eater oleae ant wit a esien 4 rr | oy Ss plazas , ~ =? = euszeiz: a Twiptady bad ‘ . =o 34 _ (eae we he rarer aga 4 ee eeeee een tae s D Le ‘ ’ 4 ' Ps exeere er Uapever tron Pe ee TP Ue ee eM a Pe ies LN, ) on ait ry ' ‘ oot chad Chowne eta ‘ thaws parte air eet Se ee LE Ck a ' ‘ |-0 # one ~*e waa Rar re ie ee Sn fee Ii ttt ih oh ' . ‘ ‘ ' vvemee eu ya a sie ey Ped EAA OVATE GY SOAS EParn an . ‘ trey eeatd an yet pew eee Lea eee eg ea ae Ae ot ge aye gD ‘ . oo te m4 ‘ mryw gs itvaed ren eee Ee Oy ew A A YD Oe oe . 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Vee; i A dl Aree Rete TW Me kG ek ACPI RRS ARM AMO AL Rano ba ‘ 4 Hye pea gens geely gd he oh toy gy “ea Cre Le tee an , fw yg it ta ee EO fet Ow Ma, PCR ie a Pa eas Bree OH, A ye4 see Hed hihes . os ry re _ rat dD thy we ae su fhar be EY 3 PE ENS CL era say ye ee ‘ ‘ wee FE eae Dye beet ee ee Peete we Sew ht ¥ eis Ce MarR ' ; ‘ eae eg rh eel ae Le eaeks 1 ay 26) Pied & be 7 : Parr Se Ge ee 0 > * Yee eat be be : : ae bebe eET OV ALOR Ey OA ; valwcesy wt ap tNard 2M ' | rats vere ger ea oe phe hades reel 1g ty eee WORDT PALE lee : ed rw ve he be a ad, ‘ : erg eh ee he tearm be Meee IN fe pt . eb eee ee ee A Oo ke wren I oe oe PRCA oe MOM RS Pd A OA Ae Vaio Se pyre eee pee CPV bo ED Ot ’ y i ae te) ie Ca Veet bean OF ) ' Rs 7 Qebyy FM EC Ose heh Ogg week a bop rep bee ‘ a ee ee woe teas a LAA xh . ‘ Ved Pw Be Oe Bt Los 5 ra ' i Lom Rope eee © i ms 1 vt n ie rT a + ' ’ 4 ‘ wert ' rrugr? ! ae Te bey tha Mer ‘ ' ' _ 4 rhay . ry erie pips Se ae) A \ Ty vou ay fia ' - rroweet w bw ie ai 4 « ’ ' hey whet © \ : ) Te Se we h tye 4 oe he BEY be fe yoyo He GH ih Mey Speer bs tgs Bee fod ah a PA Koa go de ocr Bl he ivpa peg er ! wt Wea Ah On, ui we ae vot epee ue La 1 a7 i BAA eri teh a: ; ". rhe oe! : ofa asa yo ' VPYa iis eto vis He, r A sy ny hats ; , i f ey ena Rae v2 ‘ PL owt ye bois! 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J Puta dint Pee b bee bee te de horned bt Ste pore des hoe ‘ red pane bad bg a hee ‘a ee ae whoa at wt pebe da uk hp dle 7 , ‘ * ’ 5d vt pia poke hong iw) ae pet z bee blot a Te pee e ari ' ‘ ' ‘ a4 Op, 8 ob be ag Dek ed kd ‘ ' . ’ ’ owe per ‘ sboee oe bods cbe ‘ rida & F : : A Pg | ‘ . te Parveen eras Ree eee ce ig SUpip bgt a ead e 4 ; ’ Ae eo Mead Se ae var ee Mad je fed sed ' ie fet dew eb bbe be Perera a ae) ae Pre ene ees Re Ta 7 ep Sh igi oe wd biyare ee Te eel rs ee) pede Wael eR inte 7 rea 6 ve : ' owe be A i eh Arete Vat 6 a8 Dan tL A OC ; 7 a: fl ra ’ is i ied plot acta oe ay bode doe te ble ; Pe de ee 2 beige CR eet nb Bc ik Wee A i BB F ; i , i ’ rari pcwwe ee ee gee ‘ hPhoas , baae eee ee ee) Percy ee re ee ‘ . ot bad te jot tee ee bee de ba pa 4 ' ’ ‘ peeats pptowe dl tected ead bea ped Soe B dees + % bee bit ohe a aby a bps PO abd bbe ar bate do io ptr bt sae ' oe t ' ‘ oe poebe eke t ts a3 te .. date ah : ' oe bh Dh Oe Tem} ‘ « oth) ce . a4 ‘ ty ehetak be ee ba ete a Ha re Oar A ni baby ' ' iy. 9 Pen er We ree 0 ee AD aptly Pore Oe ee ‘a : 7 . nl Paar 5.%1, ae bua et a Sa we ee dt doe LY bee cd orem eels bette be bray gh te ' treba ve ada LET bore ed toy Ne jut eh AR RA Ie te Por ee a AC) eh eb feats a t ‘ ‘ ‘ aoa ‘ aad oe prety baa PF RU Pe BAM RE BT De Bee PELTED Ak SLAG testi te ' aauao4 os bedhead eo sia eads od wide below 4b wh 7 . te + bbs sevade ra thee ee rere Sr oC Smee eat oa ; te erie ay or tee ee eda ‘ i! y ‘ P i sheath eb ed tabs gad a al bebaiey ea ee re a abate eke Bat Et Math ad Sel estan en sh te a leet ‘ ‘ ‘ ' ye rer | pov ae ll ped wins véa 4 qi * \ ean fact ale eta we Ae Be iV de ey y | wo AS ' ite pd on oi febyews ; CCAR Ae cons eal ‘ ‘ oe ee ee a Te Mi Cae ae te ir re hte Fo ba ajc PRT Se eT 6 eae Yerorwsy i a nbd be eine Be vet ' oe i re ee ee « ‘ Per eT ac ‘ on 4 (eee ee er ee : We rete prdeiBie tale ernie Mat) i ‘> ' ee eae ee ee Big thw OM td meds doin wee ne voy ' : rae eet “ git 7 oe ‘ Cent WEA ee petite rt ity Ay He ran ‘ ; A ge ee Wowie tder Or etal heh ' i Lhe tana be mY) one d] ween ‘ sivas ue Hasson pine phe ules uN Par ee i ory Sine mooie we rhe kee be EY rs pee? f mene Wet te A a vs . potrewe a . cil aeib or bain wien ei . . ‘ fae eee ti tae Pr Ad a ih 4s 1eor aervedu eba edd bectiae i . bh T vee vat ws Aarne ae sib bide une ed bt bsraeie 1p he tb eee ne np ie nO 4 1 (a44 se Gti wa dad Peace ba Oey Cae ined DEE Bp a tee ill print ae othe ate : $ en) sae u bin eve BI hh babe te Orie etd bese Aandi eh Tac ee lad ener 4.6 toque bias Ya MTL OE rt A Ged gab ” Fo eed Ue pars ; ; ; ee Fee bes bre Mihe teat bob Gora? i i » ‘ ‘ nia § a we bh kee dap eee wedi b ieee \ ef Cd i Ms ee ee tne Neer ire ty ere ae ee Se j i aaa ‘ ' ‘ tot eee wee ee eee Or ee cee a ea gee lL ‘ rere a tae . ee er eee ee ae ee La wei ee ee ’ ' Pan er bieeew bbe ’ . 1 ' ear mrt ee ee ee woe 4 650 1b) UO* . vt satu yeree H i A Ce a ee (Aer Pee va aie ye ie ay. ace ! rere Wer ae ee ath v ee we ' oe ve Pee Og oc CC ee | t spte . ihe Aer bee do dh eth Bie 8 felt CM pt ' ‘ . we of ‘ Leb ea hg te bke weston t 4 i“ ‘4 hs gail ‘ de ae Ped ore werd Poe ee ee ae ot st eae Sep tk DA Ds bie ee De bd ba ‘ ra t ' scowlebeen Cy ege Et OO bk tke wa doe So eel tb pe Oba eel ee fee bt Bas PROC Te DLA Se a Pare MT eC re ca ‘ ’ ‘ ‘4 eaeees ahi berate tans Fae ‘ ~o ee Gee oe eS 4 wee sere dae i ' qo 0° peeey eet hiatal 4 aud PART I fe ee Ce PE tab @ ted ei bbe e at reauve onetat A i ee Aare are a Oe ee betta it bb OAT ORD , ‘ ' rode SD iadan eee Paneer range fe fr ae Pa Ck pik OM NE it A Wa we ¢ aw, t Rrerertc ta eer eerie En Lr eo Fe ne i ie Rb ka wok drank det Hs 8 bam | Hide ‘ ve ve ' ' eee teuaderbhe Hegeiatoere Pee IRC AT TUK ICD CY sty a rae ar wor ot heb 4.9 oer e WR ara Oe a ee ee Porat gs ne arma dB Ne yeni eat ¥ oo Be vk fh er es iy ‘ ‘ er LAA ig ak, 4 ae ere en Arlen yy PP mae min 4 ¥ 4 » \ — > y haat ae Seo 7S I, 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 Camprwnce, Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPHI, Proressor HENRY S. WILLIAMS, or Iruaca, Proressor JOSEPH S. AMES, or Battrmmore, Mr. J. S. DILLER, or Wasuincrton. FOURTH SERIES VOL. XXII-—[WHOLE NUMBER, CLXXII.] WITH 2 PLATES. NEW HAVEN, CONNECTICUT. 9,016 IGgQo54. 1 ay ea Papa ey RAN if ye ia!) A at oa ey SE & TAYLOR PRESS. — MIE ATA aA . f Va ee i ee CONTENTS TO VOLUME XXII. Neue bere 7 27. Page Art. I.—Relative Proportion of Radium and Uranium in Radio-Active Minerals; by E. RurHerrorp and B. B. PaO a tee Re = le ees eg a Se 1 I1.—Measurement of Radium in Minerals by the y-Radiation; Demme elie peg yk ek Se ek 4 IlJ.—Absorption of the a-Rays from Polonium; by M. Levin’ 8 IV.—Thermal Constants of Acetylene; by W. G. MixTER._ 13 V.— Modification of the Lasaulx Method for Observing Inter- ference Figures under the Microscope; by F. E. Wricutr 19 Vi.—Datolite from Westfield, Massachusetts; by EK. H. Mra sates WV COOK, 32 es as Oe a 21 ViIl.—Russian Carboniferous and Permian compared with those of India and America; by C. ScuucnErT. (With EET LS Raa I ta «aT eR a 29 VIII.—Note on two interesting Pseudomorphs in the McGill University Mineral Collection; by R. P. D. Granawm, peer pee SNe ee ee ee AT IX.—Estacado Aérolite; by K. S. Howarp and J. M. a TTS SG i ae a aa Spa SIC AE aM chia cy 55 X.—Stibiotantalite ; by S. L. PENFretp and W. E. Forp -- 61 SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Properties of Liquid Nitrogen, H. ERpMaNN: Oxida- tion of Ammonia to Nitrates and Nitrites, Scomipt and BOckKER, 78.— Detection and Determination of Small Quantities of Iron, A. MouNEYRatT: Quantitative Determination of Acetone, A. JOLLES : Avogadro and Dalton, A. N. Metprvum, 79.—Electric Discharge in Gases, H. SIEVEKING, 80.— Note on the computed drop of pressure in adiabatic expansion, C. Barus: Meteorologische Optik, J. M. Pernrer: Leitfaden der Wetterkunde, R. Bornstein, 81.—Refraktionstafeln, L. pk Batu: Shaft Governors, 82. Geology and Mineralogy—Preliminary Report of the State Earthquake Inves- tigation Commission, 82.—United States Geological Survey, 84.—Pleisto- cene Geology of Mooers Quadrangle, etc., J. B. Woopwortn, 86.—Geology and Water Resources of Oklahoma, C. N. Gouutp: Bulletins of the Geo- logical Survey of Virginia, 87.—La Sierra de Cordoba, W. BODENBENDER : Columbia University: Constitution of the Silicates, TscHeRMaxK, 88.— Chemical Crystallography, GrotH and MarsHaLL: Geometrische Kristal- lographie, EK. SOMMERFELDT: Mines du Transvaal, G. Morrau: Polarisa- tionsmikroskops, E. WEINSCHENK, 89.—Tabellen zur mikroskopischen Bestimmung der Mineralien nach ihrem Breckungsindex : Minéralogie des Départements du Rhone et de la Loire, F. GonnaRp: Studien iiber Meteori- ten, C. Kuetn, 90. Miscellaneous Scientific Intelligence—Plaster-plaques for Museums, G. L. Goopatez, 90.—American Association for the Advancement of Science, 92. —Memoirs of the National Academy of Sciences, BRooks and CowLEs: Zeitschrift fir Gletscherkunde, E. BRtckner: Publications of the Field Columbian Museum, 93.—Carnegie Institution of Washington : Personal Hygiene designed for Undergraduates, A. A. WoopHULL: Bulletin of the Agricultural Experiment Station, Japan, 94. Obituary—DrR. ERNST SCHELLWIEN, 94. lv CONTENTS. Number 128. Page Art. XI.—An Investigation into the Elastic Constants of Rocks; by F. D. Apams and E. G. Cokur.._--_------ 95 XIJJ.—Dakotan Series of Northern New Mexico; by C. R. Krygsn Yee duel ee 2 ee rr XIII.—Plauenal Monzonose (Syenite) of the Plauenscher Grund; by H. S: WAssineron 2.2). 2425755 eee 129 XIV.—Colloidal Nuclei and Ions in Dust-free Air saturated with Alcohol Vapor; by C. Barus. __ ~- 22) )2 5 elie XV.—Russian Carboniferous and Permian compared with those of India and America ; by C. ScuucHERT -_--... 143 XV I.—Notes on Some Eruptive Rocks in Mexico; by F. N. GUILD ool XV: —Hydrolysis of Salts of Iron, Chromium, Tin, Cobalt, Nickel, and Zinc in the Presence of Iodides and Todates; by 8. E. Moopy 0% 210 176 SCIENTIFIC INTELLIGENCE. Geology and Natural History—Geodetic Evidence of Isostacy, J. F. Hay- FORD, 185.—Pleistocene Deposits of South Carolina, G. T. Pues, 186.— Geography and Geology of Alaska, A. H. Brooks, C. ABBE, JR. and R. U. GoopE: Geology and Mineral Resources of part of the Cumberland Gap Coal Field, Kentucky, G. H. AsHury and L. C. Gurenn: Pleistocene Deposits of ‘Sankoty head, Nantucket, and their Fossils, J. A. CUSHMAN, 187.—Tertiary and Quaternary Pectens of California, R. Arnotp: Cam- brian Faunas of China, C. D. Watcortr: Plant “Response as a Means of Physiological Investigation, J. C. Bossr, 188.—Heather in Townsend, Mass.: Biology of the Frog, S. J. HoLmms: A Course in Vertebrate Zoology, H. S. Prarr, 190.—Life of Animals, EK. InGERSOLL, 191. Miscellaneous Scientific Intelligence—Recent Text-books on Astronomy, 191. —Publications of the Royal Society of London, 192.—Physical Optics, R W. Woon, 198. Obituary--H. A. Warp: C. R. VoN DER OSTEN SAcKEN: L. BRACKEBURES, 194. CONTENTS. Number 129. Art. XVIII.—Abyssal Igneous Injection as a Causal Con- dition and as an Effect of Mountain-building; by R. LEST ASE ali eg gm gaat de XIX.—Some Interesting Beryl Crystals and their Associa- Pie OVa Wun ORD soe ge eee ee XX.—Schistosity by Crystallization. A Qualitative Proof ; RE RICHES oie ee oe ee XXI.—Fractured Bowlders in Conglomerate; by M. R. on SEEDER IL Lips sc eli se ne et arc a aR XXII.—Exploration of Samwel Cave; by EH. L. Furtone-- X XIIT.—Oceurrences of Unakite in a New Locality in Vir- Meteo MeL WENTSON 1 be yoy er eo Se XXIV.—Types of Permian Insects; by E. H. Srtiarps-.- - XX V.—Analysis of Dithionic Acid and the Dithionates ; by Sore SHUEY fo ed oe eee So SCIENTIFIC INTELLIGENCE. Page 195 217 224 Geology —Ueber Parapsonema cryptophysa Clarke und deren Stellung im System, T. Fucus: Phylogeny of the Races of Volutilithes petrosus, B. SmitH: Notes on some Jurassic Fossils from Franz Josef Land, brought by a Member of the Ziegler Exploring Expedition, R. P. WHITFIELD, Obituary—S. L. PENFIELD, 264. 263. vi CONTENTS. Number 1380. Page Art. XX VI.—Lime-Silica Series of Minerals; by A. L. Day and KE. 8. SaepHEerp, with Optical Study by F. E. WeRIGHT ooo fo eek Se Se 265 XXVIL—Analysis of “Iron Shale”? from Coon Mountain, Arizona; by O. C, FARRINGTON __2) 22) (322 303 XXVIII.—Phenomena Observed in Crookes’ Tubes; by N. oP BACON 2802/5005 oak Bel ee er XXIX.—Northward Extension of the Atlantic Preglacial Deposits; by I. Bowman _. 32.) .-222. 1... 313 XXX.—A Delicate Color Reaction for Copper, and a Micro- chemical Test for Zinc; by H. C. BRapLEY _222_2 222 326 XX XI.—Elimination and Alkalimetric Estimation of Silicon Fluoride in the Analysis of Fluorides; by A. Hiruman 329 XXXII.—Note on the Actual Drop of Pressure in the Fog Chamber; by C. Barus...-.2.:..--_. 2 ee XXXITIIL—New Method for Standardizing the Coronas of Cloudy Condensation; by C) Barus. 1-1-2322 2325e—ee 342 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Barium Sub-oxide and the Preparation of Metallic Barium, Guntz: Thermal Formation of Nitric Oxide and Ozone in Moving Gases, F. Fiscoer and H. Marx: Action upon Carbon of Oxygen, Carbon Dioxide and Steam, P. Farup, 344.—Combustion of Halogen Compounds, C. J. Ropinson : Introduction to General Inorganic Chemistry, A. SMITH : A First Course in Physics, R. A. MILLIKAN and H. G. Gaus, 345.—Labora- tory Course in Physics for Secondary Schools, R. A. MILLIKAN and H. G. GALE: Outlines of the Evolution of Weights and Measures and the Metric System, W. Hauxiock and H. T. Wapz, 346. Geology—United States Geological Survey, 346.—Geologic Map of the Buf- falo Quadrangle, D. D. LurHEr, 347.—Second Report of the Director of the Science Division, 1905: Upper Ordovician Rocks of Kentucky and their Bryozoa, J. M. Nickues: Chazy Formation dnd its Fauna, P. E. Raymonp, 348.—New American Cybele, J. E. Narnraway and P. E. RaymonpD: Ueber Phylogenie der Arthropoden, A. HANDLIRSCH: Die Ent- wickelung von Indoceras baluchistanenense Noetling. Ein Beitrag zur Ontogenie der Ammoniten, F. Noeriine, 349.—Untersuchungen tiber die © Familie Lyttoniidae Waag. emend. Noetling, F. Norruine, 350. Miscellaneous Scientific Intelligence—Les Prix Nobel en 1903, 351.—British Association : Carnegie Institution of Washington, 592. Obituary—W. B. Dwicut: P. DrupE: Sir W. L. BULLER, 302. CONTENTS. | vii Number 181. Page Peminh, E WES manN BI nD 1 oO 899. F et lee ek gh oe 350 Art. XX XIV.—Conductivity of Air in an Intense Electric Field and the Siemens Ozone Generator; by A. W. Pimpin 8 erie Soe. Soe OS XXXV.—Hydrolysis of Salts of Ammonium in the Presence of Iodides and Iodates; by 8. E. Moopy.--------.---- 379 XXXVI.—Estimation of Fluorine Iodometrically ; by A. RMNEVEN NEE Mee ie eS a a BSS XXXVII.—Minerals of the Composition MgSiO, ; A Case of Tetramorphism; by E. T. Atien, F. E. Wricur and wz LBey COUADNTESNS e015 ee 25 th See a gg Rae ee SM pt ane 385 XXX VIIT.—Contributions to the Geology of New Hamp- shire: No. II, Petrography of the Belknap Mountains ; by L. V. Pirsson and H. 8. Wasuineron ..-.-.----. 489 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Preparation of Pure Ethyl Alcohol and Some of its Properties, L. W. WINKLER: Double Salts of Mercuric Chloride with the Alkali Chlorides, Foote and Levy, 458.—Atomic Weight of Tantalum, HINRICHSON and SAHLBOM: Isomorphism of Northupite and Tychite, A. DE SCHULTEN, 459.—Separation of Antimony and Tin, A. CzERWEK: Lehrbuch der Allgemeinen Chemie, W. OstwaLp: Radio-Activity, BECKER, etc., 460.—Velocity of X-Rays, EK. Marx, 461.—Formation of Ozone from Oxygen and Atmospheric Air by Silent Discharges of Electricity, E. War- BURG and G. LEITHAUSER: Oxidation of Nitrogen by Silent Discharges in Atmospheric Air, E. WaRBuRG and G. LreitsduserR: Influence of Moisture and Temperature on the Ozonizing of Oxygen and of Atmospheric Air, E. WarsBurG and G. LerrHdussr, 462. Geology and Mineralogy—Tenth International Geological Congress at Mexico City, 463.— Descriptive Catalogue of the Tertiary Vertebrata of the Faytm, Egypt, 465.— Geology of the Owl Creek Mountains with Notes on Resources of Adjoining Regions in the Ceded Portion of the Shoshone Indian Reser- vation, Wyoming, N. H. Darton: Copper Deposits of the Robinson Mining District, Nevada, A. C. Lawson, 467.—Montana Lobe of the Kee- watin Ice Sheet, F. H. H. CatHoun: Les Lac Alpins Suisses: Htude Chimique et Physique, F.-E. Bourcart: Species of Botryocrinus, F. A. BATHER: Soils, their Formation, Properties, Composition and Relations to Climate and Plant Growth in the Humid and Arid Regions, E. W. HiteGarD, 468.—Brief Notices of some recently described Minerals, 469. Astronomy—Parallax Investigation of 162 Stars, Mainly of Large Proper Motion, 471.—Publications of the United States Naval Observatory, 475. Miscellaneous Scientific Intelligence-—A Text-Book in General Zoology, H. R. Linvitxe and H. A. Key: Illustrations of British Blood-sucking Flies, with notes, E. EK. AUSTEN: Synonymic Catalogue of Homoptera. Part I. Cicadidz, W. L. Distant, 476. Obituary—Dr. Lupwic BoLtzmann, 476. Vill CONTENTS. Nae 132. Page Art. XX XIX.—Relative Activity of Radium and Thorium, ; measured by the Gamma-Radiation; by A. 8. EvzE _.-. 477 XL.—Fossil Bird from the Wasatch; by F. B. Loomis --.-.- 481 XLI.—Iodometric Determination of Basic Alumina and of Free Acid in Aluminium Sulphate and Alums; by:S. dle Moopy 22.2 2000. 222 as a XLIL.—Separation of Arsenic from Copper as Ammo- nium-Magnesium Arseniate ; by F. A. Goocu and M. A. REEPS 0. Bo. Lo. oe 488 XLIII.—Contributions to the Geology of New Hamp- shire: No. I, Petrography of the Belknap Mountains ; by L. V. Pirsson and H. 8. WaAsHINGTON _.-.-...-_-- 493 XLIV.—Yttrocrasite, a New Yttrium-Thorium-Uranium Titanate ; by W. E. Hippren and C. H. WarrEn._.__ 515 XLV.—Note on the Estimation of Niobium and Tan- talum in the presence of Titanium; by C. H. Warren 520 XLVI.—Ceanothus Americanus L. and ovatus Desf.; a morphological and anatomical study; by T. Horm_____ 523 XLVII.—Photometric Measurements on a Person Pos- sessing Monochromatic Vision ; by EF. L. Turrs__-__-_- 531 XLVIII.—Eodevonaria, a new Sub-Genus of Chonetes ; by C. 1, BREWER oo cS eS al eco ee ee 534 XLIX.—Note on the Production of Radium by Actinium ; by B. B. Bottwo0op 2223222 a! ee 537 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Quantitative Separation of Beryllium and Alumi- nium, B. Guassman: Temperature at which Water Freezes in Sealed Tubes, Miers and Isaac, 5389.—Preparation of Fused Molybdenum, Biirz and GARTNER: Potassium-lead Chlorides, Lorenz and RuckstuHL: Ammo- nium from the Recent Eruption of Vesuvius, StoKLAsa: Beitraege zur Chemischen Physiologie und Pathologie, F. HormrEister, 540.—Change of - Colloidal Nucleation in wet dust-free Air in the lapse of time, C. Barus: Leitfaden der praktischen Optik, A. GLEICHEN, 541. Geology—New Zealand Geological Survey, J. M. Bert, 9542.—TIllinois State Geological Survey, H. F. Barn: Geological Survey of Ohio, E. Orton, 543.—Indiana: Department of Geology and Natural Resources, W. S. BLaTcHLEY : Geological Survey of New Jersey, H. B. KUmmEL : Geological Survey of Canada, R. Breuu, 544.—Bibliography of Clays and the Ceramic Arts, J. C. BrRannER: Festschrift Harry Rosenbusch, gewidmet von seinen Schiilern zum siebzigsten Geburtstag, 545.—Evidence Bearing on Tooth- cusp Development, J. W. GipLEy, 546.—Origin of Birds, 547. Miscellaneous Scientific Intelligence—National Academy of Sciences, 548.— Human Mechanism ; its Physiology and Hygiene and the Sanitation of its Surroundings, T. Houcu and W. T. Szep¢wick: Voyages and Explorations of Samuel de Champlain, translated by A. N. Bourne: Field operations of Bureau of Soils, 1904, 550. InDEx TO VoL. XXII, 551. JULY, 1906. Established by BENJAMIN SILLIMAN in 1818. . - AMERICAN || JOURNAL OF SCIENCE. EpiTor: EDWARD Ss. DANA. ew yee ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camprince, Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp-H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPHIA, Proressor HENRY S. WILLIAMS, or Itwaca, Prorsessor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, oF Wasuinerton. FOURTH SERIES. VOL. XXII—[WHOLE NUMBER, CLXXI1.]. No. 127—JULY, 1906. WITH PLATE I. NEW HAVEN, CONNECTICUT. 1906 THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. ms —_— . AMEN ENE | Published monthly. Six dollars per year, in advan VA $6.40 to countries in tha) _ Postal Union. Remittances should be made either By moydy lordéts, tépixtered} a letters, or bank checks (preferably on New York bank§). rads , CRYSTALS, FINE MINERAL SPECIMENS, METEORITES. Orders amounting to $20 or over sent carriage paid on approval, with the privilege of selection. Rejected material returned at consignee’s expense. 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Prices are the lowest, as comparison will show. ‘The volume of our trade permits it. : Free Cottection Caraxoe, containing lists and illustrations of General Mineral Collections, Series of Ores for Prospectors, Sets of Crystals, Series illustrating Hardness and other Physical ~ Characters of Minerals, with price List of Laboratory Material and Individual Specimens. FOOTE MINERAL CG Established 1876, by Dr. A. E. Foote. W. M. Foote, Manager. DEALERS IN Mineral Specimens and Commercial Rare Minerals. 1317 Arch Street, Philadelphia. Jia la AMERICAN JOURNAL OF SCIENCE POUR TH So hn s..] —_—__~++4—__ Art. ].— The Relative Proportion of Radium and Uranium in Radio-Active Minerals ; by E. Rutuerrorp and B. B. Boxtwoop. Iy the July number for last year of this Journal, the writers gave an account* of measurements which had been made to determine the amount of radium present per gram of uranium in a natural mineral. Since previous experiments had shown that the amount of radium in a mineral was always propor- tional to its content of uranium, it was pointed out that the weight of radium present per gram of uranium was a con- stant of considerable practical and theoretical importance. The method adopted depended on the preparation of a stand- ard solution of radium bromide and the amount of radium emanation formed in it was compared with that formed in a radio-active mineral containing a known quantity of uranium. Since the electrical comparison of the relative amounts of radium emanation can be made with considerable precision, the accuracy of the results obtained by the determination mainly depended on the exactness with which the solution of radium taken as the standard had been prepared. The standard solution was prepared by Rutherford and Eve. A crystal of radium bromide was taken from a stock which previous experiments had shown to emit heat at the rate of 110 gram-calories per hour per gram and was consequently probably nearly pure. The amount of radium bromide was determined by direct weighing and also by comparing its y-ray effect with that produced by a known larger weight of the same stock of radium bromide. The crystal of radium bro- mide was then dissolved in distilled water and by successive dilutions solutions were prepared to contain 10-*, 10~* and *This Journal, xx, 55, 1905. Am. Jour. Sci.—Fourts Series, Vou. XXII, No. 127.—Juny, 1906. 1 2 Lutherford and Boltwood—Radium and Uranium. 10~* milligram of radium bromide per cubic centimeter. By evaporating known quantities of these solutions and testing the a-ray activity of the residues, Eve found that the relative activities were in close agreement with their supposed content of radium. There was, therefore, every reason to assume that ~ the standard solutions were correct. About two months after preparation, a portion of one of these solutions was trans- ferred to another bottle and sent to Boltwood, who, assuming the accuracy of the standard, determined by experiment that the amount of radium corresponding to one gram of uranium in a mineral was 74107" gram. Recently, however, some experiments made by Mr. Eve in the laboratory of MeGuill University indicated that the solu- tion used for the above determination was in some way defec- tive and that the quantity of radium actually in solution was less than had been assumed to be present. It was found that a considerable proportion of the radium had been deposited on the surface of the glass vessel in which the solution had been preserved and it is probable that this action had taken place before the solution sent to Boltwood was withdrawn. . A full account of Mr. Eve’s experiments is given by him in a paper which accompanies this in the same number of the Journal. We desire to thank Mr. Eve for his kindness in drawing our attention to this matter and for his assistance in preparing a new radinm standard. | The method employed for determining the quantity of radium present in the material from which this new standard solution was prepared is described in detail in Mr. Eve’s paper. The weight of radium bromide taken was ascertained by this method to be equal to 0°27 milligram. The minute fragment of salt was removed from the small sealed vial in which it had been received and was dropped into a small beaker containing a few cubic centimeters of dilute hydro- chloric acid. The liquid was heated and was then carefully examined with a glass, when absolutely no trace of any insolu- ble material could be detected. The vial which had contained the salt was washed several times with concentrated hydro- chloric acid and water, and these washings were added to the main solution. The solution was introduced into a standard graduated flask, the volume was increased to exactly 1000° by the addition of freshly distilled water, and the whole was agitated for some time in order to insure complete mixing. Ten cubic centimeters of this solution were now withdrawn with a standard pipette and introduced into a second gradu- ated flask. A few eubic centimeters of dilute hydrochloric acid were added and the solution was diluted to 1000° with | distilled water. After thorough mixing, 10° of this second Rutherford and Boltwood—Radium and Uranium. 3 solution was removed, introduced into a bulb of about 100° capacity and diluted to about 50° with distilled water. The contents of the bulb were boiled vigorously for about ten minutes and the tubular orifice of the bulb was then sealed by fusion. After a period of exactly four days had passed the emana- tion which had accumulated in the bulb was removed by con- tinned boiling of the solution, and was transferred to an air-tight electroscope and its activity measured. The leak due to the emanation was equal to 4:27 divisions per minute, and the calculated leak corresponding to the maximum equilibrium quantity of emanation was 8°44 divisions per minute. On the basis of 0°27" of pure radium bromide originally taken, the amount of radium contained in the solution in the bulb was 157X<10~° milligram. The leak corresponding to the equilibrium quantity of radium emanation formed by the radium associated with ene eram of uranium in a natural mineral was next determined. The mineral chosen was a pure North Carolina uraninite con- taining 68°2 per cent of uranium. ‘The leak in the same elec- troscope corresponded to 206 divisions per minute per gram of uranium. From the above numbers it can readily be caleu- lated that the quantity of radium associated with one gram of uranium in &@ radio-active mineral is equal to approxi- mately 38x 10~" gram. The value of the new number is about one-half that of the old. On the present basis the ores of uranium per ton of 2,000 pounds will carry about 0:0034 gram of radium for every per cent of uranium present. A ton of 60 per cent uranium ore will therefore carry about 0°20 gram of radium equivalent to 0°35 gram of radium bromide. These numbers are more nearly in accord with the quantities of radium extracted from the ores in actual practice than were those derived on the basis of the former standard. April, 1906. 4 A. S. Lve—Radium in Minerals by the y-Radiation. Art. Il.—The Measurement of Radium in Minerals by the y-Radiation ; by A. S. Evz. THE usual method of determining the amount of radium in a mineral is by measuring the maximum activity of the emanation obtained from a solution. Good results have been obtained in this way by Strutt, and by Boltwood. Again, the quantity of uranium present is usually found by chemical analysis; and a measure of the active matter in a sample of pitchblende can be found by observing the a-radiation from a fine powder constituting an average sample of the mineral. In the present paper, an account will be given of another method capable of giving equally accurate results. It was due to a suggestion by Professor Rutherford that it would be interesting to ascertain if radium E emitted y-rays. This was to be expected because he had already proved that radium E gave rise to §-rays, and in all known eases these are accom- panied by y-rays, and are probably their immediate cause. In a newly prepared sample of radium bromide, there has not been sufficient time for the growth of the slow transformation products, so that very little radium E is present. But urani- nite, which emits but a small fraction of its emanation, must necessarily contain radium E almost in an equilibrium amount. The results of some preliminary experiments have been pub- lished in a recent number of the Philosophical Magazine.* The writer proved that the y-radiations from radium, thorium and radio-thorium were practically identical in character, being very penetrating and absorbed to an equal degree by lead. On the other hand, the y-rays from uranium and actinium were feeble and readily absorbed. It is, therefore, possible to cut off the y-rays arising from uranium or actinium in a sub- stance, and yet to have a strong y-radiation, due to radium or thorium, penetrating the screen. In this way it is easy to measure the amount of radium or of thorium present in any ore, or in a solution, and the active substance need not be powdered, or dissolved, or removed from bottle or test tube. It is only necessary to place the substance under a lead screen about one centimeter thick and to observe the fall of the gold leaf of the electroscope. Then a standard of known magni- tude, consisting of radium or thorium, is similarly placed, and the fall of potential is again observed for the same period as before. The saturation-currents in the two cases are propor- tional to the quantities of radium or of thorium present. This method of determining the amount of radium or of thorium * A. S. Eve, Phil. Mag., April, 1906. A. S. Huve—Radium in Minerals by the y-Radiation. 5 present applies to ores which contain only uranium or only thorium. If the ore consists of a mixture of these two ele- ments, the method cannot be applied except to obtain their joint amount. With these limitations, the method is capable of giving exact results, but when the amount of substance employed is large, a correction may be necessary for the absorp- tion of the rays in the substanee itself. Specimens of uraninite from Joachimstahl were obtained, weighing a kilogram, and it was found that radium E, assum- ing it to be present, either does not emit y-rays, or, more prob- ably, it emits y-rays which, like those of uranium, are of a feeble penetrating nature. The very penetrating radiation from pitchblende can therefore be wholly attributed to the presence of radium C. In the course of this work the amount of radium present in the kilogram of uraninite was found to be of the order of the amount contained in a quarter of a milligram of pure radium bromide. Consequently it was possible to estimate the amount of uranium contained in the ore, using as a basis of calculation the result of Rutherford and Boltwood that 1 gram of uranium contains 74107" grams of radium. The amount of uranium thus determined was surprisingly small, and in consequence part of the pitchblende was sent to Dr. Boltwood at New Haven in order to check the results in the two laboratories, and to get at the bottom of the divergence in results. Dr. Boltwood found that the radium present was about twice as great as in the determination by the writer at Mon- treal. As both Dr. Boltwood and myself were confident of the acctracy of our measurements, and as both methods appeared to be above suspicion, an examination was made of the standards on which the measurements depended. It is, therefore, necessary to give some account of the stand- ard solutions employed by Dr. Boltwood. In March, 1905, a crystal of radium bromide was taken from a supply which Professor Rutherford found gave a heating effect of 110 gram- calories per hour per gram, and which was presumably pure. This was compared by Professor Rutherford, using the y-ray test, with a larger known quantity of radium bromide, and it was also weighed carefully by the writer. The results were in excellent agreement, and the weight determined was: ‘95™.. The crystal was placed in 95° of distilled water, and fractions of the solution were then drawn off, and water was again added so that three glass flasks were filled, containing 107’, 10~°, 10°" of radium bromide per c¢.c. of water. Portions of these were evaporated to dryness in small zine trays, the resulting activities were measured and their ratios were found to be satisfactor y. The standards were sealed and put aside 6 y. = (100) :@il) 39 0 30 38 59 Gece? =o (00) ea LT) 49 59 49 57 Wer NA a (CLOON BACLT) 58 34 45 58 32 30 Cntr ea OO) iy ea (14s) 64 47 64 41 a’ :k = (100) : (115) 69 2 68 44 THAR OS (COO) aOR) Abe 45 TINE ee ARO) 9) eile MO 57 49 Chee 0.6 (O01) ee (103) 33 36 33 35 ¢ :u = (001) : (104) 26 35 26 29 Ti exist = OO) ya O2) Han ll 53 15 m:n = (110) : (111) 22 57 30 / 92 54 m' :v = (110) ; (111) 22 58 30 22 57 m' :> = (110) : (323) 32 98 45 32 35 Tevhenwe se (Oe (2) 40 19 40 13 Le Ra Tie (Lie) 51 56 51 49 Tie se tae (VO) peers (le) 59 20 59 15 Mens ns he (Oe eT YO) 76 49 76 52 Wie axe == (LON S ST 2M) 25 41 25 38 m :m, = (110) : (011) 65 (9 65 930 0 :@ = (120) : (102) 63 59 64 3 Ot ans (120) 22 ala) 29 40 29° Bee OB <= (120) = (121) 17 14 V7 eee Oe OM = AT 20 ie: Le) 31 45 31 43 DS NT eae OAD) ee MES) 42 50 42 32 Outen, = LONE 2 x(a) Seared 51 as Ont sit, (120) 78 (OTs) Hye Sy ar 7] 0 :m = (120) : (831) 13 13 13.08 (Ne arin = O30) eee eny 1On. 79 10 15 Go pe == (012)-: (104) 29 16 29 13 g : pl = (012) : (1:4:10) aS ale ETS + These values of Danbee modified as indicated on page 22, are also accepted by Groth, Goldschmidt and others. Kraus and Cook—Datolite from Westfield, Mass. 27 Natural etching is quite common, especially on the pyramids © r§113%, wi114t and «{115} as noted by Whitlock.* This phenomenon is also frequently observed on the prism 0/120} and the pyramid 6}121?. Inno case, however, were the figures of sufficient size to permit an accurate determination of their outline. Chemical Analysis. — For the chemical analysis one of the clearest crystals weighing about ten grams was selected. Tt was perfectly transparent and free from all inclusions. Concerning the methods which were employed, it should be stated that the boron trioxide was determined by the Goocht method. Water was estimated as loss on ignition. The other determinations were made according to the methods recom- mended by Hillebrand.t Two analysis were made, which show very close agreement. The results are: I II » Average Re eer ee Mb 0% 37°58% 37°59% On eh Se EO “10 10 PO cop eie a G5. tye ater ei "16 "15 IO) ope Pe ai Wi ake iS 34°64 34°74 34°69 EO ep py ce dapat 96's So 31 °315 BO Sess Po Aes yes 21°76 21.94 21°85 H,0 Bay Gene Rp ge aac aN Lac 5°67 5°76 5°715 Jhoty7 ee eee 100°23% 100°59% 100°41Z% The average of the above analyses agrees very closely with that required for the accepted formula HCaBSiO,. This was to be expected because of the unusual clearness and purity of the crystals. It is also to be noted that this analysis is very similar to Bodewig’s$ of the datolite from Bergen Hill, N. J., as is shown by the following comparison : Theoretical Westfield Bergen Hill Sunes Wome A 37°63 37°59 37°48 ica Ope ey ce 10 12 1 SNES SIR GR oe eee Peeper ee a "15 —. (OST 8 eal vk ea ee 34°95 34°69 39°42 BONE), ee ec 31 —_— cae) ee 2181 21°85 21°14 = Oe eae 5°61 5°72 571 DL Oe eee iy Ss 100-00 100°41 99°87 *N. Y. State Museum, Bull. 98, 12. { F. A. Gooch, Am. Chem. Jour., ix, 23, 1887. F. A. Gooch and L. OC. Jones, this Journal, vii, 34, 1899. ¢ Bulletins 148 and 176 U. S. Geol. Survey. § C. Bodewig, Zeitschr. fiir Krys., viii, 211, 1884. 28 Kraus and Cook—Datolite From Westfield, Mass. This similarity in the composition of the datolites from these two localities becomes more pronounced when we consider that the value given by Bodewig for boron trioxide is the mean of three determinations, one of which is 21°6 per cent. This agrees very closely with the values obtained by us. Specific Gravity.—For the determination of the specific gravity four clear crystals of convenient size were used. The determinations were made by means of the hydrostatic balance at a room temperature of 19°5° C., the water being 21°5° C., with the following results: Pie ae a ead Oy ive BOO Wee © Baca etiam Dias een 2°9998 Yt Rees age Raptr Hes a Mate te 3°0065 ‘ SDV ia 2 ua ite, a eas enters eae 3°0165 AVerawe: (Nil wee see 3°0058 The values for the specific gravity are usually given in the various standard text-books* as varying from 2°9 to 38. Bauer,t} however, gives 2°9-3°6. We have been unable to find any records whatever of datolites possessing a specific gravity as high as 3°6, and on account of the fact that the figures obtained by us on very pure material are much lower, we would question the correctness of the larger value given by Bauer. In conclusion, we wish to express our indebtedness to Prof. E. D. Campbell, Director of the Chemical Laboratory of this University, for advice and suggestions relating to the chemical portion of this paper. Mineralogical Laboratory, University of Michigan, Ann Arbor, Mich. March 30, 1906. * Dana, System of Mineralogy, 1892, 504; Hintze, Handbuch der Mineral- ogie, II, 167; Miers, Mineralogy, 1902, 588; Naumann-Zirkel, Elemente der Mineralogie, 14te Auflage 1901, 629. + Bauer, Lehrbuch der Mineralogie, 2te Auflage, 1904, 762. C. Schuchert—Russian Carboniferous and Permian. 29 Art. VII.—The Russian Carboniferous und Permian com- pared with those of India and America. A Review and Discussion ; by CuarLes Scuvcuert. (With Plate 1.) CONTENTS: Part JI. The Work of Tschernyschew. Part II. The Work of Noetling. Part III. The Work of Diener. Part IV. The Work of Girty in the Trans-Pecos Region of Texas. Part J, Tot Work or ‘T'SCHERNYSCHEW. Die Obercarbonischen Brachiopoden des Ural und des Timan. Von Th. Tschernyschew. Mem. du Comité Géol., vol. xvi, 1902 [1903], pp. i-vili, 1-749, and 63 plates. Tuts large and exceedingly valuable monograph describes the brachiopods collected by the author and others during eight years in the Ural and two years in the Timan districts of European Russia. The great number of 213 species are de- scribed, and two new genera— Keyserlingina and Spiriferella. In the present review of this monograph, the author’s gen- eral conclusions regarding the occurrence of these forms in the various horizons and their significance in correlation only will be taken into account. In fact, Tschernyschew’s correla- tions are of the first importance, and will be fully presented here. In the introduction the author states : — “¢ It is my opinion that the exceptional richness of the fauna of the Upper Paleozoic sediments of Russia and the positive succession of the various horizons give us the right to regard eastern and northern [ European | Russia as the starting point for the correlation of similar deposits in other countries... . Not infrequently my views differ from those of my colleagues in western Europe and America, and in recording these con- clusions in the final chapter of my work my chief object has been to present the views of one geologist who in the course of many years has studied the upper Paleozoic deposits in the vast territory of Russia. It is very probable that some of my freely-stated assertions will be strongly criticized by geologists both at home and in foreign countries, and I shall be the first to greet such criticisms with pleasure” (pp. vi, vil). Of the 213 species of brachiopods known in the “ Upper Carboniferous ” of Russia, 61 pass into the Artinsk zone and but 10 into the typical Permian. The latter are Dielasma elongutum, Lthynchopora nikitinit, R. variabilis, Camaro- phoria crumena, C.superstes, C. globulina, Athyris pectinifera, A. roissyi, Spiriferina cristata, and Productus aft. leplayt. 30 CO. Schuchert—Russian Carboniferous and Permian. These make it clear that this is not the normal marine fauna that continues the Paleozoic sequence into the Mesozoic. This point, however, will be discussed on a later page (see “ Conclusions,” paragraph 2). In regard to the Russian faunas the author states :— “JT wish to call attention to the decided differences which make their appearance in the fauna of the Omphalotrochus horizon when contrasted with the type of that of Miatschkowo [near Moscow; also see the following table for stratigraphic position], and on the other hand the great resemblance of the brachiopod fauna of the Schwagerina zone to that of the higher lying Permo-Carbon (the Artinsk deposits CPg and the Lime- stone-dolomite CPec). Inthe lower Permian fauna of Russia we have already noted a decided reduction in Brachipoda, if not in quantity, at least in variety of species; and in the still higher horizons of the Russian Permian, the total number of Brachiopoda is not more than 40 species [this number has reference to all areas correlated with the typical Perm area|. Entire groups of forms . . . that give a decided aspect to the fauna of the Upper Carboniferous Artinsk, and the Limestone-dolomite beds, are completely unknown in the Per- mian sediments of Russia and west Europe. Some of these groups therefore attract our attention because they are foreign to the Permian deposits, yet in the Mesozoic (Trias and Jura) they attain an extended development. On the other hand, others belong to such original types as the Lyttoniude, ZT egulé- fera, and Orthotichia, forms that give a decided character to the upper Paleozoic, and, so far as our knowledge goes, com- pletely disappear with the Permian epoch [of western Europe]. From a biological standpoint there can be no doubt that our Upper Carboniferous brachiopod fauna has the facies of a younger type than the Permian, and that in its entirety it has a more decided Mesozoic impress than that of the [Russian] Permian following, which when compared with the other shows atavistic trends [see note 6]. As it is my opinion that this atavism finds its proper explanation in the physico-geo- graphic conditions of the Permian sea, I hold that it is not superfluous to direct special attention to this fact, and thereby to moderate the tendency of some geologists, who in their determination of the age of this or that fauna depend mainly upon the biological peculiarities and not infrequently leave out of consideration the possible explanation that the biological differences between two synchronous or at least closely adjoin: ing faunas are partially due to facies and chorological causes” (pp. 665-4). “ Although the data presented regarding the distribution of Upper Carboniferous deposits in the region of European bial. C. Schuchert—Russian Carboniferous and Permian. 31 Russia show that we can not fix with certainty the exact shore-lines of the sea of this epoch, still from the general dis- tribution and the nature of the sediments of this time, when compared with those of the Middle Carboniferous epoch, we may conclude that there was a retreat of the sea in the west. In the north the Upper Carboniferous sea had great extension and communicated freely with the far-reaching Polar sea. In the east it was limited by the Ural barrier, behind which in Siberia lay a series of more or less extensive basins of brackish or fresh water ” (p. 679). For the sake of completeness, the reviewer will here intro- duce a somewhat detailed generalized section of the Permian and Carboniferous of Russia, compiled from various recent sources :* Brackish ? Permian or ?Triassic, Tartarian (PT). Red grits, argillaceous sands, and intercalations of clay and marl of the same color; rarely green or bright blue. Red colored marls and variegated clays, with intercalations of grayish grits and sands of the same tints. These two groups have brackish-water genera, as Unio, Anthracosia, Najadites, and Paleomutela. Permian (P) of Samara and Oufa (the Permian sensu-stricto of Murchison), Brown grits, marls, and limestone. Has some pelecypods, as Allorisma elegans, ete. Gray slaty limestones, with intercalated marls and friable grits. Has Murchisonia subangulata, Turbonilla altenburgen- sis, Macrodon kingianum, Osteodesma kutorgana, Modi- olopsis pallast, Leda speluncaria, ete. Of Crustacea, Buirdia, Estheria. Lingula orientalis. Of fishes, Pale- oniscus, Acrolepis. Grits and gray limestone, more or less copper-bearing. Rich in brachiopods: Spirifer regulatus, Spiriferina cristata, Athyris pectinifera, Dielasma elongata, Pro- ductus cancrint, P. hemisphericus, Strophalosia hores- cens. Some bivalves and corals. Red argillaceous grits, with mtercalations of clay and gray, brown, and reddish marls. Fossiliferous only in the higher beds: Productus can- crint, Athyris pectinifera, Dielasma elongata, Allorisma elegans, Macrodon kingianum, ete. *The Permian and Mecscowian section is taken from Nikitin—‘‘ De Moscou & Oufa (via Miatschkowo, Riazan, Penza, Syzran, Samara),’”’ Guide des Excursions, VII, Congres Géol. Internat., 1897, Pt. IT; the Uralian, from Tschernyschew’s great brachiopod work here reviewed; the Viséian and Artinsk, from Tschernyschew, Mém. du Comité Géol., III, No. 4, 1889. 32 CO. Schuchert—Russian Carboniferous and Permian. Argillaceous limestones and marls of variegated tints. No fossils. Gypsiferous group of limestone, gypsum, and clay. No fossils. Permo-Carboniferous, or Artinskian (Lower Permian of many authors). ‘Horizon CPe, or dolomitic:limestone zone. A gray or yellow- ish gray cavernous limestone passing often into dolomite, brecciated or conglomeratic in composition, with interca- lated beds of oolite and occasionally shale. Has a fauna smaller than, and almost identical with, that of horizon OPg. Cladodus, Dielasma hastata, D. elongata, Spiriferina cristata, Lhynchopora nikitini, Chonetes variolaris, C. verneuiliana, Productus purdoni, P. cora, Marginifera typica, Fusulina verneuli, and Bradyina nautiliformis. Horizon CPg, or Artinskian sensu stricto. “ Peppery ” sand- stone, with interealations of shales. In places conglomer- ates, limestone, shales, and slates. Has Phillipsia gruenewaldti, Pronorites prepermicus, Agathiceras uralicum, Medlicottia artiensia, Gastrio- ceras, Popanoceras, Parapronerites. Of Upper Carbon- iterous brachiopods, 61 species pass into this zone. Among the more prominent fossils of the zone are the following: Dielusma elongata, Spirifer fasciger, S. alatus, Spirifer- ma cristata, Spiriferella sarane, Rhynchopora nikitint, Camarophoria plicatae, Streptorhynchus pelargonatus, Productus spiralis, P. lineatus, Marginifera typica, Fusulina verneuili. Upper Carboniferous, or Uralian. Schwagerina zone (C3), about 60 meters thick in Timan. Abounds in Schwagerina princeps. Other Foraminifera are Husulina vernewili, F’. longissima. Of corals, there are many species, mostly of the compound type. Of Bryo- zoa, the most striking is Archimedes. This is the horizon par excellence for brachiopods, Tschernyschew recording 194 forms. ielasma in greatest abundance, with 138 species; HHemiptychina 4, none below; Lotothyris 3; Aulacothyris 2; Keyserlingina 2, none below ; Zerebrat- uloidea 2, none below; Pugnax 8; Camarophoria 14; Spiriferina 8; Spiriferclla 4; Spirifer 21; Martiniopsis 7, none below; Martinia 13; Reticularia 4; Meekella 2; Orthotichia 1, none below; Chonetes 11; Aulosteges 1; Productus 40; Proboscidella 3 (these are not of the type of the Lower Carboniferous, having had another C. Schuchert— Russian Carboniferous and Permian. 33 origin); Marginifera 8. Pelecypods also common and of the ordinary Upper Carboniferous types. Of cephalo- pods, Agathaceras uralicum, Pronorites cyclolobus wralen- sis, P. postcarbonarius. Trilobites, Gripithides roemert and G. gruenewaldti. Productus cora zone (C2), about 70 meters thick in Timan and 100 in southern Ural. The most abundant fossil'is P. cora. Other brachiopods are Drelasma, 4 species (bovi- dens); Camarophoria 4; Spiriferina 2 ; » Spir iferella sar- ane, Spirifer camer atus, S. condor, S. Fasciger, S. mar- cout (goes no higher), ‘Derbyia reguluris, D. or aSSA, Meekella striaticostata and 3 other species; Chonetes mesoloba, C. granulifera, C.flemingi, C. variolata, Aulo- steges, Productus boliviensis and 21 other forms, JZar- ginifera uralica and 4 other forms. Corals are rare, especially the compound forms so common both above and below. Archimedes rare. Large Lusulina verneuili. Gripithides scitula. Omphalotrochus zone (C#b). This zone and the one below have a united thickness of about 70 meters. Most abun- dant fossil Omphalotrochus whitneyi. Of brachiopods there are Dielasma itaitubense, Camarophoria 38, Spirt- Jer marcour, Derbya crassa, D. regularis, Meekella striaticostata, A ulosteges, Productus nebrascensis, P. cora, P. 10 species, Marginifera uralica. Corals very abundant ; this zone in the Urals is 12 meters thick. Spirifer marcoui zone (Oga). Has an abundance of S. marcowi and corals. Middle Carboniferous, or Moscowian (Cz), about Miatschkowo. 1. Greenish white fragmental limestone, °3 meter thick. 2. Greenish compact argillaceous limestone, ‘7 meter thick. 3. Yellow dolomitic limestone, 24 to 3 meters thick. Abounds in fish teeth and plates of Cladodus, Dactylodus, Deltodus, Ostinaspis, Pecilodus, Polyrhizodus, Psepho- dus, Psammodus, and Solenodus. Also Productus semi- reticulatus. 4, Grayish compact limestone, 14 to 2 meters thick. 5. White granular soft flagcy limestone, 2 to 3 meters thick. Has anormal marine fauna. Those preceded by 1 are the characteristic species. Has many of the fishes found in 8, and Cymatodus, Helodus, Orodus, Petalodus, and Tomodus. Also Nautilus mosquensis, Euomphalus pentangulatus, E. marginatus, Macrocheilus ampullace- ous, Allorisma regulare, Conocardium uralicum, Pro- ductus cora (riparius), P. lineatus, 1 P. semir eticulatus, Am. Jour. Sci.—FourtH Sreries, Vou. XXII, No. 127.—Jury, 1906. 3 34 CO. Schuchert—Russian Carboniferous and Permian. P. longispinus, P. punctatus, 1 Enteletes lamarckt, Meekella eximia, 1 Spirifer mosquensis, 1 S. strang- waaysi, S. fasciger, and 1 Seminula ambigua. In the clay bands this is also the horizon for crinoids Cromyo- crinus, Hydriocrinus, Phialocrinus, Poteriocrinus, Stem- matocrinus, etc. Also Archiocidaris rossica, Lepidesthes, and Calliastes. Several species each of Fenestella and Polypora. Of corals, Bothrophyllum conicum, Petal- axis and 1 Cheetetes radians. Also Fusulina cylindrica, but not readily seen. 6. Fusulina hmestone made up of Foraminifera and crinoidal matter, 1 meter thick. Has some of the fishes also found above, WVautiius 6 species, Productus semireticulatus, P. punctatus, Meek- ella eximia, Enteletes lamarcki, Spirifer mosquensis, Archiocidaris’ rossica, Chetetes radians, Syringopora parallela, Bothrophyllum conieum, Axophyllum rosso- phyllum, Fusulina cylindrica, Bradyina, Hndothyra, Fusulinella, Cribrostomum, and Letrataxis. 7. Yellowish white hard compact limestone, 13 to 2 meters thick. 8. Dirty white limestone. Lower (?) Carboniferous, or Viséian. Upper limestone (C2). Has Allorisma regularis, Rhynchonella pleurodon, Sem- inula ambigqua, &. subtilita, Schizophoria resupinata, Productus longispinus, P. corrugatus, P. pustulosus, Fusulina verneuili, Fusulinella spheroidea, ete. Lower limestone (C4). Has an abundance of corals, Syringopora gracilis, Litho- strotion affine, L. cespitosum, L. irregulare, and brachio- pods, Productus giganteus and Chonetes papilionacea. Also P. striatus, } division. “A lower, glacial «... This arrangement is intended only to express the relative participation of ice and sea-water in these deposits. Nowhere do we see a stratigraphic break or discordance; through local interealations of drift horizons, the lower glacial deposits, the stratified beds, and the Conularia layer are closely united with the glacio-marine division (Olive-sandstone and Lavender-clay), and from the latter there occurs a very grad- ual transition into the pure marine division. ‘“‘ Again, three very unequal faunal divisions may be distin- guished, namely : “ An upper division: characterized by an abundance of Cer- atites. “A middle division: characterized by an abundance of Pal- eozoic brachiopods and sparingly of Ammonites. “‘ A lower division: thus far without such fossils. “These three faunistic divisions do not wholly. agree with the three genetic sections. The lower division without fossils is of course in harmony with the glacial division, but the imid- dle section embraces the glacio-marine and the lower portion of the marine divisions, while the upper member includes the upper part of the marine section. The following table will make this clear :— ‘* Genetic aM te Stee Stratigraphic ad Faunistic divisions eect Characterized by the absence of Paleozoic|Paleozoic brachiopods brachiopods and the} absent. Ceratites Ceratite appearance of aj occurring in abun- beds | great abundance of) dance Pure | Ceratites 1. ‘Characterized by the ccs | retreat of the Cera- p Piaets : aleozoic brachiopods | | tites and the appear- ie Productus abundant. Ceratites ance of an abun- limestone | eras | dance of Paleozoic brachiopods eh Lavender-clay Glacio- Paleozoic brachiopods sae marine unknown ae beds | Conularia fauna wo a | Olive-sandstone Glacial | ,,- ' yee : Bowlder hada Without fossils Without fossils clay ” 42. OC. Schuchert— Russian Carboniferous and Permian. “The stratigraphic divisions represent the four or five great natural groups into which the Permian system of the Salt- Range is readily divisible, on the basis of the paleontological, lithological, and genetic characteristics.” ‘‘ Naturally of greatest importance are the two groups of the upper marine division—the Ceratite beds and the Productus- limestone—for if the age of either of them can be satisfacto- rily determined, it follows that the age of the other is also fixed. In a general way, the age of these two groups is already estab- lished: The Productus-limestone, with its very remarkable abundance of Paleozoic Brachiopoda, must belong in the Paleo- zoic, While the Ceratite beds having the Ammonites char- acterized by Ceratite suture lines must be referred to the Tri- assic. However, the Froductus-limestone was regarded as Carboniferous until the detailed description of the fauna by Waagen taught that this view must be decidedly modified. On my first trip to the Salt Range I noticed the gradual tran- sition from the Productus-limestone into the Ceratite beds at Chideru; later I was able to extend this observation through the profile in the Chnas ravine, near Virgal; here can be plainly seen the individual lithologic members of the Produc- tus-limestone and. the Ceratite beds In most mtimate succes- sion. ... Because of the indisputable succession at these two places I argued as follows: Such an intimate connection of Paleozoic and Triassic can only exist near the dividing line between the Permian and Triassic; if the Ceratite beds belong in the Triassic, then the underlying Productus-limestone must fall into the Permian, and accordingly, on account of the indi- viduality of its fauna, it must represent but a single division of the Permian, but can not at the same time be the equiva- lent of both the Zechstein and the Rothliegendes.” The author then makes comparisons with other Indian Tri- assic regions, and also discusses the possibility that the Pro- ductus-limestone may be Upper Carboniferous. He concludes that if the Ceratite beds of the Salt Range are not Triassic, then the entire lower Trias is absent in the Himalaya. He maintains that the possibility of the Triassic being transgres- sive upon the Upper Carboniferous is excluded, because the transgression would then fall in the middle of an undisturbed sequence, i. e., in the Upper Productus-limestone. Further, if these deductions are not correct, then no reliance can be placed on the development of the suture lines of ammonites for the determination of geologic age (see below for his con- clusions resulting from his studies on JMedlicottia). Noetling holds that there was a faunal transgression from -the Urals, but that the time of its spreading was at about the middle of the Permian. “ While this fauna was expanding radially, one can readily believe that. the peripheral parts of C. Schuchert—Russian Carboniferous and Permian. 48 the transgression were younger than those of the pivotal region. In transgressions, one has to calculate not only with two dimen- sions, but also with a third, because a species may occur in geologically older beds near the center than at the ‘periphery, where it may be found unchanged in younger deposits. Tt may be assumed that at the time of the Upper Carboniferous in the region of the present Urals, there existed an extended ocean, whose boundary was pushed toward the south and southeast (Uralic transgression). This transgression was not of a catastrophic or sudden nature, but was slow and continuous through a long period of time. The fauna spreading with the transgression passed, at least in part, unchanged into younger deposits ; while in the outermost boundaries of the transgres- sion, in the Salt Range and in the Himalaya, there occurs a series of forms in beds that are younger than the same species found in the central region. This crudely stated hypothesis naturally collides, of course, with the theory of guide-fossils ( Leitfossilien ), but my long-continued studies in India, namely, in respect to the Tertiary fauna, have more and more convinced me that the rigid theory of ouide- fossils, valuable as it is within restricted areas, always proves disappointing when applied to greater, more widely extended regions.’ In the author’s larger work of 1901, cited above (4), he fully presents his views regarding the sequence of the Indian Permian and Triassic sections and their correlation with that of Europe. Noetling, however, recognizes that the difficulties are great, for he states: “If the Permo-Triassic formations of the Salt Range had first been studied, it would never have occurred to anyone to draw a line in this unbroken series and to apply to the divisions two names. One would have regarded the series as a unit, which itis... If from these formations one had proceeded to seek the European equivalents, they would have been hard to force into the scheme framed for the Salt Range. Speculation of every sort would probably have been resorted to. I now find myself in an analogous position in forcing into the European scheme the Permo-Triassic series of the Salt Range, and if it is to be employed in this case then one must make a purely artificial separation” (4, p. 458). From this work, the table of Plate I is compiled, giving the seauence of the formations, their terminology, thickness, and correlations with European standards; the Himalayan section is added from Noetling’s paper here numbered 3. The second of these papers cited deals with the very impor- tant Permian ammonite Medlicottia. The genus is here studied in considerable detail and comparisons are made between the European and Indian species. The American forms are 44. C. Schuchert—Russian Carboniferous and Permian. not discussed, these being left to Prof. James Perrin Smith. In regard to the stratigraphic and evolutional conclusions attained by the author, he states: : ‘The views here presented are proved partly by ontogenetic, partly by phylogenetic examinations and observations, and there- fore they may to a certain extent be depended upon. I must, however, note the assumption on my part that the Sicilian Fusulina-limestone is older than the Artinsk [=Permo-Carb. of the Russians] horizon, and again that the latter is older than the Productus-limestone of the Salt Range. By follow- ing out this assumption and comparing the various suture lines with one another, I obtained positive results which were proved by the development of the suture lines of J. orbignyana. This especially apples to the divisions of the external saddles ” (p. 354). ewe fe connection I would [first] like to point to an observa- tion, which in spite of its scantiness permits of wholly unsur- mised deductions regarding the climatic conditions at the close of Paleozoic and the beginning of Mesozoic time. In an earlier work I had the opportunity of propounding the question—Is the abundant appearance of Productus possibly connected with a cooler temperature of the sea-water?’ [In Neues Jahr- buch, 1896, II, p. 86, this problem is stated as follows: ‘“ In India at least, but more particularly in the Salt Range, there was a glacial period at the beginning of Permian time. It would be interesting to examine the evidence to see if the great abundance of Productus has any connection with the ~ cooler temperature of the sea-water.”’ | ‘A greater knowledge of the Paleozoic deposits of the Salt Range has given undoubted evidence of the existence of a Glacial Period at the beginning of Permian time, which deposits locally were laid down im the sea. [For a full bib- liography and a good description of the late Paleozoic glaciation of India, see Noetling, Neues Jahrb., 1896, Il, pp. 61-86.] In other words, this sea must have been one with a low temperature. Subsequently, in this sea was deposited the Productus-limestone, and the conclusion is not probable that the temperature of the water rose during the melting of the glaciers and the introduction, “of the Productus-fauna. In the Salt Range, therefore, this fauna is to be regarded as an arctic one. “The studies of Medlicottia have shown that J. primas Waag. is in all probability to be regarded as a descendant of M. orbignyanus Vern. sp. of the Artinsk horizon. One can picture to himself the condition whereby the Medlicottias migrated from north to south (more correctly from northwest to southeast) at the same time that they passed into higher beds. C. Schuchert— Russian Carboniferous and Permian. 45 “ Tf this conelusion is correct, i. e., the fact that a migration of the Ammonite world from north to south took place toward the end of the Permian, then, I ask, is it not conceivable that the Productus-fauna accustomed to a cold séa was, in con- sequence of the raising of the general temperature of the water, driven from its “original northern habitat toward the south, where shortly before the disappearance of the Permian ice period it found the required normal temperature? Is it not further conceivable that, with a continued increase in the temperature of the sea, which under some circumstances may have occurred very rapidly, the Brachiopod fauna, also, may here have been suddenly exterminated, while the Ammonites, apparently better adapted to warmer water, developed in a most remarkable manner? Is it not, moreover, conceivable that the end of Paleozoic time was characterized by a probable rapid increase in temperature which spread itself from north to south? If this hypothesis is correct, we must then assume that the dividing line between Paleozoic and Mesozoic time is marked by a change of temperature which spread from the northern hemisphere, thus forcing the Paleozoic Brachiopoda southward, where for a short time in a suitable medium,—a sea cooled by the Permian glaciers, they attain a wonderful development, and then die ont when the average temperature exceeded that beneticial to them” (pp. 375-6). These suggestions of Noetling’s are of the greatest interest. However, as Medlicottia occurs in Texas in association with an undoubted Upper Carboniferous fauna of the type so well known in the Mississippi valley, the question arises—Are not these the oldest Medlicottias? If so, then the further question is raised— Was not the migration east and west through the great mediterranean Thetys instead of from north to south? In 1901, Noetling (4, p. 457) explains this change of fauna on the basis of change in the depth of the sea. He states: ‘The Brachiopoda of the deeper waters died out and are replaced by the Ammonites, lovers of shallow waters and flat coasts.” It is the impression of the reviewer that, until more is known in regard to the extremely interesting Productus- limestone fauna of the El Paso, Texas, region and similar or Artinsk faunas from California and Alaska, no safe deductions as to paths of migration can be made. From the third paper by Noetling, on the Otoceras horizon, is gleaned the following :— “In a treatise on the divisions of the pelagic Trias, Mojsiso- vics, Waagen, and Diener, supported by the statements of Waagen that there exists a hiatus in the Salt Range between the uppermost Permian and the lowest Trias, have denied the 46 CU. Schuchert—Lussian Carboniferous and Permian. existence of the Otoceras beds or their equivalents in this part of the Trias sea. ‘“‘T had serious doubts about this conclusion, for on my visit to Chideru in the Salt Range [I was convinced that there is bere a gradual transition from the Upper Productus-limestone (Permian) to the Ceratites beds (Trias). “This observation is not new, for at different times Wynne has pointed out the gradual passage in the sequence of the beds from the Productus-hmestone to the Ceratites beds, but his statements have unfortunately received too little attention ” (p. 529). On this visit Noetling looked for the Otoceras beds at the base of the Ceratites zone below the Ceratites-limestone, but did not find this diagnostic fossil. To his great surprise he did find what he took to be an Otoceras in the Ceratites- shale, 1. e., above the Ceratites-limestone. On his return to the museum at Calcutta, however, the fossil proved not to belong to this genus. After a further dissection of the Him- alaya section he states: ‘In the Himalaya the Otoceras beds lie immediately below the Hedenstroemia beds. Accordingly, in the Salt Range, either the Otoceras beds or their equivalents must be looked for immediately beneath the Ceratites beds. As, however, in the Salt Range, immediately beneath these beds lies the Permian (Upper Productus-limestone = Chideru group) it follows that we have to seek for the equivalents of the Otoceras beds in the Salt Range in the Upper Productus- limestone, probably in my Huphemus indicus zone, but over the zone with Hpisageceras wynner.” In spite of careful col- lecting none were found, and he coneludes: ‘ According to our experience we almost doubt the occurrence of Otoceras m the region of the Salt Range.”” The two regions have a differ- ent stratigraphic sequence with somewhat different faunas, and it may be that they were separated from one another by a sub- merged barrier (a rising anticline) not wholly preventive of intermigration. Then follows a long discussion or the apparently complete transition zone in the Himalaya, between the Productus-lime- stone and the Ceratites beds, and considerable detail regarding the included fauna as well. This discussion is entirely too long and too detailed to be summarized here, but Noetling’s views are clearly presented in two correlation tables, one of which has been added to the table given on Plate I. [To be continued. | | Triassic Permian | Marine Pi \Lower 2 Phuringlan stage PLATE T Horizons anv Zonan Names Salt Range Himalaya Discordance Region of Spiti Region of Niti ; ~ Upper Ceratite L i Py] Maxi : limestone Zone of Stephanites superbus thine Not known as yet Dark limestone of Byans: Ceratite pers er == Se = saridetone Zone of Plemingites flemingianus Geratite Zone of Koninekites volutus 220° Hedenstroemia beds Hedenstroemia beds: clay Zone of Prionolobus rotundatus Lower Ceratite i A aa limestone Zone of Celtites (2) sp. J Zone of Meekoceraslilangense | Zone of Prionolobus noetlingt Zone of Euphemus indicus Zone of Ophiceras libeticum | Zone of Ophiceras tibeticum 4 * Zone Of Bpisageceras dalailame Chideru group Zone of Mpisageceras wynnei 50! Zone of Otoceras woodwardi = or ance Zone of Otoceras woodwardi Productus- = =f Pee Te eS RCE Upp E Eee Zone of Bellerophonimpressus } 800! Brown eeu Zone of Cyclolobus oldhami Dark Productus slates with | Dark Productus slates with Pro- 180! Cyclolobus oldhami ductus abichi Zone of Derbya hemisphaerica ——$————— — Zone of Productus lineatus 70! Virgal group or | Zone of Xenodiscus carbonarius 20! Middle Productus- 800" limestone Light colored flinty limestone Zone of Lyttonia nobilis 130! Zone of Pusulina khattaensis 50" No Fusulina occur higher than this stage Amb group or Lower Productus- limestone Zone of Spirifer marcoui and Fusulina 200° Dark, sandy limestone S a r ‘Lavender clay a, = EAR CIN Speckled sandstone ao0 Fc Olive sandstone ; “ 2 Zone of Conularia laevigata n : Dandote| group Zone of Durydesma globosum ¥ shale 200 Olive sandstone ~ Palchir group | Bowlder-clay 150! Discordance Cambrian Graham—Pseudomorphs in McGill University Collection. 47 - Arr. VIII.—WNote on two interesting Pseudomorphs in the McGill Oniversity Mineral Collection; by BR. P. D. GraHam, B.A. 1. Pseudomorphs of Orthoclase after Laumontite from Templeton, Ottawa County, Quebec. THE specimens described below were collected some years ago by Dr. B. J. Harrington in the apatite region of Temple- ton, and had been labelled by him as pseudomorphs after lau- montite, although they were not further examined at the time. They consist chiefly of flesh-red to almost white crystals, meas- uring up to about half an inch in length for the most part, and having a very fresh appearance, the edges being quite sharp and the faces smooth with a dull and somewhat waxy lustre, although in some cases they are somewhat weathered on the surface. They are of the usual laumontite habit (fig. 1) show- ing a combination of monoclinic prism with basal plane. The faces do not directly yield reflections owing to their dull lustre, but by placing a drop of alcohol on each in succession, after adjustment on the reflecting goniometer, and taking readings at the moment when the drop is just about to dis- appear (as suggested by H. T. Whitlock*), the angles can be measured with a fair degree of accuracy, and they were found to correspond with those of laumontite. The crystals are implanted in irregu- lar groupings in a compact material of a rather paler tint, but possessing the same general char- acters, and this in turn encrusts the dark green pyroxene and brownish phlogopite which are characteristic of the Templeton locality. The pyroxene is in the form of large prismatic crystals, an inch or so in diameter, and both this mineral and the phlogopite are more or less completely coated with a layer a quarter of an inch thick of the pale-colored massive material from which the pseudomorphous crystals spring; there are also dispersed through it fragments of a pale green apatite, and in one of the specimens, a crystal of zircon. The prism faces of the crystals are usually striated vertically and sometimes exhibit a step-like structure along the directions of the original laumontite cleavages, which, however, are now entirely lacking. The fracture is fairly even, and the er ystals are solid and homogeneous throughout; in physical characters they correspond exactly with the feldspar : H=6, Sp. G.=2°56. Thin splinters fuse B. B., the pink color fading to white; and a NSN ois Museum Publication, 1905. 1 48 Graham— Pseudomorphs in Me Gull University Collection. only a slight trace of water is given off on heating in a closed tube. The finely powdered mineral is insoinble in acids, and a preliminary examination of the solution obtained after “fusion with a mixture of sodium and potassium carbonates showed that it contained no fluorine or chlorine. An analysis was made of material selected from some of the fr eshest crystals with the following result (column I): Templeton. Weissig. Orthoclase. Mie 1 ITT. SiGe a Ye TO He) Io eet es ae ODO OOS ae eens 64°7 BAO) et TAS 1 998 3: Be ee ee POro A eee 18°4 Me Oe ae Ca Parga 4 ip is ——- CaOcescrsns —-— ee 0°19 Mi O)ss eine Te ONDA rae 1 eats 8 161 KO oe Se AN SOR 2 Si ees rel eee oe 16°9 Na,O Li,O ti O55 hee ere AOE ios yee ee OS ane a ee 0°35 100°40 99°94 100°0 The sodium and lithium, which are present in only very small amount, were not separately determined, but the pres- ence of both was shown by a spectroscopic examination of a solution in hydrofluoric acid. In containing a small percent- age of lithium, this occurrence resembles the original weissigite from Dresden, the result of an analysis of which by J enzsch is given above for comparison (column II). The crystals are therefore pseudomorphs of orthoclase after laumontite and the compact material m which they are embedded doubtless had a like origin. Although such pseudomorphs have not been described before from a Canadian locality they have been found in several other districts, and the following account of some of these occurrences is taken mainly from Blum’s treatise on pseudo- morphs.* In 1853, Jenzscht examined a mineral which occurs at Weissig, near Dresden, and which he found to have the com- position of an orthoclase with a content of about one-half a per cent of lithia (see his analysis quoted above) as well as the gen- eral characters of a feldspar, the hardness being 6 and the specific gravity 2°55: these facts, together with the character- istic form of the crystals, combinations of monoclinic prism with basal plane, led Jenzsch to regard the mineral as a dis- tinct species, to which he gave the name weissigite in refer- ence to the locality at which it occurs. Weissigite, however, *Die Pseudomorphosen, II, 20; III, 60. +N. Jahrb. f. Min., 396, 1853; 405, 1854; 800, 1855. Graham—Pseudomorphsin McGill University Collection. 49 is found in a porphyritic amygdaloid, associated with quartz and chalcedony, conditions under which a feldspar had never been known to occur up till that time; this, and the similarity of the form and habit of the crystals to lanmontite subse- quently convinced Jenzsch that the orthoclase was not a pri- mary mineral in the amygdules, but that weissigite is in reality a pseudomorph of orthoclase after laumontite, which was the view held by Blum. Similar pseudomorphs are mentioned by Blum as occurring at Niederscheld, near Dillenburg in Nassau. Flesh-red crys- tals of the common laumontite habit are dispersed through the greenstone, associated with quartz, which often completely envelops them; calcite and prehnite are also present in small quantity. The prism faces of the crystals are striated verti- cally, and the crystals are often more or less split along the directions of cleavage of the original laumontite: the altera- tion to orthoclase is seldom complete. Specimens of the same kind are also found at Schelder Eisenwerk, and at Oberscheld, where crystals an inch in length occur in a druse. At Beilstein whole druses of pseudomorphs of orthoclase after laumontite occur in an altered diabase; the crystals, which are sometimes more than an inch long, have their origi- nal form well preserved, and show the usual striz and cracks along the prism faces; and their pseudomorphous nature is also evident from the hollowness of many of the crystals. There is an almost identical occurrence at Conradsreuth, between Miinchberg and Hof in Fichtelgebirge. Laumontite is among the minerals found m the Lake Supe- rior mining region of Michigan, where it occurs in clefts, coated, often completely, by calcite, and sometimes also by _native copper. The laumontite is weathered and shows vari- ous stages of alteration, and has been analyzed by Lewinstein* with the following results; I refers to a brownish laumontite which readily crumbles, breaking along the cleavage directions, whilst II is of a more weathered material which has become firm and hard, and no-longer possesses cleavage. I ibe Laumontite. Si0, Sig eS See OM ae Waar tte yi Sa Re i 51:1 EO eee Oe WOU ete U2 DONO men te © Ae eo ae eae 1 ES eee Yale ae ear ts 2°58 CAO fee ae AHS bt 1 ie 2 OG Sree wy 2 1 |g) BE Spee ee 1:31 LOT Tet OD ee aPC: a re 3°41 2 0 peiemet ater tele Ap tes 849 D2 St) - 3°45 HO aN ESE Pelee Pers ts Oso Sd ot OB 100°00 100°00 100°0 * Zeitschr. f. Chem. u. Pharm., iii Jahrg., 1860, p. 11. Am. Jour. Sci.—FourtH SERIES, Vou. XXII, No. 127.—Juny, 1906. 4 50 Graham——Pseudomorphs in Mc Gull University Collection. These analyses were made by dissolving as much as possible of a weighed quantity of the mineral in acid, and calculating the results up to 100 per cent after deducting the weight of the insoluble residue. Hence they do not show the actual composition of the material taken, although they serve to indicate that the percentage of lime falls off more and more as the alteration proceeds, as also does that of the water once the hardening of the material has commenced, whilst the alkalis make their appearance in Increasing quantities, render- ing probable the assumption that the crystals are partial psendo- morphs of feldspar after laumontite. Sharp, well formed crystals of adularia, exhibiting the forms {110{, {001}, are also found at Lake Superior, situated on calcite and native copper, and these have also been regarded as probably due to the alteration of lanmontite. On the other hand, J. D. Whit- ney* has called attention to the very common occurrence of orthoclase in all the mines of this region; he describes the crystals as being rarely more than a few hundredths of an inch in length, of a reddish color, arranged in bunches and geodes, and accompanied by native copper and the zeolites, the usual vein minerals of the region. From a consideration of the relative manner in which these minerals are associated with one another, Whitney concluded that in this case the ortho- clase was formed contemporaneously with the accompanying minerals, and that it is not a pseudomorphous product of the zeolites; from which it would appear that orthoclase does occur in the veins at Lake Superior as a primary mineral, asso- ciated with the zeolites, ete., although, at the same time, the adularia crystals referred to above may have had a different and secondary origin, as blum has suggested. It is doubtful whether orthoclase has ever been found replacing laumontite at any of the well known Scotch localities for that mineral, notwithstanding the fact that such pseudo- morphs have been described or referred to by several authors. In 1848, Haidinger+ examined a number of altered zeolites from Allan’s collection in Edinburgh, among which were some flesh-red crystals having the angles of lanmontite but the hard- ness (6) and the specitic gravity (2°5 to 2°8) of feldspar; the crystals had drusy surfaces and were ill-defined, and in addi- tion were frequently hollow or else filled with a dark green stony material. These specimens were found in the trap rock, associated with quartz, at the Kilpatrick Hills, near Dumbar- ton, and also at Calton Hill, Edinburgh. Haidinger described them as pseudomorphs of feldspar after laumontite, apparently relying on qualitative tests in their determination, since he * This Journal, xxviii, 16, 1859. + Sitz. Akad. Wien, iii, 95, 1848. Graham—Pseudomorphs in McGill University Collection. 51 gives no quantitative analysis of the material in the paper referred to. It is quite possible, however, that they were pseudomorphs of albite, and not orthoclase, after ]Jaumontite; and Greg and Lettsom quote an analysis by Heddle of such pseudomorphs from Kilpatrick, which have the composition of a soda feldspar containing about one per cent of potash. Hintze, however, under orthoclase, mentions pseudomorphs after laumontite as occurring at Kilpatrick, and in the same paragraph refers to an analysis by Bischof which he appears to suggest was made on material from this locality. The same analysis is given by Blum, although that author does not expressly state where Bischof obtained his specimens, and on referring to Bischof’s original paper* I find the same uncer- tainty exists even there, as it is not at all clear where the material he analyzed came from. The additional fact that Greg and Lettsom make no mention of pseudomorphs of ortho- clase after laumontite in their J/ineralogy of Scotland which appeared in 1858, several years after these observations of both Haidinger and Bischof, lends considerable probability to the view that such pseudomorphs had not at that time been found in Scotland, but that in all the observed cases the replac- ing mineral had been albite; nor are pseudomorphs of ortho- clase after laumontite included in the list of British Pseudo- morphs published by Prof. Mierst in 1896. However, a variety of orthoclase does occur at Kilpatrick, which was named erythrite by Thomsont{ in allusion to the flesh-red color; this he described as a compact feldspar, which he never observed in crystals, but there is nothing in his description to suggest that this was of a pseudomorphous nature. It will be seen from the foregoing that pseudomorphs of orthoclase after laumontite are of fairly wide occurrence, although in the specimens from many of the localities the alteration seems to be incomplete, and the crystals often more or less hollow; but in the case of the specimens from Temple- ton described in this note, the crystals are invariably quite solid and compact, and, except in the form, show no trace whatever of a tormer existence as laumontite material. In this complete alteration to orthoclase, and, further in the small content of lithium, the mineral resembles the original weissigite. The reverse change, from orthoclase to laumontite, has been observed from at least one locality, the Hollenstein-Klamm, Florenthals, Tyrol, where more or less altered adularia crystals, usually coated with chlorite, are found. * N. Jahrb. f. Min., 43, 1850. + Min. Mag., xi, p. 263. + Phil. Mag., xxii, p. 188, 1843. 52 Graham—Pseudomorphs in McGill University Collection. 2. Pseudomorph after corundum from Perth, Ontario. The specimen here described is an unusually large and well developed crystal of which a photograph is reproduced (fig. 2); it is about 5 inches in length and the prism has a diameter of 2 inches. At first sight it somewhat resembles a crystal: of 2 3 black quartz with rough surfaces, the predominant forms being the hexagonal prism and bipyramid, but it is terminated at one end by a fairly flat basal plane. It is also found, on closer inspection, that the edges between the prism and pyramid are truncated by faces belonging to a steeper pyramid, although these can searcely be distinguished in the photograph; the lower end of the crystal presents a somewhat blunted appear- ance. The various angles were measured by means of the hand goniometer, and were found to be those of a corundum crystal, the forms present being :—a $1120}, 7 }2243{,¢ }0001}, and v $4483) (fig. 3). The erystal is almost entirely coated with black tourmaline, usually as a compact granular layer forming a fairly smooth surface ; but sometimes the grains are more distinct and have bright facets, by which the mineral can be identified, as well as by the strong pleochroism under the microscope. On one side of the specimen (the left hand of fig. 2), however, the crust consists of rounded grains of a soft, pale apple-green mineral, associated with some pink calcite. From the low sues gravity of the crystal (G=2°6 about) it was evident that very little, if any, of the original corundum remained unaltered in the interior, and the specimen was accordingly Graham— Pseudomorphs in McGill University Collection. 53 sawn in half at right angles to the prism; it was found that the tourmaline forms a thin outer shell (except on one face, as noted above) whose thickness is very uniform and seldom exceeds 1™™, and that no visible trace of the original corundum exists. The interior is filled with a pale green material, hav- ing a greasy feel and a hardness between 2 and 3, which is, in fact, identical with that which forms the outer surface on one side of the erystal; dispersed through this are a few patches of white to pink ealcite, and numerous minute scales of pe and of a silvery white mica (damourite); there are also one or two small patches of the granular black tourmaline. For the most part, the green material appears quite compact on the smooth surfaces obtained by cutting through the crystal, but on a broken surface it has a more definite prismatic struc- ture, with a pair of fair cleavages inclined at about 90°. The cleavage angle of these prisms could only be determined approximately by maximum illumination measurements owing to its irregularity and the dull lustre. Thin flakes are trans- lucent but exhibit no definite optical characters under the microscope. The specific gravity is about 2°6 and the streak white. The mineral fuses easily and quickly in the Bunsen flame to a white glass, and gives off water when heated in a closed tube; it is insoluble in acids. Owing to the intimate mixture with calcite, and especially to the presence of the small pennine and damourite flakes , it is difficult to select a pure sample for analysis, and the material used may possibly have contained small amounts of these minerals. A single analysis gave the following : NO go Same oe eA eee fee 43°05 RRO ee ieee ec SS 30°28 DMC 0 Geert Grn ts aa See 3°30 iO eee i es See 0°49 Oe eres ee re 1°85 Ore er oe BAe Ss BLO HOOF S Aes ace se - 868 NOs ee eas 0°92 Pombo peo. ee ee 10°70 100°97 The above analysis serves at least to show the approximate composition of the pale green material which constitutes the main portion of the interior of the crystal, so far as can be judged from the surface exposed by sawing through the speci- men. This appears to be a mineral of indefinite composition belonging to the pinite group. In view of its (probable) rectangular cleavages, it may be noted that this mineral 54. Graham—Pseudomorphs in McGill University Collection. approaches in chemical composition to wilsonite and other pseudomorphs after scapolite, which it further resembles in having a low fusibility and a density of about 2°6; indicating that the pinite may here also be an alteration product of scapo- lite. ‘The presence of calcite dispersed in patches throughout the mass would be well in accord with such a replacement. It would seem, then, that the original crystal of corundum was first coated with a thin layer of granular black tourmaline ; that the corundum kernel subsequently underwent a pseudo- morphous change to some mineral having cleavages at 90° or nearly 90,° such as seapolite, and that this in turn became altered to pinite. I have not, however, been able to find any description of, or reference to, pseudomorphs of scapolite after corundum. The exact locality of the specimen is not known, but it comes from the apatite region of Perth, Ontario, and it is interesting that a cavity in one of the prism faces contains a little transparent apatite of a pale greenish yellow color. The pseudomorph is especially remarkable on account of the size, and the sharp outline and regularity of the crystal, in which respects it differs much from the majority of corundum crystals from Canadian localities, these being usually much smaller and not so well developed. Chemistry Building, McGill University, Montreal. Howard and Davison—Estacado Aérolite. 55 Art. 1X.—The Estacado Aérolite ; Description by Kennetu S. Howarp; Analysis by Joun M. Davison. I Tue aérolite from Texas recently obtained by Ward’s Nat- ural Science Establishment, as noted in the February issue of this Journal, has been brought to Rochester, sliced, and analyzed chemically and petrographieally. What is known concerning the fall of this meteorite is told by a resident of Hale Center, Texas: “The best history I can give of the meteorite is as follows: It was found twelve miles south of Hale Center, which is located in the center of Hale County, Texas, in the spring of 1902, or rather that is when it was taken home by R. A. McWhorter, who has been the owner of it all the time. In the year of 1882 a bright meteor was seen one night by the people of a Quaker colony called Esta- cado. This place is about fifteen miles southeast of where the meteor was found. The meteor was seen to pass to the west and fall northwest from them. At that time this Quaker col- ony was the only settlement on the whole Staked Plains, and the only people outside of them were a few scattering cowmen. In the following year of 1883 a few cowboys, in rounding up the range, saw this meteor and the Estacado people felt certain that this was what they saw fall the year before, and we have all considered it so.” As the region is a stoneless one, the attention of the people of the vicinity were naturally attracted to this remarkable mass. The name of the settlement, Esta- cado, seems most appropriate for the aérolite. The weight of the meteorite before sawing was about two hundred ninety kilograms, it thus being among the largest of known aérolites. Its form was trapezoidal, as shown by the photographs. Its longest diameter was 58°5, while its other two diameters measured 45°7™ and 44°4™, It was cut in half parallel to its longest and shortest diameters. Several slabs were taken off at the same time, one of them being shown in photograph 3. The greatest vertical diameter of this slab is about 18™ back of what was apparently the “nose” of the meteorite. The exterior of the mass is rusty brown in color, probably due to terrestrial oxidation. The sawed slices of the stone show a tendency to rust rapidly. Hardly any of the coating of the meteorite approaches in appearance the black of an original crust. On some of the sides the oxidation has been considerable, a scale knocked off of one side being 3 to 4™™ thick. As shown by the photographs (figs. 1, 2), the mass has 6 Howard and Davison—FEstacado Aérolite. FIGURE 2. The Estacado Aérolite. Howard and Davison—Estacaudo Aérolite. 57 eight well-marked sides, one of which (F in photograph 3) looks like an old fracture surface. The oxidation on this side is less than elsewhere and there is no apparent variation in structure as the edge is approached, such as there is on the other sides. The sides are quite flat, some of them even slightly concave, the edges between adjoining sides being, for an aérolite, fairly angular. Side A has a smoothed appearance and may have been the “nose” of the mass in flight. The surface markings on this \ <) E Figure 3. Longitudinal slice of Aérolite. side are not deep, while on sides D and E, which are opposite A, there are well defined pittings. The stone is a crystalline chondrite, its structure being very similar to the Pipe Creek aérolite, which is also from Texas. In Brezina’s classification Pipe Creek is placed in group Cka. The slab shown in the photograph is 53:4 in length and 406 in height. The polished surface shows a dull black ground mass thickly permeated with irregular particles of nickel iron. Joundish enstatite chondrules of a more shiny black are scattered through the stone. Here and there are green olivine chondrules, some of which are larger than any of the black chondrules. The largest of the green ones, which is in the center of the slice shown in the photograph (fig. 3), measures about 1™ in length. 58 Howard and Davison—Estacado Aérolite. The slice also shows some other interesting markings. Some five centimeters from the center toward the smaller end a straight dark line (ab) runs across the meteorite at an inclina- tion of about 15° from the vertical. It passes Just to one side of one of the olivine chondrules shown in the photograph. Parallel to, and 15™ from, side A is an irregular and some- what broken line composed of the metallic particles. This line runs from the edge of side F nearly to the edge of side B. The line also shows on some of the other slabs, and on one of them, just before it reaches the edge of side B, it turns and runs parallel with the edge for a couple of centimeters. On the various slabs the metallic lines are at different distances ‘ FiGuRE 4. Micro-section. x 40. from side A, indicating that a seam of this material passes throngh the meteorite obliquely to the cut surface. From the edge of side F, which shows comparatively slight oxidation, three indistinct veins run into the meteorite. They are black, indefinite in outline, and somewhat branching. A petrological analysis by W. Harold Tomlinson of Ger- mantown, Pa. shows that the mineral constituents are olivine and enstatite. Some pyrrhotite was also found. Mr. Tomlin- son remarks: “ The olivine and enstatite occur both as grains and as chondri. The grains of olivine contain frequent inclu- sions of smaller grains and of iron, and occasionally have gase- Howard and Davison—Estacado Aérolite. 59 ous inclusions. The inclusions in the enstatite are generally parallel to the cleavage.” He found the specific gravity to be 3°60. The microphotograph (fig. 4) was made between cross nicol prisms, the magnification being about forty diameters. Il Chemical Analysis by John M. Davison. The specific gravity of the Estacado aérolite is 3°63. The metallic part was separated with a magnet, and the slight amount of adhering stony matter determined and deducted. The stony part was separated by hydrochloric acid into a soluble and an insoluble portion. The insoluble portion was digested with a solution of Na,CO, and the dissolved $10, added to that dissolved by HCl. This analysis gave Metallic sees tos Ae. 16°41 per cent. ae Soluble in HCl... 41:09 ae Y Insoluble in HC]. 42°50 «“ 100 Analyses of these, omitting minor constituents and calcu- lated to 100, gave Metallic. Soluble in HCl. Insoluble in HCl. etme =. 89°45 S10, Rahat oho 32°00 SiOx epee eee Bo) 1 a 9°99 Mic: ©) 2 ae = 32°02 MgO aie aim 23°45 0 0°56 HeO 22. 31:60 He@. 222. 69:54 CaQr sk. 4°38 C2Ore ee 3°44 100 100 100 The stony part appears to be mainly olivine and enstatite. The analysis of the entire mass gave the following percentages : Ss.) ee ee HG Ole I Oe S| 5 3:60 ys 55 1°60 INGE Oe oe OS eee ee 250K 2d 2 ee 0:08 KG Oe Pei) Base oe a 0°32 2 ee eae trace TiO, found but not determined C found but not determined CreOve eo ae S Re ae Bae 1°37 MnO 66 6G 66 66 ae oe eS ee 0°15 Lhe fe eee 35°82 100°95 ie aor. ais Ee ees} Bess @O.fors.22 2 2.2 68 PPK ee ero! La DTA 60 Howard and Davison—Estacado Aérolite. Of the S found 0°82 per cent came from the metallic and the portion soluble in HCl, and 0°55 per cent from the insolu- ble portion fused with Na,CO,. In this fusion the crucible was screened by a close fitting asbestos board, and a blank experiment showed that there was no contamination from the gas flame. This distribution of the S would indicate that nearly half of the troilite was embedded in the enstatite pro- tected from action of acids. From 3°9597 grams of the aérolite 0°025 om. of chromite was separated by repeated treatment with HF and other acids. With the chromite were a few minute particles of a transparent colorless mineral that had survived this usage, though evidently attacked. Search was made for ZrO,, with negative result. Penfield and Ford—Stibiotantalite. “61 Art. X.—On Stibiotantalite; by S. L. Penrierp and W. E. Forp. LHistorical.—Stibiotantalite was first described by G. A. Goyder* in 1892 and more minutely in 1898, as occurring in rounded water-worn fragments in the tin-bearing sands of Greenbushes, West Australia. No crystals were observed, but it was evident from the cleavage of the material and its action on polarized light that it possessed a crystalline structure, and it was assumed that it belonged to the orthorhombic system, though no convincing evidence was brought forth. An analy- sis, which is quoted later in this article, indicated that the min- eral is essentially a combination of oxides of antimony and tantalum, with some niobium and a very little bismuth, but no formula was suggested. The physical properties were given as follows :—Hardness, 5 to 5:5. Specific gravity, 7:37. Luster, adamantine to resinous. Color, pale reddish-yellow to green- ish-yellow. Fracture, subconchoidal to granular. Within the past few years a considerable quantity of this material has become available to collectors through the agency of several mineral dealers. , Crystals from Mesa Grande, San Diego County, California, a New Locality. The material from Mesa Grande was brought to the atten- tion-of the present writers by Mr. Ernest Schernikow of New York. It was observed by him as occurring very sparingly with the wonderful tourmaline crystals found at the locality and described by Sterrett,+ and great pains were taken to have every crystal and fragment carefully saved. In all, some twenty-five crystals have been found, representing several years savings from a vast amount of material, so it may be considered a rare mineral at the locality. Associated with it, besides the tourmaline already referred to, are large and wonderfully beautiful crystals of pink beryl of unusual habit, fine crystals of quartz, orthoclase and lepidolite, and, as a great rarity, cas- siterite. The orthoclase is generally kaolinized to a considera- ble extent. Severai crystals of stibiotantalite were observed grown on to, or over, pink tourmaline; one group has attached to it a little feldspar and lepidolite; the others are all detached crystals and some of them are doubly terminated. None of the detached crystals show fresh fractures, and they evidently were found loose in the deposit. Stibiotantalite appears to be * Proceedings Chem. Soc., 1892, 9, p. 184. Journal Chem. Soc., 1893, 1xiii, p. 1076. + This Journal (4), xvii, p. 459, 1904. 62 Penfield and Ford —Stibrotantalite. of later origin than the tourmaline and lepidolite, though undoubtedly it was one of the primary minerals of the deposit. The crystals are mostly of a rich dark-brown color, with resinous to adamantine luster. Fragments look exactly like the resinous variety of sphalerite, and a few pieces were found of light brown color, transparent, and so closely resembling the well known sphalerite from Picos de Europa, Spain, that by appearances the two can not be told apart. Stibiotantalite crystallizes in the orthorhombie system and is hemimorphic. With few exceptions, the habit of the crystals gives no sugges- tion of hemimorphic develop- ment ,which, according to the orientation adopted, is in the direction of the brachy- or a- axis. All the crystals that have been studied are poly- synthetic twins, thus causing them to imitate the symmetry of the normal group. In habit they resemble colum- bite, and, as will be shown, the two minerals are related both in chemical composition and axial ratio. In order to bring out the crystallographic relationship, however, it has been necessary to assign rather complex symbols to some of the forms of stibiotantalite, but it is believed that it is better to do so than to give simpler symbols to the forms and refer them to other axes. The axial ratio of the two minerals are as follows : Stilorocamecalie ses ae a:b6:¢ = 0°7995 : 1: 0°8448 Columibite’ 22-235. 22 5.2 Gb) Se 10. 828a ale nOreccn The forms observed on stibiotantalite are shown in stereo- graphic projection in figure 1, but, owing to polysynthetic twinning, it is impossible to state as regards some of them whether they occur both in front and behind, or intersect only one end of the brachy-axis, as demanded by hemimorphism. The symbols are as follows: a (100) 1 (209) a’ (100) n (209) m (110) or (110)? h (203), probably also h’ (203) q (130) 8 (043) ; q' (130) w (4:12°9) probably also w' (4°12°9) Penfield and Ford—Stibiotantalite. 63 The only erystals observed which exhibit a marked hem1- morphie development are represented in figures 2, 3 and 4. They are orientated according to pyroelectric deportment, the a faces to the front all developing negative electricity on cool- ing, as tested by the carmine-sulphur-lycopodium mixture suggested by Burker.* The crystal shown by figure 2 has at the top two ridges and a valley, but no reéntrant angle at the sides: The two ridges on cooling develop positive, and the valley negative electricity. This crystal is a polysynthetic twin, and may be taken as a type for illustrating the structure of other crystals. The vertical axis is the twinning axis, and the macropinacoid @ the composition face. If it is assumed as in figure 5 that a hemimorphic crystal has the prism g (130) and the dome 7 (209) inter- secting the front end of the a-axis only, a lamella in twin position, figure 6 (as indi- eated by the letters underlined), would give a riage and a valley at the top, cor- responding to figure 2, but also reéntrant angles at the sides, which do not occur on the crystal shown in figure 2. It seems therefore necessary to assume that, in addi- tion to g to the front, there is a corre- sponding g’ (130) behind and, as will be shown, also, an 7’ (209) behind, figure 7: These forms appear in twin position as shown in figure 8, and an interspersed twin lamella, as in figure 9, may then show at the sides the prism g’ corresponding in direction with g. The prism lettered g, figure 2, is therefore to be regarded as a composite face, composed partly of g and partly of g’. Atthe top of such a crystal there may be, as in figures 2 and 9, a ridge and a valley, provided that in the twin lamella there occurs in connection with g’ not 7’ sloping to the front but 7 sloping behind. As a matter of fact, only a few of the crystals * Annalen der Physik, 1900, I, p. 474. Note. Burker states that with this mixture carmine goes to positively electrified surfaces and sulphur plus lycopodium to negative, which seems contrary to reason, for sulphur should become strongly negatively electrified by agitation and go to a positively electrified surface, the same as with the method of dusting with red oxide of lead and sulphur.. As a matter of fact, sulphur does go to the positively electrified pole, but each grain, as may be seen with the microscope, is loaded with a fine dust of carmine and gives a red effect. The lycopodium, on the other hand, goes to the positive pole, and is very free from any admixture of either carmine or sulphur, hence it gives with the sulphur- carmine mixture a strong and sharp contrast of color. 2 64 Penfield and Ford—Stibiotantalite. show reentrant angles at the top, and the faces of later figures lettered » or n’ must in reality be regarded as composite, made up partly of » and partly of 7’. Figures 8 and 4 both show hemimorphic character by the development of 7’ behind, but this face is in reality com- posite, composed in part of 7 in twin position. Figure 8 shows prominent reentrant angles at the sides, compare figure 6: none of the other crystals show these so prominently, S40 » and as a rule reentrant angles are so small as to give the effect of fine striations parallel to the vertical axis, or a rounding of the obtuse edge between g and g’, as if resulting from oscilla- tory combination, figure 4. The crystal represented by figure 4 is the only one showing any prominent development of a replacement of the edges between a and g; the form, how- ever, is so striated and distorted by the development of vicinal faces that no satisfactory measurements could be obtained ; it approximates to (801) respectively (301), but the symbols are %S SQ GO op Is) RQ~ TQ questionable. The pyramid w is developed to so slight an extent and the crystals are so complicated by polysynthetic twinning that it is impossible to state whether it occurs only in front or only behind; hence it is assumed that both forms, w (4.12.9) and w’ (4.12.9), are present. With the exception of the three crystals just described, the general habit is like that of the normal group of the orthorhombic system, as illustrated by figures 10 to 13, in which the forms are represented with ideal symmetry, whereas they all show vertical striations on the pinacoid and prism faces, and some rounding of the edges between g and g’. One erystal only, figure 12, is shorter in Penfield and Kord—Stibiotantalite. 65 the vertical than the horizontal direction. The largest crystal of the types illustrated is shown in about natural size in figure 13, which measured in the direction of the a, 6 and ¢ axes, respectively, 6x 25307", while the remaining ones average 10 JA 12 about one-fourth this size. Figure 14 shows in detail one of the corners of the crystal idealized in figure 13; it is rather unusual in showing the 7 and 7’, and w and w’ faces with numerous reentrant and salient angles, while the g and g’ faces are finely striated and round into one-another. At the opposite end of the crystal the » and w faces appear without reentrant angles. AN. Jour. Sci.—Fourtn Series, Vou. XXII, No. 127.—Jury, 1906. 5 ; 66 Penfield and Ford—Stibiotantalite. The general resemblance to columbite is shown by the prominent development on both species of the macropinacoid a, parallel to which stibiotantalite has a highly perfect and columbite a distinct cleavage, while both minerals have an indistinct cleavage parallel to the brachypinacoid 6 (010). The prism g is always present on stibiotantalite, while on columbite it is seldom wanting and often prominent. The macrodome fA occurs on both minerals but is not common, while the prominent development of rather flat macredomes, n (209) on stibiotantalite, and /# (103) and Z (106), respectively (206) and (2.0.12), on ecolumbite is a feature common to both species. The pyramid w (4.12.9), although not occurring on columbite, is in the same vertical zone as two of its prominent pyramids, s (263) and w (188), respectively, (4.12.6) and (4.12. 12). If the crystals of stibiotantalite were black and of metallic luster they certainly might be mistaken for columbite, because of similarity in appearance, habit, occurrence and association. . Columbite, it should be stated, is not hemimor- phic and does not exhibit pyroelectricity. Crystals of stibiotantalite show certain peculiarities as regards the development of the forms and the character of the surfaces, as follows :— i The macropinacoids a and @’, which are generally the most prominent of all the forms, have a bright luster and are usually striated vertically, the strie bemg rather fine and seldom giving rise to much rounding or irregularity of the surface: on a few erystals they appear almost free from striations. Both (100) and (100) occur without any apparent difference, except when tested for pyroelectricity, and then it _ generally appears that the same surface develops two kinds of electricity owing to twinning and interpenetration. The prisms g (130) and g’ (180) are present on all of the crystals and are always striated vertically, due to polysynthetic twinning and in part perhaps to oscillatory combination, both causes giving rise to a rounding of the edge between g and 9’, or as is frequently the case, to a considerable distortion when one prism face predominates over the other, figure 14. In almost all of the crystals, however, portions of the prismatic faces are quite free from striations, so that good measurements may be had. Any modification of the edge between @ and g was rarely observed. On two crystals distinct replacements, indic ating the presence of a prism corresponding to m (110) or m’ (110) were noted, but the faces were too poorly developed to give good measurements 5 compare figure 15. The macrodomes n (209) and n (209) are prominent on all of the crystals as Line by the fienres..( A single tacemis generally composed of both 7 and n’ as explained on page 58. Penfield and Ford—Stibiotantalite. 67 The domes are generally free from striations and dull in com- parison with the other faces, appearing as if corroded, but on a few of the crystals they are bright and somewhat striated, not sufticiently so, however, to interfere with measurements. The domes / (203) and perhaps 4’ (208) oceur on only a few of the crystals, two of which are shown as nearly as possible in true proportions in figures 2 and 15. On both crystals the surfaces were so dull, seemingly etched, that on the goniometer they gave no reflections of the signal, but by placing bits of mi- eroscopic cover glass against the faces satisfactory measurements were ob- tained which leave no doubt as to the correctness of the symbol. Owing to the interposition of a twin lamella, the dome /, in front, shown in figure 15, extends only about one-third way across the erystal. The pyramid w (4.12.9) appears on only a few of the crystals, is never very prominent and its development is so complicated by polysynthetic twinning, that it is difficult to state whether it occurs in fropvt (4.12.9), or behind (4.12.9), or in both positions. The pyramid faces are often striated parallel to the edge 4.12.9, 4.12.9, as if in oscillatory combination, and fre- quently distinct reentrant angles occur, figures 8, 14, and 15, which indicate rather that the striations result, in part at least, from polysynthetie twin- ning. The pyramid faces generally have bright surfaces which yield good reflections even when the accompanying dome faces are dull. A basal plane ¢ and brachypinacoid 6 have not been ob- served, but occasionally owing to oscillatory combinations of gag, oras aresult of polysynthetic twinning, a striated sur- face results, approximating in position to 0. The surfaces as a whole are not the best for reflecting light, and striations gave rise to further difficulties, but it is believed that the measurements and axial ratios derived therefrom must be very nearly correct. : The crystal shown in figure 16, considerable portions of which are missing, is unique. It measures about 5 in length, 4 in height and 3 in thickness, respectively in the directions of the a, ¢ and b axes, and weighs 150 grams (over 5 ounces), or 68 Penfield and Ford—Stibrotantalite. six times as much as the next largest crystal, which is of the type shown by figure 13. It was found at a considerably later period than the other crystals, and at a different part of the deposit. It was picked vp im two pieces, and the fracture sur- faces do not appear fresh, as if recently broken in taking the crystal from the matrix. Originally it must have been quite symmetrical in development and in shape about as shown in figure 17, which, as is also the case with figure 16, is drawn with the @ faces to the right and left, instead of front and back. in order to show the form to best advantage. It was attached at the lower left-hand corner to pink tourmaline, bits of which are still adhering to it. The upper and lower edges, and a considerable portion of the lower, right-hand corner have been broken away. The a, a’ faces to the right and left are fresh-looking cleavage surfaces; and whether the pina- coids @ and a’ were originally present, as shown in figure 17, or whether adjacent ¢ faces came together at the acute edges, cannot be told. The habit of this crystal is entirely different from that of the others, and the peculiarities of its surface are also different. The brachydome 6 (048) has been observed only on this erys- tal. The prism g is not striated vertically. The surfaces are all etched, so that only measurements with a contact goni- ometer may be had, but these all agree with those obtained from other crystals. The best-formed etchings on the prism g are rather deep depressions, shaped about as shown in figure 16, though the majority are much more rounded: in places they join one-another, giving rise to furrows running irregularly over the surface. “The “etchings on the brachydome 6 are long depressions, some of them quite deep, while those on the pyra- mid w are also long, but somewhat comma-shaped, the tails pointing away from the edge w ~ 6. The erystal is light yel- lowish-brown in color, more transparent than any of the others, and has a specific gravity of 6°69. The crystal is a. polysynthetic twin, though the outward form gives no evidence of it. The two large fragments which: make up the specimen do not of themselves exhibit pyroelec- tricity, probably because of numerous cracks running through the material, but a small homogeneous fragment, when tested, exhibited alternating bands of positively and negatively excited material, remarkably uniform and not over 2™™ in width. hae oughout a portion of its interior the crystal is curiously cavernous, although the exterior is firm and consists of remark- ably pure, transparent material. The cavity looks as though it had been eaten out by some solvent, and is lined with some secondary material which without endangering the specimen could not be gotten out in sufficient quantity for a satisfactory 69 Penfield and Ford—Stibiotantalite. Nae yyy MLE OA Pc anol WES SN CMM Saree SO ox 0 OOOO RRR KR RRS races QO S505 eats <5 oS XS sees ‘ , 15068. G 2 natene races SS route KR sae x ne xX 50% 3 = ROK 3 s sees J 3 ees se nos os £8 a te is erogeeecoconeees se eateatesetatet iy vee. <| ox oe G sz “ey ee eX cos “ ves SS oes eet Ses shee eS sates KR LILEKS LEI 500) Y SPOONS OOOOQOOOSK es RK RKR) RRS CRS Soy KS od $ <4 wocecers, Seogogd (Kx Cry LLZZZLI LIT PREECE RODS ce ves eee xy gS 50508 SS 25 <5 vee x << ere SS > 4 PD) “ <1 WAGY: Ba ese ea a iy Poeoes) P52525050504 seat 45 Regesa Persons Kes, oe) oH Persea) bakeoxonct q 4\LM' bs Via Z] Ges normal iodine solution. — Ber ichte, xxxix, 1306. HH. L. W. 5. Avogadro and Dalton ; the Standing in Chemistry of their Hypotheses ; by ANDREW N. MELDRUM; 8vo, pp. 118. Edin- burgh, 1906 (James Thin).—This is a very interesting essay deal- ing chiefly with the relative importance of the atomic and molecu- os) 0 _ Serentific Intelligence. lar chemical theories. The argument is in favor of the greater value of Avogadro’s contribution to science, while the admirers and followers of Dalton are criticized for giving him undue credit. All who are interested in the history of chemistry will find the book instructive, even though they fail to agree entirely with its conclusions; for it is ably written and displays much knowledge of the literature of the subject. H. L. W. 6. Electric Discharge in Gases.—Faraday supposed that an electric discharge occurs as soon as a determined discharge poten- tial is reached which is sufficient to break down the dielectric. This theory takes no account of polar differences. QO. Lehman has sought to reconcile Faraday’s theory with the facts by the assumption of a dark convective streaming which occurs before the discharge; and which on account of the dif- ferent discharge, fitness of positive and negative air, leads to the formation of a positive air envelope at the cathode. J. J. Thom- son, in an electrolytic theory, supposes that before the occurrence of the discharge a convective dark current is formed. H. Srevexine, following the example of O. Lehman, has employed vessels of large size in studying the question of the existence of such dark currents. Lehman showed that the cathode space is much influenced by the nearness of the walls of the exhausted vessel to the cathode; he accordingly used ex- hausted vessels of 60 liters capacity. Sieveking sums up his conclusions as follows : (1) An investigation with a vessel enclosing an electroscope suitably charged showed that a dark current did not exist before the discharge. This is against the electrolytic hypothesis. Furthermore the insulation of the exhausted space below the point of discharge was perfect. A dissipation of electricity which must accompany a dark current could not be shown by an electrometer. (2) In wide exhausted vessels the dark space is not influenced by a strong ionizing substance. ‘This fact militates against the supposition of the electrolytic theory that this region 1s a poverty stricken one. (3) The experiments indicate that the double layer which O. Lehman supposed to exist before the occurrence of the discharge does not exist. (4) The very weak current which J. Elster and H. Geitel have shown to exist in air, and upon which Kaufmann founded the characteristics of the dark current, are not present in a space pro- tected from ionization. The entire investigation leads one to believe in a pure disruptive discharge. (5) The remarkable effect of the magnetic field on the electric discharge leads one to conclude with O. Lehman, from the stand- point of the electron theory, that powerful inner movements occur in the molecules which, through rotary movements, greatly influence the effect of the electric field.— Ann. der Physik, No. 17, pp. 209-226, 1906. a, IS Chemistry and Physics. St 7. Note on the computed drop of pressure in adiabatic expan- sion ; by C. Barus.—I have hitherto expressed my results for the distribution of colloidal and other nuclei in a gas in terms of the observed fall of pressure 69 in the fog chamber... If under iso- thermal conditions p is the pressure of the fog chamber, p’ the pressure of the vacnum chamber and p, the common pressure after exhaustion of the former, éy=p—p,. Recently I computed the actual fall Ap=p-yp,, where p, 1s the true isothermal pressure in the fog chamber isolated from the vacuum chamber immediately after exhaustion. The results are d9—Ap=°225 6p, nearly. Naturally I expected some appreciable correction in the final reduction, but I did not anticipate so Jarge a difference. The result, however, is very interesting, for on applying it I find that the distribution curves obtained in the use of very large fog chambers now practically coincides with the curve which I deduced from the data obtained by Wilson with his small and unigue apparatus. It appears furthermore that the successive improvements which I have added to my fog chamber have for some time reached a limit, and that its true efficiency is greatly in excess of my estimate. 8. Meteorologische Optik ; von J. M. Pernter. Mit zahl- reichen Textfiguren. IIL Abschnitt: Seite 213-558. Wien und Liepzig, 1906 (Wilhelm Braumiiller).—The opening section of this important work was noticed in this Journal several years since (see vol. xil, p. 472), and now the third part is issued. It discusses a very interesting series of phenomena, namely, those due to the presence of minute foreign particles in the upper atmosphere. Many different forms of halos and of coronas are described and figured as well as discussed from a theoretical standpoint ; in relation to these phenomena the varied forms of snow and ice crystals are described in detail. The subject of rainbows is very fully treated and illustrated. Altogether the work is a very important contribution to our knowledge of a peculiarly interesting but difficult subject. 9. Leitfaden der Wetterkunde gemeinverstdndlich bearbeitet ; von Dr. R. Bérnsrery. Zweite umgearbeitete und vermehrte Auflage. Pp. 230, with 22 tables. Braunschweig, 1906 (Fried- rich Viewes & Sohn). —After an interval of five years, the author has brought out a second edition of his elementary work on Meteorology. This is an indication of the success that the book has had in meeting the needs of those for whom it was expressly designed. The author states, as the fundamental prin- ciple present in his mind, that any person may, if properly instructed, become his own weather prophet, and with this before him he has endeavored to treat the whole subject in such a man- ner as to make it as intelligible as possible. This he has accom- plished with marked success, but it still remains true that the subject is one not without difficulty, and requiring much study _for even superficial mastery. Some of the new points introduced into this edition concern the relation of the temperature of the Am. Jour. Sc1.—FourtTH Series, Vou. XXII, No. 127.—Jutry, 1906. 6 (os) 2 Sctentific Intelligence. air to water and forest, the heat movement in the ground, and observations above the earth by means of balloons and other methods; the discussion of the phenomena of atmospheric elec- tricity has been rewritten. 10. Refraktionstafeln ; von Dr. L. pE Bax, Direktor der v. Kuffnerschen Sternwarte. Pp. xiv, with 11 tables. Leipzig, 1906 (Wilhelm Engelmann).—The tables here included are based upon Radaw’s theory of refraction; the refraction constant assumed is that of Bauschinger, namely, 60"°15 for normal con- ditions of pressure in temperature and at sea-level at a latitude of 45°. There are eleven series of tables, and the special mathe- matical sources upon which they are based are explained in the Introduction, which is printed both in German and French. 11. Shaft Governors ; by W. Trinks and C. Housum. Pp. 11, 97, with 27 figures and 16 tables. Van Nostrand Science Series, No. 122. New York, 1905 (D. Van Nostrand Co.).—This recent addition to the Van Nostrand Science Series wiil be prop- erly valued by those who have to do with the use of shaft governors in practical machinery. Il. Grotogy anp MINERALOGY. 1. Preliminary Report of the State Harthquake Investigation Commission; 17 pp. Berkeley, May 31.—The Governor of Cali- fornia, on April 21, 1906, appointed a commission to examine and report on the phenomena connected with the earthquake which occurred three days previously at San Francisco. The members of the Commission are as follows: A. C. Lawson, of the Univer- | sity of California; G. K. Gilbert, of the U. 8. Geological Survey; H. Fielding Reid, of Johns Hopkins University ; J. C. Branner, of Stanford University; A. O. Leuschner and George Davidson, of the University of California; Charles Burkhalter, of the Chabot Observatory, and William Wallace Campbell, Director of the Lick Observatory. In the preliminary report it is stated that the plane of disloca- tion was along the well-known fault-line which extends in a remarkably straight line obliquely across the Coast Range from Point Arena to Mount Pinos in Ventura County, a distance of 375 miles. This physiographic line “affords every evidence of having been in past time a rift, or line of dislocation, of the earth’s crust and of recurrent. differential movement along the plane of rupture. The movements which have taken place along this line extend far back into the Quaternary period, as indi- cated by the major, well-degraded fault scarps and their asso- ciated valleys; but they have also occurred in quite recent times, as is indicated by the minor and still undegraded scarps. Prob- ably every movement on this line produced an earthquake, the severity of which was proportionate to the amount of movement.” “The earthquake of the 18th of April, 1906, was due to one of these movements. The extent of the rift upon which the move- Geology and Mineraiogy. 