the Hodges shale member at the base of the Bloomington formation and the Worm Creek quartzite member at the base of the St. Charles limestone. The Hodges shale member of the Bloomington formation is a persistent zone of drab clay shale about 350 “feet thick, oceur- ring at the base of the formation. It hes apparently conform- ably on the massive Blacksmith limestone, and is overlain by thin-bedded limestone of the Bloomington formation. The name is derived from Hodges Creek, which crosses the shale and enters Bear Lake 14 miles south of Garden City. * Published by permesan of the Director, U. S. Geological Survey. + Walcott, C. D. : Cambrian Geology and Paleontology, Smithsonian Mis- cellaneous Collections, vol. liii, pp. 5-9 and 190-200, 1908; also Mon, U. S. Geol, Survey, No. 51, pp, 148- 153, 1912. Kis REL 2? Paleozoic formations in Northern Utah. Series or System. fauna. ( Permian ? Carbon- 4 iferous Pennsylva- nian Mississip- | ») pian lL ( Upper Devonian + Middle and Lower Silurian ( Richmond fauna Ordo- vician Chazy ? fauna Beekman- town fauna Upper —— a Cambrian { Middle 1 Middle and Lower — ( | A | L : t ( Formation. Phosphoria forma- tion Wells formation Brazer limestone Madison limestone Threeforks lime- stone Jefferson dolomite Laketown dolomite Fish Haven dolo- mite Swan Peak quartz- ite Garden City lime- stone St. Charles lime- stone Worm Creek quartzite member Nounan limestone Bloomington formation Hodges shale member Blacksmith lime- stone Ute limestone Spence shale member | Langston limestone Brigham quartzite Base not exposed Approxi- mate thick- ness in feet. 400 less than 300 to 600 800 to 1400 600 to 1600 200 1200 1000 500 500 1000 1800 to less than 500 950 1250 700 480 to 58d 370 1600 + General character. Chert and siliceous limestone overlying shale, thin lime- stone and oolitic phosphate rock. Massive gray quartzite over- lain and underlain by thin- ner bedded quartzite and limestone. . Massive to thin-bedded light gray siliceous limestone and sandstone. Medium to thin-bedded dark limestone rich in fossils. Soft reddish rocks poorly ex- posed in Randolph quad- rangle. Massive, fine-grained dark dol- omite, weathers a character- istic brown tint. Massive light gray dolomite. Medium-bedded bluish dolo- mite. Fine textured gray quartzite. Thick- and thin-bedded gray limestone. Massive gray limestone with 300 ft. of massive gray quartzite at the base. Massive to medium-bedded gray limestone. Thin-bedded limestone and shale, Hodges shale member at the base. Massive fine-grained gray to bluish limestone. Thin limestone, interbedded with shale. Massive crystalline blue to gray limestone, Massive’ fine-grained gray quartzite locally conglom- erate. 408 Richardson—Paleozoic Section in Northern Utah. The Worm Creek quartzite member of the St. Charles lime- stone Is a massive gray quartzite occurring at the base of the formation. It is of variable thickness, having a maximum of 300 feet in the Randolph quadrangle. The Worm Creek quartzite directly overlies the Nounan limestone and is succeeded by the massive gray fossiliferous Upper Cambrian limestone which forms the bulk of the St. Charles limestone. The name is derived from Worm Creek, in the Bear River Range, 10 miles north of the Randolph quadrangle. Ordovician. Overlying this great thickness of Cambrian rocks the Ordovi- cian system likewise is well developed in the Bear River Range, notably adjacent to the Idaho-Utah state boundary, where it is represented by a continuous exposure of 2,000 feet of strata. These beds are separated into the following forma- tions: the Garden City limestone containing a Beekmantown fauna, the Swan Peak quartzite containing a Chazy ? fauna, and the Fish Haven limestone characterized by a Richmond fauna. Although the succession is apparently conformable, there is nevertheless evidence of erosional unconformity at the base of the lowermost and uppermost Ordovician formations. These unconformities are inferred from the facts that the Garden City limestone and the Fish Haven dolomite, respectively, rest on such different horizons in different parts of the Randolph quadrangle that considerable erosion apparently preceded their deposition. Details will be given in the Randolph folio. Garden City Limestone. The Garden City limestone, named from Garden City Can- yon, a tributary of Bear Lake, consists of a succession of thick and thin bedded gray limestone approximately 1,000 feet thick. A characteristic feature is the presence throughout the formation of a conglomerate or breccia consisting of elongated bits of limestone up to 2 or 3 inches in length, irregularly imbedded in a matrix of similar composition. The following fossils, identified by Edwin Kirk of the U.S. Geological Survey, were obtained from the Garden City lime- stone in the Bear River Range, Randolph quadrangle, at the horizons indicated : From the eastern flank of Bear River Range 4 miles northwest of Garden City, Utah— From the base of the Garden City limestone, within 25 feet of St. Charles limestone: Dalmanella sp. Raphistoma acuta H. & W. Syntrophia near calcifera Hormotoma sp. Billings Eccyliopterus sp. Richardson— Paleozoic Section in Northern Utah. 409 From 187 feet above the base of the Garden City limestone : Lingula sp. Asaphoid From 337 feet above the base of the Garden City limestone : Streptorhynchus minor Asaphus ? Walcott A new genus of trilobites allied to Bumastus From 375 feet above the base of the Garden City limestone : Dailmanella sp. Asaphus sp. Raphistoma sp. Ribeiria sp. Maclurea subunnulata Walcott . From 675 feet above the base of the Garden City limestone: Strophomena fontinalis White Maclurea subannulata Walcott Dalmanella pogonipensis Hormotoma sp. H. and W. Eecyliopterus sp. Streptorhynchus minor Walcott Asaphus ? curiosus Billings Eostrophomena nu. sp. Asaphus sp. Raphistoma ? near trohiscus Bathyurus sp. Meek Receptaculites sp. Raphistoma acuta H. and W. From the top of the Garden City limestone: Dalmanella pogonipensis Hormotoma sp. Heard: W, Echinoencrinus ? sp. Strophomena fontinalis White Leperditella sp. The fauna of the Garden City limestone is represented in part by that of certain portions of the Pogonip limestone of the Eureka district, Nevada. Itis equivalent to the Beekman- town fauna of the Kast. Swan Peak Quartzite. The Swan Peak quartzite, named from Swan Peak in the Bear River Range, Utah, 14 miles south of the Idaho boundary, is a fine-textured massive to thin-bedded white to gray quartz- ite about 500 feet thick which hes apparently conformably on the Garden City limestone. The following fossils, identified ‘by Edwin Kirk, were obtained from this quartzite in the N Et sec. 9, T. 14 N., R. 4 E., Orthis n. sp. near tricenaria Conrad, Eccyliomphalus sp., Endoceras sp. Ampyx?, Symphysurus ? golfusst Walcott, Bathyurus congeneris Walcott, Leperditia sp., Leperditella sp. This fauna, which is related to that occur ring in the lower part of the Simpson formation in Oklahoma, is referred tentatively to the Chazy by Ulrich and Kirk. Fish Haven Dolomite. In the Bear River Range near the Utah-[daho boundary the Swan Peak quartzite is immediately overlain by the Fish 410 Richardson—Paleozoic Section in Northern Utah. Haven dolomite, which is a fine-textured medium-bedded dark gray to blue-black, locally cherty, dolomite about 500 feet thick containing a Richmond fauna. The name is derived from Fish Haven Creek, which enters Bear Lake, Idaho, about 2 miles north of the Utah State Line. A sample from the head of Fish Haven Creek, analyzed by Walter C. Wheeler of the U. 8. Geological Survey, showed 21°35 per cent of magnesia. The following fossils, identified by Edwin Kirk, were obtained by R. W. Richards in the Fish Haven dolomite near the crest of the Bear River Range at the head of Fish Haven Creek in the Montpelier quadrangle, Idaho, immediately north of the Randolph quadrangle: Calapoecia ef. Canadensis Bill., Strep- —telasma sp., Halysites catenulatus var. gracilis Hall, Rhyn- chotrema ct. capax Conrad, Columnaria thomi Hall. This represents a widespread western Richmond fauna. SILURIAN. Laketown Doloniite. The Laketown dolomite, named from Laketown Canyon 4 miles southeast of Laketown in the Randolph quadrangle, is a massive light gray to whitish dolomite, containing lenses of calcareous sandstone, having a thickness of approximately 1000 feet. An analysis of a sample from SE sec. 17, T. 12 N., RB. 6 E. showed 21°38 per cent MgO. In the Montpelier quadran- gle, Idaho, R. W. Richards reports a few feet of the Laketown dolomite lying above the Fish Haven dolomite apparently con- formably, but the most complete section of this formation is in Laketown Canyon. There, however, because of the scarcity of fossils, the lower boundary and consequently the thickness of the Laketown dolomite has not yet been determined. Fos- sils in general are rare in the Laketown dolomite although locally there occur considerable quantities of a poorly pre- served Pentamerus cf. oblongus Sow. Specific identification is impossible, but they clearly point to the Silurian age of the - containing beds. A similar fauna was reported by Kindle* from Green Canyon east of Cache Valley. Some poorly pre- served corals, identified provisionally as Halysites catenulatus ? Linn., Lavosites sp. and Cyathophyllum ? sp., were found in the lower part of the dolomite in Laketown Canyon, but it is doubtful whether these fossils, here tentatively referred to the Silurian, may not be Richmond. It is proposed to restrict the name Laketown dolomite to beds of Silurian age. * Kindle, E. M.: The fauna and stratigraphy of the Jefferson limestone in the northern Rocky Mountain region. Bull. of American Paleontology, No. 20, p. 17, 1908. Richardson— Paleozoic Section in Northern Utah. 411 DEVONIAN. Jefferson dolomite. The Jefferson limestone of Lower and Middle Devonian age, which has a widespread distribution in the northern Rocky Mountain region, is well developed in the Randolph quadrangle, where, however, the name dolomite is applied instead of lime- stone because of the magnesian content. A sample from Lake- town Canyon showed the presence of 19°16 per cent MgO. In the area here considered the Jefferson consists chiefly of massive fine-grained dark-colored dolomite, weathering a characteristic brownish tint, but in places, as in Laketown canyon, the lower strata are thin-bedded. The Jefferson is about 1200 feet thick, and overlies the Laketown dolomite apparently conformably. Fossils are not abundant although two collections were obtained in Laketown Canyon, one from near the top of the dolomite and the other from near its base. Both lots were identified by E. M. Kindle. Fossils from Jefferson dolomite, Randolph quadrangle. From East Fork of Laketown Canyon, SE4 sec. 17, T. 12 N., R. 6 E., about 150 feet above the base of the formation : Productella sp. Aviculopecten ? sp. Spirifer englemant Fish bone fragment. Nuculites sp. From East Fork of Laketown Canyon, W#4 sec. 17, T. 12 N., R. 6 E., from several beds between 200 and 500 feet below the top of the formation. Aulopora sp. . Laphrentis sp. Kuavosites cf. limitaris Dr. Kindle reports that “the coral listed here as Favosites ef. damitaris is one of the characteristic and widely distributed fossils of the Jefferson limestone of the northern Rocky Mountain region. One of the species of the preceding faunule, Spirifer englemanni, is also a characteristic fossil of this forma- tion.” Threeforks limestone. At the type locality, Threeforks, Montana, the Threeforks limestone, there the Threeforks shale, lies conformably between the Madison and Jefferson limestones. But although the Threeforks has not been recognized over so wide an area as have the immediately overlying and underlying formations, in the Randolph quadrangle all three formations are present, the Threeforks being definitely recognized by fossil evidence. The Threeforks limestone is a soft formation lying between harder ones and in the area here considered usually occupies Am. Jour. Sci.—FourtH SErRiIEs, Vout. XXXVI, No. 214.—Octosrr, 1913. ~~ 412 Richardson—Paleozoie Section in Northern Utah. talus slopes or debris-covered lowlands so that nowhere was a complete exposure of the formation found and only thin beds of impure reddish-colored limestone were observed, the strati- graphic interval between the underlying Jefferson and over- lying Madison limestone being about 200 feet. This soft reddish zone lying between well marked massive limestone is an excellent horizon marker. | In the Randolph quadrangle the Threeforks limestone out- crops in two distinet areas m Laketown Canyon and in the Crawford Mountains but fossils were found in it only in the Crawford Mountains, where the following lot, identified by E. M. Kindle, was obtained in 84 sec. 29, T. 11 N., R. 8 E. Productella coloradensis Syringothyris cf. cartert Camarotochia cf. contracta Spirifer whitneyi var. anima- Schizophoria striatula var. Sensis australis Cleiothyridina sp. undet. Spirifer notabils Dr. Kindle states that this fauna is of Upper Devonian age and includes elements both of the Ouray limestone and Threeforks shale fauna. It may be observed in passing that reddish beds referred to by Blackwelder as constituting a “non-marine member in the Mississippian limestone” * exposed around the sources of the south fork of Ogden River, Utah, and thought by him to be of continental origin, may prove to be the marine Threeforks. Carboniferous. The Carboniferous rocks of the area under consideration outcrop in the Crawford Mountains east of the town of Ran- dolph, where the entire local section is well exposed. MIssISSIPPIAN SERIES. Madison limestone. The Threeforks limestone is apparently conformably over- lain by the well known Madison limestone, which here is a medium to thin-bedded dark limestone of variable thickness ranging from about 600 to:1600 feet thick. It is abundantly fossiliferous. The following small selected list was identified, and in part collected, by G. H. Girty: Fossils from Madison limestone, Randolph quadrangle : Menophyllum excavatum P. gallatinensis Lepteenw analoga Camaroteechia herrickana Schuchertella chemungensis Spirifer centronatus Productella concentrica Reticularia Cooperensis P. arcuata Syringothyris cartert Productus levicosta Huomphalus utahensis * Blackwelder, Eliot.: New Light on the Geology of the Wasatch Mts., Bull. Geol. Soc. America, vol. xxi, pp. 528, 529, 1910. Richardson— Paleozoic Section in Northern Utah. 413 Brazer limestone. The Madison limestone is overlain by the Brazer limestone, of upper Mississippian age, named from Brazer Canyon in the Crawford Mountains, 6 miles east by north of Randolph, where it is well exposed. The Brazer for the most part is a massive light-colored impure limestone, but it varies considerably in com position especially in its lower part. In some places much chert is present, occurring in layers a few inches thick and also in irregular bunches. In other localities chert is not conspicuous, and the lower part of the limestone is thin-bedded to shaly. About a mile east of Laketown a thin bed of phosphate rock, formerly assigned to the Park City (Phosphoria) formation, oceurs in the shaly lower part of this limestone. The Brazer lime- stone is more or less sandy throughout, and locally considerable sandstone is present. In the Randolph quadrangle this lime- stone ranges from 800 to 1400 feet in thickness, which variation suggests an erosional unconformity separating the upper Missis- sipplan from the overlying Pennsylvanian deposits. Fossils are usually scarce in the Brazer limestone. Their occurrence is characteristically bunched, and collections from different localities often show quite different facies. The following species, identified and in part collected by G. H. Girty, were obtained in the Randolph quadrangle : Fossils from Brazer limestone, Randolph quadrangle : From 13 miles east’ of Laketown, near center of sec. 32, T. 13 N., R. 6 E., and 1 mile south in N.E. 1/4 sec. 5, T. 12 N., R. 6 E.: Endothyra Bailey Composita sp. Zaphrentis sp. Cliothyridina hirsuta Productus aft. pileifor mis Concardium sp. P. Biseriatus ? Aviculipecten sp. P. aff. giganteus Astartella nucleata ? Dielasma formosum >? Euomphalus sp. Girtyella turgida FHlolopea proutana ? Spirifer bifurcatus ? Griffithides sp. Kirkbya sp. Paraparchites carbonarius ? From 14 miles east of Laketown, near center of W. 1/2 sec. 32, T. 13 N., R. 6 E., in shaly limestone near the base of the for- mation: Triplophyllum sp. Productus altonensis Michelinia sp. Martinia ? sp. Khipidomella sp. * Spirifer moorefieldanus Chonetes illinoisensis var. Platyceras sp. Productella hirsutiformis ? Paraparchites sp. 414. Richardson—Paleozoic Section in Northern Utah. Dr. Girty states that the latter fauna is related to that of the Moorefield shale of Arkansas, which is of basal upper Missis- sipplan age. Pennsylvanian and Permian ? series. There has been some confusion in the naming of the Penn- sylvanian and Permian ? rocks of northern Utah and southern Idaho. The 40th Parallel Survey introduced the term Weber quartzite, taken from a great development of gray quartzite in Weber canyon, for the beds lying between what was called “Wasatch limestone” and the “Upper Coal Measure lime- stone.” Since then down to comparatively recently the name Weber quartzite, without being clearly defined, has been in current usage, but lately somewhat conflicting terms have been introduced for what is thought to be in part the equivalent of the original Weber, although detailed work has not yet been done in the type locality. Boutwell in his report on the Park City District included in the Park City formation beds which may be the equivalent of the upper part of the original Weber quartzite; and Blackwelder, following Weeks, applied the name Morgan formation to a mass of red sandstone and shale with intercalated thin limestone that apparently was included in the lower part of the original Weber quartzite. Gale and Richards, in their Preliminary Report on the Phosphate De- posits in Southeastern Idaho and adjacent parts of Wyoming and Utah, extended the terms Weber quartzite and Park City formation to that region. But as the work in the phosphate reserves of southeastern Idaho was extended, the introduction of new names became necessary because satistactory correlation with the Weber Canyon section could not be established. Accordingly, Richards and Mansfield introduced the names Wells and Phosphoria formations defined below. Wells Formation. The Wells formation,* named from Wells Canyon in T.106., Rt. 45 E., Idaho, ineludes the beds of Pennsylvanian age lying between the Brazer limestone and the overlying Phosphoria formation. At the type locality the Wells formation is 2400 feet thick and is divisible into three portions, an upper ealea- reous sandstone or siliceous limestone series, a middle sandy series and a lower sandy and cherty limestone series. In the Randolph quadrangle, the Wells formation outcrops in’ only two areas, in the canyon 14 miles east of Laketown and in the Crawford Mountains. In the former area, where exposures * Richards and Mansfield: The Bannock Overthrust, Journal of Geology, vol. xx, pp. 689-693, 1912. Richardson— Paleozoic Section in Northern Utah. 415 are poor, the Wells appears to be less than 300 feet thick, while in the latter area this formation measures 600 feet. Approximately the lower third of the formation is composed of alternating layers of thin-bedded quartzite and limestone, the middle third of massive quartzite, and the remaining upper part of the formation consists of calcareous sandstone and sandy limestone. An unconformity at the base of the Wells formation is indicated by the varying thickness of the underlying Brazer limestone, by the apparent absence in the Randolph quadrangle of a richly fossiliferous horizon near the top of the Brazer limestone, present in the Montpelier quadrangle, and by the absence of the red sandstone, Mor- gan formation, which occurs at the base of the Pennsylvanian section in Weber Canyon. It should be noted that the thick- ness of rocks of Pennsylvanian age varies greatly in this general region. In Weber Canyon, Utah, although exact measurements have not been made, there are several thousand feet of beds of that age. This great mass of rocks is reported by Blackwelder* to have disappeared about seven miles north -of Weber River. As stated above,in the Randolph quadrangle the rocks of Pennsylvanian age range from less than 300 to about 600 feet in thickness, and in southern Idaho, Richards and Mansfield report the Wells formation to be 2400 feet thick. Phosphoria Formation. The Phosphoria formation, named by Richards and Mans- field+ from Phosphoria Gulch, a branch of Georgetown Can- yon, Bear Lake.County, Idaho, includes the phosphate deposits and associated beds of Permian ? age which le between the Pennsylvanian Wells formation and the Woodside shale of Triassic age. In northern Utah (Randolph quadrangle) the Phosphoria formation is about 400 feet thick. ‘The upper part of the formation consists of chert, cherty limestone, and some intercalated shales from 125 to 200 feet thick, and the lower part is composed of «u sequence about 200 feet thick of brown and gray clay shale, subordinate limestone, and layers up to 5 Teet thick of odlitic phosphate rock. At several widely separated localities (noted by Blackwel- der{ north of Weber Canyon, by Richards and Mansfield,§ in Idaho, and exposed in the Randolph quadrangle, a mile north of Brazer Canyon), a zone of breccia-conglomerate is present at or near the base of the Phosphoria formation. This is * Bulletin, Geological Society of America, vol. xxi, p. 531, 1910. + Richards and Mansfield: The Bannock Overthrust, Journal of Geology, vol. xx, pp. 684-689, 1912. ¢ Bulletin, Geological Society of America, vol. xxi, pp. 530-533, 1910. §$ Journal of Geology, vol. xx, p. 692, 1912. 416 Leichardson— Paleozove Section in Northern UWiah. marked by angular to semi-rounded bits of chert and quartzite, resembling that of the underlying Wells formation, irregularly scattered through a bed of limestone. That this horizon marks an unconformity separating the Phosphoria and Wells forma- tions is suggested by the varying thickness of the underlying Pennsylvanian beds. The Phosphovia formation carries an abundant fauna, part of which has been described by Girty.* This is distinetly dif- ferent from the fauna of the underlying Wells formation and serves as a means of separating the two. The Phosphoria formation is tentatively assigned to the Permian. SCIENTIFIC INTELLIGEN CR I. CHEMIstRY AND Puysics. 1. The Volatile Oxide of Manganese.—It has been long known that when permanganate is treated with strong sulphuric acid, a small amount of a red vapor or cloud may be discharged from the surface of the resulting green solution. Francke in 1887 decided that this was gaseous manganese trioxide, while soon afterwards Thorpe and Hambly decided that it was not a gas, but a cloud, of the same composition. F. R. LanxsHEar has now found that in the absence of moisture a colorless gas is evolved from the solution of permanganate in strong sulphuric acid, espe- cially under diminished pressure. By cooling with liquid air he condensed some of this in a U-tube in the form of a dark green crystalline mass which was found to be permanganic anhydride, Mn,O,. He found further that the red cloud was produced when moist air was admitted to a space containing the colorless vapor, and that the red substance, upon being condensed, contained a large amount of water, more oxygen than corresponds to MnO,, but less oxygen than is required by Mn,O,. It appears, there- fore, that the red substance is an impure product resulting from the reaction Mn,O, vapor with moisture.—Zeitschr. anorgan. Chem., 1xxxii, 97. H. L. W. 2. The Detection of Bromine and its Distribution in Nature. —I. Guarescut has devised a method for the detection of extremely minute quantities of bromine. He has found that fuchsin solution decolorized with sulphur dioxide is the best reagent for bromine, and that paper impregnated with this solu- tion gives an intense blue-violet color with bromine vapor or bromine solution. 'To prepare the reagent 1% of fuchsin (hydro- * Girty, G. H.: The Fauna of the Phosphate beds... in Idaho, Wyoming, and Utah. Bull. U. S. Geol. Survey, No. 486, 1910. Chemistry and Physics. AIT chloride or acetate of rosanilin) is dissolved in 1000° of water and to the solution, with shaking, 8°° of saturated bisulphite and about 10° of hydrochloric acid of 1:19 sp. gr. are added. To apply the test solid salts are treated with a 25 per cent solution of chromic acid, but carbonates are treated with hydrochloric or sulphuric acid and then chromic acid is added in extremely con- centrated solution, so that the dilution may not be too great. The test seems to be applied usually by hanging the test-paper in the neck of a flask in which the bromine is set free. Several aniline dyes may be used in the same way for this test, including Hofmann’s violet. The reaction succeeds even in the presence of free chlorine and iodine. When much iodine is present the paper is colored brown so that the blue bromine color is hidden, but the latter appears when the paper is exposed for a short time to the air. By these reagents the author has detected bromine in a large number of substances, including sodium carbonate and bicarbonate, wood-ashes, urine, samples of the purest chlorides and hydrochlori ic acid. —Zeitschr, J. analyt. Chem., \ii, 538. : H. L. W. 8. Caleium Hydride.—The observation by Moissan in 1899 that metallic calcium absorbs hydrogen gas at and above a dull red heat, forming a white, crystalline compound of the composi- tion CaH,, has led to the manufacture of this substance on the large scale at the electro-chemical works at Bitterfeld for the pur- pose of its use as a convenient means of producing hydrogen gas for military requirements by treating it with water. It has been found that the hydride may be produced in large solid pieces by leading hydrogen gas into molten metallic calcium, and since the melting point of calcium is at about 800°C. it appears that the hydride must be stable at a rather high temperature. MoLpENn- HAUER and Rori—HansEn, in attempting to determine the pres- sure of dissociation of this substance by heating it in porcelain tubes, found that it reacted with the porcelain and gave too high results, but by protecting the porcelain with sheet iron, the pres- sure at 780° C. was found to be 11™" of mercury, while it increased in a regular curve until at 1027° it was 705™". The results of these experiments indicated also the existence of a second hydride, Call, more stable than the CaH,.—Zeitschr. anor- gan. Chem., \xxxiii, 130. H. L. W. 4. Analysis of Special Steels.—Dr. S. Zinspere, Chief Chemist of the Putilow Works at St. Petersburg, has described his method forthe gravimetric determination of tungsten, chromium, silicon, nickel, molybdenum and vanadium in the presence of each other in steels. The whole process is too long for description here, but the method for the determination of tungsten, as a first step in the operation, appears to be novel and worthy of notice. One gram of the sample of steel is treated with dilute hydro- chloric acid (1:4), by heating, as long as there is any action. The metallic tungsten thus left as a residue is known to contain more or less chromium carbide and iron. The liquid is then 418 Scientific Intellagence. heated nearly to boiling and 2 or 3° of nitric acid, sp. gr. 1°40, areadded drop by drop. A violent reaction takes place by which all the tungsten is precipitated as tungstic acid and all the chromium and iron go into solution. After a few minutes, when the reaction is finished the liquid is diluted, then the precipitate is allowed to settle and is filtered and washed with dilute hydro- chloric acid (1:10). In this way, the author states all the tung- sten is obtained entirely free from silicon and chromium.— Leitschr. f. analyt. Chem., lil, 529. | We ds we 5. Qualitative Chemical Analysis; by Artuur A. Noyes. Fourth Edition. Completely rewritten. 8vo, pp. 110. New York, 1913 (The Macmillan Company).—The first edition of this well-known laboratory manual appeared twenty years ago. It has been improved and somewhat enlarged in the second and third editions, and now it has been thoroughly revised as a result of the extended investigations that have been made in the author’s laboratory during the past six years. The process of analysis has thus been made much more reliable, so that now it is possible, the author states, to detect one milligram, or in a few cases two milli- grams, of any constituent in the presence of 500 milligrams of any other. The methods employed for the detection of the metals are practically all well known and require no special com- ment here. The procedure for the detection of the acid radicals has been greatly modified by introducing a distillation with phos- phoricacid. The first half of this distillate is collected in barium hydroxide solution, the second half in water ; then metallic cop- per is added to the residue and a third distillate is obtained con- taining sulphur dioxide in case sulphates are present, and applying even in the case of barinm sulphate. This distillation with phosphoric acid is not intended to be applied in simpler cases, and it may be regarded as a rather difficult and complex operation for ordinary students in qualitative analysis, and, therefore, its general adoption appears to be doubtful. Hu. L. w. 6. A New Hluorescence Spectrum of Lodine.—The shortest wave-length recorded by R. W. Wood for the resonance spec- trum of iodine vapor when excited by the three very intense vis- ible radiations from mercury is 5337°63 A.U. Hoping to find fluorescence lines of shorter wave-length, J. C. McLennan has recently repeated Wood’s experiments, endeavoring, at the same time, to obtain more intense illumination, especially in the ultra- violet. Although no new resonance “lines” were found, the investigator’s labors were crowned with the discovery of a fluo- rescent band spectrum of iodine vapor. The special form of lamp which produced this spectrum may be briefly deseribed as follows: The outer wall was of the usual Cooper-Hewitt design with mercury electrodes. In the end of this wall, which extended some distance beyond the lateral elee- trode, a hole was made and then a long tube of clear, fused quartz was sealed at the hole in such a manner as to remain coaxial with the surrounding vessel. Thus the inner end of the pe ee Chemistry and Physics. 419 quartz tube was not far from the diagonal end electrode of the mercury lamp, while the exposed end of the quartz tube pro- jected some distance beyond the region of sealing. Crystals of iodine were placed in the quartz tube and the latter was then highly exhausted by the aid of a side tube, which was eventually sealed off. Consequently, when the mercury lamp was running, the iodine was simultaneously vaporized and illuminated by the very intense source of radiation. Negatives of the light emerg- ing from the outer end of the silica tube were taken with a quartz spectrograph. In addition to the ordinary mercury lines coming from the are in the outer tube the spectrum contained 80 narrow bands, the mean wave-lengths of the extreme bands being 4608 A.U. and 2129 A.U. Although the new spectrum could be photographed in less than 3 minutes, the best negatives were obtained with an exposure of one hour. Doubling the latter interval did not bring out anything additional. The following characteristics of the spectrum may be of interest. From A 4608 to 43365 the bands are faint in places and the grouping is somewhat irregular. The seven bands between 3315 and 3175 are particularly well-marked and appear to be equally spaced at intervals of about 24 A.U. There are four well-defined pairs of bands in the region between 3065 and 2915. From 2900 to 2545 the bands are quite distinct, but the spacing is irregular. The bands of shorter wave-length than 2515 are spaced about 20 A.U. apart and each band is about ° 10 A.U. wide. In order to show that the new spectrum was due to iodine, the inner tube was thoroughly washed out with methyl alcohol, dried, etc., and a “blank” exposure was taken. The mercury spectrum then came out very strong but not the slightest trace of the bands could be detected. Several other tests were made but the band spectrum could only be obtained when iodine vapor was present. In order to get an idea of the region of wave- lengths in the mercury radiation which excited the resonance bands, the fused-quartz tube was replaced by an equal length of glass combustion tubing closed at the outer end by a plate of crystalline quartz. With this apparatus the bands could not be photographed although the mercury lines came out quite dis- tinctly up to’A2893°7, “This interesting result shows, in the first place, that the emission of the band spectrum by the iodine vapor could not have been due to an elevation of the tempera- ture of the vapor by the heat from the are, for the experimental conditions for obtaining a temperature spectrum were precisely the same with the combustion glass tube closed by a quartz win- dow as with the fused quartz tube closed with the same window.” Also, the new spectrum does not appear to be directly related to the temperature band spectrum of iodine as obtained by Konen and others. It is thus seen that the resonance bands are excited by radiations of shorter wave-length than 2893-7 A.U. The exact wave-length of the exciting line has not yet been deter- a a a a = a a SSS SSS Se re E = 420) Scientific Intelligence. mined by McLennan but, at present, the evidence favors the strong mercury line at 2536°7. In none of the experiments with the coaxial lamp were the fluorescence lines discovered by Wood detected. The complete absence of these series lines may be explained as due either to the absorption in the long column of iodine vapor with the temperature gradient down towards the quartz window, or to a different constitution of iodine vapor at the relatively high temperature of the coaxial Jamp as compared with the ordinary room temperature in Wood’s investigations. At present, there is experimental evidence in favor of both ~ hypotheses.— Proc. Roy. Soc., vol. |xxxviii (A), p. 289. H. 8. U: 7. Interference of Gamma ays. —Since X-rays and y-rays seem to belong to the same type of radiation and since it has been shown experimentally, by Friedrich, Knipping, Bragg, and others, that the atomic or molecular structure of certain crystals acts like a space grating with respect to X-rays, it is natural to expect a similar phenomenon in the case of y-rays. This question has been successfully investigated by A. Norman SHAaw. A general idea of the simple apparatus used may be obtained from the following statements. The bulb which contained about 15 mg. of radium bromide was placed at the bottom of a deep hole bored in a thick block of lead. The primary y-rays passed through a sheet of lead 2™" thick which covered the mouth of the hole and which prevented the emergence of the direct B-rays. The primary beam continued through a long collimating hole ina second block of lead. A magnetic field was maintained across the outer end of this hole in order to deviate the secondary, ‘““emergence ” B-rays from the axis of the beam of primary y-rays. Beyond the electromagnet the latter rays passed through a hole in a lead screen and then struck a sheet of mica at approximately grazing incidence. The hole in this screen was slightly larger than the one in the collimating block. After leaving the mica the y-rays eventually struck a photographic plate whose plane was normal to the impinging beam. ‘It was found that the sensitiveness to y-rays was increased by placing thin layers of matter” [paper, ete.| ‘in front of, and almost in contact with, the photographic plate.” “More #-particles were thus liberated in the path of any beam of y-rays near the surface of the plate, and the impression was intensified without an appreciable amount of additional scattering.” In a typical experiment the sheet of mica was 1™™ thick and 15™ distant from the photographic plate. ‘The collimating hole had a diameter of 2™™, The time of exposure was one month and hence rays of all intensities down to 1/1500 of the intensity of the primary beam could have been detected. In general, the central image could be clearly recorded in 40min. In addition to this circular spot all the negatives show a series of roughly paral- lel, rectilinear images whose common normal lies in a direction oblique to the intersection with the photographic plate of a plane Chemistry and Physics. 421 perpendicular to the face of the mica sheet and containing the axis of the primary pencil. The number and orientation of these interference patterns are different on the various negatives, due to intentional changes in the sizes and relative positions of the mica, collimating holes, etc. Thus the possibility of interference of y-rays scattered or reflected at the cleavage planes of mica has been demonstrated experimentally. Three exposures were made with a glancing angle of about five degrees but no grating effects were recorded. The y-ray negatives were compared both with a negative obtained with X-rays under similar conditions, taken by the investigator himself, and with X-ray photographs taken by Brage. Shaw says: “ Since it is thus apparent that we get faint effects with y-rays in those directions in which very hard X-rays give their most intense reflections, and no perceptible effect in the direction in which sott X-rays give their strongest reflection, we may conclude that the wave-length of the soft y-rays from radium is less than that of hard X- -rays by an amount not differing greatly from the difference in wave-length between the softest and the hardest X-rays that can be produced with an ordinary bulb and coil.” Assuming that the «known relation between the velocity of electrons from surfaces and the fre- quency of the ultra-violet light which liberates them can be extended to y-rays and to X-rays, and using Planck’s formula $mv' = hn, it follows that ordinary y-rays from radium have wave- lengths probably about ten, or at most a hundred, times smaller than the wave-length of the hardest Réntgen rays.— Phil. Mag., vol. xxvi, July, 1913, p. 190. H. §.)U- 8. Experimental Researches on the Specific Gravity and Dis- placement of Some Saline Solutions ; by J. Y. Bucaanan. Pp. 227. Edinburgh, 1912 (Neill and Co.).—This memoir is reprinted from the Transactions of the Royal Society of Hdinburgh, Vol. XIIX, Part I, 1912.—‘‘The main purpose of the investigation was to determine the specific gray ity of solutions of moderate concentration and of high dilution.” The. data were obtained by using specially designed hydrometers, and hence a great deal of space is devoted to an account of the construction and manipula- tion of these hydrometers, and also to the high degree of accu- racy attainable. The salts studied with the closed hydrometer were the bromides, chlorides, iodides, bromates, chlorates, iodates, and nitrates of potassium, rubidium and caesium, and also the nitrates of lithium, sodium, strontium, barium and lead. ‘lhe chlorides of beryllium, magnesium and calcium were investigated with the open hydrometer. The tables are numerous and repre- sent an enormous amount of work which was apparently done in the most painstaking manner possible. The results obtained from the discussion of the numerical data are new and important, but far too numerous to admit of recapitulation in this place. One typical illustration must suffice. “The most noteworthy case is that of calcium chloride in | supersaturated solution. In it a very remarkable state of unrest 429 Scientifie Intelligence. was observed before crystallisation took place. When the crys- tallisation of this solution is finished, the sum of the volumes of the crystals and the mother-liquor is less than that of the original supersaturated solution. The state of unrest which precedes the actual appearance of the first crystal consists in a rhythmic series of isothermal expansions and contractions, which cease the moment the first crystal appears and heat is liberated. The supersaturated solution exhibits veritable symptoms of labour before giving birth to the crystals and becoming itself a mother- liquor.” H. 8. U. 9. Die elektrischen Higenschaften und die Bedeutung des Selens fiir die Hlektrotechnik ; by Dr. Cur. Rizs. Second edi- tion. Pp. 189, with 90 figures. Berlin-Nikolassee, 1913 (Admin- istration der Fachzeitschrift ‘‘ Der Mechaniker ”), _The present edition of this book was made necessary by the numerous investi- gations of the properties of selenium, and by the great improve- ments in the practical applications which have been made in the last four years. Most of the sections have been rewritten and amplified so that the volume has grown to nearly double its origi- nal size. Chapters I to XVII inclusive (pp. 1-130) are devoted to the purely physical properties of selenium, while chapter XVIII (pp. 130-160) deals with the practical applications of these properties... The next chapter gives the complete bibliogra- phy of the subject, and comprises 388 references which are grouped under the year of publication and then arranged alpha- betically according to the names of the authors. ‘The material is presented in such a clear, thorough and systematic manner that the book constitutes a very useful and interesting contribution to the subject. H. S. U. 10. Photochemische Versuchstechnik ; by JOHANNES PLOTNI- Kow. Pp. xv, 371, with 189 figures, 50 tables, 3 plates. Leipzig, 1912 (Akademische Verlagsgesellschaft).—Prior to the appear- ance of this book there existed no single volume which contained a description of the methods of experimentation and of the appara- tus used in photochemical investigations. ‘The present incom- plete development of the subject caused the author to state clearly in his preface that the text is not a laboratory manual or practical guide but that, in the nature of the case, it deals only with the technique of experimentation. ‘The value of the book is greatly enhanced by the fact that, under the direct supervision of Plotni- kow, the firm of Fritz Kohler in Leipzig has established anew department of photochemical apparatus. Some pieces of appara- tus are new and are described for the first time. As regards details, the material is presented in a very thorough and admirable manner. The first four Parts of the text deal respectively with sources of light, optical thermostats, optical measuring instruments, and photochemical demonstration experi- ments. The fifth Part comprises a very complete set of numerical tables. Of these, the tables of reciprocal wave-lengths and of *-* deserve special mention. The bibliographical references are Chemistry and Physics. 493 numerous and apparently complete. It is evident, therefore, that the volume will be especially welcome to investigators who con- template entering the field of photochemistry. BCH 107 11. A First Course in Physics ; by RopErt ANDREWS MiIttI- KAN and Henry Gorvon GALE. | Revised edition. Pp. x, 442, with 463 figures and 659 problems. Boston, 1913 (Ginn & Co.). —In this volume the authors have maintained the method which characterized the first edition and which was largely responsible for its pronounced success. In the preface to the last edition attention is called to the ten most important changes which have been introduced. In brief, most of these alterations are of two general kinds ;— (a) improved presentation brought about by shortening and by simplification, and (b) the introduction of a large number of new problems and figures. Furthermore: “The approach to the subject of physics has been made more simple and interesting by postponing the chapter on force and motion until after the discussion of the fascinating phenomena of liquids and gases.” The book is made very attractive and inspiring by the introduction of an excellent selection of about forty half-tones of portraits of physicists and of photographs of some of the most notable achievements of modern physics, both in the field of application and of pure science. Also, the number of pages has been reduced by about sixty in order to give opportunity for an extended review at the end of the course. The last edition unquestionably merits the earnest attention of all who are en- gaged in introducing the subject of physics to students. Hs, (S20 Us 12. Materialien fiir eine wissenschaftliche Biographie von Gauss ; edited by F. Kirin and M. Brenner. Pp. 143. Leip- zig, 1912 (B. G. Teubner).—The material presented in this volume has been very carefully arranged and worked up by L. Scuue- SINGER from the original notes and records ot Gauss. The subject-matter is divided into two parts entitled respectively, «< O. F Gauss: Fragmente zur Theorie der arithmetisch-geome- trischen Mittels aus den Jahren, 1797-1799,” and “ Uber Gauss’ Arbeiten zur Funktionentheorie.” The first part, which is prelim- inary to the second, is in turn subdivided into three sections. The first of these consists essentially in a table of mathematical expressions accurately copied from the original manuscripts. In the second section Schlesinger explains and comments on the for- mule of the preceding list. The last section of this part deals with the probable dates of the results obtained by Gauss. As its title implies, the second and main part of the volume relates to the investigations of Gauss in the field of the Theory of Functions. Many of the quotations from the original manuscripts are pub- lished for the first time, and the whole book throws much light on the various phases of the development of Gauss’s ideas and thoughts. Consequently this volume should be very acceptable to all who are interested in the history of mathematics in general, and in that of Gauss’s scientific career in particular. H. 8. U. 424 Scientific Intelligence. 13. Descrizione di una Macchinetta Hletiro-Magnetica ; by Dr. Anronto Pactnotri. Pp. 95, with 2 plates. Bergamo, 1912 (Istituto Italiano d’Arti Grafiche). — This little book was pub- lished under the auspices of the Associazione Elettrotechnica Italiana. It is an extract from the “Muovo Cimento” of June 1864 which appeared May 3, 1865. In addition to the original Italian the text 1s given in French, English, German, and Latin. The respective translators were Paul Janet, S. P. Thompson, Gis- bert Kapp, and P. Rasi. The paper consists in an account of the model of a small electromagnetic machine which was constructed by Pacinotti in 1860 for the Cabinet of Technological Physics of the University of Pisa. As is well known, the work of Paci- notti played an important part in the development of electro- magnetic machinery, and hence this collection of translations is both interesting and valuable from the historic standpoint. The first plate is a picture of Pacinotti, and the second plate contains four figures of plans, sections, etc., of the machine. H.'s. Ui. 14, L’attraction universelle considéree comme fonction du ‘temps ; by A.N. Panorr. Pp. 6. Reprint from Astron. Nachr., vol. cxciv, March, 1913.—The author’s reasoning is based on the assumption that gravitational forces, like electromagnetic forces, are propagated with finite velocity. Expressions for the retarded potential and the aberration of the force due to a moving body are developed, and the theory is applied to the orbital motion of the planets. The methods employed do not appear to be essen- tially different from those introduced by Lorentz into electro- magnetic theory, and applied to gravitational fields by numerous authors. LBs II. Grotogy AnD MINERALOGY. 1. Publications of the United States Geological Survey.— Recent publications of the U. 8. Geological Survey are noted in the following list (continued from p. 77) : PROFESSIONAL PaprEers.—No. 78. Geology and Ore Deposits of the Philipsburg Quadrangle, Montana; by Witiiam H. Em- mons and Frank C, Cauxins. Pp. 271; 17 pls., 55 figs. No. 79. Recurrent Tropidoleptus Zones of the Upper Devo- nian in New York; by Henry S. Witttams. Pp. 103; 6 pls., 18 figs. Ne 80. Geology and Ore Deposits of the San Francisco and Adjacent Districts, Utah; by B. S. Butter. Pp. 212; 41 pls., 16 figs. No. 85-A. The Origin of Colemanite Deposits ; by Hoyt 8. GALE ip. Butietins.—No. 465. The State Geological Surveys of the United States: compiled under the direction of C. W. Hayss. Ppa: Geology and Mineralogy. 425 No. 525. A Geologic Reconnaissance of the Fairbanks Quad- rangle, Alaska, by L. M. Prinpte. With a detailed Description of the Fairbanks District by L. M. Prinpue and F. J. Karz, and | an Account of Lode Mining near Fairbanks by Parrre 8. Surru. 220 pp. ; 2% pls. (4 maps in pocket), 20 figs. No. 528. Geology and Ore Deposits of Lemhi County, Idaho ; by Josrrpa B. Umptesy. Pp. 182; 23 pls., 24 figs. No. 532. The Koyukuk- Chandalar Region, Alaska; by A. G. Mappren. Pp. 119; 9 pls., 2 figs. No. 538. Geology of the wine and Grand Central Quadran- gles, Alaska; by Frep. H. Morrir. Pp. 140; 12 pls., 13 figs. — The Yentna District, Alaska; by SrrEPHEN R. Capes. Pps Zo; 13 pls., 7 figs. No. 540-T. Celestite Deposits in California and Arizona; by W. ©. Poaten. Advance chapter from Bulletin 540; pp. 15; 3 figs. Pee SuPPLy Papers.— No. 292. Surface Water Supply of the United States, 1910. Part XII. North Pacific Coast; pre- pared under the direction of M. O. Leienron, by F. F. Hensuaw, EK. C. La Ruz, and G. C. Stevens. Pp. 685; 3 pls. No. 314. Surface Water Supply of Seward Peninsula, Alaska; by F. F. Henspaw and G. L. Parker. With Sketch of the Geog- raphy and Geology by Puuiip 8. Smiru, and a Description of Methods of Placer Mining by AtFRED H. Brooxs. Pp. 317; 17 pls., 12 figs. _No. 318. Water Resources of Hawaii, 1909-1911. Prepared under the Direction of M. O. Leieuron, by W. F. Martin and C. H. Prrrce. Pp. 552; 15 pls., 4 figs. 2. Report of the State Geologist on the Mineral Industries and Geology of Vermont, 1911-1912, by Grorce H. PrErxins, State Geologist and Professor of Geology, University of Ver- mont. Pp. xv, 269, pls. 83. Montpelier, 1912.—This volume, well printed and with handsome illustrations, contains a number of contributions. The opening paper is by G. H. Perkins on A General Account of the Geology of the Green Mountain Region, planned as an educational article, especially for the use of teach- ers. The following paper is on the Geology of the Strafford Quadrangle by C. H. Hitchcock. The rock formations of Iras- burg, Craftsbury, and Albany are described by C. H. Richardson, assisted by EK. F. Conway and M. C. Collister. Papers on the qualities of the Vermont slate and marbles follow. An interest- ing discussion on rill channels and their cause is contributed by G. H. Hudson. The volume closes with a statement of the mineral resources by G. H. Perkins. J, 8. 3. Lhe Cretaceous deposits of Miyako; by H. Yase and S$. YeEuHARA. Science Reports, Tohoku Imperial University, second sex. (Geology), Vol. I, No. 2, pp. 9-23, pls. III-V, 1913.—An interesting and carefully wrought- out paper describing i in detail the very fossiliferous marine “Middle Cretaceous beds of the region about Miyako, in the province of Rikuchu, Japan. The 426 Scientific Intelligence. total thickness is more than 600 meters. The various biotas are not yet described, and for the present the correlation with the Cenomanian is provisional. Cc. 8. 4. Die Antike Tierwelt; by Otro KxrtieR. Zweiter Band: Vogel, Reptilien, Fische, Insecten, etc. Pp. xv, 618.5 2 plarems 161 text figures.—This volume completes an extremely valuable work by Otto Keller, of which the first part, that upon the mam- mals, was reviewed in this Journal for July, 1910. The present is necessarily the more voluminous part, embracing as it does the entire animal kingdom below the mammals, excepting, of course, the Protozoa, which from the nature of things would be outside the pale of the observation of the ancients. The sources of the material are from the literature and from the pictorial arts; sculpture, painting, mosaics—especially those from Pompeii, and from ancient coins and medals. The book is of great value and importance, though a few errors, mainly of classification, have crept in, such as the placing of the annelid Aphrodite aculeata with the myriapods, and the crusta- cean Oniscus and its allies under the annelids. Under the reptiles the “ Krocodiles” are made to include not only the true Croco- dilia but the huge monitor lizards also. Pearls and pear! fisheries are discussed at length. Printing and illustrations are admirable, greatly enhancing the value of this important work. B.S; Ais 5. A Manual of Petrology; by ¥. P. Menneti. 8°53 pp. 256, figs. 124. London, 1913 (Chapman & Hall).—This elemen- tary manual is founded on a former introductory work by the author published some years ago. So little remains of the former publication, however, that it may be considered a new and inde- pendent work. It is designed to give a general introduction to the whole field covered by the term “petrology” and conse- quently suffers those disadvantages which the compression of so much material into such a narrow compass necessarily entails. For the treatment of the rock-forming minerals, their optical and other properties ; the origin, classification and description, including their micropetrography, of the igneous rocks, sedimen- tary rocks, metamorphism in its varied aspects, alteration of rocks, their chemistry ; radio-active properties, etc., etc., are all among the subjects included. The author, who is curator of the Rhodesia Museum, and whose field experience has been largely gained in South Africa, has drawn his illustrative material to a great extent from that region, and this gives the work a corre- spondingly local character. For classification of the igneous rocks the writer divides them first, geologically into plutonics (large masses), intrusives (dikes), and ‘effusives, and these are subdivided, according to the silica content, into aed (65 per cent+), sub- a (60-65 per cent), sub- basic fee 60 per cent), basic (45-55 per cent) and ultra basic (—45 per cent). Further subdivision than this he thinks is, at present, to be deprecated. Geology and Mineralogy. | 427 The author does not believe, to any great extent, in the hypothesis of differentiation, to account for the origin of igneous rocks. He thinks rather that the solution of this problem is to be found in the refusion or melting down on a large scale of pre- existent rocks, and supports his view by what he has observed in South Africa. It would be eee the limits of this brief notice to attempt an exposition of his ideas regarding the origin and mise en place of the igneous rocks, but petrographers, while they may not agree with ‘much that is suggested by the author, will nevertheless find the work of interest and deser ving of considera- tion. BoVaP. 6. Ona supposed new occurrence of Platinerite in the Coeur d’ Alene ; by Hart V. SHANNON (communicated).—A specimen of a massive mineral apparently corresponding to plattnerite from this district has been presented to me by Mr. Henry Savage of Kellogg,Idaho. The locality is given as the old upper workings of the Mammoth Mine of the Federal Co., located high on the mountain above Mace, where Mr. Savage and Leslie Lamm are operating a lease. Several pounds of the material are said to have been discarded as “‘iron” and buried in the filling of the worked-out portion of the stope, until, recognizing the great weight of the substance, Mr. Savage brought a specimen to Kelloge and submitted it to Mr. Wm. McM. Hoff for examina- tion. The results showed a large proportion of lead and a few preliminary blowpipe tests showed that the lead ore was not one of the more common oxidized products of this metal and it was provisionally considered plattnerite. The specimen which I was fortunate enough to obtain is a ' rough nodule covered with ocherous limonite except where frac- tures show the mineral inside. Some well-bounded mammillary surfaces are present. The interior of the nodule consists of a grayish black mineral of sub-metallic luster and the peculiar greasy look of lead compounds. In appearance the mineral is entirely similar to some forms of compact pyrolusite, and might easily be mistaken for such were it not for the high specitic grav- ity which, judging roughly by comparison, must be 7°5 or8. The mineral is hard for a lead compound ; it scratches apatite but not orthoclase and is hence near 5°5, the compared hardness given for the originally described mineral by Yeates and Ayres. Alone on charcoal it fuses at a low heat and immediately reduces giving a large lead button. No oxide coating is obtained by the reduc- tion, ‘but only upon oxidizing the metallic lead obtained. Heated in the closed and open tube it fuses easily to a brown glass. No sublimate was obtained by heating up to the point where the soft glass became liquid nor was any moisture given off. In the borax bead the splinters were quickly absorbed and formed a bead which in both flames was greenish yellow when hot and clear and colorless when cold. If the substance is really plattnerite, of which there seems little doubt, it seems desirable to put on record this second definite Am. Jour. Sci.—FourtH Series, Vou. XXXVI, No. 214.—Ocrossr, 1918. 28 428 Screntifie Intellogence. known occurrence. It is hoped that further specimens may be obtained for analysis and exchange. The chief credit for the identification rests between Mr. Savage and Mr. Huff, who sug-- gested that the mineral might be the rare lead dioxide. ‘Thanks are due to Mr. Savage for the material supplied. © Kellogg, Idaho. fot=3} III. Miscetnanrous Screntiric: INTELLIGENCE. 1. Miller's Serodiagnostic Methods ; by Ross C. Wuirman, B.A., M.D. Pp. 146; 7 illustrations in text. Philadelphia, 1913 (J. B. Lippincott & Company).