83 ment of that date took place is at the time of writing not fully known. It is, however, known from direct field observations that it extends certainly from the mouth of Alder Creek near Point Arena to the vicinity of San Juan in San Benito County, a distance of about 185 miles. The destruction at Petrolia and Ferndale in Humboldt County indicates that the movement on the rift extended at least as far as Cape Mendocino, though whether the rift lies inland or offshore remains as yet a matter of inquiry. Adding the inferred extension of the movement to its observed extent gives us a total length of about three hundred miles. The general trend of this line is about N. 35° W., but in Sonoma and Mendocino counties it appears to have a shght con- cavity to the northeast, and if this curvature be maintained in its path beneath the waters of the Pacific it would pass very close to and possibly inside of Capes Gordo and Mendocino. Along the 185 miles of this rift where movement has actually been observed the displacement has been chiefly horizontal on a nearly vertical plane, and the country to the southwest of the rift has moved northwesterly relatively to the country on the northeast of the rift. By this it is not intended to imply that the northeast side was passive and the southwest side active in the movement. Most probably the two sides moved in opposite directions. The evidence of the rupture and of the differential movement along the line of rift is very clear and unequivocal. ‘The surface soil presents a continuous furrow generally several feet wide with transverse cracks which show very plainly the effort of torsion within the zone of the movement. All fences, roads, stream courses, pipe lines, dams, conduits, and property lines which cross the rift are dislocated. The amount of dislocation varies. In several instances observed it does not exceed six feet. A more common measurement is eight to ten feet. In some cases as much as fifteen or sixteen feet of horizontal displacement has been observed, while in one case a roadway was found to have been differentially moved twenty feet. Probably the mean value for the amount of horizontal displacement along the rift line is about ten feet and the variations from this are due to local causes such as drag of the mantle of soil upon the rocks, or the excessive movement of soft incoherent deposits. Besides this general hort. zontal displacement of about ten feet, there is observable ir Sonoma and Mendocino counties a differential vertical movement not exceeding four feet, so far as at present known, whereby the southwest side of the rift was raised relatively to the northeast side, so as to present a low scarp facing the northeast. This vertical movement diminishes to the southeast along the rift line and in San Mateo County is scarcely if at all observable. Still farther south there are suggestions that this movement may have been in the reverse direction, but this needs further field study. “‘ As a consequence of the movement it is probable that the lati- tudes and longitudes of all points in the Coast Ranges have been permanently changed a few feet, and that the stations occupied EE pn me PS ean Se RRS (o ) 4 Scientific Intelligence. by the Coast and Geodetic Survey in their triangulation work have been changed in position. “The great length of the rift upon which movement has occurred makes this earthquake unique. Such length implies great depth of rupture, and the study of the question of depth will, it is believed, contribute much to current geophysical conceptions. ‘“The time of the beginning of the earthquake as recorded in the Observatory at Berkeley was 5 h. 12’ 6” a. m., Pacific stand- ard time. The end of the shock was 5 h. 13’ 11” a. m., the dura- tion being 1’5”. Within an hour of the main shock twelve minor shocks were observed by Mr. 8. Albrecht of the Observa- tory and their time accurately noted. Before 6 h. 52’ Pp. m. of the same day thirty-one shocks were noted in addition to the main disturbance. These minor shocks continued for many days after April 18, and in this respect the earthquake accords in behavior with other notable earthquakes in the past. The minor shocks which succeed the main one are interpreted generally as due to subordinate adjustments of the earth’s crust in the ten- dency to reach equilibrium after the chief movement.”’ The destructive effects of the earthquake are in the main dis- tributed with reference to the line of rift, and are evident over an area approximately 50 by 400 miles. Within this area the intensity of the shocks varied greatly in accordance with topo- graphic position and the character of the underlying rocks. The facts indicate an “excessively destructive effect of the earth wave as transmitted by the little coherent formations of the valleys bottoms.” A discussion of the geological problems presented by the earthquake is left for a more exhaustive report. 2. United States Geological Survey, CuarLtes D. Watcort, Director.—The titles of publications recently received are given in the following list (see vol. xxi, 251, March, 1896): notices of some of these follow later. Third Annual Report of the Reclamation Service. 1903-4, (Second Edition.) F. H. Newexnz, Chief Engineer. Pp. 653, with 59 plates in separate cover.—The Act of Congress, looking forward to the reclamation of the arid lands in the Western States and Territories, was passed in June, 1902. Since then three reports of the Reclamation Service connected with the Sar- vey have been published; the last of which, in revised form, has recently been given to the public. It gives a summary of the various extensive operations planned, and shows that when they are brought to completion the results will be of the highest importance, not only for the regions involved, but for the country at large. Torocrapuic ATLtas.—Twenty-seven sheets. Fonios: No. 130. Rico Folio: Colorado. Description of the rico Quadrangle; by Wuitman Cross and F. L. Ransome: Geography and General Geology of the Quadrangle by Wurtr- MAN Cross. Pp. 20, with 5 colored maps and 6 figures. Geology and Mineralogy. 85 No. 131. Needle Mountains Folio: Colorado. Description of Needle Mountains Quadrangle by Wuitrman Cross, ERNEsT Howsz, J. D. Irvine, and W. H. Emmons. Topography and General Geology by Wuirman Cross and Ernest Hower. Pp. 13, with 4 colored maps and 1] figures. No. 132. Muscogee Folio: Indian Territory. Description of the Muscogee Quadrangle ; by JoserpH A. Tarr. Pp. 7, with 3 colored maps. No. 133. Ebensburg Folio: Pennsylvania. Description of the Ebensburg Quadrangle ; by Cuarutes Burts. Pp. 9, with 4 colored maps. No. 135. Nepesta Folio. Colorado. Description of the Nepesta Quadrangle ; by Cassius A. Fisner. Pp. 5, with 3 colored maps. No. 136. St. Mary’s Folio: Maryland—Virginia. Descrip- tion of the St. Mary’s Quadrangle; prepared, under the super- vision of Witiiam Buttock CrarK, geologist-in-charge, by Grorce BurBank Suatruck. Pp. 7, with 2 colored maps. No. 137. Dover Folio: Delaware—Maryland—New Jersey. Description of the Dover Quadrangle ; prepared under the super- vision of Wittiam Buttock CiarK, geologist-in-charge, by Bensgsamin LeRoy Mitzter. Pp. 10, with 2 colored maps. Monoerarus.—Atlas to accompany Monograph XXXII on the Geology of the Yellowstone National Park; by ArNnoxp Hacuer, Washington, 1904. This atlas, recently published, contains twenty-three beautifully executed maps, giving in detail the topography and geology of the Yellowstone region. The text, which this atlas illustrates, was issued several years since and then noticed in this Journal. (See vol. ix, p. 297.) PROFESSIONAL Paprrs.—No. 44. Underground Water Re- sources of Long Island, New York; by A. C. Vzeatcn, C. 8. SticHteR, Isatan Bowman, W. O. Crosspy and R. HK. Horton. Pp. 394, with 34 plates including several maps in pocket and 7 figures. ; "No. 45. The Geography and Geology of Alaska: A summary of Existing Knowledge; by Atrrep H. Brooks ; with a Section on Climate, by CLEVELAND ABBE, JR.; and a Topographic Map and Description Thereof, by R. U. Goopr. Pp. 327, with 34 plates and 6 figures. No. 47. The Tertiary and Quaternary Pectens of California ; by Ratpa ARNOLD. Pp. 264, with 53 plates and 2 figures. No. 48. Report on the Operations of the Coal-Testing Plants of the U. 8. Geological Survey at the Louisiana Purchase Expo- sition, St. Louis, Mo., 1904. Epwarp W. ParKer, JosEPH A. Hormes, Marius R. Campsetrt, Committee in charge. Pp. 1492, with 13 plates and 135 figures. Part I, Field Work, Classification of Coals, Chemical work. Pp. 1-300. Part II, Boiler Tests. Pp. 301-980. Part III, Producer Gas, Coking, Briquetting, and Washing Tests. Pp. 981-1492. 86 Seventipie Intelligence. No. 49. Geology and Mineral Resources of Part of the Cum- berland Gap Coal Field, Kentucky; by Grorer Hatt Asuiny and Lronipas CHALMERS GLENN, in cdoperation with the State Geological Department of Kentucky, C. J. Norwoop, Curator. Pp. 239, with 40 plates, 13 figures and two pocket maps. Butietins.—No. 269. Corundum, its Occurrence and Dis- tribution in the United States; by Josepa Hypr Prarr. Pp. 176, . with J8 plates and 26 figures. ‘This is a revised and enlarged edition of Bulletin No. 180. No. 274. A Dictionary of Altitudes in the United States. Fourth edition ; compiled by HENRy Gannert. Pp. 1072. No. 280. The Rampart Gold Placer Region, Alaska; by L. M. Prinpte and Frank L. Hess. Pp. 54, with 7 plates and 1 figure. Ne 281. Results of Spirit Leveling in the State of New York for the years 1896 to 1905 inclusive; by 8. 8S. Gannerr and D. H. Batpwin. Pp. 112. No. 282. Oil Fields of the Texas-Louisiana Gulf Coastal Plain; by N. M. Fenneman. Pp. 146, with 11 plates and 15 figures. No. 288. Results of Spirit Leveling in Pennsylvania for the years 1899 to 1905 inclusive; by 8S. S. Gannurr and D. H. BaLpwin. Fp. 62. | WaATER-SuPPLY AND IRRIGATION Papers.—No. 148. Geol- ogy and Water Resources of Oklahoma; by Cuartes Newron Govutp. Pp. 178, with 22 plates and 32 figures. No. 153. The Underflow in Arkansas Valley in Western Kansas; by CuaRLes 8. SLICHTER. Pp. 90, with 3 plates and 24 figures. No. 154. The Geology and Water Resources of the Hastern Portion of the Panhandle of Texas; by Cuartus N. Gounp. Pp. 64, with 15 plates and 4 figures. No. 157. Underground Water in the Valleys of Utah Lake and Jordan River, Utah; by B. Ricuarpson. Pp. 76, with 9 plates and 5 figures. Nos. 134, 165, 166, 167, 168, 169, 171. Report of Progress of Stream Measurements for the Calendar year 1905. Prepared under the direction of F. H. Newery. Parts I-V, VII, XI. 3. Pleistocene Geology of Mooers Quadrangle ; by J. B. Woopworrs. Bulletin 83 New York State Museum, pp. 60, with Bibliography and Index. One geologic map and 25 plates. Ancient Water Levels of the Champlain and Hudson Val- leys ; by J. B. Woopworru. Bulletin 84, N. Y. State Museum, pp. 265, with Bibliography and Index. One geologic map and 28 plates. Published by the New York State Education Depart- ment, Albany, New York, 1905.—An examination of the pub- lished maps depicting late Pleistocene events will show that one of the latest phases, that of ice withdrawal from the Champlain and lower St. Lawrence valleys, has been least perfectly under- stood. ‘The question of marine invasion subsequent to such with- Geology and Mineralogy. 87 drawal and its relation to the glacial attitude of the land and’ postglacial changes of level have been inferred from rather too widely scattered data; and the conclusions thus reached were perforce somewhat contradictory. The situation required ex- tended and detailed investigation of the field from Manhattan to the St. Lawrence. | The distinguishing features of Prof. Woodworth’s reports on this area are their clear and dispassionate discussion of the hypothesis of glacial retreat in a narrow valley and of the forma- tion of associated marginal deposits (pp. 79-86, No. 84); and the interpretation of complex deposits over an extended field. In these respects the reports are justly comparable to Leverett’s Monographs on the glacial history of the Great Lakes region. To the student of glacial geology the method of work is quite as interesting as the conclusions. It is found that the form of the Hudson Valley influenced the retreat of the ice so strongly that it is possible to outline the history of glacial retreat in terms of the varying cross-section of the valley, taking into account the order and arrangement of the deposits made either by ice or tributary streams. In the Champlain region the evidence col- lected is chiefly from the New York side of the lake and consists of moraines, dry gorges and falls, spillways, beaches, bars, wave- cut cliffs and benches, and marine shells. While the conclusions are based on a limited amount of field work and cannot therefore be regarded as final on account of the great extent of the field and the complexity of the details, they nevertheless have a high value because of the discriminating choice of sites critically examined for decisive evidence. I. B. 4. Geology and Water Resources of Oklahoma ; by CHARLES Newton Goutp. Water-Supply and Irrigation Paper No. 148. Pp. 178, with 32 plates and 32 figures. U.S. Geol. Survey. Washington, 1905.—This report is as much of a geologic nature as hydrographic and as such should be called to the attention of geologists. The Wichita mountains in the southern part of the territory consist of Archean and Lower Paleozoic formations and are completely surrounded by Permian strata. The lower of these “Red Beds” are believed to correspond chronologically with Carboniferous limestones in Kansas. Many sections are given showing the gypsum beds, and Prof. Gould believes the Permian here to be wholly marine. The Tertiary deposits of the High Plains and their relation to water supply are also discussed. Je Bs 5. Bulletins of the Geological Survey of Virginia ; THomas L. Watson, Geologist in charge. No. II. The Clay Deposits of the Virginia Coastal Plain, by Hzrnricu Rres ; with a chap- ter on The Geology of the Virginia Coastal Plain by WiL1L1AM Boxtiock. CiarKk and Bensamin Le Roy Mitier. Pp. 184, with 15 plates. Board of Agriculture and Immigration, 1906.—This is a thorough account of the clay occurrences and industry of Virginia, rendered more interesting from the introduction on the general geology of the Coastal Plain. D (os) Scientifie Intelligence. No. III. Hydrography of Virginia; by N. C. Grover and R. H. Botster. Pp. 234, with 10 plates and 1 text-figure. This Bulletin discusses the drainage basins of the prominent rivers of Virginia,—namely, the Potomac, the James, the Roanoke, and New River. A drainage map of the state showing gaging and rainfall stations is given, and a large amount of data are pre- sented for the individual rivers. 6. La Sierra de Cordoba: Constitucion Keategien y Productos minerales de aplicacion; by W. BopENBENDER. Rep. Argen- tina An. d. Ministerio d. Agric. Sec. Geol., Tom. I, Num. II, 1905. 8°, 150 pp.—The Sierra de Cordoba lies between 21° and 23° §. and 634° and 65° W. in Argentina with a general north and south direction and is composed of several ranges, some of whose peaks have altitudes from 6-8000 feet. The memoir is devoted first to a general geological description of the area, aided by a geological map. Then follows a list of occurrences of minerals, of which a large number of species are mentioned. The rocks are then treated and brief petrographic descriptions of the different kinds are given, both of the crystalline schists and igneous rocks. The sedimentary rocks are conglomerates, sand- stones, etc., of Cambrian and supposedly Silurian age and of the Permian-Triassic, with argillaceous beds of the Pampas terrane. The work concludes with a brief account of the economic min- eral deposits. It is illustrated by a considerable number of half- tone cuts of photographs illustrating various features of interest in the mountain region. The work is more or less general and preliminary in character; yet contains in compact form a great deal that is of interest and importance concerning a little known region. Le Ve Be 7. Contributions from the Geological Department of Colum- bia University. Vol. xii, Nos. 107, 108. Vol. xiii, Nos. 109-114. —These include numerous geological papers, published by gen- tlemen connected with Columbia University in various journals and society transactions, and now collated, in convenient form for binding, in sequence witb similar volumes previously dis- tributed. 8. The Constitution of the NSilicates.—in a paper on the Chemical Constitution of the Feldspars, presented to the Vienna Academy in 1903, Professor TscHERMAK undertook to throw light on the chemical composition of the feldspars, especially with reference to the particular type of silicic acid present. From the slow decomposition of the mineral by hydrochloric acid a hydrated silicic acid is separated which, when exposed to the air, rapidly loses water for a number of days, but finally passes into a condition where the further loss is very slow, except upon ignition. By determining the amount of water present at the point named, the author believes that he establishes the constitu- tion of the silicic acid present. For anorthite, for example, the loss of water by ignition was found to be 23°41, while the acid H,SiO, requires 22°98. The conclusion is reached, therefore, Geology and Mineralogy. 89 that anorthite is to be regarded, not as an orthosilicate, but as a metasilicate. Later papers on the same general subject (Sitz- ungsberichte Akad. Wien exiv(i), 455, 1905, exv(i) Feb., 1906), discuss the matter in more detail. The conclusion is reached that while willemite and monticellite are to be regarded as ortho- silicates, olivine is a metasilicate, and the acid present in garnet, epidote, zoisite and prehnite is H,Si,O,; the formula of olivine would be written (MgOMeg)Si0,,. 9. An Introduction to Chemical Crystallography ; by P. Groru, Authorized Translation by Huan Marsuaty. Pp. vii, 123. New York, 1906 (John Wiley & Sons).—The Chemical Crystallography of Professor Groth was noticed about a year since when the German edition was issued (see vol. xix, p. 467). We have now an authorized English translation made by Dr. Hugh Marshall of the University of Edinburgh. This will be found very useful by the English-speaking public and will extend the sphere of usefulness of this valuable work. The translation has been prepared in codperation with the author, who has super- vised the proof-sheets. It follows the original closely and adds occasional references to original papers or abstracts which have appeared in the Journal of the Chemical Society. 10. Geometrische Kristallographie ; by Ernst SOMMERFELDT. Pp. 139, with 31 Tafeln and 69 text-figures. Leipzig, 1906 (Wilhelm Engelmann).—Those interested in the problems of modern crystallography, handled particularly from the theoreti- cal side, will find much of value in the present work. A series of thirty-one ingeniously constructed plates at the close of the volume present, in a novel way, the symmetry conditions and the relations of the existing forms to each other. 11. Etude sur P Etat actuel des Mines du Transvaal: Les Gites—Leur Valeur, Etude industrielle et financiere ; by GEORGE Moreau. Pp. 218, with 48 figures. Paris, 1906 (Librairie Polytechnique, Ch. Béranger, Editeur). -—This is a useful work to these interested in the mines of South Africa, giving a descrip- tion of the country and its geology with par ticular reference to the Witwatersrand; a full discussion of methods of exploitation adopted is added. The author speaks enthusiastically of the min- eral resources of the Transvaal and its possibilities, although he recognizes some of the limitations to its development which unavoidably exist. 12. Anleitung zum Gebrauch des Polarisationsmikr oskops ; von Dr. Ernst WeinscHEenK. Pp. vi, 147, with 135 figures. Zweite, umgearbeitite und vermehrte "Anflage. Freiburg im Breisgau, 1906. (Herdersche Verlagshandlung. Zweignieder- lassungen in Wien, Strassburg, Miinchen, und St. Louis, Mo.)— An excellent presentation of the polarization microscope in its different parts, with the various methods of investigation applica- ble to it and the principles involved in their use. It is well illustrated and gives, in small compass, just the information needed by students of the subject. It should be in the hands of every one concerned with this field of investigation. 90 Scientific Intelligence. 13. Tabellen zur mikroskopischen Bestimmung der Mineralien nach ihrem Brechungsindex,; von Dr. J. L. C. ScHROEDER VAN pER Kork.. Zweite umgearbeitete und vermehrte Auflage; von EK. H. M. Berkman. Pp. vi, 68 with folded plate. Wiesbaden, 1906 (C. W. Kreidel).—The first edition of these useful tables was issued in 1900 and noticed in volume ix, p. 229, of this Journal. The tables have been rearranged and increased in size by Dr. Beekman, and in their new form will unquestionably prove still more valuable to those interested in microscopic mineralogy. The preparation of this new edition was undertaken in order to carry out the plan of the author, who died on June 17, 1905; it consequently follows the lines laid down by him. 14. Minéralogie des Départements du Rhone et de la Loire; par FrRpInanD GonnarRp. Pp. 122, with 31 text-figures. 1906. Lyon (A. Rey) and Paris (J. B. Bailliére & Fils). Annales de Université de Lyon. Nouvelle Série: I. Sciences, Médecine, Fascicule 19.—This is an account of the mineral species which occur in two of the departments of France particularly rich in this direction. Among the most conspicuous species may be mentioned the azurites of Chessy, the zeolites of Mt. Simiouse, the calcite of Couzon and the cerussites of Pacaudiére. The work is a valuable supplement to the more exhaustive treatises on mineralogy. 15. Studien tber Meteoriten, Vorgenommen auf Grund des Materials der Sammlung der Universitat Berlin; von C. KLEIN. Aus den Abhandlungen des Konig]. Preuss. Akademie der Wis- senschaften vom Jahre, 1906. Pp. 141, with three plates. Ber- lin, 1906.—The meteorite collection of the University of Berlin has always been a classical one ever since the time of Gustav Rose. For many years, however, the collection did not grow adequately, and it is only since Professor Klein took hold of the matter that it has regained its relative importance among the great collections of the world. In 1887, there were 213 localities represented, and now in 1906 the number has increased to 500. This publication is much more than a mere catalogue of the spe- cimens represented, for it also gives a description of meteorites in general, with a special account of certain important examples. One of the most interesting of these has been earlier described by the same author, namely the leucituranolite of Schafstadt. Ill. MisceLLANEous SCIENTIFIC INTELLIGENCE. 1. Plaster-plaques for Museums; by GroreE Lincotn Goop- ALE (Communicated).—The fine finish of a properly made plaster mount renders it preferable to slate or ground glass or polished wood, for specimens which require a firm support and a good contrasting surface. The excellent mounts which have been made by the Dentons show clearly the adaptability of plaster for even the most delicate and brilliant organisms. The problem in our Museum was to provide a mount which should answer not {isp tiga si Miscellaneous Intelligence. on only for very fragile and delicate specimens, but would at the same time serve to keep in perfect position specimens of con- siderable weight and size. It was imperatively necessary to secure such specimens from even the slightest bending. The Blaschka glass models of plants in flower are shipped to our Museum fastened to a firm cardboard which answers every purpose as a permanent mount for the smaller species. But even when re-enforced by strips of wood, the larger plates of card- board have a tendency to curve, sometimes in more than two directions, and this curvature seemed likely to put the larger models in some peril of breaking. Acting on a suggestion of Dr. Libbey of Boston, an attempt was made, about six years ago, to substitute plaster-plates for the heavy cardboard. More than a year was consumed in fruitless experimenting. The small plates were fairly strong and for the most part, satisfactory, but the larger ones, say from two feet square and upward, were untrustworthy and therefore of no use in our cases. Fortunately, at the time when our experiments were on the eve of abandonment, there was in the service of the Museum an expert cabinet-maker who expressed a desire to undertake a con- tinuation of the work along a different line. After a few trials which varied in success, he was able to: produce plaques of high finish and great density. Tests showed that these new plaques were sufficiently strong to bear any weight to which it was likely they could ever be subjected, and moreover, they did not show the least tendency to bend. About fifty were made four years ago, and, after they had been exposed to all reasonable risks, it was found that they had not sustained any permanent injury of any sort. During the last three years, more than seven hundred plates have been “successfully made, and these are now installed in the exhibition rooms of the botanical section of the Museum. They are so strong, so free from curvature and so attractive in general appearance, that they appear to answer every require- ment as mounts. The following is the method of their manufacture: (1) The appliances.. On a stout table perfectly levelled there is placed a plate of the finest plate-glass of the required size. On our tables we have used glass of a convenient size for our work, namely four by three feet, and five by four feet. Care is taken to choose only “ first ” plate: “seconds ” are likely to have small blow-holes or slight curvatures. For each plate on the table another of equal size and of about the same thickness is placed near at hand. In order to form a dam around the sides of the glass, to pre- vent the plaster from running off, we have used strips of wood of just the thickness of the ‘desired plaque. These are ees put in place and not fastened to the glass in any way. (2) The liquid plaster is made in the following way : tis a large pail of perfectly clear soft water, enough fine plaster of 92 Scientific Intelligence. Paris is quickly sifted in, with constant stirring, until the mass becomes of the proper density. (3) The liquid mass is now poured rapidly without the forma- tion of any bubbles upon the surface of the glass on the table, filling all the space between the strips of wood. ‘Then as quickly as possible, the other plate of glass is put over the liquid, great care being taken that no bubbles creep in, and then heavy weights are put on this glass, pressing out all excess of lquid plaster. In the course of fifteen or twenty minutes, depending on conditions not yet thoroughly understood, the upper glass can be separated from the plaque, by gradual lifting at one side. In ten or fifteen minutes more, the plaque can be separated from the floor glass. At this time, a small hole is to be made in one corner, about an inch and a half from the edge; this serves for hanging the plaque on a nail in a dry room. The drying takes place slowly in winter, but in summer the whole sheet will be thoroughly dry in a few days. The plate can now be cut into any desired shape and size by a simple device. First, make a deep scratch in the plaster where the break is desired, and then break exactly as a square of glass is cut. When the break has been made, the edge is finished by means of a plane, and it can be bevelled also, if necessary. If the surface has too glossy a finish, reduce the luster by a common stiff brush carried evenly over the whole surface. We have made many attempts to improve the color of the plaques by the addition of various fine pigments, but the effect has always been unsatisfactory. The color tints with a little Prussian-blue, and the warmer tints with a very little vermillion, ° were liked by many, but as a rule, the plain undazzling white has been found best. We are now employing plaques of this sort also for our cases in which we are installing specimens of seeds, fruits, etc., which are better exhibited without any covering at all. In this way, for instance, specimens illustrating dissemination are placed before the public in a very attractive manner. The contrast between -the specimen and the pure white plaster mount is in no instance unpleasing. Cambridge, June, 1906. 2. The American Association for the Advancement of Science. —The special summer meeting of the American Association will be held in Ithaca, New York, from June 28th to July 3d. Sev- eral Societies, including the American Physical Society and the American Chemical Society, are to meet at the same time in affiliation with the Association. Professor William H. Welch, of Baltimore, is the President of the Association for the Ithaca meeting, and the Vice Presidents of the several sections are given in the following list: Section A, Mathematics and Astron- omy: Edward Kasner, Columbia University ; B, Physics: W. C. Sabine, Harvard University; C, Chemistry: Clifford Richard- son, New York City ; D, Mechanical Science and Engineering: W.R. Warner, Cleveland; E, Geology and Geography: A. C. Miscellaneous Intelligence. 93 Lane, Lansing, Mich.; F, Zoology : E. G. Conklin, University of Pennsylvania; G, Botany: D. T. MacDougall, Carnegie Institu- tion, Washington ; H, Anthropology : Hugo Miinsterberg, Har- vard University ; I, Social and Economic Science: Chas. A. Conant, New York, N. Y.; K, Physiology and Experimental Medicine : Simon Flexner, Rockefeller Institute, New York. 3. Memoirs of the National Academy of Sciences. — The fourth memoir ot Volume X has recently been issued; the subject is: Phoronis Architecta, Its Life History, Anatomy, and Breed- ing Habits, by WititrAm Keitu Brooxs and RHEINART PARKER Cowes. Pp. 75-148, with-17 plates. 4. Leitschrift fiir Gletscherkunde, fiir Hiszeitforschung und Geschichte des Klimas. Organ der Internationalen Gletscher- commission ; herausgegeben von Epuarp BrtcKner. Band I, Heft 1, pp. 80. Berlin, 1906 (Gebriider Borntraeger).—A new journal devoted to Glaciology has recently been inaugurated as the organ of the International Glacial Commission, with Dr, Eduard Briickner as editor: He will be assisted by eleven asso- ciate editors ; the American representative is Dr. H. F. Reid, of Baltimore. The journal will contain discussions of subjects relating to glaciology and the investigation of the Ice Age in all its phases, with shorter communications on the same subjects, reviews of books and papers published elsewhere, and a general bibliography. It will be international in character; while the editorial matter will be in German, the papers and communica- tions may be in any one of the four prominent languages. It will be issued at irregular intervals, not more than five parts annually, each part containing 80 pages octavo ; subscription price, sixteen marks. The first number has just been distributed and bears the date of May, 1906. This new journal fills an important gap in the series of special scientific organs, and’ will doubtless accomplish much in promoting interest in the subjects with which it deals ; it should receive liberal support. 5. Publications of the Field Ccelumbian Museum, No. 109, Geological Series, Vol. iii, No. 2. The Shelburne and South Bend Meteorites; by OLtveR Cummines Farrineron. Pp. 23, with 15 plates.—The account of the Shelburne meteorite as described by Borgstrom was given in the January number of this Journal (p. 86). Dr. Farrington now describes a second stone of the same fall weighing 124 pounds. Its fall was quite unusual, since it came down in a narrow space between a house and a shed, narrowly escaping both of them, and burying itself — 18 inches in the ground. The South Bend meteorite, also described in this pamphlet, is a pallasite weighing 53 pounds, and was found in 1893 two miles from South. Bend, in St. Joseph county, Indiana. This is the se-enth pallasite which has been discovered in the United States; it is referred to the Imilac group and the ratio of nickel-iron to chrysolite is 21°4 to 78°6. No. 110, Geol. Series, Vol. i1, No. 7. The Carapace and Plas- tron of Basilemys sinuosus, a new Fossil Tortoise from the 94 Scientific Intelligence. Laramie Beds of Montana; by Eimer 8. Riees. Pp. 249-256, with three plates. 6. Carnegie Institution of Washington.—The following are recent publications: No. 49. Heredity of Hair-length in Guinea-pigs and its Bear- ing on the Theory of Pure Gametes; by W. E. Casrie and ALEXANDER Forses. Pp. 1-14. (No.5 of Papers of the Sta- tion for Experimental Evolution at Cold Spring Harbor, N. Y.) The Origin of a Polydactylous Race of Guinea-pigs; by W. E. CastLeE. Pp. 14-29 (No. 175 of Contributions from the Zoologi- cal Laboratory of the Museum of Comparative Zoology at Har- vard College, E. L. Mark, Director). No. 51. Studies on the Germ Cells of Aphids; by N. M. ia Pp. 28, with four plates. Personal Hygiene designed for undergraduates ; by ALFRED i Virani A.M., M.D., LL.D. Pp. vu +22 Neng tons (John Wiley & Sons), 1906.—This little book, the outcome of a course of lectures given to undergraduate students at Princeton, presents in simple language sound advice regarding the develop- ment and care of the body. A few introductory chapters briefly describing the general anatomy and physiology of the organ sys- tems of the body are followed by chapters on physical culture, fatigue, elimination of waste, bathing, clothing, food, tobacco and alcohol. Careful reading of this book cannot fail to leave in the mind of the student a better appreciation of the common rules for hygienic living, and would in all probability increase his future health and happiness. 8. The Bulletin of the Imperial Central Agricultural Eaperi- ment Station, Japan, Vol. i, No.1. Pp. 94. Nishigahara, Tokio, December, 1905.—Japan has already forty-seven indepen- dent agricultural experiment stations, and this new publication will serve to make public the results of the investigations carried on in them. The first number contains eleven articles, treating largely of the action of mineral substances on vegetable growth, or on bacterial action. OBITUARY. Dr. Ernst SCHELLWIEN, Professor of Geology at Kénigsberg, died on May 14th in his fiftieth year. 65 NEW CIRCULARS 66 We are offering Special Collections of Shells to illustrate Elementary Conchology. For descriptions and prices, see circular 65. Our Special Dissections (showing the Anatomy of Typical Animals), mounted in glass jars and accompanied by descriptive diagrams, are listed on circular 66. NEW OFFERS Sponges Euplectella aspergillum, : - Sie $1.00-2.00 Hyalonema sieboldii, — - : - : - 2.00-5.00 Shells Argonauta argo, - - . - - . $ .50-4.00 Nautilus pompilius, - - - - 1.00-2.00 s = (sectioned), - - - 2.00—3.00 Spondylus pictorum, . - - 1.50-2.50 “Everything in Natural History.” WARDS NATURAL SCIENCE ESTABLISHMENT, | 76-104 College Ave., Rochester, N. Y. Warps Natura Science EstaBisHMeENT 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, etc. 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. Dn ee ("Index XI-XX, now ready. Price $1.00. CONTENDS: Art. I.—Relative Proportion of Radium and Uranium in Radio-Active Minerals; by E. RurHerrorp and B. B. Bonny oon ' oid og Eee SE 1 IJ.—Measurement of Radium in Minerals by the y-Radiation; by A Sr Ey ie ah Sob ete 4 III.— Absorption of the a- Rays from Polonium; by M. Levin’ 8 IV.—Thermal Constants of Acetylene ; by W. G: Mixrer.. 18 V.—Modification of the Lasaulx Method for Observing Inter- ference Figures under the Microscope; by F. E. Wricur 19 VI.—Datolite from Westfield, Massachusetts; by EH. H. Kraus and-C:"W, Coon i= 2 sos ee ee 21 VIL—Russian Carboniferous and Permian compared with — those of India and America; by C. ScuucuertT. (With Plated) oo. veo ee ee “ane VIII.—Note on two interesting Pseudomorphs in the McGill University Mineral Collection; by R. P. D. Granam, Bi As co poe ee ee ee ee 44 IX.—Estacado Aérolite; by K. 8. Howarp and J. M. DAVISON 22° 8 712 ee ee X.—Stibiotantalite ; by 8. L. Penrierp and W. E. Forp .. 61 SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Properties of Liquid Nitrogen, H. ErpmManwn: Oxida- tion of Ammonia to Nitrates and Nitrites, ScHMIpT and BocksrR, 78.— Detection and Determination of Small Quantities of Iron, A. MOUNEYRAT: Quantitative Determination of Acetone, A. JoLLES : Avogadro and Dalton, A. N. Metproum, 79.—Electric Discharge in Gases, H. Sirvexine, 80.— Note on the computed drop of pressure in adiabatic expansion, C. BARUS: Bornstein, 81.—Refraktionstafeln, L. bE BaLtL: Shaft Governors, 82. Geology and Mineralogy—Preliminary Report of the State Earthquake Inves- tigation Commission, 82.—United States Geological Survey, 84.—Pleisto- cene Geology of Mooers Quadrangle, etc., J. B. Woopwortn, 86.—Geology and Water Resources of Oklahoma, C. N. Govunp : Bulletins of the Geo- logical Survey of Virginia, 87.—La Sierra de Cordoba, W. BODENBENDER ; Columbia University: Constitution of the Silicates, TscHmeRMaK, 88.— Chemical Crystallography, GRoTtH and MarRsHALL: Geometrische Kristal- lographie, E. SOMMERFELDT: Mines du Transvaal, G. Morneau: Polarisa- tionsmikroskops, EK. WEINSCHENK, 89. —Tabellen zur mikroskopischen Bestimmung der Mineralien nach ihrem Br eckungsindex : Minéralogie des Départements du Rhone et de la Loire, F. Gonnarp: Studien tiber Meteori- ten, C. Kuxrn, 90. Miscellaneous Scientific Intelligence—Plaster-plaques for Museums, Ge Be GoopaLez, 90.—American Association for the Advancement of Science, 92. —Memoirs of the National Academy of Sciences, Brooks and COWLES: Zeitschrift fir Gletscherkunde, E. BrticknreR: Publications of the Field Columbian Museum, 93.—Carnegie Institution of Washington : Personal Hygiene designed for Undergraduates, A. A. WoopHULL: Bulletin of the Agricultural Experiment Station, Japan, 94. Obituary—DrR. ERNST. SCHELLWIEN, 94, Meteorologische Optik, J. M. Pernrer: Leitfaden der Wetterkunde, R. © ae al mena VOL. XXII. | AUGUST, 1906. Established by BENJAMIN SILLIMAN in 1818. THE AMERICAN JOURNAL OF SCIENCE. Epirors: EDWARD 8S. DANA. ASSOCIATE EDITORS Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or CampBrwce, Proressors: ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PutapELPun, “Proressor HENRY S. WILLIAMS, or Irwaca, Proressor JOSEPH S. AMES, or Batrtimore, Mr. J. S. DILLER, or Wasuineron. FOURTH SERIES VOL. XXII-[WHOLE NUMBER, CLXXIL.] No. 128—AUGUST, 1906. NEW HAVEN, CONNECTICUT. 1906 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. Remittances should be made either by money Brderg, registered SRS ee or bank checks (preferably on New York banks). CRYSTALS, FINE MINERAL SPECIMENS, | METEORITES. Orders amounting to $20 or over sent carriage paid on approval, with, the peynees of selection. Rejected material returned at consignee’s expense. Send for our illustrated descriptive Catalog of ‘“ Choice Min- erals” just published. SYS PEMATICS COLLECTIONS Of Typical Specimens, In sets of twenty-five up to fifteen hundred specimens. Prices $5.00 upwards per set, the average price for students’ specimens (average size 23” x 2”) being about twenty cents. For 30 years we have been supplying reference specimens to the mining schools, universities and museums throughout the world. We refer to any curator or professor of mineralogy or geology. Our Lasrls accompany every specimen, giving correctly,— name, chemical composition and locality. QuALITY is guaranteed in our prepayment of transportation to. any address in the world (on orders of $20 or more). We could not take this transportation risk, if the quality did not insure your keeping them, as we refund money on minerals promptly returned. Prices are the lowest, as comparison will show. The volume of our trade permits it. Free Coutection Caraoe, containing lists and illustrations of General Mineral Collections, Series of Ores for Prospectors, Sets of Crystals, Series illustrating Hardness and other Physical _ Characters of Minerals, with price List of Laboratory Material and Individual Specimens. . FOOTE... MINH RAL: (Ge Established 1876, by Dr. A. KE, Foote. W. M. Foote, Manager. DEALERS IN Mineral Specimens and Commercial Rare Minerals. Removed to 107 N. 19th St., Philadel pia, Pag Ute. THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.|] Arr. XI.—An Investigation into the Elastic Constants of Rocks, more especially with reference to Cubic Compres- sibility; by Frank D. Apamsand Ernest G. Coxer. Introduction.—In a paper published in 1901 an account was given of an investigation into the deformation of marble under varying conditions of heat and pressure.* Under a grant from the Carnegie Institution of Washington to F. D. Adams, the experimental investigation into the behavior of rocks under pressure has been continued in the laboratories of McGill University. As the investigation went forward, however, it was found necessary to follow out several separate lines of resear ch, the results of which it is proposed to present - In a series of separate papers. In the present article a brief résumé is presented of the methods adopted and the results obtained in an investigation into the elastic constants of rocks, more especially with a view to ascertaining the amount of cubic compression which rocks will undergo when submitted to pressure from every side, all rocks of course being subjected to such compression to a greater or less extent, previous to the deformation which they suffer under conditions of differential pressure. A full presentation of the results of the investigation will be found in a Publication of the Carnegie Institution of Wash- ington, No. 46, having the same title as the present paper, and which is now in press, to which the reader is referred for full details of all the measurements carried out in the case of each of the specimens examined, as well as for detailed descriptions, * Adams, F. D., and Nicolson, J. T. An experimental investigation into the Flow of Marble. Phil. Trans. Royal Soc. London, Series A, vol. cxcv, pp. 363-401. Am. Jour. Sci.—FourtH Srriss, Vou. XXII, No. 128.—Aveust, 1906. 7 96 Adams and Coker—Elastic Constants of Rocks. color process photographs and microphotographs of each of the rocks employed. Before the investigation was completed, Dr. Coker was called to the Professorship of Mechanical Engineering in the Finsbury Technical Institute of London, England, and was accor dingly obliged to give up the work of the research. His place was taken by Mr. Charles McKergow, Lecturer in Mechanical Engineering in McGill University, but who, immediately on the completion of the work, was appointed to the Professorship of Mechanical Engineering in the University of Virginia. A large number of the very care- ful measurements of the elastic constants which are pre- sented in the paper were made by Professor McKergow. Methods which may be used in the determination of the Elastic Consiants of Materials. The determination of the cubic compressibility of solid substances is, as above mentioned, beset with serious difficulties. On one hand every direct method which has been suggested presents experimental difficulties which tend to impair its accuracy, while on the other hand the indirect methods are based on assumptions as to the isotropy of the materials, which are not warranted in the case of certain rocks, The indirect methods, however, depending on the theory of elas- ticity, are capable of considerable variation, and it is of inter- est to examine them in some detail in order to see whether certain of them at least may not be depended upon to give reliable and satisfactory results. The determination of the elastic constants of metals has engaged the attention of many physicists and at the present time a large amount of information exists as to the values of these constants for various metals. It is well known that in homogeneous elastic substances, a simple compression stress causes a lateral strain, which bears a fixed ratio to the compression strain for any particular sub- stance within the limit of elasticity. If then* we call p, the stress on a plane perpendicular to & in the direction a, and e, the corresponding strain, then for a direct compression stress py there will be a strain in the direction of this stress of amount p,/, where #'is Young’s modulus, and lateral strain of magnitude p,/mH, where m is the ratio of the longi- tudinal compression to the lateral extension per unit of length. If we suppose further that a body is subjected to enbical stress of intensity p,, we easily see that for small and there- fore superposable strains, the cubical strain e, is nu — 2 mi *See Ewing’s Strength of Materials, Chapters I and II. Fp 22) Drs Adams and Coker—FElastic Constants of Rocks. = 97 and since the modulus of compressibility YD is the ratio of the stress per unit of area to the cubical strain produced, we have ] m Twi 6. 3. ni—2 Hence if we know and m we can calculate the value of D. Further, itis shown in treatises on elasticity that if C is the modulus of shear, then se 2 m+ and since Cand #’are quantities which can be ascertained by experiment, we can from them calculate m and D. In an important paper by Nagaoka* this latter method has been used to determine the elastic constants of a series of rocks. The value of # was determined by supporting a bar at the ends and measuring the angular change at the support due to a given load applied at the center; the value of /# is then obtained by the formula H=3wil’/4bd°@, where / is the length of the bar between the supports, 6 is the breadth of the bar, d the depth and @ the angular change at the ends for a load VW. In order to determine the value of m, a specimen of rectangu- lar section was twisted by a given torque, 7, and the amount of the strain measured. It has been shown by St. Venant that for such a case the value of C is given by the formula on / 32°5' > tan h (2n+1) 5B ] = aera 0 (22 +1)° = T where @ is the angular change, and from this formula values of C were calculated from the observations. This method appears to be open to some minor objections in that the formula for determining is based upon a theory of flexure, which although sufficient for many purposes is never- theless only approximate, and it is well known that values of £ obtained by flexure experiments in this manner often differ from the values of / obtained by direct compression experi- ments by not inconsiderable amounts. Further, in experiments upon the deflection of beams cut from rocks, it is dificult to obtain consistent readings because of the time effect of the loading, and this difficulty is noticed in the paper cited. Experiments on the determination of the elastic constants of rocks when subjected to twist were also found to be fre- * Elastic Constants of Rocks and the Velocity of Seismic Gees H. Nag- aoka.—Phil. Mag., vol. L, 1900, p. 53. 98 Adams and Coker—EHlastic Constants of Rocks. quently unsatisfactory owing to the low ultimate shearing value of many rocks. While a glance at the lst of rocks whose elastic constants have been measured by Nagaoka will at once show that most of them are rocks whose elasticity must be of a very imperfect kind, e. g., weathered clay slate, schalstein, tuff, ete.; the method which he has employed for the determination of Young’s modulus gives very low results, even in the ease of rocks such as marble and granite, where the elasticity might be supposed to be of a high order and comparable to that which these rocks are shown to possess m the case of the types selected for investigation in the present paper. This is seen in the following fioures representing the values obtained by him for each of the marbles and granites contained in his list : Paleozoic Marble: E (Young’s modulus). No. A oS Or On he paca aah ong 10,120,000 ASL Type a Nei dena Pee cares eee 7,950,000 IP DEAS Nes isi ti Oar ers Ode nai 5,440,000 dE Be geet aet eas Aap ul APN Pr 4,770,000 Granite Nios OOS Slrodeshimia)i". = see 6,140,000 68 (elise nd) PO ees eee pee 2,853,000 Gi ASR Bers Ben ee eat 2,175,000 LOM CM marten aba wae adie a 1,588,000 SD ae EST aah a 3,265,000 Of these, marble No. 11, if a mean of the two readings be taken, has about the same modulus as the average of those on our list, while No. 12 is very much lower. The “highest value given for any granite in Nagaoka’s list, viz: No. 69, is some- what higher than that of the lowest of the oranites in our series, that from Stanstead. The other granites examined by N agaoka have values for # assigned to them which are so low that they are comparable only to that of the sandstone in our series. Of the three sandstones included in Nagaoka’s list the Izumi sandstone of the Mesozoic has modulus of 1,322,000, while the other two, which belong to the Diluvium, have values for # of 587,500 and 583,000 respectively. And so when an attempt is made to calculate the cubie com- pression (7) from the values given in Nagaoka’s list and obtained by his method, it is found that a negative value is actually obtained in about one-third of the rocks which he has examined. His figures, however, were intended chiefly for the purpose of calculating the velocity of the propagation of earth- guake shocks. In consequence of a number of somewhat unsatisfactory results obtained by the writers in some preliminary experiments Adams and Coker—Elastic Constants of Rocks. 99 with this method, as well as the facts with regard to Nagaoka’s figures just mentioned, it was decided to adopt a somwhat dif: ferent method and one which avoided both torsion and flexure and depended simply on strain produced by simple compressive stress. This will be termed the ‘‘ Method of Simple Compres- sion.”” Among the possible indirect methods, this seems to be the most satisfactory, since the assumptions necessary in the calculation of compressibility are reduced to a minimum, and the range of stress for which the ratio of stress to strain is practically constant is great. It was found possible to measure the strain obtained very accurately by means of an apparatus forming part of the equip- ment of the testing laboratory of McGill University, for the | ™ Pel ge @ Ll ] N oo S NV g le) ZZ inn ON oO se : les el. ee: COESSSSSY LOT) Fie. 1. Instrument for determining the modulus of a simple strain. ULL, a use of which we are indebted to Professor H. T. Bovey. This is an instrument designed by Professor Ewing, and of which a sketch is given in figure 1. In this, A is a specimen of the rock gripped by screws passing through a pair of collars, B, which are 1-25 inch apart, to which latter metal rods, C, are attached. ‘The upper rod carries a glass plate, D, with a fine line scratched upon it, the position of which can be adjusted by a screw, /, while the lower rod carried a micrometer-micro- scope, /. The upper and lower collars, 6, are connected by a stud, G, the upper one engaging with the conical hole of the swivel piece, //, in the lower, and contact is maintained by a spring, /, while the weights of the microscope and projecting arms are balanced by lead cylinders, /. A buzzer was attached to the upper lead cylinder which when operated caused a slight vibration in the instrument, producing a perfect adjustment as the pressure was applied. The proportions of this instrument were so adjusted that one division on the micrometer scale corresponded to szgba7 of an inch, and before using it the instrument was calibrated by aid of a Whitworth measuring machine and was found to be in correct adjustment. 100 Adams and Coker --Elastic Constants of Rocks. The linear strain perpendicular to the length of the speci- men was measured by an instrument which had been designed by E. G. Coker some time previously for experiments on the lateral strains developed in metals.* This is shown in figure 2, and consists of a pair of brass tubes, B, 6’, provided with set screws, A, A’, for attachment to the specimen, and con- nected together by a flexible steel plate, 4 forming the fal- Fic. 2. Perspective view of lateral extensometer. crum. The ends of the tubes near the fulcrum plate are pressed apart by an adjustable spring, S, to insure a uniform pressure on the screw points gripping the specimen. On the opposite end of one of the tubes is aspring, J), of ebony press- ing against a double knite-edge, A, seated in a shallow V- notch cut in the end of the other arm. The knife-edge ear- ries an adjustable mirror, J/, so that if any change in the diameter of the specimen occurs the two tubes move relatively to one another in a horizontal plane, thereby causing the knife- edge mirror to rotate; the rotation of this latter is observed and measured by a telescope and scale placed at a suitable distance. For convenience in adjustment, there is a screw, Z, for tilting the apparatus about the axis of the gripping screws, and the tubes, 6, 6’, are trussed to prevent vibration. This instrument was calibrated by aid of a Whitworth measuring * See Proceedings Royal Soc. Edinburgh, Session 1904-5, vol. xxv, pt. vi. Adams and ela Waste C Constants of oelie 101 machine and the scale adjusted so that one division corre- sponded to one millionth of an inch. Application of the Method of Simple Compression to the De- termination of the Cubic Compressibility of Metals. The behavior of such metals as wrought iron and steel over a wide range of stress shows that these metals may be con- sidered as almost perfectly elastic. The results of the theory of elastic bodies may therefore be applied in their cases with great confidence. As a typical example of the behavior of such materials we may consider the deportment of a specimen of wrought iron when subjected to a cycle of compression stresses, commencing at 1,000 pounds and rising to 9,000 pounds, afterwards re- turning to the original load. The readings obtained for the longitudinal and lateral strains will show in such a case that equal increments or decrements of load produce strains which are very exactly proportional thereto. This is clearly shown in a plot of these readings, where the ordinates represent the total load and the abscisse represent strains. In both cases the relation of stress to strain is represented by a straight line returning upon itself. ‘Traces which vary but very little from the ideal straight lie are given by black Belgian marble, as will be seen on page 114. Such results afford an arbitrary standard by which can be judged the degree of approximation to perfect elasticity ex- hibited by other metals and by rocks under similar conditions. If we now calculate the value of the modulus /# for simple compression, since this is the relation of the compression stress p to the strain e, we have p= Ee. If we call A the cross-sectional area of the spccimen when stressed by a load P, and w the decrease of length over a measured length J, oripped between the screw points of the measuring appar atus, we obtain which in the case of a specimen of wrought iron examined for a range of 8,000 pounds, gave a value of 28,100,000, the units being pounds and inches. The ratio m of the longitudinal strain to the lateral strain in the same case was 3°65, and using the formula 1 "7 3 m—2 102. =Adams and Coker—Etastic Constants of Rocks. we obtain for the modulus of cubical compression (or bulk modulus} ), the value 21,300,000, a constant for the material, the reciprocal of which gives the decrease in volume of eubie inch for 1 pound of pressure. While certain rocks, such as many of the marbles, have a structure identical with that of wrought iron, most of the rocks constituting the earth’s crust are composed of several minerals, and thus rather resemble cast iron in character, the gray variety of this substance being an aggregate of er ystals or individuals of the metal iron ( ‘wrought iron), graphite, ete. It will therefore be of interest to ascertain how a specimen of cast iron behaves under compression stress, and how far its elasticity falls short of that which would be exhibited by a perfectly elastic body. STRAIN Fic. 38. Cast iron stress strain curves. For this purpose a fine-grained specimen of somewhat hard cast iron was faced and tested. The stress strain curves are plotted in figure 3. I represents longitudinal compression and IT lateral extension. The behavior of cast iron as exhibited by these experi- mental results shows a falling away from the theoretical standard of perfect elasticity, but even in the most perfectly elastic bodies there is probably a slight hysteresis effect, so that we are justified in using the results obtained to calenlate the modulus of compressibility, if the error introduced thereby is negligible or very small. It may be pointed out that this method and others of the indirect type have been freely used to obtain values of the bulk modulus for cast iron and metals of like character, and it will be shown that the composite crystalline rocks are very similar to cast iron in their behavior under stress, although generally more perfectly elastic. Adams and Ooker—Elastic Constants of Rocks. 103 Application of the Method of Simple Compression to the Determination of the Compressibility of Rocks. As has been noted, it was found in the case of marble when subjected to bending stress, that the strain as exhibited by the deflection of a point of the bar increases with the time, and the strength under shear produced by a torque was also. so small that a determination of the strain was very difficult to measure. These difficulties have been noted by Nagaoka,* who states that “ Preliminary experiments on gr anite showed that Hooke’s law does not hold even for very small flexure and torsion, and that the after effect is very considerable when the prism is sufficiently loaded or twisted ; the deviation from the direct proportionality between strain and stress was incomparably great as compared with that observed in common metals. This must be chiefly due to the low limit of elasticity, so that it is necessary to experiment only within narrow limits of loading and twisting. These limits are widely different for different specimens of rocks, and the modulus of elasticity as well as that of rigidity was always determined with such stresses as will approximately produce strains proportional to them. The deviation from Hooke’s law was prominent in certain specimens of sandstone, and it was more marked in torsion than in flexure éxperiments; in certain rocks it is indeed doubtful if anything like a proportionality between stress and strain can be found, even for extremely small change of shape: on releasing these rocks from stress the return toward the former state is extremely small, showing that the elasticity of the rocks is of very inferior order.” If, however, the rock be subjected to direct compression, strains in which the time effect is stnall, and the lag of the strain is also small, are almost invariably obtained. This is especially the case if, before the actual experiment is carried out, the material be several times subjected te a range of stresses at least as great as those employed in the experiment itself. This preliminary stressing brings the material to a “state of ease,’ and is also commonly adopted when the elastic constants of metals are determined. It is evident therefore that this Direct Compression Method may with confidence be applied to the measurement of the cubic compression of rocks, although as mentioned below the accuracy of the results obtained will differ with different classes of rocks. If the rocks be massive, compact and erys- talline (or glassy), the method can be safely employed and good results will be obtained. If, on the other hand, the rock is * Elastic Constants of Rocks and the Velocity of Seismic Waves ; Nagaoka, H.—Phil. Mag., vol. t, 1900, p. 58. 104 Adams and Coker—FElastic Constants of Rocks. schistose, porous or loosely coherent, the method will, from the nature of the case, be very much less satisfactory. The plutonic igneous rocks as a class most nearly resemble the metals in structure, being holocrystalline and massive, and therefore present the nearest approach among rocks to perfectly elastic bodies : they are therefore a class of rocks to which this method is especially applicable. It fortunately happens that they also form a class of rocks a knowledge of whose com- pressibility is of special importance for the elucidation of geological problems, constituting as they do the greater part of the earth’s crust. | | A second class of rocks which are comparable to them in their approach to perfect elasticity, comprises the marbles and certain limestones. 7 ? A series of sixteen typical rocks representative of these two classes were accordingly selected for measurement; under the first class a number of granites were chosen as representing the acid plutonic rocks, and a number of types of the gabbro- essexite series were selected as representing the basic plutonic rocks. In all cases great care was taken to choose the most homogeneous and massive rocks of each series, and to secure test pieces free from all flaws and cracks. As representing the second class a number of typical marbles and limestones, also perfectly massive in character, were selected. For pur- poses of comparison, or contrast, a sandstone was added to the list as being a rock which, on account of its more or less porous nature, could hardly be expected to yield satisfactory results by this method. An examination of the stress strain curves of these 16 rocks, omitting the sandstone, shows that on the average they possess a rather more perfect elasticity and exhibit less hysteresis than cast iron. Some of them, as for instance, the Baveno granite, the nepheline syenite, the diabase and the black Belgian marble, show much better curves, approximating in fact to the straight lines given by wrought iron, which may be considered for our present purpose as expressing perfect elasticity. The close approximation to perfect elasticity is shown by the return of the curve to its initial or starting point, and the amount of the hysteresis is shown by the width of the loop. The width of this hysteresis (or lax) curve or loop indicates the amount of the divergence from Hooke’s law which the material exhibits—this law being that the stress and strain are directly proportional. When the curve is narrow, as it is in all cases except the Stanstead granite and the sandstone, the divergence from Hooke’s law is not great enough to seriously affect the result. The rocks, therefore, with these exceptions, fulfil the condi- tions of elasticity necessary to the successful application of the Adams and Coker—Elastie Constants of Rocks. 105 method. In these two cases the results are less certain owing to the greater hysteresis of the rock. It might at first sight appear that while the method em- ployed is theoretically perfect as applied to the measurement of the compressibility of vitreous rocks and of very fine-grained erystalline rocks, a considerable error might be introduced when the rocks are coarser in grain. In the ease of all the common erystalline rocks, the individual grains of which the rock is composed are anisotropic, that is they have different moduli of elasticity in different directions. In massive rocks such as those investigated, however, these grains occur in the rock with an absolutely irregular orientation and would in the case of a fine-grained rock mutually compensate for one another in any transverse line along which the expansion of the rock under compression might be measured. If, however, the rock were coarser In grain, fewer individual crystals would be found in any transverse line of section, and there might possibly in this way be lack of compensation, as the rock in one section might be composed of grains whose axis of greater elasticity approximated on an average more nearly to the direction of measurement than in other sections. If such were really the ease, there should be in these coarser-grained rocks an excep- tionally great variation in the readings obtained from different specimens of the same rock, as well as from the different sec- tions in the same specimen. But such is not the case, as will be seen by an examination of the figures in the accompanying table. These represent the results obtained from ten measurements of the compressibility of Baveno granite, which is coarse in grain, and ten of Sud- bury diabase, which is very fine in grain, together with eight measurements of Tennessee limestone, which is rather coarse grain, and seven of plate glass. They were made in each case on two or more specimens cut from the same mass, and the measurements of the expansion were made on several different planes through each, so that in every case the measurement was effected in a different line through the rock, all of these, however, of course being at right angles to the direction of the compressive stress and lyi ing in the medial plane of the column. Maximum. Minimum. Difference. Baveno granite (coarse), 10 Pra a eee 4,880,000. . 4/890,000 500,000 Sudbury diabase (very fine), iO iriaisu ss ees 11,170,000, 9,655,000. : 7,515,000 Plate glass, 13 trials... .._ 6,930,000 6,020,000 910,000 Tennessee marble (rather eoarse). 7 -trialseeee ss 6,130,000 5,770,000 360,000 It will thus be seen that there is no correspondence between the coarseness of grain and the magnitude of the variations in the readings obtained. The differences in glass, which is an 106 Adams and Coker— Elastic Constants of Rocks. isotropic material m which the elasticity 1s equal in all direc- tions, are greater than in the Tennessee marble, which is rather coarse in grain, and in Baveno granite, which is the coarsest rock of the set. The greatest differences obtained are those found in the finest-grained rock in the series, viz., the Sudbury diabase. It is evident therefore that the different moduli of elasticity of the constituent grains of a rock do not introduce any per- ceptible error in measurements made by this method, when a column an inch in diameter is employed, and when the rocks are not coarser in grain than the Baveno granite. In fact, when surrounded on all sides by other grains, no individual grain can expand freely, as it would if subjected to compres- sion unhampered by any surrounding medium, and thus the anisotropic character of the individual grains produces but little effect on the elasticity of the rock as a whole. These experiments also show that in the case of rocks com- posed of several minerals, it makes no perceptible difference whether the points of attachment of the instrument are em- bedded in the grains of one mineral or of another. The chief source of error, and the one to which the variations observed are for the most part to be attributed, seems to be a mechani- cal one, viz., the difficulty of getting an ideal contact between these points of attachment and the specimen, especially in view of the extremely small dimensions of the movement to be measured. The question of the influence of temperature on the elasti- city and compressibility of rocks is of course one which has an important bearing on certain problems of geophysics. The only investigation of this subject, so far as can be ascertained, consists of a few preliminary experiments by Nagaoka and Kusakabe.* In these the torsion method was employed, and the experiments were carried out on a single rock, viz., sand- stone. This rock, as has already been mentioned, being porous and stratified in character, is a material whose elastic proper- ties are far from ideal. The results are summed up by the authors in the following words: “ Preliminary experiments with sandstone show that the modulus of clastibity is much affected by the variation of temperature, i. e., about 0°5 per cent. per degree. It does not, however , necessarily diminish with the increase of temperature where the temperature is low, 1. €., 1 is maximum about 9° C.” As has been shown, however, the values for the elastic con- stants obtained by this torsion and bending method have yielded results which cannot in all cases be correct, and which differ very considerably from those obtained by the ‘much more * Modulus of Elasticity of Rocks, and Velocities of Seismic Waves, Publi- cations of the Earthquake Investigation Committee, No. 17, Tokyo, 1904, p. 43. 7h eae ye ¥ he vee Adams and Coker—Elastic Constants of Rocks. 107 direct and simple method which has been employed in the present paper. These results bearing on the variation of elasti- city Induced by changes of temperature, espécially in view of the fact that they are stated by the investigators to be “pre- liminary,” can as yet hardly be taken as, of general application to all rocks ,even if correct for the specimen of sandstone examined.* In our own investigations the laboratory was maintained at a temperature of from 63° to 68° F Melis Ot, 2040 jx and a thorough investigation into the effect of temperature was not undertaken, as this would be very difficult to carry out when employing the method of direct compression used, the difficulty consisting in heating the specimen itself without in any way affecting the measur ing apparatus attached to it. {t seemed, however, , possible fo ascertain whether any serious change in the elastic constants of the massive cr ystalline rocks employed in the present investigation would result from a ‘moderate change of temperature. [or purposes of trial the rock selected was the Sudbury diabase, a typical fine-grained plutonic rock. A column of it was placed by Mr. McKergow in a small testing machine, having a capacity of 50 tons and the temperature “of the room in which the machine was set u p having been lowered to +10° F. a cycle of compression read- ings was taken in the usual way adopted when Young’s modulus is to be determined. The temperature of the room was then raised by about 10° and ‘another cycle of readings was taken. It was then raised another 10° and a third series of readings was obtained, and so on through successive stages of 10° until the normal temperature of the room (about 65° F.) was reached. The initial reading of the instrument before the application of pressure was of course different in each case, owing to the expansion of the rock which followed from heat- ing. “These initial points were plotted on a line, and the — results obtained when this specimen was subjected to a certain maximum load, together with the increase of temperature at each stage, were plotted on a second line. If the compression was greater at 65° than at 10° for the same load, these two ro) lines should have diver ged, but as a matter of fade they were *In two very interesting papers, received while the present paper was in press (Modulus of Elasticity of Rocks and some inferences relating to Seis- mology, Journal of College of Science, Imperial University of Japan, vol. xx, article 9,1905; and Kinetic Measurements of the Modulus of Elasticity, etc., ditto, vol. xx, article 10, 1905), Kusakabe shows that the presence of moisture in a rock hasa very marked influence in diminishing its modulus of elasticity. This influence, he has ascertained, is very much more pronounced in the case of porous rocks—such as sandstone—which absorb a large quantity of water, than in the case of the compact crystalline rocks. He suggests that the effect, which in the paper above mentioned was attributed to heat, may really be due to the presence of moisture. He is now engaged in investiga- ting ‘the influence of moisture combined with a high temperature upon the modulus of elasticity of various rocks. 108 Adams and Coker—Elastic Constants of Focks. practically parallel. The differences between the readings given by the same load at different temperatures were no greater than those obtained by different measurements under the same load at the same temperature. The conclusion there- fore seems to be indicated that a change of temperature made no perceptible difference within the range of temperatures em- ployed, although a difference of 0°5 per cent. for each degree centigrade would mean a difference of about 25 per cent in range of temperature employed by Mr. McKergow. While therefore this experiment cannot be considered as supplying accurate information concerning the effect produced by a rise in temperature on the elastic constants of rocks, for the instruments themselves are in some measure affected by Detail of hole Fic. 4. Square test specimen of rock. Fic. 5. Round test specimen. the same changes of temperature, yet they serve to show that in the case of the massive crystalline rocks, the influence of temperature is probably not very great. The Method of Measurements. In carrying out the measurements, prisms of the rock 1 inch square and 3 inches long were usually employed (see fig. 4). These were cut and ground with smooth faces but were not polished. In these two small round holes were drilled in the medial line of each vertical face for the purpose of attaching the instrument, when Young’s modulus was to be measured. These holes were made by means of a small diamond drill and were perfectly round and smooth. They were each 0:05 to Adams and Coker—Elastic Constants of Rocks. 109 0-08 inch in diameter and 0°125 inch deep and 1°25 inches apart, lying at equal distances above and below the center of the prisms. These holes were chamfered at the outer end as shown in figure 4, and were found to afford the most perfect attachment which could be secured for the points of the instrument. By means of these prisms two sets of measurements of the vertical compression could be made with each prism, by attach- ing the instrument first to one pair of opposite faces and then to the other. In some eases round columns were used (see fig. 5). These were approximately 1 inch in diameter and 3 inches in length. With these it was possible to make four sets of measurements in compression with each column, by drilling eight pairs of holes as above described, whose plains intersected at angles of 45° instead of 90° as in the square prisms. It was of course necessary In every case, whether prisms or columns were employed, to exercise great care to have the end of the test pieces very carefully faced and absolutely parallel to one another. Before the actual measurements were made, the rock in every case was brought toa “state of ease” in the manner already described. The pressure was applied in most cases by a 100-ton Wick- stead testing machine, which was so carefully adjusted that it was sensitive to a load of 4 pounds. The specimen having been placed in the testing machine and brought to a state of ease was then after careful adjustment sub- mitted to loads increasing in successive stages of 1,000 pounds until the limit of safety had been reached, when the load was reduced successively by the same amounts, accurate readings being taken at each increment and decrement of load. The maximum load employed in the case of most rocks was 9,000 pounds, equivalent to from 9,000 pounds to about 11,500 pounds per square inch according to whether a square or round prism was employed. In the case, however, of some of the stronger rocks a load of as much as 15,000 pounds per square inch was employed. In the determination of the lateral strain, which was made upon the same columns as those used for measuring the ver- tical compression, care was taken that the theoretical conditions were realized, and that the material was free to expand later- ally, as otherwise the values obtained for the lateral extension would be inaccurate. In all cases, therefore, the measuring apparatus was set as nearly as possible upon the central section of the test piece, and the ends of the specimen, after being ground smooth, were coated with a thin film of oil, so that the polished pressure plates of the machine would have as little tendency as possible to prevent freedom of lateral expansion. 110 Adams and Coker—Elastic Constanis of Rocks. It was found that these precautions being observed, the expan- sion at the ends of the column was practically as great as at the center where the measurement was taken; the difference being so small that no serious discrepancy was introduced. In a number of cases accurate measurements were taken — during the successive cycles of loading and unloading to which the specimen was subjected in order to bring it to a state of rest. These were recorded in the case of the Baveno granite and the Stanstead granite and serve to show how the hyster- esis of the rock may be reduced to a minimum by subjecting the test-piece to this treatment. The measurements of each cycle usually occupied from ten to fifteen minutes. In the case of a majority of the rocks investigated, a num- ber of prisms or columns cut from the same block of rock were measured in order to ascertain whether different test pieces would give identical readings. It was found as a result of these investigations that the differences between the differ- ent specimens were no greater than those which were obtained by measuring the same specimens with the instrument attached to different sides. In the case, however, of the Quincy granite, test pieces from two different blocks of the rock were prepared, and it was found that while the several measurements made on each test piece agreed among themselves, there was a distinct divergence in the elastic constants of, the two specimens of the rock. This was probably due to a difference in composition, as the two rocks differed somewhat in appearance. In the case of the green gabbro from New Glasgow, the results obtained by measurements made upon different parts of the same prism were discordant for reasons which will be pointed out and which were dependent upon the structure of the rock. Fifty-five columns of rock, nineteen of glass, and two of iron were employed in this investigation and every precaution was taken to insure the attainment of accurate results. The rocks in all cases were air-dry, having been allowed to remain in the laboratory for several weeks after they had been cut, before the measurements were made. In the accompanying tables the following elastic constants are given : H=Young’s Modulus, 1. e., the quotient of the longitudinal stress by the longitudinal compression, o—=Poisson’s Ratio. This is the reciprocal of m. D=Modulus of Cubic Compression = ee 5 )z The reciprocal of this gives the decrease in volume of a cubic inch of the material for a pressure of 1 pound per square inch applied on every side. Adams and Coker—Flastic Constants of Rocks. 111 2\m-+1 torsional stress to torsional strain. m=The ratio of longitudinal compression to lateral extension per unit of length. C=Modulus of Shear= 5 ( a ) HH, which is the quotient of Hand m are measured directly; the other values are caleu- lated from them. These values in the case of each rock are given in inch and pound units, and the results are summarized in a general table on page 121. The measurements were made in these units on account of the fact that the testing machine employed was graduated to read pounds. For purposes of comparison, however, this latter table has been recaiculated in O.G.S. units, and the results are set forth in the second table, to be found on page 121. In the case of metal, Poisson’s ratio is generally arrived at by stretching the bar and determining the value of the longi- tudinal extension divided by the lateral contraction. In case of rocks the tensile strength being low and the materials being brittle, it is more convenient and more accurate to make the determination by compressing a short bar or column, and determining the value of the longitudinal compression divided by the lateral expansion. This gives the value designated as m, of which Poisson’s ratio is the reciprocal. Theoretically one method is as accurate as the other. In each table the first transverse line designates the spec- imen employed as a, 6, ¢, or d. _ The second line gives the diameter of the specimen, which is often slightly different in the two directions. The length of the column in all cases was about three inches, but this is not stated in the table, as the compression is not measured on the total length of the column, but on the length of that portion of it which les between the points of attachment of the instrument. The third line gives the area, which is approximately one square inch in the case of a square prism and three-quarters of a square inch in the case of a round column. The fourth transverse line contains the letters U or P, which designate the two diameters of the column when two measurements were made.on the same square prism ; these two directions being always at right angles to one another. In the case of round columns on which measurements were frequently made in several planes, these are designated as “first holes,” “second holes,” ete. In the four succeeding lines the four elastic constants 4, o, D and Care given as determined by each measurement. Am. Jour. Sct.—FourtH Series, Vou. XXII, No. 128.—Aveusrt, 1906. 8 112. Adams and Coker—Ltastic Constants of Rocks. The sixteen rocks whose elastic constants were determined are enumerated in the following list: Marbles and Limestones. 1. Black Belgian marble; an extremely fine-grained and mass- ive black marble, largely used for ornamental purposes and known in trade as “ Belgian Black ”. 2. White marble, Carrara, Italy ; a typical fine-grained sac- charoidal marble. 3. White marble, Vermont, U.S. A.; identical in appearance with the last. 4. Pink marble, Tennessee, U. 8. A.; a highly metamorphosed coralline limestone which has been converted into a marble ; largely used for purposes of construction and known as “ Pink Tennessee.” 5. Trenton limestone, Montreal, Canada; a highly fossilifer- ous variety, free from any signs of stratification, taken from a heavy bed in the Mile End quarries at this place ; used exten- sively as a building stone. Granites. 6. Granite, Baveno, Italy ; a typical biotite granite of medium grain. 7. Granite, Peterhead, Scotland; a typical, rather coarse- grained, biotite granite. 8. Granite, Lily Lake, New Brunswick, Canada; closely resem- bles No. 7. 9. Granite, Westerly, Rhode Island, U.S. A.; a typical, very fine-grained reddish biotite granite. 10. Granite, Quincy, Massachusetts, U. 8. A.; a rather coarse- grained hornblende pyroxene granite. 11. Granite, Stanstead, Quebec, Canada; a rather fine-grained muscovite biotite granite ; the mica is relatively more abundant than in either the Peterhead or the Westerly granites. Nepheline Syenite. 12. Nepheline syenite, Montreal, Canada; a typical fine-grained massive hornblende nepheline syenite. Basic Plutonic Rocks. 13. Anorthosite, New Glasgow, Quebec, Canada ; a rock com- posed of plagioclase with a subordinate amount of pale green augite and green hornblende; it is fine in grain and very tough, being used for paving sets in the city of Montreal. 14. Essexite, Mount Johnson, Quebec, Canada; a typical essex- ite, massive and uniform in character, composed of plagioclase, nepheline, augite, hornblende and biotite ; used extensively as a building stone and for monuments. 15. Gabbro, New Glasgow, Quebec, Canada; this rock is deep green in color and occurs in the form of a large dike cutting the anorthosite (No. 13); composed of augite, hornblende and plagioclase, the two former minerals preponderating largely. It Adams and Coker Liastic Constants of Rocks. 118 shows a distinct parallelism in the arrangement of the constitu- ents, to which may be attributed a considerable divergence in the results obtained in the different measurements oe the elastic con- stants. 16. Olivine diabase, near Sudbury, Ontario, Cade a typical fine-grained, perfectly massive olivine diabase, occurring as a large e dike cutting rocks of Huronian age. Sandstones. 17. Sandstone, Cleveland, Ohio, U.S. A., a fine, even-grained yellowish sandstone, extensively used for building purposes. The _ bedding is marked by a slight variation in the color of the dif- ferent beds. The prism used in the measurement of the elastic constants was cut from a single bed and was taken parallel to the plane of bedding. ~° . A summary of the results obtained in the measurement of the elastic constants of these rocks is given on p. 121. The extended results are here presented in the case of three rocks only, which may serve as representatives of the others. Carrara Marble: Three specimens of the rock were used in measuring the elastic constants, two squares prisms (@ and 6) and a round column (¢). Two sets of measurements were made on both } and ¢, the instrument as usual being affixed to the specimens in two positions at right angles to one another in each ease. In this way five sets of measurements were made. The results are set forth in the following table : Carrara Marble No. a b b Cc C mime £002 >< 1°035.: 1-017 X F016 ee Non "985 "985 Area LOT 1:033 1°033 OW “762 E 8,120,000 7,800,000 8,055,000 8,210,000 ~—-8,045,000 28] 274 De ‘215 269 6,170,000 5,750,000 5,920,000 6,100,000 5,790,000 3,170,000 3,060,000 3,160,000 3,210,000 _— 3,170,000 The averages of the results obtained for the respective con- stants are as foilows :— E=8,046,000; o=0°2744; D=5,946,000; C=3,154,000. The difference between the highest and lowest determina- tions of D is 420,000 pounds. Figure 6 shows the stress strain curves plotted from the results obtained from specimen @, the ordinates representing the load (stress) and the abscissae the amount of the strain. I 114. Adams and Coker—FKlastic Constants of Rocks. represents in all cases the longitudinal compression and II the lateral extension. The hysteresis is greater than in the case of the black Belgian marble (fig. 7), but about the same in amount as shown by the Vermont marble and the Trenton limestone from Montreal. 9000 Ee 7000 oa a) 3 5000 a a 0 40 80 120 160 200 240 STRAIN Fic. 6. Carrara Marble, stress strain curves. | ee LOAD elie.) S:TRA/N Fie. 7. Black Belgian marble, stress strain curves. Granite, Westerly, Rhode Island, U. 8. A. Four test pieces were used in measuring the elastic constants, viz: two square prisms, @ and J, and two round columns, ¢ and d. ‘Two sets of determinations were made on each of the first three specimens, the instruments being attached to dif- ferent pairs of sides in each case, and four sets of determina- tions were made on specimen d in planes making angles at 45° with one another. The results are given in the following table. Adams and Coker—Etlastic Constants of Rocks. 115 The averages of the values obtained é are as follows: E = 7,394,500 ; o = ‘2195; D = 4,897,500 ; C = 3,019,700 The difference between the highest and lowest values in the four determina- tions of Don specimen d was only 280,000. Of the other columns @ gave on an average somewhat lower and 6 some- what higher results. The stress strain curves obtained from specimen @ are shown in figure 8. The hysteresis is greater than that shown in the case of any of the other granites except that from Stanstead. In figure 9 the stress strain curves for the Peterhead granite, and in figure 10 those for the nepheline syenite are shown for purposes of comparison. Olivine Diabase, near Sudbury, Ontario, Canada. Four test pieces were used in deter- ene the elastic constants of the rock, : three round columns and one nearly oe prism. They are designated as a,6,¢andd. The three round columns were cut out of a block of the diabase by means of an annular diamond drill. Two measurements were made on each of these in planes at right angles to one another, in each case, while four meas- urements were made on the prism d using two pairs of faces. In this way ten complete sets of measurements were made for the elastic constants of this diabase. The values obtained are given in the tables on p. 117. As will be seen, the values obtained for D in this rock are considerably higher than those yielded by any other rock of the series examined. In the six inde- pendent measurements carried out on the first three specimens, the difference between the highest and lowest values for D amounted to 830,000 pounds, while on the four measurements made on specimen @ there is a rather greater difference amounting to 845,000 pounds. Granite, Westerly, Rhode Island, U. S. A. d d e-2-- c ie 75 - Ist holes b a Ct 1008 x 1-002 No. ile “75 Ist holes Size ‘981 >< +929 2d holes - TOL Area “igi, alle 7,250,000 3d ales 7,170,000 P. 7,090,000 U. Side 299 4,340,000 2,961,000 7,575,000 7,335,000 Pe 225 293 22.95 Aes 4,600,000 4,420,000 4,320,000 ee 3,090,000 2,980,000 2,940,000 7,835,000 soem = 7,625,000 17,745,000 7,670,000 ‘1985 241 214 4,925,000 4,515,000 3,070,000 3,185,000 3,950,000 2,960,000 7,180,000 21 4,110,000 2,970,000 EK o Jb, GC 116 Adams and Coker Elastic Constants of Rocks. 9000 as | Z| | | | ae (6) 40 ro6) /20 J6E0 200 240 280 320 360 STRAIN Fic. 8. Westerly granite, stress strain curves. - 7000 ~ 5000 VEXEV WE) JETER SY 3000 1/60 STRAIN Fic. 9. Peterhead granite, stress strain curves. 0 40 80 i720. J60. - POO Mae FOES STRAIN Fic. 10. Montreal nepheline syenite, stress strain curves. Adams and Coker—Elastic Constants of Locks. 117 The averages of the determinations made on each of the columns are as fol- lows: E D o C = 13,515,000 10,400,000 0°2838 5,270,000 — 14,170,000 10,945,000 +2840 5,525,000 = 14,170,000 11,085,000 2870 5,505,000 d = 13,197,750 10,076,000 ‘2812 5,155,000 Ay. 13,763,187 10,626,500 ‘2840 5,363,750 The stress strain curves given by this rock are shown in figure 11. As will be seen from these curves, in its approach to perfect elasticity the rock is comparable to plate glass. oe Xs The Elastic Constants of Glass. As in geophysical speculations, the earth in respect to its rigidity and compressi- bility is often compared to a globe of glass, it seemed advisable to determine as accu- rately as possible the elastic constants of glass, for the purpose of comparing them with the results obtained in the ease of the various rocks considered in this paper, employing the same methods and carrying out the work under exactly the same con- ditions. This material lends itself excel- lently to this method of measuring these constants, provided the glass is free from all irregularities in its substance and is isotropic in character. The first difficulty experienced was that of obtaining such a alass. At the outset it was thought that thick glass rods such as are used for vari- ous purposes in the chemical and physical laboratory might be employed, but al- though several lots of the purest variety of this material were procured, the glass constituting it was found in all cases to contain minute air bubbles, and when examined between crossed nicols in polar- ized light, showed brilliant colors—red, yellow and blue. This indicated a state of marked tension in the glass, evidently due to the rod having been drawn when the glass was in a viscous state, which was also shown by the circular ar rangement of the little bubbles in the rod, following the direction of its surface. Short lengths of this rod moreover when tested in compres- sion, so soon as the maximum load had Olivine Diabase, Sudbury, Province of Ontario, Canada. d 864 ad "864 ad 864 ,150,000 13,330,000 13,450,000 d 1000 X :864 864 1g) I~ a b 0 Cc C ‘981 "983 "983 ‘O88 "983 "756 756 758 758 758 ‘981 13,250,000 12,860,000 287 27) 10,500,000 9,655,000 5,230,000 5,020,000 285 5,200,000 "276 9,810,000 10,340,000 5,170,000 € e 1 283 5,580,000 14,320,000 14,020,000 14,320,000 NNT 291 10,720,000 11,170,000 11,000,000 5,430,000 5,620,000 ‘291 10,460,000 11,170,000 5,430,000 281 13,780,000 14,020,000 5,380,000 ‘2865 10,340,000 5,160,000 118 Adams and Coker—Elastic Constants of Rocks. St coooc been exceeded, instead Of tepite & oOo > oOoOSs & 1 > SeSconoooe ting from top to bottom, broke =xsesauasses as if composed of a series of waA*tANSSOGAS*2 9 rudely concentric shells. oer ciate tl After a prolonged search for re ° e . isotropic glass in masses of suf- ees sooo licient size to measure the elastic (amp) . Se SS Secs _ constants, it was found that plate TaASSRASSSS glass answered the requirements. ar XODSANLEADAAG : f ineh ol 1 aU {aes gatacnd A piece of one inch plate glass, nq ss OO mH 7 . 1tal ‘ hides Spe made in Great Britain, was i accordingly secured and was cut 2 into strips an inch wide, and . 2 o9 ocooco these again into three inch 5565, 5656 lengths. The square prisms thus — Dt re n n n nn a OO Seo Ss 2 7er aX SSENTSESSS produced were then properly a TO ss ©6faced and polished. “Tiregizea N So © oOo Sass was found to be absolutely free % from all flaws and impurities, and >) CoS teas ©oo6oo When examined between crossed ; 2.58, S688 ‘nicols, the prisms although an wa) — aS a i= “ nn - a e e ° € . 2 Syacoxaagecs inch thick, showed in one direc- SS SnoMaa VS] os cof co! CO Coen GN) gms ait right angles to vertical ax =) Cc = 22 ~~ axis absolute blackness through- aS — S out a complete revolution, while = 1d : : : : Pale eos eae coco «1 the other direction at right S SLonSSSS angles to this there was during SYSSSARSSSS a revolution an alternation of 5 Ek te a) - , WP wo SSHOHA-= blackness with a pale grayish (eo @) ~ “Cs re . . . . eb cows illumination. This change was = so slight that considering the thickness of the glass and the pte) S Ss £8 _SéS$E_sensitiveness of the test, the ma- SSeS Ss SS SS = 1 sider SN a eS terial may be considered to be on Bee SSRIS practically free trom imieu lo) ~ Tax ~ n = = =o e a e e Se Se osu ~ tension, and to be isotropic in Ba e character. ay In order to get a good average S and to eliminate chance errors so nN a3 = o £2. s8ses iar as possible, seven Gr ygiees & x8 SSRZRSSLS prisms were taken, and two com- e@SRaENTEOGA= plete sets of determinations were Os a Q (> eae ee ee e . eo“ So ~ssyg made on each of them, using in 2 every case different pairs of faces. ees Fourteen determinations were ONE d : the elastic pram 4 QoS thus made of each of the e Adams and Coker—Elastic Constants of Rocks. 119 constants. The figures obtained are set forth in the table on p- L118. : In this table a complete series of values obtained from eacl specimen are given in double rows. When the average of all these results is taken, the values obtained for the several con- stants of plate glass are as follows: E = 10,500,000; o =0:2273; D= 6,448,000; C= 4,290,000 The stress-strain curves given by one of the prisms is shown in figure 12. In this figure I represents longitudinal compres- sion and II lateral extension. Determinations of the cubic compressibility of glass, D, have been made by other observers using various methods. LOAD, LBS. 12 STRAIN Fie. 11. Sudbury Diabase, stress strain curves. The results go to show that different varieties of glass vary considerably in their compressibility. ‘These determinations may be tabulated as follows :* Biyerentys 2. 5,074,600 to 6,379,400 (C.G.8.=3°'5 to 4:4 x 10”) Amagat-common glass __.--. 6,745,000 (:000002181 per atmosphere) Amagat-crystal Plasse re ar 6,112,300 (000002405 “ “ ) Rai eos gees Pe? 5,657,700 (0000026 = ** agate) As will be seen, the figures obtained for plate glass in the present investigation lie a little above the average of the vari- ous values here given, and are nearly those of the highest value obtained by Everett. * See Everett, Illustrations of the C.G.S. System of Units with tables of Physical Constants. Macmillan & Co., 1902, pp. 60 to 64. The figures there expressed in various units have been here recalculated into inch-pound values. 120 Adams and Coker— Elastic Constants of Rocks. Summary of Results. In the table on the following page a summary is shown of the average values obtained for 4, o, C and / in the case of all the rocks examined in this investigation. Together with these are placed for purposes of comparison the results obtained for these constants in the case of wrought iron, cast iron and glass. In the second table these values are again presented, recal- culated into C.G.S. units. The rocks fall naturally into three groups differmg fon one ancther in compressibility, but the several members of each group agreeing fairly closely among themselves. 40 80 120 160 200. 240 STRAIN Fic. 12. Plate glass, stress-strain curves. These three groups show a corresponding difference in com- position. The first group consists of the marbles and limestones. These have an average value for D of 6,345,000. One of these, however, the Black Belgian marble, which is very much finer in grain than the others, and breaks almost like a piece of glass, has a very much higher value for than that possessed by the other rocks, which among themselves are nearly identi- cal. If we omit this Belgian marble, the average of D for the other hmestones and marbles is 5,855,000. The second group comprises the granites. These again show a close agreement of values among themselves, except in the case of the Stanstead granite, which rock as already mentioned shows a defective elasticity. The average value of / for the granites is 4,899,000. The third group embraces the basic intrusives (gabbro, anorthosite, essexite and diabase). These show greater dif- ferences, but have an average value for D of 8, 825, 000. The nepheline syenite, although higher in silica ‘and. therefore properly speaking an acid rock, in its freedom from quartz and its richness in feldspar (although the feldspar is largely orthoclase instead of plagioclase), in mineralogical composition Adams and Coker—Klastic Constants of Rocks. 121 belongs with these basic rocks eine than with the granites. It also approaches the essexite most nearly in its compressi- bility. ELASTIC CONSTANTS OF ROCKS. Summary of Results (average) expressed in Inch-Pound Units. E CO 1 ( m E 2 BEBO a Ryecouch iron). 8 22 se) 28,100,000 | 0°2800 | 11,000,000 | 21,300,000 ASHIGOMT oi teen ri 3 15,000,000 | 9°2500 | 6,000,000 | 10,000,000 Black Belgian marble____. 11,070,000 | 02780 | 4,330,000 8,303,000 Carrara marble 22.2... 8,046,000 | 0°2744 | 8,154,000 5,946,000 Vermont marble ____..___- 7,592,000 | 0°2630 | 3,000,000 5,341,000 Tennessee marble ______-.. 9,006,000 | 0°2518 3,607,000 5.967,000 Montreal limestone ______-_ 9,205,000 | 0°2522 | 3,636,000 6,167,500 Baveno granite_._.._.....| 6,833,000 | 0°2828 2,724,800 4,604,000 Peterhead emamite, jo) a 8,295,000 | 0°2112 | 3,399,000 4,792,000 Lily Lake granite __.._._.| 8,165,000 | 0°1982 | 3,380,000 4,517,500 MWiesterly eranite,.... 2-2. 7,394,500 | 0°2195 | 3,019,700 4,397,500 Quimey granite (1) 225... 6,747,000 | 0°2152 | 2,781,600 3,984,000 Quincy granite (2)__.____- 8,247,500 | O-'1977 | 38,445,000 | 4,555,000 Stanstead granite __..___.| 5,685,000 | 0°2585 | 2,258,700 5,940,000 Nepheline syenite ____ __. 9,137,500 | 0°2560 | 3,635,000 6,237,500 New Glasgow anorthosite _| 11,960,000 | 0°2620 | 4,750,000 8,368,000 Mount Johnson essexite___| 9,746,000 | 0°2583 | 3,872,600 6,750,000 New Glasgow gabbro * ___| 15,650,000 | 0°2192 6,365,000 9,505,000 Sudbury diabase _._....-- 13,763,000 | 0°2840 | 5,364,000 | 10,626,500 Ohio sandstone __..____-. 2,290,000 | 0°2900 888,000 | 1,816,000 EAero lasso i ea 10,500,000 | 0:2278 | 4,290,000 | 6,448,000 Summary of Results (average) expressed in C.G.S. Units. m B a G D=( m--2 »)B Weroue iy irons. Sr. 19°37 x 10") 0-2800 |7°590 x 10!) 14°680 x 10! cE SIETIG 5) 1 ait ie eee te 10°34 x 10") 0-2500 |4°182 x 10"| 6-897 x 101! Black Belgian marble .__.| 7°24 x 10!" 0-2780 /2°982 x 10%) 5:°786 x 10% Carrara marble 20.225. 7. 5°04 «x 10") 0°2744 |2°171 x 10", 4°090 x 101 Mewnont marble 2222002. 5°24 x 10%; 0:2630 |2:°069 x 10%) 3°680 x 10! Tennessee marble ___.___- Geile NOU ols. 2-482) 6101) Aerio x 10 Montreal limestone ____.__| 6°35 x 10!| 0-2522 |2°504 x 10%) 4:250 x 10" wbaveno granite. .___ Aide x OM 022028) |leSior x: 101 3-178) x 110" Peterhead granite __.__---| 5°71 x 101) 0-2112 |2°340 x 10") 3-300 x 10" Lily Lake granite .______. 0°60 x 101! 0-1982)|2:380 x 10") 3-108 =x 101! Westerly granite __-_..._.| 5°09 x 10"! 0-2195 |2°080 x 10") 3-029 x 10" Quincy granite (1)____._-. 4°64 x 10!"| 0-2152 |1:916 x 101!) 2°750 x 10! Quincy granite (2)__.._. ._| 5°68 x 10!) 0-1977 |2°373 x 10%) 3-140 x 10% Stanstead granite ___.___. 3°92 x 101) 0:2585 |1°556 x 10") 2-718 x 10! Nepheline syenite _____- 6°29 x 10% 0°:2560 |2°505 x 10"; 4:290 x 104 New Glasgow anorthosite _| 8°25 x 10") 0-2620 |8°275 x 10!) 5-760 x 101 Mount Johnson essexite___| 6°71 x 101) 0-2588 |2°670 x 10") 4:°650 x 10” New Glasgow gabbro * ___|10°80 x 10") 0:2192 |4°380 x 104) 6°589 x 104 Sudbury diabase ____.___- 9°49 x 10%) 0:2840 |3°700 x 10") 7:°329 x 101! Glhnowandstone! 2022322 | 1°58 x 101") 0:2900 | 612 x 10") 1:250 x 10" Rabe lass 0 4 et es! C24 x 10") 0°2273 |2:960 x 101] 4-439 x 10% If the nepheline syenite be included with the basic rocks, an average value of PD is obtained of 8,308,000. This omits from consideration the sandstone, it being a rock * See page 112. 122 Adams and Coker— Elastic Constants of Rocks. of an entirely different class from the others, and furthermore’ one which shows so much hysteresis that the application of this method to it is less satisfactory than in the case of the other rocks of the series. | These results may be presented as follows: Average of D Marbles and limestones 2.222 oe 6,345,000 Granites: 0 eo PAN OE Se ee ILL Basic iitrusives,. 000240 eS oe ee Oe te The cause of the much greater compressibility of granite as compared with the marbles and basic intrusives is not clear, but would seem to be connected with the presence of quartz. The only determination of the cubic compressibility of quartz, so far as can be ascertained, is one by Voigt,* the value obtained being 5,504,190 pounds (887 X 10° grams per. sq. cent.). This compressibility, as will be seen, is much greater than that found in the case of either the limestones or the basic intrusives, and while not in itself sufficiently great to account for the high compressibility of the granites, goes to show that in the quartz we have a mineral which is more com- pressible than the ordinary rock-making minerals which form the chief constituent in the rocks of the series examined. ’ The marbles and the limestones of the earth’s crust are con-: fined to its most superficial portion, resulting as they do from the process of sedimentation. There is every reason to believe, however, that what we may term the sub-structure of the earth’s crust is composed of acid and basic plutonic igneous rocks. These make up the lowest part of the crust to which we have access, and are found coming up from the still greater depths. The cubic compressibility, Y, of the earth’s crust must le between the values given above for the granites and the basic intrusives, approaching one or other of these values according to the relative proportion in it of one or other of these classes of rocks. ; If we take the average of the values obtained from these two classes of rocks as represented by the seven granites and the five basic intrusives (including the nepheline syenite), the value obtained for D is 6,353,500. This, as will be seen, differs but little from the value of D obtained for plate glass, which is 6,448,000. If, therefore, the earth’s crust be composed of granite and basic igneous rocks in approximately equal proportions, its compr essibility will be that of glass. If it be composed almost exclusively of granite, the earth’s crust will be more compres- sible than glass; and if the basic rocks preponderate very largely, it will be less compressible than this substance. * Quoted in Becker, Experiments on Schistosity and Slaty Cleavage, Bulletin 241, U. S. Geol. Survey, p. 32. Adams and Coker—Flastic Constants of Rocks. 128 It is, however, in any case much more compressible than steel, which has a value for J of from 26,098,000 to 27,547,000 mes to 19>< 10"; C:G:8.)™. The compression to which the rocks were subjected in this investigation ranged from 6,000 to 17,340 pounds to the square inch. Most of the rocks, however, were subjected to a load of from 9,000 to 15,000 pounds per square inch, and _ their bulk compression was determined for these loads as maxima. Higher pressures could not be employed without incurring the risk of breaking the specimen, and at the same time of de- stroying the measuring apparatus. One apparatus was in fact so destroyed. The question arises as to whether under still higher pressures, if rupture could be avoided, the ratio of load to compression would be maintained. Judging from the deportment of much stronger substances, such as steel, when similarly tested, it is inferred that this ratio of bulk compression will remain con- stant for very much higher pressures, or until deformation sets in and the rock begins to flow. With regard to the accuracy of the results obtained by this method as compared with those obtainable by any method in which cubic compression is actually produced and measured, it may be observed that by far the best method of this kind hitherto suggested seems to be that proposed by Richards and Stull.t We have endeavored to make use of this method in order to obtain results for purposes of comparison with those given in the present paper, but have not hitherto succeeded in overcoming certain experimental difficulties. The experi- mental errors in this method, though apparently small, still exist, and in applying it to rocks, which are much less com- pressible than the substances examined by Richards and Stull, these errors become proportionately more serious. Moreover, higher pressures than those used in the method employed in the present paper could scarcely be employed in this direct method, while difficulties dependent on the possible lack of absolute continuity in the substance of the rock and the danger of minute air-filled spaces, would probably present themselves in the case of most rocks. It seems that all things being con- sidered, the indirect method here employed is probably as accurate as any direct method which can be used. The attempt to apply Richards and Stull’s method to the same rocks is still being continued, however, and it is hoped that satisfactory results may be eventually obtained by its use. McGill University, Montreal. * Tilustrations of the C.G.S. System of Units with tables of Physical Constants. Macmillan & Co., 1902, p. 60. + New method of Determining Compressibility. Published by the Carnegie Institution, Washington, D. C., Dec., 1903 (No. 7). 124 Keyes—Dakotan Series of Northern New Mewico. Art. XIl.—The Dakotan Series of Norihern New Mexico ; by CHARLES Le KEYEs. Srrata that have been vepanned to the Dakota division of the Cretaceous age have been long known in the Southwest, around the southern end of the Rocky Mountains in northern New Mexico. The section there exposed has been generally regarded as exactly representing the “ Dakota Group” as first defined by Meek and Hayden* for the upper Missouri region. Late observations in the New Mexican region indicate clearly that the formation called the Dakota sandstone has never been caretully delimited, that it has been given quite different limits by different authors, and that the section usually so called actually belongs to sever al geological ages. As recently made out, the veneral Mesozoic section of north- eastern New Mexico presents the following elements : General Mesozoic Section of Northeastern New Mexico. Age. Series. Thickness. 5 o{ Wate 2-25... i; Varamian| sandstones 22 ao. ee 2500 see 6. Montana shales: isiyh 2) 09.2 ee 1600 = =e J EG Lae orga 5. Coloradan shales 2202. 02 21a me saeee 1000 | 4, Dakotan sandstones___-_.!_-- meres: U0) lesan ly oes ee 3. Comanchan shales (255.2222). ae SMUGASSICI seen 2. Morrisonian sandstones.______._-- 250 Triassi¢ -2....-.. 1. Red Beds (upper part)'-: 2.2.2 7 Se As usually considered in the literature of the subject, the Dakota sandstone has been made to cover of the above section not only No. 4, but No. 2 and No. 3, and not infrequently part of No. 1. The reasons for these long standing errors of interpre- tation recalls one of the unpleasant chapters in the history of American geology. It goes back to the very beginning, to the early sixties, when there was a concerted attempt to thor- oughly discredit the work of Jules Marcou in this country. The proofs of the conclusions which the Swiss geologist sub- mitted may have been insufficient at the time, or they may have been happy guesses, but the fact yet remains that the latest work in the region has, in the main, substantiated his observations and there are too many of his statements that are correct to assert at this day that they were anything less than a display of geological acumen such as none of his critics pos- sessed. Newberry, Hayden, Meek and others appear to have become so absorbed in their side of the controversy that they all but lost sight, of the facts, and they not infrequently went * Proc. Acad. Nat. Sci., Phila., vol. xiii, pp. 410-420, 1862. Keyes—Dakotan Series of Northern New Mexico. 125 so far as to discuss in the most positive manner sections which they had never been near. Instead of clearing up the points under discussion, this long drawn out controversy only served. to make the entire question more obscure. When I was first suddenly made acquainted with the Cretaceous formations of the region, it was in the field, before it was possible to consult carefully very much of the literature on the subject. In mapping and in local de- scriptions in the northern New Mexican province [ assumed the Dakota sandstone to be the great massive plate of yellow sandstone about 500 feet in maximum thickness. Above it were the Colorado shales and beneath in many places a pecu- liar succession of sandy shales, shaly sandstones and clay shales. Several papers were even published on New Mexican geology in which this idea of the Dakota formation of the region was expressed. The chief reasons for considering this great plate as a formation by itself and as representing the Dakota sandstone were (1) that it immediately underlay the Colorado shales, which were well identified by numerous fossils, and (2) that the sandstone rested in marked unconformity upon the formations beneath. When, later, the literature was gone over carefully in order to compare the published observa- vations of others with my own, it was with much surprise that I found that prevailing opinions included in the Dakota sec- tion a much greater sequence than I had done. This led immediately to a detailed examination of many of the more critical of the described sections; and the location of the real difficulties of former interpretations. The use of the term Dakotan series for the sequence of massive yellow sandstones which form the bottom of the Cre- taceous section over the greater part of New Mexico is based upon the accepted terminology of the general Mesozoie section of the Rocky Mountain region. a; some individuals have a narrow, irregular border of bluish green hornblende; magnetite a common inclusion, titanite and apatite less so, and orthoclase rare. Quartz.—About 10 per cent; xenomorphic, in irregular anhedra, interstitial between the other constituents, especially the feldspar and hornblendes ; occasional undulatory extinction. Oligoclase.—(Ab,An,). About 3 per cent; stout subhedral tables, twinning lamellae according to the albite law very nar- row and numerous. Magnetite.—About 2 per cent; small, subhedral to anhedral grains. Titanite—About 2 per cent; automorphic, giving the usual lozenge sections; pale brown, slightly pleochroie. Apatite.—About 1 per cent; automorphic, stout prisms; clear. Chemical composition.—The chemical composition is shown in the table, the earlier analyses by Zirkel and Griffith (quoted from Brogger) being given in columns I and II, the complete analysis of my specimen in III, that of Cross’s specimen in IV, followed by the alkali determinations of the other speci- mens, and the final average with the molecular ratios in VII and VIII. The two older analyses are very closely alike, a fact to which Brogger has called attention. They are, however, both unsatisfactory according to modern standards, the sum- mation of I being unwarrantedly high,* and both being incom- * The sum would be still higher were the ferric oxide reckoned. 132 Washington—Plauenal Monzonose (Syentte ). Analyses of syenite from the Plauenscher Grund. I I Tt) 1, Vv VI Vie ata SiO, 59°83 60°02 62:49 58°70 60°60 1-010 Al,O, 16°85 16°66 16:49 17-09 16°70, 7165 Be Oo ie ae reldie 3G. Bay 21 Ome FeO HO py ees aor O28 2°17, Oem WTO © DG Be Wee Des 2:14 one CaO 4-43) B59 4°93 | 4-71 4:47 080 Na,O 2°44 2°41 4°38 4:38 4°34 449 4:40 ‘O71 K,O 6°57 6°50 4°65 4°35 4°33 4°93 4°57 "049 2 H,.O+).. 0°32 0:89 0-61 H,O— Gactadtennts 0:28 0:23 0:25 CO, eee nha eROne a. NOME none WO eee seen Ose 0°95 0°90 20101 ZrO, BE aN ee OMG, eee none POS Oe ee Sep sok gos 0°28 002 SO, Die shee OR OTe oe aes none ) cident eg yea esastane NT ONO Cake Bk none MnO MGA, NOKEL moder yankee n.d. BaO eee a OLS. eet 0°15 SsrO He Pm mena, in CLG Sauna KG trace 101°03 100°00 100°43 99°40 100°10 Sp: Gr. 2° 730 I. F. Zirkel, Pogg. Ann. cxxii, 1864, p. 622. If. Griffith, Chem. News, xlvii, 1882, p. 170 (cf. Brégger, op. cit., p. 30). III. Specimen of H. 8. Washington, IV. Specimen from W. Cross. V. Specimen from L. V. Pirsson. VI. Specimen from J. F. Kemp. VIL Average of III, 1V, V and VI. VIII. Molecular ratios of VII. plete, especially as regards the iron oxides, while the total of II (exactly 100-00) gives rise to some uneasiness. They both resemble III and IV in the figures for silica, alumina, magnesia and lime, but differ much in those for the oxides of iron and the alkalies, though the total amount of these last is about the same in all. It may be noted, however, that the specimens analyzed by Zirkel and Griffith and that of Cross are evidently slightly more femic than mine. This is shown by the lower silica and higher iron oxides, magnesia and lime, as well as by the alumina when it is remembered that the ALO. of I and II include the TiO, and P,O, of the rocks * The SiO, will also include some of the TiO, and possibly a little Fe.Os, etc., if it was not checked as to purity by evaporation with hydrofluoric and sulphuric acids. It may be noted that the unchecked silica in IV amounted to 59°45 per cent. Washington—Plauenal Monzonose (Syenite). 1338 If the ferrous oxide of I is divided up in about the ratio shown by III, that is 3°89 Fe,O, and 3°50 FeO, the norm calcu- lated on this basis is as follows: (NTE h Ez Ns le Sian a a on 7°08 Wrihoclaset 21 i er Loe 88592 Yi] | OTE Ss ae te a ae aa ee 20°44 PAMOMUNILe ai oe osha ue 15°57 [DONG TONSTNS (ca ai ae a a a ee oaks Ebypensthene. os) Jao. oe 7°31 Mipomette; 6s Sache. Ne St 1) 100°08 VEY es CI meat ears ey Tene ieee 129 101°37 xtra Oxy CCM es ere. ves 0°38 100°99 This gives as the systematic position ciminose (L1.5.2.2), a rare subrang which is abundantly represented at the Italian voleanoes, but which is unknown outside of these except as the durbachite of the Schwarzwald, a rock with very abundant biotite, which is quite absent from the Plauen syenite. The figures for the alkalies in the new analyses are remark- ably constant, Na,O varying only from 4°34 to 4:49, while the range of K, O is slightly greater, from 4°33 to 4: 93: the for- mer being within the acceptable limits of analytical error and the latter scarcely more than this.* Silica varies within a range of 3°19 per cent, and the other constituents are some- what higher in IV than in III, though not very much so. Taken as a whole, when we remember that silica is the most abundant constituent and the one in which a greater range of variation is to be expected, and when the different times when, and the different parts of the mass where, the specimens were collected are considered, the results of my analyses imply a remarkable uniformity in the mass of syenite. It is true that highly feldspathic, as well as highly hornblendic, schlieren occur here and there, but these are of very minor importance, besides being complenientary to each other. While the close correspondence between I and II might argue a composition similar to these, their earlier date and unsatisfactory character, as well as the improbability of the systematic position to which they lead, make one feel confident that the true composition of the mass is shown by the new rather than by the older analy- ses, and that it is best represented by the average of these, as given in VIL. * Dittrich, Neues Jahrb., 1903, ii, p. 81; Washington, Manual Chem. Anal. Rocks, 1904, p. 24. 134 Washington—Plauenal Monzonose (Syenite ). The norm of VII ealeulates out as follows: Norm. Ratios. Q 6°90 6°90 Sal : Or 27-9 83°85 = =5°53, Class II; dosalane ro 27°24 Fem Ab 737-20 76°95 An 12°51 = 11°15, Order 5, germanare. ID ee ee Q Hy . 2°93 \ | KO +Na,0% 19°67). Rano ae a 3°94 saat \ 13°85 CaO’ ~ _monzonose. 1°67 > Ap 072 0 72 K ee 0°69, Subrang 3, mon- / Na,O ZONOSE. 99°22 Rest 1:01 100°23 The average rock therefore falls in monzonose (IL.5.2.3), as do both Oross’s specimen and mine, and presumably the others also. It will have been seen that Zirkel’s analysis places the rock in the same class, order and rang, but in the dopotassic instead of the sodipotassic subrang. As the somewhat more femic character of his specimen cannot be considered to be connected with, or to bring about, such a radical difference in the propor tions of the alkalies, their total amount in Land VIL being about the same, we are forced to suppose that the dis- crepancy is due to some analytical error, such as, possibly, a dehydration of the sodium platinichloride. Mode.—The mode of the plauenal monzonose was deter- mined by numerous measurements in different directions across a typical section of my specimen. ‘The results were: Vol. Wt. per cent. per cent, Ora tznee ies tee IN, Pe, cn 11°50 11°09 Soda-Ontmoclase a4. 25 2.1645 wees 63°96 Ohigoclasemte Saks eee tor OO) 2°79 Hloiniblemdie es caer cena ke pee 14°26 16°61 IMaonCtIbehee ie eee the. ele 1°38 2°61 AT GAGE ieee papa kee wee ene 0 1:55 1:97 Alpapiwes te ate seer se te a en es (1°83 0°97 100°00 100-00 As the chemical compositions of the hornblende and of the soda-orthoclase, which may contain some lime, are unknown, it is impossible to check the measured mode satisfactorily by eal- culation of the mode from the chemical composition, nor conversely to calculate the chemical composition from the Washington—Plauenal Monzonose (Syenite). 135 measured mode as given above. It is clear, however, that the mode is decidedly abnormative, the hornblende taking up nearly all of the normative diopside and hypersthene, with a very considerable amount of the anorthite, and a little of the albite, magnetite and ilmenite. The greater part of the ilmen- ite is used up in forming titanite, the silica and lime needed coming from diopside and the ferrous oxide of the ilmenite taking its equivalent of silica from the normative quartz to enter the hornblende. On the other hand the estimated amounts of quartz, orthoclase and albite as given above corre- spond well with the figures for these in the norm calculated from III. That the mode here given is close to the truth is indicated by the specific gravity. That of my specimen was found to be 2°73 at 23°, identical with Zirkel’s, while that cal- culated from the amounts of the several minerals shown by Rosiwal’s method was 2°697, a very satisfactorily close agree- ment. Name.—In a general way therefore this rock may be spoken of as hornblende grano-monzonose, but on account of its importance we may regard it as a type, to which the name of plauenal monzonose may be appropriately given. This name, it will be seen, implies the modal and textural characters involved in Rosenbusch’s Plauen Typus of the hornblende- syenites, but more strictly defined and with a very definite indication of the chemical composition as well. Locust, N. J., June. 136 C. Barus—Nuclei and Lons in Dust-free Arr. Art. XIV.—Colloidal Nuclet and Ions in Dust-free Air saturated with Alcohol Vapor ; by C. Barvs. 1. LIntroductory.—In my report* on the solutional nucleus and elsewheret I came to the conclusion that the differences in promoting condensation exhibited by positive and negative ions were more probably to be ascribed to the difference in chemical structure or composition involving a difference of size, than to the electrical differences as such. Experiments made in Wilson’s apparatus by Dr. Donnant with vapors of methyl and ethy! alcohol, carbon tetra-chloride, carbon-disul- phide, benzol, chloro-benzol, show that the supersaturation needed to produce condensation was not necessarily greater in ionizing than in non-ionizing solvents. With similar appa- ratus Dr. K. Przibram§ recently examined a series of alcohols and other bodies ionized by the X-rays, obtaining among a variety of data a noteworthy result with a direct bearing on the question here at issue. It appears that whereas in the case of water-vapor the negative ions are more efficient condensa- tion nuclei than the positive ious, the reverse holds for the . alcoholic vapors. In cases of methyl, ethyl, amyl and heptyl alcohols (including some other bodies like chloroform) the positive ions invariably require less supersaturation to precipi- tate condensation than the negative ions of the same body. Interesting differences are therefore manifest in the behavior of vapors, and it seemed desirable to test the nucleation of a dust-free medium of ethyl alcohol and air in comparison with the media of water-air and water-carbon-dioxide hitherto exam- ined. The former behaves in fact as if the nuclei were through- out larger than in the latter cases. Hence the colloidal nuclei of dust-free wet air should be associated rather with the satu- rated vapor than with the gas. 2. Apparatus. Method.—The experiments were conducted with an apparatus in which the connecting pipes between the foe chamber (18 inches long, 5 in. in diameter) and the vacuum chamber (5 feet long, 1 foot in diameter) were 4 inches in diameter containing a 4-inch counterpoised, plug stop-cock. The whole connecting system was about 22 in. long, one-half of it belonging to the fog chamber. Experiments made with water-vapor, however, did not show any further marked advantage arising from the use of the large passage way specified, over the former apparatus, in which the corre- * «Structure of the Nucleus”: Smiths. Contrib., No. 1873, 1903, p. 161. + ‘‘Tons and Nuclei’: Nature, lxix, 1903, p. 103. + F. G. Donnan: Phil. Mag. (6), iii, p. 305 to 310, 1902. $K. Przibram: Wien. Sitzungsber., exv, pt. Ila, p. 1 to 6, 1906. C. Barus—Nuclet and Tons in Dustfree Air. — 187 sponding tube was 2 inches in diameter. It is therefore super- fluous to adduce for comparison the new data for water-vapor. The general method of work was that frequently described in connection with these investigations. With the exceptions stated all data, to be at once comparable, must be obtained with a given pair of fog and vacuum chambers. 3. Properties of alcohol fog.—W hile the experiments of my last paper with the medium of water-vapor and carbon-dioxide gas showed unusually high values of the exhaustions needed to produce coronal condensation, the case of alcohol air shows correspondingly low values of exhaustion, as compared with those for water-air. The number of colloidal nuclei entrapped by alcohol vapor are about 3°5 times larger than is the case for water-vapor under like conditions. Hence the coronas for alcohol are exceedingly dense by contrast. They are also much less regular in color and, particularly at high exhaustions, become fog-like. The phenomenon is coarsened and measure- ment less satisfactory. As the alcohol fog particles are larger in size, they subside more rapidly at the same exhaustion than water particles: but the occurrences are in the former case far from simple. While in the earlier experiments the corona (if not too large) remained nearly the same throughout the slow subsidence of water parti- cles, the coronas for water and for alcohol particles in the present work decreased one-half or more in size during this period. In other words, the fog particles now experience very rapid growth* during subsidence, from which it follows many of them must evaporate to compensate in part for the eight- fold or more enlargement in bulk of the survivers, or further vapor may condense. The same fact may account in alcohol, where the phenomenon is more rapid, for the blurred coronas ; for the true initial corona, being very evanescent, is probably not seen. Conformably with this view, it is impossible to exceed large white reddish forms in the present apparatus and to reach the high greens observed with water-vapor. 4. Number of particles.—In order to determine the num- bert of particles corresponding to a given corona, it is first necessary to compute the amount of alcohol precipitated per cubic centimeter of the exhausted vessel, by the sudden cool- ing incident upon exhaustion. This may be done by a straight- forward approximationt with results shown in the following table, where ¢, is the initial temperature of the saturated air within the fog chamber, ¢, the temperature after sudden exhaustion and before condensation, and ¢ the temperature * The precise reasons for this growth may be of some importance in rela- tion to rain. ; + C. T. R. Wilson: Phil. Trans., London, vol. clxxxix, 1897, p. 300. ¢ The size of fog particles in terms of the apertures of the coronas is found as shown in my earlier papers (Smithson. Contrib., No. 1373, Chap. v1). 138 OC. Barus—Nuclei and Ions in Dust-free Air. after the precipitation of the m grams of alcoholic fog per cubic centimeter. The drop in pressure* is 6p from p = (a at 20°C. The data of the last columns will be presently explained. Op t ts t mx10—* -* p./ pe Fen em v6 °C °C grams em 10 20° +: 372° +14°8 10°08 2°42 1°44 20 20 —15°3 +10°2 18°3 6°21 re) 30 20 —36°'1 + 3°2 22°8 21°4 48 These may be compared with the case of water vapor. 85 OOF FSI eA Ge 2°68 221, 1:65 17 20 — 96 ST eOnS 4°6 5°68 aha, 22 20 —18°9 + 4°6 5°) IH "58 30 20 — 36°1 — 3°5 6°4 OO) 35 | We may infer from the table that in a perfect apparatus, water fog particles would reach freezing (0° C.) at 6p = 24™ and alcohol fog particles at 6p = 34° 5", Moreover for the same corona there must be on the average about 3°5 times more particles in the alcoholic fog than in the water- fog, which accounts for the opaqueness of the former. For the reasons adduced it is not worth while to express the results otherwise than in round numbers, for the data involved are inevitably crude. The assumption of the law of adiabatic cooling as far as —36° C. is questionable in view of the admix- ture saturated vapor: but as the densities of vapor are for alcohol about 8 per cent that of air and for water vapor about 7 per cent, this approximation in a raritied atmosphere, as well as the use of Boyle’s law for a wet gas, is probably admissible. It is different, however, with the latent heat of the vapor, which is required at the low temperatures, but is known (as a rule) only at temperatures near the boiling point. From this and similar points of view, measurements of latent heat for the more common vapors at very low temperatures would be desir- able. Finally the point at which the drop in pressure ceases to be efficient, because of the increasingly rapid inward radiation of heat from the vessel, is the most serious of the outstanding errors. I have endeavored to diminish it compatibly with the desideratum of a large and easily adjusted fog chamber, by successively increasing the bore of the exhaust pipes and stop- cocks; and this plan has been in a large measure successful. The extent to which the error is present, as the drop in pres- sure increases more and more, is nevertheless left unanswered. *The value of dp here referred to is the experimental value observed under isothermal conditions at the fog chamber. The value computed from the dimensions of fog and vacuum chambers is dp x 775, as will be shown elsewhere. C. Barus—Nuclet and Ions in Dust-free Avr. — 189 If the upper inflection of the distribution curve (fig. 2) is a criterion, 1. e., if adiabatic cooling ceases with the occurrence of identical terminal coronas for successively increasing ex- haustions, the fog chamber with water-air is efficient to about 6p = 31 or 32™, with water and carbon-dioxide to about dp = 387", with alcohol and air to about 6p = 20. In the former case the vapor would be cooled from 20° to about. —10°C. even after condensation: in the latter case to about +10°. On general principles and in view of the low tempera- tures of the water particles, it would seem probable that the efficiency of the fog chamber must vanish gradually. -But the appearance of the curves is such, as if the action were unim- paired up to a given terminal drop i in pressure. In every case the fog particles with the surrounding medium - of vapor soon reach the temperature of the air again, so that additional moisture must arrive from somewhere. It has been » instanced above that the marked constancy of the water-coronas during this period in the work done heretofore gave no evi- dence of the evaporation ; while the present water and alcohol © coronas decrease one-half in aperture, 1. e., the preponderat- ing fog particles actually grow, because the exhaustion is slowly but steadily incremented when the stop-cock is not quite tight, the fog particles acting like very large nuclei. Even if this is compatible with the evaporation of the smaller particles, there is again no evidence for it. Much of the moisture must therefore come from the wet cloth and the water within the vessel, which are not cooled by the expansion. 5. Size of the nuclec.—Here it may be. worth while to inquire into the reason why the precipitation in alcohol is apparently so much easier; or what is the same thing, into the estimated size of the nucleus on which precipitation takes place in these several cases. The Kelvin equation as moditied by Helmholtz* may be used} for this purpose (as was done by the latter and by Wilsont in the form p,/p, = &?/"*"" where p, and p,, are the vapor pressures at the convex areas of radius rand radius infinity respectively, 7 the surface tension of the liquid of density s, # the gas constant of its vapor at the absolute temper ature 0. Since p, is the adiabatically reduced vapor pressure (without condensation) in the volume expansion due to the drop of pressure 6p, and p,, the normal vapor pres- sure at the same temperature ee 273° 4-4, in Table I, 7 fol- lows from the equation. The values of S= D/P. sand. 7 SO found are both given in Table I, and have been constructed in * Helmholtz: Wied. Ann., xxvii, p. 524, 1886. +Similar estimates of my own are Buen in Bull. U. S. Weather Bureau, No. 12, 1895, p. 48. tC. 7, Ry Wilson : Phil. Trans., vol. clxxxix, 1897, p. 305. 140 C. Barus—Nuclei and Ions in Dust-free Air. the chart, figure 1, where their relation to the usual order of molecular size (m in the figure) is also indicated. Clearly these values of 7, the radius of the nuclei differing so little from molecular radii (say 107°"), ean only indicate an order of values; for apart from the difficulties above enumerated in computing @, 7 depends on surface tension 7, which has no meaning for molecular dimensions. Granting this, it is none 0 4) 10 15 40) AD BU we 235 the less remarkable that the values of 7 obtained should be so nearly alike for water and alcohol, where different constants (Z,, F, s, ete.) occur throughout; in other words, that at a given temperature a given drop of pressure will condense both vapors on nuclei of about the same size. In so far as these estimates are admissible, it follows that the alcohol air nucleus is larger than the water air nucleus; in the former case coronal condensation begins at about 6p = 15™, where 7 = 10~", while in water vapor it begins at op = 26™, where 7 = £X10~° about, less than half as large. These rela- tions once established are retained through all successions of nuclei, as the following data for alcohol vapor in compari- C. Barus—Nuclei and Ions in Dust-free Air. 141 son with water vapor show. It is a little difficult to under- stand why the ionized nuclei in alcohol vapor should, like the colloidal nuclei, be larger than the corresponding cases for water vapor, unless the ions are aggregated colloidal nuclei, a point of view tentatively advanced elsewhere.* 6. Data for alcohol vapor. —The behavior of alcohol vapor is shown in the usual way in the following chart, fig. 2, where 6p is the sudden fall in pressure from normal atmos- pheric pressure, producing the corona of the angular diameter 1400 1200 4000 | | s / 30, when the eye and the source of light are at distances 40 and 250° on the opposed sides of the fog chamber. The nucleation 2 deduced from s is computed in the way given above, $4, and indicates the number of nuclei in the exhausted fog chamber. It is assumed therefore that the nuclei are re- produced more quickly than they can be withdrawn by the exhaustion. Measurement of s is not very satisfactory, as the coronas are blurred and accompanied by dense foos and change rapidly on subsidence. The effect of X-radiation leads to the same terminal corona which appears for the non-energized vapor. The results as exhibited in fig. 2 are seen in connection with earlier results for media of water-air and water-carbon-dioxide, the same condensation apparatus and method underlying all experiments. One may notice at once that in the cases CO,- _water and air-water, both for the non-energized and for the energized state, the ‘observed data would be obtained by shift- ing the air- water diagram as a whole to the right, as if the cooling in case of CO,-water vapor were less efficient.+ The * This Journal, xx, 1905, p. 453; Phys. Review, xxii, 1906, p. 109. + Phys. Review, April, rap 5e , August, 1906. 1442 0. Barus—Nuelei and Tons in Dust-free Air. graphs are of the same kind, nearly parallel, and all of them (energized or not) again terminate in the same asymptote or large green-blue-purple corona. The alcohol curves differ from the water curves chiefly in three respects: (1) though the graphs both for the non-energized and energized states terminate in a common asymptote, this is not the green-blue-purple corona, but the white-yellow corona lying slightly below:it ; (2) the curves as a whole he with a somewhat larger slope in a region of much. lower exhaustions (67); (8) the number of nuclei caught in alcohol vapor is rela- tively very large. The second and third observations have already been discussed. The first deserves especial considera- tion. The question occurs at once why both the energized and the non-energized curves should be limited by the same final corona, irrespective of the size of the nuclei, and why this should be lower for alcohol than for water. For the ionized state one might infer that the total number of ions has been precipitated, as is actually the case at low ionization; but if under strong ionization this were true for alcohol vapor, it could not be true for water vapor, where the number of ions caught is less than one-half the number in alcohol. In general it is improbable that the terminal corona for ions should in such a case be the same as the terminal corona for colloidal nuclei. The explanation which seems plausible to me is this; each nucleus must drain the air of its supersaturated moisture within a certain radius large as compared with the size of the nucleus and increasing in the lapse of time. A limit of the phenomenon will be reached when for an indefinite number of graded nuclei the enveloping spheres free from supersaturation form a system in contact. In case of water vapor the distance between centers would be 014; in ease of alcohol :010, distances which are both enormous as compared with the estimated size of nuclei(7), Table I. At all events, when the limiting nwmber of nuclei has been cap- tured, the apparatus is powerless to produce condensation on a greater number of nuclei, be they relatively large as the ions or small as the colloidal nuclei, however many other (inefficient) nuclei may be present. Brown University, Providence, R. I. C. Schuchert—Russian Carboniferous and Permian. 148 Art. XV.—The Russian Carboniferous und Permian com- pared with those of India and America. A Leview and Discussion ; by CHARLES SCHUCHERT. [Continued from p. 46. ] Part ill. Tue Worx or DIENER. 1. The Permocarboniferous Fauna of Chitichun No. I. Mem. Geol. Surv. India, ser. xv, Himalayan Fossils, vol. i, pt. 3, 1897, pp. 1-105, pls. i-xiii. 2. The Permian Fossils of the Productus Shales of Kumaon and Gurhwal. Ibid., pt. 4, 1897, pp. 1-54, pls. i-v. 3. Permian Fossils of the Central Himdlayas. Ibid., pt. 5, 19038, pp. 1- 204, pls. i-x. In the central Himalayas at the limestone crag of Chitichun No. 1, at an elevation of 17,700 feet, Griesbach, Middlemiss, and Diener, in the year 1892, discovered a lot of fossils described in the work cited above (1). Thestratigraphical results of this collection are described by Diener on pp. 85-105, from which are taken the following extracts :— “ Karpinsky and Tschernyschew, two authors to whom the most detailed studies of the Artinskian fauna are due, strongly advocate the distinction of the permocarboniferous from carbon- iferous and permian systems, and are decidedly averse to uniting it with either the one or the other. Tschernyschew especially strongly combats the view of the majority of geologists who proposed to unite the permocarboniferous with the permian, as a lower division of the system. According to him a separa- tion of the permocarboniferous from the permian system 1s demanded by the general aspect of the fauna, in which the carboniferous ty pes greatly predominate, chiefly among the brachiopods. If it ought to be united either with the carbon- iferous or permian system, in spite of its distinctly intermediate position, it must necessarily be placed in the former, on the strength both of the carboniferous character of its fauna and of historical priority, since the Artinskian sandstone had been correlated with the carboniferons millstone-grit of Western Europe by Sir Roderick Murchison, who first introduced the name per mian. ‘Against the first argument the objection may be raised that notwithstanding the prev alence of carboniferous types in the Artinskian fauna, the latter ‘marks a very important moment in the history of development of organic remains, namely, the first appearance of true ammonites with complicated sutures.’ Nor is the large percentage of carboniferous types in the Artinskian fauna an astonishing fact, in view of the absence of any break in the sequence of marine beds from the upper carboniferous to the true per mian strata. Even in beds, which must be placed very high in the permian system, in the upper Productus limestones of the Salt Range and in the Oto- AM. JoUR. ScI.—FouRTH SERIES, VOL. XXII, No. 128.— — AUGUST, 1906. 10 144 C. Schuchert—Russian Carboniferous and Permian. ceras beds of Julfa, the fauna contains a proportionately large number of carboniferous forms. It is to the faunas of these deposits, the normal representatives of the pelagic permian [by this the author means a normal marine fauna], not to the local fauna of the Zechstein, that the permocarboniferous fauna must be compared, if we want to get a clear idea of its rela- tionship to those of the upper carboniferonus and permian. Bearing in mind the gradual passage from an upper carbon- iferous to a permian fauna through the intermediate group of rocks, the question to be answered is, which consideration is of the greater importance in defining the boundary between the two systems, the appearance of a new group of cephalo- pods, which become of an unparalleled stratigraphical value in mesozoic times, or the presence of a belated fauna, com- posed of forms which are generally not well adapted for the characterization of narrowly limited horizons. “The majority of geologists have decided in favour of the first alternative. Giimbel, Krassnopolssky, Kayser, Waagen, Credner, Munier-Chalmas and A. de Lapparent, Frech—to enumerate only a small number among them,—are unanimous in regarding the permocarboniferous as the lowest division of the permian system” (pp. 87-88). “In the Mediterranean region three different rock groups have yielded fossil remains of this pelagic development of the permian epoch. These rock groups are the Fusulina lime- stones of the valley of Sosio in Sicily, the Bellerophon lime- stone of South-eastern Tyrol and Friaul, and the Otoceras beds of Julfa in Armenia. All of them are of a rather isolated occurrence and, as far as one may judge from their faunas, of different age. “The lowest ‘position is apparently held by the Fusulina limestone of Sicily. Its cephalopod fauna seems to be more nearly related to the Artinskian one than to those of the Jabi beds of the Salt Range or of the Otoceras beds of Julfa. Ammonites with ceratitic sutures are yet absent. According to Karpinsky’s statement, one species of d/edlicottia is identi- eal with an Artinskian form; ten more species are very nearly allied. On the other hand, Karpinsky and Waagen noticed the first appearance of Waagenoceras and Hyattoceras in Sie- ily, two genera which show a much more complicated sutural line than any of the Artinskian Ammonea. Waagen conse- quently places the Fusulina limestone of Sicily on a higher level than the permo-carboniferous stage, but on slightly lower level than the Jabi beds of the upper Productus limestone. “The Otoceras beds of Julia with their strongly marked triassic affinities must certainly be higher in the upper paleeo- zoic series than the Fusulina limestone at Sosio. They cannot be much different in age from the Otoceras beds of the Him- C. Schuchert—Russian Carboniferous and Permian. 145 alayas, although the latter certainly hold a somewhat higher stratigraphical position, and they may consequently be placed on a level with the upper Productus limestone or with the Chidru group of the Salt Range. “The youngest of the three rock groups is probably the Bel- lerophon limestone of South-eastern Tyrol. Its fauna is a very peculiar one, species identical with those known outside this rock group being almost completely absent. The predomi-. nance of palseozoic types induced Stache to fix the homotaxis of these beds as upper permian, whereas Giimbel supposed them to be of lowest triassic age. . . . “In none of these three permian rock groups of the Med- iterranean region is a normal sequence of marine beds exposed, with the possible exception of the Bellerophon limestone of the Carnian Alps, which, however, is underlaid by an enor- mous mass of unfossiliferous limestones and dolomites. Their correlation must consequently be based on paleontological evidence alone” (pp. 90-91). Recently, Schellwien and Kossmat (Monatsber. No. 9, Deutsch. Geol. Gesellsch., 1905, pp. 357-9) found in the Bellerophon limestone (usually regarded as the topmost Per- mian of the Alps) of Krain, west of the Laibach plain, a fauna consisting in the main of brachiopods, corals, and Fora- minifera. As yet the fossils are not worked out of the matrix, but the following species are determined: tichtofenia aff. lawrenciana, Productus indicus, P. abichi, Marginifera ovalis, and Lonsdaleia wmdica. In regard to these fossils Schellwien concludes as follows :— “The finding of this fauna dispels all doubt as to the Per- mian age of the Bellerophon limestone. The value of this discovery in fixing the time position of this limestone, how- ever, is overshadowed by the greater one,—that of fixing the chronologic position of the Productus limestone [of India], the correlations of which, as is known, are still at variance. The fossil-bearmg beds of the Bellerophon limestone are everywhere in close association with the lower Werfen beds [Triassic]: m southern Tyrol the boundary between the Wer- fen deposits and the Bellerophon limestone is ditiicult to estab- lish. At Krain the fossiliferous zones of the Bellerophon limestone are also separated, but by a thin dolomite series from the Trias. These upper dolomites introduce micaceous layers and gradually pass into the Werfen slates, with their well- known bivalve fauna. The Bellerophon limestone, therefore, can represent only the highest zone of the Permian, and for the Productus limestone the same view may also be affirmed. Worthy of note is the fact that of this fauna of the Bellero- phon limestone, it is also not only those of the higher zones of the Indian Productus limestone but likewise forms of the / 146 CO. Schuchert—Russian Carboniferous and Permian. lower horizons. Should the detailed examination show that the fossils of the various horizons of the Productus limestone are also found associated in the thin fossiliferous zone of the Bellerophon lmestone of Krain, the conelusion will be una- voldable that the various zones of the Produectus limestone are of Upper Permian age.” In the second paper cited above, treating of the fauna of the Productus shales, Diener states the followimg :— ‘The only decisive evidence for a permian age of the Pro- ductus shales is however based on their stratigraphical rela- tions to the triassic beds of the mesozoic belt of the Central Himalayas, not on their fossil remains. One of the chief results of Griesbach’s geological survey of the Bhot Mahals of Kumaon and Gurhwal is the proof of an unconformity, exist- ing at the base of the Productus shales, which locally overlap successive strata of carboniferous age. With this unconform- ity another uninterrupted sequence begins, with conformable bedding throughout, which ranges from the Productus shales to the topmost beds of the triassic system. So intimate is the stratigraphical connection between the Productus shales and the followimg Otoceras beds of lowest triassic age, that a sharp boundary cannot be drawn between them” (pp. 53-54). In the third pubheation above cited, Diener reviews his for- mer work on the fossils of Chitichun No. 1, owing to larger and more significant collections subsequently made by Walker. These collections have not altered Diener’s correlations with the Salt Range, but they have, when interpreted in the hight of Noetling’s publications, caused him to depart strongly from the nearly unanimous views of European stratigraphers and to agree in the main with the intercontinental correlation of Noetling. Great weight should be attached to the correlation of these two paleontologists, for they have collected the fossils of the Permian in India and studied them in the laboratory. Diener’s conclusions are as follows :— ‘“So far there is no reason for any change in my correlation of the Chitichun fauna with Indian faunee of permian age, as proposed by myself in 1897. I am, however, bound to contess that the affinities of the Chitichun fauna to those of Europe have not been correctly interpreted, and that my examination of Walker’s materials is apt to lead in this respect to results remarkably different to those deduced in my first memoir. “In that memoir [here numbered 1] the conclusions at which I arrived with regard to the stratigraphical position of the Chitichun fauna were summed up as follows :— “ — l Wea sae < ; 2s , Class II, Dosalane Q _ 13°08 3 eel ae oe Roo eres? << ee Order 4, Austrare K,0+Na,O _ 89 RS SAO aK? < 5 eS 5 Rang 3, poualase K,O 20 bee Neo 49” <<. ie Subrang 4, Tonalose .No. 3. Oven oO) teers Se teres eee SS re 888g Ortioclase, KO Oval OFcSiO 22 2 22.22 .-5--" 10:01 AIGemNa Ow Al OL OSIOsl ssa .52 2556 22... 32°49 Js MOP COUNTS, ONO SIRO) sO) a eres 20°85 ( CaO.Si0, 4°52 Diopside HeOisiO} "66 8°58 ( MgO.Si0, 3°40 Mg0O.8i0 10°40 Hypersthene Fe0.8i0,; 2-1] 12751 MeonetitesMeO Me OF os 6 Ss se eek 4°18 inmentte sh CO li Oi 2 2 8 ee ek 2°28 BAN) UMUC we ern ye oe ee Sr cise a ge ena "62 LESS Sch ATE ACE, see toe ASRS ee Nea ei ALG eae 59 100°99 Salles 23 GOT Wen = gan” < a = ioe Class II, | Dosalane Q 8°88 3 a eusinake i — @gas 2 < 5, » Order 1-5) Germanare K,0+Na,0 80 5. 8 Tonalase (30mm iss SY Andase K,O 18 See Sta alae Tonalose Wal 032 Sa 7? Subrang 4 Andose Sierra de Guadalupe. The regularity of the valley of Mexico is broken in many places by branches extending from the high mountain ranges and reaching in some eases almost to the city of Mexico. One of the most conspicuous of these is the Sierra de Guadalupe located directly north of the city, and consisting of a series of rounded hills of low altitude (fig. 3). The three elevations nearest the city of Guadalupe are known as Cerro de Guerrero, Cerro de San Isabel and Cerro de Chiquihuite. At the base, 166 LN. Guild—EKruptive Rocks in Mexico. especially in the vicinity of the city, they are composed of rocks presenting the appearance of volcanic breccia with cementing material of a dark vitreous andesite, with sometimes small phenocrysts of feldspar; the fragments are of very much the same material with occasionally lighter colored and more por- phyritic varieties. The most common type is that of a dark brown to black compact rock, with a few visible phenocrysts of green pyroxene. These rocks are nearly all opal-bearing, the Fic. 3. A view of the Sierra de Guadalupe. Aqueduct of Guadalupe in the foreground. mineral occurring in cracks and occasionally in amygdaloidal cavities.* It is usually colorless (hyalite), but sometimes pre sents various shades of yellow, redand blue. More porphyritiec types of these andesites occur in other portions of the series. Microscopically these rocks are similar to those from Popoca- tepetl and are hypersthene andesites. While there is great mineralogical similarity in the specimens from different places, there is also great diversity in the arrangement of the con- stituents, variations in texture due to more or less rapid cooling. The feldspar appears as rods, broken fragments, and larger crystals with zonal structure frequently possessing a clear border, but containing dark inclusions in the interior. The * For an excellent description of the occurrence of opal in the eruptive rocks of Mexico, and how they are frequently found filling decayed spheru- litic growths, see, Las Rhyolitas de Mexico, Bul. Num. 14 y 15, Inst. Geol. de Mex, F. N. Guild—Eruptive Rocks in Mexico. 167 groundmass varies from a pure glass swarming with crystallites to a semi-crystalline condition, frequently containing obscure globulitic and microlitic growths. Hypersthene andesites of this type have been deser ibed from Crater Lake, Oregon,* and other portions ot the United States. Colima de Chapultepec. This is a small rocky eminence rising abruptly from the plains, about three miles southwest of the city of Mexico. On the summit is the beautiful castle of Chapultepec, and around its base are artificial lakes and roadways which make it one of the most beautiful parks in the world. Although isolated, it is considered to belong topographically to the Sierra de las Cruces, a range bounding the valley on the southwest.t Specimens collected from it appear as dark gray mottled rocks with porphyritic hornblendes and feldspars, the latter being most conspicuous. Under the microscope both feldspar and hornblende are found to occur in two generations, the feldspar in large idiomorphie crystals with zonal structure, and symmet- rically arranged inclusions and smaller rod-shaped growths; the hornblende is in elongated crystals and is of a basic variety possessing strong pleochroism and dark to opaque borders. The groundmass is partly crystallized, containing needles of both hornblende and feldspar with patches of transparent glass. (A, fie. 5, p. 172.) An analysis of this rock was made by the writer with the following results : Analysis of Hornblende Andesite from Chapultepec. SO) eae ee a eee 62°89% PROM eae hat Meio se A 16-42 Bich Oia Ser es, or Se 2°64 CO gee ys Ae he Ha eet es OA: INT Orta net ays Sao tL Se 2°50 CEN es SY en ee 4°77 JN) GO PN 2 se a 4°07 Oe ee eG) Ae LY Dols HO, “Above 11 ...-.-.....-. 1-00 EMO below. 110) 222252. e 555 OF eaeee ee ey ee. 88 [PUG Ae 5 5 eee en apenas ep "20 Cin Os ee ee Le ‘Ol Mini Ore eee a = On |, 08 EO ee es ee Soe 03 DAO samen een eS 07 ID) See 5 Pa ee Trace 100°45 * Diller & Patton, The Geology and Petrography of Crater Lake National Park, U. S. Geol. Sur. PP No. 3, plate xv. + Orddéfiez, Bul. Num. 2, Ins. Geol. de Mex. 168 LN. Guild—Eruptive Rocks in Mewico. Normative Mineralogical Composition and Classification. Quartz SiO sass pe WA Ri I, 79502 Orthoclase, K,0.Al,0, 6Si0, . DER ELAS G3) bee i227) Albite, Na,0.Al,0, 6810, ba is Lowe eat Se aS Anorthite, ‘CaO. Al, AO). 2810, Sper Merman hs. (0) (0S: MgO.Si0, 90 ) Diopside FeO.Si0, 13 > 2°18 CaO.SiO, 115 J Mg0O.8i0 5°40 Ilypersthene ROS SiO, : 53 5°93 Magnetite, FeO. Fe,O, Sat oe ene ae Bey Ilmenite, Fe0.Ti0, . Pauls 2U eae ge ae alee pete Bee es raise en Cavin cereus OS) Rests 7 95°: SSS a kN a eee ten eee mae 100°27 Sal 84:91 a 5 : fen Sas6r0 < CoS Class II, Dosalane OMe Wise Socal ee. is + = @rso” < eae , Order 4, Anstrare K,O0+Na,O _ 89 brea 3 Gad = 75? < ae ae Rang 3, Tonalase K,O 23 3 Ie eet a Nal = 66 : , hang 3, Comptonase N20 = os. < - > - Subrang 4, Comptonose Sierra Catarina, one of the most interesting features in the valley of Mexico, consists of a series of crater cones rising abruptly from the level plains in the southeastern part of the valley. Some are in groups of four or five, while others are isolated truncated cones with an average height of 400 feet. Five of them were visited by the writer during the summer of 1905, and all but one were found to have a well defined crater on the summit. Their component material varies from pure volcanic sand to compact lava, while scoriaceous forms, lapilli and voleanic blocks of all sizes are abundant. A compact lava is found near the base of several of them but has never flowed to great distances. The predominating color is black for the compact varieties of lava and black or red for the more scoria- ceous modifications—porphyritic types are entirely lacking. Las Calderas, perhaps the best known of these crater cones, is about one mile south of the railroad station of Los Reyes. It is an elongated truncated cone with a sloping summit due to the erosion of the rim on the southern extremity. The cone contains two craters with a narrow rim between them. Barometric observations gave the following elevations : Highest point on the rim, 650 feet above the plain. Lowest point on the rim, 275 feet above the plain. The bottom of the crater was found to be at practically the same level as the surrounding plain, its diameter is about 1,500 feet and its interior walls are quite precipitous. This cone consists almost entirely of a yellowish gray strati- fied tuff of about the hardness of adobe brick and with an occasional voleanic block embedded in it. Microscopically the ash is made up mostly of transparent glass with some micro-. lites of feldspar and decomposed particles of ferromagnesian minerals. The volcanic block mentioned above contains small and rather scattered rods of feldspar in an exceedingly dark, glassy, structureless groundmass. Ferromagnesian minerals are present only in isolated grains. The rock is of too vitreous a nature to admit of accurate classification from its mineral con- stituents. . Directly southwest of Las Calderas is a series of crater cones the best formed of which is called Cerro de Catarina. The pt cal | bo LE. N. Guild—Eruptive Rocks in Mexico. Fic. 5. Description of Photomicrographs illustrating the types of ande- sites in the valley of Mexico. A. Porphyritic hornblende andesite from Chapultepec, showing both feld- spar and hornblende in two generations. The groundmass is nearly all crystallized material. 14 diameters. B. Hornblende andesite from Xochitepetl. Zonal structure in feldspar. Crystalline groundmass. Crossed nicols. 14 diameters. C. Andesite of basaltic aspect from Popocatepetl. Abundant feldspar and less pyroxene in a vitreous groundmass. Pyroxene cannot be dis- tinguished from feldspar in the cut. 14 diameters. D. Andesite of basaltic aspect from Sierra de Guadalupe showing a large hypersthene with smaller feldspar crystals in a semi-vitreous groundmass. 14 diameters. A and B are light-colored porphyritic andesites representing an old out- flow of great extent. C and D are megascopically non-porphyritic and belong to an outflow of recent date. FN. Guild—Eruptive Rocks in Mexico. 173 approach to them from Los Reyes is over an exceedingly rough bow of compact lava. Several specimens were collected from this elevation, one of a lustrous black rock with conchoidal fracture and free from cavities or inclusions. Others collected from the loose material around the crater were more scoriaceous and contained many cavities. Under the microscope they all show about the same characteristics, the chief variation being in the relative amount Fic. 6. View taken from the interior of the crater of Las Calderas, show- ing the walls and stratified condition of the volcanic ash. of glass present. The description of the block found on Las Calderas applies to most of the fragments found near the sum- mit of Catarina. The rock of the rough lava flow mentioned above, while probably of the same mineralogical composition, has quite a different texture. It is basaltic, consisting of dark glass swarming with minute rods of feldspar. The rods are not pressed together as is usual in these types of rock but each individual appears quite distinct from its neighbor. Cerro Xaltepetl, located still further south, is similar to the last described cone except that it is of less altitude, contains a greater quantity of the finer products of volcanic activity and the outflow of lava at the base is lacking, and there are strati- tied beds of ash in its place. Sections prepared from volcanic blocks, lapilli and scoriaceons material reveal nothing new as compared with that from the other cones of the same group. The crater is very shallow and probably not more than 500 174 IN. Guld—Kruptive Rocks in Mexico. feet across; the soil formed at its bottom is very fertile and these craters seem to be favorite places for cultivating corn. Next in line in this interesting group of voleanoes is Cerro de San Nicolas, one of the smallest but most symmetrical of the cones. It is about 350 ft. high, as found by barometric meas- urements, and contains a small crater possibly 50 feet deep. The material ejected from this crater both from a megascopic and microscopic standpoint presents about the same character- istics as in the last two cones. About three miles from San Nicolas is another low eleva- tion called Cerro de Ixtapalapa whose crater has been com- pletely removed by erosion. Near the summit the component material is the same as that of the other craters of the group, but its base is of compact lava which has spread out for some distance forming gentle slopes. In this respect Cerro de Ixta- palapa resembles Cerro de Catarina more than the other cones. Under the microscopes this compact lava is more crystallized than any of the othersexamined. Feldspar occurs in two dis- tinct generations although no phenocrysts can be detected by the naked eye. Orthorhombic pyroxene is abundantly devel- oped in the form of isolated crystals and clusters. This rock resembles quite closely those already described from the Sierra de Guadalupe. It may be called a hypersthene andesite. Summary. It will be seen from the foregoing descriptions that the valley of Mexico and vicinity represent a petrographic province in which the intermediate and basic types of rocks are abundantly developed. In this respect it resembles regions of recent voleanic activity in the western portion of the United States and other parts of the world. The hypersthene andesite from Popocatepetl and the Sierra de Guadalupe are very similar to those described from Crater Lake, Ore.,* Mt. Shaster, Cal.,¢ Buffalo Peak, Col.,t and other well known loeal- ities. Further the material ejected from Colima and other active volcanoes in Mexico during their recent periods of eruption seems to be of the same general mineralogical com- position. The chemical composition is also similar, as may be observed by comparing the analyses accompanying this paper with those from the localities mentioned above. It is inter- esting to observe the relation between the chemical composi- tion of the older crystalline andesites as illustrated by the rock from Chapultepec, and the newer, non-porphyritic, more vitre- * Diller and Patton, The Geology and Petrography of Crater Lake National Park, (PE No, 3, US Geolkksur + Diller, U. S. Geol. Sur. Bul. No. 150, p. 227. t Cross, U. S. Geol. Sur. Bul. No. 150, p. 224. _ §Orddéfiez, Les Derniéres Eruptions du Volean de Colima, Mexico, 1903. Also a review by the writer in Geologisches Centralblatt, Bd. VII, No. 8. FN. Guild—Eruptiwe Rocks in Mexico. 175 ous and basaltic-like lava from Popocatepetl. These are almost identical in chemical composition yet have given rise to dissimilar mineralogical developments. The one has developed abundant hornblende, the other pyroxene. This of course is easily explained on the ground that the consolidation has taken place under diverse conditions, the one being erupted in large masses which formed mountain ranges and so cooling very slowly and under great pressure, the other in small out- flows which in some cases barely spilled over the rim of the crater. Farrington* in comparing the rocks of Popocatepetl and Ixtaccihuatl speaks of the remarkable fact that they differ completely in character, the one being hypersthene andesite and the other a quite dissimilar appearing hornblende ande- site. It is quite possible that in this case as in the one men- tioned above a similar chemical composition is masked by a dissimilar mineralogical structure. This view is further sub- stantiated by comparing the analysis given above (No. 1) with an incomplete analysis of hornblende andesite from Ixtaccih- uatl made by Felix and Lenk.t As is well understood, horn- blende requires for its formation unusual conditions of pressure, etc., while the pyroxenes do not. The recent lavas of Popo- catepet! are more acid in composition than the old. The few basalts are mostly covered up by andesitic outflows. The older andesite of Tlamacas is of a more basic type than those collected about the rim of the crater. Volcanic sand and ashes are developed in enormous quanti- ties around the base of the older mountains in many places in Mexico, and constitute one of the chief sources of the great fertility of the soil. The writer has been told that after the coffee plantations in that country have become covered for many square miles with a thin mantle of gray ash from the volcanoes, contrary to the expectations of the haciendadoes the soil has been improved and better yields experienced. The older voleanic sands frequently become cemented and consti- tute a material of sufficient strength to be used as a building stone. It is often so soft that it can be worked into various shaped bricks by means of a hatchet, and not infrequently becomes harder on exposure to the air. The texture varies from a fine-grained stratified deposit like that described from Las Calderas, to rounded semi-pumiceous grains somewhat larger than peas cemented by finer material. Many of the varieties frequently have a peculiar, not unpleasing and rusty appearance. Intermediate varieties sometimes show oolitic structures. * Op. cit., p. 109. + SiO, 61°24, Al,O; 18°32, Fe.O; and FeO 6:17, MgO 3-76, CaO 5:06, Na.O 3°15, K.0 2°37, H2O 0°67, Felix und Lenk, Btr. Geol. Mex., II, p. 229, 1899. Am. Jour. Sct.—Fourts Srrizs, Vou. XXII, No, 128.—Auveust, 1906. 12 176 S. £. Moody—Hydrolysis of Salts. Art. XVIL—TZhe Hydrolysis of Salis of Tron, Chromium, Tin, Cobalt, Nickel, and Zinc in the Presence of lodides and "Todates; by Ser E. Moopy. [Contributions from the Kent Chemical Laboratory of Yale Univ.—exlvi. | Tron. Ir has been shown in a former paper* that the action of a mixture of potassium iodide and potassium iodate upon alumi- nium chloride and aluminium sulphate may serve as the basis for the iodometric determination of aluminium. Just as salts of aluminium are hydrolyzed in the presence of the iodide-iodate mixture with the liberation of iodine, so are salts of iron. The reaction by which ferric sulphate is hydrolyzed is similar to that for the hydr olysis of aluminium chloride and aluminium sulphate, as already given. Fe,(SO,), + 5KI + KIO, +3H,0 = 2Fe(OH), +3K,SO, +61. he hydrolysis of ferrous sulphate is accompanied by oxida- tion of the ferrous hydroxide at the expense of the iodate, as follows: 3FeSO,+5KI+ KIO, + 3H,O = 3Fe(OH),+3K,S0,+61 6Fe(OH),+ K1O,+3H,O = 6Fe(OH), + KI. The iodine eliminated is an exact measure of such hydrolysis as in the case of aluminium and becomes known by the use of a standard solution of sodium thiosulphate for its titration. A solution of ferrous sul- phate was used in the experi- ments performed, made up to about N/10 strength. Its value was obtained with potassium permanganate as shown in ‘Table deaga@n this solution portions of 25°™ were drawn from a burette into a Voit flask, the iodide- iodate mixture added and the whole boiled for 30 minutes in the presence of a current of hydrogen to transfer the iodine to the receiver, a Drexel flask charged with potassium iodide, when it was estimated with a standard solution of sodium thiosulphate. Table IL shows results of these experiments. * This Journal, xx, 1905, p. 181. S. HL. Moody—Hydrolysis of Salts. nb TABLE I. Iodine FeSO.;. KeMn.Os. Fe. equivalent. em?, em? erm. erm. erm. (Mean.) 25 10°60 0:0734 0°3326 | 25 10°60 0:°0734 0°3326 | 25 10°57 OF OTe 2 0°3317 + 0°3322 25 10°58 0°0733 0°3320 | 25 10°59 0°0734 0°3323 | TABLE II. FeSO,. KI. KIO3. Time in Na.S.Q3. Iodine Diff. minutes. calculated. em’, grm. cm?, emery: erm. erm, 25 1:0 15 30 26°67 0°3324 + 0°0002 25 1:0 15 30 26°68 0°3325 + 0°0003 25 1:0 15 30 26°65 0°3321 —0°0001 25 i) 15 30 26°67 0°3324 + 0°0002 25 1:0 15 30 26°66 0°3323 +0:0001 So it appears that the hydrolysis of ferrous sulphate is com- plete in the presence of the iodide-iodate mixture and that the iodine set free is an exact measure of the SO,-ion present and of the iron in the ferrous sulphate of ideal composition. Chromium. Chromium sulphate, in the form of the alum, was next ex- amined. The standard of the solution was found by precipi- tating with ammonia and igniting the chromic hydroxide to constant weight. For the purpose of comparison other por- tions of the solution were treated with the iodide-iodate mix- ture and boiled for half an hour in a trapped Erlenmeyer beaker to expel the iodine. A few drops of sodium thivsul- phate were added to take up the last trace of iodine and thus insure complete hydrolysis. The precipitate was filtered off on asbestos, washed with boiling water and ignited to constant weight. Results of these experiments are given in the follow- ing table: TABLE Li, _ Approx. N/10 Precipitant. chrome Ammonia. Iodide-iodate Mean of alum, mixture. entire series. ; Once OF Cr.03 found. found. em? erm, erm. erm, 25 0°0643 0°0638 | P45, 0°0638 0°0645 25 0°0646 0°0641 \. 0°0642 5, 0°0641 0°0640 | 25 0°0644 00643 | 178 S. £. Moody—Hydrolysis of Salts. The sulphuric acid set free by hydrolysis upon boiling with the iodide mixture was then found by the iodide-iodate reac- tion, one gram of potassium iodide being in each case dissolved in 10™ of a solution of potassium iodate (30 grms. to a liter) and added to the measure of chrome alum in the Voit flask. The mixture was boiled thirty minutes with a current of hydrogen to aid in removing the iodine liberated to the Drexel flask containing about 3 grams of potassium iodide dissolved in water. The iodine collected in the receiver was estimated with sodium thiosulphate as in previous experiments. That the hydrolysis of the sulphate had been complete was shown by dissolving the washed precipitate in nitric acid and testing the solution with barium chloride, no barium sulphate being found. TABLE IV. Approx. Cr.0O; Excess N/10 corresponding to of chrome Time in SOs, equivalent of Cr.Oz3 alum. minutes. NazS20s. if iodine set free. (Basic.) em?. em?. erm. grim. grm. 25 30 23°50 0°2915 0°0583 0°0059 25 30 23°45 0°2908 0°0582 0°0060 25 30 23°40 0°2902 0°0580 0:0062 25 30 23°45 0°2008 0°0582 0°0060 25 30 23°44 0°2907 0°0581 00061 The fact that more chromic oxide is contained in the alum than corresponds to the SO, found by the iodide-iodate reac- tion in the complete hydrolysis of the salt shows at once that this particular preparation of chrome alum, like many ordi- nary commercial alums, is basic. Tin. In experimenting with salts of tin the difficulty is to obtain a salt of definite composition with which to start. The double salt of stannic chloride and potassium chloride was selected as a suitable salt for determining the character of the hydrolysis of stannic chloride. This salt was prepared by adding stannic chloride to a cold saturated solution of potassium chloride. The material was then filtered, washed and dried in a vacuum desiccator. The tin content of this salt was found by precipitating stannic acid with the iodide-iodate mixture, igniting and weighing the stannic oxide thus obtained. Results of these ex- periments follow in Table V. S. £. Moody—Hydrolysis of Salts. 17g TABLE V. SaCl.. SnO, Mean of 2KC1., KI. KIO; precipitated. entire series. erm. germ. em? erm. erm. 0°25 1:0 15 0:0926 | 0°25 LO 15 0°09338 | 0°25 1:0 15 0:0937 0°25 FO 15 0°0929 | 0:0931 0°25 io 15 070932 =f 0°25 EC 15 0°0930 0°25 1:0 15 0°0934 | 0°25 - 1°0 15 0°5931 J Portions of this salt were placed in the Voit flask with the iodide-iodate mixture, and the mixtures were boiled for 40 minutes in a current of hydrogen to transfer the iodine to the Drexel flask charged with potassium iodide. The iodine thus eliminated was estimated with a standard solution of sodium thiosulphate of approximate N/10 strength. The le are given in A of the following table. An abundance of iodine is liberated immediately upon the addition of the iodide-iodate mixture without boiling, and in order to see to what limit the action might go at the ordinary temperature of the room, a series of experiments was made in which the iodine was removed at once with sodium thiosul- phate, and the solution after standing two hours was titrated with sodium thiosulphate, the total amount of the thiosulphate used being a measure of the iodine eliminated in the reaction and a measure of the tin present. The results of these experiments are given in B of the table which follows: TABLE VI. Approx. SnO2 SnO2 SnCl,. KI. KIO;. Timein WN/10 E caleu- — precip- Diff. 2KC1. minutes. NagS2Qs. lated. itated. grm. grm. cm, cm’. erm. erm. erm. erm. A O25, + 1°0. 715 40 24°37 0°3137 °0°0933 0°0931 +0°0002 G20: ~ J:05"to 40 24°36 0°3135 0°0933 0°0931 +0°0002 O25.°) 170-0 25 40 24°32 0°31380 0°0932 0°0931 +0°0001 0-25... 1°0. 15 40 24°33 0°3132 0°09382 0°0931 +0°0001 O25 -1:0 .15 40 24°36 0°3135 0°0933 0°0931 +0°0002 OAs 210.15 40 24°35 0°3134 0°0933 0°0931 +0°0002 02a --:1°0 7-15 40 24°34 0°3133 0°0932 0°0931 +0:0001 O23, 10. 15 40 24°36 0°3135 0°0933 0°0931 +0°0002 180 S. £. Moody— Hydrolysis of Salts. TABLE VI (continued). Approx. SnO, SnO, SnCl,. KI. KIOs. Timein N/10 iF ealcu- _— precip- Diff. 2KCIl. minutes. NaeS.Os. lated. itated. . erm, gTm. | -cm*. em, erm. erm. erm. erm. B 0°25 120. lS 120 94°37 03137 0°0933 0:0931 =30-0002 O57 22 On elie 120 24°35 0°3134 0°0983 0:0931 +0:0002 0°25 1:0) ts 120 24°34 0°3133 0:0932 0°0931 +0:0001 0:25) "OP 15 120 24-28 0:3125 -0°09380 0:0931 —0:0008 0525+ >: 10S 120 24°3L 0°3130 0°0931 0°09381 +0°0000 0°25 HCO Ho bs 120 24°32 0°31380 0°0982 0°0931 +0°0001 0°25 LODE TS 120 24°34 0°3133 0°0932 0°0931 +0°0001 O25 10+, 15 120 24°33 0°3132 .0°0932 0°09381. ==0:0008 These results recorded in A show that stannic chloride is completely hydrolyzed in the presence of the iodide-iodate mixture, and that the iodine liberated on boiling is a measure of the tin present. The results given in B show that at the temperature of the room complete hydrolysis is also effected by removing from the sphere of action the iodine which at first appears and allowing the mixture to stand two hours before the final titration. Cobalt. When cobaltous sulphate is boiled for a considerable time with the iodide-iodate mixture, it is hydrolyzed with the libera- tion of iodine in amount indicating that the following equation shows the character of the initial reaction. 3CoSO,+5KI+KIO,+3H,0 = 3Co(OH), +3K,SO, +61 Under the conditions of the experiment potassium iodate is present in excess and exerts an oxidizing influence upon the cobaltous hydroxide, thereby forming black cobaltic hydroxide as follows: 6Co(OH), + KIO, +3H,O = 6Co(OH), + KI After filtering and washing this precipitate and dissolving it with nitric acid, no “precipitate was obtained with barium chloride and this solution. This evidence goes to show that the hydrolysis was complete. The standard of my solution was found by depositing me- tallic cobalt upon a rotating platinum crucible as the cathode, 3 grms. of ammonium sulphate being used as the electrolyte for 25° of the solution of cobaltous sulphate diluted with 25° of water, using one ampere for current and continuing thirty minutes. The following table shows these results: S. EB. Moody— Hydrolysis of Salts. - 181 TABLE VII. CoSO,. (NH,4).SO, Time in POO wis Ose a Mean of minutes. entire series. em?, germs. grm. erm. germ. erm. 25 3 30 O:0528 0°07 10 20-2250 | 25 3 30 0°0525 0°0706 0°2237 | 25 3 30 0°0524 0:°0705 0:2234 rf 0:22.49 25 3 30 Os0527 3020709) 0:22.47 25 3 30 0-0526>.0:070 7% 0:2240 | 25 3 30 0°0527 0:0709 0°2247 J Subjecting portions of cobaltous sulphate to heat with potas- sium iodide and potassium iodate in the presence of a current . of hydrogen to transfer the iodine to a Drexel flask charged with potassium iodide, the following results were obtained : TABLE VIII. Iodine Iodine Approx. value value CosG@,.. KF. KIO;.. Time N/10 caleu- of CoSO, Diff. in NaeS20s. lated. taken. en’. > orm. em?. « hours. cm’. gTm. erm. erm, 25 1°0 15 “ 17°80 02244 0°2242 +0°0002 25 1:0 15 34 dvjaLis: 0°2242 0°2242 +0°0000 25 1°0 15 34 histo 0°2238 0°2242 —0-°0004 25 AO, 15 + ery) 0°22438 0°2242 +0:0001 25 1°0 15 4 Lio 0:2243 0°2242 +0:0001 26 LO 15 a 17°78 0°2242 0°2242 +0°0000 It should be observed that the iodine value obtained by the action of the iodide-iodate mixture upon the samples of cobal- tous sulphate examined is closely comparable with the iodine equivalent of the cobalt found by the electrolytic deposition of the metal, showing that it is an exact measure of the cobalt present in the completely hydrolyzed cobaltous sulphate of ideal composition. Nickel. Nickelous sulphate, like cobaltous sulphate, is hydrolyzed completely, after a considerable time, in the presence of the iodide-iodate mixture, likewise yielding iodine, which may be collected similarly and estimated as a measure of the nickel present. Nickelous hydroxide formed in the reaction remains, however, unoxidized by potassium iodate in neutral solution and therefore the following equation will show the final pro- ducts : 3NiSO, + 5KI + KIO, + 3H,O — 3Ni(OH), +3 K,SO, + 61 The standard of the solution examined was obtained by the electrolytic process. To 25 cm* in a beaker of convenient size 182 S. E: Moody—Hydrolysis of Salts. an equal volume of water and 3 grms. of ammonium sulphate were added, and a current of one ampere was found sufficient to deposit the nickel upon a rotating platinum crucible in thirty minutes. Below is shown results of these determinations. TABLE IX. _ Mean of NiSO, (NH4,z).SO. Time INGsKge= aS Ole hat entire in series. em?, erm. minutes. grm. erm. erm. erm, 25 3 30 0°0520 0°0709 0°2246 | 25 3 30 0:05.23.) OO G3r OL2 26074 25 3 30 050521 O70 7) 1052252 r 0°2255 25 3 30 0:°0523 0°0713 0°2260 | . 25 3 30 0205225 0:02 02225 J A portion of 25°"° of the solution of nickelous sulphate was drawn from a burette into a Voit flask and a solution of 1 gm. of potassium iodide in 15° of the potassium iodate (30 grms. to a liter) was added. This was heated for three hours in the presence of hydrogen to aid in the transfer of the iodine liber- ated to the receiver—a Drexel flask about half full of water in which 3 grms. of potassium iodide is dissolved. The iodine liberated was estimated with sodium thiosulphate in the presence of starch. Results of these determinations follow. TABLE X. . Iodine Approx. I. value NiISOZS KI: KIO; Time N/10 calcu- of Ni. Diff. in NaeS20s. lated. table. (Gra aera eaneh a em’. hours. eile erm. erm. grm. 25 1°0 15 3 eS 0°2254 0°2255 —0-0001 25 10 15 5) 17°88 .0°2256 0°2250 + 0;000T 25 1:0 15 3 17°84 0°2250.. 0°2255 —0:0005 25 10) 15 3 LES i, 0°2254 0°2255 —0:0001 5) 1:0 15 5) 17°83 0°2249 0°2255 —0'0006 Thus it appears that nickel sulphate may be completely hydrolyzed in the presence of the 1odide-iodate mixture and that the nickel of nickel sulphate of ideal composition can be estimated from the amount of iodine liberated in the action of that salt upon the iodide-iodate mixture. Line. Zine sulphate is hydrolyzed in the presence of the iodide- iodate mixture and the reaction might be expected to proceed according to the following equation : 3ZnSO, + 5KI + KIO, = 3Zn(OH), + 3K,S, + 61 For the purpose of experimenting upon this salt, a solution S. £. Moody—fydrolysis of Salts. 183 was made containing 20 grms. to the liter. The standard was found both by determining the zine precipitated electrolytically and by finding the weight of barium sulphate precipitated by barium chloride. In the electrolytic process a portion of 25°™* was in each determination drawn from a burette into a beaker of convenient size; 3 grms. of sodium acetate and 1°" of acetic acid were. added and with a rotating platinum crucible as the cathode a current of one ampere was passed for 80 minutes, when the deposit was washed with water and alcohol, dried and weighed as metallic zine. . Results of these experiments are given in the following taple: TABLE I. Zine Sodium Acetic Time Equivalent sulphate. acetic. acid. Current. in Zine of SO; em?, erms. em?, amperes. minutes. erms. germs. 25 3 1:0 1:0 30 0°1158 0°14135 25 3 1°0 1:0 30 0°1146 0°1405 25 3 1°0 1S 30 0°1149 0°1408 25 3 1:0 1:0 30 O°1147 0°1406 The entire series gives a mean of 0:1408 grm. of SO, equiv- alent to the zine. The content of sulphuric anhydride was found by precipi- tation with barium chloride as barium sulphate, and the results of these experiments are given in the subjoined table : TABLE IT. Mean of Zine BaSO, Equivalent entire sulphate. BaCl, found. of SO; series. em?, cem?. erm, orm. erm. 25 10 0°4109 0°1408 1 25 10 0°4113 071410 | 25 10 0°4101 0'1406 r po ace 25 10 0°4105 0°1407 J The determinations of zine and of the barium sulphate gave in the average the same standard for the combined SO,,. Portions of this solution subjected to heat with a mixture of potassium iodide and potassium iodate liberated iodine, and the amounts of iodine found by titration with sodium thio- sulphate are given in the following table: TABLE III. Approx, Mean of Zine Time N/10 Equivalent entire sulphate. KI. KIO;. in NaeS.Qs. Hi of SO3. series. cm’, orm, em. houss. 2 sent®, germ. grm. erm. 27-8 0'3557 0-11.28.) 28:0 0°3582 01130 | .. 27°38 0°3557 0-1193 ¢ 01125 27-8 0-3557 01193 | 25 1°0 15 25 1°0 15 25 £6 15 25 EC 15 CO Co deNe 184 S. £. Moody—Hydrolysis of Salts. From these results it appears that hydrolysis of the salt ceases before all the SO, radical is removed. In another series of experiments similar portions were boiled in an Erlenmeyer beaker with the iodide-iodate mixture until all the iodine visibly liberated in the reaction was expelled, and the precipitate was then filtered, washed, dissolved in nitric acid and treated with barium chloride. The barium sulphate precipitated, filtered off on asbestos, washed, ignited and weighed was found to correspond almost exactly with the SO, radical not removed by hydrolysis.in the previous experi- ments. TABLE IV. Mean of Zine Time BaSO, Equivalent entire sulphate. KI. KIO;. in BaCl,. found. of SOs. series. em? orm: emes ehourss, )emes erm. germ. germ. 25 1:0 155 3 10 00817 0:0280 ~ 25 1°0 15 oa 10 0°0812 0°0278 ; 25 1:0 15 34 10 0:08 212, 02023827 r Oa 25 1:0 15 3% 10 00814 0:0279 J From the results of both Table II and Table ILI it appears, therefore, that zine sulphate is not completely hydrolyzed in the presence of the iodide-iodate mixture, and the mean per- centage of such hydrolysis is found to be 80°13. So it. appears that a one-fifth basic sulphate is formed. The basie sulphate contains 5Zn to ISO, and is so definite that from the iodine liberated the zine content may-be calculated with accuracy. The reaction of hydrolysis may be expressed by the equa- tion : 15ZnSO, + 20K1+4KI0, + 12H,O = 3Zn,(OH),SO,+12K,S0, + 241. Of the various metal sulphates mentioned in this paper zine sulphate is the only one which is not completely hydro- lyzed, more or less easily, in presence of the iodide-iodate mixture. Geology and Natural History. 185 SCIENTIFIC INTELLIGENCE. I. GkroLoGY AND NaAturAL HIsTory. 1. The Geodetic Evidence of Isostacy, with a Consideration of the Depth and Completeness of the Isostatic Compensation and of the Bearing of the Evidence upon some of the Greater Problems of Geology; by Joun F. Hayrorp, C.E. Proc. of the Wash. Acad. of Sciences, vol. vill, pp. 25-40, May 18, 1906.— The nature of this short paper is well indicated by its title, and instead of merely stating the more conspicuous conclusions, it may be desirable, in order to indicate its great importance, to give a brief historical review of the place of this subject in geological literature and of the problems upon which it bears, the historical side not being developed in the paper itself. Since the time of Babbage and Herschel the idea has been enter- tained by certain geologists, that the greater features of the earth’s surface were sustained, not by virtue of the internal rigidity, but in large part rested in equilibrium because of a lessened specific gravity of the crust beneath the more elevated masses; the facts leading to this hypothesis having been pointed out by Petit, who in 1849 discussed the deficiency of gravity beneath the Pyrenees,* and by Archdeacon Pratt of Calcutta, who a few years later called attention to the striking deficiency of mass found to exist by the Indian Trigonometrical Survey beneath the Himalayas and the Plateau of Thibet.+ This conception involves far-reaching consequences in regard to the nature of the earth’s interior, implying a superficial hetero- geneity of density and a capacity of viscous flowage toward that figure of equilibrium which should tend to bring equal pressures upon all parts of the earth’s interior at a certain depth. For this condition of equilibrium Dutton proposed the term of isostacy,{ now fully incorporated into geological literature. The acceptance of the principle of isostacy, however, immediately raises the ques- tions as to how deep is the zone within which the heterogeneity of density producing the larger and broader surface features is confined? What is the percentage variation in the density of various parts of this zone? What is the departure from true isostatic adjustment exhibited by the surface features? How quickly will response take place to destroyal of the isostatic adjustment through erosion and sedimentation? What is the initial cause of the internal differences in density which lead to the larger features of the earth’s surface and which having once originated, isostacy tends to preserve ? It is seen that these questions involve fundamentally the prob- * Comptes rendus de l’Acad. des Sc., xxix, p. 730. + Phil. Trans. Roy. Soc., vol. 145, p. 53. t ‘On Some of the Greater Problems of Physical Geology,” Bull. Phil. Soc. of Washington, vol. xi, p. 58, 1889. 186 Scientific Intelligence. lems of continental origin and maintenance, mountain-building and the nature of the earth’s interior. On these subjects the long-felt need has been for facts, and it is for these that the present article is especially valuable. Mr. Hayford has utilized the triangulation and astronomic determinations of latitude and longitude within the United States. The preliminary results of the investigation, which is still in progress, indicate that the most probable value of the limiting depth of isostatic compensa- tion is 71 miles and that it 1s practically certain that the limiting depth *s not less than 50 miles nor more than 100 miles, It is certain that for the United States and adjacent regions, including oceans, the isostatic compensation is more than two-thirds com- plete—perhaps much more. Internal variations of specific gravity to the extent of three per cent from the mean, both above and below, will account for the ocean basins and plateaus. As a consequence of this limited zone of isostatic compensation it is pointed out that isostatic adjustment involves a subsurface undertow away from areas of sedimentation and toward areas of erosion: this vis- cous undertow acting as a thrust tending to crumple back the continental margins upon themselves and at least aiding in the formation of mountains. In this connection the reviewer wishes to point out facts not commonly cited, viz.: that Major Dutton perceived as long ago as 1872 the inadequacy of the still popular hypothesis of terrestrial cooling as a sufficient source of mountain-making,* and in 1889 suggested the agency of this lateral undertow.t| The efficiency of this agent must depend upon the depth of the compensating zone, its thickness and viscosity. It is doubtful if Mr. Hayford’s figures justify ele- vating this factor to a major place, but the present limitation of the zone makes it at least a minor factor, and Dutton’s suggestion in this respect must stand as an.example of remarkable scientific prevision. J.B: 2. Pleistocene Deposits of South Carolina ; by GRIFFITH THompson Pucu: A thesis submitted to the Faculty of Van- derbilt University for the Degree of Doctor of Philosophy, Nashville, Tenn., 1905; 74 pp.—This paper is an attempt at ascertaining what must have been the environmental conditions under which lived the Pleistocene mollusca of the state. To that end the species are tabulated, together with the conditions of environment of their living representatives. The conclusion is reached that at least in South Carolina the Pleistocene sea tem- perature, if differing at all from that of the present, was slightly higher rather than slightly lower. The method of detailed and tabulated investigation is excellent and should be followed out for other localities. The reviewer would point out, however, * A Criticism upon the Contractional Hypothesis, by Captain C. KE. Dutton, U.S. A., this Journal, vol. viii, p. 113. + On Some of the Greater Problems of Physical Geology, Phil. Soc. of | Washington, vol. xi, pp. 51-64. Geology and Natural History. 187 that there is nothing to show that the fossiliferous beds con- cerned were deposited at a time of maximum glaciation, and this possibility must be held in mind in view of the recent tendency to enlarge the estimates of Pleistocene time and to consider it a period of great climatic variability. Such a question has greater force since Collier Cobb has recently made note of finding rounded, subangular and even striated cobbles’ on the Atlantic side of Currituck Banks off the North Carolina coast, which he regards as having been transported by icebergs from the New England coast during a period of maximum glaciation.* J. B. 3. The Geography and Geology of Alaska. A summary of existing knowledge, by ALFRED H. Brooks, with a section on climate, by CLEVELAND ABBE, JR., and a topographic map and description thereof, by R. U. Goopr. Professional Paper No. 45, U.S. Geological Survey, 1906; 327 pp., xxxiv pls., 6 figs.— For all except those who have made a specialty of Alaskan geo- logical exploration, this will be the most valuable volume pub- lished by the government on the geography and geology of Alaska, giving a general view of the physiographic provinces and of the present knowledge of the country. It shows what results may be accomplished in the course of a few years by government support for the scientific exploration of a previously unknown land. Apart from the scientific results, it is doubtless true that from an economic standpoint these explorations have increased the value of Alaska to the United States many times the sum of money spent in the explorations. Te 1B 4. Geology and Mineral Resources of part of the Cumberland Gap Coal Kield, Kentucky ; by Greorce Hatt ASHLEY and LEONIDAS CHALMERS GLENN, in coéperation with the State Geo- logical Department of Kentucky, ©. J. Norwoopv Curator. Professional Paper No. 49, U. 8. Geological Survey, 1906 ; 239 pp., xl pls., 13 figs.—This well written and illustrated report contains 40 pages on the general geography, physiography and geology of the region, followed by 170 pages on the geography and stratigraphy of the coals. The volume contains much of scientific interest and is of great economic value. fp Te 5. The Pleistocene Deposits of Sankoty head, Nantucket, and their Fossils ; by J. A. Cusuman. Pub. Nantucket Maria Mit- chell Assoc., I, 1906, 21 pp., 3 pls.—This paper brings together all that is known regarding the Sankoty Head section, the occur- rence of the fossils, horizons, a list of the fauna (86 species, of which 66 are Mollusca), and another of the literature of these deposits. This paper should be studied in connection with an article recently published on the same deposits, in the Journal of Geology, December, 1905, pp. 713-734, by J. Howard Wilson, where about 15 additional species are listed. C. 8. * Notes on the Geology of Currituck Banks, Journal of the Mitchell Society, vol. xxii, No. 1, pp. 17-19. 188 Scientific Intelligence. 6. The Tertiary and Quaternary Pectens of California ; by Ratpo ARNOLD. Prof. Paper 47, U. 8. Geol. Surv., 1906, pp. 264, 53 pls.—This extensive monograph on the Cenozoic Pectens of California also gives a very valuable “brief outline of the different Tertiary and Pleistocene formations of California ” and ‘their typical fauna as far as known” (pp. 9-40). In order to give a clear definition of the various Pectens and their geo- logic range, it was necessary to examine “all of the available marine ‘Tertiary paleontologic material from the west coast.” The total thickness of these deposits aggregates 21,000 feet. The classification of the Pectens is practically that of Dr. Dall in “Tertiary Fauna of Florida.” The genus Pecten and its subgenera Patinopecten, Nodipecten, Chlamys, Lyropecten, -diquipecten, Plagioctenium, Pseuda- musium, Amusium, Propeamusium, and Hinnites are defined on pages 45-50. Of species and varieties there are 93, and of these 50 are new. ‘These are distributed as follows: Eocene 4 (restricted), Oligocene 5 (all pass upward), Miocene 38 (28 restricted, 4 pass upward), Pliocene 37 (10 pass upward), Pleisto- cene 20 (17 in recent faunas), Recent 25 (16 also fossil). The illustrations look natural, being nearly all retouched photographs without attempting to show more than the speci- mens reveal. It will therefore be easy for subsequent workers to identify these species as defined by Dr. Arnold. The work is thoroughly up to date and is indispensable to all students of the Mollusca. C. S. 7. Cambrian Faunas of China; by Coartes D. Watcort. Proc. U. 8. Nat. Mus., 1906, pp. 563-595.—This is the third paper on the Cambrian material collected by Mr. Blackwelder in China. The final report on the fossils by Dr. Walcott, and on the geology by Dr. Willis, will be published next winter by the Carnegie Institution of Washington. This paper describes 34 new species and one new genus black- welderia. The remarkable abundance of Trilobites in the Cam- brian is again noticeable in this paper, where 27 species are described. é Crise 8. Plant Response as a Means of Physiological Investiga- tion ; by Jacapis CuuNDER Boss, M.A.,; D.Sc. Professor, Presi- dency College, Calcutta. London, New York, and Bombay, 1906. (Longmans, Green & Co.)—In a previous notice of this interest- ing and suggestive treatise, the promise was given that in a subsequent issue of this Journal a short analysis would be made of the principal chapters. The work is divided into nine parts, which are not of equal rank, some of them being merely conven- ient headings for minor but generally allied subjects. Thus, for instance, two parts are devoted to the Ascent of Sap and Growth, respectively ; topics which are special under larger questions. Part First considers Simple Response. In this the plant is regarded as a machine responding to external stimuli and giving distinct pulse-records. The sensitiveness of plants is practically Geology and Natural History. 189 universal ; according to the author, wherever there is a living tissue, no matter how sluggish it may seem, response may be elicited by appropriate means. There are certain conditions which are conspicuously favorable to the exhibition of mechani- cal response, and these conditions have been carefully studied. Such study has convinced the author that there is no difference, except in degree, between the ordinary and the so-called sensitive plants. The mechanical response in ordinary leaves and the lon- gitudinal response of radial organs have been examined in detail by means of newly-devised apparatus, which appears to possess the power of recording even the slightest possible movement after stimulation of the plant or its parts. The responsive curva- ture of molecularly anisotropic organs receives a good deal of attention, and the complex phenomena are resolved into their simpler terms or factors. Lastly, under this heading, comes the consideration of the relation between stimulus and response, and also, the effect of the superposition of stimuli. Here tetanus in plants is described. In Part 2d the author treats of the modification of response under various conditions. Ilere are studied the theories concern- ing different types of response, the effects of ansesthetics, poisons, and other chemical agents on longitudinal response. The effects of temperature receive attention in a special chapter, as does also the ‘‘death-spasm” in plants. The critical point of death is determined by inversion of the thermo-mechanical curve. In connection with this topic the author examines at considerable length the subject of local fatigue and regional death. Excitability and conductivity are considered in Part 3. Polar effects, electrotonus, electrotactile and electromotive methods, and the latent as well as the “refractory” periods are fully treated of. Then follows the consideration, in part 4, of multiple and autonomous response ; and the similarities of rythm in ani- mals and plants are clearly stated. The ascent of sap and the general subject of growth are next presented, and the supposed relations of both to certain stimuli are insisted upon. Following come Geotropism, Chemotropism, and Galvanotropism. Near the close of the last chapter in this part the author considers the effect on growth of “electrification” of the soil. To the subject of Heliotropism the author devotes the whole of part 8. He takes up even the effect of invisible radiation and the action of the high frequency Tesla current. Torsional response receives a fair share of attention. Besides this is considered the topic of pulsa- tory response ana the swimming movements. Part 9 concludes the treatise with general reviews and a final examination of the continuity of physiological response in plant and animal. ‘Three features render this work of great interest: (1) the summaries at the close of the chapters, (2) the descrip- tions of entirely new types of delicate apparatus, and (3) the fact that the greater part of the experiments were conducted under the most favorable conditions in a tropical climate upon tropical 190 Screntific Intelligence. plants. The treatise is stimulating and suggestive throughout. Even where one cannot agree with the conclusions of the author he must confess deep indebtedness for new lines of thought. G. L. G. 9. Heather in Townsend, Mass.—In this Journal, Oct., 1888, I gave a full description of the occurrence of Calluna vulgaris at a locality not far from the railroad station in West Town- send, near the New Hampshire line. On Saturday, July 14, 1906, this place was revisited by me for the purpose of ascertain- ing what changes might have occurred in the distribution of the plants. Ina subsequent notice I shall hope to give details regard- ing the present condition of the heather, but at present I will merely state that the plant has steadily extended over a larger area, and, although in certain spots it has suffered from various agencies, it appears to be so well established as to wage a strong and perhaps successful fight with the contending native plants. The best time to visit this interesting station is early August. At that date, the whole area is said to be a mass of bloom. At this present writing, however, there were only slight indications that the flowers this year would be numerous, but the dried capsules from last year’s blossoms were very plentiful. Gees 10. Lhe Biology of the Frog; by Samunt J. Hotmes, Ph.D. Pp. ix+870, with 94 figures. New York, 1906 (The Macmillan Company).—This work is designed particularly as a text-book for students in the college or university who have had some training in elementary biology. A study of this text accom- panied by suitable practical work in the laboratory will lead naturally to the study of comparative morphology and physiol- ogy. This work is in the broadest sense a natural history of the frog, whose systematic position, relationships, habits, food, ene- ° mies, parasites, breeding periods, hibernation, powers of regen- eration, movements, and so on are described. Then follow chap- ters on the external characters, internal structures, development, and general histology. Hach of the principal organ systems of the body is then taken up in detail with an account of the func- tions of each part accompanying the description of the structure. The two concluding chapters deal with instincts and tropisms, and include a brief discussion of the frog’s intelligence. ‘The figures and diagrams, which are carefully chosen and well printed, are mainly from standard works, although a few are original. Such a detailed knowledge of the biology of a single animal will meet the needs of the college student who is preparing for the study of medicine, and will form a convenient reference book for teachers of biology in secondary schools. W. RB. C. 11. A Course in Vertebrate Zoology. A Guide to the Dissec- tion and Comparative Study of Vertebrate Animals ; by Henry SHERRING Pratr. Pp. x+299. New York and Boston, 1906 (Ginn & Company).—The plan of the book follows closely the lines adopted by the author in his Invertebrate Zoology, which was published several years ago and has proven a convenient Miscellaneous Intelligence. 19r laboratory guide. Asin the earlier work, the type system is fol- lowed, a single representative of each of the more important groups of vertebrates being taken up. It contains not merely directions for the work in the laboratory but also short descrip- tions of parts difficult to study, with brief statements as to func- tion and morphological significance. Each dissection is | quite independent of the others, so that the animals can be studied in any sequence. Like its predecessor, this book is sure to form a valuable addition to the already numerous ao guides. W. RB. C. 12. The Life of Animals. The Mammals ; by Erxnest IncER- SOLL. Pp. xi+555, with numerous illustrations, including 15 colored plates. New York, 1906 (The Macmillan Company).—A popular work, written in an entertaining style, containing a store- house of facts about the familiar as well as the less generally known animals. These facts of general interest are brought together from widely scattered scientific treatises, books of travel, and reports of hunters. Hach of the groups of mammals from the highest to the lowest is taken up in turn with illustra- tions, descriptions, and anecdotes of some of the representatives. Many of the illustrations are from original photographs and drawings and greatly enhance the value of the work. w.R. c¢. Il. MiIscELLANEQUS SCIENTIFIC INTELLIGENCE. 1. Recent Text-books on Astronomy. — A Compendium of Spherical Astronomy, with its Applications to the Determination and Reduction of Positions of the Fixed Stars; by Simon New- comp. Pp. villi, 444. New York and London: 1906 (The Macmillan Company) An Introduction to Astronomy; by Forrst Ray Mov tron. Pp. xviii, 557, with 24 tables and 50 figures. New York: The Macmillan Company. London: Macmillan & Company Ltd., 1906. Laboratory Astronomy; by RosErtT WHEELER Witson. Pp. li, 189, with 89 figures and 7 tables. Boston, New York, Chicago, London: 1905 (Ginn & Company). The works here noticed meet the needs of students of Astron- omy from the Nautical Almanac Office to the High School, except for the computation of orbits and perturbations. The volume by Newcomb is the most important work in prac- tical Astronomy that has appeared in the present generation and is well worthy of the reputation of its author. Aside from its intrinsic merit, it is the more valuable as “the first of a pro- jected series having the double purpose of developing the ele- ments of practical and theoretical Astronomy for the special student of the subject, and of serving as a hand-book of conven- ient reference for the working Astronomer in applying methods and formulae.” Am. Jour. Sci.—Fourts Srerigs, Vou. XXII, No. 128.—Aveusrt, 1906. 13 192 Scientific Intelligence. If Professor Newcomb completes the series it will be a worthy monument both to himself and to American Astronomy and will leave little for other writers to do until the accumulation of new material calls for a new harvest, in the same way that the present work is made necessary by the advance of knowledge since the writings of Bessel, Chauvunt and Oppolzer. | The most urgent want which the present volume supplies is that of improved methods for deriving and reducing the posi- tions and proper motions of the fixed stars made necessary by the period of 150 years through which these positions now have to be reduced. In this and all parts the book is full of new and most valuable material, of which may be mentioned the appendix of 26 tables, most of which can be found in no other text-book, and a chapter on observatories and star catalogues. Moulton’s Introduction to Astronomy has the same justifica- tion as Newcomb’s volume. It is intended for the student of descriptive Astronomy as a part of general culture, and gives access to the stores of information which have accumulated since Young’s unequaled text-books were published, accumulations which frequent revisions of Young’s series have not been wholly adequate to keep pace with. The amount of new material is made evident at a glance by the new cuts which meet the eye wherever the book is opened, such as’ Chandler’s diagram of the variations of the pole, Todd’s chart of paths of total eclipses up to 1973, Maunder’s figure of the dimensions and distribution of sun spots for 25 years, a spectroheliograph of the sun by Hale, ete. Both in plan and arrangement the book differs considerably from the conventional form, the design being to use something of the laboratory method throughout, connecting theory as closely as possible with practice and familiarizing the student with the lines of thought and chains of reasoning by which the great theories of the noblest of the sciences have been developed. It is too much to expect the felicity of statement, the perfec- tion of clearness and conciseness which is found in Young’s writ- ings. By comparison the writer seems somewhat prolix and lacking in perspicuity. Wilson’s Laboratory Astronomy is an excellent book to use with the preceding in a course where time permits. It presents a large number of valuable practical exercises for the average student, carefully worked out and requiring such apparatus, largely of the author’s own devising, as can be provided in quan- tities at small cost, so that a large class can be set to work together on the same exercise (e. g. mapping the sun’s diurnal motion), under the supervision of an instructor in an ordinary recitation room and from data collected by themselves. w. B. 2. The Publications of the Royal Society of London.—A circular recently issued by the Royal Society calls attention to the present method of publishing the Proceedings in two series, viz., A, containing mathematical and physical papers, and B, Miscellaneous Intelligence. 193 those of biological character. Volumes 76—77 of each series have now appeared, of about 600 pages royal octavo, with ‘illustrations. “A main object of this new arrangement was to render the Pro- ceedings more accessible to workers by placing the two groups of subjects on sale separately, at a stated price attached to each separate part of a volume when it first appears. Moreover, with a view to promoting the circulation of the complete series, it has been directed that a subscription paid in advance to the Pub- lishers at the reduced price of 15 shillings per volume for either series, shall entitle subscribers to receive the parts as soon as published, or else the volumes when completed, in boards or in paper covers, as they may prefer.” Each number of Proceedings also contains an announcement on the cover of the more recent memoirs of the Philosophical Transactions as published separately in wrappers and the prices at which they can be obtained. It is hoped that this arrangement may facilitate the prompt circula- tion of the journals of the Society. 3. Physical Optics; by Rosert W. Woon, Professor of Ex- perimental Physics in the Johns Hopkins University. Pp. vi, 546, with 325 figures. New York and London, 1905 (The Macmillan * Co.).—Prof. Wood’s book is a remarkably interesting compen- dium of our present knowledge of Physical Optics. It is very complete and up to date on the experimental side, and while some of the mathematical portion is abbreviated, many results are de- rived which are found in few if any other books on light. For ex- ample, it is proven that, for regular reflection, a surface must be smooth to within an eighth wave length (p. 36), also that Fer- mat’s Law requires that the time be a minimum or a maximum (pp. 58, 61), that the phase is uniform within a quarter wave length over a surface of diameter equal to the wave length divided by the apparent diameter of the source =°05™™ for sun light (p. 123); further, Rayleigh’s proof is given that the magnification equals the compression of the wave front (p. 65). The reader is sur- prised to find no reference to Wood’s successful diffraction color photographs. Considerable attention is appropriately devoted to the author’s work on sodium vapor in the region of the D-lines ; a vapor with a refractive index as high as 1°38 and a dispersion which separates a double line with components twenty times as close as the sodium lines by an amount as great as the distance between the red and the blue of the spectrum formed by a 60° glass prism (p. 346), which shows enormous rotation in a magnetic field (p. 426), which gives a series of fluorescent spectra, corre- sponding lines in which will appear upon stimulation with proper monochromatic light (p. 408) and which exhibits optical resonance (p. 486) and lateral radiation of the stimulating light (p. 451). There is little to criticise. Misprints are few and not such as to confuse the reader. Does not the graphical explanation of the absence of a back wave (p.8) assume what is to be proven? The reviewer was unable to find a clear derivation of the con- dition for resolution. Asan American book upon Mathematical 194 Seventifie Intelligence. Optics, it is much to be desired that we may have before long Prof. Gibbs’ Lectures upon the Electro-Magnetic Theory of Light. ARTHUR W. EWELL. OBITUARY. Professor Henry A. Warp, the veteran mineralogist, scien- tific traveler and collector, was struck by an automobile in the streets of Buffalo on July 4 and died almost immediately after. Notwithstanding his seventy-two years of age, he was still in full health and vigor. He was born at Rochester on March 9, 1834, studied at Williams College, at Cambridge with Agassiz, and later for four years at the School of Mines in Paris. For six years from 1859 he taught Natural Science at the University of Rochester. The oreater part of his time and energy he devoted to travel, with-collecting in mineralogy, geology and natural his- tory as the main object and incentive. Throughout his life his interest and enthusiasm for this work never flagged ; trips to Europe, Asia, Australia, Africa and South America were repeated at short intervals. Many institutions have obtained their col- lections through his efforts and the large amount of material he accumulated has been the basis of the Natural Science Estab- lishment which bears his name. During the later years of his life his interest was particularly aroused by the study and collection‘of meteorites, the very diffi- culty of the undertaking serving to stimulate him. One large collection passed from his hands to the Field Columbian Museum in Chicago, and another to Mr. C.8. Bement. His efforts cul- minated, however, in the Ward-Coonley collection now on deposit and exhibition at the American Museum of Natural His- tory in New York City. Beginning with a smali nucleus in 1894, within ten years it had taken the first place among the great collections of the world. This was a unique work calling for all his energy, perseverance and tact, together with liberal expenditure. Could the history of the collection in detail be written it would be full of the interest of travel and adventure ; as a typical case may be mentioned his trip to Persia and inter- view with the Shah, leading to his obtaining a large mass of the remarkable Veramin meteorite.* Up to the day of his death his interest in meteorites and his energy in obtaining new specimens were unabated. He had also accumulated a large amount of material relating to the history and scientific investigation of meteorites, from which he proposed to prepare an exhaustive volume on the subject. Baron C. R. von preR Osten Sacken, the eminent Russian entomologist, died in May last at the age of seventy-eight years. Dr. Lupwie Brackersuscu, Professor of Geology at Hannover, died recently at the age of fifty-seven years. * A brief account is given in this Journal, v. xii, p. 453. ah EMERALDS. We have just obtained another consignment of choice Emerald Crystals. Prices 75c. to $10.00. Purple Apatite Crystals on Matrix, . $1.00 to $2.00 White Apatite Crystals, Oe lOO Orpiment, massive, ; £.00> 52,00 Cobaltite Crystals, large, os 50:3. 2:00 Sphalerite Crystals on Marble, : oO oe 100 Send for special list of rare minerals just received. ~ ‘Everything in Natural History.’’ WARD’S NATURAL SCIENCE. ESTABLISHMENT, 76-104 College Ave., Rochester, N. Y. Warps 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, etc. 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. [= Index XI-XX, now ready. Price $1.00. CON PEN ES: Page “Art. XJ.—An Investigation into the Elastic Constants of Rocks; by F. D’ Apams and E.-G. Cokmr =:2. =) 95 XII.—Dakotan Series of Northern New Mexico; by C. R. KEYES .J225 [2 a Se eee XIITI.—Plauenal Monzonose (Syenite) of the Plauenscher Grund; by H.-S. WAssINcTOm® 2") 2 eos XIV.—Colloidal Nuclei and Ions in Dust-free Air saturated with Alcohol. Vapor; by C.. Banus. = - 7) 275) 52 ee XV.—Russian Carboniferous and Permian compared with those of India and America ; by C. ScuucHERT .--.... 148 XVI.—Notes on Some Eruptive Rocks in Mexico; by F. N. TTD ee SR ee Be eee oa CO A eas 159 XVII.—Hydrolysis of Salts of Iron, Chromium, Tin, Cobalt roe and Zine in the Presence of Iodides and Todates; by 8.“ Moony ~25) 152.2 oe a ee SCIENTIFIC INTELLIGENCE. Geology and Natural History—Geodetic Evidence of Isostacy, J. F. Hay- FORD, 185.—Pleistocene Deposits of South Carolina, G. T, Pucu, 186.— Geography and Geology of Alaska, A. H. Brooks, C. ABBE, JR. and R. U. GoopE: Geology and Mineral Resources of part of the Cumberland Gap Coal Field, Kentucky, G: H. AsHury and L. C. Gienn: Pleistocene Deposits of Sankoty head, Nantucket, and their Fossils, J. A. CUSHMAN, 187.—Tertiary and Quaternary Pectens of California, R. ARNoLD: Cam- brian Faunas of China, C. D. Waucorr: Plant Response as a Means of Physiological Investigation, J. C. Bosr, 188.—Heather in Townsend, Mass.: Biology of the Frog, S. J. Hotmres: A Course in Vertebrate Zoology, - H. S. Pratt, 190.—Life of Animals, E. INGERSOLL, 191. Miscellaneous Scien tific Intelligence—Recent Text-books on Astronomy, 191. —Publications of the Royal Society of London, 192.—Physical Optics, R- W. Woop, 193. Obituary--H. A. Warp: C. R. voN DER OSTEN SACKEN: L. BRACKEBUSH, 194. - Librarian U. S. Nat. Museum. ee VOL. XXII. SEPTEMBER, 1906. Established by BENJAMIN SILLIMAN in 1818. THE “AMERICAN JOURNAL OF SCIENCE. Epirorn: EDWARD 8S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camsrince, Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON ann H. E. GREGORY, or New Haven, ProrEssor GEORGE F. BARKER, or PumapeLPun, Proressor HENRY S. WILLIAMS, or Iruaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or Wasuineron. . FOURTH SERIES VOL. XXII—[WHOLE NUMBER, CLXXII.] No. 129—-SHPTEMBER, 1906. NEW HAVEN, CONNECTICUT. 1906 THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. P Pa Published monthly. Six dollars per year, in advance. $6.40 to countries in the Postal Union. Remittances should be made either by money orders, registered letters, or bank checks (preferably on New York banks). See A EO es 5 CRYSTALS, FINE MINERAL SPECIIENS, | METEORITES. Orders amounting to $20 or over sent carriage paid on approval, with the privilege of selection. Rejected material returned at consignee’s expense. Send for our illustrated descriptive Catalog of “Choice Min- erals” just published. SYSTEMATIC COLLECTIONS Of Typical Specimens, In sets of twenty-five up to fifteen hundred specimens. Prices $5.00 upwards per set, the average price for students’ specimens (average size 22” x 2”) being about twenty cents. For 30 years we have been supplying reference specimens to the mining schools, universities and museums throughout the world. We refer to any curator or professor of mineralogy or geology. Our LABELS accompany every specimen, giving correctly,— name, chemical composition and locality. QUALITY is guaranteed in our prepayment of transportation to any address in the world (on orders of $20 or more). We could not take this transportation risk, if the quality did not insure your keeping them, as we refund money on minerals promptly returned. Prices are the lowest, as comparison will show. The volume of our trade permits it. Free CoLLectTion CATALoG, containing lists and illustrations of General Mineral Collections, Series of Ores for Prospectors, Sets of Crystals, Series illustrating Hardness’ and other Physical Characters of Minerals, with price List of Laboratory Material and Individual Specimens. | FOOTE MINERAL CO. Established 1876, by Dr. A. E. Foote. W. M- Foote, Manager. DEALERS IN Mineral Specimens and Commercial Rare Minerals. Removed to 107 N. 19th St., Philadelphia, Pa., U. 8. A. THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES. ] Arr. X VIUII.— Abyssal Igneous Injection as a Causal Condi- tion and as an Lifect of Mountain-building ; by Reernaxp A. Daty, Ottawa, Canada. [Published by permission of the Canadian Commissioner, International Boundary Surveys. | CONTENTS. Introduction. The shells of compression and tension in the earth. The hypothesis of a crust and fluid substratum. Purpose of the present paper; acknowledgments. Thickness of the earth’s crust. Compression of the substratum ; flotation of the crust. Stresses within the crust. Secular accumulation of tension and of cooling cracks. Injection of magma into the shell of tension. Relief of tensions through abyssal injection. Down-warping of the surface as a result of abyssal injection. The conditions for mountain-building. Expansion of the earth’s outer shell as a factor in mountain building. Renewed abyssal injection following mountain-building ; development of batholiths. Vuicanism as a result of mountain-building. Summary. Postulates. Conclusions. INTRODUCTION. The shells of compression and tension in the earth.— Whether the earth, as it cools and contracts, be solid and highly rigid throughout, or whether it consist of a solid crust with an underlying fluid substratum, it is generally held by geologists that there is a “level of no strain” beneath the sur- face. The depth of this level has been computed for a solid earth by Davison and Darwin, who have made various assump- Am. Jour. Sc1.—Fourtu Series, Vou. XXII, No. 129.—SEpPTEMBER, 1906. 14 196 Lf. A. Daly—Abyssal Igneous Injection. tions which are more or less reasonable provided the fact of complete solidity is established. ‘Their estimates for the depth of the zero-strain level vary from 2 miles to 7-79 miles.* With analogous assumptions Fisher has calculated that there will similarly be a level of zero-strain in a crust overlying the fluid substratum of a globe solidifying from the cireum- ference inwards. He found that “if the time elapsed since a crust began to be formed has been 100 million years, the depth of the level of no strain at the present time will be about four miles.”’+ In any case the depth increases very slowly with the time elapsed since the crust first formed. Rudski has pointed out that, if the earth’s initial temper- ature were not uniform, the level of no. strain would, in a given time, be deeper than by the amount calculated on the assumptions of Davison.t It is, in truth, probable that the initial temperature increased downwards. We shall see that there is a grave reason for doubting the conclusion of Kelvin that an initial uniform temperature was secured through the foundering of early crusts. The suggestion of LeConte that it might be secured through the operation of convection currents is not acceptable to those who hold the very probable view that the earth’s internal density increases downward, not only because of increasing pressure but because of differences in chemical composition as well.§ All of these calculations bave been made on the supposition that the thermometric conductivity of the material of the earth is a constant quantity. It is, however, most probable that this conductivity decreases with rise of temperature and very greatly increases on the passage of liquid magma into solid rock. Forbes showed that the “ calorimetric” conductivity of iron decreases with rise of temperature, as illustrated in the following table, which is an abridged form of his experimental results: | *C. Davison, Philosophical Transactions, Royal Society of London, vol. elxxviliA, p. 231, 1887; G. H: Darwin, ibid., p. 242; C. Davison, Proceed- ings of the Royal Society of London, vol. lv, p. 141, 1894. Cf. M. Reade, Origin of Mountain Ranges, London, 1886, 193 121. +O. Fisher, Physics of the Earth’s Crust, London, 2d ed. 1891, appendix, p. 45. tM. M. P. Rudski, Philosophical Magazine, vol. xxxiv, p. 299, 1892. § Cf. J. LeConte, American Geologist, vol. iv, p. 43, 1889. It may be noted that, in the above-mentioned calculations, no account has been taken of the special and important contraction characterizing the passage of lava from the liquid to the solid state, nor, except in the case of Fisher’s estimates, for the fact that, with a given fall of temperature, liquid lava (diabase) con- tracts about twice as much as solid lava (Barus, Bull. U. S. Geological Sur- vey, No. 103, 1898). iJ. D. Forbes, Trans. Roy. Soc. Edinburgh, xxiv, p. 105, 1867. ae an i a oe! y R. A. Daly—Abyssal Igneous Injection. ie ye Temperature. Conductivity Conductivity ist specimen. 2d specimen. 0°C ? 12°42 9°21 50 10°63 8°37 100 9°40 LS 150 8°68 7°38 200 8:14 7°10 Units in centimeter, minute and deg. Centigrade. Similarly, Weber measured the conductivity of gneiss at 0°C and at 100°C and found the conductivity to be 578/416 greater at the lower temperature than at the higher.* Barus proved that the thermometric conductivity of the substance thymol increased 56 per cent in passing from the liquid to the solid state at the same temperature (possible through undercooling).t It is true that condensation through pressure increases the conductivity for heat,-but Arrhenius has pointed out that at depths greater than only a small fraction of the earth’s radius, increment of pressure entails no corresponding increment of condensation.t This condition applies to the (gaseous) earth- matter which, at the depth of several hundred miles, has reached its co-volume. At this and at ereater depths temper- ature may be in complete control as regards the conductivity for heat—an increase of temperature with still greater depth involving a slow decrease of conductivity. These observations and conclusions indicate, first, that experimental studies on the conductivity of rock-matter at dif- ferent temperatures, in different states of compression, and in the two states of aggregation (if such studies are possible), are urgently needed ; secondly, that it is now impossible to calen- late the exact position of the level of no strain in the earth’s crust. Nevertheless, in an earth composed of a crust floating on a substratum which, because it is fluid and hot, has a lower thermometric conductivity than the solid, cool er ust, we might expect the level of no strain to be well within the crust even if the initial temperature gradient were comparable to that now observed in the earth’s superficial shell. In a personal letter to the writer, the Rev. Osmond Fisher states that, with a liquid interior, there must be a level of no strain in the crust ; and this is apparently true no matter what the initial temperature may have been. He states, further, that “the level of no strain would be the same whatever the conduc- tivity; but the time would not be the same. The position of the level would not fall so rapidly if the conductivity was less.” *R. Weber in Landolt and Bérnstein’s Phys. Chem. Tabellen. +C. Barus, this Journal, vol. xliv, p. 15, 1892. ¢S. Arrhenius, Geol. Féren. Stockholm Foérhandlingar, vol. xxii, pp. 396-7, 410, 1900. 198 LR. A. Daly—Abyssal Igneous Injection. The shell above the zero-strain level is under tangential com- pression. The shells beneath that level, for a considerable dis- tance downwards, are under tension. On account of the weight of all overlying shells any shell below the zero-strain level tends to be stretched or (using Reade’s term) to suffer “ compressive extension.” This tendency increases with depth to a maxi- mum in a level computed by Davison for a solid earth to lie 72 miles below the surface. The corresponding level for an earth with a fluid substratum has been calculated by Fisher to. lie at depths of from 380 to 55 miles, depending among other conditions on the temperature of solidification.* The hypothesis of a crust and fluid substratum.—There are many reasons why the doctrine of the earth’s complete solidity is not acceptable to the working geologist. Some of the cogent arguments against it have been summarized by De Lapparentt and other able writers on the theory of the globe. The strength of these arguments is great and by so much favors the opposed doctrine of a fluid substratum supporting a solid crust. The astronomic evidence for the hypothesis of complete solidity rested at first on the calculations of Hopkins in his well known: paper on the combined effect of tidal pull and internal fluidity upon the precession of the equinoxes. Later analyses by Kelvin and Darwin proved that Hopkins’ conclusions could afford no ‘decisive argument against the earth’s interior liquidity.” ‘‘ Here we have a remarkable instance of the final abandonment of an argument, which, from the portentous difficulties of comprehending it, had proved too hard for geologists to assail.’”’+ The stronger argument, based by Kelvin and Darwin on the observed and calculated magnitude of oceanic tides, has like- wise suffered destructive criticism by Fisher. The various dis- cussions on this most complicated subject show clearly that not enough is known either of the constitution of matter or of the oceanic tides themselves to permit of certain mathematical determination of the earth’s true rigidity. Fisher’s luminous work seems to prove that the geologist may still accept as the best working hypothesis the view that-the earth’s ‘‘ crust ” is a true crust and rests on a shell of fluid magma. Fisher has demonstrated that, if the substratum is saturated with water- gas, the bodily tide of the earth may entirely disappear, its place being taken by a density tide in the substratum. This would be true on account of the compressibility of the substra- tum.§ Since glass and presumably igneous magma are not only * Op. cit., p: 106. + See the chapters on vuleanism in his ‘‘ Traité de Géologie.” $O. Fisher, op. cit., p. 38. SO. Fisher, op. cit., p. 61. R. A. Daly—Abyssal Igneous Injection. 199. somewhat compressible but almost perfectly elastic, the same reasoning may possibly apply to an anhydrous substratum.* Again, the recently developed view that the great nucleal mass of the earth is composed of true gas immensely com- pressed, must also be reckoned with in the attempt to prove. rigidity by the oceanic tides. Purpose of the present paper ; acknowledgments.—W hile the question as to how much of the earth is fluid is now quite open, the hypothesis of crust and fluid substratum has many special points of advantage. Many writers have shown how it agrees with essential observations on the structure and history of the rocks accessible at the earth’s surface. It appears, how- eyer, that important consequences of the hypothesis, conse- quences involved in the correlation of subsurface tensions with igneous intrusion, surface deformation and mountain- building, have, so far as known to the writer, never been systematically deduced. This paper is intended to form a brief and but qualitative treatment of the subject.t The writer has pleasure in acknowledging the great courtesy of Professor F. D. Adams, who afforded much help in discuss- ing such physical. constants of rocks as form data required in the following hypothesis. Special thanks are due to Dr. A. C. Lane, who has, by correspondence, discussed anew the relation between subsurface tensions and the gases evolved from the earth’s interior; also to the Rev. O. Fisher and to Professor L. VY. Pirsson, who, similarly by correspondence, have offered valued suggestions. But, in justice to these investigators, it may be added that they should be clearly absolved from all responsibility in launching this new hypothesis on the sea of discussion, which has borne whole fleets of older hypotheses of mountain-building, has sunk many of them, and still floats the more or less battered but more seaworthy hypotheses. The ribs of this new vessel are few—assumptions which them- selves may long have to remain in the workshop of geological opinion ; ‘to these the planks of argument have been fastened and again there is a chance that the vessel is neither tight nor trim. Each postulate and almost every argument ‘of the hypothesis well merits a whole article to itself, but their elabo- ration or destruction may wisely be left to more skilful hands. This paper is little more than the barest statement of a sugges- tion which is offered expressly for criticism. The necessary brevity of treatment forbids that constant, explicit reference * Lord Kelvin states that crystals and glasses probably possess elasticity of volume ‘‘to perfection”—art. ‘‘ Elasticity” in the Encyclopaedia Britan- nica, 3d paragraph. + The relative merits of the planetesimal and nebular hypothesis of the earth’s origin are not discussed, but the older hypothesis may be regarded as basal to the argument. 200 R. A. Daly—Abyssal Igneous Injection. be made to the actual facts of outdoor nature which would be essential to a thorough presentation of the hypothesis, but it is true that each argument has been made, as far as possible to the writer, with attention to observations in the field. In fact, it has been the direct call for some kind of explanation of structures and rock-associations in the British Columbia mountains that has prompted this hypothesis. The principle of advancing reasonable deduction beyond the region of observed fact needs no apology. Nowhere in dynamic geol- ogy is an appeal to the realm of the unseen more necessary than in the problems of orogeny and igneous intrusion. These problems have already reached the stage where more observa- — tions on the visible part of the earth-crust are not so funda- mentally necessary as the reference of the abundant, now accessible, and well recorded observations to an intelligent imagining of the gigantic forces and processes resident in the earth’s invisible interior. The orology of the future, even more than that of the past, must rest on well-regulated specu- lation. The hypothesis is phrased in terms of a solid crust floating on a liquid substratum. It is possible that gases originally absorbed in the substratum, according to the conception of Lane,* should also be considered; but, on a following page, a reason for excluding them from any large share in crustal deformation is briefly noted. On that ground and because of the relative simplicity secured for the hypothesis as set forth, the dynamic influence of the absorbed gases is not discussed. It will be seen, however, that the expansional energy of gases possibly given off during the solidification of the substratum would furnish a condition favorable to the hypothesis. Thickness of the Crust.—The depth of the level where the fluid substratum is first encountered has been estimated in several ways. Of. these estimates, that founded on the most reliable determinations of the temperature gradient and of the relation between pressure and the fusion point, is clearly preferable. Kelvin has shown that for about 25 miles of depth the gradient would be essentially rectilinear in a cool- ing globe. The generally accepted gradient is approximately one degree Centigrade for 100 feet of depth. This gradient implies that at the depth of about 22°5 miles a gabbroid magma would possess the temperature appropriate to complete fusion at atmospheric pressure; (diabase melts at 1170°C. and solidi- fies at 1095°C.—Barus). Vogt has recently calculated that the pressure of 22°5 miles of rock would raise the fusion-point about 50°C.+ : * Bull. Geological Society of America, vol. v, 1894, p. 259. +J. H. L. Vogt, Die Silikatschmelzlésungen, part 2, Videnskabs-Selskabets Skrifter, I. Math.-naturv. Klasse, Christiania, 1901, p. 210. R.A. Daly—Abyssal Igneous Injection. 201 Completely fluid gabbroid magma would therefore not be expected at a depth short of 24 miles even if the temperature gradient were truly rectilmear. Allowing an extra mile of depth to correspond to a possible slight weakening of the gradient at these depths, it follows that a shell of gabbro at the depth of 25 miles might be completely fluid. . The enor- mous predominance of basalt in the world’s lava-fields, especially among the lava-floods of fissure eruptions, suggests the strong probability that the fiuid material immediately beneath the crust has actually the composition of gabbro. -It thus appears permissible to regard 25 miles as repr esenting nearly the thick- ness of the crust. The strong compression of the substratum would decrease the average intermolecular distance and thus increase the vis- cosity, but the material remains a true liquid. Though the viscosity of such a liquid is high, yet the possibility of its infinite deformation and its capacity of transmitting pressures hydrestatically are, in the long periods of geological time, as perfect as if the substratum were comparable to water in finidity. Its material is a true fluid and not a solid either rigid or plastic. If, however, the substratum material, still preserving its high temperature, is injected into higher levels in the crust, where pressures are less, it may become highly mobile under small stresses. “It is important to remember, too, that the very act of flow of a viscous fluid, by the defini- tion of viscosity, produces internal friction and additional heat and renders it more fluid.”’* Compression of the substratum ; flotation of the crust.— The gabbroid substratum at its upper surface bears a pressure of about 12,000 atmospheres. This vast pressure must com- press magma very considerably. Barus has demonstrated that liquid napthalene is about four times more compressible than solid napthalene at the same temperature.t If gabbro obeys the same law even appr oximately under the assumed conditions of pressure and temperature, it is possible to estimate roughly the density of the upper most shell of the substratum. Let it be assumed, for example, that the specific gravity of crystal- lized gabbro at 0° C is 3°02 and the volume 100-0. Its dens- ity when completely molten at 1250° C. and at 1 atm. would be about 2°54; the volume would be 118°8.t Its compressibility would be about four times that of solid gabbro, which is prob- ably of about the same compressibility as that of glass, viz., nearly 0000026 per atmosphere. The pressure of 12,000 at- mospheres would reduce the volume to 106°4; the density * Quoted from a letter to the writer from Dr. Lane. +C. Barus, Bull. 96, U. S. Geol. Surv., p. 83 ff., 1892 ¢{C. Barus, Bull. 103, U. S. Geol. Surv., p. 25 ff., 1893. 202 ft. A. Daly— Abyssal Igneous Injection. would become approximately 2°84. Barus has further shown that, so far as density is concerned, temperature and pressure, as these increase with depth on the normal earth gradients, nearly counterbalance each other’s effects in glass, though the density should be somewhat increased with increase of depth.* It is not a violent assumption that the same be taken as true for rock-matter generally. The average density of the whole crust is thus nearly equal to the average density of its rocks, provided these are at surface temperature and pressure. The average specific gravity of the visible crust is not far from 2°75; but if the specific gravity of the whole crust were as high as 2°80, it might still float on the compressed gab- broid substratum. ) The meagreness of existing experimental data will not allow that statements concerning crustal flotation can be other than in the conditional mood. It is certain that the relation between pressure and the volumetric diminution of a fluid cannot be linear for indefinitely great pressures. Yet the foregoing crude estimates clearly suggest the possibility that crustal foundering could not take place if the crust were even considerably thin- ner than it is to-day. When the difference in the compressi- bility of solid and liquid lava at great pressure is, in the future, once determined, it will first become possible really to test Kelvin’s view as to the original cooling of the earth. The analogy of Barus’s experiments raises the suspicion that the fragments of a foundering primal crust could sink only a comparatively few miles into the liquid interior. They would soon meet therein a level where their own density is matched by that of the more compressible fluid. Solidification by cool- ing would therefore not progress from the earth’s center out- wards, but would begin in a surface shell and slowly progress inwards. Stresses within the erust.—It seems, accordingly, best to conceive of the earth as exteriorly composed of a thin solid shell characterized by tangential compression, a thicker under- lying solid shell characterized by tangential tensions, and a liquid, gabbroid, perhaps highly viscous substratum of unknown thickness. This substratum is immensely elastic as to volume and is compressed by the weight of at least 25 miles of crust- rock. Beneath the surface shell of tangential compression the rate of secular cooling and contraction and the consequent tension increase from the level of no strain downwards all the way to the substratum. In his first paper Davison calculates that the average rending stress in the lower shell is, after a given time (if there be no relief by stretching or by cracking), four times the average compressive stress in the upper shell. *C. Barus Bull 96,0. 5).G: 7S. ap nol glooes R. A. Daly—Abyssal Igneous Injection. 203 So long as folding or overthrusting of the shell of compression does not occur, the two shells are in physical continuity and are strongly bound together. Secular accumulation of tensions and of cooling cracks.— It is generally agreed that, on the contraction theory of moun- tain-building, orogenic folding and crumpling is possible through the secular accumulation of compressive stresses in the outer shell. The crucial question has not yet been satisfactorily answered as to whether there may be similarly a secular accu- mulation of tension and of its effects in the inner shell of the erust. If the crust were a fluid of high though finite viscosity, the accumulation of tension would be impossible to any sensible extent; moreover; the weight of the crust overlying any sub- _ shell would necessarily close all cavities almost as fast as formed during the slow secular cooling. But the average rock of the crust is a true solid known to have a very low modulus of plas- ticity. Pfaff has, indeed, denied even the smallest measure of true plasticity to ‘the average crust-rock, and his experiments seem to prove that massive rocks like granite, gneiss cr gabbro would, at surface temperatures, not flow under the weight of even 25 miles of overlying rock.* They would rapture and shear, but the deformation would not reach the perfection of the molecular shearing implied in true flow. A vertical crack due to cooling contraction would thus tend to be partly closed by shearing in of masses from its walls. The shear-planes would be inclined to the vertical. Each partial bridging of the crack makes further shearing and closing of the crack more and more difficult. A greater weight of crust would now be required since some support of the load is formed through the local meeting of the solid walls.» The simple vertical stress becomes partially resolved into a com- plex network of oblique stresses tending to balance each other in the loci of lateral support. The portions of the crack occurring between these loci of support may remain open because of the diminished sheari ing stresses along the still gaping walls. It thus appears that, though all rocks at surface temperatures will rupture under ‘the weight of less than 6 miles of crust, yet the complete closing of cracks at the same temperatures would not be expected even under the weight of a much greater thickness of crust. The depth of the shell (“zone mye of fracture has been deduced from the crushing tests of stone and from the brilliant experiments of Adams and Nicolson on the deformation of marble enclosed in steel collars. The former tests evidently do not prove anything at all definite as to the pressures required to produce trne plastic *See Adams and Nicolson, Phil. Trans. Royal Soc. London, vol. exev, p. 367, 1901. 204 R. A. Daly—Abyssal Igneous Injection. flow. The flow of marble under confinement has been pro- duced under relatively low pressures, but this is a special phe- nomenon, the result of movement on gliding planes. A pen- knife and a few pounds of pressure will cause “flow” in a crystal of calcite. It is safe to say that similar conditions are not found in the average rock of the crust; if it flows at all the mechanism of the flow must be something entirely different. Deformation within the shell of tension is not to be esti- mated simply by the ultimate strength of surface rock deformed in the laboratory. The experiments of Spring, Hallock and others show that the rigidity of a solid increases with pres- sures ranging up to those about twice that borne by our sub- stratum.* ‘This experimental law strengthens the belief that cavities may remain open in the shell of tension. On the other hand, the downward increase of temperature tends to lower the internal friction and thus to promote the closing of cavities. The pressure-gradient (1 atmosphere to about 3:7 meters of descent) is, however, steeper than the temperature gradient (1° C. to about 30 meters of descent) and it may well be that rigidity actually increases through the shell of tension down to its bottom layer, where, on account of the high tem- perature, the change of state, from solid to liquid, is appr oached. A further indication that cavities may remain open in the shell of tension is indirect but none the less noteworthy. According to the assumption generally held by those adopting the contraction theory of mountain-building, the shell of tan- gential compression, free of load and unconfined as it is along its upper surface, can nevertheless for long periods of time endure without deformation a compressive stress perhaps sey- eral times greater than the weight of five miles of rock. It is the release of this pressure (which was not relieved by simple radial flow and thickening of the shell) that has led to the paroxysmal growth of a mountain-range. If the outer shell can long withstand such pressures, it is reasonable to believe that the material of most of the shell of tension is not perfectly plastic under the weight of overlying crust,—a pressure which is great but, in general, is only a fraction of the accumulated tangential stress of compression. The same ar eument seems to apply also to the conceivable closing of cavities through the expansion of the compressed wall-rocks which tend to “expand elastically into the opening vertical crack. For the reasons already outlined, this expan- sion must, under. the conditions, take place, through most of the shell of tension, by shearing of mass against mass rather than by molecular flow. The induced partial closing of the cavity would, here again, tend to prevent further shearing and * For references see review by C. F. Tolman, Jr., Journal of Geology, vol. vi, p. 823, 1898. R. A. Daly—Abyssal Lgneous Injection. 205 portions of the crack would remain unclosed. It is important to note that the shearing of mass against mass due to expansion along the walls is not additive to the effect of mass-shearing due to the dead weight of crust; the two kinds of deformation would progress simultaneously, and in proportion as masses moved under the one kind of stress, it would become more difficult for mass-shearing under the other kind of stress to take place. Only at the bottom of the shell of tension where the erust-matter is in the state intermediate between those of plastic solid and viscous fluid, would the cavities be closed entirely. This part of the argument may now be summarized. On the whole it seems probable that a percentage of the whole tension developed in the lower shell through secular cooling remains, at any time previous to mountain-building, unrelieved by the stretching or, cracking of that shell. At the level of zero-strain (which is above or not far below the bottom of the “shell of rock-fracture’’) cooling tension is at a minimum and resistance to stretching (shearing) is ata maximum. At the bot- tom of the crust the cooling tension is at a maximum but the resistance to stretching is at a minimum. The accumulation of tension and cooling cracks will therefore be at a maximum at some level near the middle of the shell of tension. The accumulation of compressive strains in the outer shell will be relieved to a certain extent by recrystallization leading to the development of denser minerals in the shell; but geological observation shows that, in a long period of time, enormous compressive stresses are alway stored until relieved by a more catastrophic process. The accumulation of the tensile stresses in the lower shell will be in some direct proportion to the degree in which relief is withheld in the shell of compression. Beneath a crust so diversely stressed, there is a compressed, elastic fluid which is ready, with relative suddenness and with prodigious force, to inject itself into the shell of tension as soon as there is any local relief of pressure or any breaking of the continuity of the shell. The whole system is evidently in unstable equilibrium. If each shell were of uniform thickness and composition, and if there were no external forces acting on the system, it would be difficult to forecast when or where the strains could be relieved. Injection of magma into the shell of tension.