—This authorized translation of the third German edition of Miiller’s Serodiagnostic Methods, enlarged by the addition of some of the newer tests in this field, is a “purely practical” manual presenting in a very clear way the methods of ‘‘ sero-diagnosis.” Asa compilation of the tests now in use it fills a great need to the worker and student in this line. In each case a brief statement of the theory of the test, followed by the practical applications of the theory, with all the accepted as well as the newer and still untried modifications, is given. A detailed description of the methods makes their performance possible for one inexperti- enced in this comparatively new branch of diagnosis. As expressed by the author, “The chief emphasis has... been laid on making the description of the various methods as exact as possible, and especially on giving a complete and detailed list of the reagents and apparatus required for each test.” The quality of the illustrations is by no means equal to the standard of the rest of the book ; by far the best among these being those of the capillary pipettes and capillary tubes for use in some of the tests. References to the original literature in the foot-notes greatly enlarge the value of the book as a reference work. The translator, moreover, has added “ certain suggestions offered by experience ” now and then, which ought to be of value to the beginner. Among the newer tests in this edition are the following: The Stern test for syphilis, the Much- Holzmann “ Psycho reaction,” the Miller & Jochmann (modified by Marcus) estimation of the antitryptic power of blood, and the same test according to the method of Bergmann and Meyer. S. G. 2. Planetologia; Ing. Emitio Cortese. Pp. vil, 387, 64; 12mo, 12 figures, 2 plates. Manuali Hoepli; Milan (Ulrico Hoepli), 1913.—The Hoepli Library has published a series of small volumes, popular in character, on various scientific subjects. The one in hand discusses the planetology of the earth, both from the present and the geological standpoint. Special chapters deal with the internal heat of the earth, the amount of water and the tides, the seismic phenomena, etc. Finally the comparative planetology of other prominent members of the solar system is treated in detail (pp. 297-387). Warnp’s Naturat Science EstTABLISHMENT A Supply-House for Scientific Material. Founded 1862. . 7 . === oe Gray conglomerate, pebbles up to 0°95 in. .-__-__-_------.- Base of more arenaceous and resistant Catskill, WEAKER MIDDLE CATSKILL MEMBER. 20 to 25 per cent red shale. Red argillaceous sandstone varying from maroon sandstone to red shale, some cross- bedding’ 322: eee ko ee eee 3 Red brown sandy shale, obscurely mud craGkeh.- Siecresy, oot ue ee Pale brown.sandstone> 7 22 eee * Red brown shale with obscure rainprints, mud cracks, and marks of rootlets.-_-__-. Maroon to gray sandstone, hard and thick bedded- Red shale, soft and massive___....-..._.---- Argillaceous red sandstone and shale, well bedded en uci Nae ee eee ea Olive. gray ‘sandstone 91. oe eee ee eee Red shale 225s oe ore ee ee Red argillaceous sandstone.__.____------.__- Olive ‘spray Sangstone seo esl. ken eee No exposure, largely olive gray sandstone, arellaceous) 2. 2 sobs ee Olive gray sandstone, thick bedded, weathering yellowe Bee act 8 | aah Ue ee eee Red sandy shale interbedded with red argil- laceous muscovitic sandstone. The shale is without good bedding and in places- has irregular yellow lines lacing through it._- No @xpasuneteae seb a ee Eg Red argillaceous sandstone (mud cracks at —6595 in the Schuylkill River section south. of (Pottsville) tise ons) os as eee Yellow, shalevsandye a2 2322) 2 ee eee Yellow: argillaceous sandstone... ... 2-2 -228 Red shalesc) Sheek ee eee Yellow argillaceous sandstones and red shales extend some hundreds of feet below. Ex- posures poor and structure irregular. SECTION OF BASAL CATSKILL ON THE SCHUYLKILL RIVER, SoutH oF PottsvILLE. Mostly shales, red in upper portion. 15 miles southwest from the Little Schuylkill section. Section begins at —6880___._---------_-. 23 Red lustrous shales, well bedded, showing mud cracks and rainprints, the mud crack fillings without luster... 332 eee Olive shales with plant remains____-_______-- $ Red sandstone, argillaceous, thick bedded, some layers,mud. cracked | 2.) J) i ae Red shales, fissile to massive___.___.____---- Argillaceous sandstone, greenish gray_.__.-_--- Red shale showing in soil but section not ex- posed inwWétal.. 2 2ol A Depth below Thick- top of ness Sum Pocono 310 42 12 1455 —4896 40 —9d010 A() —)072 121 594 250 — 6790 54 36 50 2034 —6930 — 6880 70 — 6950 20 20 — 6995 55 25 225 Ap palachian Geosyncline. : 455 Depth below Thick- top of ness Sum Pocono Crossing of wagon road and Lehigh Valley R. R. at elevation 590 and one-half mile N.N.W. of Conner’s Station on P. & R. R. R. is at stratigraphic level —7310. Red shale and sandstone. -_.--.....5-25--2- 140 560 —7440 CATSKILL—CHEMUNG TRANSITION BEDS. Olive shale weathering pale yellow, highest Chemung facies but probably not marine. 34 Malayer SANOSLONO Se 2a sor se Se. Sse oe wn emi oe 12 PRES AHUSEOMCES Goes eerie a ok ee 6 Sy SOUS Te AR Ee ee eee ae 23 CURE eRe Sa ee eee 40 GREER MGUEG pe ee oe ee SSL 150 a DE Red sandstone and shale interbedded. Lowest thick red beds and therefore the base of the COS SEES es ee ee 70 385 —7775 Mud cracks and rainprints were found by Dr. A. M. Bateman and the writer in 1912 four and a half miles southeast by east of this point at Landingville in the basal red shale exposed in that. section. CHEMUNG FORMATION, PASSING BELOW INTO THE SENECAN (PoRTAGE) GRouP. Gray and olive sandy shales in upper portion, but the base of this member need not correspond with base of New York Chemung. Yellowish gray shale ___________-- NSE ee ee 59 PIG © 62) Cae eee Se ee ee if Ealemeasamastone. #2 422 e ye ee 10 — 7845 Yellowish sandstone in soft olive shales_______-- 15 poft splash ergy shaleg se. oe secs ve 70 Not exposed, mostly soft gray shaies_-___-_ 293 Sandy gray and olive shales and some sandstones with marine fossils, collected from surface rock about —8250 to —8450. Section not exposed. — F. Crinoid ossicles and columns. Spirifer LCDS ORS SG LoS aie a ee ce a 230 6838 —8458 Flaggy sandstones interbedded with dark siliceous shales. Dark gray shales and flaggy sandstones, not well exposed ee 0 2s 132 A probable error introduced here of 25 or 00 feet and affecting the stratigraphic level of the beds below. Strata affected by a local fold below this member and one omission made in measurement. EK. An abundance of crinoid stems ae two species of pelecypods_...... -.-.--.. — 8590 Dark gray shales and flaggy sandstones . ___-_- 65 —8655 Red shale and brown sandstone. The lowest Uh) C1 (eye re a eclee Pee. 0s 2 RS 2 ot 25 — 8680 Thick bedded olive sandstones with thin bedded olive shales. Some conglomeratic beds holding pebbles of white quartz up to 0°5 in. in diameter. Some coarse plant im- FTES SOS Site Sie Bake a ore eee 100 —8780 456 J. Barrell— Upper Devonian Delta of the Depth below Thick- top of ness Sum Pocono Dark flaggy sandstones and blackish gray siliceous ~ shales. The bottoms of the sandstones show ripple marks. Fossils collected at the following Jevelsi:22232 ee eee 505 D. In sandstone. fragmentary land plants, —9100 C. In siliceous shales, Spirifer mesastri- alis, S. sculptilis, Camarotechia contracta, Coleolus acicula sas ease ee eee — 9127 B. In fine grained sandstone, large Spiri- fers much like S. granulosus. Tropido- leptus carinatus may be present. In sili- ceous shales, small fossils of Spirifer sculp- tilis, S. granulosus and S. mesastrialis -.-.- —9160 A. In fine grained sandstone, a small Spirifer, probably S. sculptilis, Camaro- teechia contracta, Coleolus acicula____---- — 9204 Gray black, ripple marked siliceous shales. Exposure ends at Conner’s Station, P. & ; Re OR. Rec e So ee oe ee 165 1042 —9500 The south side of the station, north side . of the wagon road, is at —9500. Fossils determined by Professor Charles Schuchert from material collected by Joseph Barrell. The section, which will be discussed from the bottom up- ward, begins with the shales exposed at Conners station on the Philadelphia and Reading Railroad, one mile northwest of © Schuylkill Haven. This is stratigraphically somewhat below the crest of the ridge made by a.series of hard dark flaggy sandstones from which strata fossils were collected at three levels, A, B, C, within 75 feet of each other. According to Professor Schuchert, locality A indicates Portage; B, Portage and Chemung; C, Chemung. A sharp delimitation is diffi- cult since it has been found that in eastern New York certain elements of the Hamilton fauna persist through Portage time and even into the Chemung, Spirifer sculptilis being such a form. The synchronous relationships of these eastern and western faunas are brought out by H. 8S. Williams in the Watkins Glen--Catatonk folio, U.S. Geol. Surv., p. 6, 1909. The fossiliferous beds of the Schuylkill River section cannot be above lower Chemung since Sperzfer disjunctus is absent. Of the two fossils Camarotechia contracta and Coleolus acicula, found together at horizon C, the first occurs only in the Chemung of Williams’s lists, the second only in the Port- age. From the lithologic standpoint the flaggy sandstones and dark siliceous shales are of Portage character; the soft gray and olive sandy shales above are Chemung in type. The division plane between the two types is, however, known to be Appalachian Geosyncline. 457 oblique, the Chemung sedi- ments appearing lower down toward the east. It is to be noted that the Jennings for- mation as seen a hundred and thirty miles southwest in the Pawpaw-Hancock quadran- eles is also stated in the folio of that region to contain Che- mung and Portage faunas. In eastern New York the Oneonta gray sandstone and red shale marks there the be- ginning of Catskill conditions early in Portage time. This section, one hundred and fifty miles to the southwest of the New York exposures, shows that the Oneonta is missing even on the eastern outcrop. Catskill conditions did not begin here until in Chemung time. The progressive change toward the southwest is seen further in that the Jennings formation, the marine upper Devonian of Virginia and Maryland, is at least twice as thick in Maryland as in Schuylkill County of Penn- sylvania. Catskill sedimen- tation did not begin in Mary- land until still later. The transition beds at the base of the Catskill are marked by the occurrence of gray or olive shales of Chemung type interbedded with Catskill red shales. These are well ex- posed on the flank of a minor syncline at Landingdale on the Schuylkill River a few miles southeast of the detailed section. The signiticant fea- ture to be observed here is that olive shales occur both above and below a horizon of red shale and sandstone. Marine fossils occur in that COLUMNAR SECTION ! pSCHUYLKILL RIVER — LITTLE SCHUYLKILL ° Feet : |: IOS 950 95 1000 a Ane eo? ct Pa 4 wv lowe") ‘'< fo} Se a o °} a2 See =+ = 52 o3 — Cc ay ss un =o UO 5970 |= eae 2000 pa Re x E “os t= Ca au x oo x eGies - 630 x? & S ; ws 3000 x? ee oO 2s ” ° 2 891 Ss <= g 2 mo} Ss Cy = 4000: = oh = 3 Ss x? 32 cH © c fs 5 E Be} = e 1455 000 Ss x 7) > s ‘= > |@ = < iS ° 000 bs Be € 3 S < SS e 4 5 aes 2 2 as r=) Sead — —. — = oe x< ns Pe) 5 ae Qs fo) v of O =e 0 on 2S 5855 = 3 wi uo & sandy shales ao o 9000 | Flaggy sandstones, |Gray+olive dark tf eens shales S + 1 Fig. 2. Columnar sections of Pocono, Catskill, and Portage-Chemung rocks on the Schuylkill and Little Schuylkill Rivers. 458 J. Barrell— Upper Devonian Delta of the which lies below, contained in a calcareous sandstone band. These red shales, on the other hand, show undoubted rain- prints. Mud cracks were found sparingly in loose blocks, and possible rootmarks occur. These contrasted marks of marine and subaerial conditions are here closely related to the change in color from olive shales to red shales and suggest that in Upper Devonian times the climate of this region was such that the contrast in color happens to offer a criterion for separating rather sharply the subaqueous and subaerial phases of sedi- mentation. . Of the Catskill section only some general notes need be made to supplement the details given in the table. It is to be ob- served that the lower portion, about 2900 feet thick, is more argillaceous and less resistant to erosion. The middle portion, about 2300 feet thick, consists of resistant gray sandstones with some conglomerate and but a minor amount of red shale. The upper 750 feet have sufficient red shale to permit, i connection with the vertical attitude of the strata, the undermining of the hard sandstone beds and produces a saddle in the Pocono- Catskill mountain crest. In this upper portion is the sharpest and most frequent oscillation from gray sandstone to red shale conditions, and owing to the partial protection from erosion given by the sandstones, the most favorable portion in which to study the bedding character of the shales. Above the last important red shale and red sandstone are 970 feet of gray and olive sandstones, moderately resistant and not yielding good outcrops on this section. The sandstone is of the Catskill type rather than that of the coarser and harder Pocono. They may therefore be put as transition beds, but their affinities are with the lower more than with the upper formation. , The Pocono here is a much coarser and cleaner grit and gravel formation than in its usual development in Pennsylva- nia and indicates a nearer relation to the source of the material. The shales of the Catskill as seen in this section are a bright “freight car” red ; the more siliceous red sandstones are, strictly speaking, maroon rather than red. The gray standstones, if argil- laceous, weather to a yellow, showing that they contained iron oxide but in a ferrous state. The purer sandstones, olive-colored on fresh fracture, weather to a grayish white. These relations show there was a tendency toward deoxidation during the for- mation of the beds of sand, of oxidation during the deposition of the Catskill muds. Where the clay and iron oxide were sparing in quantity, the deoxidation was effective. The con- ditions which accompanied the deposition of clay and iron oxide also permitted oxidation to dominate over deoxidation. A gray or olive sandstone member is commonly sharply delim- ited at bottom, but at the top grades first into maroon argilla- Appalachian Geosyncline. 459 ceous sandstone, and this in turn into red sandy shale. In the sandstones the bedding is usually smooth and even but with considerable oblique lamination. The shales commonly crum- ble rapidly to a hackly rubbish withont relation to. bedding planes. In these respects the sandstones and shales conform to the normal widespread character of the Catskill formation. To turn to the evidences of subaerial origin, for which the section was especially investigated, it is to be noted that mud-eracks or rainprints were found at intervals through- out the entire section, always in horizons of red _ shales. The section was in fact chosen for study because the beds from top to bottom are here best exposed in detail of any which the writer has seen. In the bulk of the red shales the uniformity of the material, the absence of bedding planes, and the rapidity of weathering prevent the detection of subaerial exposure even if such was the condition of origin, but even in such beds a number of mud-crack patterns were detected. It is where well-bedded shales are interstratified with sandstones, however, that the opportunities for the detection of mud cracks and rainprints are the best. This feature of the stratigraphy as noted applies especially to the upper 750 feet. In all of the mud-cracks of the Catskill the filling was a mud of nearly the same quality as the cracked stratum and the result is usually a shadowy pattern, chiefly visible through a duller luster of the fillings. In rare cases the filling, however, has become deoxi- dized and shows as a yellow pattern on the red shale. The shale surfaces are flat, the polygons not being concave upward as is commonly the case in the Mauch Chunk and Newark shales. On a part of the mud-cracked surfaces the pattern is obvious to the casual observer, but in more than half it requires careful search and observation to find the evidences and make certain that the irregularities are not mere weathering simula- tion of mud-crack structures. In this respect the Catskill is _ much more difficult to study than certain formations in which mud-cracks are a conspicuous feature. THE CATSKILL ON THE Potomac RIVER. The Catskill appears at the surface on the flanks of succes- sive folds in western Maryland and is described in the geologic reports of that region. From the southeasternmost exposure of Upper Devonian rocks in the Hancock quadrangle of Mary- land to the northwestern in the Uniontown quadrangle of Pennsylvania is a distance of about 80 miles across the strike. Having discussed the character in the Schuylkill River section it is desirable to compare it with these localities farther south and west toward the open Chemung sea. 460 J. Barrell—U; pper Devonian Delta of the On the eastern side, in the Hancock quadrangle, according to Stose and Schwartz, the Catskill attains a thickness of about 3800 feet. Fifteen miles west, in the Pawpaw quadrangle, its thickness is about 2000 feet, a diminution of more than a hundred feet to the mile. Below this are some 500 feet of beds separately mapped and transitional into the Jennings formation, 4000 to 4800 feet thick. Some 50 miles farther west, G. O. Martin reports the Catskill as 1200 to 1400 feet thick. Only the upper part of the Jennings is exposed here, but in the columnar section it is estimated at 3500 feet in thickness. In the Uniontown quadrangle, 20 miles northwest of the last locality, M. R. Campbell reports that fossiliferous ereen shales of Chemung age directly underlie the Pocono sandstone. But beginning about 700 feet below the Pocono sandstone, wells have penetrated about 150 feet of red shale. In character the rocks of the Maryland sections are more argil- laceous than in Schuylkill County, Pennsylvania, the great thicknesses of olive sandstones of the latter region apparently being replaced by red argillaceous sandstones and red shales. Cross-bedding and ripple marking are common. Stose and Schwartz mention furthermore in the Pawpaw-Hancock folio in 1912 the presence of mud-cracks. For discussions of the conditions of origin it is important to determine to what extent these marks of subaerial exposure extend southwestward from eastern Pennsylvania and are coin- cident with the Catskill phase of sedimentation. For this pur- pose the writer in 1908 studied the section between Frostburg and Cumberland, Maryland, longitude 78° 51’ W. This is forty miles west of the eastern outcrop in Maryland, fully sixty miles west of the strike of the Schuylkill River sections, and 160 to 170 miles distant from the latter in a southwest by west direction. Ascending through the Upper Devonian section, the olive shales are observed to give place to red shales of the Catskill type, some thin layers of olive shale andi gray sandstone being interstratified near the base with the red shales. Gradations into argillaceous red sandstones are common. Twenty-five feet above the top of the olive shales* well-defined. mud-cracked surfaces were noted and continued to appear through about 140 feet of beds. The polygons range from three to twelve inches in diameter on different surfaces, the fillings from one-fourth to one-half inch across, and differing from the polygons chiefly in luster. No concavity of the polygonal plates is observed, *The olive shales stop about fifty feet southeast of the east portal of the tunnel of the Cumberland and Pennsylvania Railroad. The tunnel is cut through red shale and sandstone and its waste offered a good opponbuntiy. for the study of the basal Catskill. Appalachian Geosynclne. — 461 such as is common in the Mauch Chunk and Newark forma- tions. On a number of the surfaces the larger patterns of eracks are gray-green, contrasting strongly with the red poly gons. On one of these the smaller secondary eracks on the same surface were red, contrasting with the gray-green of the larger cracks. One of these mud-cracked surfaces is shown in fig. 3, taken close to the bottom of the red shale. Fie. 3. Fie. 3. Mud cracks in the lower Catskill between Cumberland and Frost- burg, Maryland. The cracks are filled with green sand in a red shale. Photo taken July 1, 1908. Some impressions of vegetation occur and measure up to five inches in width, but most of them are of small fragments. In the waste from the tunnel were found slabs showing current marks, rainprints, and rootmarks. A drawing of a specimen of rootmarks is shown in figure 4. Thus in this section, as on the Schuylkill River, the close relation is seen between the marks of subaerial exposure and the change of color from olive to red, but the conditions involving deoxidation and oxidation Am. Jour. Sct.—Fourtu SERIES, VoL. XXXVI, No. 215.—Novemssr, 1913. 31 462 J. Barrell— Upper Devonian Delta of the are more nearly balanced in this transition zone than in the true Catskill above, as shown by the green filling of some of the mud-cracked red shales and the tendency to variegation in color in these basal beds. The upper Catskill in this section is not favorably exposed for study. The shales are sandy and have erumbled in weathering until the original characters have become destroyed, but the more significant base was still at Fig. 4. . 7 . -* ls ae Stemi « . . Sehr yay . Bedding plane, upper s 2 inches‘||°~: . ry . eee ORO Ons Caria ore . - ie ee? Su . Oy ee ee 5A . . OCs o* yy . ¢ 4 ACaOY Oe «Ale Bites ale 4 "} . . | | we” \)* othe Pre (3 . “se . eats: 7 Aes | Care eed . 7 . . rea ia *. Cates) ait] in itetne eS lighess! emia . ’ : EID Be, ole . we aay : be ion Y ‘ oe . . ewe . o, a « - ~ . . - u eaeD path thn Bile ave 5 =] SF a « 1H Bar eats Irregular section ar righFangles to Stratification Fie. 4. Rootmarks in red argillaceous sandstone. Lower Catskill, near Frostburg, Maryland. The fracture surface which exposes these rootlets is irregular but roughly at right angles to the bedding plane. this time well exposed by the tunneling and cutting for the railroad. These observations from Pennsylvania to Maryland show the widespread development of the marks of subaerial exposure through the red beds of the Catskill. They are not marginal or shoreward developments within the Catskill, but may occur as widely as the red rocks themseives. It required special char- acters of beds, however, to clearly preserve the cracks in the original deposition and fresh exposures are necessary for their observation. The red color is, however, something which is not readily destroyed, being inherited even in the soil, and in this particular formation, in widely separated localities, it is seen to mark the disappearance of marine faunas in gray or olive shales and the appearance of the marks of subaerial exposure. Following the criteria previously discussed, the red shales mark, in the Upper Devonian physiography of the Appalachian region, the subaerial plain of a far-reaching delta. NaS ” ‘ PS ie Appalachian Geosyncline. 463 RECONSTRUCTION OF PHYSIOGRAPHY AND CLIMATE OF THE CATSKILL DELTA. Comparison of the Catskill and Skunnemunk with the Siwalik formation. A formation strikingly suggestive in connection with the present subject, and one in regard to which the interpretation of subaerial origin has found general acceptance because of the clear indication of the fossil record, is the Siwalik forma- tion of the sub-Himalayas. In order to show the similarities to the Oneonta, Catskill, and Skunnemunk formations, a short description of the Siwalik will be given. These are Neocene deposits upwards of fifteen thousand feet in thickness, skirting the southern side of the Himalayas. They were laid down as alluvial outwash from the rising mountains and have become exposed through being themselves upturned and eroded in the latest movements. Medlicott and Blanford describe the Siwalik formations as follows: “Sandstone immensely preponderates in the Sub-Himalayan deposits, and is of a very persistent type from end to end of the region and from top to bottom of the series. Its commonest form is undistinguishable from the rock of corresponding age known as Mollasse in the Alps, of a clear - pepper and salt grey, sharp and fine in grain, generally soft, and in very massive beds. The whole Middle and Lower Siwaliks are formed of this rock, with occasional thick beds of red clay and very rare thin, discon- tinuous bands and nodules of earthy limestone, the sandstone itself being sometimes calcareous, and thus cemented into hard nodular masses. In the Sirmur group generally (below the Siwalik group), and locally in the Lower Siwaliks, the sandstone is thoroughly indurated and often of a purple tint, while retaining the distinctive aspect. In the Upper Siwaliks conglomerates pre- vail largely ; they are often made up of the coarsest shingle, pre- cisely like that in the beds of the great Himalayan torrents. Brown clays occur often with the conglomerate, and sometimes almost entirely replace it. This clay, even when tilted to the vertical, is undistinguishable in hand specimens from that of the recent plains deposit ; and no doubt it was formed in a similar manner, as alluvium. The sandstone, too, of this zone, 18 exactly like the sand forming the banks of the great rivers, but in a more or less consolidated condition. Thus it was suggestive, and not altogether misleading, to say that the Siwaliks were formed of an upraised portion of the plains of India. “lhe fresh-water origin of the Siwalik formation seems almost as indisputable as the marine origin of the Subathu beds; yet, until lately (1879), it has been usual to consider the Siwaliks marine. ‘lhe notion was probably a relic of the opinion that a water basin was an essential condition of the extensive accumula- 464 J. Barrell— Upper Devonian Delta of the tion of deposits, and that a sea margin would be required for such a great spread of shingle as that of the Siwalik con- glomerates. The same opinion, on the same grounds, has been extended to the plains deposits themselves. “The continued experience that the fossil remains in these Ter- tiary strata are exclusively of land or fresh-water organisms, made this view untenable ; and in time it came to be realized that the deposits themselves bear out the same opinion ; the mountain torrents are now in many cases engaged in laying down great banks of shingle at the margin of the plains, just like the Siwalik conglomerates; and the thick sandstones and sandy clays of the Tertiary series are of just the same type of form and composition as the actual deposits of the great rivers. “ Beds of this character alternate with the upper beds of the Subathu group; so it seems probable that from early Tertiary times the sea has been excluded from the Sub-Himalayan region, and that the whole of the Sub-Himalayan deposits, above the Subathu group, are fresh-water and fluviatile, and formed on the surface of the land. They are in fact, subaerial formations, like the river alluvium and bhabar deposits of the present day.* Speaking of these formations as they occur in the Salt Range in the Punjab, Wynne makes the following statements: “‘Kverywhere from one end of the range to the other, and always on its northern and eastern aspects, the uppermost rocks of the Salt Range series are innumerable alternations of grey or greenish sandstones, of no great hardness, with red or light- brownish orange clays, more rarely with conglomerates, but frequently with harder fine-grained sandy beds of peculiar con- cretionary pseudo-conglomeratic structure ... The alternating bands of sandstone and clay are from seventy to a hundred and twenty feet in thickness, being very frequently about a hundred feet each, but some zones are much thicker. at It is the middle Siwalik which especially shows the associa- tion of gray or green sandstones and red clays. All parts are associated with the bones of mammals and fresh-water reptiles. It is seen from this description that such combinations of red clays and gray or green sandstones are features of fluviatile deposition under certain intermediate climatic conditions. Conditions of Origin of the Several Appalachian Formations. The marks of subaerial exposure in the Oneonta-Catskill beds have been shown to be an integral feature of the forma- tion, were made without relation toa shore, and contrast sharply with the str atigraphic characters of the Chemung. These fea- tures constitute the strongest test stated under the subject of criteria. The general descriptions serve furtber to emphasize * A Manual of the Geology of India, ii, pp. 524-526, 1879. + Memoirs of the Geological Survey of India, xiv, p. 108, 1878. CP ae Appalachian Geosyncline. 465 the many distinctions between the subaerial and subaqueous deposits. The conclusion may be accepted, therefore, without further argument, that delta conditions prevailed and that the Catskill formation is made of the deposits on the subaerial plain. This section consequently will be devoted to an analysis of special features of the delta as derived from the study of the formation. The Portage and Chemung are seen to be the shallow sea equivalents of the Oneonta and Catskill, a subaqueous topset plain. The Skunnemunk conglomerate is a downfolded rem- nant of a piedmont alluvial gravel plain which lay between the flat delta surface and the mountains. The Pocono sandstone, into which the Catskill passes by transition, is seen to be divided into two phases,—a marine phase in western Pennsylvania and Ohio, a fluviatile phase in eastern Pennsylvania. Inthe Pocono, the sharp delimitation of the two phases is obscure but between the Catskill and Chemung the color contrast draws the dividing line separating the subaerial and subaqueous topset beds. The margin of the delta no doubt held lagoons, varying from brack- ish to fresh water; so that marine fossils should be somewhat more restricted in their range than the gray and olive shales. The delta began its existence when the rivers were given a sufficient load of detritus to stem back the planing erosion of the sea. So far as known, this was near the close of the middle Devonian. For a time the rivers gained ground and the Oneonta formation was built out. But at the close of Portage time the sea gained a temporary ascendency and advanced nearly to the eastern limit of the present Catskill Mountains. During the Chemung, however, it was again gradually dammed back and retreated to western Pennsylvania, the oscillating shore line being marked by the transition zone of sediments. Back from the margin the uniformity of the red shale shows that the delta surface was sufticiently well drained to prevent the formation of extensive swamps, such as exist over the lower and flatter lands of the Mississippi and the Ganges delta. This was doubtless in part due to the climatic factor, but also in part owing to the relatively short courses of the rivers and consequently a steeper gradient to the delta plain. The axis of the geosyncline, the line of maximum subsidence, was near the ancient mountains. The streams had to deposit most of their burden over this zone and had but little left with which to push the ocean waters farther back. The western part of the geosyncline was in consequence mostly marine, passing out into the open shallow sea; the eastern part was mostly main- tained as land, passing through a piedmont plain to the moun- tains. The Catskill formation consists typically of alternating mem- 466 J. Barrell— Upper Devonian Delta of the bers of gray sandstone and red shale. In certain regions and at certain horizons the one becomes the dominant facies, in other regions and times the other dominates the formation. Under the view that the whole constitutes a delta the alterna- tions of minor shale and sandstone members is to be ascribed to the lateral shifting of distributaries, the red shales represent- ing flood plain areas temporarily removed from the presence of currents. The delta was far from the regions of erosion, with the result that the same kind of material was brought year after year to each locality subject to change only as the distrib- utaries shifted. The oxidation of the shales shows that the soil was drained and aerated for considerable periods yearly. The stratification planes in the muds, initially poor because of uni- formity of material, were customarily more or less obliterated. There are several subaerial agencies which result in this where the rate of sedimentation is sufficiently slow.— Worms and other burrowing forms carry on a vertical mixing of the soil. The growth and decay of roots tends in some degree to the same end. But a very effective agent for vertical mixing in climates sub- ject to periodic dryness is mud-cracking, where the binding action of roots does not prevent it. Each wet season fills the cracks largely by slumping in from the top, and each dry season reopens them. The evidence seems to show that in Catskill times all of these processes were in operation, but the writer, from observations on present mud flats, is inclined to aseribe a chief place to the effect of mud-cracking. The uniformity in the character of the delta from northeast to southwest, its development marginal to the uplands, and the somewhat rapid gradation from gravel to sand and clay on leay- ing the mountains suggests the presence of a number of com- paratively short streams which built flat coalescing fans rather than the debouchement of one or two great continental rivers. - The form of the plain was somewhat similar to that plain of Tertiary alluvium which faces the Rocky Mountains, and was built by overloaded rivers in a region of semi-arid climate. Here the rivers flow out at gradients of near 10 feet per mile and fall to 7 to 5 feet per mile at a distance of some hundreds of miles. An average gradient of 5 feet per mile for the Catskill plain over a width, at the close of the Devonian, of from 80 to 100 miles would appear therefore to be a reasonable estimate. Toward the mountains the slope of the piedmont gravel plain doubtless steepened, perhaps to 15 or 20 feet per mile in the case of large streams, even higher for streams of lesser volume. Subsidence of the geosyncline under this plain, depressing the grade of the rivers, would result in alluvial sedimentation at elevations of several hundred feet above the sea and at indefi- Appalachian Geosyncline. 467 nite distances from it. This suggests a very different concep- tion from that of brackish water sedimentation or deposits in partially enclosed standing waters such as has usually been assigned as the cause of the Catskill facies. The interstratification and intermixture of sand and clay together with minor quantities of muscovite and feldspar indi- eates that the material was derived directly from the rocks and was not the reworked sands from a coastal plain. The great thickness and coarseness of the Skunnemunk conglomerates implies land of high relief, and rivers of strong grade. The large volume of the finer materials deposited farther west is equally testimony of an even larger volume of the sources of upply. -The Skunnemunk conglomerate has been partly de- stroyed by erosion, but 2,500 feet of coarse gravel still remain. Only rarely, however, during Catskill times, did gravel reach the main area in New York and Pennsylvania, 25 miles farther west. A condition existed, therefore, which prevented the sweeping outwards of gravels. When a river reaches a part of its course which is below grade it must deposit its coarser bur- den in order to carry the finer material through. This suggests that subsidence was rapid, and continued not only in the zone where the thick Catskill beds still exist, but over an eastern border which in the later folding has been uplifted and subjected to erosion, save for the single narrow syncline within the pre- Cambrian gneisses which still holds the Skunnemunk conglom- erate. Another factor which may have a bearing is,—that in a dry climate rivers which flow from high mountains tend to shrink in volume on reaching the plains and therefore quickly drop their coarser waste. This steepens the gradient but can- not continue indefinitely without progressive elevation of the mountains, or subsidence of the plain. Beyond the shore of the delta plain were the waters of a shallow sea, whose bottom was probably affected by waves throughout. The upbuilding then was wholly by the deposit of topset beds,* the sediment being spread by rivers on the landward side; by waves on the side of the sea. The delta was not built out by means of foreset beds such as are seen where small deltas grow out into relatively deep water of con- stant level. The several formations are thus seen to be the members of a larger structure—a delta system, which is marked by the existence of subaerial aggradation but which is linked to and embraces the synchronous marine formations, the latter form- ing the foundation over which the subaerial deposits are com- monly extended. * Following the classification given on pp. 385-387 in the paper by the writer ‘‘ Criteria for the recognition of ancient delta deposits.” Geol. Soc. Am., Bull. xxiii, pp. 377-446, 1912. 468 J. Barrell— Upper Devonian Delta of the Inferences Regarding Climate. The relations between climate and terrestrial deposits have been discussed by the writer elsewhere,* and the conclusions reached in that paper will be utilized as a point of departure in this. The idea, which may be traced to Russell, that red in sedi- ments is a mark of derivation from a deeply decayed regolith, has widely pervaded American geological literature and com- petes with the European view that red is significant of ancient aridity. ‘The first interpretation has been adopted by Willis in his reconstruction of Upper Devonian times; the second has been utilized by a number of British and Continental geolo- gists who have written of the Devonian deserts of Europe as recorded by the Old Red Sandstone. The redness of the Devonian rocks of northwestern Europe, made of waste from northwestern lands now largely under the sea, has led Walther to name this now dismembered continent, ‘ the Old Red North- land.” But the present writer has argued elsewheret at length that redness in rocks is not necessarily evidence of redness of the original sediment; the latter may have been red, brown, yellow, or yellowish gray. All that is necessary is the presence of ferric oxide, hydrous or anhydrous. If in the course of geologic time the water is driven out, the coloring matter will necessarily become red. Furthermore, certain red rock forma- tions have originated under conditions which show that high rainfall with seasonal dryness is competent to produce this color as well as aridity. Other formations show that rapid mechanical erosion, with imperfect decay, may be associated with redness as well as the contrary condition of deep decay over a land of low relief. In fact the latter is probably the least common condition associated with thick formations of red sandstone and shale. To cite a few examples which bear out these statements of varied conditions of origin: It is seen that the Amazon and the Congo are now depositing red marine muds off their mouths from climatic regions marked by tropic heat and seasonal rainfall. The Potomac formations of the Atlantic Coastal Plain, of Comanchean age, are marked by briliant red and orange beds associated with blue and white clays and abundant plant remains. The Newark formations of Triassic age are red to brown sandstones and shales with much feldspar and muscovite showing imperfect decomposition. Coal beds occur in this terrane in Virginia and North Carolina. The Siwalik formations of India contain a fossil record which disproves aridity and accumulated under physiographic con- * Jour. Geol., xvi, 1908, pp. 159-190, 255-295, 363-384. + The Climatic Significance of Color. Jour, Geol., xvi, 1908, pp. 285-294. Appalachian Geosyncline. 469 ditions which disprove derivation from the deep regolith of a mature topography. ‘The red clays of the Siwalik were on the contrary laid down under comparatively similar conditions to those which now give rise to the lighter-colored alluvium of the Indo-Gangetic flood plain, or the yellow floods of the Chinese rivers, or the muddy waters of the American Missouri. Lastly, the frequent association of red beds with salt and gyp- sum shows especially in the Permian that redness frequently accompanies aridity. The determination of the climatic conditions under which a terrestrial formation was laid down must therefore depend upon the analysis of a combination of characters, and this becomes especially necessary when the marks of climatic extremes, as glacial deposits on the one hand, or evaporation deposits on the other, are absent from the formation. Turning to those features of the Upper Devonian delta which are significant as to climate, the most broadly distinctive is the characteristic redness of the Catskill shales, and the gray or green colors of the cleaner sandstone members. In this the Catskill resembles the Siwalk formation and could have been deposited under similar physiographic and climatic con- ditions to those prevailing in northern India in Neocene times, rapid erosion in high mountains, deposition on river plains marked by warmth and seasonal rainfall. The red shales are associated especially with mud-cracking, and by contrast with the gray and olive shales of the Chemung show that the oxidation was due to periodic drying of the flood plain and aeration of the soil. The lack of oxidation of the iron in the sandstones, in spite of its lesser quantity, suggests that more abundant ground-waters in the sands may have kept out the air and permitted the organic matter to accomplish its _ effects, or perhaps that here the ratio of organic matter was in excess of the ferric oxide. The oxidizing conditions in general were nearly balanced by those of deoxidation as seen by the contrast in color of the shales deposited under permanent water and the yellow or green pattern occasionally observed in the filling of mud-cracks. A few rare carbonaceous streaks have been observed in the Catskill and the plant impressions are in places found in deoxi- dized shales. Coaly and pyritiferous plant fossils are also pre- served in some of the olive sandstones. In other strata mere lustrous red streaks show the marks of vegetation, implying that the oxidation of the organic matter was commonly by the free oxygen of the air, since the destruction of the organic matter did not deoxidize the adjacent ferric oxide. The climatic conditions of the Upper Devonian were equable and widespread as seen by the similarity of deposits and of 470 J. Barrell— Upper Devonian Delta of the plant types over wide ranges of latitude and longitude. The intermediate character of the climate in regard to rainfall is indicated by the almost universal absence of either carbon or evaporation deposits. Hence there was sufficient dryness and oxidation to destroy such organic matter as developed over the - river flood plains, but sufficient rainfall in excess of evapora- tion to prevent in the marginal lagoons the concentration of evaporation products. With equable rainfall. throughout the year this balance would be more delicate to maintain ; but with seasonal rainfall and dryness, the typical climate of the present tropics, a wide range may exist in the relative length of the seasons and amount of rainfall and still permit the drying of the soil at one season, the washing out of evaporation deposits at another. The climate of the Catskill delta has thus been narrowed down to two types. First, semi-aridity, characterized by a scanty rainfall throughout the year, preventing the luxuriant growth of vegetation at any time; or, second and more probable, a climate of seasonal rainfall, probably in the growing season, since this favors herbaceous rather than arboreal vegetation. Semi-aridity gives rise to the pampas of Argentina and the staked plains of Texas; abundant but seasonal rainfall to the llano of the Orinoco, the savannas of tropical Africa and the monsoon tracts in India. A rather warm climate is suggested, since such favors rapid drying and oxidation of the soil. ; The climatic conditions which have been inferred stand , between those which gave rise to the carbonaceous muds and dark sands of the Middle Devonian, even where these hold terrestrial deposits as in the Bellvale flags; and the red sand- stones of the upper Mississippian with the gypsum deposits of Nova Scotia and Virginia, and the briny strata of Michigan. The climatic movement at the close of the Middle Devonian was not severe, but was sufficient to result in effective oxidation of alluvial muds where previously this had not taken place. With the beginning of the Mississippian a greater climatic instability manifested itself, conditions favorable to the development of coal marking the early Mississippian, but not unmixed with evidences of oxidation and evaporation occasion - ally more pronounced than in Devonian times. Tinally, in later Mississippian times, a period of considerable aridity set in. Having made this analysis of climatic conditions from the physical and chemical characteristics of the strata, it is of interest to note the conclusions which have been derived regard- ing Upper Devonian climates by the students of fossil vegetation. In a study of the upper Paleozoic floras, their succession and range, David White states Appalachian Geosyncline. 471 “The first Paleozoic land flora sufficiently known to make it eligible to the series of correlation discussions is that of the Middle Devonian. This flora, whose apparent meagerness is per- haps due mostly to meagerness of information, is of strange and forbidding aspect. , “Evolution of forms and the advent of new types mark the Upper Devonian flora, which bears no evidence of any great climatic separation from the preceding. : “«The Devonian woods present no annual rings to bear evidence of seasonal changes in temperature or imterente of prolonged drought. . She step from the Upper Devonian flora to that of the Mississippian (‘Lower Carboniferous’) is marked by a floral contrast which, in some regions, is unexpectedly sharp through the warping of the Devonian floor to form the new Carboniferous synclines, and the contraction of the seas naturally premise distinct climatic as well as other environmental changes. “In this connection it may be noted that, ‘either on account of land or marine barriers, or because the. climatic conditions thr ough- out the northern hemisphere may at the outset have been less uniform than in the preceding epoch, the different areas exhibit more or less distinct local floral differences.” * G. W. Matthew states “The conditions of climate which would seem to have best suited the Devonian types was that of a dry and cool atmosphere, broken annually by a short period of rains, when the short and scanty vegetation made a rapid growth. Such conditions at least would best accord with the prevalence of xerophytic forms like the Psilophyta and the small leaved Lepidodendra, and the rarity of the Equisetine. Broad leaved plants like the Cordaites are rare in the Devonian vegetation and the filicoid plants are mostly of the genus Archaeopteris. The plants that did prevail are mostly recorded as having had rhizomes or fleshy root stalks, and in these could have stored up the nourishment which enabled them to throw out a vigorous growth at that time of the year when the season of expansion arrived. ”’+ The flora of the Little River Group, concerning which Matthew makes these remarks, is regarded by David White as of post- Devonian age. This may be accepted, but the types of vegeta- tion are such as mark also the Upper Devonian and the same inferences as to climate would apply. The physical and organic evidences must supplement each other and where there is an apparent conflict some adjustment of views must be made. In general there is no essential discordance of the two lines of evidence, but the presence of * Jour. Geol., xvii, pp. 322-824. + Review of the Flora of the Little River Group, No. III, Trans. Royal Soc. Can., Third Series 1910, vol. iv, section iv, p. 8, 1911. 472 J. Barrell— Upper Devonian Delta. seasonal dryness though not aridity, and the absence of annual rings, may seem somewhat contradictory. If the adjustment. be sought by modifying the conclusions in regard to climate, a condition of perennial intermittent raintall may be substituted for seasonal rains. Such a shorter rhythm, measured by days or weeks rather than by seasons, may be so adjusted as to give opportunity for drying and oxidation, but without stoppage of vegetable growth. A delicately balanced condition such as this would, however, be expected to pass in some regions, as previously noted, into markedly humid conditions, or in others into marked aridity, and give rise to a climatic variety of which there is not evidence in the Devonian. If the adjustment be sought within the limits of vegetal adaptation, two suggestions may be offered. First, is it possible that perennial plants of that time may have possessed such a nature as not to have recorded by rings the stoppage of growth ? This is a question for paleobotanists to answer. The most probable explanation, however, to the writer seems to lie in the proposition that at that time perennial and arboreal vegetation was restricted to regions of perpetually available ground-water. In a climate without freezing winters it was thus not affected by the coming and going of rains. This view receives some support, so far as the writer has observed, from the distribution of the plant fossils. The impressions of tree trunks and of strap-like leaves on the whole are rare, but where they do occur are found in decolorized shales or sandstones. Not infrequently coaly streaks mark their presence. These may be regarded as the deposits of swamps or marginal to river channels. The red shales, on the other hand, are doubtless the deposits of flood plains, dried out during a part of the year, air taking the place of water in the soil. In these deposits indistinet tendril-like mark- ings are not uncommon, traceable only by faint changes in luster and texture, not by the presence of deoxidation. They are sel- dom as definite as in the example shown in fig. 4, but suggest — either the thread-like burrows of small worms, or the small rootlets of an herbaceous vegetation. Such an areal distribu- tion of arboreal and herbaceous vegetation in alluvial regions is that in fact which tends to take place to-day within those parts of the tropics marked by pronounced dry seasons, but the present differentiation and adaptation of trees to a wide range of environments apparently makes the environmental control less compulsory than in Paleozoic times. Then the local com- bination of perpetual ground-water and perpetual warmth may have stimulated in the rivalry for sunlight the striving upward of sporophytes, creating the first of trees and the truly pri- meval forest. Yale University. Farwell—An Optical Bench for E lementary Work. 473 Art. XLI—An Optical Bench for Elementary Work; by H. W. Farwe.t. Tue ordinary type of optical bench found in elementary lab- oratories usually consists of a meter stick supported in wooden holders, with fittings for lenses, ete., of sheet metal bent to slide on the meter stick. These fittings offer little opportunity for small adjustments which are frequently necessary for the success of the work. In addition, frequent bending of the slides to make them fit the meter stick causes a large mortal- ity in fittings. To make our elementary work in light more successful the type of bench described below has been devised. The meter stick as before is the base of the apparatus, (though we are now using sticks two meters long). This is supported by two rather heavy supports, A, shown in the 474. Farwell—An Optical Bench for Llementary Work. diagram. This raises the stick to a convenient height above the table, where it is ready to receive the fittings. These are all attached to the stick by means of the clamp, B, the * upper part of which is drilled to receive any 4-inch stock. The face of the clamp is marked in machining with a line opposite the axis of the 4imch hole, so that the error in locating the index is made very small. ‘The clamp is entirely open on the front that it may be machined easily and that it may be quickly set on any part of the bar. It was expected that there might be some trouble on account of the ease with which the clamps might “fall” off the stick, but in the two years in which the apparatus has been used there has been practically no difficulty. The design of a lens holder required more attention than all the rest, as it was desirable that a single piece should serve to hold, firmly and properly centered, any form of lens, mirror or screen, and at the same time permit quick adjustment or exchange. The frame C meets all the requirements and has proved very satisfactory. The 4inch rod below fits into the clamp on the bar. The lower part of the frame is milled with a V groove, the full width of the frame. The movable part is made from right-angled brass stock, slotted at the ends. One great advantage of the apparatus is the ease with which a frame, holding, say, a ground-glass screen, can be replaced in the same position by a 4-inch rod bearing a pin to locate an image by the parallax method. The supports, clamps, and frames are all of cast iron, and ~ are of such form that they are easily machined. Experience has proved that they are not too clumsy for the work in hand, and that they are easily adapted to variations in method im the standard experiments. ‘ Columbia University, April 19, 1913. F. A. Perret— Volcanic Research at Kilauea. 475 Art. XLII.— Volcanic Research at Kilauea in the Summer of 1911, by FrRanx A. Perret. With a Report by Dr. Atpert Brun on the Material taken directly from “ Old Faithful.” To readers of the six preceding papers of the present series* —devoted specifically to a discussion of the various Kilauean phenomena, products and formations—it will have been evident that, by reason of the necessary concentration upon each particular subject, no detailed reference to the research work, itself, could therein be made. This must be the writer’s excuse for venturing upon a seventh paper, which, free from such restrictions, may be devoted to a brief exposition of the origin and aim of the expedition, of some of the research work accomplished and, finally, of data secured and resulting from subsequent investigation of original material collected. The expedition—and with it the initiation of regular and continuous observations at Kilanea—was due to the initiative of Prof. T. A. Jaggar, Jr., geologist of the Massachusetts Institute of Technology, who, during a previous visit to Hawaii, had become impressed with the opportunity which Kilauea, above all other volcanoes, offers for direct research work, and deter- mined to organize, if possible, a demonstration of its feasibility. To this end, negotiations were entered upon between the Institute and residents of the islands, a promise of codperation by the Carnegie Geophysical Laboratory was obtained, and a set of cables and electric thermometers, for spanning the crater and for immersion in the liquid lava, were prepared. Never- theless, for various reasons, years passed without accomplish- ment and, at the beginning of 1911, the entire project stood to expire of inanition. At this stage Prof. Jaggar, finding himself unable to assume the charge, made a personal appeal to the writer to head the expedition to Kilauea in the hope of making a demonstration of such practical utility as should result in the establishment of a permanent institution on the spot, and promising to take up the work, himself, at a later date. Although very loath to interrupt, even temporarily, his work in Italy,t+ the writer con- sidered the foundation of such a work in his own country of foremost importance, and it was thus that, in company with Dr. EK. 8. Shepherd, of the Carnegie Laboratory, he arrived at the islands in June and commenced those observations and studies * This Journal, xxxv, 139, 273, 337, 469, 611; xxxvi, 151. + After having lived through the Etna eruption of 1910, all the phases of which were observed and photographed, the still more important outbreak of 1911 was thus missed, leaving a gap which can never be filled. 476 F.. A. Perret-— Volcanic Research at Kilauea. which have been briefly considered in the preceding papers of the series. . , The project may, therefore, be said to have been founded by the Institute of Technology and the people of Hawaii through the initiative of Prof. Jaggar; with the codperation of the Carnegie Laboratory, as represented by Dr. Shepherd ; and carried into effect by the Volcanic Research Society, in the person of the present writer. It is but fair to state that the financial means of the expedi- tion were extremely limited and that, had it not been for the hearty disposition of the residents, one and all, to aid and facilitate the work by every means in their power, the results would have been very different. Noted for hospitality and good will, their attitude toward the workers was beyond all Hie: a) praise and the writer takes this opportunity of expressing his grateful appreciation of all that was done. A difficulty, graver than the financial one, lay in the changed voleanic conditions at this time as compared with Prof. Jaggar’s visit in 1909. Then, a complete “black ledge” stood within the walls of Halemaumau forming an accessible platform at no: great distance from the lake of lava over which - it was proposed to stretch the cables, but, by 1911, this was, for all practical’ purposes, non-existent, the few remaining sectors being quite unsuitable for supports and anchorages, as will have been evident from a perusal of the paper on “ Subsidence Phenomena.”* It became necessary, therefore, to work from the top of Halemauman, and this increased the magnitude and the difficulty of the operations beyond all anticipation. From figs. 1 and 2 the reader will obtain some idea of the apparatus erected for the purpose of obtaining temperature measurements of the lake lava and for collecting the material, itself, directly from the lava fountains. In the outline sketch * This Journal, May, 1913. EF. A. Perret— Volcanic Research at Kilauea. ATT it was necessary, for the sake of clearness, to greatly exaggerate the size of the trolley and the height of the A-frames consti- tuting the main cable supports, with the unfortunate result of reducing the apparent dimensions of the crater to an almost ludicrous proportion—properly, the size of the trolley should be less than a tenth of the diameter of its smallest wheel, as drawn, and the height of the A-frames, and their distance from the crater’s edge, should be reduced in proportion. Hie: 2: Fie. 2. Showing cables, trolley, and winch, at eastern edge of the crater. A #$inch Lidgerwood steel cable with hemp core was eriploved, the total length between anchorages being 530 M. of which nearly 400 M. was clear span between A- frames. This was stretched to a 5 per cent drop according to recommenda- tion of the engineers,* in which condition the center of the span hung some 56 M., at the beginning, above the surface of the lake, the subsequent sinking of which increased this con- siderably and added Be to the difticulty of lowering the instruments. * For others who may undertake similar experiments the writer would advise a greater drop, not only as lessening the strain but as actually facili- tating the sending of the trolley to the center of the span. Am. Jour. Sci.—FourtTH SERIES, VoL. XXXVI, No. 215.—NovemsBeER, 1913. 32 AO ele ae Perret— Volcanic Research at Kilauea. The western anchorage was the projecting tongue of an old lava flow around which the cable was bent and secured with clips, while at the eastern end logs were buried crosswise in a cleft of the lava rock. A team of horses, with appropriate tackle, was employed for the final stretchmg of the cable to a 5 per cent drop. The trolley, shown in fig. 2, ran on this main cable and could be brought to any desired position above the lake by means of two smaller guy cables, pulling in either direction by winches, as shown. An insulated electric cable, running over the lower wheels of the trolley and, also, under the control of a winch, served to lower the instruments into the lake and to maintain the electrical connection with the indicating apparatus “on shore.” It was found necessary to support the horizontal por- tion of this cable at intervals by small pulleys running on the main cable in order that its weight should not prevent the lowering of the instrument—an arrangement which could not well be shown on the diagram. All was thus ready, but an incident, occurring at this stage of the proceedings, has so important a beari ing upon the subse- quent experiments that it may well be related here. A kink in one of the smaller cables caused it to break and fall into the lake, where it was quickly fused. Now, the temperature of the Kilauean lava has been quite generally considered to be at least equal to the fusing point of wrought iron, for the reason that rods or wires of that metal, immersed in the lava, were rapidly fused. The lava melted the iron—ergo, it had the heat to do it—no deduction could be more simple, more direct, nor — more convincing. And yet, toa practised eye, the degree of incandescence—even in the fountains and in spatter-grottoes where the lava was protected from radiation—indicated a much lower temperature. The fusing of the steel cable would mean, let us say, 1300° C., but it was impossible to admit such a de- gree of heat. How, then, explain the fusion of the steel ? The first glance at the fused cable-end showed the metal to have been converted into the sulphide, and it was realized that, not thermal action alone, but chemical activity, as well, was here involved. The presence of sulphur—revealed by the abundant evolution of SO,—had not been considered in plan- ning the experiments, and this incident of the fused cable boded ill for the instruments destined for immersion in the lake. But another, and broader, consequence results from this demonstration of chemical activity, viz., that all estimates of the temperature of liquid lavas based upon the melting therein of wires or strips of various metals whose fusion points were known, must be considered as having practically no value. As F. A. Perret— Vo'canic Research at Kilauea. A479 will be seen later, tubes of nickel, the fusion point of which we may take as being at the least 1450° C., were readily dissolved in this lava, whose temperature could not have approached to within 300° of this. The first attempts to obtain a temperature measurement were made with resistance coils of fine platinum wire enclosed for protection in concentrically disposed tubes of quartz, nickel and iron, the electrical resistance of the platinum coil varying with its temperature and being read by suitable instruments connected with the shore end of the connecting cable. Need- less to say, the metal tubes were several meters in length, and the adjoining portion of the insulated cable was protected by a spiral steel casing. One of these instruments was successfully lowered into the lake on July 20th, but the electrical connection failed at the moment of immersion and a lava fountain carried away the instrument with all the armored cable. Just before this oc- curred, however, the spring of the main cable had lifted the instrument, for a moment, quite clear of the lake and it was seen that the metal tube had been fused off at the level of immersion. . Nine days later a second, similar instrument failed, in like manner, to register, and it was evident that this type of ther- mometer, however useful in the laboratory, was too delicate for the rough conditions of crater activity.* The third and successful attempt was made on July 31st with a thermo-electric couple of platinum and iridio-platinum. This was set up by Dr. Shepherd in a heavy iron tube and the cold end of the element was surrounded by a large iron cylin- der filled with water. It should be said here that, by this time, the conditions at the crater had become exceedingly unfavorable for the contin- uation of the experiments. The sinking of the lake greatly increased the difficulty of lowering the instruments into contact with the lava, while dense clouds of vapor rendered the lake itself quite invisible from the operating point and made neces- sary a line of signal-men around each side of the crater for receiving and transmitting previously arranged wig-wag signals from the writer, to whom, alone—perched upon the crag of a sunken ledge, mside the pit—the lake surface and the descend- ing instrument were visible. ; In this manner the element was immersed some 30 to 50™ below the surface of the lava, where a thin crust was readily perforated by the descending tube. .The shore instrument showed the increasing temperature as the element descended * The Kilauea lava fountains send tons of heavy liquid to a height of from 6 to 12 meters. 480 FE. A. Perret— Voleanic Research at Kilauea. and, when this was immersed, gave, with the correction for the cold-end temperature, 1050° ©. The cold-end temperature was taken as being virtually 100° C from the writer’s observa- tion of steam issuing strongly from the water jacket (neglecting altitude). The instrument was quickly withdrawn from the lava—its tube already almost gone—and, in a second immer- sion, was engulfed by a fountain and lost. The temperature reading thus obtained agrees with the vis- ual estimate of Dr. Shepherd, whose experience in furnace work has given him a special aptitude in this direction. The writer had estimated the fountains at slightly over 1100° C., and it may be that this difference actually exists between the fountains and the still lava beneath a crust, although it is con- trary to all the writer’s experience that there should be any very considerable difference of temperature in different parts of a mass of fully liquid lava, even in the case of a long, flow- ing stream. It is, at all events, quite obvious that the heat of Kilauean lava has been generally overestimated in the past. ‘* White heat” is a convenient expression, and is a condition easily imag- ined in contrast with dark surroundings of a warm tint, but a tungsten pocket lamp will quickly dispel the illusion. Dr. Shepherd, on his second visit to Kilauea, had the privi- lege of witnessing one of those phenomenal increases of activ- ity which fill the pit from side to side with a lake of boiling lava without a trace of crust, yet the temperature fell short of 1200° C. A curious observation by the present writer goes far, how- ever, towards explaining the many references to white heat. During the first few nights of his stay at the crater he was, himself, impressed by sudden apparent increases in the tem- perature of the lava as shown bya change from the golden glow to a whitish incandescence. There being no other indi- cations of greater activity which might account for this phe- nomenon, he continued to observe the lake and found that, at times, this whiteness appeared in places while the rest of the lava retained its original color. This clearly indicated a cause other than temperature variation, and a little further study resolved the mystery. In the paper on lava fountains refer- ence was made to the gases which, on issuing from the lava, burn in the air with a visible flame and the production of a cloud of the burnt vapors. These vapors, although transpar- ent, have, by reflected daylight, a bluish tint, but when viewed by transmitted light are of a yellowish brown or reddish brown color, according ‘to their density—a color and a quality which is highly absory ptive of those orange and yellow rays so abun- dant in the golden-hued lava. Seen at night through a veil of this transparent vapor, the glowing liquid, although somewhat F. A. Perret— Volcanic Research at Kilauea. 481 less brilliant, appears of a whitish incandescence, giving the impression of higher temperature. From all the foregoing remarks it should not-be inferred that the writer is casting doubt on the many reliable observa- tions of lava at very high temperatures, nor that he finds any difficulty in believing that lava may be brought to the surface at white heat. His contention is that such high temperatures are rare and, at Kilauea, would soon result in a return to the former condition of main-crater activity. At Vesuvius, in 1906, the lava MiG. o. Fic. 3. Pot and chain, filled and covered with lava taken from ‘‘ Old Faithful.” (Photo by H.R. Schulz.) flowed from a fissure on the southern flank at five meters per second while jets of liquid fragments shot directly from the central conduit a thousand meters into the air; at Etna, in 1910, the lava, at its source, had even greater velocity, with flames of burning eas ten meters in length; Stromboli, in 1907 and 1912, shot “the liquid contents of its conduit into view in magnificent fiery spray, and the lava fountains of Kilauea, in 1911, were ¢ele-photographed in 1/4 second, at midnight, with a working aperture of F. 10,—none of these conditions involved a temperature approximating white heat. The expedition not being provided with apparatus for the collection of gases, it was determined to, at least, attempt the taking of lava directly from a fountain by means of the cables. Ta ER SF SS ST SN ——— EEE a ee 489 F. A. Perret— Volcanic Research at Kilauea. A plumbers’ solder pot, attached by a heavy iron chain to a steel lowering cable, formed the recipient and, by great good fortune, the experiment was immediately successful —* Old Faithful” engulfing the pot and chain—and, although the strain nearly wrecked the entire plant, the very spring of the main cable aided in the immediate withdrawal of the recipient which, brought to shore, presented the appearance shown in fio. 8. The pot and chain—just too hot to be touched—were hung from a beam in the station and, at the expiration of three Fig. 4. Fic. 4. Section of contents of pot showing three zones of consolidation. hours, were still at vzrtually the same temperature, while, during the fourth hour, the entire mass turned cold. This result was unlooked for——and the taking of regular tempera- ture readings neglected——because of the negative result of an experiment on the Etna lava of 1910, when pyrometer readings were taken at one minute intervals, by the writer, on a cooling mass of lava. In that case the temperature fell from 970° C. to 150° C. in an hour, but without any notable abnormality in the regularity of its descent. The probability would seem to be that, in the case of the Etna lava, the first phases of erys- tallization had already progressed to an extent incompatible with further development in this short time of cooling, while this Kilauean fountain lava is so pure a glass that the beginning F. A. Perret— Volcanic Research at Kilauea. 483 of crystallization may occur even in so small a mass of mate- rial, evolving, in the process, a large amount of heat. On examining the material it was found, as expected, that all the lava upon the chain and that on the outside of the pot was in the condition of glass. That inside the pot showed, in section, three distinct zones (fig. 4), the outer, of the same glass; the next, a layer of gray, semi-crystalline rock, and, finally, a central mass of the same nature but even more vesi- cular and of a slightly pinkish color. The walls of the gas cavities are of a smoothness indicating a considerable gas ten- sion. It is interesting to note that, in other instances of mod- ro) erately rapid consolidation, the writer has found the same Hie. 3: Fie. 0. Section of sheet pahoehoe showing three zones of consolidation. division into three zones, as shown in fig. 5, representing a section of sheet pahoehoe, 3°" in thickness, from a drained pool on the floor of the main crater. As regards this lava from “Old Faithful,’ if we consider its source, the gaseous nature of fountain mechanism, and the almost instantaneous solidification of the outer layer of the collected mass, it will be difficult to conceive of a more fresh, more original ‘and unaltered material, and its interesting and significant evolution of heat, upon consolidation, was not needed to demonstrate the value of this product for chemical and physical examination. A portion, in section, was sent by the writer to Dr. Albert Brun, whose methods of examining lavas are so well known, and he has most kindly responded with the very interesting note herewith appended and to which the reader’s attention is now invited. A84 F.. A. Perret— Volcanic Research at Kilauea. Note on the Lava taken from the Halemaumau Pit by Mr. Frank A. Perret in July, 1911, with gas analyses and remarks by ALBERT Brun. In the accompanying article, Mr. F. A. Perret shows that he has been able to get, out of “ Old Faithful,” lava still in a state of fusion. This interesting experiment, carried out with much skill, made it possible to study in the laboratory a lava which was taken when in the midst of the process of evolution. The points which I examine in this note only include a few facts relating to the gases, as well as those relating to the action of steam on the magma. In addition I also examine a special feature in the evo- lution of crystallization of the melted magma of Kilauea. Gases.—It is well known that, during the last century, the French astronomer, Jansen, discovered with the spectroscope, that .the flames which escaped from the lava lake of Kilauea gave the spectrum rays of sodium, C, and H,. The gas analyses pub- lished during recent years by myself in my book “ Recherches sur ’Exhalaison voleanique ” (1911, page 115) confirm this com- position. The lava in fusion obtained by Mr. Perret in 1911 also gives out gases, the nature of which confirms the above men- tioned analyses. To extract the gases, I heated the glassy lava in a vacuum nearly to the melting point, or to complete fusion. This opera- tion took place in an apparatus already described. It distils quite a quantity of hydrocarbides which are condensed in the form of black bituminous rings which colored P,O, yellowish brown. It also deposited a white ring of (Na,K)Cl and NH,Cl which can be easily analysed. It is known that the composition of a complicated mixture of gases is influenced by the duration of the time of heating, the temperature, the pressure and the par- tial pressure of each individual gas, so that the final result is somewhat variable, even with the same materials. But the importance of this slight variation need not be exaggerated. The lava collected by Mr. F. A. fee gives off the following gases : A—lLava heated to complete fusion for a long time ; from 1 kilogram of lava. Solid matters : Chlorides (Na,K) Cl volatilized, ;milligramisio saa 75 Salmiac (NH,Cl) id. id. 15 SMEG HO S10 os eee ey AOL eR ee very abundant Gases: Quantity mvewbievcent.. 125.25 e eee 3.108 Compare ds Oya a ge ities Sin oe) 2 Aeneas traces [ire ys tee ha a as eat SOnsstop eek ie. Soe e ae CQ) spent ced o/s ho day OD O) Oat ea a1 Bi A sh a 8 | DOPE 2st a meee PEs, GN Nas eee ieee ae eae, Abia F. A. Perret— Volcanic Research at Kilauea. 485 I have explained elsewhere the presence of CO. The examina- tion of the composition of these gases, as well as of the substances volatilized and easily condensed at the ordinary tem- perature, shows immediately that a great part is combustible. On coming into contact with the atmosphere these substances will burn, owing to the high temperature which they possess on leaving the magma in fusion. Therefore there will also be formed CO,, and water of extra magmatic origin. This, therefore, easily explains the flames, giving more or less light, which observers have seen rising from Lake Halemaumau. It is also advisable to note that these gases contain very little N,. The percentage of N, will always be a criterium of great general importance, which will denote the purity of the gaseous products collected on the spot, either from a fumarole or from the liquid lava. Oxidization of the Lava (by water).—The lava collected by Mr. F. A. Perret from “Old Faithful” is not completely oxidized. After having extracted all the gases from it, there remains a melted mass of black silicates, opaque even in thin splinters ; this mass isrich in C. Therefore the silicate does not contain enough peroxides in order to oxidize all its C at the temperature of the lake. But if we supply the necessary O,, either in the form of water or air, we shall be able, at the temperature of the lake, to oxidize all the C easily, and to obtain a great quantity of CO, and H,; therefore this experiment proves that the magma did not contain enough water to oxidize all its C. This demonstration may be made, in a very elegant way, as follows: Let us take the black silicate residue which during the first heating gives off all its gases, and its volatile substances, and which only contained a residue of carbon. This residuum must be heated in aclosed apparatus in the presence of steam and noth- ing else, and without any traces of atmospheric air. A manom- eter shows the pressure, at every moment, of the gases formed at the given temperature. In the course of the heating a reaction is developed. The water attacks the lava and its carbon. The pressure in the apparatus which I used reached 500 millimeters of mercury at 1000°. Under the same conditions the gases of lava alone, without the action of the water, only give a pressure of 8-10 millimeters of mercury. The gases collected during this intense reaction have the following composition; B, first exp’t ; C, second exp’t : Composition of the gases. B C ae a ty areera ae re 26°2 +e CO) hee eee ee SF 550 6°4 bss teen aie Se eras yee 680 74:0 Niet Seas rete A ae tic beg 0-4 traces 99°6 100°05 486 F. A. Perret— Volcanic Research at Kilauea. The quantity given off from 1 kilogram of lava depends on the quantity of water. I obtained 4000 to 6000 cubic cent. It is advisable to remark, that the quantity of gases collected is enormously greater than that obtained by the study of the appar- ent density of the natural vesiculated lava. In our experiment the water oxidizes the. lava continually until the chemical equili- brium is reached. This reaction, which we accomplished in the laboratory, does not take place in the magma of the volcano, for the latter contains a residue of carbon. Therefore, if there was any steam, it was in too small a quantity to attack all the C. The proportion reached so low a limit that it is almost nothing. This enables us to say: that the magma of Kilauea is anhy- dric, with the exception of the enclaves, and in special cases, (as explained in my Recherches sur l’Exhalaison voleanique, p. 264,) it even seems that this proposition may be extended to the ancient magmas, such as granites. For we know that white and black micas are not chemically hydrated minerals, as has hitherto been admitted. For the details concerning this proposition, which seem to be extraordinary, see Bulletin de la Société minéralogique. de France, Feb., 1918, and Archives des Sciences, Genéve, xxv, No. 5. Crystallization.—We wish to draw attention to the interesting point brought to light by Mr. Perret’s skilful experiment. The lava was indeed collected at the very time of its volcanic and crystalline evolution ; as before explained, a fairly large mass of lava was extracted from the “Old Faithful.” When he got the lava in fusion, from the pit, Mr. Perret brought up a glass in which some crystals were floating (labradorite, peridot, and more rarely augite of old formation). Several of these crystals are in the course of digestion. ‘They are corroded and the edges rounded, which shows them to be debris of enclaves. Other crystals have clear cut and sharp angles: they probably are in the course of formation. The external part of the block, cooled suddenly, was consoli- dated into a limpid yellowish-green glass. The internal part, cool- ing more slowly, crystallized. There were no real crystals, but trichitic-centroradiated spherulites. . These trichites are generally developed around a preexisting crystal; they form around it a dark-colored hairy setting, opaque in the center and transparent at the edges. The refractive index is greater than that of glass. The fibers are extremely fine, delicate and indistinct in form. Itis easy to recognise, with polarized light, the characters of a spher- ulite, the fibers of which are elongated optically + (positive). It is impossible to say whether a pure mineral is present. We are in presence of an intermediate state of crystalline evolution. This phenomenon appears in a very short space of time—a few hours. We must be grateful to Mr. Perret for having demon- strated experimentally, on the volcano itself, this interesting epoch in the life of the lava. F. A. Perret— Volcanic Research at Kilauea. 487 The present writer had intended commenting at some length on this most interesting report, especially as regards the question of anhydricity, but lack of space absolutely necessitates defer- meut of the discussion, which, to have any value, would be long. The results obtained by the writer’s successors at Kilauea should throw great light upon the exact nature and proportions of the emanations; the field is a fertile one for direct research, and there can be no doubt that the observatory, now established and in charge of Professor Jaggar, will prove itself an insti- tution of the greatest value to the growing science of vol- canology. Some of the more salient points brought out in the present series of papers on Kilauea. Gaseous cause of the mechanism of lava fountains. Three phases of fountain action distinguished. Air oxidation (burning) of gases emanating from the lava. The burnt gases from visible cloud readily photographed. Islands supported by chilling to them of artificial shore and by gas flotation. . Formation of gas ducts to top of floating islands. . Formation of sub-surface cavity with lava dis- -levelling ae production of free flowing cascade. 8. Sinking of islands effected by lava overflows due to rapid changes of level. ®. So called “new islands” often due to chilling of lake surface by re-flotation of sunken island. 10. Cireulation of lake initiated by gas explosion, and con- tinued by sinking of heavy surface material. 11. Elongated form of lake necessary consequence of this principle of circulation. 12. Variations in height of lava column slightly influenced by atmospheric pressure changes. 13. More strongly by luni-solar gravitational influence. 14. Pronounced sinking of lava after gaseous outburst. 15. Crater ledges may subside so gradually and by so minute a subdivision as to constitute a “slow flow.” 16. Evidence of many explosive phases in the past of Kilauea. 17. Characteristically tail-less bombs. 18. “ Péle’s tears.” 19. Strong evidence from native tradition as to antiquity, normal origin, explosive, activity, etc. of Kilauea. 20. Monolithic consolidation of stagnant lava. 21. Shell or tubular consolidation of flowing lava. OU 90 bo bo 488 F. A. Perret— Volcanic Research at Kilauea. 22. “ Pressure casting” of trees. 23. Permanence of crater and conduit walls, floating islands, ete, due to slowly consolidated lava having higher fusing point by reason of crystallization. 24. Temperature of modern lake shown to be from 1050° to 1175° C— possibly from 1000° to 1200°. 25. Appearance of white heat often due to absorption of yellow rays by transparent burnt gases. 26. Thermo-electric element preferable to electric resistance thermometer for field work. 27. Chemical and physical characteristics of fountain lava collected directly. Posillipo, Naples, August, 1913. Derby—Stem Structure of Psaronius Brasiliensis. 489 Arr. XLIII.— Observations on the Stem Structure of Psaronius Brasiliensis ; by ORvitLtE A. Dersy. [Preliminary note in advance of the Annaes do Servigo Geologico e Miner- alogico do Brasil. ] Ir having been recently established by Count Solms-Laubach* that the slice of a Psaronius trunk preserved in the Paris museum, which has become so well known through the studies of Brongniart and Zeiller under the name of Psaronius brasiliensis (possibly not identical with the fossil so named by Unger), is a part of a specimen taken, in 1839, from the National Museum of Rio de Janeiro to Paris to be cut, and that other slices were preserved in the museums of Rio de Janeiro, London and Strasbourg, it occurred to me that, hav- ing the "Rio slice at hand, there was a possibility of determin- ing through the aid of photographs and dimensional notes on the other slices, the relative position and mutual relations of the different known parts of the original trunk. Through _the extreme courtesy of Drs. J. B. Lacerda and A. Smith Woodward of the Rio de Janeiro and London museums, of Prof. R. Zeiller and Count Solms-Laubach of Paris and Stras- bourg, the necessary material for the projected study was readily obtained. The alignment of the various slices, represented individually in fig. 1,¢ was found to be an easy matter, since one face of each of the Paris and Strasbourg ones, having been only par- tially evened up by cutting, retains a part of the original frac- tured surface and thus shows that these are the stub ends of the original specimen. Between these end slices the Rio and London ones readily fall into place through the agreement of accidental and structural features on the opposing ‘sides of the saw cuts by which they had been separated. The Rio slice, not having been evened up, shows that in the first cutting nearly 5" of material must have been lost and in the restora- tions in figs. 2 and 3 this width has been assigned to the various saw cuts, though it is probably too great for those sub- seauently made. According to information received from Prof. Zeiller a thin slice (5™™"+), now in the Paris museum, was cut from the lower end of the original Paris specimen to even it up, and apparently a similar operation had been per- formed on the upper end of the first London one, since its * Uber die Schicksale der als Psaronius brasiliensis beschriebenen Fossil- reste unserer Museen, Festschrift zur Feier des 70 Geburtstages von P. Ascherson, 1904. _t These sections, as also those of figs. 2 and 3, are about two-fifths natural size. 490 Derby—Stem Structure of Psaronius Brasiliensis. igs de ~ STRASBOURG LONDON 1 Derby—Stem Structure of Psaronius Brasiliensis. 491 Hig 2: ae Go: as = a 4 1ENnsis. ul 492 Derby—sStem Structure of Psaronius Bras = . 3 Fie ay x, 4 a 19/3 te FO Basto Derby—Stem Structure of Psaronius Brasiliensis. 493 mechanical features do not agree with those of the correspond- ing face of the Rio slice. As will be readily seen in fig. 2, in which the thickness of the various slices and the width _arbitrarily assigned to the intervals are represented, any inac- euracies that there may be in the latter do not materially affect the restoration of the original specimen. Based on careful plotting from photographs of the twelve eross sections, Mr. Francisco Basto, draughtsman of the Brazilian Geological Service, has prepared the figures given on the accompanying plates (x2). In those of fig. 1 the central stem of the various slices is drawn as if divested of its root sheath and inclined at an angle of 45 degrees, thus giving an apparent inequality to the two axes which in reality are sub- stantially equal. The real inequality, due to the unequal development of the involving root sheath, of the two axes of the entire trunk is shown in the ideal longitudinal sections of fig. 2. In the restoration, fig. 3, of the preserved parts of one member of each of the three pairs of F strands the figures are so placed that if imagined dislocated laterally so as to fall into line an almost complete representation of the stem portion of a single strand of this group will be obtained. In order to permit a better representation of certain features, the interval between the Paris and Rio slices has been left open. In the designation of the strands Prof. Zeiller’s nomenclature of P (eripheral) and F (oliar) has been preserved for the two outer groups with a modification in the numbering of the latter rendered necessary by the introduction of an additional pair not known to him, while the central group, of which only the outer members are marked, is designated by the letter C. An inspection of these figures makes it evident that the original specimen represented a fragment of a trunk broken somewhat above the points of emergence of a pair of oppositely placed external organs carrying the vascular strands F1 and F2, and again soniewhat above the emergence of a crosswise placed pair (#3, F4) of organs of the same kind. Of the last pair the strands of F383 are completely outside of the sclerenchymous sheath on the lower face of the Paris slice, while F4 is still enclosed within it, and correspondingly the former is seen to have disappeared before the level of the upper face of the slice was reached, while the latter still persisted at this level, showing that an interval of a few millimeters of growth inter- vened between the emergence of the two members of each pair. On the other hand, the interval between the successive pairs of this set was not far from two hundred millimeters. The numerous strands of the C group are neatly arranged in the Strasbourg and London 38 slices in a loose rectangular bundle with a pair of long bounding strands (C1, ©2) on the Am. Jour. Sc1.—FourtH SErRigs, Vou. XXXVI, No. 215.—Novemper, 1913. 33 494. Derby—Stem Structure of Psaronius Brasiliensis. longer sides and of short (C3, C4) strands on the shorter one. This symmetrical arrangement becomes disorganized higher up through the breaking up and subsequent disappearance of the longer pair, but is restored, in a reversed position, at the top of the Paris slice through the mereased development of the C3, C4 pair and the appearance of a new (C1’, C2’) pair in sub- stitution of the one that was lost. The central group of strands thus shows a periodicity at about the same levels as that above noted in the F group. The cut beween the Strasbourg and London 3 slices caught, on its upper side, the beginning of a branch of the C1 strand and for this reason this strand and its development have been selected for restoration. Before reaching the top of the Rio slice the parent C strand disappeared while the branch developed into a typical F (F1’) strand and a pair of seler- enchymous bands developed outside of it. At the top of the Paris slice this strand and its accompanying sclerenchymous bands are so nearly in the same stage of development as the F3 strand in the Strasbourg slice that the latter may be taken as representing its missing portion. On tracing this strand and its bands upward their sides are seen to draw inwards until they assume the shape presented on the upper face of the Rio slice where the portion of the sclerenchymous sheath in front of the strand has ceased to form. In the interval between the Rio and the Paris slices the mternal sclerenchymous bands evidently became completely soldered to the outer sheath and had their inner margins united so as to make the sheath again continuous, while the strand became external and divided into two parts through the loss of its central portion. Before reaching the top of the Paris slice this strand disappeared, but its companion shows one phase of its missing portion and is so like the F1 strand in the Strasbourg slice that this may be taken as representing the other phases susceptible of preserva- tion in the silicified trunk of the plant. In view of the history traced above, the F1, F2 pair of strands in the four lower slices must be regarded as the remnants of presistent stub ends of the stalks of a pair of ex- ternal organs that emerged from the trunk somewhat lower down and developed parallel with it in deep grooves produced by the formation of sclerenchyma behind them, up to near the top of the London 1 slice where the organs spread out laterally to form a part of the crown of the plant. Eventually the crownpart of these organs fell away, leaving the basal portion adherent to the trunk, where they were subsequently covered by adventitious roots, descending from above, and thus pro- tected from complete decay. Before the formation of the root covering these stubs would be exposed to the air and thus Derby—Stem Structure of Psaronius Brasiliensis. 495 subject to decay, which seems to have destroyed all their softer tissues, leaving only the lignified strands. This conclusion is based on the fact that the greater part of the space within the grooves is occupied by open cavities or by a filling of silica in which traces of organic structure are obscure or lacking. Aside from the F strands, which are tolerably distinct in these grooves, a number of rounded spots occur that look like cross sections of roots, but which may prove to be accidental. As the doubt regarding the true character of these markings can only be resolved by a microscopic examination, which there is no opportunity of making, they have been left out of account in the restoration. The mode of formation of the sclerenchymous sheath behind the emergent organ is shown in the seven lower sections of the trunk. In the interval between the incurved sides of the in- ternal sclerenchymous bands aligned shreds of sclerenchyma appear which continue detached until the fall of the organ, when they unite with each other and with the bands and thus become, with these, an integral part of the trunk sheath. It is to be noted that the cross sections present no indications of a sclerenchymous covering of the stem of the organ itself, from which it may be concluded that this, aside from being ephemeral, could have had no great extension, giving it a con- siderable weight, in its missing outspreading portion, since its only mechanical support seems to have been that afforded by the vascular strands. | The four P strands are essentially alike in the uppermost cross section of the trunk,* where each presents the form of a broad ribbon slightly ar ched in its central portion and strongly inrolled at the margins, with a loose semicircular curve on one side and a more compressed semielliptical one on the other. With a reversal in the position of the two types of inrolling, this simple form of the ribbon recurs also in the lower cross sections, in which, however, there is a departure from symme- try through the division of P38 mto two parts which become united in the interior of the London 2 slice, though the pecu- har loop of the smaller division presists for some time and the strand only becomes normal at the top of London 1. It is to be noted that the compressed subelliptical inrolled margin of these strands les between the trunk sheath and an internal sclerenchymous band where this stands subparallel to the sheath. * As noted above this cross section has only been partially cut so that it presents, ‘in part, an irregular fractured surface on which some of its struc- tural features do not appear clearly in the photograph at hand. I owe to the extreme kindness of Prof. Zeiller an accurate sketch of the stem portion of this cross section. 496 Derby—Stem Structure of Psaronius Brasiliensis. The simple form presented by the P strands in the extreme cross sections is modified in some of the intermediate ones by branching and subdivision. An external branch appears on P1 at the base of London 1, and on P2 at the top of London Q, but in neither case does this presist to the succeeding cross sec- tion. An internal branch that becomes strongly developed and subdivided in the interior parenchyma seems to be a feature common to all of this set of strands. This is best seen on the Pi and P2 strands on the faces of the London 1 and Rio slices. In the case of the former the subdivided distal end of the branch seems to have soon ceased to grow, while the proximal end forms with the reunited shattered portions of the parent strand the peculiar open loop seen at the top of the Rio slice. In the next cross section above this loop is closed, but at the top of the Paris slice it is opened in such a way as to restore the simple form of the strand. As each of the other strands presents a similar loop in a more or less perfect stage of development, this seems to be a normal feature in the growth of this set of strands. The detached subdivisions of the branches of the P strands assume the aspect of the smaller members of the central group, but as they lie outside of the magic square above noted and soon come to an end, a real connection between the P and C groups of strands seems improbable. A possible connection between the P and F' groups is suggested by the relative posi- tion of P2 and F1’ on the two faces of the Rio slice and of P3 and F1’ on the lower face of the Paris one, but in neither case can an actual anastomosis be positively affirmed. While it seems possible and even probable that anastomoses do occur between the P set of strands and one or the other, or both, of the two other sets, it is evident that the maintenance of such inter-relations cannot be the main function of the strongest and most presistent group of vascular strands that the plant possessed. Thus the conclusion seems forced upon us that the P strands must have supplied externai organs that constituted a part, and presumably the main part, of the crown of the plant. In this case, however, these organs must have been presistant during a period of growth longer than that represented by the length of the entire fraction of the original trunk here.considered ; or a substitution of an old set of four organs by a new one must have taken place in the zone in which the strands are branched and shattered. This last hypothesis involves that of a continued upward growth of the sclerenchy- mous sheath on the outside of the P strands, whereas in the case of the F strands this growth, as shown above, was alter- nately on the outer and on the inner side of the strand. Derby—Stem Structure of Psaronius Brasiliensis. 497 The cross sections of the stem show a few root sections tra- versing the sclerenchymous sheath or situated between it and the adjoining P strand, but these are so limited in number as compared with the thousands that make up the great root sheath encircling the stem, that they must apparently be con- sidered as sporadic. This consideration and the fact that the roots descend vertically in a space several centimeters wide wholly outside of the stem sheath, suggests the hypothesis that they arise, for the most part, trom the proximal free portion of outspreading external organs that formed the crown of the plant, and that furthermore these organs must have been sup- ~ plied by both the P and the F set of strands. “993 764 | 2035 | 0°241 475 BOT OL3IO54, ||). FASE |) 0-293) 52 Ge hi 94199387 6 232) 031 6 293 341 Rt 241 004 7 231 807 7 223) 130 S |i» +2409 764 8 231 584 8 222 920 9 240 528 Ose 93h 361 9 222 709 27040 | 0°240 292 2080s) 0231399 || B20, -O-229) 499 524 Ff. EL Wright—Methods in Microscopical Petrography. TaBLE II.—Continued. n 1/n? n 1/n? n 1/n? 2°120 0°222 499 2°160 0°214 335 2°200 0°206 612 1 222 F389 a "214 136 if 206 424 2 222 080 2 "213 938 2 "206 236 3 Hapa lores il 3 oo Vegetal 3 206 049 4 221 662 4 "213.543 4 205 . 862 2°125 0°2291 453 2°165 0°213 346 2°205 0°205 676 6 “22 1245 6 "213 149 6 205 489 7 “DONn Oa 7 "212 952 vi "205 303 8 *220 829 8 As SST G) 8 205) EG 9 °220 622 9 ‘212 560 9 204 931 2°130 0°220 415 Ze'7O 0°212 3864 2°210 0'204 746 1 "220 208 ] “2 GS i 204 561 2 °220 002 2 911 973 2 "204 376 3 "219 795 3 Bo he veils 3 204 191 4 "219 589 4 PO l2 58S 4 204 007 2°135 0°219 384 2A GS 0°211 389 2-915 0°203 823 6 allt) Si iiee) 6 ‘211 194 6 203 639 7 DUS) Sirs 7 “Zils OOO if °203 455 8 ‘218 768 8 "210 807 8 903 272 9 "218 564 9 2 LOM ows 9 203 089 2°140 0°218 360 2°180 0°210 420 2°220 0°202 906 1 218 156 it “DOr 227 i 202 723 2 O17 952, 2 "210 034 2 202 541 3 BoM ere fA) 3 "209 842 3 "202 358 4 "217 546 4 "209 650 4 2022176 2°145 0:°217 343 2°185 0°209 458 2°225 0°201 995 6 “217 140 6 209 267 6 ‘ 201 813 7 216 988 4 "209 O75 af 201 632 8 216736 8 "208 884 8 201 45 9 216 535 9 *208 693 9 901270 2°150 0°216 333 2°190 0°208 508 2°230 0°201 090 1 2160 iS2 ] 208 312 1 200 910 2 "215 931 2 “208w122 z 200 7380 3 SM Rsk, Wes | 3 207 933 3 200 550 4 PO lbr bal 4 WOT (ae 4 200 370 Pig WE, 0:215 331 2°195 0-207" 504 2°235 0°200) 191 6 21D LBL 6 "2071'365 6 200 O12 7 "214 931 a 2Ou1 106 if ‘199 833 8 COA IP Bey fe 2 8 "206 988 8 199 655 9 "214 533 9 ‘206 800 9 "199 477 2°160 0°214 335 2°200 0°206 612 2°240 0°199 298 F. F. Wright—Methods in Microscopical Petrography. 525 TABLE Il.—Continued. | n 1/n? n 1/n? n 1/n? 2240 0°199 298 2°280 O- 19236 i 2320 0°185 791 1 99.12 1 ] "192 198 i “so. 63 2 "198 948 2 “99030 =| 2 “Son 47 ¥ 3 "198 766 3 “191 862 3 “Ped5-'3 ll 4 198 599 4 ot | 694 | 4 Sar 152, 2245 0°198 412 2°285 O19 S267 11>) 29325 0°184 993 6 "198 235 6 "191 358 | 6 "184 834 7 "198 059 7 “1915 19:1 | i 184 675 8 °197 883 8 "191 024 8 “S426 . 9 "197 007 9 "190 857 9 "184 358 2°250 0-197. 531 2°290 0-190 690 2°330 0°184 199 1 "197 355 1 "190 5294 l. "184 041 2 MOT 180 2 "190 358 2 "183 884 3 "197 005 3 "190 192 3 "183 726 4 "196 830 4 "190 026 4 "183 569 2°255 0'196 656 2°295 0°189 861 2°335 0:183 411 6 "196 482 6 "189 695 6 "183° 254 ae | "196 308 fi 189 530 i 183 098 8 "196 134 8 "189 365 8 “182941 9 "195 960 9 "189 200 9 “Lee. 78> 2°260 0°195 787 2°300 0°189 036 2°340 0°182 628 if "195 614 Ih "188 872 il S23 472 y "195 441 2 "188 708 Zz “1S2e SF 3 shea" 268 3 "188 544 3 "182 161 4 "195 096 4 "188 380 4 "182 006 2°265 0°194 923 2°305 0'188 217 2°345 0°181 850 6 194 751 6 “"I88 054 6 "181 695 | 194 579 i "187 891 ia “Stott 8 "194 408 8 oT 728 8 "181 386 9 "194 237 9 "187 565 9 “181-2382 2°270 0°194 065 2°310 0°187 4083 2°350 0°181 O77 1 198 895 1 AST 24) 1 "180 924 2 "193 724 2 "187 079 2 “180) 7:70 3 "193 554 3 "186 917 3 180 616 4 "193 383 4 "186 755 4 180 463 2275 0°193 213 2°35 0°186 594 2°355 0°180 309 -6 193 044 6 "186 433 | 6 "180 156 7 "192 874 @ "186 272 180 003 8 "192 705 8 Sort LT 8 179" Sod 9 "192 536 9 wSovg oil 9 "179 698 2°280 | 0°192 367 2°320 0°185 791 2°360 0°179 546 Am. Jour. Scit.—Fourts Series, VoL. XXXVI, No. 215.—Novemser, 1913. : 30 526 Ef &. Wright—Methods in Microscopical Petrography. TaBLE II.—Ooncluded. n 1/n? n 1/n? n 1/n? 2°360 O°179 546 2°400 0-173 611 || 2°440 0°167 966 1 179 394 1 173 467 1 "167 828 2 179 242 Dall per 3 e300 2 "167 691 3 "179 O91 3 178178 3 "167 5538 4 "178 939 4 "173 034 4 "167 416 2°365 0178 788 2405 07172 890 || 9°445 0167 279 6 "178 637 6 "172 746 6 167 1438 ii "178 486 fi "172 603 7 167 006 8 "178 335 Sil. 7 oo 59 8 "166 870 9 "178 185 On) CR Ae Rei 9 166 733 2°370 0178 034 2°410 0°172 173 2°450 | 0°166 597 1 177 884 Livin ee B08 1 "166 461 2 miki ee! Dl. fe T1888 D) 166 326 3 177 584 3 "171 746 3 "166 190 4 "177 435 4 171 603 4 "166 055 9°375 07177. 285 2°415 0'171 461 9°455 0165 919 6 “177 136 6 “W789 6 "165 784 i ‘176 987 Te ty Tle i "165 649 8 176 838 8 "171 036 8 165 515 9 176 690 9 "170 895 9 ‘165 380 2°380 0176 541 2°420 07170 7538 2°460 0°165 246 ] 176 393 1 OMG 1 165 111 2 "176 245 OPS Seyi) 9 "164 977 3 176 097 Belts Ossi 3 "164 843 4 ‘175 949 4 ‘170 190 4 "164 710 9°385 0:175 802 A905)! » 0-170 050 2°465 0'164 576 6 "175 654 6 "169 910 || 6 "164 442 7 175 507 Tl "169 770 | "164 309 8 "175 360 8 | +169 630 8 164 176 fe) "175 214 9 +169 490 9 164 043 2°390 0175 067 2°430 | 0°169 351 2°470 | 0:163 910 1 174 921 1 "169 212 i 163 778 29 174 774 2 "169 073 2 163 645 3 174 628 203 "168 934 3 163 513 4 174 4892 4 "168 795 4 163 381 9395 01741387 2°435 0168 656 2475 0°163 249 6 174 On 6 168 518 6 "163 117 si ‘174 046 168 379 a "162 985 8 173 901 8 168 241 8 "162 854 9 173 756 9 "168 103 9 162 722 2400 0-173 611 2°440 0'167 966 2°480 | 0:162 591 ie ks 3. oe f oF " FE. Wright— Methods in Microscopical Petrography. 527 it is not actually necessary to compute the percentage, as this can be done graphically on Plate VI, which is intended prima- rily for the solution of equation 5, but which serves equally well for this purpose. Hxamples.—Solve equation 8 for a section of the mineral aragonite, the normal of the section to include the angles, # = 37° and &= 57°, with the two optic axes. The prin- cipal refractive indices of aragonite are, a = 1°530, 8 = 1°682, and y = 1°686. From Plate V_ we find, by passing along the abscissa axis to @ = 57° and then up along the vertical ordinate to the diag- onal line, 0 = 37°, that 1 1 a”? Tio = 0°505 hae | a” iN or approximately (equation 4). iE aad / u = 0°505. vin ee From Table II, we find that os = 0°427186 and 7 = : Qa 1 1 : : . 0°351791; hence Ge aes 0:075395. By using this last value and passing along the abscissa axis on Plate VI to 0:075395 < 1000 = 75-4:and up the ordinate to the diagonal line 0°505 x 100 = 50°5, we find that 2 = : = 0°0381. Equation 4 above can be solved in similar manner. y — a= 0°156 and [fs Se / = 07505. This equation can, however, be put in a better form for graphical solution by Plate VI by first multi- plying both numerator and denominator by a whole number, 500 (y'—a’) 500 (y' — a) 500), 05156) 7 78 500 (y' — a’) = 89°4 or y’ — a’ = 0:079. Equation 4, which is ordinarily used for computing the bire- fringence, furnishes values which are only approximately cor- rect. In case more accurate values are desired, they can be derived from the standard equations, as 500; then = 0505. Therefore 528 F. EL Wright—Methods in Microscopical Petrography. 1 1 il if 1 ] ] ; Raat ig es e ea 2 e v yr) e058 +9 i if 1 i i it uf | , : aD — 5 ( a + aa rarest oe cos (+ &) (22) The computations required for the solution of these equa- tions can be readily made by use of Table IL and Plate VI. The 1 Al il 1 1 ] p values a + =| and (— ~ a can be derived a \ a Y Y © 2 a , from the data of Table II, and the value of = [a pat =) cos (i — J’) can then be read off directly from Plate V, for this expression can be written : af al il 1p Pde | a Y (23) sin [90 —(S—9’)] — 1 The solution of this equation by Plate V is indicated in fig. 5, the principle involved being identical with that of the preced- Fic. “bd, ing methods. The numerical value of the right-hand side of equation (21) having been thus obtained, the value of a’ can be read off directly from Table IJ. Similarly we find the value of y’. The difference, y’— a’,is then the correct measure of the birefringence for the given section. In minerals of weak birefringence this result is not sensibly different from that derived directly from the simpler equation 4. But in more strongly birefracting substances, this difference between the | two results is perceptible and for accurate work equations 21 and 22 should be used. FB EF. Wright—Methods in Microscopical Petrography. 529 Fixample.—To illustrate the course followed in solving equa- tions 21 and 22, let us compute the correct birefringence of the section of aragonite used above (page 527)... From the values there given we have 1 — ea fe | — 0°389489 De a y Cae 1 : ( sedate a8 — 0:037698 a. y oO — Ww = 20° pa MO 04°. Equations 21 and 22 now read I ae 0:389489 — 0°037698 . cos 94° 1 y = 0'389489 — 0:037698 . cos 20° The values, 0:037698 . cos 20° = 0:0355 and 0037698 . cos 94° = — 0:0027 can be read off directly from Plate V. Therefore —— = 0389489 + 0-0027 = 0°3921 a = = 0389489 — 0:0355 = 0°3540 From Table II we now find that, y’ = 1:681, and a’= 1°597. Accordingly, y’— a’ = 0-084, a value 0:005 higher than that obtained above (page 527) by means of equation 3 and Plate V. In this particular case the error introduced by the approximate equation is over 5 per cent. A check on the above values of wan and Bean be had by 2 x aa Tbe : taking their difference —~ — = 0°0381, a value identical aQ 2 y” ies with that obtained above by use of equation 3. Optic axial angle formula (Plates VI and VII).—In these plates the variables are, abscissee = es — - or 8 — a, ordi- Qa 1 li C8 Ga or y—8§ and the diagonal lines = V. The : 1 1 L. 1 drawings are made on the assumption that —-——. >’ ® i Ah SE 5380 LF. Ek. Wright—Methods in Microscopical Petrography. and that a is the acute bisectrix ; in case pe Ad A Lee [s* y on p* y is the acute bisectrix and the formula should read ] it He At eae) tan’ Vy == iy I 1 [fs y The corresponding approximate equations are a pe tan? Va = — Bie and tan?’ Vy = oe : Be ae . y ae To solve the equation for tan* Va pass up along the ordinate : ; i : which intersects the abscissa — —,, respectively (8—a), ] ae B’ ) to the value a _ i > respectively (y— 6). The diagonal Y line passing through the point thus obtained is then the desired angle V. (Small figure a, Plate VI.) Li il It is of interest to note that the ratio E : is always aoe B? | mie : ee ie ers 2 Bi smaller than the ratio —” Bs, fp saa ee of to ae B— a 1 ae 1 yB+ay B-a a” Be ap + ay and —~—— <1. yB + ay | The effect of substituting the simple relation il 1 agp tel a es Y tan’ Va= an for the exact expression tan’ Va =—;———__— becran 8.) a. a 8 is, therefore, to increase the angle Va and to obtain an optie axial angle, 2 Va, which is too large. The error may amount to 2° and over in unfavorable instances. In the ease of a mineral in which tan’? Va ae Bae. slightly >1, 2 V, therefore, nearly faa cte OF 90° and the mineral apparently optically +, it may happen that LF. E. Wright— Methods in Microscopical Petrography. 531 if if the exact relation tan? V¢ = : is < 1 and the mineral o. ae 8 is actually optically —, even though the acute bisectrix is direction of stronger birefringence (y—- 8 >S8—a). In this instance the ordinary rule that, in a biaxial mineral, the bire- fringence of a section cut normal to the acute bisectrix is less than that of a section normal to the obtuse bisectrix, is invalid and the reverse is true. Such a reversal of sign can only occur on an optically negative mineral with large optic axial angle, 2 Va approximately 90°. The general rule is based on the approximate equation (4) above and is valid for practically all rock-making minerals. To illustrate this inference, let the prin- cipal refractive indices of a mineral be a=1°'511, 8 = 1°634, and y=1°764. In this case 8 — a= 0°123 and y — B= 0:180. 0130 which we find (Plate VI) 2 Vy) = 88:4°. But 1/a’ = 0:437997, 1 j 0 From the approximate formula we have tan’ Vy = 1/8* = 0°374538, and 1/y* = 0°321368 ; eee 0:053270, 1 SOE eee 2 063459. Hence, tan Va Go - from ‘which a B 0063459 we find (Plates VIand VI) 2 Va=85°. If we were to judge, therefore, from the principal birefringences alone and to apply the above rule, we would consider the mineral optically + with y, the acute bisectrix, and 2 Vy = 88°-4 from the approximate equation 4, while in reality the mineral is optically — with a, the acute bisectrix, and 2Va= 85°. In the examples below this relationship will be clearly shown. In the preparation of Plate VI the following short table III of the values of tan’? V for each degree from 0° to 45° was found useful. The values are listed to five places ; they were computed, however, to eight places. Hxamples:—(1) What is the optic axial angle of fayalite, whose principal refractive indices are a = 1824, 8 = 1:864, and y=1:8742 From Table II we find —~ = 0:300573, fe 2. : Q 0-287812, and =0'284748, Accordingly 2 _ += 0-003064, Ve 1 B = 0:012761, and . 0°003064 7X 0:003064 0°021448 jan Vee i 0°012761 7~<0'012761 0'089327 il and —> — a 5382) Ft. FE. Wright—Methods in Microscopreal Petrography. TasBLe ITI. Vs tan? V V tan? V Vi ! tan? V 0° 0°000 00 15° 0:071 80 30° | O-aBana8 il 000 30 6 082 22 i 361 08 y) 001 22 q 093 47 D) 390 46 3 002 75 8 "105 547 3 4921 73 4 004 89 9 118 56 4 454 96 5 000765 || 20 0°132 47 35 0490 29 6 011 05 1 "147 35 6 "527 86 7, 015 08 y) "163 24 5 564 84 8 019 75 3 -180 18 8 610 41 9 025 09 4 "198 23 8 655 75 10 0:031 08 25 0:217 44 40 0°704 09 1 037 78 ye 937 88 1 “755 66 2 "045 18 i 259 62 9 *810 73 3 053 30 8 989 71 3 869 58 4 "062 16 9 307 26 4 932 56. 15 0°071 80 || 380 | 0°333 33 45 1:000 00 From Plate VI we find with these values 2 Va = 52°92. 1°874 — 1864 0°010 1-864 — 1°824 0-040 Heute from Plate VI, 2 Va = 53°-2, a value which is 1° too (2) Compute the optic axial angle of petalite from its refrac- tive indices, a = 1504, 6 = 1°510, y=-4:516. ‘From Dablesm The approximate formula reads tan? Va= 1 1 1 I I we have —, = 0°442084, a= 0°438577, ~—=0-485118; —~— Bi Y a ae Relay ee ae, O00e dn am = 0°003507, ey ==(0°003464; tan® Va= 0-003507 170m which we find 2Va—89°-7. The mineral is therefore optically negative, if the refractive indices be given correctly. From y—B _ 0:006 B—a 0°006 the approximate formula, tan? V= = 1, we are unable to determine the optical character, for it indicates a value of 2 V—=90°. In the text books the optical character of petalite is stated to be optically + and the optic axial angle, 2 Vy —= 83°. There is, therefore, a discrepancy between these data which should be investigated. FE. Wright— Methods in Microscopical Petrography. 533 These examples and the above discussion suffice to show how much information can be readily gathered from the principal refractive indices of a mineral. Transformation equations for projection work.—In_ both erystallographical and optical work it is often of advantage to rotate the projection about one or more axes and thus to shift the positions of all directions relative to any specified direction such as the pole of the projection. On rotation of a sphere about an axis, all points on the sphere travel along cireles whose planes are normal to the axis of rotation. Thus if we denote the position of a point P by two angles X,, and w,, and then rotate the sphere about the horizontal axis OE, the point P travels to P’ along the small circle PP’, the angle u, remain- ing unchanged throughout the rotation. By thus expressing the positions of all points by means of the coédrdinate angles A, and w,, we can rotate the projection about the horizontal Fig. 6. axis by simply adding or subtracting the angle of rotation from the angles X,, of all given points, the angles thus obtained locating the positions of all points after the rotation. If now we wish to rotate the projection about the vertical axis ON, it is necessary to ascertain the angles X,, w,, (fig. 6) which corre- spond to X,, w,-of the first position. This is accomplished by means of equations 15 and 16 above, which can be solved by Plates VIII and IX. Plate VIII is based on equation 15, which can be written Vat eee ean (15a) 1 sin (90°—A,) The tangent function extends from 0 to » for values of yp, from 0° to 90°. In order to plot the entire function under 584. FL EF. Wright— Methods in Microscopical Petrography. these conditions Plate VIII has been so drawn that equation 15a can only be solved graphically for angles w, <45°. For larger angles, equation 15 can be written tan (90° — p,) __ tan (90° — A,) 1 ~ sin (90° — A) (15b) This equation can be solved equally well by Plate VIII but only for angles, w,, 245°. The two different methods of solutions are illustrated in figures 7a, 7b. | BiG. 07. This principle of reciprocation is useful in any equation which is to be solved graphically, andin which the values range from 0 to 1 and beyond, thus causing the plot to extend beyond the bounds of the diagram. The equation AW aS feta can always be written in the form ! ] Ai eG: “aS ea In case A and C are tangent functions as in the present instance, the form of the plate i is simple and yet it is competent to solve ‘equation 15 for all values of A, and p,. The actual modus operandi is best illustrated by an example : The positions of the two optic axes in oligoclase (Ab,,An,,) as determined by Becke are: for optic axis A, A,, = 67° and Hia* =— 46°; for axis B, \,3=—85°°5, and =e *This angle is sometimes designated ¢, but in view of the fact that ¢ is used to denote the azimuth angle in crystallography it would seem better to give it the same significance in optical work and to use the letter “, as above, to designate the latitude angle. FE. Wright— Methods in Microscopical Petrography. 535 Determine the extinction angles for several sections which are twinned both after the Carlsbad and albite law and show sym- metrical extinction angles. From Plate VIII, the required angles can be ascertained without difficulty. In fig. 8 let A and B be the positions of the two optic axes and Ay, @, and Ag, Mp, their spherical codrdinates. The ex- tinction direction for the direction OQ, pole of the projection, can be found by the rule of Fresnel-Biot, which states that the vibra- tion directions of any section biseet the angles between the pro- jections of the optic axes on that section. Thus in fig. 8, the ex- tinction direction bisects the angle BCA. If, therefore, the angles ¢, and dz be computed, then half their sum determines the position of the extinction direction and the angle which this direction includes with the vertical axis ON is the extinction angle. If AX, and w,, of the point A be given, the angle dh, Is readily calculated by equation de Thus, for the axis A, the equation becomes cot d, = sin 85°'5 cot 47°5. In this case w,, >45°; fig. 7b, therefore, should be used. On Plate VIII we find the intersection of the diagonal line 47°°5 with the ordinate through the abscissa 385°5, to be at og, = 180° — 41°6. Similarly hp = 42-4. Accordingly, = = 90°-4 and the desired extinction angle is 90°—90°°4 == — 0°-4. To find now the extinction angle for the section whose normal is in the albite twinning ‘plane (shows symmetrical twinning) and includes an angle of 50° with the pole C (fig. 8), we rotate the projection until this direction coincides with the 536 FF. EF. Wright—Methods in Microscopical Petrography. pole C; we accomplish this by subtracting 50° from X,4 and A,p and have the equations to solve cot d, = sin 17° cot (—46°) cot d, = sin 35°"5 cot 47°°5 From Plate VIi we read off directly | See — 5 by = 28°°1 Therefore, = 96°-2, and the desired extinction angle, bs +p 2 90" = 96"2 = 6ne2, These values might also have been obtained directly ie use of the projection plots, but the above method is more accurate and takes less time. Plate IX is a graphical solution of the general equation sin A = sin sin C (24) The equations 8, 10, 12,14, 16, 18 can all be expressed in this form and can therefore all be solved by Plate IX. Thus equation 16 may be written ‘sin pw, = sin (90° — p,) sin X,, or sin, sin (90° — p,) (16a) sin A, 1 and solved graphically by Plate LX, as indicated in figure 9. Fie. 9. sin | Kxample.