—But the earth’s crust is not perfectly homogeneous; none of the shells is of perfectly uniform thickness ; ‘and, thir dly, there are other powerful forces acting on the material of the shell of tension besides those leading to stretching during the earth’s contrac- tion. Of special importance is the shearing of the whole crust in the torsional deformation incidental to the contraction, or in the torsion due to tidal stress. Slight as may be the effect 206 f. A. Daly—Abyssal Igneous Injection. of asingle tidal period, for example, it will, in certain lines appropriately oblique to the earth’s equator, tend to wrench apart the crust even down through its viscous bottom layer. To such a powerful fluid as that composing the substratum, this viscous layer, suddenly sheared or broken, is relatively a solid mass; to the searching fluid a plane of shearing in the viscous layer is virtually a crack. Into that plane the tidal pulsations will pump the fluid, which instantly exerts its lateral hydrostatic and expansional pressures on a shell already prone to recoil because of the real though mild tension residual in the bottom of the shell. As the fluid thus works its way upward, it encounters rock which is increasingly more rigid and increasingly charged with accumulated tension and cooling cracks. In fact, if we conceive that the viscous bottom layer is once completely penetrated, it is easy to believe that the abyssal dike will be rapidly injected toward the top of the shell of tension. The shearing-in of the solid rock opposes the continued opening of the potential fissure, but this shearing, as the level of no strain is approached, becomes.slower and slower and thus more and more powerless to check the rapidly acting wedge of expanding fluid. The injection might conceivably (following Fisher’s idea) be aided by the local removal of the viscous basement through the special attack of upward convection currents in the sub- stratum ; for it is clear that the injection is most difficult at its very beginning. Fisher has suggested that water-gas given off from the substratum when it is already injected into a downwardly-opening “chasm” may contribute force tending to widen the crack. However, such gas could not, on this hypothesis (the gas being dissolved in the magma according to Henry’s law), segregate except by release of pressure. The release is a slow process. As a means of injection through the viscous layer the solution of magma and water-gas would be more effective than the compressed anhydrous magma, but their activities would be of the same kind: Fisher assumes that the magma is saturated under a pressure of 12,000 atmos- pheres. This implies that the more rapid the outflow of lava at a vent, the more imposing would be the explosive phenom- ena. It is obvious that this is not the case in nature. The exceedingly small amount of water in the lavas of fissure-erup- tions and of the Hawaiian calderas seems, indeed, to show that the abyssal fluid is essentially anhydrous.* The water actually found in lava and that accompanying explosions of the Vesu- vian type may be all or nearly all derived from the shell of rock-fracture. We conclude that it is wisest to find the posi- tive penetrating force of the magma in its own elastic expan- * Of. J. D. Dana, Characteristics of Voleanoes, New York, 1891, p. 197. R. A. Daly—Abyssal Igneous Injection. 207 sion operating wherever a line of diminished pressure is devel- oped in the viscous layer. It is also manifest that, if torsional or other shear is accom- panied by vertical faulting, the abyssal injection will be still further facilitated. | Relief of tensions through abyssal injection.—W hether the foregoing hypothesis be correct in details or not, there is no doubt that abyssally-injected dikes have actually been fed from the gabbroid substratum upward to the vents of fissure erup- tion. Granting, secondly, that there are cooling cracks and considerable unrelieved tensions in the crust, as already 1 Surface s SHELL OF COMPRESSION ’ bevet 0) noe Strain ' Approximate lower Limit of shell of fractpuxe ve + + + SHELL. OF = TENSION + © a a __|+ + + Siics en Heer eV te teeeeeert bees tee bette ttt ett FREE EE HEE EEE EH EHH teach hey at hn ae Se USh Tp TAPP ar ea ane pe ea ator brat ite delta de ete ptt gk ake teat ck: + 3a described, consequences of fundamental importance seem to be deducible. On account of the strong compression at the earth’s surface the magma of the abyssally-injected dikes will not in most cases reach the surface. The act of injection produces a great change in the conditions of equilibrium in the shell of tension and therewith in the whole crust. | Let figure 1 represent a sectional view of the system after injection, the earth’s curvature being neglected and the dike being shown in cross-section. The level of no strain is repre- sented as about five miles below the surface—a depth some- what greater than the maximum calculated by Fisher.—The principle of the following argument is not affected if the depth should be a fraction of one mile or as much as six or possibly more miles. 3 | “A” is a particle of the crust within the solid shell of ten- sion. In the stretching of the shell such a particle must move not only radially toward the earth’s center but tangentially as well. If the shell is homogeneous, the weight of the over- lying crust will.tend to shear the particle indifferently toward 208 RR. A. Daly— Abyssal Igneous Injection. m or m’ or toward any one of an infinite number of other points lying in the circumference of a horizontal circle cireum- scribed about the vertical passing through A and with radius Am. The shear-movement of particle A is, however, strictly controlled in direction so soon as a liquid dike is injected. At the level of A the point O in the wall of such a dike bears a combined hydrostatic and elastic pressure from the magma. The former pressure is sensibly equal to the weight of the column of rock Aw; the maximum elastic pressure equals the weight of the column A? y. The totalof these pressures, repre- sented by the line On, is equal to the oppositely directed force O’n’ on the other wall of the dike. On is not only a positive force compressing the matter between O and A; it is also, and yet more significantly, a directzve force which determines the direction in which particle A must move as it is affected by the tensional pull of secular cooling and by shear during the compressive extension (stretching) of the shell of tension. As long as the dike remains fluid, particle A will move in the direction of the arrow Am’. ‘The condensation of matter, which, before the dike-injection, had been only potential (being due to the accumulation of tensions and cracks in the shell), now becomes actual. As particle A is forced toward m’, a neighboring particle, A, on the same level and to the right hand of A, is similarly brought under pressure and moved in the direction of the arrow Am’. A, communicates its motion 10 -N, and so on. hes pressure at O is thus felt within the shell as far away from the dike as the relief of the accumu- lated tension and the closing of cooling cracks can take place. The movement of particles A, A,, A,,; etc., is analogous to the work of a railway engine pushing down a train of cars which had been standing on a grade with each coupling pin at full length because of the grade. Buffer meets buffer, com- municating the pressure of the engine. - If the train had been nicely poised, just ready to move before the pressure was applied, and if the grade were indefinitely long, a small pres- sure would set in motion a train of indefinite length. The analogy is not perfect since the creep of the particles in the shell of tension is not free but is controlled by mternal fric- tion and by the strong adhesion between the shells of com- pression and tension. Nevertheless, it is not difficult to believe that lateral creep would be set up at a distance perhaps several times the thickness of the whole crust. Since the conditions are precisely the same for particles B, B, (to the left of B), B,, ete., there will be similar creep on the side of the dike opposite to A in the direction of the arrow O’n’. The dike is thereby widened. ‘The correlative injection ae new fluid magma makes this new system of R.A. Daly—Abyssal [gneous Injection. 209 motions self-perpetuating until the attainable relief of tensions and closure of cracks is accomplished. Thereafter, two possibilities are open. The now much widened dike may have lost sufficient heat to solidity. The system of directed creeps or lateral movements will then be exchanged for an undirected compressive extension similar to that which prevailed before the injection. Or, if the dike remains fluid, it will cause an indefinite continuance of lateral creep keeping pace with the differential cooling contractions in the shell of tension. In the former case, the injection of a second and of yet later dikes is possible, and their net effects, provided these dikes are elongated in the same general earth- zone,* are additive to those of the first dike. Tidal or other torsion may locate such a zone of special igneous injection. Down-warping of the surface as a result of abyssal injec- tion.—We have seen that lateral creep will be fastest some- where near the middle level of the shell of tension, because it is there that the defect of condensation of matter, shown in cooling crack and in residual tension, is at a maximum. The ensuing condensation of matter in the shell is at a maximum in the immediate vicinity of the zone of injection and gradually decreases to each side of the zone. Since the two shells are still solidly knit together, the enforced creep of matter to right and left of the great dikes involves a strong downward pull exerted on the shell of compression. A down-warp of the earth’s surface is thus established. The initial down-warp is of length, breadth and depth dependent on the magnitude of the injected body or bodies. Where the injection is on a large scale the down-warp may be of geosynclinal dimensions. ‘The down-warping implies, however, that the former nice balance of stresses in the zone of compression is destroyed. Those stresses will henceforth tend directly to increase the down-warp. Sedimentation within the down-warp increases the weight on the creeping material of the shell of tension, which is also now beginning to fee] a small downward pres- sure, a component of the total thrust of the now bent shell of compression. The down-warping of the surface may thus gradually increase even after all magmatic injections in the zone of tension have frozen solid. Lhe conditions for mountain-building.—The shell of com- pression is now weakened, as experimentally illustrated by Willis in his memoir on mountain-building.| The weakening is most felt in the two lines where the down-warped surface parts from the spheroidal curve of the earth. If sediment * Throughout this paper the word ‘‘ zone” is used in its proper mathe- matical sense of a ‘‘ portion of the surface of a sphere included between two parallel planes.”—As prevailingly defined, the ‘‘zone of fracture” in the earth may here be profitably called the ‘‘ shell of fracture.” + B. Willis, 15th Annual Report, United States Geological Survey, p. 217, 1893. 210 RR. A. Daly—Abyssal Igneous Injection. accumulates to the depth of many thousands of feet in a geo- synelinal, the material of the original shell of compression is softened by the rising of the isogeotherms, while the strength of the new shell of compression occupied by the sediments is low because of the poor consolidation of this new formation. For a double reason, therefore, a broad zone of weakness in © the shell of compression is developed over the zone of igneous injection. Sooner or later the secular accumulation of com- pressive stresses will express itself in the orogenic collapse of the shell; the building of an alpine mountain range is begun. The most serious objection to the contraction theory—that the earth’s amount of contraction is insufticient for the orogenic | 2 Fic. 2.—Diagrammatic cross-section showing the relation of a geosynclinal to a zone of abyssal injection. C (vertical lines)—shell of tangential com- pression ; T (blank)—shell of tangential tension ; S (stippled)—substratum. The smaller arrows show the direction of compressive stresses ; the larger arrows show direction of rock-creep in the shell of tension. The original position of the surface before the geosynclinal down-warping is shown by the dotted line. Some of the injected bodies of magma are represented as of batholithic size; the same amount of rock-creep in the shell of tension and of down-warping of the surface would have been produced by the injection of smaller bodies, more numerous and also closely spaced in the zone of injection. Scale: about 65 miles to one inch; the curvature of the earth’s surface is exaggerated about ten times. work actually done through geological time—has been founded on mathematical deductions. As with the so-called demon- stration of the earth’s extreme rigidity, the deductions are no stronger than the assumptions as to the interior economy of the globe. If the earth’s vast nucleus is gaseous, as seems so highly probable, the larger part of the earth may be cooling and contracting according to different laws from those hitherto accepted as a basis for calculation.* or example, the con- traction of the nucleus may follow a modified “law of Charles”; secondly, we should expect that, with cooling, there will be, within the globe, the liquefaction of gas as well as the solidifi- cation of liquid—both changes of state possibly being accom- panied with special diminutions of volume. The phenomenon of earth-contraction may thus be inuch more complicated than it has been assumed to be, but the added complications would probably be favorable to the contraction theory of crustal deformation. * Cf. S. Arrhenius, Geol. Féren. Stockholm Forhandlingar, xxii, p. 390. R. A. Daly—Abyssal Igneous Injection. 211 Expansion of the earth’s outer shell as a factor in moun- tain-building.—But there is good reason to believe that the contraction theory, as usually stated, carries only half a truth. Both advocates and opponents of the theory have generally spoken of the collapsing surface shell as of nearly constant circumference since the time of original crustification, except for the amount of overthrust and overfold represented in folded and faulted regions. This shell is, indeed, conceived as itself having slightly shrunk through loss of heat during geo- logical time, little or no emphasis being placed on those agencies which tend to counterbalance this shrinking and even 3 MOUNTAIN RANGE Fig. 3.—Diagrammatic cross-section showing relation of mountain-building to simultaneous and subsequent abyssal injection of magna. Scale and symbols the same as in figure 2. a-b (heavy line): the surface on which the shell of compression shears over the shell of tension in the orogenic thrust- movement. Two large batholiths of slightly different ages are represented ; the mountain-building is supposed to have been just completed. The igneous bodies injected and crystallized before the epoch of mountain- building are not shown. produce a net expansion of the shell. Nevertheless, it seems highly probable that the original shell has actually grown larger instead of remaining sensibly of constant circumfer- ence, and that a part, perhaps the greater part, of the circum- ferential shortening observed in the world’s mountain ranges is due to this fact. The outer skin of the earth, including its overthrust por- tions, may grow areally larger according to two different pro- cesses. a. Local cavities produced in the shell of compression by crustal readjustments may be rapidly filled with magma from beneath or, more slowly, with vein matter deposited from cir- culating waters. True magmatic injections, such as dikes, laccoliths, ‘“chonoliths,’* ete., and possibly a percentage of batholithic irruptions represent just so much additional matter squeezed into the shell. These wedges when solidified, like all the countless mineral veins, aid in transmitting and increas- ing the thrusts affecting the shell as it collapses on the shrink- ing “nucleus” of the earth. This view has been clearly * Defined in Journal of Geology, vol. xiii, p. 498, 1905. Am. Jour. Sct—FourtH SErRizs, Vou. XXII, No. 129.—SEptemBer, 1906. 15 212 Rf. A. Daly—Abyssal Igneous Liyection. enforced and illustrated by Shaler* and must be regarded as embodying a true condition of crustal deformation. 6. Still more important is the consideration that the shell of compression is the home of those metasomatic changes in rocks that lead to expansion of volume. One of the most strik- ing results of Van Hise’s researches in metamorphism is his conclusion that in this shell the average effect of hydration, carbonation and oxidation is to cause such expansion on a sur- prisingly large seale.t For example, if a gabbro were com- pletely altered according to the normal reactions in the “ kata- morphie zone” (which, in position and depth, is very nearly identical with our shell of compression), there would be a volumetric increment of at least 25 per cent. If the entire shell were gabbroid, and if but 4 per cent of its substance had, in post-Archean time, been similarly hydrated and carbon- atized, the volumetric increase would be about sufticient to explain all of the observed overthrusting and overfolding of post-Archean mountain-ranges. The rocks of the continental plateaus are, however, largely composed of quartz and ortho- clase, two minerals which do not show volumetric expansion in their alteration. The part of the shell underlying the deep ocean-basins is of unknown composition, but pendulum obser- vations and other general considerations suggest that this greater part of the shell is basaltic, and has, in general, never been exposed to subaerial erosion. Under the deep seas especi- ally the maximum amount of metasomatic expansion and the maximum accumulation of corresponding compressive stress might, accordingly, be expected. It is conceivably to this cause that we may refer the fact that the thrust of mountain- building has, throughout the world, been chiefly from the ocean toward the land. In any case the average result of the alteration of rocks, whether by cold descending waters or by hot ascending waters, or by water trapped within the shell, and with all allowance made for solution of mineral matter which is thus removed to the oceans, is to bring about expan- sion of volume within the shell. This expansion must be accompanied by tremendously energetic compressive stresses; the process is homologous to the hydration of a bed of anhy- drite. Since these chemical reactions take place mainly along more or less vertical cracks, fault-planes, joints, ete., the expan- sional force will be chiefly directed in planes parallel to the earth’s surface. The relief of the strains through simple vertical expansion is resisted by the strength of the unaltered rock lying between the vertical zones of chemical alteration. * N.S. Shaler, Science, xi, p. 280, 1888. +C. R. Van Hise, Treatise on Metamorphism, Monograph xlvii, U. S. Geol. Surv., pp. 681 ff. R. A. Daly—Abyssal [gneous Injection. 213 It is manifestly impossible to test these conceptions quanti- tatively, thus comparing their calculated effects with the known needs of the orogenic problem. Yet they are worthy of attention as valuable adjuncts to the thermal-contraction theory of mountains. ‘It may in the end turn out that moun- tains are the result of a tolerably complicated series of causa- tions, in which secular refrigeration of the earth, the transfer of weight by the operations of erosion and deposition, and the subterranean migrations of matter, all take a part.”* The energy for crustal deformation may thus lie in the combination of two immense forces—the force involved in massive read- justments within an entire cooling planet, and the force involved in the molecular readjustments among its recrystalliz- ing ultimate particles. Other causes, such as the torsional shears expected in a planet suffering a progressive change in its rate of rotation, may further supplement those causes which have here been briefly noted as seemingly the most important. ftenewed abyssal injection following mountain-building: development of batholiths.—The extent to which shortening of the transverse axes of the world’s mountain ranges has occurred shows that each orogenic revolution has been accompanied by a wholesale shearing of the shell of compression over the shell of tension. The surface of shear is probably not far from the level of no strain. One effect of the shearing, faulting and crumpling may be to squeeze small bodies of magma up into the upper shell. But the grandest results of igneous intrusion would be felt in the shell of tension. The instant that the two shells are sheared asunder, the tensions that have been accumulated because of the solid continuity of the two shells, and are still residual after the preceding injection of magma, are relieved. The shell of tension is henceforth free to contract on itself. A fluid dike now injected into this shell or a dike injected previous to the shearing but still fluid, would tend, according to the process already described, and especially because of the energetic, spontaneous retreat of the country-rock on either side, to enlarge itself. Opposed to the active retreat and enforced creep of the solid rock of the shell away from the middle plane of the dike, and thus to the ready contraction of the shell, is the friction developed at the surface of shear. Since the shear is directed tangentially with respect to the curve of the earth, the strength of the friction is measured directly by the weight of the shell above the shear-surface. At the upper extremity of a dike which reaches exactly to the shear-surface, the hydrostatic pressure exerted on the dike-wall is somewhat greater than the weight of the shell above the shear-surface. The magma has, in addition, the live energy *N.S. Shaler, op. cit., p. 281. 214 R. A. Daly—Abyssal Igneous Injection. of elastic expansion measured by the compression due to the weight of the whole shell of tension. The net effect of these forces is to permit of the contraction of the shell already prone to movement on account of the sudden relief of tension, and to cause a widening of the dike which may assume batholithie proportions. It is important to note that the recoil within the shell due to the relief of tensions will characterize the whole of the area over which the shells of tension and compression have been sheared apart; this area may be several thousand miles in diameter. The piling up of the mountain-mass above would also cause an enhanced rapidity or lateral flow in the shell of tension and likewise widen the magmatic chamber. Injection into the mountain-rocks themselves would only be possible where there is local relief of compression in the now heterogeneous, unequally squeezed, and writhing mass. Sinee, in the nature of the case, compression generally dominates, igneous injection will, in this period, afford but small eeologi- cal bodies as constituents of the range. At the mountain-roots below the surface of shear there are one or more great bodies of gabbroid magma specially injected as a result of mountain-building. Through the physical and chemical activity of this magma the acid igneous stocks and batholiths so characteristic of mountain-range of the alpine type, may possibly be explained by the assimilation-differentia- tion theory.* The cycle of changes which have affected our ini- tial system (compression-shell, tension-shell and fluid substra- tum) thus began with igneous intrusion and closes with igneous intrusion. On account of the relief of compressive strains in the superficial shell, the latest and probably greatest intrusive bodies are free locally to flux or stope their way well into the shell of fracture. With certain assumptions, several authorities have calculated that the level of no strain has always lain at a depth no greater, or but very little greater, than the bottom of the shell in which rocks can readily fracture.t In rising through the shell of tension the gabbroid magma has expanded so much and attained such low viscosity that down-stoping and abyssal assimilation of shattered roof-blocks is now possible. To the differentiation of the compound magma so _ produced, the granitic batholiths and stocks, many injected laccoliths, ‘‘ chono- liths” and dikes, as also many lavas more acid than gabbro, have been attributed. There are reasons for believing that magmatic stoping is much more potent than fluxing assimila- tion on main contacts. If granites, ete., are really “secondary after the manner indicated, they can only be formed in the shell of fracture and on the large scale where the tangential * See R. A. Daly, this Journal, vol. xv, 1908, p. 269; vol. xvi, 1903, p. 107; vol, xx, 1905, p. 185. + The limits of the shell of ready fracture, as conceived by Van Hise, are shown in Fig. 1. R. A. Daly—Abyssal [gneous Injection. 215 compression of the superficial shell is relieved. Otherwise stoping is impossible, for a large magma chamber could not remain open in the zone of unrelieved compression. Granites and allied rocks are, by this hypothesis, primarily mountain- rocks. That this is the fact hardly needs statement. Vuleanism as a result of mountain-building.—By the inevitable settling-down and block-faulting which follow the orogenic paroxysm, both primary basaltic lava and secondary lavas of indefinite variety may be squeezed out to the surface. Volcanic activity is not, by the hypothesis, necessarily confined to zones of intense mountain-building, but should be specially developed in those zones. The volcanic problem .and the orogenic problem are in general both related to the same necessity of understanding the mechanical rearrangements when, for any reason, fluid material from the substratum is injected into the shell of tension. Summary. Postulates.—The assumptions on which the foregoing hypothesis has been based are the following: a. A cooling earth superficially composed of a relatively thin crust overlying a fluid gabbroid substratum of unknown thickness. 6. The substratum so much compressed by the weight of the crust as to be probably able to float the crust. e. Through differential cooling contraction the development of a level of no strain in the crust not far from the bottom sur- face of the shell of rock-fracture. d. The accumulation of pressure in the shell of compression and the simultaneous accumulation of cooling cracks and of some of the powerful tension unrelieved in the shell below the level of zero-strain. e. A steady or recurrent dislocation of the shell of tension permitting of the forceful injection of the fluid substratum to which even the viscous layer of the shell acts as a relatively solid mass at the moment of dislocation. This dislocation has been referred to the tidal torsion of the earth’s crust, but sub- equatorial torsion on the tetrahedral theory of the earth, or crustal deformation due to the play of other cosmical forces or of forces induced by the heterogeneity of the crust, may simi- larly cause dislocation in the shell of tension. Conclusions.—1. The abyssal injection involves condensation of the matter in the shell of tension. Cracks are closed and much of the accumulated tension is relieved by an enforced creep of matter away from the injected body. So long as the body re- mains fluid the stretching of this shell due to continued cooling of the earth is accomplished by creep of matter in the same 216 R. A. Daly—Abyssal Igneous Lnjection. directions. The amount of creep is at a maximum above the zone of injection and decreases to a minimum at certain dis- tances to right and left of the middle line of the zone. 2. This lateral creep induces a down-warp of the earth’s surface immediately overlying the zone of condensation. The resulting geosynclinal may be the seat of prolonged sedimenta- tion. If so, the weight of the sediment itself tends to increase the lateral creep in the shell of tension and the down-warp oe deepens. The shell of compression is already weakened at the eles of down-warp; it is further weakened by the sediment- ary blanket which, comparatively little resistant itself, causes a softening of its ‘basement through a rising of the isogeo- therms. When the filling of the geosynelinal has sutiiciently thickened, the shell of compression, owing to its secular aceumu- lation of stresses (which are intensified by metasomatic changes in the shell), begins to collapse. Mountainous forms and. structures result. 4, The complete shearing apart of the shells of compression and tension during the orogenie revolution releases the tensions still unrelieved in the underlying shell. A byssal injection on a large scale is thus initiated or continued in the shell of ten- sion. The relief of compressive stresses in the act of building the mountains first occasions the possibility of magmatic stop- ing and thus of the extensive assimilation of schists and sedi- ments by the primal gabbroid magma: The differentiation of the compound magmas of assimilation may explain the batho- lithic central granites, ete. of mountain ranges, along with their satellitic stocks, injected bodies and volcanic outflows. 5. The regional warpings of the earth’s crust may be partly at least referred to the varying strengths of abyssal injections from a fiuid substratum. 6. The location and alignment of mountain ranges, the loca- tion and elongation of geosynclinals, the final development of igneous batholiths and satellitic injections, are all inter depend- ent and related to speceal zones of powerful abyssal injections from the substratum. ‘These zones are, in the large, located by cosmical stresses affecting the earth along special azimuthal cue Mountain building causes relief of compressive stresses in fe superficial shell. The surface outflow of magma either secondary or directly derived from the substratum may there- fore be specially pronounced after an orogenic revolution. In general, the theory of vulecanism is also fundamentally affected by the doctrine of the shell of tensions which are not entirely relieved by the compressive extension of that shell. W. E. Ford—Interesting Beryl Crystals. 217 Art. XIX.—Some Interesting Beryl Orystals and their Associations; by W. E. Forp. Tue beryl erystals commonly found in pegmatite veins are prismatic in habit, consisting of a simple combination of the prism of the first order, m, with the base, c, and as a rule are only semi-transparent, and of a green color. It is the chief purpose of this article to describe several striking exceptions to ic this general rule, and to point out some interesting similarities in erystal habit, color and association shown by a series of beryl crystals from a number of different localities, all of which are noted for the occurrence of variously colored tour- malines of the lithia variety and of gem quality. The pegmatite deposits of San Diego Co., California, which have become famous on account of their beautiful tourmalines, have lately furnished some bery] crystals of an unusual habit and uncommon color. Figure 1 is of a crystal from the deposit at Mesa Grande, while figures 2 and 3 are of erystals from the locality of Pala. The short prism which they show, especially in figures 1 and 2, together with the large and 918 W. E. Ford—Interesting Beryl Crystals. prominent development of the pyramid of the second order s (1121), give them a habit of crystallization very different from that usually shown by beryl. The crystal represented by fig- ure 2 also shows smaller replacements by faces of the pyramid of the first order p (1011) with an occasional face of the dihexagonal pyramid v (2131). It is further complicated by several reéntrant angles caused by a repetition of the faces due to parallel growth. The figures are drawn to show as nearly as possible the development of the faces in their true proportions, figure 1 being about natural size while figures 2 and 3 are one half natural size. The crystals are transparent and of a beautiful light rose-pink color: their extraordinary color combined with their unusual habit of crystallization make them especially noteworthy. Figure J is of a crystal loaned for study by Mr. Ernest Schernikow of New York and which has since come into the possession of the Brush Collection, while the crystals represented by figures 2 and 3 are in the Tiffany Gem Collection in the American Museum of Natural History, New York. Figures 4, 5 and 6 are of beryl crystals showing interesting similarities in habit and association with those just described, but from other localities. Figure 4 represents an incomplete crystal found at Mt. Mica, Paris, Maine, now in the mineral collection of the American Museum of Natural History in New York. It shows a short development of the prism m with prominent faces of the second order pyramid s; also small replacements of another pyramid of the second order o (1122), of the pyramid of the first order p, and of the dihexag- onal pyramid v (2131). The crystal is transparent and color- less like pure quartz, and attached to it are plates of lepidolite. Figure 5 is likewise of a colorless crystal from Mt. Mica belonging to the Brush Collection, nearly complete, quite symmetrical in development and about 15™™ in diameter. It is characterized by small faces of the prism m and a large development of the pyramid s, while o and v were observed as W. EF. Ford Interesting Beryl Crystals. 219 small truncations. Figure 6 is of a crystal in the Brush Col- lection from the famous tourmaline locality of Haddam Neck which corresponds to these other erystals in having the pyra- mid of the second order unusually prominent, although on this erystal the prism faces are large and well developed. This erystal is transparent and has a very pale pink color. Several other light-colored erystals from Haddam Neck showing a development of faces similar to that of figure 6 are in the min- eral collection of the American Museum of Natural History. One very large one, donated to the Museum by Mr. Ernest Schernikow, measures 18 inches in length by 1 foot in diame- ter. It is doubly terminated, but so attached that only a por- tion of its faces are developed. Pink beryls were formerly found at Goshen, Massachusetts, associated with tourmalines of light to dark green color, and were given the name of goshenite by Shepard.* Specimens of beryl from this locality in the Yale College Collection show only the forms of the prism 7 and the base c. Transparent, colorless and pink beryls are also found in the Island of Elba associated-with variously colored gem varieties of tourmaline. A specimen of pink beryl in the Brush Collection from Elba shows a short prismatic development terminated only by the base. Vom Ratht describes the Elba beryls as being usually transparent and frequently of a light pink color, and although light green and blue crystals occur there as well, they are * A Treatise on Mineralogy, third edition, 1852, p 229. +Z. d. d. Ges. xxii, 661. 220 W. L. Ford—Interesting Beryl Crystals. often only semi-transparent. These crystals are described as having generally a prismatic habit, but he mentions several instances where they are markedly tabular in development. It is interesting to note the striking similarity in habit, color and association of beryl crystals from these different localities. Many of them are of an unusual crystal habit for beryl, fre- quently being short prismatic, at times even tabular parallel to the base, and occasionally are highly moditied. They are also of unusual color, some of them colorless, others of a heht tone of pink, quite distinct from the green or blue-green shades commonly shown by beryl. All of them also were found in pegmatite deposits associated with variously colored green and pink tourmalines of gem quality. Such coinci- dences of association of beryl crystal of unusual habit and color with tourmaline crystals of light colors and gem quality are interesting and suggestive. To the writer’s knowledge, the ordinary green beryl, showing a simple combination of prism and base commonly found in pegmatite veins, occurs rarely at the localities which furnish gem tourmalines. It would seem not at all improbable that the conditions favorable to the formation of tourmalines of gem quality were likewise favor- able to the formation of these beryl crystals of unusual color and habit. The factors which control such matters as mineral oceur- rence and association are undoubtedly extremely complex, being both physical and chemical in their nature. It would seem probable however, if this association which has been noted is anything but accidental in character, that some chemi- cal similarities might be found to exist between these types of tourmaline and beryl. It has been noted that gem tourmalines are usually characterized by containing about twice as much of the alkali oxides as the ordinary varieties, Li,O being prac- tically only found in the gem material. The occurrence of small amounts of alkalies, usually Na,O and Cs,O, have been frequently noted also in beryl. It was thought therefore that any chemical similarity between the gem tourmalines and the pink or colorless beryls would be in the presence in each of unusual amounts of the alkali oxides. Quantitative tests for alkalies were therefore made on two different beryls, the first being pink material from Mesa Grande, the same as that of the crystal illustrated in figure 1, while the second was a pale pink opaque crystal in the Brush Collection from Haddam Neck. Both of them showed considerable amounts of alkalies, the Mesa Grande material yielding about 3°00 per cent and that from Haddam Neck about 5°0U per cent of mixed alkali oxides. From both of them strong tests for cesium were obtained by use of the spectroscope. In this W. E. Ford—Interesting Beryl Crystals. 221 connection an analysis* by H. L. Wells of a clear and color- less beryl found associated with gem tourmalines at Hebron, Maine, might be quoted, which yielded Na,O, 1:13; Li,O, 1:60, and Cs,O, 3°60. These few instances would seem to indicate that these unusually colored beryls are liable to con- tain several per cent of alkalies, cesium being characteristi- cally present. Their association with those tourmaline crys- tals, which likewise contain unusual amounts of alkalies, can hardly be considered entirely accidental, and consequently in this fact of chemical similarity we probably find one of the conditions which influence the association of this type of beryl erystals with the gem tourmalines. Figure 7 is of a transparent green crystal (aqua- " marine) in the Brush Collection from the Mack Mine, San Diego Co., California, and is introduced here chiefly for the sake of contrasting it with the tabular type from the same general locality shown in figure 2, the two crystals representing the opposite extremes of development. The erystal is represented in the figure in its true proportions, except that its length parallel to the vertical axis should be four times as great as is shown. ‘The length of the crystal is approximately fifteen times as great as its diameter, the actual dimensions being 60x4™". The faces on the crystal are the prism of am | \\on the first order m, the dihexagonal prism 2 (21380), the pyramid of the second order s and the pyramid of the first order p, with the basal plane c¢, and are developed with almost ideal symmetry. There are also in the Brush Collection two per- fectly transparent and yellow colored beryl crystals from Ramona, San Diego Co., which show remark- able etchings: These are in the form of depressions arranged singly in line, figure 9, or in groups, figure 10, in the positions which would naturally be occupied by faces of the prism m. The prism m, however, does not appear on the crystals, the groups of pits corresponding in position to adjacent m faces being separated from each other by a dihexa- gonal prism. Measurements of a series of the faces forming the pits were made on a two-circle goniometer and the aver- ages of the results obtained were used to plot the positions of the faces on a gnomonie projection, figure 8, the plane of pro- jection being taken as parallel to m (1010). From this pro- jection figures 9 and 10 were made, which show the character and arrangement of the etched pits drawn in orthographic projection upon a plane parallel to m. The faces were all * Dana’s Sys. Min., p. 407. i 222 W. LE. Ford—Interesting Beryl Crystals. rounded and gave only approximate measurements, conse- quently no definite symbols can be assigned to them. The dihexagonal prism designated as 7, which appears on the erys- tals and forms prominent faces in the pits, is close to a form having (8140) as its symbol. The faces in the pits marked 7 are the same as the right hand prism face (3140), also marked 7, and reflect the light simultaneously with it; and those marked 1’ reflect together with the left hand prism face, (4130), designated as 7’. The bottoms of the pits are usually occupied by two small faces making a very acute angle with one another which correspond to the two prism faces desig- nated as 1” and 1’, figure 9, which lie to the right and left 8 9 10 #730) (3140) 2 beyond those marked 7 and 7’. Figure 11, which is a hori- zontal section along the dotted line in figure 9, illustrates the relations existing between the faces of the dihexagonal prism and the corresponding faces found in the pits. The pyramid of the first order, designated as 2, which always forms the upper and lower faces of the pits, approximates in its position to (18°0°13°2). In addition to these faces the etchings show two other forms, 3 and 4, which in their positions correspond to the faces of dihexagonal pyramids. They are of vicinal character, falling very close to the prism face m, as is shown in the gnomonic projection, one averaging only 4° 57’ and the other 2° 13’ from m. Because of the uncertainty of the meas- W. EF. Ford—Interesting Beryl Crystatls. 223 urements due to the vicinal character of the faces, exact sym- bols cannot be assigned to these forms. In some places the pits form a single line down the length of the crystal, not encroaching at ail on the faces of the dihexagonal prism at the sides, as shown in figure 9. More generally they are in two or more parallel and adjacent lines and interlock with each other in a very complicated manner, as shown in figure 10. he pits average 2°" by 1:5 in size. The crystals show a tendency to taper at the ends on account of the etching and rounding of the prism faces. Acknowledgment should be made of the courtesy of Mr. Ernest Schernikow of New York and of. Messrs. H. C. Bum- pus and L. P. Gratacap of the American Museum of Natural History in New York, for furnishing for study the crystals illustrated in figures 1 to 4. The writer also gratefully acknowledges the frequent help, through criticism and sugges- tion, of Prof. 8. L. Penfield during the preparation of this article. Mineralogical Laboratory of the Sheffield Scientific School of Yale University, New Haven, Conn., June, 1906. 294 FE. Wright—Schistosity by Crystallization. Art. XX.—Schistosity by Crystallization. A Qualitative Proof; by Frep. Evernz Wricur. In the general theory of the metamorphism of rocks, pres- sure, especially stress applied in one direction, has long been considered an important factor; and in recent years sufficient evidence has been accumulated by geologists from observa- tions in the field to demonstrate practically its influence on the textures of rocks during their formation. Investigations of the behavior of a body or chemical system under stress have also been made by chemists and physicists, and fundamental laws of equilibrium deduced therefrom which have a direct bearing on the broader problems of metamorphism. Le Chatelier*™ discovered a number of years ago, that in a chemical system “any change in its factors of equilibrium from outside is followed by a reverse change within the sys- tem.” At constant temperatures, therefore, an increase of external pressure tends to produce those changes which are attended by diminution of volume. In the words of Banecroft,t+ “the system in equilibrium tends to return to equilibrium by elimination of the disturbing element.” Most solids dissolve with decrease in volume: when this is the case, the solubility is increased. Riecke and also Hambuechent have proved ex- perimentally an important deduction from this general law, that a body under unequal strain dissolves most rapidly along the line of greatest stress. In accord with this law of physical chemistry, Van Hise,§ reasoning from the standpoint of geology, has shown that in the deep-seated zone or zone of anamorphism “ the deforma- tion in connection with mass mechanical action is mainly accomplished not by mechanical subdivision but by the chemi- cal action of recrystallization ;’ that “under strains with a stress difference an exceedingly small amount of water at the high temperature is capable of dissolving particles of substance under the greatest stress and depositing them along lines of less resistance, the movement of the solution being slight and * Comptes Rendus, xcix, 786, 1884; quoted in W. D. Bancroft’s ‘‘ The Phase Rule,” Ithaca, 1897, p. 4. Van’t Hoff has also derived the same law from the second principle of thermodynamics and expressed it in mathe- matical terms. Studien zur Chemischen Dynamik, Van’t Hoff and Cohen, . 229. + ‘‘ The Phase Rule,” Ithaca, 1897, p. 4. t Riecke, E., Nachr. v. d. K. Ges. d. Wissensch. zu Gottingen, Math.- phys. Klasse 1894, iv, 278-284 ; Hambuechen, C., ‘‘ An Experimental Study of the Corrosion of Iron under Different Conditions,” Bull. Univ. of Wiscon- sin, No. 42, 1900, p. 259. S$ ‘“‘Metamorphism of Rocks and Rock Flowage,” Bull. Geol. Soc. America, vol. 9, May, 1898; also ‘‘ Treatise on Metamorphism,” U.S. Geol. Survey, Mon. 47, Chap. vit: vit (1904). FE. Wright—Schistosity by Crystallization. 225 the quantity of substance in the solution at one time being extremely small.” Through the superheated water as a medium, adjustment by solution and deposition goes on con- tinuously during the deformation. Under such conditions minerals like the micas and amphiboles, which have a tendency to grow most rapidly in one direction, develop with their longer axes in the direction of least resistance, perpendicular to the line of greatest stress; and the texture of the resultant rock will be characterized by a parallel arrangement of its mineral components. Since in such metamorphic rocks the recrystallized silicates belong chiefly to the micas, amphiboles and feldspars, all of which cleave well, the cleavage of these rocks is due in large part to the cleavage of their components. In short, the tex- tures observed in metamorphic rocks of this type are charac- terized by a definite orientation of mineral components recrys- tallized at high temperatures under unequal stresses.* Becket has applied the name Krystallizationsschieferung to this process of recrystallization under stress and has reached conclusions similar to those of Van Hise outlined above. A recent investigation by G. F. Becker and A. L. Dayt{ on the development of crystals under stress shows that although crystals are able to grow in a given direction in spite of a counteracting force, their orowth in the plane normal to the pressure is vastly greater, the proportion being about 1 to 1000 or still larger. In their experiments, alum crystals were used which are isometric and which have, therefore, no pecu- liar direction of elongation. Had substances been tried which - erystallize in prismatic or tabular shapes, it is probable that there, also, the direction of most rapid crystal growth would have coincided with the direction of least resistance normal to the active stress, as in the experiments below. In the Geophysical Laboratory of ‘the Carnegie Institution, several experiments were performed in imitation of this pro- cess of nature, and results were obtained which roughly veri- fied the preceding theoretical deductions. The problem which confronted us was to produce crystallization from solution under strain. Purely aqueous solutions could not be used, Since in them hydrostatic conditions obtain and stress differ- ences are not possible. A glass, however, from a physico- * The arguments given in brief in this paragraph are essentially those of Van Hise developed in extenso in his monograph, loc. cit. + Becke, F., Uber Mineralbestand und Struktur der Krist. Schiefer ; Sit- zansber. Wiener Akad., 7 Mai, 1903. This paper was unfortunately not available to the writer. A brief statement of his conclusions, however, is given by U. Grubemann in “ Die Kristallinen Schiefer,” i, (1904). ¢ ‘‘The Linear Force of Growing Crystalis,” Proc. Wash. Acad. Sci., vii, 283-288, 1905. 226 LE. BE. Wright—Schistosity by Crystallization. chemical standpoint is an undercooled liquid, and in it the viscosity or internal friction at temperatures at which erystal- lization may begin is sufficiently great to permit application of unequal stresses. Certain glasses, as those from wollastonite, diopside, anorthite and other minerals, crystallize at tempera- tures far below the melting point of the mineral, and while still in a state of fair rigidity. These minerals are, moreover, either prismatic or tabular in habit and possess, therefore, a decided inclination to grow more rapidly in one direction than in another. If made to crystal- lize under unequal stress, they will, in consequence, tend to develop most rapidly in the direction of least resistance and their favored axis or plane of growth (prismatic or pinacoidal) will be normal to the active stress; while the resultant texture will be comparable to those produced by the recrystallization of a rock under stress. In our experiments about 50 grams of each of the above minerals were first melted separately in a Fletcher furnace and then chilled rapidly to glass by plunging the platinum crucible containing the melt into water. Cubes of about 1° edge were then cut from these glasses and subjected afterwards both to heat and stress. Heat was applied by means of an air-gas blast and concentrated by enclosing the preparation in a small reverberatory hood of asbestos. Pressure was produced in two different ways; in the first, a cube of mineral glass, shielded both above and below by thin disks of asbestos, was placed between two short vertical steel rods held in position by a suitable stand and gravity pressure obtained by weighting down the upper rod. By this method the effects of stress in one direction alone were studied, and the similarity of the textures produced compared with those of rocks formed under like conditions of stress. To obtain stresses acting along two directions normal to each other and thus to imitate the pencilled texture of many amphibolites, a device suggested by Dr. A. L. Day was employed, consisting of a wide metal pipe ring of 12°" diam- eter, into the sides of which four screws were inserted at intervals of 90°. Steel caps were fitted on the ends of these serews and between them the cube was placed. Pressure was applied by tightening the screws, while heat was derived as above from an air-gas blast. After complete crystallization under stress, the cubes were immersed in hot Canada balsam and afterwards embedded in plaster of Paris. These precautions were found by experience to be necessary, and were taken in order that satisfactory thin slices could be cut from the cubes, which, after crystallization are extremely brittle and fracture readily. Plates were then EF. E-. Wright—Schistosity by Crystallization. 227 eut after the three faces of each cube and sections ground from them. If the foregoing hypotheses are applicable in this case, the prismatic minerals crystallizing out of the glass under a stress acting in one direction only, should show in the center of the cube an arrangement along planes which are approximately perpendicular to the line of pressure; while the influence of a second stress at right angles to the first should cause the er ys- tallites to grow along the one line of least resistance and show parallel orientation in consequence. Both of these textures were produced rougbly in the cubes and were visible not only under the microscope, but also to the unaided eye. Magnification 25x. Nicols crossed. Fic. 1.—Section parallel to 100 through the center of a cube of wollas- tonite crystallized from the glass while under stresses acting in the direction indicated by the arrows. For the sake of convenience in describing the phenomena observed, the cubes will be considered as fixed in position rela- tive to the stresses applied, and the six cube faces as those of an isometric cube; the first stress being apphed vertically and perpendicular to the basal planes (001) of- the cube; the Am. Jour. Sc1.—FourtTH SERIES, Vou. XXII, No. 129.—SEPTEMBER, 1906. 16 228 FE. Wright—Schistosity by Crystallization. second normal to the side planes (010), while the front and back planes (100) remain free in every experiment. Jn view of the fact that more extended experimental work on the influence of stress on crystallization under bettered con- ditions is soon to be carried out in this laboratory, three photo- micrographs of simple cases only are reproduced below. The results, here presented, are strictly qualitative and preliminary in character. Figure 1 shows a plate through the central part of a large cube of wollastonite crystallized from its glass under stress Magnification 20x. Nicols crossed. Fic. 2.—Section parallel to 010 of a cube of anorthite crystallized from its glass under stresses in the direction marked by the arrows. normal to 001. The section was cut parallel to 100 and in it the wollastonite fibers are oriented approximately perpendicu- lar to the line of stress. Local variations occur and an indi- vidual fiber may occasionally be inclined at an angle of many degrees to the normal plane. Nevertheless, the general effect FE. Wright—Schistosity by Crystallization. 229 of the aggregate is that of an arrangement of the fibers in layers parallel to 001; along this plane the cube also showed a tendency to split. : Figure 2 is part of a cross-section parallel to 010 of an anorthite cube crystallized from glass under stress normal to 001. The photograph shows the upper part of a section which was cut nearer the outer edge of the cube than that of the preceding figure. The effect of crystallization proceeding from the outer surface inwards because of the rapid heating and in spite of the counteracting forces, is clearly marked in this section. Only after the conditions of heating had become more uniform could the effect of the unequal stress find expres- sion in the parallel arrangement of the fibers in the central portion of the cube as shown by fig. 1, and the lower part of fig, 2. V Magnification 25x. Nicols crossed. Fic. 3.—Section parallel to 100 and near exposed surface of a cube of diopside crystallized from the glass under stresses indicated. The prismatic fibers were normal to 100 and are cut, therefore, crosswise by the section. Figure 3 represents part of a thin slice taken from a erys- tallized cube of diopside glass parallel to 100 and very close to the exposed surface. The prismatic fibers which were the first to crystallize were normal to the exposed surface and are thus cut transversely by the section. 230 EE. Wright—Schistosity by Crystallization. Résunre. The schistose and gneissose textures of many metamorphic rocks have been ascribed by Van Hise and others to the orient- ing influence of pressures with a stress difference acting dur- ing the recrystallization of the rock in its new environment,— solution taking place along the line of greatest strain and deposition along the line of least resistance and normal to the maximum stress. In such cases the rock cleavage is due to the parallel arrangement of its mineral components in planes per- pendicular to the line of greatest stress. Conditions of experiment in which crystallization under unequal strains could take place were effected by using cubes of glasses made by chilling melts of different minerals rapidly, and by heating these to the point at which crystallization first began, the viscous glass at that temperature being still in a state of fair rigidity, and capable of supporting a certain amount of unequal strain. Textures similar to those of certain metamorphic rocks were produced in this way, and an experimental confirmation of the theoretical deductions thus obtained. Geophysical Laboratory, Carnegie Institution, Washington, D. C. Campbell—_Fractured Bowlders in Conglomerate. 231 Art. XXI.—Fractured Bowlders in Conglomerate ;* by Marius R. Campsett. Dvurine a visit to the Deer Creek coal field of Arizona, which the writer made in the autumn of 1903, countless num- bers of fractured bowlders were found on the outcrop of a coarse conglomerate, which seemed to require unusual and peculiar surroundings to account for their present conditions. Accordingly some hasty notes were taken of field relations and a few typical specimens secured for further study. A group of these fractured bowlders is shown in figure 2 and the following descriptions may throw some light on their mode of origin. The region in which the phenomenon was observed is an irregular syncline of Cretaceous and Carboniferous rocks in Pinal County, about ten miles east of Dudleyville at the junction of the San Pedro and Gila rivers, better known per- haps as the Deer Creek coal field. The rim of the syncline is in large part formed by the great Carboniferous limestone which also apparently underlies much of the central part of the basin, but it is effectually concealed by a great mass of later rocks consisting of lava, tuff, and beds of sandstone and shale. These beds are probably of late Cre- taceous age, and, therefore, there is a great time-break between them and the underlying limestone, although in most cases the beds at the contact are apparently conformable. The rocks immediately overlying the limestone generally consist of sandstone and shale with some small coal beds. Above this group there are many beds of andesitic tuff with interbedded sand and clay and what appears to have been great surface-flows of andesite. Some 500 or 600 feet above the base of the Cretaceous rocks is a bed of conglomerate composed of bowlders of all sizes up to 2 or 3 feet in diameter, held in a matrix of very soft andesitic tuff, a typical outcrop of which is shown in figure 1. This view was taken on Ash Creek just below the limestone box canyon east of Saddle Mountain and the bedding planes of the conglomerate dip 70 degrees to the left, or toward the center of the basin. The bowlders represent a great variety of rocks, both crystalline and sedimentary, but probably those of quartzite are most abundant. This bed of conglomerate shows at a great many points, but in most places the matrix is so soft that the rock breaks down * Published by permission of the Director of the U. S. Geological Survey. + For a more detailed description of the region and the geologic relations see “‘The Deer Creek Coal Field, Arizona,” by the writer. U. S. Geol. Surv., Bull. 225, pp. 240-258. 232 Campbell—fractured Bowlders in Conglomerate. when exposed to the atmosphere, leaving only a mass of gravel and bowlders. The material is all well rounded, and it seems evident that it has been swept into its present position by strong currents of water, presumably by surface streams. Bed of Cretaceous conglomerate on Ash Creek, Pinal County, Arizona. Andesitic tuff matrix. Dip 70 degrees to left. Bowlders fractured. After the deposition of this material, the rocks were dis- turbed by what seems to have been the upthrusting of huge masses of igneous rocks, giving to the sedimentary beds the form of an irregular basin. In some places the movement has been quite severe, and the rocks are steeply upturned and Campbell—_Fractured Bowlders in Conglomerate. 233 faulted, but in other places the movement has been gentle and the rocks dip lightly toward the center of the field. Ata point on the north side of the basin on the old Indian trail across Mescal Mountain to San Carlos, the bed of bowldery conglomerate dips toward the south or center of the basin at an angle of less than 10 degrees. The soft matrix of tuff has been dissolved and the bowlders are scattered over the ground in great profusion. Atthis place the specimens shown in figure 2 were found. They were not in position, but their original relations are apparent. Almost every bowlder of the thousands scattered over the ground at this place is marked by one or more bruises where other bowlders have been pressed against it. Considerable movement is indicated by these bruises, for the surface is 2 Fractured bowlders from coarse Cretaceous conglomerate, Pinal County, Arizona. Seale, one-half natural size. ground and crushed in a way that could only occur under repeated crushing strains. In some instances the opposing bowlder has failed to make an impression, probably because it was composed of softer rock, or because some more resistant bowlder took the strain, relieving the pressure in the surround- ing material. The large bowlder shown in the cut has at least six bruises, the two most severe being the one on the front and the one at the left end seen in profile. At these two points the opposing bowlders have been forced into this one until it has been nearly broken to pieces. Great cracks have opened in various directions and the broken parts have been thrust out until it appears like a ball of partly hardened clay that has been squeezed from several directions. The other 234 Campbell—Fractured Bowlders in Conglomerate. — bowlders show similar results, the two on the right being marked by especially deep bruises and great cracks which extend entirely through them. The bowlder on top has had another bowlder thrust into it so far that a piece of the oppos- ing bowlder is still contained in the upper part. The bowlders in question are mostly tough quartzite and they present a striking illustration of the enormous pressure that has been brought to bear upon them. Similar fractured bowlders may be seen in figure 1, but in this case they appear more like fractures due to shearing than the result of one bowlder impinging upon another. A good example may be. seen above and to the right of the hammer where a bowlder 8 or 10 inches in length is sheared in three or four places. At first sight it might seem that only a few of the bowlders in this view are broken, but close imspection shows that almost all are more or less affected. Such pressures as are shown by these bowlders are naturally associated in one’s mind with intense folding, but this relation- ship is questionable. The bowlders shown in figure 1, where the bed is tilted at an angle of 70 degrees, are not so badly fractured as are those shown in figure 2 from the north side of the basin, where the dip is only 10 degrees. It must be stated, however, that where the bed occupies the center of the basin, as for instance at the place where the Dudleyville trail first reaches Deer Creek, a short distance east of the mouth of Little Rock Creek, the bowlders are not fractured, or at least fractures were not observed. The explanation of the phenomenon prob- ably les in the peculiar conditions under which the bowlders were held. If the matrix had been solid and homogeneous and closely attached to the bowlders, it is probable that no such fractures would have been produced, but under pressure the soft turf acted much like fluid material and all of the strain came upon the bowlders themselves. Not only that, but the bowlders were held so loosely that there was opportunity for the sides to give under pressure and consequently cracks were produced and even the entire side of the bowlder was shoved off to an appreciable extent. A glance at figure 2 makes it plain that the large bowlder could not have been crushed from the spot in front unless there was room for the side to expand on what is now the upper part. If this bowlder had been sur- rounded by a strong homogeneous cement no such fracture could have been produced. The conelusion is, therefore, that such fracture can be pro- duced only where the matrix is soft and flows under pressure, leaving the bowlders to take the brunt of the strain, and afford- ing them no lateral support to prevent them being crushed under the strain. E. L. Furlong—Ezxploration of Samwel Cave. — 285 Art. XXII.—The Exploration of Samwel Cave; by E. L. FURLONG. Introduction. | Method of Excavation. History of Discovery. Fossil Remains. Description of Cave. Age of Samwel Cave Fauna. Character of the Deposits. Possible Quaternary Artifacts. INTRODUCTION. Tue first active work in the exploration of caves in north- ern California was commenced in the summer of 1902. Though the presence of caves in the region was known for many years, yet no scientific work had been carried on in them. The excellent results derived from the exploration of Potter Creek Cave* stimulated exploration in this region for other caves. Of these the Samwel Cavet has furnished the most valuable results. The cave investigations have been conducted under the auspices of the Department of Anthropology of the Univer- sity of California. The exploration of Samwel Cave in 1905 was supported by a grant from the American Archeological Institute. The work has been carried on under the immediate direc- tion of Professor J. C. Merriam, whom the writer desires to thank for material aid in the work of exploration and in the description of the cave fauna. Thanks are due Mr. Walter King and Mr. William Boynton for valuable service rendered in excavating and removing fossil remains under somewhat hazardous conditions. History of Discovery. The initial exploration of Samwel Cave in Shasta Co., Cali- fornia, for scientific purposes was carried on in the summer of 1903. An interesting legend, the scene of which was laid in Samwel cave and told by a Wintun Indian, led to its explora- tion. This story has a double value in making known an important cave, and in the verification of the legend, which now becomes an interesting piece of Wintun history. The Wintuns believe that caverns are of supernatural origin and have used them as places of magic. A courageous Indian, who had any important undertaking in view, such as a long * The Exploration of the Potter Creek Cave; by Wm. J. Sinclair, Publ. Univ. Calif., North Amer. Arch. and Eth., vol. ii, No. 1. + Prelim. Note on Expl. of Samwel Cave, Science, N.S., vol. xx, p.53; E. L. _ Furlong. {The above is submitted as a part of a report on investigations carried on under a grant from the American Archeological Institute for cave explora- tions in California, under the direction of Professor F. W. Putnam. 2360 EE. L. Furlong—Exploration of Samwel Cave. hunting trip, or a war expedition, would hide himself in the cave for a certain period, fasting and meditating on the object desired. It was the belief that through this vigil they would obtain good luck and success. Following is the version of the legend generally current among the Wintuns :— Many years ago a woman of strong medicine told three Wintun maidens that this cave contained two pools of Sawame or magic water; and that if they bathed in these it would insure good luck and make their wishes come true. Acting on the old woman’s advice, they entered the cave, lighting their way with pine torches. They found one pool of water in which they bathed, and then went in search of the second pool which contained the stronger Sawame. Following the instructions of the medicine woman, they climbed to the nar- row entrance of a large chamber. Seeing no water here, they went hand in hand through this chamber and into the wind- ing passages leading from it. In one of these they came to a large pit. One girl more curious and venturesome than the others went near the edge and looked down. Craning far over, her foot slipped and she fell over the edge. She would have fallen at once to the bottom but for the supporting hands of the other maidens. The overhanging wall at the edge of the pit was slippery and her efforts to regain the top were vain. The two girls above could with difficulty retain their footing and in their bewildered state did not have sufficient strength to lift her. At last, exhausted and slipping slowly toward the edge, they let go their hold and the unfortunate girl fell into the pit. They heard her strike, and then again far below a faint thud. ‘They fled in fright from the cave and spread the news among their relatives and friends. Some of the Indian braves went to the cave taking with them lengths of grass rope, which they knotted together and lowered into the pit. They seemed unable to touch the bottom with their rope and could do nothing. Hearing no sound below, after a time they left the place. They said the spirits had gotten the girl. From this time on the cave was held in profound awe and was seldom if ever visited by the Indians. The white people who settled in the country soon after the event thought the tale was but an Indian myth and gave it little credence. The first descent into the large chamber of the cave was made by Professor J. C. Merriam and the writer in August 1903, the other chambers having been investigated by our party a short time previous to this. The work commenced in 1903 has been continued during the past two summers. E.. L. Furlong—EKzploration of Samwel Cave. — 287 Description of the Cave. The Samwel cave is in the belt of Carboniferous limestone exposed along the lower portion of the McCloud river. It is situated about sixteen miles above the mouth and on the east bank of the river. The limestone ridge hollowed by the chambers is at the foot of a spur of Bollibokka Mountain. Fic. 1. Location of Samwel Cave. The main entrance is covered by a group of trees on the face of the highest limestone cliff, and below the arrow. The Quaternary entrance to the lower chamber (chamber II) is in the brushy canyon to the right and below. The elevations of the three low- est terraces are given by the grassy flat to the right across the river, by the small patch of open ground to the right above the lowest terrace, and by the highest point on the limestone. A small canyon which les to the south has been cut partly through the ‘limestone at its lower portion and leaves a per- pendicular limestone cliff as its northern boundary. From this canyon a small cavern’ penetrates the base of the cliff about 238 E. L. Furlong— Exploration of Samwel Cave. 70 feet below, and considerably to the east of the main entrance of Samwel Cave. As this cavern is closely associ- ated with chamber two, it will be discussed with the deposits in that chamber. Fic. 2. View looking toward the cave trom the canyon to the south. The existing entrance is behind the trees on a prominent rock shelf project- ing to the left from the cliff. The Quaternary entrance to chamber two is behind and below the large fallen block to the right. The main entrance is on a Quaternary river terrace. The terrace is 355 ft. above the McCloud and 1505 ft. above sea level. It is broad and relatively low and gives access to a large open chamber. The cave as a whole is about 352 ft. long and Lt. L. Furlong—LKxploration of Samwel Cave. 289 exhibits considerable beauty in the curious forms of its cham- bers and in the numerous stalagmite and stalactite growths contained in them. The entrance chamber is 73 ft. long and 50 ft. wide with an average height of 6 ft. At the extreme northeast end a small opening leads to a long series of lower . chambers. Of the latter, the two most important will be designated as chambers one and two. The lowest portion of the floor of chamber one is 24 ft. below its entrance. From a bench 4 ft. from the floor of the northwest corner a narrow, almost vertical shaft drops a dis- tance of 16 ft. to a winding series of chambers below. The first of these contains the first pool of water referred to in the Indian legend. About on a level with the entrance to chamber one and its extreme northeastern part, a narrow opening leads to a series of rooms running to chamber two. These have a general trend from south to north. The north chamber contains the chimney-like opening to the chamber below. From the floor of chamber two many small grottoes lead out in several direc- tions. At the southeasterly side a low-arched grotto leads to a passage way which will be discussed later. Character of the Deposits. The principal deposits are in chambers one and two. The deposit in chamber one partly fills a small fissure-like grotto which leads off from this room. It extends into the chamber and fans ont, covering a portion of the floor. This deposit is 29 ft. long, an average of 4 ft. wide and is 8 ft. deep in its thickest portion. The section is as follows: Preddishuelay 92: eons be ee 2 ALO > Sst Sialtemieescapplne. 2522.22 55. 222." “i-to. .? ft. Harth mixed with angular’gravel .... °3 to 1°6 ft ibe Cele ee ee Se 2 10 2 A floor of stalacmite ee ee I to.--3 ft Earth grading into breccia .... ...-- 12 to 4-4 ft The deposit was evidently formed by earth and limestone fragments falling from the outside, through an aperture at the top of the grotto. There is now no sign of such an open- ing. However, earth can be seen on the fissure walls and pro- jections till the ‘walls meet at the top. That there was an intermission of sufficient time for stalag- mite to form before the completion of the deposit is shown by the presence of the false floor. Probably the aperture was choked for a time and later reopened. All of the material of the deposit evidently came in at one place, as it is as much in the form of a low cone as the fissure will allow. The apex A OL ELE AL, — = 240 Ff. L. Furlong—LKxploration of Samwel Cave. was near the middle of the fissure with its sides sloping to either end. 1 material had isturbed i i A portion of the floor of chamber two, Samwel Cave, after the greater part of the foss The type skull of Huceratherium was st been removed. unGan The deposit in chamber two has greater surface area but 1s much shallower than that in chamber one. Its greatest length is 86 ft. from north to south and greatest width 18 ft. From north to south it is on an incline plane, the southern end being ll in the stalagmite to the left of the und skeleton of the Indian woman. E.. L. Furlong—Faploration of Samwel Cave. = 241 5 ft. below the surface level at the north end. It is composed of thin beds, as follows: Fine-grained reddish clay ..--.----- ‘01 to -<4 ft. Sealaemiteleap ping 2222 S22. Sets oh oes seg Mixed earth and gravel .-..-------- Ae ey Ores Sieulnomnnbe me Geers PU oo but O05 : ime earth and/oravell o3-2 2.252.252. "2 ec This shallow deposit was derived from material in the cave chamber, angular limestone gravei, stalagmite formed from dripping, and from very small streams of water carrying in material. The earth and clay were carried in by the water and possibly some part of it was tracked in by animals. On the southeast side a grotto leading off from the chamber shows the sloping stalagmite-covered surface of a deposit that fills a large space between the outside, canyon entrance before referred to and chamber two. The deposit was tunneled through, thus making open communication between the sur- face and this chamber. The deposit is 56 ft. long, running approximately southeast by northwest; its greatest depth is 28 ft. Its surface in the canyon entrance is covered by blocks of limestone. The deposit in this portion of the cave has been intermittent in its deposition. Strata of mixed earth and gravel and of red earth occur. In about the middle of the beds, in vertical section, a thick flooring of stalagmite appears. It is thicker at places where there has been drip from the roof. The material of this deposit was carried in by wash and slide from the entrance during the cutting of the canyon. It filled a former entrance of chamber two. Method of Excavation. As in the Potter Creek cave, the deposits were sectioned off in numbered squares of 4 ft. That of chamber one was first excavated. A cut was made in the deposit at the entrance to the fissure and carried through to the inner end. The fossil material was removed from benches a foot deep and each specimen labeled as to horizontal and vertical position. As the digging progressed, the waste material was thrown back to the hard floor in chamber one. It was necessary in working through the breccia to use powder and blast, though this was detrimental to the fossils contained in the breccia. Previous to the opening of the outside passage way to the grotto in chamber two, a ladder 85 ft. long was necessary to gain access to its floor. For this purpose a rope ladder with wooden rounds was used. Two holes were drilled in the floor of the chamber above. In the holes drills were securely imbedded. Thimbles that were fastened in the free upper ends of the ladder were then dropped over the drills and tied 242 Ff. L. Furlong—Exploration of Samwel Cave. there. The ladder hung free from its upper fastenings to the floor below. The deposit in chamber two was also sectioned off and the dirt removed section by section. Specimens were frequently cemented by stalagmite to the hard floor at the bottom of the deposit and had to be freed by the use of gads. The discovery of specimens imbedded in the surface of a stalagmite-covered slope led to the excavation in the southeast grotto leading from chamber two. A low tunnel 20 ft. long was run through this deposit in a southeasterly direction. At the farther end a space 8 ft. high by 4 ft. wide was hollowed out. Falling blocks of stone and the danger of a sudden cay- ing in of the loose dirt above made a discontinuance of the work at this place necessary. With the object of ascertaming the distance of the tunnel workings from the canyon outside, Professor Merriam made a series of measurements with compass and a tape line from the far end of the tunnel to the top of chamber two and through the winding passages of the cave to the canyon grotto outside. These measurements indicated that the small cave at the base of the cliff in the canyon was but a few feet from the inner tunnel workings. Work was then commenced in the foor of the canyon cave. A shaft was sunk 4 ft. square by 10°5 ft. deep, at which depth a stalagmite floor was encountered. At this place a strong draught of air which made the candles — flicker was noticed coming from a stratum of gravel in the cave. A drift 8 ft. long was run at right angles to the shaft in a northeasterly direction. As the drift progressed the draught had perceptibly increased and become so strong and cold as to make working uncomfortable. On continuing in the same direction an opening was made to a series of two sealed grot- toes. The surface of the deposit slope formed the floor of these. Signals had been previously arranged so that a person knocking against the walls in the tunnel from chamber two would be understood if heard by those above. When excava- tion had reached the sealed grottoes, signals could be distinctly heard close by. In moving about the floor to locate the signals from chamber two, we suddenly heard a voice below warning us to move carefully or we should break through. It was found that a distance of only about one and one half feet intervened between the tunnel and the grotto above, and a moment’s work with a shovel opened communication with the chamber below. Fossil Remains. The deposits in chamber one contained a relatively large quantity of material. Teeth and bones of extinct species were found on the surface. Many complete bones were taken FE. L. Furlong—EKxploration of Samwel Cave. 2.48 from the loose earth and gravel, also numerous teeth. Frag- ments and split bones were plentiful. The breccia layer was exceptionally rich in remains. Most of the specimens are in a fine state of preservation. Those on the surface had a coat- ing of stalagmite of varying thickness. When the stalagmite was removed the bone was found to be white and fresh look- ing although it contained no organic matter. The specimens from the earth were more or less discolored though in good condition. The bones of young individuals in some cases were in a crumbling condition. In the gravel layers a thin inecrustation of stalagmite covered the bones. Some old rodent burrows were dug into the upper layer of earth and in these recent rodent remains were numerous. The fragmen- tary material consisted principally of split pieces of narrow bones. The pieces were in most instances gnawed around their edges by rodents, the marks of the incisor teeth being distinct. Some fragments show long grooves and roughened places on the surface as if they had been crushed between the teeth of large carnivores. The fossils in this deposit had access through the same open- _ Ing as the earth and gravel and were deposited with it. That probably there were two distinct periods of deposition is shown by a slight difference in fauna in its top and bottom ~ layers. In the lowest portion of the deposit ground-sloth (Megalonyx?) teeth occur, but they are absent in the top layers. So far there are 20 species recognized; of these 8, or 40 per cent, are extinct. 3 Following is a list of species from the fissure deposit :— Ursus americanus Pallas. Ursus, n. sp. Vuipes, sp. Putorius arizonensis Mearns. Aplodontia major Merriam C, H. Aplodontia near major Merriam C, H. Aplodontia rufa Ratinesque. Arctomys, sp. Lepus auduboni Baird. Thomomys, sp. Thomomys monticola Allen. Citellus douglasi Richardson. Sciurus, sp. Erethizon epixanthus Brandt. | EHuceratherium collinum Sinclair and Furlong. Haplocerus, sp. Odocoileus, sp. : Equus occidentalis Leidy. Elephas, sp. (tooth fragment) Megalonyx, sp. AM, JOUR. bi a ieee Series, Vou. XXII, No. 129.—SEPTEMBER, 1906. 244 EF. L. Furlong—Exploration of Samwel. Cave. The area of deposit in chamber two when first viewed pre- sented an interesting spectacle. Its surface was strewn with skulls and limb bones. Near the foot of the ladder lay a cougar skull. It was covered with stalagmite an inch thick but showed the outlines of skull perfectly. Imbedded in stalagmite, the limb bones of the same individual were lying near it. Near the middle section the skeleton of the unfortu- nate Indian woman was stretched on its side. The pelvic girdle and skull had a thin film of stalagmite crystals over them, and the remainder of the bones were covered by a soft black mould. Near the human skeleton lay the type speci- men of Huceratherrum*. In the surface clay and lying loosely about were several raccoon skeletons. Porcupine and other rodent bones were plentiful. Mammal remains were abundant from the top of the deposit to the hard floor below. In the clay and on the stalagmite capping the fossil remains of several Myriopods were found, the exoskeletal structure and form being perfectly represented. On some of the higher slopes in chamber two and in most of the grottoes there were a number of small skeletons. Of these, several were porcupines and raccoons. An almost com- plete porcupine skeleton with the bones lightly covered by stalagmite was found in one of the grottoes. In most instances the enveloping stalagmite tended to keep them in perfect con- dition. A marked feature of the specimens deposited at this place was the completeness of several skeletons and the unbroken condition of skulls and limb bones. For this reason the supposition of entrance through the opening 85 feet above would be improbable. The presence of entire skeletons of bear, cougar, Preptoceras and small carnivores led to the belief that the animals with the exception of the ungulates had free access to the cave at some previous time. The later work of excavating from the southeast grotto to the canyon cave proved the belief to be correct. From the slope in the grotto, where the tunnel was run, to within 8 feet of the sur- face at the outside entrance, scattered parts of individuals like the animals in the main deposit were found. The well-known hibernating habit of bears readily accounts for their presence in the chamber. At the present time hunters in that region make the rounds of the known eaves where bears are in the habit of housing for the winter. It is not uncommon for cougars to use such places for a lair. It is not improbable that bears and cougars used chamber two when entrance was possible. It is true such animals do not care to go far from the light, but it would not have been necessary during the time the cave was inhabited. The deposit filling the old * Furlong and Sinclair, Bull. Dept. Geol. Univ. Calif., vol. iii, p. 411. E. L. Furlong—Exploration of Samwel Cave. 245 entrance is of considerable extent and fills a large space that when clear would probably permit rays of light to penetrate to some of the deeper parts of the chamber. That bears and cougars prey on ungulates and smaller mammals is well demonstrated in the present day, and the finding of large quantities of scattered and broken ungulate material, such as deer, Hucerathervum, Preptoceras with many rodents, as rabbits and gophers, supports the view that they were brought in by carnivores. The large carnivore skeletons were found in several cases to be nearly complete and but little disturbed, and the supposition that the carnivores inhab- ited the cave and were in the habit of dragging their prey to the lair to feast on it at leisure, is probably correct. Following is a list of the species represented in chamber two and in the deposit leading from the chamber. There are 21 species, of which 6, or 28°5 per cent, are extinct. , Ursus, 0. sp. Ursus, sp. Urocyon townsendi Merriam C. H. Procyon near lotor Linn. Felis near hippolestes Merriam C. H. Mephitis occidentalis Baird. Mustela, sp. Aplodontia near major. Erethizon epixanthus Brandt. Lepus auduboni Baird. Lepus, sp. Microtus, sp. | Neotoma fuscipes Baird. Veotoma, sp. Sciurus, sp. Citellus douglasi Richardson. EHuceratherium collinum Sinclair and Furlong. Preptoceras sinclairi Furlong. Odocoileus, sp. (a) Odocoileus, sp. (0) Megalonyx, sp. Age of Samwel Cave Fauna. The Samwel fauna through its percentage (over 30 per cent) of extinct species, and its typical Quaternary species, as the ground-sloth, Hgwus occidentalis, Teonoma spelwa ? Ursus n. sp., Llephas, Huceratherium and Preptoceras, establishes its age as Quaternary. A comparison of the species from chamber one and chamber two shows a greater percentage of extinct species from the former. That the remains may have had entrance to chamber one many years before it was possible for chamber two to be 246 =F. L. Lurlong—LExploration of Samwel Cave. used by animals or for their remains to reach it, is shown by the relative positions of the two entrances. Though the former entrance to the fissure in chamber one is closely sealed, its outer opening could only be from the top of the cliff the cave isin. The entrance to chamber two from the canyon bed is a hundred or more feet below the point where the fissure entrance was probably located. The additional time required for cutting of the canyon to the depth of the lower entrance would be considerable. The foregoing reasons, viz: the faunal difference and the probably greater age of the entrance to chamber one, tend to show that the fissure deposit is older than the deposit in cham- ber two. ; While the faunas of Potter Creek Cave and Samwel Cave are both Quaternary and are closely allied, there are some dif- ferences that suggest difference in age. Pveptoceras and the Poreupines are present in Samwel Cave and absent from Pot- ter Creek Cave. “1316+ 0041. + -0018 ° 90 3.1429 ‘3177 ‘5778 °2607 +1426 —:0006 —-00038 45 ees Io 5 (65 738468. 31033. —-0020 - —"0009 -60 eee Oa) 9993 ~-5S84 3557. “1047... +°0034 °° +:°0016 .60 eed (04.5 (1564 “so vol 4228-0685 —:0041:. —-0019: 60 eels. (1729 536194 -4637 “0700. — 0172. ,—:0078 60 Sere o43 9309 ~ 5726 “3395 -1048. -+--0012 - +:0005 30 See Oto. 2519 5892 )-3548 31054 +0025. =~ -0011 60 Meet? “2317 “6110. 3849 “1017 -—00d6 - —°0025 105 The irregularity of these results may conceivably be due to one or more of three different reasons. In the first place, it may be that the decomposition of the dithionic acid is not complete, and that this may be so is shown by the fact that after the liquid in experiment 10 was boiled for an hour and three quarters and filtered from the precipitated barium sul- phate, the addition of sulphuric acid caused further precipi- tation of barium sulphate. Secondly, it may be that some of the sulphur dioxide escapes absorption in the receiver if the current of carbon dioxide is passed through the system too rapidly. Thirdly, the concentration of the hydrochloric acid in the receiver tends, as is well known, to render the titration of the residual iodime by sodium thiosulphate less exact and the starch iodide less delicate as an indicator. To eliminate the concentration of acid in the receiver, in the following experiments sulphuric acid was substituted for hydrochloric acid in the Voit flask. A weighed amount of barium dithionate was introduced into the Voit flask and there dissolved in water. Sulphuric acid was run in through the separating funnel and the mixture then boiled, the sul- phur dioxide being collected in the Drexel receiver, trapped as before with potassium iodide. A slow current of carbon dioxide was driven through the system to sweep the sulphur dioxide into the iodine and to prevent any sucking back. When boiling had been carried so far that fumes of sulphuric acid began to appear the operation was stopped and the excess of iodine remaining was determined by means of sodium thiosulphate, starch iodide being used as an_ indicator. Results of experiments carried out in this manner are given in Table II. 262 LR. H. Ashley—Mthionic Acid and the Dithionates. TABLE II. Decomposition of barium dithionate by boiling with sulphuric acid. I value I value of of Errors Errors S.0; S20; I Na.S.03 S.O0; in in taken, taken. taken. required. found. I. S$.0;. Time. No. germ. erm. germ. erm. grm. germ. erm. min. M "1039 °23810 “5759 +3485 <=1045 . =-0014 {2 -00thiaee 2 "1046 2326 “5708 °3372 -"1051 + °0010: = 0005 maze 3 1OSOy 231 e510. 3485) OS Te 5 — 8006 —"0002 34 4 "10383 ~°2297 “5701 °*3387- :1041 +0017 = 000s 5 "L721. 3897. 5712. "1876 1726". 70009 - SS O0C aes 6 “1719. *3820 . 5702 *1894.- 71713. — "0012. ) == 000Gaeean 7 G26) 3838 Dh Ota OU Cum 2G OO ‘0000.12 8 1724>.*3832 ° *5727.. 1885 1728.) 0010 7235-000 eee 9 "1721. '°°3826 <38727 “1886 “1728 3 :0015"" 2 00G7aaene 10 (0692 +1539 °31380 °*1599 ‘0689 —:0008 ~—:0003 12 11 “O850% “O07 7 23109 | 22323) 5038545 000i seu 4 14 "2061 °4582 °6205 +1632 ‘2057 —:0009 —-0004 15 13 "2402 +5340 +6215 -0862 2408 + °0013 —E:000Ghaia These results show that dithionic acid may be determined by boiling with sulphuric acid and estimating the sulphur dioxide liberated, while when hydrochloric acid is used the results are far from satisfactory. ‘There are three reasons why sulphuric acid should work better than hydrochloric acid in this process : First, when sulphuric acid is added to the solution of barium dithionate, barium sulphate is precipitated and dithionic acid is left im free condition, this reaction proceeding at once to completion because the barium sulphate formed is removed from the system. It would seem that when hydrochloric acid is used the dithionic acid is completely liberated only by a gradual change in the conditions of equilibrium. Second, when the solution containing sulphuric acid is boiled, the water is driven off, the concentration of the solution increases and the high temperature of the fuming point of sulphuric acid is reached. Under such conditions the decom- position of the dithionic acid is rapid and complete, the time being dependent upon the original dilution of the solution. In one case, No. 11, the operation was ended in four minutes. Third, no appreciable amount of acid distils over from the Voit flask into the receiver containing the iodine to interfere with the back titration with sodium thiosulphate, the only acid present being that produced by the oxidation of the sulphur dioxide. Under these conditions the starch indicator acts sharply, which is not the case when hydrochloric is used. | Scientific [ntellugence. 263 NCEE NDER TOC INTELLIGENCE. —GroLoey. 1. Ueber Parapsonema cryptophysa Clarke und deren Stel- lung im System ; von Tu. Fucus. Centralbl. f. Min., ete., 1905, pp. 357-859.—In 1902, Clarke (54th Ann. Regents Rept. N. Y. State Mus., pp. 172-178) described a most perplexing and highly interesting fossil, under the title ‘“‘Paropsonema cryptophya: A peculiar echinoderm from the Intumescens-zone (Portage beds) of western New York.” Fuchs reviews Clarke’s paper and adds that “the entire organization is wholly different from all known Kchinodermata and can not be readily compared with any. According to my view, we here have the remains of quite another animal, namely, a medusa, related to Porpita.” A very excellent cast of one of Clarke’s finest specimens was presented by him to Peabody Museum of Yale University. It does not possess unmistakable echinoderm structures, although the radial parts, with their numerous transverse divisions, do in a way recall the ambulacra of Paleozoic echinoids. Unlike these, however, the radial parts of Paropsonema are bifurcated, in adult specimens, as many as four times, Then, too, the upper surface is wholly unlike the lower and is not made up of plates. Further, associated with this fossil crinoids occur and in these the calcareous plates are preserved, while in Paropsonema there is nothing other than a cast or the infiltrated filling of the cavi- ties. Fuchs states that the lower surface “ has a ‘great number [60 to 80] of arched folds that increase by division or intercalla- tion of new radii and carry the individual polyps. . Should it prove that my view is the correct one, we then have in this organism, as far as I am aware, the first evidence of a fossil siphonophore related to Porpita.” The present writer likewise thinks it more probable that Par- opsonema is related to Porpita and Velella (see Agassiz, ‘‘ The Porpitide and Velellide,’” Mem. Mus. Comp. Zool., Harvard, VII, No. 2, 1883) rather than to any echinoderm. Cc. S. 2. Phylogeny of the Races of Volutilithes petrosus ; by Bur- NETT SmirH. Proc. Acad. Nat. Sci. Phila., 1906, pp. 52-76, and one plate.—This interesting paper gives the results of a study based on many specimens of Volutilithes petrosus derived from nine localities, and on four other species. The forms of Voluéi- lithes first appear in non-normal marine deposits (Lignitic), hav- ing radiated from the outer deeper normal marine waters. These peripheral races undergo ‘‘a course of evolution which was a direct reflection of their unfavorable environment. ... The senility becomes more and more extreme with the course of time.” ‘The normal, slow and even development takes place in the more open favorable environment. C. S. 3. Notes on some Jurassic Fossils from Franz Josef Land, brought by a Member of the Ziegler Exploring Expedition ; by R. P. Wairrretp. Bull. Amer. Mus. Nat. Hist., May, 1906, pp. 131-134, 1 pl.—The notes relate to Ammonites, Mollusca, and land plants. SamMuEL Lewis PrEnrieip, Professor of Mineralogy in the Sheftield Scientific School of Yale University, died August 12, at Woodstock, Conn., where he had been passing the summer. T[e was in the 51st year of his age. He had been for some time in bad health. A notice of the life and work of this distin- guished mineralogist will appear in a near number of this Journal. EMERALDS. We have just obtained another consignment of choice Emerald Crystals. Prices 75c. to $10.00. : Purple Apatite Crystals on Matrix, . $1.00 to $2.00 White Apatite Crystals, ; DOs ce 2 b.00 Orpiment, massive, . ; TOO Ss 7-00) Cobaltite Crystals, large, 0. 2.00 Sphalerite Crystals on Marble, OE E00 Send for special list of rare minerals just received. ‘Everything in Natural History.’’ WARD’S NATURAL SCIENCE ESTABLISHMENT, 76-104 College Ave., Rochester, N. Y. Wearn’s Naturat Science EstaBLlisHMENT 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. Human Anatomy, including Craniology, Odontology, etc. 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. (s5~ Index XI-XX, now ready. Price $1.00. CONTENTS. Art. XVITI.—Abyssal Igneous Injection as a Causal Con- dition and as an Effect of Mountain-building ; by R. A ODATY: 2 Soh ee ae ee XIX.—Some Interesting Beryl Crystals and their Associa- tions 5 ‘by. “W.\E; Forp = 25:2 22.3422 62 ee XX.—Schistosity by Crystallization. A Qualitative Proof ; by JF. EH. WricHts 3. oe a) 0 ees es XXJ.—Fractured Bowlders in Conglomerate; by M. R. CAMPRELE 224s SoPa0Sy t Pus Be Cee Se X XII.—Exploration of Samwel Cave; by E. L. Furtone-- XXIII.—Occurrences of Unakite in a New Locality in Vir- einia >: by. T. di. WATSON to as oe XXIV.—Types of Permian Insects ; by E. H. Szriarps.. - XX V.—Analysis of Dithionic Acid and the Dithionates ; by Re eH. ASmim ys 220 a ee eee SCIENTIFIC INTELLIGENCE. Page 195 217 224 231 235 248 249 Geology—Ueber Parapsonema cryptophysa Clarke und deren Stellung im System, T. Fucus: Phylogeny of the Races of Volutilithes petrosus, B. SmitH: Notes on some Jurassic Fossils from Franz Josef Land, brought by a Member of the Ziegler Exploring Expedition, R. P. WHITFIELD, 268. Obituary—S. L. PENFIELD, 264. Smithsonian Institution. oe VOL. XXii. Established by BENJAMIN SILLIMAN in 1818. AMERICAN JOURNAL OF SCIENCE. Epiron: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp- WM. M. DAVIS, or Camprincs, Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. 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FREE CoLLECTION CATALOG, containing lists and illustrations of General Mineral Collections, Series of Ores for Prospectors, Sets of Crystals, Series illustrating Hardness and other Physical Characters of Minerals, with price List of Laboratory Material and Individual Specimens. FOOTE MINERAL CO,, Established 1876, by Dr. A. E. Foote. W. M. Foote, Manager. DEALERS IN Mineral Specimens and Commercial Rare Minerals. Removed to 107 N. 19th St., Philadelphia, Pa., U. S. A. {ERE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES. ] Art. XXVIL—TZhe Lime-Silica Series of Minerals:* by Artuur L. Day and E. 8. Sueruerp, with Optical Study by Frep E. Wricut.t Part I. Introductory. Anyone who has followed the work of the eminent Norwe- gian scientist, Prof. J. H. L. Vogt, durmg the past three or four years, must realize that an extraordinarily effective weapon has come into the service of petrology, the full power of which cannot at once be understood or appreciated. We refer to the methods and established generalizations of physi- eal chemistry. The older science of chemistry has made such strides under these new theories of solutions that we really have little more to do than to apply them ready-made to our own problems, like a smooth and powerful machine tool of guaranteed effectiveness. Mineral solutions, as Bunsen long ago maintained, are after all only chemical solutions over again with slightly different components and a different, a very different, range of temperatures and pressures. There is no need to disparage the difficulties involved in operating at high tem- peratures and under great pressures; they are very great, probably even greater than most of us appreciate, but they are certainly not insuperable, and when they are overcome, not only will a new era in the science of petrology have been inaugurated but an important return service will have been rendered to physics and physical chemistry in extending the scope of their generalizations. There is, therefore, no question of where to begin. Rooze- boom, Vogt, and many others have seen and appreciated and indicated to us with great clearness the various ways in which *Full text of a paper of this title read before the American Chemical Society at the Ithaca meeting, June 28, 1906. + The authors are indelated to Prof. A. C. Gill of Cornell University for a number of microscopic examinations of our earlier products, and for many helptu) suggestions. Am. Jour. Sci.—FourtTH Series, Vou. XXII, No. 130.—OctTogssEr, 1906. 19 266 Day and Shepherd—Lime-Silica Series of Minerals. mineral and rock formation can now be competently studied. The question is now, rather, how much of it all can we actually earry out? Vogt has already shown us,* in a paper published only a few months ago, that a great deal can be accomplished by a judicious treatment of existing observations, particularly the more trustworthy of the mineral and rock analyses, when combined with extensive field experience. It has been the purpose of this laboratory to attempt this task by a direct application of the principles and methods of quantitative physics and chemistry, or, in a word, to study mineral and rock formation by direct measurement at the tem- peratures where the minerals combine and separate like the solutions of ordinary chemistry under ordinary conditions. We further determined, wherever possible, to prepare chemi- cally pure minerals for this purpose in order that such conelu- sions as we might reach should not be dependent upon danger- ous assumptions regarding the harmless character of the five or ten per cent of “impurities” not infrequently present in hand specimens from natural sources. It is at once obvious that in order to succeed, the first experiments must be restricted to the simplest reactions, and that these will not always be the most important or the most interesting, but the results will always be in definite terms and final when the materials used are pure. Furthermore, the accumulated experience obtaimed from simple cases will safely and surely lead to suecesstul methods of a scope to meet the more complicated problems of rock formation. This plan was really entered upon several years ago in a small way and with very limited resources. The first paper, which was published in 1904-05, contained a_ laboratory study of a typical isomorphous pair, the soda-lime feldspar series, carried out in the spirit of the above plan. The second, which appeared in February of the present year, was a very careful study of enantiotropic mineral inversion between the mineral wollastonite and the pseudo-hexagonal form which has been obtained by several observers but which appears not to have been found in nature. The present paper, which is the third of the mineralogical series, undertakes to carry through a fairly complete set of measurements upon a typical eutectic pair—the lime-silica series. It is still incomplete in some — particulars, notably at the ends of the series. Mixtures very rich in lime: possess temperature constants which are beyond the reach of existing apparatus, while on the silica side the extreme viscosity and consequent inertness which were encoun- tered in the soda feldspars, effectually veil or prevent the development of the phenomena which occur there. Some approximate measurements have been made even in these * J. H. L. Vogt, Physikalisch-Chemische Gesetze der Krystallisations- folge in Eruptivgesteinen, Tschermak Min. u. petr. Mitth., xxiv, 487, 1906. Day and Shepherd-—Lime-Silica Series of Minerals. 267 regions (represented by dotted lines in the diagram fig. 3), but they have not the same accuracy as those portions of the curve which are represented by full lines. All the mixtures used were prepared with the greatest care and were chemically pure within one or two tenths of one per cent. Lime-Silica Minerals.—Of the lime-silica series only one well-defined mineral is known—wollastonite—which when meited usuaily crystallizes in a pseudo-hexagonal form of the same composition. This mineral has already been carefully studied by Allen, White, and Wright,* and the relation between the natural mineral and its second crystal form thoroughly cleared up. Pursuing the conventional methods of reasoning, we might also expect to have an intermediate mineral for the trisilicic acid, 2CaO,3S81i0, an akermanite analogue, 4CaO,38i0,; an orthosilicate, 2CaO,SiO,, and a tricalcic silicate, 83CaO,Si0.. All of these minerals are deducible from the various hypothet- ical silicic acids. We have undertaken to prepare and study the entire series of mixtures of lime and silica. Boudouard’s Measurements.—So far as known, there has been only one serious attempt to determine the constitution of this series of minerals.| According to Boudouard, the freezing point curve for the lime-silica minerals consists of four eutec- tics and three maxima (compounds), the maxima correspond- ing to the metasilicate, the orthosilicate and the tricalcic sili- eate. Unfortunately, the method used by Boudouard was a very inaccurate one. He prepared small cones of the various mixtures and placed these in a furnace alongside of Seger cones. The furnace was then heated and allowed to cool down again, after which the crucible was opened and the cone observed to see whether or not the mineral had melted. It is a common method in industrial practice, but has rarely been thought ac- curate enough for original determinations. This method is peculiarly unsuited for such investigations for several reasons: Suppose the mixture to contain an eutectic with a greater or less excess of one of the components. The cone would begin to weaken as soon as the eutectic began to melt, and its further progress would be governed entirely by the rel- ative quantity of eutectic present and its viscosity after melting. No information whatever regarding inversions in the solid or of the component in excess could be obtained, and errors of more than 500° would certainly occur (in fact did oceur in Boudou- ard’s case) in the interpretation of the softening temperature in some parts of the lime-silica curve. Let ts illustrate by a per- fectiy obvious hypothetical case (fig. 1): Assume first that the melting-points change rapidly following a steep liquidus AB * HK. T. Allen, W. P. White and Fred Eugene Wright, ‘‘On Wollastonite and Pseudo-Wollastonite, Polymorphic Forms of Calcium Metasilicate, ” this Journal. xxi, 89, 1906. + Boudouard, Journ. Iron and Steel Institute, 1905, p. 339. 268 Day and Shepherd—Lime-Silica Series of Minerals. (see also fig. 8, curve DE). The amount of eutectic in concen- trations X and Y will be so great as to soften the cone long be- fore the melting-points Z and W are reached. If, on the other hand, the liquidus slopes gently (AC), the amount of liquid eutectic as compared with the solid phase is smaller and the tem- perature of softening of the cone will approximate more closely to the change in melting-point. Furthermore, if the cones are made up from the initial com- ponents (CaCO, and 8i0,, for example), the heat of combina- ation is liberated as the cone approaches the melting temperature and raises the temperature of the cone above that of the furnace, producing sudden fusion of which the neighboring Seger cone can receive no record. | Incidentally, one finds here the explanation of Hoffman’s ex- periments* on the temperature of formation of slags. Contrary to the statement that the “ temperature of formation is above the i A P EUS temperature of fusion,” just the reverse is true. Under nor- mal conditions these mineral combinations occur at tempera- tures lower than the melting point, the exceptions occurring only when the materials are so coarsely ground or poorly mixed that combination is retarded until the melting point of the slag is passed. The orthosilicate of calcium is a very good instance of the formation of a compound below its melting temperature. We shall show later that while this compound melts at about 2080° C., it is possible to prepare it below the melting point of platinum, in fact in platinum vessels, by heating the finely ground material in the Fletcher furnace, regrinding, mixing and reheating. By this process it is possible to obtain a com- pound which gives the optical tests for the orthosilicate and is entirely without free lime or silica. Apart from the criticism which this particular application of cones appears to us to deserve, it is also well known that the *H. O. Hoffman, Trans. Amer. Inst. Min. Eng., xxix, 682, 1899. Day and Shepherd—Lime-Stlica Series of Minerals. 269 : time factor is always very important in dealing with a Seger cone. Boudouard himeelf states (p. 343) : “CA very small differ- ence in temperature, or « few minutes additional heating,* often suffices for the softening stage to pass into one of complete fusion.” If this statement was made understandingly, the method merited rejection by Boudouard himself. Furthermore, the use of Seger cones for exact work will always be unsatis- factory because it depends upon the judgment of the operator to say when a cone has “fallen” sufficiently to be considered melted, and different observers almost always obtain widely different results under like conditions. As has been pointed out by Day and Allen,+ any method of measurement which is not based upon some reasonably sharp physical ee must be expected to give different results in different hands.t Suppose *Ttalics are ours. + Arthur L. Day and E. T. Allen, ‘‘The Isomorphism and Thermal Properties of the Feldspars;” this Journal (4), xix, p. 98, 1905. Zeitschrift f. Phys. Chem. liv, p. 1, 1905. Publication of the Carnegie Institution of Washing- ton, No. 31. t Since the text of this paper was written, a very recent paper by Doelter (C. Doelter, ‘‘Die Untersuchungsmethoden bei Silikatschmelzen,” Sitzungs- ber. d. Wien. Akad. exv, 1, May, 1906) has come to our attention in which he reafirms his confidence in and preference for subjective methods for the investigation of silicate solutions,—more particularly the viscous silicates. This question of methods of attack in problems of wide scope and considera- ble difficulty is not an academic one ; itis a matter of the very first importance, particularly in view of the increased attention which is coming to be paid to the minerals as solutions. We have preferred to avoid subjective methods wherever possible on the general ground that no observation so made is exactly reproducible. Subjective observations are therefore always much more satisfactory to the observer than to any one else. Prof. Doelter has probably had a greater and more varied experience in the observation of mineral melting points than anyone now living, and he is therefore able to form consistent judgments upon the changes which he observes. But even under his exceptionally, competent hand we have seen the ‘‘melting points” of the feldspars rise a little higher each year in his successive publications upon the subject, and the feldspars are very viscous minerals of the type to which he finds the optical methods especially adapted. Doelter then criticises the thermoelectric methods in use in this laboratory on the ground of inexactness, i. e., because the recorded time-temperature curves contain no period of absolutely constant temperature, although he appears to be very familiar with the fact that the phenomena themselves are notsharp. This seems to be unfortunate and unproductive criticism. Under fair conditions a phenomenon is obviously the same, whether observed by looking at the charge or by exposing a thermoelement init. If the supposed melting ‘‘point’” does not occur at a point, it cannot be recorded as such. So far from failing in its purpose, therefore, the thermoelement has revealed to us a hitherto unfamiliar phenomenon with great fidelity. Our principle in the choice of methods is therefore diametrically opposed to Doelter’s. If the change of state were sharp and well marked, it would really matter very little how it was determined. If, on the other hand, it is a slow change, we should greatly prefer the unprejudiced record of a thermoelement if it could be obtained. Nothing is sc difficult of observation or gives rise to so much difference of opinion between observers as a slow-moving phenomenon. An interesting example of this is to be found in this (Doelter’s) paper itself (p. 12). Nearly all observers of the constants of silicates are now completely agreed that the glasses are merely undercooled liquids which of course have no melting point but change continuously from a hard amorphous to a soft 270 Day and Shepherd—Lime-Silica Series of Minerals. this method were to be applied, for example, to the determina- tion of the melting temperature of orthoclase or albite, or even pure quartz, which have been shown to possess a viscosity entirely comparable in magnitude with the rigidity of the solid erystalline mineral ; almost any conclusion could have been reached under these conditions. It is stated by M. Boudouard, for example, that all mixtures of lime and silica between 30 and 90 per cent of lime melt below 1500°. This certainly cannot be the case. Pure ortho- silicate of calcium when heated in a platinum crucible will stand without showing the slightest trace of melting while the plat- inum containing vessel melts down. The temperature must therefore be at least as high as the fusion point of platinum (1720°). We found no lime-silica mixtures richer than 60 per cent in CaO which could be melted in platinum vessels. Apart from the uncertainty in the temperature measurements offered by Boudouard, we shall undertake to show in its proper place that there is no pure lime-silica compound corresponding to Aikermanite and no tricaleic silicate. We are, therefore, somewhat at a loss to explain in any satisfactory way how the published curve which has attracted so much attention in Eng- land was really obtained. Part IL, Beeperimental. In this kind of investigation it is always desirable to begin with a careful determination of the physical properties of the pure components, although in the present case it must be admitted that this was the most inaccessible and difficult por- tion of the field over which we worked. amorphous condition. The use of subjective methods has misled Prof. Doelter into picking out points upon these curves to which he attaches great importance in the determination of eutectics. Apart from this general criticism, the particular optical methods which Doelter employs appear to us rather limited in scope for the work they will be required to perform. Jn the case of a mineral combination which is neither an eutectic nor a pure compound, they are open to all the objections of Boudouard’s method (see above) and furnish no trustworthy information whatever. It is also difficult to see how they can be used effectively to determine unknown conditions of equilibrium. Doelter’s method 4 (p. 6, loc. cit.), in which he places greatest confidence, appears to us to promise immediate and serious difficulties of another kind. It consists in observing directly with the microscope tiny grains of the substance to be studied as they lie upon a tray of amorphous silica (quartz glass) in the furnace. The glass tray, which is, of course, also heated, is in very unstable equilibrium and therefore ready to enter into solution with almost any oxide or silicate in contact with it at relatively low temperatures, and to produce what may appear to be a melting point but which of course has no necessary relation to that of the pure substance examined. Joly’s old method of examining mineral fragments on a platinum strip was much more trustworthy for melting point work, although inversions in the solid state could perhaps be advantageously studied in the new apparatus. For these reasons it does not seem to us wise to employ the subjective methods when others which are reproducible by any observer are available. Day and Shepherd—Lime-Silica Series of Minerals. 2/71 Lime.—Calcium oxide melts at a temperature so high that it is not yet possible to make a satisfactory determination of its melting point. It can be fused in the electric arc under favorable conditions to a clear liquid of low viscosity which erystallizes readily into a well developed cubic structure. Near its fusing temperature, lime either becomes quite vola- tile or the carbon of the are reduces it to the metal, which volatilizes and is immediately reoxidized outside of the heated zone. Weare unable to offer conclusive evidence in favor of the one hypothesis or the other, but the fact that pure lime at 2000° shows no signs of a high vapor pressure points rather to the second explanation as the correct one. For experiments with lime fusion, we obtained some arti- ficial graphite* practically free from all impurities, so that no contaminating substance was introduced into the fused lime from the electrodes. To further guard against possible con- tamination, only that part of the cake which formed above the {hor izontal) are was used in determining its physical properties. Density of CaO.—The density of fused calcium oxide was determined as follows: A selected portion of the crystal- line mass was finely ground, ignited to drive off adsorbed water, and weighed in carefully dried turpentine after the method of Day and Allen. The results are not in very good agreement, due probably to the difficulty of weighing out tho pr roduct without its becoming superficially hydrated or absorb- ing CQ,,. Fused CaO. H20 at 25° ally 3°313 3°307 3°329 Mean density, 3°316 (25°) This crystallized lime is much less readily attacked by water than is the amorphous oxide. It is, however, not indif- ferent to water. [ive grams of the crystals when ground and mixed with a small quantity of water in a test tube scarcely raised the temperature at all, but upon standing for some five minutes, the charge exploded with considerable violence. Unpowdered blocks of the crystalline oxide when placed in cold water dissolved slowly without appreciable heating. Hot water attacks them more rapidly, but the action of the water is Slow in both cases as compared with the amorphous lime. The hardness, according to Mohs’s scale, is between 8 and 4. Silica.—The melting temperature of silica has been vari- ously estimated at from 1200 to 2000°, but so far as known no *Prepared by the International Acheson Graphite Company, Niagara Falls, New York. 272 Day and Shepherd—Lime-Silica Series of Minerals. careful determination of it has ever been made. Since this oxide melts to an extremely viscous liquid, attempts to deter- mine the melting temperature by observing the softening of the charge are wholly misleading. The molecular deorienta- tion proceeds very slowly, extending over a considerable range of temperature, as albite and orthoclase have been found to do,* but with the disadvantage that this temperature region is too high to be reached with a thermoelement, and no other method of temperature measurement possesses sufficient sensi- tiveness in this region to locate the melting temperature by the heat absorbed during slow fusion. Determinations of the freezing-point are out of the question, owing ‘to the inertness of the viscous melt. An approximate determination of the melting temperature was made in this way: A gram or two of finely powdered quartz was placed in a small iridium crucible and heated in an iridium tube furnace (see p. 286). (Experience has shown that melting and inversion phenomena in very viscous substances take place much more readily if the material is finely divided.) A tiny fragment of piatinum foil was then laid on the top of the charge and the furnace slowly heated until the foil was observed to melt. Upon removing the charge from the fur- nace and examining it microscopically, evidence of fusion was found throughout the mass. The crystal grains had inverted to tridymite “and the superficial liquefaction had caused them to sinter tightly together, but no displacement of the grains had taken place. At the temperature of melting platinum, therefore (1720°), silica shows positive evidence of fusion. Other similar charges were then prepared and the operation repeated with longer exposures and temperatures slightly below _ the melting point of platmum, the temperatures being meas- ured with a Holborn-Kurlbaum optical pyrometert+ focused on the platinum fragment. By repeating this process at short temperature intervals and with about 20 minutes exposure, melting was definitely established as low as 1625° C. The iridium furnace is unfortunately not adapted for long- continued heating, and the platinum coil furnace will not reach this temperature, so that an effort to discover a definite temperature below which the solid is stable and above which it will melt if given time enough, was abandoned. If the heating is moderately rapid, the erystalline solid will per- sist far above the melting point of platinum; if slow enough, it liquefies completely at 1625° or even lower. It is probably a fair assumption, that pure silica begins to melt at about 1600,” and will continue to complete fusion if given time enough,— * Day and Allen, loc. cit. + Holborn and Kurlbaum: Ann. d, Phys. x, p. 225, 1903. Day and Shepherd—Lime-Silica Series of Minerals. 2738 above that point the higher the temperature, the more rapid the melting. A charge of quartz was heated for a long time in a platinum furnace at 1555° without producing a trace of fusion. There is little ae terion in pursuing an Inquiry of this kind. As has been stated elsewhere with reference to an entirely similar case,* the term “melting point” does not appear to be well applied to cases of this ‘character, in which the crystalline structure persists for davs or weeks at tempera- tures above the point where melting begins.+ If the change of state is to be defined by the absorption of heat, and the absorption of heat extends over a wide range of temperatur es and conditions, our forms of expression should be revised somewhat to include these hitherto unrecognized cases. Tridymite.—The relation between tridymite and quartz appears to be a simple one, although the literature of the sub- ject is unsatisfactory. But few trustworthy observations have been recorded and the conclusions drawn from them are vague and contradictory. So far as known, quartz has never been erystallized as such from mineral fusions except where cataly- zers were present. Tridymite has probably been obtained by several individuals through the accidental crystallization of fused silica vessels,{ but no especial attention appears to have been given to the circumstances in which it occurs, and its identification has not always been positive. Like the melting temperature, the inversion of quartz to tridymite and the crystallization of fused silica are very dif- ficult phenomena to study, owing to the extreme inertness of the material, but a number of experiments have been success- *Tsomorphism and Thermal Properties of the Feldspars, Publication 31, Carnegie Institution of Washington, p. 74 (8). + Doelter has recently offered a new general classification of silicates (loc. cit. p. 3): ‘‘Einfacher konstituierte Silikate (Gruppe A) haben scharfen Schmelzpunkt, geringere Viskositaét und grésseres Kristallisationsvermégen. ‘ Komplexere Silikate (Gruppe B) haben ein grosses Schmelzpunktsintervall, grosse Viskositét, geringere Kristallisationsgeschwindigkeit.”’ Such information as we have been able to gather in our work with pure minerals does not substantiate this generalization. We have encountered no mineral more viscous than quartz, which has the simplest of compositions. Anorthite, wollastonite and diopside differ radically in simplicity of formula but melt and crystallize at very nearly the same rate and with very nearly the same sharpness. ¢{ Prof. Dr. L. Holborn of the Physikalisch-Technische Reichsanstalt ; Dr. M. Herschkowitsch of the firm of Carl Zeiss in Jena; Dr. Kiich of the firm of Heraeus in Hanau ; and the Rey. Theodor Wulf, S. J., formerly of Gottin- gen, in the preparation and use of quartz glass vessels have noticed that the glass devitrifies at high temperatures in the presence of water vapor or after long usage. So far as we are aware, all of these observations have remained unpublished. Hahn, in the Int. Cong. f. Angewandte Chemie, Berlin, 1903 (vol. 1, p. 714), notes the devitrification of a quartz glass tube at 1100°. He also identified the crystal formation under the microscope as tridymite. 