—Let the normal to a given section be located by the two angles \, = 87°, and w, = 41°; express its position by the two angles x: and mw, (see figure 6). Equations 15 and 16 apply to this case, FE. Wright—Methods in Microscopical Petrography. 587 Whe) cob. N— cos 37° cot, 41° = sin (9074— 37°): cot 41°. With these values we find (Plate Vill) A, = 47°38. From equation 16 we have sin pp, = Sin 37° cos 41° = sin 37° sin (90° — 41”) Solving this equation by Plate IX we obtain With Plates VIII and IX it is thus possible to pass directly from 2X,, #, to r,, wu, or to g, p without any computation. The above examples are sufficient to indicate the mode of solving the general equations. They do not, however, convey an adequate idea of the wide range of application which these plates have in optical and erystallographical work, especially for verifying computations and the values obtained from projection plots by other graphical methods. It is important to emphasize the fact that all the transfor- mation equations 7 to 18 can be solved directly by means: of Plates VIII and IX, provided proper care be taken to use the complement of the angles wherever necessary. The actual subtraction need not be performed, however, as the comple- ments of all angles are given below and to the right of the actual angles in the two plates. Projections. In actual practice nearly all the optical properties of a min- eral can be deduced, if the shape and position of its index ellip- soid be known for each given wave length. This index ellipsoid has certain properties which enable the observer to determine the vibration directions and the refractive indices, a’ and y’, of any crystal section ; also to ascertain the positions of the two optic axes and the angle between them. Jy virtue of these properties the observer is able to substitute in place of the several index ellipsoids a single sphere and to operate with that alone. This sphere in turn can be projected and the rela- tions, which obtain on it, can be more or less perfectly repre- sented on a single plane (the plane of projection). Several different projections are in use in optical work at the present time, each of which has its advantages and its weak points. The orthographic projection is used chiefly to represent the relations which exist in interference figures, since the interfer- ence figures, as they are observed under the microscope, are orthographic projections of the interference phenomena in space. For graphical solutions of optical problems, the stereographic projection is commonly used, the stereographic projection plots of Penfield and Wulff rendering its application direct and accurate. ‘The stereographic projection, however, distorts the hemisphere considerably, the length of an are of 1° at the mar- 538 Ff. EL Wright—Methods in Microscopical Petrography. gin of the plot being twice that of 1° at the center of the pro- jection. Now in optical work with projections, the principle emphasized above, that the relative accuracy of the different parts of the plot should be as nearly uniform as possible and comparable to that in nature (in this case, the sphere), is of prime importance, and for this reason several other projections, as the equidistant and the angle projections, which distort less, are preferable to the stereographic. An angle meridian pro- jection plot, 20° in diameter, was published by the writer in 1911* and is superior as regards distortion to the other projec- tions which have been suggested. The equidistant and angle meridian projection plots are very similar in form. The details of construction of these projection plots are given in the publi- cation referred to and need not be repeated here. Summary. The equations which the petrographer has to solve in connection with his microscopic work are all of the general form, A = B.C, in which A, 4, and Care variables and usually trigonometric — functions. All equations of this form can be solved graphically by straight line plots, provided the functions be plotted directly. The plots are based on the properties of similar triangles and the fact that the above equation can be written in the form Ay a: Ha Baan By thus avoiding curves to represent the different values of the equation, the observer not only increases the accuracy of the results obtained but he can also prepare the plots with greater facility and in less time. Although this principle is important, regard should also be had for the distor- tion introduced, the aim in all graphical solutions being to have the relative accuracy over the entire plot as uniform as possible. In case the distortion is great for one form of equation, the form may often be changed by introducing some function of both sides of the equation, so that the plot becomes more nearly uniform. On these principles Plates II to 1X have been drawn. With them practically all the equations which the petrographer may encounter in his work can be solved graphically. In the fore- going pages these plates and methods of solution are discussed in detail and illustrated by examples. In a brief section on projection for use in optical work the principle of minimum distortion is emphasized. The angle and equidistant projection are found to meet these require- ments best and are, therefore, recommended for general use in petrographic microscopic work. * Carnegie Institution of Washington, Pub. 158, 63-67, and Plate XI, 1911. EXPLANATION: OF PLATES JI TO IX. Puate II. Graphical solution of the refractive index equation sini=n. sin r. The ordinates represent the angles 7, the abscissz, the refractive indices, n, and the diagonal lines the angles. Figure a is a graphical solu- tion of the equation sin 35°=1°760 . sin 19°. Puate III. Graphical solution of the refractive index equation sing i=n? sin? r. The ordinates represent the angles i, the abscisse, the refractive indices, n, and the diagonal lines the angles, r. Figure a is a graphical solu- tion of the equation sin 56°=1°710. sin 29°. Puate IV. Graphical solution of the refractive index equation sin i=n. sin r. The abscisse represent the angles, i, the ordinates, the angles r, and the diagonal lines, the refractive indices n. Figure a@ is a graphical solution of the equation sin 538°=1°700. sin 28°. PLATE V. Graphical solution of the birefringence equation 1 1 Pee y? = ke cin Sine, 1 1 a2 ine y? By, mt a’ or the approximate equation psi = K=sin?.sin 3’. The abscisse represent the angles @, the ordinates the vaiues of K, and the diagonal lines the angles 3’. Figure a is the graphical solution of the equation 0°500 = sin 438°. sin 47°. PuatEe VI. Graphical solution of the optic axial angle equation 1 1 pe ~ tan’ Va = 7 eee also of the approximate formula tan? Va = : mie —@ ao: QB? ; : 1 1 : 1 i In this plate the abscisse represent oles ee , the ordinates Breas is and the diagonal lines the angles Va. Figure a is a graphical solution of th fomtan? 40° == -~— as e equation tan 0051 PuaTE VII. Graphical solution of the optie axial angle equation z ey.) tan Va = / BP rom ; also of the approximate equation 1 1 eet) ay BE oe : t 1 tan Va= cae - In this plate the values of Gui ae are plot- 1 1 s : ted along the abscissze, those of ape i at along the ordinates, while the diagonal lines represent the angles Va. Figure a is a graphical solution ° 0-025 of the equation tan 38° = Cotes Puats VIII. Graphical solution of the transformation equation cot A == sin B.cot O. On the plate the angles B have been plotted as abscisse, the angles C as ordinates, and the angles A as diagonal lines. In case the angle C@ > 45°, the construction indicated in figure 6 should be followed, Figure a is a graphical solution of the equation cot 40°=sin 32°. cot 24°. Figure 6 is a graphical solution of the equation cot 65° = sin 46° . cot 57”. ; Prats IX. Graphical solution of the equation sin A = sin B. sin C, the angles A being the ordinates, the angles B the abscisse, and the angles C the diagonal lines. Figure a is a graphical solution of the equation sin 24° = sin 32°. sin 50°. 540 Wright—Graphical Plot for Use in Microscopical Art. XLVII—A Graphical Plot for Use in the Microscop- ical Determination of the Plagioclase elt by Frep. Eucenrt Wricut. With Plate X. In 1901 the writer plotted on a small sheet (12°7 x 30) of millimeter cross section paper the most important optical properties of the plagioclase feldspars together with their chemical composition. Blue prints of this sheet were used by his students at the Michigan College of Mines and later by some of the members of the Federal Geological Survey. The suggestion has been made at different times that the plot be published, but this has been postponed from time to time, chiefly inthe hope of adding to the data of measurement on the plagioclases. It has now been decided to delay no longer but to revise the table so far as possible with the best existing data, and to publish it even though it is not equally correct in all particulars. The effort has been made to give only the more important data, which the working microscopist actually needs. On Plate X there are represented graphically : Curves 1. The chemical composition of the plagioclases. Curve 2. A curve showing the relation between chemical composition and molecular proportions. The use of this curve ° may be illustrated by an example: Find the molecular per- centage of anorthite which the feldspar Ab,An, contains. This is indicated on curve 2 at the point 33-3 where the horizontal line through the ordinate 2 cuts the curve. Curve Ya is similar to curve 2 except that the unit of its vertical scale is ten times greater. Both curves are parabolas. Similar parabolic curves result when, instead of the molecular percent- ages of the two end members, the weight percentages are plotted. The derivation of the equation for the molecular proportion curves is simple. Thus to find the percentage corresponding to the molecular proportions Ab,An,, we note that in the sub- stance there are w molecules of Ab to every molecule of An. The ratio of one An molecule to the complete molecule Be A At 1 15, ae is evidently Tee, The percentage composition is, therefore, 100 1) he ee Similarly, if we wish to express the weight percentage of An in the plagioclase Ab,An,, we note that if the molecular weight of An be m,, that of Ab, m,, then the total weight of the “composition Ab,An, is @m, + 1.m, and the percentage composition is ae Determination of the Plagroclase Keldspars. 541 md, Me 1! VW =e == eine, T0e3 m, ee which is again a parabola. For convenience in plotting it is an advantage to have # always greater than unity. In ease it is less than unity the relation Ab,An, may be written Ab, An, wherein 2>1 and a second parabola drawn for which Ab is always unity. Thus Ab,An, may be written Ab,,,An, and the eurve An, used, while Ab,An, may be written Ab,An,,,, to which the curve Ab, is applicable. In the first plot of 1901, the plagioclases were plotted according to weight percentages (the variations in the chemical constituents being then represented by straight lines) and the molecular proportion curves were plotted for this case. In the - present plot the plagioclases are plotted in molecular percent- ages and the molecular proportion curves have been modified accordingly. Curves 3. Refractive indices a, 8, y, compared with and e of quartz. 3 Curve 4. Optic axial angles. Curve 5. Extinction angles on 001 (cleavage flake method). Curve 6. Extinction angles on 010 (cleavage flake method). Curve 7. Maximum extinction angles in symmetrical zone (sectfons normal to 010, the plane of albite twinning lamellee). Statistical method of Michel- Lévy. Curve &. Extinction angles on sections normal to a. Fouqué method. Curves 9. Extinction angles on section normal to y; referred in curve 9a to plagioclase lamelle (010) and in curve 9b to cleavage lines after 001. Fouqué method. Curve 10. Extinction angles. on section normal to £§, the optic normal, referred to cleavage after (010) and plagioclase lamellee. Curves 11. Curves for combined Carlsbad and albite twin- ning lamelle showing symmetrical extinction angles. Michel- Lévy’s original chart of these values was based on a formula deduced by Mallard, the values of observation used in the formula having -been supplied largely by Michel-Lévy. It has long been known that this chart is seriously in error in certain particulars, errors of 20 per cent in the molecular composition of the plagioclase being possible with certain sets of angles. In view of this fact, the writer has taken the meas- urements of Becke, Tertsch and one or two by himself on plagioclases of known composition, and calculated the extinc- tion angles for sections in the symmetrical zone, such sections being 10° apart. For each feldspar a set of 18 extinction angles was thus obtained for the poles —90° to +90°. These Am. Jour. Sct.—FourtTH SERIES, Vou. XXXVI, No. 215.—NovemBeEr, 1913. 36 542, Wright—Determination of the Plagioclase Feldspars. were plotted to scale and a smooth curve passed through the computed points. After having computed the set of extine- tion angles for each of the accepted plagioclase feldspars whose optical properties are known with a fair degree of accuracy, the different sets were plotted, each to scale on the ordinate passing through the proper plagioclase composition on the abscissa axis. ‘The variation in the extinction angles of each of the poles was then obtained by passing a curve through the extinction angles for any given pole. On this plot, when completed, there were curves representing the variation in extinction angle with composition for all poles at 10° intervals from +90° to —90°. Now if for any given plagioclase sec- tion whose normal is in the plane 010 and includes an angle 2, with the pole of the projection (e. g., +20°), the extinction angle is 6,, then the extinction angle 6, of the albite lamelle in Carlsbad twinning relations to the first set is that of the sec- tion whose normal is in the plane 010 and includes an angle --r, (e. g.. —20°) with the pole of the projection. But on the plot prepared as above such extinction angles can be read off directly, and for every extinction angle in the one set the proper extinction angle of the second set at the proper composition can be ascertained. The curves of Plate X were determined in this manner. They are smooth empirical curves passing through known points determined by definite construction from the data of observation. Althongh similar to the Michel-Lévy curves in form, they are not theoretical curves, but are strictly empirical. Their accuracy depends, therefore, directly on the data of observation. With the accumulation of more precise optical data on the plagioclases, and especially with increase in knowledge of the effect of solid solution with orthoclase, carnegieite or nephelite, and possibly kaliophillite and other substances, these empirical curves will be changed somewhat. At present, however, they are as accurate as it is possible to draw them from the available data. A comparison of these curves with the Michel-Leévy set shows on the whole fairly good agreement, although in certain spots the two plots disagree by over 20 per cent. This is especially the case between the plagioclases of the andesine and labradorite groups. In view of the detailed descriptions of the methods for determining the plagioclase feldspars in all textbooks on micro- scopic petrography, further explanation of Plate X seems unnecessary. Van Name and Hili— Alcohol and Cane Sugar. 548 Art. XLVIII.—On the Influence of Alcohol and of Cane Sugar upon the Rate of Solution of Cadmium in Dissolved lodine; by kh. G. Van Name and D. U. Hirt. [Contributions from the Kent Chemical Laboratory of Yale Univ.—ccli. | Ir has been shown by Arrhenius* that the effect of the pres- ence of certain non-electrolytes upon the rate of diffusion of electrolytes may be represented by the empirical equation D=D, —- “ mv)’, in which D, is the diffusion coefficient of the electrolyte in solution in pure water, D the coefficient after the addition of the non-electrolyte, m the molecular concentration of the latter, and @ a constant characteristic of the non-electrolyte. When the value of ais known, we may employ this relation, as Jabl- ezynskyt has pointed out, to test the dependence of a given heterogeneous reaction upon the rate of diffusion of a dissolved electrolyte, and thus obtain a test of the validity of the “ dif- fusion theory ” in the given case. Since the diffusion theory ealls for proportionality between the reaction velocity and the rate of diffusion of the active substance, the effect of a non- electrolyte upon the reaction velocity should be calculable by substituting in the above equation the reaction velocities K and K, in place of the corresponding diffusion coefficients. In a study of the catalysis of chromous chloride at the sur- face of a sheet of platinum, Jablezynsky showed that the observed effect of ethyl alcohol upon the reaction velocity agreed with that calculated as above, using the value of a determined by Arrhenius. Later, the same author, working with Jablonski,§ obtained a similar result for the effect of alcohol upon the rates of solution of magnesium and of marble in aqueous hydrochloric acid. The reaction velocity was deterinined in all of these cases by measuring the volume of gas evolved. In previous papers from this laboratory| it has been shown that the metals Hg, Cu, Ag, Zn, Cd, Fe, Ni, and Co, all dis- solve at the same rate in a solution of iodine in potassium iodide, thus indicating that the diffusion of the iodine, presum- ably in the form of potassium triiodide, is the determining * Zeitschr. phys. Chem., x, 51, 1892. + Ibid., lxiv, 748, 1908. { This is strictly true only when the thickness of the diffusion layer remains unchanged. § Zeitschr. phys. Chem., lxxv, 508, 1910. || Van Name and Edgar, this Journal, (4), xxix, 287; Van Name and Bos- worth, this Journal, (4), xxxii, 207. 544 «= Van Name and Hill—Aleohol and Cane Sugar. factor. The present article gives the results of a study of the effects of ethyl alcohol and of cane sugar at different concen- trations upon the velocity of the reaction between iodine and eadmium. Not only is this reaction especially suitable for the purpose on account of the accuracy of the iodine titration, but it possesses the great advantage over those used by the investi- gators just mentioned that no gas is evolved. The last point is of special importance. Since an evolution ~ of gas must rupture the diffusion layer and stir it to some extent with the escape of each gas-bubble, the velocity of such a reaction is by no means as strictly dependent upon the rate of diffusion as when no gas is given off. The number and dis- tribution of the points of bubble formation, for example, are important factors over which the experimenter has little or no control. Reactions in which gases are evolved are, therefore, poorly adapted for quantitative tests of the diffusion theory, a fact which has not thus far received the attention which it deserves. The apparatus and procedure were practically identical with those employed by Van Name and Bosworth. In brief, it con- sisted in subjecting to the action of the violently stirred iodine solution circular disks of cadmium, 38°3"" in diameter and 0:5" thick, which were held in an accurately fixed position relative to the stirrer and to the wall of the containing beaker. The velocity constants were calculated from the equation K = 23 5 ze j log “! in which w is the volume of the solu- tion, and ¢, and ¢, the concentrations of iodine (determined by titration) at the beginning and end of the time interval ¢, — 7, (usually ten minutes in length). All solutions were 0°5 molar with respect to potassium iodide, and either 0-01 or 0-001 molar with respect to sulphuric acid, the lower acidity being used when cane sugar was present. The temperature was 25° + 0'1°, and the rate of stirring 200 revolutions per minute. Except where otherwise stated, all details of the manipulation were the same as given in the article just cited. The method there described for determining and applying corrections for the slight variations in the rate of stirring has been systemati- cally employed in the present work, although it was again found that in most cases the corrections had a negligible effect upon the final result. Since the very full data given for some of the experiments in the former paper will serve to illustrate all essential points in the calculations, we shall in general give in this paper only the final corrected series of velocity con- stants obtained in each experiment. In the experiments in which ethyl alcohol was present, evap- oration from the solution was often much increased, making Van Name and Hill—Aleohol and Cane Sugar. 545 it necessary to take this effect into account. As is evident from the equation, loss of solvent (alcohol and water) tends to affect the calculated velocity constants in two ways; by decreas- ing the volume v, and by increasing the concentration of lodine ¢. When the last effect is small, however, it may be neutralized or reversed by the evaporation of the iodine itself. Since the corrections to be applied are only small, no appreci- able error is introduced by assuming that the free surface of the liquid has a constant area,* and that the volume, therefore, dv decreases at a constant rate, or — —- = Const. The rate of dt change in volume was determined either by re-measuring the volume at the end of the experiment or by special blank experiments under like conditions. Knowing the loss per minute, the average volume during each reaction period was calculated by deducting the loss which had occurred up to the middle of that period. The true volumes, so found, have been used in the calculations of all experiments in which the alcohol was 0°5 molar or stronger. Below this concentration the changes in volume due to ‘evaporation were negligibly small. The effect of evaporation upon the iodine concentration is the resultant of two parts: (1), evaporation of sinks which can easily be shown to yield the expression + = = ke, a ¥re- action of the second order; and (LJ), oy thes of iodine, ae ee which obeys the first order reaction equation — Tt The changes in concentration resulting from (I) may be cal- culated from the rate of evaporation. Although this reaction is of a higher order than the main reaction, we have found that in our experiments, owing to the short reaction periods and small changes involved, the resulting change in the value of each velocity constant is, under given conditions, a practically con- stant amount, which can easily be calculated and subtracted, as a uniform correction, from each velocity constant of a given experiment. To obtain corrections for (IT) the evaporation of iodine, blank experiments were made using no cadmium disk, and the constant calculated in the ordinary way. Three such experiments, A, with a solution containing 0°25 molar alcohol ; B, with cane sugar, 0°25 molar; and C, without either aleohol or sugar, gave the following results : A. K=0°051, 0032, 0°044, 0:067, 0°070, average 0°053 B. K=0-030, 0:024, 07051, 0°037, 0°055, “0-039 oe Kh —0-0s9-) 0-024" 05055. 0°044, 0-077, <2 05052 *In reality it increases slightly as the volume decreases, owing to the con- cavity produced by the rotary stirring. 546 Van Name and Hill— Alcohol and Cane Sugar. On the. basis of these figures we have taken the value —0°05 as the correction for evaporation of iodine. By combining this with the corrections for loss of solvent, determined as above described, we have calculated the following corrections for the net result of evaporation under average “atmospheric condi- tions : Noalcohol Alcohol, + molar + molar 1-molar 2-molar 3-molar —0°05 —0°04 —0°02 0°00 + 0°04 + 0°07 These corrections have been applied in calculating the values of ,, the corrected velocity constant, as given in Tables I, II and III. The cane sugar used was the kind sold in large crystals by confectioners under the name ‘ Rock Candy.” To eliminate any possibility of appreciable inversion of the sugar the con- centration of sulphuric acid was reduced in the sugar experi- ments to 0:001 molar. As shown in a previous paper* this change in the acidity should make no appreciable difference in the value of the velocity constant. The samples of both sugar and alcohol employed were care- fully tested as to their effect upon the permanency of the standard of an iodine solution. Neither showed any measurable effect under conditions of concentration comparable with those in the subsequent experiments, even after standing over night. Experimental Results, and Discussion. The observed velocity constants are recorded in Tables I, IT and IIf. It will be noticed that in nearly every case the constants show a tendency to diminish in value during the TABLE I. No Alcohol or Cane Sugar. K,=velocity constant as observed, uncorrected. K,=constant after cor- rection for variation in the rate of stirring and for evaporation. K—=most probable value by extrapolation. K 1, v= 580 . 560 540 520 500” 4804 4 G0ee Nie yall 10 10 10 10 10 Lorne C= 42°65; 37°60; 32°99; 28°84; 25°09; 21°76; 18°77; 16°08 + 7°30 Li 130° 7°32. 7°25. \7D4 0 A ie eset | KH F'31 728 7°20. TT VO ees J 2° = 7:29) 728° 125 7724. es Pee C29 3. A= 7°24 7°84 719. 7-14 TC ee rmemeeed 7°30 4, Ko 707 7°10. 7°05, 6:98). F-Ob NObama wil 5. Mo 111, 7719.9 7:09 7:04 6:89 5a nO mmonae 714 6. A= 703° 716 7°04 7-06 6-95. Omens (he Oe 7. Wo 728. Fle 714 7-16 7-09' 6a ee 22 : Average....) 7am *This Journal, xxxii, 211. 4 Van Name and Hill—Alcohol and Cane Sugar. 547 TABLE IT. Significance of K,, K, and K as in Table I. Alcohol + molar. 1v= 580 £2560 5AO. 520... 5000 480m 460 Me) G90 6 719 6°86 6:83 6°75. 6°70. 6775 Me—oreo G17 6°84 "6°80 ) 6:72” (66G 6-72 we) 6.05) 692) 677. 6:81 6:80. G64 we— 6 91 G89 6°66. 6°65. 6:71 6:60" 6-55 =— megs 6-98 6:90. 6:74-6:72 676 “6x77 —weico oO Si 6 8l 6:74 — 6°69 6-74 6:69 ROLY S694 9957-042 26°95) 6°90 GIG = "692 690 7:02. 6°89 6:96 6:94 6°89 We 689 678. 6°82 6:67 668 <£6°70 (6°67 W@— 6°83 6°39 6°82 678 "6°76 6:82: 6°76 So G2 So aE So Se Se IS OWMOseSeDWeoesS@w Ol So Hm Hm OUD pet Go OU (1 TH I OO DO || =-J SS -~T Alcohol 4 molar, 10. v= 579°8 559°3 538°7 518°3 497°8 477:°3. 456°8 We— 6 es 6°75 6°69 6°64 6:57 6°57. 6°55 Moen G86. 6°77 ' 663° 6:59. 6:53 6:55 6:53 . 6°79 Meee 671° 659 655 647 6:52 6:36 6:36 6°70 ieee ee 655 655 645 642 647 644 ‘Grb” 13. AK = 668 6°63 659 640 6°38 6°51. 6:27 46°64 Alcohol i-molar. Peo 796. 559 5382) 5175 496°8 476 (455:3 WG—eols 5:98 5:73 5°89 6:11 5°90 5°79 MGe—G 1, 5°09 5°72 5°84 6°05 5°89 ~ 581° GOA Peete |} 616" 608! 604 6:05 6 07) 5 9b G16 tee 619 6:10 610° 5:99 6:00 5°90 598 G18 imei) G07 «§ 6712, 5°99 - 5:92 5°92 6:00 5°72 ‘6°09 Alcohol 2-molar. Meee — 579'5 558° 537-4 5163 495°2 4741 458 Me Ne 505 Or 509 5:02) bal 4°87 oR soso oy ee 1s DOT Sb 490s Okt : mene =) 526% 95:04 57197 5:19 5:28 15°25 «4°90 HS meee 29 5191 510 7 26° 5°04 5°07 5°08.” 5°26 eee 2041 S20) Lee 507) 5°04). 5712-' S01 HO OMe oa nena 35, FSi 2OM tor Q6" 5el5 (5:28) 5509. O° Vk Alcohol 3-molar. Peano 19) SoS) 58676) \eollo:2 493°8. 472°4 « 451 ee AON ADA, ALBA ALOT A095. 4°28. 4°27 Ve VA AG Ay Ara Gad 4-32. 4:35, 4°32. 498d OA he A386) ABO) 4g PA-38, 4°27. 4:25 » 4:30, 4°d0 Oo, Wo 45] 436 AAG 444 4-42 4:40 , 4°40 . 4°49 Jo ene eA 2G 4 Oe 430) 6 4200604260 429 Be (~} —— 548 Van Name and Mill—Alcohol and Cane Sugar. TABLE III. K.=velocity constant, corrected for variation in rate of stirring and for evaporation. K=most probable value by extrapolation. 1 Cane Sugar 35 molar. K 1 v= 580 560 540 520 . 500 480 460° (= 694. 6°82 9 693. 672 6:80 6°78) 7G Teepe 2,K= 681 676 6:92 672 674 680 666 6°82 Cane Sugar +; molar. 3. A,= 665 6°78 663 663 648 6766, 653 eum 4, = *658. ..:. 670 657 °6 40. 6°64" (ie pseu Cane Sugar 4 molar. 5. K= 632 625 “642 6:26 6°31) 626 ie oan 6. K,= 6:23 6:34 628 6-28 6-20) 6:01) eee 7. K,= G18 634 6:13 6°32) (6°17 6:12.) (oe Cane Sugar #; molar. 8. KH= 601 5°94 5°88 5°99 5°87 583 5:81 £999 Cane Sugar + molar. aoe =i ore 5°53 aaa D744 5752 5°56 5°44 Be 10. K.= 5°49 5:61 5°53 - 5°54 5°50 548. S-46numee NU SG aes eic4 5°70 5°63 5°d0 5D 5°48 5°bd 5° Cane Sugar 4 molar. WAiK =) 4°97 SAO) ADA 405 2 SACO Rie A cis eee ees 4°26 : == 4°26) 4°28." 4116 $7,421 4°20 4:12 4°16 4°26 Cane Sugar 1-molar. Gare ON SI 9 DE) Gsyh 32D 15, C= 30-04% 19-39" 0-90 a eT 3 2:96 9:9" 7 230 2°30 bo bo bo bo course of the experiment. It is almost certain that this is due to a gradual liberation of iodine in the acidified iodide solu- tion, induced by the stirring in contact with air. Strangely enough, this effect, so persistent here, had been negligible or wholly absent in several previous series of experiments under apparently similar conditions, and for this reason the explana- tion given above was not accepted until after much time had been spent in an unsuccessful effort to find some other adequate one: As it is, no reason is apparent for the more rapid oxida- tion in the present series of experiments, unless it be justifiable to ascribe it to some slight difference in the purity of the reagents used. Although the rate of decrease of the constants is of the same order of magnitude in most cases, the presence of this effect Van Name and Hill—Alcohol and Cane Sugar. 549 tends to weaken confidence in the mean value of the velocity constant as a proper standard for comparing different experi- ments. We have therefore preferred to use values determined by graphic extrapolation. The corrected velocity constants of each experiment were plotted against the time and replaced by a smooth curve in the form of a line of very slight curvature, convex upward,* which was then extrapolated “back to time zero. The value of the constant for time zero, so fixed, has been taken as representative of the experiment. Although this method fails in some cases to give sharp results, we believe that in general the extrapolated values represent the single ex- periments more accurately than the averages of their constants. PASEE LV. Summary of Velocity Constants. K observed - K ealculated Average Mean of by Non-electrolyie value extrapolated equation of values Arrhenius _ [Lb ee eee TAL 7°21 (7°21) Alcohol, 1/4 molar ___.___- 6°82 6°92 6°99 - Ly OR a ee eae aS 6°53 6°67 Gouin a 1 > actu ete ye 5°99 6°12 - 6°34 = 2 a a a 5°16 5°24 D°d3 ce 5) pone ta SA ee 4°35 4°41 4°78 so Bea b ASF Ti eee 6°80 6°87 FOF “ | 7 AS ceil ee he 6°61 6°69 6°94 = ¥ PC jemi * 6°25 6°30 6°67 e RS Pie, he cay a 5°52 5°56 6°15 ee aS bee er Sean 4°19 4°26 aes 6 6e GCs a sit tw 2°28 i 9°99 : 3°47 A summary of the measured velocity constants is given in Table IV, including both the average and the extrapolated values. For reasons given, we shall base all further calcula- tions upon the latter, but the parallelism between the two sets of values shows: that this choice is not a matter of much impor- tance, as the general nature of the results would be the same in either ease. In the last column of Table IV are constants caleulated from the equation of Arrhenius, using the values @ = 0°124 for aleo- hol, and a = 0°613 for stgar, These two values were obtained by averaging (after reducing to 25°) various values of @ caleu- lated by Arrheniust both from his own diffusion measure- * A simple calculation shows that the constants would lie on a curve of this form if aslight oxidation were the only source of error. + Zeitsehr. phys. Chem., x, 51, 1892. 550 Van Name and [1ill— Alcohol and Cane Sugar. ments and from those of Lenz.* For the same non-electrolyte the constant @ varies but slightly with the nature of the dif- fusing substance so long as the latter is an electrolyte of simpie structure. The value 0°124 for alcohol is the average of fairly concordant determinations with sodium chloride, sodium hydrox- ide, sodium iodide, potassium iodide, and cadmium iodide, and is therefore probably near the correct value for iodine diffusing AVE l + THT bs as KI,. The value 0°613 for sugar is derived from measure- ments with sodium chloride and ammonium hydroxide as the diffusing substances. In the absence of any published data concerning measurements of this kind with iodine itself, these values of a may be regarded as the most probable. , A graphical comparison of the caleulated with the measured constants is given by figs. 1 and 2. It is evident that the measured values give very regular curves but are lower through- out, both for alcohol and cane sugar, than the calculated values. If, on the other hand, the constant @ is calculated from the * Mémoires de l’Acad. de St. Petersbourg (7), xxx, 57, 1882. Van Name and Hill—Alcohol and Cane Sugar. 551 observed rates of solution of cadmium we obtain. the figures in the middle column of Table V. The calculated values of a diminish with increasing concentration of the non-electrolyte, though much more rapidly with sugar than with alcohol. Nev- ertheless, by selecting from the series for alcohol the value of a best adapted to the purpose, and with it recalculating K from Fic. 2 the equation of Arrhenius, a good agreement with the meas- ured velocity constants is obtained (see Table V, last column). Althongh the value a = 0:144 is higher than would be expected from the diffusion measurements of Arrhenius, it cannot be regarded as an impossible value for the hitherto ‘undetermined effect of alcohol upon the diffusion of potassium triiodide, so that the validity of Arrhenius’ equation in this particular case, if not clearly established, is certainly not disproved. With cane sugar, however, this procedure gives no satistac- tory agreement between the observed and calculated results whatever value of a be employed. The value 0-925, from which the results in Table V were calculated, is perhaps as ee 552 Van Name and Hill—Alcohol and Cane Sugar. TABLE V. K obs. a cale. K eale. a=0°144 No-alcohol or sugar222eeee 7:21 ahage nae Alcohol, 1/4 molar... «/2 aes 6°92 0163 6:95 ee i / 2). sion ee 6°67 07152 6°71 Eb 1 4 jee geese: 6°12 0°157 6°19 ee 2 6 > 2 Spe eae 5°24 0°147 5°28 + 3 Oe eb ght See 4°4] 0'144 (4°41) K eale. a = 0°925 Cane sugar 1/32 molar ._-- .--- 6°87 1°53 7°00 (CG Ge Cie a aces 1:18 6°80 Reem cao 6°30 1:04 6°40 Me NR Se. 50Ke 0-975 5°64 Mp eS 4:26 0 925 (4:26) = - i eee eae 2°29 0°872 2°08 good as any. This, of course, only confirms wide was clearly Indicated by the nature and magnitude of the variation in the calculated values of a. In short, the effect of cane sugar upon the rate of solution of cadmium appears to be larger, and to increase less rapidly with the concentration, than is called for by Arrhenius’ equa- tion, while with aleohol the deviations from the equation are small but probably of the same nature. These deviations can easily be explained if we admit that a change in the viscosity, under otherwise constant conditions, may alter not only the rate of diffusion but also the thickness of the diffusion layer, the latter effect being, of course, one of which Arrhenius’ equation takes no account. As Table VI shows, both alcohol and sugar raised the viscosity of the potassium iodide solution used. In considering this hypothesis we wish to oppose the view sometimes taken that the diffusion layer consists of liquid which, relatively to the dissolving solid, is nearly or wholly at rest. On the contrary, it is probabie that its outer portions possess a very considerable motion relative to the solid, but only in a plane essentially parallel to the surface of the latter, and, therefore, normal to the direction of the concentration slope, so that the rate at which dissolved: material is transported across the diffusion layer is not materi- ally affected by the motion of the liquid layer itself. The thickness of this layer is not necessarily constant at a given point on the surface of the solid, but is more probably subject ie periodic variations dependent upon the passage of the blades { the stirrer. We are, therefore, to understand as the thick- Van Name and Hill— Alcohol and Cane Sugar. 558 ness of the diffusion layer the average distance from the sur- face of the solid at which the stirring effect of the eddies and cross-currents prevailing in the main body of liquid becomes negligible. The relation of this magnitude to the viscosity of the liquid is the question to be considered. TABLE VI. Viscosity and Density of Solutions at 25°. Viscosity Specific Gravity Coefficient Water at 20° = 1 INjo- alcohol or sugar. .2=- .L.- 0°00858 1°0606 mleconol i /4> molar 22.2 |. 0:00903 ~~ = 10624 _ 1/2 5 ig ee he ae 0°00942 1°0592 gee ye 001094 10552 RN eet 001210 1:04.78 I ES bia aioe 0-01410 10416 Cane sugar 1/32 molar .-.. -- 0 00889 1°0675 ES LY CY ee eager 0-00911 Og 0 EE OE i (te aint eee nent 0:00967 1:0799 a BU helpline, cuba peti 7: 001090 10963 ¥ ee fe Sriberers rs O°01521 11368 a * 1 cy eee 0°03272 1°2103 The strict mathematical treatment of problems in viscosity, in all but the simplest cases, offers serious difficulties, and would do so in the present instance. On purely logical grounds, however, it seems almost certain that an increase in viscosity, other factors remaining unchanged, would hinder the propagation of the eddies above referred to, and would thus produce an increase in the thickness of the diffusion layer. In reality, a change in the viscosity of a liquid usually involves an appreciable change in its density, and an increase in den- sity, with the resulting increase in the momentum of the mov- ing liquid, should tend to make the eddies more persistent, thus acting, so far as its effect was appreciable, in a direction opposite to that of an increase in viscosity. As a rule, how- ever, the change in density would be small compared with the change in viscosity, and probably of minor importance. Alcohol in our experiments raised the viscosity and lowered the density of the 0°5 molar potassium iodide solution employed. Cane sugar raised the viscosity by a large and the density by a relatively small amount, an increase of 280 per cent in the former corresponding to an increase of 14 per cent in the latter. Both are clearly cases where an increase rather than a decrease in the thickness of the diffusion layer would be expected. Such an effect would be in the right direction to explain the fact that the depression, of the reaction velocity is 554. Van Name and Hill—Alcohol and Cane Sugar. larger than would be predicted from the diffusion data, while the entrance of this new factor would account for the observed deviations from the form of Arrhenius’ equation. In general, if one grants the existence of a diffusion layer it is hard to avoid the conclusion that its thickness would vary somewhat with the viscosity. The influence of a variation of this kind seems to be perceptible in the experimental results of this investigation. Summary. 1. The effect of various concentrations of ethy] alcohol, and of cane sugar, upon the rate of solution of cadmium im an iodine-potassium iodide solution, has been measured at 25°. 2. With alcohol the observed velocity constants agree well with the constants calculated from Arrhenius’ equation for the effect of a non-electrolyte upon the diffusion of electrolytes, if an arbitrary though, so far as can be judged by analogy, not impossible value is chosen for the constant @ in that equation. 3. With cane sugar the observed results cannot be brought into good agreement with Arrhenius’ equation by any value of a. 4. In both cases, but especially in that of the sugar, the depres- — sion of the reaction velocity appears to be larger than would be expected from the available diffusion data. . 5. The probable effect of an increase in viscosity in inereas- ing the thickness of the diffusion layer is discussed, and is suggested as a possible explanation of the discrepancies. Williams— Twist in Steel and NV alge! Rods. 555 Arr. XLIX.— Comparative Siudies of Magnetic Phenomena. IV. Twist in Steel and Nickel Rods due to a Longi- tudinal Magnetic Field ,* by 8. R. WitiraMs. Ir is a well-known fact that if a ferromagnetic wire or rod is both circularly and longitudinally magnetized it will suffer a twist though no external mechanical force is used. This is known as the Wiedemannt+ magnetostrictive effect. Wiede- mann also found that if an iron rod was first twisted mechani- eally and then subjected to a longitudinal magnetic field it would also twist mechanically due to the imposed field. This last effect has received very little attention since Wiedemann first discovered it in iron and so far as the author knows no extension of the work has been done on nickel and cobalt. The method used in a former work{ for photographically registering changes in length and twist due to a magnetic field has been so successful in picking up small details of the vari- - ation that it seemed worth while to apply it to this effect, _- particularly as this special effect found by Wiedemann is superimposed upon the regular effect known as the “ Wiede- mann effect” and it should be sifted ont. As cobalt rods — could not be procured, this study deals with an investigation of a dozen steel rods and two nickel rods. Only one set of graphs for the steel rods is shown, as they are typical of the rest. The literature on this particular subject is very limited. Smith§ records that he observed in the case of one iron rod a twist due to a longitudinal magnetic field, but he merely alludes to it and devotes most of his article to the effect of magnetization upon steel rods possessing “ permanent torsional set,” produced at the time the rods were tested. Grosser] also found that under certain conditions twists in steel rods occurred due to a longitudinal field. His method consisted in setting the rod into torsional vibration and taking the means of a series of amplitudes. From these results he found that the zero points were shifted as the field strength was increased. It is evident from the accompanying graphs, figs. 1 and 2, that a nickel or steel rod which one procures from the open market may show a twist, when magnetized longitudinally. In a former paper, I have pointed out that under certain conditions one should expect, from the planetesimal theory of magnetism, a twist due to a longitudinal field. The present paper deals with these conditions in steel and nickel rods and is an attempt to find out how conditions favorable for such a twist are brought about. * Read by title before the Ohio Academy of Science, November, 1912. + Pogg. Ann., ciii, 571, 1858, 161, 1859. Wiedemann’s Elektricitat. Phys. Rev., xxxiv, 208, April, 1912. §Phil. Mag., xxxii, 385, 1891. | Inaug. Diss., Rostock, 1896. *| Phys. Rev., abstract, February, 1911. 556 Williams —Twist in Steel and Nickel Rods. Bice Co CoS) Fig. 1 Nickel Rod, No. 5. = &. ™ “~NY ‘ >. g ~ = i Ee (ea >. D ~~ ~,. ~ ~ O = D Dn o™ Ss ~ ~ 5 = >. > oN Dd ™ ey) S ~ NS se Lop ¢ Or ay Fie, 2. R Film T; 1 R L if ; - 8 if 5) 6 os 5 | f 4 . - 3 7 2 EG 1 = —— D Film T; ; Film T, Nickel Rod, No. 6. Steel Rod, No. 2. Am. Jour. Sct.—FourtTH SERIES, VoL. XXXVI, No. 215.—NOVEMBER, 1913. 37 »* Jamey 558 Williams— Twist in Steel and Nickel Rods. -MretHOD oF TAKING OBSERVATIONS. The rods used in this work were suspended by the upper end in a vertical solenoid* used in previous investigations. A coneave mirror was attached to the lower end, which threw the image of an incandescent filament upon a slit behind which a photographic film moved and on which were traced the deflections of a spot ot light: For graphs 1, 2, 3 and 4, film T,, fig. 1, graphs 1, 2, 3 and 4, film T, and graphs 5, 6, 7 and. 8, film T,, fig. 2, the rods were demagnetized before each graph was made; that is, everything being in adjustment a decreasing alternating cur- rent was sent through the solenoid and then graph 1 was run off. After the maximum field strength had been attained for graph 1 the field was suddenly broken and the rod again de- magnetized by the decreasing alternating current field. Graph 2 was then run off but with the magnetic field in the opposite direction to that of graph 1. This was repeated for graphs 38 and 4. In all cases, odd-numbered graphs are for fields directed upwards in the solenoid while even-numbered graphs have their fields downward. Graphs 1 and 3 are dupli- cates under the same conditions, which also hold for graphs 2 and 4,5 and 7, etc. In all of my previous work I have demagnetized in this way before each graph was taken so that the rods would have the same treatment before taking the next graph. The parallel straight lines in the photographs indicate defi- nite currents flowing in the solenoid. The values of the field strengths for these currents may be obtained from figs. 3 and 4. I have gone to some length in speaking of the magnetic treatment which these rods received before each graph was made, as an inspection of the curves in figs. 3 and 4 shows that the previous history makes a great difference in the results if one wishes to duplicate them. Graphs 1 and 3 or 2 and 4 in any of the figures show that by similar treatment remarkable duplications may be obtained after a cyclic state has been established. To show what the effect would be if the rods were not de- magnetized, film T,, T, and graphs 5, 6,7 and 8 of film T, have been added. The field was reversed for each graph just as in the case for the other films, but the demagnetization was omitted. Even for graph 1 a field was previously imposed on the rod opposite to that which it was to have for graph 1. In each case the field was broken suddenly, and, without demag- netization the circuit was reversed for the succeeding graph. Just as in the case of the graphs showing demagnetization so * Phys. Rev., xxxiv, 258, 1912. Williams—T wist in Steel and Nickel Rods. 559 here the odd-numbered graphs are for fields directed upwards, the even-numbered for fields directed downward. and 3 are duplicates, similarly 2 and 4, ete. Fie, 3. Graphs 1 Ht rH i ; aad Goons Goes doeee coos Goon oe = oH i 3 a ot i et : : Peet : : t tt i ct 3 aoe coe it = + ; = 7 t 4 t t i Ht = ra i EEE i T Tht i Trt tt "5 i im am rH : : mm a 7 = EEE Et H rH rH a Hoe + t ; aaa + -"]- im et ; Et i + i + : tt aaa = — Ht im Fey Fett + te + - ; ; rz t 310240 270 300 = — po = EEE [uzad Jesasanssvssaneteenssestats : He : gag suges faee0 coane ce. HH gag nae. ae nag! (BESS Seu! t at t —+—-- 1m! = pee = suas fonea sae) = aaa = = epeeatee: jan TT TTI t 2200— | aIEKeA mon ‘2 asa + pot Perris 2000-8 + DIAMETER St mm We! U T T iz 8 a 25 5228: = ' aoaeeeea a ganane ane aay ewes pecee eau bonus ca5S: guaa a) ima oan cE 160 == ea> codea sam 3s See eet poo + esos ood ees or cece Gused bose 1200 gg pega caam EEE EEE ia baa i ot t aa 1060 ade pes cesua on T= = oa feces poset iggaa pte = PA ES Rt . imu ¢) gud SBEne Seoul saad gugas 400 St ae : ag ceyee = 20055 See = Sag Q0050 Gaaua goa eggs oc geese soass sees: A | ==. = ERD SrRENGTH [== | 0 (+) $oO 150° 61800 230 300 The question may be raised as to why these My purpose has been series of experiments on the same rods and to annealed at the start. rods were not to carry out a study different 560 - Wiliams— Twist in Steel and Nickel Rods. heat treatments. Once the rods were annealed it would be impossible to come back to the condition they are now in and which from a magnetic standpoint is exceedingly interesting. I want a series of comparative studies on them in their present state. In the graphs I have indicated the direction of the motion of the films by a long arrow and the twist is marked by Rand L to indicate whether the lower end of the rod when viewed from above twisted clockwise or. counter clockwise. The photos are shown as though one stood behind a transparent screen and viewed the deflections in that way. The graphs - are numbered along the left hand margin of the photos and the letters T,, T,, T,, etc., refer to the way in which the films were catalogued in my collection of films. Discussion oF RESULTS. I have spoken of having demagnetized the rods by a decreas- ing A.C. sent through the solenoid. It was found that no matter which end of the rod was up the rod always showed permanent magnetization downwards after each demagnetiza- tion. Not only was this permanent magnetization independent of the end which was up but also it was independent of the direction of the previous magnetic field. In every case the remanent magnetism was directed downwards. Ifa steel rod is held parallel to the earth’s field and tapped with a hammer it will be found to possess a polarity corresponding to the direction of the earth’s field. In the shaking up of the ele- mentary magnets, they have settled into alignment under the influence of the earth’s field. It would seem that here a similar effect occurred when the elementary magnets were dis- turbed by the field due to the decreasing alternating current. The effect of this permanent magnetization was eliminated in the final results by taking the mean of the reversed readings. That the permanent magnetization has much to do with this effect is shown by a comparison of the curves marked U and D for both of the nickel rods, figs. 3 and 4. The rods not demag- netized, (U), show a much larger twist than those, (D), from which at least a part of the permanent magnetization has been removed. ‘This leads to another point, which, so far as I know, is new, viz., that in the magnetostrictive effects we have the analogue of the Von Waltenhofen* phenomenon. A close inspection of the rods indicated that in the process of drawing they had been given a permanent torsional set and in the case of the nickel rods this was a right-handed twist. * The data have been collected on this subject and will be presented at a later date. Williams— Twist in Steel and Nickel Rods. 56L A sample of the rod was placed in dilute nitric acid and after dissolving for a little while spiral ridges were plainly to be seen running around the samples. This showed that the rods were not homogeneous but in the process of forming had been given a definite helical-structure. We know that magnetism produces mechanical strains in ferromagnetic substances and also that mechanical stresses produce changes in magnetic prop- erties. Hence we may expect that in the case of the rods having a definite mechanical structure, as these nickel rods do, a large number of the elementary magnets would have a detinite orientation. This may help to increase the permanent magnetism observed in these rods. Again, if these elementary magnets are elongated as has been suggested and swing from one position of equilibrium to another, then in their swinging they would produce changes in length along the spiral formation of the rod and consequently a twisting due to a longitudinal field. ‘This is in agreement with the original observation of Wiedemann, who found that reversing the direction of the magnetic field did not reverse the direction of twist in rods having permanent torsional set, that is, a change in length along the helix, whether it is due to an up or a down field, produces the same sort of a twist. The conditions, therefore, for a twist due to a longitudinal magnetic field seem to be (1) the presence of a permanent tor- sional set, either produced at the time the rod was drawn or rolled or else produced by the experimenter as Weidemann and Smith did in their work; or (2) the elementary magnets may be oes into spiral formations by magnetic processes. In testing about fifteen steel rods for the effect here studied it was quite evident that in some the twist was largely due to a definite setting of the elementary magnets along helical lines in the rod. This is further corroborated by the fact that increased permanent magnetization increased the effect. The initial and final twists for the nickel rods are in a direction to increase still more the permanent torsional set. These results show that for some specimens of ferromagnetic substances two mechanical effects may occur when a longitudi- nal magnetic field is imposed upon them, viz., a change in length and a twist. These effects and also other magneto- strictive effects are larger in nickel than in iron or steel. The twist for steel was so small that it was not plotted. The maxi- mum twist shown in fig. 2, film T, and T,, amounted to about 100 seconds of are. Following each graph for both the nickel and steel rods, the spot of hight was allowed to record the posi- ' tion of deflection when the field was thrown off. This helps to make the twist m the steel rod more apparent. The twists observed in the nickel rods are, as has been said, apparently 562 Williiams— Twist in Steel and Nickel Rods. due to the orientation of elongated ellipsoids arranged along the lines of permanent torsional set. The first maximum, as will be shown in another paper, occurs at the same field strength as does the maximum elongation in the Joule effect. The fact that a mechanical effect due to magnetization, as here described, can occur in a rod because somewhere in its history it has suffered some change in its structure, points out very emphatically that one must be yery sure how the speci- mens were prepared, else there can be no way of comparing one observer’s results with another and hopeless confusion arises. This, of course, can be overcome by carrying out a comparative study of different magnetic phenomena on the ~ same specimens. This has been the object of these studies. Physical Laboratory, Oberlin College, Oberlin, Ohio. SCIENTIFIC INVER TG aes I. CHEMISTRY AND PHYSICS. 1. Hydrides of Boron.—lt has been: known for a long time that metallic borides, such as magnesium boride, give off hydro- gen containing a hydride or hydrides of boron when treated with acids, as the gas has a strong odor, but the nature of the product has not been known. ALFRED Stock has now investigated this subject and has obtained the compound B,H,, which boils at 16° C. and decomposes gradually upon standing, and rapidly upon heat- ing to 100° C. into hydrogen, another gaseous hydride, B,H,, and solid and liquid hydrides of boron. The latter have not yet been thoroughly investigated, but the compound B,H, has been ob- tained in a pure condition by condensation with liquid air, whereby the hydrogen mixed with it was removed. The condensed gas boils at 87° C., and the melting-point of the solid lies below —140° C. This gas, B,H,, is much more easily decomposed by water than B,H,,, a fact which accounts for the production of the latter by the action of aqueous acids upon magnesium boride. In view of the existence of liquid and solid hydrides of boron as well as the two gaseous ones that have been investigated, it appears that these compounds may almost approach the hydrocarbons in their complexity.— Berichte, xlvi, 1959. H. L. W. 2, Metallic Beryllium.—FicutTER and JABLCZYNSKI have pre- pared this metal by the electrolysis of mixtnres of fused sodium and beryllium fluorides. By repeated centrifugation of the im- Chemistry and Physics. 563 pure product in a mixture of ethylene bromide and alcohol, the comparatively light metal was separated from the oxide present as an impurity. The melting-point of the metal is abeut 1280° C. The fused metal is very hard, scratches glass and is only slightly marked with a file. It is steel-gray in color (not silver-white, as stated by Delray). The specific gravity is 1:842, and the atomic volume 4°94. It resists the action of water, but nitric acid readily dissolves it.— Berichte, xlvi, No. 7. | geben: 8. General Chemistry, Theoretical and Applied ; by J.C. Brake. 8vo, pp. 417. New York, 1913 (The Macmillan Com- pany. Price $1.90, net).—This text-book is intended primarily for the use of college students whose study of the subject lasts only one year. While the book contains much chemical infor- mation and possesses a number of good features, it does not appear to be an improvement upon most of the many existing books covering nearly the same ground. It is sparsely illustrated, although a few of the illustrations, being copied from standard works, are excellent. There are a good many unsatisfactory state- ments and too many mistakes in facts. It professes to introduce the subject in a novel way, through thermo-chemistry, and at the start a table of calorific values for the oxidation of a number of metals is given. This does not seem to be enlightening to the student, who may not be supposed to know, as yet, anything about either the metals or their oxides; and, further, while a good many thermo-chemical equations are given through the book, it does not appear that the “calorie” is defined or explained any- where. Moreover, in the last chapter the statement is made that the calorific value of a coal can be determined by burning it in a calorimeter, but how this is done, or what a calorimeter is, is not explained at all. On the whole, the publication of this book does not seem, to the reviewer, to have been worth while. H. L. W. 4. A Dictionary of Applied Chemistry ; by Sir Epwarp TuHorre, Assisted by Eminent Contributors. Revised and En- larged Edition. Vol. IV; large 8vo, pp. 727. London, 1913 _ (Longmans, Green and Co.).—The present volume of this impor- tant work of reference covers the portion of the alphabet including OILSTONE and sopDA-NITRE. Among the more extensive articles are those on oxygen, ozone, paints, paper, paraffine, petroleum, phenol and its homologues, phosphorus, photography (34 pages), pigments, polarimetry, potassium, pottery and porcelain, proteins, pyrometry, quinoline, quinones, radioactivity, resins, rubber, saponification, sewage, silver, soap, etc. ‘These very excellent and extensive monographs, together with a great many shorter arti- cles, make the volume very attractive and useful. H. L. W. 5. General and Industrial Organic Chemistry ; by Dr. ErtoRE Mournar!, Translated from the Second Enlarged and Revised Italian Edition by THomas H. Porr. Large 8vo, pp. 770. Phila- delphia, 1913 (P. Blakiston’s Son & Co. Price $6.00).—This is a very noteworthy work, as it is a treatise on general organic chemistry in which not only is the theoretical side considered but 564 Scientific Intelligence. also the practical applications of the science are extensively elabo- rated. It is the sequel of a similar volume on inorganic chemistry by the same author, which has already been noticed in this depart- ment of this Journal, and, like the preceding volume, it is recom- mended as a very useful and important book of reference and study for chemical students. It contains a vast amount of accu- rate information in regard to manufacturing operations and statis- tics of production. H. L. W. 6. Chemistry and its Relations. to Daily Life; by Lovts KauLENBERG and Epwin B. Harr. 12mo, pp. 393. New York, 1913 (The Macmillan Company).—This text-book is intended par- ticularly for the use of students of agriculture and home economics in secondary schools. It does not go very deeply into pure chem- istry, but it explains the more fundamental and useful chemical theories and the more important general facts in a very satisfactory manner, and it gives a good exposition of the chemistry of daily life. This seems to be a very suitable book for the perusal of persons, outside of school, who wish to gain an insight into chemistry. H. L.W. 7. Studies in Valency ; by F. H. Lorine. 12mo, pp. 47. Lon- don, 1913 (Simpkins, Marshall, Hamilton, Kent & Co., Ld. Price 2s. 6d., net).—This little book deals with speculations in regard to variable valency and the relation of valency to the periodic sys- tem. These speculations, as far as they are original, do not appear to be important contributions to chemical theory, but they may be of interest to those who make a special study of these relations. H. Le We 8. The Deviation of Rubidium Rays in Magnetic Fields.— The question as to whether slow a-rays or B-rays accompany the disintegration of rubidium has been settled by an investigation of Kart Brerewirz. The apparatus used consisted essentially of a rectangular zinc box which was screwed in place over the stem of a Wulf bifilar electrometer. This box was divided into two compartments by a partition made of the finest cigarette paper. The larger compartment was symmetrically placed with respect to the stem of the electrometer and it constituted the ionization chamber. ‘The smaller room was eccentric, it had 20 grams of rubidium chloride on its floor, and it was situated between the poles of an electro-magnet. ; In performing an experiment the normal loss of potential in nine hours was first observed with the rubidium salt in the adja- cent chamber. ‘Then the electro-magnet was excited and the decrease of potential in nine hours was again determined. Next the magnetic field was removed and the normal leak tested as in the first instance. Finally the magnetic field was excited in the reverse direction and the loss for nine hours was read. The. initial potential difference was always chosen as 250 volts. In order to obtain information concerning the softness of the rays the series of measurements was repeated with different magnetic field strengths, The numerical data and curves show that the Chemistry and Physics. 565 radiation from rubidium consists of B-rays. Further experimenta- tion enabled the author to estimate the speed of these rays as 1°85 X10" em/sec.—Physik. Zeitschr., No. 14, July 1913, p. 655. He [s.0U. 9. Researches in Magneto- Optics; by P. Zenman. Pp. xv, 219, with 74 figures and 8 plates. London, 1918 (Macmillan and Co. ). —Since this volume is a member of the series entitled “ Mac- millan’s Science Monographs” it is unique and authoritative, inasmuch as the author describes chiefly his own contributions to the subject with special reference to the magnetic resolution of spectrum lines. The material in the different chapters has been arranged in the main historically. The author’s style 1s remark- _ ably simple and lucid, the photographs reproduced in the plates are very clear, and the typographical work is a model of accuracy and neatness. ‘The index is immediately preceded by two com- plete bibliographical lists of which the first refers to Zeeman’s original papers only, while the second gives all the pertinent pub-’ lications starting with the year 1896 and including 1912. Con- sequently this monograph is a very valuable contribution to the subject of magneto-optics. ED (Siaui: 10. A New Element, Uranium X,.—The following important conclusions have been drawn by K. Fasans and O. GouRING from their latest investigations. (a) Uranium X is complex and consists of two elements symbolized by UX, and UX,. The half-value period of 24°6 days, formally ascribed to uranium X, belongs to uranium X,. (0) The half-value time for the new ele- ment, UX,, is 1°15 minutes and its constant of disintegration equals 0°0100 sec™*. (c) Uranium X, emits hard @-rays only and these are identical with the hard B-rays of uranium X. The soft B-rays of uranium X pertain to uranium X,. The coefficients of absorption in aluminium are given as 500 cm™ and 15 cm™ for the soft and hard f-rays respectively. In the case of uranium X, hard B-rays could not be detected. These facts constitute a new verification of the rule that very hard and very soft @-rays are emitted by short- and long-lived elements, in the order named. (qd) Uranium X, is electrochemically “nobler” than uranium X,. (e) The chemical properties of uranium X, are in full accord with the assumption that it belongs in the fifth group of the tenth series of the periodic table and has tantalum as its closest analogue. (jf) The beginning of the family tree of the uranium series should read : a B B a G UI —> UX, —~> UX, — UII —~> Io —~> Ra. 6 4 5 6 4 2 — Physik. Zeitschr., No. 18, Sept., 1913, p. 877. A. Si4Uh. 11. Mechanics and Heat; by J. Duncan. Pp. xiii, 381, with 314 figures. London, 1913 (Macmillan and Co.).—This volume contains the subject-matter of an elementary course in applied physics, and is especially designed for use in the upper forms of certain secondary schools and for candidates preparing to take 566 Scientific Intelligence. the civil service examinations for second division clerkships. About the same amount of space is devoted to the subjects of mechanics and heat. Ample opportunity is afforded the student to apply the principles explained in the text by solving the prob- — lems (333) collected at the ends of the chapters and by perform- ing the experiments (68) suggested. The various constituent parts of each half of the book form a very coherent whole, and the illustrations are apt and well-drawn. In particular, the sec- tions dealing with steam and internal-combustion engines seem to be especially attractive. ‘The text-proper is followed by tables of physical and mathematical constants, answers to the numerical exercises, and a subject index. 13 Ors Ul 12. Practical Physics for Secondary Schools ; by N. Henry Brack and Harvey N. Davis. Pp. ix, 487, with 465 figures and 17 plates. New York, 1913 (The Macmillan Co.).—One of the most important principles used consistently throughout this book is expressed by the following quotation: “ We believe that it is most important for teachers to select carefully just what material they can best use, and to teach that thoroughly, rather than try to touch upon many topics superficially.” The value of the text is enhanced by the summaries of principles which are given in full-faced type at. the end of each chapter. The volume contains an unusually large number (769) of numerical problems and ques- tions. ‘The latter are especially well selected and are calculated to make the student observant and thoughtful. Two examples may not be superfluous: ‘‘ Why is it that the United States and Great Britain are the only two civilized countries that do not use the metric system commercially ?” and “ Mark Twain in his ‘Tramp Abroad’ tells of stopping on his way up a mountain to ‘boil his thermometer.’ What did he do, and why ? ” On the other hand, the manner of presentation of certain topics 18 open to serious question. The authors say : ‘‘ Our treatment of acceleration, Newton’s laws, kinetic energy and momentum, is essentially different from either the dyne and poundal method common in physics textbooks, or the “slug” or ‘“ wog” method of engineers, and is apparently new.” Newton’s second law is stated : “ The acceleration of a given body is proportional to the force causing it.” This law is formulated as wv g- “Tt [the dyne] can be defined as 1/980 of agram weight.” Again: : Wo ., : “ The expression ia is called the momentum of a moving body.” Finally: “The resistance of a mil foot of wire is some- times called the specific resistance of the substance... . ” H. 8. U. 13, Beyond the Atom; by Joun Cox. Pp. 151; 11 figures and 1 plate. Cambridge, 1913 (University Press).—“ This essay Chemistry and Physics. 567 is an attempt to tell in short compass the romantic story of the discoveries which within the last decade have led us beyond the atom.” In other words, radio-active and allied phenomena are treated in the text from the historic, descriptive, and theoretical standpoints. In general, the author’s style is very pleasing and his presentation of the subject is logical and sufficiently accurate. In some places, however, the process of deriving information from old editions of standard works has led to inconsistencies and inaccuracies of statement which would probably be mislead- ing to the lay reader. Moreover, since the preface is dated “ February, 1913,” it is fair to express disappointment at the omission of the recent discoveries by Friedrich, Knipping, Laue, Bragg, and others, of the effect of crystalline structure on Ro6nt- gen rays. The book closes with a short bibliography followed by a subject-index. HS, Ui. 14, Physikalische Chemie der homogenen und heterogenen Gas- reaktionen, unter besonderer Beriicksichtigung der Strahlungs- und Quantenlehre sowie des Nerntschen Theorems ; von Dr. Kart JeLiinek. Pp. xiv, 844. Leipzig, 1913 (S. Hirzel).—The original plan of this ambitious work is undoubtedly very well stated in this title. The encyclopedic thoroughness with which it has been carried out would seem, however, to call for at least an inversion of the title. We have here in one volume a treatise in some detail on general thermodynamics ; one in quite minute detail on the thermodynamics of gas reactions, leading up to Nernst’s so-called “third law”; a very full sketch of the kinetic theory of matter, including both the older atomic and newer electronic hypotheses; and a comprehensive account of the theory of radiation and its culmination in the ‘‘ quantum” hypothesis. Further, much space is devoted to the experimental methods used in testing the predictions of the various theories. Thus it is seen that the work can fairly be called compendious, and as a ' reference book it will be found useful by others than physical chemists, for whom presumably it was written. The very complete indices and bibliography add much to its value in this respect. ‘The main purpose of such a detailed development of these diverse doctrines of physics is to afford a basis for discussion of their inter-relations ; in particular to show the significance which the “quantum ”’ hypothesis and the electron theory of matter have for Nernst’s “third law.” In the main it may be said that the discussion is as adequate as it is timely. Of course, in a work of this magnitude it is not difficult to pick flaws, but the reviewer has detected none of a serious nature. The general criticism may be made that in the mass of detail through which the author leads us, one is apt to lose sight of the main relations which it is the prime object of the work to elucidate. In particular, the phys- icist or the mathematician may object to the unnecessary discur- siveness of the mathematical portions—an objection, however, which may appear as an advantage to the less mathematically minded physical chemist. 568 . Scientifie Intelligence. In the development of the classical thermodynamics there are some apparent misstatements, notably the ascription of the Stir- ling cycle to Carnot. One omission of some importance in a work of such encyclopedic pretensions has been noted. In the discus- sion of the difficulty which arises in the electron theory of metals in the matter of specific heat, the fact that the number of free electrons demanded by the theory is vastly too great to be in accordance with the observed specific heats, is pointed out ; but the alternative hypothesis of Sir J. J. Thomson, which does away with this difficulty, is apparently overlooked. Nevertheless, as a whole (aside from the typographical errors which are too numerous) the book contains remarkably few slips, and can be recommended as a reference work of value in the very considerable fields which it aims to cover. Li Pa We Ii. Grouroey. 1. Virginia Geological Survey, T. L. Watson, Director. Bulletin No. VII, Geology of the Gold Belt in the James River Basin, Virginia; by StepHen Taser, Assistant Geologist. Pp. xli, 271, 10 pls., 22 figs., map in pocket, 1913.—The Virginia Sur- vey has planned a series of reports covering the gold-bearing rocks of the state, which will serve as detailed areal studies as well as contributions to economic geology. In the present bulletin the general geology and petrography of pre-Cambrian quartzites, schists and gneisses ; Ordovician conglomerate, quartzite, schist and slate ; T'riassic-sandstone and dikes, is discussed. The igneous rocks described include greenstone schists, quartz, feldspar porphy- ries, rhyolites, granites (with analysis), pegmatites, hornblende schists, diorite, diabase. The several periods of peneplanation are sketched in a chapter on Physiography, and a conclusion is reached that the Piedmont belt has remained above the sea since Ordovician time. Following a discussion of structure and meta- morphism, the gold mines of the area, both vein (assigned to the Cambrian) and placer are treated in detail. Most of the mines have been abandoned. Following the discovery of gold in the James River valley in 1829 and the maximum output of $104,000 iu 1838, the production averaged $56,000 yearly until the out- break of the Civil War. Since that date the production in Vir- ginia has averaged about $6,000 yearly. H. Bea. 2. Sixteenth Annual Report of the Geological Commission, Cape of Good Hope, Departinent of Mines, 1911 (1912). Fp. v, 136, 2 maps and text figures.—The Annual Report for 1911 includes three papers: Report of the Geological Survey of Parts of the Divisions of Van Rhyn’s Dorp and Namaqualand, by A. W. Rogers; Report on the Geological Survey of part of the Transkei, by A. L. duToit; Report on the Geological Survey of Part of the Stormbergen, by A. L. duToit. Geology. 569 A. W. Rogers, the Director of the Survey, has succeeded ‘in determining the order of succession in the Nieuwerust, Malmes- bury, and Ibiquas series, and correlating them with the Nama formation of German Southwest Africa. The existence of gneisses of both pre-Nama and post-Malmesbury ages has been established. Dr. Rogers does not accept the view of Hochstetter and others that the straightness of the west coast is due to faulting but believes rather that the intersection of the sea with a bent surface produced after peneplanation explains the linear quality. Detailed descriptions of the Nieuwerust Series, consisting of arkose, quartz- ite and shale ; the Malmesbury Series, chiefly slates, and of the Ibiquas Series, conglomerates in part, are given. ‘The area is intricately faulted and cut by quartz porphyry and monchiquite dikes. An interesting feature of the report is a discussion of six- teen nepheline-basalt pipes of a character new to science. Dr. duToit’s work in the Transkei has brought to light an important monoclinal flexure dipping into the Indian ocean and has made possible the restoration of an ancient coastal plateau about fifty miles wide. The present coast line is shown to be sinking. A fortunate discovery of fossils places the Umgazana beds in the Upper Cretaceous and allows correlations heretofore impossible. Dr. duToit also describes a group of remarkable volcanic necks filled with light yellow tuft of the Drakensberg type. Like some other reports of the Cape of Good Hope Geological Commission, the present volume is decreased in value by lack of suitable maps and illustrations. H. E. G. 8. Sixth Annual Report (New Series) of the New Zealand Geological Survey, Session If, 1912. Pp. 113; map bound with report.—The personnel of the New Zealand Survey is now as fol- lows: Percy Gates Morgan, M.A., Director; John Henderson, M.A., D.Sc., Mining Geologist ; James Allan Thomson, M.A., D.Sc., Paleontologist ; John Arthur Bartrum, M.Sc., Assistant Geologist ; George Edward Harris, Draughtsman ; Henry Saxon Whitehorn, Assistant Topographer. Field work for 1912 included surveys of the Bullor-Mokihinui and the Aroha subdivisions. The paleontologist with assistants is actively engaged in describing the fossils stored in the Museum ; 120,000 specimens from 847 localities obtained by geologists of the old Survey, in addition to other collections, remain to be described. Dr. Thomson is confining his attention to Cretaceous and Tertiary material, and has placed the fossils from other strata in the hands of outside specialists. H. E. G. 4. Geological Survey of Western Australia, 1912.—The fol- lowing publications have been received : (1) Bulletin No. 42, Contributions to the Study of the Geology and Ore Deposits of Kalgoorlie, East Coolgardie Goldfield. Part I, by E. 8. Simpson and C. G. Gipson. Pp. 198; 2 maps, 50 figs. Chapter Iby Mr. Gibson includes an outline of the general geology and a detailed petrographic discussion of greenstones, quartz and feldspar porphyries and peridotites. The composition 570 Scientific Intelligence. and structure of the ores at Kalgoorlie and Boulder have been studied by Mr. Simpson. The report is illustrated by 40 micro- photographs. . (2) Bulletin No. 43, Petrological Contributions to the Geology of Western Australia, by R. A. Farquuarson, Petrologist. Pp. 100, 16 figs. The first report issued by the recently appointed petrographer of the Western Australian Survey includes an ele- mentary treatise on rocks and rock-making minerals, and petro- graphic descriptions with analyses of selected rocks from eight different areas. (3) Geological Investigations in the country lying between Lati- tude 28° and 29° 45’ south, and Longitude 118° 15’ and 120° 40’ east, embracing parts of the North Coolgardie and East Murchi- son Goldfields, by H. W. B. Tarsor. Pp. 61, 11 figs., 1 geol. map. Beginning with the report of Mr. Talbot, the Survey plans to issue a series of bulletins dealing with the geology outside of those areas which, because of their commercial importance, have already been described. A reconnaissance geological map of large but little known territory 1s expected to be the result of — this work. ‘he nature of the country traversed by Mr. Talbot and Mr. Homan (topographer) may be judged from the fact that camels were used for riding and packing. (4) Bulletin No. 46, A General Description of the northern portion of the Yilgarn Goldfield and the southern portion of the North Coolgardie Goldfield, by H. P. Woopwarp. Pp. 23, 2 maps. This report is designed particularly as a guide to pro- . spectors and its chief value lies in the delineation of large sand- covered granite areas which possess no economic importance. (5) Bulletin No. 47, The Mining Geology of the Kanowna Main Reef Line, Kanowna, Northeast Coolgardie Goldfield, by T. Buarcurorp and J. T. Jurson. With Petrological notes by R. A. Farquuarson, and Chemical Notes by E. 8. Sreson. Pp. 106; 3 maps, 15 figs. The geology of the region including Kanowna has been discussed in several reports previously issued by the Western Australia Survey. The present bulletin covers the results of a special economic survey of the “ Kanowna Main Reef” and contains much structural and petrographic detail. (6) Bulletin No. 50, The Geology and Mineral Industry of Western Australia, by A. Giss Marrtanp and A. MontGomeEry. Pp. 68, 1 map, 7 figs. The summary of the geology of Western Australia will be found most helpful, especially to geologists who are unacquainted with the local features. Heretofore it has been well nigh impossible to gain from economic reports on widely separated areas a comprehensive view of the earth history of this part of the world. Following a short description of the Coastal Plain, the Hill Ranges, and the Interior Plateaus and Plains, the authors give a brief but clear account of the pre- -Cambrian granites, gneisses and schists, containing laminated cherts and jaspers, which cover 975, 920 square miles; of the Cambrian identified by Olenellus and Salterella 3 of the Nullagine series, Geology. 571 possibly also Cambrian ; of the highly contorted quartzites, sand- stones and shales assigned to the Silurian ; of the fossiliferous Devonian ; of the Permo-Carboniferous containing glaciated bowlders and an extensive flora and fauna; of the richly fossili- ferous Jurassic, and Cretaceous sediments ; and of the Tertiary sediments which, in the Champion Bay district, rest unconform- ably on Jurassic strata. ‘The occurrence and economic value of gold, copper, lead, tin, tantalum, iron, coal, salt, phosphates and water are discussed, and statistics of production, including the. year 1911, are given. H. E. G. 5. Reeurrent Tropidoleptus zones of the Upper Devonian in New York ; by Henry 8. Wittiams. U.S. Geol. Surv., Prof. Paper 79. Pp. 103, 6 plates, 1913.—An interesting paper show- ing in much detail how the Tropidoleptus faunule, a Hamilton holdover, reappears at least three times in the Upper Devonian of central New York. These reintroductions, the author states, ““may have resulted (1) from the alternate closing and reopening of an actual passageway which alternately prevented and permit- ted the access of the fauna and of waters favorable to them, or (2) from changes that affected the direction, character, or volume of existing ocean currents.” These three New York recurrent Tropidoleptus faunas are also found at very similar horizons in Maryland (Swartz, Bull. Geol. Soc. America, xx, pp. 679-686, 1910). Oo: 8! 6. Grundziige der geologischen Formations- und Gebirgs- Kunde ; by A. TORNQuist. Pp. 296, 127 text figures. Berlin, 1913.—This book, which is intended for students of natural his- tory and geography and for mining engineers, presents along broad and general lines the stratigraphy and tectonics of Europe. The presentation is from the historical viewpoint, and main stress is laid upon the geotectonics. The stratigraphy is studied rather from the paleogeographic relations and biologic environment than from the paleontologic side. The geologic time table accepted in the work is old-fashioned, for in it the Murchisonian Silurian and the still older Carbon are continued as formations or periods. The author also holds to the Laplacian theory of earth origin, and nothing is said of the plane- tesimal theory. Of illustrations there are one hundred and twenty-seven, the most instructive. being the many profiles bringing out the geo- logic structure of Europe. Of paleogeographic maps there are four (Upper Carboniferous, Triassic, Jurassic, and Gault). C4 S. “7. Igneous Rocks; by J. P. Ipprnes. Vol. IT, 8°; pp. 685. New York, 1913 (Wiley & Sons).—The first part of this work, devoted to the general and theoretical side of petrology and to the classification of igneous rocks, was published by the author in 1907. The present and completing volume treats of the descrip- tion of the rocks, and of their geographical distribution, the work being about equally divided between the two subjects. 572 Scientific Intelligence. The book opens with a discussion of the scope and method of description, in which, after the serial nature of the objects to be considered is brought out by the use of tables containing in graphic form the results'of a vast mass of chemical data, the urgent need of quantitative methods in classification is demon- strated. The author then proposes a system in which the present ill-defined qualitative one, so generally used, is brought into more definite form by the injection into it of a certain amount of quantitative method, thus correlating it in broad features with the quantitative system, as already forecast in volume I, pp. 348— 350. The rocks are thus divided into six divisions, as follows: LF characterized by quartz. om quartz and feldspar. Iil . ee Telas pale ne IN u “* feldspar and feldspathoids. Vv me ‘“< feldspathoids. Vi mF ‘“¢ mafic minerals. The feldspathic rocks are again divided according to the alkalic or alkalicalcic nature of the feldspars, and further divisioning according to the relative proportions of feldspathic (or feldspa- thoidic) and of mafic minerals is provided. The term mafic, it may be added, is a shorter equivalent for ferromagnesian. On this basis the rocks have been briefly treated, the object being to present their mineralogic and chemical characteristics, and to bring into correlation the variously named types described by petrographers rather than to furnish an encyclopedia of petro- graphical data. We believe the author has done well in thus restraining himself, for information of this nature is already available in the voluminous treatises of Rosenbusch and Zirkel. On the chemical side, however, the material is abundant and this emphasis of the chemical characteristics of igneous rocks is one of the chief and most valuable features of the book. It is shown in the presence of 71 tables, ench containing from one to two dozen well-selected analyses, with their calculated norms. ‘The apha- nitic rocks are treated in close connection with their chemically equivalent phanerites, thus showing the varied forms of erystalli- zation of chemically similar magmas. The second portion of the work devoted to the occurrence of igneous rocks furnishes the most comprehensive treatment of the problem of petrographical provinces which has been attempted. After a general discussion each great division of the earth is con- sidered in detail and the occurrence of its igneous rocks is shown upon a colored map, which facilitates the perception of their separation into different provinces. In Europe, for example, they are considered after the following grouping : Scandinavia and Finland. Ural Mountains. British Isles. France, Spain, Portugal. Hm CoO NO Geology. 573 On Switzerland, Germany, Austro-Hungary, and southern Russia. 6 Italy and West Mediterranean islands. 7 Balkan Plateau, Greece, Aegean isles. 8 Asia Minor, Persia, Arabia. The last grouping is taken as a matter of convenience. In each group the chief occurrences of the rocks are briefly described, with remarks directing attention to their salient features, while frequent tables of analyses add greatly to the value of the presentation. ‘The labor of digesting the colossal mass of literature necessary for this work must have been im- -mense, and some idea of it may be gained from the comprehen- sive bibliography submitted in the final pages. This geographical conspectus is a lasting benefit to working petrographers in ena- bling them to easily compare material with that already described in the chief publications upon all parts of the world. In addition the general résumés of the different provinces will be of value in directing attention to their chief peculiarities. The wide travels of Professor Iddings and his personal acquaintance with the rocks _of many regions give an additional authority to this portion of the work. On the whole it may be said that the completion of this great work marks a distinct step forward in the science of petrology, in that it is the most comprehensive and fundamental treatment of the subject which has yet appeared, in which also the bearing of the most recent advances in related sciences have been considered. The amended qualitative classification proposed seems the most reasonable way out of this vexed problem, in combining our heri- tage from the past with the greater precision demanded from present-day workers in science and in indicating the path along which improvement may be made in the future. It is perhaps needless to say that the volume is a necessity for every worker in the science. It is well and attractively printed and both author and publisher are to be congratulated on its appearance. Wee Be 8. Introduction to the Study of Igneous Rocks ; by Geo. I, enuax. 12°, pp. 228) 59 figs., 3 col. pls.’ > New York, 1913 (McGraw-Hill Co.).—The object of this little work is clearly indicated in the title. The author first discusses the classifica- tion of rocks from the generally used qualitative method and then takes up their determination in hand specimens. This is followed by a brief discussion of the movement of light in crys- tals and the identification of the essential rock minerals in sec- tions by optical methods. A brief description of the accessory minerals is given and the most important varieties of the igneous rocks are then presented. Less important types are mentioned in tabular form. After giving the proper method for describing rocks the work closes with a rather full account of the Quantita- tive System of Classification. Examples for the calculation of the norm are discussed and the necessary numerical tables are Am. Jour. Scr.—FourRtH SERIES, Vou. XXXVI, No, 215.—Novemser, 1913, 38 574 Scientifie Intelligence. appended. The colored chart of Michel-Lévy for maximum birefringences and the table of the chief characters of the rock minerals will be found useful in identification. On the whole the author has done his work well, the chief fault being that which is necessarily inherent in books of this class, where the attempt is made to compress into so small a com- pass any comprehensive account of such a great mass of material as the subject of petrology affords. It should not be understood, however, that, as is so often the case, the book is a mere synopsis. The author has wisely restricted himself to a relatively few important matters and has treated these with a fair degree of fullness. It is only in the description of the rocks that the synoptic character becomes evident and it would seem as if this part of the work might have been somewhat more expanded, with advantage to the student. For those who desire to obtain a general notion of the science of petrology, to famiharize themselves with the method of deter- mining the common igneous rocks by the use of the microscope and, provided a chemical analysis of a rock has been made, to properly calculate its position in the quantitative system, this little book, which cccupies a distinct place of its own, will be found very useful. It'is well printed and conveniently bound. le Vee 9. Der Vulcanismus ; von F. von Wo.urr. 2 vols.; vol. 1, first half. 8°, pp. 300, 80 figs. Stuttgart, 1913 (F. Enke).—This is intended as a rather comprehensive work on the igneous activ- ities of the earth. This may be seen from the subjects of various chapters; thus chapter two treats of the theater of volcanic activ- ity and the physical conditions ruling there, chapter three gives a full discussion of the properties of the magma, of the process of crystallization, structure of the rocks, gaseous components, etc. Then follows the treatment of the magmatic zone, in which the geographic distribution of igneous rocks, differentiation, assimi- lation, and kindred subjects are considered. Next the geologic mode of occurrence of intrusive rocks and the mechanics of intru- sion are dealt with in detail. Post volcanic processes connected _ with intrusions, that is to say contact metamorphism, follow, and the present portion ends with an account of submarine eruptions. The literature of the various subjects is quite fully considered, the author giving short, clear statements of the views of other writers, accompanied by critical comments of his own. He has introduced considerable original matter, and this and the clear method of presentation, as well as the references to the work of others, make the book not only interesting but very useful for investigators and teachers in this field of geology. It is well and clearly printed, but some of the figures, introduced from the older works, are for a modern one rather crude. While the work is to be distinctly commended, and there is no opportunity here for a critical review of the subject-matter, one detail may be consid- ered. In treating of the geographical distribution of igneous Miscellaneous Intelligence. 575 rocks, the author adopts the terms proposed by Becke of “Atlantic” and “ Pacific” families, for alkalic and sub-alkalic. After making a rather rapid but comprehensive survey of the known occur- rences of igneous rocks in the Pacific, he says: “The result of this investigation can be shortly comprised in the statement that the Pacific Ocean, with the exception of its andesitic borders (Umrah- mung) is an Atlantic magmatic province.” Further comment on the use of these terms seems unnecessary. seve Pe MiscELLANEOUS SCIENTIFIC INTELLIGENCE. 1. Publications of the Carnegie Institution of Washington. —Recent publications of the Carnegie Institution are noted in the following list (continued from vol. xxxv, p. 466) : No. 54. Research in China. In three volumes and atlas. Volume III. The Cambrian Faunas of China; by CHaruss D. Watcotr. eons MgO 0°37 0°49 0:21 0:18 0:18 0°66 009 <-012 # :005 CaO 0°69 1:00 069 0°07 0°25 1°30 013 018 30is Na.O Bio 3°62 3°68 4:35 6.444” 3°49 °061 ‘058 #:060 K,0 5°36 528) Gy 4:92 4:32 4°55 ‘057 ‘056 °051 H.O+ 0°60 Dr SOL ailvow. 0-64 1°74 0:59 H.O— 0°72 0:10 0:04 0°24 TiO, 0°38 0°47 0:08 tr. ae 0-40 ‘005 ‘006 # -001 ZrOz 0°02 iG ee Bas: eae be tf 0:05 P.O; 0:07 Ont inne tr. sie 0°22 00h 200i ENS SO; none i ney Biss phe tc 0:18 MnO tr. 0°04 n.d. TY. shee? Cpa 0:04 BaO none eRe ave $53 a 0°06 100°83 100°72 99°58 100°21 99°89 100-22 Liparite. Capanna, near Marrubiu, Monte Arci. Perlite. Punta Brenta near Uras, Monte Arci. Obsidian. Conca Cannas, near Uras, Monte Arci. . Comendite. Comende, San Pietro Island. Dittrich, analyst. H. Rosenbusch, Elemente, 1898, p. 257. EK. Comendite. San Pietro Island. A. Johnsen, analyst. A. Johnsen, Neues Jahrb. Centralbl., 1912, p. 738. F. Rhyolite. Macomer. Aa, Ba, Ca, mol numbers of A, B, C. Jakp The analyses are those of ordinary sodipotassic rhyolites and are much alike, the lower silica of the perlite (B) beg due in part to the presence of water. The relations of the iron oxides in the holocrystalline rhyolite and the glassy forms are worth Washington—Some Lavas of Monte Arci, Surdinia. 583 noting, ferric oxide predominating in the first and ferrous oxide in the others. They are much like the analyses of typical comendite (D, E), though this is slightly lower in alumina and bigher in ferric oxide, in these respects resembling the pantellerites. The last | are, however, notably more sodic.* An as yet unpublished analysis (I) of a red rhyolite which forms one of the pre-Ter- tiary sheets near Macomer is also given. This is like the others, but is somewhat higher in iron and lime. The norms of the Monte Arci rhyolites are as follows: Ae B (y MM le 28°50 26°58 31°80 Sie ee in eee BEE 31°14 28°36 EG en OR eS 31°96 30°39 31°44 AG 2 ete ost | ra 3°61 meee et! es | 4] 172, may is {pede ee 0:90 1:99 2°74 nes ee 8 OM TG 0°91 0°15 [Ut (ee een 0°48 saa cs pres pape 0°84 0°34 652 From these it is seen that all these rhyolites fall in liparose (1.4.1.3), the liparite centrally and the perlite and obsidian ~ distally,+ being transitional toward (almost on the border of) the domalkalic rang, with the full symbol [.4.1(2).8. The small amount of normative corundum in A and B belongs, of course, to the biotite, and it may be worth noting that its amount is _ roughly proportional to that of the biotite seen in the speci- mens. The amounts of mafic minerals in the lithoidal rhyo- lite are so negligible that the mode is almost absolutely norma- tive. Trachyte (Phlegrose 1.5.1.3). The only occurrence of trachyte was found as blocks in the Conca Cannas, which are apparently derived from a flow in its south wall. This was not found, but it overlies rhyolite, of which the lower parts are composed. The.rock is rather light gray, very compact, and dopatie. Numerous equant to thick tabular crystals of glassy alkali feldspar are the only phenocrysts. They vary in size from 2 to 5™™. The groundmass is gray, dense, felsitic and aphanitie. In thin section the feldspar phenocrysts are seen to be of soda-microcline, either in simple crystals or Carlsbad twins. The extinction on ¢(001) is about 7°. They are quite free ies recent analyses of these see H. S. Washington, Jour. Geol., xxi, +This term ‘‘distal” is borrowed from the organic sciences to indicate either the intermediate or transitiona] position, near the border, in opposi- tion to ‘‘central.” The terms would seem to be self-explanatory. 584 agen Sone Lavas of Monte Arci, Sardinia. from inclusions. Very small augite and magnetite anhedrons are also present, but are rare. The groundmass is dense and apparently holocrystalline. It consists of a cryptocrystalline _aggregate of feldspar and quartz, showing no microperthitic patches. There are many minute ragged anhedrons of augite and magnetite, and irregular grains of a brownish yellow, biaxial mineral, which may be a peculiar, or possibly slightly altered, pyroxene. A similar mineral is found in the sheet trachyte of Monte Muradu near Macomer. Analyses of Sardinian Trachytes. A B Aa S10. 5. 65-94 - 59-92 1:099 ATO. GR Se eres 14-30 158 Feo.) ae 2°56 7-50 ‘016 FeO eee 0-82 0°42 O11 MgO _.. 0 60 0-72 015 CaO : 1:06 1:90 019 Na,O ..- a onan, 5°32 085 KOS ice Sees 6-49 5-77 069 OE eh epee need) 015 HO ae 0:36 0°34 AG housed chs sy 1-21 0°87 015 PB Oe oe er nad 0°58 Ma! 20) the tae riGen. 0-06 +001 10073 A. Trachyte. Conca Cannas, near Uras, Monte Arci. B. Trachyte. Nuraghe Terchis, Monte Mur 20a, near Macomer. Includes 0°11 ZrO,, 0-06 SO,, 0°05 ‘BaO. The analysis of the Monte Arci rock is that of an ovd ee trachyte, somewhat high in silica. It has no known counter- part among Sardinian lavas, the Monte Muradu trachyte approaching it most closely. It will be observed that in both of these ferric oxide is much higher than ferrous, and this seems to be connected with the occurrence of the peculiar yellow pyroxene, a point to be investigated later in connection with the older rock. The norm of A is as follows: Gigi eS Atl: Ae 8-29 On TVs ered 2 eo. ue 38°36 Bie es ee 44°54 AGH Pere gee: he ae deg i DO peer ode Nr ee Pia 8: Hy se Ee eed 022" BRS cbt hoe arian aL 1°67 Pi se. se 5. A BEG Tee ee je he Pee eee 0°78 Washington—Some Lavas of Monte Arci, Sardinia. 585 The mode is essentially normative and, giving the small amounts of anorthite and titanite to the pyroxenes, would be roughly as follows: Clune eke i Spo ee POG A-MIICLOGINE 22. o-oo. Eee 83 iV EONGNCH 2 2s eee 6 Tron .ores=._ 2. 3. Semiies Hak 22d 3 Hypersthene Andesite (Dacose, [1.4.2.4 and tonalose, I1.4.3.4). Andesitic lava flows were found overlying those of rhyolite in several places. Though they differ somewhat in chemical composition, especially as regards the amount of silica, they are much alike modally, and so had best be grouped and deseribed together. They grade into the basalts, which are andesitic in character, but will be described separately. One of the best exposures found is in the north wall of Canale Perdiera, near Uras. The lower 10 to 20 meters of _ this is a gray rhyolite, covered by rhyolitic tuffs and a sheet of light gray perlite. Above this is a thick (about i5 meters) coarsely columnar flow of rather coarse-grained, basaltic-look- ing andesite. On the same level as this, but cut off by a small side valley, is a slightly thicker flow of a fine-grained, dark red, basaltic rock (andesite). Above both there is a 40 to 50 meter thick flow, with well-developed columnar structure, of 4 quite granular, light gray andesite. This extends to the visible top of the cliff, though some fallen blocks of basalt indicate that a basalt flow covers the whole. : Flows of similar basaltic-looking andesite are met with covering the rhyolite in the two ‘nmnamed coneas south of Conea su Ollastru, below the Rione Pranu Pira. What is probably a similar rock covers the ridge between Conca Per- diera and Conca Cannas, though the loss of the specimen ren- ders it uncertain. In the hand specimen these andesites look like basalts. They are all wholly devoid of phenocrysts. That which forms the visible upper flow of Canale Perdiera (analyzed below) is millimeter-grained, light gray, consisting of dark gray specks in a white to light gray base. The flow ‘below it is tinely mot- tled, of small black patches in an interstitial, pinkish brown, felsitic material. The red rock is a true brick-red, very fine- grained, aphanitic and compact, except for some small vesicles. The red color is due to weathering, but it extends to the center of the largest blocks examined and the whole flow, from top to bottom, is of the same uniform color. The blocks from the flows below Rione Pranu Pira are dark gray, almost black, fine-grained, aphanitie and compact. None of the specimens ~~ S 586 Washington—Some Lavas of Monte Arci, Sardinia. show phenocrysts, except for somé very rare, small, rounded _erystals of feldspar. Microscopically these rocks are seen to be hypersthene ande- sites and are referable to two distinct types; one holocrystal- line, with ophitic texture, carrying considerable augite along with the hypersthene ; the other vitrophyric with much hyper- sthene and very little augite. The ophitic andesite is represented by the specimens from Canale Perdiera, except the red flow. The feldspar is labra- dorite, about Ab,An,, in divergently arranged, rather thick, subhedral plates, with strongly marked twinning lamellae. These carry few inclusions, by far the greater part of the mafic minerals being intersertal between them. The hyper- sthene is colorless or gray, in subhedral stout prismoids or anhedral patches, with well-developed cleavage. It is almost entirely free from inclusions, containing rarely small magnetite grains. Colorless augite, distinguished from the hypersthene by its higher birefringence and oblique extinction, is almost invariably anhedral, either intersertal between the feldspar tables or forming a patchy border to the hypersthene, the augite individuals being much smaller than those of the ortho- rhombie pyroxene. Ores, either small irregular anhedra (magnetite) or in thin tables (ilmenite), are rather common, usually included in the augite. There are very few small anhedra of quartz, some small areas of micrographic quartz and feldspar, but no glass. The vitrophyric type is best represented by a specimen from the second valley south of Conca su Ollastru. The abundant, diversely arranged small laths of feldspar are not more than ‘1 to -2™™ long by one tenth as thick. They are all multiply twinned, with extinction angles which vary from Ab,An, to Ab,An,, and are consequently andesine. They are fairly free from inclusions, but are apt to carry thin glass cores. The hypersthenes are more abundant and larger than the feldspars, as sharply defined but subhedral prisms, from 0:2 to 1:0™™ long and about one tenth as thick. They are perfectly color- less, with well-defined cleavage cracks, uniformly parallel extinction, and quite free from inclusions in the center, though they are apt to have a fringe of very small magnetite grains along the border or be surrounded by a thin zone of colorless diopside. Colorless monoclinic pyroxene is much less abund- ant than in the preceding type. Apart from a few larger erystals (0°5™"), rounded by magmatic corrosion, and with a later fringe of minute hypersthene needles, augite is present only as very small interstitial anhedra’ Very small (0-01™™) grains of magnetite are rather abundant, chiefly fringing the hypersthenes, as mentioned above. Interstitial between the Washington—Some Lavas of Monte Arct, Sardinia. 587 andesine and hypersthene crystals is a base of colorless glass, which appears to be gray through the presence of much, exceedingly fine black dust. The brick red basaltic andesite from Canale Perdiera much resembles this, except that here the hypersthenes uniformly have a yellowish brown, transparent border, which much resembles the iddingsite that surrounds some clivines. This border, which gives the rock its peculiar color, is obviously due to incipient alteration. The small augites are less liable to attack, and the feldspars are quite unaltered. The chemical composition is represented by two analyses, with which are given for comparison two others made by me of pre-Tertiary andesitic flows. Analyses of Sardinian Andesites. A B C D Aa Ba SiO. 61-08 56°34 60°14 56°60 1:018 939 Al,03 13°66 — 18°95 16°65 16°80 134 137 Fe.O; 0°70 1:94 2°94 ° 2°52 004 012 FeO ~ 5°61 6°73 2°39 0°12 ‘078 "093 MgO 4°69 6°41 1°16 3°80 alales 160 CaO 4°84 6°20 5°21 7°29 087 ‘111 Na,O 3°84 3°10 3°41 2°43 062 050 K,0 2°23 0°76 2°51 1°98 "023 008 H.O+ 0-74 1°04 3°98 1°80 H,O0— 0°49 0°63 0°54 0:58 TiO. 1-76-— eee 0-62 0:99 “022 "028 P.05 OF 0-44 0°07 0°12 001 008 MnO Sie ies 0°06 0-13 99°81 99°79 99°68 100°16 A. Hypersthene vitro-andesite. Below Rione Pranu Pira. Monte Arci. B. Augite-hypersthene andesite, upper flow, Canale Perdiera, Monte Arci. C. Augite vitro-andesite. Monte Furru, near Bosa. D. Augite andesite. Monte Pischinale, near Bosa. Aa and Ba, mol numbers of A and B. Apart from the low alumina and high titanium these analyses resemble those of many other andesites. It is of interest to compare them with the earlier flows a little farther north. ‘With about the same silica, the two types differ in about the same way; the earlier having higher alumina, ferric oxide, lime and potash, with lower ferrous oxide, magnesia, soda, titanium and phosphorus. The relations will be discussed at length later, when more analyses are available. The norms are as follows: . A B Beto Nal eA NB ae 7 ans ee 12°36 11°64 One eee ee eee rice 19°79 4°45 Pee vad uf of GEA es 2 a A Te 4°91 lye 22 oN oo er 21°04 NMG 2 a2. Lil Pe ee ea 2°78 Wie. £26 ol Se ee ee eel 4°26 Ap? wis lel oe ee een ge 1:01 According to these A falls in dacose with the full symbol I1.4”.2(3).4, and B in tonalose with the symbol II(II1).4”.3”. 4(5). These norms are of interest in showing the presence of about 12 per cent of excess silica. ‘This is much more than is visible as quartz in the holocrystalline type (B), and must be present in the glass base in the other. Such an excess of silica is very commonly observed among the analyses of andesites, and these lavas generally show an excess of some 10 to 20 per cent. This silica is either not present at all or only in small part in the mode, and is to be regarded as “occult,” to use a term recently proposed.* Basalt (Andose, 11.6.3.4). Basalts formed the last lavas poured out by the voleano and they cover large extents of country around it, very much as they do at Monte Ferru. These flows are noted by della Marmora at many localities and were seen by me near Uras and Marrubiu along the west flank. They were always observed covering the rhyolites and other salic rocks, and were never covered by them. Della Marmora also mentions their oceur- rence as overlying the “trachytes,” and het describes the sheet which caps the rhyolites at the culminating points of the Trebinas. According to himt{ basaltic rocks also form dikes which ent Pliocene marls near Ales. These I did not see. These basalts are very dark gray, almost or quite black, and very dense, either perfectly compact or showing only a few vesicles. Very small and rare feldspars are the only pheno- — crysts visible to the naked eye. The groundmass is quite aphanitie. In thin section the specimens collected by me vary somewhat in texture as well as in mode. te That from the thick flow at Uras, an analysis of which is given beyond, is ophitic, composed of tables of labradorite (Ab,An,) with the usual twinning, and anhedral to subhedral grains of colorless pyroxene. Part of this is hypersthene and part diopside, the two being distinguishable by the extinction angles and birefringence, as in the andesites. Much of the pyroxene is apparently slightly altered, being of a yellow- * J. P. Iddings, Igneous Rocks, ii, p. 19, 1913. + Della Marmora, op. cit., pp. 500 and 622. { Della Marmora, op. cit., p. 620. Washington—Some Lavas of Monte Arc, Sardinia. 589 brown color—this color sometimes extending through the whole crystal, and less often only partially. These pyroxenes look, at first sight, like olivines partly altered to iddingsite. A little alkali feldspar occurs in patches, but the interstitial material is mostly a black dusty substance, which high powers resolve into a colorless glass thickly crowded with minute, black, spherical globulites. As the usual ore grains are entirely lacking, these are probably of titaniferous magnetite. Only a few of the feldspars and still fewer of the pyroxenes are of such size as to be called phenocrysts. Another type, represented by specimens from the Rione Muratta, near Canale Perdiera, and from Santa Suina chapel, is finer orained and decidedly andesitic or trachytic in texture. The feldspar tables are much smaller and thinner, are some- what more sodic, and show a tendency to fluidal parallel arrangement. The colorless pyroxenes are nearly all of hyper- sthene, in small anhedra or subhedral prisms, and are not colored yellow as is the preceding type. Some euhedral to subhedral grains of olivine, with iddingsite borders, are present. Magnetite grains are rather common in this type. There is very little colorless interstitial glass. Except for the presence of olivine these basalts greatly resemble the andesites just de- scribed, and are best to be regarded as andesite-basalts. Only one analysis was made of these rocks, there being given for comparison an analysis of a basalt from Monte Ferrn and one from Ploaghe. Analyses of Sardinian Basalts. Aang B (O} D Aa SiO. 52°79 © 52°40 56°34. 52°67 “880 Al,Os 16°45 15°26 13°95 sabes) 161 Fe.03 2°74. 0°74 1:94 3°82 017 FeO 6°44 8°33 6°73 5°42 “089 MgO 5°56 AS 6°41 4°40 "139 CaO 6°51 Wao 6°20 5:91 "116 Na2O 3°64 3°54 3°10 4°50 "059 K.0 ie 0°99 0°76 2°68 ‘0138 H.O+ 1:02 0°29 1°04 0:37 H.O— 0°21 0:06 0°63 0°14 TiO; 2°64 3°12 2°22 4°()4 033 P.O; 0°39 0:49 0°44 0°75 003 MnO 0:06 0:08 A, trace NiO 0°18 0-06 Fite none “002 99°84. 100°14 99°76 100: 05 A. Uras, Monte Arci. B. Near Cuglieri, Monte Ferru. C. Andesite, Canale Perdiera, Monte Arci. D. Basalt. Monte San Mateo, Ploaghe. Aa. Mol numbers of A. ' mgohye prae et hy » 5 ml 590 Washington—Some Lavas of Monte Arci, Sardinia. Q) LEP ES Se eee 4°50 Or ae a eee eee 1B} ADs bo oe ee Se eae 30°92 Ag” : apie D4 oth pie de eae Di i. cee ee ee eee FL yr sj. ore ee he a aoe 17722 Me jc. 22h eee ae ee ee, Tl 2s ee ee B02 AND 5.6.25 ceo ee a ene 107 This places the Arci basalt in andose, with the symbol II’.”5.3.4”, the Ouglieri basalt falling in the salfemie homo- logue camptonose, “III.5.3.4”, and that of Ploaghe in akerose, I1.5.2.4. The mode is approximately normative. The quartz is occult in the glass base, and most of the normative magnetite and ilmenite is present in the black globulites. The normative hypersthene and diopside express very closely the modal rela- tions of the orthorhombic and monoclinic pyroxenes. Judging from its color the latter can carry but little ferric iron. The mode may be roughly stated thus: Quartz, (Occult): teste ee Uabradonite ((AbsAn)) 222223 62 Diopside [242 naa) Uae eae 5 Hypersthene\2. 3272S cae alk, Ores) 253.00 Ree ees 8 APAtite a uae ae cee ie oP meee 1 Glass. 22k, 5 se ae ae 3 General remarks.—As only a hasty glimpse was had of a part of the volcano, the data at hand do not warrant any lengthy discussion of the general character of its lavas. My slight examination was, however, sufficient to corroborate the statements of della Marmora and show that in structure it much resembles Monte Ferru, consisting of a domal core. of rhyolites (possibly with phonolites), followed and covered by flows of trachyte, dacite and andesite, the whole closing with great outflows of rather andesitic basalts. It is noteworthy that tuffs and scoria beds are rare, just as they are at Monte ~ Ferru, except in the initial stages. So far as known the rocks are distinctly silicic, more so than at Ferru, where rhyolites are not known, but trachytes and phonolites are abundant. They are distinctly alkalic and mostly sodipotassic. These features find their modal expres- sion in the absence of sodic pyroxenes and amphiboles, and the predominance of hypersthene over diopsidic pyroxene. Titanium is rather high and its amount increases regularly with decreasing silicity. Geophysical Laboratory, Carnegie Institution of Washington. Hornor—Use of Sealing Wax, etc. 591 Arr. LI.—On the Use of Sealing Wax as a Source of Lime for the Wehnelt Cathode; by Nexium N. Hornor. In the Wehnelt* cathode as first employed various metallic oxides were used as salts. Those of calcium, bariuin, and strontium gave an abnormally large discharge of negative elec- tricity. The sign of the electrification depends upon the metal used and also upon the class of the salt.| Willows and Pictont used nickel and platinum strips for the cathode, while Richard- son § employed both the tube and strip methods, and recently Sheard || used the tube method. The conditions affecting the efficiency of this form of cathode have also been studied by Horton,4 Garrett,** and Wilson.tt In the work by Willows and Picton, referred to above, they found that when using a pressure of 002" Hg and up, a volt- age of 36, and a temperature of 1100 degrees Centigrade, there was a decided increase in the activity “of the salt when the - eathode had stood cold over a period of several days or weeks. They also found a greatly increased stream of electrons on making the discharge after it had been broken for a time, the heating current continued the while. The accumulation of electrons in the heated lime was dependent upon the interval of time. It has been known for some time that ordinary sealing wax makes a fairly good source of lime. The Bank of England wax seems quite satisfactory. Its use, however, was until recently confined to the Cavendish laboratory. For some time it has been evident that its behavior as a lime is different than that of the oxides which are generally used. Hence the fol- lowing investigation, in which the object is a study of the activity of this source of lime together with the various con- ditions best suited for its efficient working. Description of Apparatus. A sketch of the apparatus used is shown in fig. 1. Visa two liter spherical flask, 8’ is a drying bulb, B’ the heating circuit, C the cathode, and A the anode. The aluminium disc G’ was connected through a reversing switch /’’ to the galvano- * Phil. Mag., vol. x, July, 1905. + J. J. Thomson, Proc. Camb. Phil. Soc., vol. xiv, 1906. ¢ Phys. Soc., London, Proc., June, 1911. § Phil. Mag., vol. xx, 1910. || Phil. Mag., vol. xxv, March, 19138. “] Phil. Trans. Sec. A, vol. eevii, 1907. ' ** Phil, Mag., vol. xx, October, 1910. tt Phil. Mag vol. xxi, May, 1911. eee Mae lagy 592 LHornor— Use of Sealing Wax as a Source of meter and to earth. A high potential cabinet 7’ furnished the voltage, the positive terminal was connected through a water resistance to earth and to the anode and the negative through Buc ae ™M \ 2 9D \ G K' PI ALES + ll Pry + — E IS i Resistance Current in ae \o-* 0 40 120 160 20a 240 Time in se pe a switch A to the cathode. A voltmeter, VJ/, and an induc- tion coil, S, were connected to the switch A as shown. 7, 2, 3, 4, and 5 are red wax joints. The method of mounting the cathode was that recently described by Knipp.* A Nalder D’Arsonval galvanometer, G, of a fair degree of sensitiveness was employed. * Phys. Rev., vol. xxxiv, March, 1912. Lime for the Wehnelt Cathode. 593 Method. The electrons fell upon the disc G’, located opposite and about 4" from the cathode, and the resulting current was indicated by the oalvanometer: With each galvanometer reading, which was the mean of two deflections, the pressure, Rae. - Brabois FP _ 352 ee Ree Zee is {SRE Ta JANe cee ae ae _ 2d SS See eae _ Jini: pi i th Pen Mme | Rp SSSERESEEEEEETETEE 1.0 ie By sa eel in Amp. x to-+ a0. eet 355 oa = \80 210 240 270 Hive in minutes discharge voltage, and heating current readings were eee The heating current was kept strictly constant. The pressure was also kept practically constant by occasional pumping. After mounting the platinum strip, a very small piece of the red wax was placed centrally upon it. The wires D and Z’ were then connected to the heating circuit and the current was Am. Jour. Sci.—FouRTH SERIES, VoL. XXXVI, No. 216.—DrEcremBeEr, 19138. 40 Hornor— Use of Sealing Wax as a Source of 594 ime, eb Time in huge MiGs 7a! eee re s 01 x ‘dwy ul luasang Time in eaites gradually increased until the dise of lime became white. The lime was thus deposited on the platinum strip. The tube was then placed in position, sealed, and the apparatus evacuated until the pressure was °015™™ of mercur y or less. Pressures ranging from ‘003 to ‘04"" were used. The apparatus was usually allowed to stand over night after evacuating to allow the P,O; to absorb the moisture. The heating current was adjusted until the temperature of the platinum was that corresponding to a light cherry-red. Lime for the Wehnelt Cathode. 595 Fic. 6. SyjOf\ ui Spanos | 0g2 091 02! og OP mmm itt Tit iTitiietes meee ee Pa me BEE eee = _ Se Since it was necessary to renew the lime frequently, a reliable thermo-junction connection was nearly impossible and hence no attempt was made to determine the temperature. It was, however, kept strictly constant during any given run or set of runs. The discharge circuit was closed, the time noted, and the galvanometer watched for the current to start. Whena cathode with fresh lime was heated the first time the discharge did not start immediately but only after from ten to thirty minutes if conditions were favorable. An induction coil may be used to start the discharge, but this complicates matters as there seems to be a gradual rise due to the ionization caused by the induction coil discharge. The cathode stream may also be started more quickly by making the heating current larger for a short time; however if this is done the increase to a maximum and the maximum itself are not shown,—only the part of the curve due to the decay is obtained. Discussion of Curves. The effect of changes in the heating current is shown by eurve 1, fig. 2. A very small change in this current, in fact one which the eye could scarcely detect on the ammeter where two scale divisions read 1/10 of an ampere, produced quite an appreciable effect upon the galvanometer deflections. 