274 Day and Shepherd—Lime-Silica Series of Minerals. fully carried out which appear to clear up the situation, even though the inversion temperature cannot be determined with any great accuracy. First of all, we heated a large charge of finely ground quartz and followed the temperature curve carefully from 400° to 1600°. It was found after the experiment that the quartz crystals had for the most part gone over into tridymite and the change in the volume accompanying the inversion had generated enough pressure to completely shatter the open platinum crucible which contained the charge. The change was so gradual, however, that no record of it appeared upon the thermal curve. Subsequent experiments in which we endeavored to change crystalline quartz into tridymite at lower temperatures were successful as far down as 1100°. To be sure, entire crystals showed no change whatever after six hours’ exposure at 1400°, but powdered quartz is completely changed into tridymite after afew hours at that temperature. On the other hand, if finely divided amorphous silica, 1. e., fused (“‘ quartz g glass ’ *), or better, precipitated silica, be allowed to remain for a short time at any temperature above 1000°, it changes promptly to tridymite—the precipitated material very rapidly, the quartz glass much more slowly. Neither the glass nor the precipitated silica ever crystallized as quartz at temperatures above 1000°, nor is there any difference in the optical properties of the tridymite obtained at the different ' temperatures, either from the quartz crystals or the amorphous silica. The rate of change is much influenced by the fineness of the powder, although there is no difficulty in recrystallizing large blocks of solid quartz glass at the higher temperatures. In our experiments in the preparation of quartz glass, * We frequently obtained isolated spherulites of tridymite several millimeters in diameter, even with rapid cooling, which appeared to have been started by a grain of graphite or car- borundum powder accidentally falling into the melt. On one - occasion the entire block was coated with tridymite to a depth of a millimeter or more. We have therefore succeeded, by direct experiment upon pure silica, in establishing .the fact that tridymite, and not quartz, is the stable crystalline form of silica for all tempera- tures above 1000°. At lower temperatures than this it is impossible, in view of the inertness of the substance, to obtain any further reaction, even with the finest precipitated silica, within the time avail- able for a laboratory experiment. A. month’s exposure at 900° produced no change. We therefore followed the example of * Day and Shepherd, ‘‘ Quartz Glass,” Science, xxiii, p. 670, 1906. | ate ia Day and Shepherd—Lime-Silica Series of Minerals. 275 several distinguished predecessors in this field, and tried vari- ous catalyzers. Formation of Quartz —-Hautefeuille thought he had pro- duced quartz cr -ystals by fusing amorphous silica with sodium tungstate at 900°, but the methods of high-temperature meas- urement commonly employed in his time were very imperfect, and the temperature is undoubtedly too high. He has also stated that he obtained it by fusion with lithium chloride. Both Hautefeuille and Margotet have recorded the fact that in the presence of lithium chloride amorphous silica changes to tridymite at high temperatures and to quartz at low tem- peratures. We obtained quartz crystals from glass by the use of a mixture of 80 per cent KCl with 20 per cent LiCl at all temperatures below 760°, while at temperatures of 800° and higher only tridymite crystals appeared. The same results. were obtained with vanadic acid and with sodium tungstate. The inversion point uartz = tridymite —= 5 therefore occurs at about 800°. This conclusion is subject to the assumption that the inversion temperature is not lowered by the catalyzmg agent—an assumption which seems to be justitied by the fact that the quartz crystals obtained in this way (judged by the optical properties) appear to hold none of the reagent in solid solution. The situation is then, briefly, this: Both quartz and amor- phous silica at high temper atures change to tridymite. Quartz is consequently the unstable form of silica from 800° upward, and will go over into tridymite whenever conditions favorable to the change are present. The melting temperature of silica is therefore properly the melting temperature of tridymite and not of quartz as it is commonly described. We have once or twice succeeded, by extremely rapid heating, in melting quartz as such, or more correctly speaking, in carrying a quartz charge past the melting temperature of tridymite, melting a portion of it and finding a residue of quartz afterward which had neither inverted nor melted. It would hardly be possible by any known method, however, to obtain a separate melting tem- perature for quartz ‘independently of tridymite. The reverse operation, showing that tridymite inverts to quartz at temperatures below 760°, cannot be carried out in the laboratory without the use of catalyzers on account of the extreme slowness of the change. In the presence of the mix- ture of 80 per cent KCl and 20 per cent LiCl, quartz began to appear from tridymite in quantities sutticient for positive identi- fication after an exposure of five or six days, at about 750°. 276 Day and Shepherd—Lime-Silica Series of Minerals. No effort was made to invert an entire charge on account of the slowness of the change and the fact that its character was now fully established. The glass crystallizes to quartz below 760° and to tridymite above 800°, crystalline quartz goes over to tridymite above 800°, and tridymite to quartz at 750° ; the change is therefore enantiotropie and not monotropic. Incidentally, a sufficient reason has been given for the com- plete failure of experimenters to produce quartz without catal- ysis. If dry silica at 900° is so inert as to undergo no reaction at all during a month’s exposure under favorable conditions, how can we expect reaction below 800° where the viscosity is even greater? Silica must be crystallized below 800° to pro- duce quartz. om Density of Srlica.—The density of the silica used and obtained in our experiments was determined with the follow- ing results, the aggregate impurity bemg not over one-tenth of one per cent: Purified Natural Quartz. Quartz Glass. H.20 at 20° =1. 2°655 First preparation, 2-209 2°653 CoN ae 2°215 2°654 a oH 2°212 Second ce yD) h8) (15 ¢ Bory || Mean, 2°654 (25°) Mean, 2°213 (25°) It will be noted that there is a difference of more than 16 per cent between the density of the glass and that of the quartz crystals. A charge of powdered crystalline quartz heated for several days at 1200° appeared under the microscope to be homoge- neous tridymite. Some observations of its density are contained in the Subjoined table under the heading SRS from quartz.” *E. Baur (Zeitschr. f. phys. Chem. xlii, p. 575, 1903) appears to have obtained tridymite and quartz side by side from a mixture of 538™™s SiQe, 4°38" AlO.Na and 12°° water heated for six hours in a closed steel bomb at 520°. We find it very difficult to reconcile this result with our experience. That tridymite is not the stable phase at this temperature under the con- ditions of the experiment appears to be established beyond reasonable doubt by our own work, although we have never studied a mixture of exactly this composition. We should therefore not expect it to form in such a melt, certainly not in the presence of quartz. If tridymite came to be present by accident as a result of some previous operation, or by the temperature in the furnace having been too high, it might revert gradually to quartz and thus explain the presence of both forms in such a charge. Until we are in position to repeat Baur’s experiment, therefore, we are unable to explain the simultaneous appearance of quartz and tridymite except by assuming that two operations have taken place: (1) a formation of tridymite, and (2) a partial reversion to quartz, or some unchanged silica may subsequently have formed a quartz at a lower temperature. Duy and Shepherd-—Lime-Silica Series of Minerals. 277 A similar charge obtained by crystallizing the glass at 1200° (three days) also showed no residual glass under the mi- eroscope. Its density is given under the heading “tridymite from glass.” A second table contains confirmatory measure- ments upon a second preparation heated to a slightly different temperature. Tridymite. (H20 at 25° = 1) First Preparation, Second Preparation. (1200°). (6 days at 1160°). From quartz. From glass. From quartz.* From glass. 2°320 2°316 2°327 2°319 2°330 2°318 2°320 2-318 2°320 2°316 2316 2°319 Mean, 2°326 (25°) Mean, 2°317 (25°) Mean, 2°326 (25°) Mean, 2°318 (25°). ‘Whether the quartz had not completely changed to tridymite, or the glass was incompletely crystallized, or perhaps both, is of little moment. It is a very slow change and the agreement between the values obtained by the two methods is sufficiently good, when considered in the light of their identical optical properties, to establish the absolute identity of the tridymite formed from the glass and from the quartz erystals. The Lime-Silica Series.—Having determined the properties of our two component minerals, we are prepared to enter upon the study of their relation to each other in mixtures of various proportions. It will be borne in mind that inasmuch as we found no proper melting-yoznt for pure silica on account of the inert- ness (if we may so describe it) with which it resists molecular deorientation when heated, so compositions which are immedi- ately adjacent to the silica end of the series may be expected to show the same property and to yield but little information from a direct application of the usual pyrometric methods. Similarly, pure calcium oxide and its immediate neighbors are well out of reach of accurate measurement by any existing pyrometers. But even without these important measurements, we have been able to obtain sufficient information in the more inaccessible portions of the curve to enable us to describe all the reactions involved with little probability of error. Inasmuch as lime is one of the most refractory minerals known, it will require no apology if we simply leave its thermal constants until greater perfection in pyrometric measurements shall have been attained. Preliminary Orientation.—Given chemically pure and well mixed (by grinding and repeated melting) preparations, it is * This preparation was afterward found to contain some unchanged quartz. - 278 Day and Shepherd—Lime-Silica Series of Minerals. not a dificult matter to secure a preliminary survey of a field ot this kind. The mineral wollastonite is known, and more than that, is known to possess a melting temperature lower than either lime or silica. There is therefore immediate reason for anticipating eutectic relations somewhere in the series. If wollastonite forms a eutectic with components on one or both sides of it, mixtures containing slightly more lime or slightly more silica than wollastonite will have lower melting tempera- tures than it. A simple and effective mode of preliminary pro- cedure is therefore to take a tiny pmech of a number of the percentage mixtures adjacent to wollastonite, place them in order upon a narrow platinum ribbon which can be heated electrically to uniform brightness, and observe the order in which they melt. No temperature measurement is worth while; the information obtained can serve only for orientation and must be verified by more reliable pyrometric methods. If a eutectic is present on either side of the compound, it will be the first to melt, and the compound last; the interme- diate mixtures are not important. If the materials are not too viscous the melting will be sharp and the material will crystal- lize again on slow. cooling. A few repetitions, or the intro- duction of intermediate compositions in doubtful cases, will usually enable a preliminary curve to be drawn in which the compounds and eutectics which are within reach will be cor- rectly located. In fact, for many substances they can be very exactly located in this way. Intermediate compositions, on the other hand, may be very misleading, depending upon the behavior of the eutectie present after the melting temperature of the, latter has been passed. (In applying this method, very small particles (0°2"™") must be used in order to obtain com- parable results.) Proceeding in this way, a eutectic will be readily located between silica and wollastonite at the composition 63 per cent Si0,, 87 per cent CaO, and another on the other side of wollas- tonite at the composition 46 per cent SiO,, 54 per cent CaO. We will allow the othér component of this second eutectic to remain unidentified for the moment, as no stable lime-silica min- eral richer in lime than wollastonite is known. If we continue our platinum ribbon experiment with continually increasing percentages of lime, we shall find that after one or two steps beyond this second eutectic the platinum ribbon will burn out without melting the little grains. In other words, the melting temperatures of lime-silica mixtures richer in lime than 60 per cent are all higher than that of the platinum. To meet this diffi- culty we built a small but very serviceable piece of apparatus the essential portion of which is a thin ribbon of pure iridium about 2™” wide and 10™ long, stretched between electrodes Day and Shepherd—Lime-Silica Series of Minerals. 279 under constant tension. Immediately beneath the ribbon and supporting its weight was a slender block of selected magnesite. The ribbon and its supports were then enclosed within con- centric glass tubes between. which cold water was kept flowing. The atmosphere immediately sur rounding the ribbon was nitro- gen.* With this ribbon we proceeded as before, laying out a whole series of compositions from 60 per cent GaO on. With 2 this little apparatus, is which fig. 2 will convey a fairly clear idea, we promptly discovered a third and very sharp eutectic with the composition 67 1/2 per cent CaO, 32 1/2 per cent SiO,, and a maximum indicating a probable eohaal at 65 per cent CaO, 35 SiO,, which corresponds to the anticipated orthosilicate. No other points were obtained up to 2100° C. Thus in a very short time and in this aye and expeditious way we were able to locate three eutectics (37, 54 and 67 1/2 per cent CaQ) and two compounds (48 and 65 per cent CaO) between lime and silica, canvassing for the purpose practi- cally all the compositions from pure lime to pure silica at intervals of 1 or 2 1/2 per cent, and all temperatures from 500° to 2100° CO. Beyond 75 per cent lime and below 32°5 per cent the method yields no information, for reasons which have been elaborated elsewhere. All the important deter- minations were verified by numerous repetitions. If we now compare the compounds obtained by this prelim- inary investigation with those which we were led to anticipate from Boudouard’s observations, as well as from the hypothetical * Even with this precaution, the iridium volatilized so rapidly that the magnesite was black after thirty minutes heating. 280 Day and Shepherd —Lime-Silica Series of Minerals. silicic acids, we find that we have located two—the metasilieate and orthosilicate—and missed two—the akermanite analogue 4CaO, 38i0,, and the tricalcic silicate. The next step was therefore obviously to bring all our resources to bear upon these particular compositions in order definitely to ascertain whether such compounds can exist when the components are pure, and if so, under what conditions and with what proper- ties. : The Akermanite Analogue——The akermanite analogue (4Ca0.3S8i0,) was first taken up and the neighboring concen- trations investigated at intervals of 1 per cent with the great- — est care. A large charge of this particular composition was repeatedly melted and examined under the microscope, but it failed to show homogeneous structure or any characteristic property of a compound. On the other hand, the pseudo- wollastonite and the orthosilicate appeared in the proportion appropriate to its place in the series. Furthermore, since the melting temperatures of these mixtures were within the reach of our platmum furnaces, and therefore of our most sensitive pyrometric measurements, we were able to hold the tempera- ture constant at any desired point and then by rapid cooling (quenching in mercury) to fix any phase which might have been present and become unstable below that temperature. Here again we found that pseudo-wollastonite and the calcium — orthosilicate were the only phases which could be separated from this or any mixture of the pure components in this neighborhood. It is our belief, therefore, that the akermanite mineral cannot exist between the pure components and is only possible when other substances are present. This is further indicated by the fact that the metasilicate of calcium in the presence of magnesium forms a solid solution of which the limiting concentrations are relatively wide and which would easily account for the Akermanite mineral produced from the fusion of the three components. The Orthosilicate of Calcium, 2C0a0,SiO, (65:00 per cent CaQO).*—It has long been known that the orthosilicate of cal- cium, although not found in nature, can be formed by the fusion of the pure components. The temperature of fusion is very high and the erystalline material obtained disintegrates. spontaneously at the lower temperatures The cause of the disintegration has not been carefully studied heretofore, and optical determinations of it are difficult, owning to the extreme fineness of the disintegrated product. Our investigation estab- lishes the fact that the orthosilicate of calcium can exist in *The metasilicate of calcium has been made the subject of a special paper by Allen, White and Wright (loc. cit.) and will not receive detailed con- sideration here. Day and Shepherd—Lime-Silica Serres of Minerals. 281 three polymorphic forms in enantiotropic relation to each other, which we have designated as a, 8 and ¥, in the order in which they form from fusion. The a-form is the only modi- fication which is stable in contact with the melt. Its specific gravity is about 3°27, determined in methylene iodide solution upon fresh crystals. Its hardness is 5-6, Mohs’s scale; crystal system, monoclinic. Below 1410° the a-form changes into the @-form, of which the density 3°28 (measured by comparing the indices of refrac- tion) is but little different from that of the a modification. The substance was too unstable for determinations of the density to be made in the ordinary way. It crystallizes in the orthorhombic system. The inversion point between the a and 8 varieties is well marked and distinguishable over almost the entire range of compositions of which the orthosilicate is a component, as indicated in the diagram (fig. 3, ine MN). The inversion of 8 into y occurs at about 675° with a large increase of volume which at once explains the disintegration of the material. The temperature at which this inversion occurs is somewhat variable, and it is »ot readily reversed. It is much too slow a change to admit of pyrometric determination, but it is possible to locate it approximately by quenching the material from selected temperatures in the neighborhood of the inversion point. The usual procedure was to take a small portion of the disintegrated material, fold it tightly between thin strips of platinum and place these in the furnace. The temperature was then raised to any chosen value and main- tained constaut for periods of time varying from six hours to three or four days. At temperatures far enough removed from the inversion point, the transition from one form into the other was fairly rapid, but as the temperature of inversion approaches, equilibrium is attained with increasing difficulty. After the furnace had remained at this constant temperature for a length of time, it was opened, the platinum strips contain- ing the orthosilicate were removed and quickly plunged into mercury. In this way, from temperatures just above the inversion point, it was possible to fix the @6-form long enough to allow of its optical determination. The disintegration on cooling appeared to depend consider- ably upon whether or not the a-form had first been allowed to change into the 6-form. For example, if a small portion of the orthosilicate is fused before the oxyhydrogen blast and then plunged directly from the flame into mercury, the quenched material will usually be stable for a considerable time. If the flame is removed but a moment and the slightly Am. JOUR. Bese SERIES, Vout. XXII, No. 180.—Octossr, 1906. ~~ 282 Day and Shepherd—Lime-Silica Series of Minerals. i ies eee) ee ES oe ee ea pee eee JSS ae eee (alcool es a eee ee eee JSS ee eee 1800 PERRET oe So ie co eee see alee ae PS es i | Sa NEE Pale ee a4 = a he Ss & ees 14oo {300 $200 41900 1000 900 7oo Day and Shepherd—Lime-Silica Series of Minerals. 288 cooled specimen plunged from white heat into mercury, disin- tegration is immediate. This phenomenon was further veri- fied by fusing the material and dropping it into a furnace held at about 1200° C. After a few moments the charge was then removed and quickly plunged into mercury. . Treated in this way, all of a goes over into 8, which in turn will disintegrate completely with little or no delay after reaching the 8 2 y inversion temperature. One will sometimes get the a-form by slow cooling, but never the 8-form. The y-form of the orthosilicate crystallizes in the monoclinic system. Its density, determined in turpentine, by the pic- nometer method, is 2°973 2°975 Mean, 2°974 The difference in volume between the y and a or # forms is therefore nearly 10 per cent, and since the a and particularly the @-form goes over into the y at low temperatures with the greatest readiness, the disintegration of the fused orthosilicate is readily explained. Neighboring mixtures containing the orthosilicate as a com- ponent disintegrate beginning with compositions containing only 51 per cent of lime. The disintegration of this prepara- tion is, however, very slow, and usually does not take place at all unless the mixture has been held for some time at a rela- tively high temperature. The 54 per cent mixture can also be readily obtained without disintegration, but with more than 54 per cent of CaQ, disintegration always occurs under the ordinary conditions of preparation. If the orthosilicate be heated to temperatures only shghtly above QR (fig. 3) so as to produce the 8-form without sinter- ing, disintegration does not appear on cooling for the reason that the change in volume is not apparent in the powdered material. If the charge be heated to about 1400°, or above 1410° where the a modification appears, it sinters tightly together and the disintegration phenomenon is again observed. Charges sintered together at 1400° to 1500° and _ held continu- ously at any temperature above QR do not disintegrate so long as this temperature is maintained, but as soon as the temperature drops below QR, disintegration recurs, but not at a constant temperature nor at any characteristic rate, the change being very dependent upon the conditions obtaining at the time. The orthosilicate is easily attacked by water, giving analkaline reaction, even when the water is cold, while with boiling water 284 Day and Shepherd —Lime-Silica Series of Minerals. it is possible to wash out as much as 10 percent of lime. This probably accounts for the absence of this mineral in nature. Ammonium chloride solution even when cold decomposes all the mixtures of CaO and Si0.. The tricalere silicate, 3CaOSiO,.— This silicate owes its supposed existence mainly to those investigators who have found it necessary to postulate such a compound in order to explain the constitution of portland cement. So far as the literature shows, no one has ever isolated and described a pure and homo- geneous compound of this composition or defined its proper- ties.*¥ Many and varied attempts to make it have uniformly resulted in mixtures in which poor optical properties have made the conclusions insutticiently positive.+ We began the investigation of this composition by fusing the components in the proper proportions and examining the fused product microscopically as others had done. Most previous investigators, however, appear to have depended for microscopic evidence upon the ordinary optical figures and interference colors.. Now, it so happens that this mixture when fused crys- tallizes in an extr emely fine structure in which the interference colors are quite different from those of the orthosilicate to be sure, but this is merely the result of the fine state of division and the overlapping of the crystals, and not to another com- pound. If one examines any of the compositions in which the tricalcic silicate might be expected to figure, using the very sensitive index of refraction as a test of homogeneity, he will find that in every preparation containing more lime than 65 per cent (orthosilicate composition), there is an excess of free lime which can be positively identified. We have fused the tricalcic silicate composition, cooled it rapidly and slowly in various ways, without once failing to find free CaO present in quantity. Through the kindness of Dr. Clifford Richardson we were also given an opportunity to examine some of the tricalcic silicate prepared and described by him, and while its *It is sometimes described as ‘‘nearly homogeneous.”’ +A moment’s consideration should suggest that there is no real necessity for assuming the existence of the tricalcic silicate in order to explain the nature of portiand cement. It is at least a three-component system with a great number of possibilities. The real difficulty appears to have been that crystallized lime is relatively inert and does not readily give the reactions common to ordinary lime, consequently the tests which were thought to demonstrate the absence of free lime in these preparations have proved very misleading. For example, we have found that crystals of CaO are but very slowly attacked by water (see p. 271). Another argument which is freely offered—that there can be no free lime present ‘‘ because if free lime is added the cement dusts spontaneously,” is obvious fallacy. Free lime does not cause the dusting and if it did the fact that the addition of free lime caused dusting would be no proof that none was present. (Cf. 52 per-cent CaO, 48 SiO2.) Day and Shepherd—Lime-Silica Series of Minerals. 285 ordinary appearance under the microscope differed from that of the orthosilicate, a study of the mdex of refraction showed the supposed tricalcic silicate to be a mixture of the orthosili- eate with free lime. Having failed to obtain a single tricalcic silicate which did not contain free lime, and because every specimen which we examined, including many which had been prepared by others, also showed the orthosilicate to be present, we weie forced to conclude that the tricalcic silicate has no real existence. We also tried fusing the tricalcic silicate composi- tion with a flux, but the product was always the orthosilicate of calcium with free lime. Although we are anticipating pyrometric studies which fol- low, a single glance at our porary fig. 3, will show that we pens found and measured the 8 =a inversion of the ortho-. silicate in all the compositions up to 90 per cent lime, which we could never have done with a tricalcic silicate intervening unless the tricalcic silicate be assumed to possess an identical inversion,— which would be rare coincidence. We have, there- fore, complete optical and pyrometric evidence of the persist- ence of the orthosilicate throughout the supposed tricalcice silicate region, and no compound of tricaleic silicate composi- tion can exist there. By way of completing the search for hy poi etical compounds, we also examined compositions corresponding to the trisilicie acid, but found that the mixtures of lime and silica from which the salt of this acid might be expected to crystallize did not give any new phases. These mixtures showed well developed pseudo-wollastonite with the tridymite eutectic, and neither rapid cooling nor crystallization of the glass at low tempera- tures gave any indication whatsoever of the hypothetical com- pound. Thermal Apparatus.—The thermal measurements to be detailed in the pages which follow were obtained for the most part in furnaces and by methods which have been described in sufficient detail elsewhere.* The work which has been done with the apparatus since that time has exposed one weakness which will be given detailed consideration at a more appropri- ate time and place, but will be outlined here for the use of others who may have occasion to employ this extremely useful and accurate apparatus. For certain reasons of convenience rather than of necessity, the platinum coils which we have heretofore employed for heating purposes have usually con- tained 10 per cent of iridium. It has now been found that even in a nitrogen atmosphere this iridium sublimes slowly at temperatures above 1200° and enters and contaminates the wires of the thermoelement, if they are exposed, even in the *Day and Allen, loc. cit. 286 Day and Shepherd—Lime-Silica Series of Minerals. colder parts of the furnace. Unglazed porcelain offers no protection against this iridium. The effect of this contamina- tion is to make the thermoelements read too low. The error is noticeable after a single ,hour’s exposure (perhaps 1/2°), and will gradually increase to fifty degrees or more in a few weeks of continuous usage, the amount depending considerably upon the temperatures employed. The remedy is simple and sure,— use no iridium in the furnace. An element once contami- nated in this way can only be restored by cutting off the exposed portion. Above 1600° the platinum coil and the thermoelement gave place to the iridium tube furnace and the Holborn-Kurlbaum optical pyrometer. The adjoining diagram (fig 4) contains (LZLZLLLLB . am, are Me a” q <5 le = ee wise \ZZZZZZZ2) sufficient details to show almost at a glance the operation of the system. A straight iridium tube about 18 long and 4™ in diameter is fed by an alternating current of low voltage, led in through platinum and silver flanges at the ends. Fused magnesia serves as insulating material and a base of magnesia supports a small iridium crucible in the position indicated. A small opening in the magnesia cover enables the pyrometer to be sighted on any point within.* The furnace will reach tem- peratures of 2100° C. and is almost indispensable at very high temperatures where an oxidizing atmosphere is important. *This furnace was made for us by Dr. Heraeus of Hanau, Germany, to whom, as well as to his associate, Dr. Kiich, we are indebted for many cour- tesies. Day and Shepherd—Lime-Silica Series of Minerals. 287 The Holborn-Kurlbaum pyrometer is a very simple tele- scope consisting of two cheap lenses, in the focus of the first of which (eye-piece) is placed a small incandescent. lamp in which the current and therefore the brightness of the filament can be varied. The operation of measuring then consists merely in focussing the telescope upon the hot body of which the temperature is required and changing the current in the filament until the latter can no longer be seen against the hot object observed. The current then passing through the fila- ment is a measure of the temperature. Monochromatic light (preferably red) only is used. The calibration of this instru- ment is arbitrary. It requires merely to be directed at a hot object of which the temperature is known, and the current observed. The relation between current and temperature for several temperatures can then be elaborated into a curve for purposes of interpolation or extrapolation. One condition must not be overlooked in the use of such an instrument,— the radiant energy sent out at a particular temperature is differ- ent for different substances unless they are enclosed within a hol- low body of uniform temperature, in which case all bodies radi- ate alike and perfectly. Such a hollow body with a small open- ing has been called by Kirchhoff a “black body” or perfect radiator, and the radiant energy passing through the opening, black radiation. A fair working test for the “blackness” of radiation within a furnace, for example, is obtained by obsery- ing whether objects within can be distinguished. When all detail disappears within a furnace, its radiation is reasonably black. This is approximately true at the center of nearly all enclosed electrical resistance furnaces in which no combustion is going on, but if the temperature is high it is usually not entirely uniform even for small areas, and the radiation is con- sequently not black. For purposes of comparing the thermal constants of dif- ferent substances of unknown radiating power, therefore, we first obtained small incandescent lamps which had been cali- brated upon a black body at the Reichsanstalt and verified the calibration upon a similar body in our own laboratory for the purpose of comparing standards. We did not deem it safe to assume the approximate blackness of charges within the fur- nace, although the conditions sometimes appeared sufficiently good tu warrant it. We took two trustworthy fixed points, the melting temperature of anorthite (1532°) and platinum (1720°), both being in the region in which we proposed to apply the method, and observed the radiation from a tiny fragment of iridium ribbon at those temperatures. In this way we obtained two points slightly below the black body curve and passed through these an empirical curve parallel to 288 Day and Shepherd—Lime-Silica Series of Minerals. the standard curve. Our temperatures were measured in terms of this empirical curve. Since differences of less than five degrees can hardly be distinguished by this apparatus at such high temperatures, the assumption here made that the radiation from iridium is of uniform quality throughout the region between 1600° and 2100°, will hardly be called in ques- tion. After the temperature scale was established in this way the iridium fragment was laid on the top of each charge dur- ing the measurement and all determinations were made in terms of the radiation from it. With this pyrometric apparatus we undertook to examine all the mixtures within reach from lime to silica which the micro- scopic study had shown to be important. The mixtures were first examined in charges of 100 grams between 500° and 1600° in a furnace of the type described by Day and Allen (doe. cit.), supplemented where necessary by observations at higher tem- peratures in the iridium furnace with the optical pyrometer. The relative sensitiveness of the two methods is roughly one to ten, 1. e., the smallest temperature changes which the opti- cal pyrometer can detect are fully ten times as great as those | which can be readily measured with the thermoelement. Fur- thermore, the eptical pyrometer is merely a device for estima- ting temperatures by observation from without the furnace. It enables an observer to heat a charge to a certain tempera- ture but not to tell whether anything takes place there except by removing the charge from the furnace for examination. It is not adapted to the determination of thermal constants by direct observation except in the case of the melting tempera- ture of pure compounds or eutectic mixtures which melt sharply into a thin liquid. It has been our universal experience that changes of state which are subject to lag are much more easily and certainly determined from heating than from cooling curves. Under- cooling in these ultra-viscous media cannot be prevented with certainty by any of the usual methods. Superheating is also unavoidable at times, as we have already noted in the case of quartz and elsewhere. In these cases the change of state required by conventional definitions simply cannot be deter- mined as a point. Where the inertness is not so great as to be prohibitive of all measurement, our uniform experience has been that the melting temperature can often be established with confidence, where solidifying temperatures cannot. Similarly, inversions in the solid state can usually be fixed upon a curve of rising temperatures with greater certainty than upon a cooling curve. The temperature constants.— We have now definitely located the compounds of lime and silica which can exist between the Day and Shepherd—Lime-Silica Series of Minerals. 289 pure components together with the eutectics which they form. It only remains to study their thermal properties somewhat more consistently with the help of the apparatus which has been described. It was not found possible to determine the presence of the eutectic (Line HBI, fig. 3) in the 10 and 20 per cent compositions, for reasons which will have become sufficiently clear already, but the microscopic evidence shows the tridymite to be normal, whether it forms from pure silica or in the presence of lime, so that the eutectic must extend over to the silica axis. From 30 per cent on there was no dif- ficulty in observing it pyrometrically. The observations are included in Table I. TABLE I, Eutectic. Tridymite+ Pseudo-wollastonite. (Line H I, fig. 3.) Percentage of CaO. 30 32 30 4() 45 Eutectic melts CASO a4 jeyn REO 8 LAS ES OAT Oe 1419 TAS 1420 1419 — Mean LAVOE TASS. PATS pA On = aS _ The liquidus AB (fig. 3) has been drawn as a dotted line. The value assumed for the melting temperature of silica is _ based upon considerations which have been elaborated elsewhere . 272). Ht requires no further comment except perhaps to call attention to the fact that it is much lower than the tem- perature usually assigned to it. As the mixtures grow richer in lime, the melting of the excess of silica seems to be consid- erably facilitated, but there are no points sufficiently sharp to serve aly purpose as quantitative determinations until we reach the composition 80CaQ, 70SiO,. The microscopic evi- dence is however both satisfactory and suflicient as to the nature and continuity of the curve. Along the branch BOC (fig. 3) of the liquidus, the psendo- wollastonite is the solid phase. It crystallizes from these mix- tures in laths between which an extremely fine-grained, almost sub-microscopic eutectic appears. It may be remarked in passing that the “eutectic structure” in ninerals is by no means so characteristic as in the case of the alloys. Owing to the great viscosity of these melts and conse- quent slowness of diffusion, it is evident that there is no oppor- tunity for the formation of the characteristic grain structure which we have come to associate with the eutecties of alloys. This almost complete absence of diffusion in silicate melts makes it necessary to proceed with great caution in applving to minerals the methods which are easily and effectively applied to the alloys. For example, in alloys it is possible to crystallize out a portion 290 Day and Shepherd—Lime-Silica Series of Minerals. of the solid phase, then to separate the mother liquor and, by analysis of the two, to determine the composition of the solid phase. In the case of mineral mixtures, the segregation of the eutectic is, for laboratory experiments at least, very indefinite. We have repeatedly examined different regions of a charge in which the eutectic was known to separate, in the hope of find- ing it segregated towards the middle of the charge, as commonly happens - with alloys, but in no case were we able to detect more of the eutectic in one part of the charge than in another. It is usually finely divided and intimately mixed with the primary crystals. The properties of the pseudo-wollastonite which separates along the branch BC are not quite identical with those of the compound when prepared pure, from which it is evident that a certain amount of silica must be taken up by it in solid solution. The amount thus held in solution is certainly less than 2 per cent, but its exact determination microscopically is very difficult indeed. Furthermore, this pseudo-wollastonite when changed to wollastonite still shows a slightly different optical character from the pure material, showing that the solid solution appar- ently continues after the inversion. For brevity, the pseudo- wollastonite has been designated a-CaSiO,, aud wollastonite B-CaSiO, in fig. 3. The branch of the liquidus CD was read- ily deter mined, as well as the beginning of the branch DE. It was not possible, however, to follow the branch DE beyond 57 per cent owing to the steepness of the curve, which rapidly carries it out of the range of the accurate thermoelectric methods. TABLE II. Curve of Melting Points. (Curve A BCD EF G, fig. 3.) Percentage of CaO 40:0 45-0 48°2 50°0 52 54 50'd 65 67°5 Component in 1457° 1504° 1512°% 1505°% 1484° 11435° 15167 2007. ae20lom excess melts 1457 1504 1510 1483 14387 1489 2085 1445 1497 1509 1485 1434 20838 1494 1484 1435 1483 14385 1482 1432 1488 1432 1435 1433 1430 1429 — Mean 1453° 1500° 1512°* 1508° 1484° 1483° 15038° 2082°h 2015. @ * Determined by Allen and White (loc. cit.). + Determined with the Holborn-Kurlbaum optical pyrometer in the iridium furnace. Day and Shepherd—Lime-Silica Series of Minerals. 291 Observations along the curve of melting points are con- tained in Table II. The eutectic KL (pseudo-wollastonite + a-calcium orthosilicate, Table 3) was found in all compositions containing more than 50 per cent and less than 65 per cent CaO. Nota trace of it could be detected in the 65 per cent composition, though diligent search was made for it. A great many determinations were made of it of which the values are given in Table III. TaBLeE III. Eutectic. Pseudo-Wollastonite + a-Calcium Orthosilicate. (Line KL, fig. 3.) Percentage of CaO D0 d2 D4 50°) o7 60 62°5 Kutectic eS A ren aoe AO Toe AAO TST ASD yy VAQ6” melts 1435 1428 1437 1428 1428 1422 1431 1432 1428 1434 1427 1428 1425 1429 1428 1435 1428 1430 1426 © 1429 1435 1427 1429 1426 1428 1482 1428 1429 1426 1430 1432 1429 1433 1438 1435 1431 1484 1426 1433 1430 1434 1433 14380 =14380 144] 1427 1429 1438 1431 1435 1430 1426 1430 1431 Mean EAG2 A800 PAGS 14297 SM 1ASi> 496", 1499" The properties of the metasilicate separating along CD are also slightly different from those of the pure pseudo-wollas- tonite, and up to 50 per cent the mixture appears homogene- ous, so that the metasilicate probably takes up about 1 per cent of orthosilicate in solid solution. -The melting point of the orthosilicate determined in the iridium furnace was found to be 2077° 2085° 2083° Mean 2082° Another charge observed at 2035° was found entirely unmelted. Optical methods of temperature measurement are not competent to determine the melting temperature of the 292 Day and Shepherd—Lime-Stlica Series of Minerals. orthosilicate in the presence of the eutectic for reasons already explained (p. 267), but the eutectic or the compound is readily measured by itself once the composition has been determined. Applying the method to the 674 per cent mixture, therefore, it was found to melt very sharply at 2015°. Neither the orthosilicate nor the 70 per cent CaO composition showed any trace of fusion at this temperature. Since the microscopic properties of the orthosilicate remain unchanged in the pres- ence of an excess of lime or of silica, it follows that the orthosilicate does not form solid solutions with either lime or silica. Both eutectics will therefore continue up to the ortho- silicate. Above the lime-orthosilicate eutectic the pyrometer affords no further information regarding the melting point curve. . The line MN (fig. 8) represents the temperature at which the inversion to £-orthosilicate occurs. It will be noted that the inversion is frequently delayed by superheating, especially in the region remote from the eutectic, but it was always possi- ble to show by quenching the material from above and below these temperatures that the variation is merely due to the inevitable lag of the reaction. Between 50 and 65 per cent of lime, the two heat changes at MN and KL he so close together that it was very difficult to separate them. The pyrometer shows two points plainly, but each is somewhat influenced by the presence of the other. We were able, how- ever, to distinguish them beyond possibility of confusion by holding the furnace constant at 1425° and quenching the charge in water. These conditions yield a-orthosilicate + pseudo-wollastonite, while if the temperature is held at 13890- 1400°, 8-orthosilicate + pseudo-wollastonite results. The inver- sion temperatures are contained in Table IV. Mean values lose much of their significance in determinations of inver- sion temperatures where superheating can occur-and are accordingly omitted from the table. TABLE IV. Inversion $-Orthosilicate to a-Orthosilicate. Percentage of CaO 55°5 57:0 ~=—60°0 62°5 65°0 70 73 79 80 . 90 Inversion 407° 1395° 1404° 1896° 1496° 1409° 14296° 1415°° 1407 eaae tempera- 1414 1412 1411 1397 1421 1405 1425 1421 1429 1432 ture. 1403 1419 1411 1405 .1415 1412 1482 14383 1411 1415 1398 1398 1414 1425 1406 1402 1408 1412 1406 1404 1407 1413 1404 1405 1401 1417 1588 1428 1411 Day and Shepherd—Lime-Silica Series of Minerals. 298 The scattered points lying below 1300° (fig. 3) occur only in the compositions in which the metasilicate is present, and correspond, as a microscopic examination at once shows, to the change from wollastonite to the pseudo-hexagonal form. With falling temperature, the poimts occur very much lower or are lost, since the inversion does not occur quite as readily on cooling. Allen and White observed that this inversion could be brought about only with great difficulty with the pure metasilicate, but in the presence of an excess of either lime or silica, we found it to occur with comparative readiness (Table V) in many compositions. The line QR is the temperature at which the reaction 8 into a takes place. As observed in the discussion of the proper- ties of the orthosilicate, this reaction does not occur promptly, but is lable to very serious superheating or undercooling. TABLE V. Inversion P-Metasilicate to a-Metasilicate. Percentage CaO a0 a2°0 30 40 45 o7 Temperature of 1273" “12742 ) 1257" 1288°- 1254° 1286" inversion. WG63h 2399" 1266 13238 1528 Part IIL. Optical Study. The different members of the lime-silica series are well characterized optically and can generally be distinguished under the microscope without difficulty. Occasionally, how- ever, the preparations are extremely fine-grained and require repeated examination before the minute details of each sub- stance in the product are fully appreciated. In actual practice, experience has shown that the best results can be obtained by examining the preparations in powdered form rather than in thin sections cut from larger fragments. The chief advantage of thin sections over the powdered material is a textural one, since by breaking any given preparation into small particles its original texture is practically destroyed. Although prob- lems of textural differences in artificial products are not to be disregarded, actual determinations can best be made with the powder, since with it the crystallites can usually be examined separately and the optical phenomena of a single individual observed rather than those of an aggregate of overlapping and interlacing crystals, as is often the case in slides ; further- more, by embedding the fine grains in a viscous liquid, such as Canada balsam, they can be rolled about in the liquid and their optic properties in any desired direction ascertained ; the refractive indices of a substance can also be determined directly 294 Day and Shepherd—Lime-Silica Series of Minerals. on powdered particles by Schroeder van der Kolk’s method of refractive liquids and numerical constants thus obtained on grains measuring even less than -001"™ in linear dimensions. Optically, four different compounds were recognized in the lime silica series; three of these appeared in different poly- morphic modifications according to the conditions of forma- tion. Pure silica crystallized either as quartz or tridymite ; calcium metasilicate (CaSiO,) either as wollastonite* or pseudo- wollastonite ; calcium orthosilicate (Ca,SiO,) in three forms, a, 8,and y; and calcium oxide only in one form, so far as known. The experiments indicate that for each compound the different modifications bear enantiotropic relations to one another. Calcium oxide.—Well-developed crystals of this substance are rare and were observed only in preparations from large melts in the furnace. In intermediate mixtures between the oxide and the orthosilicate it occurs usually as small rounded colorless grains which are easily recognized under the micro- scope by their high refractive index and isotropism. The crystals are colorless to pale yellow, transparent, and erystal- ize in unmodified cubes of the isometric system. Their hardness is between 3 and 4. Attempts were made to etch these crystals by immersing them in water, but the etch fig- ures obtained were not sufficiently distinct to be of value. They pass rapidly into Aetzhtigel which cover the entire etched face. The crystals cleave perfectly after the cube (100). Their refractive index, 1°82, was determined by im- mersing fragments in a high refractive liquid solution of arsenic sulphide in arsenic bromide. Owing to rapid superticial decomposition, the crystals soon became coated with a thin crust which tends to decrease the accuracy of this determina- tion of the refractive index. Optical anomalies were observed occasionally, and were due probably to internal strains. On exposure to air and moisture, the crystals slowly become - hydrated and disintegrate. The orthosilicate-—The microscopic examination of the various preparations of this compound revealed the existence of three distinct forms, a, 8, and y, which are stable over different temperature ranges. ‘The optical properties of the a and £8 forms are similar and their microscopic diserimina- tion is a difficult problem, while the y-form, which is stable for emperatures below 675°, differs considerably from the a and forms and can be recognized with ease. (a) The a-form is stable only at temperatures above 1410° and on cooling has a strong tendency to invert to the 8 and y forms. It was found by experiment that if chilled very * Compare this Journal, xxi, 89-108, 1906. Day and Shepherd—Lime-Stlica Serres of Minerals. 295 rapidly, this change could be checked, in part at least, for a considerable period of time. The a-form belongs either to the monoclinie or triclinic crystal system, probably the former, and shows prismatic development, with good cleavage after a face in that zone. The crystals are transparent and colorless and occur as fine aggregates so intricately intergrown that the precise determination of their optic properties is practically impossible. ‘Twinning is a characteristic feature of this form, and is often extremely complicated. Different sets of the twinning lamellae cut each other at various angles and the sections then resemble plates of microcline or leucite. Extinc- tion angles measured along the prism axis were noted as high as ¢:a = 18°, although smaller angles appear more frequently. The hardness is between 5 and 6. The refractive indices were measured by the method of refractive liquids: a=1°714+:008 ; e720 004: y— 1-/3(2008. Birefringence about -02. The optical character is positive; 2 V = 81°; 2E> 180°. This optic axial angle was measured on a section nearly perpendicu- lar to an optic axis by the graphical method recently described by Becke.* The method is founded on the difference in cur- vature of the dark hyperbolic bar which passes through the optic axis, for different axial angles in the diagonal position. In place of the revolving drawing table of Becke, a different type of instrument which can be clamped directly to the microscope was used in this laboratory with satisfactory results. This method is only an approximate one and the figures. obtained by its use may vary considerably from the actual values, a condition recognized by Becke himself in the origi- nal paper. The plane of the optic axes is about parallel to the direction of elongation of the crystals. (b) Zhe crystallites of the B-form are stable between 675° and 1410°; they are also prismatic in shape and show good cleavage parallel to the prism axis. They are colorless and transparent, and are orthorhombic in erystal system. Their hardness and density could not be determined directly, as this form, at low temperatures, inverts rapidly to the y-form and ean furthermore be obtaiiied only in powdered condition. The least ellipsoidal axis c is parallel to the ¢ crystallographic axis and the plane of optic axes lies in the direction of elonga- tion of the erystals. The optic axial angle is very large. The refractive indices, a = 1°722+-003 and y = 1°738+:003, were determined by the method of refractive liquids. The birefringence is not strong, about ‘01. The §-form is distin- guished from. tbe preceding a-form most readily by the absence of twinning and by its parallel extinction. The pro- *F. Becke, Tscherm. Min. u. pet. Mitth. xxiv, 1905. 296 Day and Shepherd—Lime-Silica Serres of Minerals. gressive paramorphic change of this form into the y-form can be followed under the microscope and is interesting to watch. Shortly after cooling, irregular interference colors appear, as though induced by internal strains, and soon the mass resem- bles a crystalline aggregate of minute fibers. Toward the end of the process, the larger masses usually disintegrate as fine powder owing to the enormous increase in volume (about 10 per cent) during the inversion. (c) The y-form is stable at low temperatures and into it the preceding forms usually pass on cooling to ordinary tempera- tures. It is noteworthy that the properties of this form are unlike those of the above, particularly in specific gravity and refractive index. The density of the a and 8 forms is about 3°27, while that of the a-form is only 2:97. Asa result, on paramorphic change in the solid state a great increase in vol- ume takes place which at once shatters the larger fragments of the original material and causes the preparation to “ dust.” The y-form can be had, therefore, only in the form of powder. It is prismatic in habit, cleaves well parallel to the long direc- tion, is colorless and transparent, and occasionally shows indications of twinning with small extinction angles; ¢: c= 3° was measured in one instance. The form is probably, there- fore, monoclinic in system. The twinning is recognized only rarely, and the extinction usually appears parallel. The refractive indices were determined by the method of refrac- tive liquids: a=1:°640+:0038, 8B=1°645+-003, y=1-654 ‘008. The birefringence is weak, about ‘014; biaxial with an optic axial angle in air 2H=52°, measured by the graphical method of Becke on a section nearly normal to an optic axis; optical character negative; plane of optic axes perpendicular to the prism axis in contradistinction to the a and 8 forms. Com- pared with the a and @ forms this form is readily distinguished by its lower refractive index, its optical character, optic axial angle, and position of the plane of optic axes to the prism axis. The metasilicate occurs in two enantiotropic modifications, one of which corresponds to the mineral wollastonite. The second form has been called pseudo-wollastonite, and is stable above 1200°. Both these forms have been discussed so thor- oughly in a preceding paper* that repetition here is unneces- sary. The properties of the artificial wollastonite counterpart those of the mineral, while the pseudo-wollastonite is pseudo- hexagonal, probably monoclinic in erystal system. It is opti- cally positive and nearly uniaxial; its refractive indices, a= * Loc. cit. Day and Shepherd—Lime-Silica Series of Minerals. 297 1:615 y = 1°636; its birefringence is strong and considerably higher than in wollastonite. Silicon dioxide.—In nature this oxide occurs in at least two modifications, quartz and tridymite, both of which were produced artificially in this laboratory. As a result of the experiments, the fact is well established that quartz is the stable form below about 800° and tridymite over the range 800° to the melting temperature 1600°; that, on heating, the inversion of quartz into tridymite is so extremely sluggish that quartz crystals may be heated 700° or 800° above the inversion point without changing. Quartz glass, however, can be made to crystallize to tridymite as low as 1000°. The microscopic examination of the different artificial prep- arations of tridymite and quartz proved satisfactorily their identity with the natural minerals. By using the method of refractive liquids it was found possible to discriminate between quartz, tridymite and amorphous quartz with ease, even though many of the preparations were cryptocrystalline and scarcely determinable by other ordinary methods. The refractive index of amorphous quartz, obtained by precipita- ting silica from solution, was measured by the immersion method at 1°459+-0038; later the same constant was determined more accurately on a polished face of quartz glass* on an Abbe total refractometer in sodium light with the result, 1-460. (a) Quartz.—The best crystals of quartz were obtained as a byproduct from a mixture of magnesium-ammonium cbhlor- ide, sodium metasilicate and water heated for 3 days in a steel bomb at 400-450°. This mixture was used by Dr. E. T. Allen of this laboratory to synthesize one of the polymorphic forms of magnesium metasilicate and to procure measurable crystals of the same. The quartz erystals thus procured were color- less, water clear, doubly terminated and well developed crys- tallographically. The larger crystals attained a maximum length of 2°", but were usually coated with a thin film of foreign matter and were less suited to goniometric measure- ment than smaller ones. The erystals are often barrel-shaped with short rhombohedral terminal faces which pass by oscilla- tory development into steeper rhombohedrons and finally into the prism which shows the characteristic striae of the mineral quartz. Ina few of the crystals, the positive rhombohedron only was developed and the crystals were terminated by its three faces above. Several crystals were measured on the two-circled goniometer and the forms (1010) (1020) (1011) observed. Other forms were noted but gave indistinct and multiple reflection signals and are not listed in consequence. * Obtained by fusing quartz in the electric furnace under pressure. Am. Jour. Scl.—FourtH SEerizes, Vou. XXII, No. 130.—Ocrosrr, 1906. 21 298 Day and Shepherd—Lime-Silica Series of Minerals. The angle between the prism faces and the rhombohedrons (1010 : 1011) measured 37° 48’ and differs appreciably from that of pure quartz, which is given by Dana, 38° 13’. The three rhombohedron faces from which this angle was obtained _ gave perfectly sharp reflection signals, and although the obser- vations on the goniometer were made with the reducing attach- ment, the difference no doubt exists and is due probably to a solid solution of quartz with some other ingredient of the — original mixture. The hardness of the crystals is 7; their specific gravity, 2°650 determined in Thoulet solution, and their refractive indices e = 1°654+°002, to » = 1°644+°'002; measured by the method of refractive liquids, their birefring- ence is about ‘01. The crystals are unaxial and optically posi- tive, and extinguish parallel to the prism edge, which was found to be the direction of the least ellipsoidal axis c. (Quartz could not be produced by direct crystallization from silica glass, since at low temperatures at which it is stable the viscosity of the glass is too great to allow sufficient molecular mobility for the rearrangement. Fluxes or solutions were therefore used to increase this mobility, and with satisfactory results. Quartz crystallites were formed at temperatures below 760° and tridymite above that point in. the same flux. The chief effect of such crystallizing fluxes or erystallizers seems to be that they tend to increase the molecular mobility of the crystallizing material and thus procure greater freedom and power for crystallization. In many experiments per- formed in this laboratory it has been noted that erystals obtained directly from silicate melts are usually minute and ill-formed; while the addition of a few per cent of a second substance improves both size and quality of the crystals to a remarkable degree, even though the added substance may solidify as glass and enter apparently in no wise into the com- position of the crystals. (b) Zrzdymite-—In the experiments, well developed erys- tals of tridymite of sufficient size for goniometric measure- ments were not obtained, and optical properties alone were relied upon for its identification. The refractive index y was measured 1°485-+:003 on one preparation and 1°483-+°003 on a second by the method of refractive liquids. These values are slightly higher than that given for natural tridymite, which is 1-478. No reason has yet been suggested to explain this discrepancy. The birefrmgence is extremely low, appar- ently not over ‘002. The erystallites are biaxial with an optical axial angle so large and indistinct that the optical char- acter could not be determined satisfactorily. In some of the crystals an elongation in a direction diagonal to the positions of extinction was noticeable. The best preparations of tridy- Day and Shepherd—Lime-Silica Series of Minerals. 299 mite were obtained by allowing large melts of quartz glass to cool slowly. On the surface of these melts radial spherulites of tridymite frequently formed and in one instance coated the entire charge with a film 1™™ thick of crystalline material. The preparations, however, were without exception fine- grained and so intricately intergrown and affected by optical anomalies that the exact determination of its optical constants is not possible. The same conditions obtain in the mineral tridy- mite and appear to be characteristic of this phase of silicon dioxide. Intermediate mixtures.—The preparations from mixtures between pure silica and wollastonite varied greatly in texture and, with the exception of those mixtures which approached the metasilicate in composition, were found to be inhomogene- ous and to consist of tridymite and one of the forms of the metasilicate. In products with less than 87 per cent of e¢al- cium oxide,—the eutectic composition of silica and calcium metasilicate—cerystallites of tridymite were observed, often arranged in systems of lines intersecting at 90°, 60° and less angles or in rosettes and radial spher ulites. The rosettes are finer grained than the crystallites and frequently appear as mere dust particles. The metasilicate is also fine-grained, without crystal outline, and includes the larger phenocrysts of tridymite. It can be distinguished from the latter most read- ily by its higher refractive index and stronger birefringence. The eutectic itself is extremely fine- orained and tridymite occurs then only in minute dust-like particles without discern- ible crystal outline. Preparations ranging in composition between the eutectic and the metasilicate contain large, clear, lath-shaped crystal- lites of the metasilicate, often in parallel orientation and inter- rupted by a finely crystalline, less clear mixture of tridymite and the metasilicate. The optical properties of the metasili- cate in these intermediate products differ slightly from those of the pure mineral, a condition which is due undoubtedly to the presence of silicon dioxide taken up in solid solution by the metasilicate. In these products the form equivalent to the mineral wollastonite was found to differ from true wollastonite chiefly in its lower refractive index and smaller optic axial angle ; a measured in one instance 1°485 instead of 1°521, the a of pure wollastonite. The smallest value for the optic axial angle in air was found to be about 30° in air in place of the 70° of pure woliastonite. _ The second form of the metasilicate corresponding to pseudo-wollastonite showed similar variations; its refractive indices were also lower, a = 1°490 having been measured in one instance, a value °025 lower than a for pure pseudo-wol- 300 Day and Shepherd—Lime-Silica Series of Minerals. lastonite. The optic axial angle was found to increase and reached a maximum of about 25° in air, whereas pure pseudo- wollastonite is nearly uniaxial. In many of the preparations hexagonal outlines of this phase are noticeable, and two sets of imperfect cleavage lines intersecting at an angle of 120° . can then be seen on sections normal to the acute positive bisec- trix. Mixtures containing over 45 per cent of calcium oxide appear homogeneous, and the crystals from the preparations show a continuous variation in their optic properties from that point on as the composition of the metasilicate is approached. The microscopic study of the preparations ranging in com- position between calcium metasilicate and calcium orthosilicate showed that the metasilicate is capable of -absorbing a consid- erable amount of the orthosilicate and still appear homogene- ous, the resultant crystals expressing the fact of solid solution by the change in their optic properties. The limit of homo- geneity of the mass appeared to be reached at abont 50 per cent lime and in crystals from fusions of that composition the refractive index a was found to have increased from 1°615 of pure pseudo-wollastonite to about 1°630; the optic axial angle was also larger (2 E about 20°-30°); the plane of optic axes was normal to a direction of cleavage in contrast to its position in crystals of solid solutions of the metasilicate and silica in which the plane of optic axes was observed parallel to the direction of cleavage. In the 50 per cent preparations, twin- ning lamellae with small extinction angles can often be seen on sections normal to the acute positive bisectrix, thus demon- strating their monoclinic or triclinic nature, notwithstanding the hexagonal outline of the basal section and systems of cleavage lines intersecting at angles of about 120°. In products containing a little more than 50 per cent of cal- cium oxide the fine-grained eutectic begins to appear im small patches between the crystallites of the metasilicate. Fusions from mixtures of about 55 per cent lime and 45 per cent silica are usually fine-grained, and differences in size between crystals of the meta- and orthosilicate are less apparent. Preparations with more than 55 per cent lime ordinarily disintegrate to fine powder on cooling, due to the great increase in volume of the orthosilicate on inverting to the y- form at low temperatures. Studies in texture could not there- fore be made in the loose powder, and evidences of solid solu- tion near the orthosilicate were sought for by means of optical constants alone. The refractive indices of the minute ecrystal- lites from the products approaching the orthosilicate in com- position were not observed to differ appreciably from those of the orthosilicate. Day and Shepherd—Lime-Silica Series of Minerals. 301 The products whose composition extended from the ortho- silicate to pure lime were not homogeneous and contained both end members in variable amounts. If quenched quickly, the melts consisted of fine grains of the high refracting calcium oxide and the a-form of the orthosilicate ; if allowed to cool slowly, the a-form inverted ordinarily to the y-form with attendant shattering or “ dusting” of the product. Thermal evidence showed that the eutectic for the orthosil1- eate and calcium oxide is very close in composition to that of the orthosilicate. Preparations of this composition were examined under the microscope but no definite eutectic struc- ture was observed. In such cases thermal evidence alone must be relied upon to determine the eutectic point, as the optical data are entirely inadequate. Summary.—There are only two definite compounds of lime and silica capable of existing in contact with the melt. They are : (1). The pseudo-hexagonal metasilicate melting at 1512° and inverting into wollastonite at about 1200°. The metasilicate is able to take up asmall amount of either lime or silica in solid solution. (2). The orthosilicate of calcium, which melts at 2080° and possesses three polymorphic forms: The a-form, which crystallizes in the monoclinic system, has a density of 3°27 and a hardness of between 5 and 6. The §-modification erystallizes in the orthorhombic system and has a density of 3°25. The y-modification has a density of 2°97, and also erystal- lizes in the monoclinic system. The disintegration or “ dust- ing” of the orthosilicate and of all lime-silica mixtures above 51 per cent lime is due to the 10 per cent volume-change accompanying the 8 =~ y inversion. The inversion point a to 8 occurs at 1410°, 8 to y at 675°. There are three eutectics in the series :—tridymite+the metasilicate at 37 per cent CaO, 1417°; the metasilicate+ orthosilicate at 54 per cent of lime, 1430°; and orthosilicate+ lime at 674 per cent of lime, 2015°. The orthosilicate is readily attacked by water, which dis- solves out the lime in large quantities. This is probably the reason why it is not found as a natural mineral. The density of fused CaO is 3°32; its hardness 3+. It fuses in the electric arc but its fusion temperature is not accu- rately measurable. Lime crystallizes in the isometric system and possesses no polymorphic forms. Silica begins to melt at about 1600° to an extremely viscous liquid, so that an exact melting point cannot be determined. It has been shown that for all temperatures above 1000° pure 302 Day and Shepherd—Lime-Silica Series of Minerals. quartz changes into tridymite, and pure quartz glass crystal- lizes as tridymite ; so that above this temperature tridymite is unquestionably the stable phase. In the presence of fused chlorides silica crystallizes as quartz at temperatures up to 760° and as tridymite above 800°; crystalline quartz inverts to tridy- mite above 800° and tridymite goes back to quartz at 750°. The inversion temperature is therefore about 800° and the change is enantiotropic. The density of artificial tridymite was found to be 2°318, and that of quartz glass 2:213. The pure natural quartz used had a density of 2°654, the artificial crystals, 2°650. Neither the salt of the trisilicic acid, Ca,Si,O,, the akerman- ite analogue, 4CaO,3Si0,, nor the tricaleie silicate, 38CaOSi0O,, can exist in the two-component system. The optical evidence gained by the microscopic study of the crystallized products | of mixtures of silicon dioxide and calcium oxide in variable proportions confirms the pyrometrie measurements in the following particulars: (1) That siliea, calcium metasilicate, calcium orthosilicate and calcium oxide are the only compounds in the series; (2) that two different modifications of silica exist and correspond in their properties to the minerals quartz and tridymite; that the metasilicate crystallizes in two enantiotropic varieties, one of which is identical with the mineral wollastonite in its characteristics ; that three enantiotropic phases of the orthosilicate exist and are stable at different temperatures; (8) that the metasilicate forms solid solutions both with silicon dioxide and with ortho- silicate over limited ranges. The experience eained in the course of the examination of these and other laboratory preparations indicates that the best results can be obtained by observing them in powdered form and immersed in liquids of different refractive indices and> not in thin sections embedded in Canada balsam. In a liquid whose refractive index is equal to that of one of the com- ponent substances of the product, the differences in homo- geneity in the product are more readily discerned than in a thin section, and at the same time one of the optical constants of the substance is ascertained. Geophysical Laboratory, Carnegie Institution of Washington, June, 1906. 0. C. Farrington—Analysis of “Iron Shale.” 303 Arr. XX VII.—Analysis of “Iron Shale” from Coon Moun- tain, Arizona ; by Oxiver C. Farrine Ton. In the account recently published by Messrs. Barringer and Tilghman* of their investigations at Coon Mountain, Arizona, they call attention to a magnetic oxide of iron, locally known as “iron shale,” which they state occurs in considerable quan- tity upon the mountain. The distribution of the shale is stated to be around the rim of the “ crater,” especially on and in its northern portion and near by on the plain. In the form of minute particles, either as fragments or as spherules, it is also said to occur over the surface of the surrounding country concentrically around the crater for perhaps several miles. Beneath the surface large fragments are found, at varying depths, the greatest depth noted being twenty-seven feet. The pieces reported by these authors varied from one to thirty pounds in weight. No quantitative analysis of the shale is given, but qualitatively it is said that all the specimens examined contained nickel to the same extent, proportionally speaking, as in the Canyon Diablo meteoric iron. It is also stated that within the larger pieces may be seen green hydrox- ide of niekel, while in the very minute pieces of shale the nickel has leached out to a greater or lesser extent. Occurring with the shale and believed by these authors to be related to it, are so-called “shale balls,” which are described as roughly globular to oval in shape, the outside having been converted into hydrated oxide of iron, while the interior is usually magnetic oxide of iron. These are said, when broken open, to show in nearly every imstance the green hydroxide of nickel. In some cases these shale balls are said to contain a solid iron center. As the magnetic oxide-which surrounds this center usually presents a more or less laminated appear- ance, it is assumed that the so-called iron shale found on the surface, as seen on a slightly curved piece, has resulted from the alteration of the shale balls. It is also stated that the pieces of laminated oxide are often grouped, as if a shale ball or piece of meteoric iron which was once covered by a mag- netic oxide of iron had fallen on the spot and the magnetic oxide of iron had been disintegrated by the fall, or afterward by atmospheric agencies. These authors apparently consider their mention of this material the first which has been pub- lished, but in Foote’s account of the Canyon Diablo meteor- itest mention is made of material which is probably of the * Proc. Phila. Acad. Nat. Sci., vol. lvii, pp. 861-914, 1905 ; this Journal, June, 1906, p. 402. + This Journal (3), vol. xlii, pp. 413-417. 3804. OO. C. Farrington—Analysis of “Iron Shale.” same nature. Foote states that accompanying the pieces found at the base of the crater were oxidized and sulphureted fragments which were shown by a preliminary examination to be undoubtedly of meteoric origin. Foote secured about 200 pounds of this material, varying from minute particles up to pieces weighing 3 pounds 14 ounces. These fragments are described as mostly quite angular in character, and a few as showing.a greenish constituent “‘ resulting probably from oxida- tion of the nickel.”’ The oxidized material Foote states to be identical in appearance to an incrustation which covers some of the iron masses and partially fills some of the pits. In Koe- nig’s chemical examination published in the same paper he states that “ the iron is associated with a black hydroxide con- taining Fe, Ni, Co and P in the ratio of the metallic part and therefore presumably derived by a process of oxidation and hydration of the latter.” Foote evidently regarded the oxida- tion of this material as having taken place during the fall of the meteorite, as he states that “the remarkable quantity of oxidized black fragmental material that was found at those points where the greatest number of small fragments of mete- oric iron were found, would seem to indicate that an extra- ordinarily large mass of probably 500 or 600 pounds had become oxidized while passing through the air and so weakened in its internal structure that it burst into pieces not long betore reaching the earth.” Barringer’s view of the magnetic oxide seems to accord with this.* In Derby’s account of the constituents of the Canyon Diablo meteorite} reference is also made to what is undoubtedly this same material. Derby’s statement is as follows: ‘“‘T was also shown in Washington schistose masses of iron oxide found in the same region, whose connection with the meteorite was considered doubtful. These closely resemble the thicker masses of rust crust formed on the Bendego mete- orite and like it, as is well seen in sections prepared by Mr. Diller, show minute particles with a metallic luster which were almost certainly grains of schreibersite, as that mineral has been separated from the rust crust of both Bendego and S40 Francisco do Sul. In view of its occurrence it can hardly be doubted that these Canyon Diablo specimens are due to secondary alteration of the meteorite. As the iron masses in general have a thin rust crust, mdicating consider- able resistance to oxidation, it may be suggested that these thicker masses of oxide may perhaps come from original pyrite as in the case of Sao Francisco do Sul.” It is thus seen that this material has been observed by pre- vious investigators, but no detailed examination of it seems as *Op.1cit, Pp. coe: } This oud (3), vol. xlix, pp. 102- 110. O. C. Farrington—Analysis of “Iron Shale.” 805 yet to have been published. As it seems desirable to throw as much light as possible on the remarkable character of the formation of Coon Mountain, the writer deemed it advisable to determine what information might be gained from a quanti- tative analysis. Specimens of what seemed to be the same material as that described by Messrs. Barringer and Tilghman were already in the Field Museum collections, but in order to be certain to obtain the material described by them, a request was made of Mr. Barringer for specimens. These Mr. Bar- ringer very kindly furnished, in the shape of several pieces of “shale” weighing in all about half a pound, as well as one of the small “shale balls.” The pieces of shale received were of flattened or elongated form, angular, and weighing a few ounces each. All showed a quite uniform blackish-brown eolor. On fresh fracture the color appears more nearly black, and the surface has a glossy appearance. A laminated struc- ture characterized all the pieces. The laminae of which the shale is made up are more or less intercalated but average about one millimeter in thickness. The divisions between them are made in part by thin layers of a brownish-white sub- stance which effervesces with acid and is undoubtedly the aragonite coating frequently observed on the Canyon Diablo siderites and described by Foote. These layers do not affect the appearance of the shale to the naked eye, however, for without a lens only a uniform color and structure is apparent. The shale is sufficiently coherent also to take a fair polish. The “shale ball” received from Mr. Barringer is in color and texture similar to the shale. Its lamination is however concen- tric rather than horizontal. Its form is ellipsoidal and diame- ter about one inch. Its surface is broken by broad, irregular eracks extending nearly to the center. Both the shale ball and a piece of the shale showed the same specific gravity, viz: 3°73. The large pieces of shale show sufficient magnetism to affect a compass needle, and small pieces are readily attracted by a common horseshoe magnet. The shale crushes rather easily in a mortar to a dark brown powder. This powder is also quite magnetic. Heating in a closed tube causes considerable water to be given off, showing that a hydrous oxide is present. -The material appeared, therefore, to be referable neither to magnetite nor to limonite, since it was too magnetic for limonite and contained too much water for magnetite. None of the specimens showed the green hydroxide of nickel referred to by Foote and Barringer. Only the powder which was attracted by the magnet was used for analysis, but this included practically all of it. The analysis by Mr. H. W. Nichols gave the following results : 306 O. C. Farrington— Analysis of “Iron Shale.” HerOr caeates 74°63 Al. Ox 2.329 10i0S FeO eee 3°91 SOP aie sae 0°00 NiQ@ise 2 e aeetoe 9°79 a eae ak TSP, CoO Sc Sane 0°49 PiQy 4 0ene CuO tee be eee 0°00 Ngee tin 0°10 LOCK OFS Si SBP Re 127% (Oh AER 0°15 MOR cece atte 0:00 Oligo ted 0-08 12 Bs Ohya ary Wi Misti 8-02 99°93, TO hos ta 1:09 O=Cl= 0°01 CONS cates 0°35 O=P= 0-15 99°77 The results of this analysis confirm the statements of Koenig and Barringer that nickel and cobalt are to be found in the shale in the same proportion as in the meteoric iron, and leave little doubt that the “shale ” is derived by oxidation from the meteoric iron. It is obvious that the analysis may be interpreted in several ways, since much uncertainty exists as to what changes iron undergoes in the process of “ rusting.” By some it is thought that a ferrous carbonate is first formed which later alters to ferric hydroxide. Others doubt the influ- ence of carbonic acid and believe that the oxygen and water of the air produce ferrous oxide and hydrogen peroxide. By the first process it would be expected that limonite alone would be produced, while the second might form some magne- tite. Examination under the microscope of the finely pow- dered shale showed differences of color and texture not obsery- able to the naked eye. In the small grains appeared alter- nations of black and yellow colorings and compact and earthy textures which suggested associated magnetite and limonite. The analysis calculated on this basis gives fairly satisfactory results. By assuming that all the protoxide of iron and nickel is present as a constituent of magnetite, and that the remaining sesquioxide and water are present as limonite, the different constituents can be fully accounted for. Such a con- stitution also explains the magnetic character and color of the powder. Oalculated in this manner and grouping the minor constituents according to their apparent origin, the following constitution of the shale is indicated : LimMomite.: |. 2... Se ae 52°99 Magmetite 0 2 See aoe eases 42°39 Schrerbersite (2. 2 {cee oe OOF: Grapplers css Ao. 1 ae eres 0°15 Lawreneite 222 220 SSL aes Oa Avragomitet 224s (16s Cee 0:80 Andraditecee es eee east o QaantZ 2 is he 0:21 O. C. Farrington—Analysis of “Iron Shale.” 807 The andradite here reported was not observed, but its pres- ence was indicated by the percentages of lime, iron and silica remaining after the deduction of the other constituents. That it could readily become mixed with the shale from the sur- rounding sands seems probable. The other constituents indi- eated are readily referable to the accessory constituents of the meteorite and the results of the analysis are of interest as showing what changes take place in them. The Canyon Diablo meteorites, as is well known, contain as accessory con- stituents, troilite, graphite, cohenite and schreibersite. Of sulphur, representing troilite, only a trace was found. It appears, therefore, that sulphates were formed and leached out. No phosphorus was found to be present as phosphates and only 0°64 per cent as phosphides. It thus appears that while some schreibersite remained, all which had oxidized to phosphate had been removed. The percentage of carbon found, 0°15 per cent, indicated some cohenite or graphite yet remaining. The percentage of chlorine found indicates the presence of lawrencite, to which, as shown later, may be ascribed probably to some extent the oxidation of the mete- orite. The percentage of nickel oxide found is somewhat higher than usually reported for the Canyon Diablo meteorites and suggests that a concentration of nickel oxide has taken place through a greater solubility of the iron. It is well known that taenite, which is the more highly nickeliferous constituent of nickel-iron, resists oxidation longer than kama- cite, and this might tend to increase the nickel content of the oxidized product. Whether the nickel oxide when formed would be removed more or less rapidly than the iron oxide does not seem to be known as yet however. Test was made for metallic iron and nickel in the shale by treating the powder with iodine, but practically no indications of the pres- ence of these constituents were thus obtained. The shale also when immersed in a solution of copper sulphate showed no deposition of copper such as would occur if the above metals were present. Undoubtedly pieces of the shale in which oxidation had been less complete would show such a content. Comparison of the analysis of the shale with those of rust crusts of other meteorites made by other authors shows dit- ferences chiefly in the percentage of water found. Thus Pugh, in the crust of Toluca,* Haushofer in that of Cran- bournet and Cohen in that of Beaconsfieldt found an amount of water approximating closely to 13 per cent. This indicates * Inaug. Diss. Gottingen 1856, pp. 5-14. + Jour. pr. Chem. cvii, pp. 330-331 ,1869. ¢ Meteoritenkunde, Heft ii, p. 263. 308 O. O. Farrington—Analysis of “Iron Shale.” an alteration of the iron to limonite. It is not stated whether these crusts were magnetic or not. The amount of NiO and CoO found by Cohen in the Beaconsfield crust was only 1°68 per cent, and by Haushofer in Cranbourne 3:1 per cent. In these cases a leaching of the nickel-cobalt oxides has appar- ently occurred. It is probable that different climatic con- ditions would have considerable influence in affecting the composition of such rust crusts. Explanation of the origin of the laminated structure of the shale is doubtless furnished, as suggested by Barringer, by the shale balls. Oxidation and hydration proceed from the surface inward. These changes cause an increase in bulk of the layers successively reached in the process, so that they separate slightly from the unchanged material beneath, and interstices are afforded through which the oxgyen and water enter to attack the metal. Thus the process is continuous and depends only on time and exposure for its completion. The cracks in the shale balls show that the present superficial lay- ers once covered an interior which has since increased in balk. If it be accepted that the iron shale and shale balls are oxidation products of an ordinary Canyon Diablo siderite, it remains to be determined why certain of these siderites should have so oxidized while others have not. One reason is prob- ably to be found in the observation of Barringer that the iron shale often occurs beneath the surface, while the meteoric irons are found only at the surface. Those meteorites which were covered more or less by soil and rock fragments would receive a larger supply of water and hence would suffer more rapid oxidation and hydration than those at the surface. It may also be true that the individuals which have decomposed to form shale balls and shale contained more lawrencite than those which have not. Barringer states* that “the iron centers of the shale balls nearly always show a peculiar oxida- tion of drops of moisture, often colored green, partly perhaps from the presence of nickel. This exudation, Dr. Mallett explains to me, is due to the presence of chloride of iron.” It is well known that among the Toluca meteorites, for example, some individuals contain a considerable amount of lawrencite while others do not. The former “sweat” and rapidly decompose, even in a museum case, while the latter remain dry and unaltered. Mr. Nichols has called my atten- tion to a continuous decomposing action probably exerted by lawrencite which has perhaps not been noted before in this connection. Ferrous chloride in contact with air and water forms ferric hydroxide and chloride: 6FeCl, +30 +3H,0 — Fe,O,H, +4FeCl. * Op. cit. p. 882. O. C. Farrington— Analysis of “Iron Shale.” 309 The ferric chloride is, however, reduced by contact with iron to form ferrous chloride again : 4FeCl,+2Fe = 6F eC], so that the process is continuous. In addition there may occur a formation of free acid through hydrolysis of ferric chloride : 4FeCl,+6H,O = Fe,0,H,+6HCl+2FeCl,. This acid would obviously likewise exert a decomposing action. In conclusion, it may be said that the view of Foote and Barringer that the oxidation which produced the “shale” took place during the fall of the meteorite, is not that of the present writer. In the present writer’s view the oxidation occurred subsequent to the fall of the meteorite, and was so gradual that the production of the shale can be explained only by assuming that the fall took place many years ago. Field Museum, Chicago, June 15, 1906. 310 Bacon—Phenomena Observed in Crookes? Tubes. Arr. XXVUIL—Of the Phenomena Observed: in Crookes’ Tubes; by N. T. Bacon. No satisfactory explanation seems to have been made of the phenomena characterizing prolonged discharges in a Crookes tube. Results which have been recognized are A, discharge of peculiar rays from the anode; B, discharge of different pecu- liar rays from the cathode ; G, oradual attenuation of the dis- charges; D, recrudescence of the discharges on heating the walls of the tube; and E, coating of the walls with platinum black. The attempt has been made to explain C and D by suppos- ing the vacuum to increase, beyond the point where the dis- charges can pass, by absorption in the pores of the glass walls of portions of the residual gases, and redischarge of these on heating the tube. But this hardly seems rational. It is con- trary to all our ideas that an intense vacuum should be intensi- fied by absorption of gases in the walls of the containing vessel in which the vacuum was originally produced. We should expect instead a slow evolution of relics of the greater amount of the same gases absorbed in the body of the glass under the higher original pressure; and furthermore, if any such effect existed, it could hardly fail to result in a kind of osmotic trans- fusion cay the outside, where, as in this case, the containing wall is often not over at inch thick. It seems reasonable to ascribe the gradual attenuation to increasing vacuum, as it is partly overcome by heating the walls of the tube. Glass is known to have (and particularly with aqueous vapor) the property of accumulating over its surface a film denser than the average of the surrounding atmosphere, and this is even more marked with platinnm. This I lay to lack, in the solid state, of the perfect elasticity of the molecule, which is postu- lated by the received theories of gaseous tension. Why should we not consider molecular elasticity to be more or less imper- fect in the solid state? We should then find a ready explana- tion of the heating of platinum sponge in an atmosphere of hydrogen, accompanied by condensation of the hydrogen even te the point of liquefaction. The molecule of hydrogen strik- ing the imperfectly elastic platmum molecule would rebound with diminished velocity, the lost kinetic energy going to raise the temperature. In the pores of platinum sponge the hydro- gen molecule will naturally strike again and again the imper- fectly elastic mass, with further evolution of heat and loss of velocity, until it reaches nearly the orbital velocity of the vastly heavier platinum molecule, thus being reduced even to Buacon—Phenomena Observed in Crookes’ Tubes. 311 the liquid condition. Subsequent molecules of hydrogen would suffer like losses (though less rapidly, owing to occa- sional impacts on hydrogen instead of platinum) until a film of hydrogen molecules should form a more perfectly elastic coat- ing, and equilibrium would be established (with higher tem- perature in the film than in the surrounding atmosphere) when impact on the platinum of a fresh molecule of hydrogen raised the temperature of the film to the point of expelling another molecule from its surface. Evidently such a film would give off molecules when heated, and knowing platinum black to have this action on gases in higher degree than glass, we can see how the vacuum might be increased by the plati- num coating, and why heating the walls of the tube should have the effect of partially restoring its activity. It is also interesting to note that by this theory the higher the vacuum the more important relatively this action becomes, as the exposed surface of imperfect elasticity remains constant, while the number of gaseous molecules diminishes, and thus the ratio increases of impacts resulting in loss of velocity. This may sufficiently explain the recrudescence on heating the walls of the tube, but does not explain the emission of rays, and hardly seems sufficient for the continuing gradual increase of vacuum. Why should not these be accounted for on the hypothesis of a resolution of atoms into electrons or emanations under the discharge in a Crookes tube, and radia- tion of these (to which the glass walls night be pervious, more or less, as to the ether, though entirely impervious to molecu- lar matter) of different polarity from the different electrodes 4 Of these rays we know very little, except that they differ materially from the forces with which we are accustomed to deal. The X-rays, emanating from the anode, are absorbed by mass apparently much in the way that light is absorbed by partially transparent substances, as is shown by the X-ray pic- tures, and they have been considered (though perhaps on insufficient grounds) to have also the velocity of light, which would tend to suggest their relation to the electric current streaming also from the anode; but no ordinary reflection or refraction of them is possible. On the other hand, about all that we know of the cathode rays is that they can be deviated by a magnetic field, thus showing some of the characteristics of mass, and, moreover, they seem to move more slowly than light. | We are not reduced here to consideration of the electron solely. Possibly we may have to do with one or both of the still more ethereal forms of matter postulated to account for the curious changes attending the transformation of radium to helium, but, from present indications, is it not probable 312 Bacon—Phenomena Observed in Crookes’ Tubes. that, under these limiting conditions, the electric discharge can only take place by a disruption of atoms (failing chemical combinations, of which after electrolysis of the residual aque- ous vapor probably none would remain) similar to the electrol- ysis, which alone enables the current to pass through water and other liquids ¢ There is, of course, the intermediate possibility of the mere disruption of molecules into nascent atoms, but this probably would not continuously intensify the vacuum by enabling the elements to escape, though it might be an intermediate stage. The extremely tenuous condition of the residual elementary gas or gases in a Crookes tube, reducing exchanges of charges to a minimum, would apparently be a favorable condition for such disruption, and probably the high temperature would ' be another. Holderness, N. H., Aug. 18, 1906. I. Bowman—Atlantic Preglacial Deposits. 313 Art XXIX.—Worthward FEzatension of the Atlantic Pre- glacial Deposits ;* by Isatan Bowman. OUTLINE. Introduction. Lithologic and Structural Features. Preglacial Series. (1) Basal Clays. (2) White and Yellow Sands. (3) Red Sands. (4) Dark Green Sands and Clays. Glacial Series. (1) Stratified Deposits. (2) Unstratified Deposits. Succession of Events in the Deposition of the Third Cliff Beds. _Former Interpretations. Occurrence of Preglacial Deposits near Third Cliff. Correlation with similar Deposits farther South. Continuity of Deposits. Similarity of Materials. Paleontologic Evidence. Conclusion. INTRODUCTION. Heavy winter storms on the New England coast following the unusually dry autumn of 1904 resulted in many changes in coastal topography, among which were the rapid cutting back of headlands of soft material and the freshening of cliffs. Good epportunities were thus presented for the study of exposed geological sections. The Third Cliff section near Scituate, Massachusetts, is of special interest because of the lithologic and stratigraphic homologies between the exposed beds and preglacial deposits farther south and their bearing on the question of the northern limit of the Atlantic Cre- taceous and Tertiary. The nearest known outcrop of deposits of Cretaceous age is at Gay Head, Martha’s Vineyard, 52 miles south of Third Clif; the nearest known deposits of Tertiary are the Miocene Greensands at Marshfield, 7 miles south of Third Cliff. The latter are not commonly known to occur thongh they were noted by Hitchcockt as early as 1841 (p. 91), the latest text-book of Geologyt stating that ‘ The northernmost exposure of the Miocene on the Atlantic coast is on Martha’s Vineyard.” Third Cliff is one of a series of four cliffs in close succes- sion twenty miles southeast of Boston and immediately south *The suggestions of Professors Woodworth and Jaggar of Harvard and Professor Barrell of Yale University are hereby gratefully acknowledged. Special thanks are due Professor Jeffrey of the Harvard Botanical Labora- tory for identifying the lignites. + Final Report on the Geology of Massachusetts, vol. i, pp. xii to 831, 1841. ¢t Geology, Chamberlain and Salisbury, vol. iii, p. 260, 1906. Am. Jour. Sci.—FourtxH Series, Vou. XXII, No. 130.—Octossr, 1906. 22 314 I. Bowman-—Atlantie Preglacial Deposits. of Scituate Harbor. They are represented on the Duxbury Sheet, U. S. G. §., as the eroded edges of drumlin-shaped hills, from 20 to 1B feet high and aK major axes trending NNW. The accompanying sketch (fig. 1) of a part of Third Oliff depicts the chief features referred to in the following deserip- tion. Lithologic and Structural Features. Preglacial Serves. (1) Basal clays——The basal member of the Third Cliff section is a layer of clay having the light yellow color of. terra cotta. The top of the layer is about at the level of high tide, and an excavation of several feet failed to reach the bottom. It hes in a nearly horizontal position, with slight dip to eastward. It is extremely unctu- ous when wet and resists wave action to such a degree that eile ey5 Tee =|(¢,7, : ik Jaws FMD ioe, eZ rf EW 2 Vi MODIFIED / SS > ZN Vi “oRteT {f= D SANG SSN. Ge? Lae BD aoe DRIFT //ff}i\ a WAdy WHITE AND */y, z ae i S All SS CZ WHITE ANS ~-- saa aS N \ WW SSS y EE OC ey = ZW EANS YELLOW SANDS = SEAS a ae ah ea Rellow Gun ee eee i a = (= on ete °° BE ~ TPifete od} Sls / SAU AAI 1) 2 D' DAN INS AN ITE ANB — oy Nan fr w SANDS jw y 24 EER eo e WANN WANNA de ON ae 2NENIND Fic. 1. Topography and structural relations of part of Third Cliff. Heavy continuous lines represent observed structures. Heavy dotted lines represent inferred structures. Horizontal scale = 175 feet to the inch. Vertical scale = 180 feet to the inch. the height of the steeply-sloping bowlder-strewn beach (fig. 1) is determined by its upper surface. Within the body of the deposit the clay is very pure, but towards the top becomes more sandy, ontaining round inclusions of yellow sands up to a centimeter in diameter. Lamination appears near the upper surface, at first faintly and then more strongly marked, chang- ing finally into cross-bedded structure, although the bulk of the material is still clay. An 18- inch deposit of alternating yellow sands and clays, of several inches thickness each, com- pletes this lowest member of the preglacial series. The entire layer contains muscovite in considerable quantity, and under the microscope shows an occasional grain of glauconite and scattered fragments of sponge spicules, none of which have sufficient character to be identifiable, although one specimen suggested a form of (eodia. (2) Yellow and white sands——A deposit of yellow and white sands lies conformably upon the basal clay, the latter color gaining predominance towards the top. Like the clays I. Bowman—Atlantic Preglacial Deposits. 315 beneath them, these sands dip gently to the eastward. Their maximum thickness is 25 feet, with, however, many variations in thickness, as will be explained in a later ‘paragraph. But slightly cross-bedded at the base, these sands become more and more irregular towards the top, where they display excel- lent cross-bedded structure, the upper eight feet of the layer being exclusively of this character. The sands vary In tex- ture from fine at the bottom to coarse at the top, and show in the same direction a decreasing amount of the clayey constit- uent possessed throughout. Just above the clays on which they rest the sands carry sufficient clay to render them some- what plastic when wet. At the top of the sands where cross- bedding is most marked the sands are dry and _ partially indurated, so that the eroded edges retreat with a nearly verti- cal face. The indurating process has been carried so far in a few places that the material might almost be called a sand- stone. Scattered fragments of sponge spicules occur here as in the clays prev iously described, and an equal amount of glauconite. The sands are very silvery i in general appearance, owing to the great amount of muscovite present, some of the flakes attaining a size of from 4 to 6 millimeters. There is no break in the series thus far described, every change being slow with conformable relations throughout. (3) Led sands.—At the top of the white sands an uncon- formity occurs, the eroded edges of the white sands being overlaid by a layer of coarse and dark red sands with a maxi- mum thickness of 10 feet. These red sands bear large quanti- ties of muscovite, a smaller quantity of biotite, and also exhibit cross-bedding of a much greater degree of amplitude than that shown in the white sands. Occurring only in patches between the white and red sands and never present where unconformable relations between these two members are exhibited, is a thin layer (1 or 2 feet) of black, coarse sand composed of large grains of smoky quartz and with an admix- ture of biotite. It is cross-bedded after the manner of the red sands which overlie it. (4) Dark green sands and clays.—If fig. 1 be consulted, it will be seen that below the stairway near the middle of the figure the section shows greenish black sands and clays at the level of the white sands and below the level of the red sands. The whole face was so masked by talus and land- slide material near the top of the bluff that extensive exca- vation was necessary to determine the relations of the various beds. Both series of beds were evidently in place and the problem resolved itself into finding the line of contact between the two. This was accomplished with the results shown in fig. 2, which is an enlarged portion of fig. 1 at E. 316 I. Bowman—- Atlantic Preglacial Deposits. The white sands were found to exhibit in the clearest possi- ble manner the erosion of a considerable body of their material, the entire series above them being swept away in addition. Upon their eroded edges hes unconformably a layer of white and yellow clays and sands which are superseded above by the greenish black clays noted in the section. The overlying dark clays and the yellow sands and clays between them and the underlying white sands, thicken gradually toward the middle of their outcrop (fig. 1), where the sands attain a maximum thickness of 3 feet and the clays 8 feet. These clays exhibit ae at. WHITE AND YELLOW SANDS eee 5 Feet Fic. 2. Representing unconformity between dark clays and white and yellow sands at E, fig. 1. Nos. 1 and 3 in diagram represent unconformi- ties ; at 2 the deposits are conformable. the same changes as those of the lowest clays in the series—a gradual transition into more sandy members of similar color and 12 feet thickness, which completes the upper part of the preglacial section. As soon as this relation between the beds was discovered the entire section was re-examined with a view to interpreting the relations which proved puzzling elsewhere, and in each locality, no matter how disturbed by ice action or disguised by landslides, the greenish-black clays and sands were always found upon excavation to overlie stratigraphically the white sands of cross-bedded structure. | Glacial Series.—The glacial material which overlies all of the preceding beds may be divided into two classes. The low- est is stratified brown sand bearing a high percentage of erratic material and occupying the eroded depressions in the lower beds; the second is a confused mass of red and white sands (see A, fig. 1) intermingled with erratic sands and typical bowlder clay, the bowlders attaining a maximum diam- I. Bowman— Atlantic Preglacial Deposits. 317 eter of 6 feet. The two classes of deposits are in uncon- formable relation to each other, and along the entire cliff face are seen to be in strong uncontormity with the beds on which they rest (see B, OC, D, fig. 1). The detailed structure of the till is shown in fig. 3, great blocks of bowlder clay being separated by a “filling” of horizontaliy stratified sand which, being without the slightest marks of disturbance since deposi- tion, was deposited in water either contemporaneously with the till or later as a secondary de- posit between the blocks of till as fast as the ice between the blocks was melted out. At Fourth Cliff similar structures are seen with a considerable part of the material derived from the preglacial beds eroded by the ice sheet in its advance. At Indian Hill, seven miles southeast of Plymouth, a good 85-foot section shows the Fie. 3. Showing structure of till further complexity of a layer of clay entirely different than any in the Third Chiff section, just beyond left margin, fig. 1. Sand between till blocks is cross-bedded and undisturbed. Figure represents area about 5 feet square. with a thickness of 20 feet and underlaid by erratic sand and gravel. This layer may represent an interglacial deposit or a deposit formed during a temporary recession of the ice. Its homo- logue does not exist in the Third Cliff section, nor is there any indication whatever at the present time of deposits or structures developed contemporaneous with those at Indian Hill. In all three sections there exists a thin layer of iron- stained reddish and apparently older till just above the strati- fied material of aqueo-glacial origin. Succession of Events in the Deposition of the Third Cliff Beds. The points to be considered in the determination of the age of the beds below those of glacial relationships will be better understood after their interpretation in terms of the events which they represent. It appears that we have represented in the 40 or more feet of yellow clays and sands first described, marine conditions with a steady shallowing of the basin of deposition either through uplift or the gradual upbuilding of the floor through sedimentation. These conditions are marked particularly by the sand inclusions which occur on the top of the clays and the gradual transition of clay to sand with the upper part of 318 I. Bowman—Atlantie Preglacial Deposits. the sands strongly cross-bedded. There followed a period of erosion which may represent very shallow water conditions without actual exposure to subaérial processes. Ourrents and waves have already found expression in the cross-bedded strue- ture and to their increased efficiency at this time may be attributed the unconformity in question. Then came the deposition of the black sands composed of grains of smoky quartz, followed by the deposition of the red sands. The slight thickness of the beds representing the intervals of deposition, together with their cross-bedded structure and present position and attitude with respect to other beds, and the existing shoreline favors the view that coastal changes were here of a less profound order than along the more south- erly part of the Atlantic littoral, where extensive denudation followed the deposition of beds of great thickness. Apparently the greatest erosion followed the deposition of the red sands. In many places the red, black, and white and yellow sands are entirely removed down to the basal yellow clays. In the depressions thus formed was deposited the greenish black ¢lay of figures 1 and 2. Gradual shallowing of the deeper water in which the clays were deposited is represented by the greenish-black glauconitic sands at the top of the darker beds, figure 1. The succeeding events of importance in the history of this part of the New England shoreline were the erosion of the whole series thus related and successive advances of the ice. The first effect of the latter process was probably the deposi- tion of the brown erratic sands as a preliminary wash to be superseded by the deposition of the ice-borne clay and bowld- ers. The relations of the glacial material were not considered in detail, as the field of observation was too limited. The explanation , of the manner of deposition of the stratified glacial sands may therefore be erroneous when more extensive observations are made. The retreat of the ice left the surface of the till practically as we see it today, except where it is modified by shallow gullying or by the insistent attack of the sea. The weight and movement of the ice upon the unindurated preglacial sands and clays below resulted in the bodily removal of great masses of these deposits. They are clearly seen in the face of the cliff surrounded by erratic sands and bowldery clay (A, fig. 1). In addition, the remaining sands exhibit ice disturbance, for while they are practically in situ they are minutely fractured and faulted as shown in the upper right hand corner of fig. 2. In every case the blocks are easily restored in thought to their original positions by the help of slight variations in color and texture. The openings between I. Bowman—Atlantic Preglacial Deposits. 319 blocks are filled in some cases by a silty deposit which can in every instance be traced up to the till or sand above, from which it was derived by percolating waters. The great bowld- ers in the till are continually falling from the cliff face to the beach below and give added protection to the basal clays which determine the level of the beach. The clays, the par- tially indurated sands and the till—all alike possess sufficient tensile strength to stand in bold cliffs and thus yield under an encroaching sea a remarkably clean and perpendicular section. Former Interpretations. Both Third and Fourth Cliffs have been described by Upham.* As his interpretation differs widely from the one just given, the following summary of his results seems appro- priate in this place. It should be said that the section is today in much better condition than when examined by Upham and probably shows the relationships of the various deposits very much more clearly than at any time heretofore. The two cliffed hills are referred to as “two extraordinary drumlins .. . . which consist of till... . to a depth that varies from 15 to 25 feet . . but below include beds of modified drift that attain in Third Oliff a thickness of at least 40 feet, reaching to the bowlder-strewn shore . . Neither the yellow clays which, partly masked by bowlders, form the shore, nor the unconformities above and in the so- called modified drift were noted. That the material is not modified drift is shown by a wholly dissimilar structure and hithologic character; and by the total absence of erratic mate- rial, and a remarkably pronounced and persistent unconformity between the erratic and non-erratic beds, with several smaller uncontformities within the latter (see conclusion, p. 325). Upham speaks further of the anticlinal structure of the moditied drift and the approximate coincidence of the upper surface of these beds with the surface of the till at the cliff top. This is offered as evidence of the manner in which drum- lins are deposited underneath the ice, but in the better section of today the cliffs show in the clearest possible manner that the apparent anticlinal structure is in reality the effect pro- duced by successive faultings of broken blocks of white and red sands as shown near the left margin of fig. 1;-and that the coincidence or parallelism of the structural sur faces called anticlinal is due not to similar dynamic conditions imposed by the ice, but to the control exercised on ice movement and deposition by the form of the subjacent terrane. It cannot, therefore, be argued alone from the relations exhibited here that drumlins are a subglacial deposit built up by successive accretions from the debris-laden lower part of the ice. It is *“ The Structure of Drumlins.” B.S. N.H. Proc., xxiv, 228-242, 1889. 320 L. Bowman—Atlantic Pregtacial Deposits. not implied that such conditions may not have occurred else where, but that such was not the case here is clearly proved. The presence of the yellow sands was noted by Upham and also the lignitic clays, “laminated dark gray clay,” the latter being attributed to deposition of material subglacially trans- ported, the ignites being explained as the possible remnants of an interglacial forest overwhelmed by the ice, yet the absence of all bowlders and till fragments in the clays was observed. The better section of today shows also that the structure of the till is in reality like that shown in fig. 3, and not obscurely laminated. The same figure shows the presence of seams and lenses of gravel within the till, their absence having been asserted heretofore. The various anomalies, which Upham’s observations led him to believe were present here, were explained by the suggestion that the modified drift of Third Cliff was deposited under very unusual sub-glacial conditions. Occurrence of Preglacial Deposits near Third Cliff. Deposits of pre-Pleistocene age once subaérially eroded and now submerged have been presumed by several writers to occur near shore on the floor of the sea north of Martha’s Vineyard. The first to suggest this, with the possible excep- tion of Hitchcock, who vaguely refers to this matter (p. 4277), was Verrill,* who observed ‘in dredged material from the north Atlantic coast com pact calcareous sandstone and arenace- ous limestone bearing fossil shells and fragments of lgnite. About half the fossil forms were considered extinct. Ver- rill thinks that the fragments were probably “detached from a very extensive submerged Tertiary formation at least several hundred miles in length, extending ue the outer banks, from off Newfoundland “nearly to Cape Cod and perhaps constitutiug, in large part, the solid foundations of these remarkable submarine elevations.” Later on, Uphamt+ reports finding fossils of possible Eocene or Cretaceous age in the drift materials near Highland Light, Cape Cod. Hitchcockt even believed from the Miocene deposits at Marshfield (seven miles south of Third Cliff) that deposits of Tertiary age occurred ‘abundantly along the coast from Marshfield to Plymouth and not improbably also on Cape Cod,” although their actual occurrence was not noted. Professor Shaler, in his report on the geology of the Cape Cod District,§ suggested the presence, at least on the sea floor, ~*“ Occurrence of Fossiliferous Tertiary Rocks on the Grand Bank aa George’s Bank.” This Journal (3), xvi, pp. 823-824, 1878. + Marine shells and fragments of shells in the till near Boston, B. S. N. H. Proc., xxiv, pp. 127-141, 1889. + See footnote, Dia: Sy; ple Geology of the Cape Cod District,” by N. S. Shaler, 18th Annual Report, U. S. G. S. Part II, p. 580, 1896-97 (see also pp. 016 and 578). I. Bowman— Atlantic Preglacial Deposits. 321 of Cretaceous and Tertiary deposits northward as far as Cape Ann, from the general likeness of the outlines of the shoals of Stellwagen Bank to Cape Cod and the relations of the now submerged valleys.* The suggestion, though a purely analo- gous one, is of great interest in the further exploration of the field concerned. Correlation with Similar Deposits to the South. The evidence upon which age determinations are attempted is gathered from a close study of the strata themselves and of adjacent areas. The paleontologic evidence secured does not have the specific quality demanded for the purposes of correla- tions, although none of the evidence of this nature negatives the conclusions reached by other evidence. In short, the con- clusions rest upon presumptive evidence and must, therefore, be held as tentative and suggestive only. Continuity of Deposits—At Marshfield, seven miles south of Third Chiff, greensand beds were noted by Hitchcock as early as 1830. + Their age was later determined by Dr. Dall from fossil evidence and found to be Miocene, The deposit is highly glauconitic, occurs about up to 15 feet above mean tide level, and is in very close contact with the granitic floor, which outcrops two miles farther south. The sands do not outcrop, but are reached by excavating 6 to 8 feet beneath the surface. They were first discovered in digging for a well on the farm of Mr. Kent. The presence of this bed suggested that coastal sections between Third Cliff and Martha’s Vineyard might show similar deposits, but a search from Boston Harbor to Peaked Cliff, 15 miles southwest of Plymouth, proved fruitless’except for ‘the finding of drift material often in great abundance derived from preglacial beds undoubtedly similar to those at Third Cliff. This is particularly true of parts of the glacial deposits at East Marshfield, Kingston, Indian Hill, Lookout Point, and Peaked Hill. The unusual character of some of the glacial material in these places is very striking. There is a large amount of white and red sand rather poorly mixed with the more common brown sand noted in sections of glacial mate- rial farther inland. These suggest the wider extent of the pre- glacial deposits and their considerable erosion by ice. Similarity of materials—The fact that at least a part of these deposits were formed in relatively shallow water near shore, as shown by the cross-bedded structure of the lower sands, renders their correlation on this ground along with similar deposits on Martha’s Vineyard insecure, because of *See map of the Cape Cod District. + ‘* Final Report on the Geology of Massachusetts,” pp. 91-95, and 427, 1841. 322 LI. Bowman—Atlantic Preglacial Deposits. the varying physical conditions under which sedimentation takes place in shallow waters. Controlled by the evidence of the unconformities it has, however, a more certain value. The relative thinness of the deposits close to this, their northern limit, and the frequent unconformities point to even greater irregularity in the physical conditions here than farther south, the deposits being more readily affected by sheht oscillations of level common to the lands. The com- plexity of the mutual relations of coastal deposits is enhanced by the fact that continued erosion and redeposition often results in the close lithologic resemblance of beds of quite different age. In such eases there is, therefore, small value in the con- clusions based on evidence of this sort. Unconformities and fossil evidence are the closest available determinants under such circumstances, and it is quite largely on the former that the conclusions of this paper are based. The nearest known outcrop of beds lithologically similar to those at Third Cliff is at Gay Head, Martha’s Vineyard. These are described by Professor Woodworth,* who mentions the following characters of the successive beds: Lower Cretaceous : non-marine, lignitic, leaf-bearing clays. Upper Cretaceous: locally hardened bands of sands con- taining molds of fossils, locally developed beds similar to those at Indian Hill (M. V.) which have a texture varying from fine to coarse with scattered larger grains of quartz and abundant muscovite scales. Inferred unconformity between Lower and Upper Cretaceous. Miocene: thickness varies from 0 to 10 feet. Consists of two members—osseous conglomerate and foraminiferal or greensand beds, with unconformity between. The former is from 12 to 18 inches in thickness, consists of rounded bowlders or of nut-sized quartz pebbles white and well-rounded. Ceta- cean bones present. The foraminiferal bed is from 0 to 10 feet thick, green color below, brown above, basal part includes rolled fragments of osseous conglomerate and bears glauconite casts of JMacoma lyelli in the attitude of growth and the crab Archeoplox signifera in lower part of stratum. Probable Pliocene: yellowish green and brownish clays bearing glauconite and Pliocene fossils. Inferred unconform- ity between Pliocene and Miocene. The paucity of glauconite in the Gay Head Upper Creta- ceous and the variable texture of the material, the scattered quartz grains, abundant muscovite scales, cor respond precisely with the conditions found in the white and yellow sands which form the basal member of the Third Cliff section. Even the occurrence of cross-bedding on a small scale in the coarse pre- * *¢Unconformities of Martha’s Vineyard and Block Island”; B.G.S. A., viii, 197-212, 1897. I. Bowman—Atlantic Preglacial Deposits. 323 Tertiary sands (p. 200) is noted. Were lithologic identity alone a determinant in correlation, we should be. completely justified in calling these beds Upper Cretaceous. The irreg- ularity of the New England shoreline, and the considerable distance (52 miles) between Third Cliff and Gay Head, make it probable that the physical conditions under which sedi- mentation took place were not persistent throughout the entire district, and it is, therefcre, not surprising that at Third Cliff there should be present a layer of red sand cross- bedded throughout on a large pattern which does not appear in the Gay Head section. With this exception the beds over- lying the first unconformity at Third Cliff are again similar to those at Gay Head, except for the osseous conglomerate which is not present at Third Chiff, but the glauconitic sands are present bearing the white well-rounded quartz pebbles. More- over, these beds are at precisely the same altitude as those definitely known to be Miocene (p. 321) at Marshfield, seven miles south. The Marshfield beds rest upon granite, the dark sands and clays of Third Cliff upon white sands. On the whole, the relatively close agreement of unconformities and lithologic characters seems very striking. While this resem- blance, as was noted on the preceding page, may have slight value on account of marginal redeposition without the destrue- tion of characteristic features, it is in a measure significant on account of the distinctness of the separating planes in the deposits and the strongly marked individual character of each bed. It is the more convincing to one who has seen the Atlantic Cretaceous and Tertiary farther south and has noted the persistent and distinctive character of these deposits. It would be quite unsafe to base a correlation of the Third Chiff deposits with those of New Jersey entirely on the evi- dence presented here, but it is not without interest to note that with a single exception the Red Bank sands occur exclu- sively in the Monmouth formation, Upper Cretaceous, “ except in certain marginal phases of the Rancocas formation, aS which latter is itself of Upper Cretaceous age. Glauconite occurs in great abundance in the Upper Cretaceous of New Jersey, and but sparingly at Gay Head, and certain yellow sands are found alike in the Miocene and Upper Cretaceous. Paleontologic Evidence.