596 Hornor— Use of Sealing Wax as a Source of After two hours the heating current became fairly steady and a smooth curve, from A to 4, was obtained. The cathode was allowed to stand cold with the vacuum up for two days. On heating to the same temperature and starting the discharge again the current rose to a maximum value in an hour and then remained comparatively steady for the rest of the run. The steady current value shown in curve 2, fig. 2, was very little smaller than the maximum, which in turn was much smaller than the steady value for the preceding run. After five days another run was made with the same platinum strip and lime heated to the same temperature. This run gave a maximum less than the steady value for the second run, as shown by curve 38. It has the same general characteristics as curve 2. The discharge voltage for these curves was approximately 400 volts, the heating current 4°63 amperes, and the pressure varied from ‘005 to :016™" Hg. In the last two curves the heating current was steady. The curves in fig. 2 indicate that the activity of the red wax decays with time. This is also shown in a striking manner by curves 1, 2, and 3, fig. 3. The maxi- mum value of the current during any given run, after the lime had been cold from 1 to 4 days, was always less than the steady value of the current for the preceding run. Apparently when the lime is allowed to become cold it is not able to regain the activity it had at the end of the previous run. However, the activity that it does acquire it regains quickly. The relation between the maxima and the number of hours between them is shown by fig. 4. Evidently these maxima decrease very rapidly at first. . When the lime is used for the first time it is very difficult to adjust the heating current to a value that will give smooth curves similar to 2 and 3 in fig. 2. The form of the curve is more likely to be that shown in curve 1, fig. 3. In this the number of electrons emitted for the first two and one-half hours in- creased very slowly, when suddenly it rose to a very high max- imum and then almost as suddenly fell to a much lower steady value. The temperature was that corresponding to cherry-red. This sudden and very high maximum indicates that most of the electrons which may possibly be emitted under these con- ditions acquired sufficient energy to escape almost simultane- ously and thus caused, as it were, an explosion. Curves 2 and 3, in fig. 8, again show the same characteristics as curves 2 and 3 in fig. 2. After the lime has once been heated, the sub- sequent currents start much more easily and rise to a maximum more quickly, suggesting that the electrons are in a state more favorable to emission. The beam was visible to the eye in curves 1, 2, and 3, fig. 8, from A, 4, and C on. If the discharge voltage was cut off while the heating con- Lime for the Wehnelt Cathode. 597 tinued, the current obtained on again closing the discharge circuit was in ever y case smaller than it was just before break- ing. This isshown by fig.5. The behavior of the lime seemed to be much the same as though it had been allowed to stand in the cold, except that the effect was not so pronounced. This shows that the decrease in activity for short intervals of no dis- charge was slight, yet definite, if the lime was kept hot. This result does not agree with that of Willows and Picton, who observed, for the salts that they used, a decided increase in activity under the same conditions. Data on the saturation voltage were obtained as follows: for a given heating current and a discharge voltage of 40 volts the run was continued until the current became steady, after which the voltage was advanced by steps of 40 volts at inter- vals of 10 minutes, the maximum current being recorded each time. The curve in fig. 6 shows the results obtained. There was saturation at 200 volts The Bank of England wax upon analysis was found to have the following principal constituents: calcium sulphate (gyp- sum), barium sulphate (heavy spar), mercuric sulphide (cinna- bar), and shellac. Summary. It was shown that when Bank of England sealing wax is used as the source of lime there is a falling off in the activity with time. When a maximum is reached most of the electrons are emitted during the first run. When the discharge i is broken while the heating current is maintained there is a slight falling off in the negative stream. The above results are exactly Opposite to those obtained by Willows and Picton using calcium oxide on a platinum strip, while they agree in part with the observations of Sheard, who found that the activity for cadmium iodide and iodine, with the tube method, decreased during any given run. The saturation voltage was found to be 200 volts. There was a falling “off in the maxima for successive runs, and the steady current for any given run was usually much smaller than that for the preceding run with the same lime. In conclusion, the writer takes “pleasure 3 in thanking Profes- sor A. P. Carman for the facilities of the department, and Dr. C. T. Knipp for suggesting the problem and assistance in car- rying out the details of this investigation. Physical Laboratory, University of Illinois. 598 Gooch, ete. Dehydration and Recovery of Silica. Art. LIL-—The Dehydration and Recovery of Silica in Analysis; by F. A. Goocu, F. OC. Recoxrrr and 8. B. mkGuzie AN: [Contributions from the Kent Chemical Laboratory of Yale University—eclii] The Dehydration of Silica. THE question as to the temperature which must be applied, and of the duration of the ignition necessary to bring silica to a constant weight in the analysis of silicates, has been the sub- ject of much investigation and discussion. The opinion is general* that in order to obtain the correct weight of anhydrous silica derived by precipitation in the usual course of analysis, and ignition, the temperature employed must be that of the blast lamp. Lunge and Milbergt have shown, however, that silica obtained by hydrolyzing silicon fluoride sustains after ignition in the full flame of a good Bunsen burner no further appreciable loss upon application of the blast heat, and these results have been confirmed by Lohéfer{ in Lunge’s laboratory, and by Hillebrand, for silica thus derived from silicon fluoride. On the other hand, Hillebrand found in the ease of silica derived by fusing quartz with sodium carbonate, treating the product with hydrochloric acid, and evaporating three times, with intermediate extractions and filtrations, that constant weights were obtainable only by blasting, and that blasting for half an hour (as is generally recommended) is often insuf- ficient to secure constancy of weight. Quartz powder was used as the source of the silica in Hillebrand’s experiments, and this was found to be 99°88 per cent pure, by cureful treat- ment with sulphuric and hydrofluoric acids. — It has been shown recently in certain experiments by B. H. Walker and J. B. Wilson§ that silica precipitated by acid may be brought to a constant weight by prolonged ignition over the Bunsen burner, thus avoiding the danger of loss which may occur when platinum is submitted to prolonged ignition with the blast lamp. Three hours is the minimum period mentioned as requisite. It is to be noted, however, that in these experiments no test was made for impurity in the residue after ignition, and that, as will appear from the work to be described, the main source of trouble in bringing precipitated silica to a constant weight does not lie in the process of dehy- dration in ignition, but is due to the presence of an impurity * Hillebrand, Jour. Amer. Chem. Soc., xxiv, 371; Treadwell, Quant. Anal. trans. Hall, 3d ed., p. 486. , + Zeit. angew. Chem., 1897, 425. t Cf. Hillebrand, loc. cit. SU.S. Geol. Survey, Circular No. 101, August 16, 1912. Gooch, etc.—Dehydration and Recovery of Silica. 599 which must either be volatilized or made to enter into stable chemical relation with the silica. From the results of certain experiments to be detailed it will appear that, while prolonged ignition with the Bunsen burner or with the blast lamp may sometimes be necessary to secure constant weights of silica _ separated from an alkali silicate by the action of hydrochloric acid, when the difficulty of securing constant weights appears it is to be attributed to the inclusion of foreign material more or less volatile and changeable at high heat, and not to the obstinate retention of water by the silica. The original material taken for our experiments was a com- mercial “analyzed” hydrous silicic acid containing approxi- mately from 45 to 50 per cent of anhydrous silica according to the degree of exposure. When digested with boiling water this material yielded traces of a soluble chloride and soluble sulphate. After the ignition of portions’of the original sub- stance—from 0°5 grm. to 5 grms.—for fifteen minutes over a large Bunsen burner, traces of chloride or sulphate could be -still detected in the silica. When similar portions of the original substance were ignited over the burner for forty-five minutes or over the blast lamp for half an hour neither chlo- ride nor sulphate was found in the aqueous extraction of the residue, but treatment with sulphuric acid left a residue which amounted in the average to 0°24 per cent of the original sub- stance. The barium sulphate precipitable by barium chloride from the solution of this residue proved to be nearly equiva- lent to the entire residue counted as sodium sulphate. Inas- much as neither chloride nor sulphate could be found in this strongly ignited silica, it may be presumed that sodium oxide, remaining in combination with the silica, constituted, at least after the strong ignition, the impurity which after the treat- ment with the acids appeared in the form of sodium sulphate. Upon this presumption, the silica used was 99°92 per cent pure after the strong ignition. The record of experiments in which portions of the hydrous silica were heated during successive half-hour periods, with the Bunsen burner and with the blast lamp, is given in, the following table. These results show plainly that the silica used may be brought to a practically constant weight in half-hour ignitions with a good-sized Bunsen burner. The next experiments show the effects of treating similarly the produet obtained by fusion of the ignited silica with sodium carbonate, treatment with hydrochloric acid, evaporation, extraction with very dilute hydrochloric acid, and careful washing. In series A of these experiments the drying was effected at 110° in the air bath. In series B the residue obtained by evaporation to apparent dryness on the steam bath 600 Gooch, etc—Dehydration and Recovery of Silica. TABLE I. Ignition of Commercial, ‘‘ Analyzed” Silica. Hydrous Weight of SiO, found Silica taken After heating with the After heating with (Approximate Bunsen burner, the blast lamp weight) in half-hour heats in 15 minute heats af II I II III grm. grm. gTm. grm. grm. grm. A 0°2 0°1008 0°1006 - 0°1006 0°4 0°19390 O- L929 0°1926 0°4 0°1968 0°1967 0°1966 0°5 0°2501 0°2500 0°2500 1°0 0°4568 © 0°4568 0°4568 Leal 0°5343 0°5333 0°5330 0°5330 ileal 0°5309 0°5304 0°5306 0°5302 0°5302 shai 0°5325 0°5327 0°5323 0°5324 Ut 0°5374 0°5372 0°5373 ial 0°5392 : 0°5381 0°5381 ity 0°5353 0°5351 0°5347 0°5347 B 10 05464 0°5454 05447 05445 0-5444* fl 0) 0°5206 0°5204 0°5202 0°5202 ° 0°5202 1:0 0°5447 0°5443 0°5441 0°5439 0°5439* 1-0 0°5346 0°5346 0°5342 0°5342 0°5342 10 0°5427 0°5427 0°5427 0°5427 - see 1°0 0°5376 0°5373 0°5373 0°5372° pee 1°0 0°5511 0°5511 0°5511 0°5511 | *2aaee 1°0 0°5445 0°5445 0°5444 0°5443 et 1°0 075344. 0°5343 0°5340 0°5338 0°5338 e@) 0°5513 0°5513 0°5513 0°5312. a to) 0°5312 0°5312 0°5311 0°5311 =~ See 1°0 0°5536 0°5536 0°5531 0°5091 ae was moistened with acetic anhydride and warmed over a radia- tor until this reagent fumed freely, the object of this treatment being to thoroughly desiccate the silica while preventing the otherwise possible formation of sodium silicate by action between silica, included sodium chloride, and water. Each of these methods of treatment leaves the silica drier, more porous, and, therefore, more effectively washable than is the case when drying is brought about by the steam bath only. The results of these experiments are given in the following table. Every residue of silica was treated, after the final ignition, with sul- phurie acid and hydrofluoric acid, the amount of sodium sulphate remaining was weighed, and the equivalent weight of the combined sodium oxide was calculated. *Tt was found that the crucible used in this determination was subject to loss when ignited by itself over the blast lamp. Gooch, ete— Dehydration and Recovery of Silica. 601 TaBLE II. Ignition of silica separated by acid after fusion with sodium carbonate. Residue of Residue of SiO. SiO, after Loss on Residue after after ignition subsequent ignition Na.CO; H.S0,+ HF with Bunsen ignition with with the used in treatment burner blast lamp blastlamp thefusion Na,SO, t a i Na.O grm. grm. erm. grm. grm. grm. A Residue dried at 110°. 0°5300 0°5291 - 0°5290 0°5287 0°0013 ~ 0°0009 0°0004 0°5380 075373 0°5368 0°5365 0°5363 0°5363 0°0017 + 0°0010 0'0004 0°5365 0°5360 | 0°0005 +: 0°0011 0:0004 0°4583 0°4575 0°0008 a 0°0014 0°0006 0°5071 0°5068 0°0003 + 0°0015 0°0006 0°5166 0°5159 0°0007 a 0°0012 0°0005 B Residue dehydrated on steam bath and heated with acetic anhydride. 0°1984 0°1980 0°1977 0°0007 2 0'0016 0°0006 0°4566* 0°4564 0°4562 0°0004 a 0°0020 0°0008 2 ee 0°5322 4 0°5325 | 0°5325 0°00038 0°0010 0°0004 A comparison of these results with those of Hillebrand, to which reference has been made above, points to the conclusion, that the more perfect drying of the silica before attempting the process of extraction and washing, results in smaller losses when the residue which has been ignited over the Bunsen burner is subjected to the heat of the blast lamp. This fact suggests that the better desiccation is conducive to the more nearly complete washing of soluble material from the precipi- tated silica. At the best, however, the separation of foreign matter is not perfect, and the presence of material which is dif- ficultly volatilized is sufficient to account for the slight changes in weight observed when the silica ignited with the Bunsen burner is submitted to further heating with the blast flame. According to our experience, therefore, the difficulty in bring- *Tonition extended to one honr. 602 Gooch, etc.— Dehydration and Recovery of Siltea. ing to a constant weight the silica precipitated in the ordinary way, by the action of acid upon the products of fusion with an alkali carbonate, is not due to the obstinate retention of water but to the presence of foreign material difficultly volatile or slowly changeable at the temperature of ignition. In our ex- periments, the foreign material retained in the precipitated silica must have been sodium chloride, and this in the process of ignition of hydrous silica is, as we have found experimen- tally, converted by the action of water to sodium oxide, which combines with the silica. In the experiments described above, the sodium oxide retained by 0°5 grm. of silica amounted in the average to 00005 grm. After the treatment with sulphuric acid and hydrofluoric acid, the residue ignited at red heat is sodium sulphate, and from the weight found of this substance the equivalent weight of sodium oxide must be calculated in order that it may be used as the correction for the foreign material included in the silica as weighed. In the final igni- tion the use of the high heat of the blast lamp is not advisable, lest the sodium sulphate lose weight and so vitiate the correc- tion to be applied to the silica. The Recovery of Silica after Fusion with Sodium Carbonate. It is a generally recognized fact* that, after fusion with sodium carbonate, silica cannot be recovered completely by a single filtration following any number of evaporations and treatments with hydrochloric acid. To secure satisfactory results it is necessary to evaporate the filtrate after the removal of the main amount of silica by the first treatment, treat the residue with hydrochloric acid, and again filter. The experiments detailed in the following table record the results obtained in recovering silica by two such” treatments after fusion with 3 erm. of sodium carbonate. The fused mass was treated with hydrochloric acid; the liquid was evaporated on the steam bath; the residue, desiceated either at 110° in the air bath or by the treatment with acetic anhydride; according to the method and for the purpose, previously described,t+ was extracted with hydrochloric acid ; the insoluble silica was fil- tered off, washed, ignited, and weighed ; the filtrate from the silica insoluble in this first operation was evaporated ; and the residue obtained was treated like the first residue. | In these experiments the deficiency in silica found after the first thorough evaporation and desiccation at 110° amounts in the average to 0°0051 grm., after correcting for silica intro- duced in the sodium carbonate, and this is practically the * Hillebrand, Am. Chem. 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S OIL 40 woyvoorseq S “WAS “UI “WLI “UldId “UIs “Uldd “UlId “Uh “Ud “ULI “ULI “ULIS xPOsSN EQO2N spol.od Tau.Ing ss9001g spols1ed Tau.Ing (aand “9799 SpolL.od spotted OMIA ur 018 punog ’OS°H+4H “UIUT G1 uesung |’OS*H+4dH “UYU GT uosung, 1ad %6.66) “UJ UL GT INOY-J[/BY IO} paqoo109 Aq dure] 488) q LO) Ox Aq dui] ysviq LopN ON Ayand wt duel ise[q louanq uosung P9210) YIM poqyusy poqusy peqoalt0O = JM poousyT = payusy TOF Way At Ua a ‘VOITIS TIVLOY, ‘LNEALVALL GNOOUS “ENUM LVEAL YT, LSaiy a Beard oe ey, uO;j Lust TOV ‘CHUHAOORY VOLTS "SJUIUIDAAT, ONT, U2 DIIIYG fo h.xonodaxT ee ‘NEMV], VOITIG 604 Gooch, etc.—Dehydration and Recovery of Silica. amount of silica recovered in the second treatment. In the experiments in which acetic anhydride (B.P. 137°) was used to moisten the residue (after thorough desiccation on the steam bath) and then partially removed by boiling, the average deficiency in silica after the first treatment amounted to 0°0061 grm., and the amount recovered in the second treatment to 0:0051 grm. Obviously, the insolubility of the silica, after the process of desiccation, extraction, and filtration depends very largely upon the thoroughness of the drying; and, while the drying at 110° or at 137° (in acetic anhydride) greatly dimin- ishes the solubility of the silica as compared with that of the substance when simply dried on the steam bath, the treatment with acetic anhydride offers no advantage over the process of drying in the air bath at 110°, at least, when the contami- nating substance is sodium chloride. The slight variations in the weights obtained when residues which had been ignited with the Bunsen burner were submit- ted to the temperature of the blast lamp appear to be due to the presence of sodium chloride which by strong ignition is either transformed to sodium silicate or is partially volatilized. ia a , FA. Perret-—The Ascent of Lava. 605 Art. LII.—TZhe Ascent of Lava; by Frank A. PERRet. Wuy does the lava rise from below toward the earth’s surface ¢ This fundamental question resolves itself, upon examina- tion, into several parts. We may ask, for instance, why the lava should move in any direction,—why, that is to say, there should be motion of translation in this material,—why it should seek to extend itself from the position it occupies? But,— whether by reason of the pressure to which it may be sub- jected, or through actual augmentation of its substance, or by the absorption of infiltrating materials, or even through greater fluidity resulting from some lessening of pressures,— we know the magma to be endowed with the property and power of expansivity, in consequence of which it must, if pos- sible, find or form for itself an outlet through its too restrict- ing boundaries. Nor, in view of this quality of expansiveness, shall we mar- vel that the magma should rise into a fissure which may open above the-stratum or pocket which constitutes the reservoir. Assuming such injections to be abyssal, they will not, in gen- eral, perforate the outermost shells but, whether remaining as simple, lava-filled rifts or developing the expanded, top-like sections imagined by Johnston-Lavis* and Daly,t they will constitute secondary reservoirs nearer to, but not yet in com- munication with, the surface. It is from this point that the further progress of the lava forms the subject of our inquiry,— why, of all possible directions, this should still be upward or, more precisely, outward from the direction of the earth’s center toward its periphery @ Such further progress is effected, in general, by a progress of trepanning, so to speak, which results in the formation of a vertical tunnel, often of exceedingly small diameter in propor- tion to its length. But, if we remember that the rising of the lava represents work against gravity and necessitates the perforation of succes- sive strata, and that, furthermore, the progression takes place at the point farthest from the heat reservoir and where the actual contact pressure is least, it would almost appear, at first sight, that, in ascending as it does, the lava follows the path of greatest resistance and advances where its power to do so is most limited. * H. J. Johnston-Lavis: The Mechanism of Volcanic Action, Geological Magazine, London, October, 1909. t Reginald A. Daly: Abyssal Injection as a Causal Condition and as an Effect of Mountain-Building, this Journal, Sept., 1906. ¢ 606 F. A. Perret—The Ascent of Lava. In seeking to explain these anomalies we may safely assume two things, viz., some guiding principle or directive force, which determines and maintains the upward direction of prog- ress as a compass points to the north ; and, second, some mode of action,—some excavating agent other than simple heat and pressure,—which has not yet been considered. _ Beginning with the latter, we may ask ourselves if there is anything at the upper level, where the progression takes place, which is not to be found at the other contact surfaces? The answer 1s—gas. We have here another demonstration, and a notable one, of the importance of the gaseous element in the dynamics of vol- Big, 1 TEE RWW WM QZ WG WAY VW WE WAAL REO AA AAI WO QW QA RMON MMXQQAQA AA Fie. 1. Lava column with compressed gaseous head, fluxing its way upward through solid strata. canic action. If the lava were a simple liquid and its function purely hydrostatic, as has sometimes been contended, the up- ward progression, as observed, could not occur. It is the escape of free gas which results, as we shall see, in the formation of the tunnel, but before taking up that phase of the subject, we may realize that we have also discovered the guiding principle —the directive force which determines and maintains the up- ward way. This lies in the gravitative adjustment of gas and lava,—the gas, by its lightness, places itself above the lava and, constituting, as it does, the active boring agent, the direction of progression will and must be upward; nothing could be simpler. As to the modus operandi of this trepanning by the gas- headed lava, it is obvious that we must consider the nature of the material to be perforated. If this consists of strata of solid rock the gases will be largely retained above the lava column ft, A. Perret—The Ascent of Lava. 607 as a small, compressed plug. Daly has pointed out* the powerful heating effect of such compression, by which the gas acquires a true fluxing power, melting the contact walls. The fused material absorbs gas, adding heat of solution and of chemical reaction. The gaseous head of the lava column thus becomes an effective means of progression, capable of fluxing its way through the hardest strata. Examples of this action on a small scale may be seen in the many little pit-craters at ~ a iar -I NG = 17 NG Fie. 2. Lava column with expanding gaseous head, eating its way upward through incoherent material. Kilauea, which are simple, cylindrical channels rising vertically through the solid lava strata. If, on the other hand, the ascent of lava is through a con- elomerate mass of more or less incoherent materials, it is certain that the gases cannot be so perfectly retained and compressed above the column of lava. In such a case their action will be excavative, disintegrative, corrosive. Channels will be enlarged, masses dislodged and engulfed; and this “stoping” process will be combined with the peculiarly destructive effects of fumarolie activity. In contradistinction to the former method of temperature development, this is here maintained by the * Reginald A. Daly; The Nature of Volcanic Action, Proc. Amer, Acad. Sci., vol. xlvii, No. 3, p. 93. 608 HF A. Perret—The Ascent of Lava. jlow of gas through the lava column, thus continuously bring- ing up heat from below. In fig. 2 the lava is represented as eating its way upward through the chaotic materials obstructing the conduit of a vol- cano as the result of the last eruption—the lava rising to re- establish communication with the crater and inaugurate a new eruptive phase after a period of repose. The sketch repro- duces the actual condition of Vesuvius where, after seven years of external repose, during which time the conduit has been blocked, the lava has, at last, virtually reached the crater. Its gradual approach, by the process here described, has for many months been visibly manifested by a progressive increase in the temperature and volume of the fumarolic emanations at the crater bottom and especially by repeated collapses indicative of the subterranean stoping. We may conclude that the progression of a lava column and its direction are determined by the gaseous emanation. Posillipo, Naples, September, 1913. F. W. Very—Solar Radiation. 609 Arr. LIV.—Solar Radiation; by Frayx W. Very. THERE are two modes of measuring solar radiation which may be called the actinometric and the bolometric modes. The former measures the intensity of the total normal radia- tion on unit surface and is the more direct of the two. The bolometric method traces the distribution of energy in the solar spectrum, determines the wave-length of the maximum point in the spectral energy-curve, and infers by theory the temperature and radiating power of the solar surface, from which the intensity of radiation at the earth’s distance is at once known, since the radiant energy diminishes in inverse proportion to the squares of sun’s radius and earth’s distance which on the average is given by the formula log (R/D)* = 5°33535 — 10.* _ Both methods require a knowledge of the corrections to be applied for instrumental errors and for absorption by the earth’s atmosphere. There are now several reliable actinometers, capable, when properly handled, of giving results correct to 1 or 2 per cent. Unfortunately, some of these instruments may give readings which are as much as 20 per cent in error when inefficiently manipulated, or imperfectly corrected. The prime necessity, after the attainment of a moderate amount of skill, is that the observer shall make a thorough study of the theory of his instrument, become familiar with the necessary precautions, measure the instrumental constants with the greatest attainable precision, and apply all of the corrections indicated by theory which have a sensible magnitude. The spectrobolometric method, invented by Langley and now perfected by the observers at the Smithsonian Institution, has corrections which are more complicated than those of the actinometer, but with reasonable precautions either method may now be put ona tolerably safe basis as far as the instru- _ mental corrections are concerned. The corrections for atmospheric interference with the radi- ant transmission are in an altogether different category. Hypotheses and mathematical discussions are required, and when all is done that human ingenuity can accomplish, the final result can hardly be dignified as a “measurement” of a “solar constant,’ but must be conceded to be scarcely more * The distance-factor for any given date may be obtained by taking the semidiameter of the sun which is given for each day of the year in the solar ephemeris, looking out the log sine of this angle and doubling it, and sub- tracting from the above logarithm. Am. Jour. Sct.—FourtH SERIES, VoL. XXXVI, No. 216.—DrEcEmBrr, 1913. Al 610" F. W. Very—Solar Radiation. than a moderately close estimate at the best, or than a very unfortunate guess at the worst. The ablest investigators, and those whose opinions on the subject deserve the greatest weight, have said either that the solar constant can never be found in any exactly mathematical sense, or that its value is best stated with a very wide margin of probable error. Of the two methods named, the second is least encumbered by difficulties from transmissive theory, and though cireumlo- cutory, it is in many respects to be preferred. The radiant losses which are most difficult to estimate are those which affect all wave-lengths equally, or nearly so. But these losses make very little change in the form of the spectral energy- curve, and the position of the maximum energy (A,,x,) will scarcely be altered by their neglect. In fact, the chief source of uneasiness to the investigator of the spectrum lies in the possible existence of a diffuse atmospheric absorption band very near to this maximum ordinate of the spectral energy- curve. There is considerable evidence of just such a band, and a variable one at that; but conceding that some, at any rate, of the observations may have escaped fatal infection from this source, and admitting that there are probably no better curves than those which have been published by Abbot and Fowle, of which a sample is given in figure 26 of Abbot’s work on “The Sun,” we may push this method for all it is worth. I can not do better than to quote from the last- mentioned work; but first let me call attention to the follow- ing point. In a publication on “The Solar Constant ”* I noted that the extreme infra-red spectrum is much more intense than would be expected from a theoretical spectral energy-curve, for such temperatures as are indicated by the position of maximum energy in the spectrum, and I attributed this divergence to the fact that the solar radiation is the sum of emissions from layers at various depths and having a wide range of temperature. Thus the very intense radiations of short wave-length from the deeper layers are greatly absorbed by more elevated layers of the solar atmosphere, which are heated thereby and radiate in turn, but at a lower temperature and longer wave-length, besides transmitting the long-waved emissions from the deeper layers more freely, so that the long waves escape more readily than the short ones. This peculiarity may also be due in part to the predominance in the sun of metals having positive coefficients of resistance which radiate long infra-red waves at high temperatures with greater intensity than black substances do, or which more nearly approach the ideal “ black” radiator *U.S. Weather Bureau Publication, No. 254, pp. 22-28, 1901. F. W. Very—Solar Radiation. | 611 in this part of the spectrum than lampblack and similar sub- stances, which are reputed black for the shorter waves, but become transparent and less perfect radiators in the extreme infra-red, whereas metals at high temperatures become trans- parent for the short waves of the visible spectrum. Although not extending to as great wave-lengths as those on which my conclusions were based, these bolographs by the Smithsonian observers confirm the statement ma general way. The bolo- metric method which rests on the shape of the spectral energy- curve, obviously tends to underrate the solar temperature by overestimating the importance of the longer waves, and shift- ing the maximum in their direction. Referring to the distribution of energy computed by the Wien-Planck formula for temperatures 7000° and 6200° Abs. C., Mr. Abbot says of the observed curves: “ Their infra-red parts correspond to much hotter sources than do their visible and ultra-violet parts. It is evident, however, that the 7000° curve, except in the ultra-violet, is a better match for the observations than the 6200° curve” (The Sun, p. 112). On page 114 (op. crt.), the solar temperature is said to be “ cer- tainly above 6200°, and possibly near 7000°”; and on page 420, “it seems most probable that the photospheric* tempera- ture should be set not lower than 6500° Absolute.” We shail not be far from the truth if we take the effective solar temperature as 6800° Abs. C., which gives for the solar constant at the earth’s mean distance by Stefan’s law, A = (6800)* x 1:267 xX (10)-” x 60 x sin? 15’59".63 = 3°518 gram cal./sq. cm. min. This value is in close agreement with that which I have given in my paper, “A High-level Measurement of Solar Radiation,”’+ founded on an observation by Violle, and with concordant values which are obtained in my paper, “A Criterion of Accu- racy in Measurements of Atmospheric Transmission of Solar Radiation,’ + from observations by Savélief and by Kimball, when treated by a modification of Crova’s method. The latter values have been. obtained by actinometric modes which are thus shown to be capable of yielding correct results when prop- * Although continuing to use the word ‘‘ photospheric,” Mr. Abbot rejects the usual conception of a layer of opaque, incandescent cloud at a definite level, and holds that the solar radiation comes entirely from layers of rela- tively, but still imperfectly, transparent gas at various depths ; that is to say, he denies that there is any basal layer giving a continuous spectrum, or any continuous spectrum other than a virtual one produced by the broadening of gaseous emission lines through pressure. This point needs separate discus- sion, which can not be attempted here. It is sufficient to note that the ‘‘ pho- tospheric ’ temperature in the above quotation is not distinguished from the effective solar temperature. ' + Astrophysical Journal, vol. xxxvii, p. 25, January, 1918. tIbid., p. 31, January, 1913. _ _£LL i 612 F. W. Very—Solar Radiation. erly reduced ; but it is impossible to reach even approximations to the truth by such methods of reduction as have been used by Pouillet, or by Abbot and Fowle. The neglect of the diur- nal variation of atmospheric quality, and the erroneous suppo- sition that the same coefficient of transmission can be- used at all hours of the day, completely vitiates these reductions. Having obtained in this way a supposed solar constant of 1°95 eal./sq. em. min., Mr. Abbot says: “ From this, T = 5860° Absolute C. As this value falls below those obtained preyi- ously [by the bolometric method], we may suppose the sun’s constant of emission is a little less than that of a perfect radi- ator.” * This may indeed be the case, and the exponent of T in Stefan’s law possibly differs somewhat from 4 for a body of solar composition and temperature, but if the hypothesis that the sun is a perfect radiator can be tolerated for Mr. Abbot’s use in the bolometric computation, it ought to be good enough for the actinometric one. To use the hypothesis in the one case, and reject it in the other, is not admissible ; and the dis- crepancy between the temperatures computed on this basis remains as a contradiction which overthrows the alleged deter- mination of the solar constant to three significant figures. Warned by this example, we shall perhaps do well not to attempt the assignment of a definite value to the solar constant at the present time further than to say that it probably lies be- tween 3 and 4, and apparently not far from 3°5 or 3°6 gram cal./sq. em. min. If we take the spectral energy-curve of the center of the solar disk, corrected for instrumental errors and approximately for the absorption of the earth’s atmosphere, to get relative - values which are correct as far as the ratios for different wave- lengths are concerned, the maximum ordinate according to Abbott is Ayax, = 0°458u. Applying to this curve the appro- priate coefficients of transmission by the sun’s atmosphere,t we get the results given in the following table: 4 |_# le le eo} pe I Ie fe ry ye 03 |04 |05 |06 [0-7 (0-8 |09 |1°0 eam a | 0:008 | 0372 | 0:490 | 0-405 | 0-308 | 0-226 | 0-157 | 0-120 | 0-051 | 0-018 b |0-:05 | 0-18 | 0-29 | 0-37 | 0-48 | 0-475 | 0-51 | 0-54 | 0-64 | 0-69 e | 016 | 2-07 | 1:69 | 1:09 | 0°72 | 0-48 | 0°31 | 0-22 | 0-08 | 0-03 For curve ¢, Amar=0°41p. * Op. cit., p. 114. + The Sun, figure 26, page 109. {Frank W. Very: ‘‘ The Absorptive Power of the Solar Atmosphere ”—Mis- ger aia Papers of the Allegheny Observatory, New Series, No.9, Table 5, p. 18. F. W. Very—Selar Radiation. 613 where X = wave-lengths, @ = ordinates in the spectral energy- curve for the center of the solar disk (Abbot), 6 = transmission by the solar “atmosphere” (Very), ¢ = a/b, or the photo- spheric ordinates which would be observed if the sun’s “ atmos- phere” * above the photosphere could be removed. The wave-length of the photospheric maximum differs very little from a similar, unpublished reduction of these measures made in the summer of 1882 at the Allegheny Observatory during Director Langley’s absence in England, where he an- nounced at the Royal Institution his theory of the “blue sun.” If my measures had been made sooner, the form of this announcement would have been a little different, for upon re- combining the spectrum colors in the proportions required to reconstitute a light equivalent to unabsorbed sunlight, I actu- ally obtained a delicate tint of lavender, instead of blue. These provisional values of absorption by a species of solar atmos- phere were accepted by Langley at that time, although some singular relations between the apparent absorption at different radial distances remained outstanding, which are now partially explained in several papers by Professor Schuster and myself, even if it is not possible to assign definite limits to several dis- tinet yet probably simultaneously commingled processes.t+ Since Mr. Abbot has recently obtained similar curves show- ing a great diminution in the radiation of short wave-length between the center and limb of the solar disk,t perhaps the reason why he has not applied this knowledge in reproducing the energy-curve of the photospheric radiation may be his un- belief in the reality of the photosphere. My result is given for whatever it may be worth and indicates a photospheric tem- perature. = 2930/7 0Al — 746° Abs. C8 Owing to the total absorption of the shorter ultra-violet waves by the atmospheres of either sun or earth, the losses of these radiations are somewhat problematical, and both the restoration and the resulting temperature are liable to be underrated. Assuming that the photosphere is composed of nascent molecules, or molecular aggregates forming minute mist particles, this temperature is that of the complete ioniza- * The solar envelopes include, besides gaseous material (mainly dissociated by reason of the excessive heat), the dust of the coronal filaments and ‘some material (either molecules or mist particles) in close contact with, or perhaps in its denser distribution constituting, the photosphere. This comminuted material scatters the shorter waves powerfully. + See the Astrophysical Journal, vol. xvi, p. 73 and p. 320; vol, xix, p, 139; vol. xxi, p. 1 and p, 258. {The Sun, figure 25, p. 106. _ § This approximate formula requires slight modifications to adapt it to the refinements of the Wien-Planck law. 614 F. W. Very—Solar Radiation. tion of solar material, and the photospheric level is determined by the depth at which this temperature is attained. Thus in low-temperature stars the photosphere may be an ill-defined misty layer of great depth, while in hotter stars the limits within which molecular structure can exist should be narrower and more sharply defined. All observations in the solar ultra-violet spectrum show a great deficiency of energy by comparison with the theoretical curve given by the Wien-Planck law. A part of this deficiency may be due to the transference of energy, absorbed in the numerous Fraunhofer lines of the ultra-violet, to radiators of lower temperature* as already explained, but a part must be attributed to inadequate evalution of the depletion of short waves by the terrestrial atmosphere. The depletion of ultra-violet radiation in passing through the sun’s atmosphere is of interest in another way. In this region of short waves occur the widest variations of transmissive quality in stellar atmospheres. Humphreys has suggested} that the composition of the solar atmosphere itself changes from time to time, or between maximum and minimum sun- spot epochs, sufficiently to produce a variation in the quality of the solar radiation, even though no change occurs in the total quantity of energy emitted. The known variation of thesolar corona in the sun-spot period and the change in the amount of coronal dust may produce a slight alteration of transmissive quality, but by far the greater part of the change must take place in those deeply lying molecular structures in close con- tact with and interpenetrating the photospheric, which so greatly scatter the shorter waves and deplete them increasingly from center to limb. The thorough demonstration of this supposed change must be the subject of a lengthy research covering an entire 11-year period. Founding his hypothesis on a few observations by Abbot and Fowle, Dr. Humphreys notes that “‘on examining Wolfer’s curves of sun-spot numbers it is seen that the days on which Abbot and Fowle found the * For the relation between absorption and scattering in foggy media at high temperatures, see ‘‘Radiation through a Foggy Atmosphere” by Arthur Schuster (Astrophysical Journal, vol. xxi, p. 1, January, 1905). Were it not for scattering, ‘‘we should only obtain the continuous spectrum of the background, the medium not affecting the radiation at all” (op. cit., p. 11). Selective scattering of short waves and prominence of ultra- violet absorption lines increase with the condensation and greater internal heat of a star because mist particles, whose scattering action is more general, are fewer and only molecules remain which scatter short waves, while by the dissipation of mist the masking of the gaseous absorption by the latter ceases. This test shows that Arcturus is internally hotter than Vega (compare F. W. Very, ‘‘A Cosmic Cycle,” this Journal (4), xiii, p. 52, March, 1902). + W. J. Humphreys: ‘‘Solar Disturbances and Terrestrial Temperatures,” Astrophysical Journal, vol. xxxii, p. 97, Sept. 1910. fF. W. Very—Solar Radiation. 615 amount of violet radiation to be relatively small were days of many spots, while the one on which they found it relatively large was a day of exceedingly few spots” (op. cit., p. 100). More extensive observations would be desirable, “put the hypothesis is plausible. If the portion of energy in the shorter waves, cut off by the scattering, be handed on to more elevated solar “ dust,” and again emitted as an equivalent radiation of longer wave-length from particles at a lower temperature, the solar radiation at epochs of sun-spot maxima, or whenever the coronal and other “dust” is most prevalent (as after unusnal development of prominences), is richer in long waves and passes more readily through the earth’s atmosphere, whence the earth’s tropical regions (where the chief thermal effects are to be expected) receive a larger accession of heat at sun-spot maxima, as several meteorologists have maintained. Dr. Humphreys arrives at the opposite conclusion, and owing to the great importance which he attaches to the ozone absor ption bands in the earth’s atmosphere, he favors the supposition that, although more ozone may be produced in high latitudes at sun- spot. maxima on account of increased electric discharges in the upper air dur- ing auroral displays, less ozone is formed in the upper air of the tropics at this time because the sun’s ultra-violet rays are diminished ; and en the whole the earth is then cooler, because - more telluric radiation escapes in the region of the spectrum covered by the ozone bands near 104. My reasons for not accepting the role which he assigns to ozone as the most potent controller of terrestrial temperature may be seen in an article on “Sky Radiation and the Isothermal Layer.”* An increase in solar radiation does not cause higher tempera- tures over all the earth, but the one cause leads to opposite effects in diverse regions. An average of terrestrial thermal fluctuations may give either a positive or a negative residual according to the preponderance of stations in one or the other of the opposing classes, and the actual solar influence stands a good chance of remaining either unrecognized, or greatly underrated in climatological summaries. In Abbot’s work on “The Sun” we read: “The earth’s sur- face air temperature is on the whole lower at sun-spot maximum than at sun-spot minimum,’’} and this .conclusion is reiterated on page 405: “ The change of temperature of the earth seems to indicate that the sun’s radiation is at a macimuwm when sun spots are fewest.” This remark is made in connection with an allusion to the variability of Mira Ceti which “suggests the solar variability associated with sun-spots,” but which is here * This Journal (4), vol. xxxv, pp. 369-388, April, 1913. +P. 190. 616 F. W. Very—Solar Radiation. supposed to exhibit a law of change opposite to that of the sun: “ Mira increases in brightness faster than it decreases.” The discrepancy, however, arises from what I believe to be a mistaken conclusion in regard to the variation of terrestrial temperatures attributable to solar changes. In my paper on “The Variation of Solar Radiation,’ I concluded that “the maximum temperatures are higher for a time of many sun- spots in the torrid zone, and lower in the temperate zone.”’* The cause of hesitation in the acceptance of this conclusion is also pointed out: “‘ Most of our material comes from the temperate zones and is difficult to analyze. The fact that so large a part of the earth is in lower latitudes than the average storm-belts, and that the greater part of this surface is oceanic, warns us that our mid-latitude storms are a mere fringe on the grander field of tropical atmospheric activities.”+ “It does not appear to be necessary that the sign of such temperate residual should agree with that from the tropics. While higher tropical temperature produced by greater solar radia- tion must Increase convection, which may transfer extra heat to the temperate and polar zones, it is quite possible that cer- tain regions may get more than their share of the returning polar winds concerned in the convection, and may have their temperature lowered thereby. This, in fact, appears to be the case in the upper Mississippi valley and in Europe.’’t x The prevalent scientific opinion that the earth is cooler at sun-spot maximum is, I believe, contrary to fact, and has apparently arisen because most of the people who hold this opinion reside in the region of ‘the returning polar winds concerned in the convection.” Mr. Henry F. blanford, than whom there has been no more competent student of the mete- orology of the torrid zone, says in his ‘‘ Indian Meteorologists’ Vade-mecum”’§ that “the solar radiation is greatest in years of abundant sun-spots and wice versa. ... The results of eleven stations, in different parts of India, showed an increase of at least 6° in the mean equilibrium temperature of solar radiation at the earth’s surface between 1868 and 1871 (the last following a year of maximum sun-spots) ; and this, 1 am inclined to think, is in defect of the truth. The variation is thus by no means inconsiderable.” In explanation of the discrepancy between his results and those of Képpen, Blanford says: “The temperatures dealt with by Professor Képpen are, of course, those of the lowest stratum of the atmosphere as observed at land stations, and must be determined, not by the quantity of heat that falls on * Astrophysical Journal, vol. vii, p. 255, April, 1898. t+ Op. cit., p. 263. F. W. Very—Solar Radiation. 617 the exterior of the planet, but on that which penetrates to the earth’s surface, chiefly the land surface of the globe. The greater part of the earth’s surface being, however, one of water, the principal immediate effect of the increased heat must be to increase the evaporation, and therefore, as a subse- quent process, the cloud and the rainfall. Now a cloudy atmosphere intercepts a great part of the solar heat; and the re-evaporation of the fallen rain lowers the temperature of the surface from which it evaporates, and that of the stratum of air in contact with it. The heat liberated by cloud condensa- tion doubtless raises the temperature of the air at the altitude of the cloudy stratum, but this is not recorded in our registers. As a consequence, an increased formation of vapor, and there- fore of rain, following on an increase of radiation, might be expected to coincide with a low air-temperature on the surface of the land.”* This explanation does not exclude the one which I have suggested, but is to be looked upon as an additional cause of local discrepancies which do not invalidate the wider conception which includes them. Mr. Blanford refers to his explanation as a “speculation . . . in part suggested by the discovery of Messrs. Meldrum and Lockyer that the frequency and energy of cyclones and the rainfall of the globe appear to vary directly as the abundance of sun-spots.” It wiil be seen that in this case, as in some others, Mr. Abbot has included only one side of a controverted subject in his treatise. In more than one place he also cites as authorities for his statements names of investigators who have held diverse _ opinions. Mention is madet of the shifting of the zones of maximum frequency of prominences, but no notice is taken of the short period of this shift (8 to 4 years) which is shown by Lockyer’s curves for solar latitudes 30° to 60°. Bigelow finds that this shift synchronizes with a periodic change in terres- trial climates which is even more marked than the 11-year cycle. He says: “The frequency variation of the solar prom- inences in the higher latitudes gives the key that was wanted to enable us to study the meteorological conditions in the earth’s atmosphere with some prospect of success. This varia- tion shows that the meteorological pulse is registered most favorably not in the sun-spot belts, but in the zones of the sun corresponding with the temperate zones of the earth from lati- tude 30° to 60°.” t Owing to the periodic interchange of climatic conditions over extensive areas of the earth’s surface, we have the phe- * Astrophysical Journal, vol. vii, p. 159-160. + The Sun, p. 195. ¢{ Frank H. Bigelow: ‘‘ Studies onthe Diurnal Periods in the Lower Strata of the Atmosphere,” p. 41. U.S. Weather Bureau, 1905. 618 FEF. W. Very—Solar Radiation. nomenon of ‘‘inversion”* discovered by Bigelow, which com- plicates the meteorological problem still more. Into this prob- lem enter: (a) the solar constant whose estimation can not be made without hypotheses, and whose variation remains uncer- tain; (b) changes in the solar spectrum which synchronize — with the sun-spot cycle and show an alteration in at least the guality of the solar radiation; (¢) variations in the solar corona in the 11-year period, which may affect the earth by a solar emission of kathode rays or by some other process differ- ent from the ordinary radiation; (d@) climatic cycles which are of opposite nature in different parts of the earth and of several periods (including the 11-year period). No climatic theory can be considered complete which does not consistently harmonize these details. | Many attempts have been made to derive formulas connect- ing the absorption of solar radiation with the aqueous vapor of the atmosphere, but with such small success that the effort has been generally abandoned. Nevertheless, the total omission of a vapor factor in the computation of the solar constant must be remedied, for it is certain that atmospheric moisture has a depleting action on the incoming as well as on the outgoing radiation. This may be known because (1) the form of the diurnal curve of solar radiation changes from a symmetrical shape with relative freedom from fluctuations in» cold, dry winter weather, to a flattened and unsymmetrical shape beset with sinuosities in summer. (2) The total solar radiation through identical masses of air is smaller in moist, summer weather than in cold and dry winter weather, and this diminu- tion of intensity in summer is associated not only with increase of the aqueous absorption-bands in the infra-red spectrum, but with an increased depletion of the shorter waves of the visible and ultra-violet parts of the spectrum. (3) Asa result of the last-named depletion, red sunsets are characteristic of the tropics and summer, or of the approach of hot waves and increased atmospheric moisture, while the fading of the dawn and sunset tints implies a widely prevalent dryness in the atmosphere, associated with cold because the terrestrial radia- tion also escapes through the atmosphere more freely at such times. (4) If we compare the solar radiation with equal aur masses we shall find that (@) in the morning and afternoon of the same day, the afternoon measurement will usually be the smaller because, in general, evaporation of surface moisture has increased the vapor content of the air in the afternoon, and (6) that of simultaneous measures at different altitudes on a * Inversion of temperature consists not merely in a general synchronous opposition of thermal changes in different parts of the earth, but includes - minor details in the distribution and amplitude of the thermal fluctuations. F. W. Very—Solar Radiation. 619 mountain, the more elevated and drier station gives the larger radiation. The effect here is complicated by a dust-factor, but it can not be doubted that water vapor has some part to play in this variation of atmospheric quality. Bieats ‘ | 0 Q 4 6 RAG pode: 4deoemt Fic. 1. Abscissee = pressure of aqueous vapor in the free air at the level of the place of observation. Ordinates = factors for reducing observed solar radiation to corresponding values at the outer limit of the atmosphere. Full lines are for sea-level. Dotted lines are for level of Mt. Wilson = 1780 meters. € =(B/Bo) xSec. ¢. The actinometric method of solar investigation is not capable of yielding exact values of the solar constant except under rare a = Pi 620 F. W. Very—Solar Radiation. combinations of atmospheric conditions,* but since actimome- tric observations are easily made and have been accumulated in great numbers for many years, it is desirable to see whether some use, even though an imperfect one, may be made of this material, and especially whether a way may be found to elimi- nate the depleting action of aqueous vapor. The chart (fig. 1) has been constructed from the numbers in the following table.t Pressure Air-masses || 3 | 4°] 9 | 3 | 421 5 | 6 | 7 | (ieee of c= aqueous vapor. min. Radiation (gr. 9-66 | 2-22 | 1°73 | 1-46 | 1:26 | 1°12 | 1:02 | 0°94 | 0°87 | 0°81 | 0°76 0:8 hee ae 9:40 | 1°88 | 1°36 | 1:13 | 1:01 | 0°89 | 0°79 | 0°72 | 0°66 | 0°59 | 0°53 5-0 min.) 1°86 | 1:22 | 0:97 | 0:83 | 0-73 | 0°68 | 0°63 | 0°59 | 0°55 | 0°51 | 0-47 |) 15°0 Factors reduce-|| 1°316 | 1°58 | 2°01 | 2°40 | 2°78 | 3°13 | 3°43 | 3-72 | 4-02 | 4°32 4°61 0:8 ing to Solar|| 1-46 | 1°84 | 2°57 | 8-05 | 3°47 | 3-98 | 4-43 | 4°86 | 5°80 | 5°85 6°42 5:0 constant. 1°88 | 2-82 | 3-61 | 4:22 | 4°70 | 5°15 | 5°56 | 5-93 | 6°36 | 6°60 | 6:95 5:0 By the aid of this chart actinometric measures may be cor- rected for atmospheric absorption in a somewhat rude but fairly satisfactory manner, provided a sufficient body of data exists for the elimination of fluctuations in a final mean value. The method requires, in addition to the actinometric readings, simultaneous observations of the atmospheric aqueous vapor. By rights these should include the distribution of aqueous vapor through a considerable part of the air column, which can be obtained only by the meteorological records of high kite-flights, or of sounding balloons. In the absence of vapor records for the upper air, wide fluctuations in the computed solar constant must inevitably be found, because the pressure of aqueous vapor at the earth’s surface 1s only imperfectly related to the quantity of precipitable and absorbent vapor in the entire air-column. As an example of the results to be expected from this chart, I take at random from volume 2 of the Annals of the Smith- sonian Astrophysical Observatory, the actinometric observa- tions of five days at Washington, merely looking out to get a considerable range in the pressure of aqueous vapor so as to test the method. The recorded data are insufficient tor more than rough approximations. Only one, or at most two vapor readings (Aq.) are given on each day. In these examples, * For which see “A Criterion of Accuracy in Measurements of Atmos- pheric Transmission of Solar Radiation,” Astrophysical Journal, vol, Xxxvil, p. 31, January, 1913. +Read from fig. 4 of my ‘‘ Criterion” paper just cited, and checked by numerous examples. F. W. Very—Solar Radiation. 3 621 €=sun’s zenith distance. No barometric pressures are pub- lished. Consequently, I assume that the air pressure was normal and take air masses, ¢e— sec. ¢. Radiation is denoted by R, and the factor F is read by inspection from the chart with e and Aq as arguments, giving as many estimates of the solar constant, A = FR, as there are readings. Sec. ¢. R. Bis A, August 24, 1903 1°148 1°092 2°90 3°167 = 14°66", 1°188 1°107 2°94 B55) 1-242 1°:074 2°98 3°201 1°466 1-013. ole 3°191 (4 obs.) Mean=3°204 Reduced to sun’s mean distance 3°255 December 23, 1903 2°158 1°160 2°47 2°865 ae 3°30"™,* | 27150 1-121 2°47 2°769 2°150 1°060 OH 2°618 2°948 Llao 2°51 2°899 2°266 ga Beets 2°52 2°961 2°360 1151 2254 2°958 2°390 1°103 2°59 2°857 2°520 1°096 2°66 2°915 ALS 1°099 2°69 2°956 2°979 1°017 2°86 | 2°909 Silelis 1°008 2°93 2°953 (11 obs.) _ » Mean=2°878 Reduced to sun’s mean distance 2°770 May 28, 1904 1°100 1°351 Bale 2°905 Ay ==6'50™™, 1°107 1°347 2°16 2°910 eka, 1°287 2°18 2°806 1°150 1°:295 2°18 2°823 1°200 Pest 2°22 2°910 1°212 1°299 2:23 2°897 1°282 1'216 oT 2°760 TeIVOr 13) 2°29 2-599 1°390 1225 2°35 2°879 1°410 1°220 2°36 2°879 eT 1°180 2°46 2°903 1°600 LS 2°48 2°914 1°843 1:078 2°64 2°846 ~ 1°888 1°103 2°66 2°934 (14 obs.) Mean =2'855 Reduced to sun’s mean distance 2°920 622 F. W. Very—Solar Radiation. Sec. ¢. R. |e A. October 21, 1904 1568 1538 2°58 3°878 AG — (nem 1°580 1°406 2°54. 3°571 1°587 1°384 2°54 3°515 1°594 1394 2°54 3°541 1°653 1424 2°58 3°67 1.0 ae 1°666 1°384 2°59 3°585 1:680 1°435 2°60 3°731 1°820 1°304 2°69 3°508 1°844 1°354 2°70 3°656 1°870 1°394 2°79 3°791 2°172 1°321 2°89 3°818 2214 1°260 2°91 3667 2682 1°253 Bye 17) 3972 2:760 1:209 3°21 3°881 2°845 1°158 3°26 3°775 3°B45 0:999 3°69 3686 4030 0°953 3°77 3593 (17 obs.) Mean=3'697 Reduced to sun’s mean distance 3°639 January 9, 1906 2°149 1°360 2°32 3°155 Ag. =1-96"™, 2°163 1°365 2°33 3°180 2°179 1°344 2°34 3°145 2-279 1°365 2°39 3°262 2°300 1°365 2°40 3°276 2326 1°367 2°41 3°294 2°500 ch ale 2°49 3°329 2°540 1°318 2°51 3°308 2°580 1°304 2°53 3299 3°080 1°194 2°74 3271 3°163 Laz 0 3°244 3°246 1°147 2°81 3°223 3°740 1:036 2°99 3:098 3°870 1:021 3°03 3°094 (14 obs.) Mean=3'227 Reduced to sun’s mean distance 3°106 Although the observations of a given date are in tolerably good accord, considerable discrepancy is found between the mean results for days of nearly the same vapor pressure, such as May 28 and October 21, 1904. But, on the other hand, days in which the aqueous vapor at the ‘surface has varied in the ratio of 1:0:7°5 (August 24, 1903, and January 9, 1906) yield almost identical results by the reduction, showing that. the method is competent to harmonize a wide range of sum- £. W. Very—Solar Radiation. 623 Aqueous vapor between 1°5™™ and 4°5™™, or about 3™™. od ne eno Aq. mm. |efrom| to |MeanA. ane ; Obs. * | distance. 1905 | June 6 24 HON QI | OP88 PITTA 2°845 fron, JA 28 2°30 3°25 | 0°83 | 3°023 3°106 ce eeeA 8) 12 3°96 1°86-| 0°90 | 2°989 3°073 ees: 16 4°31 2°88 | 0°85 | 3°335 3°430 July 19 14 268 . 2°08 | 0:93 | 2°922 3°002 Se Ot 16 4°28 2-038 Oreo, oe he 3° 210 Oct. 26 10 3°38 OG 4A, eos lovaoe 3°280 1906 May Ly 16 4°19 9°17 | 0°84 | 2°994 3°053 eS) Le oe S103 O20 oral 3°389 ate, 3O iy 4°46 3°19 | 0°88 | 3°298 3°376 Sone 7 20 4°19 3°08 (0°89) | 323 10 3°395 co) 29 16 4°30 2°67 | 0°89 | 3°238 aoa Aug. 8 18. 4°48 2°63 | 0°86 | 3:279 3°302 (Cae a | 18 4°33 3°67 | 0:95 73° 104 Solon var OS 16 aol 3713, 02393. lerAi2 3°529 Ge Di 16 4°34 SZ 0295) | 3329 3°381 Sept.18 12 3°43 3°08 | 0°97 | 3°204 Soo Oct. 4 1 Ay 3°86 | 1:08 | 3°069 | 3-051 us 6 12 2°44 3°09 | 1°06 | 3°887 3°859 ie 9 14° De aii) Olek OSs ari orl Sey 43) pee el 14. 2°97 S229 MOO t SelA4s 3°116 CO ar ees) 12 2218 ood Pala | 3-070 3°036 LG 12 2°91 RADA Ty eG 3°366 oe Ts 11 3°76 B90 lila P3svs39 3°293 oe. 20: | AO 1°59 320) sek 6a Sea oy) wee OG Boe OS 18 1°92 ACA i} LALO 3° 287 3°232 Mean | Aq.= 3°340 Mean| A= | 3:246 mer and winter readings, and that the remaining discrepancies arise from the inadequacy of the surface vapor pressure as an indicator of total moisture. The chart is also imperfect because the absorption of radiation by water vapor varies with the relative humidity as well as with the vapor pressure, while only the latter is considered here. To illustrate the great dis- advantage under which we labor in estimating the effect of aqueous vapor upon radiation, it is only necessary to point out that a layer of air approaching saturation, but not yet visibly cloudy, may occur at various altitudes, and that sometimes several such layers are found in succession in balloon ascents. But the absorption by water vapor is strongly enhanced near the condensation point, and the unknown possibilities of the 624 Pea AW. Very—Solar Radiation. upper air in this respect are sometimes great enough to upset all calculations. In attempting to use thé chart (founded on observations at or near sea level) in the reduction of the Mt. Wilson measure- ments of solar radiation in the same volume of the Annals,* it was evident that different curves are required. Having no observations suitable for the construction of a new chart of the same extent as fig. 1 and adapted to mountain conditions, I first employed the present chart (full lines) to get a preliminary reduction. The vapor readings on the mountain are multiplied by 0°887, according to Hann’s* prescription, to get the vapor in Aqueous vapor between 4°5™™ and 7:5™™, or about 6™™, At mean Date. oe Aq.mm. |jefrom; to |MeanA.|_ soiar : distance. 1905 | June 7 14 Balen 3°59 |0°83 | 3°614 | 3°707 seatee aks) 14. 5°36 1°96 | 0°90 | 3°369 3°460 ago) 12 5°83 1°72 |0°97 | 3°373 3°469 Sy 228 14 5°63 2°32 | 0°84 | 3°426 | 3°524 July 6 12 5°14 1°77 | 0°99: | 3°262 3°356 Ber IE 12 5°67 1°76 | 0°89 | 3°239 3°332 oe tale 14 6°66 2°70 | 0°88 | 3°449 | 3:°546 pee 8 7°42 3°58 | 1°72 | 4:112-) 4:238 GAs [e239 ver 2-27 | 0°84 | 3937 | 3322 Be ys} 16 6°02 2°33 | 0°89 | 3°366 | 3°452 “Tigo 18 4°64 2°51 | 0°92 | 3°376 3°459 Aug. 3 di 5°63 2°33 | 0°92 | 3°428 3°510 Shae aS, Hz 6°63 3°42 | 1°08 | 3°504 | 3°551 Sept. 5 12 5°38 3°13 | 1°08 | 3°306 | 3°339 Oe os Gee 2-80 | 0:93 | 3-280 | 3-308 sean ala 12 6°06 3°07 °) 1°12") Saas 3°542 saps i 10 6°06 2°65 | 1°16 | 3°364 3°384 ert «Vala 12 5°74 2°38 | 0°95 | 3°353 3°370 baa Ib) 12 4°76 3°29 | 1:08 | 3°528 3°545 PED 24 5°65 2°90 | 1:00 | 3°608 | 38°600 Oct. 24 12 5°69 2°93 | 1°17 | 3°634i\ieSeame 1906 | May 18 ay 6°60 2°11 | 0°98 | 3°362 3°428 epee een 14 4°84 1°87 | 0°86 | 3:140 | 3°202 June 6 20) 4°68 3°12 | 0°90 | 3°260 | 3°345 ve 9 22 Delt 3°04 | 0°85 | 3°317 | 3°404 pied 2) 24 7°46 2°63 | 0°83 | 3°558 | 3°656 Mean | Aq.= 5942 Mean|-A= | 3°485 * Op. cit., Table 13, pages 87 to 92. FF. W. Very—Solar Radiation. 625 Aqueous vapor between 4°5™™ and 7:5™™, or about 6™™, At me Date. eee Aq. mm. {jefrom| to |MeanA. ee c distance. 1906 | Junel6 20 6°40 2°96 | 0°89 | 3°415 3°510 ao) £9 23 5°68 2°99 | 0°83 | 3°251 3°342 ae 20 16 5°79 2°00 | 0°84 | 3°377 3°471 Se A 16 5°81 2°10 | 0°83 | 3°399 3°494 So Ded 16 5°79 2°40 | 0°92 | 3°358 3°453 «30 16 S72 2°56 | 0°89 | 3°348 3°444 July 3 14 7°46 Pak OF89) | 3e415 3°514 (eee ite) 14 Tas 2°66 | 0°93 | 3°495 3°591 ce oe 16 7°08 2°60 | 0°91 | 3°480 3°5.70 eso 16 6°92 2°65 | 0°87 | 3°716 3°808 Aug. ] 14 5°22 ZO O92) 3-550 3°637 i: 3 16 4°58 2°92 | 0°90 | 3:343 3°423 s 4 16 6°24 2°67 | 0°93 | 3°516 3°599 & 7 16 5°17 2°38 | 0°86 | 3°337 3°413 ig ep ead 12 6°92 ioe) ealOn 632306 3°371 | 8 6°03 2°32 | 1°17 | 3°008 | 3°049 Ce SEAS IB 20 6°61 2°76 | 0:90 | 3°252 3°294 Sept. 1 15 0°18 2°48 | 0°91 | 3°296 3°336 ‘s 4 i 4°52 3°09 | 1°00 | 3°393 3°430 e 5 16 3°02 3°01 | 0°93 | 3°361 3°394 me a 12 4°68 2°95 | 0°94 | 3°426 3°449 me 7:20 12 4°71 3°22 | 0°98 | 3°208 3°214 Seo. 2 4:72 3°06 | 1°01 | 2°268 3°265 SS 14 5°14 3°60 | 1°00 | 3°336 3°328 Oct. 2 UG 5°81 29 1°03 | 3°354 3°33 0 Mean | Aq.= 5°775 Mean| A= | 3°430 the free air. No readings of the barometer are available, and I am therefore obliged to assume an average pressure for the mountain, which is taken = 618"™. Accordingly the air mass is made = (618 / 760) X sec. € = 0°813 sec. €. The results are given in the tables on pp. 623-626, grouped approximately for aqueous vapor pressures of 3, 6 and 9™™. The mean values, with two others which fall outside the limits of the classification, are plotted in fig. 2. Aqueous vapor=3'340 A= 3°246 (26 observations). «“ B75 3-430 (25 “ ). “ «5942 3°485 (26 «“ ‘ “ “8-861 3-744 (23 « . sf or eed — 4:391( 1 . i cc «13-84 4:489 (1 “ \s Am. Jour. Sc1.—Fourts SERies, Vout. XXXVI, No. 216.—DecremsBer, 1913. 42 626 FP. W. Very—Solar Radiation. Aqueous vapor between 7'd™™ and 10°5™™, or about 9™™. At mean | Date. Meee Aq. mm. | ¢ from | to |MeanA.} solar | : distance. : 1905 | June17| 20 10°07 2°44 | 0°83 |3°871 | 3°978 Aug.14| 14 9°92 | 2-88 |1:00 | 4-017 | 4-099 Gedepc Rc tahs ol 751 2°35 | 0°99 |3°476 | 3°540 665) BO Hil teat 9°88 9°24 | 1:00 |3°655 | 3°718 SE SKGOM Gi AL 7°64 3°24 | 1°01 | 3°503 | 3-558 oe 10°49 : y D5 a ao | 10-24 4:02 | 0°89 | 3-850 | 3-909 « 39) 29 re 4:55 |0:94 |3-740 | 3-788 Sept.19.| 20 -9°64 9°53 | 0:97 | 3°865 [areas SRO A EMG 1°85 2°82 | 0-97 |3°668 | 3:673 x26. 20 757 9°17 | 1:01 | 3°608 | See Oct. © 341 C0 8-98 2°38 | 1:04 |3°900 | 3°879 1906 | June12| 28 10°02 2°98 | 0°88 | 3918 | 4:024 July &))\ 16 8°69 2°72 | 0°87 | 3°496 | 3°596 CCE AO lat 20 8°50 2°52 | 0°88 |3°365 | 3°461 Exe 4 Mean ath 2°67 | 0°89 |3°290 | 3°384 CPT REL G 6°67 3°15 | 0°94 13°501 | 3°598 SCG Gee Ma 2 8°54 2°47 | 0°94 |3°414 | 3°505 od 8 10°02 9°74 11°34 | 3°56 | tangas G6 EO A aes 7°86 2°53 | 0:94 | 3°537 P 3°628 Aug.14| 15 8°51 2°65 | 0:92 |3°522 | 3°598 ais 8 9°50 2°73 | 1°35 13°74 | yeeene Sept. 8 6 9°11 3°12 | 2°11 |4°209 | 4°245 Ce Igy as Brae 8°31 3°83 | 0°93 |3°950 | 3-982 Mean | Aq.= 8°861 Mean} A= | 3°744 The values of A obtained by the first chart increase with the aqueous vapor. They should be constant, and fig. 2 has been used to give a corrected chart, shown by the dotted lines in fig. 1, with the following multiplying factors appropriate to conditions on the mountain : Air-Mass. | Aq.=1°0™™. | Aq,.=3™"™, | Ag.=6™™. | Aq.=9"™) | Aq? tao + 2°90 3°05 3°15 3°20 3°25 3 2°64 2°75 2°85 2°90 2°95 2 2°35 2°45 2°53 2°57 2°63 1 2°05 7a Ha 2°20 2°25 2°30 "5 1°70 1°75 ior 1'80 1°85 LW. Very—Solar Radvation. 627 The following examples are taken at random to show that the observations are satisfied by the factors read from the dotted lines of the chart : Mt. Wilson. € R F A Mt. Wilson. € R F A Oct. 20, 1906. |8°496)1°336) 2°79/3°727)|June 7, 1905 [3°59 |1°185| 3:05/3°614 3°285/1°358| 2°73)3°707 3°40 |1:217| 2:98|8°627 Ag.=1°59™™, |1°832/1°565| 2°31/3-615)|Aq.=7'17™™, (2°372/1:345) 2°66/3°578 1°791]1°558} 2°30/3°5838 2°280/1°3857| 2°64/3°582 1°555)1°596) 2°24/38:575 1°786/1°433] 2°48/3°554 Morning 1°528)1°634| 2°23)/3°644)| Morning 1°734|1-444| 2°4'7/3°567 measures. |1°380)1°628) 2°18)3°549 measures. |1°120/1°579| 2°27/38°584 1°363)1°636) 2°1'7/3°550 1°110/1°604| 2°26)3°625 1°276)1°652) 2°15)3°552 1:006/1°611] 2-23)3°593 1°263/1°642|) 2:14/3°514 0°993)1°620) 2:21/8°580 0°871/1°643) 2°13)3°500 0°871/1°675| 2°18)3°568 0°832/1°604| 2:09|3°352 0°831/1°561| 2°09/3:262 Mean 3°602 Mean 3°542 At sun’s mean distance, A= 3°547)/ At sun’s mean distance, A = 3°634 Mt. Wilson, Aug. 22, 1905, a.m. and p.m. Ag.=13°84™™, € R EF A € R F A 3°104 i229 2.97 3°650 ek? 2 1:497 2°30 3°488 2°967 e242 2°92 B26 1°138 1°458 2°34 ace 2°954 e327 DE all 3°596 1°944 1°476 POST 3°498 2°176 1°348 2°68 3°613 1°265 1°481 WOR) 3°510 : ] ‘419 | 1:437 | 2:43 | 3-492 1-261 } 1:497 | 2:37 | 3°548 |) 1-447 | 1:449 | 2-44 | 3°536 1124 | 1°520 | 2:33 | 3-542 || 1-676 | 1:403 | 2°52 | 3-536 1:110 | 1531 | 2°32 | 3:552 || 1-722 | 1:391 | 9°54 | 3-533 1023 | 1:510 | 2:29 | 3-458 || 2-053 | 1:325 | 2°68 | 3°485 1015 | 1547 | 2:29 | 3-543 || 9°126 | 1:332 | 2°66 | 3:543 ee ;o e568 | 2:18 | 3-4is. |. :*CMean 3 °526- At sun’s mean distance 7 A=3°585 The factor-curves (dotted lines, fig. 1) for the mountains are somewhat more square-shouldered than those for sea-level, and the factors to be used on the mountain for the larger air masses and vapor pressures are smaller. Apparently the moun- tain curves for values of e greater than 4 are more closely crowded together, although there are not enough low sun observations to assign the law. Scarcely any effect is produced 628 F. W. Very—Solar Radiation. on the mountain by variations of aqueous vapor pressure be- tween 14 and 15™". Consequently, the aqueous absorption has already produced very nearly its maximum effect in the upper region of the isothermal layer, and the water vapor near the level of the mountain top is not ina condition to produce much new depletion. | ine?) 0 EEEEEEELLL 0 2 4 6 8 40 iz {4 mm., Fic. 2. Abscissee = pressure of aqueous vapor. Ordinates = values of A by preliminary chart. The case is different at sea-level, where a much more promi- nent vapor factor is required. The vapor of the lower air, by its condensation-products on the dust particles out of which the haze which gives to distant hills and mountains their blue tint takes its birth, has added a new sort of depletion in the lower air layers which is very much less effective in the purer air above the mountain top (altitude = 1780 meters). The average values of A in the examples given here are: Washington (5 days), A = 3°138 + °105. Mt. Wilson (3 days), A = 3°589 + ‘017. FW. Very—Solar Radiation. 629 The result is still affected by any uncompensated depletions in addition to those considered. Thus the lower value of A from the sea-level measurement is caused by the greater infringe- ment of dust in the lower air. That lower values of solar radiation are obtained at low- level stations when compared with mountain observations for identical air-masses was recognized by Langley, who found when he computed by the madequate secant formula, from valley observations at Lone Pine, California, the radiation which might be expected at his “ Mountain Camp” on Mt. Whitney, and compared this with the observed value, the latter exceeded the calculated amount. The reason for this may be evident from the following considerations: The exponent of Dien tay Fic. 3. @ and b = observing stations. c= outer limit of air. d= upper limit of dust envelope. the dust-coefficient does not vary according to the total air mass. At a certain altitude, in itself variable, the dust disap- pears and the term representing the dust effect must drop out from the complete formula. The condition as to dust is shown in fig. 3, where the more elevated of two stations, @ and 6, expe- riences but a small fraction of the depletion of radiation by dust which affects the lower station, although the air masses are not very different. In my paper on “ The Solar Constant,” * I have treated the dust depletion separately and have used a modified air mass (e’) computed by Lambert’s formulat where it is necessary to eval- *U.S. Weather Bureau Publication, No. 254, 1901. +The word ‘‘kilometer” (op. cit., p. 14,1. 1) should be erased. The five is an approximate numerical ratio, and not a distance, as may be seen from the derivation of the formula, for which consult Ferrel, ‘‘ Recent Advances in Meteorology,” Appendix 71, p. 61. Annual Report of the Chief Signal Officer, 1885, War Department, U.S.A. There are two other typographical errors in W. B. No. 204: The expression for p on p. 18 should have the expo- nent m, and ‘‘log’’ should precede w in equation (a) p. 27. In the footnote to my ‘‘ Note on Atmospheric Radiation,” this Journal for April, 1913 (p. 536), the exponent of 10 should be —8, instead of —4, and the black-body radi- ations should be 371°1 and 186°3 (mM. K. s.), the values in small calories re- maining unchanged. The same error in the exponent occurs in Bigelow’s paper in the March number of the Journal, p. 258, 1. 9 from bottom. 630 F. W. Very—Solar Radiation. uate the air mass of the dust layer. No satisfactory mode of estimating the dust factor has yet been devised, and the sug- gested separation of the dust depletion from the air depletion, though theoretically necessary and much to be desired, is not yet on a practicable basis. Mr. Abbot* characterizes the method as arbitrary, a criticism which is partially justified since, unfortunately, the data for a reliable estimate of the amount of dust in the air, and the depletion which it exercises, are both regrettably deficient ; but to ignore the dust factor entirely and to omit even an imperfect discrimination of this important variable is equally arbitrary. One great merit of winter obser- vations in high continental latitudes is the reduction of atmos- pheric dust to a minimum over extensive snow fields, and for this reason such measures are the best we have for determining the solar constant.t The sole justification for the total omis- sion of any dust factor in the present reduction is the absence of observations on which even an approximate estimate of its amount may be founded. Increasing pressure of water vapor is apt to be accompanied by a growing mistiness of the air, which is of the nature of a dry fog and implies an increment of the action of presumably pre-existing dust particles of exces- sive fineness which are enlarged and become evident when sery- ing as nuclei of condensation. This is probably the reason why the dust depletion may be represented to a certain extent as a function of the vapor pressure, which is tacitly done when only the latter is considered, as in the present examples. The value of about 34 cal./sq. em. min. which is given by the mean of the reduced Mt. Wilson observations must not be taken as an independent determination of the solar constant. Other and better methods must be employed to get a reliable value of this quantity. The sole merits of the present reduction are that it permits the approximate utilization of measures which would be of no value without some mode of supplying the lost radiation, and that it justifies the assumption that the radiant. depletion is most intimately connected with the amount of aqueous vapor in the atmosphere. In spite of imperfections, the considerable number of obser- vations averaged justifies some general conclusions. The use of the chart very nearly corrects for the direct effect of water vapor and for some of its indirect influence, although the curves might be improved by data from tropical regions of large vapor- content. Thevery marked midday depression of solar radiation, which results from the diurnal change in atmospheric trans- missive quality and which increases with the amount of aqueous * Annals Smithsonian Observatory, vol. ii, p. 119. + Compare my ‘‘ Criterion of Accuracy,” ete. , already cited, a especially the notable work by Savélief, which is there described. F. W. Very—Solar Radiation. 631 vapor in the air, ought to appear in the separate values of A for a given date, since no attempt has been made to eliminate the diurnal change of quality, and the depression does appear in the Mt. Wilson reductions; but there is little evidence of this feature in the reductions for Washington, D.C., whence we must conclude that the ordinates of the sea-level curves, ¢« = 1 and'e = 2(full lines), which are most used in the midday reduc- tions, are relatively a little too high (i.e. the curves for e = 3 and 4 should be raised a little), and that the chart automatically, but unintentionally and indirectly, obliterates the depression to a great extent at sea level. By comparing numerous radiation measures for vapor pressures ranging between 5 and 15™", midday radiations of solar radiations covering 0-2 cal. in ther- mal equivalent may be found, but the most potent influence of aqueous vapor does not begin to appear until vapor pres- sures much less than 1™™ are reached. The need of rational methods and of judicious selection of material according to reliable criteria was never more pressing than in the reduction of observations of solar radiation. The treatment of climatic problems involving radiant functions has been vitiated by indiscriminate averaging of statistic in which delicate details, whose preservation is important, have been swamped. Professor Simon Newcomb, inan elaborate memoir of seventy-nine quarto pages, “‘A Search for Fluctuations in the Sun’s Thermal Radiation through their Influence on Ter- restrial Temperature,” * arrived at the result that no solar radi- ant variations of sensible amount can be recognized by their effect on climate. He concluded that ‘all the ordinary phe- nomena of temperature, rainfall and winds are due to purely . terrestrial causes and that no changes occur in the sun’s radia- tion which have any influence upon them” (p. 384). The fundamental principles assumed in Newcomb’s work may be seen from the following quotations: “‘ A change in the sun’s radiation will necessarily affect every part of the earth. If therefore a change of temperature in one region has this cause as a factor, we may, accidental causes aside, expect a similar change in every other region. . . . To speak more precisely, if, on any one day, it is found that the temperature in every part of the earth is in the general average above or below the normal, we might rationally attribute this result to the sun. We thus see that a very obvious way of testing the constancy of the solar radiation is to determine the deviation of the * Transactions of the American Philosophical Society, N.S., vol. xxi, Part5, pp. 309-387, 1908. The distinction of ‘‘ thermal” radiation is superfluous, since all radiation is capable of producing thermal effects. The word was not introduced in the obsolete sense of ‘‘ infra-red,” but to distinguish ordinary radiation from possible ‘‘ magnetic or radio-active emanations, whatever they may be”? (p. 382). 632 F. W. Very—Solar Radiation. temperature from the normal on any one day over all points of the globe, and form their mean. The fluctuations of this mean would represent those of the sun’s radiation” (p. 314). Of two regions, A and B, ‘‘ if we found that the mean tempera- ture at B was above normal when it was above the normal in A, and below it in the contrary case, it would show that there was some common cause affecting the two places. Should the mean temperature in B be entirely independent of A it would show that there was no common cause affecting the temperature of the two places and therefore that the fluctuations were not due to changes in the sun’s radiation” (p. 315 ). These are extraordinary principles to adopt as the basis for discovering changes in the solar radiation. One might as reason- ably anticipate a simultaneous high tide over all the earth as to “expect a similar change in every other region ” if a particular climatic effect in some one region is attributable to a variation. in solar radiation. Climatic phenomenaare seldom regulated in such a simple and direct way, but a given change in one part of the earth, even if caused by an increase or decrease of solar radiation, will set in action a long train of consequences and will be accompanied by an opposite change somewhere else, while between the localities of opposing effects he apparently neutral belts of conflicting phases. In comparing solar effects for different localities we must first be sure that the phases are the same, otherwise the signs should be changed for the region of inverted type. Next we must recognize that, while types may persist over extensive areas of the earth’s surface, there are intermediate regions in which the type varies through shifting of the great centers of action which govern world-wide circulatory phenomena of the atmos- phere. Any lag in the phase will require a time-adjustment before the waves for different locations can be compared. Finally, it is probably a mistake to assume that the solar radi- ant changes can be represented by a simple sinusoid curve, as though they were regular like the planetary revolutions. On the contrary, the solar changes are only approximately periodie, and several different periods, each of slightly varying duration, are superposed. Even harmonic analysis, which deals success- fully with simultaneous sinusoid phases of various periods, is nonplussed by such a complex. Newcomb’s rigid criterion starts with an erroneous hypoth- esis. ‘The criterion has been invented to get rid of the acci- dental fluctuations, which it does, but at the same time it also eliminates the solar radiant phases which it is proposed to investigate. No other outcome than a purely negative one was to be anticipated. It was principally to meet the special case of a periodicity of varying length that Newcomb devised his “criterion for distinguishing between a definite period F. W. Very—Solar Radiation. 633 [even though this be of fluctuating length] and complete irregularity,” always, however, subject to the supposition that there is no question in regard to the identification of max- imum and minimum in the phase, but that the maxima, or positive departures in surface temperature due to variation of solar radiation, will everywhere coincide. This is the funda- mental error which overthrows the final conclusion. There may be provision for detecting a slight lag, but there is none for deal- ing with a complete reversal of phase. If, however, instead of attempting to apply his criterion to the whole world, Newcomb had tried it on a single homogeneous region of one common type, he would not have cancelled out his opposing phases. Bigelow* has used the method for a particular region where the solar radiant impulses give rise to a climatic effect of a single type throughout the area, and finds conclusive evidence of a true solar periodicity, which leads him to remark that Newcomb has not done full justice to his criterion. When two different phénomena are related simply by coincidence of a maximum, it takes a great many recurrences to completely establish the con- nection ; but where the relation includes further details in respect to congruous curves, this is equivalent to an indefinite multiplication of coincidences and the relation may be discerned from comparatively few observations. Criteria are also needed in other departments of solar radia- tion study to decide upon the permissible limits of deduction. Questions have arisen as to the proper times and stations for actinometric measurements which can be settled in no other way than by means of decisive criteria or crucial tests. The Smithsonian observations, for example, usually stop when the air mass becomes as large : as 3 or 4 atmospheres. Some do not even extend to 2 atmospheres. Reduced by Bouguer’s for- mula, these midday readings agree among themselves, but solely because they have stopped befere reaching the point where disagreement begins. This is equivalent to shirking the difficulties, and the seeming extraordinary agreement of the measures is misleading. If the missing readings had been supplied, the discrepancies would have been obvious.t Such * Frank H. Bigelow: ‘‘ Studies in the General Circulation of the Earth’s Atmosphere,” this Journal (4), vol. xxix, p. 277, April, 1910. ¢+In Abbot’s work on ‘‘The Sun,” in the pages devoted to the solar con- stant, one looks in vain for even the bare mention of the names of Forbes, Violle, Crova, Langley, Hanski, Savélief and many others whose work has helped to solve this greatest of astrophysical problems. The only name mentioned by Mr. Abbot in this connection is that of Pouillet, whose results resemble his own, while those passed by in silence totally disagree. It is not always possible to secure complete series of actinometric observa- tions, but this does not absolve us from the duty of trying to make them. The fine work of Mr. H. H. Kimball, who, on several occasions, has followed the sun almost or quite to its setting, and whose actinometric measurements have been of great assistance to me, deserves especial mention by way of contrast, and the splendid services of M. Crova to this study will never be forgotten. 634. EF. W. Very—Solar Radiation. incomplete observations are incapable of elucidating the laws of atmospheric absorption except through the aid of more per- fect measures. By supplying deficiencies under guidance of a criterion we may in some cases rescue observations which are otherwise useless. It will sometimes be necessary to discard imperfect or dis- crepant observations on good and sufficient grounds, and to select the most suitable material for discussion, but the prin- ciple of selection must be a rational one, capable of concate- nation with known facts in other departments of scientific investigation and, if possible, one which can be subjected to some critical check. The new thermodynamics of the atmos- phere promises to provide such a check on the problems of solar radiation. The conclusion that the equivalent of the solar constant of radiation can not be less than three, though it may be as much as four gram-calories per sq. cm. per minute, has now been forced upon us in many ways. It is of prime importance that we recognize the existence of a special region of peculiarly potent incipient absorption of'solar radiation in the upper air, whereby the upper fourth of the atmosphere of oxygen and nitrogen with its contained aqueous vapor becomes a reservoir of thermal energy and a protective covering for the deeper layers.* This great upper nonadiabatic layer of permanent temperature-inversion is comparatively quiet as to alr move- ment, is free from storms, and maintains an almost constant average temperature in summer and winter irrespectively ; but thermally this region is the most actively changing in the entire atmosphere. Here occur the widest fluctuations of temperature to be found at any level in the free air within intervals of a few days.t+ It is here that a very large fraction of the solar radiation disappears, so that a radiant equivalent which may be 3°5 cal. /.sq. em. min. at the atmospheric limit (or possibly even 4) is reduced to less than 2 by the time that the rays strike the tops of some of our highest mountains. In this great isothermal layer also resides the radiant power of the atmosphere. The heat absorbed here from the sun’s rays is again lost by radiation to space, and does not appear in our sea-level observations of solar radiation, nor even in those made on mountains. Abbot’s hypothetical. radiant layer at 4000 meters simply does not exist, but a value of the solar constant *See Frank W. Very, ‘‘Sky Radiation and the Isothermal Layer,” this Journal (4), vol. xxxv, p. 369, April, 1913. +On account of this peculiarity it has been proposed to abandon the earlier name—‘‘isothermal layer”—in favor of the rather meaningless term, ‘‘ Stratosphere”; but the absence of a seasonal fluctuation of temperature still makes the older name appropriate. F. W. Very—Solar Radiation. 635 greater than three requires that a considerable part of the earth’s heat shall be lost from an atmospherie layer having the temperature of the isothermal layer and thus coincides with the known phenomena of the upper air.* When we add that many other facts, such as the observed temperature of the moon,t and the melting of the polar snows on the planet Mars, as well as my measurement of the precipitable water vapor in its atmospheret which confirms the temperature assigned by Lowell to Mars,§ all demand an eguivalent of solar radiation of this order of magnitude, the larger value of the solar con- stant appears to be thoroughly established. Westwood Astrophysical Observatory, Westwood, Massachusetts, November, 1912. * Frank W. Very: ‘‘On the Need of Adjustment of the Data of Terrestrial Meteorology and of Solar Radiation, and on the Best Value of the Solar Constant,” Astrophysical Journal, vol. xxxiv, pp. 380-386, December, 1911. +Frank W. Very: ‘‘The Probable Range of Temperature on the Moon,” Astrophysical Journal, vol. viii, pp. 199-217, and 265-286, November and December, 1898. Also ‘‘Note on the Temperature Assigned by Langley to the Moon,” Science, N. S., vol. xxxvii, No. 964, pp. 949-957, June 20, 1913. {Frank W. Very: ‘‘Measurements of the Intensification of Aqueous Bands in the Spectrum of Mars,” Lowell Observatory. Bulletin No. 36, vol. i, pp. 207-212. ‘‘Water Vapor on Mars,” do. No. 48, vol. i, pp. 239-240. ‘‘New Measures of Martian Absorption Bands on Plate Rm 3076,” do. No. 49, vol. i, pp. 260-262. See also Science, N. S., vol. xxix, pp. 191-193 ; vol. xxx, pp. 678-679 ; vol. xxxii, pp. 175-177. § Percival Lowell: ‘‘Temperature of Mars,” Proc. American Acad. of Arts and Sciences, vol. xlii, No. 25, pp. 651-667, March, 1907. 636 FR. C. Wells—New Occurrence of Cuprodescloizite. Arr. LV.—A New Occurrence of Cuprodescloizite ;* by Rogrr O. WELLS. A MINERAL recently received for inspection by the United States Geological Survey was provisionally identified as cupro- descloizite. It was collected by Philip D. Wilson of Bisbee, Arizona, who stated that it is found in some quantity in the Shattuck Arizona mine in Bisbee, and that it is the first oeeur- rence of a vanadium mineral noted in that district. On account of its unusual form and composition, an analysis seemed advisable and for this purpose Mr. Wilson generously placed a large amount of material at the disposal of the Chem- ical Laboratory of the Survey. General description.—The mineral occurs in the form of stalactites. The smaller aggregates radiate from a narrow base and end in rounded clusters 1-8"" in diameter. The larger growths occur in reniform masses several centimeters in diameter. The latter are coated with a red powder, but the smaller aggregates have an olive hue. The fractured surface of all varieties possesses a dark brown luster and shows a radiating structure. The streak is “dark olive-buff,” Plate XL of Ridgeway’s color standards,+ and the powder somewhat darker. Dr. W. T. Schaller has kindly made the following observa- tions upon the optical properties: ‘The broad fibers have parallel extinction. The elongation is XY. The pleochroism is marked: parallel elongation, yellow; normal thereto, brown. Absorption, brown > yellow. Refractive indices high, greater than 1°74. Birefringence strong, estimated 0:03 to 0°04. Indi- cations of biaxiality were seen, but the individual erystal units were too small to permit of any definite results being obtained.” Chemical Investigation.—The mineral was almost com- pletely soluble in dilute nitric acid. The small insoluble por- tion was found to be chiefly lead chromate, soluble in more concentrated nitric acid after decantation of the main solution. Hydrochloric acid transposed the mineral into lead chloride, copper chloride and vanadic acid. Sulphuric acid decomposed it with precipitation of lead sulphate. Lead was determined as sulphate, either after separation as sulphide, or after direct precipitation as sulphate. Copper’ was determined as metal after separation as sulphide and electrolysis. Lead and copper having been removed by a rapid stream of hydrogen-sulphide, arsenic was separated as sulphide after one to three days * Published with the permission of the Director of the United States Geo- logical Survey. Ft Robert pee ‘‘Color Standards and Nomenclature.” Washington, D.C., Lone Lf. C. Wells—New Occurrence of Cuprodescloizite. 637 reduction of the arsenate in a closed flask, while vanadium remained in solution in the quadrivalent state. After boiling out all hydrogen-sulphide and heating for some time, sodium carbonate was added in slight excess, thus precipitating chro- mium and zine. The latter precipitate was ignited, fused with sodium carbonate, and the melt extracted with water. Zine was determined in the insoluble portion by separating as sulphide and weighing as sulphate. Chromium was precip- itated in the water portion by adding a slight excess of nitric acid and a large excess of lead nitrate and the lead chromate weighed as such after drying at 110°. Vanadium was deter- mined in sulphuric acid solution by reduction with H,S or SO, and titration with KMnO,, the small amount of, vanadium earried down with the copper being separately determined. As a check vanadium was also determined by the method recommended by Cain and Hostetter,* which yielded a slightly higher result than by the first method, viz. 21°73 per cent instead of 20°95. No other elements could be discovered in significant amounts. There was no hygroscopic water at 105° C. In order to see if the mineral had lost water by exposure to a dry atmosphere it was kept in a moist atmos- phere for two weeks. No notable absorption of water occurred. ANALYSIS. Molecular ] 2 3 Mean values Wmsole os _2_ 16 18 [anes 17 eee: Mew@ee. ._ 55°34 55°78 55°80 55°64 "251 Cn. Lieo4 16°99 WETS 17°05 oie Oe ‘98. “34 Antes °31 "004 VO, = 20°57 WES) O73 21°21 "116 As,O, . LO ee 20) 1°24 1°35 1{933e) "006 + °124 PO. _ 2. "24 i ad: es oS °24 "002 CrO, _ Lee “D7 "492 Mae 9 "50 "005 iS 0. aa 3°63 3°51 eae 335 a °198 100°02 Discussion of Analysis.—On comparing the analysis with those of well-recognized species, the mineral is found to be best described by the name cuprodescloizite. Two interesting facts appear. The percentage of copper is higher than in any variety of cuprodescloizite hitherto reported and there is a small amount of chromium. Although the proportion of copper suggests psittacinite, it seems probable, in view of the variable amounts of lead and water reported in psittacinite, that the latter mineral is an alteration product of descloizite. The present mineral, it is true, has an excess of water over the * J. R. Cain and J. C. Hostetter: A rapid method for the determination of vanadium in steels, ores, etc. J. Ind. and Eng. Chem., iv, 250, 1912. 6388 R. C. Wells—New Occurrence of Cuprodescloizite. — requirements of the formula 2PbO.2Cu0.V,O,.H,O and a deficiency of copper, as shown by the following comparison : Theory for PbVO,.CuOH Found PbO eee 55°4 55°6 CuO) 2a eee 19°8 170 L0Q) SOEs) eee at "3 VO aes See see 22°6 21-2 As O30 eee sige 1°3 Pi oe Sere Sie 2 HO cd Gh Oe 9-9 3-6 100°0 99°2 The lead content, however, agrees very well with that required for cuprodescloizite. It is evident that the elements of the minerals of the olivinite group often suffer extensive replacement. Here we have copper appearing almost wholly in place of the zine of descloizite, the mtermediate members being already known. The present mineral, then, represents the copper end of the cuprodescloizite series. It may be that the entrance of the copper favors the addition of another molecule of water. Several investigators have commented on the tendency of the minerals of this series to carry a slight excess of water which is certainly not hygroscopic.* Chro- mium has not been reported in any descloizite heretofore. It suggests a slight admixture of a compound analogous to vauquelinite. Genesis.—The constituents of this mineral, lead, copper, vanadium, arsenic, ete., in combination yield “insoluble ” com- pounds and were, therefore, probably assembled in very dilute solutions. The stalactitic form of the mineral indicates that it erystal- lized by the evaporation of downward migrating solutions and its chemical character shows that the solutions were products of oxidation. With the data at hand it is impossible to ascribe any special geologic significance to its origin. Its chemical composition, however, is significant. Since the chromate of lead is very insoluble like the vanadate, it is evident that vaua- dium was present in the solution in excess of chromium. Some tentative experiments have shown that when lead and copper compete for asoluble vanadate, lead vanadate is the prin- cipal product. Hence it seems reasonable to assume that lead was scarcer than copper in the solution from which the mineral formed. With present data it is impossible to make any defi- nite statement, however, about the proportion of vanadium with respect to the copper in the mother solution. * Cf. Penfield, this Journal, xxvi, 364, 1883. Palache and Graham—Crystallization of Willemite. 639 Arr. LVI.—On the Crystallization - of Willeméte; by Cuarutes Pautacue and R. P. D. Granam. Tue form series of willemite has hitherto been small and few accurate measurements of its crystals have been recorded. - In a brief note in this Journal, xxix, 1910, one of the authors gave observations made on crystals from Franklin Furnace, N.J., which were believed superior to those previously obtained _ and proposed a new axial ratio based upon them. Crystals from the same locality recently secured for the Harvard Min- eralogical Museum through Mr. Lazard Cahn give a far better series of measurements as well asa number of forms new to the mineral, and it is the purpose of this paper to present these new facts. The erystals which are minute, not exceeding a millimeter in diameter, are of prismatic habit and perfectly transparent, _ colorless, or of a pale yellowish-green tint. They are implanted upon rhodochrosite which is in part gray and massive, in part pale pink and well crystallized in curved unit rhombohedrons. Most of the crystals are singly terminated, but several were noted and one measured which showed identical characteristic _ third order rhombohedrons on both extremities with no sug- gestion of hemimorphism as indicated for the mineral by Can- field.t Many of the crystals on these specimens are dull and lusterless by reason of slight etching and the deposit of a thin coating of some earthy substance upon them. But the meas- ured crystals are brilliant, and except for the small size of some of the faces leave nothing to be desired in the quality of the signal reflections. The forms observed on the six measured crystals are : Symbol Symbol P mbol Symbol Borer a Bravia 1G ee ee ravate GP @.0 (1120) Hee +41 (0) (3125) m | ee) (1010) y +41 (r) (2131) (oe haar oa (1011) a). +10°1 (2) (7341) ym | —2 (0221) =2(¢) +10°1(7) (4371) u 10(Z) (2113) a0 — 24 (2) (1232) S 01(r) (1123) =P | - (fr) (1322) *9 +21(1) | (5143) 7 Sante) (1341) i +81(/) (4132) *] —T4 (0) (1561) * The asterisk indicates new forms. + This Journal, xxiii, 20, 1907. 640 Palache and Graham—Crystallization of Willemite. Fig. 1 shows the prevailing type with the prism a dominant and narrow truncating faces of m; while the characteristic terminal planes are the complementary positive third order rhombohedrons « and y and the first order rhombohedrons 7 and ». The crystal shown in fig. 2 has in addition largely developed faces of the negative third order rhombohedrons d, Figs. la, 16 DP andq. The criterion used to determine a common position for the various measured crystals was the occurrence of the third order rhombohedrons % and 0, one or both of which are always present, and by producing a faint striation on « parallel to the intersection with a, give a sure means of orientation. The forms g and 7 when present can also be thus used without ambiguity. The figures are representative of types rather than particular crystals ; although there is much variation in the relative size of the different forms, the draw- N oti Ries Pa aa Palache and Graham—Crystallization of Willemite. 641 ings do not exaggerate the regularity of development of the most perfect crystals. The combinations presented by the measured crystals with the number of faces of each form observed are contained in Table I. The last crystal alone was doubly terminated. Fic. 4 TABLE I. Crystal a|m Te @)\s|\o)| Bl-aevagy gy) @)\ad| Digs i eee GPG Pages hh ol |— 3 | dd lit 2) ai Se PR et 61/6);2;);3);—|—}1/3/3)3;1/—|2/2)31/8 21d SE eee es ge 6/6);2;1;1)/—|1)2)3)3)/—j—|1/1)/-|j— 4: UA 6 Rae eS aes 6)6/2)2);—|—|—| 2} 3/13/2)1/2)3|—|j— ee eee ae Oe =| — | | OR | | | a ee DT he 2S RR gin 6/61511/2/2|2|313|)5|—|—/|2;2)2j— Am. Jour. Scl.—FourtTH SERIES, VoL. XXXVI, No. 216.—DxEcremBeR, 1913. 43 and the values of », calculated from the individual forms. 642 Palache and Graham—Crystallization of Willemite. Of the forms not shown in the drawings the second order rhombohedrons wu and s occur rarely as minute faces modify- ing the extreme summit of the crystals; the third order rhom- bohedrons 7, z, and /, are line faces truncating the edges of intersection of w, y, and g with the prisms. The form 2, based on a single poor reading, is doubtful. Table II presents a summary of the measurements obtained In this table the complementary forms x and y, d and D are united for the sake of brevity and the observed angles for ¢ are reduced to a single sectant. The calculated angles based on the derived value of p, are also included. This value is based on the 50 best readings from faces of the 7 forms placed first in the table. The value of p, is -4453 corresponding to the axial ratio a:¢ =1:°6679. This value is very nearly the same as that of Lévy calculated from measurements of crystals from Moresnet and differs quite widely from the one to which reference has been made, proposed by Palache and based on poorer crystals. 3 : Lévy-Morestiet_ 22 ce S22 @>¢ == 1276696 p, = 4464 i Palache and Graham F:F:;:. “ 1 : 6679 P, = *4453 i Palache 1910 of oe 1:'6612 p = aaGe t TABLE IT. =) te M nn ai 50 | », | Value 2 Ae easured Limits o 4 S of po Calculated 8 ak o8 S caleu- D 6 p ¢ p 42 | & | lated iene p r |\+1 | 29°59’) 37°41’) 29°527-30°06' | 37°39’-37°42' 8 | Best| -4459 | 30°00’ | 37°39’ n |—2 | 3000 | 57 08 | 29 57 -80 04 | 57 00 -57 06 5 ya "4451 og 57 03 k ot 116,07 | 54.17/15 57 16175) 54 1425499 6 s 4455 | 1606 5 li x& y| 41 | 10 52 | 638 57 | 10 47 -10 58 | 63 52 -64 05 23 Ze ‘4453 | 10 54 63 53 d & D |—24)| 10 54 | 45 36 | 10 50 -11 01 | 45 84 -45 41 8) cc | °4446 | 102 45 34 O 21 | 19 14 | 49 380 , 19 04 -19 29 | 49 00 -49 47 5 | poor) -. 22) eam 49 41 9) Om A Ata ae 49) 435.4 be AG zea 3 o aie 4 43 77 58 MNO TAS De TAT OU a cos Le Ee ee ee ee a ne eee ce af q |—52) 16 03 | 7019 | 15 47-1619 | 70 02 -70 88 9 fair |. 2a 16 06 7018 L |—74| 20 48 | 76 51 | 20 32 -21 00 | 76 45 -76 58 4 || poor) 22e= 21 038 76 54 In addition to the new forms determined on observations had previously been obtained on these crystals other poorer crystals from Franklin Furnace establishing the forms a, @, and 7, and two additional forms, one of which is shown in fig. 3. These measurements follow : Palache and Graham—Crystallization of Willemate. Measured : p p soe ile (7) (barat 8) 22. oe FEE OE EE EY | 7 20 71 30 @alelateds = -. .22:. 7 35 71 07 MPG" (6\(14:5-9'°1) 2. 3 038 82 07 3 01 82 30 @alewlated: =... 2: 3 00 8217 643 The relations of the forms found on the Franklin Furnace willemite are well brought out in the gnomonic projection, fig. 4, in which they are plotted and the positive and negative sec- tants with the right and left subdivisions are indicated. The most striking feature of the form development is the marked nature of the rhombohedral-tetartchedrism, more pronounced even than in phenacite. There is, moreover, the greatest TABLE Symbol g We) i Aaa 3 Ge Bravais | c 0 (0001) 00°00 | 00°00") a| 0 (1120) | 0000 | 9000 m| a (1010) | 3000 | 9000 f | 80 (5270) |—46 06 | 90 00 | h(2)| 4e0 (3120) |~10.54 | 90 00 u| 10) | (2113) | 0000 | 2400 s |} Ol(r)| (1123) | 6000 | 2400 ete e (0112) | 3000 | 2105 eae (3034) _—3000 } 30 08 renee) (i011) | 13739 aa (0111) 3000 | 37.39 n| —2 (0231) | | 5708 v |—# 2(r)| (1825) 10 54 | 2211 o | +210) | (5143) |—1906 | 49 41 k |} +317). | (4.32) |-1606 | 5417 a | +41(2) | (3121) |—10 54 | 6358 y | +41(r)| (2131) |—49 06 | 63 53 £ | +61(2) | (13°5-3°3)|— 735 | 71 07 j |+10-1()| (7341) |— 443 | 7758 i(2|+10-1(r)| (4371) |—5517 | 7758 +16°1(1)| (14°5-9°1)|— 300 | 8217 d| —24(1) | (1232) | 4906 | 45 34 D{ —24(r) | (1322) | 1054 | 45 34 q | —52(2) | (4341) | 4354 | 7018 1 | —74(t) | (1561) | 3857 | 7654 EEE. Localities M Franklin! New oresnet : Furnace | Mexico* x x x are x x x x x ~ x * fe Mes x x 25 x LTA ye x x x te ae ie x x ie ae x a x tet a Hie x é x ek at, x y bd x * ie i's x = ia x ae ae x Be ae < hs ay x Le, Ls x ae . x a2 Bei x = m- x the * Penfield, this Journal, xlvii, 305, 1894. + Boeggild, Mineral. Groenland, p. 276, 1905. Green- landt 644 Palache and Graham— Crystallization of Willemite. similarity with the latter mineral not only in type of symme- try but in the actual forms and in their angles. The new axial ratio of willemite is almost identical with that of phenacite. Willemite -.--- p, = °4453 a:¢6= \ 266s henacite sees. Pp, = 4407 a:e= 1s coma In Table III is given a complete angle-table for willemite, calculated for the new axial ratio. The angle ¢ given for each form is that of the face nearest in azimuth to the right hand face of a, taken as zero (see fig. 4). There is also added a tabulation of* the localities from which crystals have been described, the forms found at each place being indicated. Harvard Mineralogical Laboratory, Cambridge, Mass., July, 1913. SCIENTIFIC INTELLIGENCE, I. CHEMISTRY AND PuHysIcs. 1. The Action of Sulphur Trioxide upon Salis.—Many years ago H. Rose observed that dry potassium chloride absorbs the vapor of sulphuric anhydride without giving off any gas, forming a eompound that reacts violently with water. A similar behavior of several other salts has been observed by others, but the com- pounds formed have not been satisfactorily investigated. W. TravuBE has now made a further study of this subject. He found that sodium chloride takes up two molecules of sulphuric anhy- dride, forming NaCl.2SO,, which from its reactions he showed to be the sodium salt or chlor-pyrosulphonie acid, O< eee A corresponding compound was formed with ammoninm chloride and sulphur trioxide. These compounds react violently with water, giving off hydrochloric acid and forming strongly acid solutions. With sodium and ammonium fluorides sulphuric anhy- dride gave products which were very remarkable from the fact — that they dissolved in water without producing heat and gave almost neutral solutions which reacted neither for fluorides nor for sulphates. The compounds were found to be fluorsulphonates, NaSO,F and NH,SO,F. When these salts were treated with strong sulphuric acid the free fluorsulphonic acid HSO,F could be distilled off, and it was found that this acid could be readily prepared by passing hydrofluoric acid ‘gas into fuming sulphuric acid.— Berichte, xlvi, 2513. H. L. W. Chemistry and Physics. 645 2. Volumetric Determination of Fluorine.—ALFRED GREEF has devised a new volumetric method for the determination of fluorine, which promises to be important, since heretofore the determination of this element has presented many difficulties. Thus far the method has been worked out only for compounds soluble in water. It is based upon the fact that in a neutral solu- tion of sodium fluoride the addition of ferric chloride produces a precipitate of “ferric cryolite,” Na,Fel’,, which does not react with potassium sulphocyanide to produce a red color. The end reaction is not sharp, however, except under special conditions. The solution must be neutral to phenolphthalein. A volume of 25°°in an Erlenmeyer flask is recommended. Then 20% of pure sodium chloride and 18 of potassium sulphocyanide are added and it is titrated with a ferric chloride solution, made from the com- mercial salt and containing such an amount of iron that 1° is equivalent to 0°01& of NaF, until a pale yellow color is produced. Then 10° each of aicohol and ether are added, the liquid is shaken up once while the flask is open, then a stopper is put in and the liquid is shaken thoroughly until, after further addition of ferric - chloride, the ether layer no longer loses its red color upon shaking and standing. Mixtures of sodium fluoride with acid sodium fluoride and sodium silicon fluoride may be analyzed by first titrating in a platinum dish, hot, with decinormal sodium hydrox- ide, with phenolphthalein as indicator, thus measuring the effect of the two other things together, then determining the total sodium fluoride as previously described. In another portion the acid fluoride is determined by titration with sodium hydroxide after the addition of potassium chloride and alcohol amounting to about one-half of the final volume. The test analyses given by the author show very satisfactcry results, both for sodium fluo- ride alone and for the mixtures.— Berichte, xlvi, 2511. H. L. w. 3. The Behavior of Hydrogen towards Palladium.—Since there are conflicting statements in the literature in regard to the volume of hydrogen absorbed by palladium at low temperatures, GUTBIER, GEBHARDT, and OTTENSTEIN have made a new investigation of this subject. Using spongy palladium which had been prepared very carefully, they saturated it with hydrogen at various tem- peratures, then after removing the excess of hydrogen by means of a current of carbon dioxide, they drove off the hydrogen by ignition and measured it. They found a minimum absorption at 20° C. of 661 volumes of hydrogen, which increased gradually to 917 volumes at —50° C., and which increased more slowly to 754 volumes at 105° C.— Berichte, xlvi, 1453. H. L. W. 4. A New Era in Chemistry ; by Harry C. Jones. 12mo, pp. 326. New York, 1913 (D. Van Nostrand Company). Price $2.00 net.—This work gives an account of the more important developments in general chemistry during the last quarter of a century—the development, in fact, of modern physical chemistry. The discussion necessarily includes some account of older theories in order that the recent work may be more thoroughly explained. 646 Scientific Intelligence. * It is a very interesting book, and it will be extremely useful, not only to students of the present day as a clear and simple treat- ment of the subject, but it is also a very suitable source of infor- mation for those whose knowledge of chemistry has not been brought up to the present time. From the fact that Professor Jones has studied with three leaders of the modern movement— Van’t Hoff, Arrhenius, and Ostwald, he is particularly competent to discuss their work and achievements. In an appendix he has iven some very interesting personal reminiscences of Mendeléeff, Kekulé, Willard Gibbs, Van’t Hoff, Arrhenius, and Ostwald. H. L. W. 5. Haperiments Arranged for Students in General Chemistry ; by Epvear F. Smira and Harry F. Keir. 12mo, pp. 56. Philadelphia, 1913 (P. Blakiston’s Son & Co. Price 60c. net).— This is a laboratory book for beginners in chemistry, involving a short course in the subject. It is intended to be used with any text-book. It not only describes experiments, but asks many questions in connection with them. ‘The experiments appear to be very well chosen, and the numerous questions should be very useful in helping the student to gain valuable knowledge from the course of laboratory work. H. L. W. 6. Chemical German; by Francis OC. Puitiips. 8vo, pp. 241. Easton, Pa., 1913 (The Chemical Publishing Co.).—This book gives simple exercises for practice in translating chemical German ; it explains the nomenclature, contains a collection of very well selected, interesting extracts from chemical writings, and includes a vocabulary of technical and other words. 1t appears to be an excellent book for the purpose of aiding our ~ advanced students in the somewhat difficult matter of applying their school German to chemical literature. H. L. W. 7. Spectrum of the Aurora Borealis.—In order to obtain, if possible, more accurate data relating to the northern lights, an expedition to Bossekop in Finmark was made during the winter of 1912-13 by L. Vecarp. With a direct-vision spectroscope 28 observations of the green line were made and the mean of the set- tings gave, when reduced, a wave-length of 5573°7A, The stronger auroral displays made it possible to distinguish a few lines in the blue. The two most intense lines could alone be studied quantitatively and the wave-lengths were found to be 5271°5 and 4708°3 for the weaker and stronger lines respectively. Several faint lines in the neighborhood of \ 5271 were discernible. The most reliable data were obtained photographically by means of a prism spectrograph having a dispersion between Hg and Hy five times as great as had ever been used before on the same problem. Four spectrograms were obtained, the shortest time of exposure being 10 hours and the longest 1 month. The mean wave-lengths derived from the plates are 5571°3, 4708°0, 4646°8, 4278°0, 4234°2, 4200°3, and 3914°6. The average of the numbers 5573°7 and 5571°3 (as obtained by the visual and photo- graphic methods respectively), namely 5572°5, agrees very well Chemistry and Physics. 647 with the wave-length (5572°6) of one of the stronger argon lines. The wave-lengths of the prominent heads of the nitrogen band spectrum are 4708°2, 4651°2, 4278:0, 4236°3, 4200°9, and 3914°4. A comparison of these values with the figures given above for the auroral lines leaves no doubt as to the origin of the radiations in question. Moreover a weak comparison photograph of the nega- tive glow of nitrogen, taken with the same apparatus, showed that the distribution of intensity of the strongest “lines” (4708, 4978, 3914) was the same as in the spectrum of the northern lights. Also, the most intense of these auroral lines (4278) shades _ off on the more refrangible side precisely as does the correspond- ing nitrogen band. Unfortunately the lines which were of suffi- cient intensity to be measured are not numerous enough to decide the question as to whether aurore are caused by electronic rays or by rays of the atype.— Physik. Zeitschr., No. 15, August 1913, p- 677. Hoisaue 8. To Produce a Continuous Spectrum in the. Ultra-violet.— Investigators of absorption spectra have long felt the need of a source of intense, continuous radiation in the ultra-violet. This is especially true in the case of fine absorption lines as given by gases and vapors. ‘The sources of continuous ultra-violet light hitherto found have had little practical value because of their faintness, or of their great inconvenience, etc. It is pointed out in a short paper by Victor Henri that if a spark of high fre- quency, such as is used in the Tesla and d’Arsonval experiments, is employed instead of the usual condensed spark, excellent results can be obtained. The spark gap must be under water and the electrodes are preferably made of aluminium. A spark 4 or 5™™5 long may be readily produced and it is said to be very constant. With an exposure of only 30 to 60 secs. the continuous spectrum extends to about wave-length 2150 A. The spectrogram repro- duced in the plate is unusually good. The continuity of the spec- trum is broken in a few places by intense lines and by narrow reversals. In general, this lack of perfect continuity would not be a practical drawback.— Physik. Zeitschr., No. 12, June 1918, p. 516. He S3/U: 9. The Gyroscope; by F. J. B. Corpretro. Pp. vi, 105, with 19 figures. New York, 1913 (Spon and Chamberlain).