—A fourth probability is suggested by the studies of T. C. Brown of Columbiat on the Chappa- quiddic fauna from Martha’s Vineyard. A comparison of this fauna with the Eocene faunas of the Atlantic and Gulf provinces indicates that the species closely resemble those * Upper Cretaceous Formations of New Jersey, W. B. Clark; B. G. 8S. A. Vili, 313-358, 1896-97. +A New Lower Tertiary Fauna from Chappaquiddick Island, Martha’s Vineyard, Science, New Series, vol. xxi, No. 548, pp. 990-991, 1905. 324 Ll. Bowman— Atlantic Preglacial Deposits. fond in the lower Eocene, and they are accordingly desig- nated as lower Eocene. The fossils are found in ferruginous concretions, reassorted and deposited in their present position as glacial drift. They have apparently been moved. from the north, probably from the sea bottom, and raise the question as to their relation to the Third Clift deposits. Their relation is, of course, obscure at present, although future dredgings. and soundings may throw some light on the subject. As has been noted before (p. 821) fossil evidence is almost wanting. The sponge spicules, as already noted, were not identifiable with any degree of certainty. Their value even when identifiable is rarely 9 great. The impression of a single bivalve was noted in the red sands, but as only the rounded and partly obliterated outline was visible it also proved of no value. Fortunately the green glauconitic sands in the upper part of the preglacial series are lignitic and a number of excellent specimens of pyrrotized lignite were obtained. These were carefully examined for me by Dr. E. C. Jeffrey, of the Harvard Botanical Laboratory, to whom I am.greatly indebted for a statement of his conclusions, based on extensive comparative studies of henites from Martha’s Vineyard, Staten Island, and Germany. Dr. Jeffrey states :* “The hgnites from the cliffs at Scituate .... belong to an ancient type of Pityoxylon, earlier than that found in con- nection with the Baltic (Oligocene) amber. They closely resemble, although are not identical with, Pityoxylon from the Cretaceous beds of Staten Island and Martha’s Vineyard, and are of the same general antique type. eel Moet material belongs to one species . . . The fact that but one Species was identified makes correla- tion based on the above determinations quite insecure. From the paleontologic evidence the deposits might be placed any- where between the lower Cretaceous and the Pliocene with probabilities pointing to Eocene or Oligocene. On the other hand, the lithologic and stratigraphic evidence coupled with the geographic position of the deposits with respect to the Marshfield greensands points to their Miocene age. In general, plant remains are known to have a 1 low value as time markers in the geological column, especially such low forms as Pityoxylont and allied species. The presence of the former is therefore to be considered not as confirmatory but as presumptive evidence which does no violence to the conelu- sions based on stratigraphic grounds. Conclusion. The conclusions reached after an examination of the fore- going evidence may be stated as follows : * Personal letter, March 5, 1906. See Palaeophytologie, Schimper and Schenck, p. 874. I. Bowman—Atlantic Preglacial Deposits. 325 (1) The lower part of the Third Cliff section is preglacial. This is based on the character of the deposits, the entire absence of erratic material, and the relation and sequence of the unconformities. The suggestion that these beds may be interglacial is opposed by a number of facts which point to the improbability of this occurrence. In the first place, two marked unconformities such as occur within the lower deposits, to- gether with the individual character of the different beds, indi- eate a distinct even if small change in the conditions of deposition which one would expect should be marked elsewhere by deposits of a similar nature. No interglacial deposits of this character are known on the Atlantic coast. It would be singular, though not impossible, that an interglacial deposit of this thickness should elsewhere be swept away, a single rem- nant preserved in this locality only. It is more reasonable that extensive Cretaceous and Tertiary terranes should be removed leaving here and at Marshfield and Gay Head remnants of a similar nature. It would be very peculiar indeed if an inter- glacial deposit were to simulate so closely the stratigraphic suc- cession and lithologic qualities of beds of known Cretaceous and Tertiary age, and at the same time be the sole representa- tives of their kind on the coast. To this fact we may add that the oldest known bowlder bed in New England is present here (see p. 317) and that it occurs above the unconformity represen- ted at C, fig. 1, that is to say, above the most marked uncon- formity of the whole section and one which represents the most protound break in the conditions of deposition. (2) The occurrence of Cretaceous and Tertiary deposits at Martha’s Vineyard, 50 miles south of Third Chiff, and of Ter- tiary deposits at Marshfield, seven miles south of Third Cliff, make it seem not unlikely that deposits of the same age once extended farther north, as well as farther inland, though sub- sequent erosion may have all but completed the removal of such deposits. (3) The similarity of the material and the many points of similarity of sequence in these several places indicate the strong possibility that the Third Cliff beds are to be correlated with those farther south. (4) The identity of plant remains offers the same possibility based on an independent line of evidence. (5) The convergence of independent possibilities renders the following more than possibilities: they may be accepted as probabilities : (z) The underlying yellow clay and the yellow and white sands are considered as probably upper Cretaceous. (6) The overlying dark sands and clays are probably Miocene though possibly Eocene or Oligocene. 326 Hf. O. Bradley—Color Reaction for Copper. Art. XXX.—A Delicate Color Reaction for Copper, and @ Microchemical Test for Zinc ; by Harorp OC. Brapizy. — [From the Chemical Laboratory i the Yale Medical School. | Iv has been known for a number of years that the extract of logwood-haematoxylin—would produce with copper salts a dark blue color of some intensity. One of the older and little used differential stains for tissues depended upon this reac- tion. The microtome section of tissue was immersed first in a copper solution, then washed and immersed again in a dilute solution of haematoxylin. Those portions of the tissue which fixed the copper would then be colored dark blue, while the rest of the tissue remained uncolored. In this way a stain is produced which will differentiate the cell nucleus from the surrounding cytoplasm. This same reaction was used by Herd- man and Boyce* to demonstrate copper in the blood and tis- sues of the oyster, while Mendel and Bradley + made use of it in localizing the copper in the liver tissues ot other marine molluses. So far as we are aware, however, the reaction has never been used ‘as a means of identifying small amounts of copper in solution, nor has it been realized of what extreme delicacy the reaction is susceptible. Accordingly a number of trials were made with copper sul- phate solutions of varying strengths, to determine within what limits the reaction was available for the detection of copper, and also how the reaction compared in delicacy with other well known tests for that element. Ferrocyanide, ammonium sulphide, potassium iodide and starch, are the reagents most commonly employed to detect small amounts of copper, and form some of the most delicate reactions of the laboratory. Potassium ferrocyanide gives, with dilute solutions of copper salts, a characteristic brown color, becoming indistinguishable from the color of the reagent when the copper solution con- tains less than 0°001 per cent of the metal. With starch paste and potassium iodide the reaction is slightly more deli- cate—cuprous iodide and starch iodide of characteristic deep blue being formed—but reaches its limit when the copper solution contains less than 0°001 per cent of the metal. On ' the other hand, the haematoxylin. reaction is at its best in just such dilutions and will serve to recognize copper in solutions of much greater attenuation. The following table shows roughly the comparative delicacy of these reactions : Reagent 0:01% Cu0-001Z 0. ete 0:00001% 0:000001% 0:0000001% Ferrocyanide brown brown fe ee RS 2 KI + starch blue blue bie ere Rae me pe Haematoxylin blue blue blue blue blue blue * Herdman and Boyce: Report of the Thompson-Bates Laboratories, Liverpool, ii, 1899. + Mendel and Bradley : American Journal of Physiology, xiv, 313, 1900. HT. C. Bradley—Color Reaction for Copper. 327 _ That is, while under the most favorable conditions ferrocy- anide of copper is formed visibly in solutions of one part cop- per in 100,000 parts of water, blue starch iodide in solutions of one part copper in 1,000, 000 parts of water, the copper- haematoxylin compound is distinctly recognizable i in solutions of one part of copper in 1,000,000,000 parts of water. This is, we believe, one of the most delicate reactions known, chemical or physical, and is comparable with the physiological effects of copper salts on certain algae, with the catalytic effect of copper in certain oxidations, and with the reactions for detect- ing radio-active bodies of extreme dilution. It is a thousand times more delicate than the ferrocyanide test for copper. The possibilities for the use of such a reaction as a qualita- tive test for copper in drinking water from reservoirs treated with copper sulphate to destroy algae, is at once apparent. Whether the reaction can be applied dir ectly to the proximate analyses of drinking waters, what the conditions for optimum results are, and what the intensely blue copper compound is, are problems still to be worked out. Zine.—Iln carrying out some investigations on the normal presence and distribution of zinc in certain marine gastropods,* the difficulty of recognizing definitely smail amounts of that metal in tissue ash containing relatively large amounts of cop- per, iron, calcium, and phosphoric acid, was found to be very great. Zinc forms practically no colored compounds by which it may be identified in such a mixture, and the ordinary pro- cesses of separation are tedious and unsatisfactory. The desir- ability of finding some rapid and reliable test for zinc led to a thoroegh canvassing of the less common laboratory reagents for precipitating that metal, and the finding of a mier ochemi- eal test which proved to be adequate in every way. The reaction is by no means a new one, but its possibilities as a reliable test for zinc seem to have been overlooked. A moderately concentrated solution of a zine salt when treated with sodinm nitroprusside throws down a salmon-pink precipitate of zinc nitroprusside, fairly insoluble in cold water, much less so in hot. The characteristic feature of this pre- cipitate is its definite and readily identified crystal form. All the other insoluble nitroprussides of the heavy metals are amorphous, slimy precipitates resembling the ferrocyanides in general physical properties. Thus even in a mixture of several metallic salts, such as copper, silver, cobalt, zine, ete., the zine nitroprusside can be recognized under the microscope by the presence of its characteristic crystals in the amorphous mass of the other nitroprussides. In performing the test, it is desir- able to have the solution of the salts fairly concentrated—about * Bradley : Science, 1903, xix, p. 196. 328 H. C. Bradley—Color Reaction for Copper. 10 per cent strength is convenient—and to remove the copper by H,S. In such solutions of tissue ash as were used in our experiments, copper was first removed and the filtrate contain- ing iron, calcium, phosphoric acid, ete., concentrated to small bulk. A drop of this solution placed on a microscope slide and digested with a drop of the freshly prepared nitroprusside solution, deposited on cooling the rectangular plates and prisms of the zinc salt when that metal was present in such minute amounts that the ordinary methods of separation and identifi- cation failed to show it definitely, or required the ashing of large amounts of the original material. For example, by this method zine was detected readily in the blood of certain mol- luses in a few minutes, while by the ordinary methods of separation and analysis—the basic acetate method, or better, the precipitation of the metal as sulphide from a formic acid solution—many hours are required to ash sufficient material and carry through the steps of the analysis. Hileman—Alkalimetric Estimation of Silicon Fluoride. 329 Art. XX XI.— The Elimination and Alkalimetric Estumation of Silicon Fluoride in the Analysis of Fluorides ; by ALBERT HiItEMAN. [Contributions from the Kent Chemical Laboratory of Yale Univ. cxlviii.] Tue errors of the processes for the determination of fluorine, in which that element is eliminated as silicon fluoride to be subsequently estimated volumetrically, naturally fall into two categories. First, there are those errors which are due to impertect elimination and collection of the silicon fluoride from the decomposition flask, and, secondly, there are the errors of the titration processes. For the present purpose it will be most convenient to consider the latter class of errors first. The Process of Titration. As is been indicated, methods have been used for the determination, by volumetric processes, of silicon fluoride. First, the method of Pentield, which depends upon the collec- tion of the silicon fluoride in an alcoholic solution of potassium. chloride and the titration, without removal of the precipitated potassium fluosilicate, of the hydrochloric acid set free. It is assumed that in the alcoholic solution the fluosilicie acid and potassium fiuosilicate are not appreciably hydrolized and that ammonia may exactly neutralize the hydrochloric acid without attacking the precipitated potassium fluosilicate. Cochineal is used as the indicator. 351F,+4H,0 +4KCl = 2K SiF,+810,H, +4HCl NH,OH + HCl = NH,C1+H,0O The second method of titrating the silicon fluoride, resem- bling that of Penfield, except that standard sodium hydroxide or potassium hydroxide is employed instead of ammonium hydroxide in titrating the free acid, which is the method of Bullnheimer* and used by Treadwell and Koch,t involves very similar reactions. SSiF, +4H,0+4KCl — K,SiF,+Si0,H, +4HCl NaOH + HCl = NaCl+H,O The third method, that of Offerman,t differs from the pre- ceding methods in this respect, that the silicon fluoride is allowed to act upon water and the fluosilicic acid and hydro- fiuoric acid thus formed are acted upon by standard potassium * Zeitschr. Angew. Chem. 101, 1901. + Zeitschr. Anal. Chem. xliii, 444, 1904. ¢ Zeitschr. Angew. Chem. 615, 1890. Am. Jour. Scl.—FourtH Series, Vou. XXII, No. 130.—Octoser, 1906. 23 330 LTileman—Alkalimetric Hstimation of Silicon Fluoride. hydroxide to the point of complete hydrolysis of the fluosili- cate to the condition of a fluoride. sSif,+4H,O = 2H,SiF,4+810,H, H,sif, +6KOH = 6KEF+Si0, l,+ 2H, O. According to this process the amount of the standard alkali used is three times as great as that used to the end reaction of the preceding process. According to a fourth method advo- cated by Tammann* and useful when fluorides are to be deter- mined in the presence of carbonates, the potassium flnosilicate is precipitated and separated with precautions and titrated by itself with standard potassium hydroxide to the point of forma- tion of potassium flnoride and silicic acid. K,SiF, +4KOU = 6KF+Si0,H, This process is essentially similar to the second process so far as concerns the reaction involved, but only two units of the alkali used for neutralization are of the standard alkali. For the present purpose therefore, it will suffice to compare the first three methods as to the degree of agreement between individual results, and between the averages “and the processes. For this purpose measured portions of a solution of fluosilicie acid were treated according to the methods described and the results are recorded in the following table: Paraiey Titration in Aleoholic Solution. (According to (According to Penfield.) Bullnheimer. ) Standard Standard Standard Fluorine HeSik's NH,OH KOH NaOH Found. Average. em. ems;. ems. cms. erm. erm. 25 PS: tha The 071433 ) 25 73 bas nee hiee 0°1433 | 25 V2 yet ie 0°1426 } 01428 25 1°23 sat aie pews 0°1429 | 25 eS) patel eS: 071431 | 25 ne oe 10°67 coun 0°1412 | 25 aig 10°72 an 071419 | 25 Dee 10°64 EAS es 01408 + 0-1411 25 tea 10°67 Sige 0:1412 | 25 Pe 10°60 ui tit 0°1403 J 25 eh as ae ail 071416 | 25 he Bjarne 902 01418 | 25 Bee B, Saba S50%7 071410 + 071415 25 re ee i ee 9°10 071414 | 25 oh Se 2 9°12 01418 J * Zeitschr. Anal. Chem. xxiv, 328, 1885. Hileman— Alkalimetric Estimation of Silicon Fluoride. 331 The differences between the amounts of fluorine indicated by the individual determinations in any one of these processes are generally slight. The averages of the determinations by potass slum hydroxide and sodium hydroxide are very close together, being 071411 grams and 0°1415 grams of fluorine. The average of the Se ae by ammonium hydroxide is a little higher, namely, 071425 grams. That the differences between “these averages are due to gradual variations in the reading tint is shown by a comparison of three titrations as nearly simultaneous as possible, in which the greatest care was taken to bri ing all to the same tint at the final “reading. TABLE IT. Comparison of Simultaneous Titrations in Alcoholic Solution. Solution used. Fluorine Found. ems. erm. Titration by NH,OH 72 0°1414 Titration by KOH 10°71 7 071418 Titration by NaOH 9°13 0°1419 So it appears that the results obtained are practically the same by the three processes of neutralization apphed to a solution of fluosilicic acid. But it is to be observed that all are possibly subject to a common and constant error due to the presence of hydrofluoric as well as fluosilicic acid. If the former acid is present it tends to raise the apparent value of the latter. With these results of titrations in alcoholic solution are to be compared the results obtained by the method of titration in the water solution (in which the fluosilicate is completely converted to fluoride), recorded in the following table: PARE CLEP. Titrations of Fluosiliciec Acid in Water Solution. (According to Offerman.) H.SiF; Standard Standard Fluorine Taken KOH 1NaOH Found. Average. cm3. cMs. cm3. grm. grm. 25 30°9 eee 2 0°1358 | 25 30°8 SAE O-F3b3! of 25 30°9 rice pigse,.( 0 18°? 25 30°79 fobs 01353 | 25 se SESS 26°2 0°1357 ) 25 ee 26°15 071355 | 25 eae 26°25 0°1360 | Le 25 Eee 26°2 Gaissy ree 25 zee 26°13 03354 | 25 ele 26°14 01354 | 332 Hileman—Alkalimetric Estimation of Silicon Fluoride. It is obvious that the process of titrating fluosilicie acid in water solution yields uniform indications, both with potassium hydroxide and sodium hydroxide, but that the values for fluo- rine are very much below those of the titrations in alcoholic solution. And this would be the case if the solution of fluo- silicic acid contains hydrofluoric acid as is natural. In the analytical process in which silicon fluoride is passed into the alcoholic solution of potassium chloride the forma- tion of hydrofluoric acid is likely to be at a minimum and so the titration of the hydrochloric acid set free in this meta- thesis should indicate closely the actual amount of fluorine present. If, however, the silicon fluoride is passed into water instead of into this alcoholic solution of potassium chloride, it is necessary to titrate together the products of action, fluo- silicic acid and hydrofluoric acid, to the point of formation of the alkali fluoride, in order that the indication may be correct. The action of ammonium hydroxide upon fluosilicic acid in water solution proves to be comparable with that of sodium hydroxide, and inferentially with that of potassium hydroxide, though the hydrolysis of the fluosilicate appears to be not quite so complete. In the table are given the results of com- parative titrations. TABLE TV. H.Sik', NH,0H Fluorine Fluorine found by taken [1em?=0'006547| found by NH,OH NaOH cem?. Giine. erm. gTm. 25 31°04 0°2030 0°2057 25 31°00 0°2030 0°2057 10 12°39 00811 0°0828 10 12°42 6°0816 0°08238 10 12°42 00811 0:08285 The following expression represents the reaction : 6NH,OH+HSiF, = 6NH,F +Si(OH),+2H,O When silicon fluoride is passed into water containing ammo- nium hydroxide, as is suggested in Liversidge’s method for the analysis of fluorides, it is obvious that nearly complete hydrol- ysis must take place, with formation of silicic acid precipi- tated or colloidal, according to the equation SiF, +4NH,OH — 4NH,F +Si(OH),. According to Liversidge, potassium fluosilicate may be thrown down by addition of potassium chloride and alcohol, after dis- solving the precipitated silica by heating the ammoniacal liquid. In my experience, it has never been possible to thus dissolve all the silica, and the precipitate obtained by adding potassium chloride, with or without alcohol, appears to be * Chem. News xxiv, 266. * Hileman— Alkalimetric Estimation of Silicon Fluoride. 333 silica thrown out of its colloidal solution by addition of the electrolyte. The Elimination of Silicon Fluoride. As to the sources of error due to imperfect elimination, and collection, of silicon fluoride, we have the testimony of the several investigators already quoted. The importance of using the fluoride in the finest state of division, of having the sul- phurie acid of highest strength, of properly absorbing the vapors of sulphuric acid evolved from the decomposition flask, and of using quartz for the silicon dioxide in the decomposi- tion flask, have all been emphasized. Many forms of appara- tus have been employed and the results have varied widely, errors of from 0°0010 grams to 0°0050 grams im the determina- tion ef fluorine by absorption and weighing of silicon fluoride being not uncommon. _ At the outset of the work to be described, an investigation was made as to the limit of error likely to occur in the use of simple apparatus and sulphuric acid, prepared by heating to the faming point, for about a half hour. The silicon fluoride evolved was estimated by absorption in an alcoholic solution of potassium chloride following the method of Penfield,* and the hydrochloric acid set free was estimated by standard potassium hydroxide. The apparatus employed consisted of the following parts: First, there was an apparatus for purifying the air current by passing it through a sulphuric acid wash bottle and two large drying cylinders containing fused calcium chloride at the bot- tom and soda lime at the top; second, a 100°™ decomposition flask provided with a doubly perforated rubber stopper, through which passed a glass tube from the drying cylinders to the bottom of the flask, while another tube, leading from this decomposition flask, was joined to a large empty U-tube intended to condense any sulphuric acid which might be carried from the decomposition flask. Third, connected with the outer limb of the U-tube for condensing sulphuric acid was an absorption system similar to that described by Burk.t It consisted of a test tube 34™ in length and 2™ in diameter, containing a few cm* of mercury into which extended a delivery tube with a capillary opening. The test tube was placed at an angle to diminish the pressure throughout the- system. Before making a determination, the apparatus was first care- fully dried. The absorption tube was filled with a saturated solution of potassium chloride in 50 per cent alcohol, and the material to be analyzed, weighed on a watch glass, was trans- * Am. Chem. Jour., i, 27. + Jour. Am. Chem. Soc. xxiii, 825 (1901). 334 LMileman—-—Alkalimetric Estimation of Silicon Fluoride. ferred to the decomposition flask through a funnel with a short neck. To the material were added fifteen times its weight of ignited quartz sand and 50°™* of sulphuric acid which had been previously heated strongly and cooled in a desiccator. To an iron plate supporting the decomposition flask, heat was applied by a burner and regulated so that a flask of sulphuric acid placed where it received the same amount of heat as the decomposition flask should have a temperature of between 150° and 160°. During the heating a slow current of air was passed through the apparatus. In the reaction in the decom- position flask hydrofluoric acid was generated which acting on the silica formed silicon fluoride. In the absorption tubes silicon fluoride acted on water according to the following equation : ; sSiF,+4H,O = 2H,SiF,+Si0,H, In the presence of potassium chloride and alcohol the fluosil- icic acid was precipitated as potassium fluosilicate, and a corre- sponding amount of hydrochloric acid set free. HSiF,+KCl = K,SiF,+2HCl. The hydrochloric acid was then titrated with a standard potassium hydroxide solution, using cochineal as an indicator. A series of experiments, carried out in the manner described, was made with ordinary pulverized fluorite. The heating was continued in every case above the time limit of two hours. All gas bubbles had disappeared from the acid mixture, which fact, according to Fresenius* and Offerman,+ shows that the decomposition is complete. The time required to decompose fluorite is stated by Penfield to be two hours for 0°2 to 1:0 grams; by Fresenius two hours for 0°1 gram and four hours for 1:0 gram. TABLE V. Theory Found Error CaF, Silica KOH Fluorine Fluorine Fluorine erams. grams. em, erams. erams. grams. ° (ems = 0 0104aR) er Duo Wao Dior 0°2432 Oe — 0'0060 2 Ors 000 7°0 27250 0°2432 O23 fe —0:0075 3. 0°5000 0 DNAET 0°2432 On23 72 —0°0060 4, 0°5000 7°0 23°15 0'2432 O-2419 —0°0013 Sip Oa ONOKO 7°0 22°4 0°2432 0°2340 —0°0092 6. 05000 720) 2 Ne 0°2432 02277 — (00155 7. 0°5000 0 Dak 0:24:32 0°2299 —0°0133 8. 0°5000 Hay) lien 0°2432 0'2267 “—0°0165 9, 95000 7'0 Die 0°2432 0°2351 —0°0081 * Zeitschr. Anal. Chem., vi, 190. ‘1 oe, cit. Le Hileman—Alkalimetric Estimation of Silicon Fluoride. 335 The cause of the variation inthe results, and of the occa- sionally very large errors in the above series of experiments, was not apparent at the time when the experiments were made, but reference will be made to this later. Crystals of fluorite, perfectly clear and of a pale green color, were next tried. The powdered mineral on treatment with sulphuric acid yielded the theoretical amount of calcium sulphate. PARTE VEL, Fluorine Fluorine Flourine Tem- CaF, KOH Theory Found Error Time _pera- erams. em? grams. grams. grams. hours. ture. (1e™ = 0:01045 Fluorine.) 1. 0°5000 DA ale 0°2432 0°2274 —0°0158 6 ) 150° 2. 0°5000 DAs 0°2432 0°2299 —0:'01388 6 j 160° oe 05000 Bilorey 0°2432 0°2274 —0°0158 Bou 4, 0°5000 23°6 0°2432 0°2466 —0°0034 6 | Pr sOO0N 225 0.2432.) 0:-2314 070118 6 180° 6. 0°5000 2G 0°2432 0°2318 —0°0114 6 | F005 5000 OS t 0°24382 0:2014 —0°0418 6 | 8. 0°5000 16°2 0:2432 0°1692 —0°0740 3 J 9. 0°3000 22 °2, 0°2432 0°2325 —0°0107 ) boil- 10. 0°5000 Zi Nis 0°2432 022230 —0°0212 ( ing. In experiment (1) above, the heating was continued for six hours at 150-160°. In experiment (2) the powdered mineral was fused with sodium carbonate and the mixture transferred to the decomposition flask. In experiments 2-8 above, the temperature was raised as high as 180°, while the empty - U-tube was immersed in a freezing mixture of salt and ice. Blank determinations showed that some sulphuric acid was carried over under these conditions. In experiments (9) and (10) the acid was heated to boiling and allowed to cool before the air current was passed through. The effect of precipitated silica instead of quartz sand was next tried. In experiment (1) the silica was air dried; in (2) it was strongly ignited. TABLE VII. iblneroryy Aorbhare! Error Cak'. Silica KOH Fluorine Fluorine Fluorine grams. grams. em? grams. grams. erams. I: .0°5000 1e@ 6°4 O-2432 0°0668 0°1 764 Z. 0° 5000 7°0 De? Ons O22 N5 0:0217 These experiments indicate that the small amount of water in the air dried silica may cause great deficiency in the fluorine found, and suggests the idea that even the amount of water produced in the reaction involving the sulphuric acid, the fluoride and silicon dioxide may be the occasion of trouble. 336 Hileman—Alkalimetrie Estimation of Silicon Fluoride. A Specially Devised Apparatus for use at High Temperatures. Owing to the lack of success with the silicon fluoride pro- cesses In which the decomposition was effected at temperatures between 150°-160°, an attempt was made to devise a simple and convenient form of apparatus in which the acid mixture might be heated to boiling to facilitate the removal of the silicon fluoride to the absorption system. After a number of experiments with this end in view the following model of apparatus was found to be the most satis- factory: a glass stopper, made by drawing out a glass tube 1‘ in diameter and sealing a small glass tube on each end, is ground into a 70°*™ side neck flask. To one end is sealed a glass stop-cock. The other end extends to the bottom of the flask. The side neck is sealed to a Voit flask. The length of the tube between the two flasks is 17™, and it is bent at right angles, 12 from the Voit flask. The tube lead- ing from the Voit flask enters a large empty U-tube through a rubber stopper. < 59°35, 59°77 * 62-2° 59°47 63°8 50°4) ee 3. The pressures of the table are computed for dry air throughout and if charted in terms of p’, graphically, are found to lie ver y nearly on straight lines. The results of the table are very important. In the first place it will be seen not only that isothermal pressures or nearly isothermal pres- sures are not observed, but that the effect of the vacuum chamber is preponderating. Thus the pressure at the latter p,;', read off as soon as possible and nominally adiabatic, is within one millimeter of p,. Similarly the computed adia- batic pressure p, is within a few millimeters of p,” and g,. It follows, therefore, that even an approach to isothermal pres- sure, to say nothing of adiabatic pressure, cannot be observed at the fog chamber at all; or that before the exhaust cock can be closed again the vacuum chamber has practically regained its isothermal pressure by cooling and that the fog chamber is further exhausted by a corresponding amount. The pressure p,’ = p”, observed under isothermal conditions at the foe chamber, exceeds p, (computed) by about 1°9™ on the average, which “might be regarded as the average vapor pressure of water at the temperature at which the observation was made. Leaving this for further consideration, the final result of impor tance is the following: p, the computed isother- » mal pressure in the closed fog chamber is from 2 to 5°™ above the (nominally) isothermal pressure p,’ =p, observed : and correspondingly more than this above the common isothermal * Observed as soon as possible after exhaustion at the closed fog chamber. + Observed. as soon as possible after exhaustion at the vacuum chamber, stop cock-closed at once after exhaustion. { This pressure varies but slightly. He Pe C. rye us— Drop of Pressure iv Log Chamber. B41 value p, usually taken. For the region in which colloidal nuclei lie the correction will be 6 to 8™. Now this is in excess of the difference between the pressure regions in which Wilson’s data for colloidal nuclei, as reduced elsewhere,* and the region in which my own data as summarised heretofore, would lie. In other words, the data in my large coronal apparatus lie in -regions ot exhaustion at least as moderate as those observed in Wilson’s small apparatus; or the two types of apparatus comparing efficiency if the drop of pressure taken is in my case not the (apparent) experimental value, but that deduced for the computed isothermal pressure p, of the fog chamber as above explained. 4. For the case of air saturated with water vapor in both chambers, all pressures must be reduced by the corresponding vapor pressure, 7 of water, except p’,, when the vapor is slightly superheated. Apart from this, the equations take the above form, though special computation is needed, since a dif- ferent initial pressure (p—v7) enters. So compnted, the rela- tion between the observed drop of pressure p—p, and the com- puted drop p—p, was found to be (P—P.) /(P—P,) = “775 and very nearly constant with the pressure interval involved. The conclusions as to efficiency are like the above. The fact that a limit has been reached for condensations, within the given type of fog chamber, may be considered as proved, apart from comparison with Wilson’s results, since for a successively increasing drop of pressure (p—p,), no matter whether the nuclei are relatively large like the ions or rela- tively small like the colloidal nuclei, the same terminal corona is eventually reached in both instances. Higher exhaustions are thereafter powerless. Finally, since the colloidal nuclei in case of dust-free air saturated with alcohol vaport are larger than in case of water vapor (caet. par.), these nuclei must probably be associated with the saturated vapor, the gas being but secondarily in question. Brown University, Providence, R. I. * Presidential address ; Physical Review, xxii, 1606, p. 107. + This Journal, August. 342 O. Barus—New Method for Standardizing the Coronas. ‘ Art. XXXIIT—On a New Method for Standardizing the Coronas of Cloudy Condensation ; by OC. Barus. Assuming that for ions produced within the fog chamber the rate of decay in the lapse of time 7 is as the square of the number, or that 1/n—1/n' = 6(t—2') where 6 is constant, a few incidental attempts were made to compute 6, when the number, 7, of nuclei (ions) is expressed in thousands per cubic centimeter. The table gives an example of such results, obtained by exhausting the fog chamber at a stated time ¢, after the removal of radium, If the drop in pressure is below the coronal fog limit of air, precipitation takes place on ions, only. TABLE.—Decay curve. Nucleation observed and computed. b= ‘0024 relative ton x 10-°. Radium suddenly removed from top of fog chamber (glass) and exhaustion made ¢ sec. thereafter. dp = 23™ (below the coronal fog limit of dust free air). s/30 (nearly) angular diameter of coronas. (Computed for ie s (observed) 6=-0024) sec. em. nm x 10-3, m x 102: O 5°9 67 67 5 5°0 4] 37 10 4°6 32 26 15 4°0 21 20 20 3°5 15 16 30 3°3 iD. al 50 2°9 7 7 120 sey 2 3 oO 1°0 IL eo For the first five seconds 6 = ‘0019; for the first fifteen seconds 6 = (0022; etc., values obtained ranging from ‘002 to 003. This is lar. oer than the corresponding electrical datum, say ‘0014, when is given in thousands. Decay is more rapid than the equation warrants. Initial coronas are too large, final coronas too small, in spite of the presence of air nuclei, the number of which ‘should be deducted, at least in part. Other experiments show similar coefficients. Natur- ally the present method for 6 is much inferior to the electrical method, even if the two coefticients are identical; and the 6 here is obtained under possible complications with the larger gradations of the colloidal nuclei of dust free air, though these are probably inefiicient. If the values of 1/n be inserted the curves should be linear since 1/n=1/n, + b¢ where ¢ is the time dated since the occurrence of n,. The line passing through the observations at 5, 30, 50 seconds is best adapted to represent the results, and » . C. Barus—New Method for Standardizing the Coronas. 348 from it 6 = -0024 (m in thousands of nuclei per cubic centime- ter) may be roughly assumed. These computed values of n are given in the table. Shown in a chart, they are too low initially and too high finally, even if the air value is quite ignored; but the constant probably reproduces the true con- ditions better than the observation, remembering that the initial corona (¢ = 0) is not quite invariable. A very important consequence may be deduced from these results. The equations specified may be written n, = (7,/n —1)b¢. Hence if the ratio of nucleations or of ions is known (for instance by my method of geometric sequences), 7,/n is given, and the absolute value of n, may be computed if + is known. Now if 4 for the case of ions may be taken as identi- cal with the value found in electrical experiments, where 6 = ‘0014 roughly and relative to ionization in thousands, bn, = -0014n,' aaa nm, is the true nucleation. Thus in the table 4 = -0024, = 67-5; therefore n,’ = (-0024/-0014) m, or 115,000 nuclei per Bek centimeter, instead of 67,500 for the initial corona. Quite generally if ,/n and dare determined from purely coro- nal measurements | b /-0014 is the reduction factor for all the relative nucleations to abso- lute value. Another important consequence may be drawn: If the coefficient is known from direct experiments, it will then be ossible to standardize the residual curve (depressed asymptote) leading to the terminal corona, corresponding to groups of Oo nuclei of different sizes occurring together. Moreover, in any such cur ‘ve, let the ordinates denote the computed number of ions, the ‘abscissas denote the observed number of efczent nuclei, being the colloidal nuclei and ions occurring together in the course of a stated time. Then the curve gives an indication of the distribution of the precipi- tated water on the two groups of nuclei different in size. and present in different proportions, for the given supersaturation. Experiments of this kind are of the highest importance and the present cursory treatment is admitted provisionally in view of a restandardization of the coronas of cloudy condensa- tion which the variety of results since obtained has made nec- essary. Brown University, Providence, R. I. B44 Scerentific Intelligence. SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. Barium Sub-oxide and the Preparation of Metallic Barium. —According to Winkler, magnesium reduces the alkaline earth oxides, but he was unable to isolate the metals from the resulting mixtures. Guntz has now repeated Winkler’s experiment with barium oxide and magnesium in a vacuum at a high temperature with the expectation of collecting the metallic barium by distilla- tion. It was found, however, that when the calculated quantities of the substances were thus treated at about 1100°, approximately one-half of the magnesium distilled off together with traces of barium. Upon examination of the residue it appeared that a sub- oxide of barium, Ba,O, had been produced. This forms a black fritted mass, the properties of which are similar to those of metal- lic barium, since it decomposes water, gives Ba,N, with nitrogen at a red heat and at the same temperature yields BaH.,. When aluminium, a non-volatile metal, was used in place of magnesium in the experiment mentioned above, it was found that crystallized barium of 98°8 per cent purity was obtained at once at near 1200°, and by a second distillation in a vacuum it was obtained absolutely pure. This new method applies equally well to strontium and furnishes an easy means of obtaining these metals, which, up to the present time, have been so difficult to prepare.— Comptes Rendus, cxliii, 339. H. L. W. 2. The Thermal Formation of Nitric Oxide and Ozone in Moving Gases.—FRANz Fiscurr and Hans Marx have made the interesting observation that ozone, as well as hydrogen peroxide and nitric oxide, may be obtained by burning hydrogen in air or oxygen by the use of a rapid current of the oxidizing gas, as a jet blown through the hydrogen flame. It has been previously known that suddenly cooling the hydrogen flame in other ways gives nitric oxide and hydrogen peroxide, but the formation of ozone from this source is new. They have found also the previ- ously unknown fact that a rapid current of air blown over the glowing Nernst pencil gives ozone in addition to nitric oxide, and it appears that the proportion of ozone increases, in its relation to the nitric oxide, as the rapidity of the current of air increases. Quantitative results have not yet been obtained, but it seems possi- ble to produce in this way enough ozone so that the nitrogen per- oxide produced at the same time, when led into water or sulphuric acid, will yield no nitrous acid, but nitric acid exclusively.— Bericnte, xlix, 25572 ie H. L. W. 3. The Action upon Carbon of Oxygen, Carbon Dioxide and Steam.—It has been found by P. Farup that, under the same con- ditions of experiment, water vapor and carbon dicxide act upon solid carbon at 850° C. with the same speed, while oxygen acts at this speed at about 450°. According to the temperature-coeffiicient Chemistry and Physics. 345 of the oxygen reaction between 450 and 500°, it is calculated that the speed of this reaction at 850° is 310° times as great as that of the carbon dioxide and water vapor reactions. From results obtained by Nernst and v. Wartenberg in regard to the dissocia- tion of water vapor and carbon dioxide, it appears that oxygen at atmospheric pressure and 850° has a concentration about 0°7 x 10° times as great as in water vapor and carbon dioxide at the same pressure and temperature; hence it appears that there is a con- nection between their dissociation and rate of action upon carbon. —Zeitschr. anorgan. Chem., |, 276. H. L. W. 4. The Combustion of Halogen Compounds.—In determining carbon and hydrogen in substances containing halogens, CHARLES J. Roginson uses a cylinder of copper gauze filled with lead chromate in the combustion-tube. The cylinder is 6 or 7 cm. long and its copper parts are oxidized before use. The lead chromate is thus kept from contact with the glass. Some analyses are given showing satisfactory results by the use of this device with chlorine and bromine compounds, but no results are given for compounds containing iodine. Strange to say, the author recommends the use of the same device for nitrogen combustions, and gives a satis- factory result here also. It would be expected that oxygen would escape from the hot lead chromate and contaminate the nitrogen produced. H. L. W. 5. Introduction to General Inorganic Chemistry, by ALEx- ANDER SMITH. 8vo, pp. 780. New York, 1906 (The Century Co.).—This text-book contains many excellent features and it isa very interesting work for a teacher of chemistry to read. The author has wisely made the elucidation of theory the main feature of the book, but an ample amount of facts is included for the purpose in view. The clear and able treatment of the theories by basing them upon facts is noteworthy. The book is intended for the use of beginners in college courses. It is a more thorough and difficult book than those generally used, but this feature may be considered a favorable one. It may be added that the subject is treated from the most modern point of view, but without giv- ing undue prominence to the newer theories. H. L. W. 6. A First Course in Physics ; by Ropert ANDREWS MILLI- KAN and Henry GoRDON GaLE. Pp. v, 488, with 494 figures, New York, 1906 (Ginn & Co.).—This appears to be an excel- lent text-book for high schools. The aim of the authors as stated in their preface has been to give “a simple and immediate presenta- tion, in language which the student already understands, of the hows and whys of the physical world in which he lives.” This idea has been consistently carried out; the explanations are lucid and free from technicalities; at the same time they are not gen- ‘erally open to the criticism which applies to many “simple” explanations, viz: that they are not true. In some cases the traditional order of subjects has been abandoned and the changes appear to be advantageous from the pedagogical point of: view. Am. Jour. Sct.—Fourts Serizs, Vou. XXII, No. 1380.—OctToBeEr, 1906. ~ 346 — Seventifie Intellagence. The illustrations are well-chosen and attractive, and the dia- grams clear. H. AL By 7. A Laboratory Course in Physics for Secondury Schools ; by R. A. Mitiixan and H. G. Gatz. Pp. x+134. New York 1906 (Ginn & Co.).—This is a collection of fifty-one experiments designed to accompany the text-book noticed above. ‘The experi- ments are well chosen and clearly described ; the necessary appa- ratus is simple in character and well designed for its purpose. Hs AS tee 8. Outlines of the Kvolution of Weights and Measures and the Metric System; by Witu1am Hatitock and Hrrserr T, Wave. Pp. xi+304. New York, 1906 (The Macmillan Co.).— The first chapter of this work gives an interesting outline of the historical development of metrology, so far as it is known, from the earliest times. The succeeding eight chapters have to do mainly with the metric system: its origin, development and extension throughout Europe; its advantages for commerce, manufacturing, engineering, medicine and pharmacy; and the international electrical units which have been derived from the fundamental metric units. A final chapter deals with standards and methods of compari- son and an appendix contains tables of equivalents and useful constants, HALE. Il. Gronoey. 1. United States Geological Survey, CuarLes D. Watcort, Director. — Titles of publications recently received are con- tained in the following list: Foutos.—No. 138. Redding Folio, California. Description of the Redding quadrangle by J. S. Ditter. Pp. 14, with maps of topography and areal geology, structure and columnar sec- tions, No. 139. Snoqualmie Folio, Washington. Description of the Snoqualmie quadrangle by Grorce Oris SmirH and FRANK Catucarr Carxins. Pp. 14, with maps of topography, areal geology, structure and columnar sections. ProreEsstonaL Papers.—No. 50. The Montana Lobe of the Keewatin Ice Sheet; by Frep. H. H. Catnoun. Pp. 62, with 7 plates and 31 figures. Butietins.—No. 275. Slate Deposits and Slate Industry of the United States; by T. Nerson Dats, with sections by EH. C. Ecker, W. F. Hittesranp, and A. T. Coons. Pp. 154, with 25 plates and 15 figures. No. 277. Mineral Resources of Kenai Peninsula, Alaska. Gold Fields of the Turnagain Arm Region; by Frep. H. Morrir. Coal Fields of the Kachemak Bay Region ; by Raupu W. STONE. Pp. 80, with 18 plates and 5 figures. No. 278. Geology and Coal Resources of the Cape Lisburne Region, Alaska; by Arruur J. Cottier. Pp. 54, with 9 plates and 8 figures. Geology. | | BAT No. 284. Report on Progress of Investigations of Mineral Resources of Alaska in 1905; by ALtFrep H. Brooks and others. Pp. 169, with 14 plates and 10 figures. No. 285. Contributions to Economic Geology, 1905; 8S. F. Emmons, E. C. Ecker, Geologists in charge. Pp. 506, with 13 plates and 16 figures. No. 290. Preliminary Report on the Operations of the Fuel- testing Plant of the United States Geological Survey at St. Louis, Mo., 1905 ; JosepuH A. Hotmzs in charge. Pp. 240. No. 291. A Gazetteer of Colorado; by Henry Gannetr. Pp. 185. Water Suprpry anp Irrigation Paprers.—No. 155. Fluc- tuations of the Water Level in Wells, with Special Reference to Long Island, New York; by A. C. Veatcu. Pp. 83, with 9 plates and 17 figures. No. 156. Water Powers of Northern Wisconsin ; by LeonarRp S. Suirw. Pp. 145, with 5 plates and 5 figures. No. 158. Preliminary Report on the Geology and. Under- ground Waters of the Roswell Artesian Area, New Mexico ; by Cassius A. Fisuer. Pp. 29, with 9 plates. No. 160. Underground-Water Papers; Myron L. Fu tier, Geologist in charge. Pp. 104, with a map and 4 figures. No. 162. Destructive Floods in the United States in 1905; by E. C. Murruy and others. Pp. 105, with 4 plates and 11 figures. No. 163. Buibhographic Review and Index of Underground- Water Literature published in the United States in 1905; by Myron L. Fuuier, Freprrick G. Crapp, and Brertrranp L. JoHNson. Pp. 130. Nos. 170, 172, 173, 174, 176, 178. Report of Progress of Stream Measurements for the Calendar year 1905. Prepared under the direction of F. H. Newett. Parts VI, VIII, 1X, X, XII, XIV. Part. VI.—Great Lakes and St. Lawrence River Drainages ; by hk. E. Horron, F. W. Hanna, and J.C. Horr. Pp. 116, II, with one plate and two figures. Part VIIJ.—Missouri River Drainage; by C. C. Bass, M. C. HinpERLiDER and J: C. Hoyt. Pp. 283, with one plate and 2 figures. Part [X.—Meramec, Arkansas and Lower Western Mississippi River Drainages ; by M. C. Hixperiiper, J. M. Grirxs and J.C. Hoyt. Pp 103, with one plate and 2 figures. Part X.—Western Gulf of Mexico and Rio Grande Drainages ; by T. W. Taytor and J. C. Hoyt. Pp. 133, with one plate and 2 figures. Part XIL—The Great Basin Drainage ; by M. C. HINDER uIDER, G. L. SweNpDsSEN, and Henry THurTELL. Pp. 142, 11, with one plate and 2 figures. Part XIV.—Columbia River and Puget Sound Drainages; by D. W. Ross, J. T. Wuistirer, and T. A. Nosie. Pp. 250, II, with one plate and 2 figures. List of the Publications of the United States Geological Sur- vey. (Except Topographic Maps.) Pp. 58. 2. Geologic Map of the Buffalo Quadrangle; by D. D. Lutuer. bull. 99, N. Y. State Mus., 1906, 29 pp. and map.—A general description is here given of the seventeen formations 348 | Seventific Intelligence. outcropping in this quadrangle from the uppermost beds of the Silurian to the top of the Devonian, Diagnostic fossils for each formation are also listed. The map gives the areal distribution of the formations described. CG. 8. 3. Second Report of the Director of the Science Division, 1905. N.Y. State Mus., 1906, 99 pp.—This is the 59th report of the New York State Museum and the 2nd report of the Direc- tor of the Science Division, John M. Clarke. It deals with the work done and in preparation throughout the various divisions of the State Museum during the year 1905. Of particular interest to stratigraphers is the announcement,—‘“‘It is quite probable however that the Oswego sandstone [heretofore always accepted as Silurian] represents a near-shore condition, which was unfavorable for life, but farther west the Richmond fauna flourished under more suitable conditions.” In other words, it is probable that the Oswego and Medina formations are the clos- ing formations of the Ordovician. This is the view maintained by Ulrich of the U. 8S. Geological Survey, during the past three years, based on the Medina stratigraphy of the southern Appa- lachian. Another striking correlation is that the Shawangunk conglom- erate is not of Medina (Oneida) age, but “ represents the invading basal member of the Salina formation in the eastern part of the State.” C. 8. 4. Lhe Upper Ordovician Rocks of Kentucky and their Bryozoa; by Joun M. Nicxurs. Bull. 5, Kentucky Geol. Sur- vey, 1205 (not received until July, 1906), 64 pp. and 3 pls.— This report describes the rocks of the Cincinnatian series and lists the Bryozoa of the various formations as found in Ken- tucky along the Cincinnati arch. ‘Twenty-eight species are described, of which five are new. The illustrations show the - macroscopic characters of the species. C. 8. 5. The Chazy Formation and its Hauna; by P. EH. Ray- MoND. Ann. Carnegie Mus., ii, July, 1906, pp. 498-598.—This is the first article of a series of papers in which the author pro- poses to describe the stratigraphy and faunas of the Chazy as found in northeastern North America. The part now at hand deals with the stratigraphy of the various areas and lists of the fossils occurring in the various beds. The author’s main conclu- | sions are as follows:— “This fauna shows a decidedly closer affinity with the fauna of the Black River and Trenton formations of New York and Canada than with the Beekmantown of the same regions. The strong Mohawkian facies of the Chazy fauna suggests that the Chazy formation should be taken out of the Canadian, the Beek- mantown and Chazy having very little in common,” ‘There is but one species common to the two formations. ‘ While the Black River and Trenton formations have only a few species in common with the Chazy, yet when the fossils are compared with one another it is found that almost every one in the Chazy is Geology. 349 represented in the Trenton by a very closely allied species ” (p. 562). Thirteen new species are described. C. S. 6. A New American Cybele; by J. E. Narraway and P. HE. Raymonp. Ann. Carnegie Mus., ii, July, 1906, pp. 599-604,— In America, this genus of trilobites is always rare and entire examples are almost unknown. The writers describe a nearly complete specimen preserving all the essential characters. It is named Cybele ella, and occurs in the Black River limestone of the Ordovician, near Ottawa, Canada. O'S: 7. Uber Phylogenie der Arthropoden; by A. Hanprtrscu. Verh. k. k. zool.-bot. Gesellsch. Wien, 1906, pp. 88-103.—For several years, Handlirsch has had in preparation an octavo work entitled ‘‘ Die Fossilen Insekten und die Phylogenie der Rezenten Formen,’* now being printed by Wilhelm Engelmann in Leip- zig. From this work has resulted the paper under review. The writer holds that the Arthropoda are monophyletic ; that Peripatus stands much closer to the worms than to the true Arthropoda, and can not be regarded as the link uniting branehi- ate and tracheate Arthropoda. The stem group for ail Arthro- poda, he holds, must be sought among the trilobites. From these the Crustacea were first differentiated. ‘The Arachnida are united with the trilobites through the limuloids, and with these the eurypteroids are closely related. The myriopods are . Seemingly difficult to derive from trilobites, but in the Carbon- iferous are many myriopod-like forms, the majority of which had a relatively broad and large head, with well-developed, large compound eyes like those of trilobites. Many of these forms were broad and had short segments in moderate numbers; some even had distinctly marked pleural parts quite similar to those in trilobites. “From all these facts it seems clear that the primitive forms of myriopods were also relatively broad animals with homono- mous segments, compound eyes, and cloven feet, living at least part of the time in water, and gradually adapted their breathing organs to a land existence. If we assume that the trilobites possessed nephridia on all segments, it is easily explained how in the very beginning two diverging myriopod-like stems origi- nated, one of which had adapted the segmental organs situated far to the front, the other those far to the rear, to the service of sexual parts. In this event, the Progoneates and the Opistho- goneates are to be regarded as independent phyla” (p. 97). This paper is of great interest to all students of the Arthro- poda. ens: 8. Die Entwickelung von Indoceras baluchistanenense Noet- ling. Ein Beitrag zur Ontogenie der Ammoniten ; von F. Noeriine. Geol. u. Pal. Abh., Jena, viii, n. ser., 1906, pp. 1-96, *Die Fossilen Insekten und die Phylogenie der Rezenten Formen. Ein Handbuch fiir Paliontologen und Zoologen; von Anton Handlirsch. I. Lieferung (mit 9 Tafeln). Pp. 160, Leipzig, 1906 (Wilhelm Engelmann). 350 Scientific Intelligence. = 7 plates.—This elaborate work describes in great detail the development of the highest Cretaceous ammonite mentioned in the title, and having a ceratite suture line. The development is as follows: (1) Protoconch stage ; (2) Embryonic or Sphero- ceras stage ; (3) Metaconch or Oxynoticeras stage (has always five volutions wrespective of size of shell); (4) Paraconch or Indoceras stage. The author concludes that on the basis of the developmental characters of the suture line alone it is at present not safe to decide as to the age of the strata in which the form occurs, for the reason that as yet we know the complete development of but few ammonites, and further that a primitive form may occur in young beds and a highly specialized species in old deposits: In regard to the ancestry of Zdoceras, the author concludes that “it had a different descent than Sphenodiscus or Placenti- ‘ceras and that it can hardly be arranged with these in the family Pulchelliide, or with the Upper Cretaceous Oxynotus forms: Garnieria, Lenticeras and others are to be united in a family of indoceratids ” (p. 92). 9. Untersuchungen uber die Familie Lyttoniidae Waag. emend. Noetling; von F. Nortiine. Palzeontographiea, li, 1906, pp. 129-153, pls. xv-xvilli—Some years ago, the author, while in India, collected in the Upper Permian of Chideru in the Salt Range an abundance of the genera Oldhamina and Lyttonia. As some of his specimens are preserved as silicious pseudo- morphs, he was able through careful etching with hydrochloric acid to free them from the limestone and thus to reveal the entire structure of these remarkable and highly degenerate brach- 1opods. So strikingly aberrant are these forms that at first they were described as gasteropods (Bellerophon) and later as the teeth of fishes (Leptodus). The latter generic name Waagen displaced by his Oldhamina when he discovered these remains to be brachiopods. ‘This proceeding is irregular, and it is to be regretted that Noetling does not return to Leptodus, especially after he remarks that according to the law of priority Waagen had no right to make this change (p. 133). On the other hand, Oldhamina can not be confused with Oldhamia even though the names sound ‘nearly alike; and it is therefore further to be regretted that Noetling in a half-hearted way tries to dispossess the former by suggesting Oldhamella. The author prints the name in a foot-note (p. 129), and though it is only suggested, not seriously proposed, it can not be overlooked. ‘Thus another synonym is added to the terminology of these shells. Some years ago he considered these fossils to be Bryozoa, and at that time proposed the name Waagenopora. Thus is literature bur- dened by giving way to printing all the unassimilated thoughts passing through an author’s mind. These shells are cemented to foreign bodies by the umbo of the ventral valve, and the scar of attachment is plainly pre- served in young and apparently in adult specimens also (see pl. Geology. B51 xv, figs. 2a, 3). Because of the abnormal and very irregular lamellar thickenings of the posterior region of the shell margin (no two shells are alike in this character) covering over the scar of attachment, Noetling thinks these animals finally lost fixation and lay with the dorsal shell on the sea bottom. He arrives at this conclusion because the majority of the speci- mens by far are ventral shells; some show the inner side of the dorsal valve and but a few preserve both valves in place. One might suppose that if the animal finally came to live as suggested by the author, all the specimens would preserve both valves, ° because after death, as the animal matter decayed, its place would be occupied by the “very soft calcareous mud” in which it lay. The reviewer thinks that during the weathering process the very thin dorsal shell is either dissolved away, or because of its deeply cleft nature and exterior papillose condition it adheres firmly to the outer rock, only to be dissolved away by weather- ing from this side. The fact that the mantle is constantly depositing shell on the outer posterior cardinal area is evidence that in some way it embraced foreign objects by which it held the shell in place. In old age such deposition may cease, but as these animals apparently lived in large communities they are nevertheless firmly held in place by their neighbors. On the other hand, if lying with the dorsal valve down in the soft mud, as suggested by the writer, it would seem that death must soon ensue through suffocation, because of the mud squeezing in through all of the many lateral clefts of the dorsal valve, but especially in preventing free water circulation with a fresh supply of food and oxygen. Of the many cemented brachiopods, it is very rare to find one preserving the object of attachment, and on this account it should not be expected to occur here more than elsewhere. The reviewer believes that these animals lived with the deeply cleft dorsal valve uppermost, or that the posterior region of both valves lay somewhat embedded in the mud, with the greater portion of the anterior region protruding above the sea floor. The author correctly removes these shells from the Thecidiidz and regards them as more closely related to the Productide. He adds, “it may be that this aberrant group can even be included in this family so rich in forms” (p. 147). It seems now more proba- ble that the Leptodidz (new name) arose in some cemented form of the Productidz, in which case it would be best looked for among Strophalosia. ©. 8t Ill. MisceELLANEOUS SCIENTIFIC INTELLIGENCE. 1. Les Prix Nobel en 1903. Stockholm, 1906 (P. A. Norstedt & Soner).—The recipients of the Nobel prizes in 1903 were as follows: Henri Antoine Becquerel for his discovery of spon- taneous radio-activity ; Pierre and Marie Sklodovska Curie for their researches in the phenomena of radiation discovered by H. Becquerel; Svante August Arrhenius for the theory of electro- 352 Scientific Intelligence. lytic dissociation; Niels Ryberg Finsen for the treatment of diseases by light rays; Bjérnstjerne Bjérnsen for his poetical works. This interesting volume contains, in addition to an account of the ceremonies accompanying the prize distribution, bio- graphical notices of the recipients with portraits and also repro- ductions of the Nobel medals and diplomas. The addresses at the Conferences Nobel by H. Becquerel, P. Curie, 8. Arrhenius and W. Randal Cremer close the volume. 2. British Association.—The annual meeting of the British ' Association for the Advancement of Science was held at York from August 1 to 8; at which place the Association met both for the first time in 1831 and again in 1881. Prof. EK. Ray Lankester in his presidential address reviewed the scientific advance of the past quarter century. The next meeting, for 1907, will be held in Leicester, that for 1908 in Dublin, and for 1909 at Winnipeg. 3. Carnegie Institution of Washington.—The following are titles of publications recently received : No. 34. American Fossil Cycads; by G. R. Wiztanp. 4to. Pp. vii+ 296, 51 plates, 141 figures. A notice will follow. No. 46. AnInvestigation into the Elastic Constants of Rocks, especially with reference to their Cubic Compressibility; by F. D. Apvams and E.G. CokEr. 8vo. Pp. 69, 16 plates. An abstract was published in the August number, pp. 95-128. No. 50. The Relation of Desert Plants to Soil Moisture and to Evaporation; by Burron E. Livinesron. Pp. 78, 16 cuts. No. 52. Inheritance in Poultry (Paper No. 7, Station for Experimental Evolution) ; by C. B. Davenport. Pp. 136, 17 pl. No. 53. Egyptological Researches; W. Max MU LuEr. 4to. In press. OBITUARY. . Wittiam Buck Dwient, Professor of Geology at Vassar College for nearly thirty years, died at Cottage City, Mass., on August 29, at the age of seventy-three years. He was born in Constantinople, the son of an American missionary, and came to this country in 1849. He was graduated at Yale College in 1854, at the Union Theological Seminary in 1857 and received the degree of B.S. from the Sheffield Scientific School in 1859. He carried on extensive field work in geology, chiefly in Dutchess County, N. Y., between 1879 and 1890; a number of papers giv- ing his results are contained in this Journal. He invented a rock-slicing machine in 189! and had charge of the department of geology in the Standard Dictionary. He was one of the orig- inal fellows of the Geological Society of America. Dr. Paut Drunks, Professor of Physics and Director of the . Physical Laboratory at Berlin, died on July 5, at the age of forty-three years. He was the author of important theoretical and experimental researches on the electro-magnetic theory of light and since 1890 had been editor of the Annalen der Physik, during that period often known as Drude’s Annalen. Sir Watrer Lawry Buier, well known for his work on the ornithology of New Zealand, died on July 19, at the age of sixty- eight years. ae MODELS OF TYPICAL ANIMALS Vertebrate and Invertebrate Our models illustrating the anatomy of the sh, frog, Crayfish, Mussel, etc. are everywhere acknowledged to be invaluable to the teacher of Biology. Write for descriptive circular Wo. 5. BIOLOGICAL LABORATORY SUPPLIES: [906 list just out. Sent free on requesé. ‘Everything in Natural History.’’ ADDRESS WARD’S NATURAL SCIENCE ESTABLISHMENT, (INVERTEBRATE DEPT.) 76-104 College Ave., Rochester, N. Y. Warn’s Natura 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, etc. 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. CONTENTS. zs Page Art. XXVI.—Lime-Silica Series of Minerals; by A. L. Day and E. 8S. SHePpHERD, with Optical Study by F. EK. - W-RIGHD 2 3) sto oear <0 Dees ese Se eee 265 XXVII.—Analysis of “Iron Shale” from Coon Mountain, Arizona :by O, C. HARRINGTON <2)" 6° 222 ee .- 303 XX VIII.—Phenomena Observed in Crookes’ Tubes; by N. TP. BACON 2220. 23255 ee ee XXIX.—Northward Extension of the Atlantic Preglacial Deposits; ‘by E BowMAN 292250 ee 313 XXX.—A Delicate Color Reaction for Copper, and a Micro- chemical Test for Zinc; ‘by H.C. Brapuny .---2 2 326 XX XJ.—Elimination and Alkalimetric Estimation of Silicon Fluoride in the Analysis of Fluorides; by A. Hiteman 329 XXXII.—Note on the Actual Drop of Pressure in the Fog Chamber; "by °C. BaRUS 22 Ae a ee 339 XX XIIL—New Method for Standardizing the Coronas of Cloudy Condensation ; by uC: Banus. ©2223 ae 342 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Barium Sub-oxide and the Preparation of Metallic Barium, Guntz: Thermal Formation of Nitric Oxide and Ozone in Moving Gases, F. FiscHeR and H. Marx: Action upon Carbon of Oxygen, Carbon -Dioxide and Steam, P. Farup, 344.—Combustion of Halogen Compounds, C. J. Ropinson : Introduction to General Inorganic Chemistry, A. SMITH: A: First Course in Physics, R. A. Miniikawn and H. G. Gan, 345.—Labora- tory Course in Physics for Secondary Schools, R. A. Minuikaw and H. G. GALE: Outlines of the Evolution of Weights and Measures and the Metric System, W. Hatiock and H. T. Wans, 346. Geology—United States Geological Survey, 346.—Geologic Map of the Buf- falo Quadrangle, D. D. LutHEr, 347.—Second Report of the Director of the Science Division, 1905: Upper Ordovician Rocks of Kentucky and their Bryozoa, J.-M. NickLtes: Chazy Formation and its Fauna, P. E. Raymonp, 348.—New American Cybele, J. HE. Narnraway and P, HE. Raymonp: Ueber Phylogenie der Arthropoden, A. HANDLIRSCH: Die Mnt- wickelung von Indoceras baluchistanenense Noetling. Ein Beitrag zur Ontogenie der Ammoniten, F. Norrnine, 549.—Untersuchungen tiber die Familie Lyttoniidae Waag. emend. Noetling, F. NortLine, 350. Miscellaneous Scientific Intelligence—Les Prix Nobel en 1908, 351.—British Association: Carnegie Institution of Washington, 392. Obituary—W. B. Dwicut: P. DrRupE: Sir W. L. BULLER, 3882. 34 NOVEMBER, 1906. Established by BENJAMIN SILLIMAN in 1818. AMERICAN JOURNAL OF SCIENCE. Eprrorn: EDWARD S. DANA. ASSOCIATE EDITORS eins GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camprince, eer ssons ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressorn GEORGE F. BARKER, or PHILADELPHIA, Proressor HENRY S. WILLIAMS, or ItwHaca, Prorressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or Wasurincrton. FOURTH SERIES VOL. XXIJI—- WHOLE NUMBER, CLXXIII.] No. 131—NOVEMBER, 1906. NEW HAVEN, CONNECTICUT. cansonian natty oe a NOV, i 1906 0. THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS LN 23 a STREE Qs ‘tional Me Musel Published jaeuthiy. Six dollars per year, in advance. $6.40 to eotnb ries in the Postal Union. Remittances should be made either by money orders, registered letters, or bank checks (presexably on New York banks). CRYSTALS, FINE MINERAL SPECIMENS, METEORITES. Orders amounting to $5.00 or over sent carriage paid on approval with the privilege of selection. Rejected material returned at our expense. Send for our illustrated descriptive Catalog of ‘‘ Choice Min- erals” just published. SYSTEMATIC: COLLECTIONS Of Typical Mineral Specimens, Rocks and Rock-forming Minerals, In sets of twenty-five up to fifteen hundred specimens. Prices $5.00 upwards per set, the average price for students’ specimens (average size 23” x 2”) ‘being about twenty cents. For 30 years we have been supplying reference specimens to the mining schools, universities and museums throughout the world. We refer to any curator or professor of mineralogy or geology. 7 Our Double System of Labeling has met with the High- est Approval. The neat miniature label we attach to each speci- men, in addition to a loose label accompanying museum specimens, gives correctly—name, chemical composition and locality, prevent- ing the possibility of labels becoming lost or misplaced. _ Quality 1 1S guaranteed 1 in our prepayment of transportation to any address in the world. We could not take double transporta- tion risk if the quality did not insure your keeping them, as we refund money on minerals promptly returned. Prices are the lowest, as comparison will show. The volume of our trade permits it. Free Collection Catalog, containing lists and illustrations of General Mineral and Rock Collections, Series of Ores for Pros- pectors, Sets of Crystals, Series illustrating Hardness and other Physical Characters of Minerals, with Price List of Laboratory Material and Individual Specimens. FOOTE -MINHRAE, Cee Established 1876, by Dr. A. E. Foote. W. M. Foote, Manager. DEALERS IN Mineral Specimens and Commercial Rare Minerals. Removed to 107 N. 19th St.3 Phatladelphia Wa, Wee. a. had AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES] SAMUEL LEWIS PENFIELD. Iy the recent death of Samuel Lewis Penfield, the mineralo- gist, science in America has lost one of its best representatives, his chosen field of work its ablest exponent and investigator and the community in which he lived a man of the highest type of character. His loss is a heavy blow to his profession, to his University and to his friends. Men of his attainments come but rarely, and when they pass, the place they have made can never be exactly filled. Attacked some three years since by a very serious malady which occasioned great anxiety, his unwearying and _ patient fidelity to the regimen prescribed for him and the devotion and care of his family enabled him to resist the disease, and it was hoped that his ite might be prolonged for years to come. His trouble took, however, a sudden and unfavorable turn, and after a very brief illness he passed peacefully away on Aug. 12th, at the little village of South Woodstock, among the hills of eastern Connecticut, where he was spending the summer. Pentield was born Jan. 16th, 1856, in the town of Catskill on the Hudson River, where his father, George H. Penfield, who was engaged for many years in a mercantile and shipping business, was a prominent, useful and highly esteemed citizen. His mother, whose maiden name was Ann A. Cheeseman, was of Connecticut stock; she was a notable woman in her com- munity and family, and from both his parents Penfield had a Am. Jour. Sct.—FourtTH Series, VOL. XXII, No. 1381.—Novempesr, 1906. 25 354 Samuel Lewis Penfield. fine inheritance and thorough training in high principles and ideals. He was one of several children ; his father’s roof shel- tered other members of the family, all united by strong ties of affection, and he thus grew up in an atmosphere which made him feel keenly all his life the ties of kindred and gave him a humanitarianism which strongly marked him. His early education was received in his home and in the school at Catskill. Ideals of learning and culture were tradi- tional in his family; some of his ancestors had been college- bred men, and it was early determined he should have a college education. To fit himself to enter Yale he attended the academy at Wilbraham, Mass., and in-the autumn of 1874 he became a member of the freshman class of the Sheffield Scien- tific School. Like many other graduates of that institution, who have become well-known in natural science, he took the course laid out in chemistry. Languages he learned with difii- eulty though he retained them well, but in mathematics and natural science, and especially analytical chemistry, he excelled. He was graduated with honors in 1877, receiving the cus- tomary degree of Bachelor of Philosophy. While devoted to his studies, the social side of university life had not been neg- lected and he was loved and respected in his class, and made many enduring friendships. After his graduation he became one of the assistants in the laboratory of analytical chemistry, a position held for two years and which, outside of the benefits of the training which its duties conferred, gave him excellent opportunities for con- tinuing his chemical education. At this time Professors Brush and Edward Dana were engaged in their researches on the remarkable mineral locality at Branchville, Conn., which has become classic in the history of mineralogical science for the great number of new mineral species, chiefly phosphates, which it afforded. The task of ascertaining the chemical composition of these minerals was confided to Penfield and his classmate and fellow assistant, now Professor H. L. Wells. The importance of the work, its great scientific interest, the new problems in ana- lytical chemistry involved, all combined to excite the enthu- siasm of the young investigators and to stimulate their powers Samuel Lewis Penfield. 355 to the highest degree, while giving them a training of the greatest value. Penfield, who took to analytical chemistry with the keenest eagerness, no doubt in great part had his future career determined by his work during these two years and the one following, when he was transferred from the chem- ical to the mineralogical laboratory as assistant. During this period he analyzed the new minerals eosphorite, triploidite, dickinsonite, fairfieldite and fillowite, and made analyses also of triphylite, childrenite, amblygonite, cymato- lite, spodumene, ete. Up to this time his work, though deal- ing largely with minerals, had been entirely of a chemical nature and it is certain that he expected to make chemistry the subject of his life work, for in the years 1880-1881 he went to Germany to obtain advanced instruction in the organic side of this science. He spent two semesters in the laboratory of Prof. Rudolph Fittig at Strassburg and a part of the work resulted in the publication with him of a joint paper on organic compounds prepared and studied. He heard some lectures under Prof. P. Groth, at that time located at Strassburg, but there can be no doubt that, had he known the work he was to do in the future, his studies would have been almost wholly under the direction of this eminent teacher and crystallog- rapher. He never regretted, however, the time he had thus spent, for it added greatly to his general knowledge of chem- istry and to his training in the solution of chemical problems. It was at the close of this stay m Germany that the oppor- tunity opened which finally determined Penfield’s career in science. The constant growth of the Sheffield Scientitic School had laid such an increasing burden of executive duties upon its director, Professor Brush, that he was no longer able to give more instruction in mineralogy in the institution than was involved in the course of lectures on the descriptive side of the subject and suggestions and advice in advanced work. The practical work in the subject in the laboratory, the deter- minative mineralogy, was given by his assistant, who, at that time, was the late Dr. G. W. Hawes. The authorities of the National Museum offered the latter an opportunity to develop .a department of Geology, which he accepted, and Penfield was called to fill his place. He entered on his duties with 356 Samuel Lewis Penfield. the beginning of the fall term in 1881, having the title of Instructor in Mineralogy, and from that time until his death he was actively engaged in teaching and in extended researches in this subject. Feeling the need of more advanced training in certain ways, especially in methods of optical and micro- scopical research, in 1884 he again went to Germany and spent the summer semester at Heidelberg under Professor Rosenbusch and with great benefit to his future work. In 1886 he assumed entire charge of the instruction in mineral- ogy, he was appointed an assistant professor in 1888 and in 1893 was promoted to a full professorship and became a member of the Governing Board of the Sheftield Scientitie School. That which Penfield accomplished during his life divides naturally into two parts, the results of his investigations and his work as a teacher of mineralogy. In regard to the first the bibliography appended to this notice speaks far more elo- quently to those acquainted with the history of mineralogical science during the last quarter of a century than could the efforts of any pen. Yet out of this great volume of important - results of work which issued from his laboratory during the twenty-five active years of his life—results which have been equalled in scope and value by but few men during a much longer working period—certain salient facts may well be men- tioned to indicate his achievements. He published over 80 papers relating to Mineralogy and Crystallography, either under his own name or in collaboration with others, besides the large number which came from the assistants and students in his laboratory and which were directly due to his inspira- tion and oversight. Moreover this does not include a great number of notes, representing crystallographic and chemical work, scattered through the literature as published in the papers of other workers, for Penfield was ever most generous of his time and skiil in helping others and he had long come to be regarded in America as an ever present aid and final source of appeal in problems relating to mineralogy by workers in the geological sciences. The mere statement of the volume of his-‘work would, how- . ever, mean little unless it were taken in connection with its Samuel Lewis Penfield. 357 quality. Both in the importance of the problems treated and in the ability and technical skill with which they are handled his work is of the very highest scientific character, and the greater part of it, together with his methods and ideas, has already become classic in the history of his science. In regard to this the following facts are of interest and may be men- tioned. Fourteen new mineral species were established and described by him,—sometimes in combination with others. These are: Biabyite, Canfieldite, Clinohedrite, Gerhardtite, Glaucochroite, Graftonite, Hamlinite, Lluancockite, Leuco- phoenicite, Nasonite, Nesquehonite, Pearceite, Loeblingite, Spangolite. What in reality was of even greater importance was the large number of already described minerals, many of them well known and prominent species, which he studied and whose true chemical composition and mineralogical affinities he estab- lished. These include Alurgite, Ambiygonite, Argyrodite, Aurichalcite, Childrenite, Chondrodite, Clinohumite, Con- nellite, Oookeite, Ganomalite, Hanksite, Herderite, Howlite, _ Humite, Monazite, Ralstonite, Stawrolite, Sulphohatite, Topaz, Tourmaline and Turquois. Among the more important facts which he brought out as the result of his chemical work was the discovery of ger- manium in silver ores from Bolivia and the determination of the correct formula and crystallization of argyrodite, the Frei- berg mineral in which germanium was originally discovered. Another contribution of the highest value was his recognition that fluorine and hydroxyl are isomorphous in chemical strue- tures, and that they play a significant function in the com- position of many minerals whose correct formulas may be derived by the application of this principle. He showed also that the variations in the physical properties of certain promi- nent minerals were dependent upon the variations in the rela- tive amounts of these radicals. This was shown very strik- ingly to be the case with topaz, and applying these ideas to the chondrodite group of minerals, whose relations until then had proved an unsolved problem, he derived their correct com- positions and showed that they formed a definite series with related physical properties. He was, moreover, able to indi- 358 | Samuel Lewis Penfield. — cate the probable existence of another member of the series and to predict its composition and properties, a forecast whose correctness has since been established by Sjogren in the dis- covery of prolectite. The idea of the isomorphism between hydroxyl and fluorine was suggested in the first Branchville paper by Brush and Dana from Penfield’s analysis of triploidite. At first it was not accepted by prominent chemists and mineralogists, but Penfield by steady work in his laboratory again and again demonstrated its validity and importance, until now it has gained general acceptance and it has become recognized that the existence of these isomorphous radicals not only explains the structure of many minerals, but that their presence is of the greatest importance in understanding the mode of forma- tion, especially in magmatic processes. | Another contribution of the first order, in the field of chemical crystallography, was his announcement of the mass action of complicated inorganic acids in determining crystal form. Thus while the bases in combination with such acids may be of the most diverse kinds, the system of erystalliza- tion is not affected. This was brought out in his important paper with Foote on the chemical composition of tourmaline, but has since been shown to be of wide application. As an analytical chemist Penfield must be ranked as one of the great masters of this art. He had a broad and compre- hensive grasp of its principles, was very fertile in their appli- cation, suggestive in combinations and in details and joined to this a technical skill and dexterity in manipulation that.was really marvelous. In consequence of this the ease and speed with which he turned out complicated analyses of remarkable accuracy have always been a source of admiration among his friends and fellow-workers. His analysis of the rare mineral connellite and derivation of its formula was performed upon less than a tenth of a gram of material. Many similar feats of his skill might be cited. He rarely took up any new analytical method that he did not suggest excellent improve- ments in it, and he devised new methods, many of which are now in general use; his mineralogical papers in fact are full of contributions to analytical chemistry and he published several useful papers directly upon analytical methods. Samuel Lewis Penfield. 359 Penfield’s work as a erystallographer is scarcely of less importance than that which he performed.on the chemical side of mineralogy. He handled mathematical relations with ease and clearness and his work was both rapid and accurate. His perception of crystal forms and symmetry seemed almost intuitive and in practical operations he was greatly aided by the same manual dexterity that he showed in chemical manip- ulation; thus he made measurements on the goniometer of crystals of such a degree of minuteness, as in the case of sperrylite, that it seemed almost impossible that they could be handled. Besides establishing the crystallization of the new minerals already mentioned, Penfield determined that of the following species: Amarantite, Argyrodite, Bertrandite, Herderite, Lansfordite, Metacinnabarite, Penfieldite, Polybasite, SS rylite, Tiemannite, Willemite. In addition to his contributions to the crystallography of minerals we also owe to Penfield the determination of the other physical properties of many species, especially the optical; a work which he first took up in Rosenbush’s laboratory and after- wards accurately and skillfully carried out whenever possible upon all of the species which he investigated. His labors as a crystallographer were not, however, confined to minerals. For anumber of years he spent much time in the determination of the crystallization and optical properties of compounds prepared in the chemical laboratory of the Sheffield Scientific School. As may be seen by reference to the appended bibliography, this work was done either directly by himself or under his care and supervision by the assistants and advanced students in the laboratory whom he had trained. Among these compounds studied there may be mentioned as of special import- ance the large series of new double salts, particularly the double halides, prepared by his colleague Professor Wells or under his direction. During the later years of his life Penfield gave much time and thought to the perfecting of practical methods for the solution of problems in crystallography. He was led to a study of the stereographic projection as a means of expression and in 1901 published an important paper on this subject, showing how it could be used for solving problems, not only in crystallog- 360 Samuel Lewis Penfield. raphy, but also in astronomy, geodesy, navigation, etc. He pre- _ pared also an ingenious set of instruments for use in connection . with this method of projection by means of which laborious calculations could be avoided and the problems. quickly and accurately solved by graphic methods. He extended these practical methods and applied them to the drawing of crystals, devising special plates of axes to be used in connection with his instruments by which the solving of the form ofa crystal and the drawing of its figure could be easily and rapidly carried out. These methods have since come into very general use. In reviewing Penfield’s work in mineralogical science one is struck, not more by its quantity than by its quality and varied aspects. He was a thoroughly trained man and had a firm grasp on every phase of his subject. He had a wide and accurate knowledge of minerals and the correctness with which he often identified them at sight seemed almost like intuition. While he clearly apprehended principles and, as has been shown, pro- duced generalizations of wide importance, the great majority of his contributions to science are not of a theoretical nature but consist of direct and positive additions to knowledge. He had a highly analytical mind, and this combined with his inventive faculty and the great manual skill with which he was gifted made him a born investigator, one of the greatest who has yet appeared in his field of science. It is safe to say that with his gifts he would have had a successful career in whichever of the physical sciences he might have entered. The thoroughness of Penfield’s work, its high quality and the completeness with which he covered every side of his subject, is well illustrated in his last paper on stibiotantalite, published in the current July number of this Journal, in conjunction with his junior associate and former pupil Professor Ford. His services to science have been worthily recognized at home and abroad : in 1893 he was made an associate Fellow of the American Academy of Arts and Sciences in Boston : in 1896 he became a Foreign Correspondent of the Geological Society of London and his university conferred on him the degree of Master of Arts: in 1900 he was elected a member of the National Academy of Sciences : in 1902 he was chosen as a Fel- low of the American Association for the Advancement of Sci- Samuel Lewis Penfield. 361 ence, a Corresponding Member of the Royal Society of Sciences at Gottingen, Germany, and member of the Scientific Society of Christiania, Norway: in 1903 he was elected Corresponding Member of the Geological Society of Stockholm and Foreign Member of the Mineralogical Society of Great Britain: im 1904 the University of Wisconsin conferred upon him the degree of Doctor of Laws. He was also a member of the Connecticut Academy of Arts and Sciences and a Fellow of the Geological Society of America. As a teacher Penfield was a striking example of what may be accomplished by an intelligent and painstaking devotion of one’s effort toward a given end. He was not naturally gifted as a teacher—as a lecturer and speaker—as some men are. Of an extremely modest, quiet and retiring disposition and some- what reserved except among his intimate friends, he always found it ditiicult, and naturally dishked, to express himself in public. Thus at the outset the management and instruction of students in numbers was for him not an easy matter. But he so entirely overcame this and perfected to so great a degree his methods of teaching, that the many students who came under his instruction regarded him as one of the best teachers in the University. In laboratory work, where the contact with the student is personal, he always had great success from the begin- ning of his career, because, in his kindliness of disposition, great patience and persistency, and in his interest in the student and his work, he had natural aptitudes which specially fitted him for this kind of instruction, and he took morever distinct pleas- ure in it. He always insisted upon great thoroughness and completeness in allotted work, and the mental discipline and training in method which students received under him were not less valuable than the knowledge of mineralogy which they acquired. With those who. came under him for advanced instruction he was particularly fortunate. The untiring care and oversight which he gave to their work and the thoroughness and accuracy upon which he insisted gave almost invariably successful results, and thus, especially in research, he communicated his own energy and enthusiasm to his pupils and stimulated their interest. _ This is clearly shown in the large number of important pieces 362 Samuel Lewis Penfield. of work executed by him in conjunction with his students or by them under hisdirection. The writer, who was greatly aided by Pentield’s instruction at the beginning of his own scientific work in mineralogy, can abundantly testify to his generous help- fulness and sympathetic interest in others and their work. Penfield gave unlimited pains and thought to perfecting his material equipment for teaching and to this much of his suc- cess was due. In his laboratory he had many carefully chosen collections of models, of crystals and of minerals, each de- signed for particular purposes, and the arrangement of these and of the apparatus was carried out with a system and a com- pleteness for uses of instruction that always excited the admir- ation of those qualified to judge of their character. In the same way with great skill and ingenuity he constructed models and apparatus for use in teaching crystallography and the opti- cal properties of minerals to his classes and advanced students. Nor should there be forgotten in this connection the care and labor he expended in preparing the new edition of Brush’s Manual of Determinative Mineralogy, the additions to which, dictated by his experience-in teaching, are of the greatest value to students. | It was in fact a question which Penfield ever had upon his mind—how he could improve his methods and equipment for instruction, and as a result they attained to so high a degree of completeness and practice that many teachers of mineralogy who were not his pupils found a visit to his laboratories a source of help and inspiration. It is a matter of satisfaction to his friends that, after the first attack of illness, his life was spared long enough for him to realize his cherished ambition in the completing of the new laboratories he had planned in Kirtland Hall and in the arrangement and perfecting of their equipment. In his new quarters he passed, in spite of illness, two very happy years of busy work, with his students and in investigations. Penfield’s activities were not confined to his laboratory. In the middle eighties he spent two summers as assistant in geological work to Professor Iddings in the survey of the Yellowstone Park, and later a number of summers were spent by him in northern New York, in North Carolina and Colo- Samuel Lewis Penfield. 363 rado, collecting minerals and studying their modes of occur- rence and field relations. The inspiration to a number of important pieces of work was given by these experiences. He also spent two summers in Europe, in 1894 and again in 1897, visiting other workers in his science and seeing collec- tions and well known mineral localities. In these travels he was everywhere cordially received and made a large number of friends. For many years Pentield, with several of his colleagues, one of whom was the late Prof. C. E. Beecher, lived in apartments in the top of one of the buildings of the Sheffield School. In this little coterie of young scientists were knitted enduring bonds of intimacy and friendship which had the most happy effect upon his life and work and in it he both gave and received. As previously remarked, Pentield was distinguished by a broad humanitarianism, by a warm heart and ready sympathy which responded quickly to every call. He was always inter- ested in charitable work and for many years was a weekly visitor to the children’s ward in the City Hospital, where he cheered and helped the little patients. In January 1897 he married Miss Grace Chapman of Albany, N. Y., who survives him. His great happiness in his married life and in the home circle he drew around him and in its generous hospitality was evident and a matter of sincere pleasure to all his friends. The dominant notes of Penfield’s character as a.man were his benevolence, his simplicity, earnestness and downright hon- esty and sincerity in word and deed. These traits, together with a certain sweetness of disposition and a wonderful patience, never more strikingly shown than during his illness, greatly endeared him to his friends. To know him well was to love him. | Great as is the loss, that a man of Penfield’s type should be cut off in the midst of his active career, and sincere and deep as our sorrow must be thereat, there is a satisfaction, which helps somewhat to console, in the thought that all there is to such a man can never die. The work that he achieved still remains, and better yet, the influence and memory of the high 364 Samuel Lewis Penfield. principles he inculcated, not only in science but in daily life, as a man anda citizen, still mould the thoughts and feelings of his friends and students. His science is better today, not only by what he did, but still more by the imfluence he exerted and the high ideal of character he left behind him. Thisis a precious heritage which can never be lost. The portrait accompanying this notice has been reproduced from a photograph taken some four years ago. L. V. Pirsson. BIBLIOGRAPHY OF S. L. PENFIELD.* 1877 On the chemical composition of Triphylite from Grafton, New Hamp- shire. This Journal (3), xiii, 420-427. 1879 Onthe chemical composition of Triphylite. Ibid., xvii, 226-229. On a new volumetric method of determining Fluorine. Amer. Chem. Journal, i, 27-29. On the chemical composition of Amblygonite. This Journal (8), xviii, 295-301. B 1880 On the chemical composition of Childrenite. Ibid., xix, 315-316. Analyses of some Apatites containing Manganese. Ibid., 367-369. 1881 Analysis of Jarosite from the Vulture Mine, Ariz. Ibid., xxi, 160. 1882 Occurrence and Composition of some American varieties of Monazite. Tbid., xxiv, 250-254. Ueber die Phenylhomoparaconsdure (with R. Fittig), Ann. der Chem., ccxvi, 119-127. 1883 Scovillite: a new phosphate of Didymium, Yttrium and other rare earths from Salisbury, Conn. (with G. J. Brush). This Journal (3), xxv, 459-463. Analyses of the two varieties of Lithiophilite. Ibid., xxvi, 176. On a variety of Descloizite from Mexico. Ibid., 361-360. 1884 Identity of Scovillite with Rhabdophane (with G. J. Brush). Ibid., xxvii, 200-201. On the oceurrence of Alkaliesin Beryl. Ibid., xxviii, 25-82. Ueber Erwairmunesversuche an Leucit und anderen Mineralien, N eues Jahrb. fiir Min., ii, 224, 1885 Crystallized Tiemannite and Metacinnabarite. This Journal (3) xo, 449-454. Gerhardtite and Artificial Basic Cupric Nitrates (with H. L. Wells). Ibid., xxx, 50-57. Crystals of Analcite from the Phoenix Mine, Lake Superior Copper Region. Ibid., 112-118. Mineralogical Notes (with E. S. Dana). Ibid., 186-139. 1886 Brookite from Magnet Cove, Ark. Ibid., xxxi, 387-389. Chemical Composition of Herderite and Beryl (with D. N. Harper). Ibid., xxxii, 107-117. On hitherto undescribed Meteoric Stones (with E. S. Dana). Ibid., 226-231. On Pseudomorphs of Garnet from Lake Superior and Salida, Col. (with F. L. Sperry). Tbid., 3807-811. On the Chemical Composition of Ralstonite (with D. N. Harper). Ibid., 380-385. Crystallized Vanadinite from Arizona and New Mexico. Ibid., 441- 443, * This list is not absolutely complete, but contains everything of impor- tance. 1887 1888 1889 1890 1891 1892 1893 1894 Samuel Lewis Penfield. 365 Phenacite from Colorado. Ibid., xxxiii, 180-134. On the Chemical Composition of Howlite (with E.S. Sperry). Ibid., xxxiv, 220-223. Triclinic Feldspars with twinning striations on the Brachypinacoid (with F. L. Sperry). Ibid., 390-393. On the crystalline form of Polianite (with E. 8. Dana). Ibid., xxxv, 243-247. Bertrandite from Mt. Antero, Colorado. Ibid., xxxvi, 52-55. Mineralogical Notes (with E. S. Sperry). Ibid., 317-331. ; On the Crystalline form of Sperrylite. Tbid., xxxvii, 71-78. On some curiously developed Pyrite crystals from French Creek, Chester Co., Penna. Ibid., 209-212. Crystallized Bertrandite from Stoneham, Maine and Mt. Antero, Colo- rado. Ibid., 213-216. Results obtained by etching a sphere and crystals of quartz with hydrofluoric acid (with Otto Meyer). Trans. Conn. Acad., viii, 158-165. On Lansfordite, Nesquehonite a new mineral, and Pseudomorphs of Nesquehonite after Lansfordite (with F. A. Genth). This Journal (5), xxxix, 121-187. On Spangolite, a new Copper Mineral. Ibid., 370-378. On Hamlinite, a new rhombohedral mineral from the Herderite local- ity at Stoneham, Me. (with W. EK. Hidden). Ibid., 511-5138. Fayalite in the Obsidian of Lipari (with J. P. Iddings). Ibid., xl, 79-78. On Connellite from Cornwall, England. Ibid., 82-86. Crystallographic Notes (with F. A. Genth). Ibid., 199-207. Chalcopyrite crystals from French Creek, Penna. Ibid., 207-211. Anthophyllite from Franklin, Macon Co., N. C. Ibid., 394-897. On the Beryllium minerals from Mt. Antero, Col. Ibid., 488-491. Chemical Composition of Aurichalcite. Ibid., xli, 105-109. Crystallographic Notes (with F. A. Genth). Ibid., 394-400. The minerals in hollow Sperulites of Rhyolite from Glade Creek, Wyoming (with J. P. Iddings). Ibid., xli, 39-46. On Cesium Trihalides (by H. L. Wells) and their Crystallography. ibid., xliii, 17-82. Crystallographic Notes (with F. A. Genth). Ibid., 184-189. Crystallography of the Rubidium and Potassium Trihalides. Ibid., 475-487. On Polybasite and Tennantite from Mollie Gibson Mine, Aspen, Col. (with S. H. Pearce). Ibid., xliv, 15-18. Crystallography of the Alkali-Metal Pentahalides. Ibid., 42-49. On Herderite from Hebron, Maine (with H. L. Wells). Ibid., 114-116. Crystalline form of RbCl.HIO; and CsCl1.H1IO;. ITbid., 132-133. Crystallography of double halides of silver and alkali-metals. Ibid., 155-157. Crystallography of Cesium and Rubidium Chloraurates and Brom- aurates. Ibid., 157-162. Crystallography of the Czsium-Mercuric Halides. Ibid., 311-321. Crystallographic Notes (with F. A. Genth). Ibid., 381-389. On Cookeite from Paris and Hebron, Maine. Ibid., xlv, 393-396. Mineralogical Notes (Zunyite, Xenotime). Ibid., 396-399. On Pentlandite from Sudbury, Ontario. Ibid., 495-497. On Canfieldite, a new Germanium Mineral and on the Chemical com- position of Argyrodite. Ibid., xlvi, 107-115. Minerals from the Manganese Mines of St. Marcel, Piedmont. Ibid., 288-295. Chemical Composition of Staurolite and on its Inclusions (with J. H. Pratt). Ibid., xlvii, 81-89. ; Chemical Composition of Chondrodite, Humite and Clinohumite (with W. T. H. Howe). Ibid., 188-206. 1894 1895 1896 1897 1898 1899 1900 Samuel Lewis Penfield. Crystallization of Willemite. Ibid., 305-309. Crystallization of Herderite. Tbid., 329-339. Chemical Composition and related Physical Properties of Topaz (with J.C. Minor). Ibid., 387-396. On Argyrodite and a new Sulphostannate of Silver (Canfieldite) from Bolivia. Ibid., 451-454. On Thallium Triiodide and its Relation to the Alkali-Metal Triiodides (with H. L. Wells). Tbid., 463-466. On ne Methods for the Determination of Water. Ibid., xlviii, Seis Mineralogical Notes. Tbid., 114-118. Mineralogical Notes and Separation of Minerals of High Specific Gravity (with D. A. Kreider). Ibid., 141-144. Note on the Crystallization of Calaverite. Ibid., 1, 128-181. Effect of the Mutual Replacement of Manganese and Iron on the Optical Properties of Lithiophilite and Triphylite (with J. H. Pratt). Ibid., 387-390. vere a the Separation of Minerals of High Specific Gravity. Ibid., 446-448. Fayalite from Rockport, Mass., and the Optical Properties of the Chrysolite Group (with E. H. Forbes). Ibid. (4), i, 129-135. Occurrence of Thaumasite at West Paterson, N. J. (with J. H. Pratt). Ibid., 229-233. On Pearceite, a Sulpharsenite of Silver, and on the Crystallization of Polybasite. Ibid., ii, 17-29. On Roeblingite, a new Silicate from Franklin Furnace, N. J., contain- ing SO, and Lead (with H. W. Foote). Ibid., iii, 413-415. Identity of Chalcostibite (Wolfsbergite) and Guejarite and on Chalco- stibite from Huanchaca, Bolivia (with A. Frenzel). Ibid., iv, 27-39. On Bixbyite, a new Mineral, and on the Associated Topaz (with H. W. Foote). Ibid., 105-108. Note on the Composition of Ilmenite (with H. W. Foote). Ibid., 108-110. Chemical Composition of Hamlinite and its Occurrence with Ber- trandite at Oxford Co., Me. Ibid., 313-316. On Clinohedrite, a new mineral from Franklin, N. J. (with H. W. Foote). Ibid., v, 289-293. Crystallographic Note on Krennerite from Cripple Creek, Colo. Ibid., 379-377. Note on Sperrylite from North Carolina (with W. E. Hidden). Ibid., vi, 381-383. Manual of Determinative Mineralogy and Blowpipe Analysis by G. J. Brush. Revised and enlarged, with new tables. 312 pp. On the Chemical Composition of Tourmaline (with H. W. Foote). This Journal (4), vii, 97-125. On the Chemical Composition of Parisite and a new occurrence at Ravalli Co., Mont. (with C. H. Warren). Ibid., viii, 21-24. On some new Minerals from the Zinc Mines at Franklin, N. J. (Han- cockite, Glaucochroite, Nasonite, Leucophoenicite, and Note on Chemical Composition of Ganomalite (with C. H. Warren). Ibid., 339-353. On Graftonite, a new Mineral from Grafton, New Hampshire, and its Intergrowth with Triphylite. Ibid., ix, 20-82. Siliceous Calcites from the Bad Lands, Washington Co., So. Dakota (with W. E. Ford). Ibid., 352-354. Chemical Composition of Sulphohalite. Ibid., 420-428. The Interpretation of Mineral Analyses ; a Criticism of recent Articles on the Constitution of Tourmaline. Ibid., x, 19-82. On some Interesting Developments of Calcite Crystals (with W. E. Ford). Ibid., 237-244. 1900 1901 1902 1903 1905 1906 Samuel Lewis Penfield. 367 Contactgoniometer und Transporteur von Einfacher Construction. Zeitschr. fiir Kryst., xxxiii, 548-594. On the Chemical Composition of Turquois. This Journal (4), x, 346- 300. The Stereographic Projection and its Possibilities from a Graphical Standpoint. Ibid., i, 1-24. On Calaverite (with W. E. Ford). Ibid., xii, 225-246. New Occurrence of Sperrylite (with H. L. Wells). Ibid., xiii, 95-96. Use of the Stereographic Projection for Geographical Maps and Sail- ing Charts. Ibid., xiii, 249-275, 347-376. On the Solution of Problems in Crystallography by means of Graph- ical Methods based on Spherical and Plane Trigonometry. Ibid., Xili, 249-284. Tables of Minerals: Including the Uses of Minerals and Statistics of the Domestic Production. 8°, 77 pp. (New Haven, Conn.) On Crystal Drawing. This Journal, xix, 39-75. On Tychite, a New Mineral from Borax Lake, California, and on its Artificial Production and its Relations to Northupite (with G. 8. Jamieson). Ibid., xx, 217-924. On the Drawing of Crystals from Stereographic and Gnomonic Pro- jections. Ibid., xxi, 206-215. Filter Tubes for Collection of Precipitates on Asbestos (with W. M. Bradley). Ibid., 453 -466. On Stibiotantalite (with W. E. Ford). Ibid., xxii, 61-77. 368 6. Lines of growth are often distinct within the crystallites and exhibit a plumose arrangement. Although the above optical data do not suffice to prove definitely that this form of magnesium metasilicate is an amphibole, they do agree closely with the properties of the orthorhombic amphibole of similar composition found in nature. Unfortunately, the definite solution of this question must be deferred until after means have been devised to pro- duce measurable crystals. The specific gravity was determined on several different preparations, two of which (I and II) were very carefully examined microscopically and found to be practically pure; the third, having been observed by the same method to contain small quantities of glass and the monoclinic form, was separated with great care by heavy solutions (methylene iodide and ben- zene), the separation of each portion being twice repeated and controlled by the microscope. Specific gravity at 25° C. Prep. I. 2-858 Prep. Il. 2°860 Prep. ILI. 2°855 2°856 2°860 2°853 DESO 2°860 2°854 Average, 2°857 Transformation of Orthorhombic Amphibole by Heat.— The orthorhombic amphibole changes, like enstatite, and some- what more rapidly, into the monoclinic pyroxene, when heated to a sufficient temperature. Here, too, the change is sluggish, as the following table indicates : Minerals of the Composition MgSi0O,. 411 TaBLE VII. Change of Orthorhombie Amphibole to Monoclinic Pyroxene. Time. Temperature. Observations. 1 day 1020°-1040° No change. 2 days 1055 —-1077 Indications of slight ; change. 20 hours - 1100 -1100 No change observed. 18 hours 1120 —1140 Fragments dotted with pyroxene. 3 days 1127 -1153 All changed. 18 hours 1144 -1173 Partly changed. 2 days 1150 —1183 All changed. Tt is possible that at the lower temperatures the amphibole passes into enstatite; the product is there so fine-grained that a microscopic distinction between the two pyroxenes cannot be made. Part IJ].—RELATIONS OF THE DIFFERENT FORMS TO ONE ANOTHER. Stability relations.—The four forms of magnesium silicate having thus been prepared and studied in detail, the question of their relative stability arises. It is well known that a sub- stance chemically homogeneous may exist in several different physical forms, which are called polymorphic when they yield ‘identical liquids, solutions and vapors, in which case their chemical molecules, in distinction from those of isomers, are identical. Polymorphic substances are enantiotropic when, by heating, one form changes without melting into the other at a definite temperature called the inversion point, and on cooling again the reverse change takes place. In this case, the first form is stable below the inversion point only, the second above it. The form stable at lower temperatures inverts to the other with absorption of heat, and the reverse change takes place with evolution of heat.* An instance of the enantiotropic relation is the mineral wollastonite, which inverts at about 1190°, with absorption of heat, into a second form, pseudo- hexagonal in symmetry. In another class of ‘polymorphic substances there is no such inversion point, and one of the forms is more stable than the other at all temperatures below the melting point. These relations are best expressed by diagrams. * Given the relations of the vapor pressures, this follows from the second law of thermodynamics. Van’t Hoff, Vorlesungen iiber Theoret. u. Phys. Chemie, Braunschweig, 1901, ii, 128. 4120 #. T. Allen, F. E. Wright and J. K. Clement— Lnantiotropy.—In fig. 7, OT = axis of temperatures. OP = axis of vapor pressures. abe = vapor tension curve of liquid. ed = vapor tension of solid stable below T,. db = vapor tension of solid stable above T,,. T, = inversion point. T, == melting point of form stable above T,,. L Fie. 7. Vapor pressure curves in a case of enantiotropy ; ed is curve of solid stable below T.; db is curve of solid stable above T.. The full lines represent a condition of stability, the dotted lines a condition of instability. The two curves ed and fb intersect at d below the melting point curve. At this point the two forms have the same vapor pressure, and are therefore in equilibrium, and the temperature, T,, is the inversion point. Likewise, the point T, is common to two curves, bd of the solid stable at higher temperatures, and ae of the liquid; at that point, therefore, this solid and the liquid are in equilibrium, and T, is the melt- ing point. Since in general the curve ed cannot be prolonged so as to intersect with the curve ac, the solid stable at lower temperature usually has no melting point. 6d can usually be prolonged to low temperatures by sudden cooling or other- wise, a fortunate circumstance without which nearly all physi- cal and chemical data upon the solids stable only at high tem- peratures would be unattainable. Minerals of the Composition MgSi0O,. 418 Monotropy.—In fig. 8, 2 e OT = axis of temperatures. OP = axis of vapor pressures. abed = vapor pressure curve of liquid. eb = vapor pressure curve of unstable solid. fe |= vapor pressure curve of stable solid. T, = melting point of stable form. T, = melting point of unstable form. 8 0 F Fic. 8. Vapor pressure curves in a case of monotropy; eb is curve for unstable form ; fc is curve for stable form. This figure represents the relations between the vapor pres- sure curves of two monotropic solids and their corresponding liquid. The curve differs from the preceding case only in that Jb and ed do not intersect before reaching the melting point curve abc. At b the vapor pressure of one solid is equal to that of the liquid, and the two’are in equilibrium ; T, is there- fore the melting point of this form. Similarly, T, is the melt- ing point of the second (stable) solid. It will be noted that for a given temperature the vapor pressure of the first solid is always greater than that of the second; the two curves do not intersect below either melting point and therefore are not in equilibrium at any temperature; the solid of lower vapor pressure is more stable than the first throughout. The melt- ing point of the unstable solid is always lower than the other, but in practice the unstable form often changes into the more stable before its own melting point (T,) is reached. 414° EF. T. Allen, F. FE. Wright and J. K. Clement— Although many solids, like the minerals under discussion, have a vapor tension much too low for measurement at these temperatures, the relations are as represented in the diagram.* The stability relations of the four polymorphic forms of SE silicate may be shown in the same way by a simple diagram (fig. 9). These curves do not, of course, represent measured vapor pressures, but simply the order of the stability iP Fie. 9. fa is vapor pressure curve for orthorhombic amphibole; hb is vapor pressure curve for monoclinic amphibole; mc is vapor pressure curve for orthorhombic pyroxene; nd is vapor pressure curve for monoclinic pyroxene. of the forms. As is proved by the experiments described below, the monoclinic pyroxene, at atmospheric pressure, is the most stable, and the others bear a monotropic relation to it, their relative stability beng in the order indicated by the vapor pressure curves. Two lines of evidence lead to this conclusion: (1) a. Ensta- tite and the amphiboles, while still in the solid state, pass over at high temperatures into monoclinic pyroxene which cannot be changed back without passing through the amorphous state ; 6. At much lower temperatures (about 800°) the same three forms can be dissolved and recrystallized simultaneously into the monoclinic pyroxene by means of fluxes ; (2) enstatite and the two amphiboles change into monoclinic pyroxene with evolution of heat. (1) Although it was shown conclusively that the amphabeles : change into “monoclinic pyroxene above about 1150°, and * Roozeboom, Heterogen Gleichgewichte, Heft. 1, 158-159, Braunschweig, 1901. Minerals of the Composition MgSiO,,. 415 enstatite changes to the same form above 1260°, and that on cooling neither of the changes is reversible, these facts in themselves do not prove monotropy. In certain cases of enantiotropy, mere cooling of the form stable at high tem- peratures does not suffice to revert it to the other for in, even when both forms are in contact and unlimited time is allowed.* This inertia is apparently due to the great internal friction between the molecules at temperatures below the inversion point. The molecular immobility may be overcome by the use of suitable fluxes in which solution of the unstable form and precipitation of the stable go on hand in hand, the unsta- ble form being the more soluble. Thus pseudo- wollastonite is less stable than wollastonite below the inversion point, yet it does not revert to it at lower temperatures except by the aid of proper solvents. In this case, molten calcium vanadate proved well adapted to the purpose. The pseudo-wollastonite dissolved in it and cotemporaneously wollastonite crystallized out. Similar tests with solvents were applied to the different forms of magnesium silicate with the result, as we have already recounted in detail (pp. 387 et seq.), that from a considerable number of solvents magnesium silicate was found to pass into solution and gradually to erystallize, invariably as monoclinic pyroxene, whatever crystal form was originally taken. This indicates that at atmospheric pressure the monoclinic pyroxene is the most stable form of magnesium silicate at all tempera- tures between about 800° and the melting point of the mono- elinie form (1521°). (2) In order to confirm this evidence of monotropy, we soil to ascertain the direction of the heat changes, whether exother- mic or endothermic, for two of the unstable forms. The method first tried was that of Frankenheim, which consists in observ- ing at regular intervals the rise in temperature of a mass of the substance. Heat was supplied by means of the electric resistance furnace used in this laboratory, and the temperature measured by a thermoelement.t The curves thus obtained by heating the different forms are perfectly smooth, showing neither absorption nor release of heat until the melting point of the monoclinic form is reached. The fact that all forms seem to have the same melting point indicates in itself that the other forms change into the monoclinic pyroxene before melt- ing. The change, however, is so sluggish that it proceeds throughout a temperature interval of several hundred degrees, and the heat is therefore so uniformly distributed as not to be indicated by the curve. *See ‘“‘ Wollastonite and Pseudo-Wollastonite,” this Journ. ser. 4, xxi, p. 95, 1908. + Day and Allen, Phys. Rev., xix, 184. 416 ET. Allen, FE. Wright and J. K. Clement — New Method for Detecting the Direction of Sluggish Heat Changes.—A substance in which a transformation progresses so slowly that the accompanying heat change cannot be detected by the ordinary method, should show it plainly if the change could be forced to proceed with sufficient velocity. The heat change would then be concentrated and become visible on the temperature-time curve. In changes of this character, the rate of change depends on the temperature, and increases rapidly with it. If, therefore, a substance which is unstable at high temperatures be introduced into a furnace which is several hundred degrees above the lower limit of the unstable region, the heat effect is in general easily followed. In our experiments the apparatus shown in fig. 10 proved very satisfactory for the purpose. An empty ri platinum crucible is first placed on a pedestal of refractory material in the electric resist- ance furnace. The unglazed 2 porcelain tube, A, 1° in inside A diameter and open at both ends, passes through holes drilled in the two covers, B and Bb’, and is then clamped : in the position shown in the _ > \ figure, the lower end of the tube reaching down to the top (AB of the crucible. The thermo- element C is covered by a platinum shoe, D, which should occupy the same posi- tion in all the experiments, i.e, about the center of the charge. This is assured by clamping the tube in a fixed MAMAS osition and fastening the a clement securely fit by plat obtain like conditions in each experiment, especial attention being given to fitting together the parts of the furnace to obtain minimum radiation of heat, and in placing the crucible and thermoelement in the same relative position for each experiment. The furnace is now brought to a constant temperature, which should be sufficiently high to insure a rapid change of state. In the particular substances which we investigated, tempera- tures ranging from 1425°-1475° were found best adapted to show the heat effect. A weighed portion of the substance (40 L WS F pelle fens Yy SN =a ane 7 pot Minerals of the Composition MgSi0,. 417 or 50 grams) is then quickly dropped through the tube into the erucible, after which temperature readings are made at half- minute intervals until the temperature of the crucible again becomes practically constant. In a second experiment under the same conditions, the product of this first change is introduced into the furnace as before, and a second temperature curve determined under exactly the same conditions. A comparison of the two curves plainly indicates the direction of the heat change. If an evo- lution of heat has taken place, the temperature rate is accel- erated and the curve of the unstable body hes to the left and above that of the stable form, as shown in curve I of fig. 11. On the other hand, if there has been an absorption of heat, the temperature rate is retarded and the curve of the unstable form lies to the right and below that of the stable form. In order to test the method, substances were first tried in which the direction of heat change was known, e. g., wollas- tonite, which passes into pseudo-wollastonite with absorption of heat ; wollastonite glass, which crystallizes with evolution of heat ; and albite, which melts with absorption of heat,— all very ’ slow changes. Fig. 11 contains the results obtained with wollastonite and wollastonite glass. The number of curves in a single figure and their general similarity of form have made it inadvisable to confuse the figures by attempting to show the observed points on each curve. The observed electromotive forces in microvolts are therefore tabulated separately (Table VIII). The corresponding temperatures are not important, as the point which we desire to establish depends merely upon the relative displacement of that portion of the curve in which a change of state may be expected to occur. The curves II are heating curves for pseudo-wollastonite, which is the stable form at the temperatures of the experi- ment, and therefore suffers no change of state. Curve I, the corresponding curve for wollastonite glass, lies to the left and above the curves for pseudo-wollastonite, and plainly indicates an evolution of heat, since all other thermal conditions are identical in the two cases. The curves for wollastonite, III, lag behind those for pseudo-wollastonite, and indicate heat absorption. ‘The results for albite and albite glass are shown in fig. 12 (Table IX). It is interesting to compare these results for albite with those obtained for orthoclase (which resembles albite very closely in its thermal properties), in a previous investigation in this laboratory by the Frankenheim method (fig. 13).* * Arthur L. Day and EK. T. Allen, ‘‘The Isomorphism and Thermal Properties of the Feldspars,” this Journal, series 4, xix, 95, 1905. Am. Jour. Sct.—FourtH Series, Vou. XXI, No. 131.—NoOVEMBER, 1906. 29 418 Temperature in microyolts. EL. T. Allen, F. EB. Wright and J. K. Clement— alt CHEE EEEE ECE HE Rane so 18000 12000 i aoc SHEER e ee eee am (145°) EC CeeReCeecee Time—1 division = 1 minute. Fie. 11. I = Wollastonite glass (one curve). II = Pseudo-wollastonite (two curves). III = Wollastonite (two curves), 14000 | 13000 _ Temperature in microvolts. 12000 | __ 11000 (1145°) Fig. 12. Minerals of the Composition MgSi0O,. 12 Raa Tay Si RRC ah ieee HOC Cee ee eee mes |e ee a Pe LIS TS GP a Os (el ay a2 ee a PRU PAPAIES| pias sahvalitallbl lies [alsa] moe mae e ete belay bdo Uae Vee ae ae eee Se ae al oe [data aeee as SCS aaa Ree eee JAE eh See ee eeeeeeae ee ees [oad 3S la ae a [a ee Sea se eases Saal aoe CeeenEEEEEee pais (enn PY Ie sk Se ss a 1 | ! Time—1 division = 1 minute. = Albite glass. II = Albite. 419 Time. 0 min. 420 #. T. Allen, F. EF. Wright and J. K. Clement The curves in this figure (fig. 13) were obtained by heating large charges (about 100 grams) of orthoclase to a temperature During the time of melting, which, in the alkaline feldspars, extends over quite an interval, the rate at which the temperature rises is retarded by heat absorption, but the change is so slow that The indentation in the curve is which caused a complete change of state. this retardation is very slight. TABLE VIII (see fig. 11), W ollas- tonite glass. 15000 11400 11450 12210 12890 13445 790 14065 262 418 529 619 683 ioe 770 801 825 845 &61 8175 885 895 9038 On | 917 923 927 932 937 940 944 948 951 943 956 961 964 Pseudo- Wollas- tonite. 15000 15000 113800 10600 10905 9960 11450 10520 WA Ney elses Moey WANTS 13208 790. 595 13305 8x0 680 14114 970 281 14185 416 390 O14 A474 593 570 650 641 696 695 731 738 761 WYP 784 798 801 819 816 835 829 850 840 862 850 872 858 880 865 887 872 893 877 899 882 G04 888 908 891 912 895 915 898 919 901 921 94 924 908 927 911 929 W ollastonite. 15000 15000 9900 11100 9170 103880 9700 875 10585 11560 11495 12215 12245 TS 12840 13160 13215 A84 550 760 818 97 14050 14154 J209 292 368 414 473 506 558 585 620 646 670 696 706 736 735 TO 759 795 780 818 798 837 812 851 824 867 835 879 844 889 852 899 859 907 864 915 869 921 873 928 877 933 880 939 883 945 885 950 887 954 TasLE IX (see fig. 12). Time. O min. al 2 3 66 ce 6¢ (4 66 ce Albite glass. 