—The justification of the production of a new book on gyroscopic phe- nomena is expressed by the author in the following words: “ The student with an elementary knowledge of mathematics, who attempts to understand gyroscopics from a study of its scattered parts in standard treatises, and from the few monographs as yet written, will find the task tedious—probably repulsive.” ‘For this reason, it has seemed advisable to the author to write a mon- ograph which may be easily understood by anybody possessing an elementary knowledge of mechanics and the calculus.” The book is divided into two parts which deal respectively with the development of the theory from the fundamental gyroscopic equation Cw§ = Ay, and with the practical applications of the ——————— = et Nae = = by) 648 Scientific Intelligence. principles to the Griffin grinding mill, the Howell torpedo, the Obry device, the Schlick stabilisator, the Brennan monorail, the Anschiitz compass, ballistics, astronomy, geology, and meteor- ology. The subject-matter is so presented that the astronomical discussions may be omitted without loss of continuity. The text has been prepared with care and there is no hesitancy in the expression of opinion concerning modern terminology, ete. For illustration: ‘‘The term gyrostat, often used for gyroscope, is particularly objectionable.” “There is no such thing as a gyro- - stat, or instrument which maintains its plane of rotation.” Again: “The word ‘ Zorque’ is engineering ‘slang’ for couple.” “It should never be used.” Although the book seems excellent in itself, some doubt exists in the mind of the reviewer as to whether a student possessing only “an elementary knowledge of mechanics” would be prepared to read all of the theoretical sections. In one place (p. 38), at least, a proof depends on the reference in Routh’s Advanced Dynamics, Art. 519. Problems for solution by the student are not given in this volume. H. 8. U. 10. Medizinische Physik; by Dr. Ortro Fiscuzr. Pp. xx, 1120, with 334 figures. Leipzig, 1913 (S. Hirzel).—In this work the author has endeavored to present, in such a manner as to be readily comprehended by those who are not proficient in mathe- matics, certain branches and topics of physics which lie outside of the realm of the ordinary curriculum and which are nevertheless indispensable for the physician. In order to give the book finite dimensions the treatment is wisely restricted to the physical aspect of the subject, so that everything of a physical-chemical or purely physiological nature has been omitted. The average phy- sician’s training in physics is considered to need appreciable sup- plementing only in three branches, namely, mechanics, acoustics, and optics. That these three domains are discussed at great length may be inferred from the fact that 475, 124, and 521 pages are devoted to each of the general subdivisions in the order named. In mechanics, the conception of the differential calculus is very painstakingly introduced and elementary differential quo- tients are subsequently used. The author. intends not to avoid mathematical and other difficulties but rather to show how these difficulties may be overcome by forming correct physical concep- tions of the problems under consideration. Furthermore, the volume is not designed as a reference book, on the contrary, it is prepared only for consecutive reading. To this end no index is ‘given although a detailed table of contents is incorporated. The text-figures were made from the author’s own drawings and hence they invoke the precise mental and ocular impressions intended. The book is undoubtedly thorough and complete but its unusual extent may militate against its usefulness. Hie 11. The Wonders of Wireless Telegraphy ; by J. A. FLEMING. Pp. xi, 279, with 54 figures. London, 1913 (Society for Promot- ing Christian Knowledge).—This volume is a companion to the author’s little book on “ Waves and Ripples.” ‘The present Chemistry and Physics. 649 work is therefore not intended for technical students or practical wireless telegraphists, . . . . but is put forward (with diffidence) as a little attempt to furnish the general reader with a fairly non- technical account of the underlying principles and practical achievements of wireless telegraphy, and of the wonders which it has rendered possible in the transmission of intelligence.” The first chapter deals with the luminiferous ether, electricity and electrons, and the second with electric oscillations and electric waves. Since there are six chapters in ail, it is thus seen that every precaution has been taken to prepare the reader for a full _ understanding of the four chapters which relate directly to wire- less telegraphy and telephony. ‘The text is up to date and trust- worthy, the historical side of the subject is presented in a complete and fascinating manner, and it seems difficult to imagine a better book for the non-mathematical reader. ee 6S We 12. The Principles and Methods of Geometrical Optics, Second Edition ; by James P. C. Sovurnaty. Pp. xxiv, 663, with 175 figures. New York, 1913 (The Macmillan Co.).—For a review of the first edition of this standard work see this Journal, vol. xxx1i, p. 233 (1911). The modifications which the earlier edition has undergone may be briefly stated as follows: P. viii a, a list of recent books on optics is given. Art. 15, on “Character of a Bundle of Optical Rays”, has been rewritten. §51, supple- mented by p. 50d. $102, on “ Deviation (YP) of Ray Obliquely Refracted through a Prism”, rewritten. Chapter X has § 229a added. It is headed “ Trigonometric Formulae of M. Lange for Calculating the Path of an Oblique Ray through a Centered Sys- tem of Spherical Refracting Surfaces”. Anappendix of 15 pages has been added to chapter XI. The next chapter has been aug- mented by § 326a and by an 1|1-page ‘“‘ Note on the Calculation of the Spherical Errors of an Optical System of Centered Lenses, by Means of the Seidel Formulae”. Pages 612a and 612b com- prise a list of new letters and symbols. The volume ends with a supplementary index. It is therefore evident that the author and publishers are sparing no pains to make the book converge towards practical perfection as rapidly as possible. Hee Se Ur 13. Physical Measurements; by A. Witmer Durr and ArTHUR W. Ewet. Third edition. Pp. xii, 244, with 80 figures. Phila- delphia, 1913 (P. Blakiston’s Son & Co.).—For earlier notices of this excellent book see this Journal, vol. xxvii, p. 488 (1909) and vol. xxx, p. 350 (1910). “‘ With the exception of the introduc- tion of a second method for the measurement of viscosity, no considerable changes will be found in this edition; but numerous minor improvements have been made 1 in the descriptions of appa- ratus and methods”. He S. Ue 14. Uber kausale und konditionale Weltanschauung und deren Stellung zur Entwicklungsmechanik ; by WitHELM Rovx. Pp. 66. Leipzig, 1913 (Wilhelm Engelmann). —In this critical essay the author adduces a very great number of arguments to show that the “ Konditionismus ” of Max Verworn is utterly worthless. “Statt der angektindigten, neue Erkenntnis bringenden Weltans- me 650 Scientifie Intelligence. chauung fanden wir Irrtum und Verwirrung.” “Die Weltans- chauung M. Verworns wiirde, wenn sie richtig wire, statt Licht Dunkel verbreiten.” H.S.0Ue: 15. Annals of the Astrophysical Observatory of the Smithso- nian Institution ; by C. G. AsBot, Director, F. E. FowiE and L. B. Aupricu. Vol. III, pp. xi, 241, with 7 plates and 32 figures. Washington, 1913.—Since the publication of the second volume of the “Annals” in 1907 a large number of data, obtained by means of the pyrheliometer and the spectrobolometer, have been accumulated and reduced. Observations were made at three stations in addition to Washington, D.C., namely, at Mount Wil- son (1,730 meters), Mount Whitney, Cal. (4,420 meters), and near Bassour, Algeria (1,160 meters). The object of the principal investigation was “to determine the intensity of the solar radia- tion, as it is in free space at the earth’s mean solar distance, and to detect variations of the sun’s emission if these exceed 1 per cent.” The mean value of the solar constant of radiation for the epoch 1902-1912, resulting from 696 observations, was found to be 1:932 calories (15°) per square centimeter per minute. Far- thermore, when high values of the solar radiation were observed — at Mount Wilson, high values were also found at Bassour and vice versa. “The measurements seem, in fact, to prove conclu- sively that the radiation of the sun is subject to a variation, occur- ring ‘irregularly in periods of a week or 10 days, and whose fluctuations are also irregular in magnitude, but usually within the range of 7 per cent.” “In addition to this short period vari- ability of the sun, thus disclosed, an intimate association between the intensity of solar radiation and the prevalence of sun spots appears to be strongly indicated”. ‘This relation is such that the greater the number of sun spots the higher is the intensity of the solar radiation”. Another important conclusion reached is, “that while the intensities of rays of all wave lengths fall with the decrease of the total solar radiation, the decrease is much more rapid for the shorter wave rays than for the longer”. | The appendix (pp. 169-229) contains reprints from the Astro- physical and other journals on the spectroscopic determination of aqueous vapor, the determination of aqueous vapor above Mount Wilson, the sun’s energy-spectrum and temperature, the. bright- ness of the sky at night as observed on Mount Whitney, and vol- canoes and climate. ‘This very valuable contribution to the subject closes with a list of papers published by members of the observatory staff. H. 8. Gh II. Grontogy anp MINERALOGY. 1. Research in China. Vol. WI. The Cambrian faunas of China, by Coartes D. Waxcorr; A report on Ordovician fos- sils collected in eastern Asia in 1908-04, by Stuart WELLER; | A report on Upper Paleozoic fossils collected in China in 1903- O4, by Grorct H. Girty. Pp. 375; 29 pls., 9 text figs., 1913 Geology and Mineralogy. | 651 (Carnegie Institution of Washington, Publication No, 54).—This long delayed volume completes the great work of Willis and Blackwelder, ‘“‘ Research in China.” Our knowledge of the Pale- ozoie faunas, and especially of those of the Cambrian, is hereby vastly extended. The greater part of volume three is taken up with the Cambrian faunas collected by Iddings and Blackwelder, consisting of 250 forms in 63 genera and 5 subgenera. Of these, 15 forms occur in the Lower Cambrian, 185 in the Middle Cam- brian, and 54 in the Upper Cambrian, 4 being common to the Middle and Upper Cambrian. As is the rule in these early faunas, the Brachiopoda (40 forms), Trilobita (179) and Pteropoda (11) predominate, with the coiled Gastropoda (11) taking their rise. It is stated by the author that “ among the brachiopods none of the genera is pecu- liar to the Chinese Cambrian. All belong to genera found in the Middle Cambrian of western North America and northwestern Europe. .. . The exceptional genera of the Trilobita found in China and not known to occur elsewhere are Stephanocare, Tein- istion, Blackwelderia, Damesella, and Drepanura. All other -genera are represented in western North America and western Kurope, and there is a striking resemblance even to specific char- acters in many of the forms. The most noticeable omissions of American and European genera from the Chinese fauna are Para- doxides of the Atlantic Basin fauna and Olenoides, Dikelocepha- lus, and Neolenus of the North American fauna. The closely related genus Dorypyge (to Olenoides) is found abundantly in China, western United States, and on the island of Bornholm in northwestern Europe. ‘The genera Ptychoparia, Conokephalina, Acrocephalites, Inouyia, Agraulos, Lisania, Solenopleura, Ano- mocare, Anomocarella, and Coosia are well represented in China, western North America, southwestern United States, and north- western Hurope. Bathyuriscus and Asaphiscus are essentially Pacific Basin types” (47, 48). Walcott summarizes his results as follows : “The chief results obtained from the study of the Chinese col- lections are the discovery of portions of the upper part of the Lower Cambrian fauna and a great development of a Middle Cambrian fauna of the same general character as that of the Cor- dilleran Province of western North America; also an Upper Cambrian fauna comparable with that of the Cordilleran Province and the Upper Mississippi Province of the United States. . . . ‘‘ Another important discovery was that of the occurrence in the Middle Cambrian of China of a fauna comparable with that of the Middle Cambrian of Mount Stephen, British Columbia, and the southern extension of the same fauna in the Middle Cam- brian of Idaho, Utah, and Nevada in the United States. “The determination of the age of the Man-t’o shales [closing epoch of Lower Cambrian time] affords the data by which to fix the period of Cambrian time in which the Cambrian sea trans- gressed over eastern and southeastern Asia, and shows that it uM 652 Scientific Intelligence. was somewhat later than the transgression in the Siberian area now occupied by the basins ef the Lena and Yenesei rivers” (2). The Ordovician collections are small but interesting, and con- sist of 32 forms with many unnamed specifically. Weller con- cludes: “The Chinese fauna described in this paper shows clearly its strong relationship with the north European Ordovician faunas, and especially with the fauna of the Glauconite and Vaginoceras limestones of the Baltic provinces of Russia. These two forma- tions are essentially equivalents of American faunas included in the Mohawkian division of the Ordovician, and we recognize in this Chinese fauna several species among the brachiopods which are identical with or closely allied to North American Mohawkian forms. The fauna presents in its entirety a mingling of Baltic and North American forms, although the Baltic element is much the more pronounced. In age the fauna is clearly not younger than the Mohawkian faunas of North America, and it may be safely considered as the essential time equivalent of the Black River limestone of North America and of the Vaginatus lime- stone of Russia” (293-4). The faunas studied by Girty (46 forms) are in the main of Upper Carboniferous time. Regarding them he says: “'The faunas of western North America have, as compared with those of the Mississippi Valley, a distinctly Asiatic facies ; but these Chinese faunas are still distinct, the very features which ally them to the faunas of India and China and in which their Asiatic affinities chiefly reside, aiding prominently in show- ing their alien character to those of even western America”’ (301-2). Cc. S. 2. Hosseis Devonianos do Paranéd,; by Joun M. CrarKe. Pp. 353, 27 plates, many text figs., 1913. Servigo Geologico e Mineralogico do Brasil, Monographias, Vol. I. In Spanish and English.— With the fullness due to many years’ study of the Devonian faunas of North and South America, Doctor Clarke here describes new collections from Brazil, western Argentina, Falkland Islands, and South Africa. Upward of 100 forms, new - and old, are discussed and well illustrated. This study has led Clarke to reéxamine all of the Lower Devonian faunas of the southern hemisphere and his results are of great import, not only in correlation and faunal assemblages, but as well in paleogeog- raphy and the determination of phyletic lines, especially among the trilobites and brachiopods. Of new brachiopod genera there are dAustralina, Brasilia and Derbyina,; of bivalves, Pleuro- dapis ; and of trilobites, Calmonia, Pennaia, Phacopina, Probo- loides and Schizopyge. The austral Lower Devonian faunas are characterized by an abundance of brachiopods, arcoid taxodont bivalves, and trilo- bites. Capulid gastropods, elsewhere so common at this time, are practically absent, and the same is true of corals, bryozoans and cephalopods. This combination, the author concludes, is Geoloyy and Mineralogy. 653 “evidence that the waters in which the assemblage flourished were cool” (26). This evidence also appears to fall in with that of the Table Mountain tillites of South Africa. “The entire assemblage inclusive of all the Devonian faunas thus far known from Brazil (with exception of the sandstone fauna (Middle Devonian) and black shale fauna (Upper Devonian of Ereré and vicinity) ; from all horizons in Bolivia, Argentina, the Falkland Islands and Cape Colony (not including the Witte- berg series now regarded by some writers as of Carboniferous age) bears a special and distinctive impress which is characterized as austral in contrast to the boreal aspect of homotaxia] faunas north of the equator. ‘These distinctions consist in specific resemblances without identities ; in parallel developments afford- ing different resultants ; in invasions of generic structures more or less clearly disturbing generic agreements, and in irregular outgrowth of species distinctions on generic foundations common both to the north and the south. “The fauna discussed . . . shows that the assemblage repre- sents the Early Devonian stages only, and inferentially that in this region later stages of Devonian life and of sedimentation are, on the basis of present knowledge, wholly absent. “If the foregoing deduction is correct we may infer that the austral continent was either high out of water during the later Devonian, or that the deposits of this time are now deeply sub- merged under land or sea. We prefer the former conclusion” ¥5: 8): “Notwithstanding the faunal distinction north and south, which is essential, there has been no lack of opportunity for the passage of species from the platform of the southern to that of the northern Devonian continent, so closely did the two approach each other both at the east and at the west. And again there has been no departure in the species of the austral fauna from the . normal path of development shown by those of the boreal. They have traveled a similar course, building superstructures of unlike detail on a similar foundation. The order of succession in vital events has been harmonious both north and south and as a result there are superficial similarities commingled with more palpable distinctions ” (70-1). Cc. Ss. 3. A Monograph of the Terrestrial Paleozoic Arachnida of North America ; by ALEXANDER PEeTRUNKEViITCH. Trans. Conn. Acad. Arts and Sci, vol. xvili, pp. 1-137, pls. 1x11, 88 text figs., 1913.—The author here brings together all that is known of North American Paleozoic arachnids. Of specimens he studied 101, and it is not often that an author reaps so rich a harvest, for of the 25 genera treated 13 are new, and of the 42 species, 27 are new. Of the order Solifuge, no fossil forms were heretofore known, and with one bound the group is now taken back to the Coal Measures in Protosolpuga curbonaria. Then there is also defined a new order, Kustarachnae. The author discusses the system of Arachnida, the phylogenetic development, and the EE oe t? oe 654 Scientific Intelligence. interrelations of the American and European Carboniferous arachnological faunas. Now that the foundation has been prepared by a specialist, and one who is a student of living Arachnida as well, American paleontologists can work up the new material as it comes to light. Professor Petrunkevitch is to be congraniias me his excellent work. 4. The Heart of Gaspé. Sketches in the Gulf of St. Bint rence; by Joun Mason Crarke. Pp. xiv, 292; with many illustrations. New York, 1913 (The Macmillan Company). —It is now thirteen years since Doctor Clarke first visited Gaspé for the purpose of seeing the Lower Devonian formations exposed there. Since then he has been in this secluded land of cod almost every summer, and has fallen deeply in love with the “ kindly people of the Gaspé coast” and their pieturesque sea-eaten land. In his recent book he presents his “ untechnical sketches ” of this inviting country in a most sympathetic manner and in captivat- ing language. Geologists familiar with Clarke’s ‘ Karly Devonic History of New York and Eastern North America,” published in 1908 and 1909, will certainly want to read the present work, not only to learn of the quaint country, but as well to see the author from an interesting viewpoint. Here he is among the fishermen, living with them as their honored guest, learning from them tales of their fisheries, their early settlements, their ancestry, their trials and perils in a bleak land. Throughout there is woven a vivid picture of the scenery, the destructive work of the sea, and something of the geology and natural history. Bonaventure is i to him the Isle of the Golden Jug, a trophy that turns him from i a hunter of fossils to a seeker of Sunderland ware, a Cartier medallion, and old prints and maps. “The Heart of Gaspé” is the first book of its kind by an American geologist, and is a reminder of that other happy work, ‘i “ Mountaineering in the Sierra Nevada,” by Clarence King. C..8: 5. Minth Report of the Director of the Science Division ; New York State Mus., Bull. 164. Pp. 214; 50 pls., text figs., 1913,—This report recounts the progress in the various depart- ! ments of the New York State Museum for the year ending Sep- tember 30, 1912 (pp. 1-77). Of more special interest are the papers: “The Mount Morris Meteorite,” by H. P. Whitlock i (78-79); “Karly Paleozoic Physiography of the Southern Adi- 4 rondacks,” by W.J. Miller (80-94), in which the relief of the ‘ Adirondacks, the times of uplift and the degree of sea encroach- ment during the Cambrian and Ordovician are stated; ‘The Garnet Deposits of Warren County, New York,” by W. J. Miller (95-102) ; “‘ The Use of the Stereogram in Paleobiology,” by G. H. Hudson (103-131); “The Origin of the Gulf of St. Lawrence” (132-137), “A Notable Trilobite from the Perce tock” (138-139), and “Illustrations of the Devonic Fossils of Geology and Mineralogy. 655 Southern Brazil and the Falkland Islands” (pls. 1-35), ee a M. Clarke. 6. New Trilobites from the Maquoketa Beds of Fayette Eh ey Towa; by ARTHUR Ware Stocum. Field Mus. Nat. Hist., Geol. Ser., RY, No. 3, pp. 43-83, pls. xiii-xviii, 1913.—The author has secured from these beds the large number of 20 species of Rich- mondian trilobites, 17 of which are here named, 11 of them being new. The new genus Cybeloides is also defined. C. S. 7. A new Paleontologic Periodical—Palacontologische Zeit- schrift, Bd. I, Heft I, June, 1913.—This is the first number of the organ of the Palaeontologische Gesellschaft of Germany, with Professor Jaekel as editor. Three parts will appear during the year and will be sent free to the members of the Society ; otherwise the price is 25 marks per volume. All manuscripts, which may be in German, French, or English, are to be sent to the editor, and subscriptions to the publishers, Gebriider Born- traeger, W. 35 Schoneberger Ufer 12a, Berlin. The first paper in this number is by the editor, “ Wege und Ziele der Palaeontologie,” in which it is said that “ the Americans will soon harvest the fruits of the endeavor of the European workers of the past century, and further the progress of our science along its foremost lines.” Of other papers there are “ Barroisia und die Pharetronenfrage,” by H. Rauff (pages 74-144); “Uber die palaeontologische Bedeutung des Massen- sterbens unter den Tieren,” by ©. Wiman (pages 145-154) ; and another paper by Jaekel, ‘Uber die Wirbeltierfunde in der oberen Trias von Halberstadt, ” which is a partial account of the finding of thirty-five dinosaurs and other vertebrates, and which will be continued in the next number. The Society, which already has 130 German and 80 foreign members, is to be congratulated on its first printed product. One 8. Petrology of the alkali-granites and porphyries of Quincy and the Blue Hills, Mass. ; by Cuas. H. Warren. Proc. Amer. Acad. Arts and Sci., vol. xlix, No. 5, Sept., 1913, pp. 203-330.— While much work has been done on the geology of the Boston basin, none more careful, detailed and thorough on any part of the area, than the one here noticed, has yet been attempted. The alkalic rocks of this region are well known and the complete investigation of this part of them by Professor Warren affords results which are of interest and importance to all petrologists. The field studies show that the rocks are parts of a complex pro- duced by small batholithic invasion whose method of intrusion is believed to have occurred through stoping. The upper portion solidified as vitreous rocks, which give place below to porphy- ries, while at considerably lower depths granite was produced. The varied relations of these rocks are treated and their petrog- raphy, accompanied by chemical analyses, has been worked out in detail. Modern views of physical chemistry are invoked to explain the different textures and mineral constituents met with. 656 Scientific Inteiligence. / The whole is a valuable contribution and it is to be hoped that Professor Warren may be able to supplement this monograph by further ones dealing with other parts of this region. } TU as 9. Geology and Ore Deposits of the Philipsburg Quadrangle, Montana ; by Witir1am H. Emmons and Frank C. Cauxins. Pp. 271; 17pls., 55 figs. U.S.G.8., Prof. Paper, No. 78, 1913.—The Philipsburg Quadrangle is located in central western Montana, only afew miles west of the Butte copper district. The district is one of strong relief ranging in elevation from 4,500 to 10,500 feet. Within the quadrangle lie parts of three mountain masses. The sedimentary rocks of the area range in age from Algonkian to Quaternary and consist largely of limestones and shales, with smaller amounts of sandstones and quartzites. Intrusive igneous rocks occur in large, dome-like masses, and to a less extent in dikes and sheets. The batholitic masses are probably all of Ter- tiary age. They range in composition from diabase to a siliceous granitoid rock, the more common types being quartz diorite, gra- nodiorite, and granite. The ores of the district are chiefly impor- tant for their gold and silver content, although at times copper becomes important. The deposits are of three types and include fissure veins in both igneous and sedimentary rocks, contact- metamorphic replacement deposits in limestone near the granitic intrusions, and replacement deposits in the sedimentary rocks, in part conforming with their bedding planes. W. KE. F. 10. Gems and Precious Stones in 1912 ; by Dovueias B. Stur- RETT. (Adv. chapter, Min. Resources of the United States.)— Dr. Sterrett’s annual reports always contain matter of interest to the mineralogist. In the present one he notes the large output of gem sapphires from Montana, from the mines in Fergus County; also the development of opal deposits in Humboldt County, Nevada. | These promise to produce gems equal], or perhaps superior, to those of Australia; further, the finding of beautiful amethysts in War- ren County, N.C. The diamond localities in Arkansas are spoken of in detail, although the past year has seen no remarkable devel- opments. It is estimated that about 1400 diamonds, weighing nearly 550 carats, were found from August, 1906, to December, 1912. These were valued at $12,100. III. Miscerntanezovs Screntiric INTELLIGENCE. 1. National Antarctic Expedition, 1901-1904. Meteorology, Part If. Prepared in the Meteorological Office, under the Super- intendence of M. W. Camppetyt Hepwortu. London, 1913 (Pub- lished by the Royal Society).—Earlier volumes of the National Antarctic Expedition have been from time to time noticed in the pages of this Journal. Part I on Meteorology appeared in 1908 (see vol. xxvi, p. 588). The present volume, Part II, contains a remark- able series of daily synchronous charts extending from October 1, Geology and Mineralogy. 657 1901, to March 31, 1904. It gives not only the results of the observations made by the Expedition itself, but also a large number of contemporary observations by other explorers in the Antarctic, by observatories at different points in the southern hem- isphere, and by captains of vessels sailing in those seas. The total number of observations charted amounts to nearly 45,000, of which about two-thirds are marine and one-third land obser- vations. We have thus presented a “continuous daily picture of the changing meteorological conditions of the whole Antarctic region south of the 30th parallel of latitude.” The charts are given, four on each page, and the larger part give synchronous observations of sea-level pressure for noon, G. M.T., with winds and air temperature. There are also a series of charts of mean sea-level pressure and air temperatures. The records of this expedition gain a peculiar and melancholy interest from the fact that it was led by Capt. Scott, whose last expedition to the same region had so tragic an ending. 2.. Annual Report of the Board of Regents of the Smithsonian Institution, showing the operations, expenditures, and condition of the Institution for the year ending June 30, 1912. Pp. xii, 780; 72 pls., 11 figs. Washington, 1913.—This velume opens with the report of the Secretary, Dr. Cuartes D. Watcort, which has already been noticed in this Journal (see vol. xxxv, p. 200). Pp. 131-780, which follow, include the General Appendix, in which scientific papers by eminent authors in widely different fields are given to the public. The plan in this form has been followed since 1889, although the essential feature involved had been a part of the Annual Report from a very early date. The papers are well chosen and cannot fail of their object to interest and instruct the intelligent general public. Among these may be mentioned a series dealing with the nature and origin of life, including the address to the British Association by Dr. Schafer ; other related papers following deal with the evolution of man by Prof. G. KE. Smith, and the history and traditions of human speech. The other departments of science are also well repre- sented. The explorations and field work of the Smithsonian Institution in 1912 are discussed in detail in a separate pamphlet of 76 pages profusely illustrated (Publication 2178). 3. Report on the Progress and Condition of the U. 8S. Na- tional Museum for the year ending June 30, 1912. Pp. 165, Smithsonian Institution. Washington, 1913.—Dr. Rarasun gives in this volume an extended account of the National Museum, a subject briefly discussed by him in Appendix I to the volume just noticed. It is noted that the acquisitions for the year embrace some 238,000 specimens, more than half belonging to the biological department. It is interesting to remark that on Oct. 8, 1911, the Academy was, for the first time, open to the public on Sunday afternoons; the large number of visitors on these occasions has shown the wisdom of the movement. Am, Jour. Sci.—FourtH Srerigs, VoL. XXXVI, No. 216.—DxEcempBeEr, 1918. 44 658 Scientific Intelligence. Dr. Rathbun has also published, as Bulletin 80 (pp. 125) a descriptive account of the new buildings of the Museum, which being written in considerable detail and with a large number of photographs and detailed plans must be of great value, particu- Jarly to those concerned with the construction and administration of museums. 4, Publications of the British Museum of Natural History.— The following catalogues have been added recently to the long and valuable series published by the Trustees of the British Museum (see vol. xxxiv, 99 and earlier): Catalogue of the Plants collected by Mr.and Mrs P. A. Talbot in thé Oban District, South Nigeria, by A. B. Renpuiv, EK G. Baker, H. F. Wernuam, 8S. Moors, and others. Pp. x, 157; 17 pls. These collections were made in 1909-1912. They include 1016 species and varieties, 195 of which are new; there are also nine new genera. The district adjoins the Cameroons and botan- ically is an extension of the evergreen rain-forest area, the flora being practically identical with that of the Cameroons. Catalogue of the Lepidoptera Phalenz in the British Museum, Vol. XII, Plates CXCII-CCXXI. Catalogue of the Ungulate Mammals in the British Museum. Vol. I. Artiodactyla, Family Bovide, Subfamilies Bovine to Ovibovine (Cattle, Sheep, Goats, Chamois, Serows, Takin, Musk- Oxen, etc.); by R. LypexKker. Pp. xvii, 249; 55 figs. Forty years have passed since the last catalogue of ungulate mammals was published; it is not surprising, therefore, that the Museum collections during this period have enormously increased. Catalogue of the Books, Manuscripts, Maps and Drawings in the British Museum (Natural History), Vol. IV, P-SN. Pp. 1495-1956, 4to. 5. Publications of the Museum of the Brooklyn Institute of Arts and Sciences.—The following have recently been issued : Science Bulletin, Vol. Il, No.1. Long Island Fauna and Flora, L. The Bats; by Rosperr Cusaman Murvuy and Joun TREADWELL Nicwous. Pp. 15. No. 2. Long Island Fauna and Flora, Il. A Long Island Acmeea, and a new variety of Uresalpina linerea; by Sivas ©, WuEar, Pp. 17205 api 6. National Academy of Sciences.—The regular autumn meet- ~ ing of the National Academy met in Baltimore on November 18-20. The following is the list of papers presented : H. F. Osporn: Final results on the phylogeny or lines of descent in the Titanotheres. T. H. Morcan; The constitution of the chromosomes as indicated by the heredity of linked characters. H. McL. Evans: The action of vital stains belonging to the benzidine JTOUP. : ‘ 5. 0. Mast: Changes in pattern and color in fishes, with special refer- ence to flounders. D. 5S. Jonnson: The perennating fruits of the prickly pears. B. F. Lovetace: A static method for the measurement of vapor-pressures of solutions. H. C. Jones: The absorption of light by water containing strongly hydrated salts. Obituary. 659 A. G. WesBsTER: The transmission of sound through porous materials. A new portable phonometer. Smmon FLEXNER: Factors in the epidemiology of infection. Kwnicut DunLAP: The fusion of successive flashes of light. L. B. MenpeL: Factors relating to the réle of the inorganic components of the diet. H. A. Ketuy: Radio-therapeutics in surgical affections. A. H. Prunp: Measurement of stellar radiation. J. A. ANDHRSON: A method for testing screws. J. B. Watson: An experimental study of homing. G. ¥. Becker and A. L. Day: Fresh experiments on the linear force of growing crystals. | L. V. Kine: Phonometric characteristics of fog-signal equipment. H. F. Retp: Sea waves due to earthquakes. C. B. Davenport: Absence of correlation between curliness of the hair and color of the skin in offspring of negro-white crosses. S. Weir MitcHELL: Biographical memoir of Dr, John 8. Billings. 7. The Elements of Bacteriological Technique; by J. W. H. Eyre, M.D., Director of the Bacteriological Department of Guy’s Hospital, London. Second edition. Pp. 518, 219 illustra- tions. Philadelphia and London (W. B. Saunders Company), 1913.—Since the first edition of this work appeared (1903) much has been added to our knowledge of bacteria in their various relationships. The new edition contains a great deal that is not found in the old. This is most apparent in the description of methods employed in serological work. Further- more, numerous valuable illustrations have been added. Bacterological technique is new, even to the student of botany, zoology or chemistry. For this reason, and on account of the numerous methods involved, it is necessary for the student to receive almost constant help from the instructor, or with the aid of a satisfactory written guide. The present edition is compre- hensive and clear. The subject matter is divided into 21 chapters, altogether covering the field of general bacteriological technique admirably. It is not intended so much for advanced students, or investigators, as for those who are endeavoring to acquire a general thorough knowledge of bacteriological and bio-chemical technique as an essential in the study of bacteria themselves. The book is planned as a laboratory guide for the technical student generally, whether he is particularly interested in pre- ventative or curative medicine, brewing, dairying or agriculture. Tey E Rs OBITUARY. ALFRED Russert Watace, the veteran English naturalist and traveler, died on November 7 in his ninety-first year. His contributions to science were numerous, varied and of the first importance, but his name will be chiefly remembered because of his prominent share in the building up of the theory of evolution. Sir Witt1am Henry Preece, who contributed largely to the development of the telegraph and telephone in Great Britain, died on November 6 in his eightieth year. SSS SSE SS SSS INDEX TO VOLUME XXXVI* A Academy, National, History of the first half century, 185. — Baltimore meeting, 658. Alabama geol. survey, 79. Allegheny Observatory, 89. Antarctic Expedition, National, Me- teorology, Pt. IT, 657. Astrophysical Observatory, Annals, 650. Atom, Beyond the, Cox, 566. Atwood, E. L., Modern Warship, 314. Aurora Borealis, spectrum, Vegard, 646. B Bacteriological Technique, Eyre, 659. Barrell, J., Upper Devonian delta of the Appalachian geosyncline, 429. Bermuda, deep boring, Pirsson and Vaughan, 70. Bingham, H., supposed prehistoric human remains of Cuzco, 1. Black, N. H., Physics, 566. Blackwelder, E., Paleozoic faunas of Wyoming, 174. Blake, J. C., General Chemistry, 563. Bolivia, La Paz gorge, Gregory, 141. Borings, deep, Bermuda, 70; Find- lay, O., 123, 131; near Copenhagen, 3138. Bradley, W. M., composition of albite, 47; pyroxmangite, 169; com- position of chrysocolla, 180. British Museum, catalogues, 84, 658. Brooklyn Institute, publications, ~ 698. Browning, P, E., preparation of tel- luric acid, 72; preparation of tellu- rous acid, 399. Buchanan, J. Y., specific gravity, etc., of some saline solutions, 421. Bumstead, H. A., velocities of delta rays, 91. C Canada, banded gneises of Lauren- tian highlands, Wilson, 109 — Department of Mines, 79. Cape of Good Hope, annual report of Geological Commission, 568. Carnegie Institution, publications, 575. Carothers Observatory, 89. Chemical Analysis, Rockwood, 74; Qualitative, Noyes, 418. Chemical German, Phillips, 646. — News, General Index, 87. ryan Physikalische, etc., Jellinek, 567. Chemistry, Kahlenberg and Hart,564. — Applied, Dictionary of, Thorpe, vol. IV, 563. — General, Blake, 563; Smith and Keller, 646, — New Era, Tones: 645. — Organic, "Molinari, 563. — Physiological, Hawk, 75. CHEMISTRY. Alcohol and sugar cane, influence upon solution of cadmium, Van Name and Hill, 5438. Beryllium, metallic, Fichter and Jablezynski, 562. Boron, hydrides, Stock, 562. Bromine, detection, Guareschi, 416. Calcium hydride, Moldenhauer and Roll-Hansen, 417. Carbon, new oxide, Meyer and Steiner. 73. Fluorine, Greef, 645. Hydrogen, behavior towards palla- dium, Gutbier, etc., 645. Iron, etc., heat of combustion of oxides, etc., Mixter, 595. Manganese, volatile oxide, Lank- shear, 416. Per- Acids and Salts, Price, 75. Silica, dehydration and recovery, Gooch, Reckert. and Kuzirian, 598. Sodium paratungstate, Kuzirian, action of, 301 ; use of, 308. Steels, analysis of special, Zinberg, 417. Sulphates, water of crystallization in, Kuzirian, 401. Sulphur trioxide, action upon salts, Traube, 644. Telluric acid, preparation, Brown- ing and Minnig, 72. Tellurous acid, preparation, Ober- helman and Browning, 399. Tungsten compounds, Olsson, 73. China, Research in, Walcott, 650. Clarke, J. M., The heart of Gaspé, 654 ; Fosseis Devonianos do Parana, 650. Coal, Mine Explosions, Harger, 81. Coast Survey, U.S., report, 87. Cockerell, T. D A., fauna of the Florissant shales, 498. Colorado, fossil Coleoptera, Wick- ham, 83. *This Index contains the general heads, CHEMISTRY, GEOLOGY, MINERALS, OBITUARY, Rocks; under each the titles of Articles referring thereto are included. INDEX. Condit, D. D., deep wells at Findlay, Ohio, 123. . Cordeiro, F. J. B., Gyroscope, 647. Cox, J., Beyond the Atom, 566. Crawford, R. D., geology of the Mon- arch district, Coiorado, 82. Crystai Atlas, Goldschmidt, 313. Crystals, model to show symmetry | of, Phillips, 30. Cuzco, see Peru. D Dale, T. N., Ordovician outlier, Sud- bury, Vermont, 395. Davis, H. N., Physics, 566. Delta rays, velocities, Bumstead, 91. Dennis, L. M., Gas Analysis, 74. Derby, O. A., stem structure of Psaronius brasiliensis, 489. Detroit Observatory, 89. | Duncan, J. Mechanics and Heat, 565. E _ Eaton, G. F., vertebrate remains in the Cuzco gravels, 3. Ecology, Journal of, 87. Eggs, bacteria in, Kossowiez, 88. Electrons, see Delta rays. F Farwell, H. W., optical bench for elementary work, 473. Feldspars, plagioclase, graphical plot for, Wright, 541. Fenner, C.N., stability relations of silica minerals, 331. Field Museum, Chicago, annual re- port, 86. Findlay, Ohio, deep wells, geology, Condit, 123; temperature, John- ston, 131. Finlay, G. I., Igneous Rocks, 573. Sa O., Medizinische Physik, Penne J. A., Wireless Telegraphy, Florissant shales, fauna of, Cocke- rell, 498. Foote, H. W., composition of albite, 47; of chrysocolla, 180. Ford, W. E., pyroxmangite, 169. G Gale, H. G., Physics, 423. Gamma rays, interference, Shaw, 420. Gas Analysis, Dennis, 74. Gaspé, Heart of, Clarke, 654. ae Biography, Klein and Brendel, ‘GEOLOGICAL REPORTS. Alabama, 79. Cape of Good Hope, 568. Colorado, 82. 661 GEOLOGICAL REPORTS. New Jersey, 78. New Zealand, 569. Ohio, 80. United States, Publications, 77, 424. Vermont, 429. Virginia, 80, 568. Western Australia, 569. West Virginia, 79. Wisconsin, 79. Wyoming, 81. GEOLOGY. Arachnida, Paleozoic, of No. Amer- ica, Petrunkevitch, 605. Cambrian Faunas in China, Wal- cott, 650. Carboniferous and Devonian, un- conformity between, Keyes, 160. Coleoptera, fossil, Colorado, Wick- ham, 83. Cretaceous deposits of Miyako, 420. Devonian faunas of South America, etc., Clarke, 650. — formation, Ohio, Prosser, 82. — fossiliferous horizon at Littleton, N. H., Lahee, 281. — Upper, delta of the Appalachian geosyncline, Barrell, 429. Kurypterids of Kokomo, Ind., age, Kindle, 282. Fauna of the Florissant shales, Cockereli, 498. Geology and ore deposits of Philips- burg Quadrangle, Montana, Hm- mons and Calkins, 656. La Paz gorge, Bolivia, Gregory, 141. Laurentian highlands, banded gneisses of, Wilson, 109. Liassic flora of Mexico, Wieland, 201, Lower Siluric of Mohawk Valley, shales, Ruedemann, 83. Ordovician fossils in Eastern Asia, Weller, 650. — outlier, Sudbury, Vt., Dale, 395. Paleozoic faunas of Wyoming, Blackwelder, 174. — section in Utah, Richardson, 406. — Upper, fossils in China, Girty, 650. Psaronius brasiliensis, Derby, 489. Trilobites from Iowa, Slocum, 655. Tropidoleptus zones of New York Devonian, Williams, 571. Vertebrate remains from Cuzco, Peru, Eaton, 3. Geophysical Laboratory, papers from, 1381, 331, 509, 540, 577. Goldschmidt, V., Atlas der Krystall- formen, Vol. I, 318. Gooch, F. A., dehydration and recoy- ery of silica, 598. Graham, R. P. D., crystallization of willemite, 639. 662 Gregory, H. E., gravels at Cuzco, 15; La Paz (Bolivia) gorge, 141; geologic sketch of Titicaca Island, 1ST Gyroscope, Cordeiro, 647. H Heat of formation of oxides of iron, ete., Mixter, 55. Hess, F. L., triplite, Nevada, 51. Hill, D. W., influence of alcohol and sugar cane upon solution of cad- mium, 548. Hornor, N. N., sealing wax as a source of lime for Wehnelt cathode, 591. Hunt, W. F., triplite, Nevada, bie: vanadiferous egirites from Mon- tana, 289. Hurricanes, West Indian, Fassig, 88. Hutchins, Cc c., quartz spectro- graph, 328, I Iddings, J. P., Igneous Rocks, 571. Illinois, Waters of, chemical survey, Bartow, 90. Iodine, new fluorescence spectrum, McLennan, 418. Ionization, columnar, Wellisch and Woodrow, 214. Italian Seas, mission on, 88. Jellinek, K., Physikalische Chemie, | etc.. 567, Johnston, J., temperature in deep wells, Findlay, Ohio, 131. de H. C., New Era in Chemistry, K Rot H. F., General Chemistry, Keller, O., die antike Tierwelt, 426. Keyes, C. a .» unconformity between upper Mississippi Carboniferous and Devonian, 160. Kilauea, formations of, Perret, 151; volcanic research, Perret, 75. Kindle, E. M. age of Eurypterids of Kokomo, Ind., 282, Krystall formen, Atlas, Vol. I, Gold- schmidt, 313. Kuzirian, S. B., sodium paratung- state, action of, 301; use of, 305; water of crystallization i in sulphates, 401; dehydration and recovery of silica, 598, LS Lahee, F. H., new fossiliferous hori- zon, Littleton, N. H., 2381. publication of Com- | INDEX. Larsen, E. S., vanadiferous nee from Montana, 289; custerite, 385. Lava, ascent of, Perret, 605, Fees from Sardinia, Washington, 7 Littleton, N. H., new fossiliferous horizon, Lahee, 231, Lulham, R. , Zoology, 84, M Magnetic phenomena in rods due to twist, Williams, 555. Magneto-Optics, Zeeman, 565. Malaria, Herms, 84. Mechanics and Heat, Duncan, 565. 'Mennell, F. P., Petrology, 446. Meteorite, iron, Paulding County, Georgia, Watson, 165. Mexico, Liassic flora, Wieland, 201. Millikan, R. A. , Physics, 423. Minerals, silica, stability relations of, Fenner, 331. — solid solution in, Foote and Brad- ley, 47, 180. | MINERALS. AXgirites, vanadiferous, 289. Al- bite, 47. Chalcedony, 37$. Chrysocolla, com- — position, 180. Crystobalite, 334, 043, etc. Cuprodescloizite, new, 636. Custerite, Idaho, new, 385. Plattnerite, Idaho, 427. Pyrox- mangite, So. Carolina, new, 169. Quartz, 334, 349, etc. Skemmatite, So. Carolina, new, 169. Tridvmite, 334, 343, ete. Triplite, Nevada, 51. Willemite, crystallization, 639. Mines, U. Ss. Bureau of, publica- tions, 78. — Department of, Canada, 79; New Zealand, 81. Mining World Index, 90, 576. Minnig, H. D., preparation of telluric acid, 72. Mixter, W. G, heat of formation of oxides of iron, etc., 59. Miyako, Cretaceous deposits, 425. Molinari, E., Organic Chemistry, 563. Miiller’s Serodiagnostic Whitman, 428. Methods, N National Museum, United report, 658. New Jersey geol. survey, 78. New York State Museum, report of Science Division, 654. New Zealand, Dept. of Mines, 81 ; geol. survey, 569. Noyes, A. A., nein ue Chemical Analysis, 418. States, INDEX. O Oberhelman, G. O., preparation of | tellurous acid, 399. OBITUARY. Avebury, Lord, 90. Credner, H., 576. Eastman, J. R., 576. Hallock, W., 90. Hartley, W. N., | 576. "Holzapfel, K., 186. Kittl, E., 90. | Laspeyres, HM. . O16. | MacFarlane, ne: 576. Macgregor, | J. G., 90. Marshall, H., 576. Milne, J., 576. Preece, W. H., 659. Rockwood, C. R., 576. Selater. P. L., 576. Wallace, A. R., 659. | Weber, H., 576. Observatory, Allegheny, 89; Astro- physical, 650 ; Carothers, 89 : De- troit, 89. ~ Ohio, Devonian formation, Prosser, | 82 | — geol. survey, 80. Optical bench, Farwell, 473. Optics, Geometrical, Southall, 649. Ore deposits of Philipsburg, Mont., Emmons and Calkins, 656. P Pacinotti, A., Macchinetta Elettro- magnetica, 424. Page, L., photoelectric effect, 501. Palache, C., crystallization of wil- lemite, 639. Paleontology, new periodical, 655. Patterson, R. A., are spectrum of tellurium, 135. Perret, F. A. , Kilauean formations, 151; ver tical motion seismographs, 297 : volcanic research at Kilauea, | Aq : ascent of lava, 605. Peru, Yale Expedition, supposed pre- | historic human remains, Bingham,1; vertebrate remains, Haton, 3; gray- els at Cuzco, Gregory, 15; see also 141, 187. Petrography, microscopical, Wright, 509 Slory, Mennell, 426; of the Blue Hills, Mass., Warren, 655. | Phillips, A. =. model to show sym- metry of crystals, 30. Phillips, F. C., Chemical German, | 646. Photochemical Investigations, Plot- | nikow. 422. Photoelectric effect, Page, 501. Physical measurements, Duff and Eweil, 649. Physics, Millikan and Gale, 423. — Practical, Black and Davis, 566. | | Smithsonian Institution, 663 | Physik, Medizinische, Fischer, 648. Pirsson, LE. VW: , deep boring in Ber- muda, 70. | 'Planetologia, Cortese, 428. R NRodiation! solar, Very, 609. ' Radium, active deposit i in an electric field, Wellisch, 515. | Rays, see Delta rays, Gamma rays. |Reckert, F. C., dehydration and re- covery ‘of silica, 598. Richardson, G. B., Paleozoic section in northern Utah, 4(6. h ities, C. a electric properties of selen- ium, 499 ROCKS. Alkali-granites and porphyries of Blue Hills, Mass., Warren, 655. Alkaline rocks, composition and origin, Smyth, 33. Gneisses of Laurentian highlands, Canada, Wilson, 109. Igneous Rocks, Iddings, ; Finlay, "573. Lavas from Monte Arci, Sardinia, Washington, 577. Rhyolites, trachytes, etc., Sardinia, Washington, 577. Rockwood, "EL W. , Chemical Analy- sis, 74. Rubidium rays, deviation, Bergwitz, 564, = Salts, dissolved, influence on absorp- tion bands of water, Jones, Guy and Shaeffer, 75. Sardinia, lavas a Monte Arci, WwW ashington. O77 Schaller, WwW. T. cee 385. Sealing wax as source of lime for Wehnelt cathode, Hornor. Seismographs, vertical motion, Per- ret, 297. Selenium, electric properties, Ries, 422. Semon, R., die Vererbung ** Krwor- bener Eigenschaften,’ 314, pene E. V. “Sl eieer Idaho, 427 eahen. minerals, of, Fenner, 331. Smith, E. F., Chemistry, 646. annual re- stability relations port, 608. Smyth, C. H., Jr., composition and origin of nian rocks, 33. Solar radiation, Very, 609. | Southall, J. P. C., Geometrical Op- tics, 649. _ Spectrograph, quartz, Hutchins, 828. Specific Gravity of Saline Solutions, etc., Buchanan, 421. sr. — 664 INDEX. Spectrum, aurora borealis, 646;| Warren. C. H., pote iodine, 418. and Blue Hills, Mass., 655. ‘ —tellurium, Uhler and Patterson, | Warship, Modern, ‘Atwood, 3) 135. _ | Washington, H. S., lavas” — in the ultra-violet, Henri, 647. Monte Arci, Sardinia, 077. Steel rods, twist in. due to a mag-| Water, absorption bands of, 76. netic field, Williams, 555. Waters, Examination of, Thres Sterrett, D. B., Gems in 1912, 656. Watson, Tie meteoric iron - Paulding county, Georgia, 165. as Wehnelt cathode, sealing wax as source of lime, Hornor, 591. Taschenberg, ©:. Bibliotheca Zoo- Wellisch, E. M., columnar ioni logica, 89. tion, 214; active deposit of rad Tellurium, arc spectrom, Uhler and| in Bclocnae field, 315. :, Patterson, 135. Wells, deep, at Findlay, Ohio, ge - Thorpe, E., Dictionary of Applied| ogy, Condit, 128; temperatu Chemistry, vol. 1V, 563. Johnston, 131, Thresh, J.C. , Examination of Waters Wells, R. C., new occurrence — and Water Supplies, 74. cuprodescloizite, 636. : Tierwelt, die antike, Keller, 426. West Indies, Hurricanes, Fassig, 88 Titicaca Island, geologic sketch, | West Virginia geol. survey, 79 Gregory, 187. geol. map, 79. 2 Tornquist, work on geotectonics, |71.| Western Australia geol. survey 4 569. a U Whitman, R. C., Miller’s Serodiag nostic Methods, ” 428. a Uhler, H. S., arc spectrum of tellu- Wieland, G. R., Liassic floras oF rium, 139. Mexico, 251. i Umpleby, J. B., custerite, 385. Williams, H. S., Tropidoleptus zee United States Bureau of Mines, 78. zones in New York, aWAls 2 ‘ — Coast Survey, 87. Williams, S. R., twist in steel and — Geol. Survey, 77, 424. nickel rods due toa magnetic field, — National Museum, report, 657. 5DD. PM) ae Uranium X2, .a new element, Fajans| Wilson. M. E.. banded gneisses of and Gohring, 060. ; Laurentian highlands, 109. = Utah, Paleozoic section in, Richard-| Wireless Telegraphy, Fleming,, 648. Be: : son, 406. Wisconsin geol. survey, 79. — xa Woodrow, J. W., columnar ioniza-_ Vv tion, 214. g Wright, Fi eee capil methods & Valency, Loring, 564. of microscopical pet h ‘ ) pica petrography, 509 ; Van Name, R. G,, influence of alco-| graphical plot for the plagioclase ‘f hol and sugar cane upon solution of feldspars, 541. Ea cadmium, 543. Wyoming geol. survey, 81. Vaughan, T. W., deep boring in . Bermuda,, 70. ic Vermont, Geology and Mineral In- Y dustries, Perkins, 425. ‘ — Sudbury, Ordovician outlier, Dale, | Yale Peruvian Expedition, results of, 395. Bingham, 1; _ Eaton, D3 Gregory, Very, F. W., solar radiation, 609. 16, 141, 187. Virginia geol. survey, 80, 568. Volcanoes, see Kilauea. Vulcanismus, von Wolff, 574. ~ : Zeeman, P., Magneto-Optics, 565. Ww Zoologica, Bibliotheca, II, Taschen- berg, 89. ae C. D., Research in China, | Zoology, Daugherty, 314; Lulham ) 84. : ard See GB egy 6 ty: Re OO ee we } : bd te : , 5 F ‘ A “i * . \ 4 : 1 ‘ s i | ul ‘ iM if : * o . a c = ~~ 5 ’ i : r 4 V 6 ‘i 1 ‘ i s “ ys i * ‘ , ' t ¥ ' j aS . 4 ‘ ‘ . 2 i r A " a ee be , : * f i 4 . ' ; { t ‘ a; \ ‘ : ri ‘ - * \ f ‘ - ‘ ‘ i F. i * P : i i : i d - , = Aq , o A “ ‘ U , y PF Me tet ell Pata ON ae are ‘ , hg tas Socal i ; ‘ Cone ; A : / , ¥ 9, 5 : : ‘ ‘ hos Lae | - Mi . RY ' ; i Rais ster d 2h, toy ‘ ‘ So 7 Ke \ ZINN U4. N Y i) = \ 1\ Flats around Show by horizors S SLLAAIVG. Bathymetric chietly fronvu Ag and Neveuw-Le other data \ ex A \\\p 4a \) = 4 bY SS? A \ \\ AS J) i \N .N 7) WN INS AWN WS SG 2 NYAS yw ~ ] x) AN Raimondti, Markt The Feruvtarey oration and Gre Drawre by Albert H. Bumst Am, Jour. Scl.,,-V: (Fie. 1). 20 z ININLTERN TTT TAT AE HL SUA HEUSUSL ESRC H 2 HI IMEC PAPER tH a EE EA ee SUGGS EUMSBIIGUL GCSES a. A CUNEATE EET PEEVES SESS SS AS eS SCSI se FTC RAPE 1 + | | | tM SEES ie Cun MCCA | LET | He EBS ACCESS SARE INTE EEO TEESE RISE BIE = oi LI Het NEEMHAARE ARBRE rai ca LAT Ppt TT AV PORCH CECH poops RR PEORIA IES) See ISTE at ST ae ts es ea ca LUI EEC “ HERR s Se SERRE SES eee ERCP eter eet EO eee eee ees aee NT Ho HL HAINAUT Th Le (EEA E ASE eee eee eee Anes INNER Woop ELE LUNA AA TAT eet ee eae eae fa ENC TIPA SE rrar Pear Geelihelh Need ae MINT Cet Ate PREV E CE een RCE Ea Ie UN UTACT| ey SRP NUNN T Th a PINTIAUTATERCREERCEACECCAC CCRC SSS ee See SSeS IE We eee ERC CRE eR Ke MAUI (ERRAH SC EP ASE NEN eae ? uIs : Fst THE PERUVIAN EXPEDITION OF 1912 UNDER THE AUSPICBS OF E YALE UNIVERSITY & THE NATIONAL GEOGRAPHIC SOCIETY a HIRAM BINGHAM, DIRECTOR VICINITY a a ( a oe Puainstias ty Flats around lake shoviv by horizontal shading. Bathymetric data chietly fron Agasstz and Neveu-Le. Te; other data from Raimondi, Markham, The Peruvian Corp- oration and Gregory. Drawrr Albert H. Bumstead. 10 ° 10 20 30 40 50 60 70 80 90 MILES Am. Jour. Sci., Vol. XXXVI, Sept., 1913. Plate | (Fre. 1). Fee | bey ae ee eS ent ap etikt i Abel ~~ = in ees a. a mf F ee a oe ee ee ay ae oe ee 2 INUIT NNT TTNTTA TT IHNILMENTEL GO | MI HEEL iN AH NIUE AAT LATA iu ANN HAL UAT AAT ATA ute iN Leia UU XTALNC ACERT 1 NA HINASTANANEN UD UO UR UB GAT HANAN UI GAN A AAA ARTY NAMINENENACLENAUR VSO AP A Am. Jour. Sci., Vol. XXXVI, Nov., 1913. NN i 2 uis 2 us Plate Ili. Am. Jour. CECE LACAN ACT AARC ACHE TNTHNTETATECT ETCH op mL HHL ani wi KI oA H, CRAM HINTTENEN TN TATE 1 AUSUIINUNERLIAT AD - 2 =] Plate Ill. Am. Jour. Sci., Vol. XXXVI, Nov., 1913, 20 ; ; ne PUAN MINCE AMIN AENEAN UNITE EEA v 170 CAC LE TT "oO PMUINIEIN NEN PATO CCT MINIT NUN ACEACAC MTN TNA RAO PUENTE HININTIN AXLE CRRA MUNN EEN AAA AAO > AMUN UNE ADAAOC HINTINUEN UA AOA AIC NNT ENCE ACCC UMN NEN AAA COE HINTINTN EN PACER AAO MUUNENT AUN ECA ACAD AEA z +4 puis iw Same othe as Fut | ao ae tat , = A oa a aa Se Po eee , v z rs ie 4 east 4 toy 2 I bcs 5 vi — a “4 { t e baby ‘ an bay Dap tp, pas Amd: he ‘ ‘e. t a =e = Ire Meee a hr. if ‘ : N - ie - Palme | .' 1 } ~ 4 j * { iat SS) 4 q a hin pit lhe 3 Pere d acne! Cae Wh ete iif 7 pops a oe a ieee — Py * oa ml ae > Am, Jour. Sci., Vol. XXXVI, Nov., 1913, Plate IV. 4s‘ MTT ooo Pa } III 6° IAAT GPeee( Pon OMEBEGOUGRAGHENGGUONGNONGGHOAAENNIDAUPl : a Ren SHRRUREREROUENZS Sane cere wanna Aus HM AEESEE GOT Ae IGGOTOG WETITTERGMAPEGO GG Gea oe Pea ERE ZAR AHH 48:0 a VMN ea HEREEAREREO UA GRERA AOR GRGRRD 09269407102 c010%) TTT sara pra i NHHOURERRREE r rete i en PLR Lr Lee pa py p gz sg a men ies Fess] Sl ies ese ee hea] IN ap ai eta iS ao es ES ESS = eae ai ae, ame Ee! ES eral 4 ae ‘ara Sl al wae iam a anes ae pa aa ae oa = Rae MS SiN bay Se] Sites BRS was Reco ae eg = Asie) NaS Ge Ge a a= a Meas aa EBs San == Se Ss SI PSPS SS La) a aa YA ATA WAN AAS OAIA HUTT BBRe UG Aes rt ea 7 a — Nae = (canes y) b P ——— Da RSE RSa SNS ax! NEI NTN eS A ATATAT IX KA 4 = = Se Se Se sees = [esas rae Ba eal rea ne sat BmiES I arate [ney Sa ae en ae ees Lee a eg Eh ea ae (aa Ea ee, ae (al ae (ay a (ee a ed) iS a) a es ae ae SS ea ad Se ae | Se a SN es SSHINGTING| NENA aN a See EXER | ap! N aN =- \_Y \ aN iN NI NN =a SR WARS IN INN ae = == = = pee] [Raat ei I eal Pepe eel [sare] ie = BN Nel ims NK rN NICS Aw i XN YN 7 EAT (VTA AK A A ee \ N DRAG Ba 4 cL sat ecesatie a gas é ae NN HILL V94 MT ee MIM A ETMAEFBB Be 2cea%00 HTT y EE Ca RANA AS VAAN AY VY VAY AVA VA AAT : CO ete —< A 26a! ee Le INAUNON NAN AS | CO LET CET EET PTET TET SUSSHERRREBUOON VOGEL pee ef pt og [AW ae Fa Ba EeQu See Saw ee AAS MAK a ANNAN rT TANNA Y SSS Ca re ie en Pr ee RT Ee, Ye Nd ae By i * e Plate V. lA oH PALO 4 SSSN83 NSS OGGEEe NON SASSER IAA | ‘ SAAS it ; \ MASS ’ \ HH Ns SNSSACURRUUIIRRINS Naa NARNIA ARRAY a iA GY Wade NAS NONUANUANT ASSAY NAAR AAA NNSNSRANSAREN ANT : SURRNTENN SUUAAINANN NN NNO AAA ANNANSNNSNNNSAKINY RAY ANSNORANSNU ANAT ATURE AAA | AN NANAK | ANY NA NVAANNAUONATI NAAN AA ARINANNAATI AAR NANSONNOUNONIANANUAIUANO UTI AA NANINAANONUNAUNLUUU LNT AXA At Nt AAAI AAA | ANNAN ANA on Ge. SS Vit, Be AD As ZX GLa y, MEE GILL AN AN hb Ge = °° = > o z= > =< ~< ~x< i) > ‘Oo 2) aS > ° ae = < +s Ranbir yuo t ! FURR) Lerner «arteries penpergs the ia sat hel Ls rr fon ‘ ; y Ae waat) ® ree Wi bs Set ; itp tne i) a Whee Gor seston ite et this ol bone capaar cag iat ds hi ip ee aebeitnks on : j bernie pa hoe fe ee we eae ee eT yay i ded, Pe SS Bigg nape Ae ‘ trp eiet > nics we fii Rar ‘yp ion irre trea tisbadh tea ihe aa es ti ‘ F \’ Nh eh Winall bi gateces < Anwar Mega v4 ve dove aati as by * : RANDY We EMC ede oc ie od taal ie ee ic te nih party ee We: yer Plate VI. ae ax IN an NSS CNNSARINAAINT NARA SARI NUNN NNN SONA CNNSI 2 t ¥ “y t ; ; ‘ i ehie a ma eo ee ee ‘2 Ta iam So Vol. XXXVI, Nov., 1913. Am. Jour. Sc 100 VATNOUNETIL TT * 30 80 7° 60 so 40 30 20 CYS ANSE C EC LUIN TAY NIA ARS UTI RYN KARA RUN IT LV WAAAY NNAUANAATATAATATT AT NSS SSSR SSS Qn PT SSSA EM SSS tt SA | | li NY Am. Jour. Sci., Vol. XXXVI, Nov., 1913. Plate Vill. Ss. 00 = asr i if HHA ie ae ay Fea wee Ee Se 4 A4 MABOALOAt Ga, fe reer META HVAEE LNAANAANONAUE A sinacato ena LY scncseansiaalceea VA 2040207071 poe Avo sae saree a VAVAWA VA AY Ap Ap An ERCLILALLAL AAT ALLACTALL VV VAAL ea OT LAL AAA AAA 020202026 COCO C eee Cees eZ0b2206L8 eababalce EN A VA AAO AA TAIRA ANA CH] TA OV MV AMAA AAA ALAA LTA) Le LVAD Ree ee eacesesees uae IMI MMMM RAC Mbe Lace caceraeaoEE H AAAAA Ad aT WA a v Annee 22262264 COAL VA Z2Zegnes G2422224 228s SOLE ZOCeoaGeesee Z Z 4 Z Z MVAAAYARAAY AAAS peut: LZ BZes Z WWW UYYYGLZLZZZZZZZZ Eze YYYGILGEZA se 70° Bo (ey 60° Bo} eo} is \ Ha my + ae diana, Saratiias'in ies inet die be altel vite ais Kenta th val te RN VRE ee ane ie i y i i ee ee ‘ *o 0% °0% ae y x SSASANN! SSAA HOS ANY ANNU AANA AN AA oS } 2 Oo | 2 ba a ome) ww root) ~ hae SSS rolite) Ot SNSN AAS WAANARY \ i NNN WAAAY _ ANAS SSSESRERT oe) 5 : AMY oi "tg NS VARA ANAS XA AWN ae Baits)! 9 SINK 00 a) ae \NSN mo =r \\\ ANS \\ \ SAA NNINVANURUU REALE UT AYANAVANAIL ES AWN ANANUANUAAUAUTULTTLTTTT ae SVN a : — = SAA is AA 2 AKAN = SNA = AUK lo 3s AI ae 2 = f aul " 3 bs AU ae £ ul N oe oot no or is tu ac ee Pa a > e | q ’ ee Se Ee ny ne en fi ' i \ 1 ? if Plate X. Am. Jour. Sci., Vol. XXXVI, Nov., 1913. 90 80 7° 60 ES Nv te) PROPERTI a essere: att 60 60 Ci O° 5 te} Lt HEED i tia Hae ENE a COMPOSITION o ° 20 CHEMICAL EEO tH saeeltiecel Hee MOLECULAR PERCENTAGE OF ANORTHITE ———> EE EEE GE FT mere I 5 a ay tw hee a ? Dia JAS gatos » & ae i ry Ae ene mente cam gtewit = Tw em aa | is ; 5 ae eh ak te 4 9 we é \ : ale ; i pobet eat F fy ‘gl aed - sg ; ; : m har Orga ay ae nats wae") ewe ‘ - ‘ Warns Naturar Science EstaBlisHMENT A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. 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