15000 11100 9900 9900 10525 11430 12365 13145 695 14075 300 448 543 610 659 699 727 751 770 785 800 811 821 830 838 844 850 855 859 864 868 872 876 880 882 885 887 Albite. 15000 11850 315 720 12250 800 13140 478 716 919 14080 221 334 432 821 825 828 831 834 837 840 Minerals of the Composition MgSiO,. 421 made evident to the eye by continuing as a dotted line the course the curve would have followed, ‘had no absorption of heat occurred. 13 (Ge a re eee aes a ce POO ede ee eee ee abot") ST eye Se eB ee eas ae Le eI ATA HS SSR al (aE a ee a opt ff EL Pia te ea eet iene, fs Za ea cE a ee VR eles ial eee 12000 |_| | Oa eas See eae iH oateate iad 2 EE eS) Sy eee ae eT eA PS Pee Ty | Bee eee Temperature in microvolts. alia ES TRA iC dS Ts alll PU al a i i a es a A te ae il ee | SOO MVR |e PL Least ee | Ty SE ATCA EA Gy Sa a Da Time—1 interval = 10 minutes. Fic. 13. Curves showing heat absorption in melting orthoclase. Figures 14-18 (Tables X—XIV), show the curves obtained by the new method on the different forms of magnesium metasili- cate. The curves for the orthorhombic amphibole, enstatite and monoclinic pyroxene in fig. 14 (Table X) were obtained in preliminary experiments, and are less accurate than those obtained in the later experiments, due to the fact that the posi- 422 Temperature in microvolts. f. T. Allen, F. FE. Wright and J. K. Clement— 14 a 2 | see CF a i Ta) a 1 PO a Oe a Lee Ss cece SN is00 | Se i a aso esata SERRE Seesamen Per be a a ae Bik a AA (UAT aeceeUUenees fe WOW ee ie ae A a Eee ee ee VM Pee Lie eee Ae MU fe I ah 13000 See ee ea a 000 ena eS A 9307). |-cl eS s Time—1 division = 1 minute. Fic. 14. I = Orthorhombic amphibole. It = Enstatite. III = Monocline pyroxene. Minerals of the Composition MgSi0,. 423 15000 +f eed tt SEE aye tH JD Bee ee a ee sees Doone (sn noe eee ee lena ay Sean seen meses taal Te Jee Zee eae Sale oe eV (ee ULE ee pian Temperature in microvolts. ee mers a 20 TT ne Sane Time—1 division ’'= 1 minute. Fie. 15. I = Orthorhombic amphibole (two curves). Il = Monocline pyroxene (two curves). 16 494 #. T. Allen, F. EL Wright and J. K. Clement— CUCE Cec Gog eee een Cee eeGeee eGEeeeE [Wb JS Sea esa esse Sees sea ea eae seeeae LASS ea Sane eeee See eke see eee aeeees oN Sees eS Sages sae seeeeeeaeaees LOSES SS Seskes s2ask ase eeee aes seas CLES aase eae a Steese ee eeeaeehkeeskesise ee Se jens oes ese ees See eeeeeeses ie faa = ee eerie || HH See ET TT EERE EEE EEE EEE ema ee ee See Eas Sore —) =) Se = S S S as ra = 6 ® = ra 4 _ — 4 ~ ~~ ‘S}[OAOLOIUL UT 9tnyviedutey, Time—1 division =.1 minute. Orthorhombice amphibole. Monoclinic pyroxene. I II Bic, 16; Minerals of the Composition MgSi0,. 425 1) eee aa eRe IS aT eg aS ea ee eee ae dense ee me eek P| Ba ea a eee LRM oA eae ee Meee eer Sele a | A ile ee ee SES Svea sae eae aero eels Ae ee) PP | SR 16000 (1535°) | 15000 eo Re Lai ace saa REE 14000 | |_| oe eeeesraettaccit Temperature in microvolts. 15000 aa Be QU 50) 2a aa Eee ela ee 2200 Sed Ge ae ie a fan eee eee | | tt tt BdiRlee DERE Eran 000 Hea so ee eee oo eral | enees maemo ye eS es ye Time—1 division = 1 minute. Fig. 17. I = Enstatite. II = Monoclinic pyroxene. 496 E. T. Allen, F. EF. Wright and J. K. Clement— 18009 is PRieries enien a ia a eZ enna es | Rae eC eee amanenae -}-|- ae Annee: 15000 PERC ee PT PEPE A SPSS SS Soe ee PCC SAE Ea eae Ran (RARER RRBE | MPR ERSeS PSS oes | eet eee PT SS EES So) es a aR HR Pine el (lf PSR ie] as Ea cal ean eS aed | - een tina e ee PE ASE See ee PASTS Sas Pa Ses ai ee POSS PSS Eee ee pita fe Be Pee eee oth} i Ey] ie een eee | OG G@PEBEeeE Co CeL Ge | | eek esSee ee A TI silos 1 TS Fes a PE ee ee ol SST TS Ta ST a a Ae iene eee eee Fe | Se | ee eee eee ee ee Ree een eee! Bea seek eee ae Be? eee aR re ig eae a | ga) [S(T ST Time—1 division = 1 minute. 14000 Temperature in microvolts. 18000 Fig. 18. I= Enstatite (two curves). . IIT = Monoclinic pyroxene (three curves). 0 I 2 3 a oO 6 Time. min. 66 ce ce ‘4 ee ce ‘4 ce 6¢ Minerals of the Composition MgS10,. TABLE X (see fig. 14). Mono- clinic pyroxene. 15000 13500 350 440 625 830 14000 145 265 370 455 Amphi- bole. 15000 12700 415 750 13200 630 930 14180 350 495 600 706 785 803 814 831 841 855 869 878 886 876 873 877 890 892 894 898 905 910 9135 917 Enstatite. 15000 13170 12707 870 13175 005 780 14017 200 353 466 555 618 671 708 738 761 SH! 796 808 819 834 847 857 862 864 863 866 871 876 881 884 888 890 893 S95 898 66 66 66 6¢ 427 TaBLE XI (see fig. 15). Monoclinic. 15000 15000 i 4510 ee OOO) 10200 100038 10520 10280 11185 915 870 11650 12435 12285 915 830 13290 13257 613 610 860 880 14070 14100 235 266 Ss 400 479 000 566 579 630 639 687 687 728 724 763 SS) 789 778 811 796 828 S11 843 825 855 837 866 847 874 856 881 865 886 871 891 877 896 882 903 886 908" 7839 912 893 917 897 921 901 924 904 927 930 Amphibole. 15000 15000 10850 11050 9950 10200 10560 770 11530. 1 ene 12460 12575 13120 13170 640 655 980 990 14230 14240 407 424 557 585 688 716 Od 785 833 801 839 807 839 814 847 821 847 827 852 832 859 838 857 844 858 849 862 854 865 859 869 863 874 867 881 870 880 874 887 877 891 880 893 883 895 885 896 887 898 890 900 892 902 894 tion of the thermoelement was less carefully adjusted, but the relative position of the curves is clearly established. Figures 15 and 16 (Tables XI and XII) contain curves for the same amphibole and monoclinic pyroxene, and figures 17 and 18 (Tables XIII and XIV) for enstatite and the monoclinic pyroxene, which represent the results of experiments made Scene tet es 428 #. T. Allen, F. EB. Wright and J. K. Clement— TABLE. XII (see fig. 16). TABLE XIII (see fig. 17). Monoclinic Monoclinic : Time. pyroxene. Amphibole. Time. pyroxene. LEnstatite. 0 min. 15000 15000 Omin. 15800 15800 10920 10600 12100 12380 pe 3435 170 Ibe 11160 140 890 825 700 670 hate a 11570 11625 Dec 12325 13200 WPA) 12380 940 690 ore bee 740 995 Saha 13410 14065 13180 15490 805 370 ase 320 840 Ay oes 14115 615 815 14120 375 820 ares 14040 332 eee 584 980 223 500 768 15115 Ges DOs 630 Ornwae 915 215 476 739 15048 295 UD inte 559 195 Ce ae 152 352 627 lis) 242 394 Sunes 678 830 oly 312 428 720 841 372 455 Dio 751 850 Ode 418 476 778 860 458 + 495 LON 798 868 LOW 489 510 811 876 515 023 el ive 825 884 Aap ets 536 533 838 891 557 543 ise 849 897 Mo ssionce 572 551 857 903 588 558 si sf 863 908 ie Samer 601 565 871 913 612 573 14 877 QL LANs = OS) 580 885 921 631 587 PON 888 924 Pou oe 639 594 893 928 647 600 io) ah 897 931 Gas 654 606 905 933 661 612 Ne ea 909 937 LiFe 3 666 616 913 940 672 623 iPS ad 916 942 1S ies 678 628 631 with all the precautions which we have prescribed. The curves for both the enstatite and the amphibole lie to the left and above that for the monoclinic pyroxene. They therefore change into the latter with evolution of heat, and hence are monotropic with respect to it. The curve for the orthorhombic amphibole lies outside that of enstatite, and consequently the exothermic change is quantitatively greater 18 (45 (74 Minerals of the Composition MgSi0,,. 15700 8500 8645 9300 9930 10905 11800 12630 13325 890 14290. 555 808 975 15095 185 242 309 357 386 416 440 458 476 492 504 514 524 533 541 548 555 561 567 572 577 581 585 15700 9520 9915 10615 11475 12270 13005 605 14113 455 228 915 15052 152 230 289 Bel 374 406 431 453 47] 488 501 514. 525 534 043 Doll 058 565 | all By 582 587 592 597 TABLE XIV (see fig. 18). Monoclinic pyroxene. 15700 10100 9400 9848 10605 11515 12315 13075 715 14170 510 763 938 15068 161 233 287 331 565 394 417 437 454 469 48] 492 D093 dll 520 527 533 539 545 550 555 559 563 568 499 Enstatite. 15700 15700 9800 10000 8715 9765 9325 10210 10415 11035 11640 12010 12620 890 13475 13658 14065 14205 510 615 797 877 15000 15055 135 179 238 265 308 394 366 | 372 407 410 443 443 468 462 482 48] 499 S11 923 533 542 551 558 565 570: 575 579 985 588 596 600 605 604 for amphibole, which indicates that it is the least stable of the three forms. As compared with the curve of wollastonite glass, the form of the (orthorhombic) amphibole curve is significant. The change of the former begins at a much lower temperature and forms a smooth curve, while the latter changes at higher temperatures and, as a result, the influence of the heat change continues until the maximum temperature is almost reached ; consequently the curve shows the top. a sharp change in direction near 430 ET. Allen, F. E. Wright and J. K. Clement— Although this method is purely qualitative, repeated trials on all these substances have convinced us that the relative posi- tion of the curves is invariable. No point of change, of course, can be found. In the consideration of these curves the fact must not be overlooked that they include two quantities which may be independently variable, the heat of fusion or inversion and the specific heat. In general it is undoubtedly true, and therefore a justifiable assumption in this case, that latent heats are of a greater order of magnitude than specific heats. Although glasses possess higher specific heats than the solids which erys- taliize from them, polymorphic forms of the same substance in all-probability possess similar specific heats. For the pur- poses here described, we are, therefore, perfectly safe in assum- ing that the comparisons made are independent of differences of specific heat in the substances experimented upon. The results obtained for albite by this method are in full accord with well established existing data, although albite, of all the substances examined, might be expected to offer difficulties from this cause. A substance exhibiting a sluggish heat change might perhaps be found in which the relative magnitude of the specific heats of it and its product, when compared with the latent heat of the change, would be such that the latter would have less influence on the form of the curve. In such a case, the method would lead to erroneous conclusions. It goes without saying that if the change to be investigated does not take place during the time the substance is in the furnace, the method is useless. We found this true in the case of quartz. When the temperature of the furnace was held at 1560°, only about 1 per cent of the quartz was changed during the twenty minute period of experiment, even though other evidence has shown that tridymite is the stable form above a point at least as low as 800°.* Order of Stability—We have seen (pp. 402, 410 that the orthorhombic amphibole and enstatite both pass over into the monoclinic pyroxene under circumstances which point to the greater stability of the last named form;.that the heat effect which accompanies this change of state is exothermic in all cases, but quantitatively greater in the change—amphibole —~> mono- clinic pyroxene. The amphiboles are, therefore, less stable than enstatite, a conclusion which is substantiated not only by the greater difficulty of forming the amphiboles, but by the closer resemblance of all the properties of the two pyroxenes. The fact that the monoclinic amphibole probably forms directly from the orthorhombic amphibole in the presence of water at 375°—475°, though the orthorhombic form is all the while in * Day, Shepard and Wright, loc. cit. Minerals of the Composition MgSi0,. 4310 excess, indicates the greater stability of the former. In connec- tion with this it should be noted that the two amphiboles resem- ble each other as closely as do the two pyroxenes, the mono- clinic forms being the stabler in both cases. The order of stability of the four forms is represented in the diagram (p. 414). Volume Relations.—A |though theoretically there is no reason requiring it, the facts show that the specific gravities, and there- fore the specitic volumes, of the four forms of magnesium silicate he in the order of their stability: Ppecitic ay Olt CAC eteis fee oe a i he 8 ‘¢ orthorhombic amphibole -_-_-- -_- 2 8a7 aes ¢ ** monoclinic ena ee ve eesti - “‘ orthorhombic pyroxene _-..-.- 3°175 = Ge ‘¢ monoclinic “ ee earn hoe Geological Inferences. ns of Formation of Meteorites.—It has been shown above, that the monoclinic magnesian pyroxene, though not gener ally recognized as amineral, does occur in nature. After it had been found to be the stablest form of magnesium meta- silicate, its occurrence seemed altogether likely. An examina- tion of the literature then developed the fact that Fouqué and Lévy had already discovered it in meteorites.+ Still their proof lacked one essential point; they assumed the composition of the mineral. The optical study of the material of the Bishopville meteorite, which has been shown to be practically pure mag- nesium silicate,{ supplied the missing link in the chain: a care- ful measurement of all its important optical constants, and a comparison of these with the constants of our monoclinic form, established the identity of the two. Fouqué and Lévy state that in some meteorites the monoclinic form, in others the ensta- tite, is in excess. In the Bishopville and other meteorites, this form is intergrown with enstatite. In the similar inter- growths of enstatite with a “monoclinic pyroxene” so frequently observed in rocks, it is very probable that in some cases the latter has the same composition as the enstatite. The parallel growths of enstatite and the monoclinic pyrox- ene which are characteristic of meteorites, we were able to repro- duce by cooling a molten mass of pure magnesium silicate at a rather rapid rate. The slower the cooling, the more of the * The specific gravity of this form’has not been determined, because the substance has not been obtained free from other forms. Its average index of refraction is very close to that of the orthorhombic amphibole, but appears to be a trifle higher, so that we assume with some degree of probability that the specific gravities of the two amphiboles are related just as those of the two pyroxenes. + Bull. Soc. Min., iv, 279, 1881. tJ. Lawrence Smith, this Journal (2), xxxviii, 225, 1864. 432 E. T. Allen, F. E. Wright and J. K. Clement— monoclinic form is obtained; hence we conclude that the Bishop- ville meteorite was probably cooled rather rapidly from a high initial temperature. The occurrence of similar intergrowths of the same minerals in many other meteorites indicates that the above mode of formation is a general one, though ferrous sili- cate, which is generally present, would lower the temperature of crystallization. Occurrence of unstable forns of the metasilicate in nature.—- Since the monoclinic magnesian pyroxene is the stablest form, the question naturally arises, why does it not occur more fre- quently in nature. The probable explanation is that the mag- nesium silicate of nature generally crystallized from solutions or magmas, the temperature and viscosity of which conditioned the formation of the enstatite or amphibole. In the foregoing, it has been proved that under atmospheric pressure the monocline pyroxene is the most stable form of magnesium silicate, and it has been shown how various solvents may transform the other polymorphs into this one. Yet it isa very common thing for unstable forms of enantiotropic, as well as monotropic, substances to crystallize first* from solu- tion, whether we start out with a stable or unstable form, pro- vided the solution is not in contact with the stable solid; and in one instance, that of mercuric iodide,t crystals of the unsta- ble yellow variety sometimes form even in the presence of nuclei of the red (stable; form, though they soon pass over into the latter. We had already found that the unstable amphibole forms from water solutions at temperatures of 3875°-475°, and it seemed worth while to make the attempt to produce enstatite as well as the orthorhombic amphibole from sz/icate (magmatic) solutionsat higher temperature. We used for these experiments portions of 50 to 60 grams, the solutions consisting of magne- sium silicate mixed with about 10 per cent of its weight of vari- ous other substances. The results are recounted briefly below: 1. 40 grams magnesium silicate and 5 grams of ferric oxide were fused in a Fletcher furnace. The heat was then turned off and the crucible allowed to cool in the covered furnace in which, as the walls are thick, the temperature falls at such a moderate rate that the pure magnesium silicate crystallizes almost entirely in the monoclinic form. A microscopic exam- ination showed that the ferric oxide had not greatly influ enced the crystallization. * Regarding the crystallization of suphur, see Gmelin-Kraut, Handbuch der Chemie, vol. 1, part 2, p. 155; and for similar facts about phosphorus, see vol. 1, part 2, p. 10. See also O. Lehmann, Molekular-Physik, vol. 1, p. 193, for many other instances of this kind. + Kastle and Reed, Am. Chem, Journ., xxvii, 217, 1902. Minerals of the Composition MgSi0,. 433 2 42 grams of magnesium silicate and about 4 grams of labrador- ite (Ab,An,) were melted and cooled under similar condi- tions. ‘The magnesium silicate crystallized chiefly as mono- clinic pyroxene with some enstatite present. Small amounts of glass, probably plagioclase glass, filled the interstices between the pyroxene laths. 8. To solution 1, 5 grams of orthoclase were added; the whole was then fused and er ystallized as before. This time a quan- tity of coarsely cr ystalline enstatite was produced. The ortho- clase remained as glass. 4. 50 grams of magnesium silicateand 5 grams of albite were fused and cooled as before. The magnesium silicate crystal- lized mostly as enstatite, with the characteristic properties: paralled extinction, c= c, cleavage prismatic with an angle of about 90°, birefringence not strong, optically positive; 2E apparently larger than usual. The section consisted of clear enstatiie laths and intercalated patches of a cryptocrystal- line, dust-like aggregate which appears to contain albite and enstatite—perhaps a eutectic mixture of the two. Parts of the aggregate had a refractive index apparently equal to that of albite. 5. 46 grams magnesium silicate, 4 grams sodium metasilicate, and 1 gram potassium metasilicate were fused and cooled under the usual conditions. The cake was filled with beautiful prismatic crystals, the longest of which was 23™™ in length. Most of the magnesium silicate had crystallized as enstatite, though there was some of the monoclinic form. The optic axial angle of the enstatite was apparently larger than usual. 6. Preparation No. 4, consisting of the metasilicate with 10 per cent albite, was remelted and cooled more rapidly than the previous ‘solutions. The product consisted chiefly of the low refracting, orthorhombic amphibole form of the metasilicate. Many of the fragments of the product were clearer and showed brighter interference colors than the amphiboles; they con- sisted of finely intergrown fibers of refractive index slightly less than that of the amphiboles (about 1°560) which may have been due to a solid solution of albite in the amphibole. 7. 4°6 grams of albite were added to 46 grams of the magma de- scribed under 6, giving a solution containing about 20 per cent as much albite as silicate of magnesium. The fusion was cooled like 6 and the low refracting amphibole formed. The grains were not clearly transparent and exhibited the dusty appearance observed in the albite-enstatite mixture of pro- duct No. 4. Therefractive index and other optic properties coincided closely with those of the magnesium amphibole from pure melts. Silicate solutions can probably be prepared from which the amphibole will crystallize by a process of slow cooling such as prevails in nature, but thus far we have not hit upon a compo- sition which is effective. Am. Jour. Sci.—Fourtu Series, Vou, XXII, No. 131.—Novemser, 1906. 50 434 ET. Allen, FE. Wright ond J. HO Clee In explaining the formation of enstatite in the above eases, the influence of temperature is doubtless of importance. When pure magnesium silicate is cooled slowly enough, 1. e., when erystallization occurs at a temperature not too far below the melting point, only the stable monoclinic form is obtained; if cooled more rapidly, enstatite begins to form; still more rapidly, and we have amphibole; and “finally, when we chill very suddenly, glassis the result. In all these cases, the temperature at which crystallization occurs is the lower the more rapid the cooling. The first influence of these solvents is, therefore, no doubt, to lower the temperature at which crystallization ‘takes place, though not all of them are equally effective; the addition of labradorite and ferric oxide makes less difference than albite, orthoclase and the alkaline silicates. This explanation is, however, an incomplete one, otherwise — why should fluxes like the vanadates of magnesium and eal- cium, tellurous oxide, and magnesium chloride, always give the monoclinic form even at considerably lower temperatures. Comparing these solutions with those which give rise to enstatite,. we note at once that the one property which serves to distinguish the two classes is the viscosity. The monoclinic variety is obtained from thinly fluid solutions. At first sight it might appear otherwise with the vanadates, because the whole mass of silicate and vanadate from which we crystallize the silicate seems little more than pasty. The most of the mass is indeed undissolved solid, but the molten vanadates are comparatively thin and so no doubt is the solu- tion which covers the surface of the grains of silicate and colors it yellow. The enstatite, on the other hand, was obtained from solutions which are comparatively viscous at the temperature of crystallization. The influence which the viscosity of a solvent exerts on the transformation of unstable crystals which stand in contact with it, has been very well shown by Kastle and Reed.* The substance which they investigated was. mereu- ric iodide, an enantiotropic substance with an inversion point at 128°. The yellow form is only stable above this point, yet below that it is always obtained from solutions whatever the solvent may be. The rate at which this form passes over into the red variety, stable at ordinary temperatures, depends on the viscosity of the solvent. Thus with certain mobile solvents like water, the transformation was complete in a very short time, while under a concentrated sugar solution the red appeared only after several days, in glycerine after two weeks, and in vaseline none appeared after a year and a half. In the case.of mercuric iodide, so far as known, the unstable form always * Loc. cit. Minerals of the Composition MgSi0,. 435 erystallizes no matter what the solvent, but this is not true in many other instances. It seems entirely reasonable to expect that if a solvent by its viscosity can hinder a transformation in the solid state, it may also in certain cases restrain the mole- cules in the act of crystallization from assuming the configura- tion characteristic of the stablest structure. And we might also expect viscosity to be especially effective where the transfor- mation of the unstable form into the stable is effected with comparative difficulty, as itis in the case of the magnesium silicates. This would explam why enstatite comes out of a viscous silicate solution at a temperature much higher than that at which the monoclinic form is obtained from thinner solutions. At first thonght.one might be inclined to regard viscosity as directly conditioning the form of the erystal, and to look upon the temperature as merely influencing the viscosity, but further reflection convinces that this can not be so, for we obtained the amphibole from aqueous solutions at 3875°-475°. The properties of aqueous solution m general, however, differ widely from others. It is probable that those movements of the molecule which depend directly upon temperature have a very important influence on crystallization. Although tem- perature and viscosity are certainly important factors in the formation of unstable modifications, the knowledge of the sub- ject is still insutticient, and what we have is too little systema- tized to generalize in an entirely satisfactory way. Formation of Amphiboles. —Regarding the formation of forms III and IV, it seems quite beyond the bounds of proba- bility that they should be formed in nature by the rapid cooling, which, on asmall seale, 1s effective. On the other hand vassuming that these forms are really amphiboles, the formation of at least one of them from aqueous solutions, at a temperature of 375°-475°, is consistent with recosnized geological forces; at any rate, our experiments indicate that the two amphiboles form at lower temperatures than the pyroxenes. Weare inclined to regard the pressure in these experiments as an unessential factor, except in so far as it is necessary to prevent the escape of water at these temperatures, because in the first place it has been seen that both substances (III and IV) could be obtained without pressure, and secondly, the specific volume of these amphiboles, as ot all others, for that matter, is greater than that of the corresponding pyroxenes. Accor ding to Le Chatelier’s principle, pressure should tend to produce the system of small- est volume. Relation between Pyroxenes and Amphiboles.—Though we refrain from generalizing as yet in regard to the two great min- eral groups, the amphiboles and the pyroxenes, we can say that the demonstration of an irreversible (monotropic) relation between each of the two magnesian amphiboles and the stable pyroxenes accords with the experience of many other investi- 436 HL. T. Allen, F. EH. Wright and J. K. Clement— gators that, experimentally, amphiboles may be readily changed ito pyroxenes but not pyroxenes into amphiboles. false Lquilibria in Natwre.—Since these studies have shown the instability of enstatite and the amphiboles of the com- position MeSiO,, it may be at once inferred that not all natural minerals are stable. The occurrence of the unstable forms alone constitutes what is commonly called a metastable condi- tion (apparent false equilibrium of Duhem), in which it is gener- ally assumed that equilibrium may be brought about by contact with the stable phase. In another part of this paper it has been demonstrated that such a contact is madequate, in the case of the magnesium silicates, to determine equilibrium dur- ing periods of time which are within the lmits of laboratory observation. Duhem, in his Thermodynamique et Chimie (p. 486), draws avery apt comparison between chemical and mechanical sys- tems. The statics of both are commonly treated as if the sys- tems were frictionless, whereas in both we have to deal with a resistance which in the former is ordinary friction, in the latter an internal friction between the molecules. Chemical systems, in the majority of cases so far studied, seem capable of reach- ing a true equilibrium, or at least a state which approaches it within measurable limits, but where the systems are com- posed of viscous liquids or more especially of solids at low temperatures, true equilibrium may not be reached even after an indefinite time, the condition finally attained being not alone the result of molecular forces as conditioned by temper- ature and pressure, but of these retarding forces which offer an internal resistance of by no means negligible magnitude. (Duhem’s genuine false Seale We find in nature false equilibria ‘of this kind, e. g., intergrowths of pyrite and mar- casite* among the sulphides, and among the silicates inter- growths of sillimanite and andalusite, and enstatite with monoclinic pyroxene.+ It has been generally supposed that the monoclinic pyroxene in the last-named case was a diopside, but our experiments show that similar aggregates form in arti- ficial systems which contain no calcium and that they exist in the Bishopville meteorite. In some eases it is not at all impos- sible that these systems are in process of very slow change, but there is no optical evidence that this is true of the above-men- tioned silicates; in other cases it may be that the two forms were deposited at different times, though in some it would appear that they were actually crystallized together; the important fact to note in them all is that they are systems which are not in equilibrium. Because a rock or mineral aggre- * Stokes, H. N., U.S. Geol. Survey, Bull. 186. + We have also obtained intergrowths of the two magnesian amphiboles. Therefore the aggregates of monoclinic and orthorhombic amphiboles in. nature probably form another example of this principle. ae ee Minerals of the Composition MgSiO,. 437 gate is found in nature, therefore, where it might be supposed to have had sufficient time for attaining equilibrium, is not a sufficient reason for assuming that it has actually reached the state of greatest stability. Summary. 1. There are four crystal forms of magnesium metasilicate: (1) a monoclinic pyroxene, having the characteristic prismatic cleavage (92° and 88°), and a similar axial ratio a: b, but a ratio C20, which varies widely from that of the pyroxenes; (II) an orthorhombic pyroxene identical with enstatite and optically very similar to (I); (III) a monoclinic modification correspond- ing to an amphibole in its optical properties; (LV) an ortho- rhombic form, optically also an amphibole and resembling (IIT) very closely. These forms, with the exception of (III), have been prepared in pure condition or with only traces of other forms; their optical properties have been studied, their specific oravities have been determined, their behavior on heating has been investigated, and, in the case of (1), measurable crystals have been obtained. Forms (1) and ({1) occur in nature, usually in mixed crystals with ferrous silicate, and it is quite probable that the same is true of (IIT) and (IV), 2. (I) is formed in pure condition by crystallizing a melt a little below the melting point (1521°), which may “be readily accomplished by cooling slowly. Measurable crystals are obtained by heating any form of the metasilicate to about 1000° in molten magnesium chloride traversed by a stream of dry hydrochloric acid gas. Calcium vanadate, magnesium vanadate, magnesium tellurite, and other fluxes yield crystals which are not so well developed. All the other forms of magnesium silicate pass into (1) at temperatures between 1150° and 1300° depending on the crystal form taken. (II). This form (ensta- tite) crystallizes at lower temperatures than (I); the purest prep- aration, containing only traces of other forms, is made by heat- ing the glass of the same composition at a temperature between 1000° and 1100°; large crystals of enstatite (up to 23™" in length) were obtained in silicate (magmatic) solutions. (IIT) forms in very smal! quantities by rapidly cooling the melt; there is also evidence that it forms from (IV) when the latter is heated with water in a bomb to a temperature of 375°-475°. When an aqueous solution of magnesium-ammonium chloride, or magnesium chloride and sodium bicarbonate is heated with amorphous silica or sodium silicate, this substance is probably formed, though the crystal fibers are too small to decide whether the product is ‘identical with (IIT) or with(IV). (LV) is obtained by heating the molten silicate high above the melting point, say to 1600° , and then cooling rapidly in air; it cannot ‘be formed by heating the glass. 438 Allen, Wright and Clement— Composition MgSiO,. 3. Of the four polymorphic forms of magnesium metasilicate, (I) is the stable form at all temperatures and the others are monotropic toward it, the order of stability being I, I, Ill, IV. This order is established by changing one form into another at various temperatures and by proving that (II) and (LV) change to (1) with evolution of heat. (III) has not been obtained in suf- ficient quantity for this test. Though enstatite and the amphi- boles are not stable, any more than glasses are, on account of the great internal friction of the molecules, they have less ten- dency to change, when once formed, than many glasses. We cannot state definite limits of stability for the various minerals, as it is possible to do where the relation is enantiotropic; it is possible, however, to fix certain temperature limits below which one of these forms may crystallize from a melt of pure magne- sium silicate. Thus enstatite could only form below about 1250°, since above that temperature it passes into the monoclinic form; but it must be remembered that in the silicate solutions of nature this limit would probably always be lower on account of the general occurrence in them of such compounds as ferrous silicate. 4. The specific gravities of the four forms, in the order of their stability, are: (1) monoclinic pyroxene, 3°192; (II) ortho- rhombic pyroxene (enstatite), 3-175; (IIT) monoclinic amphi- bole, not determined directly, but its relation to (II and (LV) is fixed by its index of refraction; (LV) orthorhombic amphi- bole, 2°857. 5. While our experiments do not settle completely the mys- teries of the formation of unstable bodies, they do show that temperature and viscosity are two factors of prime importance. Thus, from melts or from silicate solutions, the stable mono- clinic form of magnesium metasilicate crystallizes at the highest temperature, enstatite next, and the amphiboles probably low- est of all. From thin solutions the stable form is obtained at still lower temperatures, 800°-1000°, while from agueous solu- tions at 875°-475° an amphibole results. 6. Our study of the Bishopville meteorite imdicates that it must have been cooled very rapidly from a high initial temper- ature, and there is evidence that the same is true of other mete- orites. 7. The intergrowths of enstatite with the monoclinic pyrox- ene, and of the two amphiboles, which we obtained in close resemblance to those of nature, are cases of falsee quilibrium, and their occurrence establishes the fact that it cannot be as- sumed that all rocks or mineral aggregates are systems in true equilibrium. 8. In the course of the investigation a useful method has been developed for detecting sluggish heat changes. Geophysical Laboratory, Carnegie Institution of Washington, July, 1906. Pirsson and Washingten— Geology of New Hampshire. 489 Art XXX VIUI— Contributions to the Geology of New Hamp- shire: No. IL, Petrography of the Belknap Mountains ; by L. V. Presson and H. 8. Wasurxeton. In a former paper* we presented the results of our studies in the field of the igneous rock masses composing the Belknap Mts. in New Hampshire, and in the present one we purpose to give the results of our investigations of them in the labora- tory by microscopic and chemical methods. We have found that the following rocks, classified both in the quantitative and in the older systems, are present : Class Order Rang Persalane Britannare Liparase Persalane Britannare ‘Toscanase Persalane Canadare Pulaskase - Dosalane Germanare Monzonase Salfemane Gallare Camptonase Subrang . Older System Liparose (I. 4.1.3) Aplite Lassenose (I. 4.2.4) Adamellite Pulaskose (I. 5.2.3) Syenite Akerose (II. 5.2.4) Spessartite Camptonose (III. 5.3.4) Kssexite and Camptonite These will be deseribed in the above order and the article will end with a discussion of the petrologic history and of the chemical characters of the district. Liparase. Aplites. As previously stated in the foregoing geological description of the district, the Belknap massif and the surrounding meta- morphic rocks are cut by dikes and intrusions of fine-grained to dense granitic, quartzose rocks, whose general characters place them under this rang. In Rosenbusch’s system of classi- fication they would be aplites, both im the broader and in the more special application of this term. A similar material serves also as the cement of the brecciated zone on Locke’s Mill. They have all been studied in thin section, but for pur- poses of chemical analysis an average type has been selected whose description follows herewith. Biotitic-grano-liparose (aplite). Locality.—Dike on upper southwest slope of Mt. Belknap. Megascopic. — Phanerocrystalline; fine-grained; flesh-col- ored ; persalic and dominantly feldspathic ; faintly dotted with * This Journal, vol. xx, pp. 344-352, 1905.. 440 Pirsson and Washington— Geology of New Hampshire. gray to black specks; apparently equigranular in texture but subporphyritic, with occasional phenocrysts of feldspar 2-3°"; of a sugar granular habit; fracture easy and. brittle ; superficially shghtly weathered. Microscopic.—Alkalie feldspar and quartz essential ; biotite, iron ore, allanite and zircon accessory. Alkalic feldspars consist of orthoclase and albite in roughly equidimensional anhedral grains. Some albite-oligo- clase noted, subtabular to subprismatic in form; albite and Carlsbad twinning. Phenoerystic feldspars roughly equidimen- sional or cuboidal, of orthoclase with much perthitie inter- growth of soda- microcline and albite. Quartz, equidimensional, anhedral, sometimes micrographie with feldspar. Quartz and feldspar of groundmass average 0°5™". Bzotite dark brown, pleochroic, tabular, platy and in shreds, subhedral ; about 0°2™™, thinly scattered. //ornblende very rare, pleochroic, dark green I II il IV We VI VII SiO, Se eee 75°65 76°49 76°05 76°64 “76°03 “7412. or ALO. oe 12°89 11°89. 11°68 13°50 11-76 91036 ngeeter ReO. a eo OFSO TpO1h) 0°34 0°50 1°99 O'31 ‘006 Re ORs tie Lev 1°56 1°05 n.d. n.d. Hon | "015 MeO re 0:20 TIP 0°29 0:12 0:27 0°42 “005 CaOGges Cee 0°48 0°14 0°42 0°65 0°45 0°30 "009 Na,O ae Where Hr | 4°03 3°79 3°48 3°30 3°22 "060 KO MRE Nese 5°50 5°00 5°09 oS) Il 5°61 On "059 H,O O22 Ors 0°12 1°36 n.d. 0°63 alg Lees HE OVl108 10080 Ber te oe oe DOD melee 0-05 tr. 005: Ls Open een. Eas ee Sth eae he te ae 22.0 ae Nin@ es oe Ue erie Wats sets He. pares Le en oe rl es AD earn Ene oe ae 100°71 100°77 100754 100°40 100°10 100°38 I. Biotitic-grano-liparose (aplite); dike on upper southwest slope of Mt. Belknap. H. 8. Washington analyst. Ii. Riebeckite-phyro-liparose (paisanite) ; Magnolia, Mass. Washington, Jour. Geol., vil, 1899, p. 113. Iff. Liparose (quartz porphyry vy); Drammen, Norway ; Lang, Nyt. Mag. xxx, p. 40, 1886; P. Jannasch analyst. IV. Liparose (granitite) ; ” Arild, Kullen, Sweden; A. Hennig, Act. Univ. Lund, xxxiv, 1898. Hennig analyst. V. Liparose (quartz porphyry) 4 Thal, Thiiringerwald, Baden ; K. Futterer, Mitth. Bad. Geol. Ld. Anst. II. p. 58, 1893. VI. Liparose (trachyte) ; Wantialable Creek, Gowen Co., New South Wales; G. W. Card, Rec. Geol. Surv. N. 8. W., iv, p. 116, 1895. Mingaye analyst. VII. Molecular proportions of No. 1. Pirsson and Washington-— Geology of New Hampshire. 441 and yellow, in shreds or anhedral grains, 0°1 to 0:05". = Adlan-. ite rather rare, strongly pleochroie, clear dark brown and orange yellow, zonally built; well erystallized; about 0-2"; com- monly ‘attached to iron ore or biotite. Zircon rare, colorless, equidimensional subhedral grains, about 0°-2-0:1"". Tron ore uncommon; anhedral; about 0:1™". Traces of chlorite and kaolin. Fabric porphyritic, but not markedly so, the pheno- erysts being rare ; remaining grains somewhat orading in size but te nding to be equidimensional and interlocked, Mode.—The chemical analysis and the calculation of the norm show that there cannot be over 4 per cent of iron ores, biotite, hornblende, allanite, zircon, ete., present, the remain- der being feldspars and quartz in the proportions indicated in the norm. The mode is therefore normative. Chemical Composition.—This is shown in No. 1 of the table. _ For the sake of comparison a number of analyses of liparose from other localities have been added and it is of interest to observe how these almost identical magmas under varying physical conditions have assumed different textures, so that under systems of classification where texture plays an impor- tant part they have been given quite different names and are widely separated i in the system. They are all magmas of alka- lic nature, as will be shown later. Norm and Classification.—By using the molecular ratios given in No. VI of the above table we may calculate the norm to be as follows: mare 3102 Orthoclase.. 3289 Sal 97:2 Sake Oo = =—29,JI, Persalane Peltier: 2. 2 53144. r Fem a8 ata d Anorthite -_ 1: KF 66°19 ot ieee eee) aye eee =2:1,4, Britannare Diopside -__ 0°46 7} K.O'+Na.O’ 119 Hypersthene 1-46 | CaO! === 17, 1, Liparase Magnetite_. 1°39 > Fem= 3°31 Water, etc._ 0°28 | K,O’ 59 : J NG Co = 0°98, 3, Liparose rotate. 100280 From the consideration of the analysis and the above norm and by the study of the section it is easily seen that the iron ore, allanite and biotite, are present in negligible amounts and that, as previously stated, the rock has a normative mode. ° It is therefore normative eranophy ro-liparose, but if the slightly porphyritic nature which is in no wise characteristic be neglected and the small amount of biotite be taken into con- 442 Pirsson and Washington— Geology of New Hampshire. sideration this would become biotitic grano-liparose. In the prevailing terminology it would be a granite aplite. Alkalie character of the rock.—The alkalic nature of rocks, which, like this one, are of high silica content, is to a great extent masked by the large dilution with silica. In a general way we might compare magmas to mixed solutions of salts in water. The ratios of the salts or the oxides which compose them and which give the mixture its general chemical char- acter remain the same whether the compound solution be dilute or concentrated. While the analogy with molten mag- mas is not exact, since the silica plays a role different from water, it will serve in a general way, as the ratios of the metallic oxides are a very characteristic feature. In rocks containing about 55 per cent of silica, the expression of the alkalic nature becomes most evident, so that in speaking of alkalic rocks petrographers are apt to have in mind those which contain about this percentage of silica. Yet rocks with high silica percentages may be as alkalic relatively to the other components as with low. This may be illustrated as follows. Let us take the liparose just described and reduce the silica to if II. Ta. Ila. Siw vs? Soy sO} Olmentia 2s 31:02 oe BANA ioe ps 12°89 23°14 Orthoclase ..- 32°80 58°38 Hes Onr ess 0°89 1°60 AGEs ae eee 31°44 4°19 BeOme aces cas 1:99 Nephelite 220 i= 28°12 NO oar 0:20 0°36 Anorthite_2_2 1°95 3°89 CaO ee O48 0°86 Diopside _--.- 0°46 As NiatO ee 37) 6°66 Hypersthene . 1°46 Lee iG aie wes 5°50 9°87 Olivine | ae 211 TO ere 0°23 0°41 Magnetite _.. 1°39 2°32 COs ole 0°05 0°09 Wiaiter, ete =a er eae 62 otal 222) O00 Mee 00:00 otal. 24.5 100°80 99°63 55 per cent, or in other words, we will subtract 45 per cent of silica from the magma, leave all the other oxides in the original proportions, and reduce the whole to 100. The result 1s seen in columns I and II of the above table, and their calculated norms, or those minerals which they would naturally form if in a state of dry fusion without the aid of the mineralizers neces- sary to condition the formation of such alferric minerals as mica aud hornblende, are seen in Ia and Ila. IL and Ila show the chemical and mineral composition of a characteristic “foyaite,” of a somewhat potassic character. To change this to the granite of I it is necessary to dilute it with 82 per cent of its own weight of silica, a figure which shows the great amount of dilution the alkalic magmas of high silica content Pirsson and Washington—Geology of New Hampshire. 443 - suffer, with the consequent masking in large degree of their true character. In the quantitative classification this is obviated to a great extent, for such rocks fall im peralkalic rang’s, which fact at once reveals their nature. At first thought all this may seem merely a rather forceful way of putting well known facts, but the application of it serves to bring out some points in a disputed field. In the endeavor to use the genetic relations of igneous magmas for purposes of classification, it is often implied, if not expressly stated, that we should not expect to find strictly alkalic rocks associated with those of other series, with the granite-diorite or diorite-gabbro families of Rosenbusch, alkalicalcic or docalcie maginas in the new classification. If the idea of alkalic rocks is however broad enough to include those greatly diluted with silica but in which the other oxides are in the proper propor- tions, as it rightfully should be, then numerous examples which contradict the general supposition mentioned immedi- ately come to mind. Thus in the Yellowstone Park region, as shown by Iddings,* the main lavas extruded have been “rhyolites, andesites and plagioclase basalts,” a really typical granito-diorite-gabbro series. An examination of the analyses of these lavast shows that many of the rhyolites, such as those of Obsidian Cliff, are of highly alkalic nature, belonging in peralkalic rangs which with less dilution by silica would have formed trachytes or phonolites. Liparase.—The type just described was selected as illustra- tive of the granitic dikes in the area. There is some variation among them in texture, but so far as one can tell by study of the sections they are certainly peralkalic persalanes and appar- ently are quardofelic. They fall therefore in liparase and judging by analogy are probably sodipotassic and belong in liparose. This last, however, could not be definitely determined without making chemical analyses, a work whose results would not justify the time and labor. A few words may be added concerning the textural variations of the different occurrences. Gunstock Dike.—The summit of Mt. Gunstock is cut by a dike three feet wide with the following megascopic characters : phaneroerystalline ; inequidimensional ; usually porphyritic with medium phenocrysts ; pale flesh color ; ; phenocrysts of ortho- clase 2-5™™, ill defined, cuboidal to subtabular, scattered ; groundmass fine-grained 1™™ or less, dotted with minute eray- black specks. Under the microscope the minerals are the same as those mentioned in the type described, including allanite ; the groundmass is similar but is thickly crowded with *Quar. Jour. Geol. Soc., vol. liii, 1896, pp. 606-617. + Bull. U. S. Geol. Surv., 228, p. 120, 1904. 444 Pirsson and Washington— Geology of New Hampshire. subhedral phenocrysts of alkali feldspar. The rock is grano- phyro-liparase or quartz syenite porphyry. | Belknap Dikes and other Occurrences.—On the upper slopes of Mt. Belknap dikes are found of widths varying from afew inches to twenty feet, of branching and anastamosing character. A large one, 20 feet in width, occurs on the shoulder of the west spur of Mt. Gunstock. They are also found as narrow dikelets in the massive rock composing the lower west slopes of Locke’s Hill. They are flesh-colored rocks, compact, dense, microcrystalline, ore oceasional, seat- tered phenocrysts of feldspar. Under the microscope they are very fine-grained to almost crypto-crystalline mixtures of quartz and alkali feldspar. In those where the grain is coarser shreds of biotite appear. The feldspar phenocrysts are some- times of oligoclase but mostly alkalic feldspar and offer nothing of especial interest. In those with the finest grain the material is apt to be arranged in micropoikilitie patches. They are too fine for metric analysis, but their whole char- acter and relations are such that we have placed them provis- ionally under liparase, though it is possible that sometimes they are quarfelic instead of quardofelic and should be classed as alaskase. In Rosenbusch’s systern they would probably be termed quartz-bostonites, especially if their relations and gen- etic associations with the syenite and camptonite be taken into account. Other instances are found in dikes cutting outward through the enclosing schists at the west foot of Mt. Gunstock. These are fine-erained, megascopically even granular or homometric rocks of pale yellowish to flesh color whose average diameter of grain is about 1™™. They evidently belong under this heading and no further description of them is necessary. In the older systems they would be classed as fine-grained granites or ap ites. They stand in evident relation with the pegmatitic masses of quartz and feidspar found in the schists at the head of the Gunstock River. The Breccia Cement.—As already described in, the forego- ing part on geology, there is on the lower southwest foot of Locke’s Hill a breceiated mass consisting of blocks of various character and of all sizes embedded in a fine-grained aplitic granite intrusion. The study of a number of ‘sections of the latter rock shows that it belongs here in liparase. It 1s com- posed of alkalic feldspar and of quartz with occasional larger phenoerystic alkalic feldspars, which are mostly alkalic but sometimes oligoclase. Occasional shreds of biotite, grains of iron ore and zircon occur. The rock is so like the type analyzed and described and the Gunstock dike that it must be considered as of the same mag- Pirsson and Washington— Geology of New Hampshire. 445 matic character and probably contemporaneous with them, as will be shown later. In its deficiency of plagioclase feldspar it is unlike the aplitic lassenose (adamellite) of the border facies of the main mass next described, and this fact, which is _ of importance, will be discussed later. Biotitic-grano-lassenose (adamellite aplite). As previously mentioned in the geological part of this paper, the Belknap massif of grano-pulaskose shows on nearly all sides a marginal facies of a light-colored granitic rock into which it gradually passes. Examples of this from various parts of the area have been studied and it has been found to have on the whole a pretty constant composition and character. Its geological occurrence and relationships have been described under the heading of the contact facies of fine-grained granite, using the latter name as a field term. For purposes of analysis, detailed microscopic study and description, a type specimen was selected from the south end of Piper Mountain, where it is exposed in a cliff near the high road running thr ough the notch to Young’s Pond. Megascopic. —Phanerocrystalline ; fine-orained ; hight brown- ish gray; dominantly quartzo- feldspathic but dotted with minute specks of black biotite and shining white muscovite ; of an even granular texture with sugar granular habit and feel ; distinctly gneissoid and with perceptible eutaxitic structure; of an easy fracture and rather friable. Microscopic.— Alkalic feldspar, andesine and quartz essential, biotite and muscovite accessory. Essential minerals present in approximately equal amounts. Average size of grain 0°2™™: occasional individuals much larger but not phenocrystic; some smaller. ) 4°28 oes EF GOs has. * 2 ap Hare, 4 2+ 2 i cael K_O’+Na,0° 88 Toscan- Mt ae "46 4°90 4:30 ciavonys ae -_ = 48 — eo. welt O | 76 Ko" Li ? HO. : 65 Na 0’ = ae = 0°33, Lassenose, 4 Total, 100-00 Place formula, I, 4, 2, 4. The extra alumina above that needed to produce feldspars is shown above by the production of 4°28 per cent of corundum among the normative minerals. The texture is granular, the micas are not present in notable amount and the mode is there- fore normative. If it is desired to note the small-amount of biotite present the rock is therefore a biotitic-grano-lassenose. In the prevailing qualitative systems it is somewhat difficult to place this rock. It is a marginal facies of a syenite mass with aplitic habit showing some fluidal structure, and it stands mineralogically exactly on the line between the granite and diorite families. If we determined it as an aplite from its minerals and texture and used Brégger’s definition of the monzonite family, it would be a quartz monzonite aplite or adamellite aplite+ Or it might be called a grano-diorite aplite, using grano-diorite, as many have done, to signify a transition rock between the granite and diorite families. *Chem,. Anal, Ign, Rocks, U. S. Geol. Surv., Prof. Paper 14, 1903, p. 173. + Brégger, Predazzo. Vid. Selsk. Skrift. M-N. Kl. 1895, No. 7, p. 60. 448 Pirsson and Washington— Geology of New Hampshire. Inclusions in Lassenose.—In the border facies of the mass are to be seen, as noted by Hitcheock, dark inclusions or schlieren of variable size. Sometimes these are angular and of definite shape. Under the microscope they show the char- acteristic minerals, such as quartz, brown mica, iron ore, etc., and the fabric seen in certain hornfels, and are no doubt frag ments of schists, ete. caught up and metamorphosed by the magma. In other cases, as in the occurrences on the slopes above Point Belknap, they may have no definite form but are streaks and smears through the rock. The study of them in thin section reveals a type of rock closely allied to monzonase, monzonites in the current nomenclature. They are composed of a colorless to pale green pyroxene, green hornblende and brown biotite, labradorite and alkalic feldspar with accessory iron ore, apatite, etc. The labradorite is in stout laths which serve as cores for irregular ragged masses of feldspar, the plagioclase core passing outwardly into alkalic feldspar mantles. broad areas of the soda orthoclase also occur poikili- tically enclosing other minerals. The amount of the ferro- magnesian minerals, though variable from place to place in kind, is in amount nearly equal to the feldspathic. The masses in fact closely recall types from Monzoni and Yogo Peak, Montana. ‘They are believed to be of magmatic and not of foreign origin, and the study of the breeciated zone on the west side of Locke’s Hill, as described elsewhere, throws hght on their origin. Lornblendic-grano-pulaskose (syenite). This is by far the most important rock in the area from the geologic point of view, as it forms the major part of the great massif. A certain type of it appears to be rather uniform over the exposed area, although minor variations which will be described occur from place to place. For purposes of chemical and microscopical analysis and study a representative specimen was selected from a ravine on the west slope of Mt. Belknap about a third of the way from Morrill’s farm house to the top of the peak. Megascopic. — Phanerocrystalline; medinm to _ coarse- grained ; pale reddish, white to gray ; dominantly feldspathic but sparsely dotted with anhedra of black hornblende and of biotite; of a granular to subporphyritic fabric; feldspars mostly ‘equidimensional, occasionally larger than the average and subtabular to prismatic; fracture rather crumbly ; suger ficially somewhat altered. Microscopie.—Alkalic feldspar and hornblende essential ; biotite, iron ore, apatite, oligoclase-andesine, quartz and zircon accessory. : Pirsson and Washington— Geology of New Hampshire. 449 The feldspars consist of orthoclase with microperthite inter- growths of soda microcline. In a section perpendicular to c and nearly parallel to 6 (010), oriented by the good. cleavage of c (001) and rough parting parallel to m (110) and by the arrangements of inclusions giving the direction of the vertical axis and a measured angle for 6 of 64°, the main feldspar extinguished at 7° from the trace of the base e, that of the microperthite intergrowths at 11° in the obtuse angle 6’. Thus the main crystal is of orthoclase, the intergrowths of soda-microcline (anorthoclase). The amount of these inter-— growths is very large, indeed in most cases they appear to be as great as, or even greater in volume than, that of the host erystal. Sometimes these intergrowths show distinct multiple twinning and the optical properties prove them to be of oligo- clase-andesine (Ab,An,). Feldspars enclose all the other minerals save quartz. They are in formless masses, at times haying poor tabular development, with Carlsbad twinning com- mon. No microcline was observed, and the feldspars are somewhat kaolinized. The hornblende is in anhedral masses, at times poorly developed as short columns. Prismatic cleavage is-good. It is strongly pleochroic: c, olive-green to deep green; b, olive- brown ; a, pale brown; absorption medium strong, c>b>a. Angle of ¢ on c=18°-20°. From these properties it is prob- ably a mixture of the common hornblende and _ barkevikite molecules. It rarely contains a paler green core, and includes iron ore, zircon, apatite and biotite. In some places it is alter- ing into a reddish substance, probably géthite. The rock at the summit of Gunstock contains 13:4 per cent of hornblende; the type analyzed has somewhat less, probably not over 8 per cent. Biotite is quite subordinate in amount, while in other varie- ties of the massif it becomes more abundant, increasing with the amount of quartz, and in the marginal facies, which are rich in the latter mineral, it entirely replaces hornblende. It is of the type of common biotite, brown, strongly pleochroic, with inclusions of iron ore, apatite and zircon and with pleo- chroic halos. It is older than hornblende and automorphic against it, and quite unaltered. Jon ore occurs in occasional scattered grains. Zircon is present in crystals varying from exces- sively minute microlites to some of good size, rather common and sowed through all the later minerals. It is well crystallized with m (110) and p (111) well developed. Apatite is also com- mon in slender microlites and larger stout prisms. QVuartz is seen in very small amount in the type specimen in small xenomorphic masses, serving as a cement between the other minerals. It is too rare to characterize the rock as quartz- bearing. Ina variety on the top of the hill beside the road from Gilford to West Alton it is entirely lacking in two thin Am. Jour. Scl.—FourtH Series, Vou, XXII, No. 131.—Novemser, 1906. 31 450 Pirsson and Washington—Geology of New Hampshire. sections. In the lassenose marginal facies of the massif, as noted above, it becomes quite abundant. In addition to the above, two or three small sections of an indeterminable brown mineral were noted. It is strongly pleochroic, varying from a clear chestnut brown to practically opaque, like enigmatite. The refractive index is about that of hornblende; birefringence not high, but as the sections are cut nearly perpendicular to an optic axis whose bar crosses the field, in conjunction with the deep absorption, this cannot be well told, nor can any other optic characters be determined. The bar crosses the field without apparent bending, but it is not certain that the mineral is uniaxial. The color is unusual for tourmaline, the absorption too strong for cassiterite; if biaxial the color and absorption much deeper than ordinarily seen in allanite and much like that of snigmatite, but the mineral associations scarcely suggest the latter. It seems most probable that it is an unusually deep-colored allanite. ANALYSES OF PULASKOSE, ETC. I II III IV V VI SiO, ..... 60°75 60°20 65:54 © 63°71 63 20ne uum Al,O, SOE SOLES 20°40 17°81 18°30 17°45 °193 He O02 anise fa 0-74 2-08 3°60 010 MEeOrisso. 2°98 1°88 SS) 2°52 nese "041 MgO Be, ok OOM 1:04 0:98 0:09 0°75 ‘020 CAO ee ior 2-29 2°00 192 ua is: 1°40 “041 Na,O meds er at! eas) 6°30 5°95 6°39 6°90 ‘079 K,O Bier wa PaO) 6°07 5°58 Gazal 5°88 °063 H,O 110°+ 0:08 0°23 0°54 0°17 0°50 digas 2 H,O 110°— 0°24 0-10 ane 0°09 nS Oe eee CO ee eey: Brn oe 2 none ee Ae a ae ees TiO. iaes 0°63 0-14 O-11 tr. 0°46 -008 Pi. 35 tr. 0°15 ti eye ee oe: Oni ieee touts est 0°13 ras Oe ay te: CNET ed Bes chs. 0°09 Wg ai ae See ee Nin ores Lie: tr tr tr alae a otal... 2) 99°79 100°47 99°92 100°74 100°14 I. Pulaskose (syenite). West slope of Mt. Belknap, N. H. Washington analyst. II. Pulaskose (pulaskite). Fourche Mountain, near Little Rock, Arkansas. Washington analyst (Jour. Geol. ix, 1901, p. 609). | III. Pulaskose (syenite). Highwood Peak, Highwood Mts., Montana. Pirsson and Mitchell analysts. (This Jour. i, 1896, p. 295. ry. Phlegrose (pulaskite). Salem Neck, Essex Co., Mass. Washington analyst. (Jour. Geol. vi, 1898, p. 806.) V. Nordmarkose (nordmarkite). 'Tonsenas, near Christiania, Norway. G. Forsberg analyst. (Brogger, Zeitschr. Kryst. xvi, 1890, p. 54.) VI. Molecular ratios of No. I. -Pirsson and Washington— Geology of New Hampshire. 451 Mode.—The rock is too coarse-grained to determine the actual mineral composition on ordinary sections by the Rosiwal method with any degree of accuracy, but from measurements made on the hand specimen with a millimeter scale it appears that about 10 per cent of alferric minerals, chiefly hornblende, are present, the remainder being alkalic feldspar with a little quartz. Chemical Composition.—The analysis of the specimen gave the result shown in No. I of the foregoing table: The very small amount of water yielded in the analysis proves that the rock is really in a very fresh and unaltered condition and that the pink color and slight staining are quite superficial. For comparison two other analyses of pulaskose are added, one the typical rock from Arkansas and one described by one of us from Montana, and also a phlegrose from Massachusetts. In some ways the rock is closely related to nordmarkose from Norway and the analyses are not very different. The greater amount of lime in the Belknap rock throws it in the domalka- lic rang and the larger relative amount of potash compared with the soda into the sodipotassic subrang, nordmarkose being peralkalic and dosodie. Classification.—In the quantitative system the norm is cal- culated to be: Quartz _... 2°04 | Sal 90°88 Fi Nee Persal- Orthoclase . 35°03 | Kem) of) 6-6 52) Pane Alsite 23). 41°39 \ 90°88 Anorthite __ 11°40 | Q 2:04 KeOZENa OF 142 Pulas- Be 2 ee or 4 9 Hypersthene 5°30 CaO’ me ares ta eae Maegnetite.. 2°09 8°61 KO’ : ov, 63 Ilmenite --. 1°22 7 = —— 08, 3 ulaskose WeerGer sk. 5. 32 Na, O (I, 5, 2, a ) io ee 99°81 From this table and from what has been stated regarding the fabric and component minerals, the rock should be termed a normative-hornblendic grano- -pulaskose. The lime-alumina molecules which form anorthite in the norm are divided between the oligoclase-andesine and horn- blende of the mode, but the latter of these minerals is not resent in sufficient amount to render the mode abnormative. n the prevailing qualitative systems the rock would be a typical syenite and would belong to the Albany type of Rosen- busch. 452 Poirsson and Washington—Geology of New Hampshire. Variations from the type.—The rock described may be assumed to be about the average of the Belknap massif, as it agrees with the microscopic examination of most of the speci- mens. Indeed all of them are obviously of the perfelic order and of the sodipotassic subrang. While most of the material undoubtedly belongs to the persalane class there is a distinct tendency in some to be dosalic, through increasing content in alferric minerals. Similarly labradorite appears and may be present in variable amount so that the rang will vary from peralkalic to domalkalic, the latter being the more common as in the type specimen. In order to test the amount of variation which, as stated in the geologic description, appears to take place chiefly as the outer border is approached, the mode of two other specimens - was determined by Rosiwal’s method with the results given below. Of these No. I is from the exposure in a ravine in the little drainage on the south west side of Locke’s Hill and not far from the contact. No. Il is from the very summit of Gun- stock peak. Mode. Chem. composition. Mol. ratios. (SSS faa SS Ser 5h ee. SOM (our SS SSS SS Ik. II I II. i II Qz 16°06 4°25 S10, 68°16 OOf9T OG 998 Or foo 67°95 Ov Bay 15°82 150 155 /aN| Qa), 0-00 2°53 Fe,O, 0°88 2°93 006 018 Hb 0°35 13°38 FeO esse 4°61 026 064 Bt 9°93 759 MgO 1°26 1°64 032 041 Mt 1°15 3°82 CaO 0°15 oe 003 034 Ap 0°20 (1°48 Na,O 4°30 4°52 ‘069 073 K,O 7:06 «661.075 Ome Rotalie 110070 100°00 H,O 0°37 0°45 AO, 0°59 1°39 007 018 F203 0°09 0°22 "001 002 100°00 100°00 Norms. a I. II. Qz 13°62 1°86 Co 0°61 pu Ne ah Or 41°70 38°92 Ab 36°15 38°25 An hie 3°34 Di ERE 3°65 Hy 4°92 6°00 Mt Wei) 4°18 Il 1°06 2°74 Ap 0°24 0°50 H,O 0°37 0°43 100°06 I9587 Pirsson and Washington—Geology of New Hampshire. 453 From this No. J is I, 4, 1, 8= liparose and No. II is I], 5, 1, 3,=ilmenose. While these two norms are not entitled to quite the weight of that derived from the chemical analysis, yet, as the modes were determined on sections of large size (50x40™™, rock surface) and from a very large number of measurements, a fair degree of confidence may be placed in them.* Suitable compositions were assumed for the horn- blende and biotite in working out the chemical composition, and since their amounts are not large the error in this direc- | tion must be inconsiderable. Assuming this, it is evident that considerable variation exists in the outer exposed portion of the Belknap massif, especially in regard to the amount of alferric minerals, determining the class, the amount of quartz determining the order, and that of lime which determines the rang. It is to be noted that the rock from Locke’s Hill is from near the contact, and on this account, as seen in its high silica content, it is to be regarded as homologous with the siliceous border facies which has been already mentioned in the geo- logical description, though it differs from this texturally in being much coarser-grained. On the other hand, the rock from the summit of Gunstock may reasonably be supposed to represent a more central part of the mass of magma than the specimen analyzed, which came from a spot presumably much nearer the border. There is thus a successive decrease in alferric minerals with an increase in quartz from center to circumference. This is more fully treated in another place. In a specimen from the top of Piper Mountain which is megascopically similar to that from Gunstock, the section showed the presence of a colorless diopside associated with the hornblende and more or less intergrown with it. Some oligoclase also appears and these minerals, as will be shown later, point to a small increase in lime in the massif towards the south end. Otherwise the rock is similar to that from the summit of Gunstock. Hornblende-trachi-akerose (spessartite). As previously stated, the brecciated intrusive zone at the west foot of Locke’s Hill contains in an aplitic liparase cement blocks of various rocks brought up by the ascending magma. Some of these are clearly masses of the gneisses and schists, some are of the Gilfordal camptonose (essexite), while some are of adense lamprophyric type. It was thought that a detailed study of one of these latter would be of interest and might * It is probable that the orthoclase is somewhat sodic, so that the K.O is rather too high and the Na2O too low, but to what extent is uncertain. 454 Puirsson and Washington—Geology of New Hampshire. shed some light on the sequence of magmatic eruptions in the area, and a specimen was selected from a large angular block several feet in diameter embedded in the liparase. Megascopve. — Phanerocrystalline ; fine-grained, too dense for the individual minerals to be recognized but perceptibly granular; very dark stone gray, almost black ; tough with hackly fracture. Rare, very inconspicuous, equidimensional, dull hornblende phenocrysts 0-5-1:0™. Speckled here and there with small grains, streaks and minute veinlets of pink feldspar and quartz, the grains sometimes 2-3" with feldspar cleavage and of ragged, broken or irregular contours, evidently included or injected material and not normal phenoerysts. Microscopic.—The section shows iron ore, apatite, horn- blende, plagioclase, alkalic feldspar and quartz. The iron ore occurs in two forms ; as scattered grains, some- what rounded, about 0-02-0-05™™,, and as minute spheres, ovoids and rods about 0:001"", sprinkled through all the minerals and especially the feldspar, where they are often aligned into small systems. ‘They distinctly suggested the iron ores seen in contact hornstones. Apatite occurs in excessively minute needles in the feldspars. Hornblende is of a green color, strongly pleochroic into tones of pale yellow; it includes occasional grains of iron ore and some pieces have the central part blackened by separated iron ore dust and needles much like those which in lavas have suffered partial resorption. It is in irregular forms with a tendency to columnar development. Occasional flakes of biotite are sometimes associated with it. The plagioclase is zonally developed with the customary more calcic cores and passing to alkalic feldspar mantles. It shows both albite and Carlsbad twinning, but much is un- twinned and distinguished from alkalic feldspar only by its zonal development. The cores are of labradorite, the outer portion passing into andesine. It has a somewhat columnar development parallel to the @ axis, pike like the hornblende the boundaries are irregular. The alkalie feldspars. are similar in form to the plagioclase and are not always easily distinguised from them when untwinned. From the analysis it must be concluded that they are very rich in soda. The small spots and streaks mentioned above are irregular fragments of alkalic, rarely plagioclase feldspar, often much filled with sericitic muscovite sometimes accompanied by quartz. They are clearly exotic, included or injected material, and do not belong to the rock proper. Mineral Composition or Mode.—By Rosiwal’s method the rock was measured and calculated to ae the following com- position : Pirsson and Washington—Geology of New Hampshire. 455 Milcalie Teldsparscsauc. eee ok 20:0 Piasioclise feldspar .. 2:22... 5.254- 27°2 HROrmeende owes el or Ae 8 oN, 35°3 SBS IU ee eae OR et Ono rom, GFE gr 28 oe i eee I ug 14°8 2B ORAS) Sees i SE ASS Nae ete Se, nollie Sc) Ble eae, 99°9 In obtaining this a part of the rock was selected free from inclusions to give the normal composition. On account of their characters the feldspars could not be accurately discriminated and the two were measured together and their relative amounts then estimated, the result being checked by the alkalies shown in the analysis. Thus while their total amount relative to the other minerals is nearly correct, their proportions to each other are only approximate. The small grains of iron ore in the feldspars could not be measured and a small amount was deducted for them and added to the measured ore areas. The apatite also could not be measured but is obtained from the ip II. III. IV. DIO eat ks 52°95 50°97 52°85 "883 ENIAC Joh anf 14°96 15°56 3625 Ay eO yt ee aa.) (2°44 4°43 2°36 "015 BEN pms clase sh 7°03 7°62 8°71 097 J as Ge ieee alee 3°86 4°28 6°84 "097 CAO reise oes 6°76 7:05 8°47 2 Dal INGLOn Pe Oat 4°95 5°04 AD, 080 | GAO Je Si ah is ROE 1:64 1:26 1°53 7017 IRON ON eile 2203 51055 0:93 ey ae H,O 110°— __-. bat 1°58 Pein ae CORA we kis: 0:00 digas ed: aie MOS fede Me ph eae 3°90 1°98 0°35 049 1 Ee Ja We rama 0°76 0°48 0°40 005 Ps a Pe BEER geting 0°05 0°16 pina ern LAO REGS AR a O01 ayes ii Ts ae VGC) ef ts td Sh trace 0°38 mers aid st Oe a 0-00 i hale ate Brey Papal sie. Ase LOOsow LO0K4, S004 I I. Hornblende-akerose (spessartite). Belknap Mts., N. H. Washington analyst. Ij. Augite-andose (augite kersantite). Cordillera de Dofta Ana, Coquimbo, Chile. (F. v. Wolff, Zeitschr. d. deut. Geol. Ges., li, 1899, 529) ; Soenderop analyst. III. Hypersthene-kilauose (basalt). Cerro San Miguel, Puebla, Mexico. (Felix and Lenk, Beitr. Geol. Mex., ii, 1899, p. 215). Hoppe analyst. IV. Molecular ratios of No. I. 456 Pursson and Washington— Geology of New Hampshire. P,O, of the analysis. With these corrections the composition is as stated above and it must be reasonably correct. Chemical Composition.—This is shown in the analysis given below and it will be seen that the rock has the usual charac- — ters of a lamprophyre. The most notable feature is the pre- dominance of soda over potash. The rock most nearly related to this one, both in magma composition and in geologic oceur- rence, of which we have found an account in the literature, is one from Chile given in No. II, while another of similar composition from Mexico is given in III. It should be remarked here that the analysis (1) probably does not repre- sent quite accurately the composition of the pure normal rock, since the small included fragments of feldspar and quartz pre- viously mentioned were unavoidably present to a limited extent. Their influence must be very minute, but the silica, alumina and alkalies are a trifle too high on that account. Teature.—The average grain of the rock is about 0°05™™ and the hornblendes and feldspars approximate quite closely to this and do not vary much in size. ‘Lhe fabric is that com- monly seen in rocks of lamprophyrie character, and which Rosenbusch has designated as ‘‘panidiomorphic granular” in which the constituents appear of equal age, interlock with one another and yet have a distinct tendency to a columnar form. This fabric, however, is not clean cut and clear, as one often sees it, for the hornblendes are somewhat rounded, as are the ore grains, and the feldspars are irregular in outline and everywhere dotted with the little spheroids and rods of iron ore. Thus in plain light there is a distinct impression of the hornfels fabric with its rounded grains and dots, but when the nicols are crossed this disappears and the normal fabric is revealed. This is of interest because it shows that the original fabric has been affected to some extent by the immersion of the blocks in the liparase magma, and further evidence is seen in the separation of the iron ore in the hornblendes and in the sericitic mica in the large feldspars previously described. Classification.—In the quantitative system the calculation of the norm of the rock and its position are given below. Oni 10696 Onee Go Ab 66°23 Abe er. 41-92 An 2... 13°90 Sal 66°23 Di. 12-33 cee Sarge 2 =]I, Dosalane Hy hese. S21 Q 1] le a ey = 0'°01+5, Germanare | : | Fr 65 Mt 2.24) 3748 33-05 xO aie : Ape ry 6s pO Nas Ol aah ee ae Resto te co-r ies | Gao’ Sass = 1:94=2, Monzonase Total 99°99 aaa = 0°21 = 4, Akerose Na Ooo uies 0 Pirsson and Washington—Geoloay of New Hampshire. 457 : The texture cannot be very well described in one word; it approaches roughly to the trachytic; but is not porphyritic. The mode on account of the large amount of hornblende is abnormative and thus the rock is a hornblende-trachi-akerose. In Rosenbusch’s system of classification the rock belongs in the vogesite-odinite series of lamprophyres and corresponds in general with the spessartite of this group; the hornblende is, however, not brown but common green and the considerable quantity of alkalic feldspar shows relations to the vogesites in which this mineral dominates the plagioclase feldspars. Mt. Belknap Dike.—A rock which is practically the same as that just described forms a dike, six feet in width, which cuts the top of Mt. Belknap with an east and west trend. It differs in that it contains numerous phenocrysts of labradorite with tabular development, 0:5°™ long by 0-1™™ broad on the average, which are quite thickly sprinkled through the dark gray groundmass. The latter in thin section is similar to the type just described, without however the suggestion of the hornfels texture. It may be also noted here that the above rocks mineralogi- cally are quite similar to certain facies of the grano-camptonose (essexite) mass in which the latter passes locally into a monzo- nose (monzonite) phase. They differ of course texturally and they do not contain so much biotite, but the relation is a sig- nificant one for the explanation of the origin of these dikes, as will be mentioned later. [To be continued. ] 458 Scientific Intelligence. SCIENTIFIC INTELLIGENCH. I. CHEMISTRY AND PHysIcs. 1. The Preparation of Pure Ethyl Alcohol and Some of its Properties.—Since commercial absolute alcohol contains one or two per cent of water, and is usually contaminated also with alde- hyde, L. W. Winker has worked out a method for purifying it, and has incidentally determined the specific gravity and boiling point of the pure substance. The aldehyde is first removed by adding very finely divided silver oxide and allowing it to act for several days with frequent shaking at ordinary temperature. At the same time, a little caustic alkali is added to combine with the acetic acid produced by the oxidation of the aldehyde. For dehydration, metallic calcium in the form of filings is used. An amount of this metal corresponding to about two per cent of the alcohol is added in the distilling flask, and a gentle heat is applied, so that little alcohol distils over, until the evolution of hydrogen is slight. Distillation then gives a product containing about 99°9 per cent of alcohol, and this when redistilled with about one-half per cent of: calcium gives alcohol which is unchanged in specific gravity by further treatment. It is important that a small portion of each distillate coming over at first should be discarded. Specific gravity determinations of alcohol purified in this way gave results practically identical with those of Mendeleéff between 0° and 15°, but between 15° and 30° they were slightly lower than Mendeleéff’s. The results gave the following formula based upon weights in vacuo and water at 4°: Sp. gr. O—30° = *80629—-000838/— 00000042’. The boiling point was found to be 78°37° at 760™™ and 77°69° at 740", the variation for 1™™ being °034°.— Berichte, xxxviil, 3612, H. L. W. 2. Double Salts of Mercuric Chloride with the Alkali Chlor- ides.—In continuation of similar work previously carried out in the Sheffield Laboratory by Professor H. W. Foote, Foorr and Levy have studied the sodium-mercuric, potassium-mercuric and rubidium-mercuric chlorides by the solubility’ method, which shows very precisely and conveniently all the double salts that © are formed at a given temperature. ‘The results show that only one sodium salt, NaCl.H¢Cl,.2H,O is formed at 25° and at 10°. Three potassium salts, all of which had been described by Bons- dorf, were found : , 2KCL He Cl EO KCl. HgCl,. H,O KCl.2H¢Cl,.2H,O Five different rubidium compounds were prepared, none of which corresponded to three supposed salts previously described by Godeffroy. They have the following formule : Chemistry and Physics. 459 2RbCIl. HgCl,. H,O sRbC1.2HeCl,.2H,O RbCl. HeCl,. H,O SRbCL4HeCl,. H,O RbCL5HeCl.. It is interesting to observe that only the last member of this series corresponds to one of the five czsium-mercuric chlorides | that exist, viz. : 38CsCl. HgCl 2CsCl. HgCl CsCl. HgCl : CsCl.2H¢Cl CsCl.5H¢Cl.,. There are two corresponding salts in the potassium and rubidium series, but the slight analogy existing between double salts of such closely related metals as cesium and rubidium is remarkable. —Amer. Chem. Jour., xxxv, 236. H. L. W. 3. The Atomic Weight of Tantalum.—The accepted atomic weight of this element, 183, depends solely upon Marignac’s results obtained in 1865 by analyses of the compound K,Taf’.. Since these results are subject to some uncertainty from various causes, HINRICHSEN and SAHLBOM have made some new determi- nations of this atomic weight. ‘They were unable to obtain con- cordant results by the method of Marignac, but they had, apparently, better success by determining the weight of Ta,O, produced by heating the metal in oxygen. The metal was obtained from Siemens and Halske, who now prepare it for com- mercial purposes, and no impurities could be found in the mate- rial used. The results of five determinations made in. this way indicate an atomic weight of 181, which is two units lower than the accepted one. The results varied from 180°59 to 181°77. It may be mentioned that this atomic weight adapts itself to Men- deleéff’s periodic system somewhat better than the old one, since it is three units lower than tungsten, 184.— Berichte, xxxix, 2600. HLL. W. 4. The Isomorphism of Northupite and Tychite.-—The octa- hedral mineral tychite, 2MgCO,.2Na,CO,.Na,SO,, was described by Penfield and Jamieson in this Journal of September, 1905, having been found among exactly similar crystals of nor thupite, 2MgC0, .2Na,CO,.2NaCl, from Borax Lake in California. In con- nection with the description of tychite, its artificial preparation was also carried out. A. p—E ScHuLTEN, who had previously pre- pared northupite artificially, has now succeeded in making crops of crystals which appear to contain both chloride and sulphate in the same individuals, thus indicating that the two compounds are perfectly isomorphous. He finds that the tychite is much more stable than the northupite.— Comptes Rendus, clxiii, 403. He Ly We Wey 6 2) 460 Scientific Intelligence. 5. Separation of Antimony and Tin. —A new method for this somewhat difficult separation is given by A. Czprwex. It depends upon obtaining a solution in nitric and tartaric acids, heating to boiling and adding phosphoric acid, whereby the tin is completely precipitated. The precipitate, after being washed with water containing ammonium nitrate, is dissolved in ammo- nium sulphide, and the tin is precipitated and determined in the usual manner.’ The antimony and other metals that the filtrate may contain must also be precipitated as sulphides in order to separate them from the phosphoric acid present. Satisfactory results are given in a number of test analyses.—Zetischr. Analyt. Chem., xlv, 505. : H. L. W. 6. Lehrbuch der Allgemeinen Chemie; by Dr. W. Ostwatp. Volume IJ, Part II.—The third part of Volume II of the Lehr- buch has appeared in sections, and we have just received the first part of the second section. ‘The book is so divided into volumes and parts and sections that it is a little confusing in this respect. The work is so well known to students of general chemistry that it 1s unnecessary to speak of it as a whole. The part which has just been issued covers solid solutions more fully than this has been done before.and begins the chapter on adsorption. H. W. F. 7. Radio-activity. — The literature of this subject increases very rapidly. Apart from the numerous observations on the various forms of radio-active substances and their multifarious manifestations, there are certain aspects of radio-activity which have a broad bearing upon the constitution of the sun and the radio-active constitution of this earth and its atmosphere. A recent paper on the radio-activity of the ashes and lava thrown up by the late eruption of Vesuvius (August Becker, Ann. der Physik, No. 8, 1906) is of much interest. Since it has been shown by various observers that radio-activity 1s widely present in the earth’s crust, the question has arisen, whether it would not be possible to connect the phenomena of radio-activity with the earth’s temperature ? Under the assumption of a mean value of 0:006 for the heat conduction of the earth’s crust, and a tem- perature fall of 1° C. for 30 meters, Liebenow estimates the quantity of radium per cubic meter evenly distributed, which would give the observed heat as approximately 2X1077g. Since the quantity of radium observed is 1000 times this, we must con- clude that the heat production diminishes rapidly as we recede from the crust and that at great depths there cannot be radio- active substances. Strutt corroborates the results of Liebe- now and concludes that at a depth of 75*™ radio-activity fails. Becker, therefore, submitted to test the ashes and lava of the eruption of Vesuvius, and corroborates in general the observa- tions and conclusions of Strutt, pointing out, however, that we are unable to estimate conditions of pressure and tempera- ture at the depth from which the lava and ashes came, presum- ably 30*™. Ohemistry and Physics. 461 Professor EK. RurHErrorp, in the Philosophical Magazine for August, 1906, has an article on the “ Retardation of the a-particle from Radium in passing through Matter.” “The photographic effect of the a-particles toward the end of their path in air decreases far more rapidly than the kinetic energy of the a-parti- cles themselves. It is possible to determine with accuracy the V value on for the a-particles emitted by radium, radium A, and radium F by measurements of the retardation of the a-particles of the single product radium C in passing through matter. Such a result affords an aimost certain proof that the value of e/m is the same for the a-particles expelled from. each of these products.” The same author discusses the intensity of radiation from radio- active sources, and contrasts the photographic effect of radium emanations through apertures of various forms with the radiation of the sun. In the case of the latter, Lambert’s law-of cosines applies ; that is; the intensity of radiation from any point varies as the cosine of the angle between the normal and the direction of the emitted light. This law does not apply to a thin layer of radio-active substance. Hence we find great inequalities. in the distribution of the photographic effects. A number of photo- graphs accompany the paper (Phil. Mag., August, 1906). The September number of the same journal contains an article by M. Levin, “ On the Origin of the @-rays emitted by Thorium and Actinium.” M. Levin has been working with Professor Rutherford. It was found that actinium by itself is a rayless substance. A remarkable similarity was found to exist between the modes of transformation of thorium and actinium. The same journal contains a paper “On the Radioactive Matter in the Earth and the Atmosphere,” by A. 8. Eve, communicated by Professor Rutherford. The author believes that emanation exists in the atmosphere, but thinks that more experimental work must be done before any exact value can be assigned to the number of ions produced. ‘“ About 1°8107!1 grams of radium bromide is the estimated equivalent of the active matter per c.c. present in the earth’s crust sufficient to account for the penetrating radiation. This appears to be about four times as large as the average amount found by Strutt by direct observation of rock specimens. The ionization of the atmosphere is due partly to penetrating radia- tion from the active matter in the earth, partly to a-radiation from the emanation in the atmosphere.” ste sll 8. Velocity of X-Rays.— EK. Marx describes minutely his investigation of this velocity. The method depends primarily upon the property which the X-rays possess of ionization of a gas. Electric waves were produced along parallel wires accord- ing to Lecher’s system. The velocity of these waves was assumed to be the same as the velocity of light. A Réntgen tube was, therefore, so connected with the Lecher system, that the differ- ences of potential due to the presence of nodes or ventral seg- ee eee hes he \a 462 Scientific Intelligence. ments of the electrical waves, influenced the emanation of the X-rays. The rays from such a X-ray tube proceeding through an aluminium window struck an electrode contained in a Faraday cylinder ; this electrode was connected with an electrometer. Changes in wave length were produced by moving a bridge on the two wires of the Lecher system. The X-ray tube was moved to and fro until maximum effects of ionization were pro- duced in the receiving tube. These efforts produced correspond- ing deflections of the electrometer. ‘The relation of the doubled displacement of the bridge in the Lecher system to the displace- ment of the X-ray tube gave the ratio of the velocity of light to the velocity of the X-rays. The ratios differ only one-half per cent from the value of light.—Ann. der Physik, No. 9, 1906, pp. 677-722. J. T. 9. Formation of Ozone from Oxygen and Atmospheric Air by Silent Discharges of Electricity. KE. Warnure and G, LErrt- HAUSER state that silent discharges between small spheres are necessary for the formation of ozone from atmospheric air. A number of tables are given of the output, in the case of spheres, charged in one case positively and in another case negatively. The results are plotted and appear in the form of straight lines.— Ann. der Physik, No. 9, 1906, pp. 734-742. B pe 3 10. Oxidization of Nitrogen by Silent Discharges in Atmo- spheric Air.—K. Warsure and G. LerruAuser show that : (1) Nitrose gases in the presence of ozone are easily absorbed by dilute soda lye. (2) With silent brush discharges from the positive terminal sphere in atmospheric air, at the room temperature, independ- ently of the moisture of the air, 10 liters of NO is oxidized by an ampere hour. (3) The oxidized quantity of nitrogen mixture increases with increasing temperature and then decreases with the formation of the ozone. (4) A quantity of N,O,, indicating 1°° NO in 1500% lessens the formation of ozone “when the silent discharge occurs in atmospheric air.—Ann. der Physik, No. 9, 1906, pp. 743-750. ayy 11. Influence of Moisture and Temperature on the Ozonizing of Oxygen and of Atmospheric Air.—K. Warspure and G. LzirHivuser show that with a silent discharge, moisture effects the ozonization more in the case of air than with oxygen, and that a rise of temperature to 80° and constant pressure, pro- duces little effect in the case of both oxygen and atmospheric air.—Ann, der Physik, No. 9, 1906, pp. 751-758. Jones Geology and Mineralogy. ; 463 II. Grotogy anp MINERALOGY. 1. The Tenth International Geological Congress at Mexico City.—The Congress began its sessions on Thursday, September 6, 1906, and adjourned on Friday, the 14th of the same month. Previous to the opening meeting excursions were made, as fol- lows: To the south for eight days to view the Archean and Ter- tiary in the narrow canyon of the Tomellin on the way to Oaxaca, the Lower Cretaceous in the mountains west. of Tehuacan, and the ancient ruins at Mitla. To the west for twelve days, two excursions were given,—one to Jorullo to see the volcanoes Toluca and Jorullo, and the other to the only active volcano in Mexico, Colima, and the geysers. The best attended excursion before the Congress was the one to the east for three days, to see the deeply eroded Cretaceous at the edge of the high mesas down which the railroads descend to the dissected Miocene level, and then to the present ocean level at Vera Cruz. On the way back to Mexico City a stop of a few hours was made at Orizaba to view the symmetrical volcano of the same name and the nearly vertical strata of the Middle Cretaceous. The most extensive and varied excursion was the one for three weeks immediately after the meetings of the Congress, to the north as far as El Paso and east to Tampico. On alternate days, during the sessions of the Congress, excursions were given to Cuerna- vaca, to San Juan Teotihuacan to examine the work of restoring the great pyramids of the Sun and Moon, and to the Pachuca silver mines. ‘These excursions were of great profit to all, while the hospitality received en route was lavish. The opening session of the Congress was held on the morning of September 6, at eleven o’clock, in the Salon de Actos of the School of Mines, in the presence of the President of Mexico, his cabinet, his personal and official staff, and the ministers of foreign countries. A short opening address was given by Sr. Luis Salazer, Director of the School of Mines. The address of wel- come was read by the Subsecretary of Fomento and the Hono- rary President of the Congress, Sr. Andrés Aldasoro. The retiring President of the Congress, Prof. Emilio Tietze, made a very pleasing address, and was followed by the President-elect, Sr. José G. Aguilera, Director of the National Geological Insti- tute of Mexico. The Secretary-elect, Sr. EK. Orddfiez, outlined the work of the sessions. The President of the Republic then pronounced the Congress opened. The succeeding meetings were held in the Geological Institute, a building just completed and containing accommodations for the excellent equipment, collec- tions, library, and staff of the Mexican Geological Survey. The following are the officers of the present Congress, who either in 1909 or 1910 will turn over the machinery of the Tenth Congress to the Eleventh, to be held at Stockholm: 464 Scientific Intelligence. President, Sr. José G. Aguilera. Secretary General, Sr. E. Ordéfiez. Vice Presidents: Austria, C. Diener ; Germany, H. Credner, A. Rothpletz, and IF’. Frech ; France, A. Offret; Great Britain, T. Anderson; Norway, E. Brogger; Sweden, H. Sjogren ; Russia, Th. Tschernyschew ; Roumania, G. Stefanescu ; Italy, V. Sabatini; Spain, C. R. Arango ; Hungary, von Szadeczky and B. de Inkey; Canada, F. D. Adams and A. P. Low; United States, T. C. Chamberlin, C. W. Hayes, S. F. Emmons, and A. Heilprin; Philippine Islands, M. D. McCaskey; Mexico, E. Bése ; Cuba, S. de la Huerta; Venezuela, E. Urdaneta; Aus- tralia, T. W. EK. David ; Japan, T. Iki. The members actually participating in the Congress numbered 292. Of -these 130 were from Mexico, from America 58, Manila 1, Canada 8, Honduras 1, Cuba 2, Germany 44, Austria 6, France 11, England 4, Belgium 3, Russia 3, Finland 2, Italy 2, Sweden 1, Roumania 3, Bohemia 1, Australia 1, and 1 from Japan. In other words, Europe was represented by 80 members, and the Americas by 207. At this Congress, however, the percentage of non-geologists was probably greater than usual, and of ladies there were 27. The Russian Spendiarofi prize was awarded to Tschernyschew in recognition of his great work entitled ‘‘ Die obercarbonischen Brachiopoden des Ural und des Timan.” Through the death of von Zittel the Paleontologia Univer- salis lost its President, and to this vacancy the Council of the Congress elected Prof. Frech of Breslau. To the American Committee was added R. Ruedemann, the other members being C. D. Walcott, H. S. Williams, and Charles Schuchert. Canada is represented by J. F. Whiteaves and Mexico by EH. Boése and C. Burckhardt. A large geological map of North America, including Green- land, was distributed to the members. It is the joimt:work of the National Surveys of Canada, United States, and Mexico, and was printed by the U. 8. Geological Survey for the Congress. It is understood that this map will undergo further revision and will also eventually appear as one of the Professional Papers of the U. 8. Geological Survey. It will supply a great lack in American geology. ~ In the main, the following are the titles of papers read by their authors at this Congress : F. D. Apams: Explanation of the Geological map of North America, dis- tributed to the members of the Congress. T. AnpERSON: On the principal results of the Swedish Antarctic expedi- tion. Read by H. Sjogren. H. F. Barn: Some relations of paleogeography to ore depositions in the Mississippi Valley. \ C. BurckHarRDT: Sur l’existence dans le Jurassique supérieur mexicain d’Ammonites et Aucelles. A. P. Coteman : Interglacial periods of Canada. N. H. Darron: Geologic classification in the north-central portion of the Vnited States. Geology and Mineralogy. 465 T. W. E. Davip: On the morphology and evolution of the Australian continent, and particularly in regard to the Cambrian and Permo-Carbon- iferous glacial climates. H. L. FartrcuiLp : Pleistocene of western New York. F, FrecH: Ueber die Klimaainderungen der geologischen Vergangenheit, Ueber Aviculiden von paleozoischen Habitus aus der Trias von Zacatecas, A. Heiuprin: The concurrence and interrelation of volcanic and seismic phenomena. On the Martinique eruptions. E. O. Hovey: La Sierra Madre Occidentale de l’Etat de Chihuahua. B. DE Inxey: Sur la relation entre état propylitique (Griinstein) des andésites et la genése des filons liés & cette roche, K, Krm~nack: On the onyx deposits at Etla in the State of Oaxaca. J. F. Kemp: Ore deposits at the contacts of intrusive rocks and limestones. J. KONIGSBERGER: Ueber den Verlauf der Geoisothermen in Bergen und seine Beeinflussung durch Schichtstellung, Wasserlaufe und chemische Processe. L. DE LamotHeE: Le climat de ’Afrique du Nord pendant les Périodes Pliocéne et Pleistocéne. A. C. Lawson: The earthquake of San Francisco, California. On the Quaternary history of California. W. LinpGREN : On ore deposition. M. Manson: The causes of the glacial epoch. W. G. MititeR: The Pre-Cambrian rocks of Central Canada. _ K. Renz: Ueber das ailtere Mesozoicum Griechenlands,. V. SaBatTini: Sur la derniére eruption du Vésuve. G. STEFANESCU : Description du squelette d’un nouveau genre de Dino- therium gigantissimum. J. D. VILLARELLO: Sur le remplissage de quelques gites métalliféres. W.H. WEED: Origin and classification of ore deposits. Cys. 2, A Descriptive Catalogue of the. Tertiary Vertebrata of the Faytim, Egypt, based on the collection of the Egyptian Govern- ment in the Geological Museum, Cairo, and on the collection in the British Museum (Natural History), London; by Cuar.zs Witiiam Anprews, D.Sc. 4to. Pp. xxxviii, 324 with 25 plates and 48 text-figures. London, 1906 (published by order of the Trustees of the British Museum).—This fine quarto volume gives not alone a full descriptive catalogue of the collections in the Cairo Museum and in the British Museum (Natural History) which were made in the Fayfim ; but a general discussion of the physiography and geology of the region and of the characters and relationships of the remarkable forms which ancient Egypt, ever the land of wonders, has brought to hght. Mr. H. J. L Beadnell, the maker of the Cairo collection, has given a very full account of the topography and geology of the Fayfim province in Egypt and upon his detailed report the sketch contained in the catalogue is based. The Faytim is situated west of the Nile valley in a latitude some 57 miles south of Cairo. The region is a roughly circular depression the lower part of which is occupied by a large brack- ish-water lake, the Birket-el-qurun, about 25 by 6 miles in extent. During Pleistocene times this lake was of vastly greater area, the deposits of the former waters being rich in vertebrate and mol- luscan remains. Numerous stumps of trees in one or two places Am. Jour. Sci.—Fourts Series, Vou, XXII, No. 181.—Novemper, 1906. 32 466 Scientific Intelligence. indicate that formerly portions of the surrounding country were ‘wooded. Along the northern side of the lake nearly the whole of the vertebrate remains have been gathered from beds of middle and. upper Eoceneage. Of these vertebrates all classes except the Am- phibia have been found, though bird fragments are referable to one species only. By far the most abundant are the Mammalia, which are followed in numbers by the reptiles. The Mammalia are divided into three sections; (1) the land mammals which seem to be truly endemic to the Ethiopian region ; (2) forms of which close allies occur in other regions in approximately contemporary deposits ; and (3) the aquatic mam- mals. Itseems probable that some of the, last are also of endemic origin, having arisen from native land mammals. Of the first series, curiously enough, all are ungulates of the less specialized orders. |The most notable of these is Arsinoi- therium, a most bizarre creature of elephantine proportions and massiveness, and which bore upon the snout two great upward and forwardly projecting horn cores, while above the orbits were two more though of much smaller dimensions. Andrews, while expressing doubt as to the relationships of Arsinoitherium, thinks that it may have originated from the same stock that gave rise to the Hyracoidea. The latter are quite abundant in the Fayim, but remains throw little or no light upon the history of the group. The light thrown upon the past history of the Proboscidians is the feature of the greatest scientific interest because of the ex- treme deficiency of our previous knowledge of the order, .as none were known older than the Miocene before the Fayfim forms came to light. Osborn, among others, had pointed out the pro- bability that Africa would be found to be the original home of the Proboscidea, the Hyracoidea, and several other families, believing that a succession of migrations from Africa to Europe occurred, notably at the end of the Eocene, at the beginning of the Miocene and again in the earliest Pliocene. It was in the early Miocene migration that the elephants passed out of Africa for the first time. The earliest known proboscidian is Mceritherium, which occurs first in the Quaer-el-Sagha (middle EKocene) beds and persists until the upper Eocene. ‘This creature suggests the tapir in size and general appearance, and while the dental formula is almost complete, many elephantine characters are foreshadowed in the skull. The next proboscidian genus is Paleomastodon, of which some of the smaller species are evidently intermediate between Meeritherium and the later elephants. The larger Palzo- mastodons were about the size of a half-grown Indian elephant and were elephant-like in appearance except for the elongated symphysis of the lower jaw, which was prolonged beyond the skull and was covered only by the fleshy snout. The neck was still somewhat long and the creature could reach the ground with its lower incisors and with the probably prehensile muzzle. The further evolution of the group is shown in Tetrabelodon from the Geology and M ineralogy. 467 European lower Miocene, ‘a creature similar in size and appear- ance to the Indian elephant except that the trunk was inflexible be- cause of its being supported by the more elongated symphysis. In Mastodon however the symphysis shortens, leaving the trunk free; at the same time vestiges of the elongated condition of the jaw occur in some mastodons and in the peculiar sharp process of the symphysis of modern elephants. The Faytim researches have also thrown light upon the proba- ble community of origin of the Sirenia, the Proboscidea and the Hyracoidae. The Creodonts are also present of the family Hyznodontidz and the development of the Zeuglodonts from a creodont ances- try is shown. The zeuglodonts of the Fayfiim, taken together with a species, Procetus atavus, from the near by Mokattan Hills, form a series showing a complete transition so far as the teeth are concerned from the Creodonts to the Zeuglodonts. The bird remains seem to be that of a true Ratite and suggest the Ethiopian region as a point of origin of some at least of the main sub-divisions of the Ratite. The Reptilia are represented by crocodiles, turtles, and snakes. There are no Amphibia and the fishes are either Elasmobranchs or Siluroids and of no great interest. The summary points to the great importance of Africa as a cen- ter of mammalian evolution, not alone of modern true mammals, but of their Theriodont ancestors. This being the case, not only the Tertiary, but the Mesozoic deposits of this region may be ex- pected to throw much light upon the history of the Mammalia. The Dark Continent seems to be a veritable land of promise to the vertebrate paleontologist. R. S. L. 3. Geology of the Owl Creek Mountains with Notes on Resources of Adjoining Regions in the Ceded Portion of the Shoshone Indian feservation, Wyoming ; by N. H. Darron. United States Geological Survey. Senate Document No. 219, 59th Congress, Ist Session. Pp. 48, with 11 plates and 1 text figure. Washington, 1906.—This paper, of the general form of the bulletins of the U. 8. Geological Survey, is published as a Senate document in response to a request from the Senate for such information relating to the geology and natural resources of that portion of the Shoshone Reservation which was to be opened for settlement in July, 1906, as was in the possession of the U.S. Geological Survey. The report has a geological map on the scale of 4 miles to the inch, and many attractive photographic illustrations. Jobe 4. The Copper Deposits of the Robinson Mining District, Nevada; by ANDREw C. Lawson. Univ. of Cal. Publications, Bull. of the Department of Geology, vol. iv, No. 14, pp. 287-357. May, 1906.—This bulletin gives a good account of the geology of the Egan Range, one of the larger members of the Basin Range system of mountains traversing eastern Nevada. The Archean basement is not exposed, the rocks ranging in age from the Cam- 468 Serentifie Intelligence. brian to the Carboniferous and holding in places intrusive masses of granitic and monzonitic rocks. Intrusive porphyries and extrusive rhyolites are also present. Considerable space is devoted to the contact phenomena and their relations to the ores. J. B. 5. The Montana Lobe of the Keewatin Ice Sheet ; by FrRep. H. H. Catnoun. Professional Paper No. 50, U.S. Geol. Surv., 1906. Pp. 62, with 7 plates and 31 figures.—This report covers a region of much interest to glacialists, an area which lay between the Keewatin ice sheet and the mountain glaciers com- ing from the west. In studying this region four important sub- jects were considered—the eastern drift, the mountain drift, the deposits on the intervening area (which was not glaciated), and the relations of these three surface formations to one another. It was found that for thirty miles back from the margin the average slope of the glacier must have been about 50 feet per mile. It is further stated that this ice sheet also undoubtedly turned the Missouri from a northern course and made it tribu- tary to the Mississippi River. J. 6. Les Lac Alpins Suisses. Etude Chimique et Physique ; par le Dr. Ferix-Ernesr Bourcart. Pp. 130, with plates and 22 figures. Genéve, Georg & Co., Editeurs, 1906.—This work, to which was awarded a prize by the Helvetian Society of Natu- ral Sciences, was undertaken at the suggestion of Professor Dupare as a subject for a thesis. Thirty-three lakes were exam- ined in detail and complete observations made upon the color of the water, transparency, the temperature at the surface and at maximum depth and other features. Chemical analyses were also made of the waters and the results are finally tabulated. The report thus brings together a valuable body of data. 5. B. 7. The Species of Botryocrinus ; by F. A. BatHer. Ottawa Nat.; vol. xx, pp. 98-104, August 15, 1906.—This paper contains a comparison of all previously described species, with fresh diag- noses based on the dorsal cups. The species are : Swedish, B. ramosissimus Ang., B. cucurbitaceus (Ang.): British, B. ramosus Bather, B. decadactylus Bather ex Salter MS., B. pin- nulatus Bather, B. quinquelobus Bather ; Australian, B. longi- brachiatus Chapman ; N. American, B. nucleus (Hall), B. polyxo (Hall), B. crassus (Whiteaves), B. americanus Rowley. All these are Silurian except the two last, which are Devonian and approach the Carboniferous Larycrinus in shape. American workers are invited to consider the relations of botryocrinus to Cosmocrinus, Barycrinus, and Vasocrinus. [Author’s abstract. | 8. Soils, their Formation, Properties, Composition and Lela- tions to Climate and Plant Growth in the Humid and Arid Regions ; by E. W. Hitearp. Pp. xxvii, 593, with 89 figures. —KEvery student of soils will welcome this volume from one of the oldest and ablest soil investigators in North America. The book is unique because of the full comparison between soils of humid and arid regions and its special emphasis upon the physics Geology and Mineralogy. 469 and chemistry of arid soils, a natural result of the author’s long experience in the arid west. The book is further characterized by its strong treatment of the effect of soil character upon native vegetation, for the value of which the author has been contend- ing for half a century. The fundamental question of classifica- tion as involving the relative value of physical and chemical properties in plant production and as a convenient. means of ref- erence to cultural values, is discussed in a thoroughly convincing manner. In view of the recent discussions on the relation of soil texture and chemical constitution to the composition of the soil-water, Hilgard’s conclusions are of the highest interest. and value, and strongly contravene the assertion that natural solu- tions of water-soluble soil ingredients are essentially of the same composition in all soils. A commendable feature of the soil analyses is their statement in terms which insure application. They really constitute a sort of restatement of refined analyses such as give the conclusions an immediate and practical value to the agriculturist. I. B. 9. Brief Notices of some recently described Minerals. — KLEINITE is an oxychloride of mercury described by A. Sachs from Terlingua, Texas, and named after Prof. Carl Klein of Berlin. It occurs in slender hexagonal crystals of a sulphur-yel- low to orange color; hardness 3-4; specific gravity = 7°441. The composition deduced is H,Cl,O,. Sachs regards this mineral as identical with one noted by Moses (“ No. 5,” this Journal, xvi, 263) and also with that announced by Hillebrand (Ibid., xxi, 85). —Sitzungsber. Akad. Berlin, Dec. 21,1905; Centrbl. Min., 200, 1906. BELLITE is a chromo-arsenate of lead from the Magnet Silver mine, Magnet, Tasmania ; it is named after Mr. W. R. Bell by W. F. Petterd. It occurs in delicate tufts and velvety coatings lining cavities in a soft iron-manganese-gossan ; minute hexagonal crystals are sometimes visible. The color is bright crimson to orange-yellow; hardness 2°5 ; specific gravity 5°5. An analysis by J. D. Millen gave : As2,03 CrOs; PbO P20; V20; b> a; angle of c on ¢ about 18°; double refraction c—a about 0°020; it varies into a green variety which exists also in independent masses but is not so common and is then in small individual grains, cand 6 olive-green and a pale brownish-yellow. Cleavage good. Am. JOUR. Scr.—FourTH SERIES, VoL. XXII, No. 132.—DrEcremBeErR, 1906. d4 494 Pirsson and Washington—Ceology of New Hampshire. Plagioclase in short thick tables and laths: mostly anorthite but often zonal with varying mantles of labradorite; Carlsbad and albite twinning general; altering in spots, mainly in the contact facies, into scapolite, which fills the interstices between the other minerals. F’eldspars embedded ophitically in horn- blende, less commonly in biotite and augite. Biotite varies locally in amount; in roughly developed tables up to 1™™; ordinary brown variety and strongly pleo- ehroic; slight variable openings of axial cross; of uniform coloration and not zonal; intergrown with augite and horn- blende and may include any of the other minerals; altering in places into chlorite and epidote, or into muscovite. Lron ore in anhedral to subhedral grains, sometimes inelud- ing cores of pyrite; rarely altering into a deep reddish semi- transparent substance assumed to be gdthite; older than and enclosed in the other minerals. Titanite in irregular grains, anhedral; sometimes aureoling iron ore; sometimes in masses filling angular interspaces between automorphic feldspars; sometimes independent in form. Apatite not especially abundant ; in the usual prisnigie crys- tals enclosed in other minerals. Scapolite occurs locally distributed and appears to be chiefly if not entirely confined to areas near the contact. It forms irregular masses filling the interspaces between other constitu- ents, and its mode of occurrence -and relations to the feldspars show clearly that it is of secondary origin and formed at their expense. [rom this it follows that it probably belongs to the meionite end of the series. Itis easily identified by its very definite optical properties. Chemical Composition.—The chemical composition of this rock is shown in No. [of the adjoining tables of analyses. For reasons previously stated, it was made upon a specimen not far from the border and representing rather more the bor- der facies than the main type. As this contains more biotite, as shown in the descriptions of the mode, the water is largely constitutional, as hydroxyl in the biotite and hornblende, and is not to be regarded as a necessary sign of alteration. The striking features of this analysis are the low silica and alkalies with the high alumina and bivalent oxides. It is clear that a magma of this character would form chiefly ferromag- nesian minerals and labradorite. Especially notable is the large amount of iron. For comparison the analyses of three other rocks (Nos. I, I{f and VII) which are composed of similar minerals, and which in the prevailing classification would be termed essexites, are given. It has features of agreement with them and also differ- te oe , ,o Pirsson and Washington— Geology of New Hampshire. 495 ANALYSES OF CAMPTONOSE AND RELATED ROCKS. iE ‘bE. REE EY: Ale NIA VII. Si 2 43-94. 46°99 43°65 Aes 41°63 Ff) 45°32 Pee 165 EF 17°94 11°48 14°50 13°26 "159 18°99 He@ 5° 3:96 256° 632 4:03. 3:19 *025 3-78 Heer => 3.0°06 7°56 8°00 7°28 9°92 °140 9°78 MgO ape E'S Oey o 22 7°92 5°46 (aoa °126 4°68 Ga) 2 =-4> 9°59 4-85 14-00 8°46 SesGne. 7k 9°19 INja.O- | - 2°93 6°35 2°28 or Lt 2°49 "047 3°78 BONS. 1s A: 2-62 pe 2°28 3°32 "016 212 H,0O110°-+ 1°42 0°65 1°00 3°08 1°35 he 0°31 H,0110°—0°13 guia Bysdicy f 0°36 [ere aa 0°09 wee’ 0°09 ga? 3 ie 3°76 5-207 002 ae: iO 2 ee: Se a: F923 1°09 4°30 3°95 "052 1°94 fee 1 0°69 "94 trace ES ? 005 Be aes See. gas mate ARR "18 EP Re Sy a ee Pee Cy re jy Beas Baa trace antago aay Me hioeehs 0 fs Ad eee none biigchs SSG ie ata BiRerey eee etek gat trace Pelee ye fier: rner oe 2 tr tr Laie a "19 7 a Mt ae ee BaO--_- none none Waes trace PE RT oa nen Total... 99°67 99°60 100716 100°65 100°75 eps 99°98 _ = 2ae uae ae ae pa 505 : 100°60 I. Gilfordal-camptonose (essexite). West foot of Locke’s Hill, Belknap Mts. New Hampshire. H. 8. Washington analyst. II. Hornblende grano-essexose (essexite). Salem Neck, Mass. H. 8. Washington analyst (Jour. Geol. vii, p. 57, 1899). Ill. Grano-limburgose. Brandberget, Gran, Norway ; (Brogger, Quar. Jour. Geol. Soc., vol. 50, p. 19, 1894). L. Schmelck anal. IV. Hornblende phyro-camptonose. Summit of Mt. Gunstock, Belknap Mts. New Hampshire. H.S. Washington analyst. V. Hornblende ourose (camptonite). Livermore Falls, Camp- ton, New Hampshire. G. W. Hawes (this Jour. (3), vol. xvii, 147, 1879). VI. Molecular ratios of No. 1. VII. Hornblende grano-salemose (hornblende gabbro). Salem Neck, Mass. H.S. Washington (Jour. Geol. vil, p. 63, 1899). ences; the rock of No. VII, described by one of us, is most nearly likeit. Further discussion of this point is deferred until the classification is taken up. It is to be noted how closely it resembles in composition the camptonose dike rocks of this area as shown by a comparison with No. IV, and indeed it is essen- tially the same type of magmaas that which furnishes the rocks classified in general as camptonites. This is seen from the analysis by Hawes of one from the type locality. Brogger* *Basic Eruptive Rocks of Gran, Quar. Jour. Geol. Soc., 1, p. 26, 1894. 496 Pirsson and Washington— Geology of New Hampshire. has already shown the close relationship between the rocks classed as camptonites and essexites, showing that the former could be derived from the latter by differentiation, and that since the volume of the complementary bostonite is relatively small, that of the essexite and camptonite are practically alike. If indeed in Gran the essexite magmas had been subjected to the same processes of cooling and crystallization, in undiffer- entiated condition, as those which produced the camptonites, it can scarcely be doubted that they would have produced essen- tially similar rocks which would also be termed camptonites. Mode.—'The mode or actual mineral combination was determined by Rosiwal’s method. For the coarse-grained type of the main mass a large section measuring 30x40™ of rock surface was used and a distance of 200 times the average grain was traversed. The border facies was also measured and the results obtained are given in the table. Vol. per cents. Weight per cents. Border. Main. Border. Main. A Patitered 2k eee ge eon gO 0°6 1°9 0°6 Pitaniteye see oe Oss 20) 03 22 Iron ore ac gee ie 4°5 Wen 7°6 12°5 yrOXeMe Ne ae eae 4°3 15°8 4°6 16°1 BiOtite: Ue ee rier Oi 3°3 10°4 out Hornblende ._---_-- 27°6 26°3 30°6 Typ) lacioclase ss eae 47°1 43°5 41°6 36°6 SCapOlite ee ie aver ACD Ona caper 2°4 ee pidote:.2 ae ale, OO PR 0:6 Aeee Ghiorite:: 22 ae eee 0°6 wes 0°6 Ota Mee eee ae £98 100°0 =100°0 99°6 Classification in the Quantitative System.—The calculation of the norm of this rock from the analysis and the determina- tion of its systematic position are given in the subjoined table. Norm. On 22 8°90 Sal ee 59°0 ath pA ee Ab _. 22°01 Reno 1'5 = Class 8, Salfemane An .. 26°69 L 1°4 Nee cpm £9 hea 0°02 = Order 5, Gallare Dr J24138538) KO NaO: 63 : OW NOaGg : CaO’ tga 0°66, = Rang 3, Camptonase MG 3245280 K,O’ 16 I oad a0 Na Olek a 0°34, = Subrang 4, Camptonose 2 Apneaned68 est tere 164. Total._ 99°89 Pirsson and Washington—Geology of New Hampshire. 497 In the mode the orthoclase and part of the olivine of the norm have united to form biotite, while the hornblende of the mode is made up from some of the normative olivine, diopside, magnetite and anorthite and probably it contains some or all of the nephelite as well. This is only another illustration of the complex nature of the hornblende molecule. The mode is thus abnormative, containing a notable amount of hornblende and some biotite. The fabric, as has been shown, is granular and pseudoporphyritic or poikilitic. If one wished to characterize all of these features in the name it would become biotitic hornblende-grano-phyro-camptonose, but more simply it is hornblende-poikilo-camptonose. As, however, the fabric and other characters of the rock are so peculiar and striking, it has been thought best to erect this rock into a distinct type, on which the name of gilfordal camptonose is bestowed, the type adjective being derived from the village of Gilford near the type locality. Classification in the older systems.—In these, if one con- _siders merely the qualitative statement of the chief minerals of the rock, that it is composed mainly of plagioclase and hornblende, it would be termed a diorite; if we take into account also its basic chemica] character, and the large amount of lime, iron and magnesia, it would be considered rather a hornblende gabbro; if there is also considered the nature of the hornblende, the presence of the pyroxene and biotite and the association of the rock with alkalic syenites and with camptonites and its close chemical and mineral correspondence with the latter, it would fall in Rosenbusch’s family of essex- ites. It has, it is true, less alkalies than most of these rocks show, but it is also to be noted that under the heading of granular rocks, composed chiefly of basic plagioclase and brown barkevikitic hornblende, associated with alkalic rock complexes, types which differ quite widely among themselves in various chemical features have been grotiped as essexites. This is seen, for example, in the table of analyses in Rosen- busch’s Elemente der Gesteinslehre and our analysis agrees in each of its features with some of those there given. Facies of the grano-camptonose (essexite) mass. At the southwest foot of Locke’s Hill the bench, which along the western side forms the top of the camptonose area, is eut off by a ravine, and at this. point, as previously mentioned, both it and the pulaskose (syenite) are in contact with the gneisses. Above this on the bench are outcrops forming fine exposures of the salfemic rocks, and it may be seen here that locally the camptonose passes into phases of an even granular 498 Pirsson and Washington—Geology of New Hampshire. dioritic-appearing rock in which the large poikilitic horn- blendes are much restricted in amount or even entirely dis- appear. There is also considerable variation in grain. One specimen shows a granular rock with black and white minerals evenly mixed in very nearly equal amounts, the size of grain from 2-4"™". The white mineral is feldspar, the black mostly hornblende, with some augite and here and there bronzy lustered biotites. In other places the rock is the same but of much finer grain. Under the microscope the same minerals are seen asin the gilfordal camptonose but in more variable amounts. Biotite is generally much more abundant; the brown hornblende in places yields to a green variety. Other- wise the minerals need no especial comment. ‘Their relative proportions are variable and in one case the passage into a dis- tinetly salic phase was noted, the rock containing an excess of feldspar, much of which is alkalic. Detailed study and analysis of the different facies at this place would undoubtedly show varieties bordering upon, or in, monzonase (monzonite, diorite and perhaps akerite of the older classifications), but these facies are of such restricted volume and confined to such a limited area, and play so small a role in the general petrog- raphy of the region, that it has seemed scarcely of value to undertake a complete chemical and petrographic investigation — of them. They are so involved with what we consider the later irruptions of persalic magma described under the head- ing of breccia, that from the field exposures nothing more definite can be worked out than that they are distinct differ- entiation facies of the camptonose as stated above. Hampshiral camptonose (camptonite). Basaltic dikes of salfemic rocks are rather numerous in the area and a number of localities in which they have been found are mentioned in our previous paper. ‘They are all composed of rocks made up of a brown barkevikitic hornblende and plagioclase which fall under camptonose or adjacent subrangs, or are camptonites in the older systems. One of these which affords the best preserved material occurs on the southwest side of Mt. Belknap, near the top, cutting a steep slope of syenite which is well exposed above the hillside pasture fields. The dike is about 3 feet wide with a pronounced columnar structure and is exposed for about 100 yards. A specimen of this was selected as a type for detailed study, measurement and analysis. Megascopic.—Phanerocrystalline to aphanitic ; very dark stone-gray ; thinly sprinkled with minute white dots 0-25- 1:00" in diameter (calcite fillings); the compact to fine- grained mass abundantly filled with slender dark glistening — Pirsson and Washington— Geology of New Hampshire. 499 needles 2-3™™ long (hornblende); tough, with a somewhat hackly fracture; on exposed surfaces altering to a leather brown crust dotted with black hornblende needles. Microscopic.—Hornblende and plagioclase essential; iron ore and apatite accessory; calcite and chlorite secondary. The hornblende is present in two generations; the larger average about 1°50°™ in length by 0-40™™ in breadth, the smaller about 0°25 by 0°05. There are many gradations between them. Except in size they are alike in other respects, rather long columnar in development with 110 and 010 well developed, good terminals lacking. It is strongly pleochroic ; c and 6 rich leather-brown, a pale ocher yellow; absorption markedc=6>a. Angle of extinction conc = 18°. The min- eral includes a little iron ore and is very fresh and unaltered save in a few spots where it is changed to chlorite. The plagzo- clase, as the average of several determinations by Michel-Lévy’s method shows, is a labradorite of about the composition Ab,An,. Its form is that of slender laths whose dimensions are similar to those of the small hornblendes mentioned above. Both Carls- bad and albite twinning occur. A few sporadic larger crystals of the same characters but in size like the larger hornblendes were observed. The smaller feldspars are often coated with films of an isotropic substance which also fills minute spaces. Its nature could not be ascertained, but presumably it is anal- cite and its association with. calcite leads to the supposition that it is secondary. The zvon ore is in small grains -05 to -10™™ in diameter, peppered everywhere through the rock, sometimes agglom- erated into larger lumps and often beading the edges of the hornblendes. Apatite occurs in minute needles of the charac- ter usual in such rocks. Calcite is found liberally sprinkled through the mass in very minute pieces occupying little angular interspaces between the feldspars and other minerals; in these cases it does not appear as an ordinary alteration product since the adjoining minerals are fresh, but rather as an infiltrated material, if it is not indeed an original component. In a few places, how- ever, it is agglomerated into masses which from their outlines and general appearance are evidently pseudomorphs of a former mineral, apparently augite, a few crystals of which about the size of the lar ger hornblendes were originally present. This seems to indicate that probably the calcite is to be regarded as secondary. ‘These sporadic augites are the only minerals in the rock which have suffered any considerable alteration—the others being in good condition. Mode.—The quantitative mineral composition as determined by the Rosiwal method is as follows : 500 Pirsson and Washinyton—Geology of New Hampshire. Vols. Weights. Apatitecn Geico es ley 1°8 Tron oreg = soy Sie Sie! 10°'8 Hornblende -.__.- Heyy 34°9 Plagioclase ___---- 53°2 46°6 Caleitersa2 see 6° 5°8 Wotalincs sags ee eso O89 99°9 The amount of apatite is undoubtedly too low, for, as may be seen in the norm, the phosphoric acid demands about 2 per ANALYSES OF CAMPTONOSE AND RELATED ROCKS. if II II IV Vv VI VII BLOl oc ICT 53 41°63 41°94 48°22 46°59 44°99 The AAO 14°50 13°26 15°36 A277, 17°55 Lesa: "142 FeO; + 4:08 ~° 8:19 "8-97 "2-46 1-68) a gem ReOrs: 7°28 9°92 9°89 9°00 10°46 5°18 ‘101 MgO bigs 5°46 (oor 5:01 6°24 7°76 6°98 “ow CaO. 2 8°46 8°86 9°47 8°45 10°64 Lio Tt om Nia OX? 3 el 2°49 ond 2°90 3’ol 2-12 ‘050 K One? 2°28 o"o2 0°19 1°93 0°72 ire "023 H,O 110° + 3°08 1°35 3°29 1:66 0°10 2°74 Ug H,0110°—0°36 ge es 028 007 CO, ee 3°76 5:20 2°47 0°15 aie es 3°66 (4 Na His =o 4°30 3°95 4°15 2°79 1°41 2°50 "054 POs. .0°98 ohooh et 0164 ee Soe 0°18 Ta eis Zaehle gh ee (03) ane ho tr. epee page 0:10 BAIN Cea CuO__- none eee ede tr. pt ta, ie NiO: =: TTP. se ncaa 0°03 sfoaaee ine MnO -.- 0°19 0:27 0°25 0:20 yd we 0°45 BaO__- tr. dont ete 0°04 Ee Mie 100°65 99°80 O=S .. °05 cig WE O=Cl1F 0°04 Pe at i ae ———s ——— SSS — ———— == = Total_. 100°60 100°75 100°44 99°76 100°29 100°59 I. Hampshiral-camptonose (camptonite). Mt. Belknap. H.S. Washington analyst. II. Augite-ourose (diabase). Livermore Falls, Campton, N. H. G. W. Hawes analyst. (This Jour. (3), vol. xvi, p. 150, 1879.) III. Hampshiral-livermorose (camptonite). Ibidem. IV. Hampshiral-camptonose (camptonite). Mt. Ascutney, Ver- mont. Daly (Bull. 209 U. G. Geol. Surv. 1903, p. 87). W. F. Hillebrand analyst (includes Zro,, 03; F, °05; FeS, °36). V. Hampshiral-auvergnose (camptonite). Salem Neck, Mass. Washington, (Jour. Geol. vii, p. 285, 1899.) VI. Hampshiral-camptonose (camptonite). Kjose Aklungen, Norway. Brégger (Erup. Gest. Krist. iti, p. 51, 1899). L. Schmelck analyst. VII. Molecular ratios of No. I. Pirsson and Washington—Geology of New Hampshire. 501 cent of the mineral to be present; this is due to the fact that the needles of the mineral are excessively minute and cannot be measured accurately. In the same way, many tiny flecks of calcite also escaped, and this is probably also low. With the feldspar is included a small amount of isotropic base pre- viously mentioned. All of these errors are small, however, and the result shows the rock made up of iron ore, horn- blende and plagioclase in about the proportions given. Chemical Composition.—This is shown in analysis No. I of the above table. In Nos. II-V are given for comparison analyses of rocks of similar mineral composition and occur- rence which are either in camptonose or immediately adjoin- ing subrangs. They are all classed as camptonites in the older systems. These are from the New England province and there is a strong resemblance between them in essential fea- tures. In No. III the total alkalies are about the same as in the others, but the soda very strongly predominates, throwing the rock over into the persodic subrang in the lendofelic order (IU, 6.3.5), which is as yet unnamed, but for which we pro- pose the name of livermorose, from the locality of Livermore Falls. Under the head of rocks which have been classed as camptonites in the qualitative systems, it will be found by a study of the analyses that types have been classed together which show quite wide divergences in chemical composition. When one recalls, however, that the type in sucb systems is based mineralogically upon the association of plagioclase with a relatively large amount of brown hornblende, this is not to be wondered at, for these brown hornblendes present as large a range of chemical variation as can usually be found under the heading of a single mineral name. Classijication.—In the quantitative system the norm of the rock and its position are as follows: Norm Or. 13°34 Sal 55°80 , Ab _. 20°44 Has anOk 1°5 (3), Salfemane Sao arae 8) L 3°12 wr. 2-48-90 Wea ho 6a 0:059 = (5), Gallare i K’,O’+Na,O’ — 73 Ae nie ie Gah at Be 1°1 = (3), Camptonase MEG oe 25°80 K,O' 24 5 1 eee: be | Aer 0 0°48 = (4), Camptonose piss 2.02 ; Rest_. 7°57 Total, 100°41 502 Pirsson and Washington— Geology of New Hampshire. The mode is abnormative and hornblende is the critical mineral. In texture the rock is trachytic though not of a typical character; in fabric it is megaporphyritic and hence it may be termed a hornblende- trachiphyro-camptonose. In the prevailing systems the rock is a typical, fine-grained camp- tonite. To distinguish this alferphyric type of the camptonose and other closely related magmas, characterized largely by the abundance of highly automorphic, brown hornblende pheno- erysts, and which rocks are called camptonites in the prevail- ing systems, we propose the adjective hampshiral, from the name of the state (New Hampshire) in which these rocks are common and where the first typical camptonite was found by Hawes. The general habit of these rocks may, therefore, be described as hampshirovd. Variations from the hampshiral type-—Some of the black salfemic dikes are precisely similar to the type described above, but in other cases along with the hornblende there is developed a considerable amount of a pale brown augite of large extinction angle, well crystallized and appearing only in the phenocryst stage of development. When this appears the amount of plagioclase 3 is lessened and a good deal of a cloudy, faintly doubly refracting base is present, which may perhaps be nephelite. It would seem as if lime had gone more largely into the augites and less was left for plagioclase. In one case where augite was quite abundant, no feldspar was seen. These variations in mineral development may be seen in closely contiguous dikes, as at Smith’s Neck, and they are not believed to be correlated with any notable change in chemical composition. In a few eases there is also a variation in texture, the grain becoming so densely fine that under a high power the rock is made up of an exceedingly fine mesh of minute interlaced needles of hornblende and _ plagioclase. In general none of these last rocks have the hampshiroid habit witb megaphenocrysts of hornblende like those of other well known localities. West Dike.—One of the most interésting of these varieties is found in a dike on the lower west slope of Locke’s Hill. The dike is about 20 feet in width and cuts the gilfordal camptonose (essexite) near its eastern contact as nearly as could be determined. It isin the northern part of the camp- tonose area, has an east and west trend, and is composed of a much cracked rock cut by many joint planes. Megascopic.— Medium dull gray; much whitened and leached on the joint surfaces; occasional black hornblendes as phenocrysts 1-3°" long and 0-5 broad showing 110 and 010; thickly dotted with small phenocrysts of ‘feldspar of a Pirsson and Washington— Geology of New Hampshire. 5038 stout tabular form 1-38™" long, of a pink color and with slender needles of hornblende also about 1-3™" long, these two with distinet fluidal arrangement. Groundmass compact and of a medium, somewhat brownish-gray. Microscopic.—The study of the section shows that the rock is much altered. The groundmass consists of small feld- spar granules tending to a short lath-shaped form, and although considerably changed it can be seen that both alkalic and plagioclase feldspars are present. At first glance the impres- sion is that of a rock of syemitic aspect, that the rock is an altered monzonose, a gauteite in current phraseology; but further inspection reveals the fact that it is everywhere filled with minute pseudomorphs of chlorite which, on grounds to be presently mentioned, are thought to be pseudomorphs of needles and microlites of hornblende. Were these latter pres- ent, as they must have been originally, the rock would have a distinct lamprophyrie aspect and micro-hampshiroid habit. This groundmass is dotted thickly with granules of calcite, titanite and occasional ore grains. Scattered in it are infre- quent phenocrysts of feldspar, which in spite of being more or less filled with sericite shreds, show by the albite twinning and extinction angles that they are of plagioclase. The most interesting and important features of the rock are the hornblende phenocrysts and the process of alteration which they have suffered, one hitherto unmatched in our experience. The unchanged mineral is a brown basaltic one, with strong pleochroism in yellow tones and similar to that already described in the gilfordal camptonose (essexite) and in the dikes: c and 6, dark yellowish brown; a, very pale brown almost colorless, a pleochroism lke many biotites. Absorption strong, c= b> a. Angle of ¢ on .¢, about 9% Cleavage very good. These are the properties of basaltic hornblende. What remains of the small microlites in the groundmass shows that they are similar. These hornblendes are all more or less altered into pseudo- morphs consisting of a pale green fibrous, almost isotropic chlorite. grains of calcite and of titanite. The chlorite and calcite as alteration products of hornblende present nothing unusual, but, so far as we know, titanite as a secondary mineral in this connection has not been ‘described, and at first thought it seems so unlikely an origin for it that the matter deserves some consideration. Titanite secondary from hornblende. The titanite occurs in irregular grains and masses showing no good crystal form, intermingled with the chlorite and cal- cite in the pseudomorphs. Often it can be seen running into the still unaltered hornblende in strips and wedges and 504 Persson and Washington— Geology of New Hampshire. developed along cracks. The grains of titanite in such cases often have a nearly parallel orientation. Sometimes the out line of the pseudomorph is well defined by grains of titanite running along the boundary and more or less contiguous; the interior is mostly chlorite with scattered areas of the titanite. The amount of calcite present is usually relatively small and very often entirely wanting. The whole mode of occurrence of the titanite shows clearly that it is a secondary mineral ; that it is quite similar to that of epidote in other cases of horn- blende alteration. That the mineral is titanite, however, and not epidote is very clear, its refractive index and birefringence are far too high, and in sections perpendicular to the acute positive bisectrix it shows the characteristic optical figure—the small angle of the optic axes with both hyperbolas in the field with the strong dispersion of the optic axes which causes them to be bordered red and blue, with red greater than blue. It might also be suggested that there was an original inter- growth of titanite and hornblende, but this is negatived by the fact that the unaltered fragments and crystals of hornblende are clear and free from inclusions; only where it is altered does the titanite appear. In considering the cause of this manner of alteration, it should be remembered that basaltic hornblendes have been shown by Schneider* to have a pretty constant composition and to contain TiO, in amounts ranging from 4°26 to 5°40 per cent in the specimens analyzed by him, averaging about 5 per cent. Brogger,t in his table of the alkali-iron hornblendes, ealls attention to the fact that these hornblendes rich in TiO, have extinction angles of 0-10° and pleochroism brown to light yellow, c> 6> a, characters like those of the one under - consideration. It may be considered certain that this hornblende contains several per cent of TiO, and that in the breaking up of its molecule through processes of alteration this oxide has united with the lime and silica to form titanite. Five per cent of TiO, would yield over 12 per cent of titanite; the amount present appears considerably greater than this, and moreover it is not confined to the hornblende pseudomorphs but also occurs scattered through the groundmass in the same irregular grains. The larger grains of iron ore, when examined with a high power, are not solid mineral as is usually the case, but are filled with a network of holes, so that they are mere sponges. This suggests another source for the TiO,, as that wander- ing out from the iron ore could have aided in a further increase of the titanite already forming from the hornblendes, * Zeitschr. fiir Kryst. xviii, 580, 1890. + Grorudit-Tinguait Serie, Vid-Selsk. Skrifter, M-N-K1., 1894, No. 4, p. 22. Pirsson and Washington— Geology of New Hampshire. 505 which would supply the necessary lime and silica. The basal- tic hornblendes contain about 12 per cent of lime, and if this were all used in producing titanite it would make 42 per cent in weight of the original hornblende. But as some of the lime has gone into calcite the amount of the mineral replac- ing hornblende is not so large as this, but is between this figure and that given above—probably 20-30 per cent and varying in different cases. The two analyses of camptonose rocks previously given show about 4 per cent of TiO, in the rock, and as this has apparently all gone to form titanite, the total amount present is about 10 per cent in weight of the rock mass. The appearance of the rock, and the white mica in the feld- spars would seem to indicate that the alteration was due to hydrothermal metamorphism rather than to atmospheric weathering. The occurrence of titanite as a secondary mineral seems not to have received the attention that it deserves. Every one is familar with its appearance in mantles around titanic ore grains in gabbroid rocks, and it is often mentioned in such cir- cumstances as of secondary origin, but we are not acquainted with any description of its derivation from another mineral such as hornblende, though this may of course have been mentioned in the literature. In this connection it is interest- ing to recall the fact that it often appears in chlorite schists, amphibole chlorite schists and amphibolites whose chemical compositions are similar to those of magmas which yield salfemic and dofemic rocks. GUNSTOCK GNEISS. As stated in the geological portion of this paper, the igneous rocks of the Belknap massif are in contact with micaceous gneisses along the western boundary. They constitute a dis- tinct formation worthy of especial study, but as they are heavily covered with drift and exposures are none too frequent this would have taken more time than was possible to devote to this purpose and would have led us away from the main subject of this study. In our work along the western contact, however, we came upon these rocks in a number of places and specimens from several of them were taken for investigation. From two of these, one from the borders of the little ravine on the southwest foot of Locke’s Hill and the other in the pas- ture fields at the foot of the steep slopes on the west side of Mt. Gunstock, sections were cut and studied and the results are given beyond. Since the lower valley of the Gunstock River is cut in this gneiss, we may provisionally, for purposes of reference, term it the Gunstock Gneiss. 506 Pursson and Washington— Geology of New Hampshire. Megascopic.—Oolor, dark stone-gray ; of very fine grain; strongly foliated ; even texture; highly micaceous and splitting readily along the plane of chief fracture; showing with lens an even mixture of white granules and flakes of mica. Microscopic.—The minerals seen in the section are quartz, orthoclase, biotite, plagioclase, sillimanite, garnet, muscovite, apatite, iron ore and zircon in the order of their importance. The quartz is in irregular elongated granules, filled in places with dusty specks, shows occasional lines of fluidal cavities and rarely any evidence of undulatory extinction pointing to dis- turbance of the optical system by strain. The orthoclase has a similar form and in places is filled with shreds of sericitie mus- covite; generally it is clear and unaltered and shows no twin- ning. The biotite is in small brown pleochroic flakes, well scattered but tending to lie with the base in the plane of schis- tosity, thus promoting the easy fracture. It sometimes contains iron ore with pleochroic halos. The plagioclase is similar to the orthoclase but distinguished by the albite twinning; it appears to be an oligoclase. It may be remarked here that the association of the sillimanite suggested the possible presence of eordierite, but careful search failed to reveal it by any of the usual diagnostic characters which it possesses. The sillimanite is in the usual characteristic bundles of needles, and it is not everywhere scattered through the rock but appears distinctly in layers; although these wedge out in places they soon recur again, running along at about the same horizon. The garnet, of an ordinary character, is in round grains of relatively con- siderable size associated with these sillimanite bands, which often curve around it. The apatite and zircon lie scattered in the quartz-feldspar layers; they are very small and a signifi- cant circumstance is the fact that they show no crystal outlines but are rounded ovoid bodies. In the specimen taken near the contact at Locke’s Hill the appearance of the biotite and the fabric of the rock suggested a distinct approach to the characteristic contact hornstone tex- ture, but elsewhere this is not noticeable. Origin of the Gunstock Gneiss. The characters which have been mentioned above clearly point to a sedimentary origin for this gneiss. There is no sign of shearing or granulation and the minerals show no opti- eal strain—it has therefore been recrystallized. The presence of the sillimanite-garnet bands points to fine clay layers of a somewhat marly nature interspersed among those forming the main mass of this very fine-grained arkose. The rounded forms of the apatite and zircon grains would point to their having been rolled in the fine sand; in the metamorphism q { } } | — Pirsson and Washington—Geology of New Hampshire. 507 which recrystallized the rock they are minerals which would naturally be least affected and would retain their former shape. Had the rock been a sheared and recrystallized igneous one, we should expect them to have shown crystal outlines. The alter- nation in layers of different character points in the same direc- tion. We think therefore that this gneiss was originally a very fine shaly arkose consisting of little-altered granitic debris with occasional very thin layers of a more marly clay-like nature. Often the chemical analysis of a rock helps greatly to decide its original character, but it is evident that the composition of a little altered arkose will be practically the same as that of the igneous rock from which it may have been formed, and in this case the solution of the problem, when it is metamor- phosed, must be sought in other directions such as we have indicated above. Tue SEQUENCE oF MAGMAS. This has been previously alluded to on page 350 of the fore- going geological part. Now that the petrologic characters of the different types have been described, the reasons for the adoption of the succession of magmas there given can be dis- cussed more fully. It depends upon the following facts, which have been brought out in these pages. a. The pulaskose (syenite) passes into a fine-grained lassen- ose (adamellite aplite) marginal facies. 6. The pulaskose is cut by dikes of liparose (aplite), of camp- tonose (camptonite) and of akerose (spessartite). The relative ages of these dikes were not determined, as no place was found where they cut one another. c. The grano-camptonose (essexite) shows contact facies as it approaches the pulaskose (syenite.) d. The grano-camptonose (essexite) is cut by dikes of phyro- camptonose (camptonite) and of liparase (aplite). e. The liparase (aplite) of d contains fragments of the camp- tonoses and akerose (essexite and spessartite) and of schists. J. The breccia mass is like e, consisting of a liparase cement full of masses of the same rocks as in e. From these facts we imagine then the sequence of events to have been as follows: First came the intrusion of the great body of pulaskose magma into the gneisses and schists.. By processes of differentiation there formed a persalic or more quaric border of lassenose of variable width around this. Then followed a period of cooling and solidification. During this time extended processes of differentiation had been going on deep in the magma chamber, giving rise to products on the one hand more salic, on the other more femic. Then came a second period of magma upthrusting which forced the femic 508 Pirsson and Washington—Geology of New Hampshire. magmas upward into the mass of pulaskose and into the sur- rounding area where they appeared as dikes, except in one place on the northwest boundary where the magma formed a small stock. In the dikes the texture assumed was dense and more or less porphyritic, forming trachiphyro-camptonoses and akeroses (camptonites and spessartite), but in the stock the erystallization was coarser, producting a granular texture and making grano-camptonose (essexite). This assumes that the rocks of the dikes and of the stock have a similar composition ; that this is so, has already been shown with respect to the camptonoses. In regard to the akerose dikes it has been shown also that they correspond to one facies of the stock, which is somewhat variable in its composition. The injection of the camptonose magma evidently was not everywhere a simultaneous one, for we find dikes of it in finer textured types cutting the camptonose stock, proving that this had already cooled and solidified to depths now exposed by erosion, when these later upthrusts of this magma took place. It is thus quite possible that the dikes of camptonose seen else- where are not all exactly of the same age but that their injec- tion was successive, some corresponding in age with the intru- sion of the stock and some later, like those dikes which cut it. On the general principles of differentiation as thus far devel- oped, it would also seem probable that the akerose (spessartite) dike cutting the summit of Mt. Belknap was one of the earliest of this set, since it is less differentiated. Following these came the period of the injection of the liparase (aplite), the persalic differentiate complementary to the camptonose. This has formed dikes in the pulaskose and in the camptonose stock. In the latter case it has brought up pieces of the camptonose in its various textural modifications and of the enveloping schists and gneiss involved within it, and in one place it forms an irregular mass, the breccia already described. At the time of its injection, cooling in and about the stock was becoming more pronounced and the magma was quite viscous. This is shown by the shattering and rupturing it produced on its upward way along the rock walls, the frag- ments thus broken off becoming kneaded through the mass, and also by the fact that these fragments were not melted, absorbed or changed, even when small and angular in shape. This was the final event in the formation of the igneous rocks. : The sequence thus worked out would be more certain if the actual contacts were everywhere visible, but as already stated they are in great part covered with drift. It however seems to correlate best all the facts seen in the field and determined by the laboratory studies. Moreover it has the advantage of simplicity in that it requires only three periods of injection Pirsson and Washington— Geology of New Hampshire. 509 with corresponding changes in the composition of the magmas beginning with one of medium character, then changing to a more femic type and then back to a corresponding more salic one, and thus following the general history of differentiation observed in other districts. The only objection against this view which occurs to us is, that if the aplitic liparase injections are the latest phase along the contact between the camptonose and pulaskose rocks and contain blocks of the former, why do they not contain blocks of the latter? The answer to this is twofold—first, we are not sure that they do not, we did not observe them in the exposures studied ; and second, we do not feel sure that we could identify them even if they were pres- ent, because in the field the lparose and the lassenose of the marginal facies both have the same aplitic habit and appear very much alike. They differ chemically and somewhat min- eralogically as has been described, but in the rock masses these differences might not be appreciated and blocks of the one in the other would certainly be difficult and perhaps even impos- sible to recognize. Moreover in this connection it should be pointed out that the dikes of liparase which penetrate the pulaskose were nowhere observed to contain fragments of the latter although of later intrusion into it, and it is in fact uncommon for aplitic dikes to contain such masses of the granitic rocks they pene- trate, although they sometimes do. The further discussion of this point would carry us too far, but enough has been said to show that the objection advanced is not necessarily decisive against the sequence we have postulated and which we believe is best suited to explain the facts observed. THe Apritic MARGINAL Facts The aplitic, persalic marginal facies of the main massif of pulaskose is an interesting feature of the petrology of the area. Aplitic border facies of granites are probably not uncommon and have been described by a number of observers as listed by Rosenbusch.* In these cases, however, this appears to be mainly an endomorphic textural modification of the rock mass. In the present case it is not only a textural but much more a chemical modification, the border being richer in silica than the rest of the massif. At first thought it might seem as if the syenite had enriched itself in silica by solution of the envel- oping rocks in some such way as Daly+ has recently suggested for occurrences in Canada and elsewhere. A further consid- eration of the subject, however, does not seem to favor this view. It is true that the border facies contains here and there * Mass. Gest., 3d ed., 1895-6, p. 65. + This Journal, xx, 1905, p. 185. Am. JOUR. ae ee SERIES, VoL. XXII, No, 132.—DEcEMBER, 1906. 9) 510 Persson and Washington— Geology of New Hampshire. fragments of the enclosing rocks, and that these appear at times, when very small, to be more or less absorbed, but gen- er ally even when minute they retain all their original sharpness of outline and angular form though completely metamorphosed. Moreover there is no evidence that the enclosing rocks are in general more siliceous than the syenite and in some cases they are distinctly less so. Where small fragments appear to have gone into solution the rock is not more but less siliceous, the small spot locally having more the character of 4 monzonase as already described in the inclusions in lassenose above Point Belknap. Again, it should be considered that 1f such an action took place one would expect it to be general and everywhere present, while as previously shown the syenite on the southwest foot of Locke’s Hill comes itself directly in contact with the schists. The consideration of the chemical character of the two rocks furnishes, however, the strongest argument against this view. In the syenite the percentages of the alkalies are Na,O = 4°89, K,O = 5:90, while in the granite border they are Na, O=4 06, K,O — 9-06. It is clear from this that to reduce the alkalies of the former to those of the latter an enormous amount of some rock very rich in soda must have gone into solution. It could be easily demonstrated what the composition of such a rock would have to be by calculating from the two analyses, but this is unnecessary as the enclosing schists are clearly not of such a composition as could produce this change. This explanation of the granite border being untenable, we are forced to fall back on causes endogenous to the fluid mass itself and to conelude that it is a case of magmatic differentia- tion. Cases where a massif of igneous rock has a differentiated border facies are becoming more numerous and several have been described where the border is more salic than the main portion. CHEMICAL CHARACTERS OF THE BELKNAP MAGMAS. The data for studying the chemical characters of the mag- mas which furnished the rocks described in the preceding pages are found in the analyses presented in the annexed table. Of these IL and V have been calculated from the measured modes and, while not entitled to quite the weight of the others, may yet be regarded as representing fairly well the chemical compositions of the rocks in question. The chemical range of the rocks is wide, especially as regards SiO,, Al,O,, FeO and CaO, with Fe,O,, MgO, K,O, TiO, and P, o> showing less variation, while the amount of N a,O is remarkably uniform. In general the variations of the several Pirsson and Washington—Geology of New Hampshire. 511 constituents, referred to the percentage of silica or to the ratios of salic to femic minerals, are the usual ones, Fe,O,, FeO, MgO, CaO and TiO, increasing with decreasing silica, K, O dropping sharply toward the femic end, while Na,O also drops but to a much less extent. Regarded from the point of view of the quantitative classifica- tion, the range of classes is from persalane to salfemane; the orders are only two, 4 and 5, the former being found “only among the persalanes; the rangs represented are three, 1, 2 and 3, the first being most prominent in the persalanes and the last only found in the salfemanes; while there are only two subrangs, the sodipotassic and dosodic, the more salic¢ and alka- lic rocks belonging mostly to the first of these and the more femic and more ealcic ones to the second. ANALYSES OF THE BELKNAP ROCKS. No. I EL III IV Vv VI VII VIII IX mi@. == 75:65 68:16 69:76 60°75 59°91 52:95 43°94 42°73 60°33 ee A269. 15-27 $1822 19°55, 15°82 14-96 LGN. L450) ViE-G9 He,O,- 0°89 0°88 0°25 1°54 2°93 2°44 3°96 4°03 2°24 eer. 1:1) LS 7 1°59 2°98 4°61 7°03 10°06 7°28 3°80 MeO _ 0°20 1°26 0°40 0°81 1°64 3°86 5°05 5°46 1°23 Ca 0-48 —0°15 2°68 2°29 Oey Onl 9°59 8°46 Jule Na,O_- 3°71 4°30 4°06 4°89 4°52 4°95 2°93 3°11 4°71 oO. 5°50 7°06 2°06 5°90 6°61 1°64 1°51 2°28 6°26 H,O+ 0°15 0°37 0°50 0°08 0°43 0°59 1°42 3°08 0°26 H,O— 0°08 de 0°15 0°24 tage 0°09 0°13 0°36 eee. CO, -- none none none none none _ none 0°09 3°76 none ey == 0705 0°59 0°36 0°63 1°39 3°90 4°13 4°30 101 ee 0-090 2 = 018) . 0-22. 0°76" 069", 0°93! 0-118 =) ze oe ae Ae 0°05 ae 0°18 Boe ts ie oe ess lee Tee see pe as seat tr we A ae roe Soir Hed hea HOROZ ee eae =a as RBG 15 on st fs ae tr sie MnO = 2: tr 3 tin tr tr meee tr tr 0°19 1520) ences Pe UR Py Jo Bis B= RMON 4) SOMES Muti aie 100°71 100°00 100-702 99°79 100°00 100°16 99°67 100°65 99°82 Subrang.- 1.4.1.8 1.4.1.3 1.4.2.4 1.5.2.3 I1.5.1.3 I1.5.2.4 1J1.5.3.4 II.5.3.4 I-11.5.2.3 I. Biotitic grano-liparose, (aplite). Dike, Mt. Belknap. If. Hornblendic grano-liparose, (syenite). Locke’s Hill. III. Biotitic grano-lassenose, (adamellite-aplite). Piper Moun- tain. _IV. Hornblendic grano-pulaskose, (syenite). _V. Hornblenditie grano-ilmenose, (syenite). VI. Hornblende akerose, (spessar tite). VII. Gilfordal camptonose, (essexite). VIII. Hampshiral , camptonose, 1X. Hornblendic of IV and V. (camptonite). pulaskose-monzonose, Locke’s Hill. Locke’s Hill. Mt. (syenite). Mt. Belknap. Guustock Peak. Belknap. Average 512 Pirsson and Washington— Geology of New Hampshire. It is to be noted, however, that some of the analyses are of rocks the volumes of which are very small relative to that of the whole igneous massif. This applies especially to the extremes, I and VIII, which are of the complementary dikes, whose total volume cannot be more than 5 per cent of the whole and is almost certainly considerably less than this. Similarly VI is of a rock of minor importance and of negligibly small relative mass. The area of the gilfordal camptonose (VII) of Locke’s Hill is considerable, bnt its volume is undoubtedly not over another 5 per cent of the whole mass. That of the bordering aplitic lassenose facies (III) is undoubt- edly considerably greater, though for reasons given previously it was impossible to estimate its extent with accuracy. The assumption that it forms about one-tenth of the complex will probably be not far from the truth. As to the main mass of syenite we have seen that its compo- sition is somewhat variable, different portions being represented by II, IV and V. Of these II is of a marginal facies and probably not fully representative of the whole. Analyses IV and V may therefore be held to represent the chemical com- position of the bulk of the Belknap massif. These resemble each other in certain respects, especially in Si0O,, CaO, Na,O and K,O, but differ in the lower Al,O, and higher Fe,O,, FeO and MgO of V, these resemblances and differences being clearly expressed by their respective places in the quantitative classification. Allowing equal weight to these two analyses, although V is calculated from a measured mode, we find that the composition of the syenite is that given in [X. The norm of this is as follows: Sal / Fem OZ sae 1eD@. Dies ails) Oreem recs ee ie) Ely es on Oe Alb) 2a ES Oree ; Boot Mite A se3e25 a 12°68 Anyee Bea Ti 2° 1-98: IY aL OER The main syenite falls, therefore, in the dosalane class, but almost on the border of persalane and well within the limits of order 5, rang 2, and subrang 3, so that it is a pulaskose- monzonose, (I—II. 5.2.3). We may attempt to estimate the composition of the magma as a whole, although the data are somewhat unsatisfactory and the results necessarily only approximately correct. For this purpose we may assume the relative volumes as estimated above, giving as much prominence as possible to the less abun- dant rocks. We shall thus estimate the volume of the syenite at eight-tenths of the whole, that of the border lassenose at one-tenth of the whole, that of the gilfordal camptonose at Pirsson and Washington— Geology of New Hampshire. 518 one-twentieth, and that of thecomplementary dikes the same, those of liparose and of camptonose being in the proportion of 3 to 2. The analysis of the akerose (VI) may be neglected. Taking then 80 parts of IX, 10 of III, 5 of VII, 3 of I and 2 of VIIL we obtain the follow: ing results : pIOs 2-5. 60:94 OE ea A OT | BeOS. liso | One 432780" (oa: Reo ris Ripe (oe! BeOS. 3°91 Jenigt begs A LR ey MgO .... 1-40 Di.... 0°92 } 620. 52597265 Hy ... 6-90 Na, O Le 04752 MG) es 3-09C% 13°31 MEO tS. i558 Wges (aot | NCS A eg hs Ape 0-84) PO. 222) 2. 0:20 HALE == 99°98 100°00 These figures are practically identical with those furnished by the main syenite, though $10, and CaO are a trifle higher and K,O a little lower, and the ‘classificatory position of the rock is the same, pulaskose-monzonose (I-11. 5.2.3.). That the divergence in composition of the average magma from that of the main syenite should be small follows from the fact that the combined weight of the modifying factors, that is the liparose, lassenose and camptonose, is only one-fourth that of the main mass. But the very close agreement shows that the several constituents in the more salic and the more femic magmas bal- ance each other to a very great extent, and indicates that they are in the nature of complementary differentiates. It is to be noted, however, that the main pulaskose-monzo- nose is higher in alumina, soda and potash thanany of the smaller rock bodies,* while the figures for the other constitu- ents lie between the extremes. It is perhaps justifiable to infer from this the existence in the complex of a differentiate relatively higher in these constituents. Such a rock would be composed almost wholly of soda-ortho- clase about Or,Ab,, with relatively insignificant amounts of quartz, plagioclase and alferric or femic minerals. We may possibly look for this in the syenitic cement of the breccia de- scribed above, which has not been examined chemicaily, but which we have shown to be markedly deficient in plagioclase and colored minerals, though the amount of quartz is consider- able. In conclusion a few words may be devoted to a comparison of the Belknap rocks with those of other igneous areas in New England and Canada. The best analogues are met with in the larger and more complex igneous district of Essex County, * Except as regards soda in the akerose (VI). 514 Pursson and Washington— Geology of New Hampshire. Massachusetts, which has been described by one of us.* In this rocks of very similar chemical and mineralogical composi- tions occur. ‘These include numerous types, of varying modes and textures, belonging to subrangs which are found at the Belknap Mountains, namely: liparose (granite, aplite, paisan- ite, keratophyre), lassenose (rhyolite), pulaskose (pulaskite, sdlvsbergite), and camptonose (diabase), with essexose (essexite) closely like the phyro-camptonose of Belknap. These rocks of Essex County are, it is true, associated with miaskose (foyaite and tinguaite) and with umptekose (sdlvsbergite,) but this heightens rather than detracts from the analogy, as miaskose and umptekose (nephelite-syenite), are found at Red Hill, across Lake Winnepesaukee from the Belknap Mountains. This last igneous mass will shortly be described by us, so that further consideration of this correlation may be deferred. Still nearer to the Belknap Mountains are the rocks of Ascutney Mountain, which have beeu studied by Daly,t whose descriptions and analyses make clear the very close similarity between the two areas. The resemblance between the two is shown even in such details as the poikilitic development of the alferric minerals of some of the Ascutney gabbros and diorites, in this resembling the hornblendes of the gilfordal camptonose. Analogies may also be noted with the rocks of the Monteregian Hills, in the Province of Quebec, which have been described by Canadian petrographers.t The rocks of these last, however, are generally distinctly lower im silica and are more sodic, norm- ative or modal nephelite bemg quite common. It would seem that all of these occurrences, with perhaps others in Maine, New Hampshire, Vermont, and Massachusetts, belong to one petrographic province, or comagmatic region as it may be better termed, which may be called the Novang- lian, from the many localities in New England. This is not the place for a discussion of this region, especially as our knowledge of some of the districts is as yet incomplete, but some of the chemical features may be briefly pointed out. These are the rarity of the dofemanes and perfemanes, the prevalence of quardofelic, perfelic, and lendofelic orders, of peralkalic and domalkalic rangs (alkalicalcic rangs occurring to some extent among the salfemanes), and of sodipotassic and dosodic subrangs. As features of minor importance may be mentioned the generally small amount of MgO, even in the salfemanes, the comparatively high FeO and TiO, (the amount of the latter being often very great in the salfemanes), and the almost complete absence of BaO. New Haven, Conn., and Locust, N. J., June, 1906. * Washington, Jour. Geol., vi, 787, 1898; vii, 53, 105, 284, 463, 1899. +R. A. Daly, Bull. U. S. Geol. Surv., No. 209, 1903 tJ. A. Dresser, Am. Geol., xxviii, 203, 1901; F. D. Adams, Jour. Geol., xi, 239, 1908; J. A. Dresser, this Journal, xvii, 347, 1904. Hidden and Warren— Yttrocrasite. 515 Arr. XLIV.—On Yttrocrasite, a New Yttrium-Thorium- Uranium Titanate ; by W. E. Hrppen and C. H. Warren. Tue crystal, from which the material for analysis was selected, was found about three years ago in Burnet County, Texas, by Mr. John J. Barringer, who discovered the famous gadolinite mine just across the Colorado River in Llano County, now known as Barringer Hill. The erystal was found among the debris thrown out from a small prospect pit, dug for gadolinite. and was the largest of several pieces observed in the loose peg- matite material. The locality is east of and nearly opposite Barringer Hill and distant from it about three miles. It is sit- uated in Burnet County and in a region where coarse granite and pegmatite abound. This crystal when first found weighed about sixty grams, and was complete except at one end. It. showed orthorhombic symmetry, but the faces were not smooth enough for satisfactory measuring. The type of form closely resembled the figure of yttrotantalite, on page 738 of Dana’s System of Mineralogy. The three pinacoids, the unit prism, and one orthodome were apparent. The basal plane predomi- nated. | The crystal had a thin dull brown coating of amorphous mate- rial which was evidently an hydrated alteration product, very similar to the yeliowish brown coating observed on the poly- erase (?) of North and South Carolina. The fresh underlying material is black in appearance, and has a bright pitchy to resinous luster, and closely resembles that of polycrase and euxenite, and like these has an uneven and small conchoidal fracture. Its hardness is between 5°5 and 6. Under the microscope fragments of the mineral show, through their edges, a rich amber to light yellow color. Ex- tremely thin pieces are almost colorless and transparent. In some portions near the surface minute black specks, sug- gestive of alteration products, or mechanical inclusions, were observed scattered through the material. The mineral when examined between crossed nicols is seen to consist of a mixture of isotropic and a feebly double refracting material. In sev- eral instances a distinctly spherulitic structure was observed with high powers, otherwise nothing of a definite nature could be made out regarding the optically active portion. The mineral is not now, therefore, of a strictly homogeneous structure. This fact taken into consideration with its content of water and car- bon dioxide suggests that the mineral is a hydrated alteration of an originally anhydrous species. It may be mentioned here that a very similar heterogeneous structure has been also noticed as‘characteristic of specimens of polycrase(#) from North and South Carolina. 516 Hidden and Warren— Yttrocrasite. Before the blowpipe the mineral is infusible, assumes a dark grayish color and cracks open to a slight extent. In the closed tube it decrepitates slightly, gives off water and car- bon dioxide at a temperature slightly below redness. The reactions with fluxes on platinum wire are not decisive. It is easily decomposed by hydrofluoric acid, leaving a light green- ish residue of earth fluorides. If finely powdered it is soluble with slight effervescence when boiled in strong sulphuric acid, and yields a somewhat opalescent, pale yellowish green solution. If hydrochoric acid and zine are added to this, a violet color is at first obtained, and this gradually changes to a blue-gray, and finally to a deep blue. (in this connection we would state that the South Carolina polyerase, when finally pulverized, makes a perfectly clear green solution when boiled with strong sulphuric acid, and leaves no residue. The material analyzed was that portion of the crystal which showed under the microscope practically none of the black specks above referred to. The specific gravity was found to be 48048 at 17° Cent., the mean of two careful determinations on the chemical balance. The results of the chemical analysis (Warren) were as fol- lows : Oxides. Per cent. Mol. wt. Ratio. TiO: 49-72 + 8015 = 620 ) Nb,O, present La 0. trace WoO, 1:87 +3328 = '008 $645 1612 16 UO, 0°64 +2880 = 002 S10, trace Co, 0°68 + 440 =-015 J (YtEr),O, 25°67 +2684 = 096 ) O2O cece) ane 92 +3310 = -008 }-113 2-82 yume Fe,O, 1:44 +1600 =:009 | © ThO 8°75 9686 =-033). U0, 198 +2716 = -007 080) PbO 0°48 —-222°9 == OZ MnO 0°15 = 71:0 = 5001 4%, 2056 0°90 1 CaO 1:83 ==? 5620 = *033 MgO | trace H,O 4°36 + ° 18:0 SS 249 2a 6°00 6 “ hydrose. 0°10 Total 100°57 The following points may be noted regarding the method of analysis: Water and carbon dioxide were determined directly by igniting the mineral in a platinum boat in a hard-glass com- HMidden and Warren— Y ttrocrasite. oe bustion tube reinforced with heavy platinum foil as recom- mended by Penfield and catching the products in sulphuric and potash bulbs respectively. Several blank determinations were run to test the apparatus previous to the actual determina- tion. The combined weights of the water and carbon dioxide are slightly higher (0°15 per cent) than the loss on ignition of the boat and its contents, due probably to the oxidation of the UO,. This close agreement indicates that there can be little if any helium or nitrogen present in the mineral and no evidence of their presence could be obtained. After igni- tion the mineral has a light buff color and goes into solution more difficultly than the unignited material. A qualitative test for ferrous iron, made as recommended by | Penfield,* proved its entire absence. The oxidation, therefore, of potassium permanganate by a cold sulphuric acid solution of the mineral was taken as an indication that part at least of the uranium present was in the form of the dioxide, and the figure given for this oxide in the analysis was obtained by titration with permanganate. For the main portion of the analysis, the mineral was decom- posed with hydrofluoric acid (the J. Lawrence Smith method). The greenish white residue of earth fluorides was filtered off, converted into sulphate (a little lead sulphate came out at this point) and twice precipitated with ammonium hydroxide to sep- arate the earths, etc., from the lime. The earths were sepa- rated from the iron and uranium by precipitation with oxalic acid. Thorium and cerium earths were taken out as described by ‘Hillebrand.t The cerium earths were separated from thorium by means of sodium thiosulphate and ammonium oxalate pre- cipitations.t The earths were all finally precipitated as oxalates, before ignition and weighing. Great care was taken to insure the complete recovery of earth oxalates from the filtrates. Some were almost invariably recovered, which again empha- sizes the caution, in this regard, given in the artiele re- ferred to above by Dr. Hillebrand. The yttrium earth oxides were of a light buff color and gave a pink nitrate solution. This tested spectroscopically showed the characteristic absorption spectra of erbium. The molecular weight was found to be 268°4 (R,O,). The cerium oxides were brown in color and when dissolved in hydrochloric acid gave a yellow solution. Tested spectr oscopic- ally the didymium bands were obtained and a faint band in the position of the most characteristic erbium line, indicating a sheht contamination. The molecular weight, determined as, 331-0 (k,0,), is probably not exact owing to the small total weight * Brush and Penfield’s Determinative Mineralogy, p. 87. + This Journal (4), xiii, p. 148, 1902. ¢t See Metzger, Am. Chem. Jour., xxiv, 901, 1901. 518 Hidden and Warren— Vttrocrasite. of the oxides. Iron was separated from the uranium of this por- tion by passing hydrogen sulphide through the warm solution when nearly saturated with ammonium carbonate.* The filtrate from the original hydrofluoric acid treatment was evaporated to fuming with sulphuric acid. After cooling and dilution with water, ammonium hydroxide and freshly prepared colorless ammonium sulphide were added and the pre- cipitated hydroxides were digested on the water-bath. After filtration and solution the precipitation and digestion were repeated and the tungsten thus extracted was determined in the combined filtrates. Tin was tested for, but not found. Doubtless a little tungsten remains with the titanium, etc., but in the writer’s experience the above method involves smaller errors than the one where a sodium-carbonate-sulphur fusion is made. After the second digestion with ammonium sulphide the precipitated hydroxides were allowed to stand with strong sulphurous acid, whereby the dark colored iron sulphide and some titanium and uranium passed into solution. The hydroxides were again dissolved in hydrofluori¢ acid, and later expelled with sulphuric acid, and the solution barely neutralized with ammonium hydroxide, after which an excess of ammonium carbonate was added, together with some fresh colorless ammonium sulphide. By this means the uranium was extracted together with a little titanium. By repeated reprecipitations in the presence of ammonium carbonate, the uranium was obtained free from all but a trace of iron and titanium. A little additional iron was recovered from the main precipitate by means of sulphurous acid. The small amount of titanium which goes with the iron is easily recov- ered by precipitation with sodium acetate in the presence of acetic and sulphurous acids. The ignited oxides of titanium and niobium when fused with acid potassium sulphate and leached out with cold water, pass almost completely into solution (all but 0-0021 gr. from 0°3139 gr. in the sample treated). Qualitative tests according to the procedure recommended by Dr. A. A. Noyest showed the presence of enough niobium to give the characteristic brown color to the solution after reduction by means of a zine column, and to produce immediately an abundant white per- cipitate in the solution of mercuric chloride. This test is a delicate one and the reaction may be obtained’ with only a few inilligrams of niobic acid. This taken in connection with the fact that but a small residue remains from the leaching of the bisulphate fusion, points to the presence of only a small * For suggesting this satisfactory form of the iron-uranium separation we are indebted to Dr. B. B. Boltwood of New Haven. + A System of Qualitative Analysis, Technology Quarterly, vol. xvii, No. 3, 904. . Hidden and Warren— Yttrocrasite. 519 amount of niobium and tantalum. As will be pointed out in the accompanying note on the estimation of niobium and tanta- lum in the presence of titanium, it is entirely possible for several per cent of niobium and tantalum to be present and still leave practically no residue when fused with bisulphate and leached with water. At present there appears to be no way of accurately determining the small amount of niobium present. Tantalum was found to be present only as atrace. Assuming that the amount of niobium is too small to affect the molecular ratio materially, we have on combining the acid and basic radicals, as shown in table above, the following approximate ratios: Een te OO Ce nO 2) ee OU eu TiOM ebe: 6 : 1 : 3 : 1 : 16 Where R™O is chiefly lime, R,™O, chiefly yttrium earths, RO, chiefly thorium. The mineral is therefore essentially a hydrous titanate of the yttrium earths and thorium. The above ratios may, of course, be no more than a coincidence but they are sufficiently sharp to argue in favor of the correct- ness of our assumptions. In view of the necessary incomplete- ness of the analysis and alsoof the small amount of exact knowledge which we possess regarding the true molecular relations existing between the so-called “rare-earths” and acid radicals, a further discussion here of the constitution of this mineral is hardly worth while. In fact it may be remarked that before a satisfactory understanding of the entire group of the so-called ‘“ titano-niobates”’ can be had, we must have, not only better analytical methods but also much clearer ideas of the capacity of these elements, and their compounds, to form isomorphous mixtures and solid solutions. feadio-active properties.—Some fragments of the mineral were examined for radio-activity by Professor B. B. Boltwood of New Haven, to whom we wish to express our thanks for his kindness. The total activity of the mineral was found to correspond to 10 per cent of thorium and 2°08 per cent of uranium. The amount of uranium found by analysis was 2°29 per cent and of thoria 8°75 per cent, which are in very satis- factory agreement with Dr. Boltwood’s figures. The mineral is evidently a new species and the authors would suggest the name Yttrocrasite for it. 520 C. H. Warren— Niobium and Tantalum. Art. XLV.—WNote on the Estemation of Niobium and Tan- talum wn the presence of Titanium ; by C. H. Warren. Tue obtaining of a strong reaction for niobium in the mineral described in the previous paper and the failure to obtain more than a fraction of a per cent of niobium by means of the acid potassium sulphate fusion and leaching in cold water, naturally led to an examination of the methods for estimating these ele- ments quantitatively in the presence of each other. So far as the writer can ascertain, the most common method followed is that involving a fusion with bisulphate of potash followed by leaching with cold water, these operations being repeated until all the titanium has passed into solution, while the niobie and tantalic oxides remain behind. In his System of Qualitative Analysis,* page 218, Dr. A. A. Noyes states that when treated in this manner fairly large quantities of niobium and tantalum pass into solution with titanium when much of the latter is present. With this statement in mind a few exper- iments were made to gain some further idea of the magnitude of the error involved in the method. Pure TiO, was prepared from selected crystals of rutile by the usual chemical methods. Nb,O, and Ta,O, were prepared from the columbite of Branchville, Conn., after the method described by Osborne,t except that the precipitated oxides were digested for some time with ammonium sulphide to insure the removal of any tungsten or tin which might be present. The final products were subjected to the most careful qualitative examination and no impurity other than a trace of iron could be detected. | The attempts at separating these oxides, quantitatively, when mixed together were very unsatisfactory, and although few in number seem to thoroughly confirm Dr. Noyes’ statement. Indeed, considerable quantities of niobium may be made to pass into solution with the titanium, as the figures given below show. In the first three experiments, the fusion and leachings were thrice repeated. In each case the fusion was mashed to a pow- der under cold water in an agate mortar and allowed to stand with from 250 to 300° of water for twenty-four hours. The titanium was precipitated from the combined filtrates with ammonium hydroxide, filtered, washed free from sulphates and ignited to a constant weight. The residues from the first two leachings gave a strong reaction for titanium with hydro- gen peroxide, and a small amount of titanium always remained in the last residue. : * Technology Quarterly, vol. xvii, No. 3, 1904. + This Journal (3), xxx, 330, 1885. &.. C. H. Warren—Niobium and Tantalum. 521 Weight in grams : Wet. of Of Nb.O;—Ta.O; oxides (about 3:1) taken Of TiO, extracted Excess No. 1 +2500 "2359 3046 0687 Woe?) 2103 °2039 "2580 "0541 Ne. 3 “S031 °2698 -2883* "0185 No. 4 :0178 (Nb,O, only) °3605 0010 niobium undissolved From No. 4 it would appear that as much as 5 per cent of niobium may pass into solution with an excess of titanium and thus be practically lost in the course of analysis. Although fur- ther study of the most favorable conditions of fusion and solu- tion might be of interest in themselves, the method appears to offer little chance of being modified so as to give more than roughly approximate results. The method proposed by T. B. Osbornet was next examined. This depends on the titration of a solution containing the tita- nium and niobium in the lower state of oxidation with potas- sium permanganate, thus oxidizing these elements to the higher oxides, and the subsequent estimation of titanium colori- metrically, while any tantalum, which is not reduced to the lower oxide, present in the original sample, is found by dif- ference. The method of procedure is briefly this: the mixture of the three acids, tantalic, niobie and titanic, is dissolved in hydrofluoric acid and the excess of acid expelled on the water bath. The fluorides thus obtained are dissolved in concentrated hydrochloric acid washed with the same acid into a 100° flash (total volume about 50°°) and reduced for three-quarters of an hour with amalgamated zinc and a piece of platinum foil in an atmosphere of carbon dioxide at a temperature of 80° C. The reduced solution is cooled thoroughly, diluted with freshly boiled, cold water to about 350° and titrated with permanganate. To this solution ammonia is added in slight excess, the pre- cipitate formed, just dissolved in sulphuric acid, and the volume made up to exactly 500°. The titanium is then esti- mated colorimetrically, with hydrogen peroxide in 50° por- tions of this solution. For any except small amounts of titanium the colorimetric method is open to the serious objection that any error in esti- mating the amount of titanium in the aliquot portion (and_ that error can hardly fail to be considerable where a large amount of titanium is present) is multiplied by ten in estimating the total amount present. Mr. Osborne gives the result of only a single application of the method. The figures are as follows: * Still gave a strong reaction for titanium. + The Quantitative Estimation of Niobium, this Journal (3), xxx, pp. 328- 337, 1885. 522 C. H. Warren—Niobium and Tantalum.. Nb.O; Ta.0; TiO, Taken, 3357 gr. "2246 gr. "0687 gr. Found, °3314 or. "2289 gr. ‘0667 gr. The agreement here is quite satisfactory but as the relative amount of titanic oxide is small, and as the writer had never had any experience with the method, it was decided to. make a trial of the method before using it in an analysis. In experi- ments 1—4 of those given below Mr. Osborne’s directions were followed closely. In Nos. 5 and 6 the time of reduction was increased and in No. 6 the volume of acid was doubled. One other experiment was tried and the temperature raised to nearly 100° C.: but as a separation of the metallic acids took place this one is not included. The results obtained by reduc- tion and titration are as follows - Gram Dif- Wet. taken in grams KMnO, Grams ferences Time of Vol- — ——~ re- KMnO. in No. reduct’n Temp. ume Nb.O; Ta.0, TiO. quired used grams tet 1 #hr. 80°C. 50° :2163 °1649 2453 ‘1988 -1450 —-0540 2 ee i “2084 *1062 *2088 °1783 +1551 —-02382 3 “6 re 206% :1090 °0708 +1254 13827 sO eis 4 “ 4 “12283. :1054.. -2079 \*1899 -1630-2— 302638 aes a op pe alice) "1933 °1565 ‘1317 —-0248 G7, colises Fi 100°° -2140 "2033 °1814 +1620 —-0183 The large size and irregularity of the resulting errors led the writer to abandon further work on the method with the con- clusion that it is wholly unsatisfactory as it stands. One source of error in the method is possibly the loss of some volatile, me- tallic fluoride during the removal of the hydrofluoric acid on the water bath. The addition of sulphuric acid with the hydro- chloric in order to prevent such volatilization is madvisable, since, as Mr. Osborne states, the reduction of the niobium is then far from constant, and it may be added, the tendency of the metallic acids to precipitate during reduction would be greater. There appears to be, so far as the writer can discover, no method by which more than a rough approximation toward a quantitative separation of these elements can be effected notwith- standing the numerous analyses purporting to have accomplished a separation of sufficient accuracy to warrant considerable speculation as to the chemical constitution of the group of min- erals containing these elements. The problem of their separa- tion is an’extremely interesting one mineralogically as well as chemically, since the constitution of so many highly inter- esting minerals depend on its successful solution. The increas- ing use of tantalum in lamps and perhaps in other ways, and its common occurrence with niobium and titanium make a sat- isfactory quantitative separation of these elements highly desir- able, and it is to be hoped that it may soon be realized. Laboratory of Mineralogy, Massachusetts Institute of Technology, Boston, Mass. T. Holm—Ceanothus Americanus and ovatus. 593 Arr. XLVI.— Ceanothus Americanus L. and ovatus Desf. ; a morphological and anatomical study; by Tuo. Horm. (With five figures in the text, drawn from nature by the author.) Ceanothus Americanus L. is very frequent in the vicinity of Washington, D. C., and occurs in dry copses or in open fields ; the other species ©. ovatus Desf. is contined to the Potomac shore, where it inhabits the rocks at “Little Falls” associated with Baptisia australis R. Br., Physostegia Virginiana Benth., Lythrum alatum Pursh, Scirpus lineatus Michx., ete. They both are widely distributed through the Eastern and Central States extending northward to Canada, while nearly all of the other species of the genus are Californian. The Rhamnacee, to which our genus belongs, comprises thirty-seven genera in accordance with Bentham and Hooker ; the diagram of the flower has been described by Eichler,* and the general types of the inflorescence have been br iefly mien- tioned by the same author (1. c. A few species of Lhamnus hhave been studied at the seed- linge-stage by Irmisch,} and of Colletia by Lubbock.t Lyco- rhizw were detected in Ceanothus Americanus by W. J. Beal& and the fungus identified by Geo. F. Atkinson as Frankia Ceanothi.| The internal structure seems to be better known and a very instructive discussion of the anatomical features of a number of genera and species is to be found in Solereder’s work: Sys- tematische Anatomie der Dicotyledonen.4 However, among the “hamnacee thus treated, Ceanothus has been merely briefly touched upon, and since the writer has had the opportunity of studying the two species that occur in the district of Columbia, the following notes may be presented as a small contribution to the knowledge of the genus. The germination.—As stated above, Irmisch has described the seedlings of Rhamnus cathartica and Lh. Frangula (1. c¢.), and he ealls attention to the fact that the cotyledons of the former are epigeic, but of the latter hypogeic. In Ah. cathartica the cotyledons are green, larger than the succeed- ing leaves during the first season, and borne upon a distinct hypocotyl. The leaves succeeding the cotyledons are arranged *Bliithendiagramme. Pars 2, 1878, p. 371. + Flora, 1855, p. 625. | ah contribution to our knowledge of seedlings. London, 1892, vol. i, Z § Botan. Gazette, vol. xv, p. 282. | Bull. Torrey Bot. Club, vol. xix, 1892, p. 171. “| Stuttgart, 1899, p. 247, 524 T. Holm— Ceanothus Americanus and ovatus. R. Ceanothus Americanus L. Fic. 1. Seedling, natural size. R =the primary root with mycorhize (M) ; H = Hypocotyl; Ep. = Epicotyl; L—L =the two opposite leaves ; L? and L‘ = the succeeding, spirally arranged leaves. Fie. 2. A cotyledon, magnified. Fie. 38. A young plant in the second year, natural size. St. = the dead stem of previous year; the other letters as above. Fic. 4. A plant in the third year, natural size. Letters as above. Fic. 5. Transverse section of petiole of mature leaf; Ep. = Epidermis; Coll. = Collenchyma; M=a mucilage-cell, x 240. . T. Holm— Ceanothus Americanus and ovatus. 525 spirally, and the first ones are often merely scale-like and rudimentary ; buds were observed in the axils of the cotyle- dons: In RA. Frangula, on the other hand, the cotyledons remain enclosed by the seed, and the hypocotyl is very short, but otherwise the development of leaves and buds is the same as in the former species. In fA. davuricus and Colletia cornuta, described by Lubbock (lL. ¢.), the cotyledons are epigeic. The seedling of Ceanothus Americanus agrees with that of Rhamnus cathartica so far as concerns the epigeic cotyledons with buds and the presence of a distinct hypocotyl. Our fioure 1 shows a seedling where the cotyledons (Cot.) are borne upon an erect hypocotyl (H); the epicotyl, the first internode (Ep.), is quite long, and the first two leaves, succeed- ing the cotyledons, show the same outline and venation as the typical leaf of this species, but are epposite (L and L), in con- trast to the others, which are spirally arranged (L*°—L’). Buds, though very minute, are developed in the axils of all the leaves including the cotyledons. The primary root (R) is long and slender with some of the lateral branches transformed into mycorhize (M), represented by small globular tubercles. Characteristic of the seedling is thus the presence of cotyle- donary buds, the position of the first leaves (L) being opposite and, finally, the early appearance of the mycorhize. The ramification of the shoot.—During the first season the seedling does not develop any further than the specimen, which we have figured, but the cotyledons fall off in the month of June, and at the end of the season the hypocotyl and sometimes, also, the epicotyl are the only parts remaining above ground, the other internodes having faded away entirely; at the same time the hypocotyl has bent itself downwards to the ground, though without any development of secondary roots. When the plant is one year old, we notice two oppo- site leaf-bearing shoots (fig. 3) either developed from the axils of the cotyledons or of the opposite leaves, succeeding these, while the main stem (St.) has died off, but remains as a blackish branch. It seems to be the most frequent case that the rami- fication of the shoot takes place by means of the cotyledonary buds, but as stated above, when these do not develop, the buds of the opposite leaves produce the branches. The hypocotyl is now horizontal (H) and the primary root has increased in length and thickness, besides that the mycorhize are much larger (M). While examining a number of young plants at this stage, we noticed a peculiarity, which seems to be constant in our species. This peculiarity consists in the fact that the greater Am. Jour. Sct.—Fourts Series, Vout. XXII, No. 132.—DxEcEmMBER, 1906. 36 526 T. Holyu— Ceanothus Americanus and ovatus. portion of the primary root has become compressed, and very prominently so at the base. By examining the internal strue- ture we readily noticed that a very irregular growth had taken place. The rays of hadrome had increased in thickness much more on the one side of the root than on the other, thus the vessels showed the arrangement somewhat similar to a fan. A similar case has been reported by Wigand,* who observed that while the primary root in Ononis repens and spinosa shows a normal and concentric growth during the first year (at the seedling stage), it exhibits a very conspicuous, excentric increase in the sueceeding year. This is due to the one-sided enlargement of the hadrome; besides that the medullary rays have not only been prolonged, but also very considerably broadened towards the periphery in exactly the same way as in our Ceanothus. The so-called “ Bretterwurzel” described by Haberlandtt shows the same structure, but this root-type has a special function which cannot be attributed to the roots of either Ononzs or Ceanothus, since these are completely underground. It is an anomaly, which seems to be rare among shrubs and herbs, and we are unable to offer any expla- nation as to its cause; we can only state that all the specimens examined of OC. Americanus and ovatus showed this root- structure when more than a year old, and that it seems very improbable that it might be due to the nature of the soil, since the one of these species (C. Americanus) grows in clay- ish Or somewhat sandy soil, while the other seems to thrive only among rocks with the roots tightly pressed in the narrow fissures. It would be interesting to know whether the numer- ous Californian species behave in the same manner. If we examine a plant in the third season (fig. 4), we notice the same principal structure as shown in our figure 3. The hypocotyl (H) is still very distinct, and the scars from the cotyledons (Cot.) are plainly visible with two stem-bases from the preceding year (St.), while there is no trace of the primary stem above the cotyledons. Young lateral shoots develop now from the basal leaves of the stems of the previous year ; they are yet purely vegetative and die off to near the base during the fall. In regard to the root, this has increased very con- siderably in length and thickness; the irregular structure is very pronounced, and the mycorhizee are quite large, but do not yet show any signs of ramifying. When the plant has reached the age of about five years it commences to flower; the ramification, however, is exactly the same as described above, and the flowers develop exclusively upon shoots of the same season. One point deserves men- *Einige Beispiele anomaler Bildung des Holzk6rpers. (Flora, 1856, p. 674.) + Eine botanische Tropenreise. Leipzig, 1893, p. 104. T. Holm—Ceanothus Americanus and ovatus. 5O7 tion, and that is the purely vegetative nature of the terminal bud in C. Americanus in contrast to C. ovatus, where the branches are terminated by an inflorescence. In C. Americanus it seems to be a constant character that the inflorescences are lateral; the terminal vegetative bud does not, however, seem to be of any importance to the plant, since the shoots die off to near the ground as observed in the younger pees In C. ovatus we observed no case where the apical inflorescence was not terminal, but it was frequently noticed, however, that the branches bore lateral inflorescences below the terminal; thus two or three inflorescences may be developed on the same shoot. We regret to say that the herbarium material which we have examined of the other species was not sufficient to demonstrate whether the apical vegetative or apical floral bud is the one that is most characteristic of the genus. Besides the lateral floral branches in C. Americanus, we noticed also that lateral vegetative shoots may be developed below these ; in many cases the first two leaves of these vegetative shoots were observed to be opposite, similar to those of the seedling. In regard to the inflorescence, the flowers are arranged in small helicoid cymes, destitute of fore-leaves. If we compare now the seedling of C. ovatus with that of C. Americanus, described above, we find the same structure, the epigeic cotyledons, the distinct hypocotyl and the two opposite leaves preceding the spirally arranged. The primary root shows the same development, but we were unable to detect the mycorhize; these were evidently broken off since. the roots were more or less damaged by being dug out of the stony soil. The growth of the shoots in mature specimens is identical with that of the former species with the exception of the inflorescence being terminal. The internal structure of the vegetative organs of Ceanothus Americanus. Lhe root.—During the first season the root has already com- menced to increase in thickness, but the epidermis is still pre- served, and bears numerous hairs. No exodermis is differen- tiated, and the cortical parenchyma consists only of five compact strata. The endodermis is thin-walled and surrounds a pericambium and several groups of leptome separated from the hadromatic rays by layers of cambium. No hyphe and no mucilage-cells were observed. In the second year the root has become somewhat compressed near the base; epidermis has been thrown off, and a secondary cortex of about six com- pact layers has been developed. The central cylinder shows the irregular increase in thickness as described above, due to the one-sided growth of the hadromatic rays. Near the apex of the same root the structure is normal with the various ele- ments arranged strictly concentric. The mycorhizee appear as 528 T. Holm—Ceanothus Americanus and ovatus. swellings on the lateral roots; they are unbranched and are much thicker than the normal ones. Their epidermis is simply papillose, and there is no exodermis. The cortex consists of five peripheral strata of normal structure, and of six internal, the cells of which are very large, stretched radially and filled with the fungus. The endodermis is like that of the main root and free from fungus. A pericambium surrounds five groups of leptome and a central, confluent mass of hadrome. The primary root persists and represents a long, woody taproot in old specimens, reaching a thickness of about 1™ or even a little more; such old roots are generally of a reddish brown color due to the cell-contents of the peripheral strata of the cortex. Another peculiarity possessed by the mature root is the presence of sclerotic-cells, which occur in.groups in the secondary cortex. Otherwise the mature root shows the same structure as observed in younger specimens, with a very pronounced, excentric growth of the hadrome and the medul- lary rays. The leaves.—The cotyledons (fig. 2) have stomata on both faces of the blade; these are surrounded by several cells, from. four to seven, none of which are parallel with the stoma. The stomata are most numerous on the dorsal face of the blade. The chlorenchyma is differentiated into a typical pali- sade-tissue and an open pneumatic tissue of roundish or oblong, loosely connected cells. An almost colorless parenchyma- sheath surrounds the very thin mestome-strands, which have no support of stereomatic or collenchymatic tissues. The petioles of the cotyledons have no chlorenchyma, but a large tissue of colorless cells which surrounds two separate, broad mestome-strands. The cuticle is wrinkled and epidermis quite thick-walled. A layer of collenchyma separates epidermis from the colorless tissue, in which a few, two to three, muci- lage-cells are located. In a mature leaf from a flower-bearing shoot we meet with the same bifacial structure as observed in the cotyledons, but the stomata are here confined to the dorsal face. The cuticle is quite thick and prominently wrinkled; the outer cell-wall of epidermis is moderately thickened where it covers the veins, and hairs are quite numerous. They are of two kinds: uni- and pluri-cellular, thick-walled, with the apex pointed and more or less curved. The pluri-cellular hairs (of several cells in a single row) occur above and below the larger veins, and out- side the pneumatic tissue. The chlorenchyma consists of two to three layers of palisades on the ventral face of the blade, and of four to five strata of open, pneumatic tissue on the dorsal. A thin-walled, colorless parenchyma surrounds the larger veins; it consists of about three strata above, but of six below these, and is separated from epidermis by collenchyma. T. Holm—Ceanothus Americanus and ovatus. 529 Mucilage-cells occur in the colorless tissue; they are much wider than the surrounding parenchyma-cells, but only a little longer; they contain a clear, colorless mucilage and are very conspicuous in cross-sections. These mucilage-cells were in the Rhamnacee first described by Guignard and Colin,* while the occurrence of mucilage in epidermis of Rhamnus and other genera of this family, “but not in Ce anothus, has been discussed by Blenk.t \ The midvein and the two lateral nerves from the base of the leaf are quite thick on the dorsal face of the blade. They are supported by collenchyma, as described above, but have no stereome and no parenchyma-sheath ; the leptome and had- rome is well developed, forming a broad, crescent-shaped strand in transverse section with many rows of vessels. The other veins are much thinner and are completely imbedded in the green chlorenchyma; in these the mestome is surrounded by a colorless parenchyma-sheath, but with no support of collenchyma; the cross-section of these minute veins is elliptic to almost orbicular. The petiole of the mature leaf is hemicylindric in transverse section and hairy like the blade. There is no chlorenchyma, and the very broad, single mestome-strand is directly surrounded by a mass of colorless tissue in which the mucilage-cells are very conspicuous (fig. 5.) A sheath of thick-walled collen- chyma of about five layers is noticeable beneath epidermis. If we now examine the blades of the two opposite leaves of the seedling, which succeed the cotyledons, we observe a simi- lar structure, though with the following exceptions. They are quite glabrous and epidermis is not thick-walled; moreover, the collenchyma is totally absent, besides that the colorless tissue with the mucilage-cells is much less developed. It might, alse, be mentioned that the mediane and the two prom- inent, lateral veins are surrounded by colorless parenchyma- sheaths, which in the leaves of older specimens are restricted to the thinner mestome-strands, The petiole shows the same tissues as observed in the mature leaf, but the collenchyma is much less developed, representing only a single layer beneath epidermis. Three wide mucilage- cells were observed in the colorless tissue. Lhe stem.—The hypocotyl of the seedling (H im fig. 1) is cylindrical and almost glabrous. The cuticle is smooth, but quite thick, and the outer cell-walls of epidermis are distinctly thickened; stomata and unicellular hairs were observed. There is a narrow zone of cortical parenchyma of which the innermost strata are partly collapsed and in which mucilage- * Sur la présence de réservoirs 4 gomme chez les Rhamnées. (Bull. de la soc. Bot. d. France, vol. xlv, Paris, 1888, p. 325.) + Die durchsichtigen Punkte der Blatter in anatomischer und systematis- cher Beziehung. Inaug. diss., Regensburg, 1884, p. 68. 530 T. Holu—Ceanothus Americanus and ovatus. cells are located. A thin-walled endodermis surrounds the central cylinder of leptome, cambium and hadrome, with nar- row medullary rays and a central, solid, starch-bearing pith. Inside the endodermis are furthermore four strands of thick- walled stereome bordering on the leptome and located in the same radius as the innermost four groups of vessels, which represent the proto-hadrome. The same structure was dbserved in the epicotyl (Ep. in fig. 1), with the only exception that the stereome does not occur here as four separate strands, but as several, which form a more or less interrupted sheath around the leptome. The other inter- nodes of the seedling possess a collenchymatic cortex (the peri- pheral two or three layers), and the endodermis is more dis- tinctly differentiated, and contains deposits of starch. The stereome forms here an almost completely closed sheath, and druids of calcium-oxalate were noticed in the cortex. These various stem-portions of the seedling are, thus, able to increase in thickness, even if the hypocotyl and, sometimes also, the epicotyl, are the only parts that persist. If we now examine the basal portion of a flower-bearing shoot, we notice a corresponding structure, but the various tissues show here a somewhat stronger development. The epidermis is more thick-walled, and the cortex more compact, with the mucilage-cells wider and longer; endodermis is thin- walled as in the young specimens, while the stereome js very thick-walled, forming an almost closed sheath around the cen- tral cylinder. The cambium is more distinet, and the had- rome consists of numerous rows of vessels with the medullary rays broader. The internal structure of the vegetative organs of Ceanothus ovatus.—The root showsthe same structure as that of C. Amere- canus. In regard to the mature leaves, these are almost glab- rous, the hairs being confined to the larger veins on the dorsal face of the blade. The stomata, which are surrounded by four to six cells, are in this species distributed over both faces of the blade, most numerous, however, on the dorsal, and they are raised a little above the surrounding epidermis. The pneu- matic tissue is more compact than observed in the former species but otherwise the structure is identical. The petiole shows the same structure as that of C. Amera- camus, and in regard to the stem, the flower-bearing shoot, we observed no character of any essential importance, by which to distinguish this from the stem of the former species. When compared with each other these two species resemble each other very much from seedling to mature plant. But characteristic of C. ovatus is, however, the terminal inflores- cences and the narrower leaves with stomata on both faces. Brookland, D. C., July, 1906. FL. Tufts—Photometric Measurements. 531 Art. XLVII— Photometric Measurements on a Person Pos- sessing Monochromatic Vision, by ¥. L. Turrs. Iw an article on “Color Vision and the Flicker Photome- ter,’* the late Professor Ogden N. Rood reported some meas- urements made by means of the flicker photometer on a num- ber of persons possessing normal color vision and also on three eases of red color-blindness. Through the kindness of Dr. W. S. Dennett of New York City, the writer was enabled, some three years ago, to extend these measurements to the case of a person possessing monochromatic vision. Owing to the lim- ited amount of time which the subject, referred to in this article as J. T., could give to the work, the measurements were not so complete as the writer would have liked to make them. He has not previously published the results in hopes that cir- cumstances might some time enable him to apply more exten- sive tests. This now seems very improbable, and the results of the work already done are given in the following pages. The flicker photometer used was of the same type as the one already described by Professor Rood,t and the colored glasses were the same as the three used by him in his work on color vision. The candle powers of two incandescent lamps referred to as A and B were compared by means of the flicker photometer, first directly and then when each of the three glasses respect- ively was placed between lamp A and the photometer wedge. Each of these comparisons was made by Dr. Dennett, J. T. and the writer, from ten to twenty readings being taken in each case. The numbers expressing the relative candle powers, given in the first three rows of Table I, were computed from TABLE I. SSS Candle power of — A A A through through through violet- A red glass green glass blue glass in terms in terms in terms in terms Observer of B of B of B of B Weise Dennett..3 <5... 4°00 520 385 052 Be uilts: | ae Sess 4:00 ‘480 "385 048 ea rss Ni LDS eels, AOA. Ol "683 "235 J. T., using ordinary wedge photometer... 5:00 ae “72 "23 * This Journal, vol. viii, p. 258, Oct., 1899. + Ibid., vol. viii, p. 194, Sept., 1899. t Ibid., p. 258, Oct., 1899. 532 Lf. L. Tufts—Photometric Measurements. these readings. From the numbers thus obtained the percent- age of light from the incandescent lamp transmitted by each of the three glasses respectively was calculated for the differ- ent observers. These results are given in the first three rows of the second table. TABLE II. Percentage of light from lamp A transmitted by — Observer Red glass Green glass Violet-blue glass Was. Wennettios: Moe. BO 9°62 1°30 lie Pui GS ee Sect e O 120 9°62 1:20 7 es bape ey USE es ee, ae aly 2°04 13°8 4°75 J. T., using ordinary | wedge photometer -_ 2°2 14°4 4°6 Standard eye 255. 4222) 1337 9°62 1°39 As a standard of color vision, the one already used by Pro- fessor Rood was chosen. This he defined in substance as fol- lows: The standard was the mean color vision of eleven per- sons possessing, according to ordinary tests, normal vision. This standard was indicated by 100 in the case of red, green and violet-blue. One hundred was also taken as the maximum attainable by any person in each ease, as the experiments did not deal with the general sensitiveness of the eye to light, but with its relative sensitiveness to light of different colors. That is to say, in the case of the color curve of each person, the highest ordinate, whatever it may be, is set equal to 100, the others following where the observations indicate on this assumption. Both Dr. Dennett and the writer had had their color vision expressed in terms of this standard, and the results, taken from Professor Rood’s article,* are given in the first two rows of Table III. From these figures the percentage of the light TABLE ITI. - Red Green Violet-biue IWS. Dennett: .- 22 eerteo sas 100 91°5 ReMi initio ese Se eS Oe 100 87°8 Sgt, KS Os Sine ae 4°84 45°2 100° from an incandescent lamp which the standard eye would see transmitted by the three glasses respectively, was computed both from Dr. Dennett’s readings and from the readings of the writer. The averages are given in the last row of Table LI. * * This Journal, vol. viii, p. 258, Oct., 1899. EL. Tufts—Photometric Measurements. 533 A comparison of the figures in the last row of Table II with those in the third row shows at once that the color curve for J. T. has the highest ordinate in the violet-blue. Designating © this by 100, the ordinates in the red and green were computed and are given in the third row of Table III. Measurements of the relative intensities of the white and colored lights were also made by J. T., using an ordinary wedge photometer in place of the flicker photometer. It was found that he could compare lights of different colors with the ordinary photometer with the same ease that the normal eye could make the comparison by the flicker photometer. The last row in Table I contains the results obtained by J. T. with the ordinary wedge photometer. The fourth row of Table II gives the percentages of the transmitted light calculated from these readings. Considering the small amount of practice the subject had had in photometric measurements, the agreement between these results and those he obtained with the flicker photometer is certainly very good. Some measurements were also made on the extent of the visible spectrum and the position of maximum luminosity. The spectrum of an incandescent lamp seemed to J. T. to ex- tend from 63850, Angstrém units, in the red, to 4000 in the violet, while to the writer the same spectrum seemed to extend from 7700 to 3800. For J. T. the position of maximum lumi- nosity seemed to be at wave length 5250, while for the writer it was at 5800. Phoenix Physical Laboratory, Columbia University, Oct., 1906. 534 Breger—LHodevonaria, a new Subgenus of Chonetes. Art. XLVIII.—On Hodevonaria, a new Sub-Genus of Cho- netes; by C. L. Brecer. : Amone the Strophomenoid Brachiopoda, the presence of a crenulated or denticulated hinge line has always been consid- ered as of at least generic importance. It was upon this con- sideration that the genus Stropeodonta was founded by Hall; and it is chiefly or very largely the presence of a denticulated hinge line which sharply demareates as a special group apart from the normal Strophomena’s the genera Stropheodonta, Douvillina, Leptostrophia, Brachyprion and Strophonella.* In the well-known Paleozoic genus Chonetes, the great mass of the species have a normal, non-crenulated hinge line; but, as is the case with the Strophomenoids, there occur a few closely associated and quite peculiar species in which the den- ticulated hinge line is a very prominent and characteristic peculiarity. It has been found than such a denticulated hinge line occurs in six species of Chonetes. All six species are so closely allied as to be distinguishable only with some little diticulty; and-all six species occur at very nearly the same geologic horizon in the Lower Devonian, though scattered through Europe, South Africa, South America, and North America. These facts justify setting this group apart from the normal and typical species of Chonetes, and the name Hodevonaria is hereby proposed for this group. The name is suggested by the restriction of all the known species (as well as a few more which it is believed may possibly bene here), to the Eo-Devonian. The known species are Chonetes arcuatus Hall C. dilatatus F. Roemer’s sp. C. melonicus Billings C. acutiradiatus Hall C. extensus Kayser C. arcei A. Ulrich 1. Chonetes (Hodevonaria) arcuatus.—The crenulated hinge line in this type was noted by Hallt in his description and illustrations of the species. Weller also noted the same features in New Jersey specimens of this species.{ Chonetes (Hodevonaria) arcuatus occurs in the Upper Helderberg for radium can be calculated from the above num- bers and is given as 2°1x10~*(year)~’.. The period required for the decay of the activity of radium to one-half its initial value is thus indicated as about 3300 years, and this is of the same order of magnitude as the most recent estimate made by Rutherford.+ Strong evidence has therefore been obtained in support of the assumption that actinium is the intermediate disintegra- tion product between uranium and radium. The entire series of operations from the start will be repeated with special precautions in order that a more accurate value for the various constants can be obtained. New Haven, Conn., Nov. 5, 1906. * Rutherford and Boltwood, this Journal, xxii, 1, 1906. + 2600 years, Phil. Mag. (6), xii, 367, 1906. Chemistry and Physics. | 539 SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHYSICS. 1. The Quantitative Separation of Beryllium and Aluminium. —It is well understood that the methods in use for making the separation under consideration are somewhat inconvenient or unsatisfactory, so that a more simple method, and one which appears to give very accurate results, is worthy of attention. B. GLASSMANN carries out the analysis as follows: The hydrochloric or sulphuric acid solution of the metals is nearly neutralized with sodium carbonate, an excess of sodium thiosulphate solution is added, and the liquid is boiled until the odor of sulphur dioxide has disappeared. Then the liquid is heated on the water bath for half an hour. The precipitate, consisting of aluminium hydroxide mixed with sulphur, is washed and ignited. After the excess of thiosulphate in the filtraté has been decomposed with hydrochloric acid, the beryllium is precipitated as hydroxide, either with ammonia, or, as the author prefers, with a mixture of potassium iodide and iodate. In order to use the latter method sodium hydroxide solution is added to the liquid until a precipi- tate begins to form, and then the precipitate is dissolved in a few drops of dilute acid. Then an excess of a mixture of equal vol- umes of about 25 per cent potassium iodide solution and satu- rated potassium iodate solution is added. After about five minutes the separated iodine is decolorized by the addition of exactly the proper amount of 20 per cent sodium thiosulphate solution, and then a small amount of the iodide and iodate mix- ture 1s added in order to make sure, by the fact that it does not produce an instantaneous separation of iodine, that enough has been added. Then a few drops of sodium thiosulphate are added, and the liquid is heated on the water bath for half an hour. The precipitate is easily filtered, on which account the method is recommended, and also because the liquid, being abso- lutely neutral, does not act as much upon glass as do alkaline solutions.— Ber ichte, xxx1x, 3366, 3368. HL Eee Wes 2. The Temperature. at which Water Freezes in Sealed Tubes. — Miers and Isaac have shown that in cooling a supersaturated solution in which a few crystals are growing while it is being stirred, the refractive index rises until at a certain temperature it attains a maximum yalue and then suddenly falls; at this moment also profuse crystallization takes place. They concluded that this is the temperature of spontaneous crystallization. These investi- gators have now made numerous experiments with water con- tained in sealed tubes which were violently and continuously shaken by hand, while being very slowly cooled in a bath of brine, until rapid crystallization of ice took place. Various 540 Scientific Intelligence. samples of water were used, and different kinds of glass were employed for the sealed tubes. All, the tubes froze between —2°C. and --1'6° C.; the mean of the experiments being —1°86° C., and that for the purest water with a conductivity of 1:1 x10-° being —1:9° C. The authors conclude tuat —-1:9° is the tem- perature at which under atmospheric pressure water freezes spontaneously, 1. e., 1n the absence of particles of ice, and they call attention to the remarkable fact that this is the temperature at which super-cooled water possesses a maximum refractive index according to the observations of, Pulfrich. The effect of friction was also studied by introducing glass, garnet, galena, or lead into the tubes; this caused the water to freeze at —0:4 C.— Chem. News, xciv, 89. H. L. W. 3. Preparation of Fused Molybdenum.—Molten molybdenum was first prepared by Moissan by the use of the electric furnace. It has been made also by several experimenters by the “thermite ” process, consisting in allowing the trioxide to react with finely divided metallic aluminium. The volatility of molybdenum tri- oxide, however, made this process unsatisfactory. Brrz and GARTNER have modified the ‘‘thermite” process by using the non-volatile dioxide in place of the trioxide. To prepare the dioxide the trioxide is heated to moderate redness in a glass tube in a current of hydrogen gas. The “thermite” process then works well, the authors having obtained a yield of 93 per cent of the theoretical, and a product which contained over 98 per cent of the metal.— Berichte, xxxix, 3370. H. L. W. 4, Potassium-lead Chlorides,—By fusing mixtures of the two chlorides in varying proportions, determining the temperatures at which crystals were deposited by cooling, and investigating the products thus obtained, Lorenz and Ruckstuut have found that three double salts are ‘produced from the fused mass. They are represented by the formule 2PbCl,,. KC], PbCl,.2KCl, and PbCl,. 4KOl. It is interesting to notice that these three types of double lead salts—in one case only with water of crystallization—are known among the double halides of the alkali metals and lead which crystallize from aqueous solutions, and that still eo type corresponding to the 1:1 ratio, for example, CsCl.PbCl,, also known.—Zeltschr. anorgan. Chem., ey ak H. L. W. 5. Ammonia from the Recent Eruption of Veswvius.—ST0K- LASA has examined volcanic exhalations and many eruptive products of eruption of April, 1906, and has found ammonia always present in them. He draws the conclusion that the ammonia has its origin in the chemical actions which take place in the hot lava, possibly from the presence of silicon nitride or other nitrides. He considers the view of the mineralogists, that the sublimations of ammonia are caused by the combustion of vegetation, to be entirely incorrect.— Berichte, xxxix, 3530. He Wie 6. Beitraege zur Chemischen Physiologie und Pathologie, herausgegeben von F. Hormerstrer. VIII Band. 1906, Braun- schweig (Fr. Vieweg und Sohn).—This volume is quite equal to — Chemistry and Physies. 541 its predecessors in the diversity of topics which it presents. It is impossible to make special mention of more than afew of the papers. Particularly noteworthy are the valuable studies of Embden and his collaborators on the formation of acetone in the liver, indicating a Targe number of substances as possible pre- cursors of this compound. Friedmann’s renewed investigation of the structure of adrenalin leads to a choice of the formula on /\ CH(OH)-CH,-NE-CH, oH \ for this peculiar physiological compound, the formation of which Halle, in a separate paper, refers to an enzymatic reaction of the suprarenal tissue upon tyrosin. Among a series of contributions from the laboratory of Dr. von Fiirth, reference may be made to his study of chitosan derivatives. It indicates that the “ chitin” of molluses and arthropods furnishes the same products. Two papers offer items of interest regarding nitrogenous metabo- lism: one by H. Vogt deals with the time relations in the cata- bolism of proteids of various groups; the other, by Klercker, gives evidence that creatine and creatinine may experience quite different fates in the chemical reactions to which they become subject in nutrition. The volume also contains the usual number of papers on enzymes: rennin, diastase, gastric lipase, and the blood enzymes furnishing the themes for investigation. L. B. M. 7. Change of Colloidal Nucleation in wet dust-free Air in the lapse of time ; by C. Barus (Communicated).—Observations extending over several months have now shown that the variation of the colloidal nucleation of dust free wet air in the lapse of time is independent (within the limits of accuracy of the fog chamber) of the barometric pressure and temperature of the atmosphere, of the ionization of the air or of the allied effect of natural external radiations; but that it varies to the remarkable extent of an increase of about 8000 nuclei per rise of temperature of one degree centigrade near 20 degrees. The reason for this unexpected result is yet to be found, but nothing has been sug- gested to explain it away. Brown University, Providence, R. I. 8. Letifaden der praktischen Optik; von Dr. ALEXANDER GLEICHEN. Pp. vili+221; 158 figures. Leipzig, 1906 (S. Hirzel).— This is an account of the more elementary parts of the theory of optical instruments, and is intended for the users of such instru- ments rather than for the optician or for the reader who is interested in the more complex details of geometrical optics. It is written in a clear and simple manner and no mathematics is used beyond the elements of geometry and algebra. Especial attention is given to the optics of the eye and of photographic apparatus, and the book will doubtless prove especially useful to oculists and photographers. H. A. B. AM. JOUR. Scit.—FourTH SERIES, Vou. XXII, No. 132.—DEcEMBER, 1906. 37 ; - es... 542 Serentific Intelligence. : II. Gronoey. 1. New Zealand Geological Survey.—The first New Zealand Geological Survey was inaugurated in 1867 and up to 1905: had ‘ published a number of Bulletins dealing largely with economic problems. In February, 1905, Dr. James Macxintosn Butz was made director, the Survey was reorganized, and the follow- ing staff appointed: Mr. Alexander McKay, Geologist and Pale- ontologist; Mr. Perey Gates Morgan, General Geologist; Mr. Colin Fraser, Mining Geologist; Mr. Ernest John Webb, Assist- ant Geologist; Mr. Edward Clarke, Assistant Geologist ; Mr. Reginald Palmer Greville, Topographer; Mr. Robert James Crawford, Draughtsman ; Mr. John Thompson, Seéretary. A scheme has been outlined for the preparation of a detailed topographical and geological map of New Zealand, together with reports on ten chief districts. Bulletin No. 1 (New Series) is entitled “The Geology of the Hokitika Sheet, North Westland Quadrangle” ; by James Macx- INTOSH BeLu and Conin FRazER. 101 pp., 13 maps, 42 plates. Ten formations are described in the present bulletin, ranging in age from ‘Karly Mesozoic (?) and earlier” to Pleistocene and Recent. The Arahura series consists of a group of schists, grau- wackes, argillites, and arkoses, parts of which have been assigned to different ages from Archean to Carboniferous by various authors. The Kanieri series consists largely of conglomerate and argillite. Both the Arahura and the Kanieri series are inter- sected by auriferous quartz reefs. The Tuhua formation con- sists of an extensive group of granites and syenites forming mountain bosses. The Pounamu formation is of particular petro- graphic interest. Static metamorphism and the alteration of sediments by the intrusion of the basic Pounamu rocks have pro- duced such a variety of minerals as to give the formation the name of “mineral belt.” The parent intrusive was dunite or olivinite, and the secondary rocks include many varieties of ser- pentine, talc, steatite, nephrite, tremolite-serpentine, muscovite- serpentine, etc. It is from this formation that the masses of -nephrite are derived which appear in the glacial deposits as the famous ‘“ greenstone ” bowlders. The Koiterangi series is the remnant of former widespread sedimentary deposits which contain seams of coal. Dikes of camptonite, hornblende and pyroxene porphyrite, diabase, augite . diorite, olivine basalt, cut all the bed-rock formations. Glacial débris is widely distributed over Westland, and is of great thick- ness. It is uncertain whether the period of maximum advance of the ice sheet was in Upper Pliocene or early Pleistocene time. “One thing is certain, and that is that the glaciation started in Miocene time and is still continuing.” The chief physiographic features are the Alpine Chain, re- cently uplifted but ‘submaturely dissected,” the Wainihinihi Pa Geology. 543 peneplain at an elevation of 4000 to 5000 feet and the Coastal Plain inaugurated by the Post Miocene Uplift. Theriver valleys are broad and U-shaped, and terminate in cirques. Many lakes occur, which for the most part occupy ancient valleys blocked by débris—as is indicated by soundings. Hot springs occur along fault lines. The illustrations are excellent, especially the microphotographs of metamorphic rocks by Mr. McKay. It is to be hoped that an appropriation may be obtained to make a more detailed topo- graphic map. H, E. G. 2. Illinois State Geological Survey, H. Fosver Bain, Director. Gov. C.8. Deneen, Profs. T. C. Chamberlin and EK. J. James, Com- missioners. Bulletin No. 1, the Geological Map of Illinois; by Stuart Weiter. Pp. 26, with map. Urbana, 1906. Bulletin No. 2. The Petroleum Industry of Southeastern Illinois; by W. 8. Buarcuitey. Pp. 109, 6 plates, 3 figures —A new and carefully prepared geological map is a fitting subject for the first bulletin of the Illinois State Survey. Thirty years have elapsed since the map prepared by A. H. Worthen was distributed with Volume IV of the State Geological Report. This early map has been used by Dr. Weller as a base and the additional material available from the more recent work of various geolo- gists has now enabled him to present a map which, while neces- sarily open to further change and emendation, is a notable advance upon what has been available before. The map as issued measures 30 X 16 inches, in other words has been prepared on a liberal scale; it is also well executed and colored. Columnar sections are added for Northern, Central and Southern Illinois. The value of the map for economic purposes is much increased by the careful presentation of the exact location of coal mines. The second Bulletin contains an account of the petroleum resources of the state. Until very recently the state had yielded very little either of oil or natural gas, although the search for them began as early as 1853. In 1905 and the early part of 1906, however, extensive investigations were carried on and with highly encouraging results, especially in the southeastern part of the state. In May, 1906, active production of crude oil and gas was going on over an area about 40 by 12 miles in extent between Westfield, Clark County, and Oblong, Crawford County. The oil wells all lie near—and mostly to the east of—the long line of deformation which extends across the state in a south-southeast- erly direction from Stephenson to Lawrence County. The total production of crude oil from the Casey Field, in Clark County, for the eleven months ending with April, 1906, aggregated 400,000 barrels. 3. Geological Survey of Ohio. Epwarp Orton, Jr., State Geologist. Fourth series, Bulletin No. 4, pp. 361, map and 53 figures. Bulletin No. 5, pp. 79, 2 plates, 8 figures.—These recently issued bulletins are devoted, No. 4 to the Limestone Resources and the Lime Industry of the State of Ohio, by E. 544 Scientific Intelligence. Orton, Jr. and S. V. Peppel ; No. 5 to the Manufacture of arti- ficial Sandstone and Sand-lime Brick, by 8. VY. Peppel. The rocks. of Ohio consist so largely of limestone, that it is not a matter of surprise to have it stated that these strata furnish the material which makes up almost a third of the present mineral resources of Ohio. The stratigraphical relations of the limestone have been discussed in detail in earlier publications, and the present one is devoted largely to a statement of the composition of the rock at different localities and of the uses to which it is put, for building material and particularly for making quicklime and hydraulic cements. An industry, new in this country, has also sprung up in the state, consisting in the manufacture of bricks from sand and quicklime; it promises to become an important factor in the state’s resources. The bulletin (No. 5) devoted to this subject discusses the properties of sand-lime brick and the limiting conditions for the manufacture of a safe and durable product. 4. Indiana: Department of Geology and Natural Resources. Thirteenth Annual Report. W.5. BuarcHixry, State Geologist. Pp. 1494, with 47 plates and 25 maps. Indianapolis, 1906.—The special subject of roads and road materials discussed in this report is one of the highest importance and requiring the best scientific advice, and yet not often treated so fully by a Geolog- ical Survey. This subject is discussed first in general by the ' State Geologist, and then in detail by his assistants in its appli- cations to the different portions of the state. The value of the facts stated and of the results arrived at are obviously not limited tothe state of Indiana. Statistics of the natural gas and petroleum industry for 1905 are also given and the concluding chapter by EH: R. Cumings and J. W. Beede is devoted to the fauna of the Salem limestone. 5. Geological Survey of New Jersey. Annual Report of the State Geologist, Henry B. Ktmuen, for the year 1905. Pp. 338, with 30 plates, 21 figures, and 3 pocket maps. ‘Trenton, 1905.—The subjects which are particularly discussed in this Report include the following: Changes on the New Jersey coast, by L. M. Haupt ; an account of the fossil plants, by EK. W. Berry ; the composition of the crystalline limestones of Sussex and Warren Counties, by H. B. Ktimmel; Lake Passaic as a storage reservoir, by C. C. Vermeule; and on the peat deposits of northern New Jersey. The State Geologist furnishes an administrative report which opens the volume, and also an account of the mines and mineral production of the state. 6. Geological Survey of Canada; Roserr Bex, Director.— _ There have recently appeared Volumes XIV and XV of the Annual Report (new series). Volume XIV contains the sum- mary report by the Director for the year 1901; also a series of special papers as follows: On the Klondike Gold Fields, by R. G. McConnell ; on the exploration of Ekwan River and Sutton Lakes and part of the West Coast to James Bay, by D. B. Dow- Geology. 545 ling ; on the Nickel and Copper Deposits of the Sudbury Mining District, Ontario, by A. E. Barlow ; on the Geology of a Portion - of Eastern Ontario, by R. W. Ells; on the Pictou Coal Field, Nova Scotia, by Henry 8. Poole; on the Artesian and other Type Weils on the Island of Montreal, by Frank D. Adams and Osmond EK. Leroy. These have alr eady been issued independently and several have been noticed in this Journal. The volume also contains the Annual Report of the Section of Mines for 1901 by E. D. Ingall. Maps 751-792 in separate cover accompany the report. Volume XV contains the Summary Report for the year 1902, pp. 472 ; also that for the year 1903, pp. 212. There is further a report on the Coal Fields of the Souris River, Eastern Assiniboia, by D. B. Dowling, and the Annual Report for 1902 of the Section of Mines by E. D. Ingall. As with the preceding volume, the several parts have been issued previously as completed. Maps 810-823 in a separate cover accompany the report. There has also appeared a Catalogue of Publications of the Geological Survey of Canada. Pp. 129. 7. A Bibliography of Clays and the Ceramic Arts ; by Joun CaSPER BRANNER. Pp. 451, 8vo. 1906. Published by the American Ceramic Society.—Some ten years since, the author of the present volume published, as Bulletin No. 143 of the U.S. Geological Survey, the first edition of the Bibliography which, more than doubled in size, now appears in the present volume ; this first edition contained 2961 titles while the one now issued has 6027. ‘To the work of thus expanding and completing the lit- erature of this important subject, Professor Branner has devoted much time. during the past ten years. The manuscript was pre- sented by the author to the American Ceramic Society, and the volume is now issued by them and given to the public at a very moderate cost. The attitude of the Society towards the author’s gift and the value of the work in general will be inferred from the following sentences taken from the publisher’s preface : ‘‘ The Society feels that the unselfish devotion and the utter absence of self-interest betrayed in this course is as beautiful as it is unusual. It is a fine example of the best traditions of scholarship and the true spirit of the scientist. .... We believe that this work, placing in concrete form before the young students of the rising generation the sources of the knowledge which they are seeking to acquire, is destined to profoundly affect the scholarship and progress of our time in this branch of human endeavor. . . .” 8. Hestschrift Harry Rosenbusch, gewidmet von seinen Schi- lern zum siebzigsten Geburtstag ; 24 Juni 1906. Roy. 8°, 412 pp. Stuttgart, 1906.—Entirely aside from the many valuable contri- butions to mineralogic and petrographic science which this vol- ume contains, it is a striking example of the progress which has been made in these fields of work and investigation since the master whose achievements it is intended to honor and commemo- rate began his labors. The science of petrology owes its present 546 Scientific Intelligence. position to-day more to Rosenbusch than to any other man, not ~ perhaps so much to his investigations and published writings, though in these he has been excelled by none, as to his work and influence as a teacher. | Gooch, F. A., separation of arsenic from copper, 488. Goodale, G. L., plaster-plaques for museums, 90. Graham, R. P. D., pseudomorphs after laumontite and corundum, 47. Groth, P., chemical crystallography, 89. Birds, origin of, Pycraft, 547. Botryocrinus, Bather, 468. Bowlders in conglomerate, tured, Campbell, 231. Cambrian Faunas of China, Wal- cott, 188. Carboniferous and Permian, Rus- frac- sian, Schuchert, 29, 148. Guild, F. W., eruptive rocks in Chazy formation and fauna, Ray- Mexico, 159. mond, 348. H a O20, DESC, Hallock, W., Evolution of weights @shel OL me a and measures, 346. a ae fe i ae Handlirsch, Fossile Inseckten,/349. Pee Oe : : Hayford, J. F., geodetic evidence of Dakotan series of New Mexico, isostacy, 185 9 ? Ae ete Brasee RBA Hidden, W. E., yttrocrasite, 515. Taine ee 349 Hileman, A., alkalimetric estimation SO ee nies ae of silicon fluoride, 329; estimation 822) SSUL eRe Seen Be ae abr iodometrically, 383. ford, 185 5 : 2 ne : : Hilgard, E. W., work on soils, Jurassic fossils from Franz Josef noticed, AGS. 7 Land, Whitfield, 263. P : a Keewatin ice sheet, Montana lobe, Po Wo Eeuiese vel Calhoun, 468. : Lakes, Alpine Swiss, Bourcart, 468. eae T., Ceanothus Americanus, Lyttoniidae, Noetling, 349. 5 ae Nowatain building vind abyesal | HOlGS.S. J, Biology of Frog, 190 igneous injection, Daly, 195. . Gelinas eeolosy, Gould) Si poe K. S., Estacado meteorite, Ordovician rocks cf Kentucky, upper, Nickles, 348. Owl Creek Mts., Wyoming, geology, Darton, 467. Parapsonema corytophysa, Fuchs, 263. Pectens of California, Arnold, 188. - ve insects, types of, Sellards, | Hlinois Geol. Survey, Bulletins, 1, 2, 249. 543. Hydrolysis of salts of iron, etc., Moody, 76; of ammonium salts, Moody, 579. Hygiene, Personal, Woodhull, 94. 554. INDEX. Indiana Geol. Survey, 18th Report, 544, Ingersoll, E., Life of Animals, 191. Insects, types of Permian, Sellards, 249. Interference figures under the micro- scope, Wright, 19. Iron shale from Canyon Diablo me- teorite, Farrington, 303. Japan, Imperial Agricultural Station, 94, K Kelly, H. A., Zoology, 476. Kentucky, upper Ordovician rocks, Nickles, 348. Keyes, C. R., Dakotan series of New Mexico, 124. Kraus, E. H., datolite from West- field, Mass., 21. : L Lawson, copper deposit of Nevada, 467 Levin, M., absorption of a-rays from polonium, 8. Linville, H. R., Zoology, 476. Loomis, F. B., fossil bird from the Wasatch, 481. rT Meteorite, iron, Canyon Diablo, iron shale from, Farrington, 308. — pallasite, of South Bend, Farring- ton, 93. — stone, the Estacado, Howard, 55, analysis, ' i.vison, 59; Shelburne Falls, Fa ugton, 93. Meteorites, Collection of Berlin Uni- versity, Klein, 90. — formation of, 431. Mexico, eruptive rocks, Guild, 159. — Tenth International Geological Congress, 468. Microscope, interference figures un- der the, Wright, 19. — polarization, Weinschenk, 89. Millikan, R. A., Physics, 345, 346. Mineral tables, Schroeder van der Kolk, 90. Mineralogy of France, Gonnard, 90. MINERALS. Amphibole, formation, 403, 435. Bellite, Tasmania, 469. Beryl crys- tals, 217. Chlormanganokalite, 470. Corun- dum, Perth, Ontario, pseudo- morph after, 92. Datolite, Westfield, Mass., 21. Doughtyite, Colorado, 470. Enstatite, formation, 397. Fosterite, formation and, optical constants, 390. Giorgiosite, 469. Kertschenite, 470. Kleinite, Texas, 469. Kupfferite, formation, 406. Moravite, Moravia, 470. Northupite, 409. Orthoclase, pseudomorph, Quebec, 47. Otavite, Africa, 470. — Paravivianite, 470. Pyroxene, for- mation and properties, 391. Quartz, formation, 2795. Silicomagnesiofluorite, Finland, 469» Stibiotantalite, California, 61. S lpnochloran, Moravia, 470. Tridymite, formation, ete., 275. Tychite, 459. Wollastonite, formation, 279. Yttrocrasite, Texas, 019, Minerals, lime-silica series, forma- tion, Day and Shepherd, optical study, Wright, 260. — of composition MgSiO;, formation, Allen, Wright and Clement, 385. — radium in, 1, 4. Mixter, W. G., thermal constants of acetylene, 13. Moody, S. E., hydrolysis of salts of iron, etc., 176; of salts of am- monium, 379; iodometrie determi- nation of basic alumina, 488. Moulton, F. R., Astronomy, 191. Mountain building and igneous injec- tions, Daly, 195. N Nantucket, Pleistocene deposits, Cushman, 187. Newcomb, S., Spherical Astronomy, 191. New Hampshire, geology of, Pirsson and Washington, 439, 493. New Jersey Geol. Survey, 544. New Mexico, Dakotan series, Keyes, 124. New York State Museum, report, 348. New Zealand Geological Survey, 542. Nobel Prize in 1903, 351. Noetling, F., die Entwickelung von Indoceras, 349; tiber die Familie Lyttoniidz, 349. Nuclei and ions in dust-free air Barus, 136. ——— OO +e 2 INDEX. 555 O OBITUARY. Boltzmann, L. 476. Brackenbusch, L., 194. Buller, Sir W. L., 352. Drude, P., 352. Dwight, W. B., 302. Penfield, S. L. 264, 358. Schellwien, E., 94. Von der Osten Sacken, Baron C. R., 194. Ward, H. A., 194. Observatory, United States Naval, publications, 475. — Yale. Transactions, 471. Ohio, Geol. Survey, 543. Oklahoma geology of, Gould, 87. Optics, Meteorological, Pernter, 81 : Physical, Wood, 193; Practical, Gleichen, 541. Ostwald W., Allgemeine Chemie, _ 460. i Ozone, formation from oxygen, War- burg and Leithauser, 462. — generator of Siemens, Ewell, 368. P Penfield, S. L., stibiotantalite, 61. — obituary notice, Pirsson, 353. Pernter, J. M., Meteorologische Op- tik, 81. Phelps, M. A., separation of arsenic from copper, 488. Photometric, measurements, Tufts, ddl. Physics, Millikan and Gale, 345, 346. Pirsson, L. V., obituary notice of S. L. Penfield, 353; petrography of Belknap Mountains, 439, 493. Plaster-plaques for museums, Good- ale, 90. Polarisationsmikroskop, schenk, 89. Polonium, absorption of a-rays from, Levin, 8. Pratt, H. S., Vertebrate Geology, 190. Wein- R Radio-activity, Becker, Rutherford, Levin, 460. Radium, production by actinium, Boltwood, 537. —and thorium, relative activity, Eve, 477. — and uranium in radio-active min- erals, Rutherford and Boltwood ; Eve, 4. Raymond, P. E., Chazy formation and fauna, 348. Refraktionstafeln, de Ball, 82. ROCKS. Aplite, Belknap Mts., N. H. 4389. Camptonite, 498. Elastic constants, Coker, 95. Eruptive rocks in Mexico, Guild, Adams and Essexite, Belknap Mts., N. H., 495. Gneiss, Gunstock, 505. Spessartite, Belknap Mts., N. H., 453. Syenite, Belknap Mts., 489; of Plauenscher Grund, 129. Unakite, Virginia, 248. Rosenbusch, H., Festschrift, 545. Royal Society, London, publica- tions, 192. Russian Carboniferous and Permian, Schuchert, 29, 142. Rutherford, E., radium and uranium in radio-active minerals, 1. S Samwel Cave, California, explora- tion, Furlong, 235. San Francisco, Karthquake Investi- gation Committee report, 82. Schuchert, C., Russian Carbonifer- ous and Permian, 29, 143. Sedgwick, W. T., Human Mechan- ism, 549. Sellards, E. H., types of Permian insects, 249. Shaft governors, Trinks and Housum, Shepherd, E. S., lime-si ‘a series of mineral formation, 265. Seems constitution of, 'schermak, 8 Smith, A., Inorganic Chemistry, 345. Smith, M. F., parallax investigation of 162 stars, 471. Soils, Hilgard, 468. —Bureau of, 1904 Report, 550. South Carolina, Pleistocene deposits, Pugh, 186. Stars, investigation of parallax, Chase, Smith and Elkin, 471. Swiss Alpine lakes, Bourcart, 468. Ar Transvaal, mines of, Moreau, 89. Tschermak, G., silicate formulas, 88. Tufts, F. L., photometric measure- ments, 031. U United States, Dep’t of Agriculture, 550. — Naval Observatory, publications, 457. — see Geol. Reports. V Vesuvius, ammonia from eruption, Stoklasa, 540. — radio-activity of ashes, 460. Virginia, geol. survey bulletin, 87. W Walcott, C: D., Cambrian of China, 188. Warren, C. H., yttrocrasite, 515; niobium and tantalum separation, 520. Wasatch, fossil bird. Loomis, 481. Washington, H. S., syenite of Plauenscher Grund, 129; petrog- raphy of Belknap Mountains, 439, 493. Watson, T. S., unakite in Virginia, 248. Weights and Measures, Evolution, Hallock and Wade, 346. Wetterkunde, Bornstein, 81. Wilson, R. W., astronomy, 191. INDEX. Wood, R. W., Physical Optics, 198. Wright, F. E., interference figures, under the microscope, 19; schis- tosity produced by crystallization, 224; optical study on the lime- silica minerals, 265; formation of minerals, MgSiOs, 385. x X-rays, velocity, Marx, 461. ¥ Yale Observatory, transactions, 471. Z Zoology, general, Linville and Kelly, 476 — vertebrate, Pratt, 190. ZOOLOGY. Birds, origin of, Pycraft, 547. Flies, British Blood-sucking, Aus- ten, 476. Frog, Biology of, Holmes, 190. Homoptera, Catalogue, Distant, 476. : Mammals, E. Ingersoll, 191. FROM CUMBERLAND We have just received a most showy lot of minerals. Red Hematite with Quartz crystals, coated with little rosettes of black Hematite and with flesh-colored Dolomite, making a most striking combination, $0.50 to $1.50. Hematite, Quartz and Siderite, $0.50 to $0.75. Large, brilliant Pallafiat Calcite groups, over half a foot square, for $4.00 each. ‘Everything in Natural History.’’ WARD’S NATURAL SCIENCE ESTABLISHMENT, Rochester, N. Y. oo Warps Naturat Science EstTaBlisHMENT 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, etc. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Ward Ss Natural Science Establishment, 76-104 College Ave., Rochester, New York, U. S. A. ; t be C:O N Ta N aS: Page Art. XXXIX.—Relative Activity of Radium and Thorium, measured by the Gamma-Radiation; by A. 8S. Evz .._. 477 XJ..—Fossil Bird from the Wasatch ; by F. B. Loomis -...- 481 XLI.—Iodometric Determination of Basic Alumina and of Free Acid in Aluminium Sulphate and Alums by 8.4. Moopy 2.02). 22 ” 488 XLII.—Separation of Arsenic from Copper as Ammo- nium-Magnesium Arseniate ; by F. A. Goocu and M.A. + PHELES a Oe XLIT.—Contributions to the Geology of New Hamp- shire: No. I, Petrogr aphy of the Belknap Mountains ; byob Ve Pirsson and ES. ‘WASHINGTON =. = ee 498 _XLIV.—Yttrocrasite, a New Yttrium-Thorium- Usantan Titanate; by W. E. Hippen and C. H. Warren._.__. 515 XLV.—Note on the Estimation of Niobium and Tan- talum in the presence of Titanium; by C. H. Warren 520 XLVI.—Ceanothus Americanus L. and ovatus Desf.; a morphological and anatomical study; by T. Horm___.. 528 XLVII.—Photometric Measurements on a Person Pos- sessing Monochromatic Vision ; by F. L. Turts_..._-_. 531 XLVIII —Eodevonaria, a new Sub-Genus of Chonetes ; by Goi BREGER 2220.25. 2. en 534 XLIX.—Note on the Production of Radium by Actinium ; by B..B. BOLT WOOD: 2. 2. SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Quantitative Separation of Beryllium and Alumin- ium, B. GLassMan: Tempera.ure at which Water Freezes in Sealed Tubes, Miers ar 1 Isaac, 5389.—Preparation of Fused Molybdenum, Bitrz and GAntnr 5: Potassium-lead Chlorides, Lorenz and RuckstuHnL: Ammo- nium i.0m the Recent Eruption of Vesuvius, STOKLASA: Beitraege zur Che iischen Physiologie und Pathologie, F. HormEtster, 540.—Change oF Cclioidal Nucleation in wet dust-free Air in the lapse of time, C. —— Leitfaden der praktischen Optik, A. GLEICHEN, 041. —Geology—New Zealand Geological Survey, J.°M Berti, 542.—TIllinois State Geological Survey, H. F. Barn: Geological Survey of Ohio, E. Orton, 543.—Indiana: Department of Geology and Natural Resources, Wr 38, BLaTCHLEY: Geological Survey of New Jersey, H. B. KUMMEL : Geological Survey of Canada, R. Buu, 544.—Bibliography of Clays and the Ceramic Arts, J. C. BRANNER: Festschrift Harry Rosenbusch, gewidmet von seinen Schiilern zum siebzigsten Geburtstag, 545.—Evidence Bearing on Tooth- cusp Development, J. W. GipLEy, 546.—Origin of Birds, 547. Miscellaneous Scientific Intelligence—National Academy of Sciences, 548.— Human Mechanism ; its Physiology and Hygiene and the Sanitation of its Surroundings, T. HoueH and W. T. SrepGwick: Voyages and Explorations of Samuel de ‘Champlain, eee by A. we eel Field operations of Bureau of Soils, 1904, 550. InDEX To VoL, XXII, 551. °3 130" SS LP : : - ' : - : : 4 4 ' + f. ® i} —— i J Wi 3